Summary & Overview
CPT 78645: Imaging to Assess Cerebrospinal Fluid Shunt Patency
CPT code 78645 represents a neuroradiology imaging study performed to evaluate the patency and function of a cerebrospinal fluid (CSF) shunt system by visualizing CSF flow. This service matters nationally because CSF shunt malfunction can lead to acute neurologic deterioration and costly inpatient care; timely, accurate imaging helps guide clinical decisions and resource use across hospitals and outpatient imaging centers. Key payers in national coverage discussions include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare and Medicare. Readers will learn the clinical context of CPT code 78645, typical sites of service, and which major payers are relevant to coverage and reimbursement considerations. The publication also summarizes available benchmarks and policy-relevant points where data permit, describes common billing modifiers when present in records, and outlines typical clinical indications and workflow implications for neuroradiology teams. Data not available in the input for specific associated taxonomies, ICD-10 diagnoses, and related procedure codes are noted where applicable.
Billing Code Overview
CPT code 78645 describes an imaging procedure to evaluate the patency and function of a cerebrospinal fluid (CSF) shunt system by visualizing CSF flow. The procedure assesses whether the shunt is providing an alternative fluid pathway to bypass an obstruction in the brain's fluid compartments and prevent excess cerebrospinal fluid buildup.
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Service type: Diagnostic imaging procedure to assess CSF shunt function
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Typical site of service: Hospital radiology departments, outpatient imaging centers, or other acute care settings where neuroradiology studies are performed
Clinical & Coding Specifications
Clinical Context
A 45-year-old patient with a ventriculoperitoneal (VP) cerebrospinal fluid (CSF) shunt presents with progressive headaches, nausea, and intermittent confusion. The neurosurgeon suspects shunt malfunction or partial obstruction. The clinical workflow begins with outpatient triage and neurologic assessment, followed by orders for shunt patency imaging. In the radiology suite or nuclear medicine department, the patient receives a small intrathecal injection of radiotracer via lumbar puncture or through a shunt reservoir under sterile technique. Dynamic and delayed images are obtained to visualize CSF flow through the proximal and distal shunt tubing and to confirm flow to the peritoneal cavity or other drainage site. Images are interpreted by a neuroradiologist or nuclear medicine physician; results are communicated to the referring neurosurgeon to guide decisions about shunt revision, externalization, or conservative management. Typical site of service is an outpatient radiology or nuclear medicine department, or inpatient/observation setting when the patient is admitted for suspected acute shunt failure.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 | Professional component | Use when billing only the physician interpretation component separate from technical imaging. |
TC |