Endovascular stroke therapy in Austria: a nationwide 1-year experience.

BACKGROUND AND PURPOSE: Based on a tight network of stroke units (SUs) and interventional centres, endovascular treatment of acute major intracranial vessel occlusion has been widely implemented in Austria. Documentation of all patients in the nationwide SU registry has thereby become mandatory. METHODS: Demographic, clinical and interventional characteristics of patients who underwent endovascular treatment for acute ischaemic stroke in 11 Austrian interventional centres between 1 October 2013 and 30 September 2014 were analysed. RESULTS: In total, 301 patients (50.5% women; median age 70.5 years; median National Institutes of Health Stroke Scale score 17) were identified.193 patients (64.1%) additionally received intravenous thrombolysis. The most frequent vessel occlusion sites were the M1 segment of the middle cerebral artery (n = 161, 53.5%), the intracranial internal carotid artery (n = 60, 19.9%) and the basilar artery (n = 40, 13.3%). Stent retrievers were used in 235 patients (78.1%) and adequate reperfusion (modified Thrombolysis in Cerebral Infarction scores 2b and 3, median onset to reperfusion time 254 min) was achieved in 242 patients (81.4%). Symptomatic intracranial haemorrhage occurred in 7%. 43.8% of patients (n = 132) had good functional outcome (modified Rankin Scale score 0-2) and the mortality rate was 20.9% (n = 63) after 3 months. Compared to the anterior circulation, vertebrobasilar stroke patients had higher mortality. Patients with secondary hospital transportation had better outcomes after 3 months than in-house treated patients. CONCLUSION: Our results document nationwide favourable outcome and safety rates of endovascular stroke treatment comparable to recent randomized trials. The ability to provide such data and the need to further optimize such an approach also underscore the contribution of respective registries.

Placental MRI shows preservation of brain volume in growth-restricted fetuses who suffer substantial reduction of putative functional placenta tissue (PFPT).

OBJECTIVE: Recently, a potentially useful diagnostic approach based on MR diffusion-tensor-imaging (DTI) was reported for the estimation of putative functional placenta tissue (PFPT), thus providing direct information about placental function. Yet, the relation between reduced PFPT and the phenomenon of brain-sparing remains unclear. This study aimed to investigate the relation between brain-sparing and reduced PFPT volume, as found in fetuses with intrauterine growth restriction (IUGR). METHODS: A total of 40 consecutive patients with a US-based diagnosis of placental IUGR were examined using fetal MRI. A control group of 78 patients who received fetal MRI, due to non-placental pathologies, was established. A somatic energy index was calculated as IE=1-(Vbrain/Vpfpt) from brain and PFPT volumes measured with DTI in both groups. IE, Vpfpt, and Vbrain were analyzed with respect to the gestational week. RESULTS: Vbrain corrected for gestational weeks was no different between both groups, while Vpfpt was significantly reduced in IUGR patients. IE was significantly different between both groups and indicated a higher Vbrain at a comparable Vpfpt. CONCLUSIONS: Fetuses with IUGR show preserved energetic resources necessary for brain growth. Because IE drops in IUGR more rapidly as pregnancy progresses, depending on Vpfpt, IE could prove useful for estimating fetal well-being.

Visualization of intracranial vessel anatomy using high resolution MRI and a simple image fusion technique.

A new technique for fusion and 3D viewing of high resolution magnetic resonance (MR) angiography and morphological MR sequences is reported. Scanning and image fusion was possible within 20 min on a standard 1.5 T MR-scanner. The procedure was successfully performed in 10 consecutive cases with excellent visualization of wall and luminal aspects of the intracranial segments of the internal carotid artery, the vertebrobasilar system and the anterior, middle and posterior cerebral artery.

Intra-arterial thrombolysis for the treatment of perioperative childhood cardioembolic stroke.

Local intra-arterial lysis using recombinant tissue plasminogen activator (rTPA) was performed in a 6 and 2/3-year-old patient with major cardioembolic ischemic stroke 48 hours after intracardiac surgery. Selective application of 2.5 mg rTPA (0.11 mg/kg body weight) resulted in recanalization of the occluded cerebral vasculature with good neurologic recovery.

