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ABSTRACT: We report the clinical significance of anterior cerebral artery (ACA) notching on the optic nerve and chiasm in a 3.5-year-old girl with a craniopharyngioma and progressive blindness. She presented with a headache and vomiting, followed by binocular blindness. Magnetic resonance imaging (MRI) studies demonstrated severely distended A1 segments and ill-depicted ACAs. Surgical decompression via a right subfrontal approach was performed to reverse blindness. Postoperative MRI studies showed good ACA visualization. A second operation via a right pterional approach revealed ACA notching, which appeared as a transverse groove on the right optic nerve and chiasm. ACA notching should be considered as a possible cause of progressive visual disturbance and a potential risk of ACA infarction in a child with a craniopharyngioma.
Pediatric Neurosurgery 05/2012; 47(5):376-8. · 0.70 Impact Factor
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Journal of Anesthesia 11/2011; 26(2):318-9. · 0.83 Impact Factor
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International journal of cardiology 05/2011; 150(1):118-20. · 7.08 Impact Factor
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Katsutoshi Takayama,
Toshiaki Taoka,
Hiroyuki Nakagawa,
Kaoru Myouchin,
Takeshi Wada,
Toshiteru Miyasaka,
Masahiko Sakamoto,
Akio Fukusumi, Satoru Iwasaki,
Ryota Kimura,
Shinichiro Kurokawa,
Kimihiko Kichikawa
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ABSTRACT: The Carotid WALLSTENT (CWS) and Filter-Wire EZ (FWEZ) embolic protection devices for use in carotid arterial stenting (CAS) were newly approved for national health insurance coverage in Japan in April 2010. This article describes our initial experience of CAS using the CWS and FWEZ.
A group of 14 patients (12 men, 2 women; mean age 70.1 years, range 59-83 years) with 15 carotid artery stenoses at high risk for carotid endarterectomy were treated by CAS using the CWS and FWEZ. Of these stenoses, 5 were symptomatic with ≥50% stenosis of the common or internal carotid artery (ICA), and 10 were asymptomatic with ≥80% stenosis. The rates of technical success, ICA flow impairment during filter protection, periprocedural ischemic stroke, 30-day major adverse events (MAEs) (stroke, death, myocardial infarction), and development of new ischemic lesions on diffusion-weighted imaging (DWI) were assessed.
CAS was successful in all cases. There was no ICA flow impairment, periprocedural ischemic stroke, or MAEs. DWI showed new ipsilateral ischemic lesions in only one patient (6.7%).
Our initial clinical experience using the CWS and FEWZ for CAS was generally excellent, and the incidence of postprocedural ischemic lesions was low.
Japanese journal of radiology 01/2011; 29(1):51-8. · 0.65 Impact Factor
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ABSTRACT: The torcular herophili, or "confluence of the sinuses," shows various configurations with other venous sinuses, as revealed by angiography. The aims of this study were to evaluate anatomic variations of this confluence and to assess their clinical relevance using three-dimensional (3D) computed tomographic (CT) venography.
The torcular herophili and its relevant venous sinuses were analyzed using 3D CT venography in 120 adults, consisting of 76 patients who were proven to have aneurysms and 44 patients who were proven to have no vascular malformations or aneurysms after the examinations. Three-dimensional CT venography was performed following the arterial phase of 3D CT angiography without any additional injection of contrast material. Three-dimensional volume-rendered venous images were reconstructed on a workstation and reviewed.
The superior sagittal sinus (SSS) drained into the transverse sinus (TS) in four patterns: the SSS reached the centrally located confluence, where it divided into the bilateral TS (20.0%); the SSS was prematurely duplicated into the right and left limbs and drained into the same side TS (26.7%); the SSS drained exclusively into the right TS (44.2%); or the SSS drained exclusively into the left TS (9.2%). The draining pattern of the straight sinus was also classified into four types. The right TS was larger than the left TS. The right TS were higher compared to the left TS. Persistent occipital sinuses were recognized in 57.5% of the subjects. Finally, persistent falcial sinuses were seen in 2.5% of the subjects. A septum in the SSS and complicated venous channels in the confluence were each seen in only one case.
Three-dimensional CT venography is useful as a noninvasive method to evaluate the confluence and its relevant dural sinuses and can provide useful information for surgical intervention.
