Evaluation of MRI sequences for quantitative T1 brain mapping

Tsialios, Panagiotis; Thrippleton, Michael J.; Glatz, Andreas; Pernet, Cyril

doi:10.1088/1742-6596/931/1/012038

Cited by 10 publications

(17 citation statements)

References 11 publications

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“…older than 5 years) were on average slightly lower than the results in our study: in the frontal white matter 707 ms versus 758 ms, in the thalamus 951 ms versus 1,101 ms, and in the nucleus caudatus 1,160 versus 1,272 ms. While deviations for older children probably reflect systematic technical differences as previously suggested [4], differences in the lower age range might additionally be caused by the comparatively low number of cases. In our work, separate evaluations for boys and girls were omitted because of the expected minimal differences and the significantly higher number of cases otherwise needed.…”

Section: Discussionmentioning

confidence: 64%

“…Faster T1 mapping techniques usually employ multi-echo readout modules that are very sensitive to magnetic field inhomogeneity. Moreover, even at the same field strength, T1 dependencies on sequence type or manufacturer hint to systematic deviations from the true T1 value [4]. Other limitations relate to a poor spatial resolution or a lack of multi-slice acquisitions.…”

Section: Introductionmentioning

confidence: 99%

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Quantitative T1 mapping of the normal brain from early infancy to adulthood

Gräfe¹,

Frahm

Merkenschlager

et al. 2020

Pediatr Radiol

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Background Quantitative mapping of MRI relaxation times is expected to uncover pathological processes in the brain more subtly than standard MRI techniques with weighted contrasts. So far, however, most mapping techniques suffer from a long measuring time, low spatial resolution or even sensitivity to magnetic field inhomogeneity. Objective To obtain T1 relaxation times of the normal brain from early infancy to adulthood using a novel technique for fast and accurate T1 mapping at high spatial resolution. Materials and methods We performed whole-brain T1 mapping within less than 3 min in 100 patients between 2 months and 18 years of age with normal brain at a field strength of 3 T. We analyzed T1 relaxation times in several gray-matter nuclei and white matter. Subsequently, we derived regression equations for mean value and confidence interval. Results T1 relaxation times of the pediatric brain rapidly decrease in all regions within the first 3 years of age, followed by a significantly weaker decrease until adulthood. These characteristics are more pronounced in white matter than in deep gray matter. Conclusion Regardless of age, quantitative T1 mapping of the pediatric brain is feasible in clinical practice. Normal age-dependent values should contribute to improved discrimination of subtle intracerebral alterations.

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Section: Discussionmentioning

confidence: 64%

Section: Introductionmentioning

confidence: 99%

Quantitative T1 mapping of the normal brain from early infancy to adulthood

Gräfe¹,

Frahm

Merkenschlager

et al. 2020

Pediatr Radiol

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“…To verify the accuracy of the DESPOT1-HIFI protocol for a range of R 1 values, we scanned a multi-compartment custom MRI phantom with a range of R 1 [29]. This phantom consisted of nine sealed 10 mL syringes containing 0.05, 0.07, … and 0.21 mM MnCl 2 in distilled water.…”

Section: Methodsmentioning

confidence: 99%

“…This phantom consisted of nine sealed 10 mL syringes containing 0.05, 0.07, … and 0.21 mM MnCl 2 in distilled water. The phantom container was filled with 1.5 g/L CuSO 4 and 3.6 g/L NaCl solution to increase the coil loading, reduce susceptibility artefacts around the syringes and to provide a compartment with short T 1 to mimic longitudinal relaxation in blood vessels following contrast injection [29]. Gold-standard measurements were obtained using a single-slice inversion-recovery spin-echo pulse sequence (TR/TE/TI = 1550/11/[30, 330, 730, 1130, 1530] ms).…”

Section: Methodsmentioning

confidence: 99%

MRI Relaxometry for Quantitative Analysis of USPIO Uptake in Cerebral Small Vessel Disease

