Bell T V, Fenlon H M, Davison B D, Ahari H K, Hussain S
Department of Radiology, Boston University School of Medicine, Boston Medical Center, MA 02118, USA.
Radiology. 1998 May;207(2):363-7. doi: 10.1148/radiology.207.2.9577482.
To identify imaging features at unenhanced helical computed tomography (CT) that help differentiate distal ureteral calculi from pelvic phleboliths.
Retrospective analysis was performed of 184 pelvic calcifications identified at unenhanced helical CT in 113 patients. The size, shape, and attenuation of each calcification were recorded in addition to the presence of a central lucency and the appearance of the adjacent soft tissues. With profile analysis, a graphic representation was generated of attenuation in each pixel along a line drawn through each calcification.
Geometric configuration was seen in eight (21%) calculi but not in any phleboliths. Differences were significant (P < .0001) between the mean attenuation of calculi and that of phleboliths. Among phleboliths, none had a mean attenuation greater than 278 HU, 13 (9%) had a visible central lucency, 31 (21%) had a bifid peak at profile analysis, 30 (21%) had the "comet sign" (adjacent eccentric, tapering soft-tissue mass corresponding to the noncalcified portion of a pelvic vein), and three (2%) had the soft-tissue rim sign (edema of the ureteral wall). Among calculi, none had a central lucency, bifid peak, or comet sign, but 29 (76%) had the soft-tissue rim sign.
Analysis of pelvic calcifications at unenhanced helical CT can help differentiate calculi from phleboliths.
识别非增强螺旋计算机断层扫描（CT）的成像特征，以帮助区分远端输尿管结石与盆腔静脉石。
对113例患者非增强螺旋CT检查发现的184处盆腔钙化进行回顾性分析。记录每个钙化的大小、形状和衰减情况，以及是否存在中心透亮区和相邻软组织的表现。通过轮廓分析，沿穿过每个钙化的线条生成每个像素衰减的图形表示。
8处（21%）结石可见几何形态，而静脉石未见。结石和静脉石的平均衰减存在显著差异（P <.0001）。在静脉石中，平均衰减均不超过278 HU，13处（9%）可见中心透亮区，31处（21%）在轮廓分析时有双峰，30处（21%）有“彗星征”（对应盆腔静脉非钙化部分的相邻偏心、逐渐变细的软组织肿块），3处（2%）有软组织边缘征（输尿管壁水肿）。在结石中，无中心透亮区、双峰或彗星征，但29处（76%）有软组织边缘征。
非增强螺旋CT对盆腔钙化的分析有助于区分结石与静脉石。
