Abstract
Abstract: A newly recognized fourth type of perivascular space has recently been described in the radiological literature. Despite its growing relevance, many radiologists
are still unfamiliar with its imaging characteristics, often leading to misinterpretation
as cystic neoplasms. Due to its potential for diagnostic confusion, further studies are
necessary—particularly those incorporating high-quality imaging examples across various
presentations—to facilitate accurate recognition and classification. Perivascular spaces
(PVSs) of the brain are cystic, fluid-filled structures formed by the pia mater and located
alongside cerebral blood vessels, particularly penetrating arterioles, venules, and capillaries. Under normal conditions, these spaces are small (typically <2 mm in diameter), but
in rare instances, they may become markedly enlarged (>15 mm), exerting a mass effect
on adjacent brain tissue. This newly identified fourth type of PVS is found in association
with the M2 and M3 segments of the middle cerebral artery, typically within the anterior
temporal lobe white matter. It may mimic low-grade cystic tumors on imaging due to its
size and frequent presence of surrounding perifocal edema. We present two adult male
patients with this rare PVS variant. The first patient, a 63-year-old, had a brain magnetic
resonance imaging scan (MRI) that revealed a cystic lesion in the white matter of the right
temporal lobe anterior pole, near the middle cerebral artery M2 segment, with perifocal
vasogenic edema. The second patient, a 67-year-old, had a brain MRI that showed a cystic
lesion in the white matter and subcortical region of the right temporal lobe anterior pole,
with minimal surrounding gliosis or minimal edema. The cystic lesions in both patients
remained unchanged over time on follow-up MRI. These cases illustrate the radiological
complexity of this under-recognized entity and emphasize the importance of differential
diagnosis to avoid unnecessary intervention.
are still unfamiliar with its imaging characteristics, often leading to misinterpretation
as cystic neoplasms. Due to its potential for diagnostic confusion, further studies are
necessary—particularly those incorporating high-quality imaging examples across various
presentations—to facilitate accurate recognition and classification. Perivascular spaces
(PVSs) of the brain are cystic, fluid-filled structures formed by the pia mater and located
alongside cerebral blood vessels, particularly penetrating arterioles, venules, and capillaries. Under normal conditions, these spaces are small (typically <2 mm in diameter), but
in rare instances, they may become markedly enlarged (>15 mm), exerting a mass effect
on adjacent brain tissue. This newly identified fourth type of PVS is found in association
with the M2 and M3 segments of the middle cerebral artery, typically within the anterior
temporal lobe white matter. It may mimic low-grade cystic tumors on imaging due to its
size and frequent presence of surrounding perifocal edema. We present two adult male
patients with this rare PVS variant. The first patient, a 63-year-old, had a brain magnetic
resonance imaging scan (MRI) that revealed a cystic lesion in the white matter of the right
temporal lobe anterior pole, near the middle cerebral artery M2 segment, with perifocal
vasogenic edema. The second patient, a 67-year-old, had a brain MRI that showed a cystic
lesion in the white matter and subcortical region of the right temporal lobe anterior pole,
with minimal surrounding gliosis or minimal edema. The cystic lesions in both patients
remained unchanged over time on follow-up MRI. These cases illustrate the radiological
complexity of this under-recognized entity and emphasize the importance of differential
diagnosis to avoid unnecessary intervention.
| Original language | English |
|---|---|
| Article number | 1486 |
| Journal | Diagnostics |
| Volume | 15 |
| Issue number | 12 |
| DOIs | |
| Publication status | Published - 11 Jun 2025 |
Keywords*
- opercular perivascular space
- magnetic resonance imaging
- edema
Field of Science*
- 3.2 Clinical medicine
Publication Type*
- 1.4. Reviewed scientific article published in Latvia or abroad in a scientific journal with an editorial board (including university editions)