Academic radiology 09/2010; 17(9):1103-11. · 2.09 Impact Factor
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Masahiko Sakamoto,
Toshiaki Taoka,
Hiroyuki Nakagawa,
Katsutoshi Takayama,
Takeshi Wada,
Kaoru Myouchin,
Toshiaki Akashi,
Toshiteru Miyasaka,
Akio Fukusumi, Satoru Iwasaki,
Kimihiko Kichikawa
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ABSTRACT: The purpose is to investigate the feasibility of magnetic resonance (MR) plaque imaging in predicting the arterial flow impairment (slow-flow phenomenon) during carotid artery stenting (CAS) using a filter-type protection device.
Thirty-one carotid artery stenotic lesions in 30 patients (28 men and two women; mean age, 71.8 years) were evaluated by MR plaque imaging with black blood T1- and T2-weighted and time-of-flight sequences before CAS. Main plaque components were classified as vulnerable (intraplaque hemorrhage and lipid-rich/necrotic core) or stable (fibrous tissue and dense calcification) from the signal pattern. The plaque classification was statistically compared with the occurrence of slow-flow phenomenon.
The slow-flow phenomenon was observed in ten CAS procedures (five flow arrests and five flow reductions). Flow arrests consisted of four vulnerable and one stable plaque, and flow reductions consisted of four vulnerable and one stable plaque. The slow-flow phenomenon occurred significantly (P<0.01) more frequently in patients with vulnerable plaque.
Vulnerable carotid plaques have a significantly higher risk of slow-flow phenomenon than stable plaques. The occurrence of the slow-flow phenomenon can be predicted by MR plaque imaging before CAS.
Neuroradiology 11/2009; 52(4):275-83. · 2.82 Impact Factor
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Toshiaki Taoka,
Hidehiro Hirabayashi,
Hiroyuki Nakagawa,
Masahiko Sakamoto,
Satoru Kitano,
Junko Takahama,
Nagaaki Marugami,
Katsutoshi Takayama,
Toshiaki Akashi,
Toshiteru Miyasaka, Satoru Iwasaki,
Naoko Kurita,
Toshisuke Sakaki,
Kimihiko Kichikawa
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ABSTRACT: The purpose of this study was to assess the usefulness of signs ("Sukeroku sign" and "dent internal-capsule sign") for the recognition of subthalamic nucleus (STN).
Five Parkinson's disease cases in which there was a successful placement of deep brain stimulation (DBS) electrodes at the STN were retrospectively reviewed. Five radiologists who were not engaged in localization of STNs in clinical practice were asked to locate the STNs before and after instructions on the signs. We evaluated the deviation between the reader-located points and the location of the DBS electrode for which there had been a successful installation.
After instruction, there was a significant reduction in the deviation between the reader-located points and the DBS electrode. The time required for localization was also reduced after the instructions.
Sukeroku sign and dent internal-capsule sign are feasible indicators of STN and seem to be useful in helping to identify the STN.
Neuroradiology 10/2008; 51(1):11-6. · 2.82 Impact Factor
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Katsutoshi Takayama,
Hiroyuki Nakagawa, Satoru Iwasaki,
Toshiaki Taoka,
Toshiteru Miyasaka,
Kaoru Myouchin,
Takeshi Wada,
Masahiko Sakamoto,
Akio Fukusumi,
Ichiro Nakagawa,
Shinichiro Kurokawa,
Kimihiko Kichikawa
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ABSTRACT: No filter protection devices for carotid artery stenting (CAS) have been formally approved for use in Japan; however, as of April 2008, the Angioguard XP (AGXP) was approved. This article describes our initial results using the AGXP during CAS for the treatment of carotid artery stenosis.
A group of 15 patients (14 men) with a mean age of 72.3 years (range 53-81 years) were treated by CAS using the AGXP. Among them, 10 were symptomatic with >50% stenosis of the common or internal carotid artery (ICA), and 5 were asymptomatic with >70% stenosis. The rates of technical success, periprocedural stroke, ICA flow impairment, filter movement, and development of new ischemic lesions on diffusion-weighted imaging (DWI) were assessed.
CAS using the AGXP was successful in all cases. There was one minor stroke, and flow impairment occurred in six patients. Filter movement averaged 1.9 vertebral bodies. DWI showed new ipsilateral ischemic lesions in eight of the patients.
Initial clinical experience using the AGXP for CAS has been generally sufficient. However, attention must be paid to three problems when using the AGXP: the filter may move after placement; the filter may disturb blood flow in the ICA; and debris may pass around the filter.
