Three-dimensional volume rendering for magnetic resonance angiography in the screening and preoperative workup of intracranial aneurysms

1996 ◽  
Vol 85 (6) ◽  
pp. 1050-1055 ◽  
Author(s):  
Philippe P. Maeder ◽  
Reto A. Meuli ◽  
Nicolas de Tribolet
Keyword(s):  
Magnetic Resonance ◽  
Volume Rendering ◽  
Intracranial Aneurysms ◽  
Mr Angiography ◽  
Three Dimensional ◽  
Time Of Flight ◽  
Conventional Angiography ◽  
Content Type ◽  
Aneurysm Neck ◽  
Fine Print

✓ This study was undertaken to evaluate the capacity of three-dimensional (3-D) time-of-flight (TOF) magnetic resonance (MR) angiography with VoxelView (VV) 3-D volume rendering to detect and characterize intracranial aneurysms and to compare this rendering technique with that of maximum intensity projection (MIP). Forty patients with a total of 53 intracranial aneurysms (10 giant and subgiant, 43 saccular) were consecutively admitted to University Hospital, Lausanne, Switzerland, and investigated with 3-D TOF MR angiography. Source images of the 43 saccular aneurysms were processed with both MIP and VV. The aneurysm detection rate of the two techniques and their ability to characterize features of an aneurysm, such as its neck and its relation to the parent vessel, were compared. Intraarterial digital subtraction angiography was used as the gold standard to which these techniques could be compared and evaluated. Four aneurysms, less than 3 mm in size, were missed using MIP compared to three missed using VV. The representation of aneurysmal morphology using VV was superior to that found using conventional angiography in nine cases, equal in 16 cases, and inferior in seven cases. The representation of the aneurysm neck using VV was superior to MIP in 21 cases, equal in 17 cases, and inferior in one case; it was superior to that shown using conventional angiography in 10 cases, equal in 18 cases, and inferior in four cases. Time-of-flight MR angiography in conjunction with both MIP and VV 3-D reconstruction was able to visualize all aneurysms that were larger than 3 mm. Compared to MIP, VV provides a better definition of the aneurysm neck and the morphology of saccular aneurysms, making VV valuable for use in a preoperative diagnostic workup.

Detailed anatomy of the motor and sensory roots of the trigeminal nerve and their neurovascular relationships: a magnetic resonance imaging study

2004 ◽  
Vol 101 (3) ◽  
pp. 427-434 ◽  
Author(s):  
Indra Yousry ◽  
Bernhard Moriggl ◽  
Markus Holtmannspoetter ◽  
Urs D. Schmid ◽  
Thomas P. Naidich ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Trigeminal Nerve ◽  
Mr Angiography ◽  
Three Dimensional ◽  
Content Type ◽  
Cerebellar Artery ◽  
Motor Root ◽  
Sensory Root ◽  
Angiography Sequences ◽  
Fine Print

Object. The trigeminal nerve conducts both sensory and motor impulses. Separate superior and inferior motor roots typically emerge from the pons just anterosuperomedial to the entry point of the sensory root, but to date these two motor roots have not been adequately displayed on magnetic resonance (MR) images. The specific aims of this study, therefore, were to identify the superior and inferior motor roots, to describe their exact relationship to the sensory root, and to assess the neurovascular relationships among all three roots of the trigeminal nerve. Methods. Thirty-three patients and seven cadaveric specimens (80 sides) were studied using three-dimensional (3D) Fourier transform constructive interference in steady-state (CISS) imaging. The 33 patients were also studied by obtaining complementary time-of-flight (TOF) MR angiography sequences with and without contrast enhancement. At least one motor root was identified in all sides examined: in 51.2% of the sides a single motor root, in 37.5% two motor roots, and in 11.2% three motor roots. The superior cerebellar artery (SCA) and the anterior inferior cerebellar artery (AICA) contacted the sensory root in 45.5% of patients and 42.9% of specimens. The SCA often contacted the superior motor root (48.5% of patients and 50% of specimens) and less frequently the inferior motor root (26.5% of patients and 20% of specimens). Conclusions. Three-dimensional CISS and complementary 3D TOF MR angiography sequences reliably display sensory, superior motor, and inferior motor roots of the trigeminal nerve and their relationships to the SCA and AICA.

