https://cris.maastrichtuniversity.nl/ws/files/69061548/lambin_2012_radiomics_extracting_more_information.pdf

Radiomics: extracting more information from medical images using advanced feature analysis.

Background Natalizumab is the first α4 integrin antagonist in a new class of selective adhesion-molecule inhibitors. We report the results of a two-year phase 3 trial of natalizumab in patients with relapsing multiple sclerosis. Methods Of a total of 942 patients, 627 were randomly assigned to receive natalizumab (at a dose of 300 mg) and 315 to receive placebo by intravenous infusion every four weeks for more than two years. The primary end points were the rate of clinical relapse at one year and the rate of sustained progression of disability, as measured by the Expanded Disability Status Scale, at two years. Results Natalizumab reduced the risk of sustained progression of disability by 42 percent over two years (hazard ratio, 0.58; 95 percent confidence interval, 0.43 to 0.77; P<0.001). The cumulative probability of progression (on the basis of Kaplan–Meier analysis) was 17 percent in the natalizumab group and 29 percent in the placebo group. Natalizumab reduced the rate of clinical relapse at one year...

https://www.nejm.org/doi/pdf/10.1056/NEJMoa044397

A randomized, placebo-controlled trial of natalizumab for relapsing multiple sclerosis

Scientists who study neutrophils often have backgrounds in cell biology, biochemistry, haematology, rheumatology or infectious disease. Paradoxically, immunologists seem to have a harder time incorporating these host-defence cells into the framework of their discipline. The recent literature discussed here indicates that it is appropriate for immunologists to take as much interest in neutrophils as in their lymphohaematopoietic cousins with smooth nuclei. Neutrophils inform and shape immune responses, contribute to the repair of tissue as well as its breakdown, use killing mechanisms that enrich our concepts of specificity, and offer exciting opportunities for the treatment of neoplastic, autoinflammatory and autoimmune disorders.

Neutrophils and immunity: challenges and opportunities.

Dysmyelination Revealed through MRI as Increased Radial (but Unchanged Axial) Diffusion of Water

OBJECTIVE. In this article, we present the basic principles of diffusion-weighted imaging (DWI) that can aid radiologists in the qualitative and quantitative interpretation of DW images. However, a detailed discussion of the physics of DWI is beyond the scope of this article. A short discussion ensues on the technical aspects of performing DWI in the body. The emerging applications of DWI for tumor detection, tumor characterization, distinguishing tumor tissue from nontumor tissue, and monitoring and predicting treatment response are highlighted. The challenges to widespread adoption of the technique for cancer imaging in the body are discussed. CONCLUSION. DWI derives its image contrast from differences in the motion of water molecules between tissues. Such imaging can be performed quickly without the need for the administration of exogenous contrast medium. The technique yields qualitative and quantitative information that reflects changes at a cellular level and provides unique insights about tumor cellularity and the integrity of cell membranes. Recent advances enable the technique to be widely applied for tumor evaluation in the abdomen and pelvis and have led to the development of whole-body DWI.

https://www.ajronline.org/doi/pdf/10.2214/AJR.06.1403

Diffusion-weighted MRI in the body: applications and challenges in oncology.

We describe the clinical course of a patient with multiple sclerosis in whom progressive multifocal leukoencephalopathy (PML), an opportunistic viral infection of the central nervous system, developed during treatment with interferon beta-1a and a selective adhesion-molecule blocker, natalizumab. The first PML lesion apparent on magnetic resonance imaging was indistinguishable from a multiple sclerosis lesion. Despite treatment with corticosteroids, cidofovir, and intravenous immune globulin, PML progressed rapidly, rendering the patient quadriparetic, globally aphasic, and minimally responsive. Three months after natalizumab therapy was discontinued, changes consistent with an immune-reconstitution inflammatory syndrome developed. The patient was treated with systemic cytarabine, and two months later, his condition had improved.

