Appendiceal Stump Odematous Colonoscopy

Fig. 8.25a-c. False positive diagnosis: spasm of the Ring of Rossi mimicking tumoral disease: a,b supine (a) and prone scanning (b) show persistent incomplete distention of the sigmoid (arrows). Differential diagnosis was made between spasm of the Ring of Rossi and tumoral disease. The soft contours of the lesions suggested a persistent spasm; c additional inflation was performed and subsequent re-evaluation showed normal sigmoid. Diagnosis of spasm of the Ring of Rossi was made. Lesson: Persistent spasms of colonic sphincters can mimick tumoral disease. Administration of butylhyo-scine (Buscopan) or additional inflation helps to relieve the spasm. Morphological characteristics, helpful in differential diagnosis, are the smooth contours and absence of lymph nodes in case of spasm

Appendiceal Stump Coloscopy

Fig. 8.26a,b. False positive diagnosis: lipomatous transformation of the ileocecal valve: a supine image in intermediate window settings shows a hypertrophic nodular ileocecal valve. Differential diagnosis: tumor - lipomatous or papillary transformation of the ileocecal valve; b same image as a - abdominal window setting clearly shows the lipomatous transformation of the ileocecal valve. Lesson: Lipomatous transformation is a "pseudotumoral" alteration of the ileocecal valve. Use different window settings to reveal the lipomatous nature of the valve. Compare with Figures 8.7, 8.8, and 8.9

Fig. 8.26a,b. False positive diagnosis: lipomatous transformation of the ileocecal valve: a supine image in intermediate window settings shows a hypertrophic nodular ileocecal valve. Differential diagnosis: tumor - lipomatous or papillary transformation of the ileocecal valve; b same image as a - abdominal window setting clearly shows the lipomatous transformation of the ileocecal valve. Lesson: Lipomatous transformation is a "pseudotumoral" alteration of the ileocecal valve. Use different window settings to reveal the lipomatous nature of the valve. Compare with Figures 8.7, 8.8, and 8.9

a and may mimick polyps (Fig. 8.27) (Regge et al. 2005).

Extrinsic Impression

Any organ or structure outside the colon can cause external impression. They compress the colon and may appear as focal neoplasms on 3D endolumi-nal images. We have noted impressions from the spleen, liver, other bowel loops, spine, psoas muscle, aorta and iliac arteries, as well as uterine fibroids (Fig. 8.28) (Macari and Megibow 2001).

Complex or Thickened Folds

Complex or thickened folds are typically encountered at the splenic and hepatic flexures. Axial CT images might raise the possibility of intraluminal soft tissue masses or tumoral thickened folds. Endo-luminal views are frequently helpful in identifying a

Fig. 8.27a,b. False positive diagnosis: prolapsing ileocecal valve: a endoluminal 3D image shows a nodular appearance of the ileocecal valve (arrow); b corresponding axial image shows that the polypoid appearance is caused by a prolapsing ileocecal valve. Lesson: A prolapsing ileocecal valve mimics polypoid pathology on endoluminal 3D image. Comparing with axial 2D correctly points to the diagnosis b

Fig. 8.27a,b. False positive diagnosis: prolapsing ileocecal valve: a endoluminal 3D image shows a nodular appearance of the ileocecal valve (arrow); b corresponding axial image shows that the polypoid appearance is caused by a prolapsing ileocecal valve. Lesson: A prolapsing ileocecal valve mimics polypoid pathology on endoluminal 3D image. Comparing with axial 2D correctly points to the diagnosis a

Fig. 8.28a,b. False positive diagnosis: external impression: a endoluminal 3D image shows a smoothly delineated nodule in the sigmoid (arrows); b corresponding axial image shows the nodule is caused by extrinsic uterine impression (arrows; U: uterus). Lesson: Any organ or structure outside the colon can cause external compression. On endoluminal view, these extrinsic impressions simulate tumoral or polypoid disease. Careful correlation of endoluminal 3D image with axial images points towards the diagnosis of external impression b

Fig. 8.28a,b. False positive diagnosis: external impression: a endoluminal 3D image shows a smoothly delineated nodule in the sigmoid (arrows); b corresponding axial image shows the nodule is caused by extrinsic uterine impression (arrows; U: uterus). Lesson: Any organ or structure outside the colon can cause external compression. On endoluminal view, these extrinsic impressions simulate tumoral or polypoid disease. Careful correlation of endoluminal 3D image with axial images points towards the diagnosis of external impression a a the mass as a complex pattern of normal haustral folds. Endoluminal imaging is also extremely helpful in showing the smooth contours of complex normal folds, as opposed to the irregularity caused by tumoral pathology (Fig. 8.29, compare with Fig. 8.18).

fication of afferent venous structures points towards the diagnosis (Fig. 8.31).

