Toyama H, Takeshita G, Shibata K, Nomura M, Fujiwara T, Ishikawa E, Fujiwara M, Fujii N, Ejiri K, Maeda H, Katada K, Takeuchi A, Koga S
Department of Radiology, Fujita Health University.
Kaku Igaku. 1996 May;33(5):521-9.
The purpose of this study is to assess the clinical usefulness of super dynamic SPECT of 99mTc-HM-PAO. Six patients with unilateral occlusion of middle cerebral artery (MCA) or internal carotid artery (ICA) in the chronic phase, and 5 patients with subacute cerebral infarction were studied. We used a ring-type SPECT "HEADTOME." Two types of collimator were used: a high sensitivity (HS) collimator for super dynamic scan and a high resolution (HR) collimator for static scan. First, the intravenous constant infusion of 99mTc-HM-PAO (925-1480 MBq) for 1 minute was started. After 30 seconds from the beginning of the injection, we performed the 12 seconds/frame super dynamic SPECT for 2 minutes. Then, the static SPECT for 10 minutes was done. For semiquantitative analyses, differential percentage of regional activity between affected and non-affected hemispheres was calculated in the 6th frame image of super dynamic SPECT and static SPECT image. In all 6 patients with unilateral occlusion of MCA and ICA, super dynamic SPECT images showed the better contrast of low perfusion areas in comparison with the static SPECT images. In 5 patients with subacute cerebral infarction who showed focal hyperactivities on static SPECT, focal hyperactivities (hyperperfusion or hyperemia) were displayed in 3 cases, whereas, focal hypo- or isoactivities (hypo- or isoperfusion) were shown in 2 cases on super dynamic SPECT. However, all patients with subacute cerebral infarction showed hyperfixation on static SPECT as compared with super dynamic SPECT. Although the image quality on super dynamic SPECT is not as high as that on static SPECT, cerebral hemodynamics would be detected with less backdiffusion of 99mTc-HM-PAO from the brain to blood, and with less accumulation of hydrophilic components in subacute infarct region. In conclusion, super dynamic SPECT in early distribution of 99mTc-HM-PAO using dedicated SPECT device might be helpful to detect cerebral perfusion close to true cerebral blood flow distribution.
本研究的目的是评估99mTc-HM-PAO超动态单光子发射计算机断层扫描（SPECT）的临床应用价值。对6例慢性期大脑中动脉（MCA）或颈内动脉（ICA）单侧闭塞患者以及5例亚急性脑梗死患者进行了研究。我们使用了环形SPECT“HEADTOME”。使用了两种准直器：用于超动态扫描的高灵敏度（HS）准直器和用于静态扫描的高分辨率（HR）准直器。首先，开始静脉恒速输注99mTc-HM-PAO（925-1480MBq）1分钟。注射开始后30秒，进行2分钟的每秒12帧超动态SPECT检查。然后，进行10分钟的静态SPECT检查。对于半定量分析，在超动态SPECT的第6帧图像和静态SPECT图像中计算患侧和健侧半球区域活性的差异百分比。在所有6例MCA和ICA单侧闭塞患者中，超动态SPECT图像显示与静态SPECT图像相比，低灌注区域的对比度更好。在5例静态SPECT显示局灶性高活性的亚急性脑梗死患者中，超动态SPECT显示3例为局灶性高活性（高灌注或充血），2例为局灶性低活性或等活性（低灌注或等灌注）。然而，与超动态SPECT相比，所有亚急性脑梗死患者的静态SPECT均显示放射性摄取增加。尽管超动态SPECT的图像质量不如静态SPECT，但使用专用SPECT设备在99mTc-HM-PAO早期分布时进行超动态SPECT检查，可能有助于检测接近真实脑血流分布的脑灌注情况。
