This document discusses the advancement of mammographic equipment. It begins by introducing the components and purpose of mammography equipment. Key components discussed in detail include the x-ray tube, compressor, anti-scatter grid, cassette holder, and digital detectors. The document then covers recent advancements, such as digital mammography technologies like computed radiography, full-field digital mammography, and digital breast tomosynthesis, which uses 3D imaging to improve cancer detection rates.

1. Mammographic Equipment and
its Advancement
Yashawant ku. Yadav
B.Sc MIT 2ND YEAR
NAMS (Bir Hospital)

2. Abstract / Outlines
•Introduction of Equipment
•Components of mammographic equipment
•Mammographic Cassette
•Advancement in mammography
•References

4. Introduction
The goal of mammography is the
early detection of breast cancer,
typically through detection of
characteristic masses or
microcalcifications.
Basic projection :- CC and MLO

5. Risk factors
• Age
• Hormonal History
• Family History
• Genetics presence of BRCA1 or, BRCA2 gene
• Breast architecture (density)
• Menstruation (before 12yr)
• Menopause (after 55 yr)
• Late age of birth of first child or no children
• Never breast fed

6. Anatomy
• Breast is composed of fatty tissue,
glandular tissue, and connective tissue.
• Normal and cancerous tissues in the
breast have small x-ray attenuation
differences between them
• Need x-ray equipment specifically
designed to optimize breast cancer
detection

7. • Younger breasts are make imaging difficult because it is highly dense
due glandular tissue , and older breasts are more fatty so easier to
imaging .
• Mass density and atomic number of soft tissue of breast are similar
that’s why conventional radiography is useless. (????)
• At 70-100 kVp Compton scattering is predominant than photoelectric
effect which cause low differential absorption with in soft tissue finally
the contrast and resolution is decreased.
• Low kVp is used to maximize the PE effect which enhance the
differential absorption and improve the contrast resolution .

8. Best differential between the tissues is obtained at low x-ray
energies
Mammography equipment
• High contrast sensitivity
• high resolution
• low dose

9. Components of equipment (dedicated)
• Generator
• Support system
• X-ray tube
• Collimator / cone
• Breast compressor
• Anti scatter grids
• Cassette holder
• Automatic exposure control
• Photo timers
• Detector systems

10. Generator
• In mammography we are dealing with soft
tissue of breast.
• 20-40 kvp of x ray energy is required for good
contrast.
• Max mA-200mA
• For homogenous x-ray beam, HFG is
required.
• 3 -10 kw tube rating.
• 3-5 lakh HU-heat loading capacity

11. Patient supports
• Screen
• Lead apron
• Seating table
• Holding support
• Free space

12. X –ray tube
Anode or target materials
• Molybdenum
• Rhodium
• Tungsten
Characteristic radiation produced by Mo & Rh are effective for breast
imaging.
Molybdenum is the most common anode target material used in
mammography x-ray tubes.
With digital detectors, W is becoming the target of choice.

13. Cathode
The mammography x-ray tube is configured with dual filaments in the
focusing cup to produce 0.3- and 0.1-mm focal spot sizes
• Mammographic x ray tubes have rotating anode.
• Anode angle- 0 to 16 degrees.
• Tube tilt - 6 -24 degree.
• Source-to-image receptor distance is about 60-65 cm. (80)
• Effective anode angle :- (the actual anode angle plus the physical
tube tilt) is at least 22-24 degrees for coverage of the 24 × 30-cm
field area.

15. • Be(beryllium) window: is used as it has
low atomic no.(4) and lower absorption of
less than 5 kVp x-rays.1mm of Be is
equivalent to 0.1mm Al material(inherent
filter)
• HEEL EFFECT:-Positioning the cathode
over the chest wall of the patient and the
anode over the anterior portion (nipple)
achieves better uniformity of
the transmitted x-rays through the breast .
• Orientation of the tube in this way also
decreases the equipment bulk near the
patient’s head.

17. •FOCAL SPOT SIZE :- 0.3 to 0.4
mm for contact mammography (breast
compressed against the grid and image
receptor) .
• 0.10 to 0.15 mm for magnification
imaging .
• It reduce geometric blurring so that
micro calcifications can be resolved.