Clinical significance of the flow gap in carotid magnetic resonance angiography

1996 ◽  
Vol 85 (3) ◽  
pp. 384-387 ◽  
Author(s):  
Joseph E. Heiserman ◽  
Joseph M. Zabramski ◽  
Burton P. Drayer ◽  
Paul J. Keller
Keyword(s):  
Magnetic Resonance ◽  
Carotid Stenosis ◽  
Mr Angiography ◽  
Vascular Pathology ◽  
Conventional Angiography ◽  
Content Type ◽  
Clinically Significant ◽  
Reliable Marker ◽  
Conventional Angiogram ◽  
Fine Print

✓ Magnetic resonance (MR) angiography offers a safe, noninvasive alternative to conventional angiography in patients with suspected carotid stenosis; however, it tends to overestimate the severity of stenosis. Loss of the MR signal with a resulting flow gap is a frequent finding in cases of high-grade stenosis. The authors undertook this study to define the range of carotid stenosis associated with a flow gap on two-dimensional time-of-flight (2DTF)-MR angiography. Blinded evaluations were made of 102 common carotid bifurcations in 51 patients who had undergone both conventional angiography and 2DTF-MR angiography. The percent of diameter stenosis was calculated from the conventional angiogram using the method adopted by the Asymptomatic Carotid Atherosclerosis Study (ACAS) trial. An MR flow gap was noted if there was a segment of the vessel that was completely free of signal with a reappearance of the signal distally. According to conventional angiography, the minimum percentage of stenosis associated with a flow gap is 56%. Flow gaps were present in 20 of 22 arteries (sensitivity 91%) with stenosis of 60% or more and in two of the 66 arteries (specificity 97%) with less than 60% stenosis. Flow gaps were present in all arteries with stenosis of 70% or more. Complete occlusion was correctly identified in 10 of 10 cases. These results demonstrate that the presence of a flow gap on 2DTF-MR angiography is a reliable marker of clinically significant carotid stenosis (measuring 60% or more), with sensitivity and specificity comparable to duplex carotid ultrasound. In addition, MR angiography can be used to screen the intracranial circulation for significant vascular pathology in patients being considered for carotid endarterectomy.

Limitations of three-dimensional reconstructed computerized tomography angiography after clip placement for intracranial aneurysms

2005 ◽  
Vol 103 (4) ◽  
pp. 656-661 ◽  
Author(s):  
Yoshiko Sagara ◽  
Hiro Kiyosue ◽  
Yuzo Hori ◽  
Michifumi Sainoo ◽  
Hirofumi Nagatomi ◽  
...  
Keyword(s):  
Ct Angiography ◽  
Computerized Tomography ◽  
Intracranial Aneurysms ◽  
Three Dimensional ◽  
Parent Artery ◽  
3D Ct ◽  
Metal Artifacts ◽  
Content Type ◽  
Aneurysm Neck ◽  
Fine Print

Object. The authors compared the usefulness of three-dimensional (3D) reconstructed computerized tomography (CT) angiography with 3D digital subtraction (DS) angiography in assessing intracranial aneurysms after clip placement. A retrospective review of clinical cases was performed. Methods. Between May 2001 and May 2003, 17 patients with a total of 20 intracranial aneurysms underwent 3D CT and 3D DS angiography following clip placement. The authors assessed the presence or absence of residual aneurysm necks and stenoocclusive changes in the parent artery and the neighboring artery. The efficacy of CT angiographic visualization was also evaluated. In 12 of the 20 aneurysms, both 3D modalities similarly demonstrated the residual aneurysm neck and stenoocclusive changes in the parent artery and neighboring artery. Three-dimensional CT angiography failed to demonstrate three of the aneurysms, and the studies were not considered suitable for evaluation because of the presence of metallic artifacts. In the remaining five studies, the 3D CT angiograms did not effectively demonstrate the neighboring and parent arteries. The detectability of residual aneurysm necks was correlated with the clip material and with the number of clips applied. Conclusions. Three-dimensional DS angiography is still necessary in cases involving multiple clips or with cobalt alloy clips because the clips appear as metal artifacts on 3D CT angiography.

