Bosniak classification version 2019: a prospective comparison of CT and MRI

Area of Science:

• Radiology
• Urologic Oncology
• Medical Imaging

Background:

• Complicated renal masses (CRMs) require accurate classification for appropriate management.
• The Bosniak classification version 2019 (BCv2019) is a standardized system for categorizing CRMs.
• Evaluating the performance of CT and MRI in applying BCv2019 is crucial for clinical practice.

Purpose of the Study:

• To assess and compare the diagnostic accuracy and inter-modality agreement of CT and MRI for Bosniak classification version 2019 (BCv2019).
• To identify factors contributing to discrepancies in BCv2019 classification between CT and MRI.

Main Methods:

• A prospective multi-institutional study included 63 patients with 67 CRMs.
• Patients underwent both CT and MRI scans, followed by histopathology.
• Three radiologists independently classified CRMs using BCv2019 on both CT and MRI datasets.

Main Results:

• Discordance between CT and MRI findings was observed in 50% of CRMs.
• No significant differences were found in sensitivity, specificity, or accuracy between CT and MRI for BCv2019 classification.
• Inter-reader agreement was substantial for both CT and MRI, while inter-modality agreement was moderate (κ = 0.58).

Conclusions:

• CT and MRI demonstrate comparable diagnostic accuracy and reliability in applying the BCv2019.
• Septal characteristics and the presence of enhanced nodules were primary drivers of classification variations between modalities.
• Despite moderate inter-modality agreement, both imaging techniques are valuable tools for CRM classification.