Heart valve disease: investigation by cardiovascular magnetic resonance
Saul G Myerson, Saul G Myerson
Abstract
Cardiovascular magnetic resonance (CMR) has become a valuable investigative tool in many areas of cardiac medicine. Its value in heart valve disease is less well appreciated however, particularly as echocardiography is a powerful and widely available technique in valve disease. This review highlights the added value that CMR can bring in valve disease, complementing echocardiography in many areas, but it has also become the first-line investigation in some, such as pulmonary valve disease and assessing the right ventricle. CMR has many advantages, including the ability to image in any plane, which allows full visualisation of valves and their inflow/outflow tracts, direct measurement of valve area (particularly for stenotic valves), and characterisation of the associated great vessel anatomy (e.g. the aortic root and arch in aortic valve disease). A particular strength is the ability to quantify flow, which allows accurate measurement of regurgitation, cardiac shunt volumes/ratios and differential flow volumes (e.g. left and right pulmonary arteries). Quantification of ventricular volumes and mass is vital for determining the impact of valve disease on the heart, and CMR is the 'Gold standard' for this. Limitations of the technique include partial volume effects due to image slice thickness, and a low ability to identify small, highly mobile objects (such as vegetations) due to the need to acquire images over several cardiac cycles. The review examines the advantages and disadvantages of each imaging aspect in detail, and considers how CMR can be used optimally for each valve lesion.
Figures
References
- Westermann Y, Geigenmuller A, Elgeti T, Wagner M, Dushe S, Borges AC, Dohmen PM, Hein PA, Lembcke A. Planimetry of the aortic valve orifice area: comparison of multislice spiral computed tomography and magnetic resonance imaging. Eur J Radiol. 2011;77:426–435. doi: 10.1016/j.ejrad.2009.08.014.
- Evans AJ, Blinder RA, Herfkens RJ, Spritzer CE, Kuethe DO, Fram EK, Hedlund LW. Effects of turbulence on signal intensity in gradient echo images. Invest Radiol. 1988;23:512–518. doi: 10.1097/00004424-198807000-00006.
- Krombach GA, Kuhl H, Bucker A, Mahnken AH, Spuntrup E, Lipke C, Schroder J, Gunther RW. Cine MR imaging of heart valve dysfunction with segmented true fast imaging with steady state free precession. J Magn Reson Imaging. 2004;19:59–67. doi: 10.1002/jmri.10428.
- Wagner S, Auffermann W, Buser P, Lim TH, Kircher B, Pflugfelder P, Higgins CB. Diagnostic accuracy and estimation of the severity of valvular regurgitation from the signal void on cine magnetic resonance images. Am Heart J. 1989;118:760–767. doi: 10.1016/0002-8703(89)90590-5.
- Suzuki J, Caputo GR, Kondo C, Higgins CB. Cine MR imaging of valvular heart disease: display and imaging parameters affect the size of the signal void caused by valvular regurgitation. AJR Am J Roentgenol. 1990;155:723–727.
- Bonow RO, Carabello BA, Chatterjee K, de Leon AC, Jr. Faxon DP, Freed MD, Gaasch WH, Lytle BW, Nishimura RA, O'Gara PT, O'Rourke RA, Otto CM, Shah PM, Shanewise JS, Smith SC Jr, Jacobs AK, Adams CD, Anderson JL, Antman EM, Fuster V, Halperin JL, Hiratzka LF, Hunt SA, Lytle BW, Nishimura R, Page RL, Riegel B. ACC/AHA 2006 guidelines for the management of patients with valvular heart disease: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (writing Committee to Revise the 1998 guidelines for the management of patients with valvular heart disease) developed in collaboration with the Society of Cardiovascular Anesthesiologists endorsed by the Society for Cardiovascular Angiography and Interventions and the Society of Thoracic Surgeons. J Am Coll Cardiol. 2006;48:e1–148. doi: 10.1016/j.jacc.2006.05.021.
