The document discusses the overuse of CT scans, particularly in emergency departments. It notes that CT use has increased 11 times faster than the rate of ED visits over the last 10 years. Now around 25% of all CT scans are performed in the ED. However, less than 7% of patients presenting with dizziness or syncope benefited from head CT scans. The overuse of CT scans is due to factors like fear of lawsuits, perception that patients want the test, and pressure to utilize expensive machines. Guidelines recommend reducing unnecessary CT scans by using decision rules and clinical assessments to determine who truly needs a CT scan. The document advocates judicious use of CT scans by only using them for appropriate clinical indications and considering alternative imaging methods

1. PROF & HEAD , DEPT OF RADIODIAGNOSIS,
STANLEY MEDICAL COLLEGE, CHENNAI – 1
CONSULTANT RADIOLOGIST,
SCANS WORLD, CHENNAI

2. Is CT scan overused?
 Overuse has been defined as any procedure or
test which is undergone to a patient for an
inappropriate indication.
 Definitely, the answer is “yes”.
 Virtually anyone who presents in the emergency
room with abdomen pain or a headache or
syncope or minor head injury will automatically
get a CT scan.

3.  The rate of CT use grew 11 times faster than the
rate of ED visits during the last 10 year period.
 Just 3.2 percent of emergency patients received
CT scans in 1996, while 13.9 percent of
emergency patients seen in 2007 received them.
 This means that by 2007, 1 in 7 ED patients got
a CT scan. It also means that about 25 percent of
all the CT scans done in the United States are
performed in the ED.
 Less than 7.1 percent of patients presenting to
the emergency department with dizziness and
6.4 percent complaining of syncope or near-
syncope benefited from head CT

5. Why overused?
Several factors contribute to the increased use
of CT scans:
 The greater availability of the equipment;
 Doctors’ fear of being sued for malpractice;
 A perception that patients want the test; and
 Financial pressure to make use of the
machine

6.  CT is “user-friendly” for the clinician, the
patient and the radiologist.
 It is readily available, very fast, produces
high-quality images, and is capable of
detecting a wide array of illnesses
 CT scanners are commonly housed in or near
the ED itself, and there is no barriers to get
the CT done.
 At the same time, the relatively high-
radiation doses associated with CT have also
raised health concerns

7. EMERGENCY CT
 Trauma
 headache
 vertigo, dizziness or light-headedness
 abdominal pain
 convulsions
 impairments of nerve, spinal cord or brain function
 flank pain
 general weakness

8. PAN SCAN (WHOLE BODY CTSCAN)
 Pan scan should be used only on certain
prescribed indications.
 But nowadays it is used even in minor injuries
as well as in stable patients.

9. Whole-body computed tomography in polytrauma: techniques and management.
Linsenmaier U et al Eur Radiol. 2002 Jul; 12 (7): 1728-40. Epub 2001 Dec 13

10. HOW TO REDUCE OVERUSAGE?
 Many of these recommendations are being
promoted through the “Choosing Wisely initiative”,
a campaign developed by the ABIM Foundation
that has collected and communicated guidelines
from across the medical community.
 to help physicians and patients engage in
informed conversations about unnecessary tests,
treatments and procedures.

11. Choosing Wisely Campaign guidelines
 Three specific guidelines (initial).
 American College of Emergency Physicians (ACEP),
states that doctors should “avoid CT scans of the head in
emergency department patients with minor head injury
who are at low risk based on validated decision rules.”
 For syncope: “Avoid CT of the head in asymptomatic
adult patients in the emergency department with
syncope, insignificant trauma and a normal
neurological evaluation
 The another guideline on headache: patients who come
to the emergency room with a headache but no other
complications or risk factors should not get CT scans.

12. Some other recent recommendations
 Don’t do imaging for low back pain within the
first six weeks, unless red flags are present. (
severe or progressive neurological deficits or
when serious underlying conditions such as
osteomyelitis are suspected).
 Don’t start with CT for children suspected of
appendicitis. (USG –PRIMARY)
 Neuroimaging (CT, MRI) is not necessary in a
child with simple febrile seizure.