Hemorrhoids can be tiny or extremely large, mimicking tumoral pathology. They typically appear as linear, smoothly delineated mucosal irregularities proximal to the ano-rectal margin (Figs. 8.32 and 8.33).

8.3.3.4 Lipoma

Lipomas are rare, but well-recognized "tumors" of the colon. They are more common in the right colon than the left colon. They arise from the sub-mucosa, and may protrude into the lumen as either polypoied or nodular tumor-like lesions. Diagnosis of their lipomatous nature can easily be made by viewing the "tumor" in abdominal window settings (Pickhardt 2004) (Fig. 8.30).

Appendiceal Orifice

The normal appearance of appendiceal orifice is a slit-like orifice (Fig. 8.34). The appendiceal orifice can however also protrude, simulating polypoid disease (Fig. 8.35). In case of previous appendectomy, the appendiceal stump can also simulate polypoid disease. The anatomical location, clearly illustrated on coronal or sagital reformats, points to the diagnosis (Taylor et al. 2003c).

Vascular Lesions

Colonic varices are a complication of portal hyper-tention, and can be seen in the ano-rectal region, as well as throughout the whole colon. Varices are typically smoothly delineated linear lesions. Identi

Scar after Polypectomy

After polypectomy, the colonic wall remains edema-tous, simulating flat or polypoied lesions on virtual CT colonoscopy. Knowledge of the patients history avoids this false positive diagnosis (Fig. 8.36).

Fig. 8.29a,b. False positive diagnosis: complex folds: a axial image shows the splenic flexure, with a thickened nodular-like fold (arrow); b corresponding endoluminal 3D image clearly shows that the thickened nodular appearance is to be explained by the complexity of the folds at the splenic flexure. Lesson: Complex or thickened folds are typically encountered at the splenic and hepatic flexures, and should be differentiated from sessile cancers or polyps. Endoluminal 3D images are extremely helpful for differential diagnosis. Compare with Fig. 8.18

Fig. 8.29a,b. False positive diagnosis: complex folds: a axial image shows the splenic flexure, with a thickened nodular-like fold (arrow); b corresponding endoluminal 3D image clearly shows that the thickened nodular appearance is to be explained by the complexity of the folds at the splenic flexure. Lesson: Complex or thickened folds are typically encountered at the splenic and hepatic flexures, and should be differentiated from sessile cancers or polyps. Endoluminal 3D images are extremely helpful for differential diagnosis. Compare with Fig. 8.18

Fig. 8.30a-c. False positive diagnosis: lipoma: a,b axial image (a; intermediate window settings) and endoluminal 3D image (b) show a nodular distortion of the colonic wall at the hepatic flexure (arrows); c corresponding axial image using abdominal window settings shows the lipomatous nature of this lesion. Diagnosis: lipoma. Note: arrowheads point towards tagged fluid levels. Lesson: Lipomas are submucosal lesions, that are to be considered as "leave-alone" lesions. Correct diagnosis can easily be made by viewing the "tumor" in abdominal window settings b a c

Colonic Stump

Fig. 8.31a,b. False positive diagnosis: submucosal vascular lesions: a endoluminal 3D image in a patient with severe portal hyper-tention shows multiple tiny polyp-like lesions, distributed throughout the colon. (arrows); b corresponding contrast enhanced coronal reformatted MPR image shows multiple submucosal veins, explaining the polyp-like lesions on endoluminal 3D images (arrows).Lesson: In patients with known portal hypertension, think about possible submucosal colonic varices, explaining multiple tiny nodular lesions on endoluminal 3D imaging. Identification of afferent venous structures points towards the diagnosis

Fig. 8.31a,b. False positive diagnosis: submucosal vascular lesions: a endoluminal 3D image in a patient with severe portal hyper-tention shows multiple tiny polyp-like lesions, distributed throughout the colon. (arrows); b corresponding contrast enhanced coronal reformatted MPR image shows multiple submucosal veins, explaining the polyp-like lesions on endoluminal 3D images (arrows).Lesson: In patients with known portal hypertension, think about possible submucosal colonic varices, explaining multiple tiny nodular lesions on endoluminal 3D imaging. Identification of afferent venous structures points towards the diagnosis

