FREE Computed Tomography Science Questions and Answers
Which technique allows for reduced radiation dose in CT imaging while maintaining image quality?
Low-dose CT techniques involve adjusting scan parameters to reduce radiation exposure while still producing diagnostically useful images.
What is the purpose of the CT table's indexing capability?
The CT table indexing feature allows controlled movement of the patient through the gantry, ensuring that the entire region of interest is imaged.
What is the Hounsfield unit (HU) scale used for in CT imaging?
The Hounsfield unit scale assigns numerical values to tissue densities based on their X-ray attenuation. Water is typically assigned a value of 0 HU, and air is around -1000 HU.
Which type of CT scan is commonly used to assess bone density and diagnose osteoporosis?
Dual-energy CT is used to evaluate bone density and can differentiate between different materials based on their energy-dependent attenuation properties.
Which type of artifact is caused by high-density materials like metal in the CT scan's field of view?
Beam-hardening artifacts occur due to the differential absorption of X-rays by high-density materials, leading to inaccuracies in the reconstructed images.
Which component of a CT scanner is responsible for rotating the X-ray tube and detector around the patient?
The gantry is the part of a CT scanner that contains the X-ray tube and detector array. It rotates around the patient to acquire multiple projection images.
What is the primary advantage of multislice (multidetector) CT over single-slice CT?
Multislice CT can acquire multiple slices simultaneously, leading to faster scan times and improved patient throughput.
What is the purpose of the CT reconstruction process?
CT reconstruction involves processing the raw data acquired during scanning into cross-sectional images that can be interpreted by radiologists.
Which type of contrast agent is commonly used in CT imaging to enhance blood vessels and soft tissue?
Iodinated contrast agents are frequently used in CT scans to increase the visibility of blood vessels and soft tissues due to their high X-ray attenuation properties.
In CT imaging, what does the term "slice thickness" refer to?
Slice thickness refers to the distance between two adjacent cross-sectional images in a CT scan. It determines the z-axis resolution of the scan.
What type of CT imaging is typically used for visualizing blood vessels with high contrast resolution?
Helical CT, also known as spiral CT, is particularly useful for visualizing blood vessels due to its continuous acquisition and high contrast resolution.
What is the purpose of the CT scout (topogram) image?
The CT scout image is used to help position the patient correctly within the scanner before the actual scan. It aids in ensuring that the desired anatomical region is imaged.
Which factor influences the spatial resolution of a CT scan?
Slice thickness directly affects the spatial resolution in the z-axis of a CT scan. Thinner slices provide better resolution.
What is the term for the phenomenon where a single tissue appears with different densities in different CT images due to varying X-ray attenuation angles?
The partial volume effect occurs when a voxel contains a mix of materials with different attenuation coefficients, leading to inaccuracies in tissue density representation.
What is the primary principle behind computed tomography imaging?
CT imaging is based on X-ray absorption by different tissues in the body. The varying absorption levels allow for the creation of detailed cross-sectional images.
Which imaging technique can provide information about blood flow and perfusion in addition to anatomical details?
Dynamic CT perfusion imaging can provide information about blood flow and tissue perfusion in addition to anatomical images.