CT 和MRI (英文版)

Cardiovascular MRI in Congenital Heart Disease An Imaging Atlas Shankar Sridharan · Gemma Price Oliver Tann · Marina Hughes · Vivek Muthurangu Andrew M. Taylor Cardiovascular MRI in Congenital Heart Disease An Imaging Atlas 13 From: The Centre for Cardiovascular MR UCL Institute of Child Health & Great Ormond Street Hospital for Children Cardiovascular Unit Great Ormond Street London WC1N 3JH UK Dr. Shankar Sridharan Locum Consultant Paediatric Cardiologist Gemma Price Medical Illustrator Dr. Oliver Tann Consultant In Cardiovascular Imaging Dr. Marina Hughes Consultant Paediatric Cardiologist Clinical Lead for CMR Dr. Vivek Muthurangu BHF Intermediate Research Fellow Professor Andrew M. Taylor Professor of Cardiovascular Imaging Director – Centre for Cardiovascular MR ISBN 978-3-540-69836-4 eISBN 978-3-540-69837-1 DOI 10.1007/978-3-540-69837-1 Springer Heidelberg Dordrecht London New York Library of Congress Control Number: 2009938029 © Springer-Verlag Berlin Heidelberg 2010 This work is subject to copyright. All rights are reserved, whether the whole or part of the material is concerned, specifi cally the rights of translation, reprinting, reuse of illustrations, recitations, broadcasting, reproduction on microfi lm or in any other way, and storage in data banks. Duplication of this publication or parts thereof is per mitted only under the provisions of the German Copyright Law of September 9, 1965, in its current version, and permission for use must always be obtained from Springer-Verlag. Violations are liable for prosecution under the German Copyright Law. The use of general descriptive names, trademarks, etc. in this publication does not imply, even in the absence of a specifi c statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. Product liability: The publishers cannot guarantee the accuracy of any information about dosage and application contained in this book. In every individual case the user must check such information by consulting the relevant literature. Cover design: eStudio Calamar Figueres Berlin Printed on acid-free paper 9876543210 springer.com V Preface The last 10 years has seen explosive expansion of the number of centres performing cardiovas- cular magnetic resonance (CMR) imaging. The majority of this expansion has been in the field of adult ischaemic imaging, but congenital heart disease remains one of the main indications for CMR. Importantly, the greatly improved survival of patients with congenital heart disease gives us a burgeoning adult population living with the sequelae of the disease (grown-up con- genital heart disease – GUCH). Without previous experience or formal training, the interpretation of CMR images of patients with congenital heart disease can be difficult. The main aim of this book is to create a portable resource that offers efficient access to high-quality MR (and where appropriate, CT) images of the common congenital and structural heart abnormalities. We hope that by provid- ing key images for each condition and a clear interpretation of the MR appearances, we will improve the reader’s understanding of the conditions, facilitate their interpretation of images and optimise the planning of the imaging protocols during their own practice of congenital CMR. As with any publication from a single institution, the contents of this book represent our own practice. We have not written a definitive or exhaustive description of the conditions. However, we hope that we have produced a factual, simple and eye-pleasing guide for fellows training in CMR, radiographers and technicians performing CMR scans, physician users of CMR, and perhaps those few in adult ischaemic practice, who may need the occasional aide memoir for incidental findings! We hope that you will find this book useful in your everyday