This document provides guidance on imaging strategies for evaluating abdominal pain. It discusses: 1. Sonography and CT can accurately and rapidly evaluate patients with acute abdominal pain by confirming or excluding common diseases like appendicitis and cholecystitis. 2. The recommended radiology approach is to first focus on confirming or ruling out the most likely diagnosis based on symptoms, then screen the whole abdomen for signs of pathology. 3. Key imaging findings for common conditions are discussed, including gallbladder wall thickening for cholecystitis and appendiceal diameter for appendicitis. Imaging also helps evaluate complications like abscesses. 4. Bowel obstruction is suggested by findings like dilated bowel loops and air

1. IMAGING
GUIDE TO
ABDOMINAL
PAIN
Siswidiyati

2. ABDOMINAL QUADRANTS
AND REGIONS

3. Severe
abdominal
pain
Clinical
condition non
specific
Laboratory
finding  non
conclusive
Urgent
therapeutic
decision
CHALLENGING
 Management  vary :
emergency surgery,
missdiagnosed  delayed
necessary tx/ unnecessary
surgery
 Sonography and CT enable
an accurate and rapid triage
of patients with an acute
abdomen.

4. ABDOMINAL PAIN
Life Threatening
Aortic aneurysm Rupture
Pancreatitis
Bowel Ischemia
Perforated peptic ulcer
Appendicitis
Cholecystitis
Salpingitis
Sigmoid diverticulitis
Self-limiting
Gastroenteritis
Lymphadenitis
Omental infarction
Epiploic appendagitis

5. RADIOLOGY STRATEGY ???
- Before you perform an examination, obtain relevant information from the
referring clinician.
- Don't let the clinician simply 'order' a sonogram or CT, but discuss the
patient's age and posture, laboratory results and the number one clinical
diagnosis and differential diagnosis
- Based on that information  Better USG or CT scan
- USG : close patient contact, enabling assesment of the spot of maximum
tenderness and the severity of illness without ionizing radiation.
- CT scan : diagnostic accuracy higher than USG
- We advocate the following two-step radiological approach of an acute
abdomen.
1. Confirm or exclude the most common disease
2. Screen for general signs of pathology
USG CT SCAN MRI PLAIN
RADIOGRAPH
Y
DIGITAL
FLUOROSCOP
Y

6. First Rule
Air only
inside the GI
Tract
Second
Rule
No “Free”
Fluid
Free fluid  non
specific, but is good
marker of inflammation
or trauma  should
serve to heighten
suspicion if present
Third Rule
free of
obstruction and
intact
ABDOMEN  full of
pipes : bowel, vessels,
bile duct and renal
collecting system and
ureters.
Fourth Rule
The Body hates
traffic jam,
known as stasis
Stasis due to obstruction
or disruption of normal
motility  increased risk
of infection and
associated inflamation

9. NORMAL
VARIANT
BOWEL
FIGURE
• A plain abdominal film has a limited
value in the evaluation of abdominal
pain.
• A normal film does not exclude an
ileus or other pathology and may
falsely reassure the clinician.
• Plain abdominal film useful to detect
: PNEUMOPERITONEUM AND KIDNEY
STONE

10. RADIOLOGY STRATEGY
Confirm or Exclude the most
common disease
- RLQ pain  appendicitis
- LLQ pain  sigmoid
diverticulitis
- RUQ pain  cholecystitis
- TRAUMA  free fluid
intraabdomen
Screen for general signs of
pathology
 Screening the whole abdomen
 Look for inflamed fat, bowel
wall thickening, ileus, ascites and
free air.

11. THE MOST COMMON
DISEASE

12. CHOLECYSTITIS (RUQ)
•Acute cholecystitis is one of the
most common reasons for hospital
admission with acute abdominal
pain.
•Approximately 90–95% of acute
cholecystitis is related to
gallstones, with 5–10% of cases
due to acalculous disease.
https://www.ajronline.org/doi/full/10.2214/AJR.10.4340
- sonography is the preferred
imaging method for the evaluation
of cholecystitis, also allowing
assesment of the compressiblity
of the gallbladder.
- Do not rely on measurements.
Some galbladders happen to be
small and others are large.

13. SIGN OF
CHOLECYSTITIS
- Hydrops gallbladder
- gallbladder wall thickening
- positive murphy sign

14. ACUTE CHOLECYSTITIS
The gallbladder may be
surrounded by inflamed fat,
but on sonography this
frequently is not seen, while
CT sometimes does show fat-
stranding.

15. - Gallbladder wall thickening+gallstone
using US  PPV 95% for diagnosis of
acute cholecystitis
Unfortunately, thickening of the
gallbladder wall in the absence of
cholecystitis may be observed in
systemic conditions, such as liver,
renal, and heart failure, possibly due to
elevated portal and systemic venous
pressures
https://www.ajronline.org/doi/full/10.2214/AJR.10.4340

16. APPENDICITIS
• Ultrasound should be the first imaging modality for diagnosing
acute appendicitis
• USG for acute appendicitis diagnosis will decrease ionizing
radiation and cost.
• Sensitivity of US to diagnose acute appendicitis is lower than of
CT/MRI.
• Non-visualization of the appendix should lead to clinical
reassessment.
• Complementary MRI or CT may be performed if diagnosis remains
unclear.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4805616/

