Clinical Significance of Diffusion Tensor Imaging in Metachromatic Leukodystrophy.

BACKGROUND: Metachromatic leukodystrophy (MLD) is a lysosomal enzyme deficiency disorder leading to progressive demyelination and, consecutively, to cognitive and motor decline. Brain magnetic resonance imaging (MRI) can detect affected white matter as T2 hyperintense areas but cannot quantify the gradual microstructural process of demyelination more accurately. Our study aimed to investigate the value of routine MR diffusion tensor imaging in assessing disease progression. METHODS: MR diffusion parameters (apparent diffusion coefficient [ADC] and fractional anisotropy [FA]) were in the frontal white matter, central region (CR), and posterior limb of the internal capsule in 111 MR datasets from a natural history study of 83 patients (age: 0.5-39.9 years; 35 late-infantile, 45 juvenile, 3 adult, with clinical diffusion sequences of different scanner manufacturers) as well as 120 controls. Results were correlated with clinical parameters reflecting motor and cognitive function. RESULTS: ADC values increase and FA values decrease depending on disease stage/severity. They show region-specific correlations with clinical parameters of motor and cognitive symptoms, respectively. Higher ADC levels in CR at diagnosis predicted a disease course with more rapid motor deterioration in juvenile MLD patients. In highly organized tissues such as the corticospinal tract, in particular, diffusion MR parameters were highly sensitive to MLD-associated changes and did not correlate with the visual quantification of T2 hyperintensities. CONCLUSION: Our results show that diffusion MRI can deliver valuable, robust, clinically meaningful, and easily obtainable/accessible/available parameters in the assessment of prognosis and progression of MLD. Therefore, it provides additional quantifiable information to established methods such as T2 hyperintensity.

The Power of LC-MS Based Multiomics: Exploring Adipogenic Differentiation of Human Mesenchymal Stem/Stromal Cells.

The molecular study of fat cell development in the human body is essential for our understanding of obesity and related diseases. Mesenchymal stem/stromal cells (MSC) are the ideal source to study fat formation as they are the progenitors of adipocytes. In this work, we used human MSCs, received from surgery waste, and differentiated them into fat adipocytes. The combination of several layers of information coming from lipidomics, metabolomics and proteomics enabled network analysis of the biochemical pathways in adipogenesis. Simultaneous analysis of metabolites, lipids, and proteins in cell culture is challenging due to the compound's chemical difference, so most studies involve separate analysis with unimolecular strategies. In this study, we employed a multimolecular approach using a two-phase extraction to monitor the crosstalk between lipid metabolism and protein-based signaling in a single sample (~105 cells). We developed an innovative analytical workflow including standardization with in-house produced 13C isotopically labeled compounds, hyphenated high-end mass spectrometry (high-resolution Orbitrap MS), and chromatography (HILIC, RP) for simultaneous untargeted screening and targeted quantification. Metabolite and lipid concentrations ranged over three to four orders of magnitude and were detected down to the low fmol (absolute on column) level. Biological validation and data interpretation of the multiomics workflow was performed based on proteomics network reconstruction, metabolic modelling (MetaboAnalyst 4.0), and pathway analysis (OmicsNet). Comparing MSCs and adipocytes, we observed significant regulation of different metabolites and lipids such as triglycerides, gangliosides, and carnitine with 113 fully reprogrammed pathways. The observed changes are in accordance with literature findings dealing with adipogenic differentiation of MSC. These results are a proof of principle for the power of multimolecular extraction combined with orthogonal LC-MS assays and network construction. Considering the analytical and biological validation performed in this study, we conclude that the proposed multiomics workflow is ideally suited for comprehensive follow-up studies on adipogenesis and is fit for purpose for different applications with a high potential to understand the complex pathophysiology of diseases.

Subcellular reprogramming of metabolism during cold acclimation in Arabidopsis thaliana.

