Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 53
Filter
1.
AJNR Am J Neuroradiol ; 43(11): 1615-1620, 2022 11.
Article in English | MEDLINE | ID: mdl-36229166

ABSTRACT

BACKGROUND AND PURPOSE: Flow diversion has gradually become a standard treatment for intracranial aneurysms of the anterior circulation. Recently, the off-label use of the flow diverters to treat posterior circulation aneurysms has also increased despite initial concerns of rupture and the suboptimal results. This study aimed to explore the change in complication rates and treatment outcomes across time for posterior circulation aneurysms treated using flow diversion and to further evaluate the mechanisms and variables that could potentially explain the change and outcomes. MATERIALS AND METHODS: A retrospective review using a standardized data set at multiple international academic institutions was performed to identify patients with ruptured and unruptured posterior circulation aneurysms treated with flow diversion during a decade spanning January 2011 to January 2020. This period was then categorized into 4 intervals. RESULTS: A total of 378 procedures were performed during the study period. Across time, there was an increasing tendency to treat more vertebral artery and fewer large vertebrobasilar aneurysms (P = .05). Moreover, interventionalists have been increasingly using fewer overlapping flow diverters per aneurysm (P = .07). There was a trend toward a decrease in the rate of thromboembolic complications from 15.8% in 2011-13 to 8.9% in 2018-19 (P = .34). CONCLUSIONS: This multicenter experience revealed a trend toward treating fewer basilar aneurysms, smaller aneurysms, and increased usage of a single flow diverter, leading to a decrease in the rate of thromboembolic and hemorrhagic complications.


Subject(s)
Embolization, Therapeutic , Endovascular Procedures , Intracranial Aneurysm , Humans , Endovascular Procedures/methods , Learning Curve , Intracranial Aneurysm/diagnostic imaging , Intracranial Aneurysm/surgery , Treatment Outcome , Cohort Studies , Retrospective Studies , Embolization, Therapeutic/methods , Stents
2.
Ophthalmologe ; 118(9): 919-925, 2021 Sep.
Article in German | MEDLINE | ID: mdl-33459810

ABSTRACT

BACKGROUND: Symptoms and clinical findings in patients with carotid-cavernous fistulas are specific. Nevertheless, they can be very mildly expressed. This study aims to point out the potential diagnostic value of ultrasound of the orbit. METHODS: A total of 25 patients with a reliable angiographic diagnosis of a fistula were reviewed retrospectively. We analyzed the symptoms, clinical findings and demonstrability in ultrasound of the orbit. RESULTS: The most common clinical findings were nerve palsy, dilation of episcleral vessels and exophthalmos. If an ultrasound had been part of the examination a dilation of the superior ophthalmic vein could be demonstrated in all cases. CONCLUSION: The expeditious ultrasound investigation provides valuable information for the diagnosis of red eyes which are resistant to treatment. The examiner has to consider a fistula and perform an ultrasound especially when diplopia has newly occurred. Finally, the expedient neuroimaging can be arranged.


Subject(s)
Carotid-Cavernous Sinus Fistula , Cavernous Sinus , Exophthalmos , Carotid-Cavernous Sinus Fistula/diagnostic imaging , Cavernous Sinus/diagnostic imaging , Humans , Retrospective Studies , Ultrasonography
3.
AJNR Am J Neuroradiol ; 41(4): 658-662, 2020 04.
Article in English | MEDLINE | ID: mdl-32115421

ABSTRACT

BACKGROUND AND PURPOSE: Flow diversion for the posterior circulation remains a promising treatment option for selected posterior circulation aneurysms. The Flow-Redirection Intraluminal Device (FRED) system has not been previously assessed in a large cohort of patients with posterior circulation aneurysms. The purpose of the present study was to assess safety and efficacy of FRED in this location. MATERIALS AND METHODS: Consecutive patients with posterior circulation aneurysms treated at 8 centers participating in the European FRED study (EuFRED) between April 2012 and January 2019 were retrospectively reviewed. Complication and radiographic and functional outcomes were evaluated. RESULTS: Eighty-four patients (median age, 54 years) with 84 posterior circulation aneurysms were treated with the FRED. A total of 25 aneurysms (29.8%) had previously ruptured, even though most aneurysms were diagnosed incidentally (45.2%). The intradural vertebral artery was the most common location (50%), and saccular, the most common morphology (40.5%). The median size was 7 mm. There were 8 (9.5%) symptomatic thromboembolic and no hemorrhagic complications. Thromboembolic complications occurred mostly (90.9%) in nonsaccular aneurysms. On last follow-up at a median of 24 months, 78.2% of aneurysms were completely occluded. Functional outcome at a median of 27 months was favorable in 94% of patients. All mortalities occurred in patients with acute subarachnoid hemorrhage and its sequelae. CONCLUSIONS: The largest cohort of posterior circulation aneurysms treated with the FRED to date demonstrated favorable safety and efficacy profiles of the device for this indication. Treatment in the setting of acute subarachnoid hemorrhage was strongly related to mortality, regardless of whether procedural complications occurred.


