# Quantitative susceptibility mapping of carotid intraplaque hemorrhage

> **NIH NIH R21** · WEILL MEDICAL COLL OF CORNELL UNIV · 2020 · $169,500

## Abstract

The objective of this research is to develop quantitative susceptibility mapping (QSM) for the detection of
intraplaque hemorrhage (IPH) in rupture-prone carotid atherosclerotic plaque. Compared to carotid plaque
without IPH, IPH increases the risk of stroke by 4 to 6-fold. Accurate detection of carotid IPH is critically
important for stroke risk stratification to distinguish patients who are at high risk and would benefit from carotid
surgery or stenting to prevent stroke, from those with lower risk who would derive similar risk reduction benefit
from noninvasive medication treatment alone. Our scientific premise is that QSM can resolve paramagnetic
IPH hemosiderin from diamagnetic calcification, both appearing hypointense on traditional multi-contrast MRI
(mcMRI). IPH is identified as hyperintensity on T1-weighted images, which corresponds to the transient
methemoglobin phase of hemorrhage. In the immediately ensuing hemosiderin phase, however, IPH appears
hypointense due to the strong susceptibility-induced dephasing effects of the superparamagnetic hemosiderin
(magnetic susceptibility>150 ppm). This hypointensity on T1-weighted and other mcMRI images is typically
regarded as calcification, another common component of the carotid plaque with diamagnetic magnetic
susceptibility (-2.3 ppm). Contrary to IPH, which is a marker for plaque instability, calcification indicates plaque
stability and reduces the risk of cerebral embolization by nearly 50%. Therefore, the inability of traditional
mcMRI to differentiate IPH from calcification prevents accurate stroke risk stratification. We will develop carotid
plaque QSM to directly measure magnetic susceptibility and to overcome the inherent inability of T1-weighted
imaging to distinguish between IPH hemosiderin and calcification. We have pioneered QSM development and
demonstrated the exquisite sensitivity of QSM for hemorrhagic iron. We also have substantial clinical
experience with imaging of high-risk carotid plaque. In this project, we will develop a novel 3D carotid QSM
pulse sequence with efficient conic k-space sampling to achieve high isotropic resolution and with fat navigator
for robust motion compensation. We will validate the developed QSM sequence by comparing with the gold
standard of post-surgery imaging and histopathology. A successful outcome of this research will establish
QSM as a powerful imaging biomarker to differentiate intraplaque hemorrhage and calcification for stroke
prevention.

## Key facts

- **NIH application ID:** 9958877
- **Project number:** 1R21NS116516-01
- **Recipient organization:** WEILL MEDICAL COLL OF CORNELL UNIV
- **Principal Investigator:** Ajay Gupta
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $169,500
- **Award type:** 1
- **Project period:** 2020-05-01 → 2022-04-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9958877

## Citation

> US National Institutes of Health, RePORTER application 9958877, Quantitative susceptibility mapping of carotid intraplaque hemorrhage (1R21NS116516-01). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/9958877. Licensed CC0.

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