Metabolite changes in plant leaves during exposure to low temperatures involve re-allocation of a large number of metabolites between sub-cellular compartments. Therefore, metabolite determination at the whole cell level may be insufficient for interpretation of the functional significance of cellular compounds. To investigate the cold-induced metabolite dynamics at the level of individual sub-cellular compartments, an integrative platform was developed that combines quantitative metabolite profiling by gas chromatography coupled to mass spectrometry (GC-MS) with the non-aqueous fractionation technique allowing separation of cytosol, vacuole and the plastidial compartment. Two mutants of Arabidopsis thaliana representing antipodes in the diversion of carbohydrate metabolism between sucrose and starch were compared to Col-0 wildtype before and after cold acclimation to investigate interactions of cold acclimation with subcellular re-programming of metabolism. A multivariate analysis of the data set revealed dominant effects of compartmentation on metabolite concentrations that were modulated by environmental condition and genetic determinants. While for both, the starchless mutant of plastidial phospho-gluco mutase (pgm) and a mutant defective in sucrose-phosphate synthase A1, metabolic constraints, especially at low temperature, could be uncovered based on subcellularly resolved metabolite profiles, only pgm had lowered freezing tolerance. Metabolic profiles of pgm point to redox imbalance as a possible reason for reduced cold acclimation capacity.

Destructive subependymal cysts following ventriculitis-pathomechanisms and treatment.

Ventriculitis may complicate neurosurgical procedures, for example, due to shunt or external ventricular drainage infection. Clearance of the infection with subsequent intravenous antibiotic therapy and shunt reinsertion, if necessary, are the standard treatment procedures with a high rate of success. Here, we report on a protracted complication, the development of destructive subependymal cysts, illustrate its treatment and discuss the pathomechanisms. The 2-year-and-9-month-old girl was admitted 5 weeks after a shunt revision with symptoms of shunt infection. Ventriculitis caused by Streptococcus salivarius (S. salivarius) was diagnosed and intravenous antibiotic treatment was performed. A new shunt system was implanted after clearance of infection and the girl did not show clinical signs of infection thereafter. A routine follow-up magnetic resonance imaging (MRI) revealed progressive and space-occupying multifocal subependymal cysts with partial destruction of the corpus callosum including compression of the ventricular system. Endoscopic broad-based laser fenestration of all cysts resulted in sustained regression of cavity formation. The cognitive development of the girl assessed 2 years afterward was completely normal. We conclude that routine follow-up MRI investigations are recommended 6 months after successful treatment of ventriculitis to detect protracted postinflammatory destructive subependymal cyst formations. Endoscopic broad-based laser-assisted cyst fenestration can stop progression and lead to regression of postinfectious subependymal cysts.

Metabolic mapping of gliomas using hybrid MR-PET imaging: feasibility of the method and spatial distribution of metabolic changes.

BACKGROUND AND PURPOSE: The most powerful adjunct to histopathology for the grading of gliomas seems to be the metabolic imaging using positron emission tomography and magnetic resonance spectroscopy (MRS). The purposes of this study were to examine the feasibility of simultaneous acquisition of both techniques for purposes of tumor grading in a newly launched hybrid magnetic resonance positron emission tomography (MR-PET) and to examine the spatial distributions of metabolic changes in gliomas. MATERIALS AND METHODS: Twenty-eight consecutive patients with gliomas underwent simultaneous methionine (Met) MR-PET imaging for detection of the most malignant tumor part before surgical sampling. After coregistration and fusion of MR-PET and MRS data, tumor to normal brain (T/N) Met uptake ratios and the corresponding metabolites peaks (choline [Cho], creatine [Cr], and N-acetylaspartate [NAA]) in MRS were recorded. The patients were divided into 4 types on the basis of the relation between the Met uptake area and the increased metabolite ratios: type I, the increased Met uptake area had at least 50% overlap or was completely within the area of increased Cho/NAA ratio; type II, the increased Met uptake site had less than 50% overlap of increased Cho/NAA ratio site; type III, the increased Met uptake region had no spatial relationship with the "hot" lesions in the MRS maps; and type IV, there was no pathologically increased Met uptake. The surgical sampling was performed in the tumor part with the highest Met uptake and, in the absence of increased Met accumulation, in the site with the highest Cho/NAA ratio. All surgical samples were referred to the neuropathology division for histological grading. RESULTS: A total of 16 low-grade gliomas (World Health Organization grade II) and 12 high-grade gliomas (World Health Organization grade III) were included. Three lesions (10%) of type I were identified. Four lesions (14%) were classified as type II and 6 lesions (21%) were classified as type 3, where the increased Met uptake region had no spatial relationship with the hot lesions in the MRS maps. In 15 of the 28 patients (54%), there was no increased Met accumulation (type 4 lesions). Maps of Cho/NAA and Cr/NAA showed a close spatial relationship in most of the patients. Median T/N Met uptake ratio in the pooled surgically sampled tumor sites was 1.6 (range, 1-3), and median Cho/NAA and Cho/Cr ratios were 2.1 (range, 0.9-5.8) and 1.5 (range, 0.5-8.3), respectively. Spearman rank correlations of the metabolic markers in the low-grade gliomas showed significant correlations between Met uptake and Cr/NAA ratio (ρ = 0.59; P = 0.015) as well as between Cho/NAA and Cr/NAA ratios (ρ = 0.79; P = 0.0002). The normalized tumor creatine was significantly higher in anaplastic tumors compared with the low-grade gliomas (P = 0.001). A tendency for a significant positive correlation was found between normalized tumor creatine and Met uptake in the anaplastic tumors. CONCLUSIONS: Metabolic mapping before histological sampling is feasible using simultaneous MR-PET imaging. High T/N Met uptake ratio reflecting high expression of amino-acid membrane transporters, which is indicative of proliferating tumor cell populations, does not always spatially correlate with neuronal cell loss and cell membrane proliferation (Cho/NAA) seen in MRS. Increased Cr/NAA is associated with increased methionine uptake in low-grade gliomas, whereas normalized creatine in tumor tends to correlate with methionine accumulation, which indicates a possible coupling of these metabolic indices in anaplastic tumors. Thus, spatial distribution differences in gliomas should be taken into account when planning surgical sampling.

