Somatom sessions 25

RSNA-Edition November 2009 25 SOMATOM Sessions
SOMATOM Sessions
The Difference in Computed Tomography
Issue Number 25/November 2009
RSNA-Edition I November 29th – December 04th, 2009
Cover Story
Mission Possible:
Reducing Radiation
Dose in CT
Page 6
News
International CT Image
Contest – Highest Image
Quality at Lowest Dose
Page 17
Business
Lowest Dose
Motivates Purchase
Page 24
Clinical
Outcomes
Dose Neutral Dual
Energy Carotid
CTA with SOMATOM
Defi nition Flash
Page 34
Science
Analysis of DNA
Double-Strand Breaks
Promises New View of
Dosimetry in CT
Page 52
25
mSv dose

Editorial
“For us and our customers,
patient safety means
achieving highest quality
images with the absolute
minimum dose possible.”
Sami Atiya, PhD, Chief Executive Officer,
Business Unit Computed Tomography, Siemens Healthcare, Forchheim, Germany
Cover Page: No breath hold and no anesthesia was necessary in this pediatric imaging with 0.37s scan time, by using only 1 mSv.
Courtesy of University of Erlangen-Nuremberg, Erlangen, Germany
2 SOMATOM Sessions · November 2009 · www.siemens.com/healthcare-magazine

Editorial
Dear Reader,
Siemens has always been the innovation
leader in research and development of
medical imaging. But this leadership has
always been firmly anchored in the be-lief
that advanced technology needs to
be helpful in clinical routine. Such im-provements
must offer advantages to
both medical personnel and patients in
the following areas: faster, safer and
more comfortable exams, improved
diagnostic accuracy, earlier detection
of pathologies, efficient workflow and
improved healthcare for patients.
Our success has always been based
upon listening to the needs and opin-ions
of our customers – physicians and
specialists from around the world work-ing
in the various medical facilities. We
have integrated the best of this feedback
into our research and development.
Patient safety has consistently domi-nated
this feedback. And, in computed
tomography (CT), patient safety means
highest image quality at lowest dose.
Our dedication to this principle has led
us to develop our unique CARE program
– “Combined Applications to Reduce
Exposure” – that is the cornerstone of
our research and development philo-sophy.
This principle coordinates and
compliments the ALARA principle, “As
Low As Reasonably Achievable.” But
Siemens goes one step further and
insists on respecting these two princi-ples
without loss of image integrity.
Over the years, Siemens has been highly
creative in integrating dose-reduction
André Hartung,
Vice President
Marketing and Sales
Business Unit CT,
Siemens Healthcare
innovations into CT imaging products.
The last significant milestone along
this path was the introduction of the
SOMATOM® Definition Flash Scanner
at the RSNA 2008, amazing the entire
medical imaging industry with the in-credible
scan speed and low-dose with
highest image quality. This highly suc-cessful
product has caused a paradigm
change in the CT playing field and is just
beginning to establish itself and prove
its full potential in clinical routine.
But our efforts to offer both medical
personnel and patients the ultimate in
safety, comfort and healthcare did not
end there. At this year’s RSNA, we will
introduce IRIS – “Iterative Reconstruction
in Image Space” – a new image recon-struction
algorithm that beautifully and
efficiently expands the capabilities of
the high-end SOMATOM Definition
family. IRIS promises up to 60% dose
reduction in addition to the already
remarkable reductions achieved with
other Siemens products, opening up
entirely new applications for CT in clini-cal
routine. Another quantum leap in
dose reduction and image quality is on
the CT horizon.
Our cover story in this issue includes a
summary of all the successful dose-reducing
methods achieved by Siemens
over the years. Our goal for the future
is to continuously reduce dose while
improving image quality and here we
accept no compromise. We have dedi-cated
this issue of SOMATOM Sessions
to dose reduction so that you, the
reader, can experience in the different
articles just how seriously we take
our commitment, “better care for our
patients – providing answers to life’s
most difficult questions.”
In addition to optimum healthcare and
safety for patients, another obligation
remains close to our hearts: to provide
the best possible working conditions for
physicians and other medical personnel
regarding efficient workflow, networked
communications and keeping up with
state-of-the-art developments in the
CT arena. Viewed from our customer’s
standpoint, this translates to, “My cases,
ready; My place, networked; My needs,
anticipated.” Today, when a single scan
can bring up 2,500 images and reveal
numerous pathologies that require
different diagnostic and examination
methods, an integrated, efficient and
automated data management system
is absolutely necessary. Siemens has
recognized and met this challenge
with syngo.via*, our revolutionary,
crossmodality software solution that can
fast-track your diagnostic workflow to
an incredible degree. Read the amazing
details in the special supplement to this
RSNA issue of SOMATOM Sessions.
Good reading.
Sincerely,
André Hartung
SOMATOM Sessions · November 2009 · www.siemens.com/healthcare-magazine 3
*syngo.via can be used as a standalone device or together with
a variety of syngo.via based software options, which are medical
devices in their owen rights.

Content
Content
Cover Story
6 Mission Possible: Reducing Radiation
Dose in CT
News
16 Interactive Breath-Hold Control (IBC)
System from the Mayo Clinic is now
Available Through Siemens
16 SOMATOM Emotion Facelift
17 International CT Image Contest –
Highest Image Quality at Lowest
Radiation Dose
18 New Software Versions for the
SOMATOM Definition Family
19 Flash Cardio Dose Saving Capabili-ties
Inspire Researchers to Launch
PROTECTION IV Trial
20 RSNA 2009 – Arena for SOMATOM
Definition Flash Publications
21 syngo 2009A – a New Era for Routine
and Advanced Diagnostic Imaging
22 Leading Technology in Rural Hospital
Cover Story
6 Lots of people talk about radiation
dose and CT. But for more than a
decade, Siemens Healthcare has
made dose reduction a mission.
The result: an impressive portfolio
of innovations in scanner hardware,
software, and imaging protocols
that together have cut patient radia-tion
exposure to a fraction of what
it once was. Read more about re-cently
requested feedback on some
of the most important of these inno-vations
from physicians in Germany
and the U.S.A. who have had experi-ence
with them.
24
Lowest Dose
Motivates Purchase
6
Mission Possible: Reducing Radiation
Dose in CT

Content
Oncology
40 SOMATOM Definition Flash: Ruling
out Cystic Fibrosis (CF) in a Pediatric
Patient – Scan in 0.56 Seconds at
1 mSv
Neurology
42 Moyamoya Disease: Whole Brain
Perfusion CT
Acute Care
44 SOMATOM Definition Flash Provides
the Entire Extension of Aortic Dis-section
in Just 2 Seconds Scan Time
46 Dual Energy CT Imaging of Chronic
Pulmonary Embolism
Science
48 Dose-Optimized CAD Diagnostics
50 First Study Results Using High-Pitch
Spiral Acquisition in the Dual Source
SOMATOM Definition Flash CT
52 Analysis of DNA Double-Strand
Breaks Promises New View of
Dosimetry in CT
44
SOMATOM Definition Flash Provides the
Entire Extension of Aortic Dissection
in Just 2 Seconds Scan Time
Business
24 Lowest Dose Motivates Purchase
26 RIPIT to the Rescue: A New Protocol
for Trauma Imaging
28 Payback Time: How New CTs Justify
the Investment
Clinical Results
Cardio-Vascular
30 Heart Perfused Blood Volume with
SOMATOM Definition Dual Energy
Scanning
32 SOMATOM Definition Flash: Dynamic
Myocardial Stress-Perfusion
34 Dose Neutral Dual Energy Carotid
CTA with SOMATOM Definition Flash
36 SOMATOM Definition Flash Follow-up
Examination After Stent Implan-tation
for Ruptured Aneurysm
38 Takayasu Arteritis with Atypical Aortic
Coarctation: Follow-up Exam with
Dual Energy CT
Life
54 Funding to Maintain, Improve, and
Expand Services in an Uncertain
Economy
55 TubeGuard: Proactive Tube Failure
Prediction
56 State-of-the-Art Training
57 “Discover. Try. Buy.” a New Portal
for Individually Expanding Clinical
Capabilities
58 CT 2010 – The Congress
58 How to Perform a Cardiac Scan with
Less than 1 mSv
59 Free DVD of the SOMATOM World
Summit 2009 in Valencia
59 Frequently Asked Questions
60 New Workshop Format: Diagnosis
of Congenital Heart Defects
60 Clinical Workshops 2010
61 Upcoming Events & Congresses
62 Siemens Healthcare – Customer
Magazines
63 Imprint
40
Ruling out Cystic Fibrosis (CF) in a Pediatric
Patient – Scan in 0.56 Seconds at 1mSv

Topic
1994
1999
2002
1997
1999
2005
Mission Possible: Reducing
Radiation Dose in CT
Over the past decade, Siemens has been a pioneer in creating a host of inno-vative
technical features that signifi cantly reduce radiation exposure in CT
scans. SOMATOM Sessions recently requested feedback on some of the most
important of these innovations from physicians in Germany and the U.S.A.
who have had experience with them.
By Catherine Carrington
Lots of people talk about radiation dose
and CT. But for more than a decade,
Siemens Healthcare has made dose re-duction
a mission. The result: an impres-sive
portfolio of innovations in scanner
hardware, software, and imaging proto-cols
that together have cut patient radia-tion
exposure to a fraction of what it
once was.
“Reducing radiation dose has always been
a concern for Siemens,” says Thomas
Flohr, PhD, Director of CT Physics and
Applications for Siemens Healthcare in
Forchheim, Germany. “CT is the imaging
modality of choice in many situations,
and it would be used even more if not for
the concern about radiation dose.”
Siemens’ focus was intensified in the late
CARE
Dose4D
Up to 68 %
Adaptive
ECG-Pulsing
Up to 50 %
Pediatric
80 kV
Protocols
Up to 50 %
UFC
Up to 30 %
HandCARE
Up to 70 %
X-ray off
X-ray on
X-ray
Light
UFC
DSCT
Up to 50 %
t
Siemens‘
Dose Saving
features