Radiation Medicine 07/2008; 26(6):348-54.
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ABSTRACT: The cerebrovascular complications of Takayasu arteritis are primarily related to the presence of occlusive lesions. Cerebral aneurysms rarely occur as complications; only 18 cases have been reported thus far. The use of coil embolization to treat cerebral aneurysms occurring as a complication of Takayasu arteritis has not been previously reported. We report a case of Takayasu arteritis with a basilar tip aneurysm and a P1 segment aneurysm of the left posterior cerebral artery that were successfully treated with coil embolization. Because coil embolization for cerebral aneurysms associated with Takayasu arteritis requires the use of limited access routes that have extremely curved and tortuous courses, catheter navigation was difficult. The guide catheter, microcatheter, and guidewire must be selected and navigated with greater care than is usually required for common aneurysm embolization.
Radiation Medicine 02/2008; 26(1):33-8.
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ABSTRACT: Recognizing cerebral hyperperfusion syndrome with intracerebral hemorrhage following carotid artery stenting is critical because the mortality rate is high. This type of hemorrhage usually arises from within several hours to a few days after the procedure. Here we describe a putaminal hemorrhage with extravasation during angiography that developed immediately after carotid artery stenting. A search of the literature revealed only one other similar case report. The etiology of the intracerebral hemorrhage immediately after carotid stenting might be analogous to that of hypertensive hemorrhage.
Radiation Medicine 09/2007; 25(7):359-63.
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Toshiaki Taoka,
Tesseki Kin,
Hiroyuki Nakagawa,
Makito Hirano,
Masahiko Sakamoto,
Takeshi Wada,
Katsutoshi Takayama,
Chatchada Wuttikul, Satoru Iwasaki,
Satoshi Ueno,
Kimihiko Kichikawa
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ABSTRACT: This study accessed the feasibility of using tractography-based analysis to evaluate the apparent diffusion coefficient (ADC) and fractional anisotropy (FA) of three cerebellar peduncles in subtypes of spinocerebellar degenerative disease.
We examined 7 cases of dentatorubro-pallidoluysian atrophy (DRPLA), 4 cases of multiple system atrophy, cerebellar type (MSA-C), 4 cases of late cerebellar cortical atrophy (LCCA) and 8 controls. Diffusion tensor images were obtained, and tractographies of cerebellar peduncles were generated. ADC and FA along the cerebellar peduncles and volume of cerebellar peduncle were measured, and analyses of variance were made among the control and each spinocerebellar degenerative disease groups.
There were statistically significant decrease in FA and volume and increase in ADC values between DRPLA cases and controls in all three cerebellar peduncles. On the other hand, MSA-C cases mainly showed statistically significant decreased FA and volume and increased ADC values in the middle cerebellar peduncle. LCCA cases did not show prominent difference in the three cerebellar peduncles.
The values of diffusivity and diffusion anisotropy of cerebellar peduncles evaluated by tractography based measurements seem to reflect characteristics of the different types of spinocerebellar degenerative diseases. Tractography-based measurements may be a feasible tool for differential diagnosis of spinocerebellar degenerative disease.
NeuroImage 09/2007; 37(2):387-93. · 5.89 Impact Factor
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ABSTRACT: This is the first report of percutaneous transluminal angioplasty (PTA) of an intracranial artery applying intravascular ultrasound virtual histology (IVUS-VH), which has been recently developed for tissue characterization of coronary artery plaque. We report a case of successful PTA and stenting for symptomatic intracranial vertebral artery stenosis using IVUS-VH.
Radiation Medicine 07/2007; 25(5):243-6.
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ABSTRACT: To preoperatively visualize the course of the facial nerve, which is displaced by vestibular schwannoma, using diffusion tensor (DT) tractography, and to evaluate the agreement with surgical findings.
The subjects were eight patients with vestibular schwannoma who had undergone removal surgery. DT MR images were obtained and tracts that were considered to represent the facial nerve were constructed. We assessed the success rate for tract construction and evaluated the agreement between tractography findings and surgery.
We obtained a tract that connected the internal auditory meatus and brainstem, and was considered to represent the facial nerve in seven of eight cases. The course of the constructed tract agreed with surgical findings in five of these seven cases. One exception was a case in which the tumor was too large to enable intraoperative observation of the facial nerve; however, the facial nerve appeared to be displaced anteriorly at intracapsular resection, in agreement with tractography. In the other case, the schwannoma was mostly cystic.
