Stevan B. Streem Center for Endourology and Stone Disease, Glickman Urological & Kidney Institute, The Cleveland Clinic, Cleveland, OH; Division of Urology, Hospital das Clinicas, University of Sao Paulo Medical School, São Paulo, São Paulo, Brazil.
Division of Urology, Hospital das Clinicas, University of Sao Paulo Medical School, São Paulo, São Paulo, Brazil.
Urology. 2014 Jun;83(6):1258-63. doi: 10.1016/j.urology.2013.12.066. Epub 2014 Apr 13.
To study several measurements from a single-energy noncontrast computed tomography (NCCT) that may distinguish calcium oxalate, uric acid, and cystine stones.
Patients with pure urinary stones who had at least 1 single-energy NCCT before the stone composition analysis from January 2008 to December 2012 were enrolled in this study. The analyzed data comprised stone size, volume, core Hounsfield unit (HU), periphery HU, absolute and relative HU differences between core and periphery, and HU density. After these measurements, an NCCT bone window was subjectively evaluated to study the homogeneity of each stone from core to periphery. The Spearman correlation test was used to determine the correlation between HU values and stone size and volume for each group.
A total of 113 patients were found with pure urinary stones who also had a corresponding NCCT. There were 36, 47, and 30 patients in the calcium oxalate, uric acid, and cystine groups, respectively. The core HU, periphery HU, absolute and relative HU differences, and HU density were significantly different among the 3 groups (P<.001). Stone size and volume had a positive correlation with core and periphery HUs only for calcium oxalate and cystine stones. The subjective evaluation of the urinary calculi revealed a different pattern for each stone composition.
Single-energy NCCT may predict calcium oxalate stones with a high degree of accuracy. There is an overlap in radiographic profiles of cystine and uric acid stones, making a definitive differentiation more challenging.
研究单次能非对比计算机断层扫描（NCCT）中的几项测量值，这些值可能有助于区分草酸钙、尿酸和胱氨酸结石。
本研究纳入了 2008 年 1 月至 2012 年 12 月期间因结石成分分析而接受至少一次单次能 NCCT 的纯泌尿系结石患者。分析的数据包括结石大小、体积、核心区亨氏单位（HU）值、周边区 HU 值、核心区与周边区的绝对和相对 HU 值差异以及 HU 值密度。在这些测量之后，对 NCCT 的骨窗进行主观评估，以研究从核心到周边每个结石的均匀性。采用 Spearman 相关检验确定每个组的 HU 值与结石大小和体积之间的相关性。
共发现 113 例纯泌尿系结石患者，且均有相应的 NCCT。草酸钙、尿酸和胱氨酸结石组分别有 36、47 和 30 例患者。3 组间核心 HU 值、周边 HU 值、绝对和相对 HU 值差异以及 HU 值密度均有显著差异（P<.001）。只有草酸钙和胱氨酸结石的结石大小和体积与核心区和周边区 HU 值呈正相关。对泌尿系结石的主观评估显示，每种结石成分的表现模式均不同。
单次能 NCCT 可能能够高度准确地预测草酸钙结石。胱氨酸结石和尿酸结石的影像学特征存在重叠，因此更具挑战性。
