Usefulness of a fusion protocol on SPECT and CT in lung disease

Objectives The fusion images of SPECT/CT have been widely used for various diseases. However, the procedure applied only for some cases in lung disease. Especially, in CT scan, when a pulmonary embolism was assumed, SPECT was frequently performed and SPECT/CT is need for accurate diagnosis. However, SPECT/CT is only available in some hospital. Therefore, the Fusion image of SPECT and CT was evaluated.

Methods Ten patients from 2010 June to September (male: 7, female: 3, mean age: 65.3±12.7) was evaluated. SPECT; Infinia (General Electric Healthcare, Wisconsin, MI, USA) and CT; Biograph (Siemens Medical Systems, CTI, Knoxville, TN, USA) were used. Both images were reconstructed to the fusion image using Multimodality Workstation (Siemens Medical Systems, CTI, Knoxville, TN, USA). Three Nuclear Medicine Special lists assessed the SPECT, CT and Fusion images in blind test. The 5-score test for analysis and ANOVA for statistical analysis were used.

Results When the parameter was under 6 degrees of view angle on SPECT images and under 1cm of CT slice, the Fusion images could show the most valuable diagnosis. In 5-score test, SPECT, CT, and Fusion showed 3.41±1.67, 3.37±1.35, and 4.45±1.43, respectively. It showed the Fusion image had significance(p<0.005) than independent SPECT or CT.

Conclusions In this study, we could gain optimum images for diagnosis through the fusion image of SPECT and CT. Especially, The functional data of a pulmonary vessel on SPECT images gave the more depicted data about pulmonary embolism in lung parenchyma. Combined SPECT/CT is an ideal. However, if a hospital is unequipped, this study will give a alternative way on SPECT diagnosis