SPECT/CT imaging characteristic of osteolytic lesions with increased bone metabolism and its correlation with CT manifestation

Abstract

Objective To explore the characteristic of SPECT/CT imaging of osteolytic lesions with increased bone metabolism and its correlation with CT manifestation. Methods Twenty-one cancer patients with bone metastases underwent 99Tcm-MDP SPECT/CT imaging (13 males, 8 females; age: (60.52±6.85) years) were retrospectively studied. The imaging characteristic of the lesion with high uptake of 99Tcm-MDP was observed and the correlation between the lesion/background (L/B) ratio and CT manifestation were analyzed. One-way analysis of variance, two-sample t test and linear correlation analysis were used. Results A total of 111 lesions were found in 21 patients by 99Tcm-MDP whole-body bone scan, and 125 lesions were found by SPECT/CT imaging, including 111 lesions with increased bone metabolism and abnormal CT manifestation and 14 osteolytic lesions with decreased bone metabolism. In 111 lesions with increased bone metabolism, there were 23(20.72%) osteolytic lesions, 54 (48.65%) osteoblastic lesions and 34 (30.63%) mixed lesions. The L/B ratio of osteolytic lesions with increased bone metabolism (11.82±6.61) was lower than that of osteoblastic lesions (20.03±13.24) and that of mixed lesions (25.42±19.51; F=6.00, P<0.05). The CT value of osteolytic lesions with increased bone metabolism was higher than that of osteolytic lesions with decreased bone metabolism: (167.53±79.21) HU vs (88.63±49.16) HU; t=3.345, P<0.05. The L/B ratio of lesions with increased bone metabolism was positively correlated to CT value(r=0.404, P<0.05). Conclusions A part of lesions with increased bone metabolism on SPECT/CT images are osteolytic lesions. The L/B ratio of them is positively correlated to CT value. SPECT/CT imaging can reduce missed diagnosis and misdiagnosis. Key words: Neoplasm metastasis; Skeleton; Radionuclide imaging; Tomography, emission-computed, single-photon; Tomography, X-ray computed; MDP