- Bellenger NG, Burgess MI, Ray SG, Lahiri A, Coats AJ, Cleland JG, Pennell DJ. Comparison of left ventricular ejection fraction and volumes in heart failure by echocardiography, radionuclide ventriculography and cardiovascular magnetic resonance; are they interchangeable? Eur Heart J. 2000;21:1387–1396. doi: 10.1053/euhj.2000.2011.
- Myerson SG, Bellenger NG, Pennell DJ. Assessment of left ventricular mass by cardiovascular magnetic resonance. Hypertension. 2002;39:750–755. doi: 10.1161/hy0302.104674.
- Koch JA, Poll LW, Godehardt E, Korbmacher B, Modder U. Right and left ventricular volume measurements in an animal heart model in vitro: first experiences with cardiac MRI at 1.0 T. Eur Radiol. 2000;10:455–458. doi: 10.1007/s003300050075.
- Thiele H, Paetsch I, Schnackenburg B, Bornstedt A, Grebe O, Wellnhofer E, Schuler G, Fleck E, Nagel E. Improved accuracy of quantitative assessment of left ventricular volume and ejection fraction by geometric models with steady-state free precession. J Cardiovasc Magn Reson. 2002;4:327–339. doi: 10.1081/JCMR-120013298.
- Ichikawa Y, Sakuma H, Kitagawa K, Ishida N, Takeda K, Uemura S, Motoyasu M, Nakano T, Nozaki A. Evaluation of left ventricular volumes and ejection fraction using fast steady-state cine MR imaging: comparison with left ventricular angiography. J Cardiovasc Magn Reson. 2003;5:333–342. doi: 10.1081/JCMR-120019422.
- Myerson SG, Montgomery HE, World MJ, Pennell DJ. Left ventricular mass: reliability of M-mode and 2-dimensional echocardiographic formulas. Hypertension. 2002;40:673–678. doi: 10.1161/01.HYP.0000036401.99908.DB.
- Grothues F, Smith GC, Moon JC, Bellenger NG, Collins P, Klein HU, Pennell DJ. Comparison of interstudy reproducibility of cardiovascular magnetic resonance with two-dimensional echocardiography in normal subjects and in patients with heart failure or left ventricular hypertrophy. Am J Cardiol. 2002;90:29–34. doi: 10.1016/S0002-9149(02)02381-0.
- Cheitlin MD, Armstrong WF, Aurigemma GP, Beller GA, Bierman FZ, Davis JL, Douglas PS, Faxon DP, Gillam LD, Kimball TR, Kussmaul WG, Pearlman AS, Philbrick JT, Rakowski H, Thys DM, Antman EM, Smith SC Jr, Alpert JS, Gregoratos G, Anderson JL, Hiratzka LF, Faxon DP, Hunt SA, Fuster V, Jacobs AK, Gibbons RJ, Russell RO. ACC/AHA/ASE 2003 Guideline Update for the Clinical Application of Echocardiography: summary article. A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (ACC/AHA/ASE Committee to Update the 1997 Guidelines for the Clinical Application of Echocardiography) J Am Soc Echocardiogr. 2003;16:1091–1110.
- Globits S, Frank H, Mayr H, Neuhold A, Glogar D. Quantitative assessment of aortic regurgitation by magnetic resonance imaging. Eur Heart J. 1992;13:78–83.
- Gatehouse PD, Keegan J, Crowe LA, Masood S, Mohiaddin RH, Kreitner KF, Firmin DN. Applications of phase-contrast flow and velocity imaging in cardiovascular MRI. Eur Radiol. 2005;15:2172–2184. doi: 10.1007/s00330-005-2829-3.
- Kilner PJ, Gatehouse PD, Firmin DN. Flow measurement by magnetic resonance: a unique asset worth optimising. J Cardiovasc Magn Reson. 2007;9:723–728. doi: 10.1080/10976640701465090.
