Inter-observer and Intra-observer Reproducibility for the Determination of Female Urethral Narrowing on Voiding...

Area of Science:

• Urology
• Radiology
• Female Lower Urinary Tract Imaging

Background:

• The voiding cystourethrogram (VCUG) is an imaging technique used to evaluate the lower urinary tract anatomy in women.
• While its use has declined, VCUG remains valuable in urogynecology and reconstructive pelvic surgery for identifying structural causes of recurrent urinary tract infections (RUTI), such as urethral pathology.

Purpose of the Study:

• To evaluate the inter-observer and intra-observer variability among radiologists interpreting urethral caliber and narrowing on VCUG.
• To assess the reliability of VCUG in diagnosing urethral narrowing in non-neurogenic women.

Main Methods:

• Retrospective review of 83 VCUG cases from women aged 18-85 without significant prolapse.
• Four fellowship-trained radiologists independently assessed urethral narrowing, severity, and location on upright sagittal oblique projection images.
• Inter-reader reliability was calculated using the Shrout-Fleiss statistic (intra-class correlation coefficient, ICC).

Main Results:

• All four radiologists agreed on the presence or absence of urethral narrowing in 60% of cases (50/83).
• Majority agreement (≥3 raters) was achieved in 90% of cases (75/83) for narrowing presence (ICC = 0.79).
• For cases with narrowing, majority agreement on severity was 70% (ICC = 0.89) and on location was 84% (ICC = 0.43).

Conclusions:

• This study demonstrates good inter-reader reproducibility for identifying urethral narrowing on standing VCUG in women.
• A majority of radiologists agreed on the presence, location, and severity of urethral narrowing.
• Further correlation with clinical data is needed to establish a standardized radiologic definition of urethral narrowing.