Hyperpolarised 129Xe MRI for Non-invasive Assessment of Ventilation, Perfusion and the Alveolar Membrane - a Physiological Study in Healthy Volunteers & Cystic Fibrosis Patients
试验速览
- 阶段
- 不适用
- 状态
- 撤回
- 入组人数
- 30
- 试验地点
- 1
- 主要终点
- Lung ventilation assessed by Percentage Ventilation Defect (VD%)
研究概览
简要总结
Chronic lung diseases show a gradual onset of irreversible lung damage which can lead to severe breathing problems and/or respiratory failure. Imaging is central to guiding treatment; however, current techniques are either inaccurate or involve exposure to radiation. Recent developments in lung magnetic resonance imaging (MRI) provide promise as a radiation-free alternative. However, conventional MRI cannot directly show changes in distribution of inhaled air or absorption of gas which are important signs of early lung disease. Recently MRI imaging of the inhaled gas contrast agent Xenon has been developed which can provide this important information. This study aims to determine how Xenon MRI can help determine air flow distribution and gas uptake in the lungs. The investigators will also be able to compare the information from patients with that from healthy volunteers. This should give insight into the processes involved in chronic lung diseases and help evaluate disease extent in patients.
详细描述
Hyperpolarised gas MRI (3He and 129Xe) has enabled novel methods of in-vivo functional lung imaging that do not rely on the use of ionising radiation. Hyperpolarised 129Xe (HP Xe) MRI provides additional complementary information to 3He and 1H MRI and conventional lung imaging modalities. By virtue of its solubility, the 129Xe contrast agent follows the gas exchange pathways in the lungs, offering a direct means to explore regional ventilation-perfusion (V/Q). The competing modality of nuclear medicine lung V/Q scans suffer from very poor spatial resolution and a reliance on high doses of radiation via radio-nuclide inhalation. Nuclear medicine is thus unsuitable for studies of basic physiology in healthy volunteers or in longitudinal studies in lung disease patients.
The aims and objectives of this study are:
- To assess the physiological differences in lung ventilation between the normal group (volunteers) and the cystic fibrosis disease group
- To evaluate differences in Xe diffusion across the alveolar membrane between the normal group (volunteers) and the cystic fibrosis disease group
- To understand the relationship between the extent of abnormal ventilation (and ventilation-perfusion mismatch) on MRI and the results from conventional physiological evaluation of lung function using pulmonary function tests (spirometry and gas exchange)
- To understand the relationship between gas exchange as determined by HP Xe imaging with the extent of ventilation perfusion mismatch on standard perfusion MRI
This is a physiological cross-sectional feasibility study comparing regional lung ventilation and diffusion across the alveolar membrane in normal volunteers and cystic fibrosis. 15 healthy volunteers and 15 cystic fibrosis patients will be recruited. All imaging will take place at Papworth Hospital.
Phase I: Volunteer study (n=15, aged 18-70)
研究设计
- 研究类型
- Observational
- 观察模型
- Other
- 时间视角
- Cross Sectional
入排标准
- 年龄范围
- 18 Years 至 70 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •18 years or above with proven CF, and:
- •Clinical stable disease over last month, defined as:
- •One month without intravenous antibiotics for airways disease, and:
- •One month without evidence for decrease in lung function (no evidenced drop in FEV1 or PEFR >10%).
- •Exclusion criteria:
- •Contraindications to MR (presence of non MR compatible pacemaker, aneurysm clips, artificial heart valves, ear implants, metal fragments or metallic foreign objects in the eyes, pregnancy, and severe claustrophobia),
- •Ability to breath hold below 15 seconds.
- •Current (> 6 months) smoker
- •Volunteer inclusion criteria:
- •No history of acute (within the last 6 months) or chronic illness (this will be determined by direct communication with the volunteer and not from their medical records)
- •Volunteer exclusion Criteria:
- •As patients
排除标准
- 未提供
结局指标
主要结局
Lung ventilation assessed by Percentage Ventilation Defect (VD%)
时间窗: 24 hours
Quantitative measure of lung ventilation
次要结局
- Regional ventilation: perfusion (1-VD%)/(1-PD%) ratio(24 hours)
- Percentage perfusion defect (PD%)(24 hours)
- Percentage ventilation defect assessed on CT (hypoattenuation) - patient group only(24 hours)
- Forced expiratory volume (%) in 1 second (FEV1)(24 hours)
- CF Brody score assessed on CT in patient group(24 hours)