Non-compaction cardiomyopathy evaluated with CMR

Transcription

1 Non-compaction cardiomyopathy evaluated with CMR Poster No.: C-2265 Congress: ECR 2014 Type: Educational Exhibit Authors: R. G. Saru, M. Ouhlous, K. Caliskan, C. Tudisca, A Kono, M. M. Lubbers, T. Voogd, G. P. Krestin, K. Nieman ; ROTTERDAM/NL, Palermo/IT, Kobe/JP Keywords: Congenital, elearning, Education, MR, Cardiovascular system, Cardiac DOI: /ecr2014/C-2265 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. Page 1 of 30

2 Learning objectives After viewing this educational poster the reader should: 1. Have an overview of non-compaction cardiomyopathy (NCCM). 2. Be able to set-up a cardiac MR scan (CMR), including patient preparation, safety issues, acquisition protocol and post-processing images. 3. Know the CMR criteria used for confirming NCCM. 4. Identify the diagnostic pitfalls. 5. Evaluate MR cases that fulfill the criteria for NCCM. Background Non-compaction cardiomyopathy (NCCM) is a rare congenital cardiac disease characterized by a "spongy" appearance of the myocardium. The endocardial layer of the myocardium presents a prominent trabecular meshwork and deep intratrabecular 1 recesses. NCCM is a genetically heterogeneous disorder and may occur as a sporadic mutation or as a familial form. The main complications are heart failure, supra-ventricular or ventricular arrhythmias, thromboembolic events and sudden cardiac death. Management of patients of NCCM includes treatment for heart failure, arrhythmia prevention of embolic events. Excess trabecular structures occur also in normal general population and it is important that NCCM is not overdiagnosed. Cardiac MR is a non-invasive technique that provides information about the morphology and function of the heart (figure 1), viability and tissue characterization and the cardiac flow (figure 2), all in one investigation. Page 2 of 30

3 Images for this section: Fig. 1: Morphology and function evaluated with cardiac MR. Page 3 of 30

4 Fig. 2: Cardiac flow illustrated with CMR. Page 4 of 30

5 Findings and procedure details Technique The CINE imaging is acquired using balanced Steady-State Free Precession (SSPF) technique. It is a gradient sequence with bright blood which offers a high contrast between the blood and the surrounding tissues. It is suitable for morphological analysis and also 4 for the evaluation of the functional impact of myocardial disorder. For patients that are not able to hold their breath, it is possible to use the real-time cine imaging techniques. They are the faster versions of SSFP, usually require sacrifices in terms of temporal and spatial resolution. Acquisition parameters may vary with field strength, heart rate and other patient's characteristics. Our scan parameters are presented in Table 1. For low field strength, TR may be longer, but for high field strength TR has to be short (2.8 ms ms) in order to avoid the banding artefacts. Diagnostic pitfalls: The most common artefacts in cardiac MR are: Aliasing Metallic Respiration Triggering Flow Banding Aliasing occurs when a field of view smaller than the imaged area is selected (figure 3). They can be remediated by increasing or angulating the FOV, swapping phase and frequency direction or applying saturation pulses on the non-imaged anatomy outside the FOV, to reduce signal outside the area of interest. Metalartefacts are illustrated in figure 4. They are caused by presence of metal, such as clips used in surgery, sternal wires, and heart valves with metallic components. The local field distortion caused by metals typically is bigger than the size of the implant. The 5 artefact appears as a large signal void. Page 5 of 30

