CPT 70557: Intraoperative Non-Contrast Brain MRI Including Brain Stem and Skull Base - OpenPayer

Summary & Overview

CPT 70557: Intraoperative Non-Contrast Brain MRI Including Brain Stem and Skull Base

CPT code 70557 denotes an intraoperative, non-contrast MRI of the brain including the brain stem and skull base performed during open cranial surgery to evaluate for residual tumor or vascular malformation. This procedure supports immediate surgical decision-making and can reduce the need for return procedures by identifying residual disease before surgical closure. Nationally, intraoperative imaging carries implications for surgical quality, facility resource use, and perioperative cost structures.

Key payers in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of clinical intent and typical use cases, national coverage themes, and operational considerations relevant to hospitals and surgical teams. The publication covers benchmark metrics where available, summarizes payer coverage patterns, and highlights policy updates and coding considerations that affect billing and claim adjudication for intraoperative brain MRI services.

This summary is aimed at healthcare policy analysts, hospital billing leaders, and neurosurgical program administrators seeking a clear national perspective on CPT code 70557, including clinical context, payer scope, and areas where institutions commonly focus policy or operational changes.

AetnaBlue Cross Blue ShieldCigna HealthUnitedHealthcareMedicare70557CPTintraoperative MRIbrain MRIneurosurgeryoperative imagingnon-contrast MRIintraoperative care

Billing Code Overview

CPT code 70557 describes an intraoperative magnetic resonance imaging (MRI) of the brain that includes the brain stem and skull base performed without contrast during an open brain surgery. The service is intended to allow the surgical team to assess for residual tumor or residual vascular malformation while the patient remains in the operative setting.

Service type: Intraoperative MRI, non-contrast
Typical site of service: Operating room during open cranial surgery

Clinical & Coding Specifications

Clinical Context

A 54-year-old patient undergoing craniotomy for resection of a known intracranial neoplasm returns to the operating room for intraoperative imaging to assess for residual tumor at the skull base and brain stem. The neurosurgeon pauses the resection, and an intraoperative magnetic resonance imaging (iMRI) scanner is brought into the sterile field. Without intravenous contrast, the radiology team acquires 70557 sequences of the brain including the brain stem and skull base to evaluate for residual tumor tissue or vascular malformation. Images are reviewed immediately by the operating neurosurgeon and an attending neuroradiologist to determine whether further resection is indicated. The service is coded for a non-contrast intraoperative MRI of the brain during the open cranial procedure. Typical site of service is the operating room within a hospital or an intraoperative MRI suite attached to the surgical theater. Common clinical indications include tumor resection confirmation, assessment of residual arteriovenous malformation after partial excision, or evaluation of unexpected intraoperative findings that could alter operative strategy.

Coding Specifications

Modifier	Description	When to Use
`22`	Increased procedural services	Use when work, time, or technical difficulty of the intraoperative MRI is substantially greater than typical.

Related Codes

70450

CPT 70450: CT Scan of Head or Brain Without Contrast

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CPT 70190: X‑ray of Optic Foramina for Optic Nerve and Ophthalmic Artery

cpt-70355-panoramic-jaw-radiograph-fracture-evaluation

CPT 70355: Panoramic Jaw Radiograph for Fracture Evaluation

cpt-70134-internal-auditory-canal-radiography

CPT 70134: Radiography of Internal Auditory Canals, Diagnostic

cpt-70210-paranasal-sinus-xray-sinusitis-assessment

CPT 70210: Paranasal Sinus X‑ray for Sinusitis Assessment

cpt-70330-tmj-radiography-open-closed-mouth-bilateral

CPT 70330: Bilateral TMJ Radiography, Open and Closed Mouth

cpt-70496-ct-angiography-head-intravenous-contrast

CPT 70496: CT Angiography of Head with Intravenous Contrast

cpt-70336-mri-temporomandibular-joint-tmj

CPT 70336: MRI of Temporomandibular Joint (TMJ)

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CPT 70370: Fluoroscopic/Magnified Exam of Pharynx and Larynx

cpt-70371-pharyngeal-speech-cineradiography-video-evaluation

CPT 70371: Pharyngeal and Speech Evaluation by Cineradiography/Video

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Taxonomy Code	Specialty	Notes
2084P0800X	Neurosurgery	Primary surgical specialty performing craniotomy and intraoperative decision-making.
207T00000X	Radiology	Radiologists perform intraoperative image acquisition and interpretation.
363L00000X	Neurology	Consultative role for perioperative neurological assessment and imaging correlation.
206E00000X	Anesthesiology	Provides anesthesia support for intraoperative imaging in the OR.
261QM0800X	Vascular Neurology/Endovascular Neurosurgery	Involved when vascular malformations are the operative target and intraoperative imaging guides resection.

Related Diagnoses

ICD-10 Code	Description	Clinical Relevance
`C71.0`	Malignant neoplasm of cerebrum, except lobes and ventricles	Common primary brain tumor location that may require intraoperative MRI to confirm extent of resection.
`C71.8`	Malignant neoplasm of overlapping sites of brain	Tumors spanning regions including skull base/brain stem where intraoperative imaging guides additional resection.
`D33.4`	Benign neoplasm of brain, infratentorial	Posterior fossa tumors that often need intraoperative imaging to assess residual tissue near brain stem.
`Q28.2`	Arteriovenous malformation of cerebral vessels	Vascular malformations where intraoperative MRI can detect residual nidus after partial excision.
`I67.6`	Nonpyogenic thrombosis of intracranial venous system	Complications or vascular lesions that may be evaluated intraoperatively when unexpected findings occur.
`G93.6`	Cerebral edema, unspecified	Intraoperative imaging can evaluate extent and guide intraoperative management if edema alters surgical approach.
`G45.9`	Transient cerebral ischemic attack, unspecified	Imaging sometimes used intraoperatively if ischemic complication is suspected during resection.
`R90.89`	Other abnormal findings on diagnostic imaging of central nervous system	Used when intraoperative MRI identifies unexpected residual lesion or abnormality requiring documentation.

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`61107`	Craniectomy or craniotomy for excision of lesion, supratentorial; single lobe	Performed before intraoperative MRI; the operative resection that prompts use of `70557` to assess residual lesion.
`61154`	Craniectomy or craniotomy for excision of lesion, infratentorial or posterior fossa; for lesions of the brain stem or skull base	Often the primary procedure when intraoperative `70557` is used to evaluate resection at the skull base or brain stem.
`70553`	MRI brain without contrast (standard, non-intraoperative)	Preoperative or postoperative baseline MRI that complements intraoperative `70557` for planning and follow-up.
`70552`	MRI brain without and with contrast	Sometimes performed pre- or postoperatively when contrast-enhanced evaluation is required; not used intraoperatively for `70557` (non-contrast).
`76000`	Fluoroscopic guidance for needle placement (diagnostic or therapeutic)	May be used intraoperatively for adjunct localization or biopsy before or after MRI-guided assessment.