Normal and abnormal pulmonary ventilation: visualization at hyperpolarized He-3 MR imaging.

Abstract

To assess the feasibility of helium-3 magnetic resonance (MR) imaging with a three-dimensional fast low-angle shot (FLASH) sequence, He-3 gas (volume, 300 mL; pressure, 3 x 10(5) Pa; polarized up to 45% by means of optimal pumping) was inhaled by five healthy volunteers and five patients with pulmonary diseases. All breath-hold examinations (22-42 seconds) were completed successfully. Normal ventilation was depicted with homogeneous high signal intensity, lesions were depicted as causing defects, and obstructive lung disease was depicted with severely inhomogeneous signal intensity.

MRI of lungs using partial liquid ventilation with water‐in‐perfluorocarbon emulsions

“…This may be due to the inability of the ventilation mechanism to physically transport sufficient amounts of PFC emulsions into the small bronchi. This also happens in 19 F MRI of lungs using PFC emulsions in ventilation (14), but should not occur with 129 Xe, 3 He, or other gases. Therefore, the 1 H spin density enhancing effect in these areas is not so significant as in other areas.…”

“…Thus, the ADC may be used to detect damage to the lung architecture. It has been reported that the ADC of 3 He gas in emphysematous regions of lungs increases compared to that in healthy lungs (4). The measurement of diffusion in the lungs has obvious diagnostic value.…”

“…A recent exciting development is the use of hyperpolarized 129 Xe (1) or 3 He (2)(3)(4)(5). However, the expense of the required laser optical pumping facility, and the limited availability of 129 Xe and 3 He limit its potential applications. Furthermore, the inefficiency of 129 Xe and 3 He delivery through the respiratory system can also hinder their practical use (6).…”

“…However, the expense of the required laser optical pumping facility, and the limited availability of 129 Xe and 3 He limit its potential applications. Furthermore, the inefficiency of 129 Xe and 3 He delivery through the respiratory system can also hinder their practical use (6). Oxygen ventilation MRI has been successfully employed to detect regional ventilation defects (7,8).…”

Feasibility of combining MR perfusion, angiography, and 3He ventilation imaging for evaluation of lung function in a porcine model1

“…The latter technique has shown a high signal-to-noise ratio (SNR), and permits the visualization of pulmonary arteries beyond the subsegmental branches. On the other hand, assessment of regional lung ventilation with hyperpolarized noble gas has emerged as an imaging technique for evaluating lung diseases, including tumors, emphysema, bronchiectasis, cystic fibrosis, and asthma (16)(17)(18)(19)(20)(21)(22)(23). A promising MR technique for visualizing the air spaces of the lung is the use of 3 He gas as a contrast agent.…”