The signal-to-noise ratio obtained from arteries in three-dimensional (3D) time-of-flight (TOF) magnetic resonance (MR) angiography is often too low to allow clinical diagnosis because the radiofrequency pulse decreases the magnetization of protons in the blood and suppresses the in-flow effect in the slab. The present study adjusted the position of the head coil to boost arterial signal intensity. Ten healthy volunteers, eight men and two women aged 24-78 years, underwent 3D TOF MR angiography of the intracranial arteries with the same standard GE transmit-receive birdcage head coil using both normal and half position (lower edge of the coil level with the mouth) methods. Our subjects were divided into Group 1 consisted of five relatively young volunteers aged 24-42 years (mean 31.2 years), and Group 2 consisted of five older volunteers aged 70-78 years (mean 73 years). The following four arteries were chosen for analysis: the internal carotid artery (ICA), the proximal middle cerebral artery segment (M₁), and the two distal middle cerebral artery segments (M₂, M₃). The half position method increased the signal-to-noise ratio in the ICA, M₁, M₂, and M₃ by 15%, 25%, 36%, and 44%, respectively. In general, this method resulted in the generation of stronger signals in the M₂ and M₃ in younger subjects and in all arteries examined in older subjects. The half position method can provide better MR angiograms in certain brain regions of younger people, and in all brain regions in older patients.

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Temporary intraluminal shunt was used during 72 consecutive carotid endarterectomies (CEAs) in 61 patients (bilateral CEA in 11 patients) during October 2001 and September 2005. The medical records of these patients were retrospectively reviewed. All procedures were performed with routine shunt insertion without monitoring such as electroencephalography. Pre- and postoperative diffusion-weighted magnetic resonance (MR) imaging was used to detect ischemic complications. Postoperative angiography was performed in 70 cases to detect abnormalities such as major stenosis or dissection of the distal end. Symptomatic ischemic complication occurred in one patient at 1 month. Postoperative diffusion-weighted MR imaging detected new hyperintense lesions in three patients including the symptomatic patient. Postoperative angiography confirmed that the distal end was satisfactory in all cases. The incidence of ischemic lesions of embolic origin after CEA with routine shunt usage is acceptably low if the procedure of shunt device insertion and removal is meticulously conducted.

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The cerebral circulatory dynamics were evaluated before and after intra-arterial administration of fasudil hydrochloride in 20 patients with angiographic vasospasm after subarachnoid hemorrhage (SAH). The region of interest time-density curves obtained before and after intra-arterial administration of fasudil hydrochloride were compared in the proximal portion of the middle cerebral artery in the early arterial phase, the distal portion of the middle cerebral artery in the late arterial phase, and the transverse sinus in the venous phase. In the early arterial phase, the time to peak and the time to half-peak were significantly reduced. In the late arterial phase and venous phase, the time to peak was significantly reduced. These results suggest that intra-arterial administration of fasudil hydrochloride induced dilation of the proximal arteries, and improved cerebral microcirculation. The present study suggests that intra-arterial administration of fasudil hydrochloride is effective as a treatment for vasospasm following SAH.

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A 17-year-old woman presented with a rare aneurysm at the junction of the persistent primitive trigeminal artery (PPTA) and the internal carotid artery (ICA) manifesting as left abducens nerve paresis. The aneurysm and the ICA were both successfully occluded with coils. The balloon occlusion test used the HyperForm balloon microcatheter to seal the PPTA and ICA, which is very important to determine the optimal treatment strategy for a PPTA aneurysm.

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A 62-year-old male presented with an unusually large mycotic aneurysm mimicking a saccular aneurysm manifesting as coma and hypotension. Computed tomography showed intracerebral and intraventricular hemorrhage. He was in septic shock due to acute infectious endocarditis. Cerebral angiography disclosed a large distal anterior cerebral artery aneurysm. The diagnosis was mycotic aneurysm based on the morphological features and associated endocarditis. The aneurysm and the parent artery were successfully occluded by endovascular embolization. High-dose antibiotic therapy in the following 6 weeks resulted in resolution of the infectious endocarditis. Early exclusion of ruptured mycotic aneurysm is mandatory because of the high risk of rerupture. Endovascular treatment is an effective alternative for mycotic aneurysms, especially if the patient’s general condition is poor. Parent artery occlusion can be safely tolerated if the aneurysm is located distally.