Subject(s)
Embolization, Therapeutic/instrumentation , Endovascular Procedures/instrumentation , Intracranial Aneurysm/therapy , Stents/adverse effects , Adult , Aged , Cohort Studies , Embolization, Therapeutic/adverse effects , Endovascular Procedures/adverse effects , Female , Humans , Male , Middle Aged , Postoperative Complications/epidemiology , Postoperative Complications/etiology , Registries , Retrospective Studies , Treatment Outcome
4.
AJNR Am J Neuroradiol ; 39(5): 841-847, 2018 05.
Article in English | MEDLINE | ID: mdl-29545252

ABSTRACT

BACKGROUND AND PURPOSE: Endoluminal reconstruction with flow-diverting stents represents a widely accepted technique for the treatment of complex intracranial aneurysms. This European registry study analyzed the initial experience of 15 neurovascular centers with the Flow-Redirection Intraluminal Device (FRED) system. MATERIALS AND METHODS: Consecutive patients with intracranial aneurysms treated with the FRED between February 2012 and March 2015 were retrospectively reviewed. Complications and adverse events, transient and permanent morbidity, mortality, and occlusion rates were evaluated. RESULTS: During the defined study period, 579 aneurysms in 531 patients (median age, 54 years; range, 13-86 years) were treated with the FRED. Seven percent of patients were treated in the acute phase (≤3 days) of aneurysm rupture. The median aneurysm size was 7.6 mm (range, 1-36.6 mm), and the median neck size 4.5 mm (range, 1-30 mm). Angiographic follow-up of >3 months was available for 516 (89.1%) aneurysms. There was progressive occlusion witnessed with time, with complete occlusion in 18 (20%) aneurysms followed for up to 90 ± 14 days, 141 (82.5%) for 180 ± 20 days, 116 (91.3%) for 1 year ± 24 days, and 122 (95.3%) aneurysms followed for >1 year. Transient and permanent morbidity occurred in 3.2% and 0.8% of procedures, respectively. The overall mortality rate was 1.5%. CONCLUSIONS: This retrospective study in real-world patients demonstrated the safety and efficacy of the FRED for the treatment of intracranial aneurysms. In most cases, treatment with a single FRED resulted in complete angiographic occlusion at 1 year.


Subject(s)
Endovascular Procedures/instrumentation , Intracranial Aneurysm/surgery , Stents , Adolescent , Adult , Aged , Aged, 80 and over , Cerebral Angiography , Endovascular Procedures/methods , Female , Humans , Male , Middle Aged , Retrospective Studies , Treatment Outcome , Young Adult
5.
Clin Neuroradiol ; 28(3): 367-376, 2018 Sep.
Article in English | MEDLINE | ID: mdl-28265679

ABSTRACT

PURPOSE: To evaluate the performance of an innovative image processing approach for detection of T2-weighted hyperintense multiple sclerosis (MS) lesions. METHODS: In this study 20 consecutive patients with inflammatory demyelinating lesions were retrospectively evaluated of whom 10 patients featured progressive disease and 10 a stable lesion load. 3 mm transversal FLAIRfusion imaging was processed and archived. Image processing was performed through landmark-based 3D co-registration of the previous and current isotropic FLAIR examination followed by inversion of image contrast. Thereby, the hyperintense signals of the unchanged MS plaques extinguish each other, while newly developed lesions appear bright on FLAIRfusion. Diagnostic performance was evaluated by 4 experienced readers. Consensus reading supplied the reference standard. Sensitivity, specificity, NPV (negative predictive value), PPV (positive predictive value), interreader agreement and reading time were the outcome measures analyzed. RESULTS: Combined sensitivity was 100% at a specificity of 88.2%, with PPV ranging from 83.3% to 90.1% and NPV at 100%. Reading time was nearly 5­fold faster than conventional side by side comparison (35.6 s vs. 163.7 s, p < 0.001). Cohen's kappa was excellent (>0.75; p < 0.001) and Cronbach's alpha was 0.994. CONCLUSION: FLAIRfusion provides reliable detection of newly developed MS lesions along with strong interreader agreement across all levels of expertise in 35 s of reading time.


Subject(s)
Brain/diagnostic imaging , Image Processing, Computer-Assisted , Magnetic Resonance Imaging , Multiple Sclerosis/diagnostic imaging , Adult , Female , Germany , Humans , Male , Middle Aged , Reading , Retrospective Studies , Sensitivity and Specificity , Young Adult
6.
Ophthalmologe ; 114(10): 906-921, 2017 Oct.
Article in German | MEDLINE | ID: mdl-28251307

