Evaluation of static and dynamic perfusion cardiac computed tomography for quantitation and classification tasks

Abstract

Abstract. Cardiac computed tomography (CT) acquisitions for perfusion assessment can be performed in a dynamic or static mode. Either method may be used for a variety of clinical tasks, including (1) stratifying patients into categories of ischemia and (2) using a quantitative myocardial blood flow (MBF) estimate to evaluate disease severity. In this simulation study, we compare method performance on these classification and quantification tasks for matched radiation dose levels and for different flow states, patient sizes, and injected contrast levels. Under conditions simulated, the dynamic method has low bias in MBF estimates (0 to 0.1 ml∕ min ∕g) compared to linearly interpreted static assessment (0.45 to 0.48 ml∕ min ∕g), making it more suitable for quantitative estimation. At matched radiation dose levels, receiver operating characteristic analysis demonstrated that the static method, with its high bias but generally lower variance, had superior performance (p < 0.05) in stratifying patients, especially for larger patients and lower contrast doses [area under the curve ðAUCÞ ¼ 0.95 to 96 versus 0.86]. We also demonstrate that static assessment with a correctly tuned exponential relationship between the apparent CT number and MBF has superior quantification performance to static assessment with a linear relationship and to dynamic assessment. However, tuning the exponential relationship to the patient and scan characteristics will likely prove challenging. This study demonstrates that the selection and optimization of static or dynamic acquisition modes should depend on the specific clinical task.

Promote quantitative ischemia imaging via myocardial perfusion CT iterative reconstruction with tensor total generalized variation regularization

“…In this study, static MPCT images and dynamic MPCT images were generated. In the static case, 3D MPCT data were generated during left ventricular cavity peak enhancement from 3 ml/min/g to the true perfusion level for the 70 kg patient injected with 100 ml of contrast (Bindschadler et al 2014, Bindschadler et al 2016. On the other hand, in the dynamic case, MPCT data were simulated with a cardiac output of 8 l • min −1 and perfusion level of 3 ml/min/g (Bindschadler et al 2014, Bindschadler et al 2016.…”

“…In the static case, 3D MPCT data were generated during left ventricular cavity peak enhancement from 3 ml/min/g to the true perfusion level for the 70 kg patient injected with 100 ml of contrast (Bindschadler et al 2014, Bindschadler et al 2016. On the other hand, in the dynamic case, MPCT data were simulated with a cardiac output of 8 l • min −1 and perfusion level of 3 ml/min/g (Bindschadler et al 2014, Bindschadler et al 2016. The scanning time was 30 s with 30 cardiac cycles in a sampling interval of 1 s between the sequential end-diastolic images, under the assumption of no respiratory motion and ideal end-diastolic gating.…”

“…In the clinic, there are two MPCT acquisition techniques which rely on contrast agent enhancement, i.e. static perfusion and dynamic perfusion (Varga-Szemes et al 2015, Bindschadler et al 2016 Danad et al 2016). The qualitative assessment of static perfusion is performed by visual evaluation of left ventricular myocardial contrast enhancement, i.e.…”

“…The qualitative assessment of static perfusion is performed by visual evaluation of left ventricular myocardial contrast enhancement, i.e. difference maps (Bindschadler et al 2016). In contrast, dynamic MPCT tracks the myocardial kinetics of the contrast medium distribution during the initial pass, arterial phase via serial whole cardiac data acquisitions (Varga-Szemes et al 2015, Bindschadler et al 2016, Caruso et al 2016, Danad et al 2016.…”

“…difference maps (Bindschadler et al 2016). In contrast, dynamic MPCT tracks the myocardial kinetics of the contrast medium distribution during the initial pass, arterial phase via serial whole cardiac data acquisitions (Varga-Szemes et al 2015, Bindschadler et al 2016, Caruso et al 2016, Danad et al 2016. In the dynamic MPCT mode, patients are injected with iodine contrast agent at a certain rate and are then instructed to hold their breath during repeated sequential scans.…”