C. A. Taschner

Time-resolved 3D contrast-enhanced MRA with GRAPPA on a 1.5-T system for imaging of craniocervical vascular disease: initial experience

Introduction: For three-dimensional (3D) imaging with magnetic resonance angiography (MRA) of the cerebral and cervical circulation, both a high temporal and a high spatial resolution with isovolumetric datasets are of interest. In an initial evaluation, we analyzed the potential of contrast-enhanced (CE) time-resolved 3D-MRA as an adjunct for neurovascular MR imaging. Methods: In ten patients with various cerebrovascular disorders and vascularized tumors in the cervical circulation, high-speed MR acquisition using parallel imaging with the GeneRalized Autocalibrating Partially Parallel Acquisitions (GRAPPA) algorithm on a 1.5-T system with a temporal resolution of 1.5xa0s per dataset and a nearly isovolumetric spatial resolution was applied. The results were assessed and compared with those from conventional MRA and digital subtraction angiography (DSA). Results: CE time-resolved 3D-MRA enabled the visualization and characterization of high-flow arteriovenous shunts in cases of vascular malformations or hypervascularized tumors. In steno-occlusive disease, the method provided valuable additional information about altered vessel perfusion compared to standard MRA techniques such as time-of-flight (TOF) MRA. The use of a nearly isovolumetric voxel size allowed a free-form interrogation of 3D datasets. Its comparatively low spatial resolution was found to be the major limitation. Conclusion: In this preliminary analysis, CE time-resolved 3D-MRA was revealed to be a promising complementary MRA sequence that enabled the visualization of contrast flow dynamics in various types of neurovascular disorders and vascularized cervical tumors.

Characteristics of Ultrasmall Superparamagnetic Iron Oxides in Patients with Brain Tumors

OBJECTIVEnThe aim of this study was to evaluate the characteristics of an ultrasmall superparamagnetic iron oxides (USPIO) agent in patients with brain tumors and to correlate changes on MRI with histopathologic data collected systematically in all patients.nnnSUBJECTS AND METHODSnNine patients with brain tumors were imaged before and 24 hr after administration of a USPIO at a dose of 2.6 mg Fe/kg. Analysis of MR images included qualitative and quantitative comparison of the USPIO and gadolinium enhancement of brain tumors. Brain surgery was performed 25-112 hr after administration of the USPIO. The histopathologic workup included iron histochemistry with diaminobenzidine (DAB)-enhanced Perls stain.nnnRESULTSnIn seven of nine patients, USPIO-related changes of signal intensity were observed in gadolinium-enhancing brain tumors on T1- and T2*-weighted sequences. The difference in signal intensity on T1-weighted USPIO series was 40.1% +/- 26.7% (mean +/- SD). On T2*-weighted USPIO series, the difference in signal intensity was -33.1% +/- 18.4% in solid tumor parts. Areas of suspected radiation necrosis did not enhance in three patients with prior radiation therapy. Iron histochemistry revealed the presence of iron deposits in macrophages in two patients.nnnCONCLUSIONnUSPIO agents will not replace gadolinium in the workup of patients with brain tumors. Our findings suggest that USPIO agents seem to offer complementary information and may help to differentiate between brain tumors and areas of radiation necrosis. Signal intensity changes on T2*-weighted images might be related to the blood pool properties of the agent, possibly reflecting steady-state susceptibility effects.

Predictors and impact of early cerebral infarction after aneurysmal subarachnoid hemorrhage

Cerebral infarction is a frequent and serious complication of aneurysmal subarachnoid hemorrhage (SAH). This study aimed to identify independent predictors of the timing of cerebral infarction and clarify its impact on disease course and patients’ outcome.

The predictors and clinical impact of intraventricular hemorrhage in patients with aneurysmal subarachnoid hemorrhage

Background Intraventricular hemorrhage is known to complicate the course and outcome of aneurysmal subarachnoid hemorrhage. Aims To identify independent risk factors for intraventricular hemorrhage development and its severity during aneurysm rupture. Methods Six hundred and twenty-five subarachnoid hemorrhage patients treated at our institution between January 2005 and December 2012 were included. The severity of intraventricular hemorrhage was assessed according to the original Graeb score. Clinical and radiographic features of patients present at the bleeding event were tested as potential risk factors for intraventricular hemorrhage. The characteristics of intraventricular hemorrhage were correlated with the clinical course and outcome. Results Intraventricular hemorrhage was present in 206 patients (33%) and was independently predicted by patient’s age (pu2009=u20090.001, odds ratio (OR)u2009=u20091.02/year of age increase), aneurysm size (pu2009=u20090.031, ORu2009=u20091.05/mm increase), and location (pu2009<u20090.0001, ORu2009=u20093.2 for aneurysms of posterior circulation). The severity of intraventricular hemorrhage was predicted by aneurysm size (pu2009=u20090.023) and location (higher severity for aneurysms of anterior circulation, pu2009=u20090.01). The presence of intraventricular hemorrhage (pu2009<u20090.0001, ORu2009=u20094.1) and intraventricular hemorrhage severity of >3 points on the Graeb score (pu2009=u20090.029, ORu2009=u20093.4) was independently associated with poor outcome. Shunt dependency was associated only with the occurrence of intraventricular hemorrhage (pu2009<u20090.0001, ORu2009=u20092.8) while the severity of intraventricular hemorrhage influenced the timing of shunt placement (pu2009=u20090.0156). Conclusions Increasing age, aneurysm size, and location in the posterior circulation are the main risk factors for occurrence of aneurysmal intraventricular hemorrhage, which is independently associated with poor outcome. The severity of intraventricular hemorrhage, however, is higher if the aneurysm is located in the anterior circulation and has impact on functional outcome, but not on shunt dependency.