Rectal Stump
Fig. 8.32a,b. False positive diagnosis: internal haemorrhoids: a axial image shows irregular, linear structures at the anorectal region (arrows); b corresponding endoluminal 3D image shows linear, smoothly delineated structures at the anorectal junction. (arrows)
Appendiceal Stump Coloscopy

Fig. 8.33a,b. False positive diagnosis: internal haemorrhoids. (cont'd) (note: different patient from Fig. 32): a axial image shows a small polyp-like nodule in the anorectal region. (arrow). Arrowhead: thin rectal tube; b corresponding endoluminal 3D image shows a linear, smoothly delineated lesion nearby the anorectal region. (arrows). Diagnosis: internal hemorrhoids. Lesson: Internal hemorrhoids may mimick polypoid disease. Imaging features pointing towards the diagnosis are the location nearby the anorectal margin, and the tubular-like, smoothly delineated nature on endoluminal 3D images

Fig. 8.33a,b. False positive diagnosis: internal haemorrhoids. (cont'd) (note: different patient from Fig. 32): a axial image shows a small polyp-like nodule in the anorectal region. (arrow). Arrowhead: thin rectal tube; b corresponding endoluminal 3D image shows a linear, smoothly delineated lesion nearby the anorectal region. (arrows). Diagnosis: internal hemorrhoids. Lesson: Internal hemorrhoids may mimick polypoid disease. Imaging features pointing towards the diagnosis are the location nearby the anorectal margin, and the tubular-like, smoothly delineated nature on endoluminal 3D images

Where The Appendiceal Orifice Located
Fig. 8.34a,b. Normal appendiceal orifice. Curved reformatted MPR image shows normal appendiceal orifice (arrow in a), appearing as a slit-like orifice on endoluminal 3D images (arrows in b)
Appendiceal Orifice Lesion

Fig. 8.35a,b. Prolapsing appendiceal orifice, causing false positive diagnosis: a axial image at the level of the appendiceal orifice shows a nodular-like lesion (arrows); b corresponding endoluminal 3D image shows a prolapsing appendiceal orifice (arrows). Before making the diagnosis of a polyp in the caecum, closely correlate the lesion with the anatomical landmarks to exclude prolapsing appendiceal orifice or ileal prolapse (Figs. 27 and 35)

Scars After Colonoscopy

Fig. 8.36a,b. False positive diagnosis: scar after polypectomy: a axial image shows a focal mucosal thickening in the descending colon (arrows); b corresponding endoluminal 3D image confirms the presence of a mucosal lesion, suggesting a flat lesion (arrows). This patient had a polypectomy three days prior to the examination. Diagnosis: scar after polypectomy. Lesson: The mucosa appears edematous and prominent after polypectomy, closely resembling flat lesions

Fig. 8.36a,b. False positive diagnosis: scar after polypectomy: a axial image shows a focal mucosal thickening in the descending colon (arrows); b corresponding endoluminal 3D image confirms the presence of a mucosal lesion, suggesting a flat lesion (arrows). This patient had a polypectomy three days prior to the examination. Diagnosis: scar after polypectomy. Lesson: The mucosa appears edematous and prominent after polypectomy, closely resembling flat lesions b a b a

Spasm of the Internal Sphincter

Spasm of the internal sphincter causes a smoothly delineated contour irregularity at the anorectal junction and should not be mistaken for a flat lesion (Fig. 8.37).

Intermittently Prolapsing Rectal Mucosa

Intermittently prolapsing rectal mucosa appears as a low rectal mass, causing a smooth soft tissue defect. Sigmoidoscopy shows edematous mucosa due to rectal prolapse (Taylor 2003c) (Fig. 8.38).

