Multimodality imaging of high-grade prostate adenocarcinoma with diffusion MRI, PSMA PET and dual-layer spectral CT: A case report.

Abstract

Multiparametric MRI and prostate-specific membrane antigen positron emission tomography (PSMA PET) have become established imaging modalities for the diagnosis and staging of prostate cancer. Dual-layer spectral computed tomography (DLCT) permits retrospective material decomposition and iodine quantification, which may provide additional information regarding tissue iodine distribution and vascularity. The role of spectral CT in primary prostate cancer assessment remains incompletely characterized. We present the case of a 49-year-old man with a prostate-specific antigen (PSA) level of 140 ng/mL who underwent multiparametric MRI, PSMA PET and DLCT as part of his diagnostic workup. Dual-layer spectral CT demonstrated an irregular, approximately L-shaped region of increased iodine concentration within the prostate, with increased conspicuity on 40-keV virtual monoenergetic images (VMI). Subsequent multiparametric MRI demonstrated spatially corresponding restricted diffusion on high b-value imaging, while PSMA PET demonstrated concordant radiotracer uptake. This case illustrates concordant visualization of biopsy-proven high-grade prostate adenocarcinoma across three complementary imaging techniques: restricted diffusion on MRI, PSMA radiotracer uptake on PET, and increased iodine concentration on spectral CT. The observation supports further investigation of quantitative spectral CT parameters in prostate cancer.