- Chatzimavroudis GP, Oshinski JN, Franch RH, Pettigrew RI, Walker PG, Yoganathan AP. Quantification of the aortic regurgitant volume with magnetic resonance phase velocity mapping: a clinical investigation of the importance of imaging slice location. J Heart Valve Dis. 1998;7:94–101.
- Hundley WG, Li HF, Hillis LD, Meshack BM, Lange RA, Willard JE, Landau C, Peshock RM. Quantitation of cardiac output with velocity-encoded, phase-difference magnetic resonance imaging. Am J Cardiol. 1995;75:1250–1255. doi: 10.1016/S0002-9149(99)80771-1.
- Sondergaard L, Lindvig K, Hildebrandt P, Thomsen C, Stahlberg F, Joen T, Henriksen O. Quantification of aortic regurgitation by magnetic resonance velocity mapping. Am Heart J. 1993;125:1081–1090. doi: 10.1016/0002-8703(93)90117-R.
- Sondergaard L, Thomsen C, Stahlberg F, Gymoese E, Lindvig K, Hildebrandt P, Henriksen O. Mitral and aortic valvular flow: quantification with MR phase mapping. J Magn Reson Imaging. 1992;2:295–302. doi: 10.1002/jmri.1880020308.
- O'Brien KR, Cowan BR, Jain M, Stewart RA, Kerr AJ, Young AA. MRI phase contrast velocity and flow errors in turbulent stenotic jets. J Magn Reson Imaging. 2008;28:210–218. doi: 10.1002/jmri.21395.
- Chernobelsky A, Shubayev O, Comeau CR, Wolff SD. Baseline correction of phase contrast images improves quantification of blood flow in the great vessels. J Cardiovasc Magn Reson. 2007;9:681–685. doi: 10.1080/10976640601187588.
- Miller TA, Landes AB, Moran AM. Improved accuracy in flow mapping of congenital heart disease using stationary phantom technique. J Cardiovasc Magn Reson. 2009;11:52. doi: 10.1186/1532-429X-11-52.
- Gatehouse PD, Rolf MP, Graves MJ, Hofman MB, Totman J, Werner B, Quest RA, Liu Y, von Spiczak J, Dieringer M, Firmin DN, van Rossum A, Lombardi M, Schwitter J, Schulz-Menger J, Kilner PJ. Flow measurement by cardiovascular magnetic resonance: a multi-centre multi-vendor study of background phase offset errors that can compromise the accuracy of derived regurgitant or shunt flow measurements. J Cardiovasc Magn Reson. 2010;12:5. doi: 10.1186/1532-429X-12-5.
- Firmin DN, Nayler GL, Kilner PJ, Longmore DB. The application of phase shifts in NMR for flow measurement. Magn Reson Med. 1990;14:230–241. doi: 10.1002/mrm.1910140209.
- Canstein C, Cachot P, Faust A, Stalder AF, Bock J, Frydrychowicz A, Kuffer J, Hennig J, Markl M. 3D MR flow analysis in realistic rapid-prototyping model systems of the thoracic aorta: comparison with in vivo data and computational fluid dynamics in identical vessel geometries. Magn Reson Med. 2008;59:535–546. doi: 10.1002/mrm.21331.
- Hope TA, Markl M, Wigstrom L, Alley MT, Miller DC, Herfkens RJ. Comparison of flow patterns in ascending aortic aneurysms and volunteers using four-dimensional magnetic resonance velocity mapping. J Magn Reson Imaging. 2007;26:1471–1479. doi: 10.1002/jmri.21082.
- Kramer CM, Barkhausen J, Flamm SD, Kim RJ, Nagel E. Standardized cardiovascular magnetic resonance imaging (CMR) protocols, society for cardiovascular magnetic resonance: board of trustees task force on standardized protocols. J Cardiovasc Magn Reson. 2008;10:35. doi: 10.1186/1532-429X-10-35.
