bluuebunny/crossref_metadata_2025_split huggingface dataset:
Intraoperative power Doppler ultrasonography with a contrast-enhancing agent for intracranial tumors
Authors: Kanno Hiroshi , Ozawa Yukihiko , Sakata Katsumi , Sato Hidemitsu , Tanabe Yutaka , Shimizu Nobuyuki , Yamamoto Isao 
Published: May 2009

Object. The goal of this study was to evaluate intraoperative power Doppler ultrasonography when used with a contrast-enhancing agent for operations on intracranial tumors.
Methods. Forty intracranial tumors were examined using power Doppler ultrasonography with a galactose micro-particle—based ultrasonographic contrast-enhancing agent during operations on the brain. The tumors included 37 intracranial neoplasms (14 gliomas, six meningiomas, three hemangioblastomas, two malignant lymphomas, three other primary neoplasms, nine metastatic tumors, and three nonneoplastic lesions). All patients also underwent computerized tomography and magnetic resonance imaging, and all but three of the patients underwent digital subtraction (DS) angiography. Before injection of the ultrasonographic contrast agent, intra- and peritumoral power Doppler flow signals were detected in 32 of the intracranial tumors. After the injection, the signals were enhanced in blood vessels around the tumors and in the tumor parenchyma in 36 tumors. The duration of contrast enhancement continued for 70 to 365 seconds (mean 251.8 ± 69 seconds) after the injection. Among the tumors, hemangioblastomas displayed particularly strong contrast enhancement. In these intracranial tumors, the echo signals obtained using contrast-enhanced power Doppler ultrasonography correlated with DS angiographic staining. Power Doppler ultrasonograms with the appropriate contrast agent provided better data on the precise real-time position of the tumors and their relationship to adjacent vessels than ultrasonograms obtained before the injection of the contrast agent.
Conclusions. Intraoperative power Doppler ultrasonography performed using a contrast-enhancing agent can facilitate intraoperative real-time navigation and assessment of the intratumoral vasculature and peritumoral vessels, particularly for tumors having abundant vessels such as hemangioblastomas.
Multimodal metabolic imaging of cerebral gliomas: positron emission tomography with [18F]fluoroethyl-l-tyrosine and magnetic resonance spectroscopy
Authors: Floeth Frank Willi , Pauleit Dirk , Wittsack Hans-Jörg , Langen Karl Josef , Reifenberger Guido , Hamacher Kurt , Messing-Jünger Martina , Zilles Karl , Weber Friedrich , Stummer Walter , Steiger Hans-Jakob , Woebker Gabriele , Müller Hans-Wilhelm , Coenen Heinz , Sabel Michael 
Published: May 2009

Object. The purpose of this study was to determine the predictive value of [18F]fluoroethyl-l-tyrosine (FET)—positron emission tomography (PET) and magnetic resonance (MR) spectroscopy for tumor diagnosis in patients with suspected gliomas.
Methods. Both FET-PET and MR spectroscopy analyses were performed in 50 consecutive patients with newly diagnosed intracerebral lesions supposed to be diffuse gliomas on contrast-enhanced MR imaging. Lesion/brain ratios of FET uptake greater than 1.6 were considered positive, that is, indicative of tumor. Results of MR spectroscopy were considered positive when N-acetylaspartate (NAA) was decreased in conjunction with an absolute increase of choline (Cho) and an NAA/Cho ratio of 0.7 or less. An FET lesion/brain ratio, an NAA/Cho ratio, and signal abnormalities on MR images were compared with histological findings in neuronavigated biopsy specimens.
The FET lesion/brain ratio and the NAA/Cho ratio were identified as significant independent predictors for the histological identification of tumor tissue. The accuracy in distinguishing neoplastic from nonneoplastic tissue could be increased from 68% with the use of MR imaging alone to 97% with MR imaging in conjunction with FET-PET and MR spectroscopy. Sensitivity and specificity for tumor detection were 100 and 81% for MR spectroscopy and 88 and 88% for FET-PET, respectively. Results of histological studies did not reveal tumor tissue in any of the lesions that were negative on FET-PET and MR spectroscopy. In contrast, a tumor diagnosis was made in 97% of the lesions that were positive with both methods.
Conclusions. In patients with intracerebral lesions supposed to be diffuse gliomas on MR imaging, FET-PET and MR spectroscopy analyses markedly improved the diagnostic efficacy of targeted biopsies.
Biological activity of adult cavernous malformations: a study of 56 patients
Authors: Sure Ulrich , Freman Sandra , Bozinov Oliver , Benes Ludwig , Siegel Adrian M. , Bertalanffy Helmut 
Published: May 2009

