A structured report for assessment of Tetralogy of Fallot by Cardiac MRI according to recent guidelines Poster No.: C-0125 Congress: ECR 2016 Type: Educational Exhibit Authors: N. Stagnaro, G. Trocchio, F. Rizzo, M. Marasini, G. M. 1 2 1 3 1 1 2 1 3 Magnano, G. Festa ; Genova/IT, Genoa/IT, Massa/IT Keywords: Education and training, Congenital, Structured reporting, Education, Diagnostic procedure, RIS, MR-Angiography, MR, Pediatric, Cardiovascular system, Cardiac DOI: 10.1594/ecr2016/C-0125 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. www.myesr.org Page 1 of 14
Learning objectives To provide key points of a comprehensive protocol of MRI acquisition, evaluation and reporting for a uniform and reproducible exam in patients with Tetralogy of Fallot (TOF) according to recent guidelines. Background TOF, the most common congenital heart defect associated with cyanosis and pulmonary undercirculation, accounts for approximately 6%-10% of all cases of congenital heart disease. After undergoing surgical repair, patients commonly have a variable degree of pulmonary regurgitation. Over long-term follow-up, residual pulmonary stenosis, right ventricle outflow tract aneurysm, conduit obstruction, left ventricle dysfunction, right ventricular dilatation and dysfunction, atrial and ventricular arrhythmias, congestive heart failure, and sudden death may occur. Cardiovascular magnetic resonance (CMR) has emerged as an essential diagnostic tool in this patient population because it overcomes many of the limitations of echocardiography, cardiac CT, and cardiac catheterization, while also providing unique quantitative data as well as prognostic information. CMR is a difficult exam to perform due to non orthogonal plane orientations, complex anatomy, limited compliance of the patients. Standard exam acquisition, analysis and reporting are mandatory to reach the quality level required. Findings and procedure details PATIENT PREPARATION Attention to details of patient preparation and placement in the scanner are the base to build a successful exam. Page 2 of 14
The nurse staff keep the first contact with the patient. They have to record necessary parameters as arterious blood pressure, heart rate, oxygen saturation, height and weight. Patients should leave their personal belongings and wear proper clothing provided by the Hospital, in order to exclude any potential artifact from metal insert. Placement of ECG leads is showed in picture. Doctor or radiographer should spend the right time to explain in simple word what the patient is going to do, including some realistic notes about the experiences into the scanner (noise, repetead apnea, potential claustrophobia, potential heat sensation after contrast medium injection) and why the exam is performed. Consent form to contrast injection and exclusion to MR contraindications should be signed and properly stored by the supervising Doctor. After emptying the bladder the patient is ready to enter the scanner. MRI SCAN Scan protocol is showed in figure. Scan time depends on patient compliance, radiographer skills, technical optimization of the scanner, and is usually comprised between 40 minutes and 50 minutes. IMAGE ANALYSIS Quantification of right and left ventricular size and function and blood flow is performed using dedicated software available either from the manufacturers of MRI equipment or from third party vendors. Measurements of biventricular diastolic and systolic volumes and mass are performed on ECG-gated cine SSFP images, which provide a high contrast between the blood pool and the myocardium. Accurate determination of ventricular volume requires clear depiction of the blood-myocardial boundary. The left ventricular papillary muscles and the major trabeculations of the RV (e.g., septal band) are excluded from the blood pool and are considered part of the myocardium. Ventricular volume is then determined by summation of the volumes of all slices. The process can be repeated for each frame in the cardiac cycle to obtain a continuous time-volume loop or may be performed only on end-diastolic (maximal area) and end-systolic (minimal area) frames to calculate diastolic and systolic volumes. In patients with repaired TOF particular attention should be paid when determining the end-diastolic and end-systolic phases of each ventricle. Given that conduction delay is Page 3 of 14
