Assessment of molecular markers demonstrates concordance between samples acquired via stereotactic biopsy and open craniotomy in both anaplastic astrocytomas and glioblastomas.

The classification, treatment and prognosis of high-grade gliomas has been shown to correlate with the expression of molecular markers (e.g. MGMT promotor methylation and IDH1 mutations). Acquisition of tumor samples may be obtained via stereotactic biopsy or open craniotomy. Between the years 2009 and 2013, 22 patients initially diagnosed with HGGs via stereotactic biopsy, that ultimately underwent open craniotomy for resection of their tumor were prospectively included in an institutional glioma database. MGMT promotor analysis was performed using methylation-specific (MS)-PCR and IDH1R132H mutation analysis was performed using immunohistochemistry. Three patients (13.7%) exhibited IDH1R132H mutations in samples obtained via stereotactic biopsy. Tissue derived from stereotaxic biopsy was demonstrated to have MGMT promotor methylation in ten patients (45.5%), while a non-methylated MGMT promotor was demonstrated in ten patients (45.5%); inconclusive results were obtained for the remaining two patients (9%) within our cohort. The initial histologic grading, IDH1R132H mutation and MGMT promotor methylation results were confirmed using samples obtained during open craniotomy in all but one patient; here inconclusive MGMT promotor analysis was obtained in contrast to that which was obtained via stereotactic biopsy. Tumor samples acquired via stereotactic biopsy provide accurate information with regard to clinically relevant molecular markers that have been shown to impact patient care decisions. The profile of markers analyzed in our cohort was nearly concordant between those samples obtained via stereotactic biopsy or open craniotomy thereby suggesting that clinical decisions may be based on the molecular profile of the tumor samples obtained via stereotactic biopsy.

Stereotactic biopsy of brainstem lesions: 21 years experiences of a single center.

Stereotactic biopsies are procedures performed to obtain tumor tissue for diagnostic examinations. Cerebral lesions of unknown entities can safely be accessed and tissue can be examined, resulting in correct diagnosis and according treatment. Stereotactic procedures of lesions in highly eloquent regions such as the brainstem have been performed for more than two decades in our department. In this retrospective study we focus on results, approaches, modalities of anesthesia, and complications. We performed a retrospective analysis of our prospective database, including 26 patients who underwent stereotactic biopsy of the brainstem between April 1994 and June 2015. All of the patients underwent preoperative MRI. Riechert-Mundinger-frame was used before 2000, thereafter the Leksell stereotactic frame was used. After 2000 entry and target points were calculated by using BrainLab stereotactic system. We evaluated histopathological results as well as further treatment; additionally we compared complications of local versus general anesthesia and complications of a frontal versus a trans-cerebellar approach. Median age of all patients was 33 years, and median number of tissue samples taken was 12. In all patients a final histopathological diagnosis could be established. 5 patients underwent the procedure under local anesthesia, 21 patients in general anesthesia. In 19 patients a frontal approach was performed, while in 7 patients a trans-cerebellar approach was used. Complications occurred in five patients. Thereby no significant difference was found with regard to approach (frontal versus trans-cerebellar) or anesthesia (local versus general). Stereotactic biopsies even of lesions in the brainstem are a save way to obtain tumor tissue for final diagnosis, resulting in adequate treatment. Approach can be trans-cerebellar or frontal and procedure can be performed either under local or general anesthesia without significant differences concerning complication rate.

Woven Endobridge (WEB) device for endovascular treatment of complex unruptured aneurysms-a single center experience.

INTRODUCTION: The introduction of the Woven Endobridge (WEB) device increases the feasibility of endovascular treatment of wide-neck bifurcation aneurysms with limitations given by currently available sizes and shapes of the device. Parallel to other studies, we used the new device for selected patients who were no optimal candidates for established techniques like neurosurgical clipping or endovascular coiling. We aimed to report the angiographic and clinical results of WEB implantations or combinations between WEB and coiling or intracranial stents. METHODS: We reviewed the records of n = 23 interventions in 22 patients with unruptured wide-neck aneurysms (UIA) who were assigned for aneurysm treatment with the use of the WEB or adjunctive techniques. Interventional procedures and clinical and angiographic outcomes are reported for the periprocedural phase and in mid-term FU. RESULTS: Of the included 22 patients, six patients needed additional coiling, intracranial stenting, or implantation of a flow diverter. WEB implantation was technically feasible in 22 out of the 23 interventions. Follow-up angiographic imaging proved total or subtotal occlusion of the aneurysm in 19 of 22 cases. Two minor recurrences remained stable during a period of 15 months. One patient with a partially thrombosed giant MCA aneurysm had a major recurrence and was retreated with a second WEB in combination with coiling. CONCLUSION: Despite of unfavorable anatomic conditions, broad-based and large UIA endovascular treatment with the WEB and adjunctive techniques was feasible with a low risk of complications and promising occlusion rates in mid-term follow-up.

