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Repaired aortic coarctation in adults—magnetic resonance imaging with velocity mapping shows distortions of anatomy and flow

Published online by Cambridge University Press:  19 August 2008

Philip J. Kilner*
Affiliation:
From the Magnetic Resonance Unit and the Grown-Up Congenital Heart Unit, Royal Brompton Hospital, London
Tokuko Shinohara
Affiliation:
From the Magnetic Resonance Unit and the Grown-Up Congenital Heart Unit, Royal Brompton Hospital, London
Cynthia Sampson
Affiliation:
From the Magnetic Resonance Unit and the Grown-Up Congenital Heart Unit, Royal Brompton Hospital, London
Raad H. Mohiaddin
Affiliation:
From the Magnetic Resonance Unit and the Grown-Up Congenital Heart Unit, Royal Brompton Hospital, London
David N. Firmin
Affiliation:
From the Magnetic Resonance Unit and the Grown-Up Congenital Heart Unit, Royal Brompton Hospital, London
Jane Somerville
Affiliation:
From the Magnetic Resonance Unit and the Grown-Up Congenital Heart Unit, Royal Brompton Hospital, London
*
Dr. Philip Kilner, Magnetic Resonance Unit, Royal Brompton Hospital, Sydney Street, London SW3 6HP, United Kingdom. Tel. 44-171-351-8808; Fax. 44-171-351-8816.

Abstract

Magnetic resonance velocity mapping of intraaortic flow was performed prospectively in adolescents and adults after coarctation repair. The aims were to assess the feasibility and clinical usefulness of the technique in this patient group, and to study flow velocity distributions in repaired regions. Twenty consecutive patients attending for follow-up after repair of aortic coarctation, aged 15–39, mean 25 years, were studied using a 0.5 tesla Picker magnetic resonance machine. Spin echo and cine imaging with phase velocity mapping, echo time 3.6 ms, were used to study anatomy and flow in the repaired region. Transcutaneous ultrasonic examination, with continuous wave Doppler velocity measurement was performed independently on the same day. Velocity maps, acquired successfully in all patients, showed asymmetry and nonhomogeneity of flow in relation to anatomical distortions of repaired regions. Magnetic resonance and Doppler measurements of peak velocity compared as follows: n=20, range 1.2–3.9 m/sec, mean 2.33 m/sec, mean of differences (Doppler-MR) 0.22 m/sec, standard deviation of differences ±0.27 m/sec. Localized velocity peaks adjacent to wall deformations were identified by magnetic resonance in five patients without significant restenosis. Magnetic resonance imaging with velocity mapping proved reliable and informative in follow-up assessment in adolescents and adults after surgical repair of aortic coarctation. There was satisfactory agreement between magnetic resonance and Doppler measurements of peak velocity. Velocity maps showed that localized velocity peaks may occur in limited parts of the stream adjacent to distorted aortic boundaries without stenosis. This could be a cause of overestimation of pressure gradients from peak velocity data, a possibility which requires further investigation.