Intraoperative visualization of residual tumor: the role of perfusion-weighted imaging in a high-field intraoperative magnetic resonance scanner.

BACKGROUND: High-field, intraoperative magnetic resonance imaging (iMRI) achieves free tumor margins in glioma surgery by involving anatomic neuronavigation and sophisticated functional imaging. OBJECTIVE: To evaluate the role of perfusion-weighted iMRI as an aid to detect residual tumor and to guide its resection. METHODS: Twenty-two patients undergoing intraoperative scanning (in a dual-room 1.5-T magnet setting) during the resection of high-grade gliomas were examined with perfusion-weighted iMRI. The generated relative cerebral blood volume (rCBV) maps were scrutinized for any hot spots indicative of tumor remnants, and region-of-interest analysis was performed. Differences among the rCBV region-of-interest estimates in residual tumor, free tumor margins, and normal white matter were analyzed. Histopathology of the tissue specimens and the neurosurgeon's intraoperative macroscopic estimations were considered the reference standards. RESULTS: In all cases, diagnostic rCBV perfusion maps were generated. Interpretation of perfusion maps demonstrated that gross total resection of gliomas was achieved in 4 of 22 cases (18%), which was macroscopically and histopathologically verified, whereas in 18 of 22 cases (82%), the perfusion-weighted iMRI revealed hot spots indicating subtotal tumor removal. The latter proved to be true in all but 1 case. The receiver-operating characteristic curves of the qualitative visual and quantitative analyses showed excellent sensitivity and specificity rates. Statistical analysis demonstrated statistically significant differences for the mean rCBV and maximum rCBV between residual disease and tumor-free margins (P = .002 for both). CONCLUSION: Perfusion-weighted iMRI may be implemented easily into imaging protocols and may assist the surgeon in detecting residual tumor volume.

Primarily solid intraventricular brain tumors.

Solid intraventricular-neoplasms are readily seen on cross-sectional images, but the myriad of entities to be considered may make a focused differential diagnosis elusive. Clinical symptoms of patients with intraventricular-tumors are non-specific and are generally related to increased intracranial pressure or hydrocephalus. The objective of this article is to present the most relevant demographic, clinical and imaging features of solid intraventricular-tumors for the purpose of a more comprehensive differential-diagnosis.

Contemporary microsurgical concept for the treatment of Cushing's disease: endocrine outcome in 83 consecutive patients.

