Contribution of advanced MRI to the diagnosis of giant tumefactive perivascular spaces

Background Giant tumefactive perivascular spaces (PVSs) are uncommon benign cystic lesions. They can imitate cystic neoplasms. Purpose To evaluate the contribution of advanced neuro magnetic resonance imaging (MRI) techniques in the diagnosis of giant tumefactive PVSs and to further characterize these unusual cerebral lesions. Material and Methods The MRI scans of patients with tumefactive PVS diagnosed between 2010 and 2019 were retrospectively reviewed. All imaging studies included three plane conventional cerebral MRI sequences as well as precontrast 3D T1 MPRAGE, post-gadolinium 3D T1 acquisitions, sagittal plane 3D T2 SPACE, diffusion-weighted imaging, and time-of-flight (TOF) angiography. Some patients received perfusion MR, MR spectroscopy, diffusion tensor imaging (DTI), and contrast-enhanced TOF MR angiography. Results A perforating vessel was demonstrated in 16 patients (66.7%) by TOF imaging. In four patients, there were intracystic vascular collaterals on contrast-enhanced TOF MR angiography. Septal blooming was observed in four patients in susceptibility-weighted imaging. On perfusion MR, central hyperperfusion was observed in four patients, and peripheral hyperperfusion was observed in one patient. On MR spectroscopy, choline increase was observed in two patients, and there was a lactate peak in three patients, and both a choline increase and lactate peak in one patient. On DTI, there was fiber distortion in five patients and fiber deformation in one patient. Conclusion Advanced MRI techniques and 3D volumetric high-resolution MRI sequences can provide a valuable contribution to the diagnosis and can be successfully used in the management of these lesions.