GI Investigations 2 Flashcards
When would we use an MRI over a CT? (In general)
MRI for pelvis, brain (posterior fossa), joints, spine
This is because CTs show artefacts (shadows caused by bones)
Contraindications and problems with MRIs
Contraindications: metal objects (pacemakers, clips) and claustrophobia
Problems: time consuming and has limited availability
What is Magnetic resonance cholangio-pancreaticography (MRCP)
Uses MRI to view bile ducts, pancreas in detail
What is a Defecating proctogram?
evaluates completeness of stool elimination, identifies anorectal abnormalities
Colonoscopy views the entire colon upto the ________
caecum
How is bowel screening performed and to whom is it offered?
Recommended for pts at high risk of colon CA and for everyone ≥ 60 yr
check
What is Gastroparesis?
How is it diagnosed, treated and monitored?
Condition where the stomach cannot empty. food passes through the stomach slower than usual
Gastric Emptying Scan helps diagnose and monitor response to motility drugs → metoclopramide, erythromycin
How may we evaluate patients with chronic constipation or IBSc?
What are the 2 types of IBSc shown on the image below?
Colorectal transit study -uses markers to monitor movement through the colon over 7 days with serial abdominal X-rays
- Left - slow transit constipation
- Right - anorectal diregulation / pelvic floor dyssynergia
How are contrast studies performed?
List one contrainidication and one challenge
Barium (single contrast) or Barium + Gas (double contrast) are given to pt.
- Contraindication - suspected perforation or obstruction, as Ba is highly irritating
- Challenge- Patients need to turn themselves to properly distribute barium, older patients may have difficulty with this
a) How do we assess oropharyngeal motility?
b) What parts of the GIT can this study assess
c) List 4 instances we may require this
a) Ba swallow
b) Oesophagus, stomach & duodenum
c) GORD, achalasia, stricture, ulcers
When do we use CT Enteroclysis?
Visualization of S bowel
GI Indications for Ultrasound
- Masses
- Abscess
- Organs
- Free fluid
- Biliary dilatation
- GB stones
- Guided FNAC & biopsy
What non-invasive test helps us quantify liver fibrosis?
What can CTs help diagnosis of?
- Tumours
- Vascular lesions
- Infection
- Collections or traumatic injuries
What is CT enterography and colonography
Incl indications for these
CT enterography: visualization of S bowel
CT colonography: generates 3D and 2D images of colon
Indications: obscure GI bleed, S bowel tumors, ischemia
List 4 uses of Endoscopy (there are many)
- Malignancy
- Infections (Candida, H. pylori, Giardia)
- Removal of foreign bodies
- Hemostasis
List 2 absolute and 2 relative contraindications to Endoscopy
Absolute: Shock, acute MI, perforation, toxic megacolon, severe RA of Cx spine (Atlanto-axial subluxation)
Relative: poor patient cooperation, coma, arrhythmias
What can we visualise with a Oesophagogastroduodenoscopy (OGD)
List 4 indications for this
Visualise oesophagus, stomach & duodenum (D2)
Indications: Dyspepsia, Dysphagia, Wt loss, Anaemia
What does a Sigmoidoscopy allow us to view?
List 4 indications
Endoscope is inserted through the anus to view left colon
Indications: diarrhea, LIF pain, constipation, abnormal growths, bleeding PR
When may Proctoscopy be used?
Limited exam of anal canal and rectum
Used in OPD to look for haemorrhoids and/or fissures
Indications + Theraputic Indications for a colonoscopy
Indications: chronic diarrhea, Fe deficiency anemia, unexplained abdo pain, change in bowel habits (esp looser), weight loss
Therapeutic Indications: control bleeding, polyp removal, tumour ablation, stricture dilation, reduction of sigmoid volvulus
What is ERCP
List 4 indications
Contrast injected into CBD and/or pancreatic duct, through upward viewing scope
Indications
- Obstructive jaundice - insert stents
- CBD stones - removal
- Ascending cholangitis
- Bile duct injury
When may we use video capsule endoscopy?
