Quantitative Susceptibility Mapping for Following Intracranial Hemorrhage

Sun, Hongfu; Klahr, Ana C; Kate, Mahesh; Gioia, Laura; Emery, Derek; Butcher, Ken; Wilman, Alan H.

doi:10.1148/radiol.2018171918

Cited by 47 publications

(47 citation statements)

References 26 publications

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“…This value overlaps the lower end of the SV range of cerebral cavernous malformations (125-750 ppb) 31 and is much lower than the SV range of intracranial hemorrhage (ICH, 570-1380 ppb) in the hyperacute-to-chronic stage. 18,32 This difference may be explained by differences in the microenvironment of the brain parenchyma and the carotid artery wall.…”

Section: Discussionmentioning

confidence: 99%

Characterization of Carotid Plaque Components by Quantitative Susceptibility Mapping

Azuma¹,

Maekawa²,

Yamashita³

et al. 2019

AJNR Am J Neuroradiol

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BACKGROUND AND PURPOSE: Intraplaque hemorrhage in the carotid artery is related to an increased risk of cerebrovascular ischemic events. We aimed to investigate whether quantitative susceptibility mapping can characterize carotid artery plaque components and quantify the severity of intraplaque hemorrhage. MATERIALS AND METHODS: For this ex vivo quantitative susceptibility mapping study, 9 carotid endarterectomy specimens were imaged on a 3T MR imaging scanner using a 3D multi-echo gradient-echo sequence and a microscopy coil. The samples were examined histologically using immunostains, including glycophorin A and Prussian blue. The areas of erythrocytes, iron deposits, calcification, and fibrous matrices observed on stained sections were compared with quantitative susceptibility mapping findings and their mean susceptibility values. RESULTS: Intraplaque hemorrhage and iron deposits were observed only in areas hyperintense on quantitative susceptibility mapping; calcifications and fibrous matrices were prevalent in hypointense areas. The mean susceptibility values for necrotic cores with intraplaque hemorrhage but no iron deposits, cores with iron deposits but no intraplaque hemorrhage, cores without either intraplaque hemorrhage or iron deposits, and cores with calcification were 188 6 51, 129 6 49, À11 6 17, and À158 6 78 parts per billion, respectively. There was a significant difference in the mean susceptibility values among the 4 histologic components (P , .01). The mean susceptibility values of the whole plaque positively correlated with the percentage area positive for glycophorin A (r 4 0.65, P , .001) and Prussian blue (r 4 0.47, P , .001). CONCLUSIONS: Our findings suggest that quantitative susceptibility mapping can characterize the composition of carotid plaques and quantify the degree of intraplaque hemorrhage and iron deposits. ABBREVIATIONS: CR 4 contrast ratio; GYPA 4 glycophorin A; ICH 4 intracranial hemorrhage; IPH 4 intraplaque hemorrhage; QSM 4 quantitative susceptibility mapping; SV 4 susceptibility value

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Section: Discussionmentioning

confidence: 99%

Characterization of Carotid Plaque Components by Quantitative Susceptibility Mapping

Azuma¹,

Maekawa²,

Yamashita³

et al. 2019

AJNR Am J Neuroradiol

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“…Quantitative susceptibility mapping (QSM) is a current technique using phase images to estimate the magnetic susceptibility of the underlying tissue. It is commonly applied in neuroimaging to calculate iron uptake in brain nuclei for various neurological diseases . Several recent studies have proposed application outside the brain, including the breast, prostate, and articular cartilage .…”

Section: Introductionmentioning

confidence: 99%

“…It is commonly applied in neuroimaging to calculate iron uptake in brain nuclei for various neurological diseases. [1][2][3] Several recent studies have proposed application outside the brain, including the breast, 4 prostate, 5 and articular cartilage. 6 In 2 studies the feasibility of the determination of iron uptake in the liver in patients with iron overload was shown.…”

Section: Introductionmentioning

confidence: 99%

Analysis of different phase unwrapping methods to optimize quantitative susceptibility mapping in the abdomen

