Making renal stones change size—impact of CT image post processing and reader variability

Abstract

Our results indicate a need for the standardisation of making measurements on CT images.

Urinary stone size estimation: a new segmentation algorithm-based CT method

“…The 95% limits of agreement between our method and the mean reader value was 0.0±0.5 mm. This is comparable to the intrareader limit of agreement of ±0.5 mm and a narrower interval than the inter-reader limit of agreement of ±1.3 mm previously reported for the same data [5]. The use of a reader-independent segmentation algorithm is one way to reduce the inter-reader variability and thereby improve the information whereupon the treatment decision is based.…”

“…A previous study has demonstrated a larger interreader variability compared to the intra-reader variability [5].…”

“…The previous study showed that the variability in renal calculus size estimation with respect to several image post processing parameters was approximately bias ±1 mm [5]. As we cannot infer that any of the possible parameter settings was better than the others, it is reasonable to assume that the uncertainty inherited in the CT acquisition was at least ±1 mm.…”

“…The variability in renal calculus size estimation includes image post processing factors and reader factors [5]. In a previous study the inter-reader limit of agreement in renal calculus size estimation was estimated to ±1.3 mm while the intra-reader limit of agreement was narrower at ±0.5 mm [5].…”

Evaluating the Patient with Left Lower Quadrant Abdominal Pain

“…Controversies Stone measurement on CT is not standardized and affects the reported size (whether to measure size in axial or coronal plane and whether to measure size on soft tissue or bone algorithm). 119 Ultrasound may approach CT for the initial diagnosis in the ED on clinical outcomes. 120 Pathophysiology Calcium oxalate (CaOx) and calcium phosphate are by far the most common stone composition.…”