Specific Anatomic RegionColon
ApplicationVirtual colonoscopy
AuthorElliot K. Fishman, MD
Reference SourceJHU protocol
Scanner UsedSiemens Somatom Sensation 16
KV / Effective mAs / Rotation time (sec)SUPINE 120 / 200 / 0.5PRONE 120 / 200 / 0.5
Detector Collimation (mm)0.75 - 1.50.75 - 1.5
Slice Thickness (mm)1.0 - 2.01.0 - 2.0
Feed / Rotation (mm)12.012.0
KernelB30B30
Increment (mm)1.01.0
Image Ordercr-ca
Oral ContrastNone
IV Contrast Volume and TypeNot needed but can be helpful
Injection RateN/A
Scan Delay (sec)N/A
3D Technique Used1. Use MPR to look at axial images and coronal/sagittal images and their "colonoscopy program" for the fly through.
2. The key is patient prep and we use the fleet 1 (one) prep kit.
3. Colonic distension is critical and we put around 2000 cc of air into the colon (or more as needed).
Comment: - Some people might consider this excessive and do 3mm thick sections but we prefer 1mm. The mAs can be dropped to 100-120 for a low dose study.
Recon- Sup/ prone 5x5 for filming
Recon Lung/ liver 5x5 for filming