- Poster presentation
- Open Access
3D peripheral subtraction MRA using flow-spoiled ECG-triggered balanced SSFP
© Fan et al; licensee BioMed Central Ltd. 2009
- Published: 28 January 2009
- Peripheral Arterial Disease
- Nephrogenic Systemic Fibrosis
- Peripheral Arterial Disease Patient
- Vessel Wall Imaging
- Venous Contamination
Peripheral arterial disease (PAD) is a major cause of diminished functional capacity and quality of life in a large portion of western populations. While 3D contrast-enhanced (CE) MRA is becoming a modality of choice for clinical PAD examinations, the potential for nephrogenic systemic fibrosis (NSF) in patients with renal insufficiency has triggered a renaissance of interest in non-contrast enhanced (NCE) MRA. Various NCE-MRA strategies employing 3D half-Fourier FSE  or balanced SSFP (bSSFP)  have shown great promise. Recently, flow-sensitizing dephasing-prepared (FSD) bSSFP was proposed for vessel wall imaging . The present work aimed to investigate the feasibility of MRA in lower legs utilizing FSD-bSSFP combined with ECG-triggering and image subtraction.
In the case of a laminar flow, the faster average velocity and/or greater first gradient moment m1 conveyed by FSD, the higher likelihood the flowing spins are dephased and thus suppressed. Hence, the arterial blood is more susceptible to FSD with a weak m1 compared with venous blood during systole. Since bSSFP is not truly flow-compensated, however, bright blood scan can achieve substantially high arterial blood signal during mid-diastole. For those reasons, ECG-triggering facilitates subtraction MRA. The results indicate that FSD gradient strength, or more accurately m1, should be controlled to a low level (for lower legs here, G = 10 mT/m, m1 = 34.8 mTms2/m) to selectively suppress arterial blood and to avoid otherwise venous contamination. The feasibility of this approach was demonstrated on healthy distal lower extremities. Further investigation on PAD patients, with CE-MRA or x-ray angiography correlation, is warranted. It is anticipated that this strategy could be applied to other vascular territories where appropriate choice of m1 (magnitude and direction) would vary with the specific flow patterns.
This article is published under license to BioMed Central Ltd.