CT Scanning: Principles, Applications, and Exam Preparation

Question 1

Which of the following is NOT a crucial component of a Computed Tomography (CT) scanner?

Accepted Answer

Magnetic resonance imaging (MRI) scanner

Answer

X-ray tube

Answer

Detector

Answer

Collimator

Question 2

What is the primary purpose of a collimator in a CT scanner?

Accepted Answer

To restrict the shape and size of the X-ray beam

Answer

To remove unwanted scattered radiation

Answer

To focus the X-rays on the patient's body

Answer

To detect the X-rays that pass through the patient

Question 3

In CT imaging, the Hounsfield unit (HU) primarily measures:

Accepted Answer

The extent to which X-rays are absorbed or attenuated by tissues

Answer

The intensity of the X-rays after passing through the body

Answer

The weight of the patient being scanned

Answer

The duration of the CT scan

Question 4

What is the primary role of contrast agents in CT?

Accepted Answer

To enhance the visibility of specific structures within the body

Answer

To reduce the amount of radiation required for the scan

Answer

To improve the overall image resolution

Answer

To prevent the formation of artifacts

Question 5

Which of the following is the primary component of a CT scanner, emitting X-rays towards the patient?

Accepted Answer

X-ray tube

Answer

Laser beam

Answer

Ultrasound probe

Answer

Magnetic field

Question 6

What is the key physical principle underlying the mathematical transformation used for CT image reconstruction?

Accepted Answer

Radon transform

Answer

Fourier transform

Answer

Hilbert transform

Answer

Laplace transform

Question 7

Which of the following is NOT an advantage of CT over conventional X-ray imaging?

Accepted Answer

Reduced radiation dose

Answer

Cross-sectional imaging capability

Answer

Reduced artifact susceptibility

Answer

Improved contrast resolution

Question 8

What is the purpose of contrast agents in CT, administered to enhance imaging?

Accepted Answer

To increase the visibility of specific anatomical structures

Answer

To reduce radiation exposure

Answer

To calibrate the scanner

Question 9

What is the primary factor influencing the spatial resolution of a CT image?

Accepted Answer

Detector element size

Answer

Gantry rotation speed

Answer

X-ray tube focal spot size

Answer

Patient size

Question 10

Which of the following artifacts can occur in CT due to patient movement during the scan?

Accepted Answer

Motion blur

Answer

Beam hardening

Answer

Star artifacts

Answer

Ring artifacts

Question 11

What is the main advantage of using a helical scan mode in CT?

Accepted Answer

Reduced scan time and motion artifacts

Answer

Enhanced contrast

Answer

Increased image resolution

Answer

Reduced radiation dose

Question 12

What is the key function of an image reconstruction algorithm in CT?

Accepted Answer

To convert raw X-ray projection data into cross-sectional images

Answer

To display the reconstructed images

Answer

To generate the X-ray beam

Answer

To detect and process X-ray signals

Question 13

What is the primary purpose of Computed Tomography (CT) scanners?

Accepted Answer

Medical diagnosis of internal structures and diseases

Answer

Industrial inspection

Answer

Security screening

Answer

Meteorological research

Question 14

What type of radiation is utilized by CT scanners?

Accepted Answer

X-rays

Answer

Gamma rays

Answer

Microwaves

Answer

Ultrasound

Question 15

Which component in a CT scanner captures the X-rays?

Accepted Answer

Detector array

Answer

Patient table

Answer

Gantry

Answer

X-ray tube

Question 16

What is the process of converting raw data from a CT scanner into an image called?

Accepted Answer

Image reconstruction

Answer

Image enhancement

Answer

Image registration

Answer

Image segmentation

Question 17

Which of the following is a key advantage of CT scanning compared to conventional X-rays?

Accepted Answer

Cross-sectional imaging capabilities

Answer

Lower radiation dose

Answer

Faster imaging time

Answer

Higher spatial resolution

Question 18

What is the most commonly used contrast agent in CT scans?

Accepted Answer

Iodine-based contrast

Answer

Gadolinium-based contrast

Answer

Barium sulfate

Answer

Saline solution

Question 19

Who is responsible for operating the CT scanner and ensuring patient safety during the procedure?

Accepted Answer

Radiographer

Answer

Medical physicist

Answer

Nurse

Answer

Radiologist

Question 20

What is the typical range of slice thickness used in CT scans?

Accepted Answer

1-5 millimeters

Answer

5-10 millimeters

Answer

10-15 millimeters

Answer

0.1-1 millimeter

Question 21

In Computed Tomography (CT), the type of radiation used is:

Accepted Answer

X-rays

Answer

Ultrasound waves

Answer

Gamma rays

Answer

Radiofrequency waves

Question 22

The rotating component in a CT scanner that holds the X-ray tube and detectors is known as the:

Accepted Answer

Gantry

Answer

Collimator

Answer

Reconstruction unit

Question 23

Contrast agents used in CT scans enhance the visibility of:

Accepted Answer

Specific tissues or structures

Answer

Speed up the scan process

Answer

Reduce radiation exposure

Question 24

Which algorithm is commonly employed for image reconstruction in CT?

