Department of Urologic Surgery, Vanderbilt University Medical Center, Nashville, TN, USA.
J Endourol. 2012 Mar;26(3):209-13. doi: 10.1089/end.2011.0177. Epub 2011 Oct 19.
Cumulative radiation exposure from imaging studies is hazardous. In chronic diseases such as urolithiasis, efforts are made to limit radiation exposure, particularly for routine surveillance. We sought to determine the correlation of ultrasonography (US) compared with noncontrast CT (NCCT) in detecting and determining size of stones.
Findings were evaluated in patients who underwent both imaging modalities within a 90-day period between July 2008 and June 2010. Urinary calculi were noted on NCCT in 72 patients. The sensitivity of US to determine the number, size, and location of the stones as described on official radiology reports were compared in reference to NCCT.
There were 203 urinary calculi in 90 urinary tracts identified on NCCT imaging. The sensitivity, specificity, and accuracy of detecting specific stones on US were 40%, 84%, and 53%. Correlation between US and NCCT findings decreased with smaller stone size and ureteral location and increased with right-sided laterality. For identified stones, larger stone size discrepancies were noted in up to one-third of stones on US.
Despite concern for excessive radiation exposure, urologists should recognize limitations of US in the evaluation of urolithiasis. As the ideal study to image stones, particularly for routine surveillance, remains unclear, tese data also supports the need for low-dose NCCT protocols and/or selective use of alternative modalities, such as magnetic resonance urography.
来自影像学研究的累积辐射暴露是危险的。在慢性疾病（如尿石症）中，努力限制辐射暴露，特别是常规监测。我们试图确定超声（US）与非对比 CT（NCCT）在检测和确定结石大小方面的相关性。
在 2008 年 7 月至 2010 年 6 月期间的 90 天内，对同时接受这两种成像方式的患者进行了评估。在 72 例患者的 NCCT 中发现了尿结石。将 US 确定结石数量、大小和位置的敏感性与 NCCT 进行了比较，并参考了官方放射学报告。
在 NCCT 图像上共发现 90 个尿路中的 203 个尿结石。US 检测特定结石的敏感性、特异性和准确性分别为 40%、84%和 53%。US 和 NCCT 检查结果的相关性随着结石体积减小和输尿管位置升高而降低，随着右侧偏位增加而升高。对于已确定的结石，在多达三分之一的 US 结石上注意到较大的结石尺寸差异。
尽管存在对过度辐射暴露的担忧，但泌尿科医生应认识到 US 在评估尿石症方面的局限性。由于理想的结石成像研究仍不清楚，这些数据也支持需要低剂量 NCCT 方案和/或选择性使用替代方式，如磁共振尿路造影。
