Objectives: To validate absolute measurement of myocardial blood
flow (MBF) with 1.5 Tesla (T) and 3T cardiovascular magnetic
resonance (CMR) using positron emission tomography (PET) as the
gold standard.
Methods: 21 healthy subjects and 44 patients with coronary artery
disease (CAD) were randomised to undergo PET scanning using
oxygen 15-labeled water and CMR scanning at either 1.5T or 3T,
using a saturation recovery fast-gradient echo sequence and 0.04
mmol/kg gadolinium bolus. MBF was assessed at rest and during
adenosine stress. CMR MBF was determined by model independent
deconvolution
Results: There was no significant difference in rest and stress rate
pressure product during PET and CMR scanning at either field
strength. Agreement between the two methods was tested by Bland
Altman plots The mean difference between PET MBF and 3T CMR
MBF was 0.30 ml/g/min, limits of agreement of -1.23 and 1.89
ml/g/min. For the 3T cohort the sensitivity and specificity for the
detection of coronary stenoses ≥50 % was 87% and 81 % for PET
(threshold 1.93 ml/g/min) and 61% and 78% (threshold 1.73
ml/g/min) for 3T CMR. The mean difference between PET and 1.5T
CMR was 0.05 ml/g/min, limits of agreement of -1.75 and 1.84
ml/g/min. For the 1.5T cohort the sensitivity and specificity for the
detection of coronary stenoses ≥50 % was 84% and 94% for PET
(threshold 1.98 ml/g/min) and 81% and 78% (threshold
2.29ml/g/min) for CMR.
Conclusion: This study demonstrates there is no significant
difference in mean MBF as measured by PET and CMR at either 1.5T
or 3T CMR. However there is marked variation in values of MBF
between different segments as demonstrated by the wide limits of
agreements.