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Published on: September 25, 2009
Fenestration of the middle cerebral artery detected by MR angiography
Akira Uchino1, Yukinori Takase, Keita Nomiyama
1Department of Radiology, Saga Medical School, Nabeshima, Saga, Japan. uchino@med.saga-u.ac.jp
Abstract:
Unlike fenestration of the posterior cerebral arterial circulation, fenestration of the anterior cerebral arterial circulation has not been well described. We investigated the location and configuration of fenestration of the middle cerebral artery (MCA) detected by magnetic resonance (MR) angiography. We found 6 fenestrations of the MCA among cranial MR angiography images obtained from about 2,000 patients during the past 9 years at our institution using either of two 1.5T imagers. All images were obtained by the three-dimensional time-of-flight technique. Maximum-intensity projection images in the horizontal rotation view were displayed stereoscopically. All 6 fenestrations had small slit-like configurations, five located at the proximal M1 segment, the other, at the middle M1 segment. No associated aneurysm was found. Although MCA fenestration is extremely rare and cerebral artery fenestration usually has no clinical significance, an aneurysm can arise at the proximal end of the fenestration. Thus, recognizing MCA fenestration is important when interpreting cranial MR angiograms.
Insights
Middle cerebral artery (MCA) fenestrations are rare, with 6 identified in 2,000 patients via MR angiography. These slit-like fenestrations, typically in the M1 segment, are important to recognize for interpreting angiograms.
Area of Science:
- Neurology
- Radiology
- Vascular Anatomy
Background:
- Fenestration of the anterior cerebral arterial circulation, particularly the middle cerebral artery (MCA), is infrequently documented.
- Understanding variations in cerebral artery anatomy is crucial for accurate neurovascular imaging interpretation.
Purpose of the Study:
- To investigate the occurrence, location, and configuration of middle cerebral artery (MCA) fenestrations.
- To highlight the importance of recognizing MCA fenestrations in clinical practice.
Main Methods:
- Retrospective analysis of cranial magnetic resonance (MR) angiography images from approximately 2,000 patients.
- Utilized 3D time-of-flight (TOF) MR angiography on 1.5T imagers.
- Employed stereoscopic display of maximum-intensity projection (MIP) images for detailed visualization.
Main Results:
- Six instances of MCA fenestration were identified among the patient cohort.
- All fenestrations presented as small, slit-like openings.
- Five fenestrations were located in the proximal M1 segment, and one was in the middle M1 segment.
- No associated aneurysms were observed in these cases.
Conclusions:
- MCA fenestration is an exceptionally rare finding.
- While typically asymptomatic, awareness of MCA fenestration is vital for neuro-radiologists to prevent misinterpretation and identify potential associated risks, such as aneurysm formation.
