Quantitative and textural analysis of magnetization transfer and diffusion images in the early detection of brain metastases

• Published in: Magnetic resonance in medicine Vol. 77; no. 5; pp. 1987 - 1995
• Main Authors: Ainsworth, Nicola L., McLean, Mary A., McIntyre, Dominick J.O., Honess, Davina J., Brown, Anna M., Harden, Susan V, Griffiths, John R.
• Format: Journal Article
• Language: English
• Published: United States Wiley Subscription Services, Inc 01-05-2017; John Wiley and Sons Inc
• Subjects: Aged; Animals; Brain; Brain cancer; brain metastasis; Brain Neoplasms - diagnostic imaging; Brain Neoplasms - pathology; Breast cancer; Cancer; Cell Line, Tumor; diffusion; Diffusion coefficient; Diffusion Magnetic Resonance Imaging - methods; Discriminant Analysis; Early Detection of Cancer; Female; Homing; Humans; Image detection; Lesions; Linear Models; Lung cancer; Magnetic resonance imaging; Magnetization; magnetization transfer; Male; Medicine; Metastases; Metastasis; Mice; Mice, SCID; Middle Aged; MRI; Neoplasm Metastasis; Patients; Preclinical and Clinical Imaging—Full Papers; Resonance; Sensitivity; Sensitivity analysis; Small cell lung carcinoma; Small Cell Lung Carcinoma - diagnostic imaging; Small Cell Lung Carcinoma - pathology; Texture; texture analysis; magnetization transfer; diffusion; brain metastasis; cancer; MRI; texture analysis
• ISSN: 0740-3194; 1522-2594
• DOI: 10.1002/mrm.26257

Purpose
The sensitivity of the magnetization transfer ratio (MTR) and apparent diffusion coefficient (ADC) for early detection of brain metastases was investigated in mice and humans.
Methods
Mice underwent MRI twice weekly for up to 31 d following intracardiac injection of the brain‐homing breast cancer cell line MDA‐MB231‐BR. Patients with small cell lung cancer underwent quarterly MRI for 1 year. MTR and ADC were measured in regions of metastasis and matched contralateral tissue at the final time point and in registered regions at earlier time points. Texture analysis and linear discriminant analysis were performed to detect metastasis‐containing slices.
Results
Compared with contralateral tissue, mouse metastases had significantly lower MTR and higher ADC at the final time point. Some lesions were visible at earlier time points on the MTR and ADC maps: 24% of these were not visible on corresponding T2‐weighted images. Texture analysis using the MTR maps showed 100% specificity and 98% sensitivity for metastasis at the final time point, with 77% sensitivity 2–4 d earlier and 46% 5–8 d earlier. Only 2 of 16 patients developed metastases, and their penultimate scans were normal.
Conclusions
Some brain metastases may be detected earlier on MTR than conventional T2; however, the small gain is unlikely to justify “predictive” MRI. Magn Reson Med 77:1987–1995, 2017. © 2016 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.