Giant Tumefactive Perivascular Space: Advanced Fusion MR Imaging and Tractography Study-A Case Report and a Systematic Review

Perivascular spaces (PVSs) are small extensions of the subpial cerebrospinal space, pial-lined and interstitial fluid-filled. They surround small penetrating arteries, and veins, crossing the subarachnoid space to the brain tissue. Magnetic Resonance Imaging (MRI) shows a PVS as a round-shape or linear structure, isointense to the cerebrospinal fluid, and, if larger than 1.5 cm, they are known as giant/tumefactive PVSs (GTPVS) that may compress neighboring parenchymal/liquoral compartment. We report a rare asymptomatic case of GTPVS type 1 in a diabetic middle-aged patient, occasionally discovered. Our MRI study focuses on diffusion/tractography and fusion imaging: three-dimensional (3D) constructive interference in steady state (CISS) and time of fly (TOF) sequences. The advanced and fusion MR techniques help us to track brain fiber to assess brain tissue compression consequences and some PVS anatomic features as the perforating arteries inside them.

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.

Large anterior temporal Virchow–Robin spaces: Evaluating MRI features over the years—Our experience and literature review

Dilated Virchow–Robin spaces (VRSs) are expansions of the normal perivascular spaces with a short axis greater than 2 mm or, according to some authors, greater than 3 mm. They are usually documented at the basal ganglia, at the convexity white matter (WM) and centrum semiovale, and at the mesencephalon. The anterior temporal WM is a recently described preferential location for large (≥5 mm) VRSs. The aim of our study was to evaluate the magnetic resonance imaging (MRI) features and their modifications during a long-term follow-up period (≥24 months) of the anterior temporal VRSs with a retrospective analysis among all brain MRI studies performed at our institution between January 2010 and January 2017. In our study, the presence and the stability of characteristic MRI features certainly increased our diagnostic confidence allowing us to continue conservative approach while the surrounding signal change, as reported in the literature, should not in itself prompt alternative diagnoses to be entertained.

Dilated Virchow-Robin space and Parkinson's disease: A case report of combined MRI and diffusion tensor imaging

In this manuscript we report the case of a 69-year-old female patient, who suffers from Parkinson's disease (PD) with a dilated Virchow-Robin space (dVRS) on the left anterior perforated substance. During a magnetic resonance imaging examination, the presence of a dVRS was discovered on the left anterior perforated substance. Subsequently, the patient has been subjected to further investigation of magnetic resonance imaging and diffusion tensor imaging (DTI). The DTI data of our PD patient showed increased peak frequency of left fractional anisotropy and decreases in the distribution of Mean Diffusivity(MD) with changes in the fiber density compared to the normal contralateral tract. We hypothesize that the DTI changes are due to dVRS. In the text a review of the recent literature on the presence of dVRSs, located in mono and bilateral seat, in patients with PD is reported, explaining its possible implications on disease progression, cognitive decline, and worsening of symptoms.

Enlarged Virchow-Robin Spaces in A Young Man: A Constrained Spherical Deconvolution Tractography Study

BACKGROUND AND AIM

Virchow-Robin spaces are mainly located along the path of the lenticulo-striate arteries in the basal ganglia through the anterior perforate substance, and can be found both in normal subjects, as a rare phenomenon, and in patients with different diseases. We report a case of a healthy young man with unilateral enlarged Virchow-Robin spaces in the left capsule-lenticulostriate area. Aim of this case report is to show the potential of probabilistic Constrained Spherical Deconvolution (CSD) tractography in showing abnormal diffusion tensor imaging and tractography of the anterior thalamic tracts caused by mass effect from adjacent enlarged Virchow-Robin spaces.

METHODS

The study was performed with a 3T magnetic resonance imaging (MRI) scanner (Achieva, Philips Healthcare, Best, Netherlands); equipped with a 32-channel SENSE head coil. Diffusion Weighted Images were analyzed by using CSD, a fast computation method that overcomes major limitations of Diffusion Tensor Imaging allowing reliable estimation of one or more fiber orientations in the presence of intravoxel orientational heterogeneity.

RESULTS

Tractography showed increased Fractional Anisotropy and reduced Apparent Diffusion Coefficient values, a displacement and compression of the anterior thalamic projections by part of the enlarged VRS, and a decrease of white matter fibers in the left side in comparison to the right one.

CONCLUSIONS

We report on a case of a healthy individual with unilateral dilated VRS in the capsulo-lenticulostriatal area, proving the utility of diffusion MRI and tractography in understanding the abnormal neuroanatomy of this particular condition.

Dilated perivascular spaces and fatigue: is there a link? Magnetic resonance retrospective 3Tesla study

INTRODUCTION

Fatigue (F) is a common, inexplicable, and disabling symptom in multiple sclerosis (MS) patients. The purpose of this study was to evaluate a possible correlation between fatigue and morpho-volumetric features and site of dilated perivascular spaces (dPS), visible on 3T magnetic resonance (MR) in fatigued multiple sclerosis patients (FMS).

METHODS

We studied 82 relapsing remitting (RR) FMS patients and 43 HC, matched for age, sex, and education. F was assessed by the Fatigue Severity Scale (FSS). To evaluate a possible correlation between degree of F and characteristics of dPS, patients were divided in two groups: more (mFMS) (FSS ≥ 5; n = 30) and less fatigued (lFMS) (FSS ≥ 4; n = 52), compared to a matched healthy control (HC) subject group. The MR study was performed with 3T scanner by SpinEcho T1, Fast-SpinEcho DP-T2, FLAIR, and 3D FSPGR T1 sequences. dPS volumes were measured with Medical Image Processing Analysis and Visualization (MIPAV); Global Cerebral Atrophy (GCA), expressed as Brain Parenchymal Fraction (BPF), was assessed by FSL SIENAX.

RESULTS

The t test showed significantly increased dPS number (p = 0.021) in FMS patients (mFMS p = 0.0024 and lFMS p = 0.033) compared to HC. Pearson correlation revealed a significant correlation between dPS number and FSS (r = 0.208 p = 0.051). Furthermore, the chi-squared test confirms the intragroup (HC, mFMS, lFMS) differences about dPS location (p = 0.01) and size (p = 0.0001).

CONCLUSION

Our study confirms that PS in MS patients presents with different volumetric and site characteristics as compared to HC; moreover, F severity significantly correlates with dPS number, site, and size.