Traditional, forgotten and new left ventricular systolic function parameters on a 64-row multidetector cardiac computed tomography: A reproducibility study
Background: Multidetector computed tomography angiography (MDCT) can provide data regardingcardiac function if a retrospective scanning is applied. We aimed at examination of thereproducibility of traditional and more sensitive parameters of the left ventricular (LV) contractilityby means of a 64-row CT in order to establish errors of measurement and to determine limits thatallow for a reliable detection of their changes.Methods and Results: A random sample of 25 individuals, including 15 females (aged 64 ± 13years) and 10 males (54 ± 13 years), who had MDCT examination were retrospectively includedin this study. Data reconstructions were performed on a dedicated workstation. In each case, axialimage series were created with a 10% step from 0% to 90% of the RR interval using a 2 mm slicethickness. LV volume was determined in each phase. Detailed LV volume changes within phaseswere analyzed to determine the largest difference between the neighbor phases (peak ejection volume,PEV, mL) during systole and to calculate the peak ejection rate (PER i.e. PEV/phase duration[1/10th of RR interval], mL/s). The derived parameters were calculated as the PER normalized forLVEDV (PER-V, 1/s), the PER normalized for LVM (PER-M, mL/g × s) and the PER normalizedfor LVEDV times the PER normalized for LVM product (PER-VM, ml/g × s2). Considering the errorspercentages, the respective values for intra- and inter-observer errors were around 5% and 8%for standard LV systolic measures. The percentage intra-observer errors’ ranged between –7.8% and–10.8%, and the inter-observer errors’ ranged between –11.8% and –15.7% for both PEV and PER.For the same reader, the percentage errors ranged between –8.7% and +11.9% for PER-V, –10% and+12.7% for PER-M and –18.2% and +24% for PER-VM. For the independent reader the correspondingvalues were –15.2% and +15.5%, –12.3% and +16.3%, and –26.6% and +30.9%. The intra--class coeffi cients for repeated measurements for both the same reader (intra-observer) or independentreader (inter-observer) did reach values above 0.9 and around 0.8, respectively.Conclusions: We concluded that traditional LV systolic parameters, as well as more sensitive measuresof cardiac contractility could be determined reliably by means of a 64-row MDCT. The errorsfor global LV systolic function measures amount to about 5%, for PEV and PER about 15% and forthe PER-derived parameters about 25%. The measurement errors established might help to assessthe signifi cance of changes in repeated MDCT examinations