Object.Cerebral cavernous malformations (CCMs) have previously been considered as congenital and biologically static malformations. On the other hand, the potential for growth and de novo generation of CCMs have also been reported. It is therefore important to study the proliferative and neoangiogenetic capacity of these lesions.Methods.The authors studied the surgical specimens of 56 CCMs (23 deep and 33 superficial) obtained from adult patients. The proliferative activity of the endothelium and the neoangiogenetic capacity of these lesions were considered through immunohistochemical anaylsis of proliferating cell nuclear antigen (PCNA), MIB-1, Flk-1, vascular endothelial growth factor (VEGF), hypoxia-inducible factor (HIF)-1α, and endoglin antibodies.Positive immunostaining of endothelial cells occurred in 86% of patients for PCNA and in 38% of the cases for MIB-1. The expression of Flk-1 was observed in the endothelium of 71% of the cases, for VEGF in 41%, for HIF-1α in 48.1%, and for endoglin in 63.6% of the cases. The correlation of immunohistochemical and clinical data indicated that VEGF was expressed in significantly less deep-seated lesions when compared with superficial CCMs. Neither the expression of the proliferative markers nor the expression of the angiogenetic antibodies correlated with patient age at surgery, sex, or the number of recent prior hemorrhagic episodes in the patients.Conclusions.The CCMs from adult patients are active lesions exhibiting endothelial proliferation and neoangiogenesis. According to the data in this study, neoangiogenesis is more prominent in superficial CCMs than in deep-seated CCMs and is not associated with recent prior hemorrhages.
Gamma knife surgery for trigeminal neuralgia: outcomes and prognostic factors
Authors: Sheehan Jason , Pan Hung-Chuan , Stroila Matei , Steiner Ladislau 
Published: May 2009

Object. Microvascular decompression (MVD) and percutaneous ablation surgery have historically been the treatments of choice for medically refractory trigeminal neuralgia (TN). Gamma knife surgery (GKS) has been used as an alternative, minimally invasive treatment in TN. In the present study, the authors evaluated the long-term results of GKS in the treatment of TN.
Methods. From 1996 to 2003, 151 cases of TN were treated with GKS. In this group, radiosurgery was performed once in 136 patients, twice in 14 patients, and three times in one patient. The types of TN were as follows: 122 patients with typical TN, three with atypical TN, four with multiple sclerosis—associated TN, and seven with TN and a history of a cavernous sinus tumor. In each case, the chosen radiosurgical target was located 2 to 4 mm anterior to the entry of the trigeminal nerve into the pons. The maximal radiation doses ranged from 50 to 90 Gy. The median age of the patients was 68 years (range 22–90 years), and the median time from diagnosis to GKS was 72 months (range 1–276 months). The median follow up was 19 months (range 2–96 months). Clinical outcomes and postradiosurgical magnetic resonance (MR) imaging studies were analyzed. Univariate and multivariate analyses were performed to evaluate factors that correlated with a favorable, pain-free outcome.
The mean time to relief of pain was 24 days (range 1–180 days). Forty-seven, 45, and 34% of patients were pain free without medication at the 1-, 2-, and 3-year follow ups, respectively. Ninety, 77, and 70% of patients experienced some improvement in pain at the 1-, 2-, and 3-year follow ups, respectively. Thirty-three (27%) of 122 patients with initial improvement subsequently experienced pain recurrence a median of 12 months (range 2–34 months) post-GKS. Among those whose symptoms recurred, 14 patients underwent additional GKS, six MVD, four glycerol injection, and one patient a percutaneous radiofrequency rhizotomy. Twelve patients (9%) suffered the onset of new facial numbness post-GKS. Changes on MR images post-GKS were noted in nine patients (7%). On univariate analysis, right-sided neuralgia (p = 0.0002) and a previous neurectomy (p = 0.04) correlated with a pain-free outcome; on multivariate analysis, both right-sided neuralgia (p = 0.032) and patient age (p = 0.05) were statistically significant. New onset of facial numbness following GKS correlated with undergoing more than one GKS (p = 0.002).
Conclusions. At the last follow up, GKS effected pain relief in 44% of patients. Some degree of pain improvement at 3 years post-GKS was noted in 70% of patients with TN. Although less effective than MVD, GKS remains a reasonable treatment option for those unwilling or unable to undergo more invasive surgical approaches and offers a low risk of side effects.
Basilar artery dissection
Authors: Yoshimoto Yuhei , Hoya Katsumi , Tanaka Yoshihiro , Uchida Takanori 
Published: May 2009

