Department of Urology, Ohio State University Wexner Medical Center, Columbus, OH, 43212, USA; Department of Urology, Nationwide Children's Hospital, Columbus, OH, 43205, USA.
Department of Urology, Nationwide Children's Hospital, Columbus, OH, 43205, USA.
J Pediatr Urol. 2021 Aug;17(4):475.e1-475.e6. doi: 10.1016/j.jpurol.2021.03.026. Epub 2021 Mar 30.
Nephrolithiasis is detected on ultrasound by the presence of an echogenic focus, posterior acoustic shadowing and/or twinkle artifact (TA). TA has been shown to be highly predictive of nephrolithiasis in adults with renal colic and ureteral stones. We sought to evaluate if TA is reliable for diagnosing nephrolithiasis in the pediatric population.
We reviewed renal ultrasound reports indicating presence or absence of TA associated with a single echogenic focus in the kidney or ureter. Exclusion criteria were age >18, multiple echogenic foci or medullary calcinosis, no follow-up, or TA located outside the kidney or ureter. Stone was confirmed either by CT within 3 months of color Doppler ultrasound, visualization on ureteroscopy, or patient report of passing the stone.
Five hundred and ninety-nine ultrasound reports were reviewed and 293 met inclusion criteria. Sixty-nine had diffuse twinkle without echogenic focus and 224 showed TA with single echogenic focus. 135 patients had confirmatory information available (Summary Table). Nephrolithiasis was diagnosed using TA and confirmed on confirmatory studies for 49 ultrasounds. The majority of confirmed stones were in the kidney (n = 40; 82%) and mean size of confirmed stones on ultrasound was 5 mm (range 1.5-10). Sensitivity, specificity, positive predictive value and negative predictive value of TA for detecting nephrolithiasis were 83%, 78%, 74% and 86% respectively.
Compared to the adult literature, TA in children has lower sensitivity, specificity and positive predictive value, but similar negative predictive value for diagnosing nephrolithiasis. This may be related to renal location and smaller stone size. The presence of TA should be weighed in the setting of other clinical and radiographic evidence of nephrolithiasis.
肾结石在超声检查中通过存在一个回声焦点、后向声影和/或闪烁伪影（TA）来检测。TA 已被证明在有肾绞痛和输尿管结石的成年患者中对肾结石具有高度预测性。我们试图评估 TA 是否可用于诊断儿科人群中的肾结石。
我们回顾了肾超声报告，这些报告指示在肾脏或输尿管中存在或不存在与单个回声焦点相关的 TA。排除标准为年龄>18 岁、多个回声焦点或髓质钙化、无随访或 TA 位于肾脏或输尿管外。结石通过彩色多普勒超声检查后 3 个月内的 CT、输尿管镜检查的可视化或患者报告结石排出来确认。
共回顾了 599 份超声报告，其中 293 份符合纳入标准。69 份报告显示弥漫性闪烁但无回声焦点，224 份报告显示 TA 伴单个回声焦点。135 名患者有确认信息可用（总结表）。使用 TA 诊断肾结石，并在确认研究中确认了 49 个超声检查结果。大多数确认的结石位于肾脏（n=40；82%），超声确认结石的平均大小为 5 毫米（范围 1.5-10）。TA 检测肾结石的敏感性、特异性、阳性预测值和阴性预测值分别为 83%、78%、74%和 86%。
与成人文献相比，儿童 TA 的敏感性、特异性和阳性预测值较低，但阴性预测值相似，用于诊断肾结石。这可能与肾脏位置和较小的结石大小有关。在存在其他临床和影像学肾结石证据的情况下，应权衡 TA 的存在。
