Radioactive Phantom
Radioactive Phantom - Related Videos
03:18
Radioactivity and Nuclear Equations
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2020
Nuclear chemistry is the study of reactions that involve changes in nuclear structure. The nucleus of an atom is composed of protons and, except for hydrogen, neutrons. The number of protons in the nucleus is called the atomic number (Z) of the element, and the sum of the number of protons and the number of neutrons is the mass number (A). Atoms with the same atomic number but different mass numbers are isotopes of the same element. A nuclide of an element has a specific number of protons and...
02:48
Radioactive Decay and Radiometric Dating
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2020
Radioactivity is a spontaneous disintegration of an unstable nuclide and is a random process, as all the nuclei in the sample do not decay simultaneously. The number of disintegrations per unit time is called the activity (A), which is directly proportional to the number of nuclei in the sample. The decay constant (λ) is an average probability of decay per nucleus in unit time. The SI unit for activity is the becquerel, which is one disintegration per second. Another unit of activity is the...
09:26
Preparation and Using Phantom Lesions to Practice Fine Needle Aspiration Biopsies
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Cited by 6 •
2009
Practicing of fine needle aspiration biopsies (FNAB) by trainees is relatively challenging, due to the lack of an easily available, appropriate lesion. Preparation of an AV phantom lesion for practicing the FNAB procedure and mastering proficiency is relatively easy.
03:23
Types of Radioactivity
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2020
The most common types of radioactivity are α decay, β decay, γ decay, neutron emission, and electron capture. Alpha (α) decay is the emission of an α particle from the nucleus. For example, polonium-210 undergoes α decay: Alpha decay occurs primarily in heavy nuclei (A > 200, Z > 83). Loss of an α particle gives a daughter nuclide with a mass number four units smaller and an atomic number two units smaller than those of the parent nuclide. Beta (β) decay is the emission of an electron or...
09:59
Anisotropic Polyvinyl Alcohol Phantom Fabrication for Ultrasound Elastography: Procedure and Quality Controls
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2026
This protocol describes a robust, reproducible method for fabricating anisotropic polyvinyl alcohol (PVA) phantoms—essential tools for validating ultrasound elastography techniques targeting mechanically anisotropic soft tissues (e.g., skeletal muscle).
FAQs
These factors alter how emitted radiation is recorded rather than changing the radionuclide distribution itself. Attenuation reduces detected signal as radiation passes through material, scatter can redirect emissions, and limited spatial resolution can blur nearby regions. By testing these effects against known activity and contrast, investigators can identify measurement bias and judge whether an imaging system reproduces the intended pattern accurately.
Known activity provides a reference against which the system’s measured activity can be compared. The difference reveals how accurately the instrument or imaging protocol represents the signal under the test conditions. Repeating this comparison helps quantify uncertainty and supports calibration, quality assessment, and meaningful comparisons between instruments or laboratories.
Each property tests a different aspect of biological-image performance. Size and shape determine whether the system preserves the intended geometry, while the activity distribution establishes where the signal should appear and how strongly regions should contrast. Matching these features to the measurement goal allows researchers to assess image quality and interpret discrepancies as limitations of the system or protocol.
Unlike a living subject, the model provides a controlled and repeatable activity pattern for testing. Researchers can therefore compare instruments or protocols without biological variability from a patient or specimen affecting the result. This controlled setting is especially useful when separating imaging-system performance, attenuation, scatter, and resolution effects from changes in the biological source.
Researchers first establish the phantom’s intended radionuclide distribution and activity, then place it within the imaging system for data acquisition. They compare the detected pattern and measured activity with the known configuration, considering attenuation, scatter, spatial resolution, and contrast. The resulting comparison can reveal calibration or protocol problems before the system is used for biological research.
A useful setup combines a physical model, a controlled radionuclide distribution, and an imaging detector such as PET or SPECT. The model should represent the biological features relevant to the test, including size, shape, activity, or attenuation properties. Selecting those properties deliberately helps align the measurement with calibration, image-quality, or protocol-validation objectives.
They support image-quality assessment, protocol validation, and researcher training in addition to calibration. Because the activity pattern is controlled, teams can examine how an imaging procedure performs and practice interpretation without relying on a patient or living specimen. This makes the approach useful for developing and checking biomedical imaging workflows before broader biological studies.
Using the same controlled test framework gives laboratories a common reference for instrument performance and measured activity. Researchers can track uncertainty, compare results across instruments or sites, and examine changes over longitudinal studies using a standardized approach. This consistency reduces variation caused by differing test conditions and strengthens interpretation of imaging measurements.