Bone metastasis with superimposed osteomyelitis in prostate cancer.

The following case of a male patient with a history of prostate cancer suffering from pain and swelling in the right mandibular area illustrates the well-known diagnostic problem of a superinfected tumor. Orthopan tomography and CT showed no defects in bone structure or smooth tissue. Whole-body bone scanning showed increased tracer uptake in the mandibular bone and in several other locations in the skeletal system. Antigranulocyte immunoscintigraphy showed increased uptake over the right mandible, whereas the other metastatic sites were visualized as cold spots. A second CT scan depicted a sclerotic lesion with surrounding periostal reaction and soft-tissue swelling and was interpreted as osteomyelitis. Therefore, clinical symptoms, bone scanning, antigranulocyte immunoscintigraphy and follow-up CT resulted in a diagnosis of osteomyelitis, although open needle biopsy revealed the lesion to be prostate cancer metastasis with massive leukocytic invasion.

Technetium-99m-MIBI in primary and recurrent head and neck tumors: contribution of bone SPECT image fusion.

UNLABELLED: We prospectively investigated 200 patients with the clinical suspicion for head and neck tumors. The final diagnoses were 94 primary and 56 (37 confirmed, 19 excluded) recurrent squamous cell carcinomas (SCCs), 3 primary and 7 (4 confirmed, 3 excluded) recurrent adenoid cystic carcinomas (ACCs), 6 non-Hodgkin's lymphomas, 10 distant metastases, 6 other malignancies, 10 inflammatory and 8 other nonmalignant conditions. METHODS: Bone (600 MBq 99mTc-3,3-diphosphono-1,2-propane dicarboxylic acid tetrasodium salt) and hexakis-2-methoxyisobutyl isonitrile (MIBI) (600 MBq 99mTc-MIBI) SPECT were both performed under identical conditions (triple-head gamma camera; ultra-high-resolution, parallel-hole collimators; three-dimensional postfiltering) and judged independently and after superimposition. The results were compared to the results of biopsy, surgery and CT. RESULTS: The overall sensitivity/specificity of MIBI was 90%/78% for tumor detection and 90%/95% for the identification of malignant lymph node involvement (CT: 79%/66%, respectively 90%/79%). In the subgroup of recurrent SCC and ACC the sensitivity/specificity for tumor detection was 95%/71% for MIBI versus 78%/68% for CT. The isolated assessment of bone SPECT had a sensitivity/specificity of 100%/17% for osseous tumor spread. Image fusion of MIBI and bone SPECT differentiated between regio-local bone involvement and inflammatory changes and increased the specificity of bone SPECT to 100% in primary staging. Tumor size, stage, histology and pretreatment had no statistically significant effect on tracer uptake or diagnostic utility of scintigraphy. CONCLUSION: We propose the combined 99mTc-MIBI and bone ultra-high resolution SPECT as a highly useful imaging approach in the primary and secondary staging in patients with suspected malignancies in the head and neck region. The high specificity for malignancies in the head and neck region may be used in the differential diagnosis between head and neck malignancies and inflammatory disease in patients with the accidental finding of enlarged lymph nodes and no clinical signs of a primary tumor. Image fusion with bone scanning is mandatory for the topographical orientation and increases the specificity of bone scanning to differentiate between inflammatory or malignant causes of increased bone metabolism.

A standardized method of generating time-to-peak perfusion maps in dynamic-susceptibility contrast-enhanced MR imaging.

