High-resolution anatomic, diffusion tensor, and magnetization transfer magnetic resonance imaging of the optic chiasm at 3T

Nerve fibre organisation in the human optic nerve and chiasm: what do we really know?

A recent anatomical study of the human optic chiasm cast doubt on the widespread assumption that nerve fibres travelling in the human optic nerve and chiasm are arranged retinotopically. Accordingly, a scoping literature review was performed to determine what is known about the nerve fibre arrangement in these structures. Meta-analysis suggested that the average number of fibres in each optic nerve was 1.023 million with an inter-individual range of approximately 50% of the mean. Loss of nerve fibres with age (approximately 3,400 fibres/year) could not account for this variability. The review suggested that there might be a retinotopic arrangement of nerve fibres in the orbital portion of the optic nerve but that this arrangement is most likely to be lost posteriorly with a more random distribution of nerve fibres at the chiasm. Limited studies have looked at nerve fibre arrangement in the chiasm. In summary, the chiasm is more 'H-shaped' than 'X-shaped': nerve fibre crossings occur paracentrally with nerves in the centre of the chiasm travelling coronally and in parallel. There is interaction between crossed and uncrossed fibres which are widely distributed. The review supports the non-existence of Wilbrand's knee. Considerable further work is required to provide more precise anatomical information, but this review suggests that the assumed preservation of retinotopy in the human optic nerve and chiasm is probably not correct.

Brain diffusion MRI with multiplexed sensitivity encoding for reduced distortion in a pediatric patient population

BACKGROUND

Diffusion-weighted imaging (DWI) is a valuable tool for routine imaging of the pediatric brain. However, the commonly used single-shot (ss) echo-planar imaging (EPI) DWI sequence is prone to geometric distortions and T₂*-blurring. This study aimed to investigate in a pediatric population the benefits of using multiplexed sensitivity-encoding (MUSE) without and with reversed polarity gradients (RPG) instead.

METHODS

This retrospective study compared image quality, geometric distortions, and diffusion values between three different approaches for DWI (ssEPI, MUSE, and RPG-MUSE) in 14 patients (median age = 4 (0.6-15) years, 11 males). Distortion levels were quantified and compared in two brain regions, i.e., the brain stem and the temporal lobes, using the Dice Coefficient and the Hausdorff Distance, with T₂-weighted images as reference. Expected geometrical distortion was further evaluated by comparing the effective echo spacing between the DWI sequences. Apparent diffusion coefficient (ADC) values were determined in the genu of the corpus callosum and the optic nerves. Two raters graded overall image quality and image distortions on a Likert scale.

RESULTS

Distortion levels assessed with Dice coefficient and Hausdorff distance were significantly lower for MUSE (p < 0.05) and RPG-MUSE (p < 0.01) compared to ssEPI. No significant difference in ADC values was observed between methods. The RPG-MUSE method was graded by one rater as significantly higher in overall image quality than ssEPI (p < 0.05) and by both raters as significantly lower in levels of image distortions than both MUSE (p < 0.05) and ssEPI (p < 0.05). These results were in agreement with the reduced effective echo spacing was that was attained with MUSE and RPG-MUSE.

CONCLUSION

For imaging of the pediatric brain, MUSE and even more so RPG-MUSE offers both improved geometric fidelity and image quality compared to ssEPI.

Role of Structural, Metabolic, and Functional MRI in Monitoring Visual System Impairment and Recovery

The visual system, consisting of the eyes and the visual pathways of the brain, receives and interprets light from the environment so that we can perceive the world around us. A wide variety of disorders can affect human vision, ranging from ocular to neurologic to systemic in nature. While other noninvasive imaging techniques such as optical coherence tomography and ultrasound can image particular sections of the visual system, magnetic resonance imaging (MRI) offers high resolution without depth limitations. MRI also gives superior soft-tissue contrast throughout the entire pathway compared to computed tomography. By leveraging different imaging sequences, MRI is uniquely capable of unveiling the intricate processes of ocular anatomy, tissue physiology, and neurological function in the human visual system from the microscopic to macroscopic levels. In this review we discuss how structural, metabolic, and functional MRI can be used in the clinical assessment of normal and pathologic states in the anatomic structures of the visual system, including the eyes, optic nerves, optic chiasm, optic tracts, visual brain nuclei, optic radiations, and visual cortical areas. We detail a selection of recent clinical applications of MRI at each position along the visual pathways, including the evaluation of pathology, plasticity, and the potential for restoration, as well as its limitations and key areas of ongoing exploration. Our discussion of the current and future developments in MR ocular and neuroimaging highlights its potential impact on our ability to understand visual function in new detail and to improve our protection and treatment of anatomic structures that are integral to this fundamental sensory system. LEVEL OF EVIDENCE 3:   TECHNICAL EFFICACY STAGE 3:  .