practice and learning. Shankar Sridharan Gemma Price Oliver Tann Marina Hughes Vivek Muthurangu London, UK Andrew Taylor VII Contents 1 2 3 4 5 6 7 8 Technical Considerations. . . . . . . . . . . . . . . . . . . MR Imaging Under GA. . . . . . . . . . . . . . . . . . . . Imaging Protocol . . . . . . . . . . . . . . . . . . . . . . . . . Normal Anatomy-Axial. . . . . . . . . . . . . . . . . . . . Normal Anatomy-Coronal. . . . . . . . . . . . . . . . . . Normal Anatomy-Sagittal . . . . . . . . . . . . . . . . . . Image Planes-Ventricles . . . . . . . . . . . . . . . . . . . Imaging Planes- Left Ventricular Outflow Tract . . . . . . . . . . . . . . 1 2 3 6 8 10 12 14 32 Tetralogy of Fallot: Repaired. . . . . . . . . . . . . . . . 78 33 Pulmonary Stenosis . . . . . . . . . . . . . . . . . . . . . . . 84 34 Percutaneous Pulmonary Valve Implantation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 35 Pulmonary Atresia and VSD . . . . . . . . . . . . . . . . 90 36 Transposition of the Great Arteries: Arterial Switch Operation . . . . . . . . . . . . . . . . . . 92 37 Transposition of the Great Arteries: Senning and Mustard Repair . . . . . . . . . . . . . . . . 96 9 Imaging Planes- 38 TGA with VSD and PS . . . . . . . . . . . . . . . . . . . . 100 Right Ventricular Outflow Tract . . . . . . . . . . . . . 10a Imaging Planes-Branch PAs . . . . . . . . . . . . . . . . 10b Imaging Planes-Thoracic Aorta. . . . . . . . . . . . . . 11a Imaging Planes-Tricuspid Value . . . . . . . . . . . . . 11b Imaging Planes-Mitral Value . . . . . . . . . . . . . . . . 12 Imaging Planes-Coronary Arteries . . . . . . . . . . . 13 Atrial Septal Defect . . . . . . . . . . . . . . . . . . . . . . . 14 Sinus Venosus Defect . . . . . . . . . . . . . . . . . . . . . 15 Atrioventricular Septal Defect. . . . . . . . . . . . . . . 16 Ventricular Septal Defect. . . . . . . . . . . . . . . . . . . 17 Aortic Valve Stenosis. . . . . . . . . . . . . . . . . . . . . . 18 Aortic Valve Incompetence . . . . . . . . . . . . . . . . . 19 Coarctation of the Aorta . . . . . . . . . . . . . . . . . . . 20 Repaired Coarctation of the Aorta: Complications . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 Interrupted Aortic Arch . . . . . . . . . . . . . . . . . . . . 22 Aortic Vascular Rings . . . . . . . . . . . . . . . . . . . . . 23 Left Pulmonary Artery Sling . . . . . . . . . . . . . . . . 24 Marfan Syndrome . . . . . . . . . . . . . . . . . . . . . . . . 25 Williams Syndrome . . . . . . . . . . . . . . . . . . . . . . . 26 Mitral Stenosis. . . . . . . . . . . . . . . . . . . . . . . . . . . 27 Mitral Regurgitation . . . . . . . . . . . . . . . . . . . . . . 28 Hypertrophic Cardiomyopathy . . . . . . . . . . . . . . 29 Dilated Cardiomypathy . . . . . . . . . . . . . . . . . . . . 30 Noncompaction Cardiomyopathy . . . . . . . . . . . . 31 Tetralogy of Fallot . . . . . . . . . . . . . . . . . . . . . . . . 16 18 19 20 21 22 24 26 28 32 36 40 42 46 48 50 54 56 58 62 64 66 70 72 74 39 Congenitally Corrected Transposition of the Great Arteries . . . . . . . . . . . . . . . . . . . . . . 104 40 Common Arterial Trunk . . . . . . . . . . . . . . . . . . . 108 41 Double Outlet Right Ventricle . . . . . . . . . . . . . . . 112 42 Double Inlet Left Ventricle . . . . . . . . . . . . . . . . . 116 43 Hypoplastic Left Heart Syndrome: Norwood Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . 118 44 Bi-directional Cavo-pulmonary (Glenn) shunt . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122 45 Fontan-Type Circulation (Tricuspid Atresia). . . . . . . . . . . . . . . . . . . . . . . . 126 46 Total Cavo-pulmonary Connection . . . . . . . . . . . 130 47 Anomalous Coronary Arteries. . . . . . . . . . . . . . . 134 48 Anomalous Left Coronary Artery from Pulmonary Artery . . . . . . . . . . . . . . . . . . . . 