CT Introduction

Question 1

Who discovered x-rays?

Answer 1

Wilhelm Conrad Röntgen

Question 2

In what year was x-rays discovered?

Answer 2

1895

Question 3

A type of “shadow” of all the dense tissues in the path of the x-ray beam as it passes through the patient

Answer 3

Conventional Radiograph

Question 4

Who is deemed as “father” of CT releasing the first commercial CT scanner in the early 1970s?

Answer 4

Godfrey Newbold Hounsfield

Question 5

Every CT scanner must include a source of x-rays, called _____, and at least one x-ray _____

Answer 5

CT X-ray Tube / Detector

Question 6

First-generation scanners had an x-ray tube that produced what kind of beam?

Answer 6

Pencil Beam

Question 7

For first-generation scanners, its beam passes through the patient to how many detectors?

Answer 7

One

Question 8

How many degrees did the first-generation scanners rotated by?

Answer 8

1 degree

Question 9

What was the total scan time of first-generation scanners per image?

Answer 9

5 minutes

Question 10

Second-generation scanners had an x-ray tube that produced what kind of beam?

Answer 10

Fan Beam

Question 11

For second-generation scanners, its beam passes through the patient to how many detectors?

Answer 11

Multiple detectors in a straight line

Question 12

How many degrees did the second-generation scanners rotated by?

Answer 12

5 degrees

Question 13

What was the total scan time of second-generation scanners per image?

Answer 13

20 seconds

Question 14

Third-generation scanners had an x-ray tube that produced what kind of beam?

Answer 14

Fan Beam

Question 15

For third-generation scanners, its beam passes through the patient to how many detectors?

Answer 15

Multiple detectors in an arc

Question 16

What was the total scan time of third-generation scanners per image?

Answer 16

Less than 1 second

Question 17

What is the main difference when it comes to fourth-generation scanners compared to the previous generations?

Answer 17

Multiple detectors encircles the patient, but only the tube rotates around the patient

Question 18

What are the benefits of multi-row detector CT scanners?

Answer 18

Faster scan
Increased anatomical coverage
Resolution improvement

Question 19

Why would a cone beam CT be used in the oncology department?

Answer 19

To verify patient positioning prior to receiving radiation therapy

Question 20

What are the benefits of CT?

Answer 20

Cross-sectional
Tissue differentiation
Digital
Speed

Question 21

What are the three conventional imaging planes?

Answer 21

Transverse
Coronal
Sagittal

Question 22

What are some benefits to digital information?

Answer 22

Easily stored on a computer
Always accurately reproduced from the stored data
Easily & quickly manipulated and processed on a computer
Can be stored on optical disk or CD
Can be electronically transported to remove viewing facilities

Question 23

“Throughput” refers to…

Answer 23

The number of patients one can scan in a given period of time

Question 24

Repeated exposure to ionizing radiation can result in…

Answer 24

Malignancies and birth defects

Question 25

What are some common indications for CT when looking at the head?

Answer 25

Viewing facial bones

Study the sinuses

Question 26

What are some common indications for CT when looking at the chest?

Answer 26

Infection
Cancer
Pulmonary emboli
Aneurysms

Question 27

What are some common indications for CT when looking at the abdomen?

Answer 27

Cysts
Abscesses
Infection
Bleeding
Tumors
Aneurysms
Diverticulitis
Appendicitis

Question 28

What are some common indications for CT when looking at the urinary tract?

Answer 28

Detect kidney stones
Blockages
Abnormal growths

Question 29

What are some common indications for CT in reference to an orthopedic?

Answer 29

Trauma

Evaluate extent of damage

Question 30

What is the target in the CT x-ray tube made of, and why?

Answer 30

Tungsten:
High atomic number = efficient x-ray production due to its many electrons
High melting point = prevents target from heating up when electrons hit