Diverticular Disease 8.3.3.10.1

The Diverticular Fecalith

A pseudopolypoid lesion occurs when a diverticulum becomes inspissated with fecal matter. As the divertic-ulum lacks the muscularis propria, the fecal material easily remains in the diverticulum and hardens into a fecalith. Imaging findings are unequivocal when it presents as a hyperdense ring with a hypodense centre on the axial images. The corresponding endoluminal 3D images shows a polypoid lesion. On conventional colonoscopy they are recognised as fecal balls falling into the lumen. Confusion with polyps has been

Colonoscopy Pathology Images

Fig. 8.37a,b. False positive diagnosis: spasm of the internal sphincter: a axial image shows a smoothly delineated (sub)mucosal irregularity, located at the region of the internal sphincter (arrows); b corresponding endoluminal 3D image shows a wall thickening of the rectal mucosa at the anorectal region. (arrows). Conventional colonoscopy was normal. Diagnosis: Spasm of the internal sphincter. Lesson: Submucosal contracted muscle layers may mimick pathology

Fig. 8.37a,b. False positive diagnosis: spasm of the internal sphincter: a axial image shows a smoothly delineated (sub)mucosal irregularity, located at the region of the internal sphincter (arrows); b corresponding endoluminal 3D image shows a wall thickening of the rectal mucosa at the anorectal region. (arrows). Conventional colonoscopy was normal. Diagnosis: Spasm of the internal sphincter. Lesson: Submucosal contracted muscle layers may mimick pathology

Appendiceal Stump Coloscopy

Fig. 8.38a,b. False positive diagnosis: intermittently prolapsing rectal mucosa: a axial image shows a smooth soft tissue filling defect at the anorectal region (arrow); b endoluminal 3D image shows an apparent low rectal "mass" (arrows). Conventional colonoscopy showed edematous mucosa due to rectal prolapse. Lesson: Rectal mucosa can appear very prominent, particularly in case of mucosal prolapse, simulating low rectal masses

Fig. 8.38a,b. False positive diagnosis: intermittently prolapsing rectal mucosa: a axial image shows a smooth soft tissue filling defect at the anorectal region (arrow); b endoluminal 3D image shows an apparent low rectal "mass" (arrows). Conventional colonoscopy showed edematous mucosa due to rectal prolapse. Lesson: Rectal mucosa can appear very prominent, particularly in case of mucosal prolapse, simulating low rectal masses described. Some controversy exists over the origin of these imaging findings. Fletcher et al. (Fletcher et al. 1999) described the hyperdensity as being caused by barium remnants in the diverticulum mixed with a fecalith rather than by the fecalith itself. However, Lefere et al. (Lefere et al. 2003) reported that anato-mopathological examination of a surgical specimen of a divericulum with a fecalith showed that the contents of the diverticulum corresponded to fecal material. No barium was detected in the diverticulum.

A thrombus filling the diverticulum after an intra-diverticular bleeding has been described as a possible pseudolesion by Keller et al. (Keller et al. 1984) (Fig. 8.39).

Inverted Diverticulum

A diverticulum may occasionally invert into the colonic lumen and produce a pseudopolypoid lesion.

Fig. 8.39a-c. False positive diagnosis: diverticular fecalith: a endoluminal 3D image in prone position shows a polyplike lesion in the descending colon (arrow); b corresponding axial image shows the lesion has a hyperdense ring and a hypodense centre (arrowb); c corresponding axial image in supine position shows the lesion is incorporated in a diver-ticulum (arrow). Diagnosis: diverticular fecalith. Lesson: A polypoid lesion with a hyperdense ring and hypodense centre corresponds to a diverticular fecalith c

It can be the source of colonic bleeding (Silverstern and Tytgat 1997). In a series of six patients, Glick (Glick 1991) described the lesion as a 1.5- to 2-cm lesion with a central umbilication on double-contrast barium enema. Imaging findings are unequivocal when on the axial images a sessile polypoid lesion contains some air due to a central umbilication in the inverted part of the diverticulum (Posner and SolomoN 1995) (Fig. 8.40) or when it presents with a fat attenuation due to an inclusion of perisigmoi-dal fat (Fenlon 2002). The corresponding endoluminal 3D image invariably has a polypoid aspect and does not help in making the correct diagnosis. Sometimes imaging findings are equivocal when the inverted diverticulum presents without air or fat. In CC inverted diverticula have been described to cause inadvertent diverticulectomy because of their pseudopolypoid appearance (Fenlon 2002; Yusuf and GraNt 2000); thus it is important in case of an additional conventional colonoscopy to inform the endoscopist of this finding.

Polyp-Simulating Mucosal Prolapse Syndrome

When diverticular disease progresses, further shortening, thickening and contraction of the muscular layer and taeniae cause an excess of mucosa, prolapsing into the colonic lumen as a redundant fold. This gives rise to a pseudopolypoid or non-neoplastic lesion (Yoshida et al. 1996). These polypoid lesions usually present with a broad base (Kelly 1991).