Intracerebral Hematoma Due to Aneurysm Rupture: Are There Risk Factors Beyond Aneurysm Location?

BACKGROUNDnAlong with subarachnoid hemorrhage (SAH), a ruptured aneurysm may also cause an intracerebral hematoma (ICH), which negatively impacts the functional outcome of SAH.nnnOBJECTIVEnTo identify independent risk factors of aneurysmal ICH.nnnMETHODSnSix hundred thirty-two consecutive patients with aneurysmal SAH treated at our institution from January 2005 to December 2012 were eligible for this study. Demographic parameters and preexisting comorbidities of patients, as well as various clinical and radiographic characteristics of SAH were correlated with the incidence and volume of aneurysmal ICH.nnnRESULTSnOne hundred fifty-five patients (25%) had ICH on initial computed tomography with a mean volume of 26.7 mL (±26.8 mL). Occurrence and volume of ICH were associated with the location (distal anterior or middle cerebral artery >proximal anterior cerebral or internal carotid artery >posterior circulation, P < .001/P < .001) and size (>12 mm, P = .026/P < .001) of the ruptured aneurysm. Vascular risk factors independently increased the risk of ICH as well (arterial hypertension: odds ratio [OR] = 1.62, P = .032; diabetes mellitus: OR = 3.06, P = .009), while the use of aspirin (P = .037) correlated with the volume of ICH. The predictors of ICH were included into a risk score (0-9 points) that strongly predicted the occurrence of ICH (P = .01). Poor functional outcome after SAH was independently associated with the occurrence of ICH (P = .003, OR = 2.77) and its volume (P = .001, OR = 1.07 per-mL-increase).nnnCONCLUSIONnAneurysmal ICH is strongly associated with poorer functional outcome and seems to be predictable even before the bleeding event. The proposed risk factors for aneurysmal ICH require further validation and may be considered for treatment decisions regarding unruptured intracranial aneurysms.nnnABBREVIATIONSnACA, anterior cerebral arteryDHC, decompressive hemicraniectomyEVD, external ventricular drainageICA, internal carotid arteryICH, intracerebral hematomaMCA, middle cerebral arterymRS, modified Rankin scalePC, posterior circulationSAH, subarachnoid hemorrhageSIRS, systemic inflammatory response syndromeTCD, transcranial Doppler sonography.

Endovascular stroke therapy with the Aperio thrombectomy device

Background The pharmaceutical therapy for acute ischemic stroke has shortcomings in reopening large vessels and dissolving long thrombi, and endovascular treatment has been found to provide added value. The Aperio thrombectomy device showed promising results in an experimental study. The purpose of this study was to evaluate the device clinically. Methods 119 patients with acute stroke were treated in nine centers using the Aperio thrombectomy device. Target vessel, diameter, thrombus length, procedure time, recanalization, number of deployments, additional use of anticoagulants, complications, and the use of additional devices were assessed. Results The median thrombus length was 15u2005mm (range 1.5–20u2005mm) and the average time from device insertion to recanalization was 30u2005min (range 5–120u2005min). Blood flow restoration (Thrombolysis In Cerebral Infarction (TICI) 2–3) was achieved in 85%. In the majority of cases complete clot removal was achieved (TICI 0, 12%; TICI 1, 2%; TICI 2a, 14%; TICI 2b, 18%; TICI 3, 53%). The median number of deployments was 2 (range 1–6). Twelve procedural complications (10%) occurred. Conclusions The Aperio thrombectomy device seems to be an effective and adequately safe tool for reopening occluded cerebral arteries in the setting of acute stroke.

