[Show abstract][Hide abstract] ABSTRACT: BACKGROUND: O-(2-[F-18]fluoroethyl)-L-tyrosine (18F-FET) PET has become an important diagnostic tool in addition to standard MRI to delineate cerebral gliomas. However, 18F-FET uptake has also been observed in non-tumoral lesions. METHODS AND RESULTS: We report on abnormal non-tumoral 18F-FET uptake in 6 patients with epileptic disorders: Patients A-C with clinically stable anaplastic astrocytoma over years,
Patient D with anaplastic oligodendroglioma with stable residual tumor, Patient E with initial diagnosis of glioblastoma,
Patient F with subacute cerebral ischemia. All patients presented initially with repeated epileptic seizures or status epilepticus
and typical clinical and EEG findings. Standard MRI (T1 + /-contrast, T2/FLAIR) showed cortical and subcortical contrast enhancement
and/or T2/FLAIR signal alterations and 18F-FET PET demonstrated a significantly increased cortical amino acid uptake. 18F-FET uptake and contrast enhancement on MRI resolved completely after cessation of epileptic activity. Patient C suffered
from a prolonged postictal state. In that patient, EEG monitoring demonstrated a left hemispheric deceleration without signs
of epileptic discharges; additionally, 18F-FDG PET and HMPAO SPECT showed cortical glucose hypometabolism and hypoperfusion, not consistent with a status epilepticus.
After 14 weeks, clinical symptoms and the cortical 18F-FET uptake resolved completely. CONCLUSION: Abnormal 18F-FET uptake may occur in patients with epileptic disorders in brain areas not infiltrated by tumor. The reason for this phenomenon
is yet unknown.
[Show abstract][Hide abstract] ABSTRACT: Study design:Case report.Objective:Reveal the evolution of the magnetic resonance imaging (MRI) pattern in a patient with a posterior spinal artery infarction, which belongs to a subgroup of spinal cord ischemia syndromes and presents a rare cause of spinal cord injury. Our report underlines that diagnosis of spinal cord ischemia and thus clinical decision making remains challenging.Setting:University Hospital of Innsbruck and University Hospital of Salzburg, Austria.Methods:Here we present clinical, electrophysiological and imaging data in the acute, subacute and chronic phase of a woman who developed signs and symptoms related to a bilateral posterior spinal cord infarction.Results:At the clinical nadir (24 h after symptom onset), MRI did not exhibit T2 hyperintensities. However, such MRI changes were detected 8 days after symptom onset and persisted until the latest follow-up at 5 months.Conclusions:Repeated MRI constitutes an indispensable diagnostic and follow-up tool for spinal cord ischemia. The imaging data in accordance with the electrophysiological measurements correlated well with the clinical presentation in the subacute und chronic phase. Therefore, further studies might allow using MRI following spinal cord ischemia as a prognostic marker for an individual outcome.Spinal Cord advance online publication, 14 January 2014; doi:10.1038/sc.2013.165.
[Show abstract][Hide abstract] ABSTRACT: Subcortical ischemic vascular disease (SIVD) is characterized by extensive white-matter lesions and lacunar infarcts in deep gray matter. The aim of the study was to investigate patterns of cognitive impairment in patients with SIVD. In a retrospective analysis, the authors compared the cognitive performance of 58 patients meeting MRI-defined criteria for SIVD (26 women; 47.3%) with age- and gender-matched control subjects. SIVD patients showed impairments in measures of verbal fluency, verbal memory, speed of cognitive processing, and divided attention. There were no significant differences in constructional praxis, figurative memory, verbal recognition memory, or semantic processing.
Full-text · Article · Nov 2013 · The Journal of Neuropsychiatry and Clinical Neurosciences
[Show abstract][Hide abstract] ABSTRACT: Vasculitis is a rare but severe disease. It is diagnostically challenging because patients present with nonspecific symptoms. The definitive diagnosis is therefore complicated, because many diagnostic procedures have to be performed. Currently, several systemic types are known that have a secondary affect on the nervous system; an isolated primary central nervous system vasculitis also occurs. In this review, we highlight new developments in medical treatment and provide an overview of the various combination strategies regarding the most significant types of vasculitis.
Full-text · Article · May 2013 · Drug discovery today
[Show abstract][Hide abstract] ABSTRACT: IntroductionBasilar artery occlusion (BAO) causes mortality up to 90%.MethodsA total of 99 patients with BAO received either endovascular (endovascular mechanical recanalization and/or intra-arterial with optional intravenous thrombolysis [IVT] as bridging concept) or conservative medical treatment (IVT and/or medical oral therapy). Outcome parameters were measured in accordance with the thrombolysis in cerebral infarction (TICI), National Institutes of Health Stroke Scale (NIHSS), and modified Rankin Scale (mRS) scores.ResultsIn all, 78% underwent endovascular and 22% conservative medical treatment. The NIHSS at admission was 20 in both the groups. Postprocedurally, 36% (95% confidence interval: 26%-48%) of the endovascular group and 9% (21%-64%) of the conservative group reached TICI 3 (P = .017). In all, 30% of the endovascular group and 9% of the conservative group were documented with TICI 2b (P = .057). At 90 days follow-up, 45% (31%-60%) of the endovascular-treated patientsand no patient (0%-25%) of the conservative-treated group reached mRS ≤2 (P = .012).Conclusion
Endovascular treatment of BAO provides a better chance to survive this severe condition with good clinical outcome.
