Opercular perivascular cysts: A proposed new subtype of dilated perivascular spaces

• Published in: European journal of radiology Vol. 124; p. 108838
• Main Authors: McArdle, David John Tobias, Lovell, Timothy John Haynes, Lekgabe, Ernest, Gaillard, Frank
• Format: Journal Article
• Language: English
• Published: Ireland Elsevier B.V 01.03.2020
• Subjects: Anterior temporal lobe; MRI; Neuroradiology; Opercular perivascular cyst; Perivascular space; Virchow-Robin space; Perivascular space; Opercular perivascular cyst; MRI; Anterior temporal lobe; Neuroradiology; Virchow-Robin space
• DOI: 10.1016/j.ejrad.2020.108838
• ISSN: 0720-048X

•Dilated perivascular spaces in the brain are classified based on relationship to vessels.•We describe a unique variant associated with a vascular loop of an MCA branch.•These are seen in either the anterior temporal or opercular frontal lobes.•These should be considered a type IV perivascular space. Dilated perivascular spaces are a common finding on brain MRI, traditionally classified into three types based on location and relationship to vessels. Recent studies have characterised an additional variant of dilated perivascular spaces that arise within the anterior temporal lobe and have unique neuroimaging features. These particular perivascular spaces are associated with a vascular loop of a branch of the middle cerebral artery (MCA) and commonly demonstrate perilesional T2/FLAIR signal. To our knowledge, these have not previously been described in the frontal lobe. Dilated perivascular spaces associated with a vascular loop of a branch of the middle cerebral artery (MCA) identified at our institution were reviewed for imaging characteristics and anatomical location. 18 cases were identified. 16 were located in the anterior temporal lobe and two were located in the frontal operculum. All demonstrated internal signal characteristics identical to CSF on all sequences, with no contrast enhancement or susceptibility artefact and variable perilesional T2/FLAIR signal. We report further evidence of a distinct subtype of dilated perivascular spaces occurring in the anterior temporal lobe in association with a vascular loop of a branch of the MCA. In addition, we have demonstrated that these may also occur in the frontal operculum. We therefore suggest that these dilated perivascular spaces of the operculum be recognised as a separate, fourth, subtype of perivascular space and propose the term “opercular perivascular cyst”.