Frontolimbic glutamate alterations in first episode schizophrenia: evidence from a magnetic resonance spectroscopy study.

Glutamatergic dysfunction has been implicated in the pathophysiology of schizophrenia. In this study we performed absolute-quantification short-echo magnetic resonance spectroscopy (MRS) in nine patients with first episode schizophrenia and 32 group-matched control subjects to test the hypothesis of glutamatergic dysfunction at disease onset. Regions of interest were the left dorsolateral prefrontal cortex and the left hippocampus.

Chronic insomnia and MRI-measured hippocampal volumes: a pilot study.

Study Objectives: Morphometric analysis of magnetic resonance imaging brain scans was used to investigate possible neuroanatomic differences between patients with primary insomnia compared to good sleepers.

Design: MRI images (1.5 Tesla) of the brain were obtained from insomnia patients and good sleepers.

Can homogeneous preparation encoding (HoPE) help reduce scan time in abdominal MRI? A clinical evaluation.

Purpose: To evaluate time efficiency, image quality, and diagnostic value of a clinical routine homogeneous preparation encoding (HoPE) imaging protocol in different malign and inflammatory abdominal conditions.

Materials And Methods: A total of 14 healthy volunteers and 40 patients were examined after written informed consent and approval of the local ethics committee. A standard abdominal T1-weighted (T1W) fat-saturated gradient-echo protocol was compared to the HoPE sequence protocol ensuring for comparable imaging parameters.

Cerebral correlates of muscle tone fluctuations in restless legs syndrome: a pilot study with combined functional magnetic resonance imaging and anterior tibial muscle electromyography.

Background: The pathology of restless legs syndrome (RLS) is still not understood. To investigate the pathomechanism of the disorder further we recorded a surface electromyogram (EMG) of the anterior tibial muscle during functional magnetic resonance imaging (fMRI) in patients with idiopathic RLS.

Methods: Seven subjects with moderate to severe RLS were investigated in the present pilot study.

Morphometry of the retrobulbar human optic nerve: comparison between conventional sonography and ultrafast magnetic resonance sequences.

Purpose: To compare different methods for quantification of optic nerve and nerve sheath diameter. To apply a novel magnetic resonance protocol using half-Fourier acquired single-shot turbo spin-echo (HASTE) sequences to analyze optic nerve dimensions.

Methods: Measurements were taken in right eyes of 33 subjects whose median age was 25 years.

Autoalignment of intervertebral disks.

Purpose: To develop an automated planning method to obtain double oblique slices for clinically relevant diagnoses of spine-related pathologies.

Materials And Methods: Thirty healthy volunteers, 18 patients with cervical spine (c-spine) pathologies, and 15 patients with lumbar spine (l-spine) pathologies were included in this study. The planning method requires no interaction and is calculated online on the MR scanner after two sagittal acquisitions (a MR myelogram and standard T2-weighted (T2W) acquisition).

[Flow-sensitive in-vivo 4D MR imaging at 3T for the analysis of aortic hemodynamics and derived vessel wall parameters].

Modern phase contrast MR imaging at 3 Tesla allows the depiction of 3D morphology as well as the acquisition of time-resolved blood flow velocities in 3 directions. In combination with state-of-the-art visualization and data processing software, the qualitative and quantitative analysis of hemodynamic changes associated with vascular pathologies is possible. The 4D nature of the acquired data permits free orientation within the vascular system of interest and offers the opportunity to quantify blood flow and derived vessel wall parameters at any desired location within the data volume without being dependent on predefined 2D slices.

Visualization of iliac and proximal femoral artery hemodynamics using time-resolved 3D phase contrast MRI at 3T.

Purpose: To demonstrate the feasibility of time-resolved 3D MR velocity mapping at 3 Tesla for the visualization of vascular hemodynamics in normal iliac and femoral arteries.

Materials And Methods: Electrocardiographically (ECG) synchronized three-dimensional (3D) CINE phase-contrast MRI with three-directional flow encoding was adapted to analyze flow in peripheral arteries at 3T. Visualization of peripheral arterial hemodynamics within the acquired data volume included 3D streamlines and time-resolved 3D particle traces within the major vessels and localized analysis of flow profiles using 2D-vector graphs.

