Is a CT chest scan reasonable for a patient with intermittent lower left quadrant abdominal pain, possible IBS, and persistent left-sided chest pain radiating to the arm, shoulder, and back, despite not meeting MCG criteria for nontraumatic chest wall pain?

CT Chest Is NOT Indicated for This Patient

Based on ACR Appropriateness Criteria, chest radiography—not CT—is the appropriate first imaging study for nontraumatic chest wall pain, and this patient's presentation does not meet criteria for advanced imaging. 1, 2

Why CT Chest Should Not Be Ordered

Clinical Presentation Suggests Musculoskeletal Origin

• The pain characteristics strongly indicate a benign musculoskeletal etiology: chronic (3+ months), intermittent, positional variation (less noticeable when busy), partial relief with bowel movements, and no cardiac risk features described 1, 2
• The ACR explicitly states that CT chest is NOT first-line for uncomplicated musculoskeletal chest wall pain without trauma, infection, or malignancy risk factors 2
• Costochondritis accounts for 42% of nontraumatic musculoskeletal chest wall pain and is diagnosed clinically without imaging 2

Missing Critical Prerequisites for CT

The patient does not meet any of the three conditions that would justify CT chest per ACR guidelines 1:

1. No plain radiograph performed: The ACR recommends chest radiography as the mandatory first step to evaluate for rib fracture, pneumothorax, infection, or neoplasm 1, 2, 3
2. No documented malignancy: CT is reserved for known or suspected malignancy after normal chest radiograph 1
3. No infectious/inflammatory red flags: No fever, no immunocompromise, no signs of infection documented 1

The Correct Diagnostic Pathway

Step 1: Obtain chest radiography first 1, 2, 3

• Evaluates for rib fractures (especially given chronic pain), pneumothorax, and excludes serious pathology 3
• Radio-opaque skin markers can be placed at the pain site to help localize abnormalities 1, 3

Step 2: If chest X-ray is normal and clinical suspicion remains high:

• Point-of-care ultrasound has higher sensitivity than CT for costochondral abnormalities and can detect rib fractures missed on radiography (29% detection rate after negative chest X-ray) 2, 3
• Dynamic ultrasound can diagnose slipping rib syndrome with 89% sensitivity and 100% specificity 1, 3

Step 3: Consider cardiac evaluation given radiation to back:

• An ECG should be obtained to exclude cardiac causes, particularly given the radiation pattern to arm, shoulder, and back 1, 2
• The AHA/ACC guidelines recommend evaluating for noncardiac causes only after negative cardiac workup 1

Critical Pitfalls to Avoid

Radiation Exposure Without Justification

• CT chest delivers significant radiation dose without diagnostic benefit when chest X-ray hasn't been performed first 1, 2
• The ACR specifically discourages routine rib series radiography as it adds little value beyond chest radiography (fractures detected in <5% of cases), making CT even less justified 2

Overlooking the IBS Connection

• The patient's partial relief with bowel movements and LLQ pain pattern suggests referred pain from gastrointestinal origin 1
• The AHA/ACC guidelines state that evaluation for gastrointestinal causes is reasonable in patients with recurrent chest pain without cardiac or pulmonary cause 1

Missing the Chronic Pain Context

• More than 55% of patients with chest wall pain have chronic symptoms lasting >6 months 2, 4
• This patient needs reassurance and appropriate treatment (NSAIDs, physical therapy), not advanced imaging 4

What Should Be Done Instead

1. Obtain chest radiography with skin markers at pain site 1, 2, 3
2. Perform ECG to exclude cardiac etiology (especially given radiation pattern) 1, 2
3. Physical examination focusing on:
   • Chest wall palpation for reproducible tenderness (suggests musculoskeletal) 2
   • Positional maneuvers to assess for slipping rib syndrome 1, 3
4. If radiography is normal, consider ultrasound for costochondral evaluation 2, 3
5. Address the gastrointestinal component given LLQ pain and relief with bowel movements 1

The MCG criteria are correct in this case—CT chest is not indicated without completing the appropriate diagnostic algorithm starting with plain radiography. 1, 2