Transcript 1 - muhadharaty.com

Introduction and technical
consideration
Qais A. Altimimy, DMRD, CABMS-RAD.
Lecturer, Radiology
Alkindy college of medicine, university of Baghdad
2015
Objectives:
Proper use of imaging department.
How X-rays are produced in Conventional Radiography.
Syllabus:
-The basic radiographic densities.
-Projections in conventional radiology:…PA. AP. Lateral,
Horizontal X-ray beam, Lateral decubitus
-CT Scan, Ultrasound, MRI, Radionuclide imaging & PET , Basic
principles
-Contrast agents in Conventional Radiography & CT.. Definition
& side effects
-Radiation Hazards
The radiograph of Bera
Roentgen’s hand” taken
22 Dec. 1895
Electromagnetic spectrum :
Electromagnetic radiation consists of energy (a particle) in small
packets known as photons or quanta. They are grouped according to
their wave length and frequency.
Portable
Fixed
When reviewing an MR image, the easiest way to
determine which pulse sequence was used, or the
"weighting" of the image, is to look at the cerebrospinal
fluid (CSF). If the CSF is bright (high signal), then it must
be a T2-weighted imaged. If the CSF is dark, it is a T1weighted image.
Acronym for:
Computed tomography
Application:
Suited for bone injuries, Lung and Chest Suited for ligament and tendon injury, spinal
imaging, cancer detection
cord injury, brain tumors
Principle:
X-ray attenuation was detected by
detector & DAS system, follow by math.
model (back projection model) to
calculate the value of pixels then become
a image.
Ability to change the With capability of MDCT, after helical
imaging plane without scan with Multi-plane Reformation
function, an operator can construct any
moving the patient:
Magnetic Resonance Imaging
Makes use of the fact that body tissue
contains lots of water (and hence protons)
which gets aligned to large magnetic field to
produce signal.
MRI machines can produce images in any
plane.
plane.
Cost:
cost less than MRIs.
usually more than CT
Principle used for
imaging:
Uses X-rays for imaging
Uses large external field,RF pulse and 3
different gradient fields
Details of bony
structures:
Provides good details about bony
structures
Less detailed compared to CT scan
Time taken for
complete scan:
Details of soft
tissues:
Effects on the
body:
Usually 2-3 minutes
Usually about 10 – 20 minutes.
Less tissue contrast compared to MRI
Much higher detail in the soft tissues
Despite being small, CT can pose the
risk of irradiation.
No biological hazards have been
reported with the use of the MRI.
Radiation exposure:
Moderate to high radiation
None
Patients with metal implants can get CT scan.
A person who is very large (e.g. over 250 kg
)may not fit into the opening of a conventional
CT scanner or may be over the weight limit for
the moving table.
Seldom creates claustrophobia
Patients with Cardiac Pacemakers, tattoos
and metal implants are contraindicated
due to possible injury to patient or image
distortion (artifact). Patient over 160 kg
may be over table's weight limit. Any
ferromagnetic object may cause
trauma/burn.
Often creates claustrophobia in
susceptible patients.
THIS PROCEDURE:
YOUR EFFECTIVE
RADIATION DOSE IS:
COMPARABLE TO NATURAL
BACKGROUND RADIATION
FOR:
ABDOMINAL REGION:
Computed Tomography (CT)Abdomen
10 mSv
3 years
Computed Tomography (CT)Body
10 mSv
3 years
Radiography-Lower GI Tract
4 mSv
16 months
Radiography-Upper GI Tract
2 mSv
8 months
0.001 mSv
Less than 1 day
Computed Tomography (CT)Chest
8 mSv
3 years
Radiography-Chest
0.1 mSv
10 days
0.7 mSv
3 months
BONE:
Radiography-Extremity
CHEST:
WOMEN'S IMAGING:
Mammography