BACKGROUND AND PURPOSE: Perfusion MR imaging, performed as dynamic-susceptibility contrast-enhanced MR imaging, is sensitive to hemodynamic risks for patients with cerebrovascular disease. We sought to define a quantitative parameter for perfusion MR imaging, which shows brain areas at hemodynamic risk and enables direct comparison of different perfusion MR imaging examinations. METHODS: A new standardization procedure for the time-to-peak (TTP) parameter, standardized time to peak (stdTTP), was introduced. The stdTTP automatically calculates a time offset correlated to the earliest enhancing voxels in a section and rescales all TTP values accordingly. Because of a close relation between this offset and stdTTP of early enhancing voxels in central vascular territories (CVTs), stdTTP provides an estimate of the bolus run time between CVTs and related border zones (BZs). The stdTTP in CVTs and BZs was measured in 11 patients without hemodynamic impairment by using high temporal resolution dynamic-susceptibility contrast-enhanced perfusion MR imaging. RESULTS: An excellent comparability of different dynamic susceptibility contrast-enhanced MR imaging studies was found. The stdTTP in CVTs was 0.4 +/- 0.5 s (minimum, 0 s; maximum, 1.3 s) for the anterior, 0.5 +/- 0.3 s (minimum, 0 s; maximum, 1.0 s) for the middle, and 1.4 +/- 0.5 s (minimum, 0.4 s; maximum, 2.4 s) for the posterior cerebral artery. In the anterior BZ, stdTTP was 2.3 +/- 0.4 s (minimum, 1.6 s; maximum, 3.2 s), and in the posterior BZ, stdTTP was 2.8 +/- 0.4 s (minimum, 2.0 s; maximum, 3.4 s). CONCLUSION: The results suggest a limit for stdTTP of approximately 3.5 s in the anterior and posterior BZs. The stdTTP could serve as a quantitative measure for the hemodynamic risk assessment of patients with cerebrovascular disease. Because stdTTP can be directly derived from the measured curves, the hemodynamic situation of a patient can be judged with a minimum of computational effort.

Measurement of time-to-peak parameter by use of a new standardization method in patients with stenotic or occlusive disease of the carotid artery.

BACKGROUND AND PURPOSE: A quantitative, easily obtained measure of cerebral hemodynamics would be valuable in planning surgical or interventional therapy for patients with stenotic or occlusive disease of the carotid artery. We evaluated the recently introduced standardized time-to-peak variable (stdTTP), obtained with dynamic susceptibility contrast-enhanced MR (DSC-MR) imaging, in different states of stenotic/occlusive carotid artery disease. METHODS: We examined 24 patients with unilateral, high-grade stenosis (85%-95%) of one internal carotid artery (ICA) and 10 patients with stenosis (85%-95%) of one ICA and occlusion of the contralateral ICA. Mean stdTTP was evaluated in the central vascular territories of the anterior, middle, and posterior cerebral arteries and the anterior and posterior border zones and compared with the mean stdTTP values from 36 cerebral hemispheres without hemodynamic impairment. RESULTS: Patients showed no significant prolongation of stdTTP in the central vascular territories compared with the reference group, whereas significant prolongations of stdTTP were measured in the anterior and posterior border zones in patients with ICA disease (ANOVA, P <.05) and were most prominent in higher grades of carotid disease. Hemispheres with hemodynamic impairment always showed a stdTTP > 3.5 s in the border zones. CONCLUSION: The StdTTP quantitatively describes the hemodynamic impairment in cerebral hemispheres supplied by a stenosed or occluded ICA. An stdTTP value of > 3.5 s, as has been postulated, seems to point out hemodynamic impairment.

Osteometry of the mandible performed using dental MR imaging.

BACKGROUND AND PURPOSE: On cross-sectional and panoramic reformatted images from axial (dental) CT scans of the mandible it may be difficult to identify the inferior alveolar neurovascular bundle (IANB) in patients lacking a clear-cut bony delimitation of the mandibular canal. Dental MR images are comparable to dental CT scans, which directly show the IANB; however, measurements of length may not be reliable owing to susceptibility artifacts and field inhomogeneities in the oral cavity. Therefore, the accuracy of length measurements on dental MR images was compared with that on dental CT scans and direct osteometry. METHODS: Dental T1-weighted MR imaging using a high-resolution turbo gradient-echo sequence and dental CT were performed in six anatomic specimens. The axial scans were reformatted as panoramic and cross-sectional reconstructions on a workstation and characteristic cross sections were obtained from all mandibles. The longest axis in the bucco-lingual and apico-basal directions, the distances from the top of the mandibular canal to the top of the alveolar ridge and from the bottom of the mandibular canal to the base of the mandible, and the diameter of the bone cortex at the alveolar ridge were measured with direct osteometry on the cross sections and compared with measurements on corresponding MR and CT reformatted images. RESULTS: The correlation between direct osteometry and dental MR and CT was strong, except for the bone cortex diameter at the top of the alveolar ridge, where only a moderate correlation was found. Means of comparable length measurements were not significantly different among the three methods. CONCLUSION: The accuracy of length measurements in the jaw bones obtained using dental MR is comparable to that of dental CT and is not significantly different from direct osteometry. Thus, dental MR is a potential alternative to CT for dental imaging.

