Kibar Mustafa, Yapar Zeynep, Noyan Aytul, Anarat Ali
Department of Nuclear Medicine, Cukurova University Medical School, Adana, Turkey.
Ann Nucl Med. 2003 May;17(3):219-25. doi: 10.1007/BF02990025.
Technetium-99m dimercaptosuccinic acid (Tc-99m DMSA) as a static renal agent is currently the most frequently used agent in the detection of renal scarring, and allows accurate calculation of differential renal function (DRF). But this agent has some disadvantages such as relatively higher radiation dose and time consumption.
The purpose of this study was to evaluate the potential of summed image that obtained from parenchymal phase of the dynamic technetium-99m-N,N-ethylenedicysteine (Tc-99m EC) scintigraphy in the detection of renal parenchymal defects and in the estimation of DRF, and to compare the results of this method with those of Tc-99m DMSA scintigraphy. The uptake ratios of the kidney to body background were also calculated for these two methods. Twenty-nine children with various renal disorders underwent both static Tc-99m DMSA and dynamic Tc-99m EC scintigraphy. The cortical analysis of Tc-99m EC scintigraphy was performed on the summed image obtained from dynamic images using the time interval between the first 45-120 sec.
There was a very close correlation between these two methods with respect to DRF (r = 0.99). In the detection of renal parenchymal lesions, scintigraphy with Tc-99m DMSA detected more lesions, and the sensitivity and specificity of the summed Tc-99m EC images were calculated as 92.6% and 100%, respectively. In addition, the ratios of mean uptake values for Tc-99m DMSA and Tc-99m EC images were 7.59 +/- 2.17 and 2.95 +/- 0.91, respectively. This ratio of Tc-99m EC seems to be acceptable and allows good delineation of the kidneys. But, the main disadvantages of the summed Tc-99m EC images in comparison with static Tc-99m DMSA images are the use of only posterior projection that may be an important drawback in patients with abnormal kidney positions, lower image counts and higher pixel size because of dynamic acquisition.
These results show that summed Tc-99m EC images with an acceptable high image contrast provide an accurate DRF calculation in patients without abnormal kidney positions and allow the detection of most renal parenchymal abnormalities. However, Tc-99m DMSA scintigraphy remains the gold standard method because of its well known advantages.
锝-99m二巯基丁二酸（Tc-99m DMSA）作为一种静态肾显像剂，目前是检测肾瘢痕最常用的显像剂，可准确计算分肾功能（DRF）。但该显像剂存在一些缺点，如辐射剂量相对较高且耗时。
本研究的目的是评估动态锝-99m-N，N-乙二胺二巯基丁二酸（Tc-99m EC）肾闪烁显像实质期获得的叠加图像在检测肾实质缺损和评估分肾功能方面的潜力，并将该方法的结果与Tc-99m DMSA肾闪烁显像的结果进行比较。还计算了这两种方法的肾脏与身体本底的摄取比值。29例患有各种肾脏疾病的儿童接受了静态Tc-99m DMSA和动态Tc-99m EC肾闪烁显像。使用前45 - 120秒之间的时间间隔，对从动态图像获得的叠加图像进行Tc-99m EC肾闪烁显像的皮质分析。
这两种方法在分肾功能方面具有非常密切的相关性（r = 0.99）。在检测肾实质病变方面，Tc-99m DMSA肾闪烁显像检测到更多病变，叠加的Tc-99m EC图像的敏感性和特异性分别计算为92.6%和100%。此外，Tc-99m DMSA和Tc-99m EC图像的平均摄取值之比分别为7.59±2.17和2.95±0.91。Tc-99m EC的这个比值似乎是可以接受的，并且能够很好地勾勒出肾脏轮廓。但是，与静态Tc-99m DMSA图像相比，叠加的Tc-99m EC图像的主要缺点是仅使用后位投影，这对于肾脏位置异常、图像计数较低以及由于动态采集导致像素尺寸较大的患者可能是一个重要缺点。
这些结果表明，对于肾脏位置无异常的患者，具有可接受的高图像对比度的叠加Tc-99m EC图像能够准确计算分肾功能，并能检测出大多数肾实质异常。然而，由于其众所周知的优点，Tc-99m DMSA肾闪烁显像仍然是金标准方法。
