Abdominal Imaging 4th year

Abdominal imaging

Dr Joshua Lauder, Consultant Radiologist, ELHT

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5 minutes

​Objectives

1. Know the imaging modalities used in the abdomen

   1. Ultrasound

   2. Xray

   3. CT

2. Recognize common ​pathology

   1. Large bowel obstruction and cancer

   2. Small bowel obstruction​ and mesenteric ischaemia

   3. Biliary pathology

Session format

1. Lecture/quiz on abdominal imaging

   1. Bowel

   2. Biliary​

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2. Post DICOM demonstration of CT

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3. Several self-directed cases on Post DICOM

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4. Go through the cases together​

Reminder of CT concepts

1. Anatomical planes

2. Density (Hounsfield units)

3. Windowing

4. IV Contrast​

Multiple Choice

List the anatomical planes from left to right

• Coronal - Axial - Sagittal

• Sagittal - Coronal - Axial

• Sagittal - Axial - Coronal

• Sagittal - Axial - Coronal

Multiple Choice

Hounsfield Units are a measure of:

• Radiation

• Contrast

• Density

• Anatomical planes

Hounsfield Units

Windowing

​IV Contrast

Bowel pathology

​Large bowel obstruction

Small bowel obstruction

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Inflammatory bowel disease​

Mesenteric ischaemia

Multiple Select

Choose the most appropriate investigation for this 50 year old male with severe abdominal pain and not passing flatus

• Xray

• Ultrasound

• CT

• MRI

Multiple Choice

What is the pathology?

• Gallstones

• Small bowel obstruction

• Large bowel obstruction

• Mesenteric ischaemia

Abdominal xray

​Shows gas filled structures well

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Limited information​ about soft tissue or fluid filled structures

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Large bowel obstruction

Peripherally located

Haustra do not cross entire width

May contain faeces​

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Multiple Choice

What is the most common cause of large bowel obstruction

• Cancer

• Stricture (diverticular or ischaemic)

• Volvulus

• Intussusception

​Spotting early bowel cancer

​Faecal blood test

Colonoscopy​

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CT Colon

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​Diverticulosis

​Diverticulosis

Multiple Choice

What is the cause of the large bowel obstruction here?

• Cancer

• Diverticular stricture

• Ischemic stricture

• Sigmoid volvulus

​Sigmoid Volvulus

​Caecal volvulus

Multiple Choice

This patient presents extremely unwell with diarrhoea, what does the xray show?

• Mechanical large bowel obstruction

• Volvulus

• Diverticular disease

• Toxic Megacolon

​Toxic megacolon

​Non obstructive dilation of the colon, secondary to severe colitis. ​

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Ulcerative colitis

​Crohns

Infection

Ischemia​

​

Systemically unwell​

Crohns

Crohns

​Ultrasound and MRI used to reduce radiation burden

Crohns - skip lesions

​Ulcerative colitis

​Ulcerative colitis

Barium enema - obsolete​

Multiple Choice

This 60 year old female presents with acute abdominal pain and vomiting. No previous surgery. What is the most likely cause for findings?

• Adhesions

• Hernia

• Tumour

• Inflammatory bowel disease

• Intussusception

​Small bowel obstruction

Adhesions (prior surgery)

Hernia (may be palpable)

Inflammatory bowel disease (Crohn's)

Intussusception (Children)​

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On xray​

Small bowel is centrally located

Valvulae conniventes cross the width

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Multiple Choice

Which artery supplies the small bowel?

• Coeliac

• Superior mesenteric

• Inferior mesenteric

​Mesenteric ischaemia

​Mesenteric ise

​Normal SMA

SMA thrombus

​Mesenteric ischaemia - Treated with IR or surgery

Dead bowel

Ischemic colitis

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Always affects left colon​

Bowel going inside bowel

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Most common in children

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If occurs in adults, its secondary to a lesion​

Intussusception

​Biliary pathology

Cholecystitis

Gallstones

Pancreatic cancer​​

Multiple Choice

40 Year old female presents with RUQ pain and raised bilirubin, what is the most appropriate initial test?

• Ultrasound

• CT

• MRCP

• ERCP

​Ultrasound in the abdomen

Excellent for fluid filled structures

Gallbladder

Biliary tree​

Liver​

Kidneys​

​

Can also guide procedures

Ascitic drain

Gallbladder drain​

Cholecystitis

normal comparison

Choledocholithiasis

normal comparison

MRCP

​Ultrasound has limitations

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Magnetic Resonance CholangioPancreatography

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Shows fluid in exquisite detail​

​Endoscopic retrograde cholangiopancreatography

ERCP​

Invasive procedure to treat gallstones in the CBD​

Multiple Choice

50 Year old male presents with new onset jaundice with no abdominal pain, what is the most likely diagnosis?

• Cholecystitis

• Gallstone in the CBD

• Pancreatic cancer

CT is used to detect pancreatic cancer.

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Often presents after causing duct obstruction

CBD

Pancreatic duct​

​Pancreatic cancer

Summary of abdominal imaging

​Modality	​Notes
​AXR	​Mainly for bowel obstruction Poor soft tissue resolution
​CT	​Extensive use in acute abdomen Can diagnose most pathology Need to justify use because of high radiation
​Ultrasound	​First line in biliary pathology Also good for liver, spleen, ascites First line in children with acute abdomen Can be used to diagnose and monitor inflammatory bowel disease
​MRCP	​Used to look for gallstones in the CBD if ultrasound cannot find them
​ERCP	​Invasive technique to remove gallstones in the CBD

Post DICOM - your go

https://www.postdicom.com?Share=351e4fe6-d2eb-44d3-bb1a-3ecbb250d1b3&Lang=0

password: anatomy​

​	​Notes
​Case 1 AXR and CT 70 year old female with abdominal pain and vomiting	​Look at the AXR first Then check CT to find the cause Has any procedure been performed?
​Case 2 CT ​History of acute severe abdominal pain and lactate of 8	Check the blood vessels There is an interesting incidental finding of the bowel in this case
​Case 3 CT 70 Year old male with painless jaundice	​Look at the biliary tree Try to measure the calibre of the CBD