CT Angiography for Pericarditis

Imaging Hierarchy for Pericarditis

• The American College of Radiology recommends that CT angiography is not appropriate as a first-line imaging test for pericarditis, with no relevant literature supporting its use for this indication 1, 2, 3
• The European Heart Journal suggests that transthoracic echocardiography is the first-line imaging test for suspected pericarditis, providing the most cost-effective way to detect pericardial effusion and assess hemodynamic significance 4, 5
• Echocardiography accurately detects pericardial effusion, cardiac tamponade, and ventricular dysfunction from myocardial involvement, according to the European Heart Journal 4, 5
• The American College of Cardiology states that when CT is indicated, cardiac CT with IV contrast—not CT angiography—should be used as a complementary imaging modality to echocardiography 4, 5, 6
• The Journal of the American College of Radiology recommends CT chest with IV contrast or CT heart function and morphology as the appropriate CT protocols for pericardial disease evaluation 1, 2, 3, 7
• IV contrast administration is recommended to increase blood density and depict pericardial inflammation, as suggested by the European Heart Journal 4, 5
• The American College of Cardiology notes that pericardial thickening or enhancement on CT can also represent pericardial fibrosis, not just acute inflammation 6, 8
• Cardiac MRI has 94-100% sensitivity for detecting pericardial inflammation and can distinguish acute myopericarditis from other cardiomyopathies and occult MI, according to the Journal of the American College of Cardiology 6, 8
• The American College of Cardiology recommends cardiac MRI as the preferred advanced imaging modality over CT when echocardiography is nondiagnostic or there is diagnostic uncertainty 6, 8

Clinical Algorithm

• The European Heart Journal suggests starting with transthoracic echocardiography in all patients with suspected pericarditis 4, 5
• The Journal of the American College of Cardiology recommends proceeding to cardiac MRI if echocardiography is nondiagnostic or there is diagnostic uncertainty 6, 8
• Cardiac CT with IV contrast should be considered only when MRI is contraindicated or unavailable, or when evaluating for pericardial calcification or thickening in suspected constrictive pericarditis, as suggested by the American College of Cardiology and the European Heart Journal 4, 5, 6

Common Pitfalls

• The American College of Radiology advises against ordering CTA protocols when evaluating pericardial disease, as the appropriate CT study is cardiac CT with IV contrast 1, 2, 3
• CT has limited hemodynamic assessment capability compared to echocardiography and MRI, with suboptimal temporal resolution and increased artifact with tachycardia or unstable rhythm, according to the Journal of the American College of Radiology 2, 3, 7
• The Journal of the American College of Cardiology notes that CT findings for pericarditis have modest sensitivity (54-59%) despite high specificity (91-96%), so negative CT does not exclude pericarditis 6

Diagnostic Criteria and Management of Pericarditis

Diagnostic Criteria

• The European Society of Cardiology recommends that the diagnosis of pericarditis requires at least 2 of the 4 following criteria: pericarditic chest pain, pericardial rubs, new widespread ST-elevation or PR depression on ECG, and pericardial effusion (new or worsening) 9, 10, 11
• Pericarditic chest pain is typically sharp, retrosternal, pleuritic chest pain that may worsen with inspiration and improve with sitting forward 9
• Pericardial rub is an auscultatory finding representing friction between inflamed pericardial layers 9, 10
• ECG changes include new widespread ST-segment elevation or PR depression in multiple leads 9, 10
• Pericardial effusion is a new or worsening fluid collection around the heart detected by imaging 9, 10

Laboratory Tests

• Elevated inflammatory markers, such as C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and white blood cell count, are commonly seen in pericarditis 9, 12
• Cardiac biomarkers, including troponin and creatine kinase (CK), should be assessed to evaluate for myocardial involvement 13, 14

Imaging Studies

• Transthoracic echocardiography is recommended in all patients with suspected pericarditis 14, 15
• Chest X-ray is recommended in all patients, though often normal unless pericardial effusion exceeds 300 ml 14, 15

Management Protocol

• The European Society of Cardiology recommends risk stratification, with low-risk patients managed as outpatients with empiric anti-inflammatories, and high-risk patients admitted to hospital for etiology search and treatment 14, 15
• Major risk factors for pericarditis include fever >38°C, subacute course, large pericardial effusion, cardiac tamponade, and failure to respond to NSAIDs within 7 days 15
• NSAIDs are the mainstay of therapy for idiopathic and viral pericarditis 15
• Colchicine may be added to NSAIDs to improve response and reduce recurrence rates 15

Special Considerations

• Pericardiocentesis is indicated in cases of cardiac tamponade, suspected bacterial or neoplastic pericarditis, and symptomatic moderate to large effusions not responding to medical therapy 13
• Pericardial fluid analysis should include cytology, PCR, and microbiology cultures 13

Common Pitfalls and Caveats

• ECG changes may be absent in up to 40% of cases, and cardiac biomarker elevation may indicate concomitant myocarditis rather than primary pericardial disease 9, 10, 12
• Normal inflammatory markers do not exclude pericarditis, especially if the patient is already on anti-inflammatory treatment 12