What is the recommended initial imaging modality for suspected cervical radiculopathy?

Initial Imaging for Suspected Cervical Radiculopathy

MRI of the cervical spine without IV contrast is the recommended initial imaging modality for suspected cervical radiculopathy due to its superior ability to evaluate soft tissue abnormalities and nerve root impingement. 1, 2

Rationale for MRI as First-Line Imaging

• MRI has become the modality of choice for assessment of suspected nerve root impingement due to its high spatial resolution and superior soft tissue contrast 1, 2
• MRI correctly predicts 88% of lesions in patients with clinically diagnosed cervical radiculopathy, compared to 81% for CT myelography, 57% for myelography, and 50% for CT 1
• Recent studies continue to support MRI's superiority over CT myelography in detecting disc abnormalities and nerve root compression in cervical spine degenerative disorders 1
• MRI permits visualization of the entire cervical canal and spinal cord in multiple planes, allowing better detection of unsuspected pathology at other cervical levels 3

Clinical Considerations

• Diagnosis of cervical radiculopathy should combine clinical history, physical examination, and imaging findings 1
• MRI findings should always be interpreted in conjunction with clinical findings, as both false-positive and false-negative results occur frequently 4
• In one study, 73% of patients with clinical cervical radiculopathy showed compression of the clinically affected root on MRI, while 45% showed compression of asymptomatic roots 4
• MRI was normal in 13-15% of cases with clinical radiculopathy, highlighting the importance of clinical correlation 4

Alternative Imaging Options

• CT cervical spine without IV contrast may be considered when MRI is contraindicated, offering superior depiction of osseous structures but less sensitivity for nerve root compression 1
• CT myelography can be considered as an alternative to MRI in claustrophobic patients or those with contraindications to MRI 1
• CT myelography offers higher spatial resolution than MRI and excellent depiction of the thecal sac and small nerve roots, but has been largely supplanted by MRI as first-line imaging 1

Limitations of MRI

• MRI frequently shows abnormalities in asymptomatic patients, and detected abnormalities are not always associated with acute symptoms 1, 2
• Abnormal levels on MRI do not always correspond to abnormal clinical-physical examination levels 1
• MRI has relative inability to determine whether compression is caused by soft tissue or bony structures compared to CT 5
• Susceptibility-weighted MRI sequences may improve detection of osseous foraminal stenosis compared to conventional T1- and T2-weighted sequences 6

When to Consider IV Contrast

• The addition of IV contrast is not considered useful for initial evaluation of cervical radiculopathy if there are no "red flag" symptoms 1
• MRI with IV contrast should be considered when there are concerns for infection, malignancy, or other "red flag" symptoms 1, 2

Imaging Approach Algorithm

1. For patients with suspected cervical radiculopathy: Start with MRI cervical spine without IV contrast 1, 2
2. If MRI is contraindicated: Consider CT myelography 1
3. If "red flag" symptoms are present: Consider MRI with and without IV contrast 1, 2
4. If initial imaging is negative but clinical suspicion remains high: Consider additional imaging modalities or consultation with a specialist 4