- Poster presentation
- Open Access
4D flow evaluation of abnormal flow patterns with bicuspid aortic valve
© Hope et al; licensee BioMed Central Ltd. 2009
- Published: 28 January 2009
- Aortic Aneurysm
- Thoracic Aorta
- Bicuspid Aortic Valve
- Helical Flow
- Coronary Cusp
Bicuspid aortic valve (BAV) is the most common congenital heart defect and may account for more morbidity and mortality than all other congenital cardiac malformations combined. Two theories are commonly discussed for the elevated risk of aortic aneurysm and dissection in patients with BAV: 1) an increased hemodynamic load placed on the proximal aorta results in progressive dilatation and 2) a genetic or developmental abnormality in the proximal aortic tissue leads to weakness of the aortic wall.
This study utilizes 4D Flow to collect multidirectional blood flow velocity data in the thoracic aorta of patients with BAV. The goal of the study is to characterize altered flow patterns in these patients and uncover potential hemodynamic contributors to aneurysm and dissection formation.
Time-resolved, 3D phase contrast MRI (4D Flow) was employed to assess thoracic aortic blood flow in 12 individuals: 8 patients with bicuspid aortic valve and 4 healthy subjects. The technique, which has been previously validated, was performed with parallel imaging after the standard clinical MR evaluation.
Abnormal systolic helical flow is seen in the ascending thoracic aorta of patients with bicuspid aortic valve. Similar helical flow has been described in ascending aortic aneurysms associated with BAV, but we have demonstrated this flow pattern in two patients without aneurysm, suggesting that the pattern is not secondary to the dilated aorta, but may be implicated in the pathogenesis of aneurysm formation. The marked helical flow in the ascending aorta appears to be associated with eccentric flow jets in all 6 of our cases. In the single case of left-handed helical flow, fusion of the right and noncoronary cusps was found, a geometric configuration that may create a left posterior jet as we have demonstrated (Figure 3). Identification and characterization of eccentric flow jets in patients with BAV may help risk stratify for development of ascending aortic aneurysm and dissection.
This article is published under license to BioMed Central Ltd.