Assessment of Left Ventricular Perfusion, Volumes, and Motion in Mice Using Pinhole Gated SPECT

Journal of Nuclear Medicine

Luc Mertz¹  Laurent Monassier¹  Philippe Choquet¹  André Constantinesco¹  Vincent Israel-Jost¹ 

关键词: mice;    gated SPECT;    myocardial perfusion;    ventricular function;    molecular imaging;   

DOI  :  

学科分类：医学（综合）

来源: Society of Nuclear Medicine

【 摘 要 】

Quantitative functional normal data should be a prerequisite before applying SPECT in murine models of cardiac disease. Therefore, we investigated the capability of in vivo pinhole gated SPECT for establishment of a reference database for left ventricular myocardial perfusion, volumes, and motion in normal mice. Methods: A small-animal dedicated pinhole γ-camera with a field of view of 17 cm and a focal distance of 12 cm was used with a 1.5-mm pinhole and a 2.5-cm radius of rotation. Phantoms were designed to test spatial resolution and microvolume measurements of accuracy. Eight adult normal mice (CD1) were studied using a heated mixture of air (0.3 L/min) and 1.5%–2.5% isoflurane for anesthesia. For myocardial perfusion, 350–450 MBq of 99mTc-tetrofosmin were used in 0.15–0.25 mL. Gated acquisitions (8 or 10 time bins per cardiac cycle) were obtained using a 180° circular arc and 48 anterior projections of 300 R–R intervals. Image reconstruction was done using a specific Algebraic Reconstruction Technique (ART) cone-beam algorithm. For quantification, reconstructed images were processed using standard nuclear medicine software. Results: Millimetric spatial resolution and volume calibration linear relationships (r2 = 0.99) in the 10- to 100-μL range were obtained in phantoms and used to scale in vivo volume values. In mice, left ventricular perfusion was lower in the apex (65% ± 6%) versus lateral (72% ± 5%), inferior (74% ± 5%), septum (75% ± 4%), and anterior (74% ± 2%) walls. The left ventricular ejection fraction was 60% ± 9%, end-diastolic volume was 50 ± 8 μL, end-systolic volume was 20 ± 6 μL, stroke volume was 29.5 ± 6 μL, and cardiac output was 9.6 ± 1.6 mL/min. Wall thickening was higher in the apex (47% ± 12%) versus lateral (30% ± 9%), inferior (33% ± 8%), septum (37% ± 10%), and anterior (33% ± 10%) walls. Conclusion: This work shows that in vivo pinhole gated SPECT can be used for assessment of left ventricular perfusion, volumes, and cardiac function in normal mice.

【 授权许可】

Unknown