Intro To Radiology Flashcards
Who discovered X-ray
Wilhelm Conrad Roentgen
When was the X-ray discovered
November 8, 1895
The absorption of X-rays decrease as a result of
Density and Atomic Number
On plain X-ray air/gas appears as?
BLACK
On plain X-ray fat appears as?
DARK GREY
On plain X-ray soft tissues and water appear as?
LIGHT GREY
On plain X-ray bone appears as?
OFF WHITE
On plain X-ray contrast material and metal appear as?
BRIGHT WHITE
Factors that affect X-ray are
1) Movement
2) Magnification
3) Obesity
4) Scatter
The thickness of a CT axial slide is?
2-10mm
The density of bone or metal on CT is?
+1000 Hounsfield Unit
The density of air on CT is?
-1000 Hounsfield Unit
The density of water on CT is?
0 Hounsfield Unit
Three windows in CT are:
1) Bone window
2) Soft tissue window
3) Blood window
Examples of contrast given during an abdominal CT scan are?
1) Dilute barium
2) Gastrografin
Dividing cells are particularly susceptible to ionizing radiation. These cells are
1) Gonads
2) Bone Marrow
The two types of effects are:
1) Stochastic effect
2) Deterministic effect
The three components of Basic Safety Standards are:
1) Justifiable exposure
2) As Low As Reasonable Allowable
3) Dose Limits
The 2 reasons for dose limits are:
1) To keep dose below threshold value to reduce the deterministic effects
2) To decrease the risk of stochastic effect
Main indications for ultrasound are:
1) Pregnancy
2) Uterine and ovarian lesions
3) Diseases of the liver spleen and pancreas
4) Abdominal masses
5) To confirm pleural effusion and pleural masses
Advantages of Ultrasound includes:
1) Low cost of equipment
2) Allows scanning in any plane
3) Very portable
4) Safe
5) Readily available
6) Aids biopsy and drainage procedures
Disadvantages of ultrasound are:
1) Cannot penetrate bone or gas
2) Very operator dependent
3) Obesity degrades images due to scatter phenomenon
The main difference between T1 and T2 are?
T1 gives excellent anatomical definitions but are less sensitive to pathologies as compared to T2 which is highly sensitive to pathologies
