For a patient presenting with acute right‑sided sharp chest pain at rest, should I order a contrast‑enhanced CT angiography (CTA) or a PET scan for the initial work‑up?

Order CTA Chest, Not PET Scan

For acute right-sided sharp chest pain at rest, you should order a contrast-enhanced CT angiography (CTA) of the chest, not a PET scan. PET scanning has no established role in the acute evaluation of chest pain and is not mentioned in any acute chest pain guidelines 1.

Why CTA is the Correct Choice

The clinical presentation of acute right-sided sharp chest pain at rest demands immediate evaluation for life-threatening conditions that CTA can rapidly diagnose:

Primary Life-Threatening Diagnoses to Rule Out:

Pulmonary Embolism (PE)

• Non-ECG-gated chest CTA with optimized contrast timing is the clinical standard for excluding PE 2
• In stable patients with high clinical suspicion for PE, CTA using a PE protocol is recommended (Class 1, Level B-NR) 1, 3
• CTPA is highly sensitive and specific for PE diagnosis 4

Aortic Dissection

• CTA of the chest, abdomen, and pelvis is recommended (Class 1, Level C-EO) when there is clinical concern for aortic dissection 1, 3
• CTA is both highly sensitive and specific for acute aortic syndrome 1
• This is the diagnostic modality of choice in stable patients 1

Other Critical Pathology

• CTA can identify pneumothorax, pericardial effusion, and other non-cardiac causes of acute chest pain 2

Clinical Decision Algorithm

Step 1: Assess pretest probability

• Right-sided sharp chest pain at rest raises concern for PE or aortic pathology
• Consider Wells criteria for PE or clinical features of aortic dissection (tearing/ripping quality, radiation to back)

Step 2: Order appropriate imaging

• CTA chest with IV contrast using PE protocol if PE is primary concern
• CTA chest, abdomen, pelvis if aortic dissection is suspected
• Pretest probability should guide need for testing, but in acute presentations with concerning features, proceed directly to CTA 1, 3

Step 3: Alternative if CTA contraindicated

• If contrast allergy or renal insufficiency: Consider V/Q scan for PE or TEE/CMR for aortic dissection 1
• Bedside transthoracic echocardiography can identify pericardial effusion, right ventricular dysfunction from PE, or proximal aortic dissection 1, 5

Why Not PET?

PET imaging is used for:

• Myocardial perfusion assessment in chronic chest pain evaluation 6
• Stress testing protocols for coronary artery disease evaluation 7

PET has zero role in acute chest pain evaluation for the following reasons:

• No guideline recommends PET for acute chest pain workup
• Cannot diagnose PE, aortic dissection, or other acute life-threatening conditions
• Requires stress protocols that are inappropriate in acute presentations
• Time-consuming when rapid diagnosis is critical for mortality reduction

Common Pitfalls to Avoid

1. Don't delay imaging in acute presentations with concerning features—the differential includes immediately life-threatening conditions
2. Don't order "triple rule-out" CTA routinely; use targeted protocols based on clinical suspicion 2
3. Don't confuse acute vs chronic chest pain algorithms—PET may have a role in chronic stable chest pain but never in acute presentations
4. Don't forget bedside echocardiography as an immediate adjunct—it can identify pericardial effusion, tamponade, or RV dysfunction while awaiting definitive imaging 1, 5

The evidence is unequivocal: CTA is the appropriate test, PET is not indicated 2, 1, 2, 1, 3, 4.