git radiology
TRANSCRIPT
GI Radiology
• Plain X-rays (Supine, Erect, Decubitus)
• Barium studies (Ba Swallow, Meal, Follow through, Enteroclysis, Enema)
• Ultrasound Abdomen• CT Scan/MRI Abdomen• ERCP, Cholangiography.• Angiography and Nuclear Medicine
IMAGING MODALITIES IN GIT
Plain Abdominal X-rays
• 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:– 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
• 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 aspirated.
• Gadolinium (MRI)
• Barium ( Non-water soluble)• Can cause sever peritonitis and
fibrosis in perforation or leakage.
Contrast Swallow
• Indications: • Dysphagia• Pain• Reflux• Anemia• Tracheo-esophageal fistula• Perforation
• Contraindications:• Aspiration
Barium Meal
• Indications:• Dyspepsia• Upper abdominal mass• Weight Loss• Gastrointestinal Hemorrhage.• Partial Obstruction• Assessment for perforation
• Contraindications• Complete large bowel obstruction
• Patient preparation:• NPO ---6 hrs• No smoking– increases GI motility
Small Bowel Follow through/ Small bowel enema (Enteroclysis)
• Indications:• Pain• Diarrhoea • Anemia/GI bleed• Partial Obstruction • Malabsorption• Abdominal mass
• Contraindications• Complete obstruction
• Patient Preparation:• Low residue diet• Bowel Prep (Dulcolax -2-4 Tab)
Small Bowel follow through VS Small bowel enema
Barium Enema
• Indications:• Change in bowel habits• Pain• Mass• Melaena / Anemia
• Single contrast – Obstruction & Intussusception.
• Contraindications:• Rectal biopsy—5 days• Toxic megacolon• Pseudomembranous colitis
• Preparation: (Two days)• Low residue diet• Bowel prep (Dulcolax – 4 Tab)
Ultrasound Abdomen
• Advantage• Cost effective• Adequate visceral visualization • Best for GB• No radiation
• Indications: Acute Abdomen, Obstructive jaundice, abdominal masses, collections, Free fluid, follow up- tumors.
• Disadvantage• Operator dependent• Poor in Obesity• Bowel gasses• Bones / Calcifications
CT Scan Abdomen
• Advantages• Accurate & quick• Bowel/ gasses/ bones • Reformation and angio
• Indications: Acute abdomen, Abdominal mass, tumor staging/follow up, Appendicitis/abscesses, Post op complications
• Disadvantages:• Radiation (250 CXR)• Renal failure• Contrast reaction
MRI Abdomen
• Advantages• Multiplaner• Renal failure• MRCP• Liver specific contrasts
• Disadvantages• Bowel motion/ contrast• Calcifications• Metallic implant• Relatively long procedure time• Claustrophobia
Cholangiography
• Endoscopic Retrograde Cholangiopancreatography (ERCP)
• MR Cholangiopancreatography (MRCP)
• T-tube Cholangiography.• Percutaneous Transhepatic
Cholangiography (PTC).