RADIOLOY OF GIT (BLOCK) OBJECTIVES By the end of this lecture students will be able to Know the radiological anatomy, of the esophagus, stomach, appendix, colon, liver, biliary system, pancreas, spleen, inguinal region, and peritoneum. Discuss the modalities available to image the GIT. Discuss the limitation and appropriate indications of plane radiography in GIT Know the clinical indication of contrast studies in GIT and biliary system. Know radiological features of some common pathologies.

IMAGING MODALITIES Plane x-rays. Fluoroscopy for the gut mainly Ultrasound Computerized Tomography (CT) Magnetic Resonance Imaging (MRI) Radioisotopes studies Angiography Most common use in GIT : planx-rays, Fluoroscopy Ultrasound : for detdect stone

Principles of Radiography The underlying physical principles of conventional radiography involve Emitting a stream of photons from x-ray source, strike body tissue. Photons with varying amount of energy exit the patient body and fall on image receptor/film, thus produce an image

Radiological Anatomy Plane Radiography. Normal: The routine projection is supine film; however erect film is taken in certain cases in particular, patients with suspicious of intestinal obstruction to check for air-fluid levels. AP: anterioposterior position most common In some cases we use lateral potion for esophagus

Supine

IMAGING MODALITIES Image key = shades White ----- bone and calcification Black ----- air Grey ------ soft tissue

Esophagus Esophagus is 25cm long. It has three parts Cervical Thoracic Abdominal Stomach is j shape. Cardia Fundus Body Pyloric canal and sphincter

Foreign body in esophagus

X-ray abdomen supine Normal gas pattern Small intestine intestine Stomach

SMALL VS LARGE BOWEL. SMALL INTESTINE LARGE INTESTINE Comparatively short 1.5m Four parts. Cecum, colon, rectum and anal canal. Wider . 5cm diameter Large bowel is peripheral. Haustra are present. No villi. Circular fold absent. Long 5-7m Three parts. Duodenum, jejunum and ilium Normal small bowel diameter is 3cm. Small bowel is central in distribution. Volvulae conniventes which are mucosal folds run almost the whole width. Villi are present. Haustra absent.

X-ray abdomen Erect position show fluid levels . Supine film

Normal Large intestine

Fluoroscopy: It gives a real time images of internal structures Fluoroscopy: It gives a real time images of internal structures. It consist of an x-ray source, fluorescent screen and between the two the patient is put

Contrast Studies. Barium swallow AP view and LA view of the barium-coated pharynx and hypopharynx obtained during phonation demonstrates normal anatomy but also aspiration of barium into the larynx and trachea. Ulso for esophagus Barium swallow Indication: Dysphagia Pain Obstruction Foreign body

Normal anatomic narrowing of esophagus

Normal esophageal rings and dilatations A ring at the junction of tubular and vestibular esophagus B ring. At the squamous and columnar epithelial junction Hiatus hernia demarcated by red arrow

Corkscrew esophagus Tertiary contractions Normal peristalsis

Barium meal Indications: Pain, obstruction Hematemesis Perforation Anoraxia,weight loss

Barium meal follow through Indications: Pain, obstruction, weight loss Barium meal: for stomach and duodenum ( jejunum and terminal ileum ) The name for the substanc ethat use in EVERY barium test is berium sulfate

Barium enema for large intestine Indications: Melena, Pain, weight loss and obstruction Normal Abnormal (Narrowed due to diseaase)

Contrast study of biliary tree Plane x-ray showing calcified gallbladder. Porcelain gallbladder

Ultrasound

Ultrasound: we use sound waves to produce image. Water appear dark, soft tissue appear grey and stone appear white

Liver RT Kidney Liver Hepatic vein

US is good imaging technique for gallbladder stone GB septation Gall stones

Lower abdominal aorta at bifurcation Pancreas

Liver cysts

Computerized Tomography (CT) Consist of x-ray source Detectors Computer. It cut the body in to thin slices(Cross section) Show anatomy in more detail

CT abdomen with out contrast

CT with contrast

CT images of pelvis

CT scan shows liver masses Metastasis Hemangioma Hepatocellular carcinoma

Why CT is better than ultrasound and x-rays for abdomen. CT is better because it shows cross sectional images and demonstrate soft tissues, bony structures and blood vessels at the same time, so provide better anatomical detail. Sound waves can not pass through bones and poorly pass through air.

Comparison of CT,Ultrasond and plane x-rays for gallbladder stone. Both CT and ultrasound are excellent in detecting stones, but why we prefer ultrasound? Because No radiation Inexpensive Easily available