13. Avoid
Unnecessary CT
The Canadian CT
Head Rule
(CCHR), a
clinical
decision rule
designed to
safely reduce
imaging in
minor head
injury by
differentiating
mild traumatic
brain injury
from clinically
important brain
injury
One in every three CT
scans performed on
patients with minor
head injury is
unnecessary

14. Indications for CT C-spine in ER
 The Canadian C-spine Rules and NEXUS rules -an x-ray or CT
as the their first line imaging modality.
 Clearly CT is much more accurate than x-ray at detecting
significant injuries( a moderate-high suspicion for a fracture or
dislocation).
3 factors…
 The patient’s “protoplasm” – Do they have a history of
osteoporosis? Are they very elderly? Do they have a history of
ankylosing spondylitis?
 The likelihood of obtaining a high quality x-ray image – Is the
patient bull-necked? Do they have severe osteoarthritis?
 The mechanism of injury and physical exam – Was it a high
risk mechanism of injury such as ejection from a car? Are they
altered making the physical exam unreliable? Are there any
focal neurological signs?

15. Avoid Unnecessary CT

16. Facet dislocation

17. Cervical spine fracture
dislocation

18. Burst fracture
 Involvement of middle and posterior columns
 Presence of retropulsed bone fragments

19. TRAUMATIC
PSEUDOANEURYSM

20. Post traumatic vascular
occlusion

21. Diagnostic work up
Acute Abdomen
UltrasoundAbdominal plain film
CT MRI
Which is the best choice?

22. Diagnostic work up
Acute Abdomen
US
US
CT CT
CT
CT

23. Acute Abdomen
MRI
Pregnancy Young patients
when US inconclusive

24. Cholecystitis
 Gallstone
 Wall thickening
 Intraluminal sludge
 Sonographic Murphy’s
sign +++

25. Gynecologic emergency
 Salpingitis
 Ovary cyst
 Ovary torsion

26. Case
RUQ
What does the US examination show?
1) Acute cholecystitis
2) Free fluid in the Morrison pouch
3) Increased echogenicity of the intraperitoneal fat in RUQ

27. Case
RUQ
Which is the main CT finding?
1) Ascending colon diverticulitis
2) Omental inhomogeneity
3) Mesentery inhomogeneity

28. CT as the first line examination
 CT is used as a first line modality in a number of
emergency cases where we can’t rely on other
modalities, or if there is a danger of missing
diagnosis or if there is a fear of getting delayed for
treatment.
 When ?When the sensitivity of other modalities in
acute abdomen is too low to diagnose conditions…
 Why ?
 How ?
 What side effects ?

29. CT versus APF : APF is an
insensitive modality
 Sensitivity of APF Ahn Radiology 2002
 871 patients
 Bowel obstruction : 49 %
 Urolithiasis : 9 %
 Appendicitis, pyelonephritis, pancreatitis, diverticulitis : 0 %
 Intraabdominal foreign body : 90 %
 Sensitivity of APF Mackersy Radiology 2005
 91 patients
 30 % for APF versus 96 % forCT

31. APF for the diagnosis of
pneumoperitoneum
 Sen : 50 - 70 %
 Accuracy decreases
 APF less and less analyzed (even if performed)
 Compromise Sen/Spe
 170 p with suspicion of bowel perforation
 APF upright including diaphragmatic domes
 Sen = 78 % with Spe = 50 %
Chen SCJ Emerg Med 2002

33. ACUTE ABDOMEN
 Consider abdominal
ultrasound as the initial
diagnostic test in suspected
uncomplicated appendicitis,
nephrolithiasis, or
diverticulitis, gynecologic
conditions and biliary
conditions.
Acute appendicitis
 Diameter ≥ 6 mm
PPV, NPV ≥ 95 %
Kessler Radiology 2004
Acute appendicitis

