J o u r n a l o f C a r d i o v a s c u l a r C o m p u t e d T o m o g r a p h y 8 ( 2 0 1 4 ) 3 2 3 e3 2 7
Available online at www.sciencedirect.com
ScienceDirect journal homepage: www.JournalofCardiovascularCT.com
Practical Tips and Tricks
Practical tips and tricks for assessing prosthetic valves and detecting paravalvular regurgitation using cardiac CT Ailbhe C. O’Neill MDa, Ramon Martos MDb, Gillian Murtagh MDb, Edmund Ronan Ryan MDa, Charles McCreery MDb, David Keane MDb, Martin Quinn MDb, Jonathan D. Dodd MDa,* a b
Cardiac CT/MRI Program, Department of Radiology, St. Vincent’s University Hospital, Dublin, Ireland Cardiac CT/MRI Program, Department of Cardiology, St. Vincent’s University Hospital, Dublin, Ireland
article info
abstract
Article history:
Paravalvular leaks are an uncommon but serious complication of prosthetic valves.
Received 25 March 2013
Transthoracic echocardiography is used in the assessment of prosthetic valves but can be
Received in revised form
limited by acoustic shadowing from the prosthesis and poor acoustic windowing. Small
21 June 2014
case series have previously shown cardiac CT to have promising results in detecting par-
Accepted 1 July 2014
avalvular leaks. We assessed 32 valves in our institution on cardiac CT using echocardiography results as standard and developed methods for improved evaluation of prosthetic valves. These include optimizing prescan drug therapy for heart rate control, optimum
keywords:
window and center adjustments, and carefully selected image planes to best demonstrate
Prosthetic valve
the valve ring and valve annulus. Recognition of surgical material is also important to
Paravalvular leak
recognize. In this review, we provide a detailed description of these techniques with im-
Cardiac CT
aging examples of prosthetic valve evaluation using cardiac CT.
Transthoracic echocardiography
1.
ª 2014 Society of Cardiovascular Computed Tomography. All rights reserved.
Introduction
Prosthetic valve surgery is an important part of treatment for valve dysfunction.1 Paravalvular leaks are an uncommon complication occurring in 60 beats/min after 1 hour, we give a repeat dose of 100 mg of metoprolol and scan an hour later.
4.
Fig. 4 e A 52-year-old woman with a carbomechanics number 21 mitral valve. Atrial contraction has caused motion artifact in the region of the valve, causing appearances mimicking a paravalvular leak on the left atrioventricular groove side. Echocardiography was entirely negative for paravalvular leak in this case. Paravalvular leaks are generally better evaluated when the valve leaflets are closed.
Assessment of the valve ring
Evaluation of the valve ring on an axial oblique image plane that passes precisely across the ring in 2 orthogonal image planes results in the optimum method for paravalvular leak detection. By placing the fulcrum of the reformat lines in the center of the valve prosthesis on 2 orthogonal imaging planes, and then rotating the axial oblique reformat around the valve ring, the junction between the ring and the annulus can be seen for the entire ring circumference (Fig. 5). Evaluating prosthetic valves on sagittal and coronal image planes alone are problematic because the leak may be crescentic shaped and located along the image plane, making detection difficult. Using a true axial double-oblique reformat also allows measurement of the true regurgitant orifice area, which has been shown to correlate well with echocardiographic measurements.12 Readers wishing to learn more about the technique are referred to Figure 4 in the authoritative Society of Cardiovascular Computed Tomography review on Society of Cardiovascular Computed Tomography expert consensus document on CT imaging before transcatheter aortic valve implantation or transcatheter aortic valve replacement.13
326
J o u r n a l o f C a r d i o v a s c u l a r C o m p u t e d T o m o g r a p h y 8 ( 2 0 1 4 ) 3 2 3 e3 2 7
Fig. 5 e (AeC) A 33-year-old man with a tissue aortic valve replacement. Placing the rotation lines (curved arrows) on the center of the prosthetic valve in 2 orthogonal planes allows rotation around the axial oblique reformat, optimizing visualization of the paravalvular leaks (straight arrow). (D) Image in the same patient with realignment of the orthogonal planes in a double-oblique image plane confirms a large paravalvular leak.
5.
Surgical material
Awareness of surgical pledget material is important and it should be interrogated carefully. It generally appears as an
ill-defined triangular high-density area adjacent to the valve ring (Fig. 6). It may be very thin and should not be interpreted as insufficiently thick to prevent paravalvular leak. This led to one overcall of a paravalvular leak case in our cohort. As
Fig. 6 e (A) A 49-year-old man with a prosthetic mitral valve. Note the wedge-shaped triangular pledget of suture material (arrow) characteristically seen around the valve annulus. (B) A 52-year-old woman with a St. Jude aortic valve replacement. Cardiac CT was misinterpreted as positive for a paravalvular leak because of the thinness of the suture material (arrow) and open channel below it. Subsequent transthoracic followed by transesophageal echocardiography revealed no paravalvular leak.
