Comparison of Free-Breathing 3D Phase-Resolved Functional Lung (PREFUL) MRI With Dynamic ¹⁹F Ventilation MRI in...

Non-contrast-enhanced ¹H magnetic resonance imaging (MRI) with full lung coverage shows promise for assessment of regional lung ventilation but a comparison with direct ventilation measurement using ¹⁹F MRI is lacking.

To compare ventilation parameters calculated using 3D phase-resolved functional lung (PREFUL) MRI with ¹⁹F MRI.

Prospective.

Fifteen patients with asthma, 14 patients with chronic obstructive lung disease, and 13 healthy volunteers.

A 3D gradient-echo pulse sequence with golden-angle increment and stack-of-stars encoding at 1.5 T.

All participants underwent 3D PREFUL MRI and ¹⁹F MRI. For 3D PREFUL, static regional ventilation (RVent) and dynamic flow-volume cross-correlation metric (FVL-CM) were calculated. For both parameters, ventilation defect percentage (VDP) values and ventilation defect (VD) maps (including a combination of both parameters [VDP_Combined]) were determined. For ¹⁹F MRI, images from eight consecutive breaths under volume-controlled inhalation of perfluoropropane were acquired. Time-to-fill (TTF) and wash-in (WI) parameters were extracted. For all ¹⁹F parameters, a VD map was generated and the corresponding VDP values were calculated.

For all parameters, the relationship between the two techniques was assessed using a Spearman correlation (r). Differences between VDP values were compared using Bland-Altman analysis. For regional comparison of VD maps, spatial overlap and Sørensen-Dice coefficients were computed.

3D PREFUL VDP values were significantly correlated to VDP measures by ¹⁹F (r range: 0.59-0.70). For VDP_RVent, no significant bias was observed with VDP of the third and fourth breath (bias range = -6.8:7.7%, P range = 0.25:0.30). For VDP_FVL-CM, no significant bias was found with VDP values of fourth-eighth breaths (bias range = -2.0:12.5%, P range = 0.12:0.75). The overall spatial overlap of all VD maps increased with each breath, ranging from 61% to 81%, stabilizing at the fourth breath.

3D PREFUL MRI parameters showed moderate to strong correlation with ¹⁹F MRI. Depending on the 3D PREFUL VD map, the best regional agreement was found to ¹⁹F VD maps of third-fifth breath.

3 TECHNICAL EFFICACY: Stage 2.