34. Identification of the normal
appendix
- A weakness of US
A normal appendix would be
identified in only 5 % of patients
(NEJM jan 2003)!!!
appendix is identified in 64 % of
cases (Kessler Radiology 2003)
- A strength of CT
CT identifies normal appendix in 80
% of cases (Benjaminof Radiology 2003)

35. CT or US in appendicitis
US CT first line
- thin patients - fat patients
- young women - peritoneal findings
- recent clinical findings - diffuse pain
- children - failure with US

36. Colic pain
 CT advantages :
 Sen
 Spe
 Alternatives Dgs
 Easier
 Faster

37. 37
 High velocity accident
 Middle-aged female
 Hemodynamically
unstable
 Glasgow Coma Score
3/15
Case 2
• Suggested method of
examination
1. X-ray
2. US
3. CT
4. DSA

38. 38
 CT revealed subarachnoidal bleeding, cervical spine fracture, normal chest
 Abdominal CT was also performed
Case 2

39. 39
Case No. 2.
• Any further remarkable findings?
– complex pelvic fracture
– right psoas muscle
hematoma
– liver parenchymal tear
Case 2

40. 40
 Types of shock:
 hypovolemic
 cardiogenic
 distributive
 Patient developed a hypovolemic shock due
to a large hemorrhage
 “Hypoperfusion complex” consists of
 diffuse dilatation of intestines with fluid
 intense enhancement of bowel wall
 increased enhancement of the adrenal glands
 diminished caliber of the abdominal vessels („flat cava” sign)
 decreased splenic enhancement
Case 2

41. 41
Case No. 2. – A similar case

42. 42
Abdominal injury – diagnostic algorithm
• (history, physical examination, lab tests)
• Plain X-ray
– abdomen
• erect or decubitus
• supine
– chest
– bones
• lower ribs
• spine
• pelvis
• Ultrasound
• Computed tomography
MDCT

43. 43
4 good reasons to perform CT:
 plain abdominal X-ray / abdominal US may not be executable
 plain abdominal X-ray / abdominal US may not be diagnostic
 relevant information may be expected from CT only:
(complete overview of the parenchymal organs, bowels,
mesentery, omentum, peritoneum, retroperitoneum, vessels,
bones, etc.)
 time requirement of CT is much shorter
Abdominal injury – diagnostic algorithm

44. 62 year-old female,
acute onset of
abdominal pain
What is your diagnosis?
1) Acute mesenteric ischemia
2) Crohn disease
3) Infectious enteritis
4) Portal vein thrombosis
Case

45. Acute mesenteric ischemia
Arterial contrast phase:
Embolus in SMA
•Enhancement of prox. Jejunum
• No enhancement of remaining
small bowel
• Clot or reduced lumen in SMA
• Segmental wall thickening
• Lack of mucosal enhancement
• No stranding
• Pneumatosis intestinalis

46. Bowel perforation : choice of
surgical procedure
Ulcer perforation  coelioscopy

47. Bowel perforation : choice of
surgical procedure
Jejunal diverticulitis with perforation → laparotomy

48. Bowel perforation : choice of
surgical procedure
Colic perforation with stercoral peritonitis → colostomy

49. Bowel obstruction : choice of
surgical procedure
• When a surgical procedure is
scheduled, CT has an impact +++

50. How ?
 Multidetector CT : axial 1 mm thick slice for
acquisition, 3mm for reading
 2 questions
 Added value of reformatting
 SBO
 Appendicitis
 Bowel perforation
 Added value of iv contrast

51. Value of reformatting in BO
 Same Sen and Spe
 the diagnostic
confidency
 Paulson Radiology 2005

52. Value of reformatting in
appendicitis
 Same Sen and Spe
 the diagnostic
confidency
 Paulson Radiology 2005

53. Subtle finding : the whirl
finding
 Patients with suspicion of BO in an oncologic
population : 1213 patients
 Small bowel volvulus at surgery : 11 patients
(1%)
 Sensitivity
 Specialized GI radiologist : 64 %
 Senior resident : 27 %
Gollub JCAT 2006