[Dental magnetic resonance tomography (dental MRI) as a method for imaging maxillo-mandibular tooth retention structures]. / Dentale Magnetresonanztomographie (Dental-MRT) als Verfahren zur Darstellung des maxillo-mandibulären Zahnhalteapparates.

PURPOSE: To establish a new method for dental imaging using magnetic resonance tomography named Dental-MRT and to demonstrate its usefulness in diagnosing dentogen pathologies of the mandible and maxilla. METHODS: Seven healthy volunteers, three patients with pulpitis, two patients with dentigerous cysts, two patients after tooth transplantation, and three patients with atrophic mandibles have been evaluated. Optimized axial T1- and T2-weighted gradient echo and spin echo sequences in 2D and 3D technique have been established to perform studies of the jaws. The acquired images were reconstructed with a standard dental software package on a work-station as panorama and cross-sectional views of the mandible or maxilla. RESULTS: The entire maxillo-mandibular bone, teeth, dental pulp, and the content of the mandibular canal were well depicted. Patients with pulpitis demonstrate bone marrow edema in the periapical region. Dentigerous cysts and their relation to the surrounding structures are clearly shown. After contrast media administration marked enhancement of the dental pulp can be demonstrated. CONCLUSION: Dental-MRT promises to provide a new tool for visualization and detection of dental diseases.

Contrast-enhanced computed tomography of freely transplanted jejunal patches after surgery in the oral cavity and oropharynx.

Thirty-two patients with jejunal patches in the oral cavity and oropharynx were examined with contrast-enhanced computed tomography (CT). The morphology of the intestinal wall, the mesenteric fatty tissue, mesenteric lymph nodes and the region of the anastomosis were evaluated and correlated with clinical findings. The size and number of mesenterial lymph nodes, which were found in 16 cases, did not correlate with tumour recurrence. The benign alterations of the intestinal wall ranged from flat surfaces with no enhancement to significant enhancement with persisting folds. In cases with persisting intestinal folds, separation of tumour recurrence was achieved by identification of a typical double-layer configuration of the enhancing mucosa, and the restriction of alterations to the intestinal wall compartment. Tumour recurrences occurred at patch margins and were reliably distinguished from normal patches. For differentiation of findings, an exact localization of jejunum-patch compartments and margins with contrast-enhanced CT was, therefore, necessary.

In vivo assessment of putative functional placental tissue volume in placental intrauterine growth restriction (IUGR) in human fetuses using diffusion tensor magnetic resonance imaging.

OBJECTIVES: Intrauterine growth restriction (IUGR) is a diagnostic challenge, since ultrasound fetal biometry (UFB) provides only a 50% detection rate for IUGR. This may be attributable to the fact that UFB does not allow a direct evaluation of functional placental tissue. We hypothesized that direct assessment, using magnetic resonance diffusion tensor imaging (DT-MRI), can provide better detection of IUGR by reliably distinguishing between normal and non-functional placental tissue. METHODS: Patients with normal placenta function (n = 21) and suspected IUGR (n = 14) according to UFB were examined. DT-MRI-based properties of areas of the placenta that were judged to represent normal functional tissue, in normal pregnancies, were used to perform volumetry of the putative functional placental tissue (PFPT) in a control- and an IUGR-group. Fractional anisotropy (FRC), as well as maximum and mean diffusivity were also calculated. RESULTS: PFPT volumetry showed a significant reduction of functional placental tissue in the IUGR group of up to 33%. Analysis of global PFPT, maximum diffusivity, mean diffusivity, and FRC also showed a significant difference. CONCLUSIONS: PFPT volume is dramatically reduced in IUGR. Several DT-MRI parameters suggest an additional placental micro-architecture disturbance in IUGR. PFPT volumetry appears to be a promising tool for improving the detection of IUGR.

