A comparative study of myocardial perfusion of multi b values gated cardiac magnetic resonance DWI using the PET/CT-MRI system and ^99mTc-MIBI gated SPECT

Objectives: The purpose of this study was to compare myocardial perfusion assessment of the multi b values gated cardiac magnetic resonance DWI using the PET/CT-MRI system and ^99mTc-MIBI gated SPECT. Using the gated SPECT/¹⁸F-FDG PET imaging as the gold standard, the feasibility of evaluating myocardial survival by multi b values DWI from PET/MRI was investigated.

Methods: 11 patients with coronary heart disease (CHD) were included as case group and 5 volunteers without cardiac disease were included as control group. CHD group including 4 cases of subacute myocardial infarction, 4 cases with previous myocardial infarction and 3 cases with angina pectoris, control group including 2 cases with arrhythmia, 2 with hypertension and 1 healthy volunteer. All the subjects underwent ^99mTc-MIBI myocardial perfusion SPECT,¹⁸F-FDG PET myocardial imaging and multi b values DWI using the PET/CT-MRI system (GE,USA). 8 b values (0, 30, 50, 100, 200, 300, 400, 600) s/mm2 were selected for respiratory gated cardiac magnetic resonance DWI. The results of multi b values DWI and SPECT independently combined with¹⁸F-FDG PET myocardial imaging for the assessment of myocardial viability were compared. Results: (1) All of the 16 cases completed cardiac multi b values DWI and obtained good enough quality ADC images for post processing for D[asterisk]value. (2) The results of myocardial perfusion by multi b values DWI was highly correlated with that by ^99mTc-MIBI SPECT. The correlation coefficients of LAD, RCA and LCX territories were 0.837(p<0.001), 0.850( p<0.001), 0.841(p<0.001) respectively. (3) The assessment of myocardial viability by the combination of multi b values DWI and¹⁸F-FDG were that myocardial perfusion and metabolism in 5 cases were normal, myocardial perfusion and metabolism mismatched in 10 cases, myocardial perfusion and metabolism matched in 1 cases. As the same as the combination of myocardial perfusion ^99mTc-MIBI SPECT and¹⁸F-FDG PET.

Conclusions: The multi b values gated cardiac magnetic resonance DWI using the PET/CT-MRI system was feasible for myocardial perfusion imaging. Combined with ¹⁸F-FDG PET, multi b values magnetic resonance DWI from PET/MRI would optimize the imaging evaluation of myocardial viability, and improve the clinical utility of myocardial viability assessment. Keywords: PET/MRI, diffusion weighted imaging, multi b values, myocardial perfusion, myocardial viability