scholarly journals NI-3 Magnetic resonance relaxometry for tumor cell density imaging for glioma: An exploratory study via 11C-methionine PET and its validation via stereotactic tissue sampling

2021 ◽  
Vol 3 (Supplement_6) ◽  
pp. vi18-vi18
Author(s):  
Manabu Kinoshita ◽  
Masato Uchikoshi ◽  
Souichiro Tateishi ◽  
Shohei Miyazaki ◽  
Mio Sakai ◽  
...  
Keyword(s):  
Relaxation Time ◽  
Tumor Cell ◽  
Cell Density ◽  
T2 Relaxation ◽  
T1 Relaxation Time ◽  
T1 Relaxation ◽  
Tumor Load ◽  
The Brain ◽  
And Diffusion ◽  
Met Pet

Abstract Objective: While visualization of non-enhancing tumors for glioma is crucial for planning the most appropriate surgical or non-surgical treatment of the disease, current MRI cannot achieve this goal. This study aims to test the hypothesis that quantitative and diffusion MRI can estimate tumor burden with the brain. Materials and Methods: Study 1: Ten patients who have undergone Methionine PET (Met-PET), quantitative MRI (qMRI), and diffusion MRI (DWI) were included for analysis. A cut-off of a tumor-to-normal ratio (T/Nr) 1.5 was set on Met-PET, and the values from qMRI and DWI were compared. Study 2: Seventy-nine stereo-tactically sampled tissues from 22 glioma patients were correlated with Met-PET, qMRI, and DWI measurements regarding tumor cell density. qMRI acquisition: Imaging was performed on either a 1.5 or 3 T MR scanner (Prisma or Aera; Siemens Healthcare, Erlangen, Germany). T1-relaxometry was achieved by first acquiring MP2RAGE images, then converting those images into T1-relaxation time maps. At the same time, T2-relaxometry was achieved by first acquiring multi-echo T2-weighted images and then converting those images into T2-relaxation time maps, with both relaxometries performed via Bayesian inference modeling (Olea Nova+; Canon Medical Systems, Tochigi, Japan). Results: Study 1 revealed that regions of 1850ms < T1-relaxation time < 3200ms and 115ms < T2-relaxation time < 225ms tended to be Met-PET T/Nr > 1.5. DWI was not useful to separate areas between low and high Met-PET. Study 2 showed that regions of 1850ms < T1-relaxation time < 3200ms showed high tumor cell density than other areas (p=0.04). Conclusions: Our results supported the hypothesis that qMRI is useful for predicting the tumor load within the brain among glioma patients. T1-relaxation time was notably useful for this means. On the other hand, ADC measured from DWI was limited for tumor load prediction.

scholarly journals Magnetic Resonance Relaxometry for Tumor Cell Density Imaging for Glioma: An Exploratory Study via 11C-methionine PET and Its Validation via Stereotactic Tissue Sampling

Cancers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 4067
Author(s):  
Manabu Kinoshita ◽  
Masato Uchikoshi ◽  
Souichiro Tateishi ◽  
Shohei Miyazaki ◽  
Mio Sakai ◽  
...  
Keyword(s):  
Relaxation Time ◽  
Magnetic Resonance ◽  
Tumor Cell ◽  
Relaxation Times ◽  
Tissue Sampling ◽  
T2 Relaxation ◽  
T1 Relaxation Time ◽  
T1 Relaxation ◽  
Tumor Load ◽  
T1 And T2

One of the most crucial yet challenging issues for glioma patient care is visualizing non-contrast-enhancing tumor regions. In this study, to test the hypothesis that quantitative magnetic resonance relaxometry reflects glioma tumor load within tissue and that it can be an imaging surrogate for visualizing non-contrast-enhancing tumors, we investigated the correlation between T1- and T2-weighted relaxation times, apparent diffusion coefficient (ADC) on magnetic resonance imaging, and 11C-methionine (MET) on positron emission tomography (PET). Moreover, we compared the T1- and T2-relaxation times and ADC with tumor cell density (TCD) findings obtained via stereotactic image-guided tissue sampling. Regions that presented a T1-relaxation time of >1850 ms but <3200 ms or a T2-relaxation time of >115 ms but <225 ms under 3 T indicated a high MET uptake. In addition, the stereotactic tissue sampling findings confirmed that the T1-relaxation time of 1850–3200 ms significantly indicated a higher TCD (p = 0.04). However, ADC was unable to show a significant correlation with MET uptake or with TCD. Finally, synthetically synthesized tumor load images from the T1- and T2-relaxation maps were able to visualize MET uptake presented on PET.

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.

