Attenuation correction of myocardial SPECT by scatter-photopeak window method in normal subjects

Abstract

Objective: Segmentation with scatter and photopeak window data using attenuation correction (SSPAC) method can provide a patient-specific non-uniform attenuation coefficient map only by using photopeak and scatter images without X-ray computed tomography (CT). The purpose of this study is to evaluate the performance of attenuation correction (AC) by the SSPAC method on normal myocardial perfusion database. Methods:A total of 32 sets of exercise-rest myocardial images with Tc-99m-sestamibi were acquired in both photopeak (140keV±10%) and scatter (7% of lower side of the photopeak window) energy windows. Myocardial perfusion databases by the SSPAC method and non-AC (NC) were created from 15 female and 17 male subjects with low likelihood of cardiac disease using quantitative perfusion SPECT software (QPS). Segmental myocardial counts of a 17-segment model from these databases were compared on the basis of paired T test . Results: AC average myocardial perfusion count was significantly higher than that in NC in the septal and inferior regions (P<0.02). On the contrary, AC average count was significantly lower in the anterolateral and apical regions (P<0.01). Coefficient variation (CV) of the AC count in the mid, apical and apex regions was lower than that of NC. Conclusions: The SSPAC method can improve average myocardial perfusion uptake in the septal and inferior regions and provide uniform distribution of myocardial perfusion. The SSPAC method could be a practical method of attenuation correction without X-ray CT.

Combined quantitative analysis of attenuation corrected and non-corrected myocadial perfusion SPECT: Method development and clinical validation

“…Therefore the quantitative analysis could be considered to be at a disadvantage to the visual analysis. New CT attenuation correction methods21 could have an impact on the performance or our approach and remain to be validated in this context. In the current study, we excluded patients with a prior history of CAD, cardiomyopathy, significant valve disease, left bundle branch block, and paced rhythm.…”

Normal values for nuclear cardiology: Japanese databases for myocardial perfusion, fatty acid and sympathetic imaging and left ventricular function

“…The prone positioning was also used to compensate for attenuation artifacts [61, 62]. Attenuation correction of myocardial SPECT by scatter-photopeak window method was also investigated [63]. Because myocardial count distribution in normal subjects does not show complete homogeneity with any methods, some kind of additional database matched with advanced technological capability would be required.…”

Bone SPECT-based segmented attenuation correction for quantitative analysis of bone metastasis (B-SAC): comparison with CT-based attenuation correction

“…The most common technique for attenuation correction without CT or external devices is the segmented attenuation correction (SAC) in which body structures are segmented into several kinds of tissues based on pixel values on SPECT [6, 7], positron emission tomography (PET) [8–10], and magnetic resonance (MR) images [11, 12]. As for SPECT, SAC has been used only for qualitative cardiac imaging, but not for oncologic imaging.…”