Computed Tomography (CT) Head CPT CODES: 70450 ..........CT of Head, without contrast 70460 ..........CT of Head, with contrast 70470 ..........CT of Head, without contrast, followed by re-imaging with contrast STANDARD ANATOMIC COVERAGE: · From the skull base to vertex, covering the entire calvarium and intra-cranial contents. · Scan coverage may vary, depending on the specific clinical indication. IMAGING CONSIDERATIONS: · Radiation Dosimetry: CT of Head, either without or with contrast, has a typical effective dose of approximately 2.3 milliSieverts (mSv) or 115 Chest X-Ray equivalents. · MRI of the head is preferable to CT in most clinical scenarios, due to its superior contrast resolution and lack of beam-hardening artifact adjacent to the petrous bone (which may limit visualization in portions of the posterior fossa and brainstem on CT). Notable exceptions to the use of head MRI as the neuroimaging procedure of choice are: acute intra-cranial hemorrhage (parenchymal, subarachnoid; subdural; epidural); initial evaluation of recent craniocerebral trauma; osseous assessment of the calvarium, skull base and maxillofacial bones, including detection of calvarial and facial bone fractures; and evaluation of calcified intracranial lesions. · CT of the head is an alternative exam in patients who cannot undergo MRI. Ordering and imaging providers are responsible for considering biosafety issues prior to MRI examination, to ensure patient safety. Among the generally recognized contraindications to MRI exam performance are indwelling pacemakers or implantable cardioverter-defibrillators (ICD), intracranial aneurysm surgical clips that are not compatible with MR imaging, as well as other devices that are unsafe in MRI scanners (including implanted materials in the patient as well as external equipment, such as portable oxygen tanks). · Contrast-enhanced CT may be contraindicated in certain circumstances, such as a documented allergy to intravenous contrast material and renal insufficiency. Special consideration should also be given to patients with multiple myeloma. · For CT imaging of the orbits, internal auditory canals (IACs) or temporal bones, see CPT codes 70480-70482. · According to Medicare's Correct Coding Edits, a CT of the Head is not usually performed with a CT of the Orbits. These studies are generally considered mutually exclusive procedures. · Imaging studies of the head and neck are inherently bilateral. Duplicate requests for bilateral studies to image the right and left side of the head are inappropriate. · Duplicative testing of the same anatomic area with MRI and CT may be subject to high-level review, for evaluation of medical necessity. · Request for re-imaging due to technically limited exams is the responsibility of the imaging providers. COMMON DIAGNOSTIC INDICATIONS FOR HEAD CT: The following diagnostic indications for Head CT are accompanied by pre-test considerations as well as clinical supporting data and prerequisite information: CT is the imaging modality of choice for evaluation of: · acute intra-cranial hemorrhage (parenchymal, subarachnoid, subdural and epidural hematomas); · recent head trauma; · osseous evaluation of the calvarium, skull base and facial bones, including detection of calvarial and facial bone fractures as well as assessment of the temporal bones for conductive hearing loss and an abnormal otoscopic exam; · calcified lesions CT – Head 6 Copyright 2009, American Imaging Management, Inc. All Rights Reserved. COMMON DIAGNOSTIC INDICATIONS FOR HEAD CT: MRI is the preferred technique for most other indications, unless contraindicated. 