Imaging Of The GI tract Flashcards
Indications/symptoms of Upper GI tract imaging include; ‘Barium swallow’
– Dysphagia (difficulty swallowing)
–Diverticulum (outpouching)
– Gastric band studies
– Ulcers, hernias or strictures in stomach
Diverticulum, collection of fluid in the throat, due to tumours. In the intestinal wall. Fills sac up with barium can see in colon and duodenum. Barium swallow used to assess area of outpouching.
Indications/symptoms of Lower GI tract imaging include; ‘Barium Enema’
– Tumours/Polyps sign of colorectal cancers
– Inflammatory bowel diseases
– Bowel Obstructions e.g. constipation
– Assess changes in bowel habits or rectal bleeding
Polyps use barium enema. Grow into malignancy if not treated with endoscopy.
Bowel obstruction- constipation, swallowing object. Assess in changes of bowel movements. Colour of blood. Red- colon dark- large intestine.
Rectal bleeding, bleeding in the colon can lead to bowel cancer.
Other Imaging modalities of the GI Tract
Plain film imaging
AxR
Erect CxR
Colonic Transit (pellet) Studies
Computerised Tomograpghy
Contrast enhanced CT – shows gastric wall thickening
Endoscopy confirms CT findings
CT Colonoscopy
Ultrasound
Structural & functional evaluation
Doppler blood flow studies
Perforation
Colonic transit studies, used to check how food travels through the body. Assesses large bowel in the colon to diagnose conditions and assess movement of food.
Get a patient to swallow a tablet and contains petites. A week later have X-rays to see how stool passes. Ask patient to eat and drink as normal. Avoid taking laxatives as hinders with procedure.
What is Sensivity and Specificity?
‘Sensitivity’: ‘The ability of a test to correctly identify patients with a disease’ High sensitivity – unlikely to miss diagnosis.
‘Specificity’: ‘The ability of a test to correctly identify people without the disease’
Considerations of imaging the GI Tract
Soft tissue density of GI Tract
Collapsible soft tissue structures of GI Tract
Gut motility (transit times of contrast agent)
Gastric juices (dilution of contrast agent)
Room preparation
Patient preparation
Person centred care
Patient safety
Key considerations: ask patient before exam to fast and not eat or drink to help with the bowel.
Past medical history, pregnancy anything that may affect procedure.
Patient positioning, explain what they will expect.
Plan for perforation of bowel.
Imaging the upper & Lower GI Tract Contrast studies imaging
of choice
Barium swallow
Barium meal
Barium meal & follow-through
Small bowel enema/enteroclysis
Barium swallow, examines throat and oesophagus mix barium and water. Get patient to swallow whilst standing. Used for upper GI.
Barium meal to asses the oesophagus and stomach, first part of bowel. Barium mixed with water. Images taken in transit whilst swallowing. Communicate patient throughout.
Marius meal and follow through-
barium enemas to examine colon. Barium mixed with water administration to bowel through the rectum. Liquid pushed through rectum. Mainly used for lower GI.
What are the Contrast Agents for upper GI?
Barium – single double contrast agent helps visualise upper GI tract
Gastric – alternative use to barium. Used in perforation type of exams and used to visualise abdominal CT.
Carbex – negative contrast agents. Tiny granules, get patient to drink. Give dry and then barium after.
Ideal properties of
positive contrast agents
used in imaging the upper
GI tract?
Barium- contains high atomic number, helps attenuate X-ray photons to show a wider appearance on X-ray.
Its insoluble
Stable
Unreactive
Fewer reactions
Non toxic safe to consume.
Cost effective
Easier to administer
Non carcinogenic
Varying densities/ viscosities
Tolerated by patients
What is ‘double-contrast’
and why is this technique
used for imaging the upper GIT?
Double-contrast refers to a radiographic technique that uses both a positive contrast agent (such as barium sulfate) and a negative contrast agent (usually air or gas) to enhance visualization of the gastrointestinal (Gl) tract.
Enhanced Mucosal Detail
Improved Contrast
Better Detection of Pathology
More Comprehensive Assessment
When/why would
water soluble contrast
agent be used to image the upper GIT?
- Suspected Perforation – Less irritating than barium if leakage occurs.
- Post-Surgical Leak – Detects leaks after GI surgery.
- Acute Obstruction – Identifies blockage location and severity.
- Fistula Detection – Highlights abnormal connections between structures.
- Aspiration Risk – Safer for patients at risk of aspiration.
What is ‘Buscopan’?
Why is it used?
Any safety considerations?
Any alternatives?
Buscapan, is used as a smooth muscle relaxant. Temporarily relax muscle in large bowl. Helps reduce bowel spasms.