Association between the BclI glucocorticoid receptor polymorphism and smoking in a sample of patients with obstructive airway disease.

Glucocorticoids seem to mediate the effect of stimulant drugs such as nicotine. Several studies have pointed to an association between the BclI polymorphism in the glucocorticoid receptor gene and increased glucocorticoid effects. We analysed the association of smoking behaviour and the BclI polymorphism using a case-control design within the framework of a larger pharmacogenetic study.

Evidence of disturbed amygdalar energy metabolism in patients with borderline personality disorder.

In order to detect possible links between structural and neurochemical brain abnormalities we applied high resolution morphometric imaging and short-echo time absolute-quantification magnetic resonance spectroscopy (MRS) at the left hand side to the amygdala in 12 patients with borderline personality disorder (BPD) and 10 group-matched healthy controls. Confirming earlier reports we found a significant 11-17% reduction of amygdalar volumes in patients with BPD. In addition there was a significant 17% increase of left amygdalar creatine concentrations in BPD patients.

Visualization of vascular hemodynamics in a case of a large patent ductus arteriosus using flow sensitive 3D CMR at 3T.

Comprehensive flow velocity acquisition based on time-resolved three-dimensional phase-contrast CMR with three-directional velocity encoding was employed to assess arterial hemodynamics in a patient with a large patent ductus arteriosus with Eisenmenger's physiology. Computer-aided visualization of blood flow characteristics provided detailed information about temporal and spatial distribution of left and right ventricular outflow. Main findings included the depiction of the location and extent of two flow channels for systolic aortic filling, a relatively large amount of pulmonary artery to aortic flow confirming Eisenmenger's physiology, and a slight phase difference between right and left ventricular ejection.

Infection of tobacco with different Pseudomonas syringae pathovars leads to distinct morphotypes of programmed cell death.

Tobacco plants (Nicotiana tabacum cv. Xanthi-nc) infiltrated with either of two pathovars of Pseudomonas syringae- an avirulent strain of P. syringae pv.

In vivo assessment and visualization of intracranial arterial hemodynamics with flow-sensitized 4D MR imaging at 3T.

We evaluated electrocardiogram-synchronized flow-sensitized 4-dimensional MR imaging at 3T in combination with advanced 3D visualization strategies to ascertain its feasibility for the assessment of local intracranial blood-flow patterns in vivo. In large arteries of healthy volunteers, the temporal and spatial evolution of blood flow was successfully visualized and revealed--for example, a helical flow pattern in the carotid siphon. In a patient with steno-occlusive neurovascular disease, stagnant and retrograde flow patterns were readily visible.

Time-resolved 3D MR velocity mapping at 3T: improved navigator-gated assessment of vascular anatomy and blood flow.

Purpose: To evaluate an improved image acquisition and data-processing strategy for assessing aortic vascular geometry and 3D blood flow at 3T.

Materials And Methods: In a study with five normal volunteers and seven patients with known aortic pathology, prospectively ECG-gated cine three-dimensional (3D) MR velocity mapping with improved navigator gating, real-time adaptive k-space ordering and dynamic adjustment of the navigator acceptance criteria was performed. In addition to morphological information and three-directional blood flow velocities, phase-contrast (PC)-MRA images were derived from the same data set, which permitted 3D isosurface rendering of vascular boundaries in combination with visualization of blood-flow patterns.

Impaired executive control is associated with a variation in the promoter region of the tryptophan hydroxylase 2 gene.

Current models of attention describe attention not as a homogenous entity but as a set of neural networks whose measurement yields a set of three endophenotypes-alerting, orienting, and executive control. Previous findings revealed different neuroanatomical regions for these subsystems, and data from twin studies indicate differences in their heritability. The present study investigated the molecular genetic basis of attention in a sample of 100 healthy subjects.

