Comparison of 1.5T and 3T Prostate MR Examination using Surface Array Coils in Routine Clinical Practice
Objective: Our study compares the results of magnetic resonance (MR) examination obtained by the 1.5T and 3T MR scanners using surface coils in patients with prostate carcinoma. Methods: A total of 103 consecutive patients (aged 44-72 years) with biopsy confirmed prostate carcinoma underwent MR examination at 3T or 1.5T with similar protocols including T2-weighted (T2W), diffusion weighted imaging (DWI) including apparent coefficient (ADC) maps, dynamic contrast enhancement (DCE) and magnetic resonance spectroscopy (MRS). MR results were compared with the histopathologic findings of specimen after the radical prostatectomy. The first part of the study assessed local tumor staging. The sensitivity and specificity for extracapsular tumor extension and prediction of seminal vesicles infiltration were calculated and compared using a Fisher exact test. The second part of the study evaluated the accuracy in tumor localization assessment. Results from different MR sequences were compared using a Kruskal-Wallis test. Results: The highest sensitivity and specificity (70% and 100%) as a predictor of extracapsular tumor extension were found in group B, examined at 3T when DCE was included into the standard protocol. The overall accuracy in tumor stage prediction were 66% (1.5T), 90% (3T with (DCE) and 72% (3T without DCE). No significant difference among the three patient groups was found in the accuracy of tumor localization assessment. The best results were obtained when T2 - weighted imaging was combined with DWI or DCE. Conclusion: The highest accuracy of local prostate cancer staging was obtained in patients examined with 3T MR scanner when MR protocol included DCE. No significant difference in tumor localization assessment between 3T and 1.5T MR scanners was found.