Department of Biomedical Sciences, College of Nursing, Public Authority for Applied Education and Training, Kuwait.
J Nucl Med. 2013 May;54(5):801-6. doi: 10.2967/jnumed.112.109595. Epub 2013 Mar 25.
Renal function and disease are commonly evaluated by radionuclide studies. The choice of radiopharmaceutical agent for various studies is crucial for proper interpretation. (99m)Tc-mercaptoacetyltriglycine ((99m)Tc-MAG3) is excreted almost exclusively by the renal tubules, whereas (99m)Tc-diethylenetriamine pentaacetic acid ((99m)Tc-DTPA) is predominantly excreted by glomerular filtration. The present study compared the effect of the nonsteroidal antiinflammatory drug (NSAID) diclofenac, which is the most commonly used drug to relieve kidney pain, on the kinetic behavior of administered (99m)Tc-MAG3 and (99m)Tc-DTPA in experimental animals.
Two groups of 12 New Zealand White rabbits ((99m)Tc-MAG3 and (99m)Tc-DTPA) were used for the renography. Each rabbit served as its own control. The animals were given 60 mL of saline intravenously 30 min before each renographic study. A baseline study (control) was done by injecting 48 MBq (1.3 mCi) of (99m)Tc-MAG3, and renography was performed. Two days later, a single intravenous dose of diclofenac (2 mg/kg) (treated animals) was given, and after 20 min, (99m)Tc-MAG3 renography was performed. This procedure was repeated for the (99m)Tc-DTPA group after administration of 96 MBq (2.6 mCi) of the tracer. Dynamic images (as 2-s frames for the first minute and 30-s frames for the next 30 min on a 64 × 64 matrix) were acquired using a γ-camera equipped with a low-energy high-resolution collimator interfaced with a computer. Regions of interest were drawn over the whole kidneys. Time-activity curves were generated from the region of interest. Time to peak activity (T(max)), time from peak to 50% activity (T(1/2)), and the uptake slope of each kidney were calculated from the renograms for control and treated rabbits.
Administration of diclofenac shifted the experimental renogram curves to the right, compared with the control curves, indicating that there was a delayed renal uptake of the 2 tracers and clearance of the radioactivity. The calculated average values of T(max) for control and treated rabbits using (99m)Tc-MAG3 were 1.8 ± 0.5 and 6.35 ± 0.4 min, respectively, whereas those of (99m)Tc-DTPA were 3.4 ± 0.4 and 18.2 ± 2 min, respectively. The T1/2 for control and treated rabbits for (99m)Tc-MAG3 were 3.2 ± 0.07 and 6.6 ± 0.07 min, respectively, whereas those for (99m)Tc-DTPA were 10.1 ± 1 and 35 ± 4 min, respectively. The differences were statistically significant (P < 0.05).
This study showed that diclofenac delayed both T(max) and T1/2. The NSAID-induced kinetic changes were considerably greater for (99m)Tc-DTPA than for (99m)Tc-MAG3. On the basis of these findings, it is suggested that (99m)Tc-MAG3 be used to perform renography for studies involving the use of NSAID administration to decrease any change that may occur due to the type of tracer and not to the condition of the kidney.
研究非甾体抗炎药（NSAID）双氯芬酸对实验动物给予放射性核素标记的巯基乙酰三甘氨酸[（99m）Tc-MAG3]和二乙三胺五乙酸[（99m）Tc-DTPA]后肾动态显像剂摄取和清除的影响。
12 只新西兰白兔（每组 6 只）用于肾动态显像。每只动物自身对照。在每次肾动态显像前 30min，静脉给予 60ml 生理盐水。首先注射 48MBq（1.3mCi）（99m）Tc-MAG3 作为基础状态，进行肾动态显像。2 天后，静脉给予双氯芬酸（2mg/kg）（处理组），20min 后进行（99m）Tc-MAG3 肾动态显像。给予 96MBq（2.6mCi）（99m）Tc-DTPA 后，重复（99m）Tc-DTPA 组的操作。使用配备低能高分辨率准直器的γ相机和与计算机接口，获得 64×64 矩阵的 2s 帧动态图像（第 1 分钟）和 30s 帧动态图像（随后 30min）。在整个肾脏上画出感兴趣区。从感兴趣区生成时间-活性曲线。从肾动态显像图中计算出对照组和处理组兔的峰值时间（T（max））、从峰值到 50%活性时间（T（1/2））和每个肾脏的摄取斜率。
与对照组相比，双氯芬酸给药后实验性肾动态显像曲线右移，表明两种示踪剂的肾摄取延迟和放射性清除加快。对照组和处理组兔用（99m）Tc-MAG3 测定的 T（max）平均值分别为 1.8±0.5 和 6.35±0.4min，用（99m）Tc-DTPA 测定的 T（max）平均值分别为 3.4±0.4 和 18.2±2min。对照组和处理组兔用（99m）Tc-MAG3 测定的 T1/2 平均值分别为 3.2±0.07 和 6.6±0.07min，用（99m）Tc-DTPA 测定的 T1/2 平均值分别为 10.1±1 和 35±4min。差异有统计学意义（P<0.05）。
本研究表明，双氯芬酸延迟了 T（max）和 T1/2。与（99m）Tc-MAG3 相比，NSAID 引起的动力学变化在（99m）Tc-DTPA 中更为明显。基于这些发现，建议使用（99m）Tc-MAG3 进行肾动态显像，以减少因示踪剂类型而不是肾脏状况引起的任何变化。
