Jung Yul Kim MS, RT, Presenter: Nothing to Disclose

Chun Goo Kang MS, RT, Abstract Co-Author: Nothing to Disclose

Hoon-Hee Park MS, RT, Abstract Co-Author: Nothing to Disclose

Yung-Jae Kim RT, Abstract Co-Author: Nothing to Disclose

Chang Ho Lee MS, Abstract Co-Author: Nothing to Disclose

There are few reports regarding the influence of scattered rays from surrounding organs to the heart. Thus, in this study, we are to minimize the overestimate of left ventricular ejection fraction (LVEF) by modified body position to reduce the influence of scattered rays in the background region of interest (ROI).

Gated cardiac blood pool scan using in vivo 99mTc-red blood cell was carried out in 20 patients (mean 44.8±8.6 y) with chemotherapy for a breast carcinoma. Data acquisition requires about 600 seconds and 24 frames of one heart cycle by the multigated acquisition mode, Synchronization deteriorates toward the end of the cycle and with the distance from the trigger signal by electrocardiogram gating. It was studied with conventional method (supine position) and compared with modified method (left lateral flexion position with 360 mL of drinking water).

The ROI counts of modified scan method were lower than conventional method (1429±251 versus 1853±243, <0.01). And LVEF of modified method was also decrease compared with conventional method (58.3±5.6% versus 65.3±6.1%, <0.01). Imaging analysis indicated that stomach was expanded because of water and spleen position was changed to lateral inferior compared with conventional method.

This study shows that the modified method in Gated cardiac blood pool scan reduce the influence of scattered rays from surrounding organs. Because after change the body position to left lateral flexion and drinking water, the location of spleen, left lobe of liver and stomach had changed and they could escaped from background ROI. Therefore, modified method could help to minimize the overestimate LVEF(%).

 

Kim, J, Kang, C, Park, H, Kim, Y, Lee, C, A Technique for Reducing the Influence of Scattered Rays from Surrounding Organs to the Heart during Gated Cardiac Blood Pool Scan.  Radiological Society of North America 2009 Scientific Assembly and Annual Meeting, November 29 - December 4, 2009 ,Chicago IL. http://archive.rsna.org/2009/8010856.html