CT Staging of Renal Pelvis Tumor

PURPOSE: To assess the value of computed tomography (CT) in the preoperative staging of transitional cellcarcinoma (TCC) of the renal pelvis. MATERIALS AND METHODS: We retrospectively evaluated the CT TNM staging of 38patients with TCC of the renal pelvis who had undergone preoperative abdominal CT examination between January 1990and January 1998. In CT staging for differentiation between early-stage (TO-2) and advanced-stage disease (T3-T4),three criteria were used, namely the presence or obliteration of the renal sinus fat layer, the smoothness orirregularity of margin between the tumor and renal parenchyma, and the presence or absence of hydronephrosisproximal to the tumor. CT staging was performed by two genitourinary radiologists blinded to the pathologicresults, and was compared with pathologic staging. RESULTS: Pathologic results revealed 19 cases of early stagedisease (TO=8, T1=9, T2=2) and 19 of advanced stage (T3=12, T4=7). Overall CT staging accuracy was 82%(31/38);fourcases were overstaged and three were understaged. In early-stage disease, sensitivity and specificity were 79%,and 84%, and in advanced stage disease were 83% and 80%. Three of four overstaged cases showed hydronephrosisproximal to the tumor. In the second CT staging, using proximal hydronephrosis of the tumor as a criterion forearly-stage disease, the sensitivity and specificity of early-stage disease were 95% and 75%, respectively, andthe specificity of advanced-stage disease was 95%. CONCLUSION: When hydronephrosis proximal to a tumor wasconsidered to be a sign of early stage disease, the CT staging of renal pelvic TCC was highly accurate.

Efficacy of Two-Phase Helical CT Emphasizing Gastric Mucosal Phase in Detection of Early Gastric Cancer with Atypical Enhancement Pattern

PURPOSE: To evaluate the efficacy of two-phase dynamic helical CT, including the gastric mucosal phase, for the detection of atypical non-hyperattenuating early gastric carcinoma (EGC). MATERIALS AND METHODS: In 32 patients, we evaluated the two-phase helical CT findings of endoscopically suspected EGC for changes of the inner hyperattenuating mucosal layer, the hypoattenuating outer layer and the serosal surface. Two gastrointestinal radiologists working together reached their conclusions before pathologic diagnosis had been made. The first, so-called gastric mucosal, phase was obtained 38 -45 sec after the start of IV injection of 150 ml/sec contrast material at a rate of 4 ml/sec to obtain maximum enhancement of the mucosal layer. RESULTS: Among 32 patients, EGC was confirmed in 30 and AGC (T2) in two. Using two-phase helical CT, the detection rate for typical hyperattenuating EGC was 27 % (8/30). Lesions showing focal interruption of the mucosal layer without abnormal enhancement of the outer layer (EGC atypical enhancement pattern type 1) were detected in five patients during the mucosal phase, and were pathologically confirmed as 3 EGC IIc+III, 1IIc+IIa, and I IIb+IIc. Lesions showing a locally protuding lesion of the inner and preserved outer layers, with a smooth serosal surface (EGC atypical enhancement pattern type 2) and which could be distinguished from normal folds, were detected in six patients during the mucosal phase, and were pathologically confirmed as 2 EGC IIb+IIc, 1 IIc+IIa, and 3 IIc+IIb. Lesions were less distinct during the equilibrium phase, and there was no change in the enhancement pattern. The overall detection rate for EGC in which an atypical enhancement pattern was added to the typical one showed improvement (19/30, 63 % ). CONCLUSION: Helical CT using a two-phasic scan technique including the mucosal phase was efficient for various combinations of EGC II and/or III, including IIc. The findings were atypical and non-hyperattenvating, but reliable, and improved the overall detection rate.

CT Findings of Early Right Colonic Diverticulitis

PURPOSE: To investigate the CT findings of acute right colonic diverticulitis, and to determine the differencebetween these and published reports deseribing left colonic, especially sigmoid, diverticulitis. MATERIAL AND METHODS: In 13 patients with acute right lower quadrant pain who underwent ultrasonography a normal appendix wasdemonstrated and acute right colonic diverticulitis was suspected. CT was performed within 24 hours and thefindings were analysed by two radiologists. For further confirmation of diverticulitis, follow-up barium enemaswere performed in ten patients. RESULTS: Inflamed diverticula were visible in all cases, and were solitary. Ninecases occured in the ascending colon and four in the cecum; in particular, eleven occurred around the ileocecalvalve. In three cases, the inflamed diverticulum was less than 1cm in diameter;in five cases, 1-2cm;in three,2-3cm, and in two, 3-4cm. These were able to be classified into two major forms. In three cases it was nodularwith hyperattenuation and some inhomogeneity, and ten shows the target form with thick walls and a central cavity.In five of these target lesions, the wall pattern was partially or completely inhomogenous, or multilayered. Thematerials filling the central cavity were gas in five cases, fecalith in two, and fluid in three. Abnormalpericoloic fat infiltrations were seen in twelve cases(92%), segmental colonic wall thickening in eleven(85%),other not-inflamed diverticula in five(38%), mesenteric lymph node enlargement in three(23%), free pericecal fluidcollection in three(23%), and perirenal fascial thickenings in two(15%). The complications such as remote abscesscavity, colonic obstruction, fistula or perforation were not found. On barium colon study, diverticulitis was inall cases confirmed by the presence of barium in the deformed diverticulum. CONCLUSION: Among CT findings foracute right colonic diverticulitis, the most important and pathognomonic is inflamed diverticula; the forms ofthese vary, and include gangrenous diverticulitis. The CT findings of early right colonic diverticulitis inKoreans might not, however, reveal the complications which sigmoid diverticulitis frequently involves; in patientswith right lower quadrant pain imaging studies are performed promptly, and for the mesentery, the anatomical basebetween right and left colons is different.