ABSTRACT

In Germany more than one million inhabitants suffer from glaucoma, more than 100,000 are threatened with blindness because glaucoma is often diagnosed too late or not at all. Diagnosis and monitoring is usually carried out "only" by examination of the retina and not the whole visual pathway. However, the eye is just "the tip of the iceberg" of the actual visual pathway, which extends through the brain to the visual cortex. The interdisciplinary holistic assessment of the whole visual pathway in glaucoma is of crucial importance because glaucoma is a complex neurodegenerative disease. Subtypes, such as normal tension glaucoma (NTG), seem to originate from primary damage to the intracranial visual pathway with secondary retrograde retinal degeneration. Recent studies including glaucoma patients and healthy controls could show that diffusion tensor imaging with calculation of diffusion coefficients, i.e. fractional anisotropy (FA), mean and radial diffusivity (MD and RD) as markers of axonal integrity, provide the potential to assess the intracranial visual pathway with a high correlation to established ophthalmological examinations. In particular, calculation of FA maps of the visual pathway and accompanying voxel-based approaches, can be integrated into clinical routine. Thus, detection of glaucoma-related intracranial alterations, even in early stages of the disease, as well as differentiation of different glaucoma subtypes, is made possible. Furthermore, the diagnosis of normal tension glaucoma seems to be possible much earlier with these new imaging techniques compared to established ophthalmological work-up. Moreover, holistic imaging provides new insights into the pathophysiology of this form of glaucoma. This review article gives an overview of these novel magnetic resonance imaging techniques for assessment of the visual pathway in glaucomatous optic nerve atrophy and reveals the potential of an interdisciplinary approach.


Subject(s)
Diffusion Tensor Imaging , Glaucoma/diagnostic imaging , Optic Atrophy/diagnostic imaging , Visual Pathways/diagnostic imaging , Humans , Image Enhancement , Image Interpretation, Computer-Assisted , Interdisciplinary Communication , Intersectoral Collaboration , Optic Neuropathy, Ischemic/diagnostic imaging , Risk Factors
7.
AJNR Am J Neuroradiol ; 38(3): 596-602, 2017 Mar.
Article in English | MEDLINE | ID: mdl-28104636

ABSTRACT

BACKGROUND AND PURPOSE: Endovascular flow diverters are increasingly used for the treatment of cerebral aneurysms. We assessed the safety and efficacy of the Flow-Redirection Endoluminal Device (FRED) in a consecutive series of 50 patients. MATERIALS AND METHODS: Inclusion criteria were wide-neck, blister-like, or fusiform/dissecting aneurysms independent of size, treated with the FRED between February 2014 and May 2015. Assessment criteria were aneurysm occlusion, manifest ischemic stroke, bleeding, or death. The occlusion rate was assessed at 3 months with flat panel CT and at 6 months with DSA by using the Raymond classification and the O'Kelly-Marotta grading scale. RESULTS: Fifty patients with 52 aneurysms were treated with 54 FREDs; 20 patients were treated with the FRED and coils. Aneurysm size ranged from 2.0 to 18.5 mm. Deployment of the FRED was successful in all cases. There were no device-associated complications. One patient developed mild stroke symptoms that fully receded within days. There have been no late-term complications so far and no treatment-related mortality. Initial follow-up at 3 months showed complete occlusion in 72.3% of the overall study group, Six-month follow-up showed total and remnant-neck occlusion in 87.2% of patients, distributed over 81.5% of the FRED-only cases and 95.0% of the cases with combined treatment. CONCLUSIONS: The FRED flow diverter is a safe device for the treatment of cerebral aneurysms of various types. Our data reveal high occlusion rates at 3 and 6 months, comparable with those in other flow diverters. Long-term occlusion rates are expected.


Subject(s)
Blood Vessel Prosthesis Implantation/methods , Blood Vessel Prosthesis , Intracranial Aneurysm/surgery , Adult , Aged , Blood Vessel Prosthesis/adverse effects , Blood Vessel Prosthesis Implantation/adverse effects , Blood Vessel Prosthesis Implantation/instrumentation , Brain Ischemia/diagnostic imaging , Brain Ischemia/surgery , Cerebral Angiography , Endovascular Procedures/instrumentation , Female , Follow-Up Studies , Humans , Intracranial Aneurysm/diagnostic imaging , Magnetic Resonance Angiography , Male , Middle Aged , Patient Safety , Stroke/diagnostic imaging , Stroke/surgery , Treatment Outcome
8.
Oncogene ; 35(48): 6246-6261, 2016 12 01.
Article in English | MEDLINE | ID: mdl-27157615

ABSTRACT

Microglial cells in the brain tumor microenvironment are associated with enhanced glioma malignancy. They persist in an immunosuppressive M2 state at the peritumoral site and promote the growth of gliomas. Here, we investigated the underlying factors contributing to the abolished immune surveillance. We show that brain tumors escape pro-inflammatory M1 conversion of microglia via CD74 activation through the secretion of the cytokine macrophage migration inhibitory factor (MIF), which results in a M2 shift of microglial cells. Interruption of this glioma-microglial interaction through an antibody-neutralizing approach or small interfering RNA (siRNA)-mediated inhibition prolongs survival time in glioma-implanted mice by reinstating the microglial pro-inflammatory M1 function. We show that MIF-CD74 signaling inhibits interferon (IFN)-γ secretion in microglia through phosphorylation of microglial ERK1/2 (extracellular signal-regulated protein kinases 1 and 2). The inhibition of MIF signaling or its receptor CD74 promotes IFN-γ release and amplifies tumor death either through pharmacological inhibition or through siRNA-mediated knockdown. The reinstated IFN-γ secretion leads both to direct inhibition of glioma growth as well as inducing a M2 to M1 shift in glioma-associated microglia. Our data reveal that interference with the MIF signaling pathway represents a viable therapeutic option for the restoration of IFN-γ-driven immune surveillance.


