Diagnosis of Prostate Cancer with Noninvasive Estimation of Prostate Tissue Composition by Using Hybrid Multidimensional MR Imaging: A Feasibility Study

Abstract

Purpose To evaluate whether compartmental analysis by using hybrid multidimensional magnetic resonance (MR) imaging can be used to diagnose prostate cancer and determine its aggressiveness. Materials and Methods Twenty-two patients with prostate cancer underwent preoperative 3.0-T MR imaging. Axial images were obtained with hybrid multidimensional MR imaging by using all combinations of echo times (47, 75, 100 msec) and b values of 0, 750, 1500 sec/mm, resulting in a 3 × 3 array of data associated with each voxel. Volumes of the tissue components stroma, epithelium, and lumen were calculated by fitting the hybrid data to a three-compartment signal model, with distinct, paired apparent diffusion coefficient (ADC) and T2 values associated with each compartment. Volume fractions and conventional ADC and T2 were measured for regions of interest in sites of prostatectomy-verified malignancy (n = 28) and normal tissue (n = 71). Receiver operating characteristic (ROC) analysis was used to evaluate the performance of various parameters in differentiating prostate cancer from benign tissue. Results Compared with normal tissue, prostate cancer showed significantly increased fractional volumes of epithelium (23.2% ± 7.1 vs 48.8% ± 9.2, respectively) and reduced fractional volumes of lumen (26.4% ± 14.1 vs 14.0% ± 5.2) and stroma (50.5% ± 15.7 vs 37.2% ± 9.1) by using hybrid multidimensional MR imaging. The fractional volumes of tissue components show a significantly higher Spearman correlation coefficient with Gleason score (epithelium: ρ = 0.652, P = .0001; stroma: ρ = -0.439, P = .020; lumen: ρ = -0.390, P = .040) compared with traditional T2 values (ρ = -0.292, P = .132) and ADCs (ρ = -0.315, P = .102). The area under the ROC curve for differentiation of cancer from normal prostate was highest for fractional volume of epithelium (0.991), followed by fractional volumes of lumen (0.800) and stroma (0.789). Conclusion Fractional volumes of prostatic lumen, stroma, and epithelium change significantly when cancer is present. These parameters can be measured noninvasively by using hybrid multidimensional MR imaging and have the potential to improve the diagnosis of prostate cancer and determine its aggressiveness. RSNA, 2018 Online supplemental material is available for this article.

VERDICT MRI validation in fresh and fixed prostate specimens using patient‐specific moulds for histological and MR alignment

“…The combination of T 2 ‐ and diffusion‐sensitive data is an important avenue for future in vivo studies. Indeed, hybrid multidimensional MRI, which explores T 2 using a smaller range of echo times than LWI and lower b ‐values than VERDICT, estimates lumen, epithelial and stromal fractions and correlates with Gleason score. Higher b ‐values and techniques such as VERDICT that can characterize restricted diffusion may improve specificity further.…”

Diffusion MRI of cancer: From low to high b‐values

“…In addition, the diagnostic accuracy in some high b‐value DWI studies may not be as high as those of conventional MRI. However, DWI can be combined with conventional sequences to improve the overall accuracy, as recently demonstrated by Chatterjee et al in a technique known as hybrid multidimensional MRI …”

“…However, DWI can be combined with conventional sequences to improve the overall accuracy, as recently demonstrated by Chatterjee et al in a technique known as hybrid multidimensional MRI. 69 Assessing the biological aggressiveness of tumors is another important aspect for cancer patient evaluation and management. With its correlation to cellularity, ADC can be an important marker for biological aggressiveness of tumors, as in the assessment of the NIH risk stratification of GIST.…”

A system using patient‐specific 3D‐printed molds to spatially align in vivo MRI with ex vivo MRI and whole‐mount histopathology for prostate cancer research

“…In order to validate and improve prostate mp‐MRI, comparison with ground‐truth whole‐mount histopathology (WMHP) is an important strategy and accurate spatial alignment between the two is critical. However, it is challenging to achieve accurate spatial alignment between MRI and WMHP images, due to factors such as differences in MRI acquisition and WMHP sectioning geometries, MRI and WMHP spatial resolution and contrast, prostate tissue changes during surgery and WMHP processing, and WMHP sectioning variability …”

“…1 Multiparametric magnetic resonance imaging (mp-MRI) is increasingly used to improve the diagnosis and management of PCa, including early detection, grading, staging, targeted biopsy guidance, active surveillance, therapy selection, surgical planning, focal therapy guidance, and post-therapy follow-up assessments. 2 In order to validate and improve prostate mp-MRI, comparison with ground-truth whole-mount histopathology (WMHP) is an important strategy [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] and accurate spatial alignment between the two is critical. However, it is challenging to achieve accurate spatial alignment between MRI and WMHP images, due to factors such as differences in MRI acquisition and WMHP sectioning geometries, MRI and WMHP spatial resolution and contrast, prostate tissue changes during surgery and WMHP processing, and WMHP sectioning variability.…”