Magnetic resonance angiographic evidence of sex-linked variations in the circle of Willis and the occurrence of cerebral aneurysms

2002 ◽  
Vol 96 (4) ◽  
pp. 697-703 ◽  
Author(s):  
Toru Horikoshi ◽  
Iwao Akiyama ◽  
Zentaro Yamagata ◽  
Masao Sugita ◽  
Hideaki Nukui
Keyword(s):  
Magnetic Resonance ◽  
Cerebral Aneurysms ◽  
Type A ◽  
Anatomical Variations ◽  
Circle Of Willis ◽  
Anterior Communicating Artery ◽  
Content Type ◽  
Ordinary Type ◽  
Male Patients ◽  
Fine Print

Object. In this study the authors investigated the relationship between variations in the circle of Willis observed on magnetic resonance (MR) angiograms and locations of cerebral aneurysms, and evaluated the risk of aneurysm formation. Methods. One hundred thirty-one patients with cerebral aneurysms were retrospectively selected from a series of 4518 patients who underwent MR angiography at one neurosurgical institute. Variations in the anatomy of the circle of Willis were simply classified into Type A, in which there was no visualization of a unilateral A1 segment, and Type P, in which there was a fetal type of posterior cerebral artery that was continuously delineated from the internal carotid artery (ICA) through the posterior communicating artery. All other variations in the circle of Willis were defined as Type O (ordinary type of variations). An additional 440 patients who did not harbor cerebral aneurysms were randomly selected for a comparison. Anterior communicating artery aneurysms were significantly related to the Type A anatomy and ICA aneurysms to Type P anatomy. Male patients who did not harbor aneurysms tended to have Type A anatomy, whereas women had a significantly greater incidence of Type P. Conclusions. This sex-linked difference in anatomical variations may be correlated to the well-known sex-linked difference in aneurysm distribution.

Intraoperative anatomical studies in patients with aneurysms of the anterior communicating artery complex

1992 ◽  
Vol 76 (4) ◽  
pp. 629-634 ◽  
Author(s):  
Edgar Nathal ◽  
Nobuyuki Yasui ◽  
Takeshi Sampei ◽  
Akifumi Suzuki
Keyword(s):  
Surgical Approach ◽  
Radical Surgery ◽  
Anatomical Variations ◽  
Surgical Approaches ◽  
Anterior Communicating Artery ◽  
Anatomical Studies ◽  
Content Type ◽  
Number Of Patients ◽  
Vascular Elements ◽  
Fine Print

✓ The intraoperative anatomical findings of the anterior communicating artery (ACoA) complex in 46 patients with anatomical variations were compared to those in an equal number of patients without variations in order to determine the visualization of the elements of the vascular complex. All patients underwent radical surgery for an ACoA aneurysm by one of three different surgical approaches: transsylvian, anterior interhemispheric, or basal interhemispheric. Visualization of the vascular elements was similar in patients with or without anatomical variations. The differences observed were dependent on the surgical approach selected and on the projection of the aneurysm. It was found that, even when the intraoperative anatomical field and the number of vascular elements visualized are different from those obtained in autopsy studies, the vascular microanatomical characteristics can be confirmed with each surgical approach to the extent necessary to ensure safe clipping of aneurysms in patients both with and without anatomical variations.

Pediatric cerebral aneurysms

2001 ◽  
Vol 94 (5) ◽  
pp. 733-739 ◽  
Author(s):  
François Proust ◽  
Patrick Toussaint ◽  
José Garniéri ◽  
Didier Hannequin ◽  
Daniel Legars ◽  
...  
Keyword(s):  
Adult Population ◽  
Clinical Status ◽  
Cerebral Aneurysms ◽  
Giant Aneurysm ◽  
Distal Portion ◽  
Anterior Communicating Artery ◽  
Content Type ◽  
Delay In Diagnosis ◽  
Specific Distribution ◽  
Fine Print

