title: Reproducibility and comparison of oxygen-enhanced T1 quantification in COPD and asthma patients.
abstract: T1 maps have been shown to yield useful diagnostic information on lung function in patients with chronic obstructive pulmonary disease (COPD) and asthma, both for native T1 and ΔT1, the relative reduction while breathing pure oxygen. As parameter quantification is particularly interesting for longitudinal studies, the purpose of this work was both to examine the reproducibility of lung T1 mapping and to compare T1 found in COPD and asthma patients using IRSnapShotFLASH embedded in a full MRI protocol. 12 asthma and 12 COPD patients (site 1) and further 15 COPD patients (site 2) were examined on two consecutive days. In each patient, T1 maps were acquired in 8 single breath-hold slices, breathing first room air, then pure oxygen. Maps were partitioned into 12 regions each to calculate average values. In asthma patients, the average T1,RA = 1206ms (room air) was reduced to T1,O2 = 1141ms under oxygen conditions (ΔT1 = 5.3%, p < 5⋅10-4), while in COPD patients both native T1,RA = 1125ms was significantly shorter (p < 10-3) and the relative reduction to T1,O2 = 1081ms on average ΔT1 = 4.2%(p < 10-5). On the second day, with T1,RA = 1186ms in asthma and T1,RA = 1097ms in COPD, observed values were slightly shorter on average in all patient groups. ΔT1 reduction was the least repeatable parameter and varied from day to day by up to 23% in individual asthma and 30% in COPD patients. While for both patient groups T1 was below the values reported for healthy subjects, the T1 and ΔT1 found in asthmatics lies between that of the COPD group and reported values for healthy subjects, suggesting a higher blood volume fraction and better ventilation. However, it could be demonstrated that lung T1 quantification is subject to notable inter-examination variability, which here can be attributed both to remaining contrast agent from the previous day and the increased dependency of lung T1 on perfusion and thus current lung state.
authors.affiliation: Department of Diagnostic & Interventional Radiology, University Hospital of Heidelberg, Heidelberg, Germany.|Translational Lung Research Center Heidelberg (TLRC), Member of the German Lung Research Center (DZL), Heidelberg, Germany.|Department of Experimental Physics 5, Julius-Maximilians Universität Würzburg, Würzburg, Germany.
authors.forename: Simon M F
authors.identifier: http://orcid.org/0000-0003-2068-1184
authors.initials: SM
authors.lastname: Triphan
authors.affiliation: Department of Diagnostic & Interventional Radiology, University Hospital of Heidelberg, Heidelberg, Germany.|Translational Lung Research Center Heidelberg (TLRC), Member of the German Lung Research Center (DZL), Heidelberg, Germany.|Department of Diagnostic & Interventional Radiology with Nuclear Medicine, Thoraxklinik at University of Heidelberg, Heidelberg, Germany.
authors.forename: Bertram J
authors.initials: BJ
authors.lastname: Jobst
authors.affiliation: Department of Diagnostic & Interventional Radiology, University Hospital of Heidelberg, Heidelberg, Germany.|Translational Lung Research Center Heidelberg (TLRC), Member of the German Lung Research Center (DZL), Heidelberg, Germany.
authors.forename: Angela
authors.initials: A
authors.lastname: Anjorin
authors.affiliation: Department of Diagnostic & Interventional Radiology, University Hospital of Heidelberg, Heidelberg, Germany.|Translational Lung Research Center Heidelberg (TLRC), Member of the German Lung Research Center (DZL), Heidelberg, Germany.
authors.forename: Oliver
authors.initials: O
authors.lastname: Sedlaczek
authors.affiliation: Department of Diagnostic & Interventional Radiology, University Hospital of Heidelberg, Heidelberg, Germany.|Translational Lung Research Center Heidelberg (TLRC), Member of the German Lung Research Center (DZL), Heidelberg, Germany.|Department of Radiology, Mainz University Medical School, Mainz, Germany.|Department of Diagnostic & Interventional Radiology with Nuclear Medicine, Thoraxklinik at University of Heidelberg, Heidelberg, Germany.
authors.forename: Ursula
authors.initials: U
authors.lastname: Wolf
authors.affiliation: Department of Radiology, Mainz University Medical School, Mainz, Germany.|Comprehensive Heart Failure Center, University Hospital Würzburg, Würzburg, Germany.
authors.forename: Maxim
authors.initials: M
authors.lastname: Terekhov
authors.affiliation: Department of Radiology, Mainz University Medical School, Mainz, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Hoffmann
authors.affiliation: Department of Diagnostic & Interventional Radiology, University Hospital of Heidelberg, Heidelberg, Germany.|Institute for Clinical Radiology, Ludwig Maximilians Universität München, Munich, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Ley
authors.affiliation: Department of Radiology, Mainz University Medical School, Mainz, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Düber
authors.affiliation: Department of Diagnostic & Interventional Radiology, University Hospital of Heidelberg, Heidelberg, Germany.|Translational Lung Research Center Heidelberg (TLRC), Member of the German Lung Research Center (DZL), Heidelberg, Germany.|Radiologie Darmstadt, Department of Radiology Hospital Gross-Gerau, Gross-Gerau, Germany.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Biederer
authors.affiliation: Department of Diagnostic & Interventional Radiology, University Hospital of Heidelberg, Heidelberg, Germany.|Translational Lung Research Center Heidelberg (TLRC), Member of the German Lung Research Center (DZL), Heidelberg, Germany.|Department of Diagnostic & Interventional Radiology with Nuclear Medicine, Thoraxklinik at University of Heidelberg, Heidelberg, Germany.
authors.forename: Hans-Ulrich
authors.initials: HU
authors.lastname: Kauczor
authors.affiliation: Department of Experimental Physics 5, Julius-Maximilians Universität Würzburg, Würzburg, Germany.
authors.forename: Peter M
authors.initials: PM
authors.lastname: Jakob
authors.affiliation: Department of Diagnostic & Interventional Radiology, University Hospital of Heidelberg, Heidelberg, Germany.|Translational Lung Research Center Heidelberg (TLRC), Member of the German Lung Research Center (DZL), Heidelberg, Germany.|Department of Diagnostic & Interventional Radiology with Nuclear Medicine, Thoraxklinik at University of Heidelberg, Heidelberg, Germany.
authors.forename: Mark O
authors.initials: MO
authors.lastname: Wielpütz
mesh_terms: D001249:Asthma / Q000503:physiopathology*; D003287:Contrast Media; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D010100:Oxygen / Q000378:metabolism*; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000503:physiopathology*; D015203:Reproducibility of Results; D012119:Respiration
chemical_list: D003287:Contrast Media; D010100:Oxygen