Original ArticlesResearch on the method of controlling the 99mTc-Technegas inhaled during 1-day pulmonary ventilation/perfusion imagingWu, Jiyong,*; Wang, Qiang,*; Zhao, Qingping; Li, Lvping; Zhou, Wei; Wang, HuoqiangAuthor Information Department of Nuclear Medicine, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, China * Jiyong Wu and Qiang Wang are co-first authors. Received 18 January 2019 Accepted 27 June 2019 Correspondence to Huoqiang Wang, MD, PhD, Department of Nuclear Medicine, Shanghai Pulmonary Hospital, Tongji University School of Medicine, No. 507 Zhengmin Road, Shanghai 200433, China, Tel: +86 02165115006; e-mail: email@example.com Nuclear Medicine Communications: October 2019 - Volume 40 - Issue 10 - p 995-1000 doi: 10.1097/MNM.0000000000001069 Buy Metrics Abstract Objective Our purpose was to establish a simple and feasible method for monitoring and controlling the 99mTc-Technegas inhaled to improve the success ratio of imaging and ensure the imaging quality. Materials and methods The relationship between the success ratio and the pulmonary ventilation counting rate (VCR) of 113 cases, the activity of perfusion imaging agents injected and the pulmonary perfusion counting rate (PCR) of another 114 cases were analysed retrospectively. And combined with the relationship between the surface radioactivity monitoring value and the SPECT probe counting rate of a pulmonary model, the effective range of the VCR and the surface radioactivity monitoring value were determined. Two hundred fifty cases with 99mTc-Technegas inhaled monitored and controlled were used to verify the reliability and practicability of this method. Results The VCR of the ventilation/perfusion imaging with deep venous thrombosis imaging and the ventilation/perfusion imaging without deep venous thrombosis imaging was in 1.0–3.0 kct/s and 1.0–2.0 kct/s when the monitoring values of handheld radiation monitor was within the range of 60–170 µSv/h and 60–110 µSv/h, respectively. The success ratio of the V/Q-Only increased from 48.9% (43/88) of the control group to 80.8% (122/151) of the experimental group. The VCR in the two groups was examined by the non-parametric Mann–Whitney U test (P < 0.001), which indicated that there was a significant difference between the experimental group and the control group. Conclusion The external monitoring method established in this study was of great significance in improving the success ratio of 1-day pulmonary ventilation/perfusion imaging and ensuring the image quality. Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.