Accuracy of ultrasonography for renal stone detection and size determination: is it good enough for management decisions?

作者：Ganesan Vishnu; De Shubha; Greene Daniel; Torricelli Fabio Cesar Miranda; Monga Manoj

来源：BJU International, 2017, 119(3): 464-469.

DOI：10.1111/bju.13605

<jats:sec><jats:title>Objectives</jats:title><jats:p>To determine the sensitivity and specificity of ultrasonography (<jats:styled-content style="fixed-case">US</jats:styled-content>) for detecting renal calculi and to assess the accuracy of <jats:styled-content style="fixed-case">US</jats:styled-content> for determining the size of calculi and how this can affect counselling decisions.</jats:p></jats:sec><jats:sec><jats:title>Materials and Methods</jats:title><jats:p>We retrospectively identified all patients at our institution with a diagnosis of nephrolithiasis who underwent <jats:styled-content style="fixed-case">US</jats:styled-content> followed by non‐contrast computed tomography (<jats:styled-content style="fixed-case">CT</jats:styled-content>) within 60 days. Data on patient characteristics, stone size (maximum axial diameter) and stone location were collected. The sensitivity, specificity and size accuracy of <jats:styled-content style="fixed-case">US</jats:styled-content> was determined using <jats:styled-content style="fixed-case">CT</jats:styled-content> as the standard.</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>A total of 552 <jats:styled-content style="fixed-case">US</jats:styled-content> and <jats:styled-content style="fixed-case">CT</jats:styled-content> examinations met the inclusion criteria. Overall, the sensitivity and specificity of <jats:styled-content style="fixed-case">US</jats:styled-content> was 54 and 91%, respectively. There was a significant association between sensitivity of <jats:styled-content style="fixed-case">US</jats:styled-content> and stone size (<jats:italic>P</jats:italic> &lt; 0.001), but not with stone location (<jats:italic>P</jats:italic> = 0.58). <jats:styled-content style="fixed-case">US</jats:styled-content> significantly overestimated the size of stones in the 0–10 mm range (<jats:italic>P</jats:italic> &lt; 0.001). Assuming patients with stones 0–4 mm in size will be selected for observation and those with stones ≥5 mm could be counselled on the alternative of intervention, we found that in 14% (54/384) of cases where <jats:styled-content style="fixed-case">CT</jats:styled-content> would suggest observation, <jats:styled-content style="fixed-case">US</jats:styled-content> would lead to a recommendation for intervention. By contrast, when <jats:styled-content style="fixed-case">CT</jats:styled-content> results would suggest intervention as management, <jats:styled-content style="fixed-case">US</jats:styled-content> would suggest observation in 39% (65/168) of cases. An average of 22% (119/552) of patients could be inappropriately counselled. Stones classified as 5–10 mm according to <jats:styled-content style="fixed-case">US</jats:styled-content> had the highest probability (43% [41/96]) of having their management recommendation changed when <jats:styled-content style="fixed-case">CT</jats:styled-content> was performed. The use of plain abdominal film of kidney, ureter and bladder and <jats:styled-content style="fixed-case">US</jats:styled-content> increases sensitivity (78%), but 37% (13/35) of patients may still be counselled inappropriately to undergo observation.</jats:p></jats:sec><jats:sec><jats:title>Conclusions</jats:title><jats:p>Using <jats:styled-content style="fixed-case">US</jats:styled-content> to guide clinical decision‐making for residual or asymptomatic calculi is limited by low sensitivity and inability to size the stone accurately. As a result, one in five patients may be inappropriately counselled when using <jats:styled-content style="fixed-case">US</jats:styled-content> alone.</jats:p></jats:sec>

• 出版日期2017-3