1
|
Igase K, Matsubara I, Igase M, Miyazaki H, Sadamoto K. Initial experience in evaluating the prevalence of unruptured intracranial aneurysms detected on 3-tesla MRI. Cerebrovasc Dis 2012; 33:348-53. [PMID: 22378479 DOI: 10.1159/000336015] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2011] [Accepted: 12/15/2011] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Given the very poor outcome of ruptured intracranial aneurysms, detection and treatment of unruptured intracranial aneurysms by a less invasive examination have become important. For this purpose, 3-tesla (3T) magnetic resonance imaging (MRI) is the most suitable candidate, owing to its high signal/noise ratio and frequency resolution. However, few reports have investigated the prevalence of intracranial aneurysms with high-tesla MRI. Here, we evaluated the prevalence of intracranial aneurysms and the effectiveness of a 3T MRI system in their detection. METHODS During a 1-year period, a total of 3,414 consecutive patients undergoing MR angiography with 3T MRI for the first time were enrolled. Diagnosis of intracranial aneurysm was made by two neuroradiologically trained medical doctors under complete blinding to patient information. When intracranial aneurysm was suspected, volume-rendering images were created for more accurate diagnosis. RESULTS Surprisingly, 317 unruptured intracranial aneurysms were identified in 286 of 3,414 cases (8.4%); 151 unruptured aneurysms (47.6%) occurred in the internal carotid artery, 85 (26.8%) in the middle cerebral artery, 54 (17.0%) in the anterior cerebral artery, and 27 (8.5%) in the posterior circulation. Of these, 152/317 (47.9%) were <3 mm, 104 (32.8%) ranged from 3 to 5 mm, 5 (11.0%) from 5 to 7 mm, and 26 (8.2%) were >7 mm. No significant difference in size was seen among the four locations. CONCLUSIONS For the first time, this study assessed the detection rate of intracranial aneurysms using 3T MRI. Results showed a higher detection rate than previously documented. The reason for this higher rate is likely the improved ability of this modality to detect unruptured aneurysms in the internal carotid artery and those <3 mm.
Collapse
Affiliation(s)
- Keiji Igase
- Department of Neurosurgery, Washokai Sadamoto Hospital, Matsuyama, Ehime, Japan.
| | | | | | | | | |
Collapse
|
2
|
Abstract
Continued advances in radiofrequency hardware and tailored software have, in recent times, greatly increased the power and performance of magnetic resonance imaging for noninvasive evaluation of cardiovascular diseases. Magnetic resonance imaging can uniquely be manipulated to trade temporal resolution and spatial resolution against each other, depending on whether detailed structural or functional information is required. However, to date, a number of cardiovascular magnetic resonance applications have been somewhat limited due to signal-to-noise ratio constraints, reflecting the narrow imaging window imposed by physiological cardiac motion. By increasing the operating field strength from 1.5 to 3 T, it is possible (in principle) to double the signal-to-noise ratio, which in turn may be "traded" for improvements in spatial resolution, coverage, or imaging speed. In this context, the development of parallel imaging has set the stage for impressive performance improvements in contrast-enhanced magnetic resonance angiography at 3 T. Indeed, one could argue that without parallel acquisition, the bang for the buck in going from 1.5 to 3 T would be limited. In this paper, we discuss the current status of 3-T magnetic resonance imaging for cardiovascular imaging, considering the relative gains and limitations relative to 1.5 T.
