Maskali Fatiha, Franken Philippe R, Poussier Sylvain, Tran Nguyen, Vanhove Chris, Boutley Henri, Le Gall Hervé, Karcher Gilles, Zannad Faïez, Lacolley Patrick, Marie Pierre Y
UHP-INSERM U684, Faculty of Medicine, Nancy, France.
J Nucl Med. 2006 Feb;47(2):337-44.
The rat infarct model is widely used to study left ventricular (LV) remodeling, a main cause of heart failure characterized by progressive LV dilatation. Using pinhole collimators and advances in data processing, gated SPECT was recently adapted to image the rat heart. The aim of this study was to assess this new imaging technique for predicting and quantifying variable LV remodeling from the rat infarct model.
Pinhole 99mTc-sestamibi gated SPECT was validated for determining LV volume and identifying the necrotic and nonviable LV segments (<50% of 99mTc-sestamibi uptake) in rats, and it was applied to monitor rat LV function from 48 h to 12 wk after occlusion of the left anterior descending coronary artery (LAD) (n = 20) or sham operation (n = 9).
In LAD-occluded rats, 48-h SPECT necrosis was large (> or =30% LV) in 6, limited (<30% LV) in 6, and undetectable in 8. End-diastolic volume of LAD-occluded rats was equivalent to that of sham-operated rats at 48 h (320 +/- 84 microL vs. 293 +/- 48 microL; not significant) but became higher at 12 wk (501 +/- 191 microL vs. 343 +/- 46 microL; P = 0.01). The follow-up increase in end-diastolic volume, which reflects the remodeling process, was closely related to the initial extent of necrosis revealed by the SPECT images (P < 0.001; R2= 0.85). This increase was limited in sham-operated rats (50 +/- 15 microL) and in the LAD-occluded rats with undetectable necrosis (55 +/- 35 microL) but it was around 3- and 7-fold higher in the LAD-occluded rats with limited (165 +/- 57 microL) and large (366 +/- 113 microL) necrosis, respectively.
The variable LV remodeling documented after coronary occlusion in rats closely relates to the variable extent of necrosis provided by this model. Pinhole gated SPECT allows this remodeling to be predicted and quantified and, hence, constitutes an original tool for the experiments scheduled on the rat infarct model.
大鼠梗死模型被广泛用于研究左心室（LV）重构，这是心力衰竭的主要原因，其特征为左心室进行性扩张。利用针孔准直器和数据处理方面的进展，门控单光子发射计算机断层扫描（SPECT）最近被应用于大鼠心脏成像。本研究的目的是评估这种新的成像技术，以预测和量化大鼠梗死模型中不同的左心室重构。
针孔99m锝-甲氧基异丁基异腈门控SPECT在测定大鼠左心室容积和识别坏死及无活力左心室节段（99m锝-甲氧基异丁基异腈摄取量<50%）方面得到验证，并应用于监测左冠状动脉前降支（LAD）闭塞后48小时至12周的大鼠左心室功能（n = 20）或假手术组（n = 9）。
在LAD闭塞的大鼠中，48小时SPECT显示坏死范围大（≥30%左心室）的有6只，范围有限（<30%左心室）的有6只，未检测到坏死的有8只。LAD闭塞大鼠的舒张末期容积在48小时时与假手术大鼠相当（320±84微升对293±48微升；无显著差异），但在12周时更高（501±191微升对343±46微升；P = 0.01）。反映重构过程的舒张末期容积的随访增加与SPECT图像显示的初始坏死范围密切相关（P < 0.001；R2 = 0.85）。这种增加在假手术大鼠（50±15微升）和未检测到坏死的LAD闭塞大鼠（55±35微升）中有限，但在坏死范围有限（165±57微升）和范围大（366±113微升）的LAD闭塞大鼠中分别高出约3倍和7倍。
大鼠冠状动脉闭塞后记录的不同左心室重构与该模型提供的不同坏死范围密切相关。针孔门控SPECT能够预测和量化这种重构，因此，构成了在大鼠梗死模型上进行实验的一种原始工具。
