Background Absolute quantification of myocardial perfusion with Cardiovascular Magnetic Resonance (CMR) is increasingly available and can potentially improve current qualitative and semi-quantitative analysis. The absence of ionising radiation makes CMR ideal for serial examinations for patient management or in clinical trials. Inter-study reproducibility is crucial for serial examinations but is not known for quantitative CMR perfusion.
Methods 16 healthy volunteers underwent high-resolution stress and rest perfusion imaging at 3 Tesla on 3 occasions during a single day. Scan 1 was at 0900, scan 2 immediately after and scan 3 at 1400. Absolute perfusion was determined in each coronary artery territory and globally by Fermi constrained deconvolution of myocardial signal intensity curves. Left ventricular volumes and function were also calculated. Scan 1 and 2 were used to evaluate perfusion inter-study reproducibility under the same conditions while scan 3 was used to assess for diurnal variation. Inter-study reproducibility was determined by calculation of coefficients of variation (CV) defined as the SD of the differences of the measurements from the first two examinations, divided by the mean.
Results 11 full datasets were suitable for quantitative perfusion analysis. Participants were 27±5 years old and five were male. Myocardial perfusion and haemodynamics for all 3 studies, and the significance of associated differences, are shown in Abstract 098 table 1. Inter-study reproducibility was reasonable; rest perfusion was more reproducible than stress and global more reproducible than territorial. CV was 26.8%, 16.0% and 23.9% for global stress and rest perfusion and myocardial perfusion reserve (MPR) respectively. Corresponding segmental CV were 35.2%, 27.5% and 33.5% (Abstract 098 table 2). The agreement between segmental perfusion and MPR from scans 1 and 2 are shown in Abstract 098 figure 1. The reproducibility of left ventricular volumes and function was excellent (CV 4%, 7.7% and 4.6% for end diastolic volume, end-systolic volume and ejection fraction respectively). There were no significant diurnal variations in perfusion or LV volumes and function.
Conclusions The inter-study reproducibility of quantitative myocardial perfusion is reasonable and best for global rest perfusion. No significant diurnal variation in perfusion was observed.
- Cardiovascular magnetic resonance
- quantitative perfusion