Optic Chiasm Morphometric Changes in Multiple Sclerosis: Feasibility of a Simplified Brain Magnetic Resonance Imaging Measure of White Matter Atrophy

Sophisticated volume measurements of brain structures on magnetic resonance imaging (MRI) may improve specificity in determining long-term progression of multiple sclerosis (MS), but these techniques are laborious. The optic chiasm (OC) is a white matter (WM) structure clearly visible on a routine MRI and is related to the optic nerves (ONs), which are known to atrophy in MS. We hypothesized that OC morphometric measurements would show OC atrophy in MS compared to normal patients. If so, this could help establish a novel simplified brain MRI measure of WM atrophy in MS patients. We retrospectively evaluated standard brain MRIs of 97 patients with known MS and 98 normal individuals. We electronically measured eight OC morphometrics on axial T2WIs and midsagittal T1WIs: OC width and anteroposterior (AP) diameter, diameters of each ON and optic tract (OT), and angles between the ONs or OTs. Mean OC width, AP diameter, and height in MS patients were 11.83 ± 1.25 mm (95% CI 11.58-12.09), 2.99 ± 0.65 mm (95% CI 2.85-3.12), and 2.09 ± 0.37 mm (95% CI 2-2.19), respectively. In normal individuals, they were 12.1 ± 1.4 mm (95% CI 11.78-12.34), 3.43 ± 0.63 mm (95% CI 3.3-3.58), and 2.15 ± 0.37 mm (95% CI 2.07-2.23), respectively. There were statistically significant differences between MS patients and controls for AP diameter (P = 0.000), but not for width (P = 0.204) or height (P = 0.183). The ONs were significantly smaller in MS (P < 0.0017), but not the OTs. Thus, the OC is significantly atrophied in an unstratified cohort of MS patients. Future studies may establish an MRI OC morphometric index to evaluate demyelinating disease in the brain. Clin. Anat. 32:1072-1081, 2019. © 2019 Wiley Periodicals, Inc.

Diffusion tensor imaging of the optic chiasm in patients with intra- or parasellar tumor using readout-segmented echo-planar

PURPOSE

To evaluate the impact of surgery on the optic pathway of patients with intra- or parasellar mass lesions, as evidenced by readout-segmented DTI.

MATERIALS AND METHODS

Twenty-four patients with intra- or parasellar mass lesions were included in the study. Readout-segmented DTI and T2WI were obtained before and after surgery. The ROIs were set on the optic chiasm as well as the anterior and posterior optic tracts. For each ROI, axial diffusivity (AD), radial diffusivity (RD), fractional anisotropy (FA), and ADC values were calculated. DTI parameters in preoperative studies of all patients were compared and related to the presence of tumor compression. In patients who underwent surgery, pre- and postoperative DTI parameters were compared. The correlation between DTI parameters and visual function was determined.

RESULTS

In the preoperative studies, the optic chiasm of patients with tumor compression showed significant lower AD and RD values. The optic chiasm of patients with visual field disorder showed significantly lower AD and RD values compared to patients without the disorder. There was a negative correlation with a trend toward significance between FA values and visual field disorder scores. The comparative analysis of patients in pre- and postoperative studies showed that the optic chiasm of patients with tumor compression presented a significant lower FA (0.41 versus 0.30, p=0.0068) and higher RD values after surgery.

CONCLUSIONS

DTI is a useful tool to assess the impact of surgery on the optic chiasm and nerve.

Distinguishing and quantification of the human visual pathways using high-spatial-resolution diffusion tensor tractography

Quantification of the living human visual system using MRI methods has been challenging, but several applications demand a reliable and time-efficient data acquisition protocol. In this study, we demonstrate the utility of high-spatial-resolution diffusion tensor fiber tractography (DTT) in reconstructing and quantifying the human visual pathways. Five healthy males, age range 24-37years, were studied after approval of the institutional review board (IRB) at The University of Texas Health Science Center at Houston. We acquired diffusion tensor imaging (DTI) data with 1-mm slice thickness on a 3.0-Tesla clinical MRI scanner and analyzed the data using DTT with the fiber assignment by continuous tractography (FACT) algorithm. By utilizing the high-spatial-resolution DTI protocol with FACT algorithm, we were able to reconstruct and quantify bilateral optic pathways including the optic chiasm, optic tract, optic radiations free of contamination from neighboring white matter tracts.

