Abstract
Rationale and Objectives: The objective of this study was to develop and quantitatively evaluate a radiology-pathology fusion method for spatially mapping tissue regions corresponding to different chemoradiation therapy-related effects from surgically excised whole-mount rectal cancer histopathology onto preoperative magnetic resonance imaging (MRI). Materials and Methods: This study included six subjects with rectal cancer treated with chemoradiation therapy who were then imaged with a 3-T T2-weighted MRI sequence, before undergoing mesorectal excision surgery. Excised rectal specimens were sectioned, stained, and digitized as two-dimensional (2D) whole-mount slides. Annotations of residual disease, ulceration, fibrosis, muscularis propria, mucosa, fat, inflammation, and pools of mucin were made by an expert pathologist on digitized slide images. An expert radiologist and pathologist jointly established corresponding 2D sections between MRI and pathology images, as well as identified a total of 10 corresponding landmarks per case (based on visually similar structures) on both modalities (five for driving registration and five for evaluating alignment). We spatially fused the in vivo MRI and ex vivo pathology images using landmark-based registration. This allowed us to spatially map detailed annotations from 2D pathology slides onto corresponding 2D MRI sections. Results: Quantitative assessment of coregistered pathology and MRI sections revealed excellent structural alignment, with an overall deviation of 1.50 ± 0.63 mm across five expert-selected anatomic landmarks (in-plane misalignment of two to three pixels at 0.67- to 1.00-mm spatial resolution). Moreover, the T2-weighted intensity distributions were distinctly different when comparing fibrotic tissue to perirectal fat (as expected), but showed a marked overlap when comparing fibrotic tissue and residual rectal cancer. Conclusions: Our fusion methodology enabled successful and accurate localization of post-treatment effects on in vivo MRI.
Original language | English (US) |
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Pages (from-to) | 833-841 |
Number of pages | 9 |
Journal | Academic radiology |
Volume | 25 |
Issue number | 7 |
DOIs | |
State | Published - Jul 2018 |
Bibliographical note
Funding Information:This work was supported by the National Cancer Institute of the National Institutes of Health (Grant Nos. R01CA202752-01A1 , R01CA208236-01A1 , R21CA179327-01 , R21CA195152-01 , and U24CA199374-01 ), the National Institute of Diabetes and Digestive and Kidney Diseases (Grant No. R01DK098503-02 ), the National Center for Research Resources (Award No. 1C06RR12463-01 ), the Department of Defense (Award Nos. PC120857 , LC130463 , CA150595 , and W81XWH-16-1-0329 ), the Case Comprehensive Cancer Center Pilot Grant , the Cleveland Clinic VelaSano Grant, the Wallace H. Coulter Foundation Program in the Department of Biomedical Engineering at Case Western Reserve University , and the I-Corps@Ohio Program .
Funding Information:
This work was supported by the National Cancer Institute of the National Institutes of Health (Grant Nos. R01CA202752-01A1, R01CA208236-01A1, R21CA179327-01, R21CA195152-01, and U24CA199374-01), the National Institute of Diabetes and Digestive and Kidney Diseases (Grant No. R01DK098503-02), the National Center for Research Resources (Award No. 1C06RR12463-01), the Department of Defense (Award Nos. PC120857, LC130463, CA150595, and W81XWH-16-1-0329), the Case Comprehensive Cancer Center Pilot Grant, the Cleveland Clinic VelaSano Grant, the Wallace H. Coulter Foundation Program in the Department of Biomedical Engineering at Case Western Reserve University, and the I-Corps@Ohio Program.
Publisher Copyright:
© 2018 The Association of University Radiologists
Keywords
- Radiology
- coregistration
- pathology
- rectal cancer
- treatment response