BACKGROUND: Evidence suggests that occult adenoma remnants are responsible for persistent Cushing's disease (CD) following transsphenoidal surgery (TSS). To optimize the outcome, we have adapted our microsurgical concept. The influence of our surgical strategy on remission rate and pituitary function is presented. DESIGN AND PATIENTS: 83 patients undergoing TSS for newly diagnosed CD. An enlarged resection was performed in 36 patients. A modified exploration technique with radial incisions was performed in 19 patients in whom an adenoma was not readily detectable. RESULTS: The overall remission rate of primary surgery was 84·3% (70/83). A remission rate of 87·5% (63/72) was achieved in microadenomas. Six patients with microadenomas were re-operated for persistence, and hypercortisolism was corrected in five of them. With re-operation included, the overall remission rate for microadenomas was 94·4%. No procedure-related complications occurred in primary surgery. Of the patients in remission, 72·5% had early postoperative random cortisol levels below 2 µg/dl, 17·4% had cortisol levels between 2 and 5 µg/dl, and 10·1% had cortisol levels >5 µg/dl. 15·2% of the patients with microadenomas developed postoperative partial hypopituitarism and 3% diabetes insipidus. No increased rate of hypopituitarism was found with enlarged adenomectomy compared to selective adenomectomy. Only a slightly higher rate of partial hypopituitarism (23·1%) was found if extensive exploration was required. CONCLUSION: With our microsurgical concept, a high initial cure rate is achievable with minimal surgical morbidity. Enlarged adenomectomy has no adverse effect on the rate of postoperative hypopituitarism. Early repeat surgery is a successful option if CD persists.

Distinguishing recurrent high-grade gliomas from radiation injury: a pilot study using dynamic contrast-enhanced MR imaging.

RATIONALE AND OBJECTIVES: The accurate delineation of tumor recurrence and its differentiation from radiation injury in the follow-up of adjuvantly treated high-grade gliomas presents a significant problem in neuro-oncology. The aim of this study was to investigate whether hemodynamic parameters derived from dynamic contrast-enhanced (DCE) T1-weighted magnetic resonance imaging (MRI) can be used to distinguish recurrent gliomas from radiation necrosis. MATERIALS AND METHODS: Eighteen patients who were being treated for glial neoplasms underwent prospectively conventional and DCE-MRI using a 3T scanner. The pharmacokinetic modelling was based on a two-compartment model that allows for the calculation of K(trans) (transfer constant between intra- and extravascular, extracellular space), v(e) (extravascular, extracellular space), k(ep) (transfer constant from the extracellular, extravascular space into the plasma), and iAUC (initial area under the signal intensity-time curve). Regions of interest (ROIs) were drawn around the entire recurrence-suspected contrast-enhanced region. A definitive diagnosis was established at subsequent surgical resection or clinicoradiologic follow-up. The hemodynamic parameters in the contralateral normal white matter, the radiation injury sites, and the tumor recurrent lesions were compared using nonparametric tests. RESULTS: The K(trans), v(e), k(ep), and iAUC values in the normal white matter were significantly different than those in the radiation necrosis and recurrent gliomas (0.01,

Reduced intercarotid artery distance in acromegaly: pathophysiologic considerations and implications for transsphenoidal surgery.

BACKGROUND: The objective of this study is to evaluate the significance of reduced intercarotid artery distance in the C5 segment in acromegalic patients and the implications for transsphenoidal surgery. METHODS: The skull base with the carotid canal was examined with a helical CT scan in 45 patients with acromegaly and 45 age group-matched controls. The distances between the inner walls (IWs) of the carotid sulcus (CS), the outer walls (OWs) of the CS, and the diameter of the ICA at the C5 segment were assessed. Preoperative IGF-1 and growth hormone levels and concomitant diseases were evaluated and correlated with the biometric findings. Statistical analysis was performed with JMP (JMP version 7.0.2, SAS, Cary, USA). RESULTS: The mean distance between the IW was 1.64 +/- 0.40 cm in the acromegalic patients and 1.90 +/- 0.26 cm in the control group (P = .0005). The distance between the OW measured 3.01 +/- 0.39 and 2.97 +/- 0.33 cm in the acromegalics and in the control group, respectively (P = .6230). The difference in the diameter of the ICA was statistically significant (P < .0001) between patients and control group. Within the patient group, the distance between the IW of both ICA was significantly smaller in the subgroup with arterial hypertension (P = .0256). CONCLUSION: Narrowing of the inner borders of the CS between the right and left side is a statistically significant parameter in acromegaly. Attention should be given to an altered vascular course of the ICAs when planning and performing transsphenoidal microsurgery in acromegalic patients. A preoperative skull base CT may furnish important anatomical information and further reduce the risk of vascular injury.

