Exam 1 Simulation (Monday)

3D imaging

Three-dimensional technique providing detailed anatomical views for surgical planning and treatment monitoring.

Acute dermatitis

Early historical radiation injury (radiation burns) caused by long exposure times, often leading to amputations.

Adenocarcinoma

Epithelial cells that are glandular (e.g., tissue lining the stomach).

AI integration in medical imaging

Uses deep learning algorithms to enhance image quality, automate analysis, improve diagnostic accuracy, and speed up diagnosis.

AJCC TNM Staging System

Standard staging system categorizing primary tumor size/extent (T: TX, T1-T4), regional lymph node involvement (N: NX, N0-N4), and distant metastasis presence (M: MX, M0, M1).

ALARA

Acronym for "as low as reasonably achievable," referring to minimizing radiation exposure to patient, self, and others.

Alpha Particles / Protons / Electrons

Densely ionizing, high-LET radiation types that cause direct ionization and direct DNA damage with little to no sublethal damage (SLD) or potentially lethal damage (PLD) repair.

Anaplastic

Pathologic description of cells, describing a loss of differentiation and a more primitive appearance.

Anode

The positive side of the x-ray tube that becomes the target for the source of electrons emitted from the cathode.

Aperture Size

The diameter of the hole on a scanner in which the patient is positioned; also called the bore.

Apoptosis

Programmed cell death following irradiation.

Artifact

Unwanted image abnormalities (e.g., blurring, star, beam-hardening) caused by patient motion, anatomical structures, scanner design, or system failure.

Atomic Mass Number (A)

Total number of protons and neutrons in an atomic nucleus.

Atomic Number (Z)

Total number of protons in an atomic nucleus, determining chemical element identity.

Attenuation

Removal of photons and electrons from a radiation beam by scatter or absorption as it travels through a medium.

Backscatter

The reflection of radiation back towards its source after interacting with a material.

Barium platinocyanide screen

Screen material on which Wilhelm Roentgen noticed fluorescence/bones of his hand during early x-ray experiments.

Benign

Tumors that are generally well differentiated and do not metastasize or invade surrounding normal tissue; often encapsulated and slow growing.

Biologic Effective Dose (BED)

Quantitative tool used to evaluate tumor and normal tissue response across varying total doses, fraction sizes, and overall treatment schedules.

Biopsy

Surgical removal of a small tissue sample from a solid tumor to determine the pathology for the diagnosis of disease.

Bremsstrahlung

German term for "braking" radiation; a common interaction between a high-speed electron and target material inside the x-ray tube.

Carcinomas

Tumors that originate from the epithelium and include all tissues that cover a surface or line a cavity.

Cathode

The negative side electrode found inside the x-ray tube containing the filament source.

Cell Survival Curve

Graphical model describing the relationship between radiation dose and percentage of surviving cells based on single-hit lethal killing and accumulated sublethal hits.

Cellular differentiation

A stem cell that undergoes mitosis and divides into daughter cells; the degree to which a cell resembles its cell of origin in morphology and function.

Characteristic Radiation

Radiation created inside the x-ray tube when cathode electrons interact directly with inner-shell electrons of the target material.

Chief Complaint Data

Medical history category gathering information on symptoms, current illness, and present physical condition.

Clinical Staging

Cancer staging based upon physical examination, pertinent diagnostic imaging, and initial biopsies prior to primary surgical resection.

Compton Scattering

Interaction produced when an x-ray photon ejects an outer-shell orbital electron, losing energy and altering its path.

Computed Radiography

Digital radiographic imaging technique utilizing photostimulable phosphor plates.

Computed Tomography (CT)

Modality combining X-rays from various angles to create cross-sectional views of internal body structures.

Cone-beam Computed Tomography (CBCT)

CT imaging using wider x-ray beam angles and area detectors to acquire single projection images during gantry rotation, yielding a 3D reconstruction dataset across axial, sagittal, and coronal planes.

Contrast

The tonal range of densities from black to white or the number of shades of gray (focus on shades of gray in Radiation Therapy).

Demographic Data

Medical history category gathering patient age, race, gender, marital status, and current occupation.