Freiburg Neuropathology Case Conference. A Mass Lesion of the Fourth Ventricle

cyst with its shiny white surface and waxen consistency. After incision of the tumor capsule, a tumor debulking was performed and the apex of the tumor was identified and removed to get access to the fourth ventricle. The upper and lateral part of the tumor could be easily dissected from the vermis and the tonsils and luxated downward. The lower part has a broad adhesion to the brainstem and could only be removed with microinstruments stepwise with great caution. As manipulation of the tumor capsule on the brainstem triggered electrophysiologic signals of the cranial nerves X and XII, parts of the capsule were left in place and signals returned to normal baseline. On microscopic inspection, a gross total resection could be achieved. A postoperative computed tomography (CT) confirmed this and showed no indications of bleeding. The patient was transferred to the neurosurgical intensive care unit and was extubated after 2 days when she recovered sufficient caudal cranial nerve function. Clinically, she had dysarthria and showed slightly reduced coughing and swallowing. Due to an intercurrent pneumonia with Escherichia coli, she had to be reintubated and ventilated under intravenous antibiotic treatment for 12 days. Dysarthria and swallowing due to a postoperative palatal palsy significantly improved after extubation under daily logopedic and physiotherapy treatment. The patient recovered well and was ambulatory with stable gait and no ataxia. She could be transferred into neurological rehabilitation in a clinically and neurologically stable condition.

Comparison of high-resolution X-ray and micro-CT for experimental evaluation of intracranial stent prototypes: quality evaluation beyond CE mark

IntroductionAs digital mammography and micro-computed tomography (CT) have been used for evaluation of stents deployed in experimental animal models, we compared the two methods regarding their sensitivity to detect abnormalities in three prototypes of intracranial stents.MethodsThree different prototypes of intracranial stents (nu2009=u200984) were implanted in various animal models. Explanted stents were examined using digital mammography and micro-CT. The images were compared with respect to maintenance of material and form and the stents were compared to one another. Histological analysis was performed as well.ResultsIn the open-cell stents, expansion of the stent cells was detected in the majority of cases (57.1xa0%) using micro-CT and less frequently using mammography (42.3xa0%). The closed-cell stent revealed kink stenoses in mammography as well as in micro-CT (3/7, 42.9xa0%). Detailed reconstructions of micro-CT images showed high-grade kink stenoses of the flow-diverter stent in two extremely curved vessels. Strut breaks were observed more frequently using micro-CT (6/84, 7.1xa0%) than by mammography (4/84, 4.8xa0%). Histology confirmed all changes of stent architecture.ConclusionSignificant changes of stent architecture can be observed and assessed even in the two-dimensional mammographic images. The use of micro-CT is recommended to detect subtle changes like single strut breaks and for three-dimensional information.

A haemorrhagic, contrast-enhancing lesion of the basal ganglia.

an 81-year-old woman suffered from progressive gait disturbance, stumbling and fatigue over the last 2 weeks. Before admission she observed a suddenly enhancing haemiparesis of her lower left limb. in her medical history, 66 months ago, the diagnosis of a corpus uteri carcinoma (pT1c, pn0 (0/27), pMx, R0) was made followed by resection with lymphadenectomy and subsequent external fractionated radiation. sixteen months earlier, a local vaginal recurrence of this carcinoma was treated by local excision (R1) and radiation. Furthermore, 47 months earlier the patient had a vitrectomy of both eyes due to vitreous opacity. Histopathological analyses showed an abnormal lymphocytosis without prove of a lymphoma. Finally, 42 months ago a B-cell chronic lymphocytic leukaemia (B-Cll), state Binet a, was diagnosed with a marked leucocytosis of 26,900/μl in the blood. Repeated intra-vitreal administrations of Rituximab were indicated 36 months ago. The B-Cll has been classified stable upon the last clinical controls. Upon admission to the hospital the patient presented with a left haemiparesis emphasizing the lower limb (3/5), a left facial paresis, a left positive Babinski’s sign and a mild dysarthria, without any associated disorientation. after discussion in our interdisciplinary tumour board a serial stereotactic biopsy was recommended and performed under local anaesthesia using a stereotactic system (MHT stereotactic systems, Bad Krozingen, Germany) with a 1 mm probe and biopsy forceps. Postoperatively, the patient had no discernible change of her neurological status and was discharged after an uneventful recovery to a secondary care facility.

Freiburg neuropathology case conference: an intradural mass lesion of the lumbar spine.

a 48-year-old male patient presented with a history of bilateral lumbago and sciatic pain projecting to the lateral lower legs, no palsy or sensory loss was observed. On magnetic resonance imaging (MRi), a spinal mass lesion was detected. after informed consent has been obtained, the tumor was removed microsurgically with neuromonitoring of the nerve roots l3 to s4. a laminectomy at l3 and a hemilaminectomy at l2 and l4 were performed. after paramedian opening of the dura, the nerve roots were microsurgically dissected from the tumor surface with subsequent tumor debulking. The tumor did not seem encapsulated, the color was light grey, and its consistence was hard. The tumor did not appear to be highly vascularized intraoperatively. after reduction of the tumor size and separation of additional nerve roots from the tumor surface, it became visible that the tumor was originating from the filum terminale. The filum terminale was confirmed with a negative neurostimulation. The tumor was finally removed with the adherent filum terminale. The dura was closed with resorbable sutures. Postoperatively, the patient had no neurological deficit and was discharged after an uneventful recovery. Imaging