Tractographs constructed using MR tensor images enabled us to identify tracts considered to represent facial nerves. We consider DT tractography to be a useful tool for preoperatively predicting facial nerve displacement in vestibular schwannoma.
Journal of Magnetic Resonance Imaging 12/2006; 24(5):1005-10. · 2.70 Impact Factor
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ABSTRACT: The purpose of this study was to evaluate the relationship between pituitary stalk compression by the dorsum sellae and clinical or laboratory findings in short stature children.
We retrospectively reviewed magnetic resonance images of the pituitary gland and pituitary stalk for 34 short stature children with growth hormone (GH) deficiency and 24 age-matched control cases. We evaluated the degree of pituitary stalk compression caused by the dorsum sellae. Body height, GH level, pituitary height and onset age of the short stature were statistically compared between cases of pituitary stalk compression with associated stalk deformity and cases without compression.
Compression of the pituitary stalk with associated stalk deformity was seen in nine cases within the short stature group. There were no cases observed in the control group. There were no significant differences found for body height, GH level and pituitary height between the cases of pituitary stalk compression with associated stalk deformity and cases without compression. However, a significant difference was seen in the onset age between cases with and without stalk compression.
Pituitary stalk compression with stalk deformity caused by the dorsum sellae was significantly correlated with late childhood onset of short stature.
Magnetic Resonance Imaging 07/2006; 24(5):651-6. · 1.99 Impact Factor
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ABSTRACT: Visual defect due to optic radiation injury is a complication of temporal lobectomy for temporal epilepsy. To investigate whether diffusion tensor imaging can delineate the changes in optic radiations after lobectomy, we evaluated parameters on tensor images for optic radiations and correlated them with visual defect.
We examined 14 cases after temporal lobectomy. Durations after surgeries ranged from 3 weeks to 9 years. The cases were classified into three groups on the basis of the severity of visual field defect (A-C, with group C the most severe). We evaluated signals on T2-weighted images and parameters of tensor images, including fractional anisotropy (FA) and apparent diffusion coefficient (ADC), for the optic radiation in both the operated and intact side.
On T2-weighted images, high signals in optic radiations were seen in four cases, occurring more than 4 weeks after surgery. The mean operated-to-intact side FA ratio in the optic radiation decreased according to severity of visual defect (group A, 0.88; group B, 0.89; group C, 0.73). The mean operated-to-intact side ADC ratio showed no significant difference in the overall cases. The ratio for ADC, however, tended to increase according to visual defect in cases after 10 weeks postsurgery.
Optic radiation showed a decreased FA value in cases after temporal lobectomy. In later stages, ADC values tended to increase and high signal intensities on T2-weighted images were observed. The FA value can be used for evaluating Wallerian degeneration of optic radiation even in the early stages after surgery.
American Journal of Neuroradiology 05/2005; 26(4):797-803. · 2.93 Impact Factor
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ABSTRACT: We occasionally encounter phenomena in which venous flow signals of the cavernous sinus (CS) and/or inferior petrosal sinus (IPS) are visualized paradoxically in patients without arteriovenous shunt in 3D time-of-flight magnetic resonance angiography (3D-TOF MRA) of the brain. The aims of this study are to examine the frequency and cause of this phenomenon ("pseudo-shunt" image) and to determine points of differentiation from definite arteriovenous shunt images ("real shunt").
We retrospectively examined 85 maximum intensity projection images obtained by MRA in the absence of arteriovenous shunts to detect pseudo-shunt images, and evaluated source images of pseudo-shunt studies for venous structures. Four real-shunt MRA studies were compared with pseudo-shunt studies on three points: (1) extension of sinuses, (2) extension of cortical veins, and (3) signal intensity of sinuses as assessed by the scoring method (1 point when these findings exist, 0 when they do not).
We detected five CS (3%) and six IPS (4%) signals in 9 (11%) of the 85 cases. In the source images of four pseudo-shunt images in the CS, we detected signals from the sphenoparietal sinus (SPS). The average score was significantly lower in the pseudo-shunt (0.22) than the real-shunt (2.75) images (P < .0001).
In cerebral 3D-TOF MRA, pseudo-shunt images were seen in 11% (9/85) of the study population, with antegrade upward blood flow of the SPS considered as one of the causes. Real-shunt signals can be distinguished from pseudo-shunt signals by evaluation of source images.
