Incidental Cardiac & Vascular Findings
Pericardial Sac
Normal ranges
Normal pericardial fluid is approximately 15-30 mL; up to about 50 mL may be physiologic. Normal pericardial thickness is <=2 mm; thickness >3-4 mm is abnormal.
Report
- Apparent effusion volume: trace/small versus moderate/large.
- Pericardial thickening, calcification, nodularity, or enhancement when present.
- Presence, size, location, and attenuation of a pericardial mass or cyst.
- Pericardial recess fluid is common and should not be mistaken for lymphadenopathy.
Management cues
- Small nonspecific effusions are common and usually need no imaging work-up.
- Large effusions warrant reporting and clinical correlation.
- Simple pericardial cysts are typically benign and need no further imaging unless large or symptomatic.
- Large cyst, thickened pericardium, unexplained large effusion, or suspected constrictive/acute pericarditis may prompt MRI, short-term CT, or cardiology evaluation.
Aorta / Pulmonary Artery
Measure and localize
Report maximal vascular diameter and the involved segment. Use dedicated aortic guidance for detailed surveillance and intervention decisions.
Thoracic aorta
- Average ascending aorta is roughly 34 mm in men and 32 mm in women; descending aorta roughly 26 mm in men and 23 mm in women.
- Dilation/ectasia is generally >2 SD above expected normal, adjusted for age, sex, and body size.
- Aneurysm is conventionally >=150% of expected normal, roughly 5.0 cm ascending or 4.0 cm descending.
- Diameters >=5.5 cm carry high rupture risk and should be considered for intervention; lower thresholds may apply in connective tissue disease.
- Open thoracic aorta aneurysm reference
Pulmonary artery dilation
- Main pulmonary artery diameter >=3.0 cm or equal to/larger than the ascending aorta should be reported as dilated.
- Framingham reference cutoffs are about 29 mm in men and 27 mm in women; MPA/ascending aorta ratio >=0.91 is abnormal.
- MPA >29-31.5 mm or MPA/aorta ratio >1.0 supports possible pulmonary hypertension.
- Comment on pulmonary emboli, chronic thromboembolic disease, advanced lung disease, fibrosis, or cardiac disease when present.
Coronary Calcium / Reporting
Core recommendation
Coronary artery calcification should be reported on all noncontrast chest CTs, regardless of indication or risk profile.
CAC burden
- CAC is common on noncardiac chest CT and reflects atherosclerotic plaque burden.
- Acceptable methods on nongated CT include Agatston scoring, ordinal scoring, or visual assessment.
- Visual categories: none, mild, moderate, severe/heavy.
- Agatston categories: 0 = very low risk; 1-100 = mild; 101-300 = moderate; >300 = high.
- Heavy/severe CAC should prompt cardiovascular risk assessment and management discussion.
Useful report language
- No coronary artery calcification.
- Mild coronary artery calcification.
- Moderate coronary artery calcification.
- Severe coronary artery calcification.
- Main pulmonary artery is dilated, which can be seen with pulmonary hypertension.
Sources
- ACR incidental thoracic CT guidance for mediastinal and cardiovascular findings.
- SCCT/STR guidance endorses CAC reporting on noncontrast chest CT.
- Local mediastinal and cardiovascular findings PDF