Oedema and erythema are possible due to repetitive trapping of the mucosa in a contraction of the colonic wall. These lesions can be the cause of recurrent bleeding. Imaging findings are equivocal. As on the axial and endoluminal 3D images, they present as a polypoid lesion, and the polyp-

Fig. 8.40a-d. False positive diagnosis: inverted diverticulum: a,b prone image in a patient with severe diverticular disease shows an endoluminal protruding structure with air inclusion (arrow in a), resulting in a polyp-like structure on axial (arrow in a) and endoluminal 3D view (arrow in b); c,d supine image in the same patient shows the presence of a diverticulum at the same level, seen on axial (arrow in c) and endoluminal 3D image (arrow in d). Diagnosis: inverted diverticulum. Lesson: Diverticu-lae may invert, resulting in pseudopolypoid lesions. The clue to the diagnosis is the presence of air, as in this patient, or fat, included in the lesion

Fig. 8.40a-d. False positive diagnosis: inverted diverticulum: a,b prone image in a patient with severe diverticular disease shows an endoluminal protruding structure with air inclusion (arrow in a), resulting in a polyp-like structure on axial (arrow in a) and endoluminal 3D view (arrow in b); c,d supine image in the same patient shows the presence of a diverticulum at the same level, seen on axial (arrow in c) and endoluminal 3D image (arrow in d). Diagnosis: inverted diverticulum. Lesson: Diverticu-lae may invert, resulting in pseudopolypoid lesions. The clue to the diagnosis is the presence of air, as in this patient, or fat, included in the lesion d c simulating mucosal prolapse syndrome is indistinguishable from actual polyps. On conventional colonoscopy these lesions, appearing as a hyper-aemic mass, are also difficult to distinguish from adenomatous polyps. Sometimes these ambiguous lesions are only diagnosed after biopsy with histology showing hemosiderin-laden macrophages, capillary thrombi and congestion with telangiectasia (Mathus-Vliegen and Tytgat 1986).

Kelly (Kelly 1991) suggested that these lesions were quite common in the population as they were detected in 8 of a series of 118 resected colonic specimens. The polyp-simulating mucosal prolapse syndrome is histologically similar to the prolapse described in the solitary rectal ulcer syndrome, inflammatory cloacogenic polyps and gastric antral vascular ectasia (Tendler et al. 2002) (Fig. 8.41).

Prolapsing Rectal Mucosa

Fig. 8.41a,b. False positive diagnosis: mucosal prolapse syndrome: a,b prone image in a patient with severe diverticular disease shows a focal nodular wall thickening on axial image (arrows in a) and endoluminal 3D images (arrows in b). Biopsy showed hemosiderin-laden macrophages, capillary trombi and congestion with telangiectasia. Diagnosis of mucosal prolapse syndrome was made. Lesson: When diverticular disease progresses, shortening, thickening and contraction of the muscle layer cause an excess of mucosa, prolapsing into the colonic lumen as a redundant fold. Imaging features are equivocal since on 2D and 3D images mucosal prolapse presents as a polypoied lesion

Fig. 8.41a,b. False positive diagnosis: mucosal prolapse syndrome: a,b prone image in a patient with severe diverticular disease shows a focal nodular wall thickening on axial image (arrows in a) and endoluminal 3D images (arrows in b). Biopsy showed hemosiderin-laden macrophages, capillary trombi and congestion with telangiectasia. Diagnosis of mucosal prolapse syndrome was made. Lesson: When diverticular disease progresses, shortening, thickening and contraction of the muscle layer cause an excess of mucosa, prolapsing into the colonic lumen as a redundant fold. Imaging features are equivocal since on 2D and 3D images mucosal prolapse presents as a polypoied lesion

References

Bielen D, Thomeer M, Vanbeckevoort D, Kiss G, Maes F, Marchal G, Rutgeerts P (2003) Dry preparation for virtual CT colonography with fecal tagging using water-soluble contrast medium: initial results. Eur Radiol 13(3):453-458

Bova JG, Bhattacharjee N, Jurdi R, Bennett WF (1999) Comparison of no medication, placebo, and hyoscyamine for reducing pain during a barium enema. Am J Roentgenol 172(5):1285-1287 Bruzzi JF, Moss AC, Brennan DD, MacMathuna P, Fenlon HM

