Cardiac Multidetector Computed Tomography in Infective Endocarditis: a pictorial essay

Transcription

1 Cardiac Multidetector Computed Tomography in Infective Endocarditis: a pictorial essay Poster No.: C-1284 Congress: ECR 2014 Type: Educational Exhibit Authors: A. Grob, A. Jacquier ; Marseille/FR, Marseille Cedex 5/FR Keywords: Infection, Education, CT, Cardiac DOI: /ecr2014/C 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 21

2 Learning objectives ECG-gated multislice computed tomography (MSCT) has proved to be a reliable tool in the analyse of valvular diseases. There is a lack of information about the potential role of MSCT in the assessment of infective endocarditis (IE). The objectives of this poster are: a) To review briefly what is IE. b) To give a MSCT protocol for images acquisition and valvular imaging post processing. c) To review the MSCT semiology of several valvular and perivalvular lesions that might be encountered during IE. A discussion about advantages and drawbacks of MSCT compared to echography will be proposed. d) To review several MSCT diagnosis of typical locations of septic embolism during IE. Page 2 of 21

3 Background IE is a rare but a severe disease with morbidity mortality rate in between 10% to 26%. Complications of the disease might be cardiac with a destruction of the valvular apparatus and general such as death, septic embolism, renal failure, purpura. The clinical diagnosis of IE might be delayed by the variety of clinical manifestations and complications of the disease increasing morbi-mortality. Echocardiography is the current imaging standard for assessment of cardiac valves but both TEE and TTE have technical limitations.[1] Treatment is based on effective antibiotherapy and surgery might be necessary. MSCT has shown promising results for the assessment of cardiac valves and perivalvular lesions during IE [2, 3]. MSCT allows 1) precise anatomic informations, 2) functional assessment using multiphase cine mode, and three dimensional reformations But there is sparse data in the literature about the MSCT semiology during IE. Page 3 of 21

4 Findings and procedure details 1.Protocole for images acquisition and valvular imaging post processing. Acquisition: In our center the MSCT acquisition protocol for IE is performed in 2 different phases: the first one is the cardiac acquisition under EKG gating and first pass iodine injection. The constant used for that acquisition are similar to those used for coronary imaging. The second acquisition is performed without EKG synchronization covering the thorax, abdomen, pelvic and the cerebral region. No additional iodine injection is required for the second acquisition phase. Images post processing: Usually aortic and mitral valves are post processed in diastolic phase. The aortic valve is analyzed using LVOT1, LVOT2 views and thought the aortic valve plane. The mitral valve is analyzed on the four chamber view, Vertical long axis view and through the mitral valve plane. The tricuspid valve is analyzed on the four chamber long axis and two chamber short axis, the tricuspid valve plane. The pulmonary valve is analyzed on the RVOT1 et RVOT2 view. 2. Semiology of several valvular and perivalvular lesions that might be encountered during IE. Vegetation: On MSCT, vegetations can appear as a thickened valve or as irregular, homogenous, hypodense masses attached on valve or other endocardial structure (Figure 1). Several authors showed that, vegetations are detected with a similar accuracy with MSCT compared with echocardiography. [2, 4] Echocardiography is superior in detecting small vegetations. Valvular perforation: On MSCT, valvular perforation appears as a defect in the leaflet. Several MPR reconstructions at the level of each leaflet might be required to show the perforation. MSCT has a lower sensitivity and a lower specificity compared with echocardiography for perforation analysis.[2] Page 4 of 21

5 Perivalvular involvements: Perivalvular involvements include abscess, pseudoanevrysm and fistulae. Echocardiography is known to underestimate the presence of such lesions. MSCT provides relevant informations for surgeons to characterize perivalvular extension such as anatomic extension and relationship with the mediastinal structures. Several data as well as our experience showed that MSCT might have slightly better accuracy to detect perivalvular extension during IE. [2, 5, 6] - On MSCT, Abscess appears as a perivalvular collection with a liquid density surrounded by a thick inflammatory tissue that enhanced after contrast injection (figure 2 ). -Pseudoanevrysm on MSCT is defined as abnormal cavity close to the valve enhancing concomitantly with cardiac or aortic lumen. (Figure3). -Fistula is a communication between two neighboring cavities through a perforation. In MSCT the communication between neighbourouring cavities can usually be easily assessed using multiplanar and 3D post processing. (Figure 4). 3. Review of several MSCT diagnosis of typical locations of septic embolism during IE. Embolic events are frequent. True incidence is unknown because a large number of events are asymptomatic. A cerebral, thoracic and abdominopelvic Computed tomography (CT) should be performed to detect silent embolism. Neurologic complications: [7] Embolic strokes, resulting from mechanical occlusion of cerebral arteries by the septic embolus, are typically in the gray-white junction, often multiple, hypodensity in CT, IV contrast allows visualization of contrast enhancing lesions which suggest a breakdown of the blood brain barrier (Figure 5). Intracranial hemorrhage is associated with rupture of mycotic anevrysm or with a hemorrhage transformation of embolic stroke. CT shows a sponteneous hyperdensity (figure 6). Brain abscess appears as a mixte density lesion with peripheral enhancement and surrounding by edema (figure 7). Abdominal complications: [7, 8] Page 5 of 21

