Influence of the Choice of Software Package on the Outcome of Semiquantitative MR Myocardial Perfusion Analysis

Purpose: To assess the repeatability and reproducibility of semi-quantitative magnetic resonance (MR) perfusion analysis performed by using different software packages.Materials and Methods: The study protocol was approved by the institutional ethics committee. Informed consent was obtained from each patient. Semi-quantitative perfusion analysis was performed twice by two independent observers using four dedicated software packages. MR perfusion datasets originated from eight patients with known single-vessel disease who were scheduled for percutaneous coronary intervention (PCI) on the basis of coronary angiography findings. Each patient underwent two examinations: 1 day before and 1 day after PCI. Repeatability (intra- and inter-observer agreements) and reproducibility (intersoftware agreement) were evaluated for perfusion upslope and myocardial perfusion reserve index with Student t test and Bland-Altman analyses.Results: Intra- and interobserver agreements were good and comparable for repeated measurements within each individual software platform (mean differences, <6%, intraclass correlation coefficient [ICC] >= 0.68). However, the intersoftware variability was significant (limits of agreement. 65%, ICC.Conclusion: The results indicate high repeatability within individual software but low reproducibility between different software packages, suggesting that within-group and/or sequential observation of semiquantitative perfusion parameters must be performed with the same software platform. Before semiquantitative perfusion analysis can be incorporated reliably into clinical studies, it is important to resolve the differences between the software packages. (C) RSNA, 2012