The Science of Radiology and Radiologic Technology

Flashcards covering key definitions, concepts, energy forms, spectrum regions, imaging modalities, and historical pioneers from Chapter 1 to Chapter 7 of the lecture transcript.

How is radiation defined in the lecture?

Radiation is the energy transmitted by waves through space or through a medium.

What does it mean for a patient or object to be irradiated?

It means the patient or object intercepts or absorbs part or all of the radiation energy.

What are the three methods of heat transfer described in the transcript?

Conduction, convection, and radiation.

How do conduction, convection, and radiation differ as modes of heat transfer?

Conduction moves heat through direct contact of solid material; convection moves heat through the circular movement of fluids (liquids and gases); radiation moves heat through empty space via electromagnetic waves without requiring a medium.

How is energy defined in the transcript?

Energy is defined as the capacity to operate or work.

Which specific form of energy is utilized in X-ray imaging?

Electromagnetic energy.

At what speed do electromagnetic waves travel through a vacuum?

Electromagnetic waves travel through a vacuum at the speed of light, which is approximately $3 \times 10^8\,m/s$.

How are wavelength, frequency, and energy related in the electromagnetic spectrum?

Wavelength is indirectly proportional to frequency and energy; shorter wavelengths correspond to higher frequency and higher energy, while longer wavelengths correspond to lower frequency and lower energy.

What are the seven main regions of the electromagnetic spectrum in order from longest to shortest wavelength?

Radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays.

Which region of the electromagnetic spectrum has the longest wavelength and lowest energy?

Radio waves.

Which region of the electromagnetic spectrum has the shortest wavelength and highest energy?

Gamma rays.

What is ionization?

Ionization is any process by which a neutral atom gains or loses an electron, thereby acquiring a net charge.

What defines ionizing radiation?

Ionizing radiation is any type of radiation that possesses sufficient energy to remove an orbital electron from an atom.

What components form an ion pair created during ionization?

An ion pair consists of the separated orbital electron (a negative ion) and the remaining atom (a positive ion).

Which forms of electromagnetic radiation possess sufficient energy to ionize matter?

X-rays, gamma rays, and high-energy ultraviolet light.

What are examples of non-ionizing radiation listed in the transcript?

Radio waves, microwaves, infrared, low-energy ultraviolet light, and visible light.

What are the standard color requirements for the radiation caution symbol known as the trefoil?

The trefoil symbol itself may be in magenta, purple, or black, but the background must always be yellow.

What is the primary scope difference between a radiologic technologist and an X-ray technologist?

Radiologic technologists can perform general radiography as well as advanced modalities such as CT, MRI, nuclear medicine, and radiation therapy; X-ray technologists can only perform general radiography.

What is the role of a radiologist in a healthcare setting?

A radiologist is a physician (medical doctor) who interprets radiological examinations and performs invasive radiological procedures.

What do ECG and EEG stand for, and what anatomical structures do they evaluate?

ECG stands for electrocardiography (evaluates electrical activity of the heart), and EEG stands for electroencephalography (evaluates electrical activity of the brain).

How does sonography produce anatomical images, and why is it recommended for pregnant patients?

Sonography uses the pulse-echo technique with reflected sound waves from a transducer; it does not use ionizing radiation, making it safe for pregnant patients.

How does fluoroscopy differ from general radiography?

General radiography creates static two-dimensional photos, whereas fluoroscopy uses continuous or rapid series of X-rays to display a live moving video of internal structures.

What type of fluoroscopy unit is shaped like a "C" and commonly used in operating rooms?

The C-arm.

Why is screening mammography recommended for women aged $40$ and above rather than younger women?

Women under $40$ years old have breast tissue that is too dense for effective mammographic visualization, so ultrasound is preferred for younger patients.

What mechanical action must be applied to the breast during mammography using a paddle?

Compression must be applied to the breast to properly visualize the tissue structure.

How does Computed Tomography (CT) produce images of the body?

A CT scanner uses a motorized X-ray tube and detectors rotating inside a gantry around the patient to take multiple cross-sectional X-ray images, which a computer processes into 2D and 3D slice images.