1-2 This includes assessment of the cerebral parenchyma, cerebellum, brainstem and pituitary gland. ABNORMALITIES DETECTED ON OTHER IMAGING STUDIES WHICH REQUIRE ADDITIONAL CLARIFICATION TO DIRECT TREATMENT CNS FINDINGS/DEFICITS – NEW ONSET OR PROGRESSIVELY WORSENING NEUROLOGICAL ABNORMALITY Including but not limited to the following clinical symptoms and findings: - Anosmia (loss or impairment in sense of smell) - Ataxia (inability to coordinate voluntary muscular movements) - Bell's Palsy 3 - Dysgeusia (dysfunction in sense of taste) - Facial Numbness - Gait Disorder - Other Movement Disorders - Nystagmus (rapid, involuntary, oscillating ocular movements) - Paresis or Paralysis - Tinnitus (ringing or roaring auditory sensation; may be either unilateral or bilateral; pulsatile or non-pulsatile; transient or persistent) 4 - Other cranial nerve impairment Note: Contrast-enhanced MRI, unless contraindicated, is generally recommended for evaluation of cranial nerve impairment. CEREBROVASCULAR ACCIDENT (CVA OR STROKE) AND TRANSIENT ISCHEMIC ATTACK (TIA) 5-6 · May present with a variety of signs and symptoms, including sudden onset of weakness, focal sensory loss or speech disorder · Among patients being evaluated for CVA and possible thrombolytic therapy, unenhanced CT is often performed as the initial modality (within the initial 24 hours after symptom onset), to detect a possible hemorrhagic stroke or mass lesion. CONGENITAL ANOMALY 7 Including but not limited to the following conditions: - Chiari Malformations - Dandy-Walker Spectrum - Encephalocele - Holoprosencephaly - Macrocephaly - Microcephaly - Schizencephaly - Septo-optic Dysplasia CRANIOSYNOSTOSIS DEMENTIA 8-9 · Initial evaluation, if MRI is contraindicated, or · Rapid progression, if MRI is contraindicated DEVELOPMENTAL DELAY 10 · In developmental delay, MRI is the preferred imaging modality over CT · The likelihood of making a specific neuroimaging diagnosis increases in the presence of physical exam abnormalities such as focal motor findings or microcephaly EVALUATION OF ABNORMAL FINDINGS DETECTED ON OTHER IMAGING STUDIES - SUCH AS A MASS CT – Head 7 Copyright 2009, American Imaging Management, Inc. All Rights Reserved. COMMON DIAGNOSTIC INDICATIONS FOR HEAD CT: LESION OR ABNORMAL INTRACRANIAL CALCIFICATION HEADACHE IN ADULT – WHEN ANY ONE OF THE FOLLOWING CRITERIA ARE MET: 11 · Sudden onset and severe, including thunderclap or worst headache of life; or · Increased frequency and severity; or · With new focal neurologic signs, particularly papilledema, visual field defects and nuchal rigidity; or · New-onset headaches after age 50 years, as a recommendation; age is not an absolute requirement; or · New-onset headaches in cancer or immunodeficient patient; or · With mental status changes; or · With fever, nuchal rigidity and other meningeal signs; or · With nausea and vomiting; or · With exertion; or · Frequently awakened from sleep Note: Current evidence does not support CT evaluation for chronic headache or migraines, when the patient's neurological status is unchanged. HEADACHE IN PEDIATRIC PATIENT – WHEN ANY ONE OF THE FOLLOWING CRITERIA ARE MET: 11-13 · Sudden onset and severe, including thunderclap or worst headache of life; or · Associated with neurological abnormalities such as nystagmus, papilledema, gait or motor disturbances; or · With fever, nuchal rigidity and other meningeal signs; or · Awakened repeatedly from sleep or develop upon awakening; or · Persistent headache with confusion, disorientation or vomiting; or · Persistent headaches of < 6 months duration and not responsive to medical treatment; or · Persistent headaches, without a family history of migraines; or · Familial or personal history of disorders with predisposition to CNS lesions and clinical/laboratory findings that suggest CNS involvement; HEMORRHAGE/HEMATOMA · Refers to non-traumatic, non-CVA and non-tumor-related intra-cranial bleed. Examples include hypertensive hemorrhage and hemorrhage secondary to anti-coagulation or blood dyscrasia · CT is the preferred technique for evaluation of acute intra-cranial hemorrhage 14-15 · MRI is usually