De Geeter F, Caveliers V, Pansar I, Bossuyt A, Franken P R
Department of Nuclear Medicine, University Hospital, Free University Brussels, Belgium.
J Nucl Med. 1998 Nov;39(11):1850-6.
We have evaluated whether myocardial uptake of the fatty acid analog 123I-15-(p-iodophenyl)-3-R,S-methyl pentadecanoic acid (BMIPP) is dependent on the dietary state.
We compared the biodistribution of 150 MBq of 123I-BMIPP in six healthy volunteers in two states: after at least 12 hr of fasting and after oral glucose loading (75 g) 60 min before tracer administration, followed by a meal enriched in carbohydrates and protein. Planar and tomographic acquisitions were performed over a 4-hr time period after tracer injection; data were corrected for radioactive decay and injected dose. Radioactivity was measured in blood samples drawn at several points.
Significant increases of glycemia and insulinemia and a significant drop in plasma nonesterified acids were documented after glucose loading. Half-time values for plasma radioactivity were significantly shorter in the glucose-loaded state than in the fasted state (4.3 +/- 1.4 min compared to 6.3 +/- 1.3 min, p < 0.05). Activity in the heart and liver tended to be higher in the glucose-loaded state than in the fasted state. SPECT images at 0.5 hr after tracer injection demonstrated that the myocardial wall-to-cavity ratio was higher after glucose than in the fasted state (2.53 +/- 0.59 compared to 2.11 +/- 0.21, p = 0.15). Washout from the liver between 1 and 4 hr after injection increased from 18.6% +/- 4.4% in the fasted study to 24.1% +/- 2.4% after glucose (p = 0.04). Washout from the myocardium between 0.5 and 3.5 hr after injection increased from 13.1% +/- 8.8% in the fasted study to 24.0% +/- 3.7% after glucose (p = 0.05).
These results indicate that fasting before BMIPP scintigraphy is not mandatory to obtain adequate SPECT images. At the tire when SPECT is usually performed, glucose loading may provide improved ratios between myocardial and blood pool activity.
我们评估了脂肪酸类似物123I-15-（对碘苯基）-3-R，S-甲基十五烷酸（BMIPP）的心肌摄取是否依赖于饮食状态。
我们比较了150MBq的123I-BMIPP在六种健康志愿者两种状态下的生物分布：禁食至少12小时后以及在注射示踪剂前60分钟口服葡萄糖负荷（75g）后，随后给予富含碳水化合物和蛋白质的一餐。在注射示踪剂后的4小时内进行平面和断层图像采集；数据进行放射性衰变和注射剂量校正。在几个时间点采集的血样中测量放射性。
葡萄糖负荷后记录到血糖和胰岛素血症显著升高，血浆非酯化酸显著下降。葡萄糖负荷状态下血浆放射性的半衰期值显著短于禁食状态（4.3±1.4分钟与6.3±1.3分钟相比，p<0.05）。葡萄糖负荷状态下心脏和肝脏的活性倾向于高于禁食状态。注射示踪剂后0.5小时的SPECT图像显示，葡萄糖负荷后心肌壁与腔的比值高于禁食状态（2.53±0.59与2.11±0.21相比，p = 0.15）。注射后1至4小时肝脏的洗脱率从禁食研究中的18.6%±4.4%增加到葡萄糖负荷后的24.1%±2.4%（p = 0.04）。注射后0.5至3.5小时心肌的洗脱率从禁食研究中的13.1%±8.8%增加到葡萄糖负荷后的24.0%±3.7%（p = 0.05）。
这些结果表明，在进行BMIPP心肌灌注显像前禁食并非获得足够SPECT图像的必要条件。在通常进行SPECT检查的时间，葡萄糖负荷可能会改善心肌与血池活性之间的比值。