- Reant P, Lederlin M, Lafitte S, Serri K, Montaudon M, Corneloup O, Roudaut R, Laurent F. Absolute assessment of aortic valve stenosis by planimetry using cardiovascular magnetic resonance imaging: comparison with transesophageal echocardiography, transthoracic echocardiography, and cardiac catheterisation. Eur J Radiol. 2006;59:276–283. doi: 10.1016/j.ejrad.2006.02.011.
- John AS, Dill T, Brandt RR, Rau M, Ricken W, Bachmann G, Hamm CW. Magnetic resonance to assess the aortic valve area in aortic stenosis: how does it compare to current diagnostic standards? J Am Coll Cardiol. 2003;42:519–526. doi: 10.1016/S0735-1097(03)00707-1.
- Tanaka K, Makaryus AN, Wolff SD. Correlation of aortic valve area obtained by the velocity-encoded phase contrast continuity method to direct planimetry using cardiovascular magnetic resonance. J Cardiovasc Magn Reson. 2007;9:799–805. doi: 10.1080/10976640701545479.
- Kilner PJ, Manzara CC, Mohiaddin RH, Pennell DJ, Sutton MG, Firmin DN, Underwood SR, Longmore DB. Magnetic resonance jet velocity mapping in mitral and aortic valve stenosis. Circulation. 1993;87:1239–1248.
- Sondergaard L, Hildebrandt P, Lindvig K, Thomsen C, Stahlberg F, Kassis E, Henriksen O. Valve area and cardiac output in aortic stenosis: quantification by magnetic resonance velocity mapping. Am Heart J. 1993;126:1156–1164. doi: 10.1016/0002-8703(93)90669-Z.
- Garcia J, Kadem L, Larose E, Clavel MA, Pibarot P. Comparison between cardiovascular magnetic resonance and transthoracic doppler echocardiography for the estimation of effective orifice area in aortic stenosis. J Cardiovasc Magn Reson. 2011;13:25. doi: 10.1186/1532-429X-13-25.
- Debl K, Djavidani B, Buchner S, Lipke C, Nitz W, Feuerbach S, Riegger G, Luchner A. Delayed hyperenhancement in magnetic resonance imaging of left ventricular hypertrophy caused by aortic stenosis and hypertrophic cardiomyopathy: visualisation of focal fibrosis. Heart. 2006;92:1447–1451. doi: 10.1136/hrt.2005.079392.
- Hein S, Arnon E, Kostin S, Schonburg M, Elsasser A, Polyakova V, Bauer EP, Klovekorn WP, Schaper J. Progression from compensated hypertrophy to failure in the pressure-overloaded human heart: structural deterioration and compensatory mechanisms. Circulation. 2003;107:984–991. doi: 10.1161/01.CIR.0000051865.66123.B7.
- Dweck MR, Joshi S, Murigu T, Gulati A, Alpendurado F, Mohiaddin R, Pepper JR, Pennell DJ, Newby D, Prasad S. Mid-wall fibrosis is an independent predictor of mortality in patients with aortic stenosis (abstr) Heart. 2011;97:A94.
- Dulce MC, Mostbeck GH, O'Sullivan M, Cheitlin M, Caputo GR, Higgins CB. Severity of aortic regurgitation: interstudy reproducibility of measurements with velocity-encoded cine MR imaging. Radiology. 1992;185:235–240.
- Honda N, Machida K, Hashimoto M, Mamiya T, Takahashi T, Kamano T, Kashimada A, Inoue Y, Tanaka S, Yoshimoto N. Aortic regurgitation: quantitation with MR imaging velocity mapping. Radiology. 1993;186:189–194.
- Kozerke S, Scheidegger MB, Pedersen EM, Boesiger P. Heart motion adapted cine phase-contrast flow measurements through the aortic valve. Magn Reson Med. 1999;42:970–978. doi: 10.1002/(SICI)1522-2594(199911)42:5<970::AID-MRM18>;2-I.
- Chatzimavroudis GP, Oshinski JN, Franch RH, Walker PG, Yoganathan AP, Pettigrew RI. Evaluation of the precision of magnetic resonance phase velocity mapping for blood flow measurements. J Cardiovasc Magn Reson. 2001;3:11–19. doi: 10.1081/JCMR-100000142.