Accepted Answer

Filtered back projection

Answer

Neural network reconstruction

Answer

Algebraic reconstruction technique

Answer

Maximum intensity projection

Question 25

The Hounsfield scale in CT imaging:

Accepted Answer

Assigns numerical values to tissue types based on X-ray attenuation

Answer

Determines optimal imaging parameters

Answer

Reduces image artifacts

Question 26

Which fundamental physical principle underlies the operation of Computed Tomography (CT) scanners?

Accepted Answer

X-ray attenuation

Answer

Magnetic resonance

Answer

Ultrasound reflection

Answer

Electrical impedance

Question 27

In CT, which mathematical algorithm is employed to reconstruct images from projection data?

Accepted Answer

Filtered back-projection

Answer

Maximum likelihood estimation

Answer

Expectation-maximization

Answer

Fourier transform

Question 28

What is the primary purpose of using contrast agents in CT examinations?

Accepted Answer

To enhance the visibility of specific tissues and organs

Answer

To reduce radiation dose

Answer

To improve image resolution

Question 29

Which key advantage does cone-beam CT offer over conventional CT?

Accepted Answer

Wider field of view

Answer

Improved image resolution

Answer

Lower radiation dose

Answer

Faster scanning speed

Question 30

Which technique can be used to minimize radiation exposure during CT scans?

Accepted Answer

Iterative reconstruction

Answer

Increasing X-ray tube voltage

Answer

Increasing scanning speed

Answer

Using smaller detector arrays

Question 31

When designing and operating a CT scanner, what is a crucial consideration?

Accepted Answer

Balancing image quality and radiation dose

Answer

Minimizing cost

Answer

Maximizing scanning speed

Question 32

Which component is NOT typically found in a Computed Tomography (CT) scanner?

Accepted Answer

Laser beam

Answer

Gantry

Answer

X-ray tube

Answer

Detector array

Question 33

What is the primary function of the collimator in a CT scanner?

Accepted Answer

To shape the X-ray beam into a fan-shaped cross-section

Answer

To filter out unwanted radiation

Answer

To detect X-rays

Question 34

Which of the following reconstruction algorithms is commonly employed in CT scanners?

Accepted Answer

Filtered back projection

Answer

Maximum intensity projection

Answer

Algebraic reconstruction technique

Answer

Statistical reconstruction technique

Question 35

What is the primary advantage of CT over conventional radiography?

Accepted Answer

The ability to obtain cross-sectional images

Answer

Faster imaging time

Answer

Lower radiation dose

Answer

Higher resolution

Question 36

What is the typical range for the X-ray tube voltage used in CT scanners?

Accepted Answer

120 - 140 kVp

Answer

250 kVp

Answer

50 kVp

Answer

500 kVp

Question 37

What is the primary responsibility of a medical physicist in the field of CT?

Accepted Answer

To ensure the safe and optimal use of CT scanners

Answer

To perform CT scans on patients

Answer

To develop new CT imaging techniques

Question 38

Which of the following best describes the fundamental principle behind Computed Tomography (CT)?

Accepted Answer

Reconstructing a cross-sectional image of an object from multiple X-ray projections taken at different angles.

Answer

Using high-frequency sound waves to generate images of internal structures.

Question 39

What type of radiation is used in CT scanning?

Accepted Answer

X-rays

Answer

Gamma rays

Answer

Radio waves

Answer

Ultrasound

Question 40

A CT scan is performed with a high mA setting. What impact will this have on the resulting image?

Accepted Answer

Increased signal-to-noise ratio, resulting in a clearer image

Answer

Decreased patient dose

Answer

Longer scan time

Question 41

Which of these components is NOT part of a typical CT scanner?

Accepted Answer

Image intensifier

Answer

Gantry

Answer

Collimator

Answer

Detector array

Question 42

What is the primary role of the collimator in CT scanning?

Accepted Answer

To shape and limit the X-ray beam, reducing scatter radiation.

Answer

To reconstruct the cross-sectional images from projection data.

Answer

To rotate the X-ray tube around the patient.

Question 43

Which mathematical technique is fundamental to the reconstruction of CT images?

Accepted Answer

Filtered back projection

Answer

Laplace transform

Answer

Wavelet analysis

Answer

Fourier transform

Question 44

What does the Hounsfield unit (HU) scale measure in CT imaging?

Accepted Answer

The relative attenuation of X-rays by different tissues.

Answer

The amount of radioactive tracer uptake in a particular organ.

Answer

The intensity of the magnetic field applied during scanning.

Question 45

A CT scan reveals a brain lesion with a Hounsfield unit (HU) value of +80. What type of tissue is this most likely to be?

Accepted Answer

Bone

Answer

Air

Answer

Water

Question 46

Which of the following is NOT a common application of CT scanning in medical diagnosis?

Accepted Answer

Visualizing the chambers of the heart in real-time

Answer

Detecting and staging tumors

Answer

Evaluating bone fractures and injuries

Question 47

What is a key advantage of CT angiography (CTA) over conventional angiography?

Accepted Answer

It is less invasive, as it does not require arterial catheterization.

Answer

It provides better visualization of soft tissues like the brain.

Answer

It uses lower doses of radiation, minimizing patient exposure.