RESUMO
RATIONALE AND OBJECTIVES: MRI of the prostate offers the possibility to localize and stage prostate cancer and may improve detection of disease. Currently, T2-weighted images and spectroscopy are the most commonly used MRI techniques. To assess the value of prostate MRI and its different modalities in the process of diagnosis, the currently available MRI techniques were compared. MATERIALS AND METHODS: 16 patients were examined on a 1.5 T MR system. All patients underwent the same MR protocol using an endorectal coil: T2-weighted triplanar turbo-spin-echo (TSE), axial echo-planar diffusion-weighted imaging (DWI), 3D chemical-shift imaging MR spectroscopy (MRS) and axial dynamic-contrast-enhanced TurboFLASH (DCE). Parametric maps of the choline+creatine/citrate ratio (CC-CR), apparent diffusion coefficient (ADC) and plasma flow/mean transit time (PF/MTT) were calculated. Additionally, average time for reading and scanning were evaluated. As reference, biopsy results were used. RESULTS: Sensitivity/specificity were 50.0-85.7%/44.4-72.2% for the T2 weighted images, 78.6-100.0%/38.9-55.6% for the ADC maps, 71.4-85.7%/44.4-55.6% for the PF/MTT maps and 64.3-78.6%/50.0-77.8% for the CC-CR. Average scan and reading time were 8:46/1:54 min for T2, 1:28/3:17 min for DWI, 8:41/2:12 min for DCE and 11:36/3:47 for spectroscopy. CONCLUSION: We found no significant differences in accuracy between the modalities. We observed DWI to be advantageous in examination and reading compared to DCE and MRS, therefore it might be the preferred modality when a shortened protocol is needed.
