gi pathology Flashcards
Imaging for GI pathology
Alimentary Canal
Barium swallow/meal
Abdominal X-ray
Barium Follow-Through
Barium Enema
Cross Sectional Imaging
Ultrasound
Accessory Organs
Dental X-ray
Sialogram
Cross Sectional Imaging
Ultrasound
Fluoroscopic and operative procedures.
Key Acronyms
AXR – Abdominal X-ray
Ba – Barium
GORD – Gastro Oesophageal Reflux Disease (GERD in USA)
SBO – Small Bowel Obstruction
LBO – Large Bowel Obstruction
OGD – Oesophageal Dilatation
PR – Per Rectum (i.e., PR Bleed)
RUQ/LUQ – Right and Left upper Quadrant
RIF/LIF – Right and Left Iliac Fossa
Referral for AXR (Not Exhaustive List)
Symptoms
Acute abdomen (Pain, nausea and vomiting)
Bowels not opened for significant time (multiple days or weeks)
Unable to pass flatus (gas)
Distension
Suspected Pathologies
Diverticulitis
Bowel Obstruction
Perforation
Incarcerated/strangulated hernia
Toxic Megacolon
Trauma
Foreign Body
Inappropriate AXR requests
Constipation – (unless paediatric- specialist referral)
?Appendicitis – U/S or CT more sensitive
?Cholecystitis – U/S more sensitive
?Pancreatitis – U/S, CT or ERCPs more sensitive
Specialist AXR Imaging
Colonic transit studies
Also known as “shape studies”
Used for both paediatrics and adults to measure bowel transit time
Capsules containing radio-opaque shapes are swallowed over the course of several days and AXR is taken to assess speed at which they pass through GI system
Contrast Follow-Through
Can take place either following a Barium meal study or as a standalone examination
Ba or water soluble contrast is swallowed and a plain film AXR is requested at a specified time(s) in the future
The image is taken and the time since ingested is labelled on the image
Can be used to support diagnosis and certain contrasts act as a laxative agent and so can be therapeutic
Referral for Ba Swallow
Symptoms
Dyspepsia (Upper abdominal discomfort/”indigestion”)
Dysphagia – Difficulty Swallowing
Feeling of lump in throat
Suspected Pathologies
Achalasia
GORD
Hiatus Hernia
Contraindications for Ba Swallow
Perforation
Post-Surgical setting
High risk of aspiration
Can you think of any alterations to this examination that might impact on these contraindications?
Use a water-soluble contrast agent.
Image Interpretation
A systematic approach to imaging
Reviewing AXRs can be tricky:
Organs
Bone
Air
Muscle
Soft tissues
Foreign bodies?
AXR - A Systematic Approach
Systematic review:
Air
Bowel
Calcifications
Disability
Bones and solid organs
Everything else
Foreign bodies
Rest of the image
A - Air
Air should only feature within the lumen of the bowel.
Pneumoperitoneum is more sensitive on an erect chest x-ray.
Scarcely appears on Abdomen X-rays.. Unless obvious.
A - Air
Air should only feature within the lumen of the bowel.
Pneumoperitoneum is more sensitive on an erect chest x-ray.
Scarcely appears on Abdomen X-rays.. Unless obvious.
Air Signs
Notice the resemblance between the two?
Football sign- occurs in the case of massive pneumoperitoneum
Abdomen is outlined by perforated gas from a visceral perforation.
More common in paeds.
Can be found secondary to obstruction.
Air Signs
Notice the resemblance between the two?
Football sign- occurs in the case of massive pneumoperitoneum
Abdomen is outlined by perforated gas from a visceral perforation.
More common in paeds.
Can be found secondary to obstruction.
Air Signs
Rigler’s sign or ‘double wall’ sign
Occurs when gas is present of both sides of the bowel wall.
i.e. when there is gas in the bowel lumen and in the peritoneal cavity.
GI Pathologies
In this following section we shall discuss pathologies relating to the alimentary canal. This shall include the following details:
Aetiology of the pathology
Symptoms
Imaging Strategy
Radiographic Appearances
Treatments
Potential Complications
It is important to consider all aspects so that we can empathise with our patient and consider the overall pathway that they might follow.