Subject(s)
Antigens, Differentiation, B-Lymphocyte/metabolism , Cell Transformation, Neoplastic/metabolism , Glioma/metabolism , Histocompatibility Antigens Class II/metabolism , Macrophage Migration-Inhibitory Factors/metabolism , Microglia/metabolism , Signal Transduction , Animals , Autocrine Communication , Cell Line, Tumor , Cell Transformation, Neoplastic/genetics , Disease Models, Animal , Disease Progression , Gene Knockdown Techniques , Glioma/diagnostic imaging , Glioma/genetics , Glioma/pathology , Heterografts , Humans , Interferon-gamma/metabolism , Mice , Microglia/immunology , Models, Biological , Phagocytosis , Rats
9.
Clin Neuroradiol ; 26(3): 309-15, 2016 Sep.
Article in English | MEDLINE | ID: mdl-25410583

ABSTRACT

PURPOSE: It has been reported that the extent of intravascular thrombi and the quality of collateral filling in computed tomography (CT) angiography are predictive for the clinical outcome in patients with acute stroke. We hypothesized that multi-phase four-dimensional CTA (4D-CTA) allows better assessment of clot burden and collateral flow compared with arterial single-phase CTA (CTA). METHODS: In 49 patients (33 female; age: 77 ± 12 years) with acute anterior circulation stroke, CTA and 4D-CTA reconstructed from dynamic perfusion CT data were analyzed for absolute thrombus length (TL), clot burden score (CBS), and collateral score (CS). The length of the filling defect was also defined on thin-slice nonenhanced CT as corresponding hyperdense middle cerebral artery sign (HMCAS) when present. RESULTS: There was good correlation (r = 0.62, p < 0.01) between the length of HMCAS (1.29 ± 0.62 cm) and TL in 4D-CTA (1.22 ± 0.51 cm). 4D-CTA and CTA significantly varied (p < 0.01) in TL (1.42 ± 0.73 cm (CTA) versus 1.11 ± 0.62 cm (4D-CTA)), CBS (median: 5, interquartile range: 4-7 (CTA) versus median: 6, interquartile range: 5-8 (4D-CTA); p < 0.001), and CS (median: 2, interquartile range: 1-2 (CTA) versus median: 3, interquartile range: 2-3 (4D-CTA); p < 0.001). Accordingly, CTA significantly overrated clot burden and underestimated collateral flow. CONCLUSIONS: 4D-CTA more closely defines clot burden and collateral supply in anterior circulation stroke than CTA, implicating an additional diagnostic benefit.


Subject(s)
Brain Infarction/diagnostic imaging , Cerebral Angiography/methods , Computed Tomography Angiography/methods , Four-Dimensional Computed Tomography/methods , Intracranial Thrombosis/diagnostic imaging , Radiographic Image Enhancement/methods , Aged , Algorithms , Brain Infarction/complications , Diagnosis, Differential , Female , Humans , Intracranial Thrombosis/etiology , Male , Reproducibility of Results , Sensitivity and Specificity
10.
AJNR Am J Neuroradiol ; 36(10): 1964-70, 2015 Oct.
Article in English | MEDLINE | ID: mdl-26066625

ABSTRACT

BACKGROUND AND PURPOSE: Perfusion and angiographic imaging using intravenous contrast application to evaluate stroke patients is now technically feasible by flat detector CT performed by the angiographic system. The aim of this pilot study was to show the feasibility and qualitative comparability of a novel flat detector CT dynamic perfusion and angiographic imaging protocol in comparison with a multimodal stroke MR imaging protocol. MATERIALS AND METHODS: In 12 patients with acute stroke, MR imaging and the novel flat detector CT protocol were performed before endovascular treatment. Perfusion parameter maps (MTT, TTP, CBV, CBF) and MIP/volume-rendering technique images obtained by using both modalities (MR imaging and flat detector CT) were compared. RESULTS: Comparison of MIP/volume-rendering technique images demonstrated equivalent visibility of the occlusion site. Qualitative comparison of perfusion parameter maps by using ASPECTS revealed high Pearson correlation coefficients for parameters CBF, MTT, and TTP (0.95-0.98), while for CBV, the coefficient was lower (0.49). CONCLUSIONS: We have shown the feasibility of a novel dynamic flat detector CT perfusion and angiographic protocol for the diagnosis and triage of patients with acute ischemic stroke. In a qualitative comparison, the parameter maps and MIP/volume-rendering technique images compared well with MR imaging. In our opinion, this flat detector CT application may substitute for multisection CT imaging in selected patients with acute stroke so that in the future, patients with acute stroke may be directly referred to the angiography suite, thereby avoiding transportation and saving time.


