T1 L15: Imaging of abdominal viscera

• What are the imaging modalities for the abdomen?

  X-ray (plain film) / Fluoroscopy

  Ultrasound (US)

  Computed Tomography (CT)

  Magnetic Resonance Imaging (MRI)
• What are the solid abdominal viscera organs?

  liver, spleen, pancreas

  
• What does the triad going into the liver consist of?

  hepatic artery, portal vein, common bile duct

  
• How does the biliary tract go?

  cystic duct + hepatic duct -> common bile duct + pancreatic duct -> duodenum

  
• What is the first line test for imaging the liver?

  ultrasound
• In ultrasound, the higher frequency gives more detail but less depth.
• What shaped probe with what frequency is used for imaging the abdomen via ultrasound?

  curved probe

  low frequency (as it's a depth that you need to get through)
• How does subcutaneous fat look in ultrasound and why?

  bright

  it's echogenic
• What colour is fluid in ultrasound (and give examples)?

  black

  blood, bile
• What is Doppler ultrasound and how does it look differently?

  Imaging technique that measures blood flow. It shows blood flow in color.

  Red: flow towards probe

  Blue: flow away from probe

  
• What are the structures of the liver seen in this ultrasound?

  1. Right hepatic vein
  2. Middle hepatic vein
  3. Left hepatic vein
  4. Portal vein
  5. Inferior vena cava
  6. Diaphragm

  
• What is duplex ultrasound?

  Both Doppler and greyscale ultrasound

  gives both anatomical information and dynamic function of flow in blood vessels

  
• What is the black structure in this ultrasound image?

  gallbladder

  bright thin wall with fluid in

  
• What is this pathology shown in this ultrasound image?

  Cholecystitis:

  gallstone

  casts a shadow as US waves can't pass through calcium

  causes infection and inflammation of the gallbladder

  Thickening of gallbladder wall

  
• What is this machine in the image called?

  CT scanner

  
• What is the standard plane for CT / MRI scans?

  axial (transverse) plane

  
• What does black indicate on a CT scan?

  air
• What is windowing in CT scans?

  change the brightness and contrast to see different tissue types
• What is contrast in imaging?

  IV agent given to patient

  radioopaque (blocks X-rays)

  So appears bright, highlighting the vessels
• What are the structures shown in this CT scan?

  1. Middle hepatic vein
  2. Left hepatic vein
  3. Right hepatic vein
  4. Inferior vena cava

  
• What are the structures shown in this CT scan?

  1. right portal vein (anterior)
  2. Right hepatic vein
  3. right portal vein (posterior)
  4. left portal vein

  
• What is this structure circled in this CT scan?

  right kidney

  
• What are the different anatomical planes used in imaging?

  1. coronal
  2. sagittal
  3. axial

  
• What type of scan is this image?

  CT angiogram

  
• How to tell if contrast has been given to a patient in a scan?

  look for vessels that are enhancing

  enhanced vessels will look bright white
• What is the pathology shown in this CT scan?

  gallstones

  no inflammation

  
• What is an ERCP?

  imaging technique for the biliary tract and pancreas

  Endoscopic Retrograde Cholangiopancreatography

  produces a Cholangiogram

  contrast injected against the flow of bile

  
• What is a PTC?

  imaging technique for the biliary tract

  Percutaneous Transhepatic Cholangiography

  contrast injected in the direction of bile flow

  
• What is a DSA?

  imaging technique for the arteries in liver

  Digital subtraction angiogram

  bones and soft tissue have been subtracted from image

  
• Why can you still see some structures, eg diaphragm and colon, in a DSA (digital subtraction angiogram)?

  the bones and soft tissue removed through multiple shots

  diaphragm and colon can still be seen because they move

  
• What is this machine shown?

  MRI scanner

  
• What are the advantages of a CT scan to an MRI?

  cheaper, quicker, requires less skilled staff
• What is MRI especially good for imaging the abdomen?

  to produce an MRCP - Magnetic Resonance Cholangiopancreatogram what looks like a cholangiogram without contrast being injected into the biliary tract

  
• What structures is this ultrasound showing?

  spleen and splenic vein

  
• What structure is labeled in this CT scan (coronal plane)?

  spleen

  
• What structures is this CT scan (axial plane) showing?

  1. stomach (tip: darker grey is fluid filled)
  2. spleen

  
• What is the pathology shown in this CT scan (axial plane)?

  Trauma: shattered spleen

  Hematoma: looks white as blood is solid and clotted

  
• What is the structure shown in this ultrasound image?

  pancreas

  
• What is the structure shown in this CT scan?

  pancreas

  
• What is the pathology in this CT scan (axial plane)?

  Pancreatitis

  pancreas hazy and diffuse, no sharp outline - abnormal fluid / inflammation