Inter-reader agreement of multi-parametric MR imaging for the detection of prostate cancer: Evaluation of a scoring system - Abstract

Purpose: Functional prostate MR is performed in varying combinations of T2-weighted images with diffusion-weighted imaging (DWI), dynamic contrast-enhanced MRI (DCE-MRI), and spectroscopic imaging (MRSI).

Recently, a European consensus meeting proposed the use of a simple 5-point scale for estimating the probability of a lesion being malignant. The aim of the present study was to determine the inter-reader agreement of MR imaging using a scoring system based on the recommendations of the consensus.

Materials and Methods: The appearance of 108 predefined lesions in three different MR sequences (T2-weighted images, DWI, and DCE-MRI) in 50 functional prostate MR examinations were retrospectively scored by three blinded radiologists using a 5-point scale for each MR sequence. After scoring T2/DWI and T2/DWI/DCE-MRI, every lesion was graded based on its probability for malignancy. The inter-observer reliability was evaluated using Kappa statistics (ĸ).

Results: With respect to T2-weighted images, DWI and DCE-MRI ĸ was 0.49, 0.97, and 0.77, respectively. Combined scoring of T2-weighted images and DWI demonstrated correct tumor diagnosis (true positive) in 71 - 88 % (depending on reader) of cases (ĸ = 0.78). The accuracy was further improved to 88 - 96 % after scoring all three MR sequences including DCE-MRI (ĸ = 0.90).

Conclusion: The use of a simple 5-point scoring system for T2-weighted images, DWI, and DCE-MRI is feasible in functional prostate MRI and has high inter-observer reliability.

Written by:
Quentin M, Arsov C, Röhlen S, Klasen J, Antoch G, Albers P, Blondin D.   Are you the author?
Institut für Diagnostische und Interventionelle Radiologie, Medizinische Fakultät, Heinrich-Heine-Universität Düsseldorf.

Reference: Rofo. 2012 Jun 28. Epub ahead of print.
doi: 10.1055/s-0032-1312876

PubMed Abstract
PMID: 22744328 Prostate Cancer Section