Multiparametric MR imaging of prostate cancer foci: assessing the detectability and localizability of Gleason 7 peripheral zone cancers based on image contrasts

Autor: Aaron D. Ward, Derek W. Cool, Stephen E. Pautler, Joseph L. Chin, Glenn Bauman, Cesare Romagnoli, Suha Ghoul, Mena Gaed, Cathie Crukley, W. Thomas Hrinivich, Madeleine Moussa, Jonathan Mandel, Matthew Bastian-Jordan, Aaron Fenster, Eli Gibson, Jose A. Gomez
Rok vydání: 2014
Předmět:
Zdroj: Medical Imaging: Digital Pathology
ISSN: 0277-786X
DOI: 10.1117/12.2043324
Popis: Purpose: Multiparametric magnetic resonance imaging (MPMRI) supports detection and staging of prostate cancer, but the image characteristics needed for tumor boundary delineation to support focal therapy have not been widely investigated. We quantified the detectability (image contrast between tumor and non-cancerous contralateral tissue) and the localizability (image contrast between tumor and non-cancerous neighboring tissue) of Gleason score 7 (GS7) peripheral zone (PZ) tumors on MPMRI using tumor contours mapped from histology using accurate 2D–3D registration. Methods: MPMRI [comprising T2-weighted (T2W), dynamic-contrast-enhanced (DCE), apparent diffusion coefficient (ADC) and contrast transfer coefficient images] and post-prostatectomy digitized histology images were acquired for 6 subjects. Histology contouring and grading (approved by a genitourinary pathologist) identified 7 GS7 PZ tumors. Contours were mapped to MPMRI images using semi-automated registration algorithms (combined target registration error: 2 mm). For each focus, three measurements of mean ± standard deviation of image intensity were taken on each image: tumor tissue (m T ±s T ), non-cancerous PZ tissue N ±s N ), and non-cancerous contralateral PZ tissue (m C ±s C ). Detectability [D, defined as m T -m C normalized by s T and s C added in quadrature] and localizability [L, defined as m T -m N normalized by s T and s N added in quadrature] were quantified for each focus on each image. Results: T2W images showed the strongest detectability, although detectability |D|≥1 was observed on either ADC or DCE images, or both, for all foci. Localizability on all modalities was variable; however, ADC images showed localizability |L|≥1 for 3 foci. Conclusions: Delineation of GS7 PZ tumors on individual MPMRI images faces challenges; however, images may contain complementary information, suggesting a role for fusion of information across MPMRI images for delineation.
Databáze: OpenAIRE