Variability in computed tomography diameter measurements of solid renal masses

Area of Science:

• Radiology
• Medical Imaging
• Oncology

Background:

• Accurate measurement of solid renal masses is crucial for monitoring disease progression and treatment response.
• Intra-observer variability in size measurements can impact clinical decision-making.

Purpose of the Study:

• To evaluate how solid renal mass characteristics and computed tomography (CT) contrast phases influence intra-observer measurement discrepancies of 5 mm or greater.
• To identify factors contributing to measurement variability in renal mass assessment.

Main Methods:

• Retrospective analysis of CT images from 97 patients with single solid renal masses.
• Assessment of mass characteristics including location, margin, heterogeneity, and growth pattern.
• Six readers performed repeated measurements on nephrographic phase (NP) images and compared with corticomedullary phase (CMP) images where available.

Main Results:

• Intra-reader measurement differences of ≥5 mm were infrequent (<4 cm masses, 3.7%) but increased significantly for larger masses (≥4 cm, 16.8%).
• Poorly defined margins (15.9%) and heterogeneity (15.3%) were associated with higher measurement variability.
• Measurement discrepancies were more frequent when using CMP images (14%) or comparing NP and CMP images (26%).

Conclusions:

• Intra-reader size variation of ≥5 mm for solid renal masses is uncommon on NP to NP comparisons for smaller lesions.
• Measurement variability increases for larger, poorly defined, or heterogeneous renal masses.
• The use of corticomedullary phase (CMP) CT images is associated with increased measurement discrepancies.