Introduction to Quantitative Susceptibility Mapping and Susceptibility Weighted Imaging

Ruetten, Pascal P R; Gillard, Jonathan H.; Graves, Martin J.

doi:10.1259/bjr.20181016

Cited by 59 publications

(30 citation statements)

References 96 publications

(154 reference statements)

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“…This finding also coincides with the previous report that the presence of iron in the melanin-iron complex can affect the proton transverse relaxation time [6], which is also supported by the result of significant correlation between susceptibility measurements (i.e., QSM) and T2 values of the melanin-iron complex in the nigrosome1 (Figure 8D). Due to the problem of magic angle in QSM, the calculated susceptibility values are therefore relative rather than absolute quantification [27]. We speculate that this quantification error along with the one in calculation of the absolute T2 values may lead to the limited sensitivity in correlating with the neuromelanin signal.…”

Section: Discussionmentioning

confidence: 98%

Evaluation of the Swallow-Tail Sign and Correlations of Neuromelanin Signal with Susceptibility and Relaxations

Lee

Chen

et al. 2021

Tomography

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The presence of a swallow-tail sign in the nigrosome-1 with hyperintense signal shown on the susceptibility-weighted imaging (SWI) has been shown to be sensitive in detecting the abnormal iron deposits in this area. A systematic evaluation in healthy subjects is required before this tool can be recommended in a widespread application. We evaluated a simple and practical SWI approach using a multiecho gradient-echo sequence with an improved contrast-to-noise ratio (CNR). We also evaluated the association of the neuromelanin imaging contrast behavior with the susceptibility and relaxation measurements. Twenty-five older and 23 young healthy adults were evaluated. The CNRs of the nigrosome-1 were compared along with method and group. Correlations of the nigrosome-1 neuromelanin signal in the neuromelanin-sensitive imaging with CNRs in the susceptibility, T1 and T2 mappings were examined. Two different coils were used to confirm the reproducibility. Compared with the single-echo, multiecho SWI can improve the CNR of the swallow-tail sign. We found significant correlations between neuromelanin signal and CNRs in the susceptibility and T2 mappings, and T1 value. The older subjects exhibited increased CNRs compared with the young adults. No significant difference was observed in the measurements between 20 and 64 channels. The multiecho technique allows the high-quality nigrosome-1 images in SWI and allows for a joint analysis of T2* and quantitative-susceptibility mapping at high spatial resolution. The correlations of neuromelanin-sensitive imaging with susceptibility and T2 imply that the iron content in the nigrosome-1 may have significant influences on the hyperintensity of neuromelanin in the magnetization transfer-related contrast.

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Section: Discussionmentioning

confidence: 98%

Evaluation of the Swallow-Tail Sign and Correlations of Neuromelanin Signal with Susceptibility and Relaxations

Lee

Chen

et al. 2021

Tomography

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“…Unlike GRE, QSM not only measures hematoma volume accurately, but also creates a clear delineation between paramagnetic substances (such as iron, ferritin, and hemosiderin) from diamagnetic substances (such as calcium, water, brain tissues) by positive and negative susceptibilities, respectively. The voxel intensity in QSM is linearly proportional to the source of susceptibilities (χ) and using an external calibration curve, these maps can be applied to compute iron concentrations within the hematoma and surrounding perihematomal area (21)(22)(23).…”

Section: Imaging Sequencesmentioning

confidence: 99%

Longitudinal, Quantitative, Multimodal MRI Evaluation of Patients With Intracerebral Hemorrhage Over the First Year

