Applicability of a high-resolution small semiconductor gamma camera to small animal imaging
Applicability of a high-resolution small semiconductor gamma camera to small animal imaging
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DOI：
10.1097/mnm.0b013e32828d8cbc
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发表时间：
2007-09
影响因子：
1.5
通讯作者：
Y. Kiyono;Y. Kuge;Yumiko Katada;H. Kawashima;Y. Magata;H. Saji
中科院分区：
文献类型：
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作者：
Y. Kiyono;Y. Kuge;Yumiko Katada;H. Kawashima;Y. Magata;H. Saji
近年来，开发了具有高分辨率和高灵敏度的小型半导体γ照相机（SSGC），与SPECT和PET相比，其使用更加方便，可用于标记前哨淋巴结。SSGC的高分辨率和灵敏度可能使其适用于小动物成像。因此，我们评估的适用性SSGC小动物成像使用大鼠模型的局灶性脑缺血。方法用尼龙线阻断麻醉大鼠右侧大脑中动脉。闭塞后24小时，注射99 mTc-HMPAO（3.7 MBq），并使用SSGC进行静态采集（5 min）。在水平脑图像的每个半球上设置感兴趣区域（ROI）。采集后，取出大脑，使用NaI闪烁计数器测量每个半球的放射性。结果SSGC在活体内可清晰显示右侧大脑中动脉区CBF的减少。SSGC法测定的ROI放射性与离体计数法测定的ROI放射性具有显著相关性（P<0.001，R2=0.74）。此外，无论是在体成像还是离体计数，MCA闭塞大鼠的右/左计数比（R/L比）均显著低于正常大鼠（MCA闭塞大鼠：0.77±0.08，正常大鼠：1.01±0.07，P<0.005）。结论SSGC可清晰地定量检测MCA闭塞大鼠脑血流量的减少。此外，SSGC的这些高分辨率和灵敏度可以避免使用PET和SPECT的小动物成像的缺点，例如大量注入的示踪剂和研究者暴露于辐射。因此，SSGC的高分辨率和灵敏度使其可用于小动物成像。
ObjectiveRecently, small semiconductor gamma cameras (SSGCs) with high resolution and sensitivity, which are much more convenient to use as compared with SPECT and PET, have been developed for mapping the sentinel lymph node. The high resolution and sensitivity of the SSGCs may make them useful for small animal imaging. Therefore, we assessed the applicability of the SSGC to small animal imaging using a rat model of focal cerebral ischaemia. MethodsThe right middle cerebral artery (MCA) of anaesthetized rats was occluded intraluminally with a nylon monofilament. Twenty-four hours after the occlusion, 99mTc-HMPAO (3.7 MBq) was injected and a static acquisition (5 min) was performed using the SSGC. Regions of interest (ROIs) were set on each hemisphere of the horizontal brain images. After the acquisition, the brains were removed and the radioactivity in each hemisphere was measured using an NaI scintillation counter. ResultsReduced CBF in the right MCA territory was clearly visualized with the SSGC in vivo. The radioactivity in the ROIs determined by the SSGC was significantly correlated with that determined by the ex vivo counting method (P<0.001, R2=0.74). Furthermore, in both of the in-vivo imaging and ex-vivo counting methods, the right to left count ratio (R/L ratio) was significantly lower in the MCA-occluded rats than that in normal rats (MCA-occluded rats: 0.77±0.08, normal rats: 1.01±0.07, P<0.005). ConclusionsThe SSGC clearly visualized and quantitatively detected the reduced CBF in MCA-occluded rats. Furthermore, these high resolution and sensitivity of SSGC can avoid the disadvantage of small animal imaging with PET and SPECT, such as a large mass injected tracer and the exposure of investigators to radiation. Thus, the high resolution and sensitivity of the SSGC make it useful for small animal imaging.