3D FLAIR Images Research Articles

In vivo Detection of Cortical Microinfarcts on Ultrahigh‐Field MRI

Cortical microinfarcts (CMIs) are detected as small foci restricted to the cerebral cortex in autopsy brains. CMIs are thought to be caused by cerebral amyloid angiopathy (CAA) in the elderly and may be a risk for dementia. We aimed to visualize CMIs, which remain invisible on conventional MRI, using double inversion recovery (DIR) and 3-dimensional fluid attenuated inversion recovery (3D-FLAIR) on 3-Tesla MRI. We prospectively performed DIR and 3D-FLAIR images in 70 subjects with Alzheimer disease (AD; n = 47), mild cognitive impairment (n = 14), AD with cerebrovascular disease (CVD; n = 3), vascular dementia (VaD; n = 2), CAA-associated intracerebral hemorrhage (ICH; n = 2) and one each of normal pressure hydrocephalus and dementia with Lewy bodies (DLB). Susceptibility-weighted imaging (SWI) was performed to detect cerebral microbleeds (CMBs). Nine subjects (five of AD and one each of AD with CVD, ICH, VaD, and DLB) had small intracortical high signal lesions on both DIR and 3D-FLAIR images. All the nine subjects accompanied multiple lobar CMBs. These intracortical lesions were located in close proximity to CMBs, and were suggested to be CMIs. DIR and 3D-FLAIR images may open a way to visualize CMIs.

Optimizing MR Imaging Detection of Type 2 Focal Cortical Dysplasia: Best Criteria for Clinical Practice

Type 2 FCD is one of the main causes of drug-resistant partial epilepsy. Its detection by MR imaging has greatly improved surgical outcomes, but it often remains overlooked. Our objective was to determine the prevalence of typical MR imaging criteria for type 2 FCD, to provide a precise MR imaging pattern, and to optimize its detection. We retrospectively reviewed 1.5T MR imaging of 71 consecutive patients with histologically proved type 2 FCD. The protocol included millimetric 3D T1-weighted, 2D coronal and axial T2-weighted, and 2D or 3D FLAIR images. Two experienced neuroradiologists looked for 6 criteria: cortex thickening, cortical and subcortical signal changes, blurring of the GWM interface, the "transmantle" sign, and gyral abnormalities. The frequency of each sign and their combination were assessed. We compared the delay between epilepsy onset and surgery, taking into account the time of type 2 FCD detection by MR imaging. Only 42 patients (59%) had positive MR imaging findings. In this group, a combination of at least 3 criteria was always found. Subcortical signal changes were constant. Three characteristic signs (cortical thickening, GWM blurring, and transmantle sign) were combined in 64% of patients, indicating that MR imaging can be highly suggestive. However, typical features of type 2 FCD were overlooked on initial imaging in 40% of patients, contributing to a delay in referral for surgical consideration (17 versus 11.5 years when initial MR imaging findings were positive). A combination of 3 major MR imaging signs allows type 2 FCD to be recognized in clinical practice, thereby enabling early identification of candidates for surgery.

Spotlight on the January 31 Issue

Single-slab 3D DIR (double inversion recovery) and 3D FLAIR images of 56 matched fresh brain samples from 14 patients with chronic multiple sclerosis (MS) were acquired at 1.5 T. DIR is a useful technique to visualize cortical lesions in MS; many lesions are still missed, but those that are detected are likely actual lesions in terms of histopathology. See p. 302 From editorialists Ciccarelli & Chen: “Although DIR MRI is a recent innovation, it has provided important insights into the occurrence of cortical pathology in all subtypes of MS and the association …

Comparison of 3D FLAIR, 2D FLAIR, and 2D T2-Weighted MR Imaging of Brain Stem Anatomy