Myocardial changes detected with modern cardiac magnetic resonance techniques in patients with early rheumatoid arthritis

2021 ◽  
Vol 22 (Supplement_1) ◽  
Author(s):  
J Jarvio ◽  
S Syvaranta ◽  
S Tuohinen ◽  
M Holmstrom ◽  
R Peltomaa ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Relaxation Time ◽  
Cardiac Magnetic Resonance ◽  
Magnetic Resonance ◽  
P Value ◽  
Healthy Controls ◽  
T2 Relaxation Time ◽  
T2 Relaxation ◽  
T1 Relaxation Time ◽  
T1 Relaxation

Abstract Funding Acknowledgements Type of funding sources: Public hospital(s). Main funding source(s): HUS diagnostic imaging center Aims Subclinical myocardial disease is common in patients with rheumatoid arthritis (RA). Impaired cardiac function, myocardial fibrosis and inflammation have previously correlated with RA disease activity. Our aim was to study whether myocardial changes are detectable by cardiac magnetic resonance (CMR) at the time of RA diagnosis. Material and methods: We recruited 21 untreated early RA patients without history of heart disease in Helsinki University Hospital and Lohja Hospital (Finland) between 10/2018 and 2/2020, and nine healthy volunteers. The patients underwent a clinical examination, laboratory tests, and CMR including mapping of extracellular volume fraction (ECV), and T1 and T2 relaxation times. The healthy controls underwent non-contrast CMR. Results  The RA patients were older than the controls (median 58.1 years vs. 41.6 years, respectively, table 1.). T1 was slightly higher in RA patients compared with healthy controls in anteroseptal segments (1015 ms vs. 982 ms, P = 0.017) (table 2).  No difference in T2 was detected and the ECV values were considered normal. Segmental T1, T2 or ECV showed no significant correlations with age, duration of the symptoms or with RA disease activity (DAS28-CRP score). Conclusions  The minor, but statistically significant, elevation of T1 relaxation time in the anteroseptal segments suggests that myocardial changes may occur already in the early phase of RA, the anteroseptal segments being most vulnerable. The elevation of T1 relaxation time can be caused by mild myocardial inflammation or fibrosis. Although no significant correlation with DAS28-CRP was observed, subclinical systemic inflammation may have contributed to the myocardial abnormalities. Table 1. Pre-contrast T1 relaxation time (ms) T2 relaxation time (ms) ECV (%) Mean RA patients Controls P-value RA patients Controls P-value RA patients Global myocardial mean 996 (978-1011) 982 (964-1000) 0.304 48.0 (44.6-49.7) 46.3 (44.1-48.7) 0.295 26.6 (25.7-28.5) Anterior segments 954 (919-1000) 951 (921-998) 0.929 47.7 (46.4-49.8) 47.9 (43.5-50.1) 0.871 26.7 (25.3-28.8) Anteroseptal segments 1015 (987-1041) 982 (947-996) 0.017 48.3 (45.5-49.9) 45.7 (43.8-48.4) 0.150 28.3 (26.8-29.2) Inferoseptal segments 1012 (992-1023) 998 (967-1003) 0.077 48.0 (43.5-49.4) 44.9 (43.5-46.2) 0.533 26.7 (26.0-27.9) Inferior segments 1016 (987-1064) 1003 (992-1025) 0.625 47.5 (45.1-50.3) 46.1 (44.2-48.4) 0.304 27.3 (25.6-29.0) Inferolateral segments 997 (974-1043) 992 (980-1016) &gt;0.999 46.6 (42.6-49.1) 45.1 (42.4-49.1) 0.689 25.8 (25.3-28.2) Anterolateral segments 973 (945-973) 981 (954-1010) 0.563 47.0 (45.1-48.5) 46.6 (43.5-49.6) 0.625 26.4 (24.7-28.0) T1 and T2 relaxation time mapping and ECV results. Abstract Figure. ECV mapping

NMR T1 Relaxation Time of the Brain During Alcohol Withdrawal and its Lack of Relationship with Symptom Severity

Addiction ◽  
1989 ◽  
Vol 84 (6) ◽  
pp. 669-672 ◽  
Author(s):  
A. J. MANDER ◽  
A. YOUNG ◽  
J. D. CHICK ◽  
J. RIDGWAY ◽  
J. J. K. BEST
Keyword(s):  
Relaxation Time ◽  
Alcohol Withdrawal ◽  
Symptom Severity ◽  
T1 Relaxation Time ◽  
T1 Relaxation ◽  
The Brain

scholarly journals Multislice T1 relaxation time measurements in the brain using IR-EPI: Reproducibility, normal values, and histogram analysis in patients with multiple sclerosis

2003 ◽  
Vol 18 (6) ◽  
pp. 656-664 ◽  
Author(s):  
Marianne A.A. van Walderveen ◽  
Ronald A. van Schijndel ◽  
Petra J.W. Pouwels ◽  
Chris H. Polman ◽  
Frederik Barkhof
Keyword(s):  
Multiple Sclerosis ◽  
Relaxation Time ◽  
Normal Values ◽  
Histogram Analysis ◽  
T1 Relaxation Time ◽  
T1 Relaxation ◽  
The Brain

T1 Relaxation Time of Achilles Tendon at 3 Tesla with Special Reference to Relevant Clinical Score: A Preliminary Study

