From:  Surgical interventions: new approaches in diverticulitis treatment

 CT scan grading of peridiverticular inflammation.

GradeCT peridiverticular inflammation
1: MinimalRare fine threads of high attenuation
2: MildMultiple threads of high attenuation that remain distinct, vessels are clearly visible
3: ModerateMany threads are difficult to resolve individually, and vessels are difficult to discern
4: SevereDominant pattern of increased attenuation in the fat could be mistaken for fluid collection, vessels not visible