Quantitative imaging biomarkers in the assessment of patients with pulmonary hypertension: the role of computed tomography (CT) and magnetic resonance imaging (MRI)
File(s)
Author(s)
Sathianandan, Sobitha
Type
Thesis
Abstract
The use of computed tomography (CT) and magnetic resonance imaging (MRI) in pulmonary hypertension (PH) is expanding and already plays an important role in its diagnosis, classification, and prognostication. With recent advances in CT and MRI, there is growing interest in quantitative, imaging-based biomarkers that can be used in the evaluation of pulmonary hypertension (PH).
This thesis seeks to examine the role of existing and novel CT and MRI derived imaging biomarkers in the assessment of disease severity, treatment response and prognosis in patients with PH.
CT is readily available in clinical practice and allows assessment of the pulmonary vasculature alongside the parenchyma, cardiac and mediastinal structures. The role of CT in two groups of PH patients was retrospectively analysed. In Chapter 3, CT derived measurements in a cohort of patients with severe group 3 PH (due to lung diseases and/or hypoxia) treated with sildenafil did not relate to disease severity or treatment response. In Chapter 4, CT based measurements of pulmonary artery morphology and calcification in a cohort of patients with Eisenmenger Syndrome appeared to reflect the chronicity of PH in these patients as opposed to its severity.
The pathophysiology of PH primarily involves vascular remodelling of the smaller pulmonary arterioles with progressive resistance to blood flow and subsequent increase in pulmonary vascular resistance, mean pulmonary arterial pressure and right ventricular afterload(1). Imaging of these more distal pulmonary arterioles may therefore provide a more sensitive measure of PH severity and treatment response as they are also the site of action of available treatment options.
In Chapter 5, a pilot study of a novel MRI technique (Oxygen-Enhanced MRI) in a cohort of patients with pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension showed it is feasible, can demonstrate abnormalities related to gas exchange in PH and detect changes following treatment.
This thesis seeks to examine the role of existing and novel CT and MRI derived imaging biomarkers in the assessment of disease severity, treatment response and prognosis in patients with PH.
CT is readily available in clinical practice and allows assessment of the pulmonary vasculature alongside the parenchyma, cardiac and mediastinal structures. The role of CT in two groups of PH patients was retrospectively analysed. In Chapter 3, CT derived measurements in a cohort of patients with severe group 3 PH (due to lung diseases and/or hypoxia) treated with sildenafil did not relate to disease severity or treatment response. In Chapter 4, CT based measurements of pulmonary artery morphology and calcification in a cohort of patients with Eisenmenger Syndrome appeared to reflect the chronicity of PH in these patients as opposed to its severity.
The pathophysiology of PH primarily involves vascular remodelling of the smaller pulmonary arterioles with progressive resistance to blood flow and subsequent increase in pulmonary vascular resistance, mean pulmonary arterial pressure and right ventricular afterload(1). Imaging of these more distal pulmonary arterioles may therefore provide a more sensitive measure of PH severity and treatment response as they are also the site of action of available treatment options.
In Chapter 5, a pilot study of a novel MRI technique (Oxygen-Enhanced MRI) in a cohort of patients with pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension showed it is feasible, can demonstrate abnormalities related to gas exchange in PH and detect changes following treatment.
Version
Open Access
Date Issued
2022-05
Date Awarded
2024-09
Copyright Statement
Creative Commons Attribution NonCommercial Licence
License URL
Advisor
Wort, John
Padley, Simon
Price, Laura
Semple, Tom
Sponsor
National Institute for Health Research (Great Britain)
Publisher Department
National Heart & Lung Institute
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Medicine (Research) MD (Res)