- Myerson SG, D'Arcy J, Mohiaddin R, Greenwood JP, Karamitsos TD, Francis JM, Banning AP, Christiansen JP, Neubauer S. Aortic regurgitation quantification with cardiovascular magnetic resonance predicts clinical outcome. Heart. 2011;97:A93–94.
- Bonow RO. Aortic regurgitation: time to reassess timing of valve replacement? JACC Cardiovasc Imaging. 2011;4:231–233. doi: 10.1016/j.jcmg.2011.01.006.
- Underwood SR, Klipstein RH, Firmin DN, Fox KM, Poole-Wilson PA, Rees RS, Longmore DB. Magnetic resonance assessment of aortic and mitral regurgitation. Br Heart J. 1986;56:455–462. doi: 10.1136/hrt.56.5.455.
- Stork A, Franzen O, Ruschewski H, Detter C, Mullerleile K, Bansmann PM, Adam G, Lund GK. Assessment of functional anatomy of the mitral valve in patients with mitral regurgitation with cine magnetic resonance imaging: comparison with transesophageal echocardiography and surgical results. Eur Radiol. 2007;17:3189–3198. doi: 10.1007/s00330-007-0671-5.
- Chan KM, Wage R, Symmonds K, Rahman-Haley S, Mohiaddin RH, Firmin DN, Pepper JR, Pennell DJ, Kilner PJ. Towards comprehensive assessment of mitral regurgitation using cardiovascular magnetic resonance. J Cardiovasc Magn Reson. 2008;10:61. doi: 10.1186/1532-429X-10-61.
- Buchner S, Debl K, Poschenrieder F, Feuerbach S, Riegger G, Luchner A, Djavidani B. Cardiovascular Magnetic Resonance for Direct Assessment of Anatomic Regurgitant Orifice in Mitral Regurgitation. Circ Cardiovasc Imaging. 2008;1:148–155. doi: 10.1161/CIRCIMAGING.107.753103.
- Fujita N, Chazouilleres AF, Hartiala JJ, O'Sullivan M, Heidenreich P, Kaplan JD, Sakuma H, Foster E, Caputo GR, Higgins CB. Quantification of mitral regurgitation by velocity-encoded cine nuclear magnetic resonance imaging. J Am Coll Cardiol. 1994;23:951–958. doi: 10.1016/0735-1097(94)90642-4.
- Gelfand EV, Hughes S, Hauser TH, Yeon SB, Goepfert L, Kissinger KV, Rofsky NM, Manning WJ. Severity of mitral and aortic regurgitation as assessed by cardiovascular magnetic resonance: optimizing correlation with Doppler echocardiography. J Cardiovasc Magn Reson. 2006;8:503–507. doi: 10.1080/10976640600604856.
- Kon MW, Myerson SG, Moat NE, Pennell DJ. Quantification of regurgitant fraction in mitral regurgitation by cardiovascular magnetic resonance: comparison of techniques. J Heart Valve Dis. 2004;13:600–607.
- D'Arcy J, Christiansen JP, Mohiaddin R, Karamitsos TD, Francis JM, Neubauer S, Myerson SG. Prediction of clinical outcome in asymptomatic mitral regurgitation using CMR. European Society of Cardiology Congress; 27-31 Aug 2011; Paris. 2011.
- Enriquez-Sarano M, Avierinos JF, Messika-Zeitoun D, Detaint D, Capps M, Nkomo V, Scott C, Schaff HV, Tajik AJ. Quantitative determinants of the outcome of asymptomatic mitral regurgitation. N Engl J Med. 2005;352:875–883. doi: 10.1056/NEJMoa041451.
- Myerson SG, Francis JM, Neubauer S. Direct and indirect quantification of mitral regurgitation with cardiovascular magnetic resonance, and the effect of heart rate variability. MAGMA. 2010;23:243–249. doi: 10.1007/s10334-010-0222-y.