Intra-individual crossover comparison of gadobenate dimeglumine and gadopentetate dimeglumine for contrast-enhanced magnetic resonance angiography of the supraaortic vessels at 3 Tesla.

OBJECTIVE: To compare gadobenate dimeglumine (Gd-BOPTA) and gadopentetate dimeglumine (Gd-DTPA) for contrast-enhanced magnetic resonance (MR) angiography of the supraaortic vessels at 3 Tesla. MATERIALS AND METHODS: Twelve healthy volunteers each underwent two contrast-enhanced magnetic resonance angiography examinations, one with Gd-BOPTA and one with Gd-DTPA each at a dose of 0.1 mmol/kg bodyweight. The 2 examinations were performed in randomized order and were separated by at least 72 hours. Imaging was performed in the coronal plane at 3T (Magnetom TIM Trio Siemens) using a 12-channel neurovascular array coil. The MR sequence parameters were identical for all examinations. Maximum intensity projection reconstructions were evaluated separately and in matched-pairs by a single independent blinded reviewer in terms of qualitative (5-point scales for technical quality and vessel delineation) and quantitative (relative contrast-to-noise ratio) contrast enhancement across 19 arteries/arterial segments comprising the internal carotid arteries; anterior, middle, and posterior cerebral arteries; vertebral arteries; and basilar artery. Findings were compared using the Wilcoxon signed rank test. RESULTS: The mean technical quality across all examinations was significantly (P = 0.031) greater after Gd-BOPTA. The overall median score for vessel delineation was also significantly higher for Gd-BOPTA than for Gd-DTPA (4.3 vs. 3.7; P = 0.005). Matched-pairs assessment revealed significant (P

Three-dimensional constructive interference in steady-state magnetic resonance imaging in syringomyelia: advantages over conventional imaging.

OBJECT: Neuroradiology has become indispensable in detecting the pathophysiology in syringomyelia. Constructive interference in steady-state (CISS) magnetic resonance (MR) imaging can provide superior contrast at the sub-arachnoid tissue borders. As this region is critical in preoperative evaluation, the authors hypothesized that CISS imaging would provide superior assessment of syrinx pathology and surgical planning. METHODS: Based on records collected from a database of 130 patients with syringomyelia treated at the authors' institution, 59 patients were prospectively evaluated with complete neuroradiological examinations. In addition to routine acquisitions with FLAIR, T1- and T2-weighted, and contrast-enhanced MR imaging series, the authors obtained sagittal cardiac-gated sequences to visualize cerebrospinal fluid (CSF) pulsations and axial 3D CISS MR sequences to detect focal arachnoid webs. Statistical qualitative and quantitative evaluations of spinal cord/CSF contrast, spinal cord/CSF delineation, motion artifacts, and artifacts induced by pulsatile CSF flow were performed. RESULTS: The 3D CISS MR sequences demonstrated a contrast-to-noise ratio significantly better than any other routine imaging sequence (p < 0.001). Moreover, 3D CISS imaging can detect more subarachnoid webs and cavitations in the syrinx than T2-weighted MR imaging with less flow-void artifact. The limitation of 3D CISS imaging is a susceptibility to motion artifacts that can cause reduced spatial resolution. Lengthy acquisition times for axial segments can be reduced with multiplanar reconstruction of 3D CISS-generated sagittal images. CONCLUSIONS: Constructive interference in steady-state imaging is the MR sequence of choice in the preoperative evaluation of syringomyelia, allowing significantly higher detection rates of focal subarachnoid webs, whereas standard T2-weighted MR imaging shows turbulent CSF flow voids. Constructive interference in steady-state MR imaging enables the neurosurgeon to accurately identify cases requiring decompression for obstructed CSF. Motion artifacts can be eliminated with technical variations.

Clinical and molecular characterisation of a Parkinson family with a novel PINK1 mutation.