Full-text · Article · May 2013 · Vascular and Endovascular Surgery
[Show abstract][Hide abstract] ABSTRACT: BACKGROUND AND PURPOSEIn multiple sclerosis (MS) the individual disease courses are very heterogeneous among patients and biomarkers for setting the diagnosis and the estimation of the prognosis for individual patients would be very helpful. For this purpose, we are developing a multidisciplinary method and workflow for the quantitative, spatial, and spatiotemporal analysis and characterization of MS lesion patterns from MRI with geostatistics. METHODS
We worked on a small data set involving three synthetic and three real-world MS lesion patterns, covering a wide range of possible MS lesion configurations. After brain normalization, MS lesions were extracted and the resulting binary 3-dimensional models of MS lesion patterns were subject to geostatistical indicator variography in three orthogonal directions. RESULTSBy applying geostatistical indicator variography, we were able to describe the 3-dimensional spatial structure of MS lesion patterns in a standardized manner. Fitting a model function to the empirical variograms, spatial characteristics of the MS lesion patterns could be expressed and quantified by two parameters. An orthogonal plot of these parameters enabled a well-arranged comparison of the involved MS lesion patterns. CONCLUSIONS
This method in development is a promising candidate to complement standard image-based statistics by incorporating spatial quantification. The work flow is generic and not limited to analyzing MS lesion patterns. It can be completely automated for the screening of radiological archives.
Full-text · Article · Feb 2013 · Journal of neuroimaging: official journal of the American Society of Neuroimaging
[Show abstract][Hide abstract] ABSTRACT: Background
To assess the sensitivity and specificity of [(18)F]-fluoro-ethyl-l-tyrosine ((18)F-FET) PET in brain tumors and various non-neoplastic neurologic diseases.Methods
We retrospectively evaluated (18)F-FET PET scans from 393 patients grouped into 6 disease categories according to histology (n = 299) or distinct MRI findings (n = 94) (low-grade/high-grade glial/nonglial brain tumors, inflammatory lesions, and other lesions). (18)F-FET PET was visually assessed as positive or negative. Maximum lesion-to-brain ratios (LBRs) were calculated and compared with MRI contrast enhancement (CE), which was graded visually on a 3-point scale (no/moderate/intense).ResultsSensitivity and specificity for the detection of brain tumor were 87% and 68%, respectively. Significant differences in LBRs were detected between high-grade brain tumors (LBR, 2.04 ± 0.72) and low-grade brain tumors (LBR, 1.52 ± 0.70; P < .001), as well as among inflammatory (LBR, 1.66 ± 0.33; P = .056) and other brain lesions (LBR, 1.10 ± 0.37; P < .001). Gliomas (n = 236) showed (18)F-FET uptake in 80% of World Health Organization (WHO) grade I, 79% of grade II, 92% of grade III, and 100% of grade IV tumors. Low-grade oligodendrogliomas, WHO grade II, had significantly higher (18)F-FET uptakes than astrocytomas grades II and III (P = .018 and P = .015, respectively). (18)F-FET uptake showed a strong association with CE on MRI (P < .001) and was also positive in 52% of 157 nonglial brain tumors and nonneoplastic brain lesions.Conclusions(18)F-FET PET has a high sensitivity for the detection of high-grade brain tumors. Its specificity, however, is limited by passive tracer influx through a disrupted blood-brain barrier and (18)F-FET uptake in nonneoplastic brain lesions. Gliomas show specific tracer uptake in the absence of CE on MRI, which most likely reflects biologically active tumor.
[Show abstract][Hide abstract] ABSTRACT: Stroke still remains a major healthcare problem. The growing understanding of the mechanism of cell death in ischemia leads to new approaches in stroke treatment. The aim of neuroprotection is to reduce the post-stroke impairment and the overall costs that are accompanied in patients with severe disability. Despite encouraging data from experimental animal models, almost all neuroprotective therapies have, to date, not been established in clinical routine. In this part B of our review on stroke therapies we provide an overview on future candidates in stroke therapy and neuroprotective agents that are under investigation.
Full-text · Article · Mar 2012 · Drug discovery today
[Show abstract][Hide abstract] ABSTRACT: Spinal stab wound injuries are quite rare and only few patients have been reported on the basis of MRI scan.
A 25-year-old man was stabbed at C1/2 and had an incomplete Brown-Sequard syndrome. He underwent surgical exploration because of CSF leakage on the fourth day.
After a follow-up period of 32 months, he was left with a remaining loss of the proprioception of the right foot. We show detailed CT and MR images with the focus on the lesions of the dura and myelon and compared them with intraoperative images. In addition, we contrast our findings with a review of literature published over the last three decades.
