[Can primary kidney clear cell adenocarcinoma be differentiated from kidney metastasis with computed tomography?]. / Peut-on différencier les adénocarcinomes rénaux primitifs à cellules claires des métastases rénales en tomodensitométrie?

PURPOSE: To determine if CT scan provides morphologic criteria allowing differentiation between primary renal cell cancer of the clear type (PRCCCT) and renal metastasis (RM). MATERIALS AND METHODS: Twenty cases of PRCCCT and 20 cases of RM from various origins (excluding lymphomatous origin) were retrospectively analyzed by two independent readers. CT scans were evaluated with respect to tumor size, shape, location and number of tumors, encapsulation, contour sharpness, presence of calcification, and extrarenal involvement by tumor. RESULTS: A tumor size > 3 cm was more frequently seen in PRCCCT than in RM (100% vs 70% respectively, P < .05). Rounded shape was more frequent in PRCCCT than in RM (90% vs 50% respectively, P < .01). Encapsulation was more frequent in PRCCCT than in RM (70% vs 10%, P < .01, respectively). Calcification was depicted only in PRCCCT (35% vs 0%, P < .01). Enlarged perirenal lymph nodes were less frequent in PRCCCT than in RM (20% vs 55% respectively, P < 0.05). CONCLUSION: Results of our study show that a constellation of morphologic features suggest the diagnosis of PRCCCT rather than that of RM. Our study suggests that calcification is highly specific for the diagnosis of PRCCCT. However, percutaneous biopsy remains indicated to ascertain the diagnosis.

T2-weighted spin-echo MR imaging of the liver: breath-hold fast spin-echo versus non-breath-hold fast spin-echo images with and without fat suppression.

OBJECTIVE: The goal of our study was to compare a T2-weighted breath-hold fast spin-echo (BHSE) technique with T2-weighted non-breath-hold fast spin-echo techniques for imaging the liver. SUBJECTS AND METHODS: Thirty-three patients with hepatic lesions had T2-weighted BHSE images obtained in 22 sec and conventional T2-weighted non-breath-hold fast spin-echo images obtained in 3 min 12 sec with and without fat suppression. Images were analyzed quantitatively by measuring the lesion-liver contrast, spleen-liver contrast, and signal-to-noise ratios of lesions and qualitatively by evaluating the sharpness of hepatic contours, visibility of intrahepatic vessels and other segmental landmarks, and presence of artifacts. RESULTS: Quantitatively, lesion-liver contrast, spleen-liver contrast, and signal-to-noise ratios obtained with the BHSE technique were inferior to those obtained with fast spin-echo techniques with and without fat suppression (11.2 +/- 7.1 versus 15.4 +/- 10.6 and 14.5 +/- 9.8, p < .001; 5.3 +/- 3.7 versus 8.7 +/- 3.5 and 7.0 +/- 3.8, p < .001; 16.2 +/- 8.2 versus 20.1 +/- 10.9 and 19.7 +/- 9.5, p < .01, respectively; Student's t test). Qualitatively, image artifacts and intrahepatic vessel depiction on BHSE images were similar to those obtained with the fast spin-echo techniques. The BHSE technique was superior to fat-suppressed fast spin-echo technique for showing hepatic contours (p < .01; Wilcoxon signed-rank test). CONCLUSION: The BHSE technique is quantitatively inferior to non-breath-hold fast spin-echo techniques. However, further studies with a surgical standard of reference are needed to compare the three techniques in terms of sensitivity.