Magnetic Resonance Microscopy May Enable Distinction Between Normal Histomorphological Features and Prostate Cancer in the Resected Prostate Gland.
In vivo high-resolution magnetic resonance imaging (MRI) at a microscopic level for the identification of prostate cancer (PCa) has not yet been achieved. This may be accomplished using MRI with high spatial resolution for ex vivo examination of prostate specimens. The objective was to determine imaging protocol parameters for characterization of prostate tissue at histologic length scales.
Rapid acquisition with relaxation enhancement (RARE), spin echo (SE) and gradient echo (GRE) fast low angle shot (FLASH) data were acquired using ex vivo 3 Tesla or 7 Tesla magnetic field strengths from fresh prostatectomy specimens (n=15) obtained from either organ donor or PCa patients under Institutional Review Board approval. To achieve the closest correspondence between histopathological components and MRI images in terms of resolution and sectioning planes, multiple high resolution imaging protocols (ranging from few minutes to overnight) were tested. Ductograms were generated as part of image post-processing. Specimens were subsequently submitted for histopathological evaluation.
A total of 7 imaging protocols were tested. Ex vivo 7 Tesla MRI identified normal components of prostate glands including ducts, blood vessels, concretions, and stroma at a spatial resolution of 60 X 60 X 60 μm3 to 107 X 107 X 500 μm3. Malignant glands and nests of tumor cells identified at 60 X 60 X 90 μm3 were highly comparable to low magnification (x2) histopathology. Ductograms enhanced the differentiation between benign and malignant glands. The results of this study are encouraging, and further work is warranted with a higher sample size.
We demonstrated that critical histopathological features of the prostate gland can be identified with high resolution ex vivo MRI examination and offer promise that MR microscopy of PCa will ultimately be possible in vivo. This article is protected by copyright. All rights reserved.
This article is protected by copyright. All rights reserved.