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

Abstract

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.

Pretreatment synthetic magnetic resonance imaging predicts disease progression in nonmetastatic nasopharyngeal carcinoma after intensity modulation radiation therapy

“…The research [17] in head and neck region proved the clinical feasibility of generating synthetic T1WI and T2WI images from quantitative relaxometry mapping. Recently, preliminary SyMRI studies have demonstrated a potential role in evaluating prognostic factors in breast [18,19], prostate [20], bladder [21], and rectal cancer [22,23].…”

“…The benefit of SyMRI is twofold, providing relaxometry maps in a clinically feasible time and the ability to generate different contrast images in a single acquisition [ 17 ]. Quantitative T1, T2, and PD Mean values were reported to be lower in malignant tumors vs. benign tumors [ 20 , 27 , 28 ], and in poor prognostic relevant factors tumors vs. good prognostic relevant factors [ 20 – 23 , 29 ].…”

“…After adjusting for conventional clinical factors as confounding variables, the T1_Kurtosis and ADC remained significant predictors of PFS. The SyMRI + DWI + Clinic model significantly increased the diagnostic performance compared with DWI or Clinic The benefit of SyMRI is twofold, providing relaxometry maps in a clinically feasible time and the ability to generate different contrast images in a single acquisition [17]. Quantitative T1, T2, and PD Mean values were reported to be lower in malignant tumors vs. benign tumors [20,27,28], and in poor prognostic relevant factors tumors vs. good prognostic relevant factors [20][21][22][23]29].…”

“…Synthetic MRI (SyMRI), using multi-delay and multi-echo (MDME) sequence, could generate quantitative T1, T2, and proton density (PD) maps and multi-contrast qualitative images (including T1WI, T2WI, and PDWI) within the clinically feasible time. The research [ 17 ] in head and neck region proved the clinical feasibility of generating synthetic T1WI and T2WI images from quantitative relaxometry mapping. Recently, preliminary SyMRI studies have demonstrated a potential role in evaluating prognostic factors in breast [ 18 , 19 ], prostate [ 20 ], bladder [ 21 ], and rectal cancer [ 22 , 23 ].…”

Quantitative Relaxometry Metrics for Brain Metastases Compared to Normal Tissues: A Pilot MR Fingerprinting Study

“…The relaxometry values estimated with MAGiC were slightly lower on comparison to MRF results mentioned above. MAGiC and MRF are two prominent new sequences for rapid MR relaxometry and the former uses a multiple-dynamic multiple-echo (MDME) sequence for data acquisition and synthetic image reconstruction, including post-processing which is different from MRF as detailed in the method section [ 59 , 60 ]. The differences in the acquisition and reconstruction approaches could be attributed to the marginal variation observed in the mean T1 and T2 values.…”