Right iliac fossa pain should not be related only to digestive diseases, but also to urinary and gynecological disorders. Fig. 1
Imaging techniques that are suggested are ultrasound and CT scan.
Ultrasound should be preferred in children, pregnant women and throught young patients.
CT scans are more often used in first line when there are signs of seriousness from the start, in elderly subjects or in second line if the ultrasound is non contributive.
Multislice CT scan hold a key role as an effective and rapid diagnostic technique to be done in acute phase, in order to approach the correct diagnosis, to evaluate for complications and to guide the therapeutic choice betwen either medical or surgical treatment.
According to etiology, the main causes of septic syndrome of the right iliac fossa are digestive, urinary and gynecological.
Acute appendicitis :typical disease of children and young adults
Clinical findings: localized pain with Mc Burney sign, fever, leucocitosys, nausea and vomiting.
Sometimes, an infectious syndrome can be missing with even a normal number of WBC and normal CRP levels.
Imaging: dilated thickened appendix more than 6 mm in diameter on the ultrasound and CT scan. Fig. 2
US :
- Non compressible appendix
- Peri appendicular fat infiltration
- Non specific peri caecal ganglions
- The compression manoeuvre increase pain
CT :
- Dilated appendix, thickened and enhanced wall
- Extraluminal fluid
- Peri-appendicular and peri-caecal fat stranding
- Stercolith
We can use the Alvarado score which is a clinical/biological score for the prediction of appendicitis when there are a non-specific presentation.
Complicated appendicitis :
Clinical findings: pain, fever and leucocytosis. Fig. 3
Imaging: CT scan is mainly used to show :
- Extra-luminal gas or stercolith
- Localized thickening of the parietal peritoneum
- A necrotic central zone encapsulated by enhancing wall
Appendiceal mucocele : tipically present in middle aged patients, due to abnormal accumulation of mucin that causes abnormal dilatation of the appendix. Fig. 4
Clinical findings : abdominal pain.
Imaging :
- Dilated appendix
- Well-circumscribed,mural calcification
Epiploic appendagitis : ischaemic process involving an appendix epiploica of the colon. Fig. 5
Clinical findings: highly localized pain with no septic syndrome at the beginning.
Imaging:
- Fat density oval-shaped mass surrounded by a dense ring
- Pericolonic fat stranding
- Localized thickening of the parietal peritoneum
Right colon diverticulitis (RCD) : particularly common within young males. Fig. 6
Clinical findings : right lower quadrant pain without migration, less systematic inflammatory response.
Imaging :
- Thickening and contrast enhancement of colonic wall
- Intramural air bubbles "diverticula"
- Pericolonic fat stranding
- Pricolonic abscesses
Crohn’s disease : idiopathic inflamatory bowel disease defined by widespread gastrointestinal tract involvement between 15 and 30 years old. Fig. 7
Clinical findings : chronic diarrhea, recurrent abdominal pain.
Imaging:
- Circumferential thickening with marked enhancement of the terminal ileum and/or the rightcolon
- Dilated vasa recta with "comb sign" referring to the hypervascular appearance of the mesenter
- Phlegmon or fistulae
Ischemic colitis : particularly among elderly subjects at cardiovascular risk. Fig. 8
Clinical findings: highly localized pain with fever.
Imaging:
- Decreased bowel wall enhancement
- Pericolonic fat stranding
- Parietal pneumatosisis, mesenteric or portal venous gas
Infected caecum tumor : particularly common within elderly subjects. Fig. 9
Clinical findings : palpable mass with septic syndrome.
Imaging:
- Caecal circumferential mass
- Significant parietal thickening
- Pericolonic fat stranding with peri-caecal adenomegaly
- localized pneumoperitoneum in case of tumoural perforation
Pelvic inflammatory diseases (PID) : infection ascending from the endocervix causing endometritis, salpingitis, tubo-ovarian abscess and/or pelvic peritonitis.
Untreated PID can lead to chronic pelvic pain and infertility. Fig. 10
Clinical findings : abdominal pain with abnormal cervical discharge and cervical and/ or uterine tenderness.
Imaging:
- thickened wall with fluid-filled fallopian tube
- enlarged ovary with pelvic fat stranding
- Latero uterine abscess
- Localized thickening of the parietal peritoneum in pelvic peritonitis
Endometriosis: defined as the presence of endometrial tissue outside the uterine cavity, mostly localized on the surface of the ovaries among young females.
Clinical findings: pelvic pain related to menses, dysmenorrhea, dyspareunia and infertility.
Imaging: MRI is able to determine the presence or extent of endometriosis
Complicated ovarian torsion
Urolithiasis : defined as the process of forming stones in the urinary tract including kidney, bladder, and/or urethra. Fig. 11
Clinical findings: sudden onset of severe and colicky pain, not improved by changes in position.
Imaging:
CT :
- Detects all types of urinary tract calculi
- Shows dilatation of the urinary tract upstream of the lithiasic obstacle