Topic
2008
Selective
Photon
Shield
2008
spiral cardiac CT scans, ECG-pulsing
maintains nominal tube current only
during targeted phases of the cardiac
cycle, markedly reducing tube current
during phases that will not be used for
image reconstruction. Dose savings:
30% to 50%.
■ 2005: Introduction of the SOMATOM®
Definition Dual Source CT scanner,
which offers further dose efficiencies
in cardiac CT through faster scanning,
Adaptive ECG-Pulsing, and automated
adaptation of table speed to heart rate.
Dose savings: up to 50%, compared to
single source CT.
■ 2007: Introduction of the Adaptive
Cardio Sequence, a prospective ECG-triggered
“step and shoot” technique
that reduces the average dose for CT
coronary angiography to about 2.5 mSv.
■ 2007: Introduction of the Adaptive
Dose Shield, a technique of asymmetric
collimator control that eliminates over-scanning
at the beginning and end of
the CT spiral. Depending on the length
of the scan, it reduces dose by 5% to
25%.
2009
2008
Image data
recon
■ 2008: Introduction of the SOMATOM
Definition Flash CT scanner. With dual
detectors and a table speed of up to
45 cm/s, the Flash cuts radiation dose
for coronary CT angiography to less than
1 mSv in many patients.
■ 2008: Introduction of X-CARE, organ-based
dose modulation that reduces out-put
of the X-ray tube when it is directly in
front of the breast and other dose-sensi-tive
organs, such as the thyroid gland and
eye lens. Reduces radiation dose to the
breast by 30% to 40%.
■ 2009: Introduction of Iterative
Reconstruction in Image Space (IRIS).
By “cleaning up” image noise, iterative
reconstruction makes it possible to
reduce radiation dose by up to 60% and
still produce high-quality images.
Several dose-reduction strategies de-serve
special attention, including CARE
Dose4D, the Adaptive Dose Shield, the
SOMATOM Definition Flash CT scanner,
and IRIS. Each of these is an example not
only of Siemens’ commitment to mini-mizing
radiation exposure but also its
track record of innovation.
Adaptive
Cardio
Sequence
Dose Shield
2008
2007
1990s, when the company began to
systematically search for new ways to
reduce radiation dose. A timeline shows
not only how relentless Siemens has
been in pursuing this goal over the years,
but also how creative Siemens Research
& Development was. Key milestones in-clude:
■ 1994: Introduction of DOM, later
extended to CARE Dose4D, a fully auto-mated,
real-time, anatomical dose
modulation technology that reduces
radiation dose, depending on the area
of the body, by 20% to 68% – without
degrading image quality.
■ 1997: Introduction of an ultra-fast
ceramic (UFC) detector designed with a
new gadolinium-oxy-sulfite scintillator.
The UFC detector – still a key component
of multidetector and Dual Source CT
systems – cut radiation dose by 30%
when compared to previous generations
of CT detectors.
■ 1999: Introduction of ECG-pulsing, a
technique that synchronizes tube current
to the electrocardiogram. Used during
2007
Flash
Spiral
< 1 mSv Cardio
4D Noise
Reduction
Up to 50 %
Iterative
Reconstruction in
Image Space (IRIS)
Up to 60 %
Adaptive
Dose
Shield
Up to 25 %
Selective
Photon
Shield
No dose penalty
X-CARE
Up to 40 %
140 kV
Attenuation A
80 kV
Attenuation B
X-ray off
Dose Shield X-ray on
1–3 mSv Cardio
Compare
Image
correction
Master
recon
Vol
< 1 sec
Tube 1 Tube 2
Image data
recon
Image
correction

Coverstory
CARE Dose4D
Determining the right tube current and,
therefore, the right radiation dose, has
always been crucial, says Marilyn J.
Siegel, MD, Professor of Radiology and
Pediatrics at the Mallinckrodt Institute of
Radiology, Washington University School
of Medicine, St. Louis, Missouri, USA.
But achieving that goal was much more
difficult before CARE Dose4D, because
adjustments in tube current had to be
made empirically.
“CARE Dose4D has really been a great
advantage for a number of reasons,”
Siegel says. “We get great image quality,
reduced dose, and increased patient
comfort. And it’s automated, so it’s
easier for the technologist.”
CARE Dose4D automatically adapts radi-ation
dose to the size and shape of the
patient, achieving optimal tube current
modulation in two ways. First, tube
current is varied on the basis of a topo-gram,
by comparing the actual patient
to a “standard-sized” patient. As might
be expected, tube current is increased
for larger patients and reduced for small-er
patients. Differences in attenuation
in distinct body regions are taken
into account. For example, in an adult
patient, 140 mAs might be needed in
the shoulder region, whereas 55 mAs
would be sufficient in the thorax,
110 mAs in the abdomen, and 130 mAs
in the pelvis.
In addition, real-time angular dose
modulation measures the actual attenu-ation
in the patient during the scan and
adjusts tube current accordingly – not
only for different body regions, but also
for different angles during rotation. This
“With children, you want as low a dose as possible
but also excellent spatial resolution. CARE Dose4D
allows us to reduce radiation exposure in all three
planes without impairing diagnostic image quality.”
Marilyn J. Siegel, MD, Professor of Radiology and Pediatrics at the Mallinckrodt Institute of
Radiology, Washington University School of Medicine, St. Louis, Missouri, USA
is particularly important in efficiently
reducing dose in the shoulder and pelvic
region, where the lateral attenuation is
much higher than the anterior-posterior
attenuation.
Siemens has further refined this process
with CARE Dose4D. Clinical experience
has shown that the relationship between
optimal tube current and patient size is
not linear. Larger patients clearly need a
higher dose than average-sized patients,
but they also have more body fat, which
increases tissue contrast. Smaller patients
need a lower dose than average-sized
patients, but they have less fat and less
tissue contrast, which would result in
noisy images if the dose were too low.
Therefore, during real-time dose modula-tion,
CARE Dose4D reduces radiation dose
less than might be expected for smaller
patients, while increasing the dose
less than might be expected for larger
patients. This maintains excellent diag-nostic
image quality while achieving an
optimal radiation dose.
“CARE Dose4D is different from dose
modulation approaches used by other
vendors,” says Flohr. “It uses measured
attenuation data in real time, not just
information from topograms; it makes
use of a wide mA-range; and it can fine-tune
dose on the fly.”
Nowhere is CARE Dose4D more impor-tant
than in pediatric imaging, where
the risk associated with radiation expo-sure
is many times higher in children
than in adults. A child’s smaller body
absorbs more of the radiation dose than
does a larger body. In addition, the can-cer
induction risk is higher in children,
because they have a longer lifespan
ahead of them. At the same time,
because children’s anatomy is smaller it
can be more difficult to visualize.
“With children, you want as low a dose as
possible but also excellent spatial resolu-tion,”
explains Siegel. “CARE Dose4D
allows us to reduce radiation exposure in
all three planes without impairing diag-nostic
image quality, and that’s key.”
Publications in scientific journals have
shown that in adults, CARE Dose4D
reduces radiation dose by 68% in the
cervical spine, 37% in the lumbar spine,
“There’s more and more
awareness about the
amount of radiation
used for CT scanning.
Siemens has thoroughly
looked into this and is
one of the fi rst vendors
to implement the tools
we need to improve our
scanning.”
Christoph Becker, MD, Professor of Radio-logy
and Section Chief of CT and PET/CT at
Munich University Hospital in Germany

Topic
Scan with
constant mA
Reduced dose
level based on
topogram
mAs for constant image noise
CARE Dose4D
X-ray dose
1 Instead of just taking into account the patient’s external dimensions and apparent size, CARE Dose4D analyzes the cross-sectional anatomy
in real-time and adjusts the emitted X-ray dose accordingly – providing excellent image quality with minimized exposure.
Quality ref.
mAs
75 kg reference patient
180
160
140
120
100
80
60
40
20
0
200 400 600 800
Body Size (lo/l)
mAs
1000 1200 1400 1600 1800 2000
1600 mA
20 mA
Slice position
Real-time
angular dose
modulation
1

Coverstory
30% in the thorax, and 38% in the abdo-men
and pelvis. In pediatric scans of the
heart, a 58% dose reduction has been
reported for CARE Dose4D.1
Adaptive Dose Shield
In spiral CT, it is routine to do an extra
half-rotation of the gantry before and
after each scan, fully irradiating the
detector throughout, even though only
part of the acquired data is necessary.
As a result, the wide-cone beam exposes
tissue that will never be part of recon-structed
images. Until recently, no one
gave much thought to this needless radi-ation
exposure to patients. Such “over-scanning”
beyond the targeted scan
range was simply accepted as an in-evitable
part of spiral CT.
Siemens took a fresh look at the problem
and, in 2007, introduced the Adaptive
Dose Shield, a technology based on pre-cise,
fast, and independent movement
of both collimator blades. Instead of ex-posing
patients to unnecessary radiation,
the Adaptive Dose Shield asymmetrically
opens and closes collimators at the be-ginning
and end of each scan, tempo-rarily
blocking those parts of the X-ray
beam that are not used for image recon-struction.
As a result, only the targeted
tissue is irradiated. Like many other dose-saving
innovations, it is a feature pio-neered
by Siemens.
“There’s more and more awareness
about the amount of radiation used for
CT scanning,” says Christoph Becker, MD,
Professor of Radiology and Section Chief
of CT and PET/CT at Munich University
Hospital in Germany. “Siemens has thor-oughly
looked into this and is one of the
first vendors to implement the tools we
need to improve our scanning.”
At Munich University Hospital, Becker
has two Siemens scanners equipped with
an Adaptive Dose Shield, the SOMATOM
Definition AS+ and the SOMATOM
Definition Flash. Although the Adaptive
Dose Shield reduces the radiation dose in
every study, the savings are especially
notable over shorter scan ranges. Dose
savings can reach 25% or more in cardiac
imaging, for example.
The Adaptive Dose Shield is especially
well suited to pediatric imaging. “In any
circumstance in which children have to
be investigated, I would always prefer to
use a scanner with the Adaptive Dose
Shield,” Becker says. “It’s always on, and
it always reduces the radiation dose.”
Flash
At the German Heart Center, Jörg Haus-leiter,
MD, has been using a SOMATOM
Definition Flash CT scanner since April.
With this revolutionary scanner, he can
image the heart in a quarter of a single
heart beat. Equally impressive, he has
been able to achieve a radiation dose of
1mSv or less in a large proportion of
patients undergoing CT coronary angio-graphy.
“That’s unbeatable compared to
other CT scanners,” says Hausleiter, an
Associate Professor of Medicine at the
Munich-based hospital.
The SOMATOM Definition Flash gets its
name from its flash-fast speed. Equipped
with two detectors, two X-ray sources,
and a gantry that rotates in 0.28 sec-onds,
the scanner boasts a temporal
resolution of just 75 ms. Moreover,
thanks to an innovation unique to the
SOMATOM Definition Flash, the patient
table no longer slowly inches forward
during scanning. Instead, in low-dose
Flash Spiral mode, the table can glide
along at 45 cm/s while the scanner
integrates data from both detectors,
achieving a gap-free scan even though
each spiral is wide open.
Still, according to Hausleiter, the key
question is whether excellent image
quality can be achieved at such a high
scan speed and low dose. With the
SOMATOM Definition Flash, the answer
is clearly yes. “This ultra-low dose was
never possible before, but with this scan-ner
– with its high temporal resolution
and improvements in the X-ray tube and
detector – it is now possible,” he says.
Of the first 100 coronary CT scans per-formed
on the Definition Flash at the
German Heart Center, more than 70%
could be done in Flash mode. As a result,
the average radiation dose for all coro-nary
CT scans – including longer scans
needed for presurgical evaluation and
triple rule-out studies – dropped from a
median of 5 to 7 mSv down to 1.8 mSv.
Of the 70% of patients scanned in Flash
“This ultra-low dose was
never possible before,
but with SOMATOM
Defi nition Flash – with
its high temporal reso-lution
and improve-ments
in the X-ray tube
and detector – it is now
possible.”
Jörg Hausleiter, MD, Cardiologist, Associate
Professor of Medicine, German Heart
Center, Munich, Germany
“With Siemens Iterative
Reconstruction I can
save up to 60% dose
for wide range of rou-tine
applications while
maintaining excellent
image quality.”
Joseph Schoepf, MD, Department of
Radiology, Medical University of South
Carolina, Charleston, USA