Subject(s)
Cerebral Angiography/instrumentation , Cerebral Angiography/methods , Infarction, Middle Cerebral Artery/diagnostic imaging , Perfusion Imaging/instrumentation , Perfusion Imaging/methods , Tomography, X-Ray Computed/instrumentation , Tomography, X-Ray Computed/methods , Adult , Aged , Aged, 80 and over , Feasibility Studies , Female , Humans , Image Processing, Computer-Assisted/methods , Magnetic Resonance Angiography/instrumentation , Magnetic Resonance Angiography/methods , Male , Middle Aged , Pilot Projects , Sensitivity and Specificity
11.
Clin Neuroradiol ; 25 Suppl 2: 291-7, 2015 Oct.
Article in English | MEDLINE | ID: mdl-26091842

ABSTRACT

Originally aimed at improving standard radiography by providing higher absorption efficiency and a wider dynamic range, flat-panel detector technology has meanwhile got widely accepted in the neuroradiological community. Especially flat-panel detector computed tomography (FD-CT) using rotational C-arm mounted flat-panel detector technology is capable of volumetric imaging with a high spatial resolution. By providing CT-like images of the brain within the angio suite, FD-CT is able to rapidly visualize hemorrhage and may thus improve complication management without the need of patient transfer. As "Angiographic CT" FD-CT may be helpful during many diagnostic and neurointerventional procedures and for noninvasive monitoring and follow-up. In addition, spinal interventions and high-resolution imaging of the temporal bone might also benefit from FD-CT. Finally, using novel dynamic perfusion and angiographic protocols, FD-CT may provide functional information on brain perfusion and vasculature with the potential to replace standard imaging in selected acute stroke patients.


Subject(s)
Angiography/methods , Neuroradiography/methods , Radiographic Image Enhancement/instrumentation , Radiographic Image Enhancement/methods , Tomography, X-Ray Computed/methods , Angiography/instrumentation , Humans , Neuroradiography/instrumentation , Stroke/diagnostic imaging , Tomography, X-Ray Computed/instrumentation
13.
Clin Neuroradiol ; 24(1): 43-9, 2014 Mar.
Article in English | MEDLINE | ID: mdl-23712863

ABSTRACT

INTRODUCTION: Improvements in the imaging capabilities of angiographic C-arm computed tomography (CT) using flat detector angiographic (FD-CT) systems now provide a means for the in vivo visualization of devices used for the treatment of intracranial aneurysms. One such device, the WEB embolization device, is made of a braided mesh of nitinol wires, the size of which are near to the limits of visualization using conventional x-ray fluoroscopy. Our hypothesis was that the imaging of these implants C-arm CT would provide useful information regarding their positioning and deployment. METHODS: In five New Zealand white rabbits elastase induced aneurysms were created and subsequently treated using a WEB. Imaging was performed using digital subtraction angiography (DSA), X-ray imaging and two different Angiographic C-arm CT protocols. The images were evaluated by two neuroradiologists using an evaluation scale. RESULTS: The mesh of the WEB was barely visible on the DSA or x-ray fluoroscopy images. Volume rendering technique (VRT) reconstruction and multiplanar reconstruction (MPR) of images done using the C-arm CT protocols clearly delineated the shape and structure of the device. Contrast-enhanced MPR and VRT reconstructions allowed assessment of the status of blood flow in the aneurysms. Beam hardening artifacts caused by platinum markers on the WEB were present. CONCLUSION: In vivo C-arm CT imaging of the WEB is feasible and allows precise determination of the position and deployment status of the device. On contrast-enhanced images the occlusion status of aneurysms and the positioning of the WEB in relationship to the parent artery can be evaluated. C-arm-CT may serve as a minimal-invasive follow-up imaging modality.


Subject(s)
Cerebral Angiography/methods , Intracranial Aneurysm/diagnostic imaging , Intracranial Aneurysm/therapy , Mechanical Thrombolysis/instrumentation , Radiography, Interventional/methods , Surgical Mesh , Tomography, X-Ray Computed/methods , Animals , Equipment Failure Analysis , Intracranial Aneurysm/chemically induced , Mechanical Thrombolysis/methods , Pancreatic Elastase , Prosthesis Design , Rabbits , Treatment Outcome
14.
Clin Neuroradiol ; 24(4): 337-45, 2014 Dec.
Article in English | MEDLINE | ID: mdl-24346229