Although 3D FLAIR imaging visualizes detailed structures of the brain stem, it has not been used to evaluate its normal anatomy. The purpose of this study was to evaluate whether 3D FLAIR images can provide more detailed anatomic information of the brain stem than 2D FLAIR and 2D T2WI. We prospectively evaluated MR images in 10 healthy volunteers. 3D and 2D FLAIR images, 2D T2WI, and DTI were obtained on a 3T MR imaging scanner. A VISTA technique was used for 3D FLAIR imaging. White matter tracts and nuclei of the brain stem were determined on 3D and 2D FLAIR images and 2D T2WI by referring to anatomic atlases and DTI color maps. The subjective assessment of the visibility by using a 4-point grading system and the contrast ratio of the structures on 3D and 2D FLAIR images and 2D T2WI were evaluated. The visibility of the SCP and MCP, DSCP, CST, and CTT was higher on 3D FLAIR images than on 2D T2WI and 2D FLAIR images. The contrast ratio for the CST, SCP, MCP, DSCP, and CTT was significantly different on 3D FLAIR images and 2D T2WI and on 3D FLAIR and 2D FLAIR images; there was no significant difference in contrast ratio for the SCP at the pons on 3D FLAIR and 2D T2WI. 3D FLAIR images provide detailed anatomic information of the brain stem that cannot be obtained on 2D T2WI and 2D FLAIR images.

Enhancement Pattern of the Normal Facial Nerve on Three - Dimensional (3D) - Fluid Attenuated Inversion Recovery (FLAIR) Sequence at 3.0 T MR Units

Purpose : To compare the enhancement pattern of normal facial nerves on 3D-FLAIR and 3D-T1-FFE-F) sequences at 3.0 T MR units. Materials and Methods: We assessed 20 consecutive subjects without a history of facial nerve abnormalities who underwent temporal bone MRI with contrast enhancement between January 2008 and March 2009. Two neuroradiologists independently reviewed pre-/post-enhanced 3D-T1-FFE-FS and 3D-FLAIR images respectively with 2-week interval to assess the enhancement of normal facial nerves divided into five anatomical segments. The degree of enhancement in each segment was graded as none, mild or strong, and the results of 3D-FLAIR and 3D-T1-FFE-FS image sets were compared. Results: On 3D-FLAIR images, one of the two reviewers observed mild enhancement of the genu segment in two (10%) subjects. On 3D-T1-FFE-FS images, at least one segment of the facial nerve was enhanced in 13 (65%) subjects. At least one reviewer found that 17 of the 100 segments showed enhancement on 3D-T1-FFE-FS images, with the mastoid segment being the most commonly enhanced. Interobserver agreement on 3D-T1-FFE-FS images was good for enhancement of the normal facial nerve (= 0.589). Conclusion: In contrast to 3D-T1-FFE-FS, normal facial nerve segments rarely showed enhancement on 3D-FLAIR images.

MR Diagnosis of Facial Neuritis: Diagnostic Performance of Contrast-Enhanced 3D-FLAIR Technique Compared with Contrast-Enhanced 3D-T1-Fast-Field Echo with Fat Suppression

Current MRI with the CE T1-weighted sequence plays a limited role in the evaluation of facial neuritis due to prominent normal facial nerve enhancement. Our purpose was to retrospectively investigate the usefulness of the CE 3D-FLAIR sequence compared with the CE 3D-T1-FFE sequence in facial neuritis patients. We assessed 36 consecutive patients who underwent temporal bone MR imaging at 3T for idiopathic facial palsy. Two readers independently reviewed CE 3D-T1-FFE and CE 3D-FLAIR images to determine the degree of enhancement in each of 5 segments of the facial nerve. We compared AUCs using the Z-test, compared diagnostic performance of 2 MR techniques with the McNemar test, and evaluated interobserver agreement. The Pearson χ(2) test was used for each segment of the facial nerve. The AUC of CE 3D-FLAIR (reader 1, 0.754; reader 2, 0.746) was greater than that of CE 3D-T1-FFE (reader 1, 0.624; reader 2, 0.640; P < .001). The diagnostic sensitivities, specificities, and accuracies were 97.2%, 86.1%, and 91.7%, respectively, for CE 3D-FLAIR, and 100%, 56.9%, and 78.5%, respectively, for CE 3D-T1-FFE. The specificity and accuracy of CE 3D-FLAIR were greater than those of CE 3D-T1-FFE (specificity, P = .029; accuracy, P = .008). The interobserver agreements for CE 3D-FLAIR (κ-value, 0.831) and CE 3D-T1-FFE (κ-value, 0.694) were excellent. Enhancement of the canalicular and anterior genu segments on CE 3D-FLAIR were significantly correlated with the occurrence of facial neuritis (P < .001 for canalicular; P = .032 and 0.020 for anterior genu by reader 1 and reader 2, respectively). CE 3D-FLAIR can improve the specificity and overall accuracy of MR imaging in patients with idiopathic facial palsy.