Topic
2 Pediatric imaging: no breath hold and no anesthesia was necessary for the scan with 0.37s scan-time by using only 1 mSv (Fig. 2A);
Split-second thorax scan by using only 1.65 mSv (Fig. 2B and 2C).
mode, approximately half could be
scanned at 100 kV. (In general, a tube
voltage of 100 kV is suitable for patients
with a body mass index of less than 30
or a body weight of less than 90 kg). In
these patients, Hausleiter found that the
median radiation dose was just 1 mSv.
The other half of the patients were
scanned at 120 kV, and received a radia-tion
dose of 1.6 to 1.8 mSv, still far lower
than the typical radiation dose for coro-nary
CT angiography.
The PROTECTION I study highlights how
much progress has been made. In 2007,
Hausleiter and an international group of
researchers from 50 medical centers set
out to determine the typical radiation
dose for patients undergoing coronary CT
angiography, using CT scanners manufac-tured
by a variety of vendors. Published in
the February 4, 2009, issue of JAMA, the
study showed that the median dose was
12 mSv.
“It’s important to realize the large steps
we’ve taken,” says Hausleiter. “The dose
we can achieve today is one-tenth of
what it was in the PROTECTION I study.
That’s a major improvement.”
Such a low radiation dose could expand
CT’s horizons in the evaluation of heart
disease. For example, for patients with
high heart rates and irregular heart
rhythms, the “step and shoot” Adaptive
Cardio Sequence, with prospective ECG-triggering
and arrhythmia detection, is
ideal and keeps radiation dose to about
2.5 mSv. For patients with reasonably
low and stable heart rates, the Flash
Spiral is the method of choice. But even
for patients with mild arrhythmia,
Hausleiter thinks the Flash mode, which
captures all necessary data in a single
heart beat, may be fast enough to do the
job, and at a radiation dose of 1mSv.
And, if that one heart beat happens to
be an extra unwanted beat generated by
the arrhythmia, the Flash’s low radiation
dose means there is little risk in repeating
the study.
A radiation dose of below 1 mSv also
raises the possibility of using CT for
screening patients at risk for heart dis-ease.
“We need to start thinking about
that question,” Hausleiter says. “With
coronary CTA, we would gain informa-tion
on calcification, the location of
plaques, and the presence of noncalci-fied
plaques – the type we really worry
about. In the end, screening could
reduce the number of heart attacks.”
Iterative Reconstruction
Iterative reconstruction, which Siemens
is slated to debut at the 2009 RSNA meet-ing
in Chicago, is the latest success story
in the company’s mission to reduce radia-tion
dose. Essentially, iterative reconstruc-tion
introduces a correction loop in the
image generation process that cleans up
artifacts and noise in low-dose images.
Other vendors are working on iterative
reconstruction, but Siemens has
developed a unique method. A typical
approach to iterative reconstruction is to
measure data in the reconstructed image
2A
2B
2C

Coverstory
4A 4B
4 Image data reconstruction of an abdominal scan with Standard FBP at full dose (Fig. 4A) and scanned at 60% lower dose while reconstructed
with Iterative Reconstruction in Image Space (Fig. 4B). Despite the fact that Fig. 4B was acquired at significantly lower dose it shows the same low
noise compared to the standard FBP at full dose.
and compare it to the original data, using
differences to identify ways to improve
the image. This approach is time-consum-ing
because, with each iteration, new
measurement data must be calculated.
Siemens instead takes the original data
and reconstructs a super-high-resolution
image. The image is very noisy, because
the filtering that ordinarily reduces image
noise is not used, in order to avoid any
loss of information. Then prior knowledge
of the scanned object is used to smooth
the image and reduce noise within homo-geneous
regions, while contrast edges
are preserved. This process is repeated
over several steps, or iterations.
“Why is Siemens’ approach better?
Because we start with a super-high-resolution
image and clean it up,” says
Thomas Flohr. “We can fine-tune the
process, so we don’t lose object informa-tion.
We maintain image texture that is
familiar to readers, so the resulting
image looks like a standard CT image
and doesn’t have the plastic-like look that
is often the drawback of other iterative
reconstruction approaches. And the pro-cess
is very fast and efficient.”
3 Image cardio sequence: Fully flexible X-ray pulsing in combination with 75ms
temporal resolution results in low dose cardio scan (0.36 mSv dose).
3

5 Single Source CT requires slow-er
table feeds to prevent gaps in
the acquired volume (top, center).
Dual Source CT combines the data
from 2 detectors for faster table
feeds above a pitch of 3 (bottom).
6 When fully flexible X-ray pulsing
meets 75 ms of temporal resolution,
the result is the Flash Cardio
Sequence, the most versatile low
dose cardio scan on the market. It´s
an intelligently triggered sequence
that shuts off radiation in the
systolic phase when not required and
dynamically reacts to irregularities
during the ECG-trace. For the first
time, a step and shoot mode is
robust and fast enough to freeze the
heart and visualize the coronary
arteries even at high heart rates,
thus allowing even low dose
cardiac CT without the need for beta-blockers.
Additionally the Flash
Cardio Sequence introduces the
Siemens-only dual-step pulsing, that
maintains a low dose level during
the systolic phase to calculate ejec-tion
fraction in addition to coronary
imaging. Therefore, the never before
possible combination of low dose
coronary imaging and functional
information now becomes a reality.
Vol pitch 1
pitch >1
pitch 3.4
Vol
Vol
Conventional Sequence
Dose
Dose
Low dose
no function
High dose
with function
Low dose
with function
Flash Cardio Sequence
Dose
necessary dose
inefficient dose
Tube 1 Tube 2
5
6

Coverstory
CT Radiation Dose
in Perspective
Most important, Siemens’ iterative
reconstruction technique can reduce
radiation dose by up to 60%, depending
on the body region and the original scan
dose. “With Siemens Iterative Recon-struction
I can save up to 60% dose for
wide range of routine applications while
maintaining excellent image quality”
says U. J. Schoepf, MD, Professor of
Radiology and Cardiology and Director
of CT Research and Development at the
Medical University of South Carolina.
Theoretical Iterative Reconstruction
Raw data
recon
Exact image
correction
Full raw
data
projection
7 To accelerate the convergence of the reconstruction IRIS applies the raw data re-construction
only once. During this newly developed initial raw data reconstruction
a so called master image is generated that contains the full amount of raw data in-
Future Directions
The next automated tool for dose re-duction
is likely to be automatic kV
adaptation to the patient’s size and the
examination type. Researchers are
beginning to understand and further
evaluate its effect on image quality
and dose. In the PROTECTION II study,
for example, Hausleiter and his
colleagues randomly assigned 400
patients to undergo coronary CT angio-graphy
with either a 100 kV protocol
or the more conventional 120 kV proto-col.
Reported at the 2009 American
College of Cardiology Annual Scientific
Session, the study showed that the use
of 100 kV reduced radiation dose by
31%, while image quality scores were
virtually identical. “This proves you can
use 100 kV very liberally when looking
at the coronary arteries,” says Hausleiter.
At the Mallinckrodt Institute, Siegel
has also been evaluating the radiation
savings possible through use of a lower
7
No one would argue that radiation ex-posure
is unimportant in CT. But as
dose levels fall, and the risk of induc-ing
cancer shrinks, it’s reasonable to
take a fresh look at the risk-benefit
ratio associated with CT scanning.
First, it’s important to know that esti-mates
of the long-term risk of devel-oping
cancer from radiation exposure
are based on studies of atomic bomb
survivors. Such studies have a high
level of statistical uncertainty at
the low radiation doses associated
with CT.
The most commonly cited estimate of
the additional lifetime risk of dying
from cancer is 0.05% per 10 mSv of
radiation exposure. Not only do many
CT scans today deliver far less than
10 mSv, but natural background radia-tion,
which is unavoidable, is about
2 to 3 mSv. In addition, the average
lifetime risk of dying from cancer in
western society is about 25% – which
means that after a 10 mSv CT scan,
the risk goes up by 0.05% to 25.05%.
By comparison, the lifetime risk of
dying from heart disease is about
40%. Decisions about whether to eat
a healthy diet, quit smoking, and get
regular exercise are likely to have a
substantial cumulative impact on
longevity. Which makes you wonder:
Just how safe is it to eat a double
cheeseburger?
Slow Raw Data Space Fast Image Data Space
Compare
Dose reduction or image quality improvement
Well-established image impression
Very time-consuming reconstruction

Topic
Statistical Iterative Reconstruction Iterative Reconstruction in Image Space
Image data
Basic image
correction
formation. The following iterative corrections known from true iterative reconstruction are consecutively performed in the image space. In addition,
the noise texture of the images is comparable to standard well-established convolution kernels. The new technique results in artifact and noise reduc-tion,
tube voltage. Her work with Lucite
phantoms that simulate the size of
various body regions in children has
shown that at a tube voltage of 80 kV
the radiation dose is reduced when
compared to a tube voltage of 140 kV,
even when the tube current is increased
to ensure good image quality.
At the St. Louis Children’s Hospital,
Siegel has been using the SOMATOM
Definition AS 64-slice CT scanner
to scan pediatric patients. She will
continue her research in pediatric
phantoms and in patients with this
newer generation scanner to determine
the impact on radiation dose and
image quality of modulating kV.
She anticipates that with this newer-generation
scanner, the quality of
CT studies will improve even further
as radiation dose is decreased.
“There is an old saying, ‘Beautiful
pictures come at the cost of higher
radiation dose,’ ” Siegel says.
Medical writer Catherine Carrington holds a
master’s degree in journalism from the University
of California Berkeley and is based in Vallejo,
California.
increased image sharpness and dose savings up to 60% for a wide range of clinical applications.
“We’ve already disproved that, and
we intend to further disprove it.”
Dose reduction
Fast reconstruction with few parameters
Unfamiliar and plastic-like image impression
Dose reduction or image quality improvement
Well-established image impression
Fast reconstruction in image space
Compare
Master
recon
Compare
recon
Exact image
correction
Raw data
recon
Basic
raw data
projection
1 Mulkens et al.: Use of an Automatic Exposure Control
Mechanism for Dose Optimization in Multi-Detector
Row CT Examinations: Clinical Evaluation, Medical
Physics.

