Blood longitudinal (T 1) and transverse (T 2) relaxation time constants at 11.7 Tesla

Lin, Ai Ling; Qin, Qin; Xiao, Zhao; Duong, Timothy Q.

doi:10.1007/s10334-011-0287-2

Cited by 40 publications

(37 citation statements)

References 24 publications

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“…Also, T1 values of human blood in the present study were linearly dependent on B 0 , which is consistent with previous studies [15][16][17][18] (Fig. 4).…”

supporting

confidence: 82%

“…T1 values of blood may be influenced by Hct, temperature, pH, and oxygenation levels. 9,[15][16][17][18][19] In fact, accurate measurements of human blood T1 values are an important topic in itself because these values are an important MR parameter for quantitative physiological and functional MR measurements, such as arterial spin labeling with cerebral blood volume calculations. Previously, T1 values of bovine blood had been measured at 1.5 T, 3 T, 18 4.7 T, 7 T, and 9.4 T. 17 T1 values of rat blood have also been measured at 11.7 T. 16 Human blood T1 values have also recently been measured at 3 T 19 and 7 T.…”

Section: Discussionmentioning

confidence: 99%

“…However, conflicting conclusions regarding the influence of blood oxygen content have been reached in previous studies. [15][16][17][18][19] In the study of Lin et al, 16 rat blood T1 values were found to be independent of oxygenation. The study of Rane et al 15 demonstrated that T1 values of human blood at 7 T differed depending on whether arterial or venous blood was examined.…”

mentioning

confidence: 99%

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T1 Relaxivities of Gadolinium-Based Magnetic Resonance Contrast Agents in Human Whole Blood at 1.5, 3, and 7 T

Shen

Goerner

Snyder

et al. 2015

Investigative Radiology

212

187

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OBJECTIVES Calculation of accurate T1 relaxivity (r1) values for gadolinium-based magnetic resonance contrast agents (GBCAs) is a complex process. As such, often referenced r1 values for the GBCAs at 1.5 T, 3 T, and 7 T are based on measurements obtained in media that are not clinically relevant, derived from only a small number of concentrations, or available for only a limited number of GBCAs. This study derives the r1 values of the 8 commercially available GBCAs in human whole blood at 1.5 T, 3 T, and 7 T. MATERIALS AND METHODS Eight GBCAs were serially diluted in human whole blood, at 7 concentrations from 0.0625 to 4 mM. A custom-built phantom held the dilutions in air-tight cylindrical tubes maintained at 37 ± 0.5°C by a heat-circulating system. Images were acquired using inversion recovery sequences with inversion times from 30 milliseconds to 10 seconds at 1.5 T and 3 T as well as 60 milliseconds to 5 seconds at 7 T. A custom MATLAB program was used to automate signal intensity measurements from the images acquired of the phantom. SigmaPlot was used to calculate T1 relaxation times and, finally, r1. RESULTS Measured r1 values in units of s[BULLET OPERATOR]mM at 1.5 T (3 T/7 T) were 3.9 ± 0.2 (3.4 ± 0.4/2.8 ± 0.4) for Gd-DOTA, 4.6 ± 0.2 (4.5 ± 0.3/4.2 ± 0.3) for Gd-DO3A-butrol, 4.3 ± 0.4 (3.8 ± 0.2/3.1 ± 0.4) for Gd-DTPA, 6.2 ± 0.5 (5.4 ± 0.3/4.7 ± 0.1) for Gd-BOPTA, 4.5 ± 0.1 (3.9 ± 0.2/3.7 ± 0.2) for Gd-DTPA-BMA, 4.4 ± 0.2 (4.2 ± 0.2/4.3 ± 0.2) for Gd-DTPA-BMEA, 7.2 ± 0.2 (5.5 ± 0.3/4.9 ± 0.1) for Gd-EOB-DTPA, and 4.4 ± 0.6 (3.5 ± 0.6/3.4 ± 0.1) for Gd-HP-DO3A. The agents can be stratified by relaxivity, with a significant additional dependency on field strength. CONCLUSIONS This report quantifies, for the first time, T1 relaxivity for all 8 gadolinium chelates in common clinical use worldwide, at current relevant field strengths, in human whole blood at physiological temperature (37°C). The measured r1 values differ to a small degree from previously published values, where such comparisons exist, with the current r1 measurements being that most relevant to clinical practice. The macrocyclic agents, with the exception of Gd-DO3A-butrol, have slightly lower r1 values when compared with the 2 much less stable linear agents, Gd-DTPA-BMA and Gd-DTPA-BMEA. The 2 agents with hepatobiliary excretion, Gd-EOB-DTPA and Gd-BOPTA, have, at 1.5 and 3 T, substantially higher r1 values than all other agents.

