Download GIT class I

GI Radiology
Imaging modalities in GI
• Plain X-rays (Supine, Erect, Decubitus)
• Barium studies (Ba Swallow, Meal, Follow through, Enteroclysis,
Enema)
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Ultrasound Abdomen
CT Scan/MRI Abdomen
ERCP, Cholangiography.
Angiography and Nuclear Medicine
Plain Abdominal X-rays
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Erect Chest
Supine Abdomen
Erect / Decubitus Abdomen ( 10 min )
Radiation Dose ( 1 Abd = 75 CXR)
Contraindicated – pregnancy
Indications.
• “Acute Abdomen”
• Abdominal Pain.
• ?Obstruction.
• Not Indicated for:
– Trauma.
– Solid organ assessment.
Basic Principles
• Five radiographic densities:
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Gas/Air
Fat.
Soft Tissue/Water
Bone/Calcium
Metals
• Interface/line only visible when two of
these densities interface with each other.
Approach to a AXR
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Technical Assessment.
Projection.
Bowel/Gas Shadows.
Normal/Abnormal Calcifications.
Solid Organs.
Look at lung bases and at the skeleton.
Normal Vs Abnormal Gas shadows
• Stomach.
• Colon.
• Small Bowel.
• Within the Lumen:
– Dilated bowel
?Obstruction
• Outside the Lumen:
– Free ?perforation
– In a cavity ?abscess
Contrast Medium for GI
Water Soluble
• Ionic (gastrografin) Can
lead to pulmonary edema if
aspirated.
• Non- Ionic ( Low
Osmolar) Relatively safer if
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aspirated.
Gadolinium (MRI)
• Barium ( Non-water soluble)
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Can cause sever peritonitis and
fibrosis in perforation or leakage.
Contrast Swallow
• Indications:
• Contraindications:
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Dysphagia
Pain
Reflux
Anemia
Tracheo-esophageal fistula
Perforation
Aspiration
Barium Meal
• Indications:
• Contraindications
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Dyspepsia
Upper abdominal mass
Weight Loss
Gastrointestinal Hemorrhage.
Partial Obstruction
Assessment for perforation
Complete large bowel obstruction
• Pateint preparation:
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NPO ---6 hrs
No smoking– increases GI motility
Small Bowel Follow through/ Small
bowel enema (Enteroclysis)
• Indications:
• Contraindications
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Pain
Diarrhoea
Anemia/GI bleed
Partial Obstruction
Malabsorption
Abdominal mass
Complete obstruction
• Patient Preparation:
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Low residue diet
Bowel Prep (Dulcolax -2-4 Tab)
Small Bowel follow through VS Small bowel enema
Barium Enema
• Indications:
• Contraindications:
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Change in bowel habits
Pain
Mass
Melaena / Anemia
• Single contrast –
Obstruction & Intussusception.
Rectal biopsy—5 days
Toxic megacolon
Pseudomembranous colitis
• Preparation: (Two days)
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Low residue diet
Bowel prep (Dulcolax – 4 Tab)
Ultrasound Abdomen
• Advantage
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Cost effective
Adequate visceral visualization
Best for GB
No radiation
• Indications: Acute
Abdomen, Obstructive
jaundice, abdominal masses,
collections, Free fluid, follow
up- tumors.
• Disadvantage
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Operator dependent
Poor in Obesity
Bowel gasses
Bones / Calcifications
CT Scan Abdomen
• Advantages
• Disadvantages:
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Accurate & quick
Bowel/ gasses/ bones
Reformation and angio
• Indications: Acute abdomen,
Abdominal mass, tumor
staging/follow up,
Appendicitis/abscesses, Post op
complications
Radiation (250 CXR)
Renal failure
Contrast reaction
MRI Abdomen
• Advantages
• Disadvantages
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Multiplaner
Renal failure
MRCP
Liver specific contrasts
Bowel motion/ contrast
Calcifications
Metallic implant
Relatively long procedure time
Claustrophobia
Cholangiography
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Endoscopic Retrograde
Cholangiopancreatography (ERCP)
MR Cholangiopancreatography
(MRCP)
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T-tube Cholangiography.
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Percutaneous Transhepatic
Cholangiography (PTC).