News
Interactive Breath-Hold Control (IBC)
System from the Mayo Clinic is now
Available Through Siemens
By Stefan Wünsch, PhD, Business Unit CT, Siemens Healthcare,
Forchheim, Germany
cedures or modalities where respiratory
motion is an issue. The device does not
physically interface with imaging equip-ment
and is therefore fully portable. The
wireless display includes a simple belt
with expandable bellows to be wrapped
around a patient’s upper abdomen or
lower chest and connected to the IBC
system. Individual light displays are
located next to the patient, the radiolo-gist’s
image monitor and the CT opera-tor
console. All displays have a wireless
connection to the system control, which
sits next to the patient on the CT table.
Interactive Breath-Hold Control System from Mayo Clinic
was developed to assist CT interventional procedures.
SOMATOM Emotion Facelift
By Steven Bell, Business Unit CT, Siemens Healthcare, Forchheim, Germany
The Interactive Breath-Hold Control
(IBC)* is a unique Mayo Clinic medical
device that allows physicians to
more rapidly and accurately diagnose
patients, reducing the need for a more
invasive surgical biopsy. Monitoring
patient respiratory motion using a
simple light display, it allows for precise
imaging at a consistent reproducible
breath-hold level. The IBC device was
developed to assist CT interventional
procedures, but may also be very useful
for PET CT, radiation therapy, ultra-sound,
fusion imaging, and other pro-
Siemens’ customer-focused philosophy
has always been to continually integrate
cutting-edge imaging technology into the
daily clinical routine, providing high qual-ity
patient care while simultaneously low-ering
costs. This continual innovation is
focused throughout the Siemens CT
product portfolio and has now resulted
in the release of the new SOMATOM®
Emotion 6- and 16-slice configurations.
The new SOMATOM Emotion builds on
this platform and features an innovative
Key Characteristics
■ Increased patient care and comfort
■ Increased safety
■ Potential decrease in healthcare ex-penses
for patients, by avoiding the
necessity for more invasive and costly
surgical biopsy procedures
■ Decrease in needle placement and
procedure time
■ Decrease in complications
■ Increase in accuracy
*This device will be distributed by Medspira (USA).
The newly designed SOMATOM Emotion dem-onstrates
Siemens’ commitment to continually
bringing new technology to all segments of
the CT market.
* *based on system sales.
new product design and new software
features. It showcases Siemens’ commit-ment
to offering not only remarkable
image quality, but also bringing leading
workflow features, and reducing the on-going
costs of CT service.
The new SOMATOM Emotion 6- and 16-
slice configurations continue to offer the
smallest tube focal spot and the highest
number of effective detector channels in
the mid-range CT market, both of which
underpin the excellence in image detail.
The new software developments that
have been brought to the SOMATOM
Emotion platform have a significant
focus on CT workflow. A key feature now
available on the SOMATOM Emotion
6- and 16-slice configurations is syngo
Expert-i which enables remote access to
the scan console from any remote com-puter
with access to the hospital or prac-tice
network. This feature alone has the
ability to significantly improve workflow
in any practice because medical staff are
no longer required to physically attend
the CT suite to assess images or decide
on appropriate scan protocols.
The newly designed SOMATOM Emotion
also builds on the Total Cost of Owner-ship
advantages for which the SOMATOM
Emotion is known. With lower power
requirements, reduced heat output and
significantly smaller installation space,
the SOMATOM Emotion is a cost effec-tive
profit center for many customers
worldwide.
With over 6,700 systems installed
SOMATOM Emotion remains the most
popular CT system in the world**
through continually bringing new
clinical, workflow and cost innovations
to Siemens’ CT customers.

News
International CT Image Contest – Highest
Image Quality at Lowest Radiation Dose
By Rami Kusama, Business Unit CT, Siemens Healthcare, Forchheim, Germany
Fleischmann, MD – Stanford University
Medical Center, Professor Elliot K.
Fishman, MD – Johns Hopkins Hospital,
Professor Yutaka Imai, MD – Tokai Uni-versity
School of Medicine, Professor
Zengyu Jin, MD – Beijing Medical Union
College, Professor Borut Marincek, MD –
University Hospital Zurich, Professor
Maximilian Reiser, MD – Ludwig-Maxi-milians-
University Munich, Professor
Uwe Joseph Schoepf, MD – Medical
University of South Carolina.
Prizes and Awards
There will be six categories for image
submission, and, accordingly, six winners
in total. Winning images will be exhibited
at the ECR 2010 in Vienna, Austria, as
well as at RSNA 2010 Chicago, USA. Win-ners
will receive the official image gallery
book that concludes the International
CT Contest. Along with the image, the
participant’s name and institution will be
honored. Furthermore, the winner will
receive an honors certificate, a large print
out of their own winning image, a Canon
EOS 50D camera*, and the opportunity
to be honored in several different media
(e.g. SOMATOM Sessions).
Participation
Images can be submitted online by
users of the SOMATOM Definition AS,
SOMATOM Definition, and SOMATOM
Definition Flash.
Timeline
Closing date for image submission is
February 1st, 2010. Please visit our web-site
for more details on how to enter and
compete for one of the most prestigious
awards in the international community
today.
* The winners will receive the opportunity to person-ally
present their images. Each presentation will be
covered by a written contractual fee in the amount
of 1000 Euro.
www.siemens.com/
image-contest
For years physicians have been educated
to follow the ALARA (As Low As Reason-ably
Achievable) principle. That is, to use
the minimum amount of dose required to
obtain the necessary images. Siemens
sees its responsibility to provide physi-cians
with the solutions that enables
them to further lower radiation dose
without having to compromise on image
quality.
Siemens wants to encourage physicians
from all over the world to utilize their
SOMATOM® Definition CTs to the fullest
extent and to share their excellent imag-es
obtained with the lowest possible
radiation dose. Participants can share
their work with the world by joining the
Siemens International CT Image Contest.
The Jury
A highly prominent jury consisting of
pioneers in the field of CT will be judging
the images.
Professor Stephan Achenbach, MD – Uni-versity
of Erlangen, Professor Dominik
The Siemens International CT Image Contest is Siemens’ first contest where physicians and technologists from around the world send in their work to
compete for the best image quality at the lowest possible radiation dose.

Topic
For the SOMATOM Definition AS, (Fig. 1), SOMATOM Definition Flash (Fig. 2) and the SOMATOM Definition the new software versions
syngo CT 2010A and syngo CT 2010B will be available.
New Software Versions for the
SOMATOM Defi nition Family
By Rami Kusama, Business Unit CT, Siemens Healthcare, Forchheim, Germany
The new software version for the
SOMATOM® Definition and SOMATOM
Definition Flash, syngo CT 2010A, will be
introduced in the first quarter 2010,
syngo CT 2010B for the SOMATOM
Definition AS in the second quarter 2010.
syngo CT 2010A and
syngo CT 2010B will offer:
■ IRIS* (Iterative Reconstruction in Image
Space) is a method which uses multiple
iteration steps for the reconstruction of
CT data with every step further reducing
image noise and thus allowing lower ra-diation
dose. IRIS starts by reconstructing
a complex master image, and then itera-tively
improves image quality to achieve
superior, natural looking images.
■ syngo Remote Assist takes clinical ap-plications
support and training to a new
dimension. This on-demand, remote ser-vice
puts real-time troubleshooting and
support, as well as virtual education at
the users fingertips. Its seamless and si-multaneous
virtual interaction will help
to enhance image quality and equipment
optimization. syngo Remote Assist is easy
to implement and use, and requires no
modification to customer’s system or
IT-network.
■ CARE Contrast: This unique CARE solu-tion
is based on the international stan-dard
for the communication between CT
scanner and injector. It synchronizes CT
scan and contrast media injection, allow-ing
for efficient and confident monitor-ing
of patients during contrast media in-jection
and scan start, even if only one
technician is present. In addition, the in-jection
parameters are then transferred
from the injector to the patient protocol.
Due to its open interface technology,
it is ready for future applications.
■ Neuro BestContrast: The challenge in
neuro imaging is to achieve better con-trast
without an increase in noise. Neuro
BestContrast supports this by intelligent-ly
improving gray white matter differenti-ation
on a routine basis.
■ 4D Noise Reduction: Already success-fully
introduced on the SOMATOM
Definition Flash, 4D Noise Reduction
significantly improves image quality and
reduces radiation dose by up to 50% for
perfusion examinations.
syngo CT 2010A will offer:
■ X-CARE: Previous attempts at dose re-duction
were very successful but did
not specifically take into consideration
highly dose-sensitive areas such as the
thyroid gland, eye lens or women’s
breasts. X-CARE enables organ-sensitive
dose protection by reducing sensitive-area
exposure up to 40% without loss of
image quality.
■ Hi-Pitch Spiral: Even the most advan-ced
single source CTs are limited in their
scan speed by the maximum table feed
that can be used and still allow the
acquisition of contiguous data. Dual
Source technology, combining the data
from two detectors, in combination with
the Hi-Pitch Spiral, offers maximum
pitch of 3.0 and therefore high scan
speed.
syngo CT 2010B will offer:
■ ASB (Adaptive Signal Boost): This new
feature improves the signal to noise
ratio by selectively optimizing lower sig-nals,
for example, when obese protocols
are used.
1 2
*Optional, needs to be purchased separately.

News
Flash Cardio Dose Saving Capabilities Inspire
Researchers to Launch PROTECTION IV Trial
By Peter Aulbach, Business Unit CT, Siemens Healthcare, Forchheim, Germany
Coronary CTA in Flash Spiral mode at a dose of 0.7 mSv.
Coronary CT angiography with
SOMATOM® CT Scanners provides stable
image quality and, due to its ability to
detect coronary artery stenoses with a
high negative predictive value (99.7%1),
its use is meanwhile considered “appro-priate.”
The method’s major advantage
lies in the fact that adequate image
quality is provided, so that coronary
artery stenoses can be safely ruled out.
Coronary CT angiography can be used to
avoid invasive angiography in patients
who are symptomatic, but do not have
high pre-test likelihood for actually hav-ing
hemodynamically significant lesions.
Such patients are often of young age, and
female patients are often among those
who present with atypical symptoms. So
radiation exposure associated with coro-nary
CT angiography is of particular con-cern
in this group.
The latest SOMATOM Definition Flash,
with 75 ms temporal resolution, even
exceeds the ability to perform ECG-trig-gered
spiral data acquisition by using
very high pitch values of up to 3.4 in its
Flash Cardio mode, leading to unprece-dented
scan speed of up to 45 cm/s. The
high pitch and fast table speed of the
Flash Cardio mode allow performing im-age
acquisition for the entire heart with-in
a single cardiac cycle. Radiation expo-sure
is kept low since no slice overlap is
needed which allows a dose of 1 mSv
and below for coronary CT angiography.
In clinical trials like the international
“Prospective Randomized Trial on Radia-tion
Dose Estimates of CT Angiography in
Patients” (PROTECTION I) the dose for car-diac
CT of five CT units from four differ-ent
manufacturers were compared. The
basis of the study was 1,965 cardiac CT
scans that were carried out in a total of
50 clinics and heart centers. The study
showed clear differences in radiation
doses depending upon both the CT sys-tem
manufacturer and the behavior of
www.siemens.com/ct-cardiology
www.siemens.com/SOMATOM-Definition-
Flash
the operator. The dose values for cardiac
CT angiography reached up to 30 mSv 2.
The study especially emphasizes that
radiation can be significantly reduced by
more consistently using already existing
technologies for dose reduction in CT
systems.
The subsequent PROTECTION II trial eval-uated
the impact of 100 kV scan protocol
for coronary CT angiography on diagnos-tic
image quality and radiation dose. The
data showed that with the 100 kV setting
dose could be lowered by 50%, compared
to the 120 kV protocol, while at the same
time preserving the high image quality.
The ongoing PROTECTION III trial evalu-ates
the dose savings which can be
achieved with sequential scanning mode.
The new SOMATOM Definition Flash
with its sub-mSv cardiac capabilities
through Flash Cardio inspired the re-searchers
from Munich to initiate the
PROTECTION IV study, which is currently
ongoing as well. Preliminary studies
already demonstrated the feasibility of
this new and promising scan technology.
Institutions already using the SOMATOM
Definition Flash in daily clinical practice
scan more than 70% of their patients
using the Flash Cardio protocol. The re-searchers
want to proof that the image
quality is being maintained with the
reduced radiation dose of this new
scan technique when compared with
established conventional scanning
techniques. First results are expected
towards the end of 2009.
1, Coronary CT angiography predicts outcome in inter-mediate
pre-test probability individuals: A prospective
study on 1157 patients, G M. Feuchtner et al. Dept.
Radiology II and Cardiology; Innsbruck Medical Uni-versity,
Moderated Poster, ESC, Barcelona, 08/2009.
2, Estimated Radiation Dose Associated With Cardiac
CT Angiography, J. Hausleiter et al. JAMA, February 4,
2009 – Vol 301, No. 5.

