Question: Our office performs CSF flow studies with head MRIs, usually for Chiari malformations. The flow studies use the same software as the MRA studies, so should we use head MRA or unlisted MRI codes? Or should I just include this in the head MRI? Connecticut Subscriber Answer: You should include the cerebrospinal fluid (CSF) flow study in the head MRI. The head MRA codes are specific to blood flow, so using an MRA code for a CSF study would not be accurate. A magnetic resonance CSF flow study is an MRI of the brain or spine. That means you should look to codes in the ranges of 70551-70553 (Magnetic resonance [e.g., proton] imaging, brain [including brain stem] ...) and 72141-72142 (Magnetic resonance [e.g., proton] imaging, spinal canal and contents, cervical ...). The radiologist uses the test to evaluate the CSF flow around the brain, brainstem, and spinal cord.