Misleading FLAIR imaging pattern after glioma surgery with intraoperative MRI.

Intraoperative MRI (iMRI) allows a more detailed appreciation of the extent of resection than does conventional neurosurgery and results in longer overall survival in patients with malignant glioma. However, it is unknown whether the intraoperative application of contrast agent influences the early postsurgical MRI. The preceding iMRI could alter the signals of MR sequences in the early postsurgical MRI, especially in sequences influenced by T1 contrast. Hereby, we investigate such iMRI-induced influences on the fluid-attenuated inversion recovery (FLAIR) sequence. We retrospectively analyzed postsurgical T2w, T1w, and FLAIR images by visual inspection and by signal measurements in 46 patients with malignant gliomas after tumor resection. Of these, n = 25 patients were operated with conventional microsurgery, and n = 21 patients were operated with contrast-enhanced iMRI-guided microsurgery. We measured signal intensity in the resection cavity, in the cerebrospinal fluid (CSF) of the ventricles, and in the normal brain tissue contralateral to the tumor-bearing hemisphere on axial FLAIR images and T1-weighted and T2-weighted images. In 18 patients, the FLAIR sequence revealed hyperintense signal changes of the CSF in the subarachnoid or ventricular spaces. Seventeen of these 18 patients had received intraoperative MRI. In both FLAIR and T1-weighted images, the signal of the CSF in the ventricles was significantly higher in patients with iMRI than in patients without iMRI. The intraoperative application of contrast agent that is used for iMRI significantly influences postsurgical MRI within the first 72 h. We found hyperintense signal changes of the CSF in the FLAIR sequence in the subarachnoid and intraventricular spaces mimicking subarachnoid hemorrhage. The findings may result in a misdiagnosis of subarachnoid hemorrhage (SAH) in these patients.

Combination of 5-ALA and iMRI in re-resection of recurrent glioblastoma.

Background Tumour resection plays a role in the initial treatment but also in the setting of recurrent glioblastoma (rGBM). To achieve maximum resection, 5-aminolevulinic acid (5-ALA) and intraoperative MRI (iMRI) are used as surgical tools. Aiming at complete tumour re-resection, we started combining iMRI with 5-ALA to find out if this leads to better surgical results. Methods We performed tumour resections in seven patients with rGBM, combining 5-ALA (20 mg/kg bodyweight) with iMRI (0.15 T). Radiologically complete resections were intended in all seven patients. We assessed intraoperative fluorescence findings and compared these with intraoperative imaging. All patients had early postoperative MRI (3 T) to verify final iMRI scans and received adjuvant treatment according to interdisciplinary tumour board decision. Results Median patient age was 63 years. Median KPS score was 90, and median tumour volume was 8.2 cm(3). In six of seven patients (85%), 5-ALA induced fluorescence of tumour-tissue was detected intraoperatively. All tumours were good to visualise with iMRI and contrast media. One patient received additional resection of residual contrast enhancing tissue on intraoperative imaging, which did not show fluorescence. Radiologically complete resections according to early postoperative MRI were achieved in all patients. Median survival since second surgery was 7.6 months and overall survival since diagnosis was 27.8 months. Conclusions 5-ALA and iMRI are important surgical tools to maximise tumour resection also in rGBM. However, not all rGBMs exhibit fluorescence after 5-ALA administration. We propose the combined use of 5-ALA and iMRI in the surgery of rGBM.

Quantitative T1 and T2 mapping in recurrent glioblastomas under bevacizumab: earlier detection of tumor progression compared to conventional MRI.