6 Respiration artefact are shown as "ghosting' the signal across the image in the phase encoding direction (figure 5). Triggering artefacts occur usually when the heart rate is not regular (figure 6). Banding artefacts (figure 7) are caused by field inhomogeneity, for which the field is 6 changing rapidly at the edges of the imaged volume. The remedy might be using the FIESTA-C sequence, but the aquisition time is longer. Flow artefacts (figure 8) are caused by turbulent flow that produces field inhomogeneity 7 and the SSPF sequence is very sensitive to that. It is important to recognize imaging artefacts, not to lead to misinterpretations. Safety issues The magnetic field is always on. The contraindications for CMR are the same for all MR scans and may be conditional or absolute. Absolute contraindications for MR are, for example, the pacemakers and the implanted defibrillators. The list of questions for screening the patient should include: feromagnetic objects or non-mr compatible implants, cardiac pacemaker, implanted cardiac defibrillator, neurostimulator, insulin pump, aneurysm clip, cochlear implant, heart valve prosthesis, artificial limb or joint Swan-Ganz catheter, IUD, tattoos, body piercing, claustrophobia, 4 claustrophobia. Patient preparation After filling in the screening form, if the patient doesn't have any contraindication, the MRI scan can be performed. ECG-compatible electrodes are placed on the patient chest as in figure 9. The respiration sensor is placed below. The position of the patient in the magnet is supine, feet-first. The phased array coil is placed over the chest of the patient. Headphones are provided. Before starting the scanning we have to be sure that emergency medication is available on site. Page 6 of 30

7 Acquisition planning The first step is to plan an axial and a coronal localizer. On the axial image you plan a 2chamber localizer, with a line through the apex and mitral valve (figure 10). On the 2 chamber localizer, you plan a short-axis localizer (figure11). After obtaining the short-axis localizer, plan on it with a line via the papillary muscles and the apex and in the same time on 2 chamber localizer the double-oblique 4 -chamber image (figure 12). Using the end-diastolic phase of the 4-chamber view and the short axis localizer, plan the double-oblique 2-chamber view (figure13). Using both the end-diastolic frame of the 2-chamber and 4-chamber, you plan the shortaxis for the whole heart, from the mitral valve through the apex (figure14). Three chamber view it is planned on the first image of the short axis and localizer coronal 8,11 (figure15). Post-processing Acquired images are analyzed on dedicated workstations. In order to evaluate ejection fraction end-systolic and end-diastolic endocardial contours must be identified, including in the blood pool the noncompacted area (figure 16) In order to evaluate NCCM using both Petersen and Stacey criteria we measure NC/C ratio on both end-systolic and end-diastolic on short-axis as well as on long-axis images (figure 17). NCCM criteria With echocardiographic studies NCCM is considered to be present when the ratio between noncompacted (NC) versus compacted (C) layer is higher than 2, measured end-systolic 12. However, echocardiographic views are operator dependent and off-axis views may affect the morphological assessment of myocardial trabeculations. CMR has become the imaging tool of choice because of its high spatial resolution and independence of acoustic windows. It diagnoses NCCM accurate and differentiates it from hypertrophic cardiomyopathy. Page 7 of 30

8 The criteria used nowadays for CMR are NC/C ratio >2.3 measured end-diastolic a ratio >2 measured end-systolic 10 9 or (figure 17). CMR may also play a role in detecting complications of NCCM, for example a left ventricle (LV) thrombus. A CMR report for NCCM should include LV volumes and function, RV volumes and function, name of the LV segments involved and the highest NC/C ratio and where it is localized. Our centre is reference center for NCCM. We present three cases to evaluate the CMR criteria for NCCM. Case 1 is a 40 years old female with recurrent non-sustained VT's and suspicion of NCCM at echocardiography. CMR is confirming the diagnosis and she had a prophylactic ICD implanted to prevent sudden cardiac death (figures 19, 20, 21 & 22). Case 2 is a 67 years old male who was referred for screening. The patient has no complains, but his brother died for sudden cardiac death. At CMR we identified has prominent hypertrabeculations but not enough to fulfill the CMR criteria for NCCM (figures 23, 24, 25 & 26). Case 3 is a 32 years old female with chronic heart failure. Her CMR examination was positive for NCCM (figures 27,28). She will be followed-up for possible complications. Images for this section: Page 8 of 30

9 Table 1: Scan parameters for CMR using SSFP sequence. Page 9 of 30

10 Fig. 1: Morphology and function evaluated with cardiac MR. Fig. 2: Cardiac flow illustrated with CMR. Page 10 of 30

11 Fig. 3: Aliasing artefact. Page 11 of 30

12 Fig. 4: Metal artefact due to post-surgical sternal wires. Page 12 of 30

13 Fig. 5: Respiration artefact. Page 13 of 30

14 Fig. 6: Triggering artefact Fig. 7: Banding artefact.the blue arrow indicates an a banding artefact, but also aliasing. Page 14 of 30

