Phasesensitive Inversion Recovery (PSIR) Single Shot TrueFISP for Assessment of Myocardial Infarction at 3 Tesla

Purpose: The aim of the current study was to show if CNR can be improved without loss of diagnostic accuracy for the assessment of myocardial infarction, if a PSIR Single Shot TrueFISP sequence is used at 3.0 Tesla instead of 1.5 Tesla.

Methods: 10 patients with myocardial infarction were examined at a 1.5 Tesla MR System (Sonata, Siemens, Medical Systems) and at a 3.0 Tesla MR system. Imaging of delayed contrast enhancement was started 10 minutes after application of contrast media. A phasesensitive inversion recovery (PSIR) Single Shot TrueFISP sequence was used at 1.5 and 3.0 Tesla and compared with a segmented IR turboFLASH sequence at 1.5 Tesla, that served as reference method. Infarct volumes and CNR of infarction and normal myocardium were compared with the reference method.

Results: The PSIR Single Shot TrueFISP technique allows to image 9 slices during a single breathhold without adaptation of the inversion time. The mean value of CNR between infarction and normal myocardium was 5.9 at 1.5 T and 9.5 at 3.0 Tesla. The CNR mean value of the reference method was 8.4. The CNR mean value at 3.0 Tesla was significantly (p=0.03) higher than the mean value of the reference method. The correlation coefficients of the infarct volumes, determined with the PSIR Single Shot TrueFISP technique at 1.5 Tesla and at 3.0 Tesla and compared to the reference method, were r=0.96 (p=0.001) and r=0.99 (p=0.0001).

Conclusion: The use of PSIR Single Shot TrueFISP at 3.0 Tesla allows for accurate detection and assessment of myocardial infarction. Compared to an examination at 1.5 Tesla, the CNR gain at 3.0 Tesla is higher than the loss caused by the Single Shot technique at 1.5 Tesla.