The impact of different imaging modalities of ~(67)Ga scintigraphy on the image quality and the ability in detection of lesions

Objective ~(67)Ga scintigraphy is an important method in detection of active sarcoidosis.The aim of this research was to study the influence of planar and tomography.with and without CT attenuation correction(AC and NAC),on ~(67)Ga images on the image quality and the ability in detection of lesions.Methods Thirty one patients(13 male,18 female,age range:33-87 years)with sarcoidosis underwent ~(67)Ga planar and tomographic scans.AC and NAC.The imaging quality and the ability in detection of hyper-radioactive lymph nodes in lung hilar and mediastinal(1esion)among the planar,AC and NAC images were compared.The paired t-test and χ~2-test were used for data analysis with SPSS 10.0 software.Results From planar,NAC to AC,the image quality was better and better in proper order(χ~2=25.88,P<0.001).The planar imaging showed seventy lesions.while both AC and NAC images showed seventy-eight lesions.The radioactivity of lesions on AC image was significantly higher than that in NAC image (67.24l±35.049 and 15.240±8.865,respectively,t=-17.230,P<0.001).The radioactivity ratio of lesion to 3.298,7.032,P<0.01,=0.01 and<0.01.Conclusions ~(67)Ga tomographic scintigraphy can impmve the ability in detection of hyperradioactive lung hilar and mediastinal lymph nodes compared with planar image does.CT AC for ~(67)Ga tomography can improve the tomographic imaging quality. Key words: Tomography,emission-computed,single-photon; Tomography,X-ray computed;  Image processing,computer-assisted; Gallium radioisotopes; Quality control