Achalasia: Overview
Achalasia is a physiological pathology of the oesophagus
Caused by absent or disorganised oesophageal peristalsis and impaired relaxation of lower oesophageal sphincter.
Symptoms include:
Dysphagia
chest discomfort
regurgitation of food
Achalasia: Overview
Achalasia is a physiological pathology of the oesophagus
Caused by absent or disorganised oesophageal peristalsis and impaired relaxation of lower oesophageal sphincter.
Symptoms include:
Dysphagia
chest discomfort
regurgitation of food
Achalasia: Radiographic Appearances
Some Achalasia appearances on Ba Swallow examinations include:
Dilated sections of oesophagus
Tapering of the inferior oesophagus “Bird Beak Sign”
Pooling of stasis of the Barium within the oesophagus
Achalasia: Treatment and Complications
No curative treatments, symptomatic treatments include:
Prescribing muscle relaxants
OGD
Botox Injection
Laparoscopic surgery –”Heller’s Myotomy” procedure
Hiatus Hernia: Overview
Hiatus Hernia is the herniation of abdominal anatomy through the diaphragm into thoracic cavity
More common in female and older individuals
Often asymptomatic and found incidentally
(Radiographic Appearances combined with next pathology…)
Hiatus Hernia: Overview
Hiatus Hernia is the herniation of abdominal anatomy through the diaphragm into thoracic cavity
More common in female and older individuals
Often asymptomatic and found incidentally
(Radiographic Appearances combined with next pathology…)
Hiatus Hernia: Treatment and Complications
If asymptomatic then usually no treatment
Surgical management if severe and causing symptoms (such as epigastric pain and nausea/vomiting)
Complications include:
Gastric Volvulus
Tension Gastrothorax
Cameron Lesions (Erosions at the hernia site)
Gastro-Oesophageal Reflux Disease
GORD is a very common pathology, estimated to effect 13.98% of people worldwide (Nirwan et al., 2020).
Pathophysiology is influenced by a variety of factors including laxity/compliance of the gastro-oesophageal sphincter, pressure across this sphincter and diet.
Treatment can be via medicine to neutralise or reduce the quantity of stomach acid, or in severe cases there is a surgical approach called a “fundoplication”. (NHS, 2020)
Complications include oesophagitis, ulceration, haemorrhage and aspiration pneumonia.
Gastro-Oesophageal Reflux Disease
GORD is a very common pathology, estimated to effect 13.98% of people worldwide (Nirwan et al., 2020).
Pathophysiology is influenced by a variety of factors including laxity/compliance of the gastro-oesophageal sphincter, pressure across this sphincter and diet.
Treatment can be via medicine to neutralise or reduce the quantity of stomach acid, or in severe cases there is a surgical approach called a “fundoplication”. (NHS, 2020)
Complications include oesophagitis, ulceration, haemorrhage and aspiration pneumonia.
Gastric (peptic) Ulcer - Overview
Gastric ulcers are ulcerations of the stomach for which there are a number of risk factors:
H.Pylori Infection
Taking regular NSAIDs
Smoking
Symptoms include:
Abdominal pain
Vomiting
Loss of Appetite
Weight Loss
Gastric (peptic) Ulcer - Imaging
Radiographic imaging is not routinely used to diagnose gastric ulcers. It can be visible on Ba meals.
It is important to be aware of this pathology however, as it’s complications include:
Perforation
Upper GI bleeding
Haematemisis
Which may trigger an imaging request.
Gastric (peptic) Ulcer - Imaging
Radiographic imaging is not routinely used to diagnose gastric ulcers. It can be visible on Ba meals.
It is important to be aware of this pathology however, as it’s complications include:
Perforation
Upper GI bleeding
Haematemisis
Which may trigger an imaging request.
Gastric (peptic) Ulcer – Treatment
Gastric Ulcers are treated depending on their severity and causes:
Antibiotics for H.Pylori infections
Proton Pump Inhibitor medication
H2-receptor antagonist medication
Small Bowel Obstruction - Overview
Mechanical or physiological obstruction of small intestine.