18. Target and filter combination
• The filters used in mammography are based on the "k edge" principle
and attenuate the radiation above the k-edge energy of the specific filter
material, either molybdenum or rhodium
• Mo target with 0.03mm(30µm)Mo filter (42)
• Rh target with 0.025mm (25µm)Rh filter (45)
• W target with 0.05mm (50µm) Rh filter (74)

22. Molybdenum target with molybdenum filter
combinations are appropriate for breasts less than 5
cm thick
Molybdenum target with rhodium filters or rhodium
target with rhodium filters may be appropriate for
breasts greater than 5 cm thick

23. Collimator / cones
• Cones are required for proper direction of x ray beam, proper
collimation , for rejecting scatter radiation and protection of chest
wall and lungs from unnecessary radiation.
THREE DESIGN ARE CURRENTLY USED :-
Fixed aperture.
A set of interchangeable cones for various sizes of breast.
An internal set of collimating blades.

24. • for magnification and spot
compression studies, manually
adjusted shutters allow the x-ray field
to be more closely matched to the
volume being imaged.

25. Anti scattered grid
The anti scattered grid must be a moving grid.
Carbon fiber is the preferred interspace material.
 Focused grid, with a grid ratio of 3:1 or 5:1.
 Grid frequencies of 30-40 lines/cm.

26. • Use of such grid doesn’t compromise the spatial resolution but it does
increase the patient dose .
• Use of 4:1 ratio grid approximately double the pt. dose as compare to
non grid contact mammography
• A unique grid is developed specially for the mammography (HTC) high
transmission cellular grid. (crossed type )
• It reduce the scattered radiation in two direction, HTC grid has a copper
as a grid stripe and air as a interspace , physical dimension grid ratio
(3.8:1)

27. Compressor devices
• COMPRESSION PLATE: flat
surfaced plate used for uniform
compression.
1. In Conventional compression
plate anterior portion of breast is
not compressed properly.
2. Newer slanted S.O.F.T paddles
are now available for equal
compression to all areas of the
breast .

28. ADVANTAGE :-
 Provides immobilization of the part during exposure.
 Produces radiograph of uniform density.
 Reduces geometric unsharpness due to closer object to IR distance.
 Reduces scatter and improves contrast.
 Reduces tissue overlap and improves resolution.
 Enhances recognition of architectural distortion produced by tumors.
DISADVANTAGE – is only patient discomfort
SPOT COMPRESSION –it is used to magnify small area of breast for
better visualization.

29. Amount of compression is
between 25 and 40 pounds
of pressure

30. Image receptor
FILM –SCREEN COMBINATION
single-coated film –screen combination is commonly used today
(GADOLINIUM OXYSULPHITE) provide higher film contrast and
require significantly lower radiation exposure as compared to direct
exposure film.
• Currently in mammography single emulsion film are used in
combination with a single back screen.
• MAMMOGRAPHIC CASSETEE ;These are dedicated cassette used
for mammography only (18X24/ 24X30 cm)

32. Automatic exposure control
• Phototimers are design not only to measure x –ray intensity at image
receptor but also for x –ray quality .
• Phototimers are also called AEC device . And it is place after the image
receptor .
• and consists of a single ionization chamber or an array of three or more
semiconductor diodes.
• x-rays transmitted through the breast, antiscatter grid (if present), and
the image receptor generate a signal in the detector.

33. • The signal is accumulated (integrated) and, when the
accumulated signal reaches a preset value, the exposure is
terminated.
• The preset value corresponds to a specified signal-to-noise ratio
(SNR) in a digital mammography unit or an acceptable optical
density (OD) if a film-screen system is used.

34. Digital mammography
 Used with existing Film
Mammography unit
 Film cassettes are
replaced with CR
imaging plates with
photo-stimulable
phosphor (BaFBr:Eu2)
 Image reader or ADC
 Image Processor or the
computer system for
post -processing
Also called full-field
digital mammography
(FFDM),
The x-ray film is
replaced by solid-state
detectors (aSi or a
selenium) that convert x-
rays into electrical
signals.
The electrical signals are
used to produce images,
can be seen on a
computer or printed on
Special film
CR MAMMOGRAPHY DR MAMMOGRAPHY

35. DIRECT” conversion
• Amorphous selenium (direct conversion) using (TFT) flat panel
technology (Siemens, Hologic)
• ~70 micron pixels
“INDIRECT” conversion
• Scintillating phosphor (CsI columns) on an array of amorphous silicon
photodiodes using thin-film transistor (TFT) flat panel technology
• ~100 micron pixels
• Computed radiography
• ~50 micron pixels
• Slot scanning CCD
• ~27 micron pixels
Digital mammography

36. Pixel size
pixel size decreases:
• Spatial resolution improves
• Noise increase
• Signal-to-noise decreases

37. Advantages
• Post acquisition manipulation possible
• Enhances detection of anomalies
• Selectively increases magnification
• Distinguishes between malignant and benign lesions.
• High contrast resolution

38. • Potential in reduction of radiation dose.
• Storage and transfer of image possible.
• Lower image noise.
• Quicker than conventional mammography.