In patients with occult GI bleed for detecting S bowel polyps and detection of mucosal abnormalities
What is a Gastric Emptying scan?
Nuclear Isotope Scan
Radiolabeled meal ingesting and observed as it passes out of stomach
What condition is significantly associated with Gastroparesis and why?
Diabetes
Gastropares is sign of autonomic neuropathy as ↑blood glucose has caused damage to the vagus nerve
Clinical use of Gastric Emptying Scan?
- To diagnose gastroparesis +
- Monitor response to motility drugs (metoclopramide, erythromycin)
What is a Meckle scan?
How is it used clinically?
Identifies ectopic gastric mucosa
Used to diagnose Meckels diverticulum
List the 4 types of Manometry used in the GIT and where each measures
Oesophageal: effectiveness & coordination of peristalsis
Gastroduodenal: dysmotility with normal gastric emptying or unresponsive to therapy
Barostat: measures gastric accommodation with distension in stomach
Anorectal: contractility of anal sphincter
What is 24 Hour Oesophageal pH Monitoring
List 2 Indications
Measures amount of acid that enters oesophagus during 24-hour period
Indications: refractory acid reflux symptoms, non-cardiac chest pain
What is Gastric Fluid Analysis?
How is it used clinically?
NGT to measure gastric acid output in basal & stimulated state (Pentagastrin)
Used to test for ZES, pernicious anemia, atrophic gastritis, with PPIs. Sometimes used for AFB staining for abdominal TB
What does Hypochlorhydria in presence of elevated gastrin indicate on gastric fluid analysis?
Impairment of acid output
eg. pernicious anemia, atrophic gastritis & with PPIs
What does Hyperchlorhydria in presence of elevated gastrin indicate on gastric fluid analysis?
ZES
List 4 diseases associated with malabsorption
- Chronic pancreatitis
- Cancer
- ZE syndrome,
- Chronic liver disease
- Coeliac
List 4 Diagnostic Procedures in GI Diseases
- Ascitic tap
- Nasogastric tube insertion
- PEG tube insertion
- Liver Bx
- Diagnostic laparoscopy
What is Meckel’s diverticulum and what is its associated rule of 2s?
What scan is used to detect this?
Congenital outpouching/malformation of the distal ileum (persistent yolk sac?)
- 2% of the population
- 2 feet from the ileocecal valve
- 2 inches long
- usually detected in under 2’s
- 2:1 male:female
Detected using Meckel scan
What is Manometry and list 4 indications for oesophageal manometry
Measurement of pressure using pressure transducers
Indications:
- dysphagia
- Nutcracker oesophagus
- achalasia
- scleroderma
- amyloidosis
What is Nutcracker oesophagus?
Hypercontracting oesophagus
What is the H2 breath test?
List 2 indications for this
When sugars (lactose, glucose) are not completely absorbed by S intestine, bacteria within GI produce H2 gas from them
Indications: lactose intolerance, bacterial overgrowth
What is Zollinger-Ellison syndrome
Gastrin secreting tumour of the pancreas
How do we test pancreatic function using an oroduodenal tube? (Invasive test)
Tube placed to collect pancreatic secretions after a hormonal secretagogue is given
- When CCK is administered → output of lipase measured
- When secretin is administered → output of HCO3 is measured
How can we non-invasively test for pancreatic insufficiency?
Faecal elastase
levels of < 100 μg/g of stool are seen in patientss with advanced chronic pancreatitis
How can we non-invasively test for pancreatic insufficiency?
Faecal elastase
levels of < 100 μg/g of stool are seen in patientss with advanced chronic pancreatitis
How can we non-invasively test for pancreatic insufficiency?
Faecal elastase
levels of < 100 μg/g of stool are seen in patientss with advanced chronic pancreatitis
