radiology appendicitis

1. APPENDICITIS
DR. SABHILASH SUGATHAN
https://www.pacsbin.com/c/ZyenvVwTS4

2. Here!
Transverse colon
Asc . colon
Desc . colon
Sigmoid colon
Terminal Ileum
Caecum
ASIS

3. GROSS ANATOMY
The appendix arises from the posteromedial surface of the caecum, approximately 2-3 cm
inferiorly to the ileocaecal valve, where the taena coli converge. It is a blind diverticulum, which is
variable in length from 2-20 cm.The appendix lies on its own mesentery, the mesoappendix.
The tip of the appendix can have a variable position within the abdominal cavity :
-retro-caecal (65-70%)
-pelvic (25-30%)
-pre- or post-ileal (5%)

4. PATHOPHYSIOLOGY
Mechanical obstruction of fecolith in caecum
Secretions distend obstructed appendix
Increase in intraluminal preassure
Ischemia , Mucosal ulceration , Invasion of wall by bacteria
Inflamation of appendix
Perforation of appendix
Free intraperitoneal spill
PERITONITIS
Spill off pus and is walled off
by omentum, mesentry,
bowel loop adhesions
APPENDICULAR MASS

5. Natural course of untreated appendicitis

6. CLASSIC PRESENTATION
Seen in 60 %
Anorexia
Periumbilical pain, nausea, vomiting RLQ pain developing over 24hrs.
Anorexia and pain are most frequent
Usually nausea, sometimes vomiting
Diarrhea, esp. with pelvic location
Usually tender to palpation
Rebound is a later finding

7. TIME COURSE
Appendiceal
obstruction/early
appendicitis –
visceral peritoneal
irritation
• Periumbilical
colicky pain
Appendiceal
distension
• Anorexia, vomi
ting, malaise
Irritation of parietal
peritoneum
( localised )
• Constant RIF
pain, pain on
coughing, going
over bumps etc
Perforation, localised
/generalised
peritonitis, mass
• Fever/Sepsis

8. Special Clinical signs
Abdominal examination
 Psoas Sign – pain on hip extension
 Rovsing Sign – RIF pain on palpating LIF
 “The walk” – walk with R hip flexed, bent over
 Pain on coughing/unable to cough

10. PLAIN FILMS
Low sensitivity and specificity
Appendicolith specific, but seen in
2% only
May see local air-fluid levels, psoas
obliteration, soft tissue mass, gas in
appendix : all nonspecific

11. BARIUM STUDIES
Non filling of appendix with extra or intramural mass intending medial
aspect of caecum
Displaced or narrowed terminal ileum
Thickening of terminal ileal mucosal folds
Barium extravasation in periappendecial abscess

12. ULTRASOUND
• -Aperistaltic, noncompressible, dilated appendix (
>6 mm outer diameter)
• blind-ending
• - concentrically layered (Distinct appendiceal wall
layers)
• in a constant position, usually at the site of
maximum tenderness
• -Echogenic prominent pericaecal fat
• -Periappendiceal fluid collection
• -Appendicolith(in 35% an intraluminal fecolith
(arrows) is found at the level of obstruction )
• -Target appearance (axial section)

13. •Calcified appendicolith
•Ileal and caecal fluid level – Focal Ileus
•Poorly defined mass with displacement of
adjacent loops of bowel
•Small bowel obstruction
•Blurring of properitoneal fat line
•Blurring of right psoas line
•RLQ haze due to fluid or edema
•Gas in the appendix – unreliable

14. DOPPLER IMAGING
Hyperemia in the appendecial wall
and adjacent meso appendix
In gangrenous – no / decreased
perfusion
In CE USG – Contrast enhancement
because of hyperemia

15. Inflamed fat
The fatty tissue that is first involved in appendicitis,
the appendix or meso-appendix.
Roughly 4-6 hours after the onset of symptoms, the
begins to affect the meso-appendix, which becomes
hyperechoic and non-compressible (arrowheads).
This patient presented with severe, acute
periumbilical pain since 4 hours and had no
localized pain over the dilated appendix. (visceral
pain-phase).
Note the bulging of the tense appendix in the
abdominal wall (arrowheads) during compression.
fatty tissue around the appendix tends to increase in
volume.
This represents the fatty omentum, which has
migrated towards the appendix in an attempt to
wall-off the imminent perforation.

