Quantitative MRI analysis of structural changes in tomato tissues resulting from dehydration

2021 ◽  
Author(s):  
Rodolphe Leforestier ◽  
Anna Fleury ◽  
François Mariette ◽  
Guylaine Collewet ◽  
Sylvain Challois ◽  
...  
Keyword(s):  
Structural Changes ◽  
Quantitative Mri

Quantitative MRI of the hippocampus and amygdala in severe depression

2000 ◽  
Vol 30 (1) ◽  
pp. 117-125 ◽  
Author(s):  
E. MERVAALA ◽  
J. FÖHR ◽  
M. KÖNÖNEN ◽  
M. VALKONEN-KORHONEN ◽  
P. VAINIO ◽  
...  
Keyword(s):  
Major Depression ◽  
Structural Changes ◽  
Brain Size ◽  
Relaxation Times ◽  
Severe Depression ◽  
Quantitative Mri ◽  
Drug Resistant ◽  
Left Hippocampus ◽  
Temporal Structures ◽  
Mri Study

Background. There is little evidence to support possible structural changes in the amygdala and hippocampus of patients with severe depression.Methods. Quantitative MRI of the amygdala and hippocampus, as well as proton spectroscopy (MRS) of mesial temporal structures were studied in 34 drug-resistant in-patients with major depression and compared with 17 age-matched controls. Volumetric MRI data were normalized for brain size.Results. The volume of the left hippocampus was significantly smaller in the patients compared with the controls. Both groups exhibited similar significant hippocampal asymmetry (left smaller than right). The patients, but not the controls, had significant asymmetry of the amygdalar volumes (right smaller than left). No differences were observed between the patients and controls in the T2 relaxation times for the hippocampus and amygdala. Mesial temporal lobe MRS revealed a significantly elevated choline/creatine ratio in the patients compared with the controls.Conclusions. This quantitative MRI study provides support for a possible association between structural and biochemical substrates and severe drug-resistant major depression.

scholarly journals The Cerebellar Dysplasia of Chiari II Malformation as Revealed by Eye Movements

2009 ◽  
Vol 36 (6) ◽  
pp. 713-724 ◽  
Author(s):  
Michael S. Salman ◽  
Maureen Dennis ◽  
James A. Sharpe
Keyword(s):  
Eye Movements ◽  
Posterior Fossa ◽  
Smooth Pursuit ◽  
Structural Changes ◽  
Visual Fixation ◽  
Quantitative Mri ◽  
Eye Tracker ◽  
Ocular Reflex ◽  
Cerebellar Dysplasia ◽  
Vestibulo Ocular Reflex

Introduction:Chiari type II malformation (CII) is a developmental deformity of the hindbrain. We have previously reported that many patients with CII have impaired smooth pursuit, while few make inaccurate saccades or have an abnormal vestibuloocular reflex. In contrast, saccadic adaptation and visual fixation are normal. In this report, we correlate results from several eye movement studies with neuroimaging in CII. We present a model for structural changes within the cerebellum in CII.Methods:Saccades, smooth pursuit, the vestibulo-ocular reflex, and visual fixation were recorded in 21 patients with CII, aged 8-19 years and 39 age-matched controls, using an infrared eye tracker. Qualitative and quantitative MRI data were correlated with eye movements in 19 CII patients and 28 controls.Results:Nine patients with CII had abnormal eye movements. Smooth pursuit gain was subnormal in eight, saccadic accuracy abnormal in four, and vestibulo-ocular reflex gain abnormal in three. None had fixation instability. Patients with CII had a significantly smaller cerebellar volume than controls, and those with normal eye motion had an expanded midsagittal vermis compared to controls. However, patients with abnormal eye movements had a smaller (non-expanded) midsagittal vermis area, posterior fossa area and medial cerebellar volumes than CII patients with normal eye movements.Conclusions:The deformity of CII affects the structure and function of the cerebellum selectively and differently in those with abnormal eye movements. We propose that the vermis can expand when compressed within a small posterior fossa in some CII patients, thus sparing its ocular motor functions.

scholarly journals Progressive neurodegeneration following spinal cord injury

Neurology ◽  
2018 ◽  
Vol 90 (14) ◽  
pp. e1257-e1266 ◽  
Author(s):  
Gabriel Ziegler ◽  
Patrick Grabher ◽  
Alan Thompson ◽  
Daniel Altmann ◽  
Markus Hupp ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Neuropathic Pain ◽  
Clinical Outcomes ◽  
Structural Changes ◽  
Quantitative Mri ◽  
Anterior Cingulate ◽  
Iron Accumulation ◽  
Cord Injury ◽  
Progressive Neurodegeneration

