Semi-quantitative Assessment Using [18F]FDG Tracer in Patients with Severe Brain Injury

Patients with severe traumatic brain injury (sTBI) have difficulty knowing whether they are accurately expressing their thoughts and emotions because of disorders of consciousness, disrupted higher brain function, and verbal disturbances. As a consequence of an insufficient ability to communicate, objective evaluations are needed from family members, medical staff, and caregivers. One such evaluation is the assessment of functioning brain areas. Recently, multimodal brain imaging has been used to explore the function of damaged brain areas. [¹⁸F]-fluorodeoxyglucose positron emission tomography-computed tomography ([¹⁸F]FDG-PET/CT) is a successful tool for examining brain function. However, the assessment of brain glucose metabolism based on [¹⁸F]FDG-PET/CT is not standardized and depends on several varying parameters, as well as the patient's condition. Here, we describe a series of semiquantitative assessment protocols for a region-of-interest (ROI) image analysis using self-produced [¹⁸F]FDG tracers in patients with sTBI. The protocol focuses on screening the participants, preparing the [¹⁸F]FDG tracer in the hot lab, scheduling the acquisition of [¹⁸F]FDG-PET/CT brain images, and measuring glucose metabolism using the ROI analysis from a targeted brain area.