RT Journal Article
SR Electronic
T1 Generation of Parametric Image of Regional Myocardial Blood Flow Using H<sub>2</sub><sup>15</sup>O Dynamic PET and a Linear Least-Squares Method
JF Journal of Nuclear Medicine
JO J Nucl Med
FD Society of Nuclear Medicine
SP 1687
OP 1695
VO 46
IS 10
A1 Lee, Jae Sung
A1 Lee, Dong Soo
A1 Ahn, Ji Young
A1 Yeo, Jeong Seok
A1 Cheon, Gi Jeong
A1 Kim, Seok-Ki
A1 Park, Kwang Suk
A1 Chung, June-Key
A1 Lee, Myung Chul
YR 2005
UL http://jnm.snmjournals.org/content/46/10/1687.abstract
AB Although a parametric image of myocardial blood flow (MBF) can be obtained from H215O PET using factor and cluster analysis, this approach is limited when factor analysis fails to extract each cardiac component. In this study, a linear least-squares (LLS) method for estimating MBF and generating a MBF parametric image was developed to overcome this limitation. The computer simulation was performed to investigate the statistical properties of the LLS method, and MBF values obtained from the MBF parametric images in dogs were compared with those obtained using the conventional region of interest (ROI) and invasive microsphere methods. Methods: A differential model equation for H215O in the myocardium was modified to incorporate the partial-volume and spillover effect. The equation was integrated from time 0 to each PET sampling point to obtain a linearlized H215O model equation. The LLS solution of this equation was estimated and used to calculate the MBF, the perfusable tissue fraction (PTF), and the arterial blood volume fraction (Va). A computer simulation was performed using the input function obtained from canine experiments and the tissue time–activity curves contaminated by various levels of Poisson noise. The parametric image of the MBF, PTF, and Va was constructed using the PET data from dogs (n = 7) at rest and after pharmacologic stress. The regional MBF from the parametric image was compared with those produced by the ROI method using a nonlinear least-squares (NLS) estimation and an invasive radiolabeled microsphere technique. Results: The simulation study showed that the LLS method was better than the NLS method in terms of statistical reliability, and the parametric images of the MBF, PTF, and Va using the LLS method had good image quality and contrast. The regional MBF values using the parametric image showed a good correlation with those using the ROI method (y = 0.84x + 0.40; r = 0.99) and the microsphere technique (y = 0.95x + 0.29; r = 0.96). The computation time was approximately 10 s for the 32 × 32 × 6 ×18 (pixel × pixel × plane × frame) matrix. Conclusion: A noninvasive, very fast, and accurate method for estimating the MBF and generating a MBF parametric image was developed using the LLS estimation technique and H215O dynamic myocardial PET.