15 Fig. 8: Flow artefact due to SSFP sequence. Fig. 9: ECG-compatible electrodes are placed on patient chest in a "LL shape or in a square shape. Page 15 of 30

16 Fig. 10: Planning the 2 chamber localizer. Page 16 of 30

17 Fig. 11: Planning the short-axis localizer. Page 17 of 30

18 Fig. 12: Double-oblique 4-chamber images. Page 18 of 30

19 Fig. 13: 2-chamber double-oblique images. Page 19 of 30

20 Fig. 14: Short-axis double-oblique images. Page 20 of 30

21 Fig. 15: 3-chamber double-oblique images. Page 21 of 30

22 Fig. 16: End-systolic and end-diastolic endocardial contours must be identified to calculate ejection fraction. Fig. 17: NC/C ratio measured mid-ventricular end-systolic and end-diastolic on 4chamber view. Page 22 of 30

23 Fig. 18: NC/C ratio measured end-systolic and end-diastolic mid-ventricular on shortaxis view. Fig. 19: Case 1: 2-chamber view in a patient with NCCM. Page 23 of 30

24 Fig. 20: Case 1: 3-chamber view in a patient with NCCM. Fig. 21: Case 1:4-chamber view in a patient with NCCM. Page 24 of 30

25 Fig. 22: Case 1: Short-axis view in a patient with NCCM. Fig. 23: Case 2: patient with prominent trabeculations, but does not fulfill the CMR criteria for NCCM - 2 chamber view. Page 25 of 30

26 Fig. 24: Case 2: 3-chamber view. Fig. 25: Case 2: NC/C ratio measured both end-systolic and end-diastolic on 4-chamber view have not fulfilled the CMR criteria for NCCM. Page 26 of 30

27 Fig. 26: Case 2: Measurement of the NC/C ratio, end-diastolic and end-systolic on shortaxis view does not fulfill the CMR criteria for NCCM. Page 27 of 30

28 Fig. 27: Case 3: 2-chamber view. Fig. 28: Case 3: 4-chamber view in a patient that have fulfilled the CMR criteria for NCCM. Page 28 of 30

29 Conclusion Due to its ability to assess all the segments of the heart and due to its high spatial and temporal resolution, CMR is the "state of the art" imaging modality for NCCM and plays an important role in patient management. Images for this section: Fig. 29: CMR illustrates noncompacted layer of the myocardium and plays an important role in patient management. Page 29 of 30

30 Personal information References 1 Gaetano Nucifora, Giovanni D. Aquaro, Alessandro Pingitore et al, Myocardial fibrosis in isolated left ventricular non-compaction and its relation to disease severity. 2 Erwin Oechslin, d Rolf Jenni, Left ventricular non-compaction revisited: a distinct phenotype with genetic heterogeneity? 3 Bas van Dalen, Kadir Caliskan, Osama I Soliman et al, Diagnostic value of rigid body rotation in Noncompaction Cardiomyopathy. 4 Raymond Kwong, Cardiovascular Magnetic resonance imaging. 5 Sven Plein, John Greenwood, Jojn Ridgway, Cardiovascular manual. 6 Gary Liney, MRI from A to Z. 7 A.L.Baert, M. Knauth, K. Sartor, Parallel Imaging in Clinical MR Applications. 8 Charles Higgins, Albert de Roos, MRI and CT of the Cardiovascular System. 9 Steffen E. Petersen, Joseph B. Selvanayagam, Frank Wiesmann et al, Left Ventricular Non-Compaction Insights From Cardiovascular Magnetic Resonance Imaging. 10 R. Brandon Stacey, Mousumi M. Andersen, Mitchell St. Clair et al, Comparison of Systolic and Diastolic Criteria for Isolated LV Noncompaction in CMR. 11 Warren j Manning, Dudley J. Pennell, Cardiovascular Magnetic Resonance. 12 R Jenni, E N Oechslin, B van der Loo, Isolated ventricular non-compaction of the myocardium in adults. Page 30 of 30