Table 1.

Pulse sequence acquisition parameters for 2-D phase-contrast MRI and 4-D flow MRI

Sequence parameter	2-D phase-contrast MRI				4-D flow
	Ao	MPA	RPA	LPA
Temp. resolution (ms)	24.3–56.1	24.0–56.1	21.6–56.5	24.3–55.9	36.8–40.0
TR (ms)	5.7–5.8	5.7–5.8	5.7–5.8	5.7–5.8	4.6–5.0
TE (ms)	2.1–4.4	2.1–4.4	2.1–4.4	2.1–4.3	2.3–2.5
Flip angle (°)	15–20				15
VENC (cm/s)	150–400	150–400	200–400	200–400	100–250
Respiratory motion	Free breathing				Free breathing-navigator
Cardiac gating	Retrospective				Prospective
Reconstructed cardiac time frames	30				9–24
Number of slices	1				22–52
Field of view (mm)	149–308	170–309	149–350	149–340	128–112
	x	x	x	x	x
	199–340	210–340	199–350	199–340	300–400
Phase encoding steps	172–232	172–336	176–360	188–360	68–96
Bandwidth (Hz/pixel)	480–511	480–511	488–491	480–511	445–460
Spatial resolution (mm)	1.0–1.9	1.0–1.9	1.0–1.6	1.0–1.8	2.7–4.1
	x	x	x	x	x
	1.0–1.9	1.0–1.9	1.0–1.6	1.0–1.8	2.0–2.7
Slice thickness (mm)	5–6				2.0–3.5
Signal averages	2–3				1
Acquisition time* (minutes) and acceleration factor (R)	5.86±3.19 (R=2)				R=2: 12.6±5.1 R=5: 6.6±3.0

Ao aortic root, LPA left pulmonary artery, MPA main pulmonary artery, R acceleration factor, RPA right pulmonary artery, TE echo time, TR repetition time, VENC velocity encoding

^*Listed mean (+/−SD) acquisition time for 2-D phase-contrast MRI represents the mean sum time of all 2-D phase-contrast MRI flow sequences performed per patient