A comparative study of multimodal magnetic resonance in the differential diagnosis of acquired immune de�ciency syndrome related primary central nervous system lymphoma and infection

Background: Patients with acquired immune de�ciency syndrome (AIDS) often suffer from opportunistic infections and related primary central nervous system lymphoma (AR-PCNSL). Both diseases showed multiple ring enhancement lesions in conventional magnetic resonance (MR). It is very di�cult to make the differential diagnosis. We aimed to investigate whether multimodal MR (diffusion weighted imaging (DWI)/ apparent diffusion coe�cient (ADC), 3D pseudo-continuous arterial spin labeling (3D-pCASL) and susceptibility-weighted imaging (SWI)) combined with conventional MR can differentiate AR-PCNSL from infection. Methods: This was a prospective study. We recruited 19 AIDS patients who were divided into AR-PCNSL group (9 cases) and infection group (10 cases) by pathological results. We analyzed whether there was statistical (Fisher’s method) difference in multimodal MR between the two groups. We analyzed whether multimodal MR combined with conventional MR could improve the diagnosis of AR-PCNSL. Results: The lesions were more likely involved the paraventricular (0.020) and corpus callosum (0.033) in AR-PCNSL group in conventional MR. In multimodal MR, AR-PCNSL group showed low ADC value, with p values of 0.001. Infection group more inclined to high ADC value, with p was 0.003. In multimodal MR, AR-PCNSL group had more low signal intensity(grade 2-3) in the degree of intratumoral susceptibility signal intensity in SWI(SWI-ITSS) ,with p values of 0.001. The sensitivity, speci�city of conventional MR in the diagnosis of AR-PCNSL was 88.9%, and 70.0%. The conventional MR sequence combined with DWI/ADC sequence in the diagnosis of AR-PCNSL had a sensitivity of 100.0%, and a speci�city of 60.0%. The sensitivity and speci�city of the conventional MR sequence combined with the SWI-ITSS sequence in the diagnosis of AR-PCNSL were 100% and 70.0%. The conventional MR combined with ADC or SWI-ITSS improved the diagnosis of AR-PCNSL. lymphoma, one case of Burkitt lymphoma, and two cases of highly invasive B-cell lymphoma. Of the nine cases, seven cases were positive for EBV nucleic acid (using a probe for EBV-encoded small RNA (EBER)) in biopsy material, one case was negative and the other one was not tested. Biopsies were in infection were to empiric antibiotics for toxoplasmosis and tuberculosis. All ten cases were con�rmed by pathology. There were three cases of toxoplasmosis, four cases of PML, one case of tuberculoma (positive for acid-fast pus), one case of brain abscess. In�ammatory/infectious changes were reported in one case, but the aetiology was �bers diffusion of water molecules in the high DWI signal [33] 8 cases of AR-PCNSL group high signal on DWI and low signal on ADC, was limited. 7 cases of infectious lesions were hyperintense on DWI, their ADC values were also hyperintense, was not limited. cause of DWI hyperintensity was the T2 penetration effect. ADC value attached in clinical work. ADC value excluded the in�uence of the T2 penetration effect on DWI signals, the interpretation of diffusion weighted imaging more reasonable. SWI is an imaging sequence based on differences in magnetic sensitivity and the blood oxygen level-dependent (BOLD) effect between tissues. SWI can sensitively display paramagnetic substances in tissues and has signi�cant advantages in displaying microvascular structures and microhemorrhage foci. Hemorrhage and necrosis often occur in AR-PCNSL and present as uneven, slightly high signal on T1WI and as multiple punctate/linear and patchy low signal on SWI. Refer to Park [17] for the classi�cation of low SWI signal. The ITSS in AR-PCNSL was signi�cantly higher (2-3 times) than in the infection group. There were 3 cases