- Djavidani B, Debl K, Lenhart M, Seitz J, Paetzel C, Schmid FX, Nitz WR, Feuerbach S, Riegger G, Luchner A. Planimetry of mitral valve stenosis by magnetic resonance imaging. J Am Coll Cardiol. 2005;45:2048–2053. doi: 10.1016/j.jacc.2005.03.036.
- Lin SJ, Brown PA, Watkins MP, Williams TA, Lehr KA, Liu W, Lanza GM, Wickline SA, Caruthers SD. Quantification of stenotic mitral valve area with magnetic resonance imaging and comparison with Doppler ultrasound. J Am Coll Cardiol. 2004;44:133–137. doi: 10.1016/j.jacc.2004.03.038.
- Klein AL, Burstow DJ, Tajik AJ, Zachariah PK, Taliercio CP, Taylor CL, Bailey KR, Seward JB. Age-related prevalence of valvular regurgitation in normal subjects: a comprehensive color flow examination of 118 volunteers. J Am Soc Echocardiogr. 1990;3:54–63.
- Karamlou T, McCrindle BW, Williams WG. Surgery insight: late complications following repair of tetralogy of Fallot and related surgical strategies for management. Nat Clin Pract Cardiovasc Med. 2006;3:611–622. doi: 10.1038/ncpcardio0682.
- Rebergen SA, Chin JG, Ottenkamp J, van der Wall EE, de Roos A. Pulmonary regurgitation in the late postoperative follow-up of tetralogy of Fallot. Volumetric quantitation by nuclear magnetic resonance velocity mapping. Circulation. 1993;88:2257–2266.
- Geva T. Indications and timing of pulmonary valve replacement after tetralogy of Fallot repair. Semin Thorac Cardiovasc Surg Pediatr Card Surg Annu. 2006. pp. 11–22.
- Vliegen HW, van Straten A, de Roos A, Roest AA, Schoof PH, Zwinderman AH, Ottenkamp J, van der Wall EE, Hazekamp MG. Magnetic resonance imaging to assess the hemodynamic effects of pulmonary valve replacement in adults late after repair of tetralogy of fallot. Circulation. 2002;106:1703–1707. doi: 10.1161/01.CIR.0000030995.59403.F8.
- Li W, Davlouros PA, Kilner PJ, Pennell DJ, Gibson D, Henein MY, Gatzoulis MA. Doppler-echocardiographic assessment of pulmonary regurgitation in adults with repaired tetralogy of Fallot: comparison with cardiovascular magnetic resonance imaging. Am Heart J. 2004;147:165–172. doi: 10.1016/S0002-8703(03)00527-1.
- Ammash NM, Dearani JA, Burkhart HM, Connolly HM. Pulmonary regurgitation after tetralogy of Fallot repair: clinical features, sequelae, and timing of pulmonary valve replacement. Congenit Heart Dis. 2007;2:386–403. doi: 10.1111/j.1747-0803.2007.00131.x.
- Oosterhof T, van Straten A, Vliegen HW, Meijboom FJ, van Dijk AP, Spijkerboer AM, Bouma BJ, Zwinderman AH, Hazekamp MG, de Roos A, Mulder BJ. Preoperative thresholds for pulmonary valve replacement in patients with corrected tetralogy of Fallot using cardiovascular magnetic resonance. Circulation. 2007;116:545–551. doi: 10.1161/CIRCULATIONAHA.106.659664.
- Frigiola A, Redington AN, Cullen S, Vogel M. Pulmonary regurgitation is an important determinant of right ventricular contractile dysfunction in patients with surgically repaired tetralogy of Fallot. Circulation. 2004;110:II153–157.