High resolution MRI anatomy of the cat brain at 3 Tesla

BACKGROUND

Feline models of neurologic diseases, such as lysosomal storage diseases, leukodystrophies, Parkinson's disease, stroke and NeuroAIDS, accurately recreate many aspects of human disease allowing for comparative study of neuropathology and the testing of novel therapeutics. Here we describe in vivo visualization of fine structures within the feline brain that were previously only visible post mortem.

NEW METHOD

3Tesla MR images were acquired using T1-weighted (T1w) 3D magnetization-prepared rapid gradient echo (MPRAGE) sequence (0.4mm isotropic resolution) and T2-weighted (T2w) turbo spin echo (TSE) images (0.3mm×0.3mm×1mm resolution). Anatomic structures were identified based on feline and canine histology.

RESULTS

T2w high resolution MR images with detailed structural identification are provided in transverse, sagittal and dorsal planes. T1w MR images are provided electronically in three dimensions for unrestricted spatial evaluation.

COMPARISON WITH EXISTING METHODS

Many areas of the feline brain previously unresolvable on MRI are clearly visible in three orientations, including the dentate, interpositus and fastigial cerebellar nuclei, cranial nerves, lateral geniculate nucleus, optic radiation, cochlea, caudal colliculus, temporal lobe, precuneus, spinocerebellar tract, vestibular nuclei, reticular formation, pyramids and rostral and middle cerebral arteries. Additionally, the feline brain is represented in three dimensions for the first time.

CONCLUSIONS

These data establish normal appearance of detailed anatomical structures of the feline brain, which provide reference when evaluating neurologic disease or testing efficacy of novel therapeutics in animal models.

Insights from magnetic resonance imaging

Recent years have witnessed impressive advancements in the use of magnetic resonance imaging (MRI) for the assessment of patients with multiple sclerosis (MS). Complementary to the clinical evaluation, conventional MRI (cMRI) provides crucial pieces of information for the diagnosis of MS, the understanding of its natural history, and monitoring the efficacy of experimental treatments. Measures derived from cMRI present clear advantages over the clinical assessment, including their more objective nature and an increased sensitivity to MS-related changes. However, the correlation between these measures and the clinical manifestations of the disease remains weak, and this can be explained, at least partially, by the limited ability of cMRI to characterize and quantify the heterogeneous features of MS pathology. Quantitative MR-based techniques have the potential to overcome the limitations of cMRI. Magnetization transfer MRI, diffusion-weighted and diffusion tensor MRI with fiber tractography, proton magnetic resonance spectroscopy, T1 and T2 relaxation time measurement, and functional MRI are contributing to elucidate the mechanisms that underlie injury, repair, and functional adaptation in patients with MS. All conventional and nonconventional MR techniques will benefit from the use of high-field MR systems (3.0T or more).

Fractional anisotropy of the optic radiations is associated with visual acuity loss in optic pathway gliomas of neurofibromatosis type 1

BACKGROUND

No more than half of patients with neurofibromatosis type 1 (NF1)-associated optic pathway gliomas (OPGs) develop vision loss. Prospectively identifying those who will require therapy remains challenging, because no reliable factors have yet been identified that predict future vision loss. To determine whether brain tissue microstructure is associated with visual acuity loss, we examined diffusion tensor imaging (DTI) and ophthalmologic evaluations in children with NF1-associated OPG.

METHODS

We retrospectively reviewed ophthalmology records and concurrent DTI measurements of the optic nerves, tracts, and radiations from 50 children with NF1-associated OPGs. Multivariate linear regression measured the association between fiber trajectory quantity and white matter integrity on visual acuity measured by the logarithm of the minimal angle of resolution (logMAR).

RESULTS

In multivariate analysis, fractional anisotropy (FA) of the optic radiations was associated with visual acuity loss (adjusted coefficient = -6.081 logMAR/FA; P = .006) after adjusting for age, extent of tumor, DTI acquisition type, prior chemotherapy, and fundus examination findings. The association remained after eliminating tumors involving the optic radiations. In an evaluation of 15 subjects with paired ophthalmologic examination and DTI a year apart, initial FA of the optic radiation was associated with a trend toward change in visual acuity a year later (coefficient = -2.652 logMAR/FA; P = .069).

