Diagnostic Radiology Residents Physics Curriculum

Diagnostic Radiology Residents Physics CurriculumAAPM Subcommittee of the Medical Physics Education of Physicians CommitteeUpdated with Q&A – November 2013Supported by: AAPM Education Council and the Academic Council of the Association ofUniversity RadiologistsAuthors: See complete list in Appendix AHistory and comments: See complete details in Appendix BPrefaceThe purpose of this curriculum is to outline the breadth and depth of scientific knowledge underlying thepractice of diagnostic radiology that will aid a practicing radiologist in understanding the strengths andlimitations of the tools in his/her practice. This curriculum describes the core physics knowledge relatedto medical imaging that a radiologist should know when graduating from an accredited radiologyresidency program. The subject material described in this curriculum should be taught in a clinicallyrelevant manner; the depth and order of presentation is left to the institution.Although this curriculum was not developed specifically to prepare residents for the American Board ofRadiology (ABR) examination, it is understood that this is one of the aims of this curriculum. The ABRExam of the Future (EOF) will affect radiology residents who enter residency programs in 2010 or later,with the first core exam to be given in 2013. The ABR certification in diagnostic radiology is to bedivided into two examinations, the first covering basic/intermediate knowledge of all diagnosticradiology and a second certifying exam covering the practice of diagnostic radiology. The first examwill be broken into three primary categories: 1) fundamental radiologic concepts, 2) imaging methods,and 3) organ systems. This curriculum is designed to address the fundamental radiologic concepts andimaging methods categories directly. The last category on organ systems is not addressed directly withinthe curriculum; however, the educator needs to continuously associate the concepts within the modulesto different organ systems to assure that the clinical applications are evident.The question sets contained in this curriculum were created to provide additional educational materialsfor teaching residents as well as for resident self-education. The questions are not based on recalls of oldAmerican Board of Radiology examination questions. Any similarity with the past or current ABRexamination is purely coincidental. It is likely that some of the information contained in these questionsets will appear in some form on the ABR examination due to the importance of these concepts.Committee members who are item writers for the current ABR examinations abstained fromcontributing content for these question sets.This curriculum contains 17 modules covering imaging physics. The first nine modules cover basicradiation physics and biology, and the remaining modules utilize this base information to examine1

clinical applications of physics to each modality. Each module presents its content in three sections: (1)learning objectives, (2) concise syllabus, and (3) detailed syllabus.The first section of each module presents the learning objectives for the module. These learningobjectives are organized into three subsections: (1) fundamental knowledge relating to module concepts,(2) specific clinical applications of this knowledge, and (3) topics to permit demonstration of problemsolving based on the previous sections. The clinical applications and problem-solving subsectionscontain concepts that a resident should be able to understand and answer following completion of eachmodule.The second area within each module presents concise syllabi that delineate the concepts the module isaddressing. These concise syllabi may be used as an outline for a course in imaging physics. Not allareas of each concise syllabus module need be taught with the same emphasis or weight, so long as thestudent can demonstrate an understanding of the educational objectives and solve clinically relevantproblems. The concise syllabus should be considered a base or minimal curriculum to present theeducational objectives.The last area within each module is a detailed syllabus that expands upon the concise syllabus andprovides a more thorough coverage of each subject. The detailed syllabus is presented as a guide to theinstructor providing specific topic details that may be needed to cover a subject more thoroughly.2

Module 1: Structure of the AtomAfter completing this module, the resident should be able to apply the “Fundamental Knowledge” and“Clinical Applications” learned from the module to example tasks, such as those found in “ClinicalProblem-solving.”Fundamental Knowledge:1. Describe the components of the atom.2. Explain the energy levels, binding energy, and electron transitions in an atom.3. For the nucleus of an atom, describe its properties, how these properties determine its energycharacteristics, and how changes within the nucleus define its radioactive nature.4. For an atom, describe how its electron structure and associated energy levels define its chemicaland radiation-associated properties.5. Explain how different transformation (“decay”) processes within the nucleus of an atomdetermine the type of radiation produced and the classification of the nuclide.Clinical Application:NoneClinical Problem-solving:NoneConcise Syllabus:Same as detailed curriculumDetailed Curriculum:1. Structure of the Atom1.1. Composition1.1.1. Electrons1.1.2. Nucleus1.2. Electronic Structure1.2.1. Electron Orbits1.2.2. Orbital Nomenclature1.2.3. Binding Energy1.2.4. Electron Transitions1.2.5. Characteristic Radiation1.2.6. Auger Electrons1.3. Nuclear Structure1.3.1. Composition1.3.2. Nuclear Force1.3.3. Mass Defect1.3.4. Binding Energy1.3.5. Nuclear Instability–Overview3