Object. The exceptional pediatric aneurysm can be distinguished from its adult counterpart by its location and size; however patient outcomes remain difficult to evaluate based on the published literature. Methods. Twenty-two children, all consecutively treated in three neurosurgery departments, were included in this study. Each patient's preoperative status was determined according to the Hunt and Hess classification. Routine computerized tomography scanning and angiography were performed in all children on the 10th postoperative day. Each patient's clinical status was evaluated 2 to 10 years postoperatively by applying the Glasgow Outcome Scale (GOS). Twenty-one children presented with a subarachnoid hemorrhage (SAH) and one child harbored an asymptomatic giant aneurysm. Thirteen patients were in good preoperative grade (Hunt and Hess Grades I to III) and eight in poor preoperative grade (Hunt and Hess Grade IV or V). The symptomatic aneurysms were located on the internal carotid artery bifurcation (36.4%); middle cerebral artery (36.4%), half of which were found on the distal portion; anterior communicating artery (18.2%); and within the vertebrobasilar system (9.1%). A giant aneurysm was observed in 14% of patients. Overall outcome was favorable (GOS Score 5) in 14 children (63.6%) and death occurred in five (22.7%). Causes of unfavorable outcome included the initial SAH in four children, a complication in procedure in three children, and edema in one child. Conclusions. Pediatric aneurysms have a specific distribution unlike that of aneurysms in the adult population. The incidence of giant aneurysms and outcomes were similar to those in the adult population. The major cause of poor outcome was the initial SAH, in particular, the high proportion of rebleeding possibly due to a delay in diagnosis.

Use of spiral computerized tomography angiography in patients with subarachnoid hemorrhage in whom subtraction angiography did not reveal cerebral aneurysms

2000 ◽  
Vol 92 (2) ◽  
pp. 278-283 ◽  
Author(s):  
Hiroyuki Hashimoto ◽  
Jun-Ichi Iida ◽  
Yasuo Hironaka ◽  
Masato Okada ◽  
Toshisuke Sakaki
Keyword(s):  
Subarachnoid Hemorrhage ◽  
Ct Angiography ◽  
Cerebral Aneurysms ◽  
Spiral Ct ◽  
The Other ◽  
Anterior Communicating Artery ◽  
Content Type ◽  
Spiral Ct Angiography ◽  
Spiral Computerized Tomography ◽  
Fine Print

Object. Patients with subarachnoid hemorrhage (SAH) in whom angiography does not demonstrate diagnostic findings sometimes suffer recurrent disease and actually harbor undetected cerebral aneurysms. The management strategy for such cases remains controversial, but technological advances in spiral computerized tomography (CT) angiography are changing the picture. The purpose of this prospective study was to examine how spiral CT angiography can contribute to the detection of cerebral aneurysms that cannot be visualized on angiography.Methods. In 134 consecutive patients with SAH, a prospective search for the source of bleeding was performed using digital subtraction (DS) and spiral CT angiography. In 21 patients in whom initial DS angiography yielded no diagnostic findings, spiral CT angiography was performed within 3 days. Patients in whom CT angiography provided no diagnostic results underwent second and third DS angiography sessions after approximately 2 weeks and 6 months, respectively.Six patients with perimesencephalic SAH were included in the 21 cases. Six of the other 15 patients had small cerebral aneurysms detectable by spiral CT angiography, five involving the anterior communicating artery and one the middle cerebral artery. Two patients in whom initial angiograms did not demonstrate diagnostic findings proved to have a ruptured dissecting aneurysm of the vertebral artery; in one case this was revealed at autopsy and in the other during the second DS angiography session. A third DS angiography session revealed no diagnostic results in 13 patients.Conclusions. Spiral CT angiography was useful in the detection of cerebral aneurysms in patients with SAH in whom angiography revealed no diagnostic findings. Anterior communicating artery aneurysms are generally well hidden in these types of SAH cases. A repeated angiography session was warranted in patients with nonperimesencephalic SAH and in whom initial angiography revealed no diagnostic findings, although a third session was thought to be superfluous.

Experimental induction of cerebral aneurysms in monkeys

1987 ◽  
Vol 67 (6) ◽  
pp. 903-905 ◽  
Author(s):  
Nobuo Hashimoto ◽  
Choegon Kim ◽  
Haruhiko Kikuchi ◽  
Masayuki Kojima ◽  
Yoo Kang ◽  
...  
Keyword(s):  
Carotid Artery ◽  
Internal Carotid ◽  
Cerebral Aneurysms ◽  
Anterior Communicating Artery ◽  
Experimental Hypertension ◽  
Content Type ◽  
Experimental Induction ◽  
The Common ◽  
The Brain ◽  
Fine Print

✓ Saccular cerebral aneurysms were successfully induced in two monkeys treated with ligation of the common carotid artery, experimental hypertension, and β-aminopropionitrile feeding. The cerebral aneurysms developed on the large arteries at the base of the brain, such as the anterior communicating artery and the internal carotid artery at the origin of the posterior communicating artery. Because of the similarity of the monkey to man as a species, the present results strongly suggest the significance of postnatal aggravating factors in the development of cerebral aneurysms in man.