Safety considerations- affects vision
Alternative – glucagon
What are the key roles
of the radiographer for
imaging the GI tract?
Patient Preparation - Providing instructions on fasting, bowel preparation, and contrast media administration to ensure optimal imaging results.
Imaging Procedure Execution - Operating fluoroscopy, X-ray, CT, or MRI equipment to capture detailed images of the GI tract, such as during barium studies or CT enterography.
Contrast Administration - Assisting in or directly administering oral or IVcontrast agents to enhance visualization of the Gl structures.
Positioning and Technique - Properly positioning patients to obtain clear images and adjusting imaging parameters for the best diagnostic quality.
Radiation Safety - Minimizing radiation exposure through proper technique, shielding, and adherence to safety protocols.
Collaboration with Radiologists - Assisting radiologists during dynamic studies like barium swallows or enemas and ensuring images meet diagnostic needs.
Patient Care and Communication - Explaining procedures, addressing patient concerns, and ensuring comfort before, during, and after imaging.
Quality Control and Documentation - Reviewing images for clarity and accuracy before submission for interpretation and maintaining accurate records.
Patient prep and safety- what to expect during a barium enema
1) 24 hours before test: Laxatives and liquid diet clear colon
2) Lubricated enema tube placed in rectum.
3) mixture of barium sulfate and water fills colon.
4) X-rays taken for 15-20 mins
5) barium solution is drained through tube
Patient Aftercare
Physical care: EG, back to changing cubicles, getting dressed.
Information regarding diet & possible side effects.
Results
Drug effects
Re-hydration to avoid barium impaction.
Mild laxatives if necessary.
Warn about ‘white’ motions.
Remain in the department until blurred vision has subsided.
Barium swallow Clinical indications:
Achalasia
Dysphagia
Dyspepsia
Haematemesis
? Oesophageal stricture
Reflux
Assessment of tracheo- oesophageal fistula in children *
Assessment of perforation site *
- Water soluble contrast
Dyspepsia, indigestion cause discomfort and pain in upper abdomen area.
Coughing, vomiting of blood. Issues with upper GI tract.
Barium meal Clinical indications:
Dyspepsia
Weight loss
Upper abdominal mass
GI bleed or unexplained iron deficiency anaemia
Partial obstruction
? Duodenal strictures
Failed gastrocopy
Assessment of perforation site*
Assessment of anastamosis site*
Barium meal Double contrast:
Carbex granules
Citric acid
Barium sulphate
IV buscopan (20mg)
Barium meal and follow-through
Serial plain films to demonstrate passage of barium
suspension through the small bowel to the ileo-caecal valve
Visualise mucosa of stomach, duodenum, jejunum & proximal
terminal ileum.
Crohn’s Disease
Fistulas
Adhesions
Loops have been dilated and obstructed. Assess air fluid levels.
Small intestine highlighted and air contained within it. Small bowel considered normal if bowel less than 3 cm.
369 rule
3 upper bowel
6 large bowels
9 cecum
Transit Studies
Post-operative assessment
Barium meal and follow-through Clinical indications:
Abdominal pain
Diarrhoea
Bleeding
Partial obstruction
Abdominal mass
Failed small bowel enema
Inflammatory bowel disease
Malabsorption
Small bowel enema/enteroclysis
Anaesthetic gel & spray applied to aid insertion of naso-jejunal (NJ) tube
Reduced density barium sulphate (75mls/min)
Methylcellulose (provides double contrast effect)
Small bowel enema/enteroclysis vs Barium Meal & FT Advantages
Rapid infusion of barium sulphate & not reliant on gut motility/passage of barium sulphate
Controlled infusion of barium sulphate
Improved visualisation of small bowel
Improved distension of small bowel
Once
Small bowel enema/enteroclysis vs Barium Meal & FT Disadvantages
Intubation may be unpleasant for the patient
More time consuming for radiologist due to involvement in entire procedure
Increased radiation dose to the patient to screen NJ tube into position and monitor passage of barium sulphate to the ileo-caecal junction
Example exam Qs
Compare & contrast the small bowel enema and the small bowel FT
Discuss the role of the radiographer during a Barium ** Examination
Qs related to the use of contrast/double-contrast
Qs related to the use of buscopan
With reference to a fluoroscopic imaging of the upper GI tract:
a) State 2 indications and 2 contraindications 4 marks
b) Explain why Buscopan or Glucagon may be used during this examination 6 marks
c) Discuss the type of contrast agents used 10 marks
d) Outline patient preparation and after care 6 Marks
Using the following headings discuss the role of the radiographer during fluoroscopic imaging of the GI tract:
i. Radiation protection
ii. Management of the patient
iii. Radiographic skills
iv. Teamwork
.
