T2* mapping combined with conventional T2-weighted image for prostate cancer detection at 3.0T MRI: a multi-observer study

Abstract

Background: T2* relaxation is a primary determinant of image contrast with Gradient echo (GRE) sequences, and it has been widely used across body regions.

Purpose: To compare the diagnostic performance of T2* mapping in combination with T2-weighted (T2W) imaging to T2W imaging alone for prostate cancer (PCa) detection.

Material and methods: The study included 31 patients (mean age, 62 ± 3 years; age range, 45-78 years) who underwent magnetic resonance imaging (MRI) at 3.0T and histological examination. Three observers with varying experience levels reviewed T2W imaging alone, T2* mapping alone, and T2W imaging combined with T2* mapping. A five-point scale was used to assess the probability of PCa in each segment on MR images. Statistical analysis was performed using Z tests after adjusting for data clustering.

Results: The area under the curve (AUC) of T2W imaging and T2* mapping data (observer 1, 0.93; observer 2, 0.90; observer 3, 0.77) was higher than T2W imaging (observer 1, 0.84; observer 2, 0.79; observer 3, 0.69) for all observers (P < 0.01 in all comparisons). The AUC of T2W imaging and T2* mapping data was higher for observers 1 and 2 than for observer 3 (P < 0.01). The sensitivity and specificity of T2W imaging and T2* mapping data (observer 1, 95%, 85%; observer 2, 90%, 83%; and observer 3, 82%, 63%, respectively) was higher than T2W imaging (observer 1, 78%, 79%; observer 2, 76%, 72%; observer 3, 74%, 51%, respectively) for all observers (P < 0.01 for observer 1; P < 0.01 for observers 2 and 3).

Conclusion: The addition of T2* mapping to T2W imaging improved the diagnostic performance of MRI in PCa detection.

Keywords: T2* mapping; multi-observers; prostate cancer (PCa); sensitivity; specificity.