title: Spiral laminar flow in the abdominal aorta: a predictor of renal impairment deterioration in patients with renal artery stenosis?
abstract: BACKGROUND
  Spiral or helical arterial blood flow patterns have been widely observed in both animals and humans. The absence of spiral flow has been associated with carotid arterial disease. The aim of this study was to detect the presence of aortic spiral flow using magnetic resonance imaging (MRI) and to evaluate the relationship of the presence of spiral aortic flow with renal arterial disease and renal function in the follow-up of patients with suspected renal atheromatous disease.
  
  
  METHODS
  Prospective study of 100 patients with suspected renal arterial disease and 44 patient controls. Using a 1.5 T MRI unit (Siemens Symphony), phase contrast flow quantification and three-dimensional contrast enhanced MR angiography of the abdominal aorta were performed. Renal arterial stenoses (RAS) were classified minimal, moderate or severe. Renal function was followed at 3 months before and 6 months after MRI.
  
  
  RESULTS
  Non-spiral flow was more prevalent in patients with more severe RAS. Renal impairment progressed significantly in severe RAS without spiral flow (P = 0.0065), but did not progress significantly in severe RAS with spiral flow (P = 0.12). In minimal or moderate RAS with or without spiral flow there was no significant progression (P = 0.16, 0.13, 0.47, 0.092, respectively).
  
  
  CONCLUSIONS
  Aortic spiral blood flow can be assessed with MRI. Lack of aortic spiral blood flow in patients with severe RAS is associated with significant short-term renal function deterioration. Determination of blood flow patterns may be a useful indicator of renal impairment progression in patients with suspected renal artery stenosis.
authors.affiliation: Tayside University Hospitals, Clinical Radiology, Dundee, UK. graeme.houston@tuht.scot.nhs.uk
authors.forename: J Graeme
authors.initials: JG
authors.lastname: Houston
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Gandy
authors.forename: Wendy
authors.initials: W
authors.lastname: Milne
authors.forename: John B C
authors.initials: JB
authors.lastname: Dick
authors.forename: Jill J F
authors.initials: JJ
authors.lastname: Belch
authors.forename: Peter A
authors.initials: PA
authors.lastname: Stonebridge
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001012:Aorta, Abdominal / Q000503:physiopathology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007674:Kidney Diseases / Q000209:etiology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012039:Regional Blood Flow; D012078:Renal Artery Obstruction / Q000150:complications* / Q000503:physiopathology*