title: The benefit of non contrast-enhanced magnetic resonance angiography for predicting vascular access surgery outcome: a computer model perspective.
abstract: BACKGROUND
  Vascular access (VA) surgery, a prerequisite for hemodialysis treatment of end-stage renal-disease (ESRD) patients, is hampered by complication rates, which are frequently related to flow enhancement. To assist in VA surgery planning, a patient-specific computer model for postoperative flow enhancement was developed. The purpose of this study is to assess the benefit of non contrast-enhanced magnetic resonance angiography (NCE-MRA) data as patient-specific geometrical input for the model-based prediction of surgery outcome.
  
  
  METHODS
  25 ESRD patients were included in this study. All patients received a NCE-MRA examination of the upper extremity blood vessels in addition to routine ultrasound (US). Local arterial radii were assessed from NCE-MRA and converted to model input using a linear fit per artery. Venous radii were determined with US. The effect of radius measurement uncertainty on model predictions was accounted for by performing Monte-Carlo simulations. The resulting flow prediction interval of the computer model was compared with the postoperative flow obtained from US. Patients with no overlap between model-based prediction and postoperative measurement were further analyzed to determine whether an increase in geometrical detail improved computer model prediction.
  
  
  RESULTS
  Overlap between postoperative flows and model-based predictions was obtained for 71% of patients. Detailed inspection of non-overlapping cases revealed that the geometrical details that could be assessed from NCE-MRA explained most of the differences, and moreover, upon addition of these details in the computer model the flow predictions improved.
  
  
  CONCLUSIONS
  The results demonstrate clearly that NCE-MRA does provide valuable geometrical information for VA surgery planning. Therefore, it is recommended to use this modality, at least for patients at risk for local or global narrowing of the blood vessels as well as for patients for whom an US-based model prediction would not overlap with surgical choice, as the geometrical details are crucial for obtaining accurate flow predictions.
authors: Department of Biomedical Engineering, Maastricht University Medical Center, Maastricht, The Netherlands. m.a.g.merkx@alumnus.tue.nl
authors: Maarten A G
authors: MA
authors: Merkx
authors: Wouter
authors: W
authors: Huberts
authors: E Mariëlle H
authors: EM
authors: Bosboom
authors: Aron S
authors: AS
authors: Bode
authors: Javier Oliván
authors: JO
authors: Bescós
authors: Jan H M
authors: JH
authors: Tordoir
authors: Marcel
authors: M
authors: Breeuwer
authors: Frans N
authors: FN
authors: van de Vosse
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001158:Arteries / Q000000981:diagnostic imaging / Q000473:pathology; D001783:Blood Flow Velocity; D001811:Blood Volume Determination / Q000379:methods*; D003198:Computer Simulation; D005260:Female; D006801:Humans; D007089:Image Enhancement; D007676:Kidney Failure, Chronic / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009010:Monte Carlo Method; D011379:Prognosis; D006435:Renal Dialysis; D016896:Treatment Outcome; D018616:Ultrasonography, Doppler, Duplex; D034941:Upper Extremity / Q000098:blood supply*
references: Kidney Int. 2002 Oct;62(4):1109-24
references: 12234281
references: Radiology. 1990 May;175(2):545-52
references: 2326480
references: Nephrol Dial Transplant. 2007 May;22 Suppl 2:ii88-117
references: 17507428
references: Eur J Vasc Endovasc Surg. 2004 Jan;27(1):1-5
references: 14652830
references: PLoS One. 2012;7(4):e34491
references: 22496816
references: Med Eng Phys. 2013 Jun;35(6):827-37
references: 22964064
references: Ann Biomed Eng. 2000 Nov-Dec;28(11):1281-99
references: 11212947
references: J Vasc Access. 2013 Oct-Dec;14(4):348-55
references: 23817956
references: Eur J Vasc Endovasc Surg. 2012 Jan;43(1):88-94
references: 22070856
references: Med Eng Phys. 2012 Mar;34(2):233-48
references: 21840239
references: Ultrasound Med Biol. 2005 Oct;31(10):1327-33
references: 16223635
references: Comput Math Methods Med. 2012;2012:156094
references: 22654957
references: Ultrasound Med Biol. 2007 May;33(5):727-33
references: 17383804
references: J Biomech. 2012 Jun 1;45(9):1684-91
references: 22516855
references: Eur Radiol. 2009 Jan;19(1):110-20
references: 18704438
references: Radiographics. 2002 May-Jun;22(3):651-71
references: 12006694
references: Nephrol Dial Transplant. 1998 Jan;13(1):125-9
references: 9481727
references: J Magn Reson Imaging. 2012 Nov;36(5):1186-93
references: 22826150
references: Nephrol Dial Transplant. 2003 Feb;18(2):378-83
references: 12543895
references: Nephrol Dial Transplant. 2006 Mar;21(3):802-6
references: 16364992
references: Med Eng Phys. 2007 Dec;29(10):1106-18
references: 17197229
references: Nephrol Dial Transplant. 2005 Dec;20(12):2587-93
references: 16204281
references: Med Biol Eng. 1973 Nov;11(6):710-23
references: 4787930
references: Med Biol Eng Comput. 2013 Aug;51(8):879-89
references: 23526414
references: Artif Organs. 2005 Dec;29(12):960-4
references: 16305651
references: Med Eng Phys. 2011 Mar;33(2):195-203
references: 20980191
references: J Magn Reson Imaging. 1998 Nov-Dec;8(6):1228-35
references: 9848733
references: J Vasc Surg. 2006 Aug;44(2):353-8
references: 16890868
references: Artif Organs. 2006 Dec;30(12):895-7
references: 17181829
references: J Vasc Access. 2011 Oct-Dec;12(4):369-76
references: 21667457
references: Eur J Vasc Surg. 1990 Apr;4(2):179-84
references: 2190848