16. large quantities of inflamed fat (*) and the thickened ileum
representing successful walling-off of the (imminent) perforation o
(imminent) perforation of the appendix (arrow).
The more the layer structure is affected, the higher the chance for
perforation.
The first sign being echolucent changes in the hyperechoic
submucosa.

17. THE “APPENDICEAL MASS”
Not infrequently, patients seek medical help (or are admitted) with considerable
delay (> 4-5 days).
These patients often present with a palpable mass and relatively mild peritonitis.
US and CT often show a large mass of non-compressible fat around the appendix,
often also with wall thickening of neighboring bowel loops.
If there is a circumscribed pus collection, the diagnosis is appendiceal abscess. If
not, the diagnosis is appendiceal phlegmon.

19. If conservative treatment of an appendiceal phlegmon is successful, follow up US shows a decrease in size of the
periappendiceal mass (arrowheads) within the course of weeks to months.

20. APPENDICEAL ABSCESS
If next to the inflamed appendix, a more or less circumscribed
fluid collection is found, this is suggestive for an appendiceal
abscess.
The collection often contains air, not infrequently (~50 %) a
fecolith and is surrounded by inflamed non-compressible fatty
tissue.
Patient with a small appendiceal abscess, ventrally
walled-off by the ileum.
The appendix (arrows) is small because it has
evacuated its purulent contents in to the abscess.
Note the calcified fecolith (arrowhead) on the bottom
of the abscess.
Drainage was performed from laterally.

23. CT SCAN
The need for contrast (IV, oral or both) is debatable and varies from institution to institution. Findings include :
•-appendiceal dilatation (>6 mm outer diameter) 4
•wall thickening (>3 mm) and enhancement
•thickening of the cecal apex: cecal bar sign, arrowhead sign
•intraluminal fluid depth >2.6 mm in a dilated (>6 mm) appendix without periappendiceal inflammation
•periappendiceal inflammation
• fat stranding
• thickening of the mesoappendix
• extraluminal fluid
• phlegmon (inflammatory mass)
• abscess
•focal wall non-enhancement representing necrosis (gangrenous appendicitis) and a precursor to perforation
Less specific signs may be associated with appendicitis:
•appendicolith
•periappendiceal reactive nodal enlargement
Luminal diameter
6mm with 2nd ry changes
• Fat stranding
• Cecal thickening
• Crowding of mesentry
9mm with out 2nd ry
changes

26. CAECAL BARSIGN
The caecal bar sign is a secondary
sign in acute appendicitis.
• It refers to the appearance of
inflammatory soft tissue at the
base of the appendix, separating
the appendix from the contrast-
filled caecum.Inflamed caecal
wall interposed between the
caecal content and obstructing
appendicolith.

27. ARROWHEADSIGN
The arrowhead sign refers to the focal
caecal thickening centered on the
appendiceal orifice, seen as a secondary
sign in acute appendicitis.
•The contrast material in the cecal lumen
assumes an arrowhead configuration,
pointing at the appendix
The arrowhead sign is applicable only when
enteric contrast distends the caecum.

28. MRI
Indication – Sonography is equivocal and CT is not available or c/I
T1WI – Enhancemment of wall
T2WI – Hyperintense wall with markedly hyperintense center(intraluminal fluid)

29. MAJORCOMPLICATIONS
1.Perforation
If appendicitis is allowed to progress, portions of the appendiceal wall eventually become
ischemic or necrotic and the appendix perforates.
CT findings—extraluminal air, extraluminal appendicolith, abscess, phlegmon, and a defect in
the enhancing appendiceal wall—allows excellent sensitivity (95%) and specificity (95%) for
perforation in patients with known appendicitis who underwent preoperative CT.
In that study, the individual finding with highest sensitivity was a mural enhancement defect
(64%).