Excipients and Their Role in Approved Injectable Products: Current Usage and Future Directions

This review article is a current survey of excipients used in approved injectable products. Information provided includes concentration ranges, function, frequency of use, and role in dosage form. This article is an update of a paper published more than a decade ago (reference 11). Since then many new products have been approved. Safety concerning excipients has evolved as the scientific community continues to learn about their usage. New excipients are being used in early phases of clinical trials to support novel therapeutic entities like RNAi, aptamers, anti-sense, fusion proteins, monoclonal antibodies, and variant scaffolds. Because these excipients are not inert, various pharmacopoeias are responding with monographs or informational chapters addressing excipient functionality. The final sections of this article discuss new excipients, serving specific needs that traditional excipients are unable to provide and for which safety studies are necessary to support a novel excipient for marketing applications. Excipients are added to parenteral dosage forms to serve a variety of functions including stabilization and as vehicles. This review article is a survey of excipients used in approved injectable products. Information provided includes excipient concentrations, functional roles, and frequency of use. This article is an update of an article originally published over a decade ago. Since then new products have been approved and safety concerns have evolved as the scientific community has learned about the usage of excipients. In addition, new excipients are being used in early phases of clinical trials to support novel therapeutic entities such as RNAi, aptamers, anti-sense, fusion proteins, monoclonal antibodies, and variant scaffolds. Because these excipients are not inert, various pharmacopoeias are responding with monographs or informational chapters addressing excipient functionality. The final sections of this article discuss new excipients, serving specific needs that traditional excipients are unable to provide and for which safety studies are necessary to support a novel excipient for marketing applications.

Identification and Clinical Impact of Multiple Sclerosis Cortical Lesions as Assessed by Routine 3T MR Imaging

Histopathologic studies have reported widespread cortical lesions in MS; however, in vivo detection by using routinely available pulse sequences is challenging. We investigated the relative frequency and subtypes of cortical lesions and their relationships to white matter lesions and cognitive and physical disability. Cortical lesions were identified and classified on the basis of concurrent review of 3D FLAIR and 3D T1-weighted IR-SPGR 3T MR images in 26 patients with MS. Twenty-five patients completed the MACFIMS battery. White matter lesion volume, cortical lesion number, and cortical lesion volume were assessed. Overall, 249 cortical lesions were detected. Cortical lesions were present in 24/26 patients (92.3%) (range per patient, 0-30; mean, 9.6 ± 8.8). Most (94.4%, n = 235) cortical lesions were classified as mixed cortical-subcortical (type I); the remaining 5.6% (n = 14) were classified as purely intracortical (type II). Subpial cortical lesions (type III) were not detected. White matter lesion volume correlated with cortical lesion number and cortical lesion volume (r(S) = 0.652, r(S) = 0.705, respectively; both P < .001). After controlling for age, depression, and premorbid intelligence, we found that all MR imaging variables (cortical lesion number, cortical lesion volume, white matter lesion volume) correlated with the SDMT score (R(2) = 0.513, R(2) = 0.449, R(2) = 0.418, respectively; P < .014); cortical lesion number also correlated with the CVLT-II scores (R(2) = 0.542-0.461, P < .043). The EDSS scores correlated with cortical lesion number and cortical lesion volume (r(S) = 0.472, r(S) = 0.404, respectively; P < .05), but not with white matter lesion volume. Our routinely available imaging method detected many cortical lesions in patients with MS and was useful in their precise topographic characterization in the context of the gray matter-white matter junction. Routinely detectable cortical lesions were related to physical disability and cognitive impairment.

Endolympathic hydrops in patients with vestibular schwannoma: visualization by non-contrast-enhanced 3D FLAIR

Signal intensity of ipsilateral labyrinthine lymph fluid has been reported to increase in most cases with vestibular schwannoma (VS) on 3D fluid attenuated inversion recovery (FLAIR). The purpose of this study was twofold, (1) to evaluate if endolymphatic space can be recognized in the patients with VS on non-contrast-enhanced 3D-FLAIR images and (2) to know if the vertigo in the patients with VS correlates to vestibular endolymphatic hydrops. From the introduction of 32-channel head coil at 3 T in May 2008 to June 2010, 15 cases with unilateral VS were identified in the radiology report database. The two cases without a significant signal increase on 3D FLAIR were excluded. Resting 13 cases were retrospectively analyzed in regard to the recognition of endolymphatic hydrops in the cochlea and vestibule and to the correlation between the patients' symptoms and endolymphatic hydrops. In all cases, vestibular endolymphatic space can be recognized on non-contrast-enhanced 3D FLAIR. Cochlear endolymphatic space can be identified only in one case with significant hydrops. Vestibular hydrops was identified in four cases. Among these four cases, three had vertigo, and one had no vertigo. In those nine cases without hydrops, two had vertigo, and seven did not have vertigo. No significant correlation between vertigo and vestibular hydrops was found. Vestibular endolymphatic space can be recognized on non-contrast-enhanced 3D FLAIR. In some patients with VS, vestibular hydrops is seen; however, endolymphatic hydrops in the vestibule might not be the only responsible cause of vertigo in the patients with VS.