Collapse
|
3
|
Tsushima Y, Taketomi-Takahashi A, Endo K. Prevalence of abnormal findings on brain magnetic resonance (MR) examinations in adult participants of brain docking. BMC Neurol 2005; 5:18. [PMID: 16207376 PMCID: PMC1266373 DOI: 10.1186/1471-2377-5-18] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2005] [Accepted: 10/05/2005] [Indexed: 11/10/2022] Open
Abstract
Background To determine the prevalence of abnormal findings on brain magnetic resonance (MR) examinations in adult participants of brain docking in order to assess its usefulness. Methods We analyzed screening brain MR examinations for 1113 adults (age, 52.6+/-8.5 years; range, 22–84; 761 male and 352 female) performed during 6-year period from April 1998 to March 2004. All participants voluntarily sought a brain MR examination at their own expense. All subjects were studied using the same 1.0-T MR scanner, on axial T1-weighted spin echo (SE) images, proton-density-weighted and T2-weighted fast SE images, and intracranial MR angiography (MRA). All abnormal findings were classified into three basic categories: (1) findings with no referral necessary; (2) findings not requiring further evaluation, but which needed to be reported to the referring physician; (3) findings requiring further evaluation. Results Participants with abnormal MR findings requiring further evaluation accounted for 1.3 %, but five of seven suspected intracranial aneurysms were not confirmed by other imaging modalities (false positive). No malignant tumors or other life-threatening pathology was detected, and only three participants (0.27 %) with abnormalities underwent surgical treatment. No participant groups were identified from our data as being high risk for MR abnormal findings requiring further evaluation. Conclusion Brain-docking participants had a variety of abnormalities on brain MR examinations, but only a small percentage of these findings required further evaluation. The usefulness of the brain docking with MRI and MRA has yet to be proven, and at this time we cannot approve this screening procedure.
Collapse
Affiliation(s)
- Yoshito Tsushima
- Department of Radiology, Motojima General Hospital, Ohta, 373-0033 Japan
| | - Ayako Taketomi-Takahashi
- Department of Diagnostic Radiology and Nuclear Medicine Gunma University Hospital, Maebashi, Japan
| | - Keigo Endo
- Department of Diagnostic Radiology and Nuclear Medicine Gunma University Hospital, Maebashi, Japan
| |
Collapse
|
4
|
Broderick JP, Sauerbeck LR, Foroud T, Huston J, Pankratz N, Meissner I, Brown RD. The Familial Intracranial Aneurysm (FIA) study protocol. BMC MEDICAL GENETICS 2005; 6:17. [PMID: 15854227 PMCID: PMC1097731 DOI: 10.1186/1471-2350-6-17] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 03/31/2005] [Accepted: 04/26/2005] [Indexed: 12/21/2022]
Abstract
Background Subarachnoid hemorrhage (SAH) due to ruptured intracranial aneurysms (IAs) occurs in about 20,000 people per year in the U.S. annually and nearly half of the affected persons are dead within the first 30 days. Survivors of ruptured IAs are often left with substantial disability. Thus, primary prevention of aneurysm formation and rupture is of paramount importance. Prior studies indicate that genetic factors are important in the formation and rupture of IAs. The long-term goal of the Familial Intracranial Aneurysm (FIA) Study is to identify genes that underlie the development and rupture of intracranial aneurysms (IA). Methods/Design The FIA Study includes 26 clinical centers which have extensive experience in the clinical management and imaging of intracerebral aneurysms. 475 families with affected sib pairs or with multiple affected relatives will be enrolled through retrospective and prospective screening of potential subjects with an IA. After giving informed consent, the proband or their spokesperson invites other family members to participate. Each participant is interviewed using a standardized questionnaire which covers medical history, social history and demographic information. In addition blood is drawn from each participant for DNA isolation and immortalization of lymphocytes. High- risk family members without a previously diagnosed IA undergo magnetic resonance angiography (MRA) to identify asymptomatic unruptured aneurysms. A 10 cM genome screen will be performed to identify FIA susceptibility loci. Due to the significant mortality of affected individuals, novel approaches are employed to reconstruct the genotype of critical deceased individuals. These include the intensive recruitment of the spouse and children of deceased, affected individuals. Discussion A successful, adequately-powered genetic linkage study of IA is challenging given the very high, early mortality of ruptured IA. Design features in the FIA Study that address this challenge include recruitment at a large number of highly active clinical centers, comprehensive screening and recruitment techniques, non-invasive vascular imaging of high-risk subjects, genome reconstruction of dead affected individuals using marker data from closely related family members, and inclusion of environmental covariates in the statistical analysis.