et al. 2021

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In most patients with intracerebral hemorrhage (ICH), the hematoma and perihematomal area decrease over the subsequent months but patients continue to exhibit neurological impairments. In this serial imaging study, we characterized microstructural and neurophysiological changes in the ICH-affected brain tissues and collected the National Institute of Health Stroke Scale (NIHSS) and modified Rankin Score (mRS), two clinical stroke scale scores. Twelve ICH patients were serially imaged on a 3T MRI at 1, 3, and 12 months (M) after injury. The hematoma and perihematomal volume masks were created and segmented using FLAIR imaging at 1 month which were applied to compute the susceptibilities (χ), fractional anisotropy (FA), mean diffusivity (MD), and cerebral blood flow (CBF) in the same tissues over time and in the matching contralesional tissues. At 3 M, there was a significant (p < 0.001) reduction in hematoma and perihematomal volumes. At 1 M, the χ, FA, and CBF were decreased in the perihematomal tissues as compared to the contralateral side, whereas MD increased. In the hematomal tissues, the χ increased whereas FA, MD, and CBF decreased as compared to the contralesional area at 1 M. Temporally, CBF in the hematoma and perihematomal tissues remained significantly (p < 0.05) lower compared with the contralesional areas whereas MD in the hematoma and χ in the perihematomal area increased. The NIHSS and mRS significantly correlated with hematoma and perihematomal volume but not with microstructural integrity. Our serial imaging studies provide new information on the long-term changes within the brain after ICH and our findings may have clinical significance that warrants future studies.

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“…Susceptibility-based magnetic resonance imaging (MRI), which distinguishes tissues based on their magnetic susceptibility, is exquisitely sensitive to mineral content in the brain and has been applied to a variety of neurological conditions [ 1 ]. While phase images have historically been largely disregarded, they have recently gained renewed interest given their potential to inform about local susceptibility effects.…”

Section: Introductionmentioning

confidence: 99%

The prevalence of paramagnetic rim lesions in multiple sclerosis: A systematic review and meta-analysis

et al. 2021

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Background Recent findings from several studies have shown that paramagnetic rim lesions identified using susceptibility-based MRI could represent potential diagnostic and prognostic biomarkers in multiple sclerosis (MS). Here, we perform a systematic review and meta-analysis of the existing literature to assess their pooled prevalence at lesion-level and patient-level. Methods Both database searching (PubMed and Embase) and handsearching were conducted to identify studies allowing the lesion-level and/or patient-level prevalence of rim lesions or chronic active lesions to be calculated. Pooled prevalence was estimated using the DerSimonian-Laird random-effects model. Subgroup analysis and meta-regression were performed to explore possible sources of heterogeneity. PROSPERO registration: CRD42020192282. Results 29 studies comprising 1230 patients were eligible for analysis. Meta-analysis estimated pooled prevalences of 9.8% (95% CI: 6.6–14.2) and 40.6% (95% CI: 26.2–56.8) for rim lesions at lesion-level and patient-level, respectively. Pooled lesion-level and patient-level prevalences for chronic active lesions were 12.0% (95% CI: 9.0–15.8) and 64.8% (95% CI: 54.3–74.0), respectively. Considerable heterogeneity was observed across studies (I2>75%). Subgroup analysis revealed a significant difference in patient-level prevalence between studies conducted at 3T and 7T (p = 0.0312). Meta-regression analyses also showed significant differences in lesion-level prevalence with respect to age (p = 0.0018, R2 = 0.20) and disease duration (p = 0.0018, R2 = 0.48). Other moderator analyses demonstrated no significant differences according to MRI sequence, gender and expanded disability status scale (EDSS). Conclusion In this study, we show that paramagnetic rim lesions may be present in an important proportion of MS patients, notwithstanding significant variation in their assessment across studies. In view of their possible clinical relevance, we believe that clear guidelines should be introduced to standardise their assessment across research centres to in turn facilitate future analyses.

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Introduction to Quantitative Susceptibility Mapping and Susceptibility Weighted Imaging

Cited by 59 publications

References 96 publications

Evaluation of the Swallow-Tail Sign and Correlations of Neuromelanin Signal with Susceptibility and Relaxations

Evaluation of the Swallow-Tail Sign and Correlations of Neuromelanin Signal with Susceptibility and Relaxations

Longitudinal, Quantitative, Multimodal MRI Evaluation of Patients With Intracerebral Hemorrhage Over the First Year

The prevalence of paramagnetic rim lesions in multiple sclerosis: A systematic review and meta-analysis

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