39. Advancement in digital mammography
1. Tomosynthesis
2. Photon counting
3. CAD computer aided detection

40. Tomosynthesis
• Digital Breast Tomosynthesis (DBT) is a 3D imaging technology that
acquires a series of low-dose projection images of the compressed or
uncompressed breast at different angles.
• 3D captures multiple slices of the breast, all at different angles. The
images are brought together to create crystal clear 3D reconstruction of
the breast.
• The radiologist is then able to review reconstruction, one slide at a
time, almost like turning pages in a book.
• This makes it easier for doctors to see if there’s anything to be
concerned about.

41. https://www.youtube.com/watch?v=EvpGVww4mzU

42. Benefits
• Minimal pressure is needed, just enough to hold the breast in place.
• A lower dose of radiation is required, up to 50% reduction for dense breasts.
• The cost of DTS is expected to drop below the cost a of traditional
mammogram.
• Tomosynthesis allow easier differentiation between benign and malignant
lesions
• Early detection of small breast cancers that may be hidden during 2D
mammography
• Greater accuracy in pinpointing size, shape and location of abnormalities

43. • Typical exposure parameters are 29 kVp and 44 mAs
(recorded during imaging of an American College of
Radiology phantom), which would result in a total radiation
dose of 1.45mGy to a breast thickness of 4.2 cm.

44. Photon counting
Photon-counting mammography is one of the
newer forms of X-ray-based mammography
technologies.
In 2003, the Micro Dose Mammography (MDM)
system was introduced by Sectra Mamea.
Photon-counting systems employ a slot-
scanning design in which the system performs a
lateral scan of the breast with a slot collimator.
The main principle is that smaller the detector
used, lower the risk that a scattered photon will
interact and increase image quality.
No grid is needed.

45. • The detector system consists of a large
number of crystalline silicon strip detectors, .
• Silicon has excellent electronic properties
and strip detectors are placed in edge-on
geometry with their long axis parallel to the
direction of the X-ray beam.
• In this way, a sufficient absorption length is
created, resulting in high quantum efficiency
for the full energy spectrum used in
mammography.

46. Technology
• The x-ray beam is collimated to a fan beam
matching the pre-collimator. It remove that photons
which are not initially directed towards the detector
• The pre-collimator transforms the beam into
several equidistant line beams.
• Beneath the breast support there is a detector box
containing a post-collimator and the x-ray detector.
Si-strip detectors matching the line beams exiting
the breast. The number of counted photons in each
channel is accumulated during a single sampling
interval before being sent to the workstation for
image reconstruction and display,

47. Computer Aided detection
• Radiologists misdiagnose 10-30% of the malignant cases
• Of the cases sent for surgical biopsy, only 10-20% are actually
malignant
• The CAD technology basically works like a second pair of eyes,
reviewing a patient's mammogram .
Can detect stage 1 cancers CAD systems
can assist
radiologists to
Reduce these
problems

48. Contd..
Highlights suspicious areas
• marks clusters of calcifications
with a small triangle and breast
masses with a star
• 100% sensitivity,
• decrease false negative
readings.
• Requires digital input.

49. aSi flat panel
X-ray Photon
Scintillator
Amplification
light
Capacitor charge
Storage
analog signal
A/D – Converter
Digital signal
X-ray Photon
aSe
X-ray into electrons
Electron
electron
Capacitor charge
Storage
analog signal
Analog signal
A/D – Converter
Digital signal
Photon Counting
X-ray Photon
MicroDose
Detector
Digital signal
5 (00000000000101)
Se flat panel
COMPARISON
49

50. Limitation of mammography
1. Not always certain between benign and malignant tumours.
2. Interpretations of mammograms can be difficult because a normal
breast can appear differently for each woman.
3. Appearance of an image may be compromised if there is powder or
cream on the breasts or post operative cases.
4. Not all types of cancers of the breast can be seen on mammography.

51. Other modalities of mammography
• Although mammography is the most sensitive exam available for
detecting small breast ca. False Negative Rate is 5-10% .
• USG
• DEDICATED BREAST CT
• BREAST MRI

54. Question for discussions
1. Why subject contrast is high in conventional radiography?
2. In conventional mammography intensifying screen is kept below the film
why?
3. Incidence of breast cancer is higher in upper lateral quadrant why?
4. What is double tack anode ?
5. What is the ratio of radiation induced breast cancer resulting from x ray
mammography ? Benefit VS risk
6. Can we perform mammogram with general x - ray ?