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.

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 &lt; T1-relaxation time &lt; 3200ms and 115ms &lt; T2-relaxation time &lt; 225ms tended to be Met-PET T/Nr &gt; 1.5. DWI was not useful to separate areas between low and high Met-PET. Study 2 showed that regions of 1850ms &lt; T1-relaxation time &lt; 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.

Evaluation of Relaxation Time Measurements by Magnetic Resonance Imaging

1987 ◽  
Vol 28 (3) ◽  
pp. 345-351 ◽  
Author(s):  
L. Kjær ◽  
C. Thomsen ◽  
O. Henriksen ◽  
P. Ring ◽  
M. Stubgaard ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Relaxation Time ◽  
Magnetic Resonance ◽  
Diffusion Processes ◽  
Relaxation Times ◽  
Gradient Field ◽  
Maximum Deviation ◽  
Resonance Imaging ◽  
T2 Relaxation ◽  
T1 And T2

Several circumstances may explain the great variation in reported proton T1 and T2 relaxation times usually seen. This study was designed to evaluate the accuracy of relaxation time measurements by magnetic resonance imaging (MRI) operating at 1.5 tesla. Using a phantom of nine boxes with different concentrations of CuSO4 and correlating the calculated T1 and T2 values with reference values obtained by two spectrometers (corrected to MRI-proton frequency=64 MHz) we found a maximum deviation of about 10 per cent. Measurements performed on a large water phantom in order to evaluate the homogeneity in the imaging plane showed a variation of less than 10 per cent within 10 cm from the centre of the magnet in all three imaging planes. Changing the gradient field strength apparently had no influence on the T2 values recorded. Consequently diffusion processes seem without significance. It is concluded that proton T1 and T2 relaxation times covering the majority of the biologic range can be measured by MRI with an overall accuracy of 5 to 10 per cent. Quality control studies along the lines indicated in this study are recommended.

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

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.

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.

Magnetic resonance relaxometry in monozygotic twins discordant and concordant for schizophrenia

2005 ◽  
Vol 20 (1) ◽  
pp. 41-44 ◽  
Author(s):  
Filip Spaniel ◽  
Vit Herynek ◽  
Tomas Hajek ◽  
Monika Dezortova ◽  
Jiri Horacek ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Globus Pallidus ◽  
Relaxation Times ◽  
Monozygotic Twins ◽  
T2 Relaxation ◽  
T1 Relaxation ◽  
Significant Prolongation ◽  
Healthy Control ◽  
Genetic Loading ◽  
Mz Twins

AbstractT1 and T2 relaxation times were examined in four pairs of monozygotic (MZ) twins discordant and concordant for schizophrenia with low and high genetic loading for the illness and five healthy control MZ twin pairs. Patients with schizophrenia (n = 11) showed significant prolongation in T1 relaxation times in the globus pallidus (GP) bilaterally (P < 0.005, Bonferroni corrected) when compared to 14 healthy MZ twins.

scholarly journals Reliability of Synthetic Brain MRI for Assessment of Ischemic Stroke with Phantom Validation of a Relaxation Time Determination Method

2020 ◽  
Vol 9 (6) ◽  
pp. 1857
Author(s):  
Chia-Wei Li ◽  
Ai-Ling Hsu ◽  
Chi-Wen C. Huang ◽  
Shih-Hung Yang ◽  
Chien-Yuan Lin ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Relaxation Time ◽  
Brain Mri ◽  
Relaxation Times ◽  
Onset Time ◽  
Magnetic Resonance Images ◽  
Diagnostic Tools ◽  
Cupric Sulfate ◽  
T2 Relaxation ◽  
T1 And T2

The reliability of relaxation time measures in synthetic magnetic resonance images (MRIs) of homemade phantoms were validated, and the diagnostic suitability of synthetic imaging was compared to that of conventional MRIs for detecting ischemic lesions. Phantoms filled with aqueous cupric-sulfate (CuSO4) were designed to mimic spin-lattice (T1) and spin-spin (T2) relaxation properties and were used to compare their accuracies and stabilities between synthetic and conventional scans of various brain tissues. To validate the accuracy of synthetic imaging in ischemic stroke diagnoses, the synthetic and clinical scans of 18 patients with ischemic stroke were compared, and the quantitative contrast-to-noise ratios (CNRs) were measured, using the Friedman test to determine significance in differences. Results using the phantoms showed no significant differences in the interday and intersession synthetic quantitative T1 and T2 values. However, between synthetic and referenced T1 and T2 values, differences were larger for longer relaxation times, showing that image intensities in synthetic scans are relatively inaccurate in the cerebrospinal fluid (CSF). Similarly, CNRs in CSF regions of stroke patients were significantly different on synthetic T2-weighted and T2-fluid-attenuated inversion recovery images. In contrast, differences in stroke lesions were insignificant between the two. Therefore, interday and intersession synthetic T1 and T2 values are highly reliable, and discrepancies in synthetic T1 and T2 relaxation times and image contrasts in CSF regions do not affect stroke lesion diagnoses. Additionally, quantitative relaxation times from synthetic images allow better estimations of ischemic stroke onset time, consequently increasing confidence in synthetic MRIs as diagnostic tools for ischemic stroke.

S11-4 Associations between exposure to MN and T1 relaxation time in magnetic resonance imaging

2016 ◽  
Author(s):  
Anne Lotz ◽  
Beate Pesch ◽  
Clara Quetscher ◽  
Chien-Lin Yeh ◽  
Martin Lehnert ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Relaxation Time ◽  
Magnetic Resonance ◽  
Resonance Imaging ◽  
T1 Relaxation Time ◽  
T1 Relaxation
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