Question 1

The ring diameter of most clinical PET scanners is about:

Accepted Answer

Most clinical PET scanners have a ring diameter of about 50 cm, which allows for adequate coverage of the human body for imaging purposes.

Question 2

Clinical examples of PET imaging include each of the following except:

Accepted Answer

PET imaging is commonly used in cardiac, epilepsy, and oncology studies to assess metabolic activity and function, but it is not typically used for trauma, which is more often evaluated with other imaging modalities like CT or MRI.

Question 3

A disadvantage of using isotopes such as ¹⁵O, ¹³N, and ¹¹C are their:

Accepted Answer

These isotopes have short half-lives, which means they decay quickly and require rapid synthesis and use, posing logistical challenges in medical and research applications.

Question 4

The crystals in the construction of a positron emission tomography (PET) scanner's detectors are:

Accepted Answer

PET scanners use scintillation detectors, which are typically made of crystals like bismuth germanate (BGO) or lutetium oxyorthosilicate (LSO), to detect gamma rays emitted from positron-electron annihilation events.

Question 5

What type of coincidence detection occurs when both annihilation photons exit the patient without incident and are detected in coincidence?

Accepted Answer

True coincidence detection occurs when both annihilation photons exit the patient without incident and are detected in coincidence.

Question 6

The most commonly used radiopharmaceutical for PET imaging is:

Accepted Answer

FDG is the most commonly used radiopharmaceutical in PET imaging due to its ability to mimic glucose, allowing for the assessment of glucose metabolism in tissues, which is useful in oncology, neurology, and cardiology.

Question 7

If the nucleus contains too many protons, it may emit a:

Accepted Answer

If the nucleus contains too many protons, it may emit a positron to reduce the number of protons and increase the number of neutrons.

Question 8

An atom that has too many protons or too many neutrons or they are configured in such a way so as to render the nucleus unstable is said to be a(n):

Accepted Answer

An atom with an unstable nucleus due to an imbalance of protons and neutrons is considered radioactive.

Question 9

Radioactive fluorine can be chemically substituted for a:

Accepted Answer

Radioactive fluorine can be substituted for a hydrogen atom in organic compounds due to its similar size and ability to form stable covalent bonds.

Question 10

When using FDG for a whole-body scan, the uptake waiting period is usually:

Accepted Answer

The uptake waiting period for FDG in a whole-body scan is typically 45-90 minutes to allow optimal distribution and uptake of the tracer in tissues.

Question 11

All of the following are scintillating materials used in PET detectors except:

Accepted Answer

Calcium tungstate is not typically used in PET detectors; it is more commonly used in X-ray imaging. The other materials listed are used in PET detectors.

Question 12

When a photon undergoes Compton scattering prior to exiting the patient, it is referred to as a random coincident detection.

Accepted Answer

Compton scattering refers to the interaction of a photon with a loosely bound outer electron, resulting in a change in the photon's direction and energy. Random coincident detection is a term used in PET imaging to describe unrelated events that are detected simultaneously, not related to Compton scattering.

Question 13

A positron has the same mass as an electron but has a positive rather than a negative charge.

Accepted Answer

A positron is the antimatter counterpart of an electron, having the same mass but opposite charge.

Question 14

What modality of imaging provides less noise when reconstructed to a PET or single-photon emission tomography (SPECT) image compared to traditional measured attenuation correction?

Accepted Answer

Computed tomography (CT) provides less noise when used for attenuation correction in PET or SPECT imaging compared to traditional methods, due to its high-resolution anatomical information.

Question 15

NaI and bismuth germinate are newer scintillating materials that have reasonably high detection efficiency.

Accepted Answer

NaI (sodium iodide) is a well-established scintillating material, not a newer one. Bismuth germinate (BGO) is also a known scintillator, but it is not new.

Question 16

One approach to reducing scatter includes introducing __________ between detection rings.

Accepted Answer

Interplane septa are used to reduce scatter by physically blocking scattered photons between detection rings.

Question 17

The probability of detecting the photons from an annihilation event from one center of an object is less than that for an event on the periphery.

