Dale S M, Bone D E, Brodin L A, Lindström C
Department of Medical Laboratory Sciences and Technology, Karolinska Institute, Huddinge, Sweden.
J Nucl Med. 1997 May;38(5):754-9.
This study compared myocardial perfusion scintigraphy performed with ectomography to corresponding SPECT studies.
In a comparative study between SPECT and ectomography, 19 patients with suspected coronary artery disease were imaged under similar conditions. A two-day protocol using 99mTc-sestamibi was followed. In SPECT, 32 projection images were acquired by rotating the gamma camera detector through 180 degrees, from 45 degrees left posterior oblique to 45 degrees right anterior oblique. Short-axis view sections and polar tomograms were reconstructed. In ectomography, a 30 degrees slant-hole collimator was rotated through 360 degrees in front of a stationary detector to obtain 64 projection images with different projection directions. The gamma camera was orientated perpendicular to the long axis of the left ventricle; the orientation was determined from the SPECT examination. Short-axis section images through the projected conical volume were reconstructed using a two-dimensional filtered back projection technique. In a blind test, the relative diagnostic value and image quality of the two methods were evaluated by three independent observers assessing short-axis view sections and polar tomograms. An objective evaluation based on relative values in the polar tomograms was also performed. The interpretations were evaluated with analysis of variance.
After injection during exercise, there was no significant difference between SPECT and ectomography. After injection at rest, visualization of the left ventricle was superior (p < 0.05) and influence of external activity was less (p < 0.005) in ectomography. The activity level within a perfusion defect was significantly lower (p < 0.05) and its extension significantly larger (p < 0.05) in ectomography than in SPECT. There was no difference between the diagnosis based on SPECT or ectomography.
In myocardial perfusion imaging with 99mTc-sestamibi, ectomography provides information similar to that obtained with SPECT and can, therefore, be used clinically for evaluation of myocardial perfusion when the gamma camera is postitioned perpendicular to the long axis of the left ventricle.
本研究比较了采用断层摄影术进行的心肌灌注闪烁显像与相应的单光子发射计算机断层扫描（SPECT）研究。
在一项SPECT与断层摄影术的对比研究中，对19例疑似冠状动脉疾病的患者在相似条件下进行成像。采用了为期两天的使用99m锝-甲氧基异丁基异腈的方案。在SPECT中，通过将γ相机探测器从左后斜45度旋转至右前斜45度，旋转180度获取32幅投影图像。重建短轴视图切片和极坐标断层图。在断层摄影术中，一个30度斜孔准直器在固定探测器前旋转360度，以获得具有不同投影方向的64幅投影图像。γ相机垂直于左心室长轴定位；该定位由SPECT检查确定。使用二维滤波反投影技术重建穿过投影圆锥体的短轴切片图像。在一项盲法试验中，由三名独立观察者评估短轴视图切片和极坐标断层图，以评估两种方法的相对诊断价值和图像质量。还基于极坐标断层图中的相对值进行了客观评估。通过方差分析对解释进行评估。
运动注射后，SPECT与断层摄影术之间无显著差异。静息注射后，断层摄影术中左心室的显影更佳（p < 0.05），外部活动的影响更小（p < 0.005）。断层摄影术中灌注缺损内的活性水平显著更低（p < 0.05），其范围显著更大（p < 0.05）。基于SPECT或断层摄影术的诊断之间无差异。
在使用99m锝-甲氧基异丁基异腈进行心肌灌注成像时，断层摄影术提供的信息与SPECT获得的信息相似，因此，当γ相机垂直于左心室长轴定位时，可用于临床评估心肌灌注。