Example Q&A:Q1. The maximum number of electrons in the outer shell of an atom is:A. 2n2B. 8C. 16D. 32E. 2Answer: A – 2n2Explanation: The arrangement of electrons outside the nucleus is governed by the rules of quantummechanics and the Pauli exclusion principle. Accordingly, the maximum number of electrons in an orbitis given by 2n2, where n is the orbit number. The innermost orbit or shell is called the K-shell, followedby L-, M-, N-, and O-shells. Hence, a maximum of 2 electrons can exist in the K-shell, 8 in the L-shell,and 18 in the M-shell.Reference:1. Bushberg, J.T., et al. The Essential Physics of Medical Imaging, 2nd ed. Philadelphia: LippincottWilliams & Wilkins, 2002.Q2. Elements which have the same Z (atomic number) but different A (mass number) are called:A. isobarsB. isomersC. isotonesD. isotopesAnswer: D – isotopesExplanation: Isotopes are forms of the same element, and thus have the same atomic number Z, thenumber of protons, but have different numbers of neutrons, thus different mass number A (neutrons plusprotons). Isobars have the same A but different Z. Isomers have the same A and Z, but different energystates. Isotones have the same number of neutrons but different Z.Reference:1. Bushberg, J.T., et al. The Essential Physics of Medical Imaging, 2nd ed. Philadelphia: LippincottWilliams & Wilkins, 2002.Q3. The mass number (A) of an atom is equal to the sum of the:A. neutronsB. protonsC. neutrons and protonsD. protons and electrons4

E. atomic masses plus the total binding energyAnswer: C – neutrons and protonsExplanation: The mass number is defined as the number of nucleons (protons and neutrons) in theatomic nucleus.Reference:1. Bushberg, J.T., et al. The Essential Physics of Medical Imaging, 2nd ed. Philadelphia: LippincottWilliams & Wilkins, 2002.Q4. The binding energy of an electron in the K-shell is:A. the energy the electron needs to stay in the K-shellB. the energy needed for an electron to make a transition to the L-shell from the K-shellC. the energy needed for an electron to jump from the L-shell to K-shellD. the energy needed to remove an electron from the K-shellE. none of the aboveAnswer: D – the energy needed to remove an electron from the K-shellExplanation: The binding energy of an electron at a certain shell is defined as the energy needed toremove that electron from the specific shell.Reference:1. Bushberg, J.T., et al. The Essential Physics of Medical Imaging, 2nd ed. Philadelphia: LippincottWilliams & Wilkins, 2002.Q5. A proton is electrostatically repelled by:A. electronsB. neutronsC. positrons and neutronsD. alpha particles and electronsE. positrons and alpha particlesAnswer: E – positrons and alpha particlesExplanation: As a proton, a positron, and an alpha particle are all positively charged particles, while anelectron is negatively charged and a neutron is neutral, a proton will be repelled by both a positron andan alpha particle.Reference:1. Bushberg, J.T., et al. The Essential Physics of Medical Imaging, 2nd ed. Philadelphia: LippincottWilliams & Wilkins, 2002.5

Module 2: Electromagnetic (EM) RadiationAfter completing this module, the resident should be able to apply the “Fundamental Knowledge” and“Clinical Applications” learned from the module to example tasks, such as those found in “ClinicalProblem-solving.”Fundamental Knowledge:1. Describe the wave and particle characteristics of electromagnetic (EM) radiation.2. Within the EM radiation spectrum, identify the properties associated with energy and the abilityto cause ionization.Clinical Application:1. Explain how the relative absorption of electromagnetic radiation in the body varies across theelectromagnetic energy spectrum.Clinical Problem-solving:NoneConcise Syllabus:Same as detailed curriculumDetailed Curriculum:2. Electromagnetic (EM) Radiation2.1. Wave–Particle Duality2.1.1. Wave Characteristics2.1.2. Particle Characteristics2.2. Electromagnetic Spectrum2.2.1. Ionizing2.2.2. Non-ionizingExample Q&A:Q1. All but which of the following modalities uses electromagnetic radiation during diagnostic imagingprocedures?A. fluoroscopyB. mammographyC. MRID. ultrasoundE. CTAnswer: D – ultrasoundExplanation: Ultrasound is produced when electrical energy is converted into mechanical energy. Thismechanical energy causes molecules in a compressible medium to move, which generates ultrasoundenergy. Unlike electromagnetic radiation, ultrasound propagation requires transmission though amedium, and its interactions are determined by the acoustic properties of the medium. Its wavelength isdependent on the medium.6