Radiological insights into diverticulitis: Clinical manifestations, complications, and differential diagnosis

Table 1 Classifications in use for staging of acute diverticulitis

Stage	Hinchey classification[16]	Modified Hinchey classification by Kaiser et al[17]	AAST grade[18]	WSES classification by Sartelli et al[20]
0	N/A	Mild clinical diverticulitis	N/A	Uncomplicated diverticulitis
1	Pericolic abscess or phlegmon	1A: Confined pericolic inflammation-phlegmon	Colonic inflammation	1A: Pericolic air bubbles or little pericolic fluid without abscess
		1B: Pericolic-mesocolic abscess		1B: Abscess ≤ 4 cm
2	Pelvic, distant intrabdominal, or retroperitoneal abscess	Pelvic, distant intraabdominal, or retroperitoneal abscess	Colon microperforation or pericolic phlegmon without abscess	2A: Abscess > 4 cm
				2B: Distant air (> 5 cm from inflamed bowel segment)
3	Generalized purulent peritonitis	Generalized purulent peritonitis	Localized pericolic abscess	Diffuse fluid without distant free air (no hole in colon)
4	Generalized fecal peritonitis	Generalized fecal peritonitis	Distant and/or multiple abscesses	Diffuse fluid with distant free air (persistent hole in the colon
5	N/A	N/A	Free colonic perforation with generalized peritonitis	N/A

AAST: American Association for the Surgery of Trauma; WSES: The World Society of Emergency Surgery; N/A: Not applicable.