- Lurz P, Coats L, Khambadkone S, Nordmeyer J, Boudjemline Y, Schievano S, Muthurangu V, Lee TY, Parenzan G, Derrick G, Cullen S, Walker F, Tsang V, Deanfield J, Taylor AM, Bonhoeffer P. Percutaneous pulmonary valve implantation: impact of evolving technology and learning curve on clinical outcome. Circulation. 2008;117:1964–1972. doi: 10.1161/CIRCULATIONAHA.107.735779.
- Schievano S, Coats L, Migliavacca F, Norman W, Frigiola A, Deanfield J, Bonhoeffer P, Taylor AM. Variations in right ventricular outflow tract morphology following repair of congenital heart disease: implications for percutaneous pulmonary valve implantation. J Cardiovasc Magn Reson. 2007;9:687–695. doi: 10.1080/10976640601187596.
- Kuehne T, Saeed M, Reddy G, Akbari H, Gleason K, Turner D, Teitel D, Moore P, Higgins CB. Sequential magnetic resonance monitoring of pulmonary flow with endovascular stents placed across the pulmonary valve in growing Swine. Circulation. 2001;104:2363–2368. doi: 10.1161/hc4401.098472.
- Mahle WT, Parks WJ, Fyfe DA, Sallee D. Tricuspid regurgitation in patients with repaired Tetralogy of Fallot and its relation to right ventricular dilatation. Am J Cardiol. 2003;92:643–645. doi: 10.1016/S0002-9149(03)00746-X.
- Rees S, Somerville J, Warnes C, Underwood R, Firmin D, Klipstein R, Longmore D. Comparison of magnetic resonance imaging with echocardiography and radionuclide angiography in assessing cardiac function and anatomy following Mustard's operation for transposition of the great arteries. Am J Cardiol. 1988;61:1316–1322. doi: 10.1016/0002-9149(88)91176-9.
- Choi YH, Park JH, Choe YH, Yoo SJ. MR imaging of Ebstein's anomaly of the tricuspid valve. AJR Am J Roentgenol. 1994;163:539–543.
- Eustace S, Kruskal JB, Hartnell GG. Ebstein's anomaly presenting in adulthood: the role of cine magnetic resonance imaging in diagnosis. Clin Radiol. 1994;49:690–692. doi: 10.1016/S0009-9260(05)82661-3.
- Shellock FG. MR imaging of metallic implants and materials: a compilation of the literature. AJR Am J Roentgenol. 1988;151:811–814.
- Shellock F. Reference Manual for Magnetic Resonance Safety, Implants and Devices. 2011. Los Angeles: Biomedical Research Publishing Group; 2011.
- Botnar R, Nagel E, Scheidegger MB, Pedersen EM, Hess O, Boesiger P. Assessment of prosthetic aortic valve performance by magnetic resonance velocity imaging. Magma. 2000;10:18–26. doi: 10.1007/BF02613108.
- Hasenkam JM, Ringgaard S, Houlind K, Botnar RM, Stodkilde-Jorgensen H, Boesiger P, Pedersen EM. Prosthetic heart valve evaluation by magnetic resonance imaging. Eur J Cardiothorac Surg. 1999;16:300–305. doi: 10.1016/S1010-7940(99)00215-8.
- von Knobelsdorff-Brenkenhoff F, Rudolph A, Wassmuth R, Bohl S, Buschmann EE, Abdel-Aty H, Dietz R, Schulz-Menger J. Feasibility of cardiovascular magnetic resonance to assess the orifice area of aortic bioprostheses. Circ Cardiovasc Imaging. 2009;2:397–404. doi: 10.1161/CIRCIMAGING.108.840967. 392 p following 404.
- Reiter G, Reiter U, Kovacs G, Kainz B, Schmidt K, Maier R, Olschewski H, Rienmueller R. Magnetic Resonance-Derived 3-Dimensional Blood Flow Patterns in the Main Pulmonary Artery as a Marker of Pulmonary Hypertension and a Measure of Elevated Mean Pulmonary Arterial Pressure. Circ Cardiovasc Imaging. 2008;1:23–30. doi: 10.1161/CIRCIMAGING.108.780247.
Source: PubMed