2020 ◽  
Vol 16 (2) ◽  
pp. 164-173
Author(s):  
Zeineb Tbini ◽  
Mokhtar Mars ◽  
Mouna Bouaziz
Keyword(s):  
Relaxation Time ◽  
Achilles Tendon ◽  
Clinical Score ◽  
3 Tesla ◽  
Acquisition Time ◽  
Short Term ◽  
T1 Relaxation Time ◽  
T1 Relaxation ◽  
Spin Echo Sequence ◽  
Significant Difference

Purpose: The purpose of this study was to investigate T1 relaxation time of the human Achilles tendon, to test its short-term repeatability as well as the minimal detectable change, and to assess the extent that correlate with clinical symptoms. Methods: Twenty asymptomatic volunteers and eighteen patients with clinically and sonographically confirmed tendinopathy were scanned for ankle using a 3 Tesla (T) MR scanner. T1 maps were calculated from a variable flip angle gradient echo Ultra-short echo time sequence (VFA-GE UTE) and inversion recovery spin echo sequence (IR-SE) using a self-developed matlab algorithm in three regions of interest of Achilles Tendon (AT). Signal to Noise Ratio (SNR) between the two sequences was evaluated. INTRA-class Correlation Coefficient (ICC), Coefficient of Variation (CV) and the Least Significant Change (LSC) were calculated, to test short-term repeatability of T1. Subjects were assessed by the VISA-A clinical score. P values less than 0.005 were considered statistically significant. Results: Mean T1 values were 427.09 ± 53.37 ms and 528.70 ± 103.50 ms using IR-SE sequence and 575.43 ± 110.60 ms and 875.81 ± 425.77 ms with VFA-GE UTE sequence in the whole AT for volunteers and patients, respectively. : T1 values showed a significant difference between volunteers and patients (P=0.001). Regional variation of T1 in healthy and tendinopathic AT were greater for VFA-GE UTE sequence than for IR-SE sequence. VFA-GE UTE sequence showed clearly higher SNR compared to IR-SE sequence. Short-term repeatability of T1 values for volunteers showed an LSC of 22% and 14% for IR-SE sequence and VFA-GE UTE sequence, respectively. For patients, LSC was 14% and 5% for IR-SE sequence and VFA-GE UTE sequence, respectively. There was no correlation between T1 and VISA-A clinical score (p>0.005). Conclusion: VFA-GE UTE sequence used for T1 mapping calculation demonstrated short acquisition time and clearly high SNR. Results revealed that T1 relaxation time can be used as a biomarker to differentiate between healthy and pathologic Achilles tendon. However, T1 showed no correlation with the VISA-A clinical score.

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 &lt; 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 &lt; 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 &lt; 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 Blood-brain barrier breakdown in non-enhancing multiple sclerosis lesions detected by 7-Tesla MP2RAGE ΔT1 mapping

PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0249973
Author(s):  
Seongjin Choi ◽  
Margaret Spini ◽  
Jun Hua ◽  
Daniel M. Harrison
Keyword(s):  
Multiple Sclerosis ◽  
Relaxation Time ◽  
White Matter ◽  
Blood Brain Barrier ◽  
White Matter Lesions ◽  
Brain Barrier ◽  
7 Tesla ◽  
T1 Relaxation Time ◽  
T1 Relaxation ◽  
Blood Brain

Although the blood-brain barrier (BBB) is altered in most multiple sclerosis (MS) lesions, gadolinium enhancement is seen only in acute lesions. In this study, we aimed to investigate gadolinium-induced changes in T1 relaxation time in MS lesions on 7-tesla (7T) MRI as a means to quantify BBB breakdown in non-enhancing MS lesions. Forty-seven participants with MS underwent 7T MRI of the brain with a magnitude-prepared rapid acquisition of 2 gradient echoes (MP2RAGE) sequence before and after contrast. Subtraction of pre- and post-contrast T1 maps was used to measure T1 relaxation time change (ΔT1) from gadolinium. ΔT1 values were interrogated in enhancing white matter lesions (ELs), non-enhancing white matter lesions (NELs), and normal appearing white matter (NAWM) and metrics were compared to clinical data. ΔT1 was measurable in NELs (median: -0.139 (-0.304, 0.174) seconds; p < 0.001) and was negligible in NAWM (median: -0.001 (-0.036, 0.155) seconds; p = 0.516). Median ΔT1 in NELs correlated with disability as measured by Expanded Disability Status Scale (EDSS) (rho = -0.331, p = 0.026). Multiple measures of NEL ΔT1 variability also correlated with EDSS. NEL ΔT1 values were greater and more variable in patients with progressive forms of MS and greater in those not on MS treatment. Measurement of the changes in T1 relaxation time caused by contrast on 7T MP2RAGE reveals clinically relevant evidence of BBB breakdown in NELs in MS. This data suggests that NEL ΔT1 should be evaluated further as a biomarker for disease severity and treatment effect in MS.

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