6 On the CT Splenic (figure 8) and kidney infraction (figure 9) is a hypodense area with its base on the periphery. Formation of abscess can occur following infraction. Vascular complications: [7] Mycotic anevrysm appears on CT as a segmental vascular dilatation more frequently saccular (figure 10). The presence of perianevrysmal oedema and infiltration should advocated the diagnosis. The presentation of peripheral emboli is the same as acute extremity ischemia. The IV contrast enhancement CT in arterial phase shows defect in the artery. Musculoskeletal complications: (figure 11) [7] The characteristics of spondylodiscitis in MRI are: a low signal T1 and a hight signal on T2 of disc and adjacent vertebral bodies, with gadolinium enhancement of discs. Thoracic complications : [7] They are the complication of right endocarditis. In CT pulmonary emboli are cavitary nodules with peripheral predominance (figure 12), pulmonary infracts is a peripheral triangle opacity. Pleural effusion and empyema is a pleural collection with enhancement of pleurae (figure 13). Page 6 of 21

7 Images for this section: Fig. 1: Ultrasound (A) and the corresponding multiplanar reconstruction image form MSCT: four chamber long axis (B), the valve plane (C),the coronal plane (D) show the large vegetation on the anterior leaflet of the mitral valve (white arrow). Page 7 of 21

8 Fig. 2: Ultrasound (A) and the corresponding multiplanar reconstruction image form MSCT: LVOT 1(B)(C), the valve plane (D)(F),The coronal view at the level of the aortic root (E) show a vegetation (thin arrow) and a abscess (thick arrow). Page 8 of 21

9 Fig. 3: The coronal view (A) at the level of the aortic root shows a desinsertion of the prosthetic valve (thin arrows) and a large pseudoaneurysm around the prosthetic valve (thick arrows). On (B) the valvular plane view shows a large pseudoaneurysm around the prosthetic valve. Page 9 of 21

10 Fig. 4: Ultrasound (A) and the corresponding multiplanar reconstruction image form MSCT: LVOT 1(B), the valve plane (C),The coronal view at the level of the aortic root (D) show a fistula between aortic root and left atrium(thin arrow) and a vegetation (thick arrow) on the aortic valve. Page 10 of 21

11 Fig. 5: cerebral CT : IV contrast allows visualization of contrast enhancing lesion which suggest a breakdown of the blood brain barrier (white arrow)in the left Sylvian region. Page 11 of 21

12 Fig. 6: Intracranial hemorrhage. Cerebral CT shows a spontenaous hyperdensity in basal cistern. Page 12 of 21

13 Fig. 7: Brain abscess.cerebral CT shows a mixte density lesion with peripheral enhancement and surrounding by edema in the left parietal region. Page 13 of 21

14 Fig. 8: Splenic infraction. Abdominal CT shows multiple hypodense areas with base on the periphery. Page 14 of 21

15 Fig. 9: Renal infraction. Abdominal CT shows multiple and bilateral hypodense areas with base on the periphery. Page 15 of 21

16 Fig. 10: Mycotic anevrysm. CT shows a segmental vascular dilatation of the left hypogastric artery. Page 16 of 21

17 Fig. 11: Spondylodiscitis. CT shows endplate destruction of L1 and T12. Page 17 of 21

18 Fig. 12: Pulmonary emboli. CT shows peripheral cavitary lesion (black arrows) with lung nodules(white arrows). Page 18 of 21

19 Fig. 13: Empyema. contrast CT shows pleural collection with enhancement of pleurae(white arrows). Page 19 of 21

20 Conclusion The MSCT represents today a good alternative to echocardiography for valvular and cardiac involvement. Furthermore MSCT is able to assess in one shot peripheral embolic events and a preoperative coronary assement. Page 20 of 21

21 References 1. Thuny F, Gaubert JY, Jacquier A, Tessonnier L, CammilleriS,Raoult D, Habib G. Imaging investigations in infective endocarditis: current approach and perspectives. Arch Cardiovasc Dis Jan; 106(1): Feuchtner GM, Stolzmann P, Dichtl W, et al. Multislice computed tomography in infective endocarditis: comparison with transesophageal echocardiography and intraoperative findings. J Am Coll Cardiol 2009;53: Fagman E, Perrotta S, Bech-Hanssen O, et al. ECG-gated computed tomography: a new role for patients with suspected aortic prosthetic valve endocarditis. Eur Radiol Gahide G, Bommart S, Demaria R, et al. Preoperative evaluation in aortic endocarditis: findings on cardiac CT. AJR Am J Roentgeno 2010;194: Matsuo Y, Kimura F, Inoue K, Ogawa H, Tabata M, Uwabe K, Nishi N, Komiyamam N, Niinami H. Evaluation of perivalvular infectious ventricular pseudoaneurysm by ECGgated cardiac computed tomography: 2 case reports. J Thorac Imaging Nov; 27(6): Budde RP, Kluin J, Symersky P, Chamuleau SA, van Herwerden LA, Prokop M. Visualization by 256-slice computed tomography of mycotic aortic root aneurysms in infective endocarditis. J Heart Valve Dis Sep;19(5): Colen TW, Gunn M, Cook E, Dubinsky T. Radiologic manifestations of extra-cardiac complications of infective endocarditis. Eur Radiol Nov;18(11): Luaces Méndez M, Vilacosta I, Sarriá C, et al. Hepatosplenic and renal embolisms in infective endocarditis. Rev Esp Cardiol Dec;57(12): Page 21 of 21