Clinical Use of Functional Magnetic Resonance Imaging: Reflections on the New CPT Codes

Abstract

Functional magnetic resonance imaging (fMRI), a noninvasive method for mapping human brain function, was developed 15 years ago. This technique, based on the blood oxygen level dependent (BOLD) contrast, is sensitive to the localized hemodynamic changes that occur with increased neural activity. Over the first decade following this discovery, fMRI was used extensively to map brain activity evoked from sensory, motor, cognitive, and emotional tasks in healthy individuals. More recently, this technique has been applied to further our understanding of neurobehavioral disorders, such as Alzheimer’s disease, epilepsy, brain tumors, stroke, traumatic brain injury, and multiple sclerosis. fMRI has become widespread because it is relatively easy to perform, is reproducible, does not involve the use of exogenous contrast agents, can be performed with the majority of existing MR scanners, and yields superior temporal and spatial resolution relative to other functional imaging techniques (e.g., positron emission tomography). Not surprisingly, some clinicians have appreciated the potential of fMRI as a tool for diagnosis and management of patients. Several professional specialties have begun to apply fMRI techniques to patient care, including clinical neuropsychology, neurology, neuroradiology, neurosurgery, psychiatry, and rehabilitation. The best developed clinical application has involved the use of fMRI in the presurgical mapping of patients with brain tumors and epilepsy. The strength of clinical fMRI research in this area culminated in the approval of fMRI-specific CPT codes (see below), effective January 2007. One of the three approved fMRI codes was specifically designed for clinical neuropsychologists and physicians with education and training in the administration of neurofunctional tests. The advent of CPT codes has raised concerns regarding the appropriate qualifications of clinical neuropsychologists applying fMRI in clinical practice. Regardless of the purpose of study, fMRI is technically challenging with regard to study design, image analysis, and interpretation of findings. The complex nature of this technique increases the risk of over-interpretation or misuse of data when individuals practice this technique without adequate training. To address this concern, Division 40 of the American Psychological Association published a position paper identifying the role of neuropsychologists in clinical fMRI (The Clinical Neuropsychologist, volume 18, 2004). The task force noted that clinical fMRI is a team effort; consequently, clinical neuropsychologists will typically collaborate with professionals with expertise in neuroradiology, neurosurgery, MR physics, and statistical image analysis. Neuropsychologists have extensive training in the development of cognitive tasks and statistical analysis, recognizing the importance of reliability and validity. In clinical practice, neuropsychologists are trained to recognize confounds to assessment of human behavior, interpret findings of cognitive performances, and make appropriate recommendations for treatment. Given the basic, fundamental training in brain-behavior relationships and human behavior, the role of neuropsychology in fMRI is well supported. This paper will first discuss the CPT codes and then provide possible models of education and training that will ensure that the clinical fMRI study is administered and interpreted by a qualified practitioner.