Functional MRI Brain - CAM 761

Functional MRI (fMRI) of the brain is a non-invasive imaging technique, using radio waves and a strong magnetic field, to image the brain activity of a patient prior to undergoing brain surgery for tumors or epilepsy. It is based on the increase in blood flow to the local vasculature when parts of the brain are activated and helps to determine the location of vital areas of brain function. fMRI images capture blood oxygen levels in parts of the brain that are responsible for perception, cognition, and movement allowing neurosurgeons to operate with less possibility of harming areas that are critical to the patient’s quality of life

fMRI and Brain Tumors fMRI may significantly affect therapeutic planning in patients who have potentially resectable brain tumors. Due to its non-invasiveness, its relatively high spatial resolution, and its pre-operative results, fMRI is used before surgery in the evaluation of patients with brain tumors. fMRI may have a significant role in mapping lesions that are located in close proximity to vital areas of brain function (language, sensory motor, and visual). It can determine the precise spatial relationship between the lesion and adjacent functionally essential parenchyma, allowing removal of as much pathological tissue as possible during resection of brain tumors without compromising essential brain functions. fMRI provides an alternative to other invasive tests such as the Wada test and direct electrical stimulation.

fMRI and Seizures – Brain fMRI can influence the diagnostic and therapeutic decisions of the seizure team, thereby affecting the surgical approach and outcomes. Brain surgery is often the treatment for patients with epilepsy, especially patients with s single seizure focus. fMRI can be used to image and localize abnormal brain function in patients with seizures. fMRI can help determine brain functions (language, sensory motor, and visual) of areas bordering the lesion, resulting in better outcomes with less neurologic deficit.

fMRI as an Alternative to the Invasive WADA test and Direct Electrical Stimulation fMRI is considered an alternative to the Wada test and direct electrical stimulation as it is a non-invasive method for location of vital brain areas. The Wada test is used for the pre-operative evaluations of patients with brain tumors and seizures to determine which side of the brain is responsible for vital cognitive functions, e.g., speech and memory. It can assess the surgical risk of damaging the vital areas of the brain. The Wada test is invasive, involving an angiography procedure to guide a catheter to the internal carotid where a barbiturate is injected, putting one hemisphere of the brain to sleep. Direct electrical stimulation mapping is invasive requiring the placement of electrodes in the brain. The electrodes are used to stimulate multiple cortical sites in the planned area of resection to allow the surgeons to identify and mark which areas can be safely resected.

FUNCTIONAL BRAIN MRI is considered MEDICALLY NECESSARY for the following indications:

Pre-operative/procedural Evaluation:
In the following where fMRI may have a significant role in the mapping a lesion in relation to eloquent cortex (i.e., language, motor, sensory and visual centers) 

  • Focal brain lesion (i.e., tumor or vascular malformation) for presurgical planning.
  • Brain tumor for radiation treatment planning.
  • Pre-operative evaluation for epilepsy surgery.

Post-operative/procedural Evaluation:

  • Therapeutic follow-up. A documented medical reason must clearly explain the medical necessity for follow up (i.e., evaluation of post-treatment eloquent cortex).


  1. American College of Radiology (ACR). ACR–ASNR–SPR practice parameter for the performance of functional magnetic resonance imaging (fmri) of the brain. Published 2017.
  2. Benjamin CFA, Dhingra I, Li AX, et al. Presurgical language fMRI: Technical practices in epilepsy surgical planning. Hum Brain Mapp. 2018 Oct; 39(10):4032-4042. doi: 10.1002/hbm.24229. Epub 2018 Jul 1.
  3. Binder JR. Functional MRI is a valid noninvasive alternative to Wada testing. Epilepsy Behav. 2011; 20:214-222.
  4. Bizzi A, Blasi V, Falini A, et al. Presurgical functional MR imaging of language and motor functions: validation with intraoperative electrocortical mapping. Radiology. 2008; 248:579-589.
  5. Janecek JK, Swanson SJ, Sabsevitz DS, et al. Language lateralization by fMRI and Wada testing in 229 patients with epilepsy: Rates and predictors of discordance. Epilepsia. 2013; 54:314-322.
  6. Jiao Y, Lin F, Wu J, et al. Brain arteriovenous malformations located in language area: Surgical outcomes and risk factors for postoperative language deficits. World Neurosurg. 2017 Sep; 105:478-491. doi: 10.1016/j.wneu.2017.05.159. Epub 2017 Jun 8.
  7. Kovács A, Tóth L, Glavák C, et al. Integrating functional MRI information into conventional 3D radiotherapy planning of CNS tumors. Is it worth it? J Neurooncol. 2011 Dec; 105(3):629-37. doi: 10.1007/s11060-011-0633-2. Epub 2011 Jul 2.
  8. Petrella JR, Shah LM, Harris KM, et al. Preoperative functional MR imaging localization of language and motor areas: Effect on therapeutic decision making in patients with potentially resectable brain tumors. Radiology. 2006; 240:793-802. doi: 10.1148/radiol.2403051153.
  9. Silva MA, See AP, Essayed WI, et al. Challenges and techniques for presurgical brain mapping with functional MRI. Neuroimage Clin. 2017; 17:794–803. doi:10.1016/j.nicl.2017.12.008.
  10. Stancanello J, Cavedon C, Francescon P, et al. fMRI integration into radiosurgery treatment planning of cerebral vascular malformations Med Phys. 2007 Apr; 34(4):1176-84.
  11. Vysotski S, Madura C, Swan B, et al. Preoperative FMRI associated with decreased mortality and morbidity in brain tumor patients. Interdiscip Neurosurg. 2018 Sep; 13:40-45. doi: 10.1016/j.inat.2018.02.001. Epub 2018 Feb 14.
  12. Wang M, Ma H, Wang X, et al. Integration of BOLD-fMRI and DTI into radiation treatment planning for high-grade gliomas located near the primary motor cortexes and corticospinal tracts. Radiat Oncol. 2015 Mar 8; 10:64. doi: 10.1186/s13014-015-0364-1.
  13. Wengenroth M, Blatow M, Guenther J, et al. Diagnostic benefits of presurgical fMRI in patients with brain tumours in the primary sensorimotor cortex. Eur Radiol. 2011; 21(7):1517–1525. doi:10.1007/s00330-011-2067-9.  

Coding Section

Codes Number Description
CPT 70554 Magnetic resonance imaging, brain, functional MRI; including test selection and administration of repetitive body part movement and/or visual stimulation, not requiring physician or psychologist administration 
  70555 Magnetic resonance imaging, brain, functional MRI; requiring physician or psychologist administration of entire neurofunctional testing 

Procedure and diagnosis codes on Medical Policy documents are included only as a general reference tool for each policy. They may not be all-inclusive. 

This medical policy was developed through consideration of peer-reviewed medical literature generally recognized by the relevant medical community, U.S. FDA approval status, nationally accepted standards of medical practice and accepted standards of medical practice in this community, Blue Cross Blue Shield Association technology assessment program (TEC) and other non-affiliated technology evaluation centers, reference to federal regulations, other plan medical policies, and accredited national guidelines.

"Current Procedural Terminology © American Medical Association.  All Rights Reserved" 

History From 2014 Forward     


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