Quantifying brain iron deposition in patients with Parkinson's disease using quantitative susceptibility mapping, R2 and R2*

Barbosa, Jeam Haroldo Oliveira; Santos, Antônio Carlos dos; Tumas, Vítor; Liu, Manju; Zheng, Weili; Haacke, E. Mark; Salmon, Carlos Ernesto Garrido

doi:10.1016/j.mri.2015.02.021

Cited by 213 publications

(223 citation statements)

References 37 publications

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“…They rely on the assumption that the [Fe] is the sole determinant of either T 2 or T 2 *, and ignore the many other contributions to transverse relaxation. Other methods, such as QSM, [47][48][49] require measurement of the absolute tissue susceptibility and suffer from the large background variations in the phase of the MR image due to susceptibility variations independent of [Fe] or from susceptibility jumps at the air-tissue boundaries of the body. Also, the expertise and software to accomplish QSM are not widely available.…”

Section: Discussionmentioning

confidence: 99%

Quantitative [Fe]MRI of PSMA-targeted SPIONs specifically discriminates among prostate tumor cell types based on their PSMA expression levels

Sillerud

2016

IJN

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We report the development, experimental verification, and application of a general theory called [Fe]MRI (pronounced fem-ree) for the non-invasive, quantitative molecular magnetic resonance imaging (MRI) of added magnetic nanoparticles or other magnetic contrast agents in biological tissues and other sites. [Fe]MRI can easily be implemented on any MRI instrument, requiring only measurements of the background nuclear magnetic relaxation times (T 1 , T 2 ) of the tissue of interest, injection of the magnetic particles, and the subsequent acquisition of a pair of T 1 -weighted and T 2 -weighted images. These images, converted into contrast images, are subtracted to yield a contrast difference image proportional to the absolute nanoparticle, iron concentration, ([Fe]) image. [Fe]MRI was validated with the samples of superparamagnetic iron oxide nanoparticles (SPIONs) both in agarose gels and bound to human prostate tumor cells. The [Fe]MRI measurement of the binding of anti-prostate specific membrane antigen (PSMA) conjugated SPIONs to PSMA-positive LNCaP and PSMA-negative DU145 cells in vitro allowed a facile discrimination among prostate tumor cell types based on their PSMA expression level. The low [Fe] detection limit of ~2 μM for SPIONs allows sensitive MRI of added iron at concentrations considerably below the US Food and Drug Administration’s human iron dosage guidelines (<90 μM, 5 mg/kg).

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Section: Discussionmentioning

confidence: 99%

Quantitative [Fe]MRI of PSMA-targeted SPIONs specifically discriminates among prostate tumor cell types based on their PSMA expression levels

Sillerud

2016

IJN

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“…26,27 Nevertheless, the production of susceptibility maps requires particular acquisition settings: in most quantitative susceptibility mapping implementations such as ours, the MR imaging system is programmed to provide the complex MR imaging data divided into real and imaginary parts, which are of no radiologic use. In fact, quantitative susceptibility mapping requires additional scan time in addition to the conventional 3D T2* multiecho sequence that is included in the clinical protocol.…”

Section: Methodsologic Considerationsmentioning

confidence: 99%

Semiautomated Evaluation of the Primary Motor Cortex in Patients with Amyotrophic Lateral Sclerosis at 3T

Donatelli¹,

Retico

Ienco

et al. 2017

AJNR Am J Neuroradiol

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BACKGROUND AND PURPOSE:Amyotrophic lateral sclerosis is a neurodegenerative disease involving the upper and lower motor neurons. In amyotrophic lateral sclerosis, pathologic changes in the primary motor cortex include Betz cell depletion and the presence of reactive iron-loaded microglia, detectable on 7T MR images as atrophy and T2*-hypointensity. Our purposes were the following: 1) to investigate the signal hypointensity-to-thickness ratio of the primary motor cortex as a radiologic marker of upper motor neuron involvement in amyotrophic lateral sclerosis with a semiautomated method at 3T, 2) to compare 3T and 7T results, and 3) to evaluate whether semiautomated measurement outperforms visual image assessment.

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“…Studies comparing QSM and R2* as surrogate markers of brain iron deposition within cortical regions of healthy young individuals (Deistung et al, 2013) and in subcortical regions in PD (Barbosa et al, 2015), have shown QSM may provide superior sensitivity to detect differences in local GM. No study to date, however, has directly compared QSM and R2* differences as a result of normal aging.…”

Section: Introductionmentioning

confidence: 99%

High-resolution characterisation of the aging brain using simultaneous quantitative susceptibility mapping (QSM) and R2* measurements at 7 T

et al. 2016

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Quantitative susceptibility mapping (QSM) has recently emerged as a novel magnetic resonance imaging (MRI) method to detect non-haem iron deposition, calcifications, demyelination and vascular lesions in the brain. It has been suggested that QSM is more sensitive than the more conventional quantifiable MRI measure, namely the transverse relaxation rate, R2*. Here, we conducted the first high-resolution, whole-brain, simultaneously acquired, comparative study of the two techniques using 7 Tesla MRI. We asked which of the two techniques would be more sensitive to explore global differences in tissue composition in elderly adults relative to young subjects. Both QSM and R2* revealed strong agerelated differences in subcortical regions, hippocampus and cortical grey matter, particularly in superior frontal regions, motor/premotor cortices, insula and cerebellar regions. Within the basal ganglia system-but also hippocampus and cerebellar dentate nucleus-, QSM was largely in agreement with R2* with the exception of the globus pallidus. QSM, however, provided superior anatomical contrast and revealed age-related differences in the thalamus and in white matter, which were otherwise largely undetected by R2* measurements. In contrast, in occipital cortex, age-related differences were much greater with R2* compared to QSM. The present study, therefore, demonstrated that in vivo QSM using ultra-high field MRI provides a novel means to characterize age-related differences in the human brain, but also combining QSM and R2* using multigradient recalled echo imaging can potentially provide a more complete picture of mineralization, demyelination and/or vascular alterations in aging and disease.

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Quantifying brain iron deposition in patients with Parkinson's disease using quantitative susceptibility mapping, R2 and R2*

Cited by 213 publications

References 37 publications

Quantitative [Fe]MRI of PSMA-targeted SPIONs specifically discriminates among prostate tumor cell types based on their PSMA expression levels

Quantitative [Fe]MRI of PSMA-targeted SPIONs specifically discriminates among prostate tumor cell types based on their PSMA expression levels

Semiautomated Evaluation of the Primary Motor Cortex in Patients with Amyotrophic Lateral Sclerosis at 3T

High-resolution characterisation of the aging brain using simultaneous quantitative susceptibility mapping (QSM) and R2* measurements at 7 T

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