ABSTRACT

PURPOSE: To define K(trans) and fractional anisotropy (FA) thresholds in correlation to histology for improved magnetic resonance imaging (MRI) tumor assessment in an animal model of brain glioma. METHODS: Twelve rats underwent 4.7 T MRI at day 10 after tumor implantation. Anatomical scans (T2, T1 at 8 min after double dose contrast application) as well as dynamic contrast-enhanced (DCE) imaging with calculation of K(trans) and diffusion tensor imaging (DTI) with calculation of FA were performed. T2- and T1-derived tumor volumes were calculated and thresholds for K(trans) and FA were defined for best MRI tumor assessment correlated to histology. RESULTS: Tumor volumes were 159 ± 14 mm(3) (histology), 126 ± 26 mm(3) (T1 with contrast, r=0.76), and 153 ± 12 mm(3) (T2, r=0.84), respectively. K(trans)- and FA-derived tumor volumes were 160 ± 16 mm(3) (for K(trans ≥ 0.04 min(-1), r=0.94), and 159 ± 14 mm(3) (for FA £0.14, r=0.96), respectively. CONCLUSIONS: DCE-MRI and DTI with calculation of K(trans) and FA maps allow very precise brain glioma assessment comparable to histology if established thresholds for the given tumor model are used.


Subject(s)
Algorithms , Brain Neoplasms/pathology , Diffusion Tensor Imaging/methods , Glioma/pathology , Image Enhancement/methods , Image Interpretation, Computer-Assisted/methods , Tumor Burden , Animals , Cell Line, Tumor , Feasibility Studies , Rats , Rats, Inbred F344 , Reproducibility of Results , Sensitivity and Specificity
15.
Clin Neuroradiol ; 23(4): 285-92, 2013 Dec.
Article in English | MEDLINE | ID: mdl-23525670

ABSTRACT

BACKGROUND: Temporary balloon test occlusion (BTO) might be performed prior to procedures in which occlusion of the internal carotid artery (ICA) might be necessary. We tested the hypothesis that parametric color coding (PCC) of angiographic series (digital subtraction angiography (DSA)) along with the assessment of cerebral blood volume (CBV) in the angiography suite would simplify and enhance the identification of candidates who are most likely to tolerate occlusion. MATERIALS AND METHODS: Fifteen patients underwent angiographic series (DSA) and perfusion imaging before and during BTO. Pre- and postocclusion DSA acquisitions were evaluated for venous delay by conventional methods ("eye balling") and by PCC measurements. Comparison of CBV values between the left and right hemisphere in 6 defined regions was performed. RESULTS: Values of venous delay by eye balling and PCC showed a high correlation (r = 0.87, p < 0.01). Bland-Altman plot indicated slightly lower values (-0.05 s) by the PCC method. One of the 15 patients developed an asymmetrical CBV map with an increase in CBV of more than one standard deviation in 3 of the 6 regions of interest (ROIs). Acquisition of angiographic series and perfusion imaging did not prolong the test occlusion time. CONCLUSION: PCC and CBV mapping are feasible during BTO. The use of PCC seems to simplify the ability to measure changes in venous filling delay. Perfusion imaging may show an increase in CBV in patients reaching the limits of cerebral autoregulation. These patients may be at risk for delayed infarction, even though they seem to tolerate temporary occlusion, and could be unsuitable candidates for permanent ICA occlusion.


Subject(s)
Angiography, Digital Subtraction/methods , Balloon Occlusion/methods , Carotid Artery, Internal/diagnostic imaging , Carotid Stenosis/diagnostic imaging , Carotid Stenosis/therapy , Radiographic Image Interpretation, Computer-Assisted/methods , Radiography, Interventional/methods , Cerebral Angiography/methods , Color , Female , Humans , Male , Middle Aged , Pilot Projects , Reproducibility of Results , Sensitivity and Specificity
16.
Klin Monbl Augenheilkd ; 229(2): 143-8, 2012 Feb.
Article in German | MEDLINE | ID: mdl-22334412

ABSTRACT

BACKGROUND: In primary open angle glaucoma (POAG) and its non-barotraumatic subgroup, normal tension glaucoma (NTG), the pathophysiological differences are not clear. A participation of the 4th neuron of the visual pathway (optic radiation) appears possible on the basis of related experimental studies. The goal of the present study was the evaluation of the optic radiation by diffusion tensor imaging (DTI), which is based on the magnetic resonance imaging. The diffusion and anisotropy parameters of the optic radiation as a marker of axonal integrity and demyelination/damage of glial cells, respectively, were used to investigate the relation between the morphology of the papilla (BLDF, linear discriminant function of Burk) and the contrast sensitivity (FDT, frequency doubling test). PATIENTS AND METHODS: In this prospective observational study 13 POAG patients, 13 NTG patients, and 7 control patients of the same mean age were included. For segmentation of the optic radiation a semi-automated algorithm was applied and the diffusion and anisotropy parameters were calculated. The importance of the covariates age, BLDF, and FDT for the DTI parameters was determined using partial correlation analysis. RESULTS: Analysis of the covariates partially showed a clear autocorrelation. The correlations between the DTI parameters and BLDF were significant in all groups after correction of the measurement values for the covariates. FDT correlated with DTI parameters in controls and POAG. The NTG group did not show this correlation due to a strong spreading of the FDT values. CONCLUSION: After statistical elimination of the autocorrelation of the covariates age, BLDF, and FDT the morphology of the papilla correlated with the axonal integrity and demyelination/glia cell impairment of the optic radiation in controls and glaucoma. In NTG the impaired contrast sensitivity is highly variable and is not associated with the condition of the 3rd or 4th neuron, respectively, as compared to POAG. The autocorrelation between individual covariates represents an important element for the judgement of the visual pathway.