ObjectiveTo quantify atrophy, demyelination, and iron accumulation over 2 years following acute spinal cord injury and to identify MRI predictors of clinical outcomes and determine their suitability as surrogate markers of therapeutic intervention.MethodsWe assessed 156 quantitative MRI datasets from 15 patients with spinal cord injury and 18 controls at baseline and 2, 6, 12, and 24 months after injury. Clinical recovery (including neuropathic pain) was assessed at each time point. Between-group differences in linear and nonlinear trajectories of volume, myelin, and iron change were estimated. Structural changes by 6 months were used to predict clinical outcomes at 2 years.ResultsThe majority of patients showed clinical improvement with recovery stabilizing at 2 years. Cord atrophy decelerated, while cortical white and gray matter atrophy progressed over 2 years. Myelin content in the spinal cord and cortex decreased progressively over time, while cerebellar loss decreases decelerated. As atrophy progressed in the thalamus, sustained iron accumulation was evident. Smaller cord and cranial corticospinal tract atrophy, and myelin changes within the sensorimotor cortices, by 6 months predicted recovery in lower extremity motor score at 2 years. Whereas greater cord atrophy and microstructural changes in the cerebellum, anterior cingulate cortex, and secondary sensory cortex by 6 months predicted worse sensory impairment and greater neuropathic pain intensity at 2 years.ConclusionThese results draw attention to trauma-induced neuroplastic processes and highlight the intimate relationships among neurodegenerative processes in the cord and brain. These measurable changes are sufficiently large, systematic, and predictive to render them viable outcome measures for clinical trials.

scholarly journals Quantitative MRI of the spinal cord and brain in adrenomyeloneuropathy:in vivoassessment of structural changes

Brain ◽  
2016 ◽  
Vol 139 (6) ◽  
pp. 1735-1746 ◽  
Author(s):  
Antonella Castellano ◽  
Nico Papinutto ◽  
Marcello Cadioli ◽  
Gianluca Brugnara ◽  
Antonella Iadanza ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Structural Changes ◽  
Quantitative Mri

scholarly journals The Aging Brain: Crossroad of Normal Aging and Dementia

2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 766-766
Author(s):  
Qu Tian ◽  
Luigi Ferrucci
Keyword(s):  
White Matter ◽  
Structural Changes ◽  
Underlying Mechanism ◽  
Neural Substrates ◽  
Normal Aging ◽  
Quantitative Mri ◽  
Aging Brain ◽  
Metabolic Derangement ◽  
White Matter Degeneration ◽  
Age Related

Abstract The functional consequences of the aging brain include several aspects of physical and cognitive decline that ultimately cause loss of mobility and dementia. Although in certain individuals, the cognitive and physical correlates of the aging brain occur in parallel, others show decline in one of these functional parameters. Underlying mechanism of this complex process that lead to different manifestations is not well understood. Proposed mechanisms include brain structural changes, tau pathology, specific white matter degeneration, metabolic derangement mostly including lipids metabolism and others. This symposium aims to address the complexity of the aging brain by showcasing studies that span the continuum from normal aging to dementia using data from the Baltimore Longitudinal Study of Aging (BLSA). The wealth of neuroimaging and phenotype data from the BLSA provides the unique opportunity to investigate neural substrates and predictors of aging phenotype, and mechanisms of age-related neurodegeneration and pathology, such as dementia, and loss of mobility. First, we identify multimodal neuroimaging predictors of important aging phenotypes of gait decline (Sargent/Tian) and memory decline (Bilgel). Second, using advanced quantitative MRI technology, we investigate underlying mechanisms of age-related white matter degeneration through potential oligodendrocyte metabolism (Bouhrara). Third, we demonstrate unique cognitive and neuroimaging profiles of dual memory and gait decline (Tian) and neural substrates for bile acids, the primary cholesterol breakdown products (Varma) in relation to dementia. We seek to generate discussions of mechanisms of the aging brain that connect the age-related phenotypes, such as decline of mobility and cognition, to the development of dementia.

scholarly journals A systematic review on the use of quantitative imaging to detect cancer therapy adverse effects in normal-appearing brain tissue

