Objective: The aim of this study was to compare myocardial T2∗ assessment with region-based (RB) T2∗ multiecho technique (CMRtools) with the pixel-wise (PW) inline myocardial T2∗ mapping (Siemens) in patients with thalassemia major for myocardial iron characterization. MATERIALS AND METHODS: Forty-three thalassemia major patients were examined on a 1.5-T scanner using conventional gradient multiecho sequence. All the images were analyzed using both RB and PW T2∗ mapping. Coefficients of reproducibility (CRs) were used to assess the interoperator and intraobserver variability of each software. RESULTS: The mean (SD) myocardial T2∗ values using RB and PW software resulted significantly different (30.7  milliseconds [range, 4.8-52.6 milliseconds] vs 24.3 [10.5] milliseconds [range 4.6-38.2 milliseconds]; P <0.0001). Interestingly, we found that SD had exponential relationship with T2∗ with evidence of increase in SD for T2∗ values greater than 20 milliseconds. For myocardial T2∗ values less than 20 milliseconds, intraobserver CR was 1.2 milliseconds for RB and 1.8 milliseconds for PW T2∗ mapping, and the interoperator CR was 3.4 and 1.6 milliseconds for RB and PW T2∗ mapping, respectively. Comparing iron overload classification by both software, we found that 7 patients (16%) were differently categorized using the standard T2∗ thresholds. CONCLUSIONS: Our data show that RB and PW T2∗ mapping can be used interchangeably to measure severe myocardial and hepatic iron overload, whereas for borderline T2∗ values, we observed differences among the 2 methods causing different categorization.
- iron overload
- MRI relaxometry
- tissue iron characterization
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging