This is a retrospective study observational study that has IRB approval with waiver of consent for use of deidentified data (STU-2020-0116).
Cases were identified by a search of our imaging database using keywords for CT reports that included the word “endocarditis” in any text field (including indication). All studies performed over the last four years (2018–2022) were included in our study. Inclusion criteria for our patient were: patient referred to our tertiary heart center for management of suspected IE, age less than 25 years old at the time of the study, and endocarditis diagnosis proven by surgical pathology specimens or by receiving full treatment for endocarditis based upon clinical diagnosis.
Demographics and background data were collected and included:
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Age at time of the study and gender
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Initial cardiac diagnosis and any additional diagnosis relevant to endocarditis
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Initial clinical presentations including any immunologic or vascular phenomena
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Echocardiography (TTE/TEE) data
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CT data
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Blood culture results
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RV-PA conduit (Contegra, Hancock or Homograft)
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Modified Duke criteria classification before CT
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CT findings and PET findings
Additional risk factors relevant to endocarditis included any predisposing factors: immunocompromise, congenital heart disease, or prolonged IV line(14). Since all of our patients had congenital heart disease, we also collected data for type of immunocompromise e.g. DiGeorge syndrome.
Echocardiographic studies were considered positive for major modified Duke echocardiographic criteria (14) prior to cardiac CT. Follow up echo studies done after CT imaging were not included in our analysis.
Echo study is considered positive if vegetation/thrombosis was mentioned clearly at the report rather than sentence “endocarditis could not be ruled out”. Our echo lab is credentialed by intersocietal accreditation commission(IAC) and our studies are done following pediatric echocardiography protocol guidelines (15, 16). Our echo lab utilizes different echo machines including Siemens Acouson SC2000 and GE Vivid E95 ultrasounds systems. Our institutional protocol for possible infective endocarditis patients does not include routine Transesophageal echo. TEE was done only during cardiac surgical procedure. All echo studies were reviewed by high level of experience faculty.
Patients underwent retrospectively-ECG gated CCT(80 KV,260 mAs per rotation on a SOMATOM Definition Flash Dual- Source (2 x 128 slices) CT Scanner (Siemens Healthcare, Erlangen, Germany). Omnipaque was dosed 2 ml/kg using a power injector with a rate 2–4 ml/sec according to the age of the patient. Omnipaque concentration was 270–300 mg iodine /L for less than 40 kg patients and 320–350 mg iodine/L for more than 40 Kg patients. CCT images were analyzed, post-processed, and reformatted by using Philips IntelliSpace Portal version 9 (Philips Healthcare, Best, the Netherlands). CT scan protocol was either triggered by contrast in the left atrium or ascending aorta.
CT images were considered as a Major Criterion for Endocarditis if any of the following findings existed: vegetation (oscillating intracardiac mass on valve or supporting structures, or in the path of regurgitant jets, or on implanted material, in the absence of an alternative anatomic explanation) or aneurysm formation or valve perforation or valve dehiscence or abscess formation. Distal Embolization was recorded as a vascular phenomenon and hence a minor Duke Criterion.
PET scan at our institution is done only for patients who did not have any recent thoracic surgery (within the last 2 months) and it was considered positive if it showed high uptake relative to blood pool.