Diffusion-weighted magnetic resonance imaging of cerebrospinal fluid in patients with and without communicating hydrocephalus.

BACKGROUND: Recent concepts about cerebrospinal fluid (CSF) circulation in communicating hydrocephalus (CoHy), which is also termed "restricted arterial pulsation hydrocephalus," suggest reduced arterial pulsations of subarachnoid vessels with a smaller amount of CSF shifted in subarachnoid spaces during the early systole. The postulated restriction of subarachnoid arterial pulsations in CoHy should induce a smaller motion artifact and reduced local stream effects in CSF in magnetic resonance (MR) diffusion-weighted imaging (DWI). PURPOSE: To investigate the maximum diffusivity in CSF in patients with and without CoHy using DWI. MATERIAL AND METHODS: 12 patients without CSF circulation disturbances and six cases with proven CoHy were assessed. Diffusion was measured in six non-collinear directions without triggering the arterial pulse wave (scan time 6:45 min, voxel size 2x2x2 mm). Due to expected artifacts, the calculated maximum diffusivity was called apparent diffusivity. Regional high and low apparent diffusivity was assessed in CSF spaces on newly created 3D CSF motion maps. RESULTS: Patients with regular CSF circulation exhibited high apparent diffusivity in CSF in basal subarachnoid spaces, whereas apparent diffusivity was low there in patients with CoHy. CONCLUSION: DWI opens a feasible approach to study CSF motion in the neurocranium. Restricted arterial pulsations seem to be involved in CoHy.

[Measuring perfusion and diffusion in neuroradiology]. / Perfusions- und Diffussionsmessung in der Neuroradiologie.

Neuroradiology should be regarded as a discipline with a strong focus on integral diagnosis of morphology and function of the central nervous system. With perfusion magnetic resonance imaging (P-MRI) and diffusion-weighted magnetic resonance imaging (DWI) the functional micro-structural analysis of the central nervous system has been made possible. So, disease processes may be characterised on a molecular level and P-MRI as well as DWI are now integrated in clinical routine diagnosis to improve therapy planning.

[Cerebrovascular emergency in neuroradiology]. / Der vaskuläre Notfall in der Neuroradiologie.

Common causes to consultate a neuroradiologist in case of emergencies are trauma, brain infarction, or intracranial bleeding. Patients with brain infarction need a rapid assessment of the potentially nonnecrotic area within the ischaemic lesion. If haemorrhage, mostly occurring in the form of subarachnoid bleeding, is suspected, the source of bleeding has to be detected. With cranial computed tomography (CT) a thorough evaluation and staging of ischaemic stroke is possible with respect to thrombolysis. To detect irreversible damage of brain tissue, a combined perfusion-diffusion MRI should be performed.

[Xenon-CT and perfusion MRI in the diagnosis of cerebral gliomas]. / Xenon-CT und Perfusionskernspintomographie in der Diagnostik von Gliomen des Gehirns.

Within certain limits the vascularity of cerebral gliomas correlates with dysplasia. Xenon CT and perfusion MRI can be used to investigate tumor vascularity. Using an optimized wash in/out protocol with inhalation of 30% xenon gas, xenon CT was performed and regional cerebral blood flow (rCBF) and blood/tissue partition coefficient (lambda) calculated. Furthermore, perfusion MRI was performed using a dynamic T2*w EPI sequence with intravenous administration of Gd-DTPA. The relative regional cerebral blood volume, arrival time, time to peak and mean transit time were calculated. Both modalities were used in patients with supratentorial gliomas and compared with conventional contrast-enhanced MRI (ceMRI). Calculation of regional cerebral blood flow, as compared to ceMRI, did not contribute to the diagnostic approach of tumor dysplasia. Tumour vascularity was better estimated by measurement of lambda. Measurement of relative regional cerebral blood volume also correlated with tumor vascularity. Mainly the possibility of direct quantification of the Xe-CT data was advantagenous compared to perfusion MRI, and the XeCT data could be interpreted more clearly. Further upgrades of the technical equipment of MR as well as upgrades of available software will increase the applicability of perfusion MRI. However, both modalities offer a more precise investigation of tumor vascularization compared to ceMRI since potential dysplastic alteration may be detected earlier, which will be advantageous for planning bioptical approach of such tumours.