Subject(s)
Contrast Sensitivity/physiology , Demyelinating Diseases/diagnosis , Diffusion Magnetic Resonance Imaging , Glaucoma, Open-Angle/diagnosis , Image Interpretation, Computer-Assisted , Low Tension Glaucoma/diagnosis , Nerve Fibers/pathology , Optic Disk/pathology , Optic Nerve/pathology , Retina/pathology , Visual Pathways/pathology , Adult , Aged , Algorithms , Axons/pathology , Axons/physiology , Demyelinating Diseases/pathology , Demyelinating Diseases/physiopathology , Female , Glaucoma, Open-Angle/pathology , Glaucoma, Open-Angle/physiopathology , Humans , Low Tension Glaucoma/pathology , Low Tension Glaucoma/physiopathology , Male , Middle Aged , Neurons/pathology , Neurons/physiology , Optic Disk/physiopathology , Optic Nerve/physiopathology , Prospective Studies , Sensitivity and Specificity , Statistics as Topic , Visual Pathways/physiopathology
17.
AJNR Am J Neuroradiol ; 33(4): 618-25, 2012 Apr.
Article in English | MEDLINE | ID: mdl-22207301

ABSTRACT

BACKGROUND AND PURPOSE: A new FPCT application offers the possibility of perfusion (FPCT CBV) and parenchymal (FPCT) imaging within the angiography suite. We tested the hypothesis that findings in FPCT CBV and FPCT would correlate with those obtained using MSCT and PCT. MATERIALS AND METHODS: In 16 patients with acute MCA occlusion, FPCT CBV was performed immediately posttreatment. The volume of tissue having abnormal CBV values was determined by FPCT CBV and PCT images. Stroke volume on follow-up MSCT was determined, CBV values in the effected parenchyma were measured, and FPCT images were reviewed. RESULTS: In 6 cases, we found a FPCT CBV value identical or higher (hyperemia) in comparison with the contralateral side. In 10 cases, we found CBV lesions with values lower (oligemia) than the contralateral brain tissue. We found a high correlation of CBV lesion volume on FPCT CBV images to stroke volume on follow-up MSCT (r = 0.9, P < .05) in the oligemia group. Absolute FPCT CBV and PCT CBV values were comparable and showed good correlation (r = 0.9, P < .05). In 8 patients, contrast medium extravasation was visible. CONCLUSIONS: The new FPCT application allows assessment of CBV in acute stroke patients. Our initial results indicate that these measurements may predict final infarct volume. The ability to assess this key parameter of cerebral perfusion within the angiographic suite may improve the management of these patients.


Subject(s)
Blood Volume Determination/instrumentation , Cerebral Angiography/instrumentation , Cerebrovascular Circulation , Intracranial Aneurysm/diagnostic imaging , Intracranial Aneurysm/physiopathology , Tomography, X-Ray Computed/instrumentation , Aged , Blood Flow Velocity , Blood Volume Determination/methods , Equipment Design , Equipment Failure Analysis , Feasibility Studies , Female , Humans , Intracranial Aneurysm/surgery , Male , Pilot Projects , Tomography, X-Ray Computed/methods , Treatment Outcome
18.
Dtsch Med Wochenschr ; 136(46): 2355-8, 2011 Nov.
Article in German | MEDLINE | ID: mdl-22068445

ABSTRACT

HISTORY AND ADMISSION FINDINGS: A 54-year-old man reported having had nonspecific attacks of dizziness. His BMI was 27.7. Since 11 years he had been treated for arterial hypertension and had received oral medication for type 2 diabetes for one year. The latest blood pressure value was 134/109 mm Hg during treatment with a combination of atenolol, chlortalidone und hydralazine-HCl; furthermore hr received simvastatin, metformin, glimepirid und ramipril. A standardized telemedical imaging of the retina ("talkingeyes (®) ") was undertaken, revealing focal and generalized arteriolar narrowing of the retinal vessels and a retinal microinfarction (cotton wool spot) in the right eye. The arterial/venous ratio was decreased to 0.74 in the right and 0.77 in the left eye. INVESTIGATIONS: Optical coherence tomographie (OCT) revealed an ischemic microinfarction of the retina with marked axonal swelling. The digital subtraction angiography of the cerebral vessels revealed a 40 % stenosis of the right internal carotid artery and a proximal, highgrade stenosis of the basilary artery. TREATMENT AND COURSE: Angioplasty with stent insertion of the basilary artery was performed. Long-term observation showed no restenosis and a reduction in the size of the the retinal microinfarct. CONCLUSION: Retinal microinfarctions denote localized retinal areas of hypoxia and underperfusion. They may act as markers of a generalized micro- and macroangiopathy. Patients with severe retinal microangiopathic changes should be examined thoroughly to detect early macroangiopathic changes. These can be treated by interventional procedures thus avoiding irreversible end-organ damages.