Nonvisualization of a large cerebral aneurysm despite highresolution magnetic resonance angiography

1995 ◽  
Vol 82 (2) ◽  
pp. 294-295 ◽  
Author(s):  
Alan Turtz ◽  
David Allen ◽  
Robert Koenigsberg ◽  
H. Warren Goldman
Keyword(s):  
Magnetic Resonance ◽  
High Resolution ◽  
Magnetic Resonance Angiography ◽  
Cerebral Aneurysm ◽  
Mr Angiography ◽  
Cerebral Aneurysms ◽  
Arterial Aneurysm ◽  
Content Type ◽  
Fine Print

✓ The use of magnetic resonance (MR) angiography as a safe, accurate, and reliable substitute for invasive cerebral arteriography has been anticipated as refinements in this technique are introduced. We present the case of an unruptured, 11-mm pericallosal arterial aneurysm not visualized on high-resolution MR angiography. Although this case may be atypical, we caution against complete reliance on this test for exclusion of the presence of cerebral aneurysms.

Postoperative intracranial pressure in patients operated on for cerebral aneurysms following subarachnoid hemorrhage

1981 ◽  
Vol 54 (6) ◽  
pp. 726-732 ◽  
Author(s):  
Andrew H. Kaye ◽  
David Brownbill
Keyword(s):  
Subarachnoid Hemorrhage ◽  
Intracranial Pressure ◽  
Postoperative Period ◽  
Cerebral Aneurysms ◽  
Anterior Communicating Artery ◽  
Antifibrinolytic Agents ◽  
Content Type ◽  
Plateau Waves ◽  
Arterial Vasospasm ◽  
Fine Print

✓ The postoperative intracranial pressure (ICP) in 36 patients operated on for cerebral aneurysm following subarachnoid hemorrhage was studied. Not only was the baseline ICP significantly lower in patients whose outcome was assessed as “good” as compared with those patients with a worse outcome at 1 month after surgery, but also the height of the plateau waves and B-waves was significantly less in the patients who did well. The baseline ICP and the height of the B-wave formation were unrelated to the position of the aneurysm. Plateau waves were marginally significantly higher in aneurysms of the anterior communicating artery complex. Neither preoperative hypertension nor the use of antifibrinolytic agents made any difference to postoperative ICP. In patients with cerebral arterial vasospasm found preoperatively on the angiograms, the ICP tended to be lower in the postoperative period than in those without spasm.

A new magnetic resonance head coil and head immobilization device for gamma knife radiosurgery: an analysis of geometric distortion and signal/noise characteristics

2002 ◽  
Vol 97 ◽  
pp. 563-568 ◽  
Author(s):  
Paul Jursinic ◽  
Robert Prost ◽  
Christopher Schultz
Keyword(s):  
Magnetic Resonance ◽  
Gamma Knife Radiosurgery ◽  
Geometric Distortion ◽  
Gradient Field ◽  
Main Magnetic Field ◽  
Content Type ◽  
Signal Noise ◽  
Noise Characteristics ◽  
Head Coil ◽  
Fine Print

Object. The authors report on a new head coil into which the Leksell aluminum localization frame can be easily and securely mounted. Mechanically, the head coil interferes little with the patient. Methods. The head coil, which is for magnetic resonance (MR) imaging, is a 12-element quadrature transmitand-receive high-pass birdcage coil with a nominal operation frequency (63.86 MHz). The coil was built into a plastic housing. This new head coil minimizes patient motion and provides a 20% increase in signal/noise ratios compared with standard head coils. An MR image test phantom was mounted in the coil and this allowed quantification of image distortion due to inhomogeneities in the main magnetic field, nonlinearity in the gradient field, and paramagnetism of the aluminum headframe. There were no significant differences in geometric distortion between the new head coil and the standard coil. Conclusions. The new head coil has advantages for reducing patient movement artifacts and has a better signal/noise ratio with no reduction in geometric accuracy.