Magnetic resonance imaging of the distribution of local anesthetic during the three-in-one block.

UNLABELLED: The three-in-one technique of simultaneously blocking the femoral, the lateral femoral cutaneous (LFC), and the obturator nerves by a single injection of a local anesthetic was first described in 1973, and it was suggested that the underlying mechanism was one of cephalad spread resulting in a blockade of the lumbar plexus. Today, the technique is widely used in surgery and pain management of the lower limb. Many investigators have, however, reported suboptimal analgesia levels, particularly in the obturator nerve. The purpose of this prospective study was to trace the distribution of a local anesthetic during a three-in-one block by means of magnetic resonance imaging (MRI). Seven patients scheduled for surgery of the lower limb were analyzed with the aid of a primary MRI and then received three-in-one blocks using 30 mL of bupivacaine 0.5% under the guidance of a nerve stimulator. A secondary MRI was performed to determine the distribution pattern of the local anesthetic. It emerged that the local anesthetic blocks the femoral nerve directly, the LFC nerve through lateral spread, and the anterior branch of the obturator nerve by slightly spreading in a medial direction. No involvement of the proximal and posterior portions of the obturator nerve was observed, nor was there any cephalad spread that could have resulted in a lumbar plexus blockade. We therefore conclude that the basis of the three-in-one block is confined to lateral, medial, and caudal spread of the local anesthetic, which effectively blocks the femoral and LFC nerves, as well as the distal anterior branch of the obturator nerve. IMPLICATIONS: We demonstrate by using magnetic resonance imaging that the mechanism of a three-in-one block is one of lateral, caudal, and slight medial spread of a local anesthetic with subsequent blockade of the femoral, the lateral femoral cutaneous, and the anterior branch of the obturator nerves. It does not involve cephalad spread of the local anesthetic with blockade of the lumbar plexus.

[The indications and embolism monitoring in lumen-opening therapies of the a. carotis]. / Indikationen und Embolie-Monitoring bei lumeneröffnenden Therapien der A. carotis.

Carotid endarterectomy (CEA) is proven to be beneficial in symptomatic patients with high-grade carotid stenosis (70% to 99%; residual lumen as a percentage of the normal distal internal carotid artery) on condition that the peri-operative risk for mortality and morbidity is less than 6%. A minority of the "leading experts" in North America (48%) and Western Europe (28%) recommends carotid endarterectomy in asymptomatic patients in general. Most experts suggest to perform surgery only in asymptomatic patients who are at risk for carotid occlusion in the near future or embolism. At its present state, angioplasty and stenting is an experimental although promising technique which will have to be compared to carotid endarterectomy. Criteria for duplex grading of internal carotid stenosis have been established and systematically validated to results of angiography. Pre-surgical use of angiography will more and more be restricted to selected patients in whom the results of duplex sonography remain inconclusive. The detection of microemboli with transcranial doppler sonography seems to be of particular importance before and during carotid angioplasty and stenting.

Functional imaging of effects of fragrances on the human brain after prolonged inhalation.

Beside olfactory or trigeminal stimulation of chemosensory receptor-cells some results in published literature suggest that fragrances show a direct affect on the brain. The effect of the fragrance 1,8-cineol, which was described in literature as 'stimulating', on regional and global cerebral blood flow (rCBF and gCBF) in the human brain after prolonged inhalation was investigated. The results show an increase of global-CBF without preference to primary or secondary olfactory centres after an inhalation-time of 20 min.