What are the recommendations for a patient with CT pulmonary arteriography findings showing no pulmonary embolus, but with atelectasis, coronary artery calcification, and dilatation of the ascending thoracic aorta?

Management of CT Pulmonary Arteriography Findings: No PE with Incidental Findings

For patients with CT pulmonary arteriography showing no pulmonary embolus but with incidental findings of atelectasis, coronary artery calcification, and dilatation of the ascending thoracic aorta (42 mm), further cardiovascular evaluation is strongly recommended due to the significant risk of cardiovascular morbidity and mortality.

Assessment of Negative Pulmonary Embolism Study

The CT pulmonary arteriography shows no evidence of pulmonary embolism, which is a reliable finding. Modern multidetector CT pulmonary angiography has high sensitivity (83-100%) and specificity (89-98%) for detecting pulmonary emboli 1. The absence of pulmonary embolus on this study effectively rules out clinically significant PE.

The atelectasis noted in the right lower lobe and left basal regions is a common finding on CT pulmonary angiography studies. Atelectasis is frequently seen as an alternative diagnosis in patients undergoing CT-PA for suspected PE, with one study showing it was present in 19% of patients evaluated for PE 2. These findings typically resolve with deep breathing exercises and do not require specific treatment unless they persist or worsen.

Management of Incidental Findings

1. Coronary Artery Calcification (CAC)

The coronary artery calcification involving the left anterior descending coronary artery requires attention:

• CAC is a significant predictor of coronary heart disease risk and should be reported and evaluated 1
• According to the ACR Incidental Findings Committee, CAC classified as moderate to severe should be further evaluated 1
• CAC findings are often not reported in pulmonary CT angiography (up to 45% of cases), representing a missed opportunity for early intervention 3

Management recommendations:

• Cardiovascular risk assessment
• Consider referral to cardiology for evaluation of coronary artery disease
• Initiate or optimize preventive therapies (statins, aspirin, lifestyle modifications) based on overall cardiovascular risk

2. Dilated Ascending Thoracic Aorta (42 mm)

The 42 mm dilatation of the ascending thoracic aorta is clinically significant:

• According to the ACR guidelines, this measurement meets criteria for aortic dilatation 1
• Thoracic aortic aneurysms increase the risk of aortic dissection and rupture, which carry high mortality rates

Management recommendations:

• Referral to cardiovascular specialist for evaluation
• Baseline imaging with dedicated aortic protocol CT or MRI to better characterize the aneurysm
• Blood pressure control to reduce wall stress
• Follow-up imaging at appropriate intervals based on size and growth rate
• Consider genetic testing if there are features suggesting hereditary aortopathy

Follow-up Algorithm

1. Immediate management:

   • Reassure patient regarding absence of pulmonary embolism
   • Educate about the significance of incidental findings
   • Initiate blood pressure control if elevated

2. Short-term follow-up (within 1-3 months):

   • Cardiology consultation for evaluation of coronary artery calcification
   • Cardiovascular risk assessment including lipid profile, HbA1c, and other risk factors
   • Dedicated imaging of thoracic aorta (CT or MRI with aortic protocol)

3. Long-term management:

   • Regular monitoring of aortic dimensions (interval based on size and growth rate)
   • Aggressive cardiovascular risk factor modification
   • Consider beta-blockers or other antihypertensives to reduce aortic wall stress

Common Pitfalls and Caveats

1. Underestimating incidental findings: Incidental findings on CT pulmonary angiography often receive less attention than the primary indication for the study, but may represent significant pathology requiring intervention 3.

2. Inadequate follow-up: Ensure proper communication of incidental findings to primary care providers and appropriate specialists to prevent loss to follow-up.

3. Over-reassurance: While the absence of PE is reassuring, the incidental findings represent significant cardiovascular risk factors that require attention and management.

4. Failure to recognize aortic dilatation significance: A 42 mm ascending aorta meets criteria for dilatation and requires appropriate surveillance to monitor for progression.

By addressing these incidental findings proactively, you can potentially prevent future cardiovascular events and improve long-term patient outcomes.