J o u r n a l o f C a r d i o v a s c u l a r C o m p u t e d T o m o g r a p h y 8 ( 2 0 1 4 ) 3 2 3 e3 2 7
percutaneous closure devices become increasingly used to treat paravalvular leaks, familiarity with their appearances will also be important in image interpretation.14 Measuring the pledget material density on CT can also assist in differentiating it from paravalvular leaks as it is typically higher than contrast-enhanced blood.15
5.
6.
7.
6.
Conclusion
Cardiac CT is a useful adjunctive investigation to echocardiography for the evaluation of paravalvular leaks in prosthetic heart valves. Careful attention to cardiac CT technique, achieving prescan target heart rates, extensive windowing adjustments, and awareness of normal postoperative paravalvular structures can help confirm or exclude paravalvular leaks in most cases.
8.
9.
10.
references 11. 1. Bonow RO, Carabello BA, Chatterjee K, et al. 2008 focused update incorporated into the 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). Endorsed by the Society of Cardiovascular Anesthesiologists, Society for Cardiovascular Angiography and Interventions, and Society of Thoracic Surgeons. Circulation. 2008;118(15):e523e661. 2. Pibarot P, Dumesnil JG. Prosthetic heart valves: selection of the optimal prosthesis and long-term management. Circulation. 2009;119(7):1034e1048. 3. Akins CW, Bitondo JM, Hilgenberg AD, Vlahakes GJ, Madsen JC, MacGillivray TE. Early and late results of the surgical correction of cardiac prosthetic paravalvular leaks. J Heart Valve Dis. 2005;14(6):792e799. discussion 799e800. 4. Tsai IC, Lin YK, Chang Y, et al. Correctness of multi-detectorrow computed tomography for diagnosing mechanical
12.
13.
14.
15.
327
prosthetic heart valve disorders using operative findings as a gold standard. Eur Radiol. 2009;19(4):857e867. Hara M, Nishino M, Taniike M, et al. Impact of 64 multidetector computed tomography for the evaluation of aortic paraprosthetic regurgitation. J Cardiol. 2011;58(3):294e299. Kim RJ, Weinsaft JW, Callister TQ, Min JK. Evaluation of prosthetic valve endocarditis by 64-row multidetector computed tomography. Int J Cardiol. 2007;120(2):e27ee29. Konen E, Goitein O, Feinberg MS, et al. The role of ECG-gated MDCT in the evaluation of aortic and mitral mechanical valves: initial experience. AJR Am J Roentgenol. 2008;191(1):26e31. Teshima H, Hayashida N, Fukunaga S, et al. Usefulness of a multidetector-row computed tomography scanner for detecting pannus formation. Ann Thorac Surg. 2004;77(2):523e526. Habets J, Symersky P, van Herwerden LA, et al. Prosthetic heart valve assessment with multidetector-row CT: imaging characteristics of 91 valves in 83 patients. Eur Radiol. 2011;21(7):1390e1396. Sucha´ D, Willemink MJ, de Jong PA, et al. The impact of a new model-based iterative reconstruction algorithm on prosthetic heart valve related artifacts at reduced radiation dose MDCT. Int J Cardiovasc Imaging. 2014;30(4):785e793. Symersky P, Budde RPJ, Westers P, de Mol BAJM, Prokop M. Multidetector CT imaging of mechanical prosthetic heart valves: quantification of artifacts with a pulsatile in-vitro model. Eur Radiol. 2011;21(10):2103e2110. Symersky P, Budde RPJ, de Mol BAJM, Prokop M. Comparison of multidetector-row computed tomography to echocardiography and fluoroscopy for evaluation of patients with mechanical prosthetic valve obstruction. Am J Cardiol. 2009;104(8):1128e1134. Achenbach S, Delgado V, Hausleiter J, Schoenhagen P, Min JK, Leipsic JA. SCCT expert consensus document on computed tomography imaging before transcatheter aortic valve implantation (TAVI)/transcatheter aortic valve replacement (TAVR). J Cardiovasc Comput Tomogr. 2012;6:366e380. Hein R, Wunderlich N, Wilson N, Sievert H. New concepts in transcatheter closure of paravalvular leaks. Future Cardiol. 2008;4(4):373e378. Habets J, Meijer TS, Meijer RCA, Mali WPTM, Vonken E-JPA, Budde RPJ. CT attenuation measurements are valuable to discriminate pledgets used in prosthetic heart valve implantation from paravalvular leakage. Br J Radiol. 2012;85(1017):e616ee621.
