Appendicitis

	The appendix is markedly swollen. The serosa is hyperemic and covered by a fibrinous exudate. Compare the inflamed appendix to the adjacent segments of a normal appendix.
Pathology	Imaging
The appendix is inflamed. The lumen is filled with neutrophils. The mucosa is ulcerated.	Appendix measures 7 mm or more Abnormally distended appendix Thick-walled appendix Appendix is not compressible on ultrasound.
There is inflammation of visceral and parietal peritoneum.	Ileus: Dilated loops of bowel Periappendiceal inflammation/inflammatory infiltration of fat Free fluid in cul de sac Cecal thickening Pericecal lymphadenopathy.
Appendiceal inflammation is associated with obstruction in 50 to 80% of cases (due to fecolith, tumor or ball of worms - Oxyuriasis vermicularis).	Appendicolith
Complications
Perforation (most serious)	Free air in abdomen
Pyelophlebitis with thrombosis of the portal vein
Abscess	Inflammatory mass, air pockets, contrast enhancement
Diagnosis of appendicitis is based on clinical picture and imaging studies can be normal


CT scan showing Appendicolith Arrow points to the appendicolith. Arrowhead points to the appendix. Arrow points to the thickened bowel wall. Arrowheads point to inflammatory infiltration of the fat.
	Acute Appendicitis - Appendicolith CT showing appendicolith and pericecal inflammation of fat (white strands).

CT scan showing Acute Appendicitis Dilated appendix Dilated loops of bowel	CT scan showing findings of appendiceal abscess. Arrows point to the inflammatory mass in the right lower quadrant with an air pocket, indicating an abscess. Mass demonstrates contrast enhancement.