News
RSNA 2009 – Arena for
SOMATOM Defi nition Flash Publications
With the introduction of the new CT scanner SOMATOM Defi nition Flash during
RSNA 2008, Siemens set new standards regarding speed and dose reduction.
One year later, the great number of publications submitted and accepted for
RSNA exceeds all expectations. Experience shows that promise becomes reality.
Scientifi c Papers
Dual Source Spiral CT at Pitch Values up
to 3.2: Assessment of Image Quality
S. Leng, PhD, Rochester, MN; L. Yu, PhD;
C. Eusemann, PhD; B. Schmidt, PhD;
T. G. Flohr, PhD; C. H. Mccollough, PhD
Sedation-free Pediatric CT: Use of a
High Pitch DSCT Scan Mode with 75 ms
Temporal Resolution to Obtain Artifact-free
Images of a Rapidly Moving Child
T. Allmendinger; C. Eusemann, PhD;
B. Schmidt, PhD; T. G. Flohr, PhD;
C. H. McCollough, PhD, Rochester, MN
Improving the Differentiation of Uric Acid
Stones Using Dual Energy Computed To-mography
Flash Technology
P. Stolzmann, MD, Zurich ; H. Scheffel,
MD, PhD; S. Leschka, MD; L. M. Desbi-olles,
MD; K. Rentsch, MD; H. Alkadhi,
MD; et al.
Performance of Different Dual Energy
CT (DECT) Protocols Using the Definition
Flash System for the Discrimination of Re-nal
Cysts and Enhancing Masses
S. Leschka, MD, Zurich, CHE; P. Stolz-mann,
MD; H. Scheffel, MD, PhD; S. Bau-mueller;
B. Marincek, MD; H. Alkadhi,
MD; et al.
Assessment of an Image-based Method to
Calculate Monoenergetic Images from
Dual Energy (DE) Image Data
B. Krauss, PhD; B. Schmidt, PhD;
M. U. Sedlmair, MS; T. G. Flohr, PhD
Quantitative Whole Heart Stress Perfusion
CT Imaging as Noninvasive Assessment of
Hemodynamics in Coronary Artery Steno-sis:
Preliminary Animal Experience
A. H. Mahnken, MD, Aachen, GER; H. Pi-etsch,
PhD; B. Schmidt, PhD; T. Allmend-inger;
U. Haberland; E. Klotz, PhD; et al.
Assessment of Image Quality of Different
Image Reconstruction Approaches for the
Evaluation of Myocardial Perfusion De-fects
T. Allmendinger; R. Raupach, PhD;
B. Schmidt, PhD; E. Klotz, PhD; H. Pietsch,
PhD; T. G. Flohr, PhD
Use of a Pitch Value of 3.2 in Dual Source
Cardiac CT Angiography: Dose Perfor-mance
Relative to Existing Scan Modes
C. H. McCollough, PhD, Rochester, MN;
S. Leng, PhD; B. Schmidt, PhD; T. All-mendinger;
C. Eusemann, PhD; T. G.
Flohr, PhD
Comparison of Temporal Resolution in
Dual Source (DS) Images and Dual Energy
(DE) Images Based on Cardiac Motion
Phantom Data R. Raupach, PhD;
T. Allmendinger; B. Schmidt, PhD;
B. Krauss, PhD; T. G. Flohr, PhD
2nd Generation Abdominal Dual Energy CT
with Tin Filtering: Assessment of
Image Quality and Radiation Exposure
A. Graser, MD, Munich, GER; T. R. John-son,
MD; W. H. Sommer, MD; M. F. Reiser,
MD; C. R. Becker, MD; K. Nikolaou, MD
Dual Energy CT – How about the Dose?
T. R. Johnson, MD; J. C. Schenzle; W. H.
Sommer, MD; G. Michalski; K. Neumaier;
C. R. Becker, MD; et al.
Pulmonary Perfusion Imaging with Dual
Energy CT – Image Quality and Dose
T. R. Johnson, MD; W. H. Sommer, MD;
J. C. Schenzle; G. Michalski; K. Neumaier;
C. R. Becker, MD; et al.
Sub-second ECG-synchronized Chest CT
using Dual Spiral Acquisition
W. H. Sommer, MD; J. C. Schenzle; C. R.
Becker, MD; K. Nikolaou, MD; M. F. Reiser,
MD; T. R. Johnson, MD
Education Exhibits
128-slice Dual Source CT: How Does it
Work and What Can it Do?
These and many more results, sessions,
discussions, education exhibits and sym-posia
about SOMATOM® Definition Flash
and its novel low dose CT scanning can be
found on the RSNA 2009.
www.rsna.org
Just published:
Diagnostic accuracy of high-pitch Dual Source
CT for the assessment of coronary stenoses:
first experience. H. Alkadhi et al. Eur Radiol,
Sept 2009, Epub ahead of print
Prospectively ECG-triggered high-pitch spiral
acquisition of coronary CT angiography using
Dual Source CT: technique and initial experi-ance.
S. Achenbach et al. Eur Radiol, Sept
2009, Epub ahead of print

News
By Stefan Wünsch, PhD and Daniel J. Ruzicka, MD, MSc, Business Unit CT, Siemens Healthcare, Forchheim, Germany
1 4D Noise Reduction
in CT perfusion imaging
allows to reduce slice
thickness with improved
image quality. (e.g
10mm p 5mm),
(Fig. 1A).
Dual Energy (DE) VRT
image of the right foot
(sagittal tendons image)
visualizing multiple ten-dons
around the joints
(Fig. 1B), courtesy of
Shandong Medical Imag-ing
Research Institute,
Shandong, P.R. China.
DE image shows Xenon
concentration in the lung
(Fig. 1C), courtesy of
University Munich,
Campus Großhadern,
Germany.
syngo 2009A – a New Era for Routine and
Advanced Diagnostic Imaging
With syngo 2009A, the latest software
version for the MultiModality Workplace
(MMWP), a whole set of new functional-ities
has been introduced as well as
numerous improvements to existing
applications.
An important growth area for clinical
applications is the functional evaluation
of whole organs. In the field of neuro-im-aging,
the new syngo Volume Perfusion CT
(VPCT) Neuro provides 3D analyses of
volumetric datasets of the brain. In com-bination
with Adaptive 4D Spiral of the
SOMATOM® Definition AS+ or SOMATOM
Definition Flash, the entire brain can be
examined. Applying a newly developed,
elaborate technique implanted with
syngo 2009A on MMWP in the syngo
Volume Perfusion software, noise reduc-tion
of dynamically acquired data is pos-sible
(Fig. 1A). Thus, the radiation dose
of dynamic CT perfusion exams can be
reduced by up to 50%, while retaining
equivalent diagnostic information.
Furthermore, it will allow using a higher
pitch for perfusion scans, which gives
the capability to enlarge the scan-range.
Also, thinner slices providing more de-tailed
information about the perfusion
are now possible.
Following the 3D evaluation concept
of CT data, the current syngo VPCT Body
evaluates dynamic 3D perfusion CT data
of the body, e.g. for lung and liver tumors.
Having updated the current algorithm
and implemented 4D Noise Reduction
as well, whole organ perfusion can be
performed on fewer time-points, which
significantly reduces the necessary dose
in these examinations. Deconvolution-based
perfusion maps like BloodFlow,
BloodVolume, MeanTransitTime are now
available in syngo VPCT Body as well.
By further improving Dual Energy applica-tions,
syngo 2009 provides important
additional value for Dual Energy CT (DECT)
users. For SOMATOM Definition Flash
users, for example, Dual Energy with Selec-tive
Photon Shield opens the door to a
new world of characterization, visualizing
the chemical composition of material.
Within the syngo 2009 application,
syngo DE Musculoskeletal uses this infor-mation
to display tendons and ligaments
in a CT image (Fig. 1B), providing addi-tional
information without additional
scans for faster diagnosis, especially in
emergency situations. With the syngo
DE Xenon application available for the
SOMATOM Definition Flash, the Xenon
concentration in the lung can be visual-ized
without use of an additional non-contrast
scan.
The new application syngo DE Lung
Nodule uses Dual Energy information
to visualize the contrast agent concen-tration
in lung nodules without use of
an additional non-contrast scan.
With a special focus on supporting the
routine workflow Siemens further en-hanced
InSpace4D including: Auto Table
Removal, parallel and radial range on all
image types, PET/SPECT images loadable,
fusion functionality, opacity slider for re-moved
bones (BR) and InSpace AVA
(centerline, ranges for CPR and cross
sections and improved reporting).
10 mm
5 mm
1A
No 4D Noise Reduction
With 4D Noise Reduction
1B
1C

News
Leading Technology in Rural Hospital
By Karen Schweizer*, Jakub Mochon* and Steven Bell**
* Computed Tomography Division, Siemens Medical Solutions, Malvern, USA
** Business Unit CT, Siemens Healthcare, Forchheim, Germany
Situated in northern Box Elder County in
Utah, Intermountain Bear River Valley
Hospital serves about 18,000 people.
Box Elder County is primarily a farming
community, and it is not uncommon for
some of its people to simply forgo medi-cal
care if getting it means they have to
travel a significant distance. All the more
reason why executives from this 16-bed
hospital felt it was important to upgrade
their single-slice CT scanner.
With the single-slice scanner, Bear River
was unable to perform arterial studies,
which represented an increasing need of
its patient population. “We were sending
all of these studies out,” says Bret
Rohde, radiology manager at Bear River.
“In fact, that was one of the biggest ben-efits
of upgrading. We were able to stop
transferring patients who needed these
studies from our Emergency Department
(ED) to other hospitals.”
Bear River is part of Intermountain
Healthcare, a nonprofit system of hospi-tals,
surgery centers, and clinics that
serves Utah and southeastern Idaho. In-termountain
Healthcare narrowed down
Bear River’s CT choice to three vendors.
After an extensive review, Bear River se-lected
the SOMATOM® Emotion® 16. Al-though
there were many benefits to
selecting the Emotion, the biggest fac-tors
were real-time scanning, Siemens’
commitment to reducing CT dose, and
the simplification of this process from
the user’s perspective.
Superior Real-Time Scanning
& Dose Modulation
“The main thing that attracted me toward
the Emotion was its real-time scanning
capabilities,” says Rohde. “As far as I’m
concerned, real-time scanning is essen-tial.
If we’re scanning a patient and he
moves, we can correct it. And, we’ll often
open our field of view a little bit further
than we need, which enables us to ac-quire
all the information we need. There-fore,
we’re not repeating exams, our effi-ciency
is better, and we’re not giving
patients more dose than necessary.”
The SOMATOM Emotion uses an Ultra
Fast Ceramic detector, which requires
the smallest amount of dose to deliver
exceptional image quality. In addition,
since every patient is unique in terms
of size, weight, and anatomy, the
Emotion’s fully automated dose man-agement
system, CARE Dose4D™, can
tailor dose to a specific patient’s need.
It is embedded right into the Emotion
system for seamless dose modulation
while still providing the radiologist read-ing
the study with a high-quality image.
“We don’t have to worry about dose
modulation any longer,” says Rohde.
“CARE Dose4D runs automatically. We
don’t even consider shutting it off. Our
technologist can just go in, pick a proce-dure,
get the examination done, and the
patient receives the least amount of ra-diation
possible.” The dose advantages
of the SOMATOM Emotion is one reason
behind the great success of over 6,700
installed systems.
Simplifi ed Studies
The SOMATOM Emotion offers a full
range of advanced clinical applications,
many of which are helping Bear River at-tend
to its patients quickly, efficiently,
and effectively. “Not only are we able to
do arterial studies but we’ve also had a
huge increase in PE (pulmonary embo-lism)
chest studies. Our old scanner just
did not provide the information we need-ed
for these, so we had to send them out.
But now, we’re bringing almost every-thing
back in-house,” says Rohde. “Take
IVPs (intravenous pyelograms) for exam-
One of the biggest fac-tors
for selecting the
SOMATOM Emotion was
Siemens’ commitment to
reducing CT dose and
the simplification of this
process from the users
perspective.