Optic pathway glioma infiltrating into somatostatinergic pathways in a young boy with gigantism

1994 ◽  
Vol 81 (4) ◽  
pp. 595-600 ◽  
Author(s):  
Thomas J. Manski ◽  
Charles S. Ha worth ◽  
Bertrand J. Duval-Arnould ◽  
Elisabeth J. Rushing
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Optic Pathway Glioma ◽  
Optic Pathway ◽  
Resonance Imaging ◽  
Content Type ◽  
Hyperintense Signal ◽  
Immunocytochemical Studies ◽  
Stereotactic Biopsies ◽  
Fine Print

✓ The authors report gigantism in a 16-month-old boy with an extensive optic pathway glioma infiltrating into somatostatinergic pathways, as revealed by magnetic resonance imaging and immunocytochemical studies. Stereotactic biopsies of areas showing hyperintense signal abnormalities on T2-weighted images in and adjacent to the involved visual pathways provided rarely obtained histological correlation of such areas. The patient received chemotherapy, which resulted in reduction of size and signal intensity of the tumor and stabilization of vision and growth velocity.

Application of magnetic resonance neurography in the evaluation of patients with peripheral nerve pathology

1996 ◽  
Vol 85 (2) ◽  
pp. 299-309 ◽  
Author(s):  
Aaron G. Filler ◽  
Michel Kliot ◽  
Franklyn A. Howe ◽  
Cecil E. Hayes ◽  
Dawn E. Saunders ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Time Course ◽  
Spin Echo ◽  
Fast Spin Echo ◽  
Mr Neurography ◽  
Magnetic Resonance Neurography ◽  
Cross Sectional ◽  
Content Type ◽  
Direct Nerve ◽  
Fine Print

✓ Currently, diagnosis and management of disorders involving nerves are generally undertaken without images of the nerves themselves. The authors evaluated whether direct nerve images obtained using the new technique of magnetic resonance (MR) neurography could be used to make clinically important diagnostic distinctions that cannot be readily accomplished using existing methods. The authors obtained T2-weighted fast spin—echo fat-suppressed (chemical shift selection or inversion recovery) and T1-weighted images with planes parallel or transverse to the long axis of nerves using standard or phased-array coils in healthy volunteers and referred patients in 242 sessions. Longitudinal and cross-sectional fascicular images readily distinguished perineural from intraneural masses, thus predicting both resectability and requirement for intraoperative electrophysiological monitoring. Fascicle pattern and longitudinal anatomy firmly identified nerves and thus improved the safety of image-guided procedures. In severe trauma, MR neurography identified nerve discontinuity at the fascicular level preoperatively, thus verifying the need for surgical repair. Direct images readily demonstrated increased diameter in injured nerves and showed the linear extent and time course of image hyperintensity associated with nerve injury. These findings confirm and precisely localize focal nerve compressions, thus avoiding some exploratory surgery and allowing for smaller targeted exposures when surgery is indicated. Direct nerve imaging can demonstrate nerve continuity, distinguish intraneural from perineural masses, and localize nerve compressions prior to surgical exploration. Magnetic resonance neurography can add clinically useful diagnostic information in many situations in which physical examinations, electrodiagnostic tests, and existing image techniques are inconclusive.

Early changes measured by magnetic resonance imaging in cerebral blood flow, blood volume, and blood-brain barrier permeability following dexamethasone treatment in patients with brain tumors

1999 ◽  
Vol 90 (2) ◽  
pp. 300-305 ◽  
Author(s):  
Leif Østergaard ◽  
Fred H. Hochberg ◽  
James D. Rabinov ◽  
A. Gregory Sorensen ◽  
Michael Lev ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Magnetic Resonance ◽  
Brain Tumors ◽  
Mr Imaging ◽  
Blood Volume ◽  
Cerebral Blood Volume ◽  
Clinical Effects ◽  
Content Type ◽  
Fine Print

Object. In this study the authors assessed the early changes in brain tumor physiology associated with glucocorticoid administration. Glucocorticoids have a dramatic effect on symptoms in patients with brain tumors over a time scale ranging from minutes to a few hours. Previous studies have indicated that glucocorticoids may act either by decreasing cerebral blood volume (CBV) or blood-tumor barrier (BTB) permeability and thereby the degree of vasogenic edema.Methods. Using magnetic resonance (MR) imaging, the authors examined the acute changes in CBV, cerebral blood flow (CBF), and BTB permeability to gadolinium-diethylenetriamine pentaacetic acid after administration of dexamethasone in six patients with brain tumors. In patients with acute decreases in BTB permeability after dexamethasone administration, changes in the degree of edema were assessed using the apparent diffusion coefficient of water.Conclusions. Dexamethasone was found to cause a dramatic decrease in BTB permeability and regional CBV but no significant changes in CBF or the degree of edema. The authors found that MR imaging provides a powerful tool for investigating the pathophysiological changes associated with the clinical effects of glucocorticoids.

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