Inversion recovery prepared turbo spin echo sequences with reduced SAR using smooth transitions between pseudo steady states.

This study investigates the contrast behavior of 2D inversion recovery (IR) prepared turbo spin echo (TSE) sequences that use RF pulse schemes with variable low flip angles (hyperTSE) to reduce RF power deposition. A framework of equations and calculations for adapting the sequence parameters is presented by which equivalent image contrast is achieved compared to conventional IR-TSE imaging. Although the inversion time (TI) and repetition time (TR) do not need to be changed, the echo time (TE) has to be prolonged such that the effective TE (TE(eff)) is preserved.

Reduced cingulate glutamate/glutamine-to-creatine ratios in adult patients with attention deficit/hyperactivity disorder -- a magnet resonance spectroscopy study.

Background: The dopaminergic system is thought to be essentially involved in the pathogenesis of attention deficit/hyperactivity disorder (ADHD). However, there is also evidence for abnormalities in the glutamatergic system and recent theories focus on a disturbed interaction between the two systems as the essential pathogenetic mechanism of ADHD. In the present study, we wanted to test the hypothesis that prefrontal glutamate signals indirectly indicate dopaminergic dysfunction in adult patients with ADHD.

Inferior frontal white matter microstructure and patterns of psychopathology in women with borderline personality disorder and comorbid attention-deficit hyperactivity disorder.

Background: Inferior frontal white matter circuits are likely to be relevant to dysfunctional affect regulation, aggression, dissociative symptoms, neuropsychological functioning and psychopathology in women with borderline personality disorder (BPD) and comorbid attention-deficit hyperactivity disorder (ADHD).

Methods: 20 women with BPD and comorbid ADHD and 20 healthy women were investigated, and groups were matched for age, education and premorbid intelligence. Mean diffusivity and fractional anisotropy were measured bilaterally in the inferior frontal white matter by diffusion tensor imaging (DTI).

Kinetics of PME/Pi in pig kidneys during cold ischemia.

Quality assessment of renal grafts via (31)P magnetic resonance spectroscopy (MRS) has been investigated since 1986. As ATP concentrations decay rapidly during cold ischemia, the ratio of phosphomonoesters (PME) to inorganic phosphate (Pi(O)) within the organ (PME/Pi(O)) is commonly used as a quality marker and is considered to be the most reliable parameter. MRS did not lead to any delay in the transplantation procedure since it was performed during the time necessary for immunological matching (cross-match).

Time-resolved, 3-dimensional magnetic resonance flow analysis at 3 T: visualization of normal and pathological aortic vascular hemodynamics.

Flow-sensitive 3-dimensional magnetic resonance imaging at 3 T and advanced 3-dimensional visualization were used to visualize local and global vascular hemodynamics in the thoracic aorta. In patients with pathological geometric alterations of the thoracic aorta, this technique revealed considerable changes in local blood flow characteristics, compared with normal volunteers. Specifically, relatively small geometric changes, such as a partially thrombosed aortic arch or a mild aneurysm of the ascending aorta, resulted in major disturbances of local blood flow patterns within and even further downstream to the pathology.

Systematic investigation of balanced steady-state free precession for functional MRI in the human visual cortex at 3 Tesla.

Previous studies have applied balanced steady-state free precession (bSSFP) to functional brain imaging. Methods that exploit the strong frequency dependence of the MR signal in the bSSFP transition band are strongly affected by field inhomogeneity and frequency drifts. Recent bSSFP studies using "on-resonance" (in the bSSFP passband) acquisition claimed that higher sensitivity was achieved compared to traditional fMRI methods.

Association between a polymorphism in the promoter region of the TPH2 gene and the personality trait of harm avoidance.

In a genetic association study the role of the -703 G/T (rs4570625) polymorphism, located in the promoter region of the tryptophan hydroxylase 2 gene (TPH2), in personality traits was investigated in a sample of 404 healthy Caucasian subjects. A significant association between harm avoidance (HA), a trait related to anxiety, and the -703 G/T polymorphism was detected supporting the findings by Gutknecht and colleagues.