White matter impairment in type 2 diabetes mellitus with and without microvascular disease.

BACKGROUND AND OBJECTIVE: Type 2 diabetes mellitus (T2DM) is a serious public health problem, and the phenomenon of T2DM occurring in younger people has directed more attention to functional changes in the brain. In this study, the microstructural integrity of white matter (WM) was evaluated in three groups of middle-aged subjects: healthy controls (HCs) and T2DM patients with and without peripheral microvascular complications (T2DM-C and T2DM-NC patients, respectively). METHODS: Diffusion tensor imaging (DTI) and related clinical examinations were performed in 66 subjects, including 20 T2DM-C patients, 20 T2DM-NC patients, 26 age- and sex-matched HCs. Magnetic resonance imaging (MRI) at 3 T was used to perform DTI; then, FSL and tract-based spatial statistics (TBSS) software were used to assess differences in the fractional anisotropy (FA) and mean diffusivity (MD) among the groups. The use of the FA and MD as parameters was evaluated by receiver operating characteristic (ROC) curve analysis. RESULTS: There were no significant differences in sex or age among the groups, and the clinical data of the groups met the experimental requirements. There was no significant difference in the FA values between the HCs and T2DM-NC groups. Compared with the HCs, the T2DM-C patients showed decreased FA values and increased MD values in the corpus callosum, bilateral anterior limb of the internal capsule, right retrolenticular part of the internal capsule, bilateral posterior thalamic radiation, right superior longitudinal fasciculus, bilateral superior corona radiata and left middle frontal gyrus (P < .01). Compared with the T2DM-NC patients, the T2DM-C patients showed decreased FA values and increased MD values in the corpus callosum, bilateral fornix, right retrolenticular part of the internal capsule, middle cerebral peduncle, right superior longitudinal fasciculus, right posterior thalamic radiation, and left middle frontal gyrus (P < .01). CONCLUSIONS: This study indicates that WM impairment is present in T2DM patients and may be related to microvascular complications. More importantly, this study also shows that such impairment may be diagnosed using the DTI mode of functional MRI before it can be diagnosed clinically.

Magnetic Resonance Imaging of the Human Ferritin Heavy Chain Reporter Gene Carried by Dendrimer-Entrapped Gold Nanoparticles.

This paper aimed to find an effective method to destroy cancer cells by targeting breast cancer cells with natural killer (NK) cells transfected with the human ferritin heavy chain (hFTH1) gene by polyethylene glycol (PEG)-modified dendrimerentrapped gold nanoparticles (Au DENPs). In this study, fifth-generation polyamidoamine (G5 PAMAM) dendrimers modified with PEG were used as templates to entrap gold nanoparticles to transfect hFTH1 into NK cells. Our results revealed that the prepared Au DENPs/FTH1 provided high-quality imaging performance (hypointensity on T2-weighted MR imaging) and efficient transfection efficiency (reaching 80.2%) at a N/P ratio (ratio of the number of surface primary amines on {(Au0)25-G5 · NH2-mPEG17} to the number of phosphate groups in the hFTH1 backbone) of 5:1. Interestingly, the results showed that Au DENPs/FTH1 effectively guided NK-92 cells to concentrate around tumor cells for effective gene therapy without severely impacting their activity. This work will provide a new research platform for immunotherapy based on NK cells and lead to the optimization and even individualization of breast cancer immunotherapy through nanomolecular visualization research, which has a broad scope for future clinical applications.

Use of diffusion kurtosis imaging and quantitative dynamic contrast-enhanced MRI for the differentiation of breast tumors.