Available online at www.sciencedirect.com
ScienceDirect journal homepage: www.JournalofCardiovascularCT.com
Practical Tips and Tricks
Practical tips and tricks for assessing prosthetic valves and detecting paravalvular regurgitation using cardiac CT Ailbhe C. O’Neill MDa, Ramon Martos MDb, Gillian Murtagh MDb, Edmund Ronan Ryan MDa, Charles McCreery MDb, David Keane MDb, Martin Quinn MDb, Jonathan D. Dodd MDa,* a b
Cardiac CT/MRI Program, Department of Radiology, St. Vincent’s University Hospital, Dublin, Ireland Cardiac CT/MRI Program, Department of Cardiology, St. Vincent’s University Hospital, Dublin, Ireland
article info
abstract
Article history:
Paravalvular leaks are an uncommon but serious complication of prosthetic valves.
Received 25 March 2013
Transthoracic echocardiography is used in the assessment of prosthetic valves but can be
Received in revised form
limited by acoustic shadowing from the prosthesis and poor acoustic windowing. Small
21 June 2014
case series have previously shown cardiac CT to have promising results in detecting par-
Accepted 1 July 2014
avalvular leaks. We assessed 32 valves in our institution on cardiac CT using echocardiography results as standard and developed methods for improved evaluation of prosthetic valves. These include optimizing prescan drug therapy for heart rate control, optimum
keywords:
window and center adjustments, and carefully selected image planes to best demonstrate
Prosthetic valve
the valve ring and valve annulus. Recognition of surgical material is also important to
Paravalvular leak
recognize. In this review, we provide a detailed description of these techniques with im-
Cardiac CT
aging examples of prosthetic valve evaluation using cardiac CT.
Transthoracic echocardiography
1.
ª 2014 Society of Cardiovascular Computed Tomography. All rights reserved.
Introduction
Prosthetic valve surgery is an important part of treatment for valve dysfunction.1 Paravalvular leaks are an uncommon complication occurring in 60 beats/min after 1 hour, we give a repeat dose of 100 mg of metoprolol and scan an hour later.
4.
Fig. 4 e A 52-year-old woman with a carbomechanics number 21 mitral valve. Atrial contraction has caused motion artifact in the region of the valve, causing appearances mimicking a paravalvular leak on the left atrioventricular groove side. Echocardiography was entirely negative for paravalvular leak in this case. Paravalvular leaks are generally better evaluated when the valve leaflets are closed.
Assessment of the valve ring
Evaluation of the valve ring on an axial oblique image plane that passes precisely across the ring in 2 orthogonal image planes results in the optimum method for paravalvular leak detection. By placing the fulcrum of the reformat lines in the center of the valve prosthesis on 2 orthogonal imaging planes, and then rotating the axial oblique reformat around the valve ring, the junction between the ring and the annulus can be seen for the entire ring circumference (Fig. 5). Evaluating prosthetic valves on sagittal and coronal image planes alone are problematic because the leak may be crescentic shaped and located along the image plane, making detection difficult. Using a true axial double-oblique reformat also allows measurement of the true regurgitant orifice area, which has been shown to correlate well with echocardiographic measurements.12 Readers wishing to learn more about the technique are referred to Figure 4 in the authoritative Society of Cardiovascular Computed Tomography review on Society of Cardiovascular Computed Tomography expert consensus document on CT imaging before transcatheter aortic valve implantation or transcatheter aortic valve replacement.13
326
J o u r n a l o f C a r d i o v a s c u l a r C o m p u t e d T o m o g r a p h y 8 ( 2 0 1 4 ) 3 2 3 e3 2 7
Fig. 5 e (AeC) A 33-year-old man with a tissue aortic valve replacement. Placing the rotation lines (curved arrows) on the center of the prosthetic valve in 2 orthogonal planes allows rotation around the axial oblique reformat, optimizing visualization of the paravalvular leaks (straight arrow). (D) Image in the same patient with realignment of the orthogonal planes in a double-oblique image plane confirms a large paravalvular leak.
5.
Surgical material
Awareness of surgical pledget material is important and it should be interrogated carefully. It generally appears as an
ill-defined triangular high-density area adjacent to the valve ring (Fig. 6). It may be very thin and should not be interpreted as insufficiently thick to prevent paravalvular leak. This led to one overcall of a paravalvular leak case in our cohort. As
Fig. 6 e (A) A 49-year-old man with a prosthetic mitral valve. Note the wedge-shaped triangular pledget of suture material (arrow) characteristically seen around the valve annulus. (B) A 52-year-old woman with a St. Jude aortic valve replacement. Cardiac CT was misinterpreted as positive for a paravalvular leak because of the thinness of the suture material (arrow) and open channel below it. Subsequent transthoracic followed by transesophageal echocardiography revealed no paravalvular leak.
