Diagnostic Accuracy and Measurement Variability of Urinary Stones Across CT Window Settings: A Systematic Review and...

The CT scan plays a vital role in diagnosing and managing urolithiasis. However, variability in CT windowing techniques may alter the measurement of stone dimensions, thus affecting decision-making. This study aims to analyse the diagnostic accuracy and variability of urinary stone measurements with different CT window settings.

An electronic search was performed in PubMed, Scopus, Web of Science, and the Cochrane Library until July 2025 for studies comparing stone size measurements between standard soft-tissue and bone window settings. Meta-analysis was conducted using a random-effects model.

The findings suggest that stone measurement through bone window settings is more accurate and shows less inter-observer variability than soft-tissue window settings. Smaller slice thickness and multi-planar reformatting further improved accuracy. Bone window settings also showed better consistency in diagnostic judgement, especially for smaller stones relevant to treatment planning such as ureteroscopy or conservative management.

Bone window imaging should be applied when assessing urinary stones using CT as it improves measurement accuracy and reduces variability. However, standardisation of imaging protocols is still required. This review highlights the need for consensus guidelines on CT windowing in urinary stone evaluation to support accurate diagnosis and improved patient management.