NIMG-53. RATIO OF T1-WEIGHTED TO T2-WEIGHTED SIGNAL INTENSITY AND IDH MUTATION IN GLIOMA

2021 ◽  
Vol 23 (Supplement_6) ◽  
pp. vi141-vi141
Author(s):  
Manabu Kinoshita ◽  
Masato Uchikoshi ◽  
Koji Takano ◽  
Mio Sakai ◽  
Hideyuki Arita ◽  
...  
Keyword(s):  
Relaxation Time ◽  
Signal Intensity ◽  
Surrogate Marker ◽  
Radiological Feature ◽  
Lower Grade ◽  
Idh Mutation ◽  
T2 Relaxation Time ◽  
T2 Relaxation ◽  
Mutation Status ◽  
T1 And T2

Abstract INTRODUCTION Identifying IDH mutation status before treatment is essential for Lower-grade glioma (LrGG) treatment. We have previously revealed that IDH mutated LrGG consists of tumor tissues with significantly longer T1 and T2 relaxation time and is a useful radiological feature to identify IDH mutation status. The ratio of T1-weighted to T2-weighted signal intensity (rT1/T2) is a way to retrieve semi-quantitative relaxation time information of the tissue bypassing the need to perform relaxometry. This investigation aimed to elucidate the correlation between rT1/T2 and T1-, T2-relaxation time (-relax) in glioma tissue and to explore the possibility of rT1/T2 as a radiological surrogate marker to identify IDH mutation status in LrGG. MATERIALS AND METHODS We analyzed 8 LrGGs (IDHwt:4, IDHmt:2, IDHmt&1p19q-CODEL:2) in which relaxometry was performed. rT1/T2 maps were reconstructed as described in previous literature. Regions-of-interest were designed based on T2WI and FLAIR. The correlations between rT1/T2 and T1- and T2-relax were analyzed. Furthermore, We also investigated the correlation of IDH mutation status and rT1/T2. RESULTS 106,488 voxels were analyzed. The correlation between rT1/T2 and T1- and T2-relax were rT1/T2=1.6e-0.0003T1-relax and rT1/T2=1.2e-0.002T2-relax (R=0.77 and 0.70). rT1/T2 of IDH-wildtype tumor was significantly higher than that of IDH-mutant tumor (1.0 vs. 0.75, p< 0.0001). Voxel-wise analysis of rT1/T2 map was able to discriminate IDH-wildtype tumor from the mutant tumor with an AUC of 0.82. CONCLUSIONS rT1/T2, which can be calculated from MRI acquired during routine clinical practice, is a promising radiological surrogate marker to identify IDH mutation status in LrGG.

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 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.

T1 and T2 relaxation time estimates and brain measures during withdrawal in alcoholic men

1991 ◽  
Vol 29 (2) ◽  
pp. 157-169 ◽  
Author(s):  
Ingrid Agartz ◽  
Jan Sääf ◽  
Lars-Olof Wahlund ◽  
Lennart Wetterberg
Keyword(s):  
Relaxation Time ◽  
T2 Relaxation Time ◽  
T2 Relaxation ◽  
Time Estimates ◽  
T1 And T2

scholarly journals Magnetic resonance imaging in skeletal muscle following denervation and electrical stimulation

1996 ◽  
Vol XXVIII (1-2) ◽  
pp. 19-23
Author(s):  
Т. Mokrusch
Keyword(s):  
Electrical Stimulation ◽  
Relaxation Time ◽  
Signal Intensity ◽  
T2 Relaxation Time ◽  
Denervated Muscle ◽  
T2 Relaxation ◽  
New Type ◽  
Chronic Denervation ◽  
Mri Evaluation ◽  
Distinct Increase

Following chronic denervation, MRI evaluation of fast rabbit muscles revealed a distinct increase of signal intensity and T2 relaxation time. These changes were missing or less pronounced after treatment with a new type of electrical stimulation, which previously had proved effective in avoiding muscle atrophy. One month after denervation, there was a slight increase of signal intensity as well in the stimulated as in the untreated animals, after two months, however, the increase was statistically significant only in the non-stimulated muscles. T2 relaxation time showed a slight increase after one month of therapy, while there was a significant increase after one and two months without therapy. After 36 months of electrical stimulation, there was no increase of T2 at all. The results indicate 1), that MRI can be used when monitoring stimulation effects on denervated muscle, and 2), that, for this purpose, T2 relaxation time is more useful than signal intensity.