138 49 Kawasaki Disease . . . . . . . . . . . . . . . . . . . . . . . . 140 50 Total Anomalous Pulmonary Venous Drainage . . . . . . . . . . . . . . . . . . . . . . . . . 144 51 Partial Anomalous Pulmonary Venous Drainage . . . . . . . . . . . . . . . . . . . . . . . . . 146 52 Ebstein’s Anomaly . . . . . . . . . . . . . . . . . . . . . . . 150 53 Right Isomerism . . . . . . . . . . . . . . . . . . . . . . . . . 154 54 Left Isomerism. . . . . . . . . . . . . . . . . . . . . . . . . . . 158 55 List of Abbreviations . . . . . . . . . . . . . . . . . . . . . . 162 56 Further reading . . . . . . . . . . . . . . . . . . . . . . . . . . 164 1 1 Technical Considerations Paediatric Challenges ¼ The usual technical difficulties faced when perform- ing a cardiac MR examination are further amplified when imaging small children ¼ Optimal image quality may be compromised because of – The smaller size of structures – Faster heart rates – The reduced time for image acquisition (inability or difficulty with breath-holding) ¼ The imaging protocol should be prioritised to obtain the most crucial diagnostic information, in case the patient’s cooperation is limited 1. Spatial Resolution Smaller field-of-views (FOVs) and the use of thinner slices are required to image small anatomical structures. This leads to increased image resolution, but a corresponding reduction in signal:noise (S/N) ratio. This can be compensated by ¼ Increasing the number of acquisitions – (disadvan- tage: increase in scan time) ¼ Removing parallel imaging features – (disadvan- tage: increase in scan time) ¼ Using a coarser matrix, to increase diagnostic image quality, albeit at the cost of reduced resolution 2. Appropriate Coil Selection Appropriate coil selection is important to maximise S/N ratio. ¼ A dedicated extremity (knee coil) should be used in neonates or very small children. ¼ A transmit/receive coil can reduce noise and increase S/N ratio. ¼ If the child is too large for this, then a body matrix and spine coil combination achieves good results. 3. Faster Heart Rates Faster heart rates in small children result in a short R-R period. ¼ For sequences where repetition times (TR) are longer than the R-R period, gating, using the sec- ond or third R wave as the trigger facilitates more time for the appropriate recovery of longitudinal magnetisation. ¼ For cine-imaging, reducing the number of phase encode steps in each frame will decrease the acqui- sition period for each frame, improving temporal resolution and image sharpness. However, this increases scan times. 4. Strategies to Reduce Motion Artefact ¼ Play therapy or pre-examination visits to the scan- ner can help a child overcome any anxiety and improve in-magnet stillness. ¼ Installing a DVD/Video system is a worthwhile investment to promote prolonged distraction and cooperation. ¼ For children who have difficulty breath-holding, images can be acquired during free breathing. Additionally: – Use manual shimming techniques, as they are essential to minimise flow artefacts, particularly on balanced SSFP sequences – Increase the number of acquisitions (NEX) from 1 to 3 – Use respiratory compensation methods to acquire data, e.g. use of navigator echoes, phase re-ordering algorithms. – Acquire data using real time imaging sequences (where imaging systems allow). 5. Contrast Administration in Children For angiography, we use 0.2–0.4 mL/kg of Dotarem, (Guerbet, Paris) which corresponds to 0.1–0.2 mmol/ kg. All Gadolinium contrast agents need to be given in accordance with Institutional and National guide- lines to avoid nephrogenic sytemic fibrosis (NSF). For further information on this, see the UK Royal College of Radiologists document on this subject: h t t p : / / w w w. r c r. a c . u k / d o c s / r a d i o l o g y / p d f / BFCR0714_Gadolinium_NSF_guidanceNov07.pdf 6. Consider Alternative Imaging Strategies CT is potentially useful if MR assessment is limited or hampered by technical restraints. 