“The recent technical progresses in PET have the potential to broaden the spectrum of applications of nuclear medicine for both research and clinical investigations.

Dynamic scans at rest, assessing ¹⁸F-FDG uptake in the first minutes after bolus injection, allow to capture the cortical and subcortical distribution occurring at the same time. In these first minutes, in which the most of the radiopharmaceutical is extracted by the brain before reaching a plateau after about thirty minutes, ¹⁸F-FDG uptake, representing neuronal and glial activity, is consistently couple with brain perfusion [1]. The substantial advancements improving the sensitivity and time resolution of the cameras have paved the way to the implementation of the so-called functional PET, a new methodology implying a slow and constant infusion allowing to monitor tracer uptake during time and to measure within the same session its distribution at rest and while performing a task [2]. Furthermore, dual-phase amyloid-PET scans exploiting the high lipophilicity of the radiopharmaceuticals make of the early dynamic acquisition phase a good perfusion surrogate and a topographical/functional biomarker reflecting disease progression, while the late-phase corresponds to the pathophysiological state [3].

It is in this frame that, in the August 2019 issue of the European Journal of Nuclear Medicine and Molecular Imaging, it is reported an original and well-conducted study aiming at describing in fifteen soldiers suffering from post-traumatic stress disorder (PTSD) following war combat the functional changes occurring before and after eye movement desensitization and reprocessing (EMDR), a trauma-focused psychotherapy promoting the reprocessing of dysfunctionally stored information in traumatized patients [4]. In order to disclose such neurobiological changes, they were exposed from 10 minutes before to 7 minutes after ¹⁸FDG injection to a virtual reality war scene with strong autobiographic connotations. Therefore, the PET images acquired thirty minutes after injection represented the distribution of metabolism in the minutes peri-injection in which the emotional stimulus was administered. This procedure, performed during the symptomatic phase, was repeated after EMDR therapy, thus allowing to detect the metabolic changes associated with symptoms remission. Applying this elegant methodology, they were able to speculate on the role of the precuneus in reprocessing traumatic memories. After EMDR therapy, its modulation of anxious and fearful states made patients perceiving their traumatic event at a cognitive level without overwhelming emotionality.”