Smith R C, Verga M, Dalrymple N, McCarthy S, Rosenfield A T
Department of Diagnostic Imaging, Yale University School of Medicine, New Haven, CT 06510, USA.
AJR Am J Roentgenol. 1996 Nov;167(5):1109-13. doi: 10.2214/ajr.167.5.8911160.
The purpose of our study was to determine the value of secondary signs of ureteral obstruction on helical unenhanced CT.
Over a 19-month interval, 312 patients with acute flank pain were imaged with helical unenhanced CT. Ureteral stone disease was confirmed to be present in 109 patients and confirmed to be absent in 111 patients Ninety-two remaining patients had no confirmatory imaging studies or surgery and were unable to be contacted for follow-up. For each of the 220 patients with a confirmed diagnosis, we determined the presence or absence of ureteral or collecting system dilatation, perinephric stranding, symmetry of renal size, and renal stones. In all patients with a ureteral stone, we noted the presence or absence of a circumferential rim of soft-tissue attenuation ("tissue-rim" sign) surrounding each stone and each phlebolith.
The sensitivity of each secondary sign was ureteral dilatation, 90%; perinephric stranding, 82%; collecting system dilatation, 83%; and renal enlargement, 71%. The specificity of each secondary sign was ureteral dilatation, 93%; perinephric stranding, 93%; collecting system dilatation, 94%; and renal enlargement, 89%. Ureteral dilatation and perinephric stranding were both present or both absent in 181 of the 220 patients with a confirmed diagnosis. In this subgroup, this combination of signs had a positive predictive value of 99% and a negative predictive value of 95%. The odds ratio for the frequency of the tissue-rim sign with stones versus tissue-rim with phleboliths was 31:1.
When using unenhanced CT to help diagnose acute flank pain, if one does not see a ureteral stone or does see an indeterminate but suspicious calcification, then secondary signs of obstruction are important for diagnosis. The results of this study form the basis of an imaging algorithm that can be used when interpreting unenhanced CT images of patients with acute flank pain.
我们研究的目的是确定螺旋CT平扫时输尿管梗阻继发征象的价值。
在19个月的时间里，对312例急性腰痛患者进行了螺旋CT平扫。109例患者确诊为输尿管结石病，111例患者确诊无输尿管结石病。其余92例患者未进行确诊性影像学检查或手术，且无法联系到进行随访。对于确诊的220例患者中的每一例，我们确定是否存在输尿管或集合系统扩张、肾周条索影、肾大小对称性以及肾结石。在所有输尿管结石患者中，我们记录了围绕每个结石和每个静脉石的软组织衰减环形边缘（“组织边缘”征）的有无。
每个继发征象的敏感性分别为：输尿管扩张90%；肾周条索影82%；集合系统扩张83%；肾增大71%。每个继发征象的特异性分别为：输尿管扩张93%；肾周条索影93%；集合系统扩张94%；肾增大89%。在确诊的220例患者中，181例患者同时存在或同时不存在输尿管扩张和肾周条索影。在这个亚组中，这种征象组合的阳性预测值为99%，阴性预测值为95%。结石出现“组织边缘”征与静脉石出现“组织边缘”征的频率比值比为31:1。
在使用CT平扫帮助诊断急性腰痛时，如果未看到输尿管结石或看到不确定但可疑的钙化，则梗阻的继发征象对诊断很重要。本研究结果构成了一种影像学算法的基础，可用于解读急性腰痛患者的CT平扫图像。