Magnetic Resonance Imaging 12/2004; 22(9):1289-93. · 1.99 Impact Factor
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ABSTRACT: We report a case of benign intracranial hypertension (BIH) caused by all-trans retinoic acid (ATRA) in a patient with acute promyelocytic leukemia. A 21-year-old male was admitted to our hospital with pancytopenia. He was diagnosed as having acute promyelocytic leukemia due to increased promyelocytes, and PML-RAR alpha chimeric mRNA was detected. The administration of ATRA and idarubicin was started immediately. After 26 days of the chemotherapy, he complained of diplopia. Ophthalmologic examination revealed bilateral papilledema and hemorrhage. The cerebrospinal fluid showed an increase in pressure, but no other abnormalities. Computed tomography showed no intracranial abnormalities. The orbital MR imaging showed distension of the perioptic subarachnoid space and flattening of the posterior sclera. A diagnosis of BIH was made. After the discontinuation of ATRA, the symptoms improved and the MR abnormalities disappeared. As far as we know, there have been no reports illustrating MR abnormalities of BIH caused by ATRA, for the diagnosis and monitoring of which orbital MR imaging can provide important clues.
[Rinshō ketsueki] The Japanese journal of clinical hematology 03/2004; 45(2):139-43.
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ABSTRACT: The purpose of this study was to evaluate collateral circulation by describing anterior cerebral artery and middle cerebral artery perfusion areas. Pairs of image sets spin labeled on the medial and lateral side were used. A pixel-by-pixel t test was performed, with blue gradation used to display lateral perfusion (ie, middle cerebral artery) and orange gradation for anterior cerebral artery perfusion. Extensions of anterior cerebral artery perfusion areas in cases of middle cerebral artery stenosis were described. This method may aid in estimation of collateral circulation for stroke treatment.
American Journal of Neuroradiology 03/2004; 25(2):248-51. · 2.93 Impact Factor
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ABSTRACT: To examine the correlation between tissue water content and signal intensity on fluid-attenuated inversion recovery (FLAIR) images, we analyzed infarcted rat brain, verified the results by theoretical simulation, and compared them with conventional spin-echo images. We produced brain infarction with cavitation in five rats by middle cerebral artery occlusion. After in vivo MRI, histologic sections of the MRI plane were obtained. We measured the signal intensity of regions on FLAIR and spin-echo images, and measured the area of cavitation on histologic sections. We plotted curves of cavity percentage to signal intensity. Theoretical values were calculated using a two-compartment model. On the curve of cavity area to signal intensity, the signal on FLAIR images peaked in tissues with 20% to 30% area of cavitation. On the theoretical curve, the signal on FLAIR images peaked at 90% tissue water content. These results seem to be characteristic of FLAIR.
Magnetic Resonance Imaging 03/2004; 22(2):221-7. · 1.99 Impact Factor
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Masahiko Sakamoto,
Toshiaki Taoka, Satoru Iwasaki,
Akio Fukusumi,
Hiroyuki Nakagawa,
Shinji Hirohashi,
Katsutoshi Takayama,
Takeshi Wada,
Kimihiko Kichikawa,
Hideo Uchida,
Hajime Ohishi,
Katsutoshi Murata,
Jun Okamoto
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ABSTRACT: We evaluated the detection of early venous filling of gliomas by 2D time resolved dynamic contrast enhanced MR digital subtraction angiography (MR-DSA) with echo-sharing technique and compared the results with those of conventional contrast digital subtraction angiography (C-DSA). C-DSA and MR-DSA examinations were performed in eight patients with malignant gliomas and compared with regard to the visualization of early filling veins; time intensity curves of arteries, early filling veins and normal veins were made, and rise time and time to peak were evaluated. MR-DSA visualized 12 out of 17 early filling veins depicted on C-DSA. The failure of five veins to be depicted may be due to the overlapping of other structures, such as other vessels and tumor stain. On time intensity curves, the mean difference in rise time was 0.9 sec between the artery and early filling vein, and the mean difference of time to peak was 1.6 sec. C-DSA has been the modality of choice in demonstrating early venous filling, a useful finding in the differential diagnosis of gliomas. However the high temporal resolution of MR-DSA with echo-sharing technique provides sufficient visualization of early venous filling of gliomas. Additional information for precise differential diagnosis may be obtained by adding MR-DSA to the imaging protocol for gliomas.
Magnetic Resonance Imaging 12/2001; · 1.99 Impact Factor
