title: Anatomical-based partial volume correction for low-dose dedicated cardiac SPECT/CT.
abstract: Due to the limited spatial resolution, partial volume effect has been a major degrading factor on quantitative accuracy in emission tomography systems. This study aims to investigate the performance of several anatomical-based partial volume correction (PVC) methods for a dedicated cardiac SPECT/CT system (GE Discovery NM/CT 570c) with focused field-of-view over a clinically relevant range of high and low count levels for two different radiotracer distributions. These PVC methods include perturbation geometry transfer matrix (pGTM), pGTM followed by multi-target correction (MTC), pGTM with known concentration in blood pool, the former followed by MTC and our newly proposed methods, which perform the MTC method iteratively, where the mean values in all regions are estimated and updated by the MTC-corrected images each time in the iterative process. The NCAT phantom was simulated for cardiovascular imaging with (99m)Tc-tetrofosmin, a myocardial perfusion agent, and (99m)Tc-red blood cell (RBC), a pure intravascular imaging agent. Images were acquired at six different count levels to investigate the performance of PVC methods in both high and low count levels for low-dose applications. We performed two large animal in vivo cardiac imaging experiments following injection of (99m)Tc-RBC for evaluation of intramyocardial blood volume (IMBV). The simulation results showed our proposed iterative methods provide superior performance than other existing PVC methods in terms of image quality, quantitative accuracy, and reproducibility (standard deviation), particularly for low-count data. The iterative approaches are robust for both (99m)Tc-tetrofosmin perfusion imaging and (99m)Tc-RBC imaging of IMBV and blood pool activity even at low count levels. The animal study results indicated the effectiveness of PVC to correct the overestimation of IMBV due to blood pool contamination. In conclusion, the iterative PVC methods can achieve more accurate quantification, particularly for low count cardiac SPECT studies, typically obtained from low-dose protocols, gated studies, and dynamic applications.
authors: Department of Diagnostic Radiology, Yale University, New Haven, CT 06511, USA. Key Laboratory of Particle & Radiation Imaging (Tsinghua University), Ministry of Education, Beijing 100084, People's Republic of China.
authors: Hui
authors: H
authors: Liu
authors: Chung
authors: C
authors: Chan
authors: Yariv
authors: Y
authors: Grobshtein
authors: Tianyu
authors: T
authors: Ma
authors: Yaqiang
authors: Y
authors: Liu
authors: Shi
authors: S
authors: Wang
authors: Mitchel R
authors: MR
authors: Stacy
authors: Albert J
authors: AJ
authors: Sinusas
authors: Chi
authors: C
authors: Liu
mesh_terms: D000818:Animals; D001810:Blood Volume; D055426:Cardiac-Gated Single-Photon Emission Computer-Assisted Tomography / Q000295:instrumentation / Q000379:methods*; D004285:Dogs; D004307:Dose-Response Relationship, Radiation; D004912:Erythrocytes / Q000378:metabolism; D006321:Heart / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D006801:Humans; D007089:Image Enhancement; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008955:Models, Cardiovascular; D055414:Myocardial Perfusion Imaging / Q000379:methods*; D009943:Organophosphorus Compounds / Q000493:pharmacokinetics; D015609:Organotechnetium Compounds / Q000493:pharmacokinetics; D019047:Phantoms, Imaging; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D015203:Reproducibility of Results; D013552:Swine; D014018:Tissue Distribution; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; C078700:technetium tc-99m tetrofosmin