The Identification of the Benign and Malignant Adrenal Tumors By Spectroscopy CT in Single-Phase Imaging

Objective To investigate the value of CT single spectral imaging in the quantitative analysis of adrenal adenomas and adrenal metastases. Methods From Jun.2011 to Mar.2012,31 patients with adrenal adenomas and 16 patients with adrenal metastases confirmed by pathologic findings or clinical follow-up and 10 patients with normal adrenal gland as a control group,underwent spectroscopy computed tomography scan(GE Discover CT 750 HD).CT spectral imaging was performed in the arterial phase.101 sets of monochromatic images,iodine and fat based maps were generated.Spectral curve and material content at each adrenal area were obtained.The iodine and fat concentration,slope of the spectral curve(λHU) and the CT values under the quality control were compared among different groups. Results There was significant difference of iodine concentration,fat concentration and λHU(F碘(腺瘤VS转移瘤)=1.25,F碘(腺瘤VS对照)=0.48,F碘(转移VS对照)=-0.77;F脂(腺瘤VS转移瘤)=12.83,F脂(腺瘤VS对照)=6.12,F脂(转移VS对照)=-6.71;FλHU(腺瘤VS转移瘤)=0.43,FλHU(腺瘤VS对照)=0.18,FλHU(转移VS对照)=-0.26,P0.01) between any two of adrenal adenomas,metastases and normal adrenals.The iodine concentration and fat concentration of adenomas(4.66±0.89,997.95±4.32) were significantly higher than that of metastases(3.40±0.98,985.12±6.52)(F碘(腺瘤VS转移瘤)=1.25,F脂(腺瘤VS转移瘤)=12.83,P0.001).For CT values under the quality control,there were significant difference between adrenal adenomas/metastases and normal adrenals(FCT(腺瘤VS对照)=15.35,FCT(转移VS对照)=14.06,P0.05),but there was no statistical difference existed between adrenal adenomas and metastases(FCT(腺瘤VS转移瘤)=1.29,P=0.83). Conclusion Monochromatic imaging and material decomposition-based quantitative analysis using spectroscopy CT spectral imaging in the arterial phase has potential in differential diagnosis between benign and malignant adrenal tumors.