News
CT dose reduction on
the SOMATOM Emotion:
CARE Dose4D™
This means true, real-time modulation,
dose calculations made from a single
topogram and real-time feedback from
detectors to the X-ray tube to continual-ly
monitor and adjust the exposure.
Exportable Dose Report
for All Patients
Implemented on the new SOMATOM
Emotion, this report is a comprehensive
summary of the patient’s exposure and is
fully DICOM compliant and exportable to
a PACS system automatically.
Real-time Imaging
Implemented for both the topogram and
spiral acquisition, this feature can save
unnecessary dose by allowing the user
to stop the scan early if required anato-my
is covered or if movement has ren-dered
the scan non-diagnostic.
Ultra-fast Ceramic Detector
The SOMATOM Emotion uses exactly
the same high-end detector material as
implemented in the industry-leading
SOMATOM Definition™ Flash. The detec-tor’s
efficiency is key to Siemens dose
reduction leadership.
Hand CARE for Intervention
The exposure can be turned off for a
section of each tube rotation, signifi-cantly
reducing dose to staff during
interventional procedures.
ple. We used to perform a lot of these but
now we can handle them with CT uro-grams,
which are noninvasive and easier
for the patient and our staff.”
Similarly, confidence in Bear River’s ED
studies has increased. Prior to the instal-lation
of the SOMATOM Emotion 16,
Rohde and his staff had to perform mul-tiple
scans for the chest, abdomen, and
pelvis. Now, the SOMATOM Emotion can
handle traumagrams, covering all areas
at once and with one injection – again,
further reducing dose. “I was surprised
how quickly the physicians bought into
the system and how fast they started us-ing
it,” says Rohde. “Our volumes went
up even quicker than I expected.”
“We more than doubled our volumes al-most
immediately after installation,”
says Eric Packer, the hospital’s CEO and
administrator. “And, it’s been a constant
growth since then. Therefore, members
of our community no longer have to
travel extensively for access to these ser-vices
at larger facilities. We brought ad-vanced
technology closer to home.”
Bear River’s radiology group reads its
scans remotely 24/7, providing reports
within 20 minutes of the scan. If the
study was ordered through the ED, the ra-diologist
will call the ED physician with
the results. This ability to share top quali-ty
images quickly helps speed this process
and instills additional clinical confidence.
“One of the radiologists from our group
told me that they are confident that any
images they receive from a Siemens
product will be of the highest quality. It
makes their job so much easier when
they receive a high-quality image, and
they can dictate their findings with confi-dence,”
says Rohde. “That’s saying a lot.”
Importance of Technology
in a Rural Setting
Access to this kind of state-of-the-art
technology can make all the difference
to a rural hospital like Bear River. “I think
technology is as important – or more im-portant
– for a small hospital like ours,”
says Rohde. “Because we’re remote and
we don’t have in-house radiologists to
support us, the proper technology
makes it a lot easier to communicate
with them and enable us to provide
services similar to a large hospital.”
Packer agrees.” Technology like this CT
scanner lets people know that when
they come here, their care is equal to
what they might get at a larger, tertiary
facility.”
Impeccable Service
State-of-the-art technology is one of the
cornerstones of Bear River’s new
44,000-sq.-ft. facility, which opened in
February 2009. The SOMATOM
Emotion’s sleek, modern look lends itself
well to this high-tech facility and has ad-ditionally
helped bolster the image and
reputation of the hospital. “People are
really impressed when they see it,” says
Packer. “They can see that it is a modern
piece of equipment, which adds to our
facility’s overall high-tech feel.”
Bret Rohde, Radiology Manager, RT, RPA, Bear
River Valley Hospital, Tremonton, UT.
Eric Packer, CEO and Administrator, Bear River
Valley Hospital, Tremonton, UT.
Installation, which occurred twice (once
at the old facility and again at the new
location), went very smoothly. “The
scanner was in our previous location for
one year before it was relocated to our
new facility,” says Rohde. “The transition
was fairly seamless and the installation
crew was awesome.”
“The Siemens product, with its German
engineering, is very high quality and the
service has been impeccable,” Rohde
continues. “I would recommend them to
everyone.”

Business
Lowest Dose
Motivates Purchase
Young patients present several special challenges
when it comes to diagnostic imaging. Without doubt,
one of the most critical is keeping radiation exposure
at a minimum. The industry’s lowest dose and fastest
scan speed make the SOMATOM Defi nition Flash
ideal for pediatric applications.
By Sameh Fahmy
Arnold Palmer Hospital for Children, Or-lando,
Florida, prides itself on providing
advanced, specialized care for children. It
is no surprise that when the 158-bed pe-diatric
hospital decided to purchase a
new CT scanner, it chose the one that de-livers
the fastest speed and the lowest
dose of any CT on the market. Siemens’
SOMATOM® Definition Flash combines
Dual Source technology with the fastest
available hardware components and in-novative
features, enabling thoracic scan-ning
without breath holds and, in many
cases, producing high-quality images
with doses of less than one milliSievert
(mSv).
“It is certainly going to give patients and
their families a higher level of comfort
about CT,” says John Bozard, President
of Arnold Palmer Medical Center, which
includes the children’s hospital and the
adjacent 285-bed, Winnie Palmer Hospi-tal
for Women and Babies. “I can’t think
of a better way to explain quality than by
saying, ‘this technology is the best there
is – there is nothing out there that com-pares.”
Small Dose for Small Patients
Arnold Palmer Hospital was founded 20
years ago as Central Florida’s first hospi-tal
exclusively for children. It has grown
steadily with the region’s population, and
last year alone performed nearly 11,000
CT exams using two scanners: a Siemens
Sensation 64-slice and an aging Siemens
SOMATOM +4. The growing patient load
and the need to replace the aging, 4-slice
CT scanner put the hospital in the market
for a new scanner, and the low dose that
the SOMATOM Definition Flash offers
made an ideal choice for the hospital,
says Joseph Foss, MD, Chair of Pediatric
Radiology. “Because we are a pediatric
hospital, minimal dose for diagnostic
imaging was a key factor,” Foss says. “We
reviewed all of the systems available, and
the Definition Flash definitely provided
the lowest dose possible for our patients,
which is very important for us.”
He goes on to explain that, while reduc-ing
radiation exposure is important for all
patients, pediatric patients in particular
are thought to be more vulnerable to the
adverse effects of ionizing radiation. He
adds that many pediatric patients, such
as those with cancer, must undergo re-peated
scans over an extended period,
making the need to reduce radiation ex-posure
even more critical. Foss was im-pressed
by the depth at which Siemens
considered all of the means possible to
reduce dose. Exposure time is minimized
in the so called Flash Spiral mode be-cause
the two X-ray sources and detec-tors
of the SOMATOM Definition Flash
simultaneously acquire data to allow for
pitch values of up to 3.4 and an unprece-dented
scan speed of 45 cm/s. That en-ables
a routine acquisition of the entire
heart in a quarter of a second with less
“I can’t think of a better way to
explain quality than by saying,
‘this technology is the best there
is – there is nothing out there
that compares.”
John Bozard, President, Arnold Palmer Medical Center,
Orlando, Florida, USA

Bus Tinoepsics
The Arnold Palmer Medical Center is composed of Arnold Palmer Hospital for Children (left) and Winnie Palmer Hospital for Women & Babies (right).
parents to watch their child being sedat-ed
and even more difficult to watch as
a child emerges from sedation, confused
and unsure of what just occurred.
In addition to benefiting patients by re-ducing
dose, Foss says the rapid speed of
the SOMATOM Definition Flash can im-prove
diagnostic capability by allowing
him and his colleagues to obtain images
free of motion artifacts that can make
scans difficult to interpret. He adds that
the ability to clearly image small vessels
in the periphery of the lungs will espe-cially
benefit the hospital’s growing Con-genital
Heart Institute. The Dual Energy
nature of the imaging can also benefit
patients by significantly reducing the rate
and volume of intravenous contrast bolus
required, Foss says. Bozard notes that, al-though
his hospital did not purchase its
new CT scanner as a differentiator for the
purposes of marketing or expanding its
referral base, being the world’s first pedi-atric
hospital to install the SOMATOM
Definition Flash is tangible evidence of its
focus on the health of children. “We are
committed to having the highest quality
level available,” Bozard says. “And that
mandates us to stay on the cutting edge
of everything medical, whether it is ideas
for new services, new ideas about build-ings
and building structures, or new ideas
about equipment.”
“Because we are a pedi-atric
hospital, minimal
dose for diagnostic
imaging is a key factor.
The low dose that the
SOMATOM Defi nition
Flash offers made it
an ideal choice for the
hospital.”
Joseph Foss, MD, Chairman, Pediatric Radiol-ogy,
Arnold Palmer Medical Center, Orlando,
Florida, USA
than 1 mSv of radiation dose. Dual Ener-gy
is as dose efficient as a single 120 kV
scan, because the Selective Photon Shield
blocks unnecessary photons of the X-ray
energy spectrum. X-CARE automatically
switches off the X-ray tube during por-tions
of the rotation that would expose
sensitive areas, such as the eye lens or
thyroid gland. And Siemens’ unique
Adaptive Dose Shield automatically
moves shields into place to block unnec-essary
pre- and post-spiral dose. “Putting
all of these together in one scanner is the
most comprehensive system for dose re-duction
on the market-period,” Foss says.
“And it persuaded us without any ques-tion
that this was the system for us.”
Flash Speed Eliminates
Breath Holds
The requirement for breath holding
during CT scans has always been a chal-lenge
with pediatric patients and often
resulted in the need for sedation. But
Bozard notes that the speed of the
SOMATOM Definition Flash can eliminate
the need for a breath hold and therefore
result in a scan that is less burdensome
and safer for patients. “When you have to
sedate a child for any type of procedure,
whether it’s a surgical procedure or a
test, there are always risks involved,”
Bozard says, adding that it is difficult for
Sameh Fahmy, MS, is an award-winning
freelance medical and technology journalist
based in Athens, Georgia, USA.

