Objective: This paper aims to discuss the diagnostic value of quantitative DTI on AIDS patients with brain tuberculosis or toxoplasmosis. Materials and methods: 22 subjects (12 with brain tuberculosis and 10 with toxoplasmosis) were recruited, who underwent routine MRI, T1WI-CE and DTI imaging sequence. The morphological characteristics of lesions were observed, and FA and ADC values of the solid areas, edematous areas and the contralateral normal areas of the lesions were calculated. Results were compared by one-way ANOVA and independent sample t-test. The TB diagnosis efficiency of these two values was analyzed by ROC curve. Results: ADC and FA values were detected with significant differences among the three regions between subjects with brain tuberculosis and subjects with toxoplasmosis (P < 0.05). Statistically significant difference was recorded between solid and edematous areas and contralateral areas in ADC and FA values (P < 0.05). And so was between the solid areas and edema areas in either group. Moreover, the FA values of the solid areas between two groups also presented statistically significant difference (P < 0.01). ROC curve of TB showed the AUC of FA value was larger than that of ADC value (0.914 vs. 0.715, respectively, P < 0.05). DTT imaging showed infiltrative changes of white matter fibers in the lesion areas. Conclusions: Quantitative DTI is valuable for diagnosis and differential diagnosis of patients with AIDS-associated infections, and also could provide references for clinical physicians for proper medications. The quantitative FA value could help better reveal different changes of microstructural integrity between different opportunistic infections.

Background Lipoma arborescens is characterized by the villous proliferation of the synovium and diffuse hyperplasia of fatty tissue in the subsynovial layer, almost always with a periarticular lesion. According to past articles, fewer cases have depicted the imaging features of lipoma arborescens. Purpose To evaluate the computed tomography (CT) and magnetic resonance imaging (MRI) features of lipoma arborescens. Material and Methods The imaging features of 15 patients with pathologically proven lipoma arborescens were retrospectively analyzed including lesion number, shape, location, size, margins, attenuation on CT, and signal intensity and enhancement patterns on MR images. Results All cases (n=15) showed joint or bursa effusion. The primary lesion attached to the bursa wall adjacent to the bone in 13 cases and to the lateral wall in two cases. CT shows a mass with fatty tissue attenuation values in the suprapatellar pouch (n=3) or subdeltoid bursa with an erosion of the humeral head (n=2), among them two cases showed branched slightly high density in the center of the fat density tissue. Fifteen cases on routine MRI display mass-like subsynovial mass with fatty tissue signal on all of the sequences and suppression of the signal on fat-suppression sequences. Among them, five lesions showed branched slightly low T1-weighted imaging, high proton density-weighted imaging, and T2-weighted imaging signals in the center. It showed the enhancement of the linear surface and the bursa wall in contrast-enhanced MRI (n=3). Conclusion Lipoma arborescens have specific CT and MRI features that enable them to make a conclusive diagnosis of this rare condition, which helps the diagnosis before treatment.