ABSTRACT
PURPOSE: To evaluate the effectiveness of the single ROI approach for the detection of hepatic iron burden in thalassemia major (TM) patients in respect to a whole liver measurement. MATERIALS AND METHODS: Five transverse hepatic slices were acquired by a T2* gradient-echo sequence in 101 TM patients and 20 healthy subjects. The T2* value was calculated in a single region of interest (ROI) defined in the medium-hepatic slice. Moreover, the T2* value was extracted on each of the eight ROIs defined in the functionally independent segments. The mean hepatic T2* value was calculated. RESULTS: For patients, the mean T2* values over segments VII and VIII were significantly lower. This pattern was substantially preserved in the two groups identified considering the T2* normal cutoff. All segmental T2* values were correlated with the single ROI T2* value. After the application of a correction map based on T2* fluctuations in the healthy subjects, no significant differences were found in the segmental T2* values. CONCLUSION: Hepatic T2* variations are low and due to artifacts and measurement variability. The single ROI approach can be adopted in the clinical arena, taking care to avoid the susceptibility artifacts, occurring mainly in segments VII and VIII.
Subject(s)
Image Interpretation, Computer-Assisted/methods , Iron Overload/diagnosis , Iron Overload/etiology , Liver Diseases/diagnosis , Liver Diseases/etiology , Magnetic Resonance Imaging/methods , Transfusion Reaction , Adolescent , Adult , Child , Female , Humans , Image Enhancement/methods , Imaging, Three-Dimensional/methods , Male , Middle Aged , Reproducibility of Results , Sensitivity and Specificity , Young AdultABSTRACT
PURPOSE: To assess the transferability of the magnetic resonance imaging (MRI) multislice multiecho T2(*) technique for global and segmental measurement of iron overload in thalassemia patients. MATERIALS AND METHODS: Multiecho T2(*) sequences were installed on six MRI scanners. Five healthy subjects (n = 30) were scanned at each site; five thalassemia major (TM) patients were scanned at the reference site and were rescanned locally (n = 25) within 1 month. T2(*) images were analyzed using previously validated software. RESULTS: T2(*) values of healthy subjects showed intersite homogeneity. On TM patients, for global heart T2(*) values the correlation coefficient was 0.97, coefficients of variation (CoV(s)) ranged from 0.04-0.12, and intraclass coefficients (ICC(s)) ranged from 0.94-0.99. The mean CoV and ICC for segmental T2(*) distribution were 0.198 and 88, respectively. CONCLUSION: The multislice multiecho T2(*) technique is transferable among scanners with good reproducibility.
