[The Measurement Precision and Accuracy of T1 Mapping Using Polarity Corrected (PC) TI Prep Tool].

The aim of this study was to evaluate the measurement precision and accuracy of T1 mapping using a polarity corrected (PC) TI prep tool, which was based on fast field echo (FFE) and obtained one data point with one inversion recovery (IR) pulse. A phantom was used consisting of eight materials with different Gd concentrations. T1 mappings were measured by changing the trigger interval and the inversion time (TI) interval. The T1 mapping measurement precision using the PC TI prep tool increased as the trigger interval was made longer. The measurement precision didn't depend on the interval of TI. On the other hand, when the trigger intervals are more than 1000 ms, the measurement accuracy was less than approximately 8%. By setting the optimal end of TI, the T1 mapping using a PC TI prep tool could measure the T1 value precisely and accurately.

Evaluation of the homogeneity of native T1 myocardial mapping using the polarity corrected inversion time preparation method in a myocardial phantom and healthy volunteers.

Myocardial T1 mapping is a useful technique for the diagnosis of diffuse fibrosis. Although modified look-locker inversion recovery is a widely used T1 mapping method, variation in T1 values has been reported. Non-uniform T1 maps may hinder differentiation between healthy and diseased myocardial tissue. The purpose of this study was to investigate the uniformity of T1 mapping using polarity corrected inversion time preparation (PC TI prep) in a myocardial phantom and healthy volunteers. The myocardial phantom was scanned between polyvinyl alcohol (PVA) and air. T1 values were measured using inversion recovery fast spin-echo (IR-FSE) and PC TI prep in areas adjacent to PVA and air. For the volunteer study, the short-axis plane was imaged using the PC TI prep to compare T1 values in the myocardium of the septal and lateral walls. The T1 value of the phantom using the IR-FSE was not significantly different in the area between PVA and air, whereas the T1 value using the PC TI prep in the air area was significantly lower than that in the PVA area. T1 mapping of the healthy myocardium exhibited no significant difference between the septal and lateral walls. The T1 value using the PC TI prep in the air area was 6.3% lower than that using IR-FSE. In this study, T1 mapping using the PC TI prep exhibited high uniformity of T1 values.