A preliminary diffusion tensor and magnetization transfer magnetic resonance imaging study of early-onset multiple sclerosis

BACKGROUND: Early-onset multiple sclerosis (MS) typically has a more favorable course than adult-onset disease. OBJECTIVE: To assess the extent of microscopic tissue damage in the brain and cervical cord of patients with early-onset MS. DESIGN: During a single magnetic resonance imaging session, images of the brain and spinal cord were obtained using diffusion tensor and magnetization transfer magnetic resonance imaging. PATIENTS: We studied 13 patients with early-onset MS and 10 healthy volunteers. RESULTS: Compared with control subjects, patients with early-onset MS showed only a slight increase of the average mean diffusivity of the normal-appearing brain tissue. CONCLUSION: The relatively modest central nervous system damage detected in these patients might explain why early-onset MS typically has a more favorable clinical course than adult-onset MS.     

European study on intravenous immunoglobulin in multiple sclerosis: results of magnetization transfer magnetic resonance imaging analysis

BACKGROUND: Magnetization transfer magnetic resonance imaging (MT MRI) can provide in vivo markers reflecting the severity of multiple sclerosis-related brain damage occurring within and outside T2-visible lesions. OBJECTIVE: To investigate the effect of intravenous immunoglobulin (IVIG) treatment on the accumulation of brain damage in patients with secondary progressive multiple sclerosis (SPMS), measured using MT MRI.Design, Patients, and Intervention Seventy patients with SPMS participating in the European, multicenter, randomized, double-blind, placebo-controlled trial of IVIG in SPMS underwent brain T2-weighted and MT MRI at baseline and after 12 and 24 months. The MT MRI scans were post-processed and analyzed to obtain MT ratio values from T2-visible lesions and MT ratio histograms from the normal-appearing brain tissue (NABT). RESULTS: At baseline, a significant difference was found for NABT MT ratio histogram peak height (P =.003) between treated patients and patients receiving placebo. No significant differences between treated patients and those receiving placebo were found for any of the considered MT MRI-derived metrics in terms of treatment x time interaction. Nevertheless, over the 24-month period, the placebo patients experienced a 6.75% reduction of the NABT MT ratio histogram peak height, whereas treated patients experienced only a 0.92% reduction of the NABT MT ratio histogram peak height. CONCLUSIONS: This study did not show any statistically significant effect of IVIG on MT MRI quantities. Nevertheless, the markedly different percentage change of the NABT MT ratio histogram peak height over time between patients receiving placebo and treated patients suggests a possible role of IVIG treatment in preventing the loss of "truly" normal brain tissue in SPMS patients.     

Failure of gamma-hydroxybutyric acid both to increase neuroactive steroid concentrations in adrenalectomized-orchiectomized rats and to induce tolerance to its steroidogenic effect in intact animals

Gamma-Hydroxybutyric acid (GHB), a drug proposed in the treatment of alcohol withdrawal syndrome, increases the cerebrocortical and plasma concentrations of the neuroactive steroids allopregnanolone and allotetrahydrodeoxycorticosterone (THDOC). In the present study, we examined the role of hypothalamic-pituitary-adrenal (HPA) axis in the effect of GHB by measuring the concentrations of these steroids in the brain and plasma of adrenalectomized-orchiectomized (Adx-Orx) rats. The acute administration of GHB (500 mg/kg, i.p.) induced in 30 min an increase in the concentrations of allopregnanolone, THDOC and their precursors pregnenolone and progesterone in different brain areas (cerebral cortex, hypothalamus and cerebellum) and plasma of sham-operated rats but had no effect on the concentrations of these compounds in Adx-Orx rats, suggesting that activation of the HPA axis mediates the effect of GHB on brain and plasma concentrations of neuroactive steroids. Moreover, we evaluated whether repeated exposure of GHB induces tolerance to its steroidogenic effects. Chronic administration of GHB (500 mg/kg, i.p., twice a day for 10 days) to intact animals failed to affect the levels of progesterone, allopregnanolone, or THDOC measured 3 or 48 h after the last drug administration, whereas a challenge injection of GHB or ethanol was still able to increase the concentrations of these steroids in brain and plasma. These results indicate that repeated exposure to GHB fails to induce tolerance or cross-tolerance to the steroidogenic action of GHB or ethanol, respectively.     

