medical imaging: the glass patient prof.dr.ir. bart m. ter haar romeny technische universiteit...
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Medical Imaging:Medical Imaging:the Glass Patientthe Glass Patient
Prof.dr.ir. Bart M. ter Haar RomenyProf.dr.ir. Bart M. ter Haar RomenyTechnische Universiteit EindhovenTechnische Universiteit Eindhoven
Dept. of Biomedical EngineeringDept. of Biomedical Engineering
Image Acquisition TechniquesImage Acquisition Techniques
Classical X-RayClassical X-Ray
Computed TomographyComputed Tomography
Nuclear MedicineNuclear Medicine
UltrasoundUltrasound
Magnetic Resonance ImagingMagnetic Resonance Imaging
28 December 1895
Prof. Röntgen presentinghis invention at Würzburg,
23 January 1896
The first X-ray ever:the hand of Röntgen’s wife,end 1895.
One of the firstmedical examples:a shot of hailin a hand, 1896
Anodeconnection
+ kV
Filamentconnection
High Voltagesupply
+-
Principle of the X-ray tube:
The kinetic energy of the electrons is released by the collisionat the anode. The tube is vacuum.
vacuum
Tungsten anodecathode
X-rays output
Classical X-ray imagesClassical X-ray images
Fluoroscopy with the image intensifier during angioplasty:Real-time visualization of catheters and vessels.
Imageintensifier
X-raytube
High voltagegenerator
DSA = Digital Subtraction Angiography DSA = Digital Subtraction Angiography = Röntgen X-ray with contrast in vessels= Röntgen X-ray with contrast in vessels
Dotter procedure:
Blow up balloon in obstructed vessel
Tomoscan AV Tomoscan AV EasyVisionEasyVision
CT = Computed Tomography = CT = Computed Tomography = Röntgen X-ray slices Röntgen X-ray slices 3D 3D
Greek = to cut, to slice
CT: CT: solve for 512x512 pixels by 512x512 equationssolve for 512x512 pixels by 512x512 equations
Result: Result: a slicea slice
Examples CTExamples CT
3D visualization3D visualization
Simulation of the physicsof light reflection(ray casting/tracing)
“2.5D” image
Nuclear MedicineNuclear Medicine
Principle:Principle: Instable radioactive isotopes are Instable radioactive isotopes are
made, and build in a pharmaconmade, and build in a pharmacon Patient gets contrast medium Patient gets contrast medium
injected, which injected, which specificallyspecifically stores stores in tissuein tissue
Signal position is measured with a Signal position is measured with a gamma-cameragamma-camera
IoniIonizing radiationzing radiation: GAMMA: GAMMA
When the nucleus gets too large, the “strong force” is not strong When the nucleus gets too large, the “strong force” is not strong enough to compensate the repulsive force of the protonsenough to compensate the repulsive force of the protons
AlphaAlpha radiation: He nuclei radiation: He nuclei (come only microns far in tissue)(come only microns far in tissue) BetaBeta radiation: electrons radiation: electrons (come only cm far in tissue)(come only cm far in tissue) GammaGamma radiation: high energy photons (easily go through tissue) radiation: high energy photons (easily go through tissue)
GAMMA photon(s)
Nuclear Imaging Nuclear Imaging CameraCamera
3-rotating-head SPECT scanner
SPECT =SinglePhotonEmissionComputedTomography
PET = Positron Emission TomographyPET = Positron Emission Tomography
No task During task
Positron = anti-electronWhen it meets an electron → annihilation (explosion)Two photons go in opposite direction, ring coincidence detector
Molecular ImagingMolecular Imaging
Nano-vesicles: - antibody bindings - 90.000 Gadolinium atoms - container for pharmaca - break by US shockwave - less side effects - chemotherapy on target
Highly specific tracer biomolecules
UltrasoundUltrasound
Kretz Medicor 530D
F0 F1
skin
vessel
(red) bloodcells
FFdd = F = F00 - F - F1 1 == 2 x V x cos
cc
V
FFd d = Doppler (‘difference’) frequency= Doppler (‘difference’) frequency
transducer
Doppler
3D ultrasound
Magnetic Resonance Imaging (MRI)Magnetic Resonance Imaging (MRI)
X
Y
Z ( )
Receiver Coil
Philips Medical Systems
1000 x 1000 pixels =1 million measurements
Superconducting MagnetSuperconducting Magnet
MR AngiographyMR Angiography• Excitation only of a thin slice• Non excited blood flows in the slice• Readout of little ‘zero-signal’ areas• For all slices → angiogram
Why so many imaging modalities?Why so many imaging modalities?
Choice modalityChoice modality: Tissues have different : Tissues have different properties for different physical properties for different physical interactionsinteractions
ContrastContrast: Tissue types differ in one or : Tissue types differ in one or more of these propertiesmore of these properties
Anatomical imagingAnatomical imaging versus versus functional functional imagingimaging
CT
MR
Anna Vilanova, Vienna TU / TUE - BMT
Univ. of Dusseldorf
Philips Medical Systems
A new 3D technique:
Virtual endoscopy
New Eyes are assisting the Radiologist
The overwhelming amount of data calls for condensed presentation and analysis
Philips Medical SystemsVital ImagesGroeller - TU Vienna
Image Guided SurgeryImage Guided Surgery
Bev Doolittle: The forest has eyes
Physics everywhere
• Image Acquisition• Pattern recognition
• Computer aided diagnosis
• Biomedical research• New researchers
• Strong benefit forthe patient