https://www.nejm.org/doi/pdf/10.1056/NEJMoa051847

Progressive Multifocal Leukoencephalopathy in a Patient Treated with Natalizumab

VOLUME ONE Principles Instrumentation: Magnets, Coils, and Hardware John F. Schenck and Cherik Bulkes Contrast Development and Manipulation in MR Imaging Mark Haacke Principles of Image Formation Peter M. Joseph Fundamentals of Flow and Hemodynamics Norbert J. Pelc, Marcus T. Alley, John Listerud, and Scott Atlas Fast Imaging Principles Robert V. Mulkern Artifacts in MR Peter M. Joseph Brain Disorders of Brain Development Paul A. Caruso The Phakomatoses and Other Inherited Syndromes Susan Blaser Epilepsy Richard A. Bronen and Vivek Gupta White Matter Diseases and Inherited Metabolic Disorders Annette O. Nusbaum, Kar-Ming Fung, and Scott Atlas Adult Brain Tumors Mahesh Jayaraman et al. Pediatric Brain Tumors Robert A. Zimmerman Intracranial Hemorrhage Scott Atlas and Keith R. Thulborn Intracranial Vascular Malformations and Aneurysms Huy Do et al. Cerebral Ischemia and Infarction Michael P. Marks MR Angiography: Techniques and Clinical Applications John Huston et al. Head Trauma Ed Knopp Intracranial Infection Michelle L. Hansman Whiteman, Brian C. Bowen, M. Judith Donovan Post, and Michael D. Bell Normal Aging, Dementia, and Neurodegenerative Disease Clifford R. Jack, Jr., Frank J. Lexa, John Q. Trojanowski, Bruce H. Braffman, and Scott Atlas VOLUME TWO Skull Base The Skull Base Hugh D. Curtin The Sella Turcica and Parasellar Region Walter Kucharczyk et al. Anatomy and Diseases of the Temporal Bone Alexander S. Mark and Jan W. Casselman Eye, Orbit, and Visual System Pamela Van Tassel Spine and Spinal Cord Congenital Anomalies of the Spine and Spinal Cord: Embryology and Malformations Thomas P. Naidich et al. Degenerative Disease of the Spine Richard Kaplan Neoplastic Disease of the Spine and Spinal Cord Gordon Sze Spinal Trauma Adam E. Flanders and Sidney E. Croul Vascular Disorders of the Spine and Spinal Cord Robert W. Hurst Spinal Infection and Inflammatory Disorders Renato Adam Mendonca Advanced Applications Fetal Brain and Spine MRI Debbie Levine Diffusion and Diffusion Tensor Imaging: Principles Peter J. Basser Perfusion MR Imaging David C. Alsop Clinical Functional MR Imaging Keith R. Thulborn Psychiatric Disease Perry F. Renshaw et al. MR Spectroscopy and the Biochemical Basis of Neurological Disease Gil Gonzalez Contrast Agents and Molecular MR John C. Gore

Magnetic Resonance Imaging of the Brain and Spine

Despite the brain's central role in sexual function, little is known about relationships between brain activation and sexual response. In this study, we employed functional MRI (fMRI) to examine relationships between brain activation and sexual arousal in a group of young, healthy, heterosexual males. Each subject was exposed to two sequences of video material consisting of explicitly erotic (E), relaxing (R) and sports (S) segments in an unpredictable order. Data on penile turgidity was collected using a custom-built pneumatic pressure cuff. Both traditional block analyses using contrasts between sexually arousing and non-arousing video clips and a regression using penile turgidity as the covariate of interest were performed. In both types of analyses, contrast images were computed for each subject and these images were subsequently used in a random effects analysis. Strong activations specifically associated with penile turgidity were observed in the right subinsular region including the claustrum, left caudate and putamen, right middle occipital/ middle temporal gyri, bilateral cingulate gyrus and right sensorimotor and pre-motor regions. Smaller, but significant activation was observed in the right hypothalamus. Few significant activations were found in the block analyses. Implications of the findings are discussed. Our study demonstrates the feasibility of examining brain activation/sexual response relationships in an fMRI environment and reveals a number of brain structures whose activation is time-locked to sexual arousal.

