1. When US? When CT?
Fern Karlicki, MD

2. When US? When CT? After this talk, participants should:
Be familiar with the strengths and weaknesses of US & CT
Be familiar with how to use the ACR appropriateness criteria

3. US Strengths Multiplanar Real time No ionizing radiation
Minimal bio-effects
No IV contrast
Inexpensive
Portable

4. US Weaknesses Operator dependent Limited by: Need patient cooperation
Gas - pancreas, lung, bowel
Bone – ribs
Obesity
Metal
Need patient cooperation
Less sensitivity and specificity

6. CT Strengths Prettier pictures Better resolution
Better sensitivity & specificity

7. CT Weaknesses Ionizing radiation Limited planes
Contrast allergy, nephrotoxicity
Expense
IONIZING RADIATION

8. CT & Cancer / Leukemia
1:1000 cancer induction in children after single abdominal CT scan!
Adults have same risk after 5-6 abdominal CT scans
Younger women and children have highest risk

9. ACR Website
For an excellent discussion of appropriateness of different imaging modalities in various clinical scenarios
/ac or
Google - acr appropriateness criteria

10. ACR - AC RLQ pain
Reprinted with permission of the American College of Radiology No other representation of this material is authorized without expressed, written permission from the American College of Radiology. Refer to the ACR website at for the most current and complete version of the ACR Appropriateness Criteria..

11. ACR – AC RLQ pain
Reprinted with permission of the American College of Radiology No other representation of this material is authorized without expressed, written permission from the American College of Radiology. Refer to the ACR website at for the most current and complete version of the ACR Appropriateness Criteria..

12. ACR – AC RLQ pain
Reprinted with permission of the American College of Radiology No other representation of this material is authorized without expressed, written permission from the American College of Radiology. Refer to the ACR website at for the most current and complete version of the ACR Appropriateness Criteria..

13. ACR – AC Hematuria
Reprinted with permission of the American College of Radiology No other representation of this material is authorized without expressed, written permission from the American College of Radiology. Refer to the ACR website at for the most current and complete version of the ACR Appropriateness Criteria..

14. ACR – AC Hematuria
Reprinted with permission of the American College of Radiology No other representation of this material is authorized without expressed, written permission from the American College of Radiology. Refer to the ACR website at for the most current and complete version of the ACR Appropriateness Criteria..

15. ACR – AC Hematuria
Reprinted with permission of the American College of Radiology No other representation of this material is authorized without expressed, written permission from the American College of Radiology. Refer to the ACR website at for the most current and complete version of the ACR Appropriateness Criteria..

16. ACR Appropriateness Criteria Acute Onset Flank Pain
Reprinted with permission of the American College of Radiology No other representation of this material is authorized without expressed, written permission from the American College of Radiology. Refer to the ACR website at for the most current and complete version of the ACR Appropriateness Criteria..

17. Last thought
When US and CT have a similar appropriateness level , consider US first especially in children, young slim adults and in women of child-bearing age in order to minimize the risks of radiation in these patients.