Thrippleton

Blair

Valdés-Hernández

et al. 2019

IJMS

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A protocol for evaluating ultrasmall superparamagnetic particles of iron oxide (USPIO) uptake and elimination in cerebral small vessel disease patients was developed and piloted. B1-insensitive R1 measurement was evaluated in vitro. Twelve participants with history of minor stroke were scanned at 3-T MRI including structural imaging, and R1 and R2* mapping. Participants were scanned (i) before and (ii) after USPIO (ferumoxytol) infusion, and again at (iii) 24–30 h and (iv) one month. Absolute and blood-normalised changes in R1 and R2* were measured in white matter (WM), deep grey matter (GM), white matter hyperintensity (WMH) and stroke lesion regions. R1 measurements were accurate across a wide range of values. R1 (p < 0.05) and R2* (p < 0.01) mapping detected increases in relaxation rate in all tissues immediately post-USPIO and at 24–30 h. R2* returned to baseline at one month. Blood-normalised R1 and R2* changes post-infusion and at 24–30 h were similar, and were greater in GM versus WM (p < 0.001). Narrower distributions were seen with R2* than for R1 mapping. R1 and R2* changes were correlated at 24–30 h (p < 0.01). MRI relaxometry permits quantitative evaluation of USPIO uptake; R2* appears to be more sensitive to USPIO than R1. Our data are explained by intravascular uptake alone, yielding estimates of cerebral blood volume, and did not support parenchymal uptake. Ferumoxytol appears to be eliminated at 1 month. The approach should be valuable in future studies to quantify both blood-pool USPIO and parenchymal uptake associated with inflammatory cells or blood-brain barrier leak.

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“…Multi-contrast sequences may offer a novel alternative for eliminating the requirement of registration and resampling of separate scans while simultaneously reducing scan acquisition time ( Figure 2 ) [ 152 ]. A recently developed multiparametric imaging sequence is the Multi Echo (ME) MP2RAGE, which is largely unaffected by B1 inhomogeneities [ 153 , 154 , 155 , 156 , 157 , 158 , 159 , 160 ]. This allows for the acquisition of T2*-based contrasts from which subsequent SWI and quantitative susceptibility maps (QSM) can be created in the same space as the T1 images [ 158 , 160 ].…”

Section: Sequence Types and Contrastsmentioning

confidence: 99%

Methodological Considerations for Neuroimaging in Deep Brain Stimulation of the Subthalamic Nucleus in Parkinson’s Disease Patients

Isaacs

Keuken

Alkemade

et al. 2020

JCM

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Deep brain stimulation (DBS) of the subthalamic nucleus is a neurosurgical intervention for Parkinson’s disease patients who no longer appropriately respond to drug treatments. A small fraction of patients will fail to respond to DBS, develop psychiatric and cognitive side-effects, or incur surgery-related complications such as infections and hemorrhagic events. In these cases, DBS may require recalibration, reimplantation, or removal. These negative responses to treatment can partly be attributed to suboptimal pre-operative planning procedures via direct targeting through low-field and low-resolution magnetic resonance imaging (MRI). One solution for increasing the success and efficacy of DBS is to optimize preoperative planning procedures via sophisticated neuroimaging techniques such as high-resolution MRI and higher field strengths to improve visualization of DBS targets and vasculature. We discuss targeting approaches, MRI acquisition, parameters, and post-acquisition analyses. Additionally, we highlight a number of approaches including the use of ultra-high field (UHF) MRI to overcome limitations of standard settings. There is a trade-off between spatial resolution, motion artifacts, and acquisition time, which could potentially be dissolved through the use of UHF-MRI. Image registration, correction, and post-processing techniques may require combined expertise of traditional radiologists, clinicians, and fundamental researchers. The optimization of pre-operative planning with MRI can therefore be best achieved through direct collaboration between researchers and clinicians.

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Evaluation of MRI sequences for quantitative T1 brain mapping

Cited by 10 publications

References 11 publications

Quantitative T1 mapping of the normal brain from early infancy to adulthood

Quantitative T1 mapping of the normal brain from early infancy to adulthood

MRI Relaxometry for Quantitative Analysis of USPIO Uptake in Cerebral Small Vessel Disease

Methodological Considerations for Neuroimaging in Deep Brain Stimulation of the Subthalamic Nucleus in Parkinson’s Disease Patients

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