Business
RIPIT to the Rescue: A New
Protocol for Trauma Imaging
Savvas Nicolaou, MD, Director of General and Emergency Trauma Radiology
at Vancouver General Hospital in British Columbia, is challenging today’s
standard of care in the emergency department. Nicolaou and his team have
developed an innovative process called the Rapid Imaging Protocol In Trauma
(RIPIT) that uses Dual Source CT scanning to quickly diagnose patients and
save lives.
By Amy K. Erickson
In June 2009, Savvas Nicolaou, MD,
from Vancouver General Hospital gave a
presentation at the SOMATOM World
Summit in Valencia, Spain, where he dis-cussed
the impact of routine whole-body
imaging in a trauma setting and high-lighted
the many benefits of RIPIT. This
article is a report on that presentation.
Savvas Nicolaou begins his presentation
by explaining why imaging critically in-jured
1A 1B
patients is essential for accurate
treatment. “Understanding the full spec-trum
of injuries leads to better decision-making
and pre-operative planning,” he
says. Nicolaou notes that clinical find-
1 Axial image from the base of the scull, looking along the left temporal lobe. The scan was done with Neuro Perfused Blood Volume (PBV) mode on the RIPIT
protocol: an abnormality could be seen on the PBV image (Fig. 1A), while the non contrast image (Fig. 1B) was normal, not showing any aberrance.

patients and is implemented before the
primary survey. “We scan directly from
the emergency department, right on the
trauma table. It is a very fast imaging
process, and the time saved in the acute
traumatic setting is a critical benefit to
patient outcomes,” says Nicolaou. “We
believe it is faster and more accurate in
identifying airway injuries and circulatory
abnormalities.”
Video clips of poly-trauma patients
imaged from brain to pelvis were shown
throughout the presentation. One
patient had fallen 20 feet. The scan
identifies a vascular injury to the liver,
as well as kidney trauma and a bowel
perforation. “The bowel perforation
would have been very difficult for the
surgeon to identify if he didn’t know the
initial interpretation of the CT examina-tion,”
explains Nicolaou. RIPIT is also
useful prior to treating penetrating ob-ject
(Fig.2) and gunshot injuries because
the scan clearly depicts the trajectory
and reveals any damage to vascular
structures or bony anatomy, he says.
A Clear Benefi t
Vancouver General Hospital is a level
one trauma center with approximately
6,000 trauma-related cases each year,
including 1,000 severe poly-trauma
patients. Nicolaou presents the results
of a retrospective analysis conducted at
Vancouver General Hospital on the
effectiveness of RIPIT, based on three
outcome measures: scanning time, radi-ation
dose and image quality. After ana-lyzing
the data from about 100 patients,
Nicolaou says he identified a 36% reduc-ings
2 VRT of a penetrating
trauma, scanned with the
RIPIT protocol: a dagger
penetrated through the
posterior aspect of the
body. The surgeon need-ed
to know the trajectory
before removing the
object, to see whether it
damaged any vascular
structures – which turned
out not to be the case, in
this patient.
can be misleading in 20% - 50% of
blunt poly-trauma patients. In cases
where there is a loss of consciousness
or a head injury, a physical examination
is only 16% reliable in detecting abdomi-nal
injuries. Additionally, adds Nicolaou,
imaging decreases the mortality in poly-trauma
patients. “We believe that death
begins in the trauma bay, and we strong-ly
believe it can often be stopped with
the Dual Source CT scanner in the emer-gency
department,” he says.
Nicolaou refers to a recent study pub-lished
in the journal Lancet that investi-gates
the benefits of routine whole-body
imaging in a trauma environment. The
retrospective, multicenter study demon-strates
that when compared to a tradi-tional
imaging approach, a whole-body
CT protocol, when instituted early, has
been shown to improve mortality and
morbidity by reducing the number of
missed diagnoses by up to 28%, reduc-ing
the time to definitive diagnosis, and
correctly managing the course of treat-ment.
The protocol is based on 0.5 s ro-tation
and a pitch of 1.0. The contrast
medium is applied as follows: 4cc/s total
of 120cc followed by 50/50 cc mixed
saline chaser. The initial arterial phase is
followed by a portal phase without a
delay phase. The initial read is done by
3mm axial scans of the whole body in
arterial and portal venous phase.
RIPIT Protocols
for Trauma Patients
Two types of rapid imaging protocols
have been developed for emergency sit-uations.
The first protocol is for semi-unstable
patients and is used as part of
the primary survey, a typical routine
where physicians identify life-threaten-ing
conditions. “According to standard-ized
trauma guidelines, the primary
survey is usually Airway, Breathing, Cir-culation
(ABC),” explains Nicolaou.
“However, we believe that after Airway
and Breathing, C stands for CT, not Cir-culation.
We strongly believe that CT can
identify the source of bleeding better
than clinical parameters. We know for a
fact that clinical parameters are not able
to predict which patients are in shock.”
The second protocol is for unstable
tion in scanning time and a dose reduc-tion
of approximately 23% when using
RIPIT versus not using RIPIT. However,
there was a slight decline in image quali-ty
with the RIPIT. “Overall, we saw a de-crease
in time and a decrease in radia-tion
dose at the expense of a slightly
elevated image noise with the RIPIT pro-tocol,”
says Nicolaou. Although the num-bers
indicate a clear benefit to using RIP-IT,
he notes that additional analysis
needs to be done using a larger study
population.
Nicolaou believes that the integration
of rapid whole-body imaging into early
trauma care can provide more accurate
diagnoses and significantly increase
patient survival. “Future directions in-clude
the development of computer-aided
detection devices that will allow for
rapid ease of interpretation of critical
findings,” he says, concluding, “The devel-opment
of the RIPIT protocol means that
no person is left behind. It is true full-body
imaging.”
Amy K. Erickson is a health and medical jour-nalist
based in Chicago, Illinois, USA. Her work
has been published in numerous magazines,
including CURE and Nature Medicine.
Savvas Nicolaou,
MD, Vancouver
General Hospital,
University of
British Columbia,
Vancouver, Cana-da,
speaking at
the SOMATOM
World Summit in
Valencia, Spain.
2

Business
Payback Time: How New CTs
Justify the Investment
Upgrading to next generation Computed Tomography (CT) systems benefi ts
the bottom line, thanks to lower radiation and higher resolution.
By Eric Johnson
As the Americans say, “It takes money
to make money.” And judging from the
experience of the University Hospital
Zurich, this really is the case. Almost
two years ago, the hospital’s Institute of
Diagnostic Radiology took on board
two unique scanners from the high-end
of Siemens’ range: a Dual Source
SOMATOM® Definition and a SOMATOM
Definition AS. In a curtain-raising look at
these new scanners (see pages 20–21
of SOMATOM Sessions, November 2008
at www.siemens.com/healthcare-maga-zine),
the institute’s head of radiology,
Professor Borut Marincek, MD, justified
the outlay on the basis of reduced dos-age.
“For the sake of our patients,” he
said, “we will always opt for the latest
technology that offers the best results
with the lowest possible dosage.” So
SOMATOM Sessions recently went back
to the Institute to ask the hanging ques-tion:
Was the investment worth it?
“Definitely,” answers Marincek’s col-league,
Sebastian Leschka, MD. With
the new scanners, the institute is not only
lowering patient exposures, it is also
saving time, money and hassle in the day-to-
day workflow, thanks to the machines’
high scanning speeds and optimized
workflows. “They have provided signifi-cant
economic benefits,” says Leschka,
adding that the “next-next” generation
scanner, the SOMATOM Definition Flash,
promises to trump these improvements
even more.
At the Heart of the Matter
Cardiac CT scanning at the Institute of
Diagnostic Radiology has been revolutio-nized
by the introduction of the
SOMATOM Definition, Leschka notes.
The hospital’s previous scanner had only
half the Definition’s temporal resolution
of 83 milliseconds. The lower temporal
resolution of the previous system
required that, prior to a scan, most
patients’ hearts had to be slowed down
“We will always opt for the latest
technology that offers the best
results with the lowest possible
dosage.”
Prof. Borut Marincek, MD, Head of Radiology,
University Hospital Zurich

Business
by a dose of beta-blockers. This meant
they needed to report to the hospital
nearly two hours ahead of the scan –
and wait about an hour for the beta-blockers
to kick in. “Of course, we had to
have extra space where patients could
wait for the beta-blockers to take effect,”
recalls Leschka, “and sometimes the
waiting went into overtime because of
schedule changes or other problems.”
“With the new SOMATOM Definition,”
says Leschka, “all we need now is 10–15
minutes in the CT room.” Workflow has
simplified, and cardiac CT scans have
climbed 20% from 2008 to 2009.”
A significant source of this increase is
represented by patients who previously
would have undergone a purely diagnos-tic
procedure (about 40% of all catheter-izations).
Compared to a catheterization,
a CT scan is lower in radiation, takes less
time (minutes, as opposed to the better
part of a day, including an overnight in
the hospital) and more comfortable
(non-invasive). And then there is the fi-nancial
benefit: Leschka points out that
a cardiac CT scan costs about CHF 800,
while an equivalent catheterization costs
nearly seven times as much, a whopping
CHF 5,400.
“With the new scanners, the
institute is not only lowering
patient exposures, it is also
saving time, money and hassle
in the day-to-day workfl ow.”
Sebastian Leschka, MD, Institute of Diagnostic Radiology,
University Hospital Zurich
Meanwhile, non-cardiac CT scans have
benefited from the addition of the
SOMATOM Definition AS. Its higher reso-lution
allows CT-guided interventions
to go more quickly and smoothly. In the
case, for example, of extracting lung
tissue via a needle, “With the old scan-ner,”
remembers Leschka, “we often had
to ask the patient to hold his or her breath
and we could not see what was going
on from some planes of view. With the
Definition AS, no breath holding is need-ed,
and we can see all we need to.”
Things Can Only Get Better
Even more will be seen with the Defini-tion
Flash, the latest member of the
SOMATOM Defintion family of CT scan-ners,
one of which was recently deliv-ered
to Zurich University Hospital’s Insti-tute
of Diagnostic Radiology. Leschka
and his colleagues are cautiously opti-mistic
that the new technology might
bring together the distinct disciplines
of thoracic and cardiac scanning.
Up to now, the heart has been, as Leschka
puts it, a “black hole” in routine thoracic
scanning. Because of the differences in
resolution required for cardiac views, “We
didn’t even bother to look at the heart
in a non-ECG-gated thoracic scan,” he
points out. But the SOMATOM Definition
Flash – which can cover the entire tho-rax
in less than a second – could change
that, because it can virtually conduct the
two scans simultaneously.
“We could combine excellent visualiza-tion
of the coronary arteries and the
thoracic-abdominal arteries in a single
scan”, Leschka speculates. Or take the
case of a patient who comes in with a
vague chest pain. With a Definition Flash
CT scan, “We could find out whether the
problem is, say, in his pulmonary vessels,
his aorta, his lungs or his heart. That
would allow treatment to start more
quickly, and we could do all the scanning
without generating any extra radiation
or cost.” Yet another case of, it takes
money to make money” and save money
and … most important, improve patient
care and save lives as well.
Eric Johnson writes about technology, business
and the environment from Zurich.