MRI gives the most detailed view of soft tissue lesions in SSWs and is in accordance with our intraoperative findings.
Full-text · Article · Feb 2012 · European Spine Journal
[Show abstract][Hide abstract] ABSTRACT: Stroke is the third leading cause of death with an increasing prevalence. In previous years many important achievements and new therapeutic strategies have been established. This article provides an overview on recent developments and is an update to the article of Green et al. that was published in 2004. As this article is a comprehensive review we divided it in two parts. In this Part A of our review, recent developments in acute stroke treatment and in stroke prevention are described. In Part B we will reflect on neuroprotection.
No preview · Article · Nov 2011 · Drug discovery today
[Show abstract][Hide abstract] ABSTRACT: We evaluated hydrogel filaments loaded with barium sulphate and either gadolinium or superparamagnetic iron oxide (SPIO) in an effort to develop an embolic material that is visible with fluoroscopic and magnetic resonance imaging.
Hydrogel filaments were prepared with gadolinium and iron concentrations ranging from 1,500 to 7,500 and 500 to 2,500 ppm, respectively. The filaments were encased in agar and imaged using an MR scanner. Embolisation of eight aneurysms (seven bifurcation, one sidewall) in seven rabbits was performed using hydrogel filaments loaded with gadolinium (n = 4) or SPIO (n = 4). Angiographic evaluations occurred immediately post-treatment and at 13 weeks. Magnetic resonance angiography (MRA) evaluations occurred immediately post-treatment or 13 weeks post-treatment.
Based on the in vitro results, we selected 4,500 and 2,000 ppm for gadolinium and iron loadings, respectively, for the in vivo experiments. Loading the filaments with gadolinium or SPIO did not affect the angiographic results, as embolic masses were readily evident with some distinguishing of individual filaments. In MRA, the hydrogel filaments loaded with SPIO were hypointense, and the hydrogel filaments loaded with Gd were hyperintense. The hyperintensity of the Gd-loaded filaments confounded the ability to distinguish between flow and the embolic devices. The hypointensity of the hydrogel filaments loaded with SPIO provided sufficient contrast between the embolic devices and the blood flow to allow of aneurysm occlusion evaluation using MRA.
Based on these results, we are focusing on loading hydrogel filaments with SPIO in an effort to provide adequate visualisation for use in MR-guided interventions.
[Show abstract][Hide abstract] ABSTRACT: Marginal zone B-cell lymphoma is a rare disease which can be considerably difficult to recognize and diagnose when signs of systemic involvement are absent.
We report the case of a 57-year-old woman with initial olfactory disturbance, followed by psychosis, diabetes insipidus and hypothalamic eating disorder as an uncommon clinical presentation of marginal zone B-cell lymphoma.
Marginal zone B-cell lymphoma should be considered as a potential differential diagnosis in patients with hypothalamic disturbances.
Full-text · Article · May 2011 · Case Reports in Neurology
[Show abstract][Hide abstract] ABSTRACT: We compared experimental rabbit carotid bifurcation aneurysms embolised with platinum coils or hydrogel filaments by using digital subtraction angiography (DSA) and computed tomography angiography (CTA).
Embolisation was performed using platinum coils (n = 2), hydrogel filaments loaded with iodine (n = 3) and hydrogel filaments loaded with barium sulphate (n = 3). In one case, a stent was deployed in the parent vessel to determine the effect of hydrogel filaments on stent visualisation. DSA evaluations occurred immediately post-treatment. CTA evaluations occurred at 0-13 weeks post-treatment. The DSA and CTA images were evaluated for the lack of artefacts and the visibilities of the embolic mass, individual coils and residual flow in the aneurysm sac and neck.
The DSA results were largely concordant among the three groups. The embolic masses were readily evident with some individual coils being distinguished. In the aneurysms embolised with hydrogel filaments, visualisation of the individual coils, residual flow and stent with minor or no artefacts was possible using CTA. On the other hand, the beam hardening artefacts precluded analysis of aneurysms embolised with platinum coils.
CTA-compatible embolic devices could have wide applications in diverse locations throughout the vasculature, particularly in combination with stents or stent grafts.
No preview · Article · Sep 2009 · European Radiology
[Show abstract][Hide abstract] ABSTRACT: Clinical findings and neuroimaging techniques (cerebral computed tomography - CCT, cerebral magnetic resonance imaging - MRI) were analysed in 100 patients with intracerebral bleeding. 53 patients had haemorrhagic infarctions, 47 patients had intracerebral haematoma. There were no significant differences in the clinical symptoms. Differences were shown in respect of risk factors (significantly more patients with adipositas and alcohol abuse were found in the group with intracerebral haematoma.) Cerebral CT showed in the acute stage a low sensitivity and specificity of 27% in the group of haemorrhagic infarction in contrast to the high sensitivity and specificity of 81% in the group with intracerebral haematoma. There were no relevant differences in CCT results in a two week follow-up (specificity 35% vs 81%). The findings in MRI, apart from differentiation between both groups, conveyed only little information regarding the aetiology of the bleeding with a slight advantage in the group of patients with intracerebral haematoma (17%).