30. 32-year-old man with acute appendicitis.Unenhanced CT shows
appendicolith (arrowhead), periappendiceal fat stranding (black
arrows), lateral conal fascia thickening (white arrow), and
periappendiceal fluid. Perforation was confirmed on surgery

31. 2.Periappendiceal Abscess
Abscess is the most frequent complication of
perforation.The abscess remains localized if
periappendiceal fibrinous adhesions develop
before rupture.
CT shows a loculated, rimenhancing fluid collection
that may have mass effect on adjacent bowel loops.
If the abscess is large (> 4 cm), percutaneous drainage
followed by delayed appendectomy is the preferred
treatment .
47-year-old man with periappendiceal abscess. Helical CT
after IV contrast injection shows periappendiceal abscess
extending into psoas muscle (arrowheads).

32. 3.Peritonitis
4.Bowel Obstruction
5.Septic Seeding of Mesenteric Vessels
6.Gangrenous Appendicitis

33. DIFFERENTIAL DIAGNOSIS
1.Mesenteric Adenitis
• Mesenteric adenitis is the most common alternative
condition identified at negative appendectomy.
• It is defined as a benign self-limiting inflammation of
right-sided mesenteric lymph nodes without an
identifiable underlying inflammatory process,
occurring more often in children than in adults.
• Sonography and CT show- enlargement (> 5 mm) of
mesenteric lymph nodes,thickening of the adjacent
cecum and ileum, and a normal appendix

34. 2. Bacterial ileocecitis
• This presentation may occur in bacterial
ileocecitis,caused byYersinia,
Campylobacter, or Salmonella.
• Imaging studies show –mural thickening
of the terminal ileum and cecum
without inflammation of the surrounding
fat and moderate mesenteric
adenopathy.
Sonography shows moderate mural thickening of the terminal ileum
and cecum, surrounded by normal noninflamed fat. Moderate
mesenteric lymphadenopathy was also present

35. 3. Epiploic appendagitis
• small adipose protrusions from the serosal
the colon. Undergo torsion and secondary
inflammation, causing focal abdominal
simulates appendicitis when located in the
quadrant.
• Epiploic appendagitis is a self-limiting
been reported in approximately 1% of
suspected of having appendicitis.
• Sonography and CT depict an inflamed
adjacent to the colon containing a
hyperattenuating ring of thickenend
visceral peritoneal lining on CT.
• Mc left
hyperechoic inflamed fatty mass (arrowheads)
adjacent to the colon (arrow), at the spot of
maximum tenderness

36. 4.Omental Infarction
• Omental infarction has a
presentation similar to that of epiploic
with the infarcted fatty tissue being a
segment of the omentum.
• Imaging shows a cakelike inflamed fatty
than in epiploic appendagitis and
hyperattenuating ring on CT.
• Mc right

37. 5. Right-sided colonic diverticulitis
• In contrast to sigmoid diverticula, right-
diverticula are usually true diverticula, that
outpouchings of the colonic wall
the wall.
This may possibly explain the essentially
limiting character of right-sided
• Sonography and CT findings consist of
changes in the pericolic fat with segmental
the colonic wall, at the level of an inflamed
(Fig. 10).
Unenhanced CT shows extensive with fat-standing along the
cecal wall (arrowheads), and a normal appendix (arrow). B,
Sonography reveals the cause of the inflammation by depicting
an inflamed cecal diverticulum (arrow) centred in the hyperechoic
fat.

38. 6.Crohn's Disease
• Crohn's disease is a chronic granulomatous inflammatory
condition that can involve any segment of
thegastrointestinal tract but most commonly involves
theterminal ileum and right colon.
• Crohn disease often causes long-standing symptoms, but
up to one third of patients with ileocecal Crohn disease
present with initial symptoms so acute that they are
misdiagnosed as appendicitis.
• In the acute active phase of ileocecal Crohn disease,
imaging shows transmural bowel wall thickening, often
predominantly of the submucosal layer, with frequent
inflammatory changes of the surrounding fat.
Uncomplicated Crohn disease can initially be treated with
anti-inflammatory drugs.
Sonography shows transmural wall thickening of the terminal ileum (arrows) in
longitudinal (A) and transverse (B) section, with hyperechoic inflammatory
changes of the surrounding fat (arrowheads).C, Contrast-enhanced CT confirms
the wall thickening and luminal narrowing of the terminal and pre-terminal ileum
(arrowheads), with regional fat-stranding.

39. Others
Gynecologic conditions - pelvic inflammatory disease or a hemorrhagic
functional ovarian cyst
Urolithiasis
Rectus sheath hematoma

40. THANK YOU..

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