The measurement of ventilation dynamics with 2D proton MRI (PREFUL) might offer a sensitive lung function test but lacks a high spatial resolution and whole-lung acquisition is time consuming. Recently, the feasibility of 3D PREFUL was demonstrated. In this work, ventilation dynamics assessment using flow-volume loop (FVL) analysis is performed on 2D and 3D data of a healthy volunteer and an asthma patient. Full respiratory cycle was reconstructed to calculate regional ventilation and cross-correlation metric of FVL. Similar results suggest that 3D PREFUL might be an interesting alternative to 2D PREFUL due to its improved spatial resolution and acquisition efficiency.