Author: Neil James StewartPublisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
Hyperpolarised 129Xe Magnetic Resonance Imaging Techniques for Assessment of Human Lung Function
Author: Neil James StewartMagnetic Resonance Imaging of Hyperpolarised 129Xe Gas in the Human Lungs
Author: Xiaojun XuHyperpolarized 129Xe Magnetic Resonance Imaging of Radiation-induced Lung Injury
Author: Ozkan DoganayPublisher:
ISBN:
Category :
Languages : en
Pages : 302
Book Description
Lung cancer is the largest contributor to cancer-related mortality worldwide. Only 20% of stage III non-small cell lung cancer patients survive after 5-years post radiation therapy (RT). Although RT is an important treatment modality for lung cancer, it is limited by Radiation-Induced Lung Injury (RILI). RILI develops in two phases: (i) the early phase (days-weeks) referred to radiation pneumonitis (RP), and (ii) the late phase (months). There is a strong interest in early detection of RP using imaging to improve outcomes of RT for lung cancer. This thesis describes a promising approach based on 129Xe gas as a contrast agent for Magnetic Resonance Imaging (MRI) of the lung airspace due to the large increase in signal possible by spin exchange optical pumping, or hyperpolarization (Hp). Additionally, 129Xe provides unique functional information due to its relatively high solubility and significant chemical shift in pulmonary tissue (PT) and red blood cell (RBC) compartments. In this thesis, a specialized Hp 129Xe MRI method was developed for detection of gas exchange abnormalities in the lungs associated with thoracic RT. In particular, the feasibility of quantifying the early phase of RILI is demonstrated in a rat model of RILI two weeks post-irradiation with a single fraction dose of 18 Gy. The challenge of low signal-to-noise ratio (SNR) in the dissolved phases was addressed in this work by development and construction of a Transmit-Only/Receive-Only radiofrequency coil. Another challenge addressed in the thesis was the lack of imaging techniques that provide sufficient spatial and temporal information for gas exchange. Therefore, a novel Hp 129Xe MRI technique was developed based on the multi-point IDEAL pulse sequence. The combination of these two developments enabled investigation of regional gas exchange changes associated with RP in the rat lung two weeks post-irradiation to assess the feasibility of early detection of RILI. Theoretical analysis of the gas exchange curves enabled measurements of average PT thickness (LPT) increases consistent with histology and relative blood volume (VRBC) reductions in the irradiated animal cohort compared to a non-irradiated cohort, and between irradiated right lungs compared to unirradiated left lungs in the irradiated cohort.
Dissolved Hyperpolarized 129Xe MRI for Functional Imaging of Radiation-Induced Lung Injury
Author: Brandon ZanettePublisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Hyperpolarized (HP) 129Xe Magnetic Resonance Imaging (MRI) of the lungs allows for the visualization of the spatial distribution of gas in the pulmonary airspaces upon inhalation by taking advantage of the 100,000 fold increase in signal. This technique yields high quality anatomical and functional images of the lungs that is otherwise difficult with conventional MRI. Direct imaging of lung ventilation is useful for the detection and quantification of obstructive lung diseases such as cystic fibrosis, chronic obstructive pulmonary disorder, and asthma. An added advantage of 129Xe is its solubility in bodily tissues such as the lung parenchyma and red blood cells, allowing for the detection of signals from beyond the airspaces. This property of 129Xe may be exploited to probe gas exchange upon inhalation, making HP 129Xe MRI a powerful tool for the investigation of terminal airway dysfunction in a variety of pulmonary diseases. However, the inherent challenges associated with dissolved 129Xe MRI has caused development of these techniques to lag ventilation (gas-phase) HP 129Xe MRI. The work in this thesis is focused on the technical development of dissolved 129Xe imaging techniques for use in both human and rodent experiments. A particular focus is given to radiation-induced lung injury (RILI), a serious and debilitating consequence of radiotherapy that affects a subset of patients. A new rat model of RILI that better represents regional injury is developed and tested. Temporally-resolved dissolved 129Xe imaging techniques for gas exchange mapping are developed and applied to the study of RILI in this model. Changes in lung physiology associated with radiation injury are quantified by parametrically mapping gas exchange. Finally, the techniques developed preclinically are modified and improved for clinical use. Parametric gas exchange mapping is demonstrated in humans. Accelerated dissolved 129Xe MRI with parallel imaging is also demonstrated. The results of this work will aid in the translations of dissolved 129Xe MRI into a clinically useful technique for a variety of lung diseases affecting gas exchange in the lungs, such as RILI.
