What does a hyperintense signal in the cervical vertebral bodies on T2‑weighted MRI represent and what are the appropriate next steps?

Hyperintense Signal in Cervical Vertebral Bodies on T2-Weighted MRI

Bright bone (T2 hyperintensity) in cervical vertebral bodies most commonly represents bone marrow edema from acute vertebral compression fractures, infection (discitis/osteomyelitis), or metastatic disease, and requires immediate correlation with clinical presentation and additional MRI sequences to determine the underlying cause. 1, 2

Primary Differential Diagnosis

The pattern and distribution of T2 hyperintensity determines the most likely etiology:

Acute Vertebral Compression Fractures

• Osteoporotic fractures show T2 hyperintensity representing bone marrow edema, typically with a linear or triangular "fluid sign" adjacent to fractured endplates in 40% of cases 3
• The fluid sign exhibits signal intensity isointense to cerebrospinal fluid and is significantly associated with benign osteoporotic fractures rather than malignancy 3
• On diffusion-weighted imaging, benign osteoporotic fractures appear hypo- to isointense relative to normal vertebral bodies, reflecting persistent free water proton mobility 4, 5

Metastatic/Pathologic Fractures

• Malignant compression fractures demonstrate hyperintensity on diffusion-weighted sequences compared to normal bone marrow due to altered water proton mobility within neoplasm 4, 5
• Pathologic fractures show positive bone marrow contrast ratios on diffusion-weighted imaging, whereas benign fractures show negative values (p < 0.001) 4
• The fluid sign occurs in only 6% of neoplastic compression fractures 3

Discitis/Osteomyelitis

• Characteristic findings include inability to distinguish margins between disc space and adjacent vertebral marrow on T1-weighted images, with increased signal intensity on T2-weighted images 2
• Multilevel involvement averaging three vertebral bodies with abnormal bone marrow signal is typical 6
• Infection most frequently affects C5 and C6 levels, with 72% of infections occurring at or below C4 6
• Anterior epidural inflammation extending an average of four levels is common, with abscess formation in 50% of contrast-enhanced cases 6

Essential Diagnostic Algorithm

Step 1: Obtain Complete MRI Protocol

• Sagittal T2-weighted or STIR sequences are mandatory for detecting bone marrow edema, with spatial resolution of at least 3 × 1 × 1 mm 1
• T1-weighted sequences are essential to assess for hypointensity, which combined with T2 hyperintensity predicts worse outcomes in cervical myelopathy 1
• Diffusion-weighted imaging differentiates benign from malignant fractures with high accuracy 4, 5
• Gadolinium-enhanced sequences identify abscess formation (peripheral enhancement) and active inflammation 6

Step 2: Assess Clinical Context and Red Flags

Infection indicators:

• Recalcitrant neck pain unresponsive to conservative measures 2
• Fever, elevated inflammatory markers (ESR, CRP) 2
• Recent bloodstream infection, particularly Staphylococcus aureus, infective endocarditis, or immunocompromised state 2
• Multilevel involvement with anterior epidural inflammation 6

Malignancy indicators:

• Known cancer history or constitutional symptoms 4
• Hyperintensity on diffusion-weighted imaging with positive bone marrow contrast ratios 4
• Absence of fluid sign (present in only 6% of metastatic fractures) 3

Benign fracture indicators:

• Acute trauma or known osteoporosis 3
• Linear or triangular fluid sign adjacent to endplates 3
• Hypo- to isointense signal on diffusion-weighted imaging 4, 5

Step 3: Obtain Confirmatory Testing

For suspected infection:

• Blood cultures in all patients 2
• Image-guided aspiration biopsy for microbiologic diagnosis 2
• Withhold empiric antibiotics until cultures obtained, except in hemodynamic instability, sepsis, or severe neurologic symptoms 2

For suspected malignancy:

• Tissue diagnosis via CT-guided biopsy 1
• Staging workup if metastatic disease confirmed 4

For suspected benign fracture:

• Bone density assessment (DEXA scan) 1
• Follow-up MRI at 6-8 weeks to confirm healing pattern 3

Prognostic Implications for Cervical Myelopathy

If T2 hyperintensity involves the spinal cord rather than vertebral bodies:

• Multisegmental high signal changes in the cervical cord predict poor outcome following cervical surgery 1
• T1 hypointensity combined with T2 hyperintensity predicts worse surgical outcomes 1
• Conflicting evidence exists for focal T2 hyperintensity, with some studies showing negative prognostic value and others not 1
• Restricted transverse spinal cord area (<30-45 mm²) portends poor surgical prognosis 1

Critical Management Decisions

Immediate neurosurgical consultation required for:

• Spinal cord compression with neurologic deficits (present in 74% of cervical epidural infections) 6
• Progressive neurologic deficits, progressive deformity, or spinal instability despite antimicrobial therapy 2
• Cord hyperintensity on T2-weighted sequences indicating myelopathy 6

Medical management:

• Definitive antimicrobial therapy based on culture results and susceptibility testing for confirmed infection 2
• Monitor ESR and CRP after 4 weeks of treatment; values >50 mm/hour and >2.75 mg/dL respectively indicate higher risk of treatment failure 2

Common Pitfalls to Avoid

• Do not assume benignity based solely on T2 hyperintensity, as both benign and malignant pathology can appear hyperintense 7
• Do not start empiric antibiotics before obtaining cultures in stable patients, as this compromises microbiologic diagnosis 2
• Do not overlook pediatric physiologic marrow changes, which show T2 hyperintensity in 56% of children, most commonly at C4-C6 levels, particularly during rapid growth phases (ages 8-14 years) 8
• Do not rely on T1 and T2 sequences alone; diffusion-weighted imaging provides unique diagnostic information that significantly impacts accuracy 4, 5
• Do not delay diagnosis of infection, as cervical epidural spinal infection is aggressive with 74% showing cord compression and 63% showing cord hyperintensity 6