Landoni C, Bettinardi V, Lucignani G, Gilardi M C, Striano G, Fazio F
INB CNR, Department of Nuclear Medicine, University of Milan Institute H San Raffaele, Milan, Italy.
Eur J Nucl Med. 1996 Jan;23(1):18-24. doi: 10.1007/BF01736985.
Quantitative positron emission tomography (PET) heart studies require the accurate localization of regions of interest (ROIs) on the myocardial wall (MW) and left ventricle (LV). The procedure is often inaccurate, especially when there is low tracer uptake. We implemented a data processing technique to improve the accuracy of the localization of ROIs on the MW and LV in fluorine-18 labelled deoxyglucose ([18F]FDG) PET heart studies. This technique combines transmission data, acquired before tracer administration and used for attenuation correction, and dynamic emission data (DY), acquired to obtain myocardial time-activity curves and used to calculate regional myocardial glucose utilization, to generate a new set of "transmission" images (TRDY) with enhanced contrast between MW and LV. These new transmission images identify the extravascular myocardial tissue and can be used for ROI placement. Validation of the method was performed in 25 patients, studied after an oral glucose load, by drawing irregular ROIs on three transaxial slices outlining the septum and anterior-apical and lateral wall on the last frame of the DY images (steady state) and then on the TRDY images. Two kinds of analysis were performed on a total of 225 myocardial segments: (1) mean counts per pixel in the DY images from ROIs independently drawn on DY and TRDY images were compared; (2) TRDY ROIs were copied onto DY images and repositioned in the event of mismatch between ROIs and myocardial tissue edge. Mean counts per pixel in the DY images from the original and the repositioned TRDY ROIs were compared. An excellent correlation was found in both cases (using TRDY and DY ROIs: y=0.908 x+0.068, r=0.97; using TRDY ROIs alone: y=0.975 x+0.006, r=0.99). This technique can be used for clinical applications in physiological and pathological conditions in which the myocardial [18F]FDG uptake is reduced or minimal, including diabetes and myocardial infarction.
定量正电子发射断层扫描（PET）心脏研究需要在心肌壁（MW）和左心室（LV）上准确地定位感兴趣区域（ROI）。该过程常常不准确，尤其是在示踪剂摄取较低时。我们实施了一种数据处理技术，以提高在氟-18标记的脱氧葡萄糖（[18F]FDG）PET心脏研究中MW和LV上ROI定位的准确性。该技术将在注射示踪剂之前采集并用于衰减校正的透射数据，与为获得心肌时间-活性曲线并用于计算局部心肌葡萄糖利用率而采集的动态发射数据（DY）相结合，以生成一组新的“透射”图像（TRDY），其在MW和LV之间具有增强的对比度。这些新的透射图像可识别血管外心肌组织，并可用于ROI放置。通过在口服葡萄糖负荷后对25例患者进行研究，在DY图像（稳态）的最后一帧上，在勾勒出隔膜、前尖和侧壁的三个横轴切片上绘制不规则ROI，然后在TRDY图像上绘制，对该方法进行了验证。对总共225个心肌节段进行了两种分析：（1）比较在DY图像上分别独立绘制在DY和TRDY图像上的ROI的每像素平均计数；（2）如果ROI与心肌组织边缘不匹配，则将TRDY ROI复制到DY图像上并重新定位。比较原始TRDY ROI和重新定位后的TRDY ROI在DY图像中的每像素平均计数。在两种情况下均发现了极好的相关性（使用TRDY和DY ROI：y = 0.908x + 0.068，r = 0.97；仅使用TRDY ROI：y = 0.975x + 0.006，r = 0.99）。该技术可用于心肌[18F]FDG摄取减少或极少的生理和病理状况的临床应用，包括糖尿病和心肌梗死。
