Can a 32-year-old female with a recent history of pneumonia or influenza-like symptoms, now presenting with pleuritic pain and shortness of breath but no hypoxia, and having a normal pro-brain natriuretic peptide (proBNP) and recent echocardiogram showing normal cardiac function, expect the ground glass opacities (GGOs) on her computed tomography (CT) scan to resolve with time, given her past medical history of pulmonary embolism (PE)?

Ground Glass Opacities Following Recent Pneumonia: Expected Resolution vs. Recurrent PE

In a 32-year-old woman with recent pneumonia/influenza-like illness now improving, presenting with pleuritic pain and dyspnea but no hypoxia and normal cardiac workup, the ground glass opacities are most likely post-infectious changes that should resolve with time; however, given her history of pulmonary embolism, recurrent PE must be actively excluded before attributing symptoms to resolving pneumonia. 1, 2

Immediate Risk Stratification for PE

Your patient requires formal PE probability assessment despite clinical improvement from pneumonia. The combination of pleuritic chest pain, dyspnea, and prior PE history creates intermediate-to-high pre-test probability regardless of normal oxygenation. 1, 2

Key Clinical Decision Points:

• Up to 40% of PE patients have normal arterial oxygen saturation, making the absence of hypoxia unreliable for excluding PE. 1, 2
• Pleuritic chest pain occurs in 52% of PE cases and represents pleural irritation from distal emboli causing pulmonary infarction—this is a cardinal PE symptom. 2, 3
• Prior PE is an independent risk factor (OR = 5.3) for recurrent thromboembolism, particularly in the context of recent illness. 4
• Normal proBNP and echocardiogram do not exclude PE—these tests assess cardiac function but cannot rule out thromboembolic disease. 1

Diagnostic Algorithm

Step 1: Calculate Clinical Probability Score

Use the Wells or revised Geneva score to quantify PE risk. Her prior PE history alone adds significant points. 1

Step 2: D-Dimer Testing

• If low-to-intermediate probability: Obtain D-dimer. Negative result safely excludes PE. 1, 5
• If high probability: Proceed directly to CT pulmonary angiography (CTPA) without D-dimer, as negative D-dimer cannot overcome high pre-test probability. 1, 5

Step 3: Imaging Decision

• CTPA is the definitive test and should be performed within 24 hours for stable patients with suspected PE. 5
• CTPA will simultaneously evaluate: intravascular thrombus, ground glass opacities, wedge-shaped infarcts, and alternative diagnoses. 5

Ground Glass Opacities: Post-Infectious vs. PE-Related

Expected Post-Pneumonia/Influenza Changes:

• Ground glass opacities are common after viral pneumonia and typically resolve over 2-6 weeks. 1, 6
• Bilateral symmetric GGOs suggest post-infectious inflammation rather than PE, which typically shows wedge-shaped peripheral opacities. 1, 5
• Clinical improvement with persistent mild symptoms favors resolving infection over acute PE. 7

PE-Associated Imaging Findings:

• Wedge-shaped pleural-based opacities (Hampton's hump) occur in 23% of PE cases and represent pulmonary infarction—highly specific when present. 5
• Decreased pulmonary vascularity (Westermark sign) appears in 36% of PE cases. 5
• PE can coexist with pneumonia: Multiple case reports document pneumonia masking concurrent PE, particularly when systemic symptoms predominate. 7, 8, 6

Critical Clinical Pitfalls to Avoid

Do Not Assume Symptoms Are Residual from Pneumonia Without Excluding PE:

• Pneumonia frequently masks PE diagnosis, especially when fever and cough dominate the presentation. 7
• Initial improvement followed by persistent or worsening pleuritic pain is a red flag for concurrent PE that was initially overlooked. 7
• Influenza-associated pneumonia specifically increases thrombotic risk through endothelial activation and hypercoagulability. 8

Do Not Rely on Normal Oxygenation:

• 20% of PE patients have normal alveolar-arterial oxygen gradient, and respiratory symptoms in PE predominantly reflect hemodynamic disturbances rather than gas exchange impairment. 1, 2

Do Not Delay Imaging Based on "Improving" Clinical Status:

• Small peripheral PE causes mild, transient dyspnea that can be mistaken for resolving pneumonia. 3
• In patients with recent illness, worsening dyspnea may be the only PE symptom, particularly subtle in young patients without cardiopulmonary disease. 3

Management Pathway

If PE is Confirmed:

• Initiate anticoagulation immediately unless contraindicated. 5
• Investigate for underlying thrombophilia given young age and recurrent PE. 1

If PE is Excluded:

• Reassure regarding GGO resolution: Post-infectious changes typically resolve within 4-8 weeks. 1
• Follow-up chest imaging in 6-8 weeks to document radiographic resolution, particularly given persistent symptoms. 9
• Symptomatic management: NSAIDs for pleuritic pain if no contraindications. 9

Monitoring Strategy:

• Serial clinical assessment for worsening dyspnea, hemoptysis, or syncope—any of which mandate immediate re-evaluation for PE. 1, 3
• Consider prophylactic anticoagulation during future illnesses given recurrent PE history. 1

The bottom line: While post-infectious GGOs likely explain the imaging findings, her symptom complex (pleuritic pain + dyspnea) combined with PE history mandates formal exclusion of recurrent thromboembolism before attributing everything to resolving pneumonia. 1, 2, 7