COURSE OUTLINE

PHYS 540 Radiological Imaging:

John E Aldrich

Credits 3

Lectures/week 3

Text to be decidedDescription: An introduction to the use of x-rays and ultrasound to produce diagnostic medical images. To include imaging principles, x-ray production, radiography, fluoroscopy, angiography, computed tomography, digital imaging and image networks, patient dosimetry and radiation protection. Ultrasound will cover principles of imaging, tranducers, phased arrays, Doppler and artifacts.

Course Outline

X-ray production

The x-ray tube, Production of brehmstrahlung, Production of characteristic x-rays, The total x-ray energy spectrum, X-ray beam quality and beam quantity,

The x-ray tube

Introduction, The protective tube housing, The x-ray tube (or insert), Principle of operation -the line-focus principle, The heel effect, Effective focal spot sizes, Grid controlled x-ray tubes, Metallic x-ray tubes, X-ray tube aging and tube conservation, Anode damage, Filament damage.

X-ray generators

The basic x-ray generator, The primary circuit, The high voltage (or secondary) circuit), The filament circuit, The classification of x-ray generators, Voltage ripple.

Fluoroscopy

The general fluoroscopic setup, The image intensifier, Principle of operation, Image quality: Spatial resolution, Contrast, Veiling glare, Vignetting, Conversion factor, CCD Cameras, Dose and Image Control, ABC and AGC, Patient Dose, Image Intensifier Dose, Filters, Contrast, ABC Algorithms, Digital Processing, Video frame digitization, DSA, Practical Tips for Fluoroscopy, Display systems, Television, TV camera, TV monitor.

The Imaging Process

Contrast, Blur (Resolution), Noise, Image Views, Viewing Radiographs, The Absorption Processes, Photoelectric Effect, Compton Effect, Attenuation, Practical Examples, Mammography, Iodine and Barium Contrast Materials, Scattered Radiation, Grids.

Radiation dose and radiation detectors

Quantities used to measure radiation, Definitions, Radiation exposure, Dose, Equivalent Dose, Radiation Weighting Factors, Effective Dose, Tissue Weighting Factors, Hierachy of Quantities, Example: Lung perfusion scan, Typical Patient Doses from Radiological Procedures, Radiation Detectors, Pocket Dosimeter, Gaseous Ion Chambers, Current Ionization Chamber, Proportional Counters and GM Tubes, The GM Counter as an Exposure Meter, Semiconductor Detectors, Scintillation Detectors, NaI(TI) Detector, Thermoluminescent Dosimetry, Accident and Emergency, Dosimetry

The Physics of Ultrasound

Ultrasound Definitions, Wave parameters, Frequency, Period, Wavelength, Propagation speed, Amplitude, Intensity, Pulsed ultrasound, Intensity of pulsed beams, Interaction of ultrasound with matter, Normal incidence, Oblique incidence, Attenuation, Depth of penetration, Transducers, Construction of an ultrasound probe, Quality factor, Ultrasound beams, Side lobes, Lateral resolution, Arrays, Pulse echo systems, Time-gain compensation, Display, A-mode, B-mode, M-mode, Image storage, Digital scan converter, Binary numbers, Real-time ultrasound, Real-time transducers, Mechanical scanners, Electronic scanners, Phased array, Doppler ultrasound, Uses, Instrumentation, Understanding ultrasound physics artifacts, Enhancement

 

Computerized Tomography

The linear attenuation coefficient, Electron densities, Physical densities, CT number, Ideal CT numbers, Polyenergetic (or heterogenous) x-ray beam, "Beam hardening", The five generations of CT scanners, First generation, Second generation (translate-rotate action), Third generation, Fourth generation, Fifth generation - the Imatron, Physical properties of CT scanners, X-ray tubes, Detectors, Collimation, X-ray generator, Methods of image reconstruction, Simple back projection method, Filtered back projection method, Iterative method, Radiation dose, CT dose index (CTDI), Image artifacts, Aliasing (or wrap-around) artifact, Partial volume artifact, Beam hardening artifact, Detector artifact, High density foreign artifact, Patient motion

Marking Scheme

Assignments 20%

Midterm 20%

Term paper/presentation 20%

Final 40%