INTRODUCTION: Treatment with the humanized anti-vascular endothelial growth factor (VEGF) antibody bevacizumab in glioblastoma patients suppresses contrast enhancement via the reduction of vascular permeability, which does not necessarily indicate real reduction of tumor cell mass. Therefore, other imaging criteria are needed to recognize tumor growth under bevacizumab more reliably. It is still unknown, whether quantitative T1 mapping is useful to monitor the effects of anti-angiogenic therapy or to indicate a tumor progression earlier and more reliable compared to conventional magnetic resonance imaging (MRI) sequences. This raised the question whether quantitative T1 mapping is more suitable to monitor treatment effects of bevacizumab. METHODS: Conventional and quantitative MRI was performed on six consecutive patients with recurrent glioblastoma before treatment with bevacizumab and every 8 weeks thereafter until further tumor progression. Quantitative T1 maps before and after intravenous application of contrast agent and quantitative T2 maps were performed to calculate serial differential maps and subtraction maps from one time point, subtracting contrast-enhanced T1 maps from non-contrast T1 maps. RESULTS: In five illustrative cases, tumor progression was documented earlier in differential T1 relaxation time (DiffT1) and T2 relaxation time (DiffT2) maps before changes in the conventional MRI studies were obvious. Four patients showed previous prolongation of T1 relaxation time in the DiffT1 maps, suggesting tumor progression, and subtraction maps revealed faint contrast enhancement matching with the areas of T1 prolongation. CONCLUSION: Our results emphasize that quantitative relaxation time mapping could be a promising method for tumor monitoring in glioblastoma patients under anti-angiogenic therapy. Quantitative T1 mapping seems to detect enhancing tumor earlier than conventional contrast-enhanced T1-weighted images.

Time window for postoperative reactive enhancement after resection of brain tumors: less than 72 hours.

OBJECT: Early postoperative MRI within 72 hours after brain tumor surgery is commonly used to assess residual contrast-enhancing tumor. The 72-hour window is commonly accepted because previous 1.5-T MRI studies have not found confounding postoperative reactive contrast enhancement in this time frame. The sensitivity to detect contrast enhancement increases with the field strengths. Therefore, the authors aimed to assess whether the 72-hour window is also appropriate for the MRI scanner with a field strength of 3 T. METHODS: The authors retrospectively analyzed findings on early postsurgical MR images acquired in 46 patients treated for high-grade gliomas. They performed 3-T MRI within 7 days before surgery and within 72 hours thereafter. The appearance of enhancement was categorized as postoperative reactive enhancement or tumoral enhancement by comparison with the pattern and location of presurgical enhancing tumor. RESULTS: Postoperative reactive enhancement was present in 15 patients (32.6%). This enhancement, not seen on presurgical MRI, had a marginal or leptomeningeal/dural pattern. In 13 patients (28.3%) postsurgical enhancement was found within the first 72 postoperative hours, with the earliest seen 22:57 hours after surgery. Subsequent MR scans in patients with postoperative reactive enhancement did not reveal tumor recurrence in these regions. CONCLUSIONS: Postoperative reactive enhancement earlier than 72 hours after brain tumor surgery can be expected in about one-third of the cases in which a 3-T scanner is used. This might be due to the higher enhancement-to-brain contrast at higher field strengths. Therefore, the time window of 72 hours does not prevent reactive enhancement, which, however, can be recognized as such comparing it with presurgical enhancing tumor.

Surgery for Glioblastoma in Light of Molecular Markers: Impact of Resection and MGMT Promoter Methylation in Newly Diagnosed IDH-1 Wild-Type Glioblastomas.

BACKGROUND: Previous studies addressing the influence of surgery on the outcome of patients with glioblastomas (GBM) have not addressed molecular markers. The value of surgery versus the tumor's major biological markers remains unclear. OBJECTIVE: We investigate the extent of resection as a prognosticator for patients with newly diagnosed primary GBM with the incorporation of molecular diagnostics as per the updated WHO 2016 diagnostic criteria for GBM. METHODS: Patients with newly diagnosed GBM who underwent resection were prospectively included within a database. We analyzed patients with newly diagnosed GBM and excluded patients who presented with IDH1 R132H mutations. Gross total resection (GTR) was defined as complete removal of enhancing disease. RESULTS: One hundred seventy-five patients were included within the analysis. One hundred four patients (59.4%) had GTR, 71 patients (40.6%) had subtotal or partial resection. Eighty patients (45.7%) displayed O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation, 95 patients (54.3%) showed no MGMT promoter methylation. In Cox regression analysis, MGMT promoter methylation (hazard ratio [HR] 1.55; 95% confidence interval [CI], 1.01-2.19; P = .0133) and GTR (HR 1.48; 95% CI, 1.06-2.07; P = .0206) were significantly associated with favorable progression-free survival. MGMT promoter methylation (HR 2.13; 95% CI, 1.45-3.12; P = .0001) and GTR (HR 1.81; 95% CI, 1.24-2.63; P = .002) were associated with favorable overall survival (OS). Of other risk factors analyzed, age (>60 vs ≤ 60 yr) was significantly associated with progression-free survival (HR 1.60; 95% CI, 1.14-2.24; P = .006) and OS (HR 2.19; 95% CI, 1.51-3.19; P < .0001). CONCLUSION: GTR and MGMT promoter methylation are independent prognosticators for improved overall and progression-free survival in a homogeneous cohort of newly diagnosed patients with IDH wild-type glioblastoma.

