Qualitative and Quantitative Performance of Magnetic Resonance Image Compilation (MAGiC) Method: An Exploratory Analysis for Head and Neck Imaging

Simple Summary Magnetic resonance imaging (MRI) is a widely used noninvasive imaging modality in the head and neck (HN) region to detect tumors. The new synthetic MRI method termed MAGnetic resonance imaging Compilation (MAGiC) uses a multi-dynamic multi-echo (MDME) sequence to generate quantitative T1 and T2 maps and multi-contrast qualitative images within a clinically feasible time. The testing of the synthetic MRI method was initially performed in the brain and subsequently extended to extracranial regions, including the prostate, breast, cervix, and rectum. The present exploratory study aims to investigate the performance of this new, rapid, synthetic MRI method for diagnostic image quality assessment and measurement of relaxometry metric values in HN tumors and normal-appearing masseter muscle. Initial results from 14 patients support the feasibility of generating synthetic T1w and T2w images from quantitative relaxometry mapping in the HN region. The present exploratory study investigates the performance of a new, rapid, synthetic MRI method for diagnostic image quality assessment and measurement of relaxometry metric values in head and neck (HN) tumors and normal-appearing masseter muscle. The multi-dynamic multi-echo (MDME) sequence was used for data acquisition, followed by synthetic image reconstruction on a 3T MRI scanner for 14 patients (3 untreated and 11 treated). The MDME enables absolute quantification of physical tissue properties, including T1 and T2, with a shorter scan time than the current state-of-the-art methods used for relaxation measurements. The vendor termed the combined package MAGnetic resonance imaging Compilation (MAGiC). In total, 48 regions of interest (ROIs) were analyzed, drawn on normal-appearing masseter muscle and tumors in the HN region. Mean T1 and T2 values obtained from normal-appearing muscle were 880 +/- 52 ms and 46 +/- 3 ms, respectively. Mean T1 and T2 values obtained from tumors were 1930 +/- 422 ms and 77 +/- 13 ms, respectively, for the untreated group, 1745 +/- 410 ms and 107 +/- 61 ms, for the treated group. A total of 1552 images from both synthetic MRI and conventional clinical imaging were assessed by the radiologists to provide the rating for T1w and T2w image contrasts. The synthetically generated qualitative T2w images were acceptable and comparable to conventional diagnostic images (93% acceptability rating for both). The acceptability ratings for MAGiC-generated T1w, and conventional images were 64% and 100%, respectively. The benefit of MAGiC in HN imaging is twofold, providing relaxometry maps in a clinically feasible time and the ability to generate a different combination of contrast images in a single acquisition.