Density

Degree of darkening on an image (focus on blacks and whites in Radiation Therapy).

Detector Array

Key component of a CT scanner that senses x-ray radiation partially attenuated by body tissues and converts it into digital signals.

Detectors

Solid-state sensors in a CT scanner designed to convert radiation into light signals.

Deterministic Effects

Radiation effects exhibiting a clear threshold dose where severity of organ harm increases as dose rises above the threshold.

Differential Absorption

Variations in photon absorption across tissue types (air, fat, water, muscle, bone) based on density and atomic number (Z); forms the physical basis of radiographic imaging.

Direct Action / Ionization

Radiation interaction where the primary incident particle directly damages the critical target (DNA) without intermediate steps.

Dose Rate Effect

Biological impact where decreasing the radiation dose rate increases exposure time and reduces cell death, resulting in higher cell survival.

Early radiation injuries

Severe health impacts (acute dermatitis, amputations, gross injuries leading to death) suffered by early technicians and patients due to long exposure times.

Early uses of radiographs

Physicians initially applied radiographs to locate bullets, kidney stones, gallbladder stones, and broken bones.

Electron Shell Capacity Formula (2n^2)

Mathematical rule defining maximum electron occupancy per shell level (n=1 for K, n=2 for L, n=3 for M, n=4 for N).

Electron Shells

Defined electron orbits starting from innermost K-shell outward to L, M, N, and the outermost valence shell.

Electromagnetic Wave Parameters

Physical characteristics defining EM radiation including frequency (cycles/second), wavelength (peak-to-peak distance), and velocity (speed of light).

Epidemiology

Study of disease incidence (helps determine trends in disease); study of defining the distribution and determinants causing disease and injury in human populations.

Essential x-ray production elements

Fundamental physics of generating x-rays remain unchanged since discovery; only medical applications and technology have advanced.

Etiology

Study of the causes of disease (e.g., carcinogenic agents/risk factors).

Excitation

Radiation interaction where an outer-shell electron gains energy and vibrates/oscillates without being ejected from the atom.

Exponential Tumor Growth

Pattern of tumor expansion where cell replication rate closely balances cell death, leading to rapid increase in size and potential areas of tissue necrosis.

Exposure times (Historic vs. Modern)

Historic exposure times ranged from 20-30 minutes up to 2 hours due to inefficient tubes; modern exposure times are milliseconds/fractions of a second.

False Negative

A false-negative reading is when the test indicates no disease when, in fact, the disease is present.

False Positive

A false-positive reading indicates disease when in reality none is present.

Family History Data

Medical history category gathering information on family illnesses, causes of death, genetic disorders, and mental health conditions.

Filament

Small coil of wire made of thoriated tungsten with an extremely high melting point (3380°C) located at the cathode.

Film/Image Density

The degree of darkening (blacks and whites) apparent on a film or digital imaging display.

First radiographic image

X-ray image of Anna Bertha Ludwig's hand (featuring her ring).

First subject of a radiographic image

Anna Bertha Ludwig (Wilhelm Roentgen's wife).

Five Rs of Radiobiology

The five core biological factors governing fractionated radiation therapy: Repopulation, Redistribution/Reassortment, Repair, Reoxygenation, and Radiosensitivity.

Flat-Panel Detectors

Imaging device using amorphous silicon and solid-state integrated circuit technology to produce image quality far superior to film-screen combinations.

G0 Cell Cycle Phase

Fully functioning rest phase where reserve pool cells are not actively preparing for DNA replication.

G1 Cell Cycle Phase

First growth phase characterized by rapid growth, active metabolism, and synthesis of RNA and proteins required for cellular function.

G2 Cell Cycle Phase

Second growth phase where enzymes and proteins are synthesized in preparation for actual cellular division.

Gadolinium

Non-iodine-based IV contrast agent used in CT and MRI scans to help differentiate between edema and tumor tissue.

Grade G1

Pathologic grade indicating well-differentiated tumor cells that closely resemble origin tissue.

Grade G2

Pathologic grade indicating moderately differentiated tumor cells.

