Effects of radiopharmaceutical injection leakage on the image quality of myocardial perfusion imaping

Objective: Imaging quality of myocardial perfusion scintigraphy is important for diagnosis. This study was to evaluate the effects of radiopharmaceutical extravasation on the image quality of myocardial perfusion imaging. Methods: Of 2106 patients who underwent 99Tcm-methoxyisobutylisonitrile (MIBI) rest-stress myocardial perfusion images, there were 25 patients with 99Tcm-MIBI extravasation in their injection sites (20 of them with normal myocardial perfusion imaging). Thirty two patients with normal myocardial per-fusion imaging and coronary angiography were included as the control group. SPSS 12.0 software was used for data analyses. Results: The extravasation group ( 25 person-studies) accounted for 0.59% of all examined patients. The mean radioactivity count of axillary lymph nodes on the extravasation side (144.41 ± 45.45) was significantly higher than that of the control group (78.3 ± 34.42, t=5.983, P<0.001). The radioactivity count of myocardium [(139.38 ± 55.74) vs (225.54 ± 77.02)] and lung [(106.10 ± 61.14 ) vs (162.95 ± 106.05)]of extravasation group was significantly less than that of control group, t=-5.471, -2.276, all P<0.001.The image quality of the control group was significantly better than that of extravasation group(χ2=12.517, P<0.001). Conclusion: Radiopharmaceutical extravasation can reduce the myocardial perfusion image quality by lowering radiopharmaceutical uptake in the myocardium and higher background activity immediately surrounding the heart. (authors)