BACKGROUND: Breast MRI is a sensitive imaging technique to assess breast cancer but its effectiveness still remains to be improved. PURPOSE: To evaluate the diagnostic performance of diffusion-weighted imaging (DWI), diffusion kurtosis imaging (DKI), and quantitative dynamic contrast-enhanced (DCE)-MRI in differentiating malignant from benign breast lesions independently or jointly and to explore whether correlations exist among these parameters. STUDY TYPE: Retrospective. POPULATION: In all, 106 patients with breast lesions (47 malignant, 59 benign). SEQUENCE: DKI sequence with seven b values and quantitative DCE sequence on 3.0T MRI. ASSESSMENT: Diffusion parameters (mean diffusivity [MD], mean diffusivity [MK], and apparent diffusion coefficient [ADC]) from DKI and DWI and perfusion parameters from DCE (Ktrans , kep , ve , and vp ) were calculated by two experienced radiologists after postprocessing. Disagreement between the two observers was resolved by consensus. STATISTICAL TESTS: The parameters in benign and malignant lesions were compared by Student's t-test. The diagnostic performances of DKI and quantitative DCE, either alone or in combination, were evaluated by receiver operating characteristic (ROC) analysis. The Spearman correlation test was used to evaluate correlations among the diffusion parameters and perfusion parameters. RESULTS: MK, MD, ADC, Ktrans , and kep values were significantly different between breast cancer and benign lesions (P < 0.05). MK from DKI demonstrated the highest AUC of 0.849, which is significantly higher than ADC derived from conventional DWI (z = 3.345, P = 0.0008). The specificity of DCE-MRI-derived parameters was improved when combining diffusion parameters, such as ADC and MK. The highest diagnostic specificity (93.2%) was obtained when kep and ADC were combined. kep was correlated moderately positively with MK (r = 0.516) and moderately negatively with MD (r = -0.527). Ktrans was weakly positively correlated with MK with an r of 0.398 and weakly negatively correlated with MD with an r of -0.450. DATA CONCLUSION: DKI is more valuable than conventional DWI in distinguishing between benign and malignant breast lesions. DKI exhibits promise as a quantitative technique to augment quantitative DCE-MRI. Diffusion parameters derived from DKI were statistically correlated with perfusion parameters from quantitative DCE-MRI. LEVEL OF EVIDENCE: 3 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018;47:1358-1366.

Combined resting state functional magnetic resonance imaging and diffusion tensor imaging study in patients with idiopathic restless legs syndrome.

OBJECTIVE: Restless legs syndrome (RLS) is a common neurological disorder characterized by an urge to move the legs along with paraesthesia deep within them. In this study, we aimed to use diffusion tensor imaging (DTI) and regional homogeneity (ReHo) to investigate the changes in regional spontaneous brain activity change for RLS patients against age- and gender-matched normal control (NC) subjects. METHODS: A total of 35 RLS patients and 27 age- and gender-matched NC subjects were recruited for group comparison research that used DTI and ReHo techniques. DTI was analysed by FSL and tract-based spatial statistics (TBSS) software to measure the values of fractional anisotropy (FA) or mean diffusivity (MD) in brain regions. Statistical Parametric Mapping 8 (SPM8) was used for data preprocessing and Data Processing Assistant for Resting-State fMRI (DPARSF) toolbox was used for ReHo calculation. For multiple comparison correction, the AlphaSim program implemented in AFNI was used to control the false-positive rate (corrected p < 0.05). RESULTS: There was no significant difference between the iRLS and NC groups in age or gender. In the one-sample t-test, both the NC and RSL groups showed increased ReHo in the bilateral posterior cingulate/precuneus cortex compared to the groups' global means, indicating that the default mode network was at rest. The RLS group showed a smaller cluster size than the NC group. In the two-sample t-test, the RLS group showed increased ReHo in the bilateral middle frontal gyrus, anterior cingulate cortex, caudate nucleus, insula, thalamus, putamen and left posterior cingulate cortex compared to the NC group. The statistical analysis of DTI images did not show any difference between the two groups. TBSS group comparison did not reveal any difference in FA or mean diffusivity (MD) of any brain region. CONCLUSION: RLS patients showed that greater ReHo within the striatum, thalamus and the limbic system, which implies that the emotional processing, motion control and cognition in the cortico-striatal-thalamic-cortical (CSTC) loop may be the site of dysfunction in RLS patients. This finding may provide imaging evidence to explore the pathophysiology of RLS. On the other hand, we did not see any change in the microstructure in the DTI analysis for RLS patients when compared to the NC group, which suggests a metabolic impairment.