scholarly journals Age-Related Loss of Brain Volume and T2 Relaxation Time in Youth With Type 1 Diabetes

Diabetes Care ◽  
2012 ◽  
Vol 35 (3) ◽  
pp. 513-519 ◽  
Author(s):  
G. S. Pell ◽  
A. Lin ◽  
R. M. Wellard ◽  
G. A. Werther ◽  
F. J. Cameron ◽  
...  
Keyword(s):  
Type 1 Diabetes ◽  
Relaxation Time ◽  
Brain Volume ◽  
T2 Relaxation Time ◽  
T2 Relaxation ◽  
Age Related

scholarly journals Hypothalamic Gliosis in Adolescents With Type 1 Diabetes and Disordered Eating Behaviors

2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. A459-A459
Author(s):  
Angel Siu Ying Nip ◽  
Catherine Pihoker ◽  
Ellen A Schur ◽  
Susan Melhorn ◽  
Christian L Roth
Keyword(s):  
Type 1 Diabetes ◽  
Relaxation Time ◽  
Disordered Eating ◽  
Eating Behaviors ◽  
Relaxation Times ◽  
Structural Mri ◽  
T2 Relaxation Time ◽  
T2 Relaxation ◽  
Disordered Eating Behaviors

Abstract Background: The hypothalamus and brainstem are thought to be the principal homeostatic brain areas responsible for regulating appetite and weight. Research suggests that inflammation plays a role in the onset and maintenance of eating-related maladaptive behaviors. Hypothalamic inflammation and reactive gliosis mediate disruptions in energy homeostasis, especially with obesity. Data from SEARCH in Youth for Diabetes has demonstrated high prevalence of disordered eating behaviors (DEB) including insulin omission and binge eating, in individuals with type 1 diabetes (T1D). Limited studies have used neuroimaging techniques for investigation of hypothalamic gliosis in individuals with T1D and DEB. Objectives: To determine the feasibility of assessing hypothalamic gliosis with structural MRI in adolescents with T1D with and without DEB. Research Design and Methods: Adolescents with T1D with and without DEB, aged 13–19, were invited to participate. Participants with current use of medications known to alter appetite were excluded. They completed the Diabetes Eating Problem Survey - Revised (DEPS-R). A score ≥ 20 was indicative of DEB. Height, weight and waist circumference were obtained, and BMI was calculated. HbA1c was obtained from their prior clinic visit, within 2 months of the study visit. Basal insulin (glargine) was administered the night before, and participants on insulin pump continued with their basal insulin infusion. Participants received rapid-acting insulin prior to the MRI study, and blood glucoses were measured before and after the MRI. Mediobasal hypothalamic (MBH) gliosis was measured by T2 relaxation time. Results: Eight subjects (50% female, mean age 17.8±2.3 years) have completed the study without adverse outcomes. Mean HbA1c was 8.5% (range 7.3–10%). Five subjects screened positive for DEB. There was no significant difference in BMI between DEB and non-DEB groups. In this cohort, females had longer T2 relaxation times in left MBH than males (p=0.035). Compared to non-DEB group, participants with DEB had longer T2 relaxation time in left MBH, adjusted for sex and age (p=0.001). In this initial sample, relationships between MBH T2 relaxation times and glycemic control, BMI or waist circumference did not emerge. Conclusion: The study protocol with insulin injection and MRI to study the hypothalamic gliosis in individuals with T1D is feasible. Structural MRI indicates increased T2 relaxation times as a marker of hypothalamic gliosis in participants with DEB. Further studies with larger sample size are crucial to validate these findings and to study specific eating behaviors and their associations with MBH gliosis in individuals with T1D.

scholarly journals The Effect of Intraventricular Hemorrhage on Brain Development in Premature Infants: A Synthetic MRI Study

2021 ◽  
Vol 12 ◽  
Author(s):  
Chunxiang Zhang ◽  
Xin Zhao ◽  
Meiying Cheng ◽  
Kaiyu Wang ◽  
Xiaoan Zhang
Keyword(s):  
Relaxation Time ◽  
Premature Infants ◽  
Intraventricular Hemorrhage ◽  
Brain Volume ◽  
Relaxation Times ◽  
T2 Relaxation Time ◽  
T2 Relaxation ◽  
T1 And T2 ◽  
The Brain ◽  
Synthetic Mri

