CT Enterography Crohn Disease - Active Mural Enhancement with Comb Sign and Skip Lesions

A 28-year-old male with known Crohn disease presents with a 2-week history of worsening abdominal pain and diarrhea. CT enterography is performed and shows the findings depicted in the diagram. The structure marked **A** (mural enhancement at the terminal ileum) demonstrates marked hyperenhancement with a stratified target appearance on the arterial phase. Which of the following best describes the pathophysiological basis for this imaging finding in active Crohn disease?