Imaging lung function using rapid dynamic acquisition of T <sub>1sub>-maps during oxygen enhancement
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- 作者：J. F. T. Arnold <SUP>A1 ; F. Fidler <SUP>A1 ; T. Wang <SUP>A1 ; E. D. Pracht <SUP>A1 ; M. Schmidt <SUP>A2 ; P. M. Jakob <SUP>A1
- 关键词：Fast imaging ; Lung imaging ; Oxygen- enhancement ; Pulmonary function ; T <sub>1sub>-mapping
- 刊名：MAGMA Magnetic Resonance Materials in Physics ; Biology and Medicine
- 出版时间：May 2004
- 出版年：2004
- 期刊代码：85_0968-5243
- 类别：ph
- 卷：16
- 期：5
- 页码：246-253
- 数据来源：sp
摘要
This paper describes imaging of lung function with oxygen-enhanced MRI using dynamically acquired T <sub>1sub> parameter maps, which allows an accurate, quantitative assessment of time constants of T <sub>1sub>-enhancement and therefore lung function. Eight healthy volunteers were examined on a 1.5-T whole-body scanner. Lung T <sub>1sub>-maps based on an IR Snapshot FLASH technique (TE = 1.4 ms, TR = 3.5 ms, FA = 7 <sup>掳sup>) were dynamically acquired from each subject. Without waiting for full relaxation between subsequent acquisition of T <sub>1sub>-maps, one T <sub>1sub>-map was acquired every 6.7 s. For comparison, all subjects underwent a standard pulmonary function test (PFT). Oxygen wash-in and wash-out time course curves of T <sub>1sub> relaxation rate ( R <sub>1sub>)-enhancement were obtained and time constants of oxygen wash-in ( w <sub>insub>) and wash-out ( w <sub>outsub>) were calculated. Averaged over the whole right lung, the mean w <sub>outsub> was 43.90 卤 10.47 s and the mean ( w <sub>insub>) was 51.20 卤 15.53 s, thus about 17%higher in magnitude. Wash-in time constants correlated strongly with forced expired volume in one second in percentage of the vital capacity (FEV <sub>1sub>%VC) and with maximum expiratory flow at 25%vital capacity (MEF25), whereas wash-out time constants showed only weak correlation. Using oxygen-enhanced rapid dynamic acquisition of T <sub>1sub>-maps, time course curves of R <sub>1sub>-enhancement can be obtained. With w <sub>insub> and w <sub>outsub> two new parameters for assessing lung function are available. Therefore, the proposed method has the potential to provide regional information of pulmonary function in various lung diseases.