nearly universal in this population, peak RV contraction typically lags after that of the LV by 1-3 cardiac phases. The technique for measuring blood flow is well established. PR fraction is calculated as retrograde flow volume divided by antegrade flow volume in the proximal MPA using ECG-gated, free-breathing cine phase contrast sequence obtained in the short-axis of the proximal MPA. The operator should adjust the imaging plane to avoid impingement on the MPA by metallic artifacts from sternal wires and implants. REPORT Main advantages of structured report are: create uniformity and improve communication with referring clinician enable physician practice to meet accreditation criteria support analysis for research and decision-support Key findings to report are: Vital parameters of the patient [body surface area, blood pressure, heart rate, O2 saturation]. Note about allergic reaction after contrast medium injection [Yes (describe), No] Anatomy of the RVOT and main branch pulmonary arteries with emphasis on obstruction and/or dilatation or aneurysm formation Biventricular size and function, global and regional [EDV indexed, ESV indexed, Stroke Volume, Ejection Fraction, Cardiac Output]. Right atrium size. Interventricular septum motion abnormalities Vessel morphology and dimensions: aortic root, ascending aorta, MPA, right and left pulmonary arteries Flow measurements of Aorta, MPA, RPA, LPA [Stroke Volume, Forward Flow]. Pulmonary valve regurgitation and other valve regurgitation [regurgitant fraction] Late gadolinium enhancement: presence, location, and extent. Associated anomalies: systemic and pulmonary veins, aortic arch sidedness and branching order Origin and proximal pathway of coronary arteries, and their spatial relationships to neighboring structures Comparison with previous MRI scans including re-measurement of the biventricular size and function by the same operator Page 4 of 14
Noncardiovascular findings Most representative images Images for this section: Fig. 2: MRI scan protocol Cardiac MRI Unit. Great Ormond Street Hospital. London (UK) Page 5 of 14
Fig. 1: Correct positioning of electrodes and wires (Philips scanner). Page 6 of 14
Radiologia, Istituto Giannina Gaslini, Istituto Giannina Gaslini - Genova/IT Fig. 4: 3D Volume Rendering: Few key images should be included in the report to improve the communication Radiologia, Istituto Giannina Gaslini, Istituto Giannina Gaslini - Genova/IT Page 7 of 14
Fig. 3: Cine short axis: RV trabeculations should be excluded from segmentation to avoid volume over estimation Radiologia, Istituto Giannina Gaslini, Istituto Giannina Gaslini - Genova/IT Page 8 of 14
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Fig. 5: Report Example. Gaslini Institute, Genova (IT). Radiologia, Istituto Giannina Gaslini, Istituto Giannina Gaslini - Genova/IT Page 10 of 14
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Fig. 6: Report Example. Gaslini Institute, Genova (IT). Radiologia, Istituto Giannina Gaslini, Istituto Giannina Gaslini - Genova/IT Page 12 of 14
Conclusion CMR has evolved during the last two decades as the reference imaging modality to assess the anatomic and functional sequelae in patients with repaired TOF. Reliable serial cardiac MR imaging data can help determine when to intervene to preserve ventricular function and improve long-term outcome. Standardized cardiac MRI exam and structured report are essential for producing highquality, effective images as well as reproducibile and comparable data. Personal information Dott. Nicola Stagnaro Radiology Unit Giannina Gaslini Institute, Genova nicolastagnaro@gaslini.org References Ventricular Fibrosis Suggested by Cardiovascular Magnetic Resonance in Adults With Repaired Tetralogy of Fallot and Its Relationship to Adverse Markers of Clinical Outcome. Sonya V. et al. Circulation 2006, 113:405-413 The Role of Cardiovascular Magnetic Resonance in Pediatric Congenital Heart Disease. Hopewell N Ntsinjana et al. Journal of Cardiovascular Magnetic Resonance 2011, 13:51 Effects of Regional Dysfunction and Late Gadolinium Enhancement on Global Right Ventricular Function and Exercise Capacity in Patients With Repaired Tetralogy of Fallot. Rachel M. Wald et al. Circulation. 2009 March 17 Page 13 of 14
Repaired tetralogy of Fallot: the roles of cardiovascular magnetic resonance in evaluating pathophysiology and for pulmonary valve replacement decision support. Tal Geva. Journal of Cardiovascular Magnetic Resonance 2011, 13:9 Multimodality Imaging Guidelines for Patients with Repaired Tetralogy of Fallot: A Report from the American Society of Echocardiography. Developed in Collaboration with the Society for Cardiovascular Magnetic Resonance and the Society for Pediatric Radiology. Anne Marie Valente et al. J Am Soc Echocardiogr 2014;27:111-41. Cardiac MR Imaging Assessment Following Tetralogy of Fallot Repair. Karen I. Norton et al. RadioGraphics 2006; 26:197-211 Cardiovascular MR Imaging in Neonates and Infants with Congenital Heart Disease. Christian J. Kellenberger et al. RadioGraphics 2007; 27:5-18 Assessment of cardiac function by magnetic resonance imaging. Fogel MA. Pediatr Cardiol 2000;21(1):59-6 Blood flow measurement by magnetic resonance imaging in congenital heart disease. Powell AJPediatr Cardiol 2000;21(1):47-58 Page 14 of 14