Synthesis and Evaluation of Butyrylcholinesterase Ligands for Neuroimaging Alzheimer's Disease

Background: White matter lesions (WML) are common in MRI images of the elderly. We have previously developed an analysis program AAL, the automated anatomical labeling of brain structures in SPM using a macroscopic anatomical parcellation. In this study we added an additional function to label the white matter lesions and test the program in 64 MRI studies collected from patients with Alzheimer’s disease (AD), mild cognitive impairment (MCI), and normal controls (NC). Methods: Sixty-four subjects, including 39 patients with AD (age 1⁄4 72.5 6 8.5, M/F 1⁄4 14/25), 13 individuals with MCI (age 1⁄4 72.8 6 4.3, M/F 1⁄4 3/10) and 12 normal controls (age 1⁄4 71.1 6 8.1, M/F 1⁄4 5/7) were analyzed in the study. The high-resolution 3D T1-weighted images, T2-weighted images, and FLAIR images acquired with a Siemens 3T scanner were input into the program. The gross compartment volumes in GM, WM, CSF and intracranial volume (ICV) were obtained in all subjects. The AAL program also yielded volumes from 106 regions-of-interest (ROI). For analysis of WML, all three aligned datasets (T1, T2, FLAIR) were segmented into GM, WM and CSF in the intracranial volume, and a lesion probability map was generated. The WML was defined as the pixels with the probability above a threshold, and the volume was integrated over the entire white matter space. Results: The AD group had a smaller GM volume than normal controls (P 1⁄4 0.011), and had higher CSF volume than MCI (P 1⁄4 0.003) and control groups (P 1⁄4 0.000). The volumes of medial temporal lobe structures in the AD group were significantly smaller than in the MCI or NC groups. The cerebellum was not significantly different among all 3 groups. Figure 1 shows an example of the WML segmented using the automated labeling procedure. Conclusions: The AAL program provides an efficient method for segmentation of each individual brain, and shows a significant gray matter loss in AD patients. The initial results of WML segmentation were promising, and currently being verified against other established methods, including visual rating and manual segmentation.

Increased signal intensity of the cochlea on pre- and post-contrast enhanced 3D-FLAIR in patients with vestibular schwannoma

In the vestibular schwannoma patients, the pathophysiologic mechanism of inner ear involvement is still unclear. We investigated the status of the cochleae in patients with vestibular schwannoma by evaluating the signal intensity of cochlear fluid on pre- and post-contrast enhanced thin section three-dimensional fluid-attenuated inversion recovery (3D-FLAIR). Twenty-eight patients were retrospectively analyzed. Post-contrast images were obtained in 18 patients, and 20 patients had the records of their pure-tone audiometry. Regions of interest of both cochleae (C) and of the medulla oblongata (M) were determined on 3D-FLAIR images by referring to 3D heavily T2-weighted images on a workstation. The signal intensity ratio between C and M on the 3D-FLAIR images (CM ratio) was then evaluated. In addition, correlation between the CM ratio and the hearing level was also evaluated. The CM ratio of the affected side was significantly higher than that of the unaffected side (rho < 0.001). In the affected side, post-contrast signal elevation was observed (rho < 0.005). In 13 patients (26 cochleae) who underwent both gadolinium injection and the pure-tone audiometry, the post-contrast CM ratio correlated with hearing level (rho < 0.05). The results of the present study suggest that alteration of cochlear fluid composition and increased permeability of the blood-labyrinthine barrier exist in the affected side in patients with vestibular schwannoma. Furthermore, although weak, positive correlation between post-contrast cochlear signal intensity on 3D-FLAIR and hearing level warrants further study to clarify the relationship between 3D-FLAIR findings and prognosis of hearing preservation surgery.

