Reduced dose measurement of absolute myocardial blood flow using dynamic SPECT imaging in a porcine model

Abstract

Dynamic SPECT measurement of MBF and MFR in pigs can be performed with 1/4 (Tc99m-tracers) or 1/2 (Tl-201) of the standard injected activity without significantly reducing accuracy and precision.

Optimization of SPECT Measurement of Myocardial Blood Flow with Corrections for Attenuation, Motion, and Blood Binding Compared with PET

“…5). Pig studies suggest that reducing the injected activity may be possible (29), but further human studies are needed to determine the extent to which patient dose can be reduced while maintaining an accurate MBF estimate. In addition to higher noise, tetrofosmin has a lower extraction fraction at high MBF, which reduces the contrast in K 1 between normal and abnormal flow responses.…”

Avoiding full corrections in dynamic SPECT images impacts the performance of SPECT myocardial blood flow quantitation

“…Our data therefore supported the utilization of CT images from a separate scan unit for SPECT only scanners as other studies have already demonstrated. 2,5 Recently some SPECT MBF study with a CZT scanner proposed to quantify MFR parameter with kinetic modeling and without physical corrections. 12 The method assumed physical errors in rest and stress scans can be similar so that they can be directly neutralized in MFR calculation.…”

“…[1][2][3][4][5] These studies consistently demonstrated that accurate flow measurement can be achieved by either conventional dual-head SPECT/computed tomography (SPECT/CT) scanners or a new cadmium zinc telluride (CZT) SPECT scanner while dynamic SPECT (DySPECT) acquisition and full physical corrections were applicable to accurately perform kinetic modeling. [2][3][4][5] The human study further showed that absolute flow parameters can be superior to detect coronary artery disease (CAD) over perfusion abnormality scores for a patient population with high prevalence of multi-vessel CAD. 3 Consequently, the capability of SPECT MBF quantitation brought an important clinical application to enhance CAD detection for areas where flow quantitation with position emission tomography (PET) cannot be applicable due to lack of economically affordable PET flow tracers.…”

“…[1][2][3][4][5][6][7][8] In fact, PET imaging in quantitative image configuration (e.g., pixel value with physical unit (Bq/mL)) has been employed in daily clinical utilization for few decades and become the standard. [6][7][8] Although this standard has not yet been established for SPECT imaging, to date, many SPECT cameras are well designed to perform DySPECT scan for research purposes, but without the capability to execute full physical corrections to dynamic image data.…”

Novel SPECT Technologies and Approaches in Cardiac Imaging

“…Good correlations of MBF (r = 0.75–0.90) compared with invasive microsphere measurements for all tracers studied and somewhat worse correlations of MFR were shown. The authors also showed recently in subsequent animal studies that low-dose SPECT flow measurements are feasible with such a solid-state camera with doses as low as one-quarter of the standard dose for 99mTc and a half dose for 201Tl [71]. Recently, human validation studies have been performed comparing fast SPECT and PET flow directly.…”