Regarding “CTA Evaluation of Basilar Septations: An Entity Better Characterized as Aberrant Basilar Fenestrations”
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* J. Hynes
* E. Kavanagh

We read with great interest the recent article by Small et al,1 “CTA Evaluation of Basilar Septations: An Entity Better Characterized as Aberrant Basilar Fenestrations,” a retrospective review describing luminal abnormalities of the basilar artery. We wish to highlight a recent case at our institution that we believe constitutes an interesting example of a further variation in the luminal morphology of the basilar artery.

A 71-year-old male patient presented with transient sensory disturbance of the right upper limb, clinically considered to be suggestive of a transient ischemic attack. The patient underwent noncontrast CT of the head, CT angiography of the head and neck, and subsequently MR imaging of the brain. Imaging did not demonstrate an acute infarct or vascular occlusion; however, note was made of abnormal morphology of the vertebrobasilar system with what was interpreted as a small communicating vessel joining the distal V4 segments of the vertebral arteries (Fig 1). It is possible, however, that this, in fact, represents a further transversely orientated variant of basilar fenestration morphology, not conforming directly to the classification described by Small et al. We have been unable to identify additional previously described examples of this in the literature.2⇓-4 Incidentally,the patient’s imaging also demonstrated a right-sided persistent trigeminal artery (Fig 2).

![FIG 1.](http://www.ajnr.org/https://www.highwirestage.com/content/ajnr/42/9/E71/F1.medium.gif)

[FIG 1.](http://www.ajnr.org/content/42/9/E71/F1)

FIG 1. 
MIP TOF-MRA image demonstrates a small vascular communication (*arrow*) between the distal vertebral arteries.

![FIG 2.](http://www.ajnr.org/https://www.highwirestage.com/content/ajnr/42/9/E71/F2.medium.gif)

[FIG 2.](http://www.ajnr.org/content/42/9/E71/F2)

FIG 2. 
MIP TOF-MRA image demonstrates a right-sided persistent trigeminal artery (*arrow*).

## References

1.  1.Small JE, Macey MB, Wakhloo AK, et al. CTA evaluation of basilar septations: an entity better characterized as aberrant basilar fenestrations. AJNR Am J Neuroradiol 2021 Feb 18. [Epub ahead of print] doi:10.3174/ajnr.A7008 pmid:33602748
    
    [CrossRef](http://www.ajnr.org/lookup/external-ref?access_num=10.3174/ajnr.A7008&link_type=DOI) 
    
    [PubMed](http://www.ajnr.org/lookup/external-ref?access_num=33602748&link_type=MED&atom=%2Fajnr%2F42%2F9%2FE71.atom) 

2.  2.Pérez-Carrillo GJ, Hogg JP. Intracranial vascular lesions and anatomical variants all residents should know. Curr Probl Diagn Radiol 2010;39:91–109 doi:10.1067/j.cpradiol.2009.07.005 pmid:20307787
    
    [CrossRef](http://www.ajnr.org/lookup/external-ref?access_num=10.1067/j.cpradiol.2009.07.005&link_type=DOI) 
    
    [PubMed](http://www.ajnr.org/lookup/external-ref?access_num=20307787&link_type=MED&atom=%2Fajnr%2F42%2F9%2FE71.atom) 

3.  3.Case D, Kumpe D, Roark C, et al. Neuroangiography: review of anatomy, periprocedural management, technique, and tips. Semin Intervent Radiol 2020;37:166–74 doi:10.1055/s-0040-1709171 pmid:32419729
    
    [CrossRef](http://www.ajnr.org/lookup/external-ref?access_num=10.1055/s-0040-1709171&link_type=DOI) 
    
    [PubMed](http://www.ajnr.org/lookup/external-ref?access_num=32419729&link_type=MED&atom=%2Fajnr%2F42%2F9%2FE71.atom) 

4.  4.Thurlow PC, Andrus JM, Wholey MH. Common cervical and cerebral vascular variants. Interv Cardiol Clin 2014;3:123–34 doi:10.1016/j.iccl.2013.09.002 pmid:28582148
    
    [CrossRef](http://www.ajnr.org/lookup/external-ref?access_num=10.1016/j.iccl.2013.09.002&link_type=DOI) 
    
    [PubMed](http://www.ajnr.org/lookup/external-ref?access_num=28582148&link_type=MED&atom=%2Fajnr%2F42%2F9%2FE71.atom) 

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