Dose correction for post-contrast T1 mapping of the heart: the MESA study

Abstract Post-contrast myocardial T1 (T1myo,c) values have been shown to be sensitive to myocardial fibrosis. Recent studies have shown differences in results obtained from T1myo,c and extracellular volume fraction (ECV) with respect to percentage fibrosis. By exploring the relationship between blood plasma volume and T1myo,c, the underlying basis for the divergence can be explained. Furthermore, dose administration based on body mass index (BMI), age and gender can mitigate the divergence in results. Inter-subject comparison of T1myo,c required adjustment for dose (in mmol/kg), time and glomerular filtration rate. Further adjustment for effective dose based on lean muscle mass reflected by blood/plasma volume was performed. A test case of 605 subjects from the MESA study who had undergone pre- and post-contrast T1 mapping was studied. T1myo,c values were compared between subjects with and without metabolic syndrome (MetS), between smoking and non-smoking subjects, and subjects with and without impaired glucose tolerance, before and after dose adjustment based on plasma volume. Comparison with ECV (which is dose independent), pre-contrast myocardial T1 and blood normalized myocardial T1 values was also performed to validate the correction. There were significant differences in T1myo,c (post plasma volume correction) and ECV between current and former smokers (p value 0.017 and 0.01, respectively) but not T1myo,c prior to correction (p = 0.12). Prior to d...
Source: The International Journal of Cardiovascular Imaging - Category: Radiology Source Type: research