Collapse
Affiliation(s)
- Joseph P Broderick
- Department of Neurology, University of Cincinnati, 231 Albert Sabin Way, Cincinnati, OH 45267-0525, USA
| | - Laura R Sauerbeck
- Department of Neurology, University of Cincinnati, 231 Albert Sabin Way, Cincinnati, OH 45267-0525, USA
| | - Tatiana Foroud
- Medical & Molecular Genetics, Indiana University, 975 West Walnut St., IB 130, Indianapolis, IN 46202-5251, USA
| | - John Huston
- Department of Radiology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA
| | - Nathan Pankratz
- Medical & Molecular Genetics, Indiana University, 975 West Walnut St., IB 130, Indianapolis, IN 46202-5251, USA
| | - Irene Meissner
- Division of Cerebrovascular Disease and Department of Neurology, Mayo Clinic, 200, First Street SW, Rochester, MN 55905, USA
| | - Robert D Brown
- Division of Cerebrovascular Disease and Department of Neurology, Mayo Clinic, 200, First Street SW, Rochester, MN 55905, USA
| |
Collapse
|
5
|
Wilson GJ, Hoogeveen RM, Willinek WA, Muthupillai R, Maki JH. Parallel Imaging in MR Angiography. Top Magn Reson Imaging 2004; 15:169-85. [PMID: 15479999 DOI: 10.1097/01.rmr.0000134199.94874.70] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The recently developed techniques of parallel imaging with phased array coils are rapidly becoming accepted for magnetic resonance angiography (MRA) applications. This article reviews the various current parallel imaging techniques and their application to MRA. The increased scan efficiency provided by parallel imaging allows increased temporal or spatial resolution, and reduction of artifacts in contrast-enhanced MRA (CE-MRA). Increased temporal resolution in CE-MRA can be used to reduce the need for bolus timing and to provide hemodynamic information helpful for diagnosis. In addition, increased spatial resolution (or volume coverage) can be acquired in a breathhold (eg, in renal CE-MRA), or in otherwise limited clinically acceptable scan durations. The increased scan efficiency provided by parallel imaging has been successfully applied to CE-MRA as well as other MRA techniques such as inflow and phase contrast imaging. The large signal-to-noise ratio available in many MRA techniques lends these acquisitions to increased scan efficiency through parallel imaging.
Collapse
|
6
|
Willinek WA, Born M, Simon B, Tschampa HJ, Krautmacher C, Gieseke J, Urbach H, Textor HJ, Schild HH. Time-of-Flight MR Angiography: Comparison of 3.0-T Imaging and 1.5-T Imaging—Initial Experience. Radiology 2003; 229:913-20. [PMID: 14657322 DOI: 10.1148/radiol.2293020782] [Citation(s) in RCA: 136] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Intracranial three-dimensional time-of-flight (TOF) magnetic resonance (MR) angiography was performed in seven healthy volunteers and eight patients with both 1.5-T and 3.0-T MR systems with standard and high spatial resolutions (true voxel sizes, 0.48 x 0.75 x 2.00 mm and 0.30 x 0.44 x 1.00 mm, respectively). Superior image quality and significantly better depiction of small vessel segments and vascular disease were observed at high-spatial-resolution 3.0-T TOF MR angiography but not at standard 1.5-T or standard 3.0-T TOF MR angiography (P <.01, respectively). Intracranial high-spatial-resolution TOF MR angiography at 3.0-T imaging provides diagnostic improvement in studies of cerebrovascular disease.
Collapse
Affiliation(s)
- Winfried A Willinek
- Department of Radiology, University of Bonn, Sigmund-Freud-Strasse 25, D-53105 Bonn, Germany.