Time-resolved 3D rotational angiography: display of detailed neurovascular anatomy in patients with intracranial vascular malformations.

PURPOSE: The purpose of this pilot study was to demonstrate the applicability of time-resolved three-dimensional (3D) reconstructions from 3D digital subtraction angiography (DSA) rotational angiography (RA) datasets (four-dimensional (4D) DSA) to provide a more detailed display of the architecture of intracranial vascular malformations. METHODS: The experimental reconstruction software was applied to the existing 3D DSA datasets obtained with Siemens Artis zee biplane neuroangiography equipment. We included 27 patients with clinical indications for 3DRA for preinterventional or preoperative evaluation of intracranial dural arteriovenous fistulas (dAVFs, n=8) or arteriovenous malformations (AVMs, n=19). A modified DSA acquisition protocol covering an extended rotation angle of the C-arm of 260° during a scan time of 12 s was used. 4D volumes were displayed with up to 30 frames/s in a transparent volume rendering (VRT) mode and time-resolved multiplanar reconstructions (MPRs). Arterial feeders, fistulous points, or the shunt zone within the AVM nidus and venous drainage patterns as well as associated aneurysms were assessed after definition of a standardized evaluation procedure by consensus of two reviewers in comparison with 2D DSA and conventional 3D reconstructions. RESULTS: In all cases calculation of 4D reconstructions were technically feasible and evaluable. In two cases image quality was slightly compromised by movement artifacts. Compared with standard DSA projection images and 3D reconstructions, 4D VRTs and MPRs were rated significantly superior to define a proper projection and display of the shunt zone. In 12 out of 27 cases 4D reconstructions showed details of the angioarchitecture at the fistulous point or the nidus better than the other modalities and came close to the quality of superselective angiography. The efficacy of 3D and 4D applications was equal in the detection of pre- and intranidal aneurysms. The course of long arterial feeders and draining veins was difficult to assess on VRTs and MPRs. Especially for dAVFs, 2D DSA was clearly superior in identifying meningeal feeders. For detecting smaller vessels and for distinction between angiographic phases, 2D DSA is still considered to be superior to 4D imaging. Venous drainage was slightly better displayed in 4D reconstructions. CONCLUSIONS: Time-resolved 3DRA with 4D VRTs and MPRs is technically feasible and provides a detailed display of the angioarchitecture at the fistulous point or the nidus. Visualization of all angiographic features demands additional post-processing. Further standardization of evaluation tools and studies with blinded independent reviewers are necessary before the new technique can replace conventional neuroangiographic approaches.

Outcome, Prognostic Factors, and Follow-Up Results After Subarachnoid Hemorrhage from Pericallosal Artery Aneurysms.

OBJECTIVE: Pericallosal artery aneurysms (PAAs) are usually rare (2%-5%), and treatment is challenging for both surgical and endovascular modalities. We performed this analysis to determine the outcome and prognostic factors after subarachnoidal hemorrhage (SAH) caused by ruptured PAAs. METHODS: A total of 32 patients with ruptured PAA were admitted to our hospital between 1999 and 2014, added to our prospective database, and analyzed retrospectively. Outcome was measured based on the modified Rankin Scale (mRS) at 6 months after ictus (favorable mRS score, 0-2 vs. unfavorable mRS score, 3-6). RESULTS: Only 16 (50%) patients had a good clinical status at admission (World Federation of Neurological Surgeons Grading System [WFNS] grades I-III), whereas 12 patients (37.5%) were comatose (WFNS grade V). In 18 patients (56%), intracerebral hemorrhage was confirmed, in 18 patients (56%) cerebrospinal fluid drainage was required immediately after admission, and in 5 cases (16%) decompressive craniectomy was performed. There were 17 patients (53.1%) who achieved a favorable outcome (mRS score 0-2) at follow-up. Unfavorable outcome was associated with smoking, cerebral infarction, and worse admission status after multiple logistic regression analysis. CONCLUSIONS: Poor admission status, cerebral infarction, and smoking seem to be crucial factors for unfavorable outcome after SAH from PAA.

