Smart Medical Imaging

EPSRC Centre for Doctoral Training

Students

104 - A Simultaneous Multicontrast PET-MR Sequence for Comprehensive Coronary Plaque Characterization

1st Supervisor: Claudia Prieto
2nd Supervisor: Rene Botnar
 

Acute myocardial infarction (AMI) is a leading cause of death worldwide. AMI is predominantly caused by rupture or erosion of high-risk plaque leading to thrombus formation and sudden occlusion of the coronary arteries. The current strategy for managing patients at high risk of myocardial infarction, based on invasive tests and population-derived risk factors, fails to predict up to 50% of acute coronary events. Personalising individual patient risk with non-invasive multi-modality imaging could allow much better targeting of treatment, substantially reducing costs and unwanted drug side effects, as well as motivating high risk patients to manage their risk factors more aggressively, leading to improved clinical outcomes. Thus, the development of non-invasive coronary plaque imaging could lead to a paradigm shift as it would allow, for the first time, to assess a patient’s individual risk of having a heart attack based on the total underlying coronary plaque burden, metabolic activity and the number of high-risk coronary lesions.

The ideal test for coronary plaque imaging should simultaneously and non-invasively identify the location/degree of coronary lumen stenosis and detect/characterize coronary plaque and thrombus, features that have diagnostic and prognostic value. Magnetic Resonance Imaging (MRI) has shown great potential for non-invasive coronary lumen (stenosis), coronary wall (plaque burden) and thrombus/haemorrhage visualization.

Recent studies have demonstrated the feasibility of using 18F-NaF PET imaging as a novel marker of microcalcification activity in coronary atherosclerotic plaque demonstrating that 18F-NaF binds more avidly to culprit coronary lesions (plaques that have ruptured or eroded) than to stable coronary plaque. Therefore, the complementary information provided by recently introduced simultaneous PET-MR systems is likely to provide higher sensitivity and specificity for high-risk/vulnerable plaque detection and characterization than with the current use of PET or MRI alone.

Aim of the project:

In this project we aim to develop, implement and test the clinical feasibility of a novel acquisition and reconstruction multicontrast PET-MR framework for comprehensive coronary plaque characterization. This approach could enable an integrative single-scan imaging test for identifying patients at risk of myocardial infarction.

Literature:
1. Naghavi, M. et al. From vulnerable plaque to vulnerable patient: a call for new definitions and risk assessment strategies: Part II. Circulation 108, 1772-1778 (2003).
2. Saam, T.  et al. The vulnerable, or high-risk, atherosclerotic plaque: noninvasive MR imaging for characterization and assessment. Radiology 244, 64-77 (2007).
3. Joshi, N.V. et al. 18F-fluoride positron emission tomography for identification of ruptured and high-risk coronary atherosclerotic plaques: a prospective clinical trial. Lancet 383, 705-713 (2014).
4. Andia M. et al. Flow-independent 3D whole-heart vessel wall imaging using an interleaved T2-preparation acquisition. Magn Reson Med 69:150-7 (2013).
5. Ginami G. et al. Simultaneous Bright- and Black-Blood Whole Heart Phase Sensitive Inversion Recovery (PSIR) for Non Contrast Enhanced Coronary Lumen and Plaque Characterization, Proc. Intl. Soc. Mag. Reson. Med. 25:3132 (2017).
6. Cruz, G. et al. Highly efficient nonrigid motion-corrected 3D whole-heart coronary vessel wall imaging. Magn Reson Med 77:1894-1908 (2017).
7. Munoz, C. et al. Motion-corrected simultaneous cardiac positron emission tomography and coronary MR angiography with high acquisition efficiency. Magn Reson Med doi: 10.1002/mrm.26690 (2017).
 

Figure: This approach will provide a single-scan whole-heart PET-MR imaging test that simultaneously interrogates: coronary lumen (stenosis), coronary wall imaging (plaque burden), coronary black-blood imaging (thrombus/haemorrhage visualization) and allows T1 and T2 quantitative tissue characterization from an MR sequence, and 18F-NaF imaging of microcalcification activity from the simultaneously acquired PET data.
Alina Psenicny

Alina Psenicny

2018 entry