(2003) Efficacy of IV Buscopan as a muscle relaxant in CT colonography. Eur Radiol 13(10):2264-2270

Callstrom MR, Johnson CD, Fletcher JG, Reed JE, Ahlquist DA, Harmsen WS, Tait K, Wilson LA, Corcoran KE (2001) CT colonography without cathartic preparation: feasibility study. Radiology 219(3):693-698 Dachman AH, Zalis ME (2004) Quality and consistency in CT colonography and research reporting. Radiology 230(2):319-323

Dachman AH, Schumm P, Heckel B, Yoshida H, LaRiviere P

(2004) The effect of reconstruction algorithm on con-spicuity of polyps in CT colonography. Am J Roentgenol 183(5):1349-1353

Embleton KV, Nicholson DA, Hufton AP, Jackson A (2003) Optimization of scanning parameters for multi-slice CT colonography: experiments with synthetic and animal phantoms. Clin Radiol 58(12):955-963 Fenlon M (2002) CT colonography: pitfalls and interpretation.

Abdom Imaging 27:284-291 Fidler JL, Johnson CD, MacCarty RL, Welch TJ, Hara AK, Harmsen WS (2002) Detection of flat lesions in the colon with CT colonography. Abdom Imaging 27(3):292-300 Fidler JL, Fletcher JG, Johnson CD, Huprich JE, Barlow JM, Ear nest F IV, Bartholmai BJ (2004) Understanding interpretive errors in radiologists learning computed tomography colonography. Acad Radiol 11(7):750-756 Fletcher JG, Johnson CD, MacCarty RL, Welch TJ, Reed JE, Hara AK (1999) CT colonography: potential pitfalls and problem-solving techniques. Am J Roentgenol 172(5):1271-1278 Fletcher JG, Booya F, Johnson CD, Ahlquist D (2005) CT colonography: unraveling the twists and turns. Curr Opin Gastroenterol 21(1):90-98 Galdino GM, Yee J (2003) Carpet lesion on CT colonography: a potential pitfall. Am J Roentgenol 180(5):1332-1334 Glick SN (1991) Inverted colonic diverticulum: air contrast barium enema findings in six cases. Am J Roentgenol 156:961-964

Gluecker T, Meuwly JY, Pescatore P, Schnyder P, Delarive J, Jornod P, Meuli R, Dorta G (2002) Effect of investigator experience in CT colonography. Eur Radiol 12(6):1405-1409

Gluecker TM, Fletcher JG, Welch TJ, MacCarty RL, Harmsen WS, Harrington JR, Ilstrup D, Wilson LA, Corcoran KE, Johnson CD (2004) Characterization of lesions missed on interpretation of CT colonography using a 2D search method. Am J Roentgenol 182(4):881-889 Gryspeerdt S, Lefere P, Dewyspelaere J, Baekelandt M, van Holsbeeck B (2002) Optimisation of colon cleansing prior to computed tomographic colonography. JBR-BTR 85(6):289-296

Gryspeerdt SS, Herman MJ, Baekelandt MA, van Holsbeeck BG, Lefere PA (2004) Supine/left decubitus scanning: a valuable alternative to supine/prone scanning in CT colonography. Eur Radiol 14(5):768-777 Goei R, Nix M, Kessels AH, Ten Tusscher MP (1995) Use of anti-

spasmodic drugs in double contrast barium enema examination: glucagon or buscopan? Clin Radiol 50(8):553-557 Hoppe H, Quattropani C, Spreng A, Mattich J, Netzer P, Dinkel HP (2004) Virtual colon dissection with CT colonography compared with axial interpretation and conventional colonoscopy: preliminary results. Am J Roentgenol 182(5):1151-1158 Hwang I, Wong RK (2005) Limitations of virtual colonoscopy.