Grade G3

Pathologic grade indicating poorly differentiated tumor cells.

Grade G4

Pathologic grade indicating undifferentiated or anaplastic tumor cells.

Grade GX

Pathologic grade classification indicating that the tumor grade cannot be assessed.

Gray (Gy)

Modern SI unit replacing the Roentgen for quantifying x and gamma ray dose; used for patient treatment dose in Radiation Therapy.

Histology: Breast

Most common histology is infiltrating ductal carcinoma.

Histology: Endometrium

Most common histology is adenocarcinoma.

Histology: Gastrointestinal (Colon/Rectum/Stomach)

Most common histology is adenocarcinoma.

Histology: Head & Neck / Respiratory / Cervix / Anus

Most common histology is squamous cell carcinoma.

Histology: Prostate

Most common histology is adenocarcinoma.

Historical radiographic method

Created by exposing photographic plates directly to x-rays.

Hyperfractionation

Fractionation schedule delivering multiple smaller daily radiation fractions (e.g., BID twice daily or TID thrice daily).

Hypofractionation

Fractionation schedule utilizing daily radiation doses substantially larger than conventional fraction sizes.

Image Contrast

Imaging element providing visual evidence of differential absorption rates across body tissues, defined by the range of gray shades.

Image Fusion

Process of combining images from different modalities (e.g., MRI or PET) with a CT image to combine enhanced functional/anatomical imaging with CT spatial accuracy.

Imaging challenges & solutions

Challenges like radiation exposure, cost, and interpretation errors are addressed via improved algorithms and dose reduction techniques.

Imaging in medical education

Serves as an essential tool providing students with visual insights into anatomy, pathology, and clinical cases.

Imaging in research

Pivotal for understanding disease mechanisms, drug development, and evaluating therapeutic outcomes.

In situ

An early form of cancer (pre-cancerous cells; prior to stage 1 cancerous cells) defined by the absence of invasion.

Indirect Action / Ionization

Most common radiation mechanism where x-rays/gamma rays interact with intermediate molecules (water) to produce charged secondary particles that subsequently damage DNA.

Interfraction Uncertainties

Setup variations that exist between individual daily treatment fractions (e.g., positioning inaccuracies, machine variables, patient physiological differences).

Interphase Death

Cellular death occurring during the G1, S, or G2 phase prior to entering mitosis.

Inverse Square Law

Mathematical relationship describing beam intensity as inversely proportional to the square of the distance from the radiation source.

Ionization

Occurs when incoming ionizing radiation ejects an electron from an atomic orbit, creating a charged atom/ion pair.

Kinetic vs Potential vs Binding Energy

Kinetic energy is energy of motion; Potential energy is stored energy; Binding energy holds the atomic nucleus or orbital electrons together.

Law of Bergonié and Tribondeau

Radiosensitivity principle stating that ionizing radiation is most effective against cells that are actively mitotic, undifferentiated, and have a long mitotic future.

Linear Energy Transfer (LET)

Measure of energy transferred/deposited per unit distance as an ionizing particle travels through tissue (Low: X-rays/Gamma; High: Alpha/Protons).

M Cell Cycle Phase (Mitosis)

Phase where actual cellular division occurs; cells are most radiosensitive during late G2 and M phases.

Magnetic Resonance Imaging (MRI)

Diagnostic, non-ionizing imaging modality visualizing internal anatomy through hydrogen nuclei alignment using magnetic fields and radio waves.

Malignant

Tumors that are malignant (i.e., cancerous) often invade and destroy normal surrounding tissue and, if left untreated, can cause the death of the host.

Medical History Data

Medical history category gathering childhood illnesses, allergies, immunizations, injuries, prior hospitalizations, psychological issues, and current medications.

Medical imaging role in oncology

Critical for diagnosis, workup, treatment planning, patient positioning, treatment verification, and adaptive radiation therapy.

Metastasize

Process of tumors spreading to a site in the body distant from the primary site.

Mitotic Death (Reproductive Failure)

Cell death occurring as a cell attempts cellular division due to uncorrected chromosomal damage.