17-09-2012, 05:37 PM
Medical Imaging
1Medical Imaging.pdf (Size: 1.32 MB / Downloads: 45)
Imaging Modalities
Ultrasound Imaging
Represents a mapping of changes in acoustic impedances.
X-ray Imaging
Represents a mapping of X-ray attenuation coefficients.
Radioisotope Imaging
Represents the internal functional distribution of an administered
radiopharmaceutical.
Magnetic Resonance Imaging
Represents a mapping of proton density weighted with nuclear
relaxation times associated with different molecular environments.
Conventional X-ray Imaging
Anatomy removes photons from the beam.
Information coded as a variation in the number of photons in emerging beam.
Interaction of diagnostic x-ray photons with tissue – PHOTOELECTRIC EFFECT.
Attenuation = absorption and scatter. Approximately EXPONENTIAL.