Comprises 80% of all bowel obstructions
Wide variety of risk factors and underlying causes
Symptoms Include:
Abdominal pain
Nausea and vomiting
Distension of abdomen
Unable to pass gas or stool
Small Bowel Obstruction – Imaging Presentation
AXR poor sensitivity for SBO. (50-60%)
Central dilated loops (>3cm)
Visible valvulae conniventes
Rarer- ‘string of pearls’ sign
Small Bowel Obstruction – Treatment and Complications
Treatments:
Varies with cause of SBO
Correction of electrolyte balances
Removal of fluid from dilated region via NG/NJ tube
If SBO does not resolve, surgical resection
Risk of perforation if not treated in a timely fashion
Lower Bowel Obstructions - Overview
A mechanical or physiological obstruction of the large bowel
LBOs comprise 20% of all bowel obstructions
They are often secondary to another pathology such as colon cancer
Symptoms include:
Abdominal pain
Nausea and vomiting
Distension of abdomen
Unable to pass gas or stool
Dehydration
Lower Bowel Obstructions - Overview
A mechanical or physiological obstruction of the large bowel
LBOs comprise 20% of all bowel obstructions
They are often secondary to another pathology such as colon cancer
Symptoms include:
Abdominal pain
Nausea and vomiting
Distension of abdomen
Unable to pass gas or stool
Dehydration
Lower Bowel Obstructions – Imaging Presentation
Dilated large bowel loops visible on AXR
For erect imaging air-fluid levels are present
Lower Bowel Obstructions – Treatment and Complications
Treatment route depends on underlying cause, options include:
Surgical resection
Colonic stent
Treatment of electrolyte imbalance
Risk of perforation if not treated in a timely fashion
Pneumoperitoneum - Overview
Pneumoperitoneum is the presence of air within the peritoneum. It can be an incidental finding if the patient has had very recent laparoscopic abdominal surgery.
Pneumoperitoneum can also be indicative of a GI perforation, which is a medical emergency.
Symptoms of GI perforation include:
Sepsis
Constipation
Abdominal Bloating
Nausea/Vomiting
Pneumoperitoneum - Imaging
Both AXR and erect CXRs are frequently used to diagnose pneumoperitoneum.
For CXR, patients should be sat upright for at least 10 minutes prior to imaging.
Following a diagnosis of pneumoperitoneum, patients will often undergo CT imaging to determine the cause and/or plan for surgery
Perforation – Treatment and Complications
Treatment depends on the cause of the perforation and the condition of the patient.
Sometimes conservative management such as IV antibiotics is sufficient.
Surgical treatment is also commonly utilised.
Bowel perforations can lead to severe illness such as peritonitis and sepsis.
Volvulus - Overview
Volvulus from the Latin word “to roll” is a twisting of the intestines. There are two main forms of volvulus: sigmoid and caecal, depending on the anatomy that is affected.
Risk factors include:
Chronic constipation
High fibre diet
Congenital disorders
Neurological conditions
Abdominal tumours
Symptoms include:
Constipation
Abdominal Bloating
Nausea/Vomiting
Can be acute or chronic
Sigmoid Volvulus – Imaging Presentation
On plain film AXR the sigmoid volvulus presents as:
Significantly dilated bowel
“Coffee bean sign”
No visible rectal gas
Caecal Volvulus – Imaging Presentation
On plain film AXR the caecal volvulus will present with:
Significantly dilated bowel
Sometimes presents as an “embryo” sign. Where the dilated portion of bowel appears similar to the shape of an embryo.
Volvulus – Treatment and Complications
Treatment depends on the cause and location of the volvulus. Complications include:
Bowel ischaemia (lack of blood supply)
Recurrence
Treatments include:
Sigmoid- repaired via endoscopic depression/ detorsion
Caecal- laparotomy and relocation
Sigmoid/caecal coloplexy (fixation) if recurrent
If ischaemia occurs then surgical resection may occur