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A 47-year-old woman presented with unilateral ventricular enlargement detected by magnetic resonance imaging during a medical checkup. Neuroendoscopic exploration identified a multilocular lesion in which dark red fluid formed a niveau near the right side of the foramen of Monro. The diagnosis was intraventricular cavernous angioma. Restricted flow of cerebrospinal fluid at the foramen of Monro was observed. Xanthochromia, which seemed to be due to previous bleeding, was observed at the fornix. When the neuroendoscope touched the angioma, the wall collapsed and bled. Endoscopic removal of the angioma was abandoned, and craniotomy and resection of the angioma were performed. No new neurological anomalies were observed after surgery. Preoperative diagnosis of intraventricular cavernous angioma is difficult based on neuroimaging. Neuroendoscopy is effective for diagnosis and the decision-making process regarding treatment.

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A 63-year-old, previously healthy man presented with a rare large intradural retroclival chordoma without bone involvement. Computed tomography showed that the tumor was completely intradural and did not involve the bone, as confirmed at intraoperative inspection. The tumor was totally excised via the anterior transpetrosal approach. Surgery is the most effective first-line treatment for patients with chordoma despite the typical extradural extension and bone destruction. Complete resection is feasible for intradural extraosseous chordoma because of the sharply circumscribed margins and absence of bone involvement. Specialized skull base techniques should be used instead of conventional surgical approaches for intradural skull base chordoma.

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A 67-year-old man presented with a rare case of ligamentum flavum hematoma manifesting as progressive tetraplegia following cervical traction therapy. Magnetic resonance imaging of the cervical spine showed a posterior mass that was continuous with the ligamentum flavum at the C3-4 levels. Complete resection of the mass that contained brownish hemorrhage was performed, resulting in excellent symptom relief. We speculate that repeated trivial trauma to the degenerative ligamentum flavum was the main predisposing factor in the present case. Ligamentum flavum hematoma is a rare cause of spinal root or cord compression which typically occurs in the lower thoracic or lumbar spine, but may also appear in the cervical spine.

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A 22-year-old woman presented with a cervical perimedullary arteriovenous fistula (AVF) manifesting as right upper and lower extremity weakness. T₂-weighted magnetic resonance (MR) imaging showed intramedullary hyperintensity believed to be caused by venous congestion. Preoperative diffusion-weighted MR imaging showed increased apparent diffusion coefficient (ADC) value. Spinal angiography demonstrated an AVF fed mainly by the right C-5 radicular artery. Complete obliteration of AVF was achieved by endovascular embolization and microsurgical shunt occlusion. The ADC value was normalized and her neurological deficits improved after endovascular surgery, whereas T₂-weighted MR imaging still demonstrated the lesion. The high preoperative ADC value probably indicated reversible vasogenic edema and immediate normalization of the ADC value suggests a good clinical outcome.

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A 62-year-old man presented with shunt failure manifesting as consciousness disturbance 4 years after placement of a ventriculoperitoneal shunt for subarachnoid hemorrhage. Physical examination found subcutaneous pneumocele around the peritoneal catheter extending from the abdomen to the neck. He had undergone pelvic radiation therapy for bladder cancer 2 years before. The peritoneal catheter was removed from the cervical region, and external ventricular drainage and a descending colon stoma for ileus release were positioned. The cerebrospinal fluid was clear and yielded no cultures. No inflammatory changes were seen. He developed carcinomatous peritonitis and died 4 months later. Retrograde colon gas reflux due to catheter perforation into the colon occluded by metastatic sigmoid cancer was probably the cause. Fragility of the wall of colon associated with the prior abdominal radiation therapy might have been a contributing factor. Subcutaneous pneumocele around the peritoneal catheter, i.e. pneumocele within the fibrous sheath surrounding the catheter, is a differential diagnosis to cerebrospinal fluid collection in patients with subcutaneous swelling around the catheter.

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