Individual patient variation and inter‐rater reliability of lower calyceal infundibular width on routine intravenous pyelography

• Published in: BJU international Vol. 92; no. 6; pp. 607 - 609
• Main Authors: Pace, K.T., Weir, M.J., Harju, M., Tariq, N., D’A.Honey, R.J.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Science Ltd 01.10.2003; Blackwell
• Subjects: Adolescent; Adult; Aged; Aged, 80 and over; Analysis of Variance; Biological and medical sciences; Humans; infundibular width; Investigative techniques, diagnostic techniques (general aspects); Kidney Calculi - diagnostic imaging; Kidney Calculi - pathology; Kidney Pelvis - diagnostic imaging; kidney stones; lower calyx; measurement; Medical sciences; Middle Aged; Observer Variation; Prognosis; Radiodiagnosis. Nmr imagery. Nmr spectrometry; reliability; renal anatomy; Sensitivity and Specificity; Urinary system; Urography - standards; Human; lower calyx; Intravenous administration; Radiodiagnosis; reliability; renal anatomy; kidney stones; Infundibulum; Width; Nephrography; measurement; infundibular width
• ISSN: 1464-4096; 1464-410X
• DOI: 10.1046/j.1464-410X.2003.04452.x

Three papers in this section all relate, directly or indirectly, to minimally invasive procedures. When John Wickham coined this phrase several years ago, it was not possible to predict how widely used it would become, and how relevant to the future not only of urology, but of surgery in general. Obviously, minimally invasive techniques are not only used in the upper urinary tract, but also in most other parts of the urinary tract. There have been many advances in recent years, but we acknowledge John Wickham as a very important founding father. OBJECTIVE To standardise infundibular width (IFW) measurement, to determine patient variability, and to determine inter‐rater variability on intravenous pyelography (IVP). PATIENTS AND METHODS Fifty outpatient IVP films were randomly drawn from two hospitals between 1 July 1998 and 31 August 1999, and examined to measure the lower calyceal IFW on the 5, 10 and 20 min films with compression, and after voiding. Kidneys with previous renal surgery, hydronephrosis or renal anatomical anomalies were excluded; in all, 81 kidneys from 50 patients were examined. The IFW was measured at the narrowest point along the infundibulum. All 50 films were then reviewed by two urologists unaware of their origin, to determine the inter‐rater reliability of the infundibular measurements. RESULTS Analysis of variance (anova) with posthoc analysis showed a significant difference in IFW at each phase of the IVP (repeated measures anova, P < 0.001). The mean (95% confidence interval) IFW was greatest on the compression film, at 4.4 (2.6) mm, and least on the postvoid film, at 1.6 (2.1) mm. Overall inter‐rater reliability was 0.9780 (intraclass correlation coefficient), and the Pearson correlation between each rater for the IFW at each phase of the IVP was ≥ 0.886. CONCLUSIONS There is wide variability in lower calyceal IFW among the various IVP films in a given study. Thus any predictive value of the IFW must be standardized for the timing and IVP film type (compression, postvoid, etc.). The inter‐rater reliability of IFW is high, suggesting that if used correctly it may be more useful in predicting the outcome after shock wave lithotripsy.