Biomedical Imaging Devices
Lecture 01
- Text Book: Medical Imaging Signals and Systems 2nd Edition, Jerry L. Prince (Pearson)
- Evaluation: Attendence (10%), Homework (10%), Mid exam (40%), Final exam (40%)
Basic Imaging Principles & Signal and Systems
❑ Introduction to Basic Imaging Principles
❑ Physical Signals and Imaging Modalities
❑ Signals and Systems
❑ Signals and Sampling
❑ Linear Systems: Impulse response, Shift Invariance..
❑ Fourier Transform
❑ Convolution
❑ Transfer Function
❑ Image Quality
❑ Contrast,
Filters
Resolution, Noise, Signal-to-Noise Ratio (SNR), Nyquist Sampling Theorem,
Contents of Lecture
❑ Medical Imaging is a technique and process of imaging the interior of a body for clinical
analysis and medical intervention.
❑ Five Major Medical Imaging Modalities
❑ X-Ray Imaging
❑ Computed Tomography (CT)
❑ Positron Emission Tomography (PET), Single-Photon Emission Computed Tomography (SPECT)
❑ Magnetic Resonance Imaging (MRI)
❑ Ultrasound Imaging
❑ Optical imaging
❑ Optical Microscopy (OM),
❑ Optical Coherence Tomography (OCT)
❑ Diffuse Optical Tomography (DOT)
❑ Functional Near-Infrared Spectroscopy (fNIRS)
X-Ray Imaging (Projectional radiography)
• Radiography: an Imaging technique using X-rays, gamma rays, or other radiations to view the
internal form of an object
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X-ray generator
Detector
X-ray attenuation
Radiographic density & Contrast
Computed Tomography (CT)
• Tomography: imaging by sections (slices), derived from Greek ‘tomos’.
• CT scan: an imaging procedure that uses a combination of X-rays and computer technology.
• A tomogram (sectioned image) is produced from multiple projectional radiographs.
Basic principle of tomography
A typical CT scanner
Scanner geometry
Positron Emission Tomography (PET)
• Positron: an positive electron, the antiparticle of an electron.
• CT scan: an imaging procedure that uses a combination of X-rays and computer technology.
• A tomogram (sectioned image) is produced from multiple projectional radiographs.
PET
Whole-body FDG-PET
Magnetic Resonance Imaging (MRI)
• An MRI scan can be used to examine almost any part of the body
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brain and spinal cord
bones and joints
breasts
heart and blood vessels
internal organs, such as the liver, womb or prostate gland
https://www.nhs.uk/conditions/mri-scan/
Ultrasound Imaging
• Ultrasound: sound with frequencies > 20 kHz
• Time gating: measuring travel time of Sona pulses
Optical imaging
• Optical Coherence Tomography (OCT)
Optical imaging
• Diffuse Optical Tomography (DOT)
Photoacoustic Imaging (PAI)
This lecture will cover topics..
• Imaging signals
• Basic Principles of Medical imaging modalities
• Hardware
• Signal acquisition
• Post image processing