CONCLUSIONS

A decrease in FA of the optic radiations is associated with abnormal visual acuity in NF1-associated OPGs and may be predictive of visual acuity loss during the following year.

Diffusion tensor imaging of the optic nerve in multiple sclerosis: association with retinal damage and visual disability

BACKGROUND AND PURPOSE

There is a well-known relationship between MS and damage to the optic nerve, but advanced, quantitative MR imaging methods have not been applied to large cohorts. Our objective was to determine whether a short imaging protocol (< 10 minutes), implemented with standard hardware, could detect abnormal water diffusion in the optic nerves of patients with MS.

MATERIALS AND METHODS

We examined water diffusion in human optic nerves via DTI in the largest MS cohort reported to date (104 individuals, including 38 optic nerves previously affected by optic neuritis). We also assessed whether such abnormalities are associated with loss of visual acuity (both high and low contrast) and damage to the retinal nerve fiber layer (assessed via optical coherence tomography).

RESULTS

The most abnormal diffusion was found in the optic nerves of patients with SPMS, especially in optic nerves previously affected by optic neuritis (19% drop in FA). DTI abnormalities correlated with both retinal nerve fiber layer thinning (correlation coefficient, 0.41) and loss of visual acuity, particularly at high contrast and in nerves previously affected by optic neuritis (correlation coefficient, 0.54). However, diffusion abnormalities were overall less pronounced than retinal nerve fiber layer thinning.

CONCLUSIONS

DTI is sensitive to optic nerve damage in patients with MS, but a short imaging sequence added to standard clinical protocols may not be the most reliable indicator of optic nerve damage.

Diffusion tensor imaging of the optic tracts in multiple sclerosis: association with retinal thinning and visual disability

BACKGROUND AND PURPOSE

Visual disability is common in multiple sclerosis, but its relationship to abnormalities of the optic tracts remains unknown. Because they are only rarely affected by lesions, the optic tracts may represent a good model for assessing the imaging properties of normal-appearing white matter in multiple sclerosis.

METHODS

Whole-brain diffusion tensor imaging was performed on 34 individuals with multiple sclerosis and 26 healthy volunteers. The optic tracts were reconstructed by tractography, and tract-specific diffusion indices were quantified. In the multiple-sclerosis group, peripapillary retinal nerve-fiber-layer thickness and total macular volume were measured by optical coherence tomography, and visual acuity at 100%, 2.5%, and 1.25% contrast was examined.

RESULTS

After adjusting for age and sex, optic-tract mean and perpendicular diffusivity were higher (P=.002) in multiple sclerosis. Lower optic-tract fractional anisotropy was correlated with retinal nerve-fiber-layer thinning (r=.51, P=.003) and total-macular-volume reduction (r=.59, P=.002). However, optic-tract diffusion indices were not specifically correlated with visual acuity or with their counterparts in the optic radiation.

CONCLUSIONS

Optic-tract diffusion abnormalities are associated with retinal damage, suggesting that both may be related to optic-nerve injury, but do not appear to contribute strongly to visual disability in multiple sclerosis.

In vivo diffusion tensor imaging of the human optic chiasm at sub-millimeter resolution

In this work we report findings from an in vivo diffusion tensor imaging (DTI) study of the human optic chiasm at sub-millimeter voxel resolution. Data were collected at 3 T using a diffusion-weighted radial-FSE sequence, which provides images free from typical magnetic susceptibility artifacts. The general DTI features observed in the optic chiasm region were consistent across subjects. They included a central area with high anisotropy and highest diffusivity in a predominately right/left direction corresponding to the decussation of nasal hemiretinae fibers, surrounded by a band of low anisotropy reflecting heterogeneous orientation of fibers within the voxel, and a lateral area with high anisotropy and highest diffusivity in a predominately anterior/posterior direction corresponding to temporal hemiretinae fibers that do not cross. Animal studies indicate that there is a significant dorsal-ventral reorganization of the retinotopic distribution of fibers along the optic pathways. We found that diffusion ellipsoids in the central portion of the optic chiasm show considerable planar anisotropy in the coronal plane indicating fiber crossings in the superior/inferior direction, rather than strictly right/left. This architectural feature of the chiasm suggests that dorso-ventral reorganization of fibers in the optic pathways also occurs in humans. We have shown that by collecting sub-millimeter resolution data, DTI can be used to investigate fine details of small and complex white matter structures, in vivo, with a clinical scanner. High spatial resolution, however, is necessary in the slice direction as well as in-plane to reduce the CSF contribution to the signal and to increase fiber coherence within voxels.

