MR elastography and diffusion-weighted imaging of ex vivo prostate cancer: quantitative comparison to histopathology.

ABSTRACT: The purpose of this work was (1) to develop a magnetic resonance elastography (MRE) system for imaging of the ex vivo human prostate and (2) to assess the diagnostic power of mono-frequency and multi-frequency MRE and diffusion weighted imaging (DWI) alone and combined as correlated with histopathology in a patient study. An electromagnetic driver was designed specifically for MRE studies in small-bore MR scanners. Ex vivo prostate specimens (post-fixation) of 14 patients who underwent radical prostatectomy were imaged with MRE at 7?T (nine cases had DWI). In six patients, the MRE examination was performed at three frequencies (600, 800, 1000?Hz) to extract the power-law exponent Gamma. The images were registered to wholemount pathology slides marked with the Gleason score. The areas under the receiver-operator-characteristic curves (AUC) were calculated. The methods were validated in a phantom study and it was demonstrated that (i) the driver does not interfere with the acquisition process and (ii) the driver can generate amplitudes greater than 100?µm for frequencies less than 1?kHz. In the quantitative study, cancerous tissue with Gleason score at least 3?+?3 was distinguished from normal tissue in the peripheral zone (PZ) with an average AUC of 0.75 (Gd ), 0.75 (Gl ), 0.70 (Gamma-Gd ), 0.68 (apparent diffusion coefficient, ADC), and 0.82 (Gd ?+?Gl ?+?ADC). The differentiation between PZ and central gland was modest for Gd (p?

SUBMITTER: Sahebjavaher RS 

PROVIDER: S-EPMC5478374 | biostudies-literature | 2015 Jan

REPOSITORIES: biostudies-literature