Homozygous mutations in the PINK1 gene have been shown to cause early-onset parkinsonism. Here, we describe a novel homozygous mutation (Q126P), identified in two affected German sisters with a clinical phenotype typical for PINK1-associated parkinsonism. We analysed lactate, pyruvate, carnitine and acylcarnitine blood levels, lactate levels under exercise and in the cerebrospinal fluid, activity of respiratory chain complexes I-IV in muscle biopsies and proteasomal activity in immortalized lymphoblasts, but found no evidence for mitochondrial or proteasomal dysfunction. MR spectroscopy revealed raised myoinositol levels in the basal ganglia of both patients, reflecting possible astroglial proliferation.

Management and outcome after internal carotid artery laceration during surgery of the paranasal sinuses.

CONCLUSIONS: The injury to the cavernous portion of the internal carotid artery (ICA) during endonasal sinus surgery is a potentially fatal complication, which can be prevented by systematic analysis of preoperative CT imaging in order to exclude vascular malformations. Immediate management is critical and requires interdisciplinary cooperation between the otolaryngologist and interventional neuroradiologist. OBJECTIVE: The purpose of this article is to present two cases of injury to the cavernous portion of the ICA during routine endonasal sinus surgery for chronic sinusitis and to review the management and outcome of this vascular emergency. PATIENTS AND METHODS: A database of all patients surgically treated for chronic sinusitis between 1994 and 2004 was reviewed retrospectively. Additionally a review of the literature for all published case reports of ICA injury was performed. RESULTS: We report two cases of ICA lacerations that occurred during routine endoscopic sinus surgery. Both patients were successfully treated by employing neuroradiological procedures including balloon and/or coil occlusion of various portions of the cavernous ICA. According to the literature the outcome depends on the presence or absence of vascular anomalies or aneurysm of the ICA with a very poor prognosis in cases of laceration of a pre-existing and unrecognized aneurysm.

Stenting of vertebrobasilar arteries in symptomatic atherosclerotic disease and acute occlusion: case series and review of the literature.

PURPOSE: Two of three patients with vertebrobasilar stroke harbor a stenosis of the vertebral or basilar arteries. The best treatment for secondary prophylaxis in vertebrobasilar occlusive disease has not been defined. In patients with high-grade stenoses, and especially those refractory to medication, stenting offers the chance to restore normal flow and prevent major strokes. METHODS: We provide data regarding outcome and complications on 20 consecutive patients who underwent vertebrobasilar stenting at our institution (9 V0, 2V3, 5 V4, and 4 basilar artery lesions). Furthermore, we provide a comprehensive overview of the literature on >600 cases of vertebrobasilar stenting, including all published cases up to 2005. RESULTS: Primary interventional success was achieved in all cases, with a mean residual stenosis of 3% +/- 4% in V0, 5% +/- 4% in V3/4, and 7% +/- 3% in basilar artery lesions. No peri-interventional neurologic complications and no transient ischemic attack or stroke at follow-up were noted in patients with vertebral ostial lesions, whereas two transient and three permanent clinical deteriorations occurred in patients with V4 or basilar artery lesions, some of which had presented with acute stroke. Patency rate was 100% at the last examination. According to published data on proximal vertebral artery stenting, mortality is 0.3%, the rate of neurologic complications is 5.5%, and the risk of posterior stroke at follow-up is 0.7%. Interventions for distal vertebral or basilar artery disease carry a 3.2% mortality risk, a 17.3% risk for neurologic complications and a 2% risk for stroke at follow-up. CONCLUSIONS: Stenting of the vertebral origin can be performed safely and with a low rate of cerebral ischemic events at follow-up, although restenosis may occur. Larger comparative trials are needed. Treatment decisions in distal vertebrobasilar disease have been made on an individual basis.

"Pusher syndrome" following cortical lesions that spare the thalamus.

Stroke patients with "pusher syndrome" show severe misperception of their own upright body orientation although visual-vestibular processing is almost intact. This dissociation argues for a second graviceptive system in humans for the perception of body orientation. Recent studies revealed that the posterior thalamus is an important part of this system. The present investigation aimed to study the cortical representation of this system beyond the thalamus. We evaluated 45 acute patients with and without contraversive pushing following left-or right-sided cortical lesions sparing the thalamus. In both hemispheres, the simple lesion overlap associated with contraversive pushing typically centered on the insular cortex and parts of the postcentral gyrus. The comparison between pusher patients and controls who were matched with respect to age, lesion size, and the frequency of spatial neglect, aphasia and visual field defects revealed only very small regions that were specific for the pusher patients with cortical damage sparing the thalamus. Obviously, the cortical structures representing our control of upright body orientation are in close anatomical proximity to those areas that induce aphasia in the left hemisphere and spatial neglect in the right hemisphere when lesioned. We conclude that in addition to the subcortical area previously identified in the posterior thalamus, parts of the insula and postcentral gyrus appear to contribute at cortical level to the processing of the afferent signals mediating the graviceptive information about upright body orientation.