Magnetic resonance techniques to quantify tissue damage, tissue repair, and functional cortical reorganization in multiple sclerosis

A dramatic paradigm shift is taking place in our understanding of the pathophysiology of multiple sclerosis (MS). An important contribution to such a shift has been made possible by the advances in magnetic resonance imaging (MRI) technology, which allows structural damage to be quantified in the brains of patients with MS and to be followed over the course of the disease. Modern quantitative MR techniques have reshaped the picture of MS, leading to the definition of the so- called "axonal hypothesis" (i.e., changes in axonal metabolism, morphology, or density are important determinants of functional impairment in MS). Metrics derived from magnetization transfer and diffusion-weighted MRI enable us to quantify the extent of structural changes occurring within T2-visible lesions and normal-appearing tissues (including gray matter), with increased pathological specificity over conventional MRI to irreversible tissue damage; proton MR spectroscopy adds valuable pieces of information on the biochemical nature of such changes. Finally, functional MRI can provide new insights into the role of cortical adaptive changes in limiting the clinical consequences of MS-related irreversible structural damage. Our current understanding of the pathophysiology of MS is that this is not only a disease of the white matter, characterized by focal inflammatory lesions, but also a disease involving more subtle and diffuse damage throughout the white and gray matter. The inflammatory and neurodegenerative components of the disease process are present from the earliest observable phases of the disease, but appear to be, at least partially, dissociated. In addition, recovery and repair play an important role in the genesis of the clinical manifestations of the disease, involving both structural changes and plastic reorganization of the cortex. This new picture of MS has important implications in the context of treatment options, since it suggests that agents that protect against neurodegeneration or promote tissue repair may have an important role to play alongside agents acting on the inflammatory component of the disease.

Disability in optic neuritis correlates with diffusion tensor-derived directional diffusivities

OBJECTIVE

To determine the potential of directional diffusivities from diffusion tensor imaging (DTI) to predict clinical outcome of optic neuritis (ON), and correlate with vision, optical coherence tomography (OCT), and visual evoked potentials (VEP).

METHODS

Twelve cases of acute and isolated ON were imaged within 30 days of onset and followed prospectively. Twenty-eight subjects with a remote clinical history of ON were studied cross-sectionally. Twelve healthy controls were imaged for comparison. DTI data were acquired at 3T with a surface coil and 1.3 x 1.3 x 1.3 mm(3) isotropic voxels.

RESULTS

Normal DTI parameters (mean +/- SD, microm(2)/ms) were axial diffusivity = 1.66 +/- 0.18, radial diffusivity = 0.81 +/- 0.26, apparent diffusion coefficient (ADC) = 1.09 +/- 0.21, and fractional anisotropy (FA) = 0.43 +/- 0.15. Axial diffusivity decreased up to 2.5 SD in acute ON. The decrease in axial diffusivity at onset correlated with visual contrast sensitivity 1 month (r = 0.59) and 3 months later (r = 0.65). In three subjects followed from the acute through the remote stage, radial diffusivity subsequently increased to > 2.5 SD above normal, as did axial diffusivity and ADC. In remote ON, radial diffusivity correlated with OCT (r = 0.81), contrast sensitivity (r = 0.68), visual acuity (r = 0.56), and VEP (r = 0.54).

CONCLUSION

In acute and isolated demyelination, axial diffusivity merits further investigation as a predictor of future clinical outcome. Diffusion parameters are dynamic in acute and isolated optic neuritis, with an initial acute decrease in axial diffusivity. In remote disease, radial diffusivity correlates with functional, structural, and physiologic tests of vision.

Assessing optic nerve pathology with diffusion MRI: from mouse to human

The optic nerve is often affected in patients with glaucoma and multiple sclerosis. Conventional MRI can detect nerve damage, but it does not accurately assess the underlying pathologies. Mean diffusivity and diffusion anisotropy indices derived from diffusion tensor imaging have been shown to be sensitive to a variety of central nervous system white matter pathologies. Despite being sensitive, the lack of specificity limits the ability of these measures to differentiate the underlying pathology. Directional (axial and radial) diffusivities, measuring water diffusion parallel and perpendicular to the axonal tracts, have been shown to be specific to axonal and myelin damage in mouse models of optic nerve injury, including retinal ischemia and experimental autoimmune encephalomyelitis. The progression of Wallerian degeneration has also been detected using directional diffusivities after retinal ischemia. However, translating these findings to human optic nerve is technically challenging. The current status of diffusion MRI of human optic nerve, including imaging sequences and protocols, is summarized herein. Despite the lack of a consensus among different groups on the optimal sequence or protocol, increased mean diffusivity and decreased diffusion anisotropy have been observed in injured optic nerve from patients with chronic optic neuritis. From different mouse models of optic nerve injuries to the emerging studies on patients with optic neuritis, directional diffusivities show great potential to be specific biomarkers for axonal and myelin injury.

