Download Ridology of GIT -imp points

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
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.
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.
X-ray abdomen Erect position show fluid
levels .
Supine film
Normal Large intestine
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
Indication:
Dysphagia
Pain
Obstruction
Foreign body
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
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
Abnormal (Narrowed due to
diseaase)
Normal
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