Chronic Obstructive Pulmonary Disease: Safety and Tolerability of Hyperpolarized¹²⁹Xe MR Imaging in Healthy Volunteers and Patients

Abstract

Purpose:To evaluate the safety and tolerability of inhaling multiple 1-L volumes of undiluted hyperpolarized xenon 129 ( 129 Xe) followed by up to a 16-second breath hold and magnetic resonance (MR) imaging. Materials and Methods:This study was approved by the institutional review board and was HIPAA compliant. Written informed consent was obtained. Forty-four subjects (19 men, 25 women; mean age, 46.1 years 6 18.8 [standard deviation ]) were enrolled, consisting of 24 healthy volunteers, 10 patients with chronic obstructive pulmonary disease (COPD), and 10 age-matched control subjects. All subjects received three or four 1-L volumes of undiluted hyperpolarized 129 Xe, followed by breath-hold MR imaging. Oxygen saturation, heart rate and rhythm, and blood pressure were continuously monitored. These parameters, along with respiratory rate and subjective symptoms, were assessed after each dose. Subjects' serum biochemistry and hematology were recorded at screening and at 24-hour follow-up. A 12-lead electrocardiogram (ECG) was obtained at these times and also within 2 hours prior to and 1 hour after 129 Xe MR imaging. Xenon-related symptoms were evaluated for relationship to subject group by using a x 2 test and to subject age by using logistic regression. Changes in vital signs were tested for signifi cance across subject group and time by using a repeated-measures multivariate analysis of variance test.

Chronic Obstructive Pulmonary Disease: Lobar Analysis with Hyperpolarized 129Xe MR Imaging

“…The inherent properties of 129 Xe may be exploited to regionally quantify ventilation and diffusion within the lung and enable comprehensive in vivo assessment of lung function. Hyperpolarized 129 Xe MR imaging is safe, free from ionizing radiation, and well tolerated in small cohorts of healthy volunteers and patients with COPD who have been imaged to date (4,5).…”

“…Ventilation assessment with hyperpolarized 3 He MR imaging has shown utility in the detection of functional abnormalities in a range of obstructive lung abnormalities (eg, COPD, cystic fibrosis, asthma, and bronchiolitis obliterans) (8). High-spatial-resolution imaging of pulmonary ventilation is also possible with hyperpolarized 129 Xe MR imaging (4,5,7). With wider availability and lower cost than 3 He, 129 Xe MR imaging is a more clinically viable alternative and studies have compared ventilation image quality for the two gases (9).…”

Perfluoropropane Gas as a Magnetic Resonance Lung Imaging Contrast Agent in Humans

“…For example, hyperpolarized (hP) gas MRI using the stable gaseous isotopes helium 3 ( 3 He) and xenon 129 ( 129 Xe) has offered hope for delivering noninvasive, regional assessment of lung function coupled with conventional MRI to assess structural integrity and variability. [21][22][23][24][25][26] Unfortunately, the increasing costs and limited supply of 3 He gas 27 limits the feasibility of disseminating the technology within multicenter clinical trials. Thus, attention has turned to 129 Xe hP MRI, 28 facilitating ventilatory, microstructural, and gasexchange mapping of pulmonary function, with similar quality to 3 He.…”

Systematic T1 improvement for hyperpolarized 129xenon

“…3 He, 129 Xe) up to six orders of magnitude beyond the thermal polarization has opened up several applications, which could hardly be carried out otherwise. These applications stretch from uses as varied as spin-polarized target in accelerator experiments [1,2], neutron filters [3,4] and spinclocks [5] in fundamental physics to contrast agents in clinical MRI [6][7][8] or materials science [9,10]. This enormous increase of the nuclear spin polarization is usually termed ''hyperpolarization'' (HP) and achieved either via Spin Exchange Optical Pumping (SEOP) [11] or Metastability Exchange Optical Pumping (MEOP) [12].…”