General Anesthesia Versus Local Anesthesia in Stereotactic Biopsies of Brain Lesions: A Prospective Randomized Study.

BACKGROUND: Stereotactic biopsy of brain lesions with unknown entities is a common neurosurgical procedure to obtain tumor tissue. Pathologists can then provide an exact diagnosis on which further therapy, such as resection, radiotherapy, or chemotherapy, can be based. These procedures can be performed under local or general anesthesia. In this prospective study, we aim to show whether stress levels are higher for patients who undergo stereotactic biopsy under local or general anesthesia. METHODS: Between January 2013 and December 2014, we screened 157 patients. Of these, 43 were included and evaluated in this study. Twenty-one patients gave their written consent and were randomized for either local or general anesthesia. A Post Traumatic Stress Score (PTSS) questionnaire was filled out by the patients preoperatively and postoperatively. Also, patients who did not agree to randomization had an opportunity to fill out the PTSS questionnaire. Twenty-two patients agreed only to fill out the stress-level questionnaire but refused randomization. These patients were evaluated as a subgroup. Scores achieved in the PTSS were compared by using the Fisher exact test. RESULTS: Among the randomized patients, 9 underwent the procedure under local anesthesia and 12 under general anesthesia. Median PTSS was 24 preoperatively in the patients who received local anesthesia versus 20 among the patients with general anesthesia (P = 0.37; Fisher exact test). Postoperatively, PTSS was 29.5 in median for patients with local anesthesia versus 23 for patients with general anesthesia (P = 0.30; Fisher exact test). Postoperatively, the PTSS showed a median increase of 5.5 points in the LA and 3 points in the GA group (P = 0.87; Fisher exact test). P values of 0.05 and lower were considered statistically significant. CONCLUSIONS: The willingness of patients to undergo randomization in this setting was low (13.3%). Within this highly selective group of patients, there was no significant difference for stress levels in patients who underwent stereotactic biopsy under local anesthesia versus general anesthesia. However, median values indicate a trend for higher stress-level values for patients undergoing local anesthesia.

Intracranial Ameloblastoma Arising from the Maxilla: An Interdisciplinary Surgical Approach.

Background Ameloblastomas are a rare tumor entity accounting for only 10% of all odontogenic tumors. They mostly originate from the mandible. Only a few cases are known to grow aggressively and to invade the orbit, nasal cavity, or even the brain. Patient and Methods/Case Report We present the case of a 57-year-old patient who was admitted with a huge tumor involving the nasal cavity, the left maxilla, and the anterior fossa. Histologic diagnosis was made by biopsy. A combined two-stage neurosurgical maxillofacial approach was planned. First the intracranial tumor mass was removed using bifrontal trepanation. A duraplasty was sewn in to cover the brain. In the second procedure, a combined bifrontal and midfacial approach was used by craniofacial plastic surgeons and neurosurgeons. A perisinusoidal tumor mass and retropharyngeal tumor mass was removed up to the skull base. The left orbit was completely exenterated, and a fibular bone-muscle graft was used for palatal, orbital, and facial reconstruction. The facial vein and artery were carefully prepared to feed the bone-muscle graft by end-to-end anastomoses. Conclusion Ameloblastomas are very rare slow-growing tumors that show a tendency to recur. They are responsible for only 1% of all oral tumors. Their growth can be enormous, and they can extend into sinusoidal cavities, the orbit, and the brain. Complex and extensive palliative surgery can ease the concerns of these patients and prolong their survival.

Paediatric patients with sudden vision impairment - An overview of MRI findings.