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“…Also, T1 values of human blood in the present study were linearly dependent on B 0 , which is consistent with previous studies [15][16][17][18] (Fig. 4).…”

supporting

confidence: 82%

Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

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T1 Relaxivities of Gadolinium-Based Magnetic Resonance Contrast Agents in Human Whole Blood at 1.5, 3, and 7 T

Shen

Goerner

Snyder

et al. 2015

Investigative Radiology

212

187

View full text Add to dashboard Cite

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“…The transverse relaxation time of the white and grey matter at 3T is assumed to be 80 ms [7], while the transverse relaxation time in tumour tissue may be longer (up to 200 ms). The transverse relaxation time of blood at 3T depends on the oxygenation level, and is in the range of 80-120 ms [8,9], considering that the blood water T2 value was reported to be approximately 127 and 163 ms at 1.5 T for an oxygen fraction of 0.6 and 0.7, respectively [10], and the T2 also decreases with increasing B 0 [11]. Finally, the transverse relaxation time of CSF should be much longer, and relevant CSF partial volume would increase the T2 fast value.…”

Section: Post-processing Of Dw-mr Imagingmentioning

confidence: 95%

IVIM analysis of brain tumors: an investigation of the relaxation effects of CSF, blood, and tumor tissue on the estimated perfusion fraction

Bisdas

Klose

2014

Magn Reson Mater Phy

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Due to the complex interaction in the relaxation rates of CSF, blood, and tumour tissue, the estimation of f values is affected by the choice of TE. Only f values in normal white matter and tumour tissue--which largely comprise blood voxels with minor CSF partial volume--may be clinically applicable in the present form of IVIM-based DWI analysis. Going a step further, and after removing voxels with heavily TE-susceptible f values, we were able to obtain accurate and TE-independent f values in contrast-enhancing tumour tissue, white matter, and grey matter, which were essentially consistent with those reported in the literature.

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“…It is however difficult to extrapolate whether these components are mainly unilateral or bilateral; most of the studies in rats clearly showed the presence of a bilateral cortical connectivity in several cortical regions (mainly visual, somatosensory, auditory, and motor) also under isoflurane (Liang et al, 2012;Zhou et al, 2014); nevertheless, not all studies in mice using isoflurane as anesthetic found the same degree of bilateral connectivity (Jonckers et al, 2011;Guilfoyle et al, 2013), whereas a more prominent interhemispheric connectivity has been found using other anesthetics (Nasrallah et al, 2014;Sforazzini et al, 2014). In this study, we detected significant interhemispheric direct connectivity (with partial correlation analysis) in hippocampal, motor, auditory, visual, and piriform cortices, and intrahemispheric connectivity between somatosensory, motor, and auditory cortices.…”

Section: Fc In the Aging Mouse Brainmentioning

confidence: 99%

Resting-State Functional Connectivity Changes in Aging apoE4 and apoE-KO Mice

Zerbi

Wiesmann²,

Emmerzaal³

et al. 2014

J. Neurosci.

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It is well established that the cholesterol-transporter apolipoprotein (APOE) genotype is associated with the risk of developing neurodegenerative diseases. Recently, brain functional connectivity (FC) in apoE-4 carriers has been investigated by means of resting-state fMRI, showing a marked differentiation in several functional networks at different ages compared with carriers of other apoE isoforms. The causes of such hampered FC are not understood. We hypothesize that vascular function and synaptic repair processes, which are both impaired in carriers of 4, are the major contributors to the loss of FC during aging. To test this hypothesis, we integrated several different MRI techniques with immunohistochemistry and investigated FC changes in relation with perfusion, diffusion, and synaptic density in apoE4 and apoE-knock-out (KO) mice at 12 (adult) and 18 months of age.Compared with wild-type mice, we detected FC deficits in both adult and old apoE4 and apoE-KO mice. In apoE4 mice, these changes occurred concomitant with increased mean diffusivity in the hippocampus, whereas perfusion deficits appear only later in life, together with reduced postsynaptic density levels. Instead, in apoE-KO mice FC deficits were mirrored by strongly reduced brain perfusion since adulthood. In conclusion, we provide new evidence for a relation between apoE and brain connectivity, possibly mediated by vascular risk factors and by the efficiency of APOE as synaptic modulator in the brain. Our results show that multimodal MR neuroimaging is an excellent tool to assess brain function and to investigate early neuropathology and aging effects in translational research.

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Blood longitudinal (T 1) and transverse (T 2) relaxation time constants at 11.7 Tesla

Cited by 40 publications

References 24 publications

T1 Relaxivities of Gadolinium-Based Magnetic Resonance Contrast Agents in Human Whole Blood at 1.5, 3, and 7 T

T1 Relaxivities of Gadolinium-Based Magnetic Resonance Contrast Agents in Human Whole Blood at 1.5, 3, and 7 T

IVIM analysis of brain tumors: an investigation of the relaxation effects of CSF, blood, and tumor tissue on the estimated perfusion fraction

Resting-State Functional Connectivity Changes in Aging apoE4 and apoE-KO Mice

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