Ann Intern Med 142(2):154-155; author reply 155 Johnson CD, Harmsen WS, Wilson LA, Maccarty RL, Welch TJ, Ilstrup DM, Ahlquist DA (2003) Prospective blinded evaluation of computed tomographic colonography for screen detection of colorectal polyps. Gastroenterology 125(2):311-319

Keller CE, Halpert RD, Fecsko PJ, Simms SM (1984) Radiologic recognition of colonic diverticula simulating polyps. Am J Roentgenol 143:93-97 Kelly JK (1991) Polypoid prolapsing mucosal folds in diverticular disease. Am J Surg Pathol 15:871-878 Laks S, Macari M, Bini EJ (2004) Positional change in colon polyps at CT colonography. Radiology 231(3):761-766 Lefere PA, Gryspeerdt SS, Dewyspelaere J, Baekelandt M, Van Holsbeeck BG (2002) Dietary fecal tagging as a cleansing method before CT colonography: initial results polyp detection and patient acceptance. Radiology 224(2):393-403

Lefere P, Gryspeerdt S, Baekelandt M, Dewyspelaere J, van Holsbeeck B (2003) Diverticular disease in CT colonography. Eur Radiol 13 Suppl 4:L62-74 Lefere P, Gryspeerdt S, Baekelandt M, Van Holsbeeck B (2004) Laxative-free CT colonography. Am J Roentgenol 183(4):945-948

Luo MY, Shan H, Yao LQ, Zhou KR, Liang WW (2004) Postprocessing techniques of CT colonography in detection of colorectal carcinoma. World J Gastroenterol 1 10(11):1574-1577

Macari M, Megibow AJ (2001) Pitfalls of using three-dimensional CT colonography with two-dimensional imaging correlation. Am J Roentgenol 176(1):137-143 Macari M, Lavelle M, Pedrosa I, Milano A, Dicker M, Megibow AJ, Xue X (2001) Effect of different bowel preparations on residual fluid at CT colonography. Radiology 218(1):274-277

Macari M, Bini EJ, Jacobs SL, Lange N, Lui YW (2003) Filling defects at CT colonography: pseudo- and diminutive lesions (the good), polyps (the bad), flat lesions, masses, and carcinomas (the ugly). Radiographics 23(5):1073-1091 Macari M, Bini EJ, Jacobs SL, Lui YW, Laks S, Milano A, Babb J (2004) Significance of missed polyps at CT colonography. Am J Roentgenol 183(1):127-134 Mathus-Vliegen EMH, Tytgat GNJ (1986) Polyp-simulating mucosal prolapse syndrome in (pre-) diverticular disease. Endoscopy 18:84-86 McFarland EG (2002) Reader strategies for CT colonography.

Abdom Imaging 27(3):275-283 McFarland EG, Zalis ME (2004) CT colonography: progress toward colorectal evaluation without catharsis. Gastroenterology 127(5):1623-1626 Morrin MM, Farrell RJ, Keogan MT, Kruskal JB, Yam CS, Rap-topoulos V (2002) CT colonography: colonic distention improved by dual positioning but not intravenous gluca-gon. Eur Radiol 12(3):525-530 Park SH, Ha HK, Kim MJ, Kim KW, Kim AY, Yang DH, Lee

MG, Kim PN, Shin YM, Yang SK, Myung SJ, Min YI (2005) False-negative results at multi-detector row CT colonography: multivariate analysis of causes for missed lesions. Radiology 235(2):495-502 Pickhardt PJ (2004) Differential diagnosis of polypoid lesions seen at CT colonography (virtual colonoscopy). Radiographics 24(6):1535-1556; discussion 1557-1559 Pickhardt PJ (2005) CT colonography (virtual colonoscopy) for primary colorectal screening: challenges facing clinical implementation. Abdom Imaging 30(1):1-4 Pickhardt PJ, Choi JR (2005) Adenomatous polyp obscured by small-caliber rectal catheter at low-dose CT colonography: a rare diagnostic pitfall. Am J Roentgenol 184(5):1581-1583

