Fig 1.
An example image including FSD (a), QISS (b), and CE-MRA (c) from which the SNR, CNR, and vessel sharpness were derived.
The circles drawn in the cross-section of arterial segments (yellow circles) and the adjacent tissue (red circles) indicated the representative ROIs for the calculation of signal intensity of arterial blood and tissue, respectively. The circles drawn in the background (green circles) indicated the representative large air ROI for the calculation of noise. The line drawn perpendicularly to the vessel wall indicated the representative user-selected line for the calculation of vessel sharpness.
Fig 2.
MIP images with the identical window level of FSD (a) and CE-MRA (c) of the calf arteries show no significant stenosis in the bilateral calf arteries in a 54-year-old woman with diabetes.
Soft tissue artifacts and a false stenosis caused by signal loss are seen at the left distal peroneal artery (PA) (arrowhead) on the MIP image of QISS (b), of which the optimal window level is different from that of FSD and CE-MRA. MIP: maximum intensity projection; FSD: flow-sensitive dephasing; CE-MRA: contrast-enhanced MR angiography; QISS: quiescent-interval single-shot; ATA: anterior tibia artery; PTA: posterior tibia artery.
Fig 3.
MIP images with different optimal window level of FSD (a), QISS (b), and CE-MRA (c) of the calf arteries demonstrate diffused severe lesions in the left anterior tibia artery (ATA) and occlusions in the right ATA and left posterior tibia artery (PTA) in a 65-year-old man with diabetes and renal insufficiency.
Collaterals are seen at the right proximal peroneal artery and PTA (arrow head) as well as the distal calf arteries (arrow). FSD shows better delineation of the arterial lesions and small collaterals compared to QISS. Soft tissue and deep venous contaminations caused by faster deep venous flow appear on the FSD image. But it doesn’t affect the evaluation of arterial lesions because of the high arterial contrast as well as isotropic spatial resolution. MIP: maximum intensity projection; FSD: flow-sensitive dephasing; QISS: quiescent-interval single-shot; CE-MRA: contrast-enhanced MR angiography; PA: peroneal artery (PA).
Table 1.
Comparison of image quality of three calf arterial segments for NCE-MRA in 26 patients with diabetes.
Table 2.
The number of different kinds of artifacts for NCE-MRA in 26 patients with diabetes.
Fig 4.
Comparison of SNR, CNR, and vessel sharpness between FSD, QISS, and CE-MRA in three arterial segments of the calf.
Each column represents average measurements and error is shown as standard deviation. Asterisks indicated significant difference (P < 0.05). SNR: signal-to-noise ratio; CNR: contrast-to-noise ratio; FSD: flow-sensitive dephasing; QISS: quiescent-interval single-shot; CE-MRA: contrast-enhanced MR angiography.
Fig 5.
Comparison of the time efficiency of SNR (SNR eff) and CNR (CNR eff) between QISS and FSD with only dark and bright blood scan (a, b) or adding the phase-contrast and m1-scout scan (c, d)) in three arterial segments of the calf.
Each column represents average measurements and error is shown as standard deviation. Asterisks indicated significant difference (P < 0.05). SNR: signal-to-noise ratio; CNR: contrast-to-noise ratio; QISS: quiescent-interval single-shot; FSD: flow-sensitive dephasing.
Table 3.
Comparison of stenosis scores of three calf arterial segments between NCE-MRA and CE-MRA techniques in 26 patients with diabetes.