Bechler

Stabinska

Wittsack

2019

Magnetic Resonance in Med

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Purpose Quantitative susceptibility mapping (QSM) is heavily impacted by phase processing of gradient echo imaging data. So far, phase unwrapping algorithms have mostly been developed and tested for neuroimaging applications. In this work, a numerical human abdomen phantom was created and used to assess the feasibility of different phase unwrapping algorithms in abdominal QSM. Furthermore, in vivo data were acquired to evaluate consistency with the simulations. Methods Laplacian‐based, quality‐guided region growing and graph‐cuts unwrapping techniques were evaluated using the numerical phantom as well as an in vivo measurement. As a quality metric, root mean square error (RMSE) was calculated in order to analyze the performance of the examined unwrapping algorithms. Subsequently, susceptibility maps were generated from the resulting phase maps and compared to the ground truth. The evaluation was carried out on the whole phantom as well as individual organs. Results Graph‐cuts led to the most accurate and robust results among the investigated unwrapping methods. The other algorithms showed severe errors in regions with large susceptibility changes (i.e., around the lungs). Deviations from the ground‐truth susceptibility were higher than in the previous brain simulations for all tested algorithms. Conclusion Graph‐cuts–based unwrapping algorithms should be preferred in QSM studies in the human abdomen, where large susceptibility changes occur. For further improvement of QSM studies, unwrapping algorithms should be optimized for abdominal applications.

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“…Previous ICH studies have proved QSM to be useful for distinguishing hemorrhage from calcification and measuring hematoma volume . Susceptibility studies have examined various stages of hematoma, including following individual subjects, and examining changes with therapy . Susceptibility measures might also be useful for tracking the effects of potential iron chelating therapy in ICH patients .…”

mentioning

confidence: 99%

“…Susceptibility measures might also be useful for tracking the effects of potential iron chelating therapy in ICH patients . Moreover, mean ICH susceptibility has shown better separation of various stages of hemorrhage as compared with conventional relaxation‐weighted magnetic resonance imaging (MRI) . These studies of ICH with QSM have used multiecho GRE or single‐echo susceptibility‐weighted imaging (SWI), with the latter often included in clinical exams of suspected ICH.…”

mentioning

confidence: 99%

Rapid quantitative susceptibility mapping of intracerebral hemorrhage

Sun

Emery

et al. 2019

Magnetic Resonance Imaging

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Background Quantitative susceptibility mapping (QSM) offers a means to track iron evolution in hemorrhage. However, standard QSM sequences have long acquisition times and are prone to motion artifact in hemorrhagic patients. Purpose To minimize motion artifact and acquisition time by performing rapid QSM in intracerebral hemorrhage (ICH) using single‐shot echo planar imaging (EPI). Study Type Prospective method evaluation. Population/Subjects Forty‐five hemorrhages were analyzed from 35 MRI exams obtained between February 2016 and March 2019 from 27 patients (14 male / 13 female, age: 71 ± 12 years) with confirmed primary ICH. Field Strength/Sequence 3T; susceptibility‐weighted imaging (SWI) with 4.54‐minute acquisition and 2D single‐shot gradient EPI with 0.45‐minute acquisition. Assessment Susceptibility maps were constructed from both methods. Measurement of ICH area and mean magnetic susceptibility were made manually by three independent observers. Motion artifacts were quantified using the magnitude signal ratio of artifact‐to‐brain tissue to classify into three categories: mild or no artifact, moderate artifact, or severe artifact. The cutoff for each category was determined by four observers. Statistical Tests Pearson's correlation coefficient and paired t‐test using α = 0.05 were used to compare results. Inter‐ and intraclass correlation was used to assess observer variability. Results Using 45 hemorrhages, the ICH regions measured on susceptibility maps obtained from EPI and SWI sequences had high correlation coefficients for area (R2 ≥ 0.97) and mean magnetic susceptibility (R2 ≥ 0.93) for all observers. The artifact‐to‐tissue ratio was significantly higher (P < 0.01) for SWI vs. EPI, and the standard deviation for the SWI method (SD = 0.05) was much larger than EPI (SD = 0.01). All observers' measurements showed high agreement. Data Conclusion Single‐shot EPI‐QSM enabled rapid measurement of ICH area and mean magnetic susceptibility, with reduced motion as compared with more standard SWI. EPI‐QSM requires minimal additional acquisition time and could be incorporated into iron tracking studies in ICH. Level of Evidence: 2 Technical Efficacy Stage: 1 J. Magn. Reson. Imaging 2020;51:712–718.

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Quantitative Susceptibility Mapping for Following Intracranial Hemorrhage

Cited by 47 publications

References 26 publications

Characterization of Carotid Plaque Components by Quantitative Susceptibility Mapping

Characterization of Carotid Plaque Components by Quantitative Susceptibility Mapping

Analysis of different phase unwrapping methods to optimize quantitative susceptibility mapping in the abdomen

Rapid quantitative susceptibility mapping of intracerebral hemorrhage

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