Is a CTA runoff of the upper extremity more appropriate than a plain CT upper extremity without contrast for evaluating neck pain and right hand tingling after a car accident?

Imaging Recommendation for Post-Traumatic Neck Pain with Radicular Symptoms

Neither CTA runoff nor plain CT of the upper extremity is appropriate as the next imaging step—you need cervical spine imaging (MRI preferred, or CT cervical spine if MRI unavailable) to evaluate for cervical radiculopathy, disc herniation, or nerve root compression causing the neck pain and hand symptoms. 1

Why Upper Extremity Vascular Imaging is Not Indicated

Clinical Presentation Does Not Suggest Vascular Injury

• The patient's symptoms (neck pain with shooting pains and tingling in the hand) are classic for cervical radiculopathy, not vascular compromise 1
• CTA runoff of the upper extremity is indicated when vascular injury is suspected—specifically when there are "hard signs" of vascular injury (absent pulses, expanding hematoma, active bleeding) or when the ankle-brachial index (ABI) is <0.9 in trauma patients 2, 3
• The American College of Radiology recommends CTA of extremities primarily for suspected arterial injury in penetrating trauma or high-energy blunt trauma with vascular compromise, not for radicular symptoms 1, 4

Timing and Mechanism Make Vascular Injury Unlikely

• Vascular injuries from trauma typically present acutely (within hours to days), not 4-6 weeks later 5
• Hyperflexion neck injury from rear-end collision is a mechanism for cervical spine injury and whiplash-associated disorders, not upper extremity vascular injury 4
• If vertebral artery dissection were present from the hyperflexion mechanism, CTA of the neck vessels (not upper extremity) would be the appropriate study 4

The Correct Imaging Approach

First-Line Imaging: Cervical Spine MRI

• MRI of the cervical spine without contrast is the gold standard for evaluating suspected cervical radiculopathy, disc herniation, and nerve root compression 1
• The American College of Radiology states that MRI accurately depicts soft tissue injuries including disc pathology, spinal cord abnormalities, and nerve root compression 1
• MRI can identify post-traumatic disc herniation, ligamentous injury, spinal cord contusion, or foraminal stenosis causing radicular symptoms 1

Alternative if MRI Unavailable: CT Cervical Spine

• Since you state "no MRI is currently available," CT of the cervical spine without contrast is the appropriate alternative 1
• CT cervical spine will identify fractures, subluxation, or significant bony foraminal stenosis that could cause nerve root compression 1
• However, CT has limited sensitivity for disc herniation and soft tissue injuries compared to MRI 1

Consider Plain Radiographs First

• The American College of Radiology recommends starting with cervical spine radiographs (AP, lateral, and oblique views) to screen for fractures or malalignment before proceeding to advanced imaging 1
• This is cost-effective and may identify gross abnormalities requiring immediate intervention 1

When Would Upper Extremity CTA Be Appropriate?

Specific Clinical Scenarios for CTA Upper Extremity

• Absent or diminished pulses in the affected extremity 5, 2
• ABI <0.9 in the injured extremity 2
• Penetrating trauma to the upper extremity with suspected vascular injury 4, 3
• Clinical signs of acute limb ischemia: the "6 P's" (Pain, Pallor, Pulselessness, Paresthesias, Paralysis, Poikilothermia) 5
• Suspected thoracic outlet syndrome with vascular compression 1

CTA Neck Vessels Might Be Considered If:

• There were neurological deficits suggesting vertebral artery dissection (posterior circulation stroke symptoms, Horner's syndrome) 4
• High-velocity mechanism with concern for blunt cerebrovascular injury 4

Critical Pitfalls to Avoid

• Do not order vascular imaging for radicular symptoms—this wastes time and resources while delaying appropriate diagnosis 1
• Do not assume all post-traumatic upper extremity symptoms are vascular—most are neurogenic (radiculopathy) or musculoskeletal 1
• Do not skip cervical spine imaging in whiplash-type injuries with persistent symptoms beyond 4 weeks—this suggests structural pathology requiring imaging 1
• If you order CT cervical spine due to MRI unavailability, recognize its limitations for soft tissue pathology and consider transferring the patient for MRI if CT is negative but symptoms persist 1