Detection of Presumed Hemorrhage in the Ampullar Endolymph of the Semicircular Canal: A Case Report

We examined a 61-year-old woman with sudden left-side hearing loss accompanied by severe vertigo. High signal in the ampullar endolymph of the left semicircular canal on magnetic resonance (MR) fluid attenuated inversion recovery (3D-FLAIR) images suggested labyrinthine hemorrhage. The patient had been treated for chronic heart failure and prescribed 100 mg/day of acetylsalicylic acid (aspirin) for its antiplatelet effect. The 3D-FLAIR images demonstrated a small amount of focal hemorrhage in the labyrinthine fluid that may have been overlooked on T(1)-weighted images.

Endolymphatic Hydrops of the Labyrinth Visualized on Noncontrast MR Imaging: A Case Report

We admitted an 11-year-old girl with enlarged endolymphatic duct and sac syndrome to our hospital with severe nausea and vertigo. Three-dimensional constructive interference in steady state (3D-CISS) and fluid-attenuated inversion recovery (3D-FLAIR) images revealed a reflux of proteinous or hemorrhagic fluid into enlarged endolymphatic space in the labyrinth. This is the first imaging report to show endolymphatic hydrops visualized by noncontrast-enhanced MR imaging in a living human patient.

S206 – Efficacy of MRI for Management of Labyrinthine Fistulae

Objectives Surgical management of cholesteatomas with labyrinthine fistulae has been reported and several techniques have also been advocated, however, no uniform surgical technique can be adopted in all cases with fistulae. We examined the efficacy of MRI evaluation for surgical management of cholesteatoma with a labyrinthine fistula. Methods The case histories of 23 patients who had undergone surgery for middle ear cholesteatoma with a labyrinthine fistula were examined. Imaging analysis was performed using a 3-dimensional fluid-attenuated inversion recovery (3D-FLAIR) magnetic resonance imaging (MRI) sequence. Clinical symptoms, presence of fistulae, surgical management, and postoperative outcomes were compared between groups who had or had not undergone preoperative 3D-FLAIR MRI. Results Safe surgical management was achieved in the group without MRI evaluation. The group with MRI evaluation contained cases with larger fistulae and more severe clinical symptoms; however, MRI provided precise information concerning the degree of labyrinthitis, which enabled adequate surgical management and successful outcomes including improvement of sensorineural hearing loss in some cases. Conclusions Information provided by 3D-FLAIR images is valuable in the surgical management of cholesteatoma with a labyrinthine fistula, especially in cases with large fistulae and severe symptoms related to inner ear disturbances.

Does high-field MR imaging improve cortical lesion detection in multiple sclerosis?

Cortical lesions in multiple sclerosis (MS) are notoriously difficult to visualize with standard MR imaging (MRI) techniques. However, the use of higher field-strengths with intrinsically higher signal-to-noise, which can partly be used to increase spatial resolution, may improve cortical lesion detection. Therefore, in this post mortem study, the sensitivity of high field-strength MRI (4.7 T) for cortical lesions was investigated, and compared to that of standard field-strength (1.5 T). At 1.5 T, dual-echo T2-weighted spin-echo, as well as 3D-FLAIR images of seventeen formalin-fixed coronal MS and four control hemispheres were acquired. At 4.7 T, the same specimens were imaged with a mainly proton-density (PD)- weighted sequence. Proteolipid protein (PLP)-stained tissue sections (10 microm) of the same brain slices were matched to the corresponding MR images, and cortical lesions were scored on all three MR sequences (blinded to histology) and in tissue sections (blinded to MRI). Sensitivity of the sequences for four cortical lesion types was calculated. Additionally, an unblinded, retrospective MR scoring was performed. Sensitivity for purely intracortical lesions (histological lesion types II, III, and IV; n = 128) was below 10 % for both 1.5 T and 4.7 T MRI, while mixed gray matter-white matter (type I) lesions (n = 5) were detected in four out of five cases. All lesion counts increased upon retrospective (unblinded) scoring. However, up to 80% of the intracortical lesions still remained undetected. MRI sensitivity for post mortem detection of cortical lesions is low, even when a higher field-strength was used. It varies, however, for different subtypes of cortical lesions.