| | | | | | | | | | | | | | | | | |
Collapse
|
7
|
Kondoh T, Kurihara E, Kohmura E. Distal anterior inferior cerebellar artery aneurysm occult on magnetic resonance angiography one month prior to rupture--case report. Neurol Med Chir (Tokyo) 2003; 43:345-8. [PMID: 12924594 DOI: 10.2176/nmc.43.345] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A 77-year-old man suffered subarachnoid hemorrhage due to a ruptured aneurysm of the distal anterior inferior cerebellar artery (AICA). He had a history of hearing disturbance in the left ear for more than 3 years. Computed tomography on three separate occasions had found no abnormalities. One month before the hemorrhage, he came to our outpatient service complaining of vertigo. Magnetic resonance (MR) imaging and MR angiography detected no abnormality. Conventional angiography demonstrated an aneurysm of 8 mm diameter in the distal AICA region after the hemorrhage. Filling and wash out of the aneurysm sac by contrast medium was markedly delayed, which suggested that MR imaging had failed to detect the flow void because of the slow blood flow in the dome. The aneurysm was clipped successfully. He was discharged with mild dysarthria on the 33rd postoperative day. MR angiography has limitations in detecting unruptured aneurysms and there is certainly a high risk group of false negatives, including aneurysms located in the distal region of the main trunk.
Collapse
Affiliation(s)
- Takeshi Kondoh
- Department of Neurosurgery, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan.
| | | | | |
Collapse
|
8
|
Klötzsch C, Bozzato A, Lammers G, Mull M, Lennartz B, Noth J. Three-dimensional transcranial color-coded sonography of cerebral aneurysms. Stroke 1999; 30:2285-90. [PMID: 10548659 DOI: 10.1161/01.str.30.11.2285] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE The role of 2-dimensional transcranial color-coded sonography (2D-TCCS) as a diagnostic tool in cases of vascular alteration is unquestioned. The skill of the operator, however, may be responsible for some intertrial variability. The clinical value of a new, workstation-based, 3D reconstruction system for TCCS was evaluated in patients with intracranial aneurysms. METHODS Thirty patients with 30 intracranial aneurysms were investigated (8 men, 22 women; mean+/-SD age 54+/-17 years). The TCCS examinations were performed with a 2-MHz probe using the power mode. The 3D system (3D-Echotech, Germany) consisted of an electromagnet, which induced a low-intensity magnetic field near the head of the patient. A magnetic position sensor was attached to the ultrasound probe and transmitted the spatial orientation of the probe to a workstation, which also received the corresponding 2D-images from the video-port of the duplex machine. The echo contrast enhancer D-galactose (Levovist, Schering, Germany) was used in all patients to improve the signal-to-noise ratio. All patients underwent presurgical digital subtraction angiography (DSA) to demonstrate the aneurysm. RESULTS Twenty-nine of 30 angiographically proven intracranial aneurysms (97%) were detected by 3D-TCCS. The aneurysmal diameter estimated by DSA ranged from 3 to 16 mm (mean 7. 2+/-3.6 mm). A comparison of the 3 main diameters of each aneurysm revealed a correlation coefficient of 0.95 between DSA and 3D-TCCS. The 3D determination of the aneurysmal size by 2 experienced sonographers correlated with 0.96. CONCLUSIONS 3D-TCCS is a new, noninvasive method to investigate intracranial aneurysms. The differentiation between artifacts and true changes of the vessel anatomy is much easier in 3D-TCCS than in conventional 2D-TCCS. The new method yields an excellent correlation with the gold standard, DSA. Because the same 3D-TCCS data can be postprocessed by different investigators, it may be possible to improve reproducibility and increase the objectivity of transcranial color-coded duplex sonography.
Collapse
MESH Headings
- Angiography, Digital Subtraction
- Artifacts
- Computer Systems
- Contrast Media
- Electromagnetic Phenomena/instrumentation
- Female
- Galactose
- Humans
- Image Processing, Computer-Assisted/instrumentation
- Image Processing, Computer-Assisted/methods
- Intracranial Aneurysm/diagnostic imaging
- Male
- Middle Aged
- Observer Variation
- Polysaccharides
- Reproducibility of Results
- Signal Processing, Computer-Assisted
- Ultrasonography, Doppler, Color/instrumentation
- Ultrasonography, Doppler, Color/methods
- Ultrasonography, Doppler, Transcranial/instrumentation
- Ultrasonography, Doppler, Transcranial/methods
- Video Recording
Collapse
Affiliation(s)
- C Klötzsch
- Department of Neurology, Universitätsklinikum der Rheinisch-Westfälischen Technischen Hochschule, Aachen, Germany.
| | | | | | | | | | | |
Collapse
|