Objectives: Synthetic MRI can obtain multiple parameters in one scan, including T1 and T2 relaxation time, proton density (PD), brain volume, etc. This study aimed to investigate the parameter values T1 and T2 relaxation time, PD, and volume characteristics of intraventricular hemorrhage (IVH) newborn brain, and the ability of synthetic MRI parameters T1 and T2 relaxation time and PD to diagnose IVH.Materials and methods: The study included 50 premature babies scanned with conventional and synthetic MRI. Premature infants were allocated to the case group (n = 15) and NON IVH (n = 35). The T1, T2, PD values, and brain volume were obtained by synthetic MRI. Then we assessed the impact of IVH on these parameters.Results: In the posterior limbs of the internal capsule (PLIC), genu of the corpus callosum (GCC), central white matter (CWM), frontal white matter (FWM), and cerebellum (each p < 0.05), the T1 and T2 relaxation times of the IVH group were significantly prolonged. There were significant differences also in PD. The brain volume in many parts were also significantly reduced, which was best illustrated in gray matter (GM), cerebrospinal fluid and intracranial volume, and brain parenchymal fraction (BPF) (each p < 0.001, t = −5.232 to 4.596). The differential diagnosis ability of these quantitative values was found to be excellent in PLIC, CWM, and cerebellum (AUC 0.700–0.837, p < 0.05).Conclusion: The quantitative parameters of synthetic MRI show well the brain tissue characteristic values and brain volume changes of IVH premature infants. T1 and T2 relaxation times and PD contribute to the diagnosis and evaluation of IVH.

scholarly journals T1 and T2∗ relaxation time in the parcellated myocardium of healthy Taiwanese participants: A single center study

2020 ◽  
Author(s):  
Chih-Chien Tsai ◽  
Shu-Hang Ng ◽  
Yao-Liang Chen ◽  
Yu-Hsiang Juan ◽  
Chao-Hung Wang ◽  
...  
Keyword(s):  
Relaxation Time ◽  
T2 Relaxation Time ◽  
Single Center ◽  
T2 Relaxation ◽  
Single Center Study ◽  
T1 And T2 ◽  
Center Study

scholarly journals T2 Relaxation Time of Cartilage at MR Imaging: Comparison with Severity of Knee Osteoarthritis

Radiology ◽  
2004 ◽  
Vol 232 (2) ◽  
pp. 592-598 ◽  
Author(s):  
Timothy C. Dunn ◽  
Ying Lu ◽  
Hua Jin ◽  
Michael D. Ries ◽  
Sharmila Majumdar
Keyword(s):  
Relaxation Time ◽  
Mr Imaging ◽  
Knee Osteoarthritis ◽  
T2 Relaxation Time ◽  
T2 Relaxation

Textural and pore size analysis of carbonates from integrated core and nuclear magnetic resonance logging: An Arbuckle study

2015 ◽  
Vol 3 (1) ◽  
pp. SA77-SA89 ◽  
Author(s):  
John Doveton ◽  
Lynn Watney
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Relaxation Time ◽  
Magnetic Resonance ◽  
Pore Size ◽  
Relaxation Times ◽  
T2 Relaxation Time ◽  
T2 Relaxation ◽  
Nmr Logging ◽  
The Core ◽  
Nuclear Magnetic

The T2 relaxation times recorded by nuclear magnetic resonance (NMR) logging are measures of the ratio of the internal surface area to volume of the formation pore system. Although standard porosity logs are restricted to estimating the volume, the NMR log partitions the pore space as a spectrum of pore sizes. These logs have great potential to elucidate carbonate sequences, which can have single, double, or triple porosity systems and whose pores have a wide variety of sizes and shapes. Continuous coring and NMR logging was made of the Cambro-Ordovician Arbuckle saline aquifer in a proposed CO2 injection well in southern Kansas. The large data set gave a rare opportunity to compare the core textural descriptions to NMR T2 relaxation time signatures over an extensive interval. Geochemical logs provided useful elemental information to assess the potential role of paramagnetic components that affect surface relaxivity. Principal component analysis of the T2 relaxation time subdivided the spectrum into five distinctive pore-size classes. When the T2 distribution was allocated between grainstones, packstones, and mudstones, the interparticle porosity component of the spectrum takes a bimodal form that marks a distinction between grain-supported and mud-supported texture. This discrimination was also reflected by the computed gamma-ray log, which recorded contributions from potassium and thorium and therefore assessed clay content reflected by fast relaxation times. A megaporosity class was equated with T2 relaxation times summed from 1024 to 2048 ms bins, and the volumetric curve compared favorably with variation over a range of vug sizes observed in the core. The complementary link between grain textures and pore textures was fruitful in the development of geomodels that integrates geologic core observations with petrophysical log measurements.

T2* relaxation time in Achilles tendinosis and controls and its correlation with clinical score

2015 ◽  
Vol 43 (6) ◽  
pp. 1417-1422 ◽  
Author(s):  
Anna Gärdin ◽  
Pawel Rasinski ◽  
Johan Berglund ◽  
Adel Shalabi ◽  
Helene Schulte ◽  
...  
Keyword(s):  
Relaxation Time ◽  
Clinical Score ◽  
T2 Relaxation Time ◽  
T2 Relaxation ◽  
Achilles Tendinosis
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