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Medical Image AnalysisMedical Image AnalysisIntroduction
Figures come from the textbook: Medical Image Analysis, by Atam P. Dhawan, IEEE Press, 2003.
ModalitiesModalities
Figures come from the textbook: Medical Image Analysis, by Atam P. Dhawan, IEEE Press, 2003.
X-ray Computed Tomography (X-ray CT)
Magnetic Resonance Imaging (MRI)
Single Photon Emission Computed Tomography (SPECT)
Positron Emission Tomography (PET)
Ultrasound
An X-ray mammogram
Figures come from the textbook: Medical Image Analysis, by Atam P. Dhawan, IEEE Press, 2003.
Figures come from the textbook: Medical Image Analysis, by Atam P. Dhawan, IEEE Press, 2003.
An X-ray CT
Figures come from the textbook: Medical Image Analysis, by Atam P. Dhawan, IEEE Press, 2003.
Physiology and CurrentUnderstanding
Physics of Imaging
Instrumentationand Image Acquisition
Computer Processing,Analysis and Modeling
Applications andIntervention
Figure 1.1. A collaborative multidisciplinary paradigm of medical imaging research and applications.
Medical image modalities◦Energy◦Anatomical, physiological, or
functional◦External, internal, or combination
Figures come from the textbook: Medical Image Analysis, by Atam P. Dhawan, IEEE Press, 2003.
Figures come from the textbook: Medical Image Analysis, by Atam P. Dhawan, IEEE Press, 2003.
10-10
Radio Waves
TVWaves Radar
WavesMicrowaves Infrared
RaysVisibleLight
UltravioletRays
X-rays GammaRays
102 101 1 10-1 10-2 10-3 10-4 10-6 10-7 10-8
Wavelength in meters
Frequency in Hz
10-5 10-9 10-10 10-11 10-12 10-13 10-14103
106 107 109 1010 1011 1012 1014 1015 10161013 1017 1018 1019 1020 1021 1022105 108
Energy in eV
10-9 10-8 10-6 10-5 10-4 10-3 10-1 1 10110-2 102 103 104 105 106 10710-7
MRIX-ray
Imaging
Gamma-ray Imaging
CosmicRays
Figure 1.2: Different sources of imaging modality in the electromagnetic spectrum.
Figures come from the textbook: Medical Image Analysis, by Atam P. Dhawan, IEEE Press, 2003.
Source of EnergyUsed for Imaging
ExternalInternal
Combination:External andInternal
Nuclear Medicine:Single PhotonEmission Tomography(SPECT)
Nuclear Medicine:Positron EmissionTomography(PET)
Magnetic ResonanceImaging: MRI, PMRI,FMRI
Optical FluorescenceImaging
Electrical ImpedanceImaging
MedicalImaging
Modalities
X-Ray Radiographs
X-Ray Mammography
X-Ray ComputedTomography
Optical Transmissionand TransilluminationImaging
Ultrasound Imaging andTomography
From Physiology to From Physiology to Information ProcessingInformation ProcessingUnderstanding image medium
◦Tissue density, blood flow, perfusion, cardiac motion
Physics of imaging◦Transmission of X-rays, emission of
gamma rays, MR imagingImaging instrumentation
◦Collecting the data, signal-to-noise ratio, resolution
Figures come from the textbook: Medical Image Analysis, by Atam P. Dhawan, IEEE Press, 2003.
Data acquisition methods for image formation◦Active filtering, post-processing
methods◦Back-projection, iterative and Fourier
transform methodsImaging processing and analysis
◦Enhancement, transformations, features of interest
Figures come from the textbook: Medical Image Analysis, by Atam P. Dhawan, IEEE Press, 2003.
General Performance General Performance MeasuresMeasuresPositive: Object was observedNegative: Object was not
observedTrue PositiveFalse NegativeTrue NegativeFalse Positive
Figures come from the textbook: Medical Image Analysis, by Atam P. Dhawan, IEEE Press, 2003.
Figures come from the textbook: Medical Image Analysis, by Atam P. Dhawan, IEEE Press, 2003.
True Positive
True Negative
FalseNegative
FalsePositive
True Condition
Object is
present.Object is
NOT present.
Object is
observed.
Object is
NOT observed.
ObservedInformation
Figure 1.4. A conditional matrix for defining four basic performance measures as defined in the text.
Figures come from the textbook: Medical Image Analysis, by Atam P. Dhawan, IEEE Press, 2003.
TNF
TPF
b
a
c
Figure 1.5: ROC curves with curve “a” indicating better overall classification ability than the curve “b” while the curve “c” shows the random probability.
SensitivitySpecificityAccuracy
Figures come from the textbook: Medical Image Analysis, by Atam P. Dhawan, IEEE Press, 2003.
An example of feature-adaptive contrast enhancement processing as applied to a mammogram to enhance microcalcification areas◦Histogram equalization
Figures come from the textbook: Medical Image Analysis, by Atam P. Dhawan, IEEE Press, 2003.
Figures come from the textbook: Medical Image Analysis, by Atam P. Dhawan, IEEE Press, 2003.
Figure 1.6. (a) A part of the digitized breast film-mammogram with microcalcification areas. (b): Enhanced image through feature adaptive contrast enhancement algorithm. (c): Enhanced image through histogram equalization method.