The pivotal role of cardiac computed tomography angiogram and 18F-fluorodeoxyglucose positron emission tomography-computed tomography in the diagnosis of right sided endocarditis: a case report

Abstract

Background Infective endocarditis (IE) poses many clinical and diagnostic challenges. Echocardiography is regarded as the imaging modality of choice for the diagnosis of IE, and plays a key role in both the diagnosis and management of endocarditis. We report on a case in which one could have overlooked an endocarditis of a pulmonary homograft if one had relied on echocardiography alone. Case summary A 38-year-old man presented with intermittent fever and fatigue for 1 month. He had undergone a Ross procedure for a bicuspid aortic valve stenosis at the age of 17 years. At the age of 36 years a valve-sparing aortic root replacement was performed because of aortic root dilatation. Besides a systolic murmur 3/6 noted at the left sternal border, physical examination was normal. Multiple blood cultures grew Streptococcus mitis . Both transthoracic and transoesophageal echocardiogram could not detect any signs of endocarditis. As endocarditis can be overlooked due to reverberations and acoustic shadowing, we performed 18 F-fluorodeoxyglucose positron emission tomography-computed tomography (FDG-PET/CT) and cardiac computed tomography angiogram (cardiac CTA). Both imaging modalities showed large vegetations attached to the pulmonary homograft. Discussion Endocarditis poses diagnostic challenges. While echocardiography is the cornerstone of imaging, one may overlook a pulmonary homograft endocarditis due to reverberations and acoustic shadowing. Therefore, if clinical suspicion of endocarditis is strong, one should consider additional imaging by means of cardiac CTA and/or 18 F-fluorodeoxyglucose positron emission tomography-computed tomography imaging to assess valves in pulmonary position, especially in those whom have had prior surgical intervention at this location.

Multimodality cardiovascular imaging in the diagnosis and management of prosthetic valve infective endocarditis in children report of two cases and brief review of the literature

“…9 These studies showed that when CTA was added to standard diagnostic workup of suspected infective endocarditis, an overall sensitivity of 100% and specificity of 83% for prosthetic valve infective endocarditis was achieved. 9 There was also a change in treatment strategy in 25% of patients with the added use of CTA. 9 18 FDG-PET/CT had 73-100% sensitivity for diagnosis of infective endocarditis and 71-100% specificity.…”

“…9 18 FDG-PET/CT also detected unexpected extracardiac complications and additional potential infectious foci in 11-24% of patients. 9 To our knowledge, Meyer et al were the first investigators to publish a study of the use of 18 FDG-PET/CT for the diagnosis of infective endocarditis in children with CHD. In this retrospective study, five patients with prosthetic valves were diagnosed with prosthetic valve infective endocarditis using 18 FDG-PET/CT, of which three were children under 18 years old.…”

“…9 The authors stated that if clinical suspicion of endocarditis is strong, one should consider additional imaging via CTA and/or 18 FDG-PET/CT to assess valves in the pulmonary position, especially in patients that have had prior surgical intervention at this location. 9 There are benefits and limitations to each imaging technique. Transesophageal echocardiogram does not employ ionising radiation, but typically requires sedation in the paediatric and adolescent population and, as mentioned above, the image quality may be reduced by artefacts caused by implanted metallic devices.…”

“…A systematic review published in 2017 found 3 studies addressing the value of CTA and 13 studies addressing the value of 18 FDG-PET/CT in diagnosis of infective endocarditis in patients with prosthetic valves. 9 All of these were done in an adult population and were all classified as low or very low quality according to the GRADE approach. 9 These studies showed that when CTA was added to standard diagnostic work-up of suspected infective endocarditis, an overall sensitivity of 100% and specificity of 83% for prosthetic valve infective endocarditis was achieved.…”

“…9 All of these were done in an adult population and were all classified as low or very low quality according to the GRADE approach. 9 These studies showed that when CTA was added to standard diagnostic work-up of suspected infective endocarditis, an overall sensitivity of 100% and specificity of 83% for prosthetic valve infective endocarditis was achieved. 9 There was also a change in treatment strategy in 25% of patients with the added use of CTA.…”