PURPOSE: Sudden visual impairment in children occurs sporadically but, when present, needs urgent attention. Optimal management strategies and timely recognition are required. Often psychogenic disorders are the cause in school-age children; however, this is a diagnosis of exclusion. Therefore, MRI plays an important role in ruling out pathology along the optic pathways or helping with the diagnosis of underlying life threatening diseases, such as hydrocephalus or intracranial mass. The purpose of this study was first to evaluate non-traumatic (tumoural and non-tumoural) causes of acute vision impairment; and, second, to assess whether conventional cerebral and orbital MR imaging is helpful for children with sudden visual impairment. PATIENTS AND METHODS: We retrospectively analysed the MRI scans and clinical findings of 95 children (47 male, 48 female; median age: 12.5 years, range: from 2 to 17 years) who presented symptoms of monocular or bilateral acute vision impairment. RESULTS: Patients with acute visual impairment were usually older than 7 years. In 36% of the patients a correlation between the MRI findings and the clinical symptoms was found. The most common causes of visual impairment were: infectious diseases (16%), migraine (12%), autoimmune diseases (11%), optic nerve neuritis with unknown aetiology (8%), neoplasms (8%), idiopathic intracranial hypertension (5%) and orthostatic hypotension (4%). Still, in 23% of the patients the cause remained unclear. CONCLUSION: Acute vision impairment is frequently caused by infectious diseases, migraine, autoimmune diseases or tumours in children. MRI is highly recommended, especially in the case of children younger than 5 years of whom clinical assessment can be difficult.

Analysis of T2 signal intensity helps in the differentiation between high and low-grade brain tumours in paediatric patients.

PURPOSE: Previous studies hypothesized that the analysis of magnetic resonance intensity of the solid portion in paediatric tumours can provide pre-surgical information about the histopathology. Classically, high signal-intensity in T2weighted (T2w) images identifies low-grade tumours, while anaplasia is characterized by T2 hypointensity. We aimed to investigate if T2w signal intensities can pre-operatively distinguish between low-grade and high-grade brain tumours in paediatric patients. METHODS: Two raters, blinded to the histological diagnosis, rated the signal intensity of MR images (T2w) from 36 children with newly diagnosed brain tumours, 17 children with low-grade brain tumours and 19 children with high-grade brain tumours were included in this study. Relative T2 values were obtained by dividing the T2w values of the solid portion of the tumour by the T2w values of the vitreous humour. RESULTS: The best cut-off point to distinguish low and high-grade paediatric brain tumours was 0.8. If the signal intensity was less than or equal to 0.8 the tumour was expected to be a high-grade tumour with a sensitivity of 100%. Prediction of a low-grade tumour was more uncertain with a sensitivity of 70.5%. Overall, 86% of the tumours would have been predicted correctly. CONCLUSION: Our data suggest that T2w signal intensities of the solid portion of brain tumours in paediatrics can pre-operatively differentiate between low-grade and high-grade tumours. In addition, T2 hypointensity may be helpful in targeting stereotactic biopsy.

Evaluation of the perforators of the anterior communicating artery (AComA) using routine cerebral 3D rotational angiography.

BACKGROUND: Damage to perforating branches of the anterior communicating artery (AComA) is a known complication of surgical or interventional treatment procedures for AComA aneurysm leading to neurologic deficits. In spite of the clinical relevance of these AComA branches, they have not been systematically analyzed using imaging techniques and most of our knowledge is based on post-mortem injection studies or neurosurgical reports. We therefore analyzed three-dimensional rotational angiography (3DRA) images of the AComA, and propose a first imaging definition of the microvascular structures surrounding the AComA. METHODS: Reconstructed 3D data derived from standard-of-care rotational angiography acquisitions (5 s DSA) were retrospectively analyzed. 20 patients undergoing selective cerebral angiography and 3DRA for therapy assessment were included in our study. 3DRA datasets were reconstructed and displayed using the volume rendering technique (VRT). Additionally, multiplanar reformatted CT-like cross-sectional images (MPR) were used to evaluate the number, size, and origin of the perforators of the AComA. RESULTS: Perforating branches of the AComA could be demonstrated in all cases with large interindividual variations in vessel visibility. MPRs appeared to be superior to total VRT volumes in the visualization of the perforating branches of the AComA. CONCLUSIONS: 3DRA can be used to visualize perforating branches of the AComA in vivo. Since damage to these perforators may result in neurologic deficits, visualization of these vessels prior to surgery or endovascular aneurysm treatment could help in the planning of therapeutic interventions. Further refinement of current imaging techniques will be necessary, however, to increase the reliability of small vessel angiography.