Whole-body MR angiography using a novel 32-receiving-channel MR system with surface coil technology: first clinical experience.

PURPOSE: To demonstrate the feasibility of detecting atherosclerotic vascular disease using an innovative magnetic resonance angiography (MRA) protocol in combination with a dedicated whole-body MR scanner with new surface coil technology. MATERIALS AND METHODS: A total of 10 volunteers and eight patients with peripheral arterial occlusive disease (PAOD) were examined at 1.5 T. Conventional digital subtraction angiography (DSA) of the symptomatic region was available as a reference standard in all eight patients. Depending on subjects' size, four to five three-dimensional data sets were acquired using an adapted injection protocol. Images were assessed independently by two readers for vascular pathology. Additionally, signal-to-noise ratios (SNRs) and contrast-to-noise ratios (CNRs) were measured. RESULTS: Whole-body MRA yielded excellent sensitivity and specificity of more than 95% for both readers with high interobserver agreement (k = 0.93). Surface coil signal reception rendered a high SNR (mean 151.28 +/- 54.04) and CNR (mean 120.75 +/- 46.47). Despite lower SNR and CNR of the cranial and cervical vessels, a two-step injection protocol exhibited less venous superposition and therefore proved to be superior compared to single-bolus injection. CONCLUSION: Our approach provides accurate noninvasive high-resolution imaging of systemic atherosclerotic disease, covering the arterial vasculature from intracranial arteries to distal runoff vessels. The recently introduced MR scanner and coil technology is feasible to significantly increase the performance of whole-body MRA.

Proton MRS in Kennedy disease: absolute metabolite and macromolecular concentrations.

PURPOSE: To investigate whether glutamine and glutamate (Glx) were elevated in Kennedy Disease (KD), and whether pathological proteins were spectroscopically visible as altered macromolecular (MM) resonances. MATERIALS AND METHODS: Ten patients with KD and twelve healthy volunteers were investigated using a stimulated echo acquisition mode (STEAM) spectroscopy sequence with metabolite-nulling. RESULTS: The concentrations of Glx remained unchanged in KD. An increased myo-inositol (Ins), and elevated MM at 0.9 ppm were found within the motor area. The N-acetyl-aspartate (NAA)/creatine (Cr) ratio was negatively correlated to the number of cytosine adenosine guanine (CAG) repeats in the motor area. CONCLUSION: The elevated MM at 0.9 ppm may be attributed to a pathologically altered protein in KD. Additionally, the changes of Ins point to a clinically unexpected involvement of the motor cortex. The correlation of NAA/Cr with the number of CAG repeats indicates a link between metabolites and genetic failure.

Intraorbital aneurysm of the ophthalmic artery: a rare cause of apex orbitae compression syndrome.

PURPOSE: The purpose of this study was to report the case of a patient with a saccular, intraorbital aneurysm of the ophthalmic artery and to analyze the correlation between clinical symptoms and aneurysm localization with regard to the literature. METHOD: We correlated the patient's clinical findings with anatomical substrates on magnetic resonance imaging and angiographic studies. RESULTS: A 64-year-old woman presented with a rapidly progressive loss of visual acuity in her right eye, temporo-basal visual field defects, a temporal pallor of the optic disc and third and sixth nerve palsies. This apex orbitae compression syndrome was due to an aneurysm of the proximal intraorbital segment of the ophthalmic artery at a position inferolateral to the optic nerve, inferior to the third and medial to the sixth cranial nerve. CONCLUSION: The symptoms caused by an aneurysm of the ophthalmic artery depend on its localization and spatial relationship to neural structures. While aneurysms of the intracranial and distal intraorbital segments may remain asymptomatic, those arising from the intracanalicular segment become clinically apparent with optic nerve conduction disorders. Aneurysms in the proximal intraorbital segment additionally provoke oculomotor disturbances due to compression of the third and sixth cranial nerves.