Object. Little is understood about the clinical manifestations of basilar artery (BA) dissections, which can present with subarachnoid hemorrhage (SAH), brainstem compression, or ischemia. In any instance, the prognosis seems poorer than that for vertebral artery (VA) dissection. The authors analyzed clinical presentations and radiological features of BA dissection with and without rupture.
Methods. Between 1998 and 2003, the authors treated 10 patients (eight men and two women, ranging in age from 32–78 years; mean age 54 years) with BA dissection. Diagnosis was based on clinical and radiological findings, including those from magnetic resonance imaging and cerebral angiography studies.
Of the 10 patients, five had impaired consciousness at disease onset. Among four patients presenting with SAH, two were treated conservatively and had fair outcomes without recurrent hemorrhage. The other two patients with SAH were treated using unilateral endovascular VA occlusion, but one of them subsequently suffered fatal rebleeding. A fifth patient presented with progressive signs of a mass involving the brainstem, whereas the remaining five patients showed brainstem ischemia; all were treated conservatively. Four patients could not return to their previous daily activities.
Conclusions. Basilar artery dissections are rare lesions associated with significant morbidity and death. The natural course of and the treatment options for BA dissection differ considerably from those for VA dissections. Management of these lesions is controversial and difficult, and requires particular care.
Multiple aneurysms of the anterior communicating artery: radiological and surgical difficulties
Authors: Inci Servet , Özgen Tuncalp 
Published: May 2009

Object. Multiple aneurysms of the anterior communicating artery (ACoA) occur rarely and have not been well investigated previously. The authors report on a consecutive series of six patients who each harbored multiple ACoA aneurysms. The radiological and surgical difficulties encountered in treating these complex and uncommon aneurysms are described and the pertinent literature is reviewed.
Methods. Between October 1996 and August 2003, the authors surgically treated 146 patients with ACoA aneurysms. Six (4.1%) of these patients harbored multiple aneurysms of the ACoA. Four of these patients were men and two were women; their ages ranged from 36 to 72 years. Five patients had two aneurysms and one patient had three. All underwent surgery performed using the pterional approach. The clinical presentations, angiograms, intraoperative difficulties, and surgical results were retrospectively analyzed.
All patients had premorbid hypertension. In two cases, the aneurysms were initially misdiagnosed as a single complex aneurysm based on routine cerebral angiograms, but special angiographic views demonstrated double aneurysms. In one case, multiple ACoA aneurysms could be identified using three-dimensional (3D) computerized tomography (CT) angiography. The size of the ACoA aneurysms ranged from 3 to 12 mm (mean 5.3 mm). A total of 13 ACoA aneurysms were successfully occluded in the six patients. Four patients were discharged in good condition, and two patients died.
Conclusions. Although multiple ACoA aneurysms are quite rare, the following points should be kept in mind. 1) In bilobular ACoA aneurysms, special angiographic projections and 3D CT angiography or 3D digital subtraction angiography should also be performed to obtain a correct diagnosis. The differentiation of two aneurysms from a bilobular aneurysm during the preoperative period is important for surgical planning. 2) Angiographically, detection of the ruptured aneurysm is often difficult. 3) Resection of the gyrus rectus is necessary to obtain a good operative exposure. 4) Clip selection and sequencing are important. Straight clips with short blades should be preferred to avoid narrowing of the surgeon's view and a collision between the clips.
Combined use of tractography-integrated functional neuronavigation and direct fiber stimulation
Authors: Kamada Kyousuke , Todo Tomoki , Masutani Yoshitaka , Aoki Shigeki , Ino Kenji , Takano Tetsuya , Kirino Takaaki , Kawahara Nobutaka , Morita Akio 
Published: May 2009