J o u r n a l o f C a r d i o v a s c u l a r C o m p u t e d T o m o g r a p h y 8 ( 2 0 1 4 ) 3 2 3 e3 2 7
percutaneous closure devices become increasingly used to treat paravalvular leaks, familiarity with their appearances will also be important in image interpretation.14 Measuring the pledget material density on CT can also assist in differentiating it from paravalvular leaks as it is typically higher than contrast-enhanced blood.15
5.
6.
7.
6.
Conclusion
Cardiac CT is a useful adjunctive investigation to echocardiography for the evaluation of paravalvular leaks in prosthetic heart valves. Careful attention to cardiac CT technique, achieving prescan target heart rates, extensive windowing adjustments, and awareness of normal postoperative paravalvular structures can help confirm or exclude paravalvular leaks in most cases.
8.
9.
10.
references 11. 1. Bonow RO, Carabello BA, Chatterjee K, et al. 2008 focused update incorporated into the 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). Endorsed by the Society of Cardiovascular Anesthesiologists, Society for Cardiovascular Angiography and Interventions, and Society of Thoracic Surgeons. Circulation. 2008;118(15):e523e661. 2. Pibarot P, Dumesnil JG. Prosthetic heart valves: selection of the optimal prosthesis and long-term management. Circulation. 2009;119(7):1034e1048. 3. Akins CW, Bitondo JM, Hilgenberg AD, Vlahakes GJ, Madsen JC, MacGillivray TE. Early and late results of the surgical correction of cardiac prosthetic paravalvular leaks. J Heart Valve Dis. 2005;14(6):792e799. discussion 799e800. 4. Tsai IC, Lin YK, Chang Y, et al. Correctness of multi-detectorrow computed tomography for diagnosing mechanical
12.
13.
14.
15.
327
prosthetic heart valve disorders using operative findings as a gold standard. Eur Radiol. 2009;19(4):857e867. Hara M, Nishino M, Taniike M, et al. Impact of 64 multidetector computed tomography for the evaluation of aortic paraprosthetic regurgitation. J Cardiol. 2011;58(3):294e299. Kim RJ, Weinsaft JW, Callister TQ, Min JK. Evaluation of prosthetic valve endocarditis by 64-row multidetector computed tomography. Int J Cardiol. 2007;120(2):e27ee29. Konen E, Goitein O, Feinberg MS, et al. The role of ECG-gated MDCT in the evaluation of aortic and mitral mechanical valves: initial experience. AJR Am J Roentgenol. 2008;191(1):26e31. Teshima H, Hayashida N, Fukunaga S, et al. Usefulness of a multidetector-row computed tomography scanner for detecting pannus formation. Ann Thorac Surg. 2004;77(2):523e526. Habets J, Symersky P, van Herwerden LA, et al. Prosthetic heart valve assessment with multidetector-row CT: imaging characteristics of 91 valves in 83 patients. Eur Radiol. 2011;21(7):1390e1396. Sucha´ D, Willemink MJ, de Jong PA, et al. The impact of a new model-based iterative reconstruction algorithm on prosthetic heart valve related artifacts at reduced radiation dose MDCT. Int J Cardiovasc Imaging. 2014;30(4):785e793. Symersky P, Budde RPJ, Westers P, de Mol BAJM, Prokop M. Multidetector CT imaging of mechanical prosthetic heart valves: quantification of artifacts with a pulsatile in-vitro model. Eur Radiol. 2011;21(10):2103e2110. Symersky P, Budde RPJ, de Mol BAJM, Prokop M. Comparison of multidetector-row computed tomography to echocardiography and fluoroscopy for evaluation of patients with mechanical prosthetic valve obstruction. Am J Cardiol. 2009;104(8):1128e1134. Achenbach S, Delgado V, Hausleiter J, Schoenhagen P, Min JK, Leipsic JA. SCCT expert consensus document on computed tomography imaging before transcatheter aortic valve implantation (TAVI)/transcatheter aortic valve replacement (TAVR). J Cardiovasc Comput Tomogr. 2012;6:366e380. Hein R, Wunderlich N, Wilson N, Sievert H. New concepts in transcatheter closure of paravalvular leaks. Future Cardiol. 2008;4(4):373e378. Habets J, Meijer TS, Meijer RCA, Mali WPTM, Vonken E-JPA, Budde RPJ. CT attenuation measurements are valuable to discriminate pledgets used in prosthetic heart valve implantation from paravalvular leakage. Br J Radiol. 2012;85(1017):e616ee621.