Volume-rendered helical computerized tomography angiography in the detection and characterization of intracranial aneurysms

2000 ◽  
Vol 93 (2) ◽  
pp. 254-264 ◽  
Author(s):  
J. Pablo Villablanca ◽  
Neil Martin ◽  
Reza Jahan ◽  
Y. Pierre Gobin ◽  
John Frazee ◽  
...  
Keyword(s):  
Ct Angiography ◽  
Computerized Tomography ◽  
Intracranial Aneurysms ◽  
Mr Angiography ◽  
Content Type ◽  
Aneurysm Neck ◽  
Computerized Tomography Angiography ◽  
Impact On Treatment ◽  
Fine Print

Object. The goal of this study was to evaluate the utility of volume-rendered helical computerized tomography (CT) angiography in patients with intracranial aneurysms. The authors compared the abilities of CT angiography, digital subtraction (DS) angiography, and three-dimensional time-of-flight magnetic resonance (MR) angiography to characterize aneurysms.Methods. Helical CT angiography was performed in 45 patients with suspected intracranial aneurysms by using volume-rendered multiplanar reformatted (MPR) images. Digital subtraction angiography was performed using biplane angiography. These studies and those performed using MR angiography were interpreted in a blinded manner. Two neurosurgeons and two interventional neuroradiologists independently graded the utility of CT angiography with respect to aneurysm characterization.Fifty-five aneurysms were detected. Of these, 48 were evaluated for treatment. Computerized tomography angiography was judged to be superior to both DS and MR angiography in the evaluation of the arterial branching pattern at the aneurysm neck (compared with DS angiography, p = 0.001, and with MR angiography, p = 0.007), aneurysm neck geometry (compared with DS angiography, p = 0.001, and with MR angiography, p = 0.001), arterial branch incorporation (compared with DS angiography, p = 0.021, and with MR angiography, p = 0.001), mural thrombus (compared with DS angiography, p < 0.001), and mural calcification (compared with DS angiography, p < 0.001, and with MR angiography, p < 0.001). For surgical cases, CT angiography had a significant impact on treatment path (p = 0.001), operative approach (p = 0.001), and preoperative clip selection (p < 0.001). For endovascular cases, CT angiography had an impact on treatment path (p < 0.02), DS angiography study time (p = 0.01), contrast agent usage (p = 0.01), and coil selection (p = 0.02). Computerized tomography angiography provided unique information about 39 (81%) of 48 aneurysms, especially when compared with DS angiography (p = 0.003). The sensitivity and specificity of CT angiography compared with DS angiography was 1. The sensitivity and specificity of CT and DS angiography studies compared with operative findings were 0.98 and 1, respectively.Conclusions. Computerized tomography angiography is equal to DS angiography in the detection and superior to DS angiography and MR angiography in the characterization of brain aneurysms. Information contained in volume-rendered CT angiography images had a significant impact on case management.

Detachable balloon embolization therapy of posterior circulation intracranial aneurysms

1989 ◽  
Vol 71 (4) ◽  
pp. 512-519 ◽  
Author(s):  
Randall T. Higashida ◽  
Van V. Halbach ◽  
Leslie D. Cahan ◽  
Grant B. Hieshima ◽  
Yoshifumi Konishi
Keyword(s):  
Basilar Artery ◽  
Intracranial Aneurysms ◽  
Posterior Circulation ◽  
Parent Artery ◽  
Parent Vessel ◽  
Detachable Balloon ◽  
Content Type ◽  
Aneurysm Neck ◽  
Balloon Embolization ◽  
Fine Print

