In vivo MR spectroscopy of bilateral hippocampi in HIV-seropositive or neurosyphilis patients at 3T

Abstract

PURPOSE: As a result of changing sexual behaviors which led to the human immunodeficiency virus (HIV) epidemic, neurosyphilis (NS) also has experienced a worldwide resurgence and the infections are often concurrent. Mild cognitive impairment has been observed in early stages of neurosyphilis. In this study, magnetic resonance spectroscopy (MRS) was used to investigate the effect of neurosyphilis on the bilateral hippocampi of HIV-positive patients. MATERIALS & METHODS: Experiments were performed on 12 cognitively normal patients (Mini-mental-state-examination ≥ 28; age: 42 ± 12.66 years) with HIV-seropositive or neurosyphilis positive (status defined by the 2010 Sexually Transmitted Diseases Treatment Guidelines by the Centers for Disease Control and Prevention). Of the 12 patients, six were HIV-seropositive with NS, four were HIV-seropositive without NS and two were HIV-seronegative with NS. Twenty-one healthy age-matched controls also were recruited. A 3.0T MR scanner was used (Achieva, Philips Healthcare) with an 8-channel SENSE head coil. Single-voxel-spectroscopy with short echo-time (TE) 38 ms, repetition time (TR) 2000 ms was employed. Single voxels of size 2.5 cm x 1.5 cm x 1cm were placed in the left and right hippocampi with point-resolved spectroscopy (PRESS) as volume selection method. MR spectroscopy data were analyzed with offline software jMRUI version 4.0 using absolute quantification based on quantum estimation (QUEST). Choline (Cho), creatine (Cre) and N-acetylaspartate (NAA) levels were investigated with internal water as reference. Cerebrospinal fluid normalization was done. Metabolic ratios of the above metabolites also were calculated. SPSS 18.0 was employed for statistical analysis using 2-sample t-test. The level of significance was p<0.05. RESULTS: Table 1. Mean values with standard deviations of metabolites obtained from HIV patients with or without NS, NS patients with or without HIV and their respective …