https://cds.ismrm.org/ismrm-2001/PDF3/0662.pdf

Brain activation and sexual arousal in healthy, heterosexual males

BACKGROUND AND PURPOSE: We used quantitative diffusion MR imaging to investigate the microstructural changes that occur in white matter during normal aging in order to identify regional changes in anisotropy and to quantify global microstructural changes by use of wholebrain diffusion histograms. METHODS: Full diffusion tensor MR imaging was performed in 20 healthy volunteers, 20 to 91 years old. Thirteen subjects also underwent high-resolution T1-weighted imaging, so that diffusion images could be coregistered and standardized to normal coordinates for statistical probability mapping. Relative anisotropy (RA) was calculated, as was linear regression of RA with age for each pixel; pixels with a significant correlation coefficient were displayed. For histographic analysis, the average apparent diffusion coefficient (ADC) histograms were calculated on a pixel-by-pixel basis. Subjects were divided into two equal groups by the median age (55 years) of the population and plotted for statistical comparison. RESULTS: Regional analysis showed statistically significant decreases in RA with increasing age in the periventricular white matter, frontal white matter, and genu and splenium of the corpus callosum, despite the absence of signal abnormalities on visual inspection of conventional images. Significant increases in RA were found in the internal capsules bilaterally. ADC histograms showed higher mean ADC and reduced peak height and skew in the older age group on group comparisons. CONCLUSION: Quantitative diffusion histograms correlate with normal aging and may provide a global assessment of normal age-related changes and serve as a standard for comparison with neurodegenerative diseases.

http://www.ajnr.org/content/ajnr/22/1/136.full.pdf

Regional and Global Changes in Cerebral Diffusion with Normal Aging

BACKGROUND AND PURPOSE: Previous studies have addressed the prevalence of incidental findings in symptomatic and healthy adult populations. Our study aims to elucidate the prevalence of incidental findings in a healthy pediatric population. METHODS: We retrospectively reviewed 225 conventional brain MR imaging studies obtained during structural and functional brain imaging research in a cohort of neurologically healthy children (l00 boys [44%] and 125 girls [56%]) ranging in age from younger than 1 month to 18 years. All MR images were reviewed, and two board-certified neuroradiologists categorized the findings by consensus. RESULTS: Incidental abnormalities were detected in 47 subjects (21%), while 79% of the images were normal. Of the 47 abnormalities detected, 17 (36%) required routine clinical referral; a single lesion (2%) required urgent referral. The occurrence of these findings in the male cohort was twice that of the female cohort; however, the percentage of subjects requiring either routine or urgent referral did not differ by sex (male subjects, 34%; female subjects, 39%). CONCLUSION: Although the frequency of clinically important incidental abnormalities was not high in the sample of children studied, the presence and variety of findings in any pediatric group is particularly important for both the welfare of the subject and for research in which knowledge of the subject’s neurologic status is vital to the interpretation of the results. Despite the limitations of the study in terms of the age and ethnic distribution, this work highlights the need for the routine involvement of trained radiologists in these studies to ensure that such incidental findings are detected and that appropriate follow-up is provided. With the advent of MR imaging as a powerful means of detecting both anatomic and functional information about the brain in health and disease, large numbers of presumably neurologically healthy volunteers have participated in imaging research studies over the past decade. From a research point of view, the confidence in the findings from such studies resides, at least in part, in the confidence that subjects are of the neurologic status intended. However, several groups have reported incidental radiologic findings in symptomatic and healthy adult populations. To our knowledge, the occurrence and management of incidental radiologic findings in a pediatric population, in whom the lifelong implications of such findings may be profound, have not been documented or well established. Moreover, from a subject-welfare point of view, MR imaging studies involving volunteers are frequently performed by persons other than physicians, and a trained radiologist may never review the images. Any unanticipated findings on these images may therefore go unrecognized, and the subjects may not receive the appropriate referral. The goals of the present study were 1) to determine the frequency and severity of incidental findings in a sample population of specifically of children who underwent brain MR imaging for research, and 2) to consider the implications of routinely involving neuroradiologists in these research studies.

http://www.ajnr.org/content/ajnr/23/10/1674.full.pdf

Scott W. Atlas

Papers

Progressive Multifocal Leukoencephalopathy in a Patient Treated with Natalizumab

Magnetic Resonance Imaging of the Brain and Spine

Brain activation and sexual arousal in healthy, heterosexual males

Regional and Global Changes in Cerebral Diffusion with Normal Aging

Incidental Findings on Pediatric MR Images of the Brain