2021 ◽  
Author(s):  
Jan Petr ◽  
Louise Hogeboom ◽  
Pavel Nikulin ◽  
Evita Wiegers ◽  
Gwen Schroyen ◽  
...  
Keyword(s):  
Systematic Review ◽  
Side Effects ◽  
Cancer Therapy ◽  
Brain Tissue ◽  
Structural Changes ◽  
Quantitative Imaging ◽  
Quantitative Mri ◽  
Future Research ◽  
Imaging Method ◽  
Monitoring Therapy

AbstractCancer therapy for both central nervous system (CNS) and non-CNS tumors has been previously associated with transient and long-term cognitive deterioration, commonly referred to as ‘chemo fog’. This therapy-related damage to otherwise normal-appearing brain tissue is reported using post-mortem neuropathological analysis. Although the literature on monitoring therapy effects on structural magnetic resonance imaging (MRI) is well established, such macroscopic structural changes appear relatively late and irreversible. Early quantitative MRI biomarkers of therapy-induced damage would potentially permit taking these treatment side effects into account, paving the way towards a more personalized treatment planning.This systematic review (PROSPERO number 224196) provides an overview of quantitative tomographic imaging methods, potentially identifying the adverse side effects of cancer therapy in normal-appearing brain tissue. Seventy studies were obtained from the MEDLINE and Web of Science databases. Studies reporting changes in normal-appearing brain tissue using MRI, PET, or SPECT quantitative biomarkers, related to radio-, chemo-, immuno-, or hormone therapy for any kind of solid, cystic, or liquid tumor were included. The main findings of the reviewed studies were summarized, providing also the risk of bias of each study assessed using a modified QUADAS-2 tool. For each imaging method, this review provides the methodological background, and the benefits and shortcomings of each method from the imaging perspective. Finally, a set of recommendations is proposed to support future research.

Fine Structural Changes in the Microvasculature of the Mouse Pinna: Aging and Radiation Injury

1974 ◽  
Vol 32 ◽  
pp. 54-55
Author(s):  
S. Phyllis Steamer ◽  
Rosemarie L. Devine
Keyword(s):  
Structural Changes ◽  
Radiation Treatment ◽  
Arterial Stenosis ◽  
Ultrastructural Changes ◽  
Vascular Effects ◽  
Microvascular Changes ◽  
Surrounding Connective Tissue ◽  
Fission Neutrons ◽  
Total Body

The importance of radiation damage to the skin and its vasculature was recognized by the early radiologists. In more recent studies, vascular effects were shown to involve the endothelium as well as the surrounding connective tissue. Microvascular changes in the mouse pinna were studied in vivo and recorded photographically over a period of 12-18 months. Radiation treatment at 110 days of age was total body exposure to either 240 rad fission neutrons or 855 rad 60Co gamma rays. After in vivo observations in control and irradiated mice, animals were sacrificed for examination of changes in vascular fine structure. Vessels were selected from regions of specific interest that had been identified on photomicrographs. Prominent ultrastructural changes can be attributed to aging as well as to radiation treatment. Of principal concern were determinations of ultrastructural changes associated with venous dilatations, segmental arterial stenosis and tortuosities of both veins and arteries, effects that had been identified on the basis of light microscopic observations. Tortuosities and irregularly dilated vein segments were related to both aging and radiation changes but arterial stenosis was observed only in irradiated animals.

Evaluation of single-electron movies of glutamine synthetase molecules

1983 ◽  
Vol 41 ◽  
pp. 280-281
Author(s):  
W. Kunath ◽  
E. Zeitler ◽  
M. Kessel
Keyword(s):  
Electron Microscope ◽  
Glutamine Synthetase ◽  
Electron Irradiation ◽  
Structural Damage ◽  
Structural Changes ◽  
Single Electron ◽  
Continuous Series ◽  
Digital Recording ◽  
Recording Device ◽  
Low Exposure

The features of digital recording of a continuous series (movie) of singleelectron TV frames are reported. The technique is used to investigate structural changes in negatively stained glutamine synthetase molecules (GS) during electron irradiation and, as an ultimate goal, to look for the molecules' “undamaged” structure, say, after a 1 e/Å2 dose.The TV frame of fig. la shows an image of 5 glutamine synthetase molecules exposed to 1/150 e/Å2. Every single electron is recorded as a unit signal in a 256 ×256 field. The extremely low exposure of a single TV frame as dictated by the single-electron recording device including the electron microscope requires accumulation of 150 TV frames into one frame (fig. lb) thus achieving a reasonable compromise between the conflicting aspects of exposure time per frame of 3 sec. vs. object drift of less than 1 Å, and exposure per frame of 1 e/Å2 vs. rate of structural damage.

Sign in / Sign up

Export Citation Format

Share Document