Stereotactic Biopsy of Pineal Lesions.

BACKGROUND: Stereotactic biopsies are carried out to obtain tumor tissue of unknown entity from cerebral lesions. Thus, tumor tissue can be examined, resulting in correct diagnosis and treatment. These procedures go in hand with high accuracy, high diagnostic yield, and low complication rates. OBJECTIVES: The aim of this study is to evaluate the results and complications of stereotactic biopsies carried out for lesions of the pineal region. METHODS: We performed a retrospective analysis of our prospective database and included 14 patients who underwent stereotactic biopsy of a pineal lesion between 2006 and February 2016. The Leksell stereotactic frame was used in all patients, and entry and target points were calculated using the BrainLab stereotactic system. We evaluated histopathologic results and postoperative complications such as hydrocephalus and hemorrhage. RESULTS: Histopathologic diagnosis was established in all patients. On postoperative computed tomography, 7 patients (50%) showed a circumscribed blood collection at the site of biopsy. Six patients (42.8%) required a cerebrospinal fluid drain preoperatively. Two patients needed external ventricular drain postoperatively (14.2%). One of these patients showed a small hemorrhage area that caused the hydrocephalus. The other patient showed only postoperative swelling. Preoperatively, 2 patients (14.2%) already had a ventriculoperitoneal (VP) shunt, whereas postoperatively, another 4 patients (28.5%) needed a VP shunt. Thus, of the 14 patients, 6 (42.8%) required a VP shunt. CONCLUSIONS: Because of their localization, pineal lesions may result in emergence of a hydrocephalus. Stereotactic biopsies in this area may increase this effect and, thus, even VP shunts are necessary in some patients.

A novel reconstruction tool (syngo DynaCT Head Clear) in the post-processing of DynaCT images to reduce artefacts and improve image quality.

BACKGROUND: Latest generations of flat detector (FD) neuroangiography systems are able to obtain CT-like images of the brain parenchyma. Owing to the geometry of the C-arm system, cone beam artifacts are common and reduce image quality, especially at the periphery of the field of view. An advanced reconstruction algorithm (syngo DynaCT Head Clear) tackles these artifacts by using a modified interpolation-based 3D correction algorithm to improve image quality. MATERIALS AND METHODS: Eleven volumetric datasets from FD-CT scans were reconstructed with the standard algorithm as well as with the advanced algorithm. In a two-step data analysis process, two reviewers compared dedicated regions of the skull and brain in both reconstruction modes using a 5-point scale (1, much better; 5, much worse; advanced vs standard algorithm). Both reviewers were blinded to the reconstruction mode. In a second step, two additional observers independently evaluated image quality of the 3D data (non-comparative evaluation) in dedicated regions also using a 5-point scale (1, not diagnostically evaluable; 5, good quality, perfectly usable for diagnosis) for both reconstruction algorithms. RESULTS: Both in the comparative evaluation of dedicated brain regions and in the independent analysis of the FD-CT datasets the observers rated a better image quality if the advanced algorithm was used. The improvement in image quality was statistically significant at both the supraganglionic (p=0.018) and the infratentorial (p=0.002) levels. CONCLUSIONS: The advanced reconstruction algorithm reduces typical artifacts in FD-CT images and improves image quality at the periphery of the field of view.

Benefit of Stereotactic Procedures in a Series of 43 Children.

OBJECTIVES: Stereotactic biopsies are procedures that enable neurosurgeons to obtain tissue samples of brain tumors located in eloquent areas with a low risk of perioperative complications. In this study, we examined stereotactic procedures (STX) in children. We focused on effectiveness, safety, and histopathological results to evaluate the benefits of the procedure. METHODS: We performed a retrospective analysis of our prospective database and included 43 children aged less than 18 years who underwent STX between 1998 and May 2015. All MRIs were evaluated by a single, experienced neuroradiologist. For all biopsies, Leksell stereotactic frame was used and fixed to the children's head with four pins. Entry and targetpoints were calculated by BrainLab navigation system. We assessed age, tumor localization, number of samples, histological diagnosis, and postoperative treatment. RESULTS: Median age of the patients was 11 years (range 1-18 years), and median number of tissue samples taken was 12 (range 1 with mere puncture of a cyst to 36). Histopathological examination revealed a final diagnosis in all patients. 3 patients underwent puncture of a cyst. 27 patients had a postoperative imaging. Only in 3 patients, CT scan revealed blood in the area where the biopsy had been taken. All bleedings were small and without clinical sequelae. CONCLUSION: Stereotactic procedures are accurate and save surgeries to obtain tumor tissue from eloquent areas to base further therapy on. This not only applies to adults but also to children of all ages.