T1 and T2 relaxation time estimates in the normal human brain.

Radiology ◽  
1991 ◽  
Vol 181 (2) ◽  
pp. 537-543 ◽  
Author(s):  
I Agartz ◽  
J Sääf ◽  
L O Wahlund ◽  
L Wetterberg
Keyword(s):  
Relaxation Time ◽  
Human Brain ◽  
T2 Relaxation Time ◽  
T2 Relaxation ◽  
Normal Human Brain ◽  
Time Estimates ◽  
Normal Human ◽  
T1 And T2

scholarly journals NIMG-19. T1- AND T2-RELAXOMETRY FOR TISSUE CELL DENSITY QUANTIFICATION IN GLIOMA IMAGING: EXPLORATORY STUDY VIA 11C-METHIONINE PET AND VALIDATION VIA STEREOTACTIC TISSUE SAMPLING

2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi165-vi165
Author(s):  
Manabu Kinoshita ◽  
Masato Uchikoshi ◽  
Souichiro Tateishi ◽  
Shohei Miyazaki ◽  
Mio Sakai ◽  
...  
Keyword(s):  
Relaxation Time ◽  
Cell Density ◽  
Tissue Sampling ◽  
T2 Relaxation Time ◽  
T2 Relaxation ◽  
T1 Relaxation Time ◽  
T2 Relaxometry ◽  
T1 Relaxation ◽  
Tumor Load ◽  
T1 And T2

Abstract Visualization of non-contrast-enhancing tumor lesions in glioma is one of the most crucial yet challenging issues for patients with this pathology. This study examined the hypothesis that quantitative T1- and T2-relaxometry could reflect glioma tumor load within the brain and could further be used for visualizing non-enhancing heavily tumor-loaded areas. Participants comprised patients with low- or high-grade glioma. Correlation between T1- or T2-relaxation time and 11C-methionine uptake as measured by positron emission tomography (Cohort-1) was investigated followed by comparing T1- or T2-relaxation time with tumor cell density as measured by stereotactic image-guided tissue sampling in a different cohort (Cohort-2). T1-relaxometry was achieved by converting Magnetization Prepared Rapid Gradient Echo (MP2RAGE) images and T2-relaxometry by multi-echo T2-weighted images via Bayesian inference modeling. T1-relaxation time >2000 ms but < 3200 ms or T2-relaxation time >115 ms but < 265 ms were indicative of high 11C-methionine uptake. Stereotactic tissue sampling study confirmed that tissue cell densities obtained from locations with a T1-relaxation time of 2000–3200 ms or a T2-relaxation time of 125–225 ms were significantly higher than those obtained from other locations (p < 0.001 and p = 0.03, respectively). Synthetic tumor load images were successfully reconstructed using T1- and T2-relaxation mapping. T1- and T2-relaxation times both correlated well with tumor cell density in glioma tissues. The ideal ranges for identifying high tumor load tissues were 2000–3200 ms for T1-relaxation time and 115–220 ms for T2-relaxation both measured at 3.0 T.

scholarly journals Reproducibility of myocardial T1 and T2 relaxation time measurement using slice-interleaved T1 and T2 mapping sequences

2016 ◽  
Vol 44 (5) ◽  
pp. 1159-1167 ◽  
Author(s):  
Steven Bellm ◽  
Tamer A. Basha ◽  
Ravi V. Shah ◽  
Venkatesh L. Murthy ◽  
Charlene Liew ◽  
...  
Keyword(s):  
Relaxation Time ◽  
T2 Mapping ◽  
Time Measurement ◽  
T2 Relaxation Time ◽  
T2 Relaxation ◽  
Relaxation Time Measurement ◽  
Myocardial T1 ◽  
T1 And T2
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