Is a thoracic spine MRI (CPT 72146) medically necessary for a patient with chronic thoracic intercostal pain, despite lack of indication for invasive treatment and significant interference with daily activities?

Medical Necessity Determination for CPT 72146

Based on MCG criteria and ACR guidelines, the thoracic spine MRI (CPT 72146) is NOT medically necessary for this patient because they do not meet the critical requirement of being considered for invasive treatment, despite meeting the duration of conservative therapy criterion. 1, 2

MCG Criteria Analysis

The patient's case fails to meet 2 of 3 required MCG criteria for thoracic spine MRI:

• MET: Failure to improve after 6+ weeks of nonoperative treatment (patient has 8 years of pain with multiple physiotherapy sessions) 1
• NOT MET: Patient being considered for invasive treatment (no documentation of planned epidural steroids or surgery) 1
• NOT MET: Significant interference with daily function (ADLs interference not documented) 1

The MCG criteria require ALL three elements to be present simultaneously for medical necessity. Since only 1 of 3 criteria is met, the study does not meet medical necessity standards. 1

ACR Appropriateness Criteria Alignment

The ACR 2024 guidelines strongly support this denial:

• For subacute or chronic thoracic back pain without myelopathy, radiculopathy, or red flags, imaging is not typically indicated. 1
• The ACR explicitly states "there is no relevant literature to support the use of MRI thoracic spine without IV contrast in the initial evaluation of subacute or chronic TBP without red flags or neurologic deficits." 1
• Plain radiography of the thoracic spine is the appropriate initial study for chronic thoracic back pain without red flags, not MRI. 2

Red Flag Assessment

This patient lacks critical red flags that would justify advanced imaging:

• No myelopathy signs (spasticity, hyperreflexia, gait disturbance, bladder dysfunction) 1
• No true radiculopathy with motor/sensory deficits 1
• No constitutional symptoms suggesting malignancy 2
• No infection risk factors 2
• No significant trauma history 2
• The diagnoses listed (fibromyalgia, intercostal pain, disc displacement) are clinical diagnoses that do not constitute imaging red flags 1, 2

Clinical Context Considerations

The sudden worsening over 5 days does not change the medical necessity determination because:

• The pain has been present for 8 years, making this a chronic condition with an acute exacerbation 1
• Acute exacerbations of chronic pain without new neurologic deficits do not meet criteria for advanced imaging 1, 2
• The menstrual cycle correlation suggests a functional pain component rather than structural pathology requiring MRI 3

High Prevalence of Incidental Findings

Ordering MRI in this clinical scenario risks harm through overdiagnosis:

• 73% of asymptomatic individuals have positive anatomical findings on thoracic spine MRI, including disc herniations (37%), disc bulging (53%), annular tears (58%), and spinal cord deformation (29%) 4
• These anatomical irregularities represent roentgenographic abnormalities only and do not correlate with clinical symptoms 4
• Finding incidental abnormalities may lead to unnecessary interventions and increased patient anxiety without improving outcomes 2, 4

Appropriate Clinical Pathway

The evidence-based approach for this patient should be:

• Continue conservative management with activity modification, NSAIDs or acetaminophen, and physical therapy 2
• Consider plain radiography of the thoracic spine as the initial imaging study if imaging is deemed necessary after 4-6 weeks of conservative management 2
• Reserve MRI for development of true red flags: myelopathy, progressive neurologic deficits, or concerning findings on plain radiographs 1, 2
• Document specific functional limitations and ADL interference if present, as this is required for MCG criteria 1
• Document consideration of invasive treatment options (epidural steroids, surgery) if clinically appropriate, as this is required for MCG criteria 1

CPT 73218 (Arm MRI) Determination

The arm MRI (CPT 73218) DOES meet MCG criteria and should be certified:

• MCG criteria for arm MRI requires only "pain localized to arm, with normal or indeterminate findings on plain x-ray or CT scan" [@case documentation@]
• This single criterion is met, making the arm MRI medically necessary [@case documentation@]

Critical Pitfall to Avoid

Do not confuse chronic pain duration with meeting imaging criteria. The 8-year history and recent 5-day worsening do not constitute medical necessity without documented plans for invasive intervention or significant ADL interference. 1, 2 The ACR specifically warns against premature imaging in the absence of red flags, as this increases costs without improving outcomes. 2