Multislice CT anatomy of hepatic artery in patients undergoing liver transplantation using 3D reconstructions

PURPOSE: To evaluate the accuracy of multislice CT angiography, investigating vascular anatomy and anatomical variants of hepatic artery in patients undergoing liver transplantation. MATERIALS AND METHODS: The study concerns 20 patients (12 male and 8 female) candidates to liver transplantation were examined using multislice CT with a triphasic protocol following the administration of Iomeron 400 mg/ml at a rate of 5 ml/s using Sure Start technique. The following protocol was applied in all patients: row thickness 3, pitch 5.5, image thickness 3, reconstruction 1. Vascular reconstruction was obtained with 3D Maximum Intensity Projection and Volume Rendering algorithms using the data of the arterial phase. All variants were classified by Michels's classification. All patients were transplanted and the anatomical results of CT have been verified surgically. RESULTS: CT angiography detected 5 anatomical variants of the hepatic artery and one aneurysm of the celiac trunk; the other 14 patients had a normal anatomy. In all patients the results of CT correlates with the surgical ones. CONCLUSIONS: Our results suggest that multislice CT angiography is useful for planning surgical transplantation, giving precise information about vascular anatomy and its variants, (those are common). In our opinion this technique can replace conventional angiography.     

Diagnostic work up of arrhythmogenic right ventricular cardiomyopathy by cardiovascular magnetic resonance (CMR). Consensus statement

Cardiovascular Magnetic Resonance (CMR) has become a widespread diagnostic tool. Since its introduction CMR has been used to image patients with known or suspected arrhythmogenic right ventricular cardiomyopathy (ARVC). Several abnormalities have been found and described by CMR and at present this diagnostic tool is considered very important for the diagnosis. However, the diagnosis of ARVC relies upon the fulfillment of both clinical and functional criteria and CMR can provide several but not all the information useful for the diagnosis. Furthermore, some findings such as evidence of right ventricular epicardial fat once considered a peculiar marker of ARVC, have been shown to possess a low specificity. This document was prepared by representatives of the three Italian official Organizations involved in CMR. Its main scope is to highlight the problems encountered when studying patients with suspected ARVC by CMR, to indicate the basic technical equipment needed, to recommend a proper imaging protocol and to offer a consensus on the main diagnostic features relevant for the diagnosis.     

Diagnostic applications of cardiac multislice CT with sixteen-row scanner: state of the art

Coronary angiography is nowadays the diagnostic standard in the evaluation of coronary artery anatomy, in the identification of stenoses and in the follow-up of revascularization procedures (PTCA-stenting, bypass). The limitations of such technique in terms of invasivity and high cost has targeted research efforts towards the development of non invasive diagnostic tools. Technological evolution in the field of helical CT has provided 2, 4, 8 and 16 detector-row multislice scanners characterized by progressive improvements in terms of spatial and temporal resolution that have made them increasingly suitable for the analysis of moving structures with high quality anatomic detail. The main cardiologic applications of multislice CT include coronary calcium scoring, the evaluation of coronary vascular anatomy and disease, follow-up of revascularization procedures (stenting, bypass), and the evaluation of cardiac walls and chambers. The aim of this paper is to describe the applications of sixteen detector-row multisclice CT in non invasive evaluation of cardiac and coronary diseases.     

Huntington disease: volumetric, diffusion-weighted, and magnetization transfer MR imaging of brain

PURPOSE: To investigate whether diffusion-weighted and magnetization transfer (MT) magnetic resonance (MR) imaging depict regional and/or global brain abnormalities in patients with Huntington disease (HD). MATERIALS AND METHODS: Twenty-one carriers of the HD mutation (mean age, 58 years +/- 11 [SD]) and 21 healthy control subjects (mean age, 54 years +/- 13) underwent conventional, diffusion-weighted, and MT MR imaging. Volumes, mean apparent diffusion coefficients (ADCs), and MT ratios (MTRs) for left and right caudate nucleus, putamen, and cerebral periventricular white matter-as well as an index of normalized brain volume and whole-brain ADC and MT histograms-were computed. Asymmetry in volume, ADC, and MTR measurements in caudate nucleus, putamen, and periventricular white matter in control subjects and HD carriers were evaluated with Wilcoxon testing for paired samples. Differences in MR imaging variables between HD carriers and control subjects were evaluated with Mann-Whitney U testing; correlations between stages of clinical severity and MR imaging data were investigated with Spearman rank correlation testing. RESULTS: No significant asymmetry was observed for any of the MR imaging variables. Caudate nucleus, putamen, and whole-brain volumes were smaller (P <.001 for all) in HD carriers than in control subjects. HD carriers also had increased ADC in the caudate nucleus (P =.002), putamen (P <. 001), cerebral periventricular white matter (P <.001), and whole brain (P <.001). MTR was not significantly different between HD carriers and control subjects. Correlation was observed between stages of increasing clinical disease severity and both decrease in volume of caudate nucleus (Spearman rho = -0.63), putamen (rho = -0.64), and whole brain (rho = -0.46) and increase in ADC in caudate nucleus (rho = 0.52), periventricular white matter (rho = 0.45), and whole brain (rho = 0.44). CONCLUSION: Regional and global volume loss in HD is accompanied by an increase in ADC; this correlates with disease severity.