FIGURE 3. Menstruation. (A) Axial PET/CT image shows increased endometrial 18F-FDG (arrows point to endometrial cavity on, from left to right, CT, PET, and fusion images). (B) Sagittal PET/CT image shows a linear increased 18F-FDG uptake in the endometrium (arrows point to endometrial cavity on, from left to right, CT, PET, and fusion images).