Cerebral vasospasm and delayed cerebral infarctions in 225 patients with non-aneurysmal subarachnoid hemorrhage: the underestimated risk of Fisher 3 blood distribution.

OBJECTIVE: Recent data have shown increasing numbers of non-aneurysmal subarachnoid hemorrhage (NASAH). However, data are limited and often only small series have been published. Our objective was to analyze the rate of cerebral vasospasm (CVS), delayed cerebral infarction (DCI), and their influence on the clinical outcome, especially in patients with diffuse Fisher 3 bleeding pattern NASAH (Fi3). METHODS: Between 1999 and 2014, 225 patients had NASAH. CVS, DCI, and outcome (according to the modified Rankin Scale at 6 months) were analyzed retrospectively. Patients were stratified according to the bleeding type. After univariate analysis a multivariate analysis was performed and NASAH Fi3 was also compared with aneurysmal SAH Fi3. RESULTS: Patient characteristics and the outcome of perimesencephalic (PM) and non-PM (NPM) SAH were similar. Excluding Fi3, PM and NPM without Fi3 had similar patient characteristics, clinical course, and outcome. In particular, the Fi3 subgroup had a significantly increased risk of CVS, DCI, unfavorable outcome, hydrocephalus, and death. Early hydrocephalus was associated with Fi3 and intraventricular hemorrhage. The multivariate regression model showed the variables elderly patients, Fi3, and early hydrocephalus as independent and significant predictors for an unfavorable outcome. A further comparison of NASAH Fi3 with aneurysmal SAH Fi3 showed similar characteristics, CVS rate, and mortality. CONCLUSIONS: Patients with NASAH without a Fi3 bleeding pattern had a similar excellent outcome to patients with PM-SAH. Patients with Fi3 had a high risk for early hydrocephalus, CVS, DCI, and an unfavorable outcome, similar to patients with aneurysmal SAH. After multivariate analysis, early hydrocephalus, elderly patients, and Fi3 were identified as negative prognostic factors. Therefore, patients with Fi3 are at risk and need careful clinical observation.

Impact of Stereotactic Biopsy in HIV Patients.

OBJECTIVE: During their disease a significant number of human immunodeficiency virus (HIV)-infected patients develop neurologic symptoms due to intracerebral pathologies. Entities commonly found are toxoplasmosis, lymphomas, or progressive multifocal leukoencephalopathy. In some patients, diagnosis is not feasible with imaging alone, requiring biopsy. The objective of this study was to evaluate the impact of stereotactic biopsy in HIV patients on adjustment of therapy. METHODS: Between January 2004 and May 2015 at our clinic, 26 HIV-infected patients underwent stereotactic biopsy. Thin-layer magnetic resonance images were obtained and fused with computed tomography scans, taken with the stereotactic frame (Leksell) mounted. Biopsy material was evaluated pathologically and microbiologically. RESULTS: Histologic analysis revealed B-cell lymphoma in 6 patients (23.1%) and progressive multifocal leukoencephalopathy in 2 patients (7.7%). Abscess and toxoplasmosis were found in 3 patients each (11.5% and 11.5%), and encephalitis occurred in 4 patients (15.4%). In 2 patients each (7.7%), vasculitis, metastasis, and glioblastoma were diagnosed. Further findings comprised non-Hodgkin lymphoma and Burkitt lymphoma in 1 patient each. After biopsy, treatment was significantly changed in 18 (69.2%) patients (P < 0.01). Antibiotic therapy was adjusted in 6 patients (23.1%), and chemotherapy in 3 patients (16.7%). Other changes included antibiotic/antiviral therapy to chemotherapy in 3 patients (16.7%), chemotherapy to radiation, cortisone to chemotherapy, and aciclovir to cortisone in 1 patient each. One patient with glioblastoma underwent resection, and another patient received radiation. One patient underwent palliative care. CONCLUSION: Stereotactic biopsy in HIV-infected patients results in significant changes of therapy in more than two thirds of the patients.