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Introduction: Doppler‐derived pulmonary pulse transit time (pPTT) is an auspicious hemodynamic marker in chronic pulmonary diseases. The aim is to compare four distinct pPTT measurements and its relation to right cardiac and pulmonary function. Methods: Prospectively, 25 chronic obstructive pulmonary disease (COPD) patients (four patients excluded) and 32 healthy subjects underwent repeated distinct pPTT measurements, standard echocardiography, and pulmonary function testing on the same day. pPTT was defined as the interval from the R or Q‐wave in the electrocardiogram to the corresponding pulse wave Doppler peak late systolic (S) 2 or diastolic (D) pulmonary vein flow velocity (pPTT R‐S, Q‐S, R‐D, Q‐D). Reproducibility was assessed using Bland–Altman analysis, coefficient of variation (COV), intraclass correlation coefficient (ICC), and power calculations. Associations with right ventricular RV tissue and pulse wave Doppler velocities (RV E', RV S', RV A', RV E, RV A, RV E/E', RV E/A), TAPSE, right ventricular fractional area change, left ventricular systolic and diastolic function (LV ejection fraction, E, A, E/A, E/E', septal E', lateral E'), LA diameters, as well as forced expiratory volume in 1 s, forced vital capacity (FVC) predicted (%), and in liters were analyzed. Results: There was no significant difference and no bias between pPTT measures (p range:.1–.9). COV was in COPD 1.2%–2.3%, in healthy subjects 1.0%–3.1%. ICC ranged from.92 (COPD) to.96 (healthy subjects). In COPD significant correlations were found for pPTT R‐S, Q‐S and R‐D with RV E', (all > ρ:.49, < p =.0364), pPTT R‐S, Q‐S with RV E/E' (both > ρ:.49, < p =.0291), pPTT Q‐S with RV S´ (ρ:.58, p =.0134), RV A (ρ:.59, p =.0339) and heart rate > ρ: −.39, < p =.0297). pPTT R‐S, R‐D showed significant correlations with FVC predicted (%) (ρ:.48 p =.0224) and FVC (l) (ρ:.47 p =.0347). Conclusions: All pPTT measures exhibited high reproducibility. In COPD patients pPTT measures correlate with diastolic right ventricular function. Defining Q as starting point seems clinically advantageous considering electromechanical desynchrony in patients with conduction disorders. [ABSTRACT FROM AUTHOR]

Purpose: To test the feasibility of 3D phase‐resolved functional lung (PREFUL) MRI in healthy volunteers and patients with chronic pulmonary disease, to compare 3D to 2D PREFUL, and to investigate the required temporal resolution to obtain stable 3D PREFUL measurement. Methods: Sixteen participants underwent MRI using 2D and 3D PREFUL. Retrospectively, the spatial resolution of 3D PREFUL (4 × 4 × 4 mm3) was decreased to match the spatial resolution of 2D PREFUL (4 × 4 × 15 mm3), abbreviated as 3Dlowres. In addition to regional ventilation (RVent), flow‐volume loops were computed and rated by a cross‐correlation (CC). Ventilation defect percentage (VDP) maps were obtained. RVent, CC, VDPRVent, and VDPCC were compared for systematic differences between 2D, 3Dlowres, and 3D PREFUL. Dividing the 3D PREFUL data into 4‐ (≈ 20 phases), 8‐ (≈ 40 phases), and 12‐min (≈ 60 phases) acquisition pieces, the ventilation parameter maps, including the heterogeneity of ventilation time to peak, were tested regarding the required temporal resolution. Results: RVent, CC, VDPRVent, and VDPCC presented significant correlations between 2D and 3D PREFUL (r = 0.64‐0.94). CC and VDPCC of 2D and 3Dlowres PREFUL were significantly different (P <.0113). Comparing 3Dlowres and 3D PREFUL, all parameters were found to be statistically different (P <.0045). Conclusion: 3D PREFUL MRI depicts the whole lung volume and breathing cycle with superior image resolution and with likely more precision compared to 2D PREFUL. Furthermore, 3D PREFUL is more sensitive to detect regions of hypoventilation and ventilation heterogeneity compared to 3Dlowres PREFUL, which is important for early detection and improved monitoring of patients with chronic lung disease. [ABSTRACT FROM AUTHOR]