Prompt Contrast Enhancement of Cerebrospinal Fluid Space in the Fundus of the Internal Auditory Canal: Observations in Patients with Meningeal Diseases on 3D-FLAIR Images at 3 Tesla

We speculated that meningeal pathologies might facilitate the permeability of cranial nerves at the fundus of the internal auditory canal (IAC), causing prompt enhancement after administration of Gd-DTPA. Using a 3D- fluid-attenuated inversion recovery (FLAIR) sequence, we evaluated the enhancement of the cerebrospinal fluid (CSF) space in the IAC fundus 10 min after Gd-DTPA administration in patients with meningeal diseases. Twenty patients (aged 22 to 79 years) were divided into 2 groups, a group with meningeal disease comprising 9 patients with meningeal abnormalities (6, tumor dissemination; 3, infection) and a control group of 11 patients with unilateral IAC pathology whose healthy sides were included as controls. Six of the 9 patients in the group with meningeal disease showed bilateral enhancement; one showed unilateral enhancement. None of the control group showed enhancement in the healthy side. One patient with Ramsay-Hunt syndrome showed only ipsilateral enhancement. Enhancement in the IAC fundus was frequently observed in patients with meningeal disease, even just 10 min after administration of contrast agent. This enhancement in the IAC fundus was never visible on T1-weighted 3D-FLASH images.

Observation of contrast enhancement in the cochlear fluid space of healthy subjects using a 3D-FLAIR sequence at 3 Tesla

In animals, the enhancement of perilymph in the cochlea has been reported using 1.25 mmol/kg of Gd-DTPA, allowing the separate visualisation of perilymph and endolymph for the diagnosis of Meniere's disease. The purpose of this study was three-fold: (1) to determine the optimal timing for detecting cochlear fluid enhancement using 3D-FLAIR (fluid-attenuated inversion recovery) after intravenous administration of 0.1 mmol/kg of Gd-DTPA in healthy human subjects; (2) to examine the reliability of enhancement in multiple healthy subjects; and (3) to investigate whether endolymph and perilymph space can be visually discriminated. In two healthy subjects, 3D-FLAIR images were obtained before, immediately after and 2 h, 4 h and 6 h after the injection. Three more healthy subjects were scanned before and 4 h after the injection. In all four ears of the initial two subjects, cochlear fluid was found to be most intensely enhanced 4 h after the injection. In all of the additional three subjects, the cochlear fluid signal had increased after 4 h from injection. However, visual differentiation of endolymph and perilymph fluid could not be achieved. Using 3D-FLAIR and Gd-DTPA, cochlear fluid enhancement can be observed in healthy human ears, even with a single dose of contrast-medium injection.

Effect of bran particle size on stool weight.

The increase in stool weight after feeding 20 g (dry weight) of bran daily was measured when this was of large particle size and after milling to small particle size. Twenty-eight investigations were carried out in 21 normal subjects. With coarse bran, stool weight was significantly greater than with the fine bran (mean 219.4 g/d coarse bran, 199-0 g/d fine bran: difference 20.4 g SE +/-6.4, P less than 00.1). The coarse bran also had a greater water-holding capacity (7.3 g water/g coarse bran, 3.9 water/g fine bran). Coarse bran was 2 1/2 times the volume of fine gran for a given weight and more fine bran will, therefore, be taken when bran is prescribed by the spoonful.

Shortage of Nurses

<h3>Abstract</h3> <h3>Background and Objectives</h3> Expansion of chronic lesions in MS patients and recently described CSF-related gradient of tissue damage are linked to microglial activation. The aim of the current study was to investigate whether lesion expansion is associated with proximity to ventricular CSF spaces. <h3>Methods</h3> Pre- and post-gadolinium 3D-T1, 3D FLAIR and diffusion tensor images were acquired from 36 RRMS patients. Lesional activity was analysed between baseline and 48 months at different distances from the CSF using successive 1-mm thick concentric rings radiating from the ventricles. <h3>Results</h3> Voxel-based analysis of the rate of lesion expansion demonstrated a clear periventricular gradient decreasing away from the ventricles. This was particularly apparent when lesions of equal diameter were analysed. Periventricular lesional tissue showed higher degree of tissue distraction at baseline that significantly increased during follow-up in rings close to CSF. This longitudinal change was proportional to degree of lesion expansion. Lesion-wise analysis revealed a gradual, centrifugal decrease in the proportion of expanding lesions from the immediate periventricular zone. <h3>Discussion</h3> Our data suggest that chronic white matter lesions in close proximity to the ventricles are more destructive, show a higher degree of expansion at the lesion border and accelerated tissue loss in the lesion core.