Type
Original Manuscripts
Copyright
Copyright © Cambridge University Press 1996

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References

1. Nayler, GL, Firmin, DN, Longmore, DB. Blood flow imaging by cine magnetic resonance. J Comput Assist Tomogr 1986; 10: 715722.CrossRefGoogle ScholarPubMed
2. Kilner, PJ, Firmin, DM, Rees, RSO, Martínez, JE, Pennell, DJ, Mohiaddin, RH, Underwood, SR, Longmore, DB. Magnetic resonance jet velocity mapping for assessment of valve and great vessel stenosis. Radiology 1990; 178: 229235.CrossRefGoogle Scholar
3. Kilner, PJ, Manzara, CC, Mohiaddin, RH, Pennell, DJ, Sutton, MJ St, Firmin, DN, Underwood, SR, Longmore, DB. Magnetic resonance jet velocity mapping in mitral and aortic stenosis. Circulation 1993; 87: 12391248.CrossRefGoogle Scholar
4. Mohiaddin, RH, Kilner, PJ, Rees, RSO, Longmore, DB. Magnetic resonance volume flow and jet velocity mapping in aortic coarctation. J Am Coll Cardiol 1993; 22: 15151521.CrossRefGoogle ScholarPubMed
5. von Schultess, GK, Higashino, SM, Higgins, SS, Didier, D, Fisher, MR, Higgins, CB. Coarctation of the aorta: MR imaging. Radiology 1986; 158: 469475.CrossRefGoogle Scholar
6. Boxer, RA, La Corte, MA, Singh, S, Cooper, R, Fishman, MC, Goldman, M, Stein, HL. Nuclear magnetic resonance imaging in evaluation and follow-up of children treated for coarctation. J Am Coll Cardiol 1986; 7: 10951098.CrossRefGoogle ScholarPubMed
7. Simpson, IA, Chung, KJ, Glass, RF, Sahn, DJ, Sherman, FS, Hesselink, J. Cine magnetic resonance imaging for evaluation of anatomy and flow relations in infants and children with coarctation of the aorta. Circulation 1988; 78: 142148.CrossRefGoogle ScholarPubMed
8. Rees, RSO, Somerville, J, Ward, C, Martínez, J, Mohiaddin, RH, Underwood, R, Longmore, DB. Magnetic resonance imaging in late post-operative assessment of coarctation of the aorta. Radiology 1989; 173: 499502.CrossRefGoogle Scholar
9. Underwood, SR, Firmin, DN. Magnetic Resonance of the Cardiovascular System. Blackwell, Oxford, 1990.Google Scholar
10. Kilner, PJ, Yang, GZ, Mohiaddin, RH, Firmin, DN, Longmore, DB. Helical and retrograde flow in the aortic arch studied by three-directional magnetic resonance velocity mapping. Circulation 1993; 88: 22352247.CrossRefGoogle ScholarPubMed
11. Wyse, RKH, Robinson, PJ, Deanfield, EJ, Tunstall Pedoe, DS, Macartney, FJ. Use of continuous wave Doppler ultrasound to assess the severity of coarctation of the aorta by measurement of aortic flow velocities. Br Heart J 1984; 52: 278283.CrossRefGoogle ScholarPubMed
12. Carvalho, JS, Redington, AN, Shinebourne, EA, Rigby, ML, Gibson, D. Continuous wave Doppler echocardiography and coarctation of the aorta: gradients and flow patterns in the assessment of severity. Br Heart J 1990; 64: 133137.CrossRefGoogle ScholarPubMed
13. Bland, JM, Altman, DG. Statistical methods for assessing agreement between two methods of clinical measurement. Lancet 1986; i: 307310.CrossRefGoogle Scholar
14. Levine, RA, Jimoh, A, Cape, EG, McMillan, S, Yoganathan, AJ, Weyman, AE. Pressure recovery distal to a stenosis: potential cause of gradient “overestimation” by Doppler echocardiography. J Am Coll Cardiol 1989; 13: 706715.CrossRefGoogle ScholarPubMed
15. Baumgartner, H, Schima, H, Tulzer, G, Kuhn, P. Effect of stenosis geometry on the Doppler-catheter relation in vitro: a manifestation of pressure recovery. J Am Coll Cardiol 1993; 21: 10181025.CrossRefGoogle ScholarPubMed
16. Segadal, L, Matre, K. Blood velocity distribution in the human ascending aorta. Circulation 1987; 76: 90100.CrossRefGoogle ScholarPubMed
17. Massey, BS. Mechanics of Fluids. Van Nostrand Reinhold, United Kingdom, 1983.Google Scholar
18. Weber, HS, Cyran, SE, Grzeszczak, M, Myers, JL, Gleason, MM, Baylen, BG. Discrepancies in aortic growth explain aortic arch gradients during exercise. J Am Coll Cardiol 1993;21: 10021007.CrossRefGoogle ScholarPubMed