The consequences of a new software package for the quantification of gated-SPECT myocardial perfusion studies

Abstract

PurposeSemiquantitative analysis of myocardial perfusion scintigraphy (MPS) has reduced inter- and intraobserver variability, and enables researchers to compare parameters in the same patient over time, or between groups of patients. There are several software packages available that are designed to process MPS data and quantify parameters. In this study the performances of two systems, quantitative gated SPECT (QGS) and 4D-MSPECT, in the processing of clinical patient data and phantom data were compared.MethodsThe clinical MPS data of 148 consecutive patients were analysed using QGS and 4D-MSPECT to determine the end-diastolic volume, end-systolic volume and left ventricular ejection fraction. Patients were divided into groups based on gender, body mass index, heart size, stressor type and defect type. The AGATE dynamic heart phantom was used to provide reference values for the left ventricular ejection fraction.ResultsAlthough the correlations were excellent (correlation coefficients 0.886 to 0.980) for all parameters, significant differences (p < 0.001) were found between the systems. Bland-Altman plots indicated that 4D-MSPECT provided overall higher values of all parameters than QGS. These differences between the systems were not significant in patients with a small heart (end-diastolic volume <70 ml). Other clinical factors had no direct influence on the relationship. Additionally, the phantom data indicated good linear responses of both systems.ConclusionThe discrepancies between these software packages were clinically relevant, and influenced by heart size. The possibility of such discrepancies should be taken into account when a new quantitative software system is introduced, or when multiple software systems are used in the same institution.

Comparison of left ventricular functional parameters obtained from three different commercial automated software cardiac quantification program packages and their intraobserver reproducibility

“…If the two methods are in total agreement, all measured values will be situated on the mean deference line (bias) in the BlandAltman plot, and this line should coincide with the line of equality (zero line). For perfect (but not total) agreement, calculated values are located around the mean line within a 95% confidence interval [12]. In our study, we did not observe total agreement on Bland-Altman graphs (Fig.…”

“…In gated SPECT techniques determining LV volumes by MPS, many commercially available software programs have been developed [12,14]. These programs use an automated algorithmic approach to quantify LV volumes.…”

“…However, cardiac MRIs are increasingly being used for functional evaluation of the heart in clinical practise. All modalities for quantitative cardiac analyses produce different results, which indicate that the results are not interchangeable [12,13].…”

Influence of Reconstruction Parameters During Filtered Backprojection and Ordered-Subset Expectation Maximization in the Measurement of the Left-Ventricular Volumes and Function During Gated SPECT

“…On the other hand, nuclear cardiology techniques such as gated SPECT have been proved to be accurate and highly reproducible for the measurement of LV volumes and LVEF, thus making it a reliable technique (1). Gated SPECT provides additional information such as the myocardial mass and temporal evaluation of the wall thickness (4,5) and allows the calculation of end-diastolic volume (EDV) and end-systolic volume (ESV) and, through these, the measurement of LVEF (5)(6)(7)(8)(9).…”

“…Gated SPECT permits, in fact, the determination of global and regional function of the left ventricle (4,6,(10)(11)(12); however, the measurement of LV quantitative param-eters is dependent on endocardial surface detection by the reconstruction algorithms (4,5,9,11,13).…”