GI Tract Imaging Flashcards
There are three types of endoscopy, what are they?
Upper GI
ERCP
Colonoscopy
What precautions must be used for an endoscopy?
Sedation
Laxative (for lower GI tract)
What are the possible problems with an endoscopy?
Small risk of perforation
Can be poorly tolerated by some people
What must be done in order to perform a fluoroscopy?
It required contrast (barium or gastromiro)
Requires distension of the tube with gas or air
What is a fluoroscopy?
A study of moving body structures
- a continuous X-Ray beam is passed though the body part being examined
What are the benefits of using ultrasound?
It uses sonar - not radiation
Fast
Cheap
Safe
List some of the ways in which the GI tract is imaged?
Endoscopy Plain X-Ray Fluoroscopic studies Cross sectional studies CT Ultrasound MRI
What are the limitations of ultrasound?
Habitus - the position of the body
Gas inside the tube - you can’t see inside it
What are the negatives of CT scanning?
Uses a lot of radiation
Doesn’t have very good tissue differentiation
Used an intravenous and oral dye, or water
What is a CT scan mainly used for?
Diagnosis of disease
Staging of malignagcy
Assessing response to treatment
Percutaneous biopsy
Describe a PET-CT
It’s a combined imaging modality
- a functional imaging of radioactive tracer uptake fused with anatomical information from CT
What’s the most commonly used tracer in a PET-CT and what is it for?
FDG - flurodeoxyglucose (a glucose analogue)
It accumulates in metabolically active cells, making them easier to see
What are the benefits of an MRI machine?
It uses no radiation
Has excellent soft tissue differentiation
What are the limitation of using an MRI machine?
Can’t be used on people who have pacemakers or cerebral aneurysm clips
It’s a very slow procedure
What is the specific GI roles of using an MRI?
Non invasive imaging of biliary tree and small bowel
Can stage rectal cancer
Can diagnose liver lesions
What is an MRCP (magnetic resonance cholangiopanceatography) scan?
It’s a scan that uses magnetic resonance imaging to
produce pictures of the liver, bile ducts, gall bladder and pancreas.
What are the pros and cons of a rigid sigmoidoscopy?
Pros - immediate, unprepared
Cons - very limited
What are the pros and cons of a flexible sigmoidoscopy And radiology?
Pros - 2 unseated examinations
Cons - 2 preparations
What are the pros and cons of a CT pneumocolon?
Pros - gives you information on outside the colon as well
Cons - doesn’t allow biopsies
What are the pros and cons of a colonoscopy?
Pros - can take a biopsy
Cons - needs preparation, small risk, sedated
What are the pros and cons of a minimal preparation stool CT?
Pros - easy for the frail elderly
Cons - quite crude
What are the pros and cons of a back to back colonoscopy?
Pros - quality assurance
Cons - cant be done simply for quality assurance because it’s very stressful
What are two of the structures colonic polyps can take?
Tubular adenoma
Villous adenoma
Name some of the types of cancer that can be found in the GI system.
Rectal cancer
Polaroid carcinoma
Colonic adenocarcinoma
What is a mesorectal excision?
A transverse slice through rectal cancer in the large intestine
What things are risk factor for the development of a stress ulcer?
Shock
Sepsis
Hypotension
Trauma (e.g. Sever head injury, burns)
What is the most common cause of gastric ulceration?
Drugs - e.g. Iron medication, gold, caffeine, cocaine
Ulcer erodes blood vessels
Who qualifies for the bowel screening programme in Scotland?
Men and women between the ages of 50 and 74
- once every two years
