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Radiology
Radiology is a medical specialty that uses
imaging to diagnose and treat diseases seen
within the body.
https://en.wikipedia.org/wiki/Radiology
Radiographic modality
 Plain radiographs
 Ultrasonography
 Computer tomography (CT)
 Magnetic resonance imaging (MRI)
 Fluoroscopy
Plain radiography
X-ray production
Image production
Density of the plain radiographs
 Air  air in the bowel loops and stomach
 Fat  subcutaneous layer of the abdominal wall
 Water  same density as other soft tissue and internal
organ
 Bone  all of the bony structures and calcification
 Metallic  medical instrument and foreign bodies
Contrast agents
 Barium sulfate
 Water-soluble contrast
 Negative contrast
Barium sulfate
 White crystalline powder
 High specific gravity
 Inert, not support bacterial growth
 Radiodensity
 Coat GI mucosa
Adverse effect of barium sulfate
 Inflammation of the abdominal cavity or mediastinum
- Mediastinitis
- Peritonitis
Do not use in case of suspected leakage within
thorax or abdomen
Water-soluble contrast
agents
 Iodine compound
 Do not coat the GI mucosa
 Use in case of suspected leakage or post operative
evaluation
 High cost
 Adverse effect  cause pneumonia or pulmonary
edema if aspirate into lung
Negative contrast agent
 Air  use for double-contrast study
 Carbon dioxide
 Drug  Simeticone
Esophagography
 Contrast-enhanced fluoroscopy of the esophagus
 Ingestion of the contrast while performing
radiographic study
 Can detect intraluminal/transmural esophageal lesion
 Interesting in anatomy and function
 Indication: Evaluation of the esophageal obstruction
and function
Double-contrast
esophagography
Contrast
Air
Area of interest
 Upper GI study
-
Esophagus
 GI follow
through
-
Hypopharynx/larynx
- Esophagus
-
Stomach
- Hypopharynx/larynx
-
Duodenal bulb and
duodenal loop
- Stomach
- Duodenal bulb and
duodenal loop
- Small bowel loops
- Ceacum
Anatomy on
upper GI study
GI follow through
Barium enema
 Area of interest: Colon, sigmoid colon and rectum
 Introduce barium into rectum via rectal tube, through
colon to ceacum
 Push air into colon

Double contrast study
BE machine
Intravenous pyelography
(IVP)
 Good modality to evaluate urinary system
 Can evaluate  Anatomical and functional
abnormality
 Indication  Urinary tract obstruction, Urinary leak
from trauma or post operation, urothelial tumor
Procedure of IVP
 “ Plain radiographs along phases of the renal function
and excretion”
 Plain radiographs on
1. Pre-contrast (Scout film)  to detect stone, renal
shadow, psoas shadow
2. 1 minute after contrast administration  evaluate
nephrogram
3. 3 minutes after contrast administration  evaluate
excretory function
Procedure of IVP
4. 10 minutes after contrast administration  evaluate
pelvocaliceal system and ureter
5. 25-30 minutes after contrast administration  evaluate
lower part of ureter and urinary bladder
6. Full bladder  evaluate urinary bladder
7. Post voiding  residual urine
IVP device
Principle of IVP
Scout film
1 minute
3-5 minutes
10 minutes
25-30 minutes
Both oblique views
Full bladder
Retrograde pyelography
 Retrograde injection of the contrast material into
ureters  extending to pelvocaliceal system
 Use to evaluate collecting system of the patient who
has poor renal function
 Quality of the imaging can be controlled by
concentration of the contrast material and rate of
injection
Left
retrograde
pyelography
Intraluminal
filling defect
within right
upper pole
calyx
Cystography/voiding
cystourethrography (VCUG)
 Input contrast material into urinary bladder
 Imaging of the urinary bladder on AP, lateral and both
oblique views
 Evaluate urothelial tumor, diverticulum or leakage
from trauma or surgery
Cystography/voiding
cystourethrography (VCUG)
 Voiding cystourethrography  take pictures while
voiding
 Indication for VCUG  to rule out vesicoureteral
reflux (VUR) ; use in urinary tract infection of the
children, evaluation of the urethra
Contrast
leakage
Normal anatomy on VCUG
Imaging of VCUG
Abnormal VCUG
Hyterosalpingography
 Examination of the lumen of uterus and fallopian
tubes
 Injection of the contrast material into uterine cavity,
via cervix
 Use in infertility (primaryy, secondary), spontaneous
abortion, preoperative evaluation to tubal anastomosis
Hysterosalpingography
 Contraindication
- Pregnancy
- Active menstrution
- Acute pelvic inflammatory disease
- Recent undergo uterine or tubal surgery
Hysterosalpingography
 Take pictures on AP, both oblque views after contrast
injection
 Complication  pain, fever, sepsis (if has intravastion
of the contrast material)
Normal anatomy on
hysterosalpingography
US Device
US probe
Ultrasonography
 Real time imaging
 Use ultrashort sound wave
 Transmit and receive sound wave by transducer
 Piezoelectric crystal  emit sound wave when a
voltage is applied
 Then convert received sound wave to digital
 No radiation !!!!
Ultrasonography
 Adjust frequency of the sound wave  adjust depth
 Interaction between sound wave and tissue
- Reflection
- Absorbtion
- Scatter
Differentiation
of the tissue
Ultrasonography
 Due to transmission of the sound wave between soft
tissue and air is as described
 Limit study for the gastric and bowel lesion
 Operator dependent
Computer tomography
 Tomos = slices
 Use X-ray beam to scan the body and collect data
digitally
 Image production and reconstruction from the data
CT Reconstruction Matrix
Image reconstruction
MR study
 Imaging modality that uses non-ionizing radiation to
create diagnostic useful images
 Advantage
-
The ability to image without the use of ionizing
radiation (x-ray) unlike CT scanning  can be use in
pregnant women
-
Superior soft tissue contrast than CT scans and plain
films making it the ideal examination of the brain,
spine, joints and other soft tissue body parts
MR study
 Advantage (cont.)
-
Some angiographic images can be obtained without the
use of contrast material, unlike CT or conventional
angiography
-
Advanced techniques such as diffusion, spectroscopy
and perfusion allow for specific tissue characterisation
rather than merely 'macroscopic' imaging
MR study
 Disadvantage
- More expensive than CT scans
- Longer study time
- MRI scanning is not safe for patients with some metal
implants and foreign bodies
MR technique
 Every tissue have proton (due to large component of
H2O in body  respresenting proton of H2O)
 Hydrogen in H2O molecule of different tissue has
different magnetic field
 Put the RF pulse to hydrogen atom to push atom into
same dirrection
 Then stop the RF pulse  recoil vector of the
hydrogen atom
 Different time of recoil  analyze into digital data 
form the images
MR sequences
Thank you for your attention
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