2 Cardiovascular MRI in Congenital Heart Disease 2 MR Imaging Under GA Indications for General Anaesthesia (GA) for Paediatric MR Practice varies throughout the world. However, most centres in the UK will perform cardiovascular MR under general anaesthetic (GA) for children under the age of 7 years. General Safety Issues Specific to Paediatric Cardiac Imaging ¼ Patient metal checked and the safety questionnaire performed with parents before the child is anaesthetised. ¼ Senior cardiac anaesthetist continuously present in every case. ¼ Full monitoring: pulse oximetry, end-tidal gas anal- ysis, ECG and non-invasive BP. ¼ Wrap the patient in gamgee or blankets to keep him or her warm. ¼ Ten metre circle breathing system needed, to link the patient to anaesthetist in MR control room. ¼ Breath-holding in passive expiration, controlled by Technical Factors Specific to MR in Infants and Small Children ¼ Prolonged, multiple breath holds are required. This can cause hypoxia. Adequate pause for ventilation control between breath holds is required. ¼ A reliable ECG is vital for gating during image acquisition. ¼ Monitor patient temperature closely. The low ambi- ent temperature in MR scanning room produces a hypothermia risk, particularly for small infants. breaking the circuit in the control room. ¼ The large dead space prohibits low flow anaesthesia. ¼ Reversal of anaesthesia and extubation in CMR induction room. Ensure that the team is aware of the cardiac arrest procedure. Importantly, the child MUST be withdrawn from the MR room for resuscitation. Metallic objects such as resuscitation trolley MUST NOT be brought into the scanning room. Environmental and Physical Constraints Performing general anaesthesia (GA) in a magnetic resonance (MR) environment is challenging for many reasons ¼ During the scan, there is limited access to the child Power injector Anaesthetic machine Physiological monitoring and ventilation equipment. ¼ Care is required for staff and patient safety with regard to ferromagnetic equipment. ¼ There is a potential for RF interference with moni- toring equipment. Fig. 2.1. Photography showing one of our dedicated paediatric cardiac MR labs. Inset, control room with monitoring equipment and long anaesthetic tubing to enable the anaesthetist to sit in the controlroom during MR scanning 3 Imaging Protocol 3 Imaging Protocol 3 4 Cardiovascular MRI in Congenital Heart Disease 3 Imaging Protocol 5 6 Cardiovascular MRI in Congenital Heart Disease 4 Normal Anatomy-Axial The transverse or axial plane is useful for studying morphology and the relationships of the four cardiac chambers and the pericardium. Images (a) through (f ) show axial planes in a head to foot direction. a f InA a BCV LCC LSA SVC Azy b AAo DAo 4 Normal Anatomy-Axial 7 SVC AAo RAA LAA PT AAo RPA LPA LA c DAo d DAo RVOT e RAA RLPV Ao LA f RA IVC RV DAo LV 8 Cardiovascular MRI in Congenital Heart Disease 5 Normal Anatomy-Coronal Frontal or coronal images are most useful for investigation of the LVOT, of the left atrium, and the pulmonary veins. Images (a) through (f ) show coronal planes through the heart in an apex-to-base direction. f a a c SVC RA Ao RV PT LV LV b RCA d RV RPA LV RVOT Ao Arch LPA 5 Normal Anatomy-Coronal 9 RV IVC RA LV e Ao Arch LPA f LPA LA RLPV LAA LLPV DAo 10 Cardiovascular MRI in Congenital Heart Disease 6 Normal Anatomy-Sagittal Saggital images can be used to study the connections between the ventricles and the great vessels. Images (a) through (f ) show saggital planes through the heart in a right-to-left direction. a f a SVC c RA IVC b SVC RV d RA Azy 6 Normal Anatomy-Sagittal 11 AAo DAo RPA LA RVOT LA RV RV e PT RV LV DAo