MRI of the Lung
Author: Hans-Ulrich KauczorPublisher: Springer Science & Business Media
ISBN: 354034618X
Category : Medical
Languages : en
Pages : 315
Book Description
During the past decade significant developments have been achieved in the field of magnetic resonance imaging (MRI), enabling MRI to enter the clinical arena of chest imaging. Standard protocols can now be implemented on up-to-date scanners, allowing MRI to be used as a first-line imaging modality for various lung diseases, including cystic fibrosis, pulmonary hypertension and even lung cancer. The diagnostic benefits stem from the ability of MRI to visualize changes in lung structure while simultaneously imaging different aspects of lung function, such as perfusion, respiratory motion, ventilation and gas exchange. On this basis, novel quantitative surrogates for lung function can be obtained. This book provides a comprehensive overview of how to use MRI for imaging of lung disease. Special emphasis is placed on benign diseases requiring regular monitoring, given that it is patients with these diseases who derive the greatest benefit from the avoidance of ionizing radiation.
Functional Lung Magnetic Resonance Imaging Using Hyperpolarized 129Xe
Author: Agilo Luitger KernFunctional Lung Assessment Using Hyperpolarised Xenon Gas Magnetic Resonance Imaging
Author: Tahreema Nihad Hashmi MatinPublisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Global Surveillance, Prevention and Control of Chronic Respiratory Diseases
Author: World Health OrganizationPublisher: World Health Organization
ISBN: 924156346X
Category : Chronic diseases
Languages : en
Pages : 156
Book Description
Chronic respiratory diseases, such as asthma and chronic obstructive pulmonary disease, kill more than 4 million people every year, and affect hundreds of millions more. These diseases erode the health and well-being of the patients and have a negative impact on families and societies. This report raises awareness of the huge impact of chronic respiratory diseases worldwide, and highlights the risk factors as well as ways to prevent and treat these diseases.
Pulmonary Functional Imaging
Author: Yoshiharu OhnoPublisher: Springer Nature
ISBN: 3030435393
Category : Medical
Languages : en
Pages : 363
Book Description
This book reviews the basics of pulmonary functional imaging using new CT and MR techniques and describes the clinical applications of these techniques in detail. The intention is to equip readers with a full understanding of pulmonary functional imaging that will allow optimal application of all relevant techniques in the assessment of a variety of diseases, including COPD, asthma, cystic fibrosis, pulmonary thromboembolism, pulmonary hypertension, lung cancer and pulmonary nodule. Pulmonary functional imaging has been promoted as a research and diagnostic tool that has the capability to overcome the limitations of morphological assessments as well as functional evaluation based on traditional nuclear medicine studies. The recent advances in CT and MRI and in medical image processing and analysis have given further impetus to pulmonary functional imaging and provide the basis for future expansion of its use in clinical applications. In documenting the utility of state-of-the-art pulmonary functional imaging in diagnostic radiology and pulmonary medicine, this book will be of high value for chest radiologists, pulmonologists, pulmonary surgeons, and radiation technologists.
Reproducibility of Hyperpolarized Xenon-129 Magnetic Resonance Imaging
Author: Nikhil B. E. KanherePublisher:
ISBN:
Category :
Languages : en
Pages : 190
Book Description
Spirometry and plethysmography provide gold standard measurements of obstructive lung disease, although these are global measurements of lung function made at the mouth, of a highly regionally heterogeneous disease. Hyperpolarized 129Xe magnetic resonance imaging (MRI) is a non-invasive, non-radiation-based imaging tool for visualizing regional lung structure and function. However, the reproducibility of 129Xe MRI measurements has not yet been studied or determined. Hence, in this thesis, we evaluated the reproducibility of 129Xe MRI using quantitative measurements such as ventilation defect percent (VDP). We showed that 129Xe VDP had high intra-observer and inter-observer reproducibility for repeated scans acquired on the same-day and after 1-week and its reproducibility was comparable to that of 3He VDP. 129Xe VDP showed strong and significant correlations with pulmonary function tests. These results suggested that 129Xe VDP is reproducible over short periods of time and can be a reliable measurement to study pulmonary function in imaging studies.