What are common incidental findings in inpatient cardiology?

Common Incidental Findings in Inpatient Cardiology

The most common incidental findings in inpatient cardiology include mediastinal lymph nodes, mediastinal masses, pericardial abnormalities, aortic dilation, coronary artery calcification, and pulmonary artery dilation, which require systematic evaluation and management to prevent adverse outcomes. 1

Mediastinal Findings

Lymph Nodes

• Incidental enlarged mediastinal lymph nodes are found in 1-3% of lung cancer and coronary artery disease screening CT scans 1
• Evaluation should focus on location, size, and clinical context to determine significance 1
• Common causes include:
  • Reactive changes due to infection or inflammation
  • Malignancy (lymphoma, metastatic disease)
  • Sarcoidosis 1

Mediastinal Masses

• Most commonly found in the prevascular (anterior) compartment 1
• Differential diagnosis varies by compartment location:
  • Prevascular compartment: thymic lesions, lymphoma, germ cell tumors
  • Middle compartment: lymphadenopathy, vascular abnormalities
  • Posterior compartment: neurogenic tumors 1
• Homogeneous or slightly heterogeneous prevascular soft tissue masses in patients >40 years often represent thymoma, especially with symptoms of myasthenia gravis 1

Cardiovascular Findings

Pericardial Abnormalities

• Pericardial fluid is a common incidental finding associated with infection, malignancy, trauma, myocardial disease, and post-operative states 1
• Pericardial effusions >50 mL usually indicate significant disease and warrant reporting 1
• Incidental pericardial cysts generally don't require follow-up unless they are large enough to risk compression of adjacent structures 1

Aortic Dilation

• Aortic disease is incidentally detected on chest CT in up to 3.4% of cases 1
• Aortic diameters are influenced by gender, age, and body surface area:
  • For men: average ascending aorta diameter is 34.1 ± 3.9 mm; descending aorta 25.8 ± 3.0 mm
  • For women: average ascending aorta diameter is 31.9 ± 3.5 mm; descending aorta 23.1 ± 2.6 mm 1
• Aneurysm is defined as diameter ≥150% of normal (approximately 5.0 cm for ascending aorta and 4.0 cm for descending aorta) 1
• Diameters ≥5.5 cm place patients at high risk for rupture and should be considered for intervention 1

Coronary Artery Calcification (CAC)

• Commonly detected on non-contrast chest CT 1
• CAC classified as heavy or severe should be further evaluated due to association with increased cardiovascular risk 1
• Incidental CAC findings provide an opportunity for cardiovascular risk assessment and potential preventive interventions 1

Pulmonary Artery Dilation

• Main pulmonary artery ≥3.0 cm, or equal in diameter to the ascending aorta, should be reported as dilated 1
• Correlates with increased pulmonary artery pressure:
  • Main pulmonary artery diameter >29.5 mm has 71% sensitivity and 79% specificity for pulmonary hypertension
  • Ratio of main pulmonary artery diameter to ascending aorta diameter >1.0 has 71% sensitivity and 75% specificity for pulmonary hypertension 1
• Unsuspected acute pulmonary embolism is found in 0.6-4.0% of outpatients and 4-6.4% of inpatients on routine contrast-enhanced chest CT 1

Thyroid Abnormalities

• Subclinical hypothyroidism is a common incidental finding that can impact cardiac function 2, 3
• Patients with TSH ≥10.0 mU/L have:
  • Greater incidence of heart failure compared to euthyroid individuals (41.7 vs. 22.9 per 1,000 person-years) 3
  • Alterations in cardiac function including increased left ventricular mass over time 3
  • Impaired left ventricular diastolic function with delayed relaxation 4

Management Considerations

• Incidental findings require systematic evaluation and reporting to guide appropriate management 1
• The American College of Radiology Incidental Findings Committee recommends:
  • Characterizing findings based on patient characteristics and imaging features
  • Managing findings to balance risks and benefits to patients
  • Using reporting terms that reflect confidence level regarding findings 1
• During cardiovascular imaging, approximately 50-61% of CT examinations performed for other indications reveal potentially significant cardiovascular findings 1
• Incidental non-cardiac findings on cardiac CT should be specifically interpreted despite the limited field of view 1
• For genetic incidental findings related to cardiovascular diseases, the American College of Medical Genetics recommends reporting pathogenic or likely pathogenic variants in 30 cardiovascular-related genes 1

Pitfalls and Caveats

• Overdiagnosis is common when sensitive diagnostic tests are used for screening, potentially leading to unnecessary interventions 1
• Incidental findings (incidentalomas) are found in 39.8% of research imaging examinations but lead to clear medical benefit in only 1% of cases 1
• Radiologists should feel comfortable deviating from standard algorithms based on specific imaging appearances and patient characteristics 1
• Recommendations should be viewed as guidance rather than "standard of care" 1
• For cardiac CT, the small field of view precludes complete evaluation of the entire thorax, which should be communicated to patients and referring physicians 1