Is 78830 - RP (Radiopharmaceutical) LOCLZJ (Localization) TUM (Tumor) SPECT (Single Photon Emission Computed Tomography) W/CT (with Computed Tomography) 1 medically indicated for a patient with a history of multiple lumbar spine surgeries and recent infection, now experiencing low back pain?

SPECT/CT (CPT 78830) is NOT medically indicated as initial imaging for this patient

For a 65-year-old male with multiple prior lumbar spine surgeries, recent infection, and current low back pain, MRI lumbar spine without and with IV contrast is the appropriate initial imaging study, not SPECT/CT. 1

Primary Imaging Recommendation

MRI lumbar spine without and with IV contrast is the gold standard for this clinical scenario because it can:

• Accurately distinguish recurrent disc herniation from postoperative scar tissue 1
• Evaluate for nerve root compression or arachnoiditis in patients with new or progressive symptoms after previous lumbar surgery 1
• Identify and evaluate the extent of infection, including epidural abscess, with sensitivity of 96% and specificity of 94% 2
• Assess for hardware-related complications and spinal instability 1

Role of SPECT/CT in Post-Surgical Spine

SPECT or SPECT/CT is explicitly NOT the initial imaging modality in this clinical context. 1

SPECT/CT may serve only as an adjunct study in highly specific scenarios:

• Painful pseudoarthrosis (non-union of fusion) 1
• Periprosthetic hardware loosening 1

These indications require that initial MRI has already been performed and specific hardware-related complications are suspected but not fully characterized. 1

Critical Red Flags in This Patient

Given the recent completion of 12 weeks of antibiotics for infection, this patient requires evaluation for:

• Recurrent or persistent infection (discitis, osteomyelitis, epidural abscess) 1
• Treatment failure - CRP >2.75 mg/dL (27.5 mg/L) after 4 weeks of therapy suggests treatment failure 2, 3
• Hardware-related infection - mean incidence of postoperative instrumented spine infection is 2-3% 1

Why MRI is Superior to SPECT/CT for This Patient

MRI with contrast excels at detecting post-surgical infection because it:

• Shows bone marrow abnormalities with high sensitivity 1
• Distinguishes abscess from phlegmon 1
• Detects epidural and paraspinal soft tissue involvement 1
• Provides superior soft tissue characterization compared to SPECT/CT 1

FDG-PET/CT (not SPECT/CT) has emerging utility in postoperative spine infection when MRI is nondiagnostic or inconclusive, showing sensitivity of 94.8% and specificity of 91.4% in a meta-analysis of 396 patients. 1 However, even PET/CT is complementary to MRI, not a replacement. 1

Complementary Imaging Studies

Plain radiographs are complementary to MRI and helpful to:

• Evaluate alignment and hardware integrity 1
• Assess for abnormal motion with flexion-extension views 1

CT without IV contrast can be useful if:

• MRI is contraindicated or produces significant metallic artifact 1
• Assessment of osseous fusion is needed 1
• Hardware failure (loosening, malalignment, fracture) is suspected 1

Clinical Pitfall to Avoid

Do not order SPECT/CT as initial imaging for post-surgical low back pain with recent infection. This represents inappropriate utilization that delays definitive diagnosis and potentially worsens outcomes through diagnostic delay. 1 The ACR Appropriateness Criteria explicitly state SPECT/CT is not initial imaging for this indication. 1

Recommended Diagnostic Algorithm

1. Obtain laboratory markers before imaging: ESR, CRP, WBC with differential, blood cultures 2, 3
2. Order MRI lumbar spine without and with IV contrast as the initial imaging study 1
3. Add plain radiographs (AP, lateral, flexion-extension if indicated) to assess hardware and alignment 1
4. Consider CT without IV contrast only if MRI is contraindicated or shows significant artifact 1
5. Reserve SPECT/CT for cases where MRI has been performed and specific hardware complications (pseudoarthrosis, loosening) remain incompletely characterized 1