Imaging anatomy of the vestibular and visual systems

PURPOSE OF REVIEW

This review will outline the imaging anatomy of the vestibular and visual pathways, using computed tomography and magnetic resonance imaging, with emphasis on the more recent developments in neuroimaging.

RECENT FINDINGS

Technical advances in computed tomography and magnetic resonance imaging, such as the advent of multislice computed tomography and newer magnetic resonance imaging techniques such as T2-weighted magnetic resonance cisternography, have improved the imaging of the vestibular and visual pathways, allowing better visualization of the end organs and peripheral nerves. Higher field strength magnetic resonance imaging is a promising tool, which has been used to evaluate and resolve fine anatomic detail in vitro, as in the labyrinth. Advanced magnetic resonance imaging techniques such as functional magnetic resonance imaging and diffusion tractography have been used to identify cortical areas of activation and associated white matter pathways, and show potential for the future identification of complex neuronal relays involved in integrating these pathways.

SUMMARY

The assessment of the various components of the vestibular and the visual systems has improved with more detailed research on the imaging anatomy of these systems, the advent of high field magnetic resonance scanners and multislice computerized tomography, and the wider use of specific techniques such as tractography which displays white matter tracts not directly accessible until now.

Reconstruction of the human visual system based on DTI fiber tracking

PURPOSE

To apply and to evaluate the newly developed advanced fast marching algorithm (aFM) in vivo by reconstructing the human visual pathway, which is characterized by areas of extensive fiber crossing and branching, i.e., the optic chiasm and the lateral geniculate nucleus (LGN).

MATERIALS AND METHODS

Diffusion tensor images were acquired in 10 healthy volunteers. Due to the proximity to bony structures and air-filled spaces of the optic chiasm, a high sensitivity encoding (SENSE) reduction factor was applied to reduce image distortions in this area. To reconstruct the visual system, three different seed areas were chosen separately. The results obtained by the aFM tracking algorithm were compared and validated with known anatomy.

RESULTS

The visual system could be reconstructed reproducibly in all subjects and the reconstructed fiber pathways are in good agreement with known anatomy.

CONCLUSION

The present work shows that the advanced aFM, which is especially designed for overcoming tracking limitations within areas of extensive fiber crossing, handles the fiber crossing and branching within the optic chiasm and the LGN correctly, thus allowing the reconstruction of the entire human visual fiber pathway, from the intraorbital segment of the optic nerves to the visual cortex.

3D MRI in multiple sclerosis: a study of three sequences at 3 T

The objective of this study was to assess the feasibility of using 3D acquisition at 3 T for imaging patients with multiple sclerosis (MS). Feasibility was assessed by three criteria based on acquisition time, specific absorption rate (SAR) and image quality. 47 patients with clinically definite MS underwent imaging in a Siemens 3T Trio MR scanner. Patient safety data were obtained following the scan sessions. The study had local ethics approval. The following three-dimensional (3D) sequences, all acquired coronally, were used: T2 fluid attenuated inversion recovery (FLAIR) (repetition time (TR) 6000 ms, echo time (TE) 353 ms, inversion time (TI) 2200 ms), 0.5x0.5x1 mm voxels, acquisition time 10 min 38 s; T2 turbo spin echo (TSE) (TR 3000 ms, TE 354 ms), 1x1x1 mm voxels, acquisition time 8 min 29 s; T1 inversion recovery (IR) (TR 2040 ms, TE 5.56 ms, TI 1100 ms), matrix 512x448 (0.5x0.5 mm pixels), 0.5x0.5x1 mm voxels, acquisition time 7 min 38 s. Total acquisition time was 26 min 45 s. Example images are presented. 3D scanning at 3 T provides highly detailed, high quality images with acquisition times tolerated by MS patients, even by those with severe disability. The volumetric data are suitable for a wide variety of post-processing techniques; the authors suggest that 3D studies at 3 T should be considered as the possible brain imaging protocol for either cross-sectional or longitudinal studies in MS and that the 3D T2 FLAIR sequence should be considered for the purposes of radiological diagnosis.