May Philip C, Haider Yasser, Dunmire Barbrina, Cunitz Bryan W, Thiel Jeff, Liu Ziyue, Bruce Matthew, Bailey Michael R, Sorensen Mathew D, Harper Jonathan D
1 Department of Urology, University of Washington , Seattle, Washington.
2 Center for Industrial and Medical Ultrasound, University of Washington Applied Physics Lab , Seattle, Washington.
J Endourol. 2016 Sep;30(9):958-62. doi: 10.1089/end.2016.0341.
The purpose of this study was to measure the accuracy of stone-specific algorithms (S-mode) and the posterior acoustic shadow for determining kidney stone size with ultrasound (US) in vivo.
Thirty-four subjects with 115 renal stones were prospectively recruited and scanned with S-mode on a research US system. S-mode is gray-scale US adjusted to enhanced stone contrast and resolution by minimizing compression and averaging, and increasing line density and frequency. Stone and shadow width were compared with a recent CT scan and, in 5 subjects with 18 stones, S-mode was compared with a clinical US system.
Overall, 84% of stones identified on CT were detected on S-mode and 66% of these shadowed. Seventy-three percent of the stone measurements and 85% of the shadow measurements were within 2 mm of the size on CT. A posterior acoustic shadow was present in 89% of stones over 5 mm versus 53% of stones under 5 mm. S-mode visualized 78% of stones, versus 61% for the clinical system. S-mode stone and shadow measurements differed from CT by 1.6 ± 1.0 mm and 0.8 ± 0.6 mm, respectively, compared with 2.0 ± 1.5 mm and 1.6 ± 1.0 mm for the clinical system.
S-mode offers improved visualization and sizing of renal stones. With S-mode, sizing of the stone itself and the posterior acoustic shadow were similarly accurate. Stones that do not shadow are most likely <5 mm and small enough to pass spontaneously.
本研究旨在测量结石特异性算法（S模式）和后方声影在体内通过超声（US）确定肾结石大小的准确性。
前瞻性招募了34名患有115颗肾结石的受试者，并在研究型超声系统上采用S模式进行扫描。S模式是一种灰阶超声，通过最小化压缩和平均化、增加线密度和频率来增强结石对比度和分辨率。将结石及声影宽度与近期CT扫描结果进行比较，并且在5名患有18颗结石的受试者中，将S模式与临床超声系统进行比较。
总体而言，CT上识别出的结石中有84%在S模式下被检测到，其中66%有后方声影。73%的结石测量值和85%的声影测量值与CT上的大小相差在2毫米以内。直径超过5毫米的结石中有89%出现后方声影，而直径小于5毫米的结石中这一比例为53%。S模式可显示78%的结石，而临床系统为61%。与临床系统相比，S模式下结石及声影测量值与CT的差异分别为1.6±1.0毫米和0.8±0.6毫米，临床系统则为2.0±1.5毫米和1.6±1.0毫米。
S模式能改善肾结石的可视化及大小测量。采用S模式时，结石本身及后方声影的大小测量准确性相似。无后方声影的结石很可能直径小于5毫米，小到足以自行排出。