preferred for evaluation of subacute and chronic hemorrhage HYDROCEPHALUS (VENTRICULOMEGALY) · MRI is often the preferred for initial evaluation of patients with hydrocephalus. For patients with an indwelling shunt, CT is usually adequate in the diagnostic follow-up of hydrocephalus. INCREASED INTRACRANIAL PRESSURE OR HERNIATION COMMON DIAGNOSTIC INDICATIONS FOR HEAD CT: INFECTIOUS OR INFLAMMATORY PROCESS 16 Including but not limited to the following: - Cerebral or Cerebellar Abscess - Encephalitis - Meningitis - Neurocysticercosis - Opportunistic Infection, particularly with AIDS or other immunodeficient condition - Subdural Empyema CT – Head 8 Copyright 2009, American Imaging Management, Inc. All Rights Reserved. MENTAL STATUS CHANGES, WITH DOCUMENTED OBJECTIVE EVIDENCE FROM NEUROLOGIC EXAM MOVEMENT DISORDERS · Including Parkinson's disease (particularly atypical cases with poor response to levodopa, in which there may be an underlying structural disorder producing parkinsonian features); Huntington's disease; idiopathic sporadic cerebellar ataxia (olivopontocerebellar atrophy); and other conditions. MULTIPLE SCLEROSIS AND OTHER WHITE-MATTER DISEASES, WHEN MRI IS CONTRAINDICATED 17 · Multiple Sclerosis may manifest a diverse range of symptoms, including but not limited to the following: - Ataxia (loss of coordination) and Spasticity - Cognitive Dysfunction - Muscle Weakness - Paresthesias - Speech (dysarthria, or slurred speech) - Visual Disturbances (diplopia; nystagmus; evidence of optic neuritis) NEUROCUTANEOUS DISORDERS Including but not limited to the following: - Neurofibromatosis - Sturge-Weber Syndrome - Tuberous Sclerosis - Von Hippel-Lindau Disease (VHL) NEUROENDOCRINE ABNORMALITY SUGGESTIVE OF A PITUITARY LESION · MRI is usually preferred over CT for evaluation of pituitary lesions · Relevant laboratory and clinical abnormalities are required PAPILLEDEMA (refers to swelling and elevation of optic disc – a sign of increased intracranial pressure) PRE- AND POST-NEUROSURGICAL EVALUATION PRIOR TO LUMBAR PUNCTURE SEIZURE DISORDER – new onset or increasing frequency and severity 18 SENSORINEURAL HEARING LOSS, DOCUMENTED BY AUDIOLOGY · As work-up for Acoustic Neuroma (Vestibular Schwannoma) – also see Primary Intra-cranial Tumors Note: Contrast-enhanced MRI, unless contraindicated, is generally recommended for evaluation of sensorineural hearing loss. SYNCOPE 19 - Syncope (partial or complete loss of consciousness) and near syncope (lightheadedness) are infrequently of primary neurological origin, particularly in the absence of abnormal neurological findings. - Neurological consultation (for assessment of possible vertebrobasilar TIAs) and cardiovascular evaluation should be considered. COMMON DIAGNOSTIC INDICATIONS FOR HEAD CT: TRAUMA TO HEAD 20-21 · CT is usually preferred for the initial evaluation of acute head trauma, due to the high sensitivity for hemorrhage and ability to display fractures · Particularly when associated with: - Calvarial fracture (as demonstrated on plain film radiography) - Change in Mental Status or Amnesia CT – Head 9 Copyright 2009, American Imaging Management, Inc. All Rights Reserved. - Focal Neurological Deficits - Loss of Consciousness - Seizures - Signs of Increased Intracranial Pressure - Nausea / Vomiting - Worsening Headaches TUMOR EVALUATION – BENIGN AND MALIGNANT: 22 Including but not limited to the following lesions: · Primary Intra-cranial Tumors 1. Intra-axial Neoplasms of the Cerebrum and Cerebellum 2. Extra-axial Tumors, including Meningiomas and Schwannomas, such as: - Cerebello-pontine Angle (CPA) and internal auditory canal (IAC) Vestibular Schwannoma of CN 8 (also referred to as an Acoustic Neuroma), and - Non-Acoustic Neuromas at the CPA involving cranial nerves (CN) 5, 7, 9, 10, 11 and 12, such as a CN 7 Schwannoma 3. Pituitary Tumors, including Macroadenomas and Microadenomas · Metastatic Disease UNEXPLAINED MASS LESION IDENTIFIED ON PRIOR IMAGING – SURVEILLANCE, WITHOUT PATHOLOGIC TISSUE CONFIRMATION. · Examples include suspected Arachnoid Cyst or Epidermoid Cyst VASCULAR ABNORMALITIES · Including but not limited to: - Aneurysm - Arterio-Venous Malformation (AVM) - Cavernous Malformation - Cerebral Vein Thrombosis - Dural Arteriovenous Fistula (DAVF) - Dural Venous Sinus Thrombosis 21 - Venous Angioma · Either CTA or MRA are usually the imaging modalities of choice for some of these vascular abnormalities, such as aneurysm evaluation. VENTRICULAR SHUNT ASSESSMENT VERTIGO AND DIZZINESS · With recurrent or persistent symptoms and when evaluation for other etiologies has not been revealing · Abnormal hearing test or Auditory Brainstem Response VISUAL DISTURBANCE – SUCH AS VISUAL FIELD LOSS, DIPLOPIA AND OTHER ALTERATIONS IN VISION THAT ARE UNEXPLAINED BY OPHTHALMOLOGIC EXAM AND PATIENT HISTORY WHEN THE PATIENT'S CONDITION MEETS THE HEAD MRI GUIDELINES, BUT MRI IS EITHER CONTRAINDICATED OR THE PATIENT IS CLAUSTROPHOBIC AND CANNOT TOLERATE MRI EXAMINATION. REFERENCES/LITERATURE REVIEW: 1. Morón FE, Morriss MC, Jones JJ, Hunter JV. Lumps and Bumps on the Head in Children: Use of CT and MR Imaging in Solving the Clinical Diagnostic Dilemma. RadioGraphics 2004; 24: 1655-1674. 2. Adelman AM, Daly MP. Initial Evaluation of the Patient with Suspected Dementia. American Family Physician 2005; 71(9): 1745-1750. 3. Petrella JR, Coleman RE, Doraiswamy PM. Neuroimaging and Early Diagnosis of Alzheimer Disease: A look to the future. Radiology 2003; 226: 315-336. CT – Head 10 Copyright 2009, American Imaging Management, Inc. All Rights Reserved. REFERENCES/LITERATURE REVIEW: 4. Morón FE, Morriss MC, Jones JJ, Hunter JV. Lumps and Bumps on the Head in Children: Use of CT and MR Imaging in Solving the Clinical Diagnostic Dilemma. RadioGraphics 2004; 24: 1655-1674. 5. Adelman AM, Daly MP. Initial Evaluation of the Patient with Suspected Dementia. American Family Physician 2005; 71(9): 1745-1750. 6. Petrella JR, Coleman RE, Doraiswamy PM. Neuroimaging and Early Diagnosis of Alzheimer Disease: A look to the future. Radiology 2003; 226: 315-336. 7. Shevell M, Ashwal S, Donley D, et al. Practice Parameter: Evaluation of the child with global developmental delay. Neurology 2003; 60: 367-380. 8. Medina LS, D'Souza B, Vasconcellos E. Adults and Children with Headache: Evidence-based diagnostic evaluation. Neuroimaging Clinics of North America 2003; 13: 225-235. 9. Strain JD. ACR Appropriateness Criteria on Headache-Child. J Am Coll Radoil 2007; 4: 18-23. 10. Lewis DW, Ashwal S, Dahl G, et al. Practice Parameter: Evaluation of Children and Adolescents with Recurrent Headaches. Neurology 2002; 59: 490-498. 11. Qureshi AI, Tuhrim S, Broderick JP, et al. Spontaneous Intracerebral Hemorrhage. N Engl J Med 2001; 344: 1450-1460. 12. Edlow JA, Caplan LR. Avoiding Pitfalls in the Diagnosis of Subarachnoid Hemorrhage. N Engl J Med 2000; 342: 29-36. 13. Osborn, Anne G., Editor. Diagnostic Imaging: Brain. Salt Lake City, Utah: Amirsys; 2004. 14. McDonald WI, Compston A, Edan G, et al. Recommended Diagnostic Criteria for Multiple Sclerosis: Guidelines from the International Panel on the Diagnosis of Multiple Sclerosis. Annals of Neurology 2001; 50(1): 121-127. 15. Bernal B, Altman NR. Evidence-Based Medicine: Neuroimaging of Seizures. Neuroimaging Clinics of North America 2003; 13: 211-224. 16. Hauer KE. Discovering the Cause of Syncope: A Guide to the Focused Evaluation. Postgraduate Medicine 2003; 113(1): 31- 38. 17. Haydel MJ, Preston CA, Mills TJ, et al. Indications for Computed Tomography in Patient with Minor Head Injury. N Engl J Med 2000; 343(2): 100-105. 18. Gean, Alisa D. Imaging of Head Trauma. New York: Raven Press; 1994. 19. Provenzale JM. CT and MR Imaging of Nontraumatic Neurologic Emergencies. AJR 2000; 174: 289-299.