Clinical Results Cardio-Vascular
Case 1
Heart Perfused Blood Volume
with SOMATOM Defi nition Dual
Energy Scanning
By Balazs Ruzsics, MD, PhD and U. Joseph Schoepf, MD
Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, USA
HISTORY
A male 64-year-old patient with positive
nuclear stress test, and a medical history
of coronary heart disease and coronary
bypass surgery was seen at the depart-ment
of Radiology.
DIAGNOSIS
Coronary artery disease, status post
coronary artery bypass graft surgery,
was determined.
COMMENTS
A retrospectively ECG-gated Dual Energy
CT exam shows myocardial blood vol-ume
deficit of the inferior myocardium
in confirmation of findings at stress nu-clear
myocardial perfusion imaging. This
finding is consistent with prior infarct in
the right coronary artery territory.
A color-coded iodine map shows the
distribution of contrast agent within the
myocardium in short axis (Fig. 1) and
long axis (Fig. 2) reconstructions. The
inferior/apical myocardium shows
decreased iodine content, representing
chronic infarction. The infero-apical
myocardial blood volume defect is also
clearly visible on the 3D volume-ren-dered
reconstruction in Fig. 3. The same
Dual Energy CT dataset was used to visu-alize
the coronary tree displayed as 3D
volume-rendered reconstruction (Fig. 4)
and delineating the left internal mam-mary
artery and saphenous vein grafts
without additional radiation or contrast
medium administration.
EXAMINATION PROTOCOL
Scanner SOMATOM Definition
Scan mode DE Coronary CTA Rotation time 0.33 s
Scan area Heart Slice collimation 0.6 mm
Scan length 165 mm Slice width 0.75 mm
Scan direction Cranio - caudal Reconstruction increment 0.4 mm
Scan time 13 s Reconstruction kernel D30f and B25f
Tube voltage 140/80 kV Postprocessing syngo InSpace
Tube current 144 eff. mAs/ 165 eff. mAs syngo DE Heart PBV

Cardio-Vascular Clinical Results
1 Short axis reconstruction showing myocardial ischemia. 2 Long axis reconstruction with apical myocardial ischemia.
3 VRT and Heart Perfused Blood Volume (PBV) data fused to
visualize iodine distribution.
4 VRT of the heart showing the course of the bypass graft and native LAD.
1 2
3 4

Case 2
SOMATOM Defi nition Flash:
Dynamic Myocardial Stress-Perfusion
By Konstantin Nikolaou, MD*, Fabian Bamberg, MD, MPH*, Alexander Becker, MD**, Ernst Klotz***, Thomas Flohr, PhD***
*Department of Clinical Radiology, University of Munich, Campus Großhadern, Munich, Germany
**Department of Medicine, Cardiology Division, University of Munich, Campus Großhadern, Munich, Germany
***Business Unit CT, Siemens Healthcare, Forchheim, Germany
HISTORY
A 60-year-old female patient with
known history of stent placement (right
coronary artery, RCA), was referred for
evaluation of recurrent, atypical chest
pain. Presence and extent of coronary
atherosclerotic plaque and stenosis as
well as myocardial perfusion was as-sessed
using a prospective coronary CT
angiography and dynamic myocardial
stress perfusion image acquisition. Find-ings
included two consecutive subtotal
occlusions in the intermediate and distal
segment of the RCA (Figs. 1 and 2,
arrows, RV= right ventricle, LV= left ven-tricle)
and moderate calcified and non-calcified
atherosclerotic plaque in the
proximal segment of the vessel. In addi-tion,
myocardial perfusion analysis (syngo
VPCT Body-Myocardium) application re-vealed
a corresponding segment of myo-cardial
hypo-perfusion as indicated by
delayed enhancement pattern in the
myocardial segment (Figs. 3A and 3B,
arrows). Fig. 3C displays the delayed myo-cardial
enhancement pattern in the corre-sponding
myocardial region of interest
(as indicated by the arrow in Fig. 3B).
DIAGNOSIS
Subtotal occlusion of the RCA with cor-responding
myocardial perfusion defect
was detected by Cardiac CT image in the
inferior wall.
1 Volume-rendered cardiac CT image demonstrates the proximal subtotal occlusion
of the right coronary artery (arrow) just distal to the acute marginal branch.
1

Topic
3A 3B
The dynamic myocardial perfusion imag-ing
was performed using intravenous
adenosine (140μl/kg min). Total radia-tion
exposure including 2.4 mSv coro-nary
angiography of the protocol was
Scanner SOMATOM Definition Flash
Scan mode Stress Perfusion Scanning
Scan area Left ventricular
myocardium
Scan length 72 mm, shuttle
Scan direction Cranio-caudal
Scan time 28 s
Heart rate 60 bpm
Tube voltage 100 kV
Tube current 370 mAs/rot.
Volume 50 ml
Flow rate 5 ml/s
Start delay 18s
Dose Coronary CTA 2.4 mSv
Body-Myocardium
Dynamic Perfusion 9.6 mSv
Postprocessing syngo Volume Perfusion
CT Body
12 mSv.
COMMENTS
This case demonstrates that cardiac CT
imaging has the potential to provide
information on coronary anatomy and
hemodynamic relevance simultaneously.
In this patient, both a coronary CT
angiography and a dynamic myocardial
perfusion scan were performed. Coro-nary
CTA was acquired with a standard
“Adaptive Sequence” protocol at a dose
of 2.4 mSv, which is not further dis-cussed
here.
Cardiovascular Clinical Results
2
2 Maximum Intensity Projection of the right coronary artery demonstrating two
consecutive subtotal occlusions in the intermediate and distal segment of the right
coronary artery (arrows). RV= right ventricle, LV= left ventricle.
3C
3 Dynamic myocardial perfusion analysis reveals a segment of myocardial hypo-perfusion
in the inferior wall (Figs. 3A and 3B, arrows) corresponding to the lesion in
the right coronary artery. Fig. 3C shows temporal course of myocardial enhancement
in normal (red curve) and ischemic (green curve) region of interest: upslope and peak
are significantly lower.

Case 3
Dose Neutral Dual Energy Carotid CTA
with SOMATOM Defi nition Flash
By Filipo Civaia, MD*, Philippe Rossi, MD*, Stéphane Rusek*, Andreas Blaha**
*Department of Cardiology, Centre Cardio-Thoracique de Monaco, Monaco
**Siemens Healthcare, Forchheim, Germany
HISTORY
The patient was referred to the cardiology
department in the Centre Cardio-Thora-cique
de Monaco prior to vascular surgery.
In addition to the previously performed
doppler ultrasound, a Dual Energy scan
was conducted in order to see the entire
vascular status of the carotid arteries
and the carotid stenosis morphology.
DIAGNOSIS
The patient examination revealed a
bilateral high grade common carotid
artery stenosis and severe calcified
plaques in both internal and external
carotid arteries, all close to the bifurca-tion.
Dual Energy scan mode enables
quick volume rendered (VRT) and maxi-mum
intensity projections (MIP) without
overlaying vertebra bodies of cervical
spine to accurately measure the extent
of the stenosis.
COMMENTS
The fast acquisition time of 6 seconds
using Dual Energy technique from the
aortic arch to the Circle of Willis did
show a pure arterial contrast filling.
No venous backflow obstructed the
viewing on the carotid arteries. Cardiac
pulsation also did not impair the diag-nostic
quality of the common carotids
near the aortic arch.
Dual Energy acquisition allows a fast
separation of bones and vessels, even
the closely embedded vertebral artery
and basilar artery were well separated
and diagnosed. The patient immediately
underwent further treatment.
Scan mode DE Carotid Angio Rotation time 0.28 s
Scan area Carotid CTA Pitch 0.9
Scan length 354 mm Slice collimation 0.6 mm
Scan direction Caudo-cranial Slice width 0.75 mm
Scan time 6 s Reconstruction increment 0.7
Tube voltage 100/140 kV Reconstruction kernel D26
Tube current 104/90 mAs Volume 50 ml
Dose modulation CARE Dose4D Flow rate 4.5 ml/s
CTDIvol 8.24 mGy Postprocessing syngo InSpace;
syngo DE Direct Angio

1 Maximum Intensity Projec-tion
(MIP) highlights calcified
Topic
bilateral carotid artery plaques
(arrows, Fig. 1A); inverted MIP,
“angio like view” of the vascular
status (Fig. 1B).
2 Dual Energy software sepa-rates
contrast enhanced arteries
(arrow) and bones/calcium
(red; Fig. 2A). Axial MIP of the
same slice position as Fig. 2A
shows the relationship of lumen
and plaque (arrow, Fig. 2B).
3 Curved maximum intensity
reformations (MIP) of the right
carotid artery (Fig. 3A); curved
maximum intensity reformations
(MIP) of the left carotid
artery (Fig 3B).
4 Volume rendered
image of the pure arterial
enhancement, from aortic
arch to circle of Willis.
1A 1B
2A 2B
3A 3B
4A 4B

Case 4
SOMATOM Defi nition Flash Follow-up
Examination After Stent Implantation for
Ruptured Aneurysm
By Sebastian Leschka, MD
Institute of Diagnostic Radiology, University Hospital Zurich, Zurich, Switzerland
1 VRT of the entire elongated aorta,
highlighting stent in right iliaca commu-nis
(arrow), RCA (arrowhead).
2 Maximum Intensity Projection (MIP) of
the entire aorta showing stented right arteria
iliaca communis (arrow).
HISTORY
An 81-year-old male patient presented
at the radiology department for a
follow-up examination. Six weeks prior
the patient had been delivered to the
hospital for coiling and stent implanta-tion
because of a ruptured aneurysm.
Previous to implantation, the patient
had complained of pain in the lower
abdominal region. One day after stent
implantation, a type II endoleakage
appeared. Four days after intervention,
an acute bleeding of the urethra due to
removal of a permanent catheter was
found. The scheduled follow-up exam
was requested to indicate progress of
convalescence.
DIAGNOSIS
During examination with the Dual
Source CT SOMATOM Definition Flash
scanner, supra-aortic vessels were shown
to be normal. No pathologically increased
lymph nodes could be found. There were
no findings regarding pleural contusion
or pneumothorax. Moderately decreased
dorso-basal left-sided lung-ventilation
was noted but no pathological pulmonary
or mediastinal lesions could be detected.
The abdomen was found to be adequate-ly
perfused and the previously coiled
right aorta iliaca interna was retrogradely
supplied with blood. In the right-sided
pelvis minor, the known interna aneu-
1 2

3 Non-per-fused,
sack-like
aneurysm with
maximum
dimension of
6.9 cm x 7.2 cm
(arrow).
rysm, a non-perfused sack-like aneurysm
with maximum dimension of
6.9 cm x 7.2 cm, was visible. Additionally,
an arising, cyst-like hematoma (max.
6.4 cm x 3.3 cm) was detected. The
boundary area of the hematoma showed
increased contrast media uptake. The
implanted stent in the right arteria iliaca
communis showed a regular position not
indicating any endoleak. No intraperito-neal
fluid was visible. No pathological
increased lymph nodes were found in the
abdomen.
COMMENTS
The follow-up could be conducted quickly
and progress of the patient’s convales-cence
indicated with reliable image re-sults.
Regular follow-up investigations
for monitoring future recovery have
been recommended. For the scan, only a
total dose of 3.0 mSv was necessary.
With one and the same scan, substantial
coronary artery stenosis could be ex-cluded.
Scan mode Flash spiral
Scan area Thorax and Abdomen
Scan length 653 mm
Scan direction Cranio-caudal
Scan time 1.5 s
Tube voltage 100 kV / 100 kV
Tube current 320 mAs /rot
CTDIvol 2.83 mGy
DLP 201 mGycm
Dose 3.0 mSv
Rotation time 0.28 s
Pitch 3.2
Slice collimation 0.6 mm
Slice width 0.75 mm
Reconstruction 0.4 mm
increment
Spatial Resolution 0.33 mm
Reconstruction B26f
kernel
Volume 100 ml contrast
Flow rate 5 ml/s
Start delay 10 s
Postprocessing CT Cardiac Engine
3
4 VRT view of
the coronaries;
RCA, LAD, and
LCX.
4
5 Curved
planar refor-mation
of the
right coronary
artery (RCA,
arrow).
5

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