title: Evaluation of pulmonary function using single-breath-hold dual-energy computed tomography with xenon: Results of a preliminary study.
abstract: Xenon-enhanced dual-energy computed tomography (xenon-enhanced CT) can provide lung ventilation maps that may be useful for assessing structural and functional abnormalities of the lung. Xenon-enhanced CT has been performed using a multiple-breath-hold technique during xenon washout. We recently developed xenon-enhanced CT using a single-breath-hold technique to assess ventilation. We sought to evaluate whether xenon-enhanced CT using a single-breath-hold technique correlates with pulmonary function testing (PFT) results.Twenty-six patients, including 11 chronic obstructive pulmonary disease (COPD) patients, underwent xenon-enhanced CT and PFT. Three of the COPD patients underwent xenon-enhanced CT before and after bronchodilator treatment. Images from xenon-CT were obtained by dual-source CT during a breath-hold after a single vital-capacity inspiration of a xenon-oxygen gas mixture. Image postprocessing by 3-material decomposition generated conventional CT and xenon-enhanced images.Low-attenuation areas on xenon images matched low-attenuation areas on conventional CT in 21 cases but matched normal-attenuation areas in 5 cases. Volumes of Hounsfield unit (HU) histograms of xenon images correlated moderately and highly with vital capacity (VC) and total lung capacity (TLC), respectively (r = 0.68 and 0.85). Means and modes of histograms weakly correlated with VC (r = 0.39 and 0.38), moderately with forced expiratory volume in 1 second (FEV1) (r = 0.59 and 0.56), weakly with the ratio of FEV1 to FVC (r = 0.46 and 0.42), and moderately with the ratio of FEV1 to its predicted value (r = 0.64 and 0.60). Mode and volume of histograms increased in 2 COPD patients after the improvement of FEV1 with bronchodilators. Inhalation of xenon gas caused no adverse effects.Xenon-enhanced CT using a single-breath-hold technique depicted functional abnormalities not detectable on thin-slice CT. Mode, mean, and volume of HU histograms of xenon images reflected pulmonary function. Xenon images obtained with xenon-enhanced CT using a single-breath-hold technique can qualitatively depict pulmonary ventilation. A larger study comprising only COPD patients should be conducted, as xenon-enhanced CT is expected to be a promising technique for the management of COPD.
authors.affiliation: Department of Pulmonary Medicine Department of Radiology, Saitama Medical Center, Saitama Medical University, Saitama Research and Collaborations Department, Siemens Healthcare KK, Tokyo, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kyoyama
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Hirata
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kikuchi
authors.forename: Kosuke
authors.initials: K
authors.lastname: Sakai
authors.forename: Yuriko
authors.initials: Y
authors.lastname: Saito
authors.forename: Shintaro
authors.initials: S
authors.lastname: Mikami
authors.forename: Gaku
authors.initials: G
authors.lastname: Moriyama
authors.forename: Hisami
authors.initials: H
authors.lastname: Yanagita
authors.forename: Wataru
authors.initials: W
authors.lastname: Watanabe
authors.forename: Katharina
authors.initials: K
authors.lastname: Otani
authors.forename: Norinari
authors.initials: N
authors.lastname: Honda
authors.forename: Kazutsugu
authors.initials: K
authors.lastname: Uematsu
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008171:Lung Diseases / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D058996:Quality Improvement; D012129:Respiratory Function Tests; D014057:Tomography, X-Ray Computed; D014978:Xenon
chemical_list: D014978:Xenon