Small high-signal lesions posterior to the intracranial vertebral artery incidentally identified by 3D FLAIR: retrospective study of 127 patients

• Published in: Neuroradiology Vol. 60; no. 6; pp. 591 - 597
• Main Authors: Kogue, Ryota, Maeda, Masayuki, Umino, Maki, Tsuchiya, Kazuhiro, Sakuma, Hajime
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.06.2018; Springer Nature B.V
• Subjects: Accessory nerve; Benign; Diagnostic Neuroradiology; Etiology; Females; Imaging; Lesions; Magnetic resonance imaging; Males; Medicine; Medicine & Public Health; Neurology; Neuroradiology; Neurosciences; Neurosurgery; Patients; Radiology; Signs and symptoms; Surgery; Vertebrae; Foramen magnum; Vertebral artery; 3D FLAIR; Spinal accessory nerve; Magnetic resonance imaging
• ISSN: 0028-3940; 1432-1920
• DOI: 10.1007/s00234-018-2027-z

Purpose A small, benign high-signal lesion (HSL) posterior to the intracranial vertebral artery (VA) at the foramen magnum is a new entity revealed by a 3D FLAIR sequence. However, this entity has not been sufficiently investigated. We aimed to investigate the MR imaging findings of HSLs posterior to the intracranial VA that were incidentally detected by 3D FLAIR. Methods We retrospectively evaluated 3717 patients using a 3-T MR unit. HSLs on 3D FLAIR were assessed for prevalence, size, contact with the spinal accessory nerve (SAN), and size changes on follow-up images. Results Of 3717 patients, 127 (3.4%) (58 males and 69 females; age, 60.0 ± 18.9 years) showed 142 HSLs posterior to the intracranial VA. In total, 114 patients (89.8%) had a single lesion, whereas 13 patients (10.2%) had multiple lesions. The mean lesion size was 3.8 ± 1.6 mm. All HSLs showed contact with the ipsilateral SAN. Of 69 HSLs that were imaged during follow-up, the size was stable in 91.3% and increased in 8.7%. Conclusion HSLs posterior to the intracranial VA were incidentally detected in 3.4% of patients by 3D FLAIR. Our results indicated a possible association between HSLs and SAN. These lesions appear to be benign in etiology and thus would not require any surgical intervention without continuous growth in a short period or relevant signs and symptoms.