✓ Treatment of complex and surgically difficult intracranial aneurysms of the posterior circulation is now being performed with intravascular detachable balloon embolization techniques. The procedure is carried out under local anesthesia from a transfemoral arterial approach, which allows continuous neurological monitoring. Under fluoroscopic guidance, the balloon is propelled by blood flow through the intracranial circulation and, in most cases, can be guided directly into the aneurysm, thus preserving the parent vessel. If an aneurysm neck is not present, test occlusion of the parent vessel is performed and, if tolerated, the balloon is detached. Twenty-six aneurysms in 25 patients have been treated by this technique. The aneurysms have involved the distal vertebral artery (five cases), the mid-basilar artery (six cases), the distal basilar artery (11 cases), and the posterior cerebral artery (four cases). The aneurysms varied in size and included three small (< 12 mm), 15 large (12 to 25 mm), and eight giant (> 25 mm). Fifteen patients (60%) presented with hemorrhage and 10 patients (40%) with mass effect. In 17 cases (65%) direct balloon embolization of the aneurysm was achieved with preservation of the parent artery. In nine cases (35%), because of aneurysm location and size, occlusion of the parent vessel was performed. Complications from therapy included three cases of transient cerebral ischemia which resolved, three cases of stroke, and five deaths due to immediate or delayed aneurysm rupture. The follow-up period has ranged from 2 months to 43 months (mean 22.5 months). In cases where posterior circulation aneurysms have been difficult to treat by conventional neurosurgical techniques, intravascular detachable balloon embolization may offer an alternative therapeutic option.

Clinical application of functional magnetic resonance imaging in presurgical identification of the central sulcus

1998 ◽  
Vol 88 (5) ◽  
pp. 863-869 ◽  
Author(s):  
Jesús Pujol ◽  
Gerardo Conesa ◽  
Joan Deus ◽  
Luis López-Obarrio ◽  
Fabián Isamat ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Three Dimensional ◽  
Functional Magnetic Resonance ◽  
Central Sulcus ◽  
Clinical Context ◽  
Content Type ◽  
Sensorimotor Region ◽  
Specific Factors ◽  
Eloquent Cortex ◽  
Fine Print

Object. The authors sought to evaluate the advantages and limitations of functional magnetic resonance (fMR) imaging when it was used regularly in the clinical context to identify the central sulcus. Methods. A 1.5-tesla MR system comprising a spoiled gradient recalled acquisition in the steady-state functional sequence and a cross-hand cancellation analysis method were used to evaluate 50 surgical candidates with centrally located space-occupying lesions in the brain. Three-dimensional (3-D) models of the patient's head and brain showing the relative position of the tumor and the eloquent cortex were obtained in each case. A selective and reproducible focal activation was found, indicating the probable central sulcus position in 41 patients (82%). Direct cortical stimulation confirmed the fMR findings in 100% of 22 intraoperatively assessed patients. Failure to identify the central sulcus occurred in 18% of cases and was mainly a consequence of intrinsic damage in the primary sensorimotor region that resulted in severe hand paresis. Conclusions. Although specific factors were identified that contributed to reduced sensitivity of fMR imaging in the clinical context, the present study supports functional assessment and 3-D representation of specific surgical situations as generally feasible in common practice.

Intracranial aneurysms: diagnostic accuracy of three-dimensional, Fourier transform, time-of-flight MR angiography.

Radiology ◽  
1994 ◽  
Vol 193 (1) ◽  
pp. 181-186 ◽  
Author(s):  
Y Korogi ◽  
M Takahashi ◽  
N Mabuchi ◽  
H Miki ◽  
S Fujiwara ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Diagnostic Accuracy ◽  
Intracranial Aneurysms ◽  
Mr Angiography ◽  
Three Dimensional ◽  
Time Of Flight

Distortion in magnetic resonance images obtained for stereotactic localization

2000 ◽  
Vol 93 (supplement_3) ◽  
pp. 191-192 ◽  
Author(s):  
Lee Walton ◽  
Anna Hampshire ◽  
Paul Vaughan ◽  
David M. C. Forster ◽  
Andras A. Kemeny ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Mr Imaging ◽  
Three Dimensional ◽  
Magnetic Resonance Images ◽  
Side Plate ◽  
Content Type ◽  
Potential Source ◽  
Minimal Distortion ◽  
Source Of Error ◽  
Fine Print

✓ The purpose of this paper was to note a potential source of error in magnetic resonance (MR) imaging. Magnetic resonance images were acquired for stereotactic planning for GKS of a vestibular schwannoma in a female patient. The images were acquired using three-dimensional sequence, which has been shown to produce minimal distortion effects. The images were transferred to the planning workstation, but the coronal images were rejected. By examination of the raw data and reconstruction of sagittal images through the localizer side plate, it was clearly seen that the image of the square localizer system was grossly distorted. The patient was returned to the MR imager for further studies and a metal clasp on her brassiere was identified as the cause of the distortion.

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