Pickhardt PJ, Choi JR, Hwang I, Butler JA, Puckett ML, Hildebrandt HA, Wong RK, Nugent PA, Mysliwiec PA, Schindler WR (2003) Computed tomographic virtual colonoscopy to screen for colorectal neoplasia in asymptomatic adults. N Engl J Med 349(23):2191-2200 Pickhardt PJ, Choi JR, Hwang I, Schindler WR (2004a) Nonade-nomatous polyps at CT colonography: prevalence, size distribution, and detection rates. Radiology 232(3):784-790 Pickhardt PJ, Nugent PA, Choi JR, Schindler WR (2004b) Flat colorectal lesions in asymptomatic adults: implications for screening with CT virtual colonoscopy. Am J Roentgenol 183(5):1343-1347 Pickhardt PJ, Taylor AJ, Johnson GL, Fleming LA, Jones DA, Pfau PR, Reichelderfer M (2005) Building a CT colonog-raphy program: necessary ingredients for reimbursement and clinical success. Radiology 235(1):17-20 Pineau BC, Paskett ED, Chen GJ, Espeland MA, Phillips K, Han JP, Mikulaninec C, Vining DJ (2003) Virtual colonoscopy using oral contrast compared with colonoscopy for the detection of patients with colorectal polyps. Gastroenterology 125(2):304-310 Posner R, Solomon A (1995) Dilemma of an inverted cecal diverticulum simulating a pedunculated polyp: CT appearance. Abdom Imaging 20:440-441 Reeders J, Rosenbush G (1994) Clinical radiology and endoscopy of the colon. Thieme Medical Publishers, New York Regge D, Gallo TM, Nieddu G, Galatola G, Fracchia M, Neri E, Vagli P, Bartolozzi C (2005) Ileocecal valve imaging on computed tomographic colonography. Abdom Imaging 30(1):20-25

Silverstein FE, Tytgat GNJ (1997) Gastrointestinal endoscopy,

3rd edn. Mosby, London Spinzi G, Belloni G, Martegani A, Sangiovanni A, Del Favero C, Minoli G (2001) Computed tomographic colonography and conventional colonoscopy for colon diseases: a prospective, blinded study. Am J Gastroenterol 96(2):394-400 Taylor SA, Halligan S, Bartram CI (2003c) CT colonography: methods, pathology and pitfalls. Clin Radiol 58(3):179-190

Taylor SA, Halligan S, Bartram CI, Morgan PR, Talbot IC, Fry N, Saunders BP, Khosraviani K, Atkin W (2003d) Multi-detector row CT colonography: effect of collimation, pitch, and orientation on polyp detection in a human colectomy specimen. Radiology 229(1):109-118 Taylor SA, Halligan S, Goh V, Morley S, Atkin W, Bartram CI (2003b) Optimizing bowel preparation for multidetector row CT colonography: effect of Citramag and Picolax. Clin Radiol 58(9):723-732 Taylor SA, Halligan S, Goh V, Morley S, Bassett P, Atkin W,

Bartram CI (2003a) Optimizing colonic distention for multi-detector row CT colonography: effect of hyoscine butylbromide and rectal balloon catheter. Radiology 229(1):99-108

Taylor SA, Halligan S, Burling D, Morley S, Bassett P, Atkin W, Bartram CI (2004) CT colonography: effect of experience and training on reader performance. Eur Radiol 14(6):1025-1033 Tendler DA, Aboudola S, Zacks JF, O'Brien MJ, Kelly CP (2002) Prolapsing mucosal polyps: an underrecognized form of colonic polyp-a clinopathological study of 15 cases. Am J Gastroenterol 97:370-376 Thomeer M, Carbone I, Bosmans H, Kiss G, Bielen D, Van-beckevoort D, Van Cutsem E, Rutgeerts P, Marchal G (2003) Stool tagging applied in thin-slice multidetector computed tomography colonography. J Comput Assist Tomogr 27(2):132-139

Vos FM, van Gelder RE, Serlie IW, Florie J, Nio CY, Glas AS, Post FH, Truyen R, Gerritsen FA, Stoker J (2003) Three-dimensional display modes for CT colonography: conventional

3D virtual colonoscopy versus unfolded cube projection. Radiology 228(3):878-885 Yee J (2002) CT colonography: examination prerequisites.

Abdom Imaging 27(3):244-252 Yee J, Hung RK, Akerkar GA, Wall SD (1999) The usefulness of glucagon hydrochloride for colonic distention in CT colonography. Am J Roentgenol 173(1):169-172 Yoshida M, Kawabata K, Kutsumi H, Fujita T, Soga T, Nis-himura K, Kawanami C, Kinoshita Y, Chiba T, Fujimoto S (1996) Polypoid prolapsing mucosal folds associated with diverticular disease in the sigmoid colon: usefulness of colonoscopy and endoscopic ultrasonography for the diagnosis. Gastrointest Endosc 44:489-491 Yusuf SI, Grant C (2000) Inverted colonic diverticulum: a rare finding in a common condition? Gastrointest Endosc 52:111-115

Zalis ME, Perumpillichira J, Del Frate C, Hahn PF (2003) CT colonography: digital subtraction bowel cleansing with mucosal reconstruction initial observations. Radiology 226(3):911-917

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