How does Magnetic Resonance Imaging (MRI) generate soft tissue images without ionizing radiation?

MRI uses giant magnets inside the gantry to line up water protons in the body and radio frequency waves to manipulate them; when the waves stop, the protons snap back and emit signals captured by coils.

What are the two primary methods of delivering radiation therapy for cancer treatment?

External beam therapy (aiming radiation from a machine outside the body) and brachytherapy or internal radiation therapy (placing radioactive sources directly inside or near the tumor).

What distinguishes Nuclear Medicine from modalities such as general radiography, CT, and radiation therapy regarding the source of radiation?

In Nuclear Medicine, the patient becomes radioactive after receiving injected radiopharmaceuticals and emits radiation, whereas in the other modalities, the machine emits the radiation.

Who discovered X-rays, on what exact date, and at what location?

Wilhelm Conrad Roentgen discovered X-rays on Friday, November 8, 1895, at Wurzburg University in Germany.

What type of experimental tube was Wilhelm Conrad Roentgen using when he discovered X-rays?

A Crookes tube.

What chemical coating on a plate glowed green when Roentgen operated his enclosed Crookes tube?

Barium platinum cyanide (barium platinocyanide).

Whose anatomical structure was depicted in the first published medical X-ray image produced in early 1896?

The hand of Roentgen's wife, Bertha Ludwig.

In what year did Wilhelm Conrad Roentgen receive the first Nobel Prize in Physics?

In the year 1901.

What scientific contributions were made by Archimedes, Democritus, and Thales?

Archimedes explained the reaction of solids in liquids; Democritus described materials as composed of ultimate particles; Thales discovered the effects of electricity.

What instrument did Evangelista Torricelli invent in 1643 that produced the first recognized vacuum?

The barometer.

What device did Otto von Guericke invent in 1646 to evacuate air from a vessel?

An air pump.

What instrument improved by Abbé Jean-Antoine Nollet served as a forerunner to the X-ray tube?

The electroscope.

What two types of electricity were distinguished by Charles Dufay?

Electrodynamic electricity and static electricity.

What concept did Michael Faraday establish in 1831 by moving a magnet in and out of a coil?

Electromagnetic induction.

What energy capability of cathode rays was demonstrated by William Crookes?

He demonstrated that cathode rays emitted from the cathode possessed enough energy to rotate a wheel placed inside the tube.

What properties of cathode rays were investigated by Philipp Lenard?

Philipp Lenard found that cathode rays could penetrate thin metal, project a few centimeters into the air, and deflect in a magnetic field.

Who invented fluoroscopy, and who was his assistant that became the first recorded radiation fatality?

Thomas Alva Edison invented fluoroscopy, and his assistant Clarence Dally was the first recorded radiation fatality.

What electrical distribution system did Thomas Edison switch on on September 4, 1882?

He switched on the Pearl Street station electrical power distribution supplying $110\,V$ direct current (DC) to $59$ customers in Lower Manhattan.

What electrical phenomenon discovered by Pierre Curie and his brother Jacques in 1880 is used in ultrasonography?

Piezoelectricity (generating electric potential by compressing crystals).

What discovery did Henri Becquerel make using uranium salts?

He discovered radioactivity (stated in the transcript as 1869) when uranium salts spontaneously emitted rays resembling X-rays.

What three major achievements of Marie Curie were noted in the lecture?

Developing the theory of radioactivity, isolating radioactive isotopes, and discovering radium and polonium.

In what year and field did Marie Curie receive a Nobel Prize mentioned in the transcript?

In 1911 in Chemistry.

What particle accelerator was invented by Ernest Lawrence?

The cyclotron.

What nuclear achievement was induced by Enrico Fermi at the University of Chicago in 1942?

A successful chain reaction in a uranium pile.

What device did Isaac Newton improve that converts mechanical energy into electrical energy?

The static generator.

What three physical science aspects helped pave the way for the discovery of X-rays?

Electricity, vacuums, and image recording materials.