7. Emergency abdominal imaging

Question 1

What is acute abdomen?

Answer 1

• severe abdominal pain is the leading symptom
• requires early diagnosis and urgent therapeutic decision

Question 2

What is the modality of choice in case of acute abdomen?

Answer 2

• ultrasound: primary examination but has a limitation in case of meteoristic patient, obesity, postoperative bandages/drains
• CT: useful if US examination is inconclusive or in case of complications

Question 3

Imaging of acute appendicitis

Answer 3

appearance of acute appendix (US):
- blind-ended tubular structure
- non-compressible
- periappendiceal fluid or abscess
- increased vascularity (doppler)
- diameter >6mm

*CT can be helpful in detecting abscess or perforation

Question 4

Imaging of gall stones

Answer 4

• usually using US: appears hyperechoic, with positive murphy sign (patient is unable to inspire fully due to severe pain when pressing on the right upper quadrant)
• CT can be used to examine the stones as well but some stones are difficult to see when hypodense or isodense

Question 5

MR imaging of the biliary system

Answer 5

• MR is rarely used for emergency settings but can be useful for pregnant women
• has more precise depiction that CT
• MR cholecysto-pancreatography

Question 6

What is MRCP?

Answer 6

• heavily T2W MRI sequence
• great imaging for the biliary system and pancreatic duct
• non-invasive visualization
• no need for contrast material, since the fluid filled biliary system has high signal intensity

Question 7

Imaging of ileus

Answer 7

• look for normal non-distended bowel loops, which if present strongly suggest obstructive ileus (not paralytic)
• small bowel follow-through is great for further examination after contrast enhanced CT
• small bowel ileus is suggested if the contrast agent does not reach the large bowels within 3 hours

Question 8

Detecting free abdominal air

Answer 8

• free abdominal air is detected on X-ray, especially useful to use lateral decubitus position
• it is normal to find free abdominal air for a week after lapaporoscopy
• CT is more sensitive than X-ray (lung window should be used for detecting of free abdominal air)

Question 9

US for acute pancreatitis

Answer 9

• depiction of biliary stones and dilation
• follow-up for pseudocysts and fluid collection

Question 10

Contrast-enhanced CT for acute pancreatitis

Answer 10

• detection and follow-up of any complications (ie. fluid collections, extent of necrosis, abscess, hematoma)
• in case there’s no improvement with treatment

Question 11

MRI for acute pancreatitis

Answer 11

• can be an alternative for CT if available
• gall or biliary stone detection is more sensitive than CT (MRCP)

Question 12

Angiography for acute pancreatitis

Answer 12

diagnosis and treatment of vascular complications

Question 13

Low dose non-enhanced CT for kidney stone detection

Answer 13

• gold standard!!
• excellent specificity and sensitivity
• can be supplemented with iv. contrast material if wanted

Question 14

US for kidney stone detection

Answer 14

• hydronephrosis can be detected
• stones in the pelvis, calyces or juxtavesical parts of the ureter can be visualized
• ureter cannot be visualized in the retroperitoneum

Question 15

Abdominal X-ray for kidney stone detection

Answer 15

• 30% stones are missed
• high false negative rate

Question 16

X-ray urography for kidney stone detection

Answer 16

• replaced by CT diagnostics
• but can be used for follow-up