3D phase-resolved functional lung ventilation MR imaging in healthy volunteers and patients with chronic pulmonary disease.

Abstract

To test the feasibility of 3Dphase-resolved functional lung (PREFUL)MRIin healthy volunteers and patients withchronicpulmonary disease, to compare 3D to 2D PREFUL,and to investigatethe required temporal resolution to obtainstable3D PREFULmeasurement. Sixteen participants underwent MRIusing 2D and 3D PREFUL. Retrospectively, the spatial resolutionof 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 toregional 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, theventilation parameter maps, includingthe heterogeneity ofventilation time to peak,weretested regarding the requiredtemporal resolution. RVent, CC,VDPRVent , and VDPCC presented significant correlationsbetween 2D and 3D PREFUL (r = 0.64-0.94).CC and VDPCC of 2D and 3Dlowres PREFULwere significantlydifferent (P < .0113).Comparing3Dlowres and 3D PREFUL,all parameters were found to be statistically different (P < .0045). 3D PREFUL MRI depicts the whole lung volume and breathing cycle with superior image resolutionand with likely more precisioncompared to 2D PREFUL.Furthermore,3DPREFUL is more sensitive to detect regions of hypoventilation andventilation heterogeneitycompared to 3Dlowres PREFUL, which is important for earlydetectionand improved monitoring of patients with chronic lung disease.