Subject(s)
Cerebrovascular Disorders/complications , Cerebrovascular Disorders/diagnosis , Retinal Diseases/complications , Retinal Diseases/diagnosis , Retinal Vessels/pathology , Angioplasty , Carotid Stenosis/complications , Carotid Stenosis/diagnosis , Carotid Stenosis/pathology , Carotid Stenosis/surgery , Cerebrovascular Disorders/pathology , Cerebrovascular Disorders/surgery , Humans , Male , Middle Aged , Retinal Diseases/pathology , Tomography, Optical Coherence , Treatment Outcome
19.
Minim Invasive Neurosurg ; 54(4): 187-90, 2011 Aug.
Article in English | MEDLINE | ID: mdl-21922449

ABSTRACT

BACKGROUND: Epistaxis is one of the most common emergencies of ENT surgery and can be managed conservatively in most cases. However, transarterial embolization is an accepted treatment option for intractable epistaxis, if conservative management fails. But often, direct detection of the bleeding point by obvious contrast extravasation is not possible in conventional subtracted angiographic series (DSA). Then the suspected bleeding point is treated by endovascular embolization based on the clinical suspicion. CASE REPORT: We here present the case of a young woman with intractable epistaxis where hemorrhage with contrast extravasation was only faintly visible. We used the new imaging modality of flat detector computed tomography (FD-CT) to visualize acute hemorrhage and treatment effect accurately. CONCLUSION: FD-CT was helpful to visualize both irregular branches of the bleeding mucosa and active hemorrhage and also to monitor an effective embolization within the angio suite. Acquisition of FD-CT imaging in addition to conventional 2-D imaging with the same system enhances the possibility to a better understanding of the individual patient's anatomy and could be beneficial in the accurate depiction of active bleeding, and it might also improve surgical management, if endovascular attempts should fail.


Subject(s)
Embolization, Therapeutic/methods , Endovascular Procedures/methods , Epistaxis/diagnostic imaging , Epistaxis/therapy , Acute Disease , Adult , Angiography , Female , Humans , Tomography, X-Ray Computed , Treatment Outcome
20.
Cerebrovasc Dis ; 31(5): 448-54, 2011.
Article in English | MEDLINE | ID: mdl-21346350

ABSTRACT

BACKGROUND: Approximately 5-10% of all acute ischemic strokes (AIS) occur in the territory of the posterior cerebral artery (PCA). Little is known about intravenous thrombolysis (IVT) in this infarct subgroup in terms of outcome and intracerebral hemorrhage rates. The aim of our study was to evaluate differences between supratentorial PCA infarcts and anterior circulation infarcts regarding baseline characteristics, stroke severity, outcome, safety and clinical findings, which would implicate a change in the existing thrombolysis practice in patients with PCA stroke. METHODS: All patients with AIS in the supratentorial PCA territory receiving IVT between 01/2006 and 01/2010 were selected from the Erlangen Thrombolysis Database (group 1, n = 21). They were compared to all IVT patients with strokes in other supratentorial vascular territories over the same period of time (group 2, n = 398). Baseline demographic data, as well as clinical and laboratory findings were analyzed. The outcome was assessed using the modified Rankin Scale at 3 months. RESULTS: Only serum glucose levels at baseline (110.5 ± 36.1 vs. 127.2 ± 48.2 mg/dl; p = 0.036) and the baseline National Institutes of Health Stroke Scale score (median 6.5 vs. 9; p = 0.016) were significantly lower in group 1 compared to group 2. Favorable clinical outcome (57.1 vs. 48.6%; p = 0.445) and intracerebral hemorrhage rates (4.8 vs. 4%; p = 1.000) were comparable in both groups. CONCLUSIONS: No substantial differences were found between supratentorial PCA and anterior circulation infarcts. Our data on safety and efficacy support the present common thrombolysis practice in supratentorial PCA infarct patients, though an indication for IVT should rather be based on the existence of functionally disabling deficit than merely on the National Institutes of Health Stroke Scale.


Subject(s)
Fibrinolytic Agents/administration & dosage , Fibrinolytic Agents/therapeutic use , Infarction, Posterior Cerebral Artery/drug therapy , Thrombolytic Therapy/methods , Aged , Aged, 80 and over , Brain Ischemia/complications , Female , Fibrinolytic Agents/adverse effects , Hemodynamics/physiology , Humans , Image Processing, Computer-Assisted , Infarction, Posterior Cerebral Artery/mortality , Injections, Intravenous , Magnetic Resonance Imaging , Male , Middle Aged , Retrospective Studies , Risk Factors , Safety , Stroke/drug therapy , Stroke/etiology , Thrombolytic Therapy/adverse effects , Tomography, X-Ray Computed , Treatment Outcome
SELECTION OF CITATIONS
SEARCH DETAIL
...