B

Value of multiplanar reconstructions. (A) Axial CT scan of sigmoid shows a 9-mm lobular filling defect (arrow) suspicious for polyp in a moderately distended sig-moid colon with some muscular hypertrophy. (B) Coronal image shows that this has linear morphology (arrow) consistent with an interhaustral fold. Figure 4.4. Value of multiplanar reconstructions. (A) Axial CT scan of sigmoid shows a 9-mm lobular filling defect (arrow) suspicious for polyp in a moderately distended sig-moid...

Advanced 3D Display Methods

Paik, Sandy Napel, and R. Brooke Jeffrey, Jr. With conventional 2D computed tomography (CT) sections, polyps may be difficult to detect and, conversely, normal structures such as haustra may appear polypoid and be mistaken as pathology. This provides the rationale for 3D displays such as virtual endoscopy, which depicts more intuitively the topographical features of the colon. At the same time, 3D displays in and of themselves are insufficient to fully...

References

Ahlquist DA, Wieland HS, Moertel CG, et al. Accuracy of fecal occult blood screening for colorectal neoplasia. A prospective study using Hemoccult and HemoQuant tests. JAMA 1993 269 1262-1267. Beaulieu CF, Jeffrey RB, Jr, Karadi C, et al. Display modes for CT colonography. Part II. Blinded comparison of axial CT and virtual endoscopic and panoramic endoscopic volume-rendered studies. Radiology 1999 212 1 203-212. Beaulieu CF, Napel S, Daniel BL, et al. Detection of colonic polyps in a phantom...

How to Perform and Interpret a Virtual Colonoscopic Examination

Colonography Air Adequate Topogram

Dachman In this chapter, we discuss computed tomography CT of the cleansed colon performed in a manner to detect polyps and masses. The use of CT colonography CTC in the partially prepared or unprepared colon is discussed in chapter 5. Technical considerations critical to the successful performance and interpretation of CTC are reviewed. This chapter presents an overview of how to perform and interpret an examination and will touch on some of the controversies....