Free Computed Tomography Ultimate Questions and Answers

Question 1

Which artifact occurs when an object is positioned partially in and partially out of the scan field of view?

Accepted Answer

Partial volume artifact

Answer

A partial volume artifact occurs when a voxel contains tissues or structures with significantly different attenuation values, such as bone and soft tissue, or when an object is only partially included in the slice thickness. The CT number assigned to that voxel represents an average of these different attenuations, leading to a misrepresentation of the true density and potentially blurring or obscuring small structures.

Question 2

What is the purpose of using a convolution kernel in CT image reconstruction?

Accepted Answer

To improve image quality

Answer

Convolution kernels, also known as reconstruction filters, are applied during the image reconstruction process to enhance specific aspects of image quality. Different kernels emphasize either spatial resolution (e.g., sharp or bone kernels) or contrast resolution and noise reduction (e.g., smooth or soft tissue kernels). Choosing the appropriate kernel is crucial for optimizing the image for the specific diagnostic task.

Question 3

Which type of CT scan involves acquiring images at multiple time points to visualize the distribution of contrast agent in tissues?

Accepted Answer

Answer

Dynamic CT involves acquiring a series of images over time after the administration of a contrast agent. This technique allows for the visualization of the contrast agent's uptake, distribution, and washout kinetics within tissues and organs. It is used to assess vascularity, perfusion, and the enhancement patterns of lesions, providing valuable functional information.

Question 4

What is the primary purpose of CT fluoroscopy?

Accepted Answer

To monitor needle guidance during procedures

Answer

CT fluoroscopy provides real-time CT images, similar to conventional fluoroscopy but with cross-sectional views. Its primary purpose is to guide interventional procedures, such as biopsies, drainages, and pain injections, by allowing the operator to continuously monitor the advancement of a needle or catheter. This real-time visualization significantly improves accuracy and safety during these procedures.

Question 5

Which term refers to the ability of a CT scanner to acquire images in a very short time interval?

Accepted Answer

Temporal resolution

Answer

Temporal resolution in CT refers to the ability of the scanner to capture images of moving structures with minimal motion blurring, essentially how quickly the data for a single image can be acquired. High temporal resolution is critical for imaging rapidly moving organs like the heart, reducing artifacts caused by cardiac motion or patient breathing. It is often achieved with faster gantry rotation times and multi-detector arrays.

Computed Tomography Test Practice Test

Computed Tomography Test Practice Test

Free Computed Tomography Ultimate Questions and Answers