Object. The aim of this study was better preoperative planning and direct application to intraoperative procedures through accurate coregistration of diffusion-tensor (DT) imaging—based tractography results and anatomical three-dimensional magnetic resonance images and subsequent importation of the combined images to a neuronavigation system (functional neuronavigation).
Methods. Six patients with brain lesions adjacent to the corticospinal tract (CST) were studied. During surgery, direct fiber stimulation was used to evoke motor responses to confirm the accuracy of CST depicted on functional neuronavigation. In three patients, stimulation of the supposed CST elicited the expected motor evoked potentials. In the other three, stimulation at the resection borders more than 1 cm away from the supposed CST showed no motor response. All patients underwent appropriate tumor resection with preservation of the CST.
Conclusions. Integration of the DT imaging—based tractography information into a traditional neuronavigation system demonstrated spatial relationships between lesions and the CST, allowing for the avoidance of tract injury during lesion resection. Direct fiber stimulation was used for real-time reliable white matter mapping, which served to adjust for any discrepancy between the neuronavigation system data and potentially shifted positions of the brain structures. The combination of these techniques enabled the authors to identify accurate positions of the CST during surgery and to accomplish optimal tumor resections.
Integration of three-dimensional corticospinal tractography into treatment planning for gamma knife surgery
Authors: Maruyama Keisuke , Kamada Kyousuke , Shin Masahiro , Itoh Daisuke , Aoki Shigeki , Masutani Yoshitaka , Tago Masao , Kirino Takaaki 
Published: May 2009

Object. In the radiosurgical treatment of critically located lesions, the effort to minimize the risk of complication is essential. In this study the integration of diffusion-tensor (DT) imaging—based tractography was clinically applied to treatment planning for gamma knife surgery (GKS).
Methods. Seven patients with cerebral arteriovenous malformations located adjacent to the corticospinal tract (CST) underwent this technique. Data provided by DT imaging were acquired before the frame was affixed to the patient's head and the CST of the DT tractography was created using our original software. Stereotactic three-dimensional imaging studies were obtained after frame fixation and then coregistered with the data from DT tractography. After image fusion of the two studies, the combined images were transported to a GKS treatment-planning workstation. The spatial relationship between the dose distribution and the CST was clearly demonstrated within the 2 hours it took to complete the entire imaging process. The univariate logistic regression analysis of transient or permanent motor complications revealed a significant independent correlation with the volume of the CST that received 25 Gy or more and with a maximum dose to the CST (p < 0.05).
Conclusions. The integration of DT tractography into the GKS treatment planning was highly useful in confirming the dose to the CST during treatment planning.
Intraoperative control of extracranial—intracranial bypass patency by near-infrared indocyanine green videoangiography
Authors: Woitzik Johannes , Horn Peter , Vajkoczy Peter , Schmiedek Peter 
Published: May 2009

Object. Recently, intraoperative fluorescence angiography in which indocyanine green (ICG) is used as a tracer has been introduced as a novel technique to confirm successful aneurysm clipping. The aim of the present study was to assess whether ICG videoangiography is also suitable for intraoperative confirmation of extracranial—intracranial bypass patency.
Methods. Forty patients undergoing cerebral revascularization for hemodynamic cerebral ischemia (11 patients), moyamoya disease (18 patients), or complex intracranial aneurysms (11 patients) were included. Superficial temporal artery (STA)—middle cerebral artery (MCA) bypass surgery was performed 35 times in 30 patients (five patients with moyamoya underwent bilateral procedures), STA—posterior cerebral artery bypass surgery in two patients, and saphenous vein (SV) high-flow bypass surgery in eight patients. In each patient, following the completion of the anastomosis, ICG (0.3 mg/kg body weight) was given systemically via an intravenous bolus injection. A near-infrared light emitted by laser diodes was used to illuminate the operating field and the intravascular fluorescence was recorded using an optical filter—equipped video camera. The findings of ICG videoangiography were compared with those of postoperative digital subtraction (DS) or computerized tomography (CT) angiography.
In all cases excellent visualization of cerebral arteries, the bypass graft, and brain perfusion was noted. Indocyanine green videoangiography was used to identify four nonfunctioning STA—MCA bypasses, which could be revised successfully in all cases. In two cases of SV high-flow bypasses, ICG videoangiography revealed stenosis at the proximal anastomotic site, which was also revised successfully. In all cases the final findings of ICG videoangiography could be positively validated during the postoperative course by performing DS or CT angiography.
Conclusions. Indocyanine green videoangiography provides a reliable and rapid intraoperative assessment of bypass patency. Thus, ICG videoangiography may help reduce the incidence of early bypass graft failure.
Functional and phenotypic differences between glioblastoma multiforme—derived and normal human brain endothelial cells
Authors: Charalambous Christiana , Hofman Florence M. , Chen Thomas C. 
Published: May 2009