f LV LV 12 Cardiovascular MRI in Congenital Heart Disease 7 Image Planes-Ventricles Planned using HASTE axial stack, and acquired using a b-SSFP sequence. These figures illustrate the process with normal anatomy. The same principles are used for patients with any ventricular arrangement. a b Fig. 7.1. The LV vertical long axis plane (LVLA) is aligned using the axial plane, through the mitral valve and the LV apex, which may be on a separate more inferior slice a b Fig. 7.2. The RV vertical long axis plane (RVLA) is aligned using the axial plane, through the tricuspid valve and the RV anterior wall – apex 7 Image Planes-Ventricles 13 a b c Fig. 7.3. The short axis plane (SA) is aligned using the VLA views and the axial plane, and is perpendicular to both a c b d Fig. 7.4. The 4-chamber view is planned using the SA and the VLA views. A perpendicular line is placed through the anterior mitral valve papillary muscle and the apex of the RV in the SA, and then adjusted to intersect the LV and RV apices in VLA views 14 Cardiovascular MRI in Congenital Heart Disease 8 Imaging Planes-Left Ventricular Outflow Tract Planned and acquired using b-SSFP sequence. LVOT view useful for septal hypertrophy and LVOT obstruction in HCM. Aortic valve plane used for through-plane Ao flow, and valve morphology. These figures illustrate the process with normal anatomy. The same principles are used for patients with any ventricular arrangement. a c b d 8 Imaging Planes-Left Ventricular Outflow Tract 15 Fig. 8.1. Imaging planes can be aligned from the basal SA slice (a). The LV inflow (mitral valve)/outflow (aortic valve) view (b) acquired with a plane passing across mid-point Ao and mitral valves on the basal SA slice. A per- pendicular cross-cut of the LVOT produces image (c). Alignment of the aortic valve plane (d) for aortic flow assess- ment from the LV inflow/ outflow (b) and the left ventricular outflow tract (LVOT) (c) views (dotted lines). The imaging plane should be placed just above the aortic valve, yet just below the origin of the coronary artery origins 16 Cardiovascular MRI in Congenital Heart Disease a 9 Imaging Planes-Right Ventricular Outflow Tract RVOT planned using HASTE axial images, and acquired using b-SSFP. Pulmonary valve plane used for through-plane PA flow, and valve morphology. These figures illustrate the process with normal anatomy. The same principles are used for patients with any ventricular arrangement. b c e Pulmonary outflow d 9 Imaging Planes-Right Ventricular Outflow Tract 17 Fig. 9.1. Alignment of the pulmonary valve plane (e) for pulmonary flow assessment from two perpendic- ular right ventricular outflow tract (RVOT) (c, d) views (dotted lines). The imaging plane should be placed just above the pulmonary valve. The first RVOT view is prescribed from an oblique plane through the main pulmonary artery and RV on a set of axial images (a, b). The second RVOT plane is prescribed perpendicular to the first RVOT view (complete line on (c)) 18 Cardiovascular MRI in Congenital Heart Disease a c 10a Imaging Planes-Branch PAs The branch PAs (RPA and LPA) do not lie in the same axial plane (LPA is slightly superior to the RPA). b d Fig. 10.1 (a-d). Both arteries can be shown in an oblique axial plane (a). An oblique coronal plane can be used to show the RPA (b). An oblique sagittal plane used to show the LPA (c). PA MRA shown in (d). Imaging Planes-Thoracic Aorta 19 10b Imaging Planes-Thoracic Aorta The thoracic aorta has a complex morphology, which does not lie in a single saggital or coronal plane. e h f i g Fig. 10.1 (e -i). Alignment of the thoracic aorta using a 3-point plan. Points placed on “black-blood” axial images: (e) ascending aorta, (f) aortic arch, and (g) proximal descending aorta. The in-plane image of the tho- racic aorta in (h) shows a tight