Guidelines Indications for Imaging
Radiology Benefits Management companies (RBMs) usually approve requests for scans (CT or MRI) of the head when providers indicate the presence of one of the following:
• any red flag sign (see the table below plus any red flag on list A)
• focal neurological signs (see list B)
• a change in character, severity, or frequency of a chronic or recurring headache. For example, when a migraine headache changes to a chronic daily headaches, guidelines would support approving a CT or MRI head.
LIST A: Additional Red Flags (provided by another RBM):
• Headache that wakes patient from sleep,
• Headache worse with sexual activity, cough, or physical exertion
• Post-traumatic headache within one year of injury event
• Acute systemic infections with meningeal neck stiffness
• Unilateral or bilateral severe suspected Horner or dissection
• New onset of headache in adult with hydrocephalus and shunts
• Suspected low pressure hydrocephalus and CSF leak
• New onset headache in pregnancy
List B: Focal Neurological Signs
Lack of coordination Memory loss
Papilledema Gait disturbance
Vomiting Mental status change
Personality changes Unilateral facial and/or body paralysis
Drowsiness Unilateral sensory loss
Dizziness Loss of vision
Seizure Cranial nerve palsy
Confusion Sensory deficit
Nystagmus Dysarthria and dysphagia
Which imaging study to request?
CT scan: Although many providers would choose to perform a Head CT scan as the initial imaging to investigate a headache, most guidelines support using MRI brain as the only test, with a few exceptions.
CT may be the preferred imaging study for:
• Suspected or known hemorrhage (traumatic or spontaneous),
• Head trauma,
• Prior to lumbar puncture if imaging is required before LP,
• Viewing bony structures.
• Urgent settings due to speed and availability of CT
• Patients who cannot have an MRI due to metal objects or implants in the body.
Some CT scans focus on specific parts of the head
Sinus CT imaging
The traditional CT scan of the head does not adequately visualize certain structures in the head, such as the maxillary and ethmoid sinuses. Imaging for sinusitis usually requires a CT of the maxillofacial area and is usually performed without contrast (70486). For follow-up sinus imaging, a limited CT scan (76380) may be used.
Orbital CT imaging
Similarly, CT head is often inadequate for assessing subtle orbital bone abnormalities, but CT scan of the orbit/temporal bone give a much better view. Scan of the maxillofacial area and CT orbit/temporal bone have some overlap, so requesting both CTs is rarely necessary.
The indications for MRI are extensive and are included in specific radiology benefits management guidelines. However, the following general tips may be helpful
1. MRI in children: In small children the long scan time for MRI (30 minutes vs. 15 seconds for CT scan) means anesthesia is often required. The cost and adverse effects of anesthesia are considerations in the final decision to use CT or MRI, and is usually left to the requesting provider.
2. MRI and metal objects: MRI is often contraindicated when patients have metal objects, pacemakers, or implants in the body. However, newer medical devices made from a non-metalic material, may allow use of MRI. Radiology departments, pacemaker cardiologists, or implant facilities should be consulted to see whether MRI is allowed.
3. Pituitary MRI imaging: If one MRI brain is performed for any non-endocrine reason and the scan suggests a pituitary tumor, a repeat MRI of the pituitary (70553) or an MRI orbit, face or neck (70543) with special views of pituitary may be approved.
4. Eye, face and neck MRI imaging: MRI orbit, face, or neck may also be used for eye lesions, facial lesions, mandible, submandibular space, or neck visualization. This test is usually performed without and with contrast (70543)
5. Suspected tumors or masses in the internal auditory meatus are best imaged using an MRI brain with special “internal auditory canal” (IAC) views (70553). Follow-up views of the internal auditory canal may be requested as limited MRI of the IAC (70543)
6. The CPT code for Temporo-mandibular Joint is 70336 (MRI of the TMJ).
Lesson #34: Most headache imaging scans will be approved if there is either a red flag sign or a focal neurological sign, or for any change in character, severity, or frequency of a chronic or recurring headache.