17. WHEN TO USE
IMAGING
 Classic symptoms of appendicitis are well described
 One third of patients with acute appendicitis have
atypical presentations
 Patients with alternative abdominal conditions may
present with clinical findings indistinguishable from
acute appendicitis .
Thus, although appendicitis traditionally has been a
clinical diagnosis, many patients are found to have
normal appendixes at surgery.
 The misdiagnosis of this acute condition has led to
the inappropriate removal of a normal appendix in
8–30% of patients . A rate of unnecessary removal as
high as 20% has been considered acceptable in the
surgery literature
 However, negative laparotomy can be avoided in
many patients if modern diagnostic methods are
used to confirm or exclude acute appendicitis.
Read More: https://www.ajronline.org/doi/10.2214/ajr.185.2.01850406

18. Direct Sign
•Non compressible app
•Diameter > 6 mm
•Single wall thickness ≥ 2 mm
•Target sign
•Appendicolith
•Color Doppler US :
•Hypervascular in acute
•Hypo/avascular in
necrosis/abscess
Indirect Sign
•Free fluid surrounding appendix
•Local abscess formation
•Increased echogenicity of local
mesenteric fat
•Enlarge local mesenteric lymph node
•Thickening of peritoneum
•Signs of secondary small bowel
obstruction

19. 16-year-old girl with acute
appendicitis. Axial CT after oral
and IV contrast material shows
cecal wall thickening around
appendiceal orifice

20. Abscess is the most frequent complication of perforation.
The abscess remains localized if periappendiceal
fibrinous adhesions develop before rupture.
If the abscess is large (> 4 cm), percutaneous drainage
followed by delayed appendectomy is the preferred
treatment
https://www.ajronline.org/doi/10.2214/ajr.185.2.0185040
6

21. Enhanced scan
shows dilated
appendix with
thickened,
hyperenhancing wall
(arrows, B). Notice
mural stratification of
appendix wall.

22. ABDOMINAL TRAUMA
RUQ
•Hepato-renal recess (Morrisons
pouch)
• Inferior pole of kidney into right
paracolic gutter
• Below diaphragm
LUQ
•Below the diaphragm (peri-splenic
space)
•Between spleen and left kidney
•Inferior pole left kidney (left
paracolicgutter)
Suprapubic
•Rectovesical space
•Vesicouterine space
•Rectouterine pouch (pouch of
Douglas)
• Posterior wall of bladder
Subcosta
1 2
3
4

25. GENERAL SIGN OF
PATHOLOGY

26. IMAGING
BOWEL
OBSTRUCTION
addressing the
following questions
:
• Is the small/large
bowel obstructed?
• How severe is the
obstruction
• Where is it located
and what is its
cause?
• Is strangulation
present?

27. THE KEY RADIOGRAPHIC SIGN
- diagnostic accuracy and specificity of
abdominal radiography  low (50-60%)
- SBO and LBO
Radiographic sign of small bowel
obstruction :
• Small bowel distention (25 mm), Large
bowel distention ( > 50 mm)
• collapsed or normal caliber bowel distal to
the transitional point
• bowel wall thickening surrounding
mesenteric fat stranding indicating
inflammation
• the presence of more than two air-fluid
levels
• air-fluid levels wider than 2.5 cm, and air-
fluid levels differing more than 2 cm in
height from one another within the same
small bowel loop

28. -sonography is not commonly the
first choice for the initial work-
up of patients with SBO
- Findings USG :
-the fluid-filled small bowel loops is
dilated to more than 3 cm
-the length of the segment is more than
10 cm
-peristalsis of the dilated segment is
increased, as shown by the to-and-fro
or whirling motion of the bowel
contents
Real-time sonography may
differentiate between mechanical
and functional Intestinal
Obstruction
The movement of the
mechanically obstructed bowel
will initially increase but will
decrease later with the progress
of the obstruction and
development of bowel ischemia

29. • CT criteria for SBO. Axial CT
scan shows a disparity in caliber
between distended proximal
small bowel loops (diameter >3
cm) (dotted line) and collapsed
distal small bowel loops (arrows).
• The SEVERITY of obstruction
can be assessed
• The presence of free fluid
between dilated small bowel
loops, aperistalsis, and wall
thickening (>3 mm) in a fluid-
filled distended bowel
segment suggests bowel
infarction

30. BOWEL OBSTRUCTION

31. GASTRITIS
The antrum is usually the most
common site of inflammation,
and the submucosal layer is
frequently colonized by H pylori.
Radiologically, gastric wall
thickening is one of the most
important signs
Sonography can be used
effectively to evaluate the
stomach and duodenum.
Loss of the normal multilaminar
gut signature at the posterior wall
of the gastric antrum is another
useful sonographic characteristic
of inflammation.
Antral Wall Thickness (> 6 mm),
Mucosal Layer Thickness (4 mm)

32. MESENTERIC
LYMPHADENITIS
• Mesenteric lymphadenitis is a common
mimicker of appendicitis.
• It is the second most common cause of
right lower quadrant pain after
appendicitis
Key finding: Lymphadenopathy with
a normal appendix and normal mesenteric
fat

33. CONCLUSION
Patients with an acute abdomen have high risk.
Serious consequences may result from
misdiagnosis
We advocate a systematic approach:
1. First focus on the most common diseases
and make a firm diagnosis or exclude them.
2. Always screen the whole abdomen for
general signs of pathology.

34. THANKYOU