Nickel O, Schad N, Andrews E J, Fleming J W, Mello M
J Nucl Med. 1982 May;23(5):404-10.
An experimental model was developed using ellipsoidal balloons of different volumes to derive an empirical formula linking the "normalized" total count rates on gamma-camera images to volume. The normalized total count rate (NTC) is defined as the total count rate divided by the maximum count density. If an object is at a constant distance from the collimator, the NTC is found to be a linear function of volume. This formula was then applied to calculate left-ventricular end-diastolic volume from scintigraphic images obtained by radionuclide ventriculography in 71 consecutive patients. The distance from the left ventricle to the collimator was estimated from the patient's height and weight. The volumes calculated by the radionuclide method were compared with angiographic volumes obtained at cardiac catheterization, and good correlation was found (r = 0.95).
利用不同体积的椭圆形球囊建立了一个实验模型，以推导将γ相机图像上的“归一化”总计数率与体积联系起来的经验公式。归一化总计数率（NTC）定义为总计数率除以最大计数密度。如果物体与准直器的距离恒定，则发现NTC是体积的线性函数。然后将该公式应用于从71例连续患者的放射性核素心室造影获得的闪烁图像中计算左心室舒张末期容积。根据患者的身高和体重估计左心室到准直器的距离。将放射性核素法计算的容积与心导管检查时获得的血管造影容积进行比较，发现相关性良好（r = 0.95）。