Object. Glioblastomas multiforme (GBMs) are hypervascular tumors characterized by endothelial cell (EC) proliferation. There is increasing evidence that ECs that infiltrate systemic tumors are different from normal blood vessel cells; whether this difference is seen in the central nervous system between GBM and normal brain tissue is not known. The goal of this investigation was to characterize and compare the functional and phenotypic properties of GBM-associated ECs and normal brain ECs.
Methods. Human ECs were isolated from fresh tissue specimens, purified using flow cytometry, and characterized by immunostaining. Proliferation was measured by determining bromodeoxyuridine incorporation and Ki-67 staining, and by performing the monotetrazolium assay. The migration rate of the cells was determined using the modified Boyden chamber technique. Apoptosis was evaluated by performing the TUNEL assay, cell death enzyme-linked immunosorbent assay (ELISA), and annexin V staining. Growth factor production was analyzed using the ELISA technique.
The brain tumor ECs differed from normal brain ECs morphologically and by their expression and distribution of specific markers (that is, vascular endothelial cadherin [VE-cadherin] and CD31). Functional differences between the two cell populations were also evident. The brain tumor ECs proliferated more slowly and underwent less apoptosis than normal brain ECs; however, the tumor ECs migrated faster than the normal ECs. The normal ECs were sensitive to growth factors such as vascular endothelial growth factor (VEGF) and endothelin-1 (ET-1), whereas the tumor ECs were not. In addition, the brain tumor ECs constitutively produced higher levels of ET-1 and VEGF, compared with the normal ECs.
Conclusions. The data demonstrated that ECs derived from normal brain and from GBMs have significant phenotypic and functional distinctions. Further characterization of brain tumor ECs is essential for efficient antiangiogenic treatment of gliomas.
Risk of hemorrhage from an arteriovenous malformation confirmed to have been obliterated on angiography after stereotactic radiosurgery
Authors: Shin Masahiro , Kawahara Nobutaka , Maruyama Keisuke , Tago Masao , Ueki Keisuke , Kirino Takaaki 
Published: May 2009

Object. Radiosurgery has been widely adopted for the treatment of cerebral arteriovenous malformations (AVMs) in which the practical endpoint is angiographic evidence of obliteration, presumed to be consistent with elimination of the risk of hemorrhage. To test this unverified assumption, the authors followed 236 radiosurgery-treated AVMs between 1 and 133 months (median 77 months) after angiographic evidence of obliteration.
Methods. Four patients experienced hemorrhage between 16 and 51 months after angiographic confirmation of AVM obliteration, and two underwent resection. The histological findings in these patients showed occlusion of the AVM by thickening of the intimal layer with dense hyalinization as well as a small amount of residual AVM vessels and a tiny vasculature. The risks of hemorrhage from these presumaby obliterated AVMs were 0.3% for the annual bleeding risk and 2.2% for the cumulative risk over 10 years. Continuous enhancement of the nidus on computerized tomography (CT) or magnetic resonance (MR) imaging was the only significant factor positively associated with hemorrhage in the statistical analysis (p = 0.0212).
Conclusions. Because the study was based on limited follow-up data, its significance for defining predictive features of hemorrhage after angiographic evidence of obliteration is still indeterminable. Nevertheless, disappearance of the AVM on angiography after radiosurgery does not always indicate total elimination of the disease, especially when CT or MR imaging continues to demonstrate an enhancing lesion. The authors therefore recommend continual follow up even after evidence of AVM obliteration on angiography.