54. MidgutVolvulus

55. MidgutVolvulus

56. Whirl sign
Soft-tissue mass
with an internal
architecture of
swirling strands of
soft tisssue and fat
attenuation
Best shown in the
plane perpendicular
to the axis of
rotation

57. Non specialized physician
will ask CT
 Prevalence of disease decreases
 Suspicion of appendicitis
 Surgeon : 70 %
 Emergency department physician : 40 %
 Suspicion of colic pain
 urologist : 80 %
 Emergency department physician : 60 %
 Predictive positive value decreases

58. OMGE
(6 097 cases)
ARC
(3 772 cases)
MODALITY
Appendicitis 24,1 % 26 % CT / US
Cholecystitis 8,9 % 10 % US
Gynecologic
disease
6 % 7 % US
Obstruction 4 % 9 % CT SAP in FU
Colic pain 3,4 % 4 % CT or nothing
GI perforation 2,8 % 4 % CT
Pancreatitis 2,3 % 4 % CT
Diverticulitis 2,1 % 2 % CT
Mesenteric
ischemia
1 % 1 % CT
NSAP 43 % 22 % CT or nothing

59. Is the abdominal x-ray dead?
There still remains several indications for the use of
abdominal x-rays in emergency radiology.
1. Radio-opaque foreign body – metal, leaded glass
or large objects such as packets found in drug
mules
2. To look for free air in suspected perforated
viscous in patient who is not stable enough to
leave the ED for a CT
3. Known chronic diagnosis with multiple frequent
recurrent acute exacerbations such as recurrent
small bowel obstruction, especially in patients
who have had multiple CT scans in the past

60. RADIATION HAZARD
 There is no safe dose of radiation.
- Edward P Radford, MD
 Scholar of the Risks from Radiation

61. Diagnostic Imaging RiskProcedures Effective Dose
(mSv)
Risks
CXR (PA), extremity XR <0.1 Negligible
Abdomen XR, LS spine XR 0.5- 1 Extremely low “death from flying
7200 km”
Brain CT, single-phase
abdomen CT, single-phase
chest CT
1-10 Very low “death from driving 3200
km)
Multiphase CT 10-100 Low
Interventions, repeated CT >100 Moderate

62. Comparative dose
Dose
Equivalent
background
radiation
Estimated
deaths
Chest X-ray PA 0.1 mSv 3 d
1/1 million
examinations
Abdomen X-ray
3 views
1.5 mSv 8 months
1/12,500
examinations
Standard-dose
MDCT
10-15 mSv
100-150 times
7.2 y
1/1,250
examinations
Fo r
adults

63. Children who undergo CT scans in early childhood tend to be at greater risk for
developing leukemia , primary brain tumors , and other malignancies later in life

64. Justification
 Main goal: reducing radiation dose (ALARA).
 Only when properly indicated:
 is this examination of importance (essential) for
diagnosis and therapy in this patient?
 Consider alternatives:
 Ultrasound: abdomen, neck, soft tissues, chest
 MRI: small bowel, liver, brain

65. Conclusion
 CT ideally should be used as a diagnostic test rather than a
screening one because of its expense and unnecessary
radiation exposure to the patient
 CT scan overused –brain, Pulmonary angio
 There are recommendations about when it is appropriate for
physicians to order CT scans.- guidelines
 CT may be considered as the first line imaging test in acute
abdomen EXcept for suspicion of gynecologic conditions,
biliary conditions, appendicitis in some cases, and except in
children
 Select the Right Imaging Exam-Radiation (ALARA)
Alternative diagnostic imaging

66. Thank you
Good luck &
all the best !!!

67. Thank you for your
attention