Accepted Answer

The probability of detecting photons from an annihilation event is influenced by factors such as attenuation and scattering, which are generally higher for events occurring deeper within an object compared to those near the periphery.

Question 18

Displaying two data sets from two separate modalities as a single fused image is referred to as:

Accepted Answer

Registering involves aligning and combining data from different modalities into a single image, often used in medical imaging to provide comprehensive information.

Question 19

A modern PET scanner might contain tens of thousands of small scintillating detectors.

Accepted Answer

Modern PET scanners use a large number of small scintillating detectors to accurately capture and reconstruct the 3D distribution of radioactive tracers in the body, improving image resolution and sensitivity.

Question 20

All of the following are limitations of PET/CT technology except:

Accepted Answer

PET/CT technology provides excellent anatomical correlation by combining metabolic information from PET with anatomical details from CT, which is not a limitation.

Quiz 14: Positron Emission Tomographyct Petct and Single-Photon Emission Computed Tomographyct Spectct Hybrid Scanners

The ring diameter of most clinical PET scanners is about:

Clinical examples of PET imaging include each of the following except:

A disadvantage of using isotopes such as ¹⁵O, ¹³N, and ¹¹C are their:

The crystals in the construction of a positron emission tomography (PET) scanner's detectors are:

What type of coincidence detection occurs when both annihilation photons exit the patient without incident and are detected in coincidence?

The most commonly used radiopharmaceutical for PET imaging is:

If the nucleus contains too many protons, it may emit a:

An atom that has too many protons or too many neutrons or they are configured in such a way so as to render the nucleus unstable is said to be a(n) :

Radioactive fluorine can be chemically substituted for a:

When using FDG for a whole-body scan, the uptake waiting period is usually:

All of the following are scintillating materials used in PET detectors except:

When a photon undergoes Compton scattering prior to exiting the patient, it is referred to as a random coincident detection.

A positron has the same mass as an electron but has a positive rather than a negative charge.

What modality of imaging provides less noise when reconstructed to a PET or single-photon emission tomography (SPECT) image compared to traditional measured attenuation correction?

NaI and bismuth germinate are newer scintillating materials that have reasonably high detection efficiency.

One approach to reducing scatter includes introducing __________ between detection rings.

The probability of detecting the photons from an annihilation event from one center of an object is less than that for an event on the periphery.

Displaying two data sets from two separate modalities as a single fused image is referred to as:

A modern PET scanner might contain tens of thousands of small scintillating detectors.

All of the following are limitations of PET/CT technology except:

Quiz 14: Positron Emission Tomographyct Petct and Single-Photon Emission Computed Tomographyct Spectct Hybrid Scanners

The ring diameter of most clinical PET scanners is about:

Clinical examples of PET imaging include each of the following except:

A disadvantage of using isotopes such as 15O, 13N, and 11C are their:

The crystals in the construction of a positron emission tomography (PET) scanner's detectors are:

What type of coincidence detection occurs when both annihilation photons exit the patient without incident and are detected in coincidence?

The most commonly used radiopharmaceutical for PET imaging is:

If the nucleus contains too many protons, it may emit a:

An atom that has too many protons or too many neutrons or they are configured in such a way so as to render the nucleus unstable is said to be a(n) :

Radioactive fluorine can be chemically substituted for a:

When using FDG for a whole-body scan, the uptake waiting period is usually:

All of the following are scintillating materials used in PET detectors except:

When a photon undergoes Compton scattering prior to exiting the patient, it is referred to as a random coincident detection.

A positron has the same mass as an electron but has a positive rather than a negative charge.

What modality of imaging provides less noise when reconstructed to a PET or single-photon emission tomography (SPECT) image compared to traditional measured attenuation correction?

NaI and bismuth germinate are newer scintillating materials that have reasonably high detection efficiency.

One approach to reducing scatter includes introducing __________ between detection rings.

The probability of detecting the photons from an annihilation event from one center of an object is less than that for an event on the periphery.

Displaying two data sets from two separate modalities as a single fused image is referred to as:

A modern PET scanner might contain tens of thousands of small scintillating detectors.

All of the following are limitations of PET/CT technology except:

A disadvantage of using isotopes such as ¹⁵O, ¹³N, and ¹¹C are their: