The Role of Medical Imaging Informatics in Healthcare

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The Role of Medical Imaging Informaticsin
Healthcare
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Outline Medical Imaging and System
Integration Medical Imaging Informatics and
CAD Integration of CAD to PACS Operation
Image-assisted Treatment The Creation of a
Continuum Across the Chasm from Diagnosis to
Treatment
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Academic Excellence The Nobel Prize 1979 For
the Development of computer assisted tomography
(CAT) Hounsfield Cormack 2003 For the
Discoveries concerning magnetic resonance imaging
(MRI) Paul Lauterbur Peter Mansfield
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Magnetic resonance imaging (MRI),
Magnetic resonance imaging (MRI), is a
non-invasive method used to render images of the
inside of an object. It is primarily used in
medical imaging to demonstrate pathological or
other physiological alterations of living
tissues. Definition Pathology is the study and
diagnosis of disease through examination of
organs, tissues, cells and bodily fluids
Definition Physiology is the study of the
mechanical, physical, and biochemical functions
of living organisms.
MRI Hand animation scan
MRI vs CT A computed tomography (CT) , originally
known as computed axial tomography (CAT) scanner
uses X-rays, a type of ionizing radiation, to
acquire its images, making it a good tool for
examining tissue composed of elements of a
relatively higher atomic number than the tissue
surrounding them, such as bone and calcifications
(calcium based) within the body (carbon based
flesh), or of structures (vessels, bowel) which
have been artificially enhanced with contrast
agents containing elements of a higher atomic
number than the surrounding flesh (iodine,
barium). MRI, on the other hand, uses
non-ionizing radio frequency (RF) signals to
acquire its images and is best suited for
non-calcified tissue.
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Magnetic resonance imaging (MRI) (continued)

• The magnet is the largest and most expensive
  component of the scanner, and the remainder of
  the scanner is built around the magnet. Just as
  important as the strength of the main magnet is
  its precision. The straightness of flux lines
  within the centre or, as it is known as, the
  iso-centre of the magnet, need to be almost
  perfect.
• Magnetic gradients are generated by three
  orthogonal coils, oriented in the x, y and z
  directions of the scanner. These are usually
  resistive electromagnets powered by sophisticated
  amplifiers which permit rapid and precise
  adjustments to their field strength and
  direction.
• In 1983 Ljunggren9 and Tweig10 independently
  introduced the k-space formalism, a technique
  that proved invaluable in unifying different MR
  imaging techniques. They showed that the
  demodulated MR signal S(t) generated by freely
  precessing nuclear spins in the presence of a
  linear magnetic field gradient G equals the
  Fourier transform of the effective spin density
  i.e.

MRI Animation 1
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PET Positron Emission Tomography

• Positron emission tomography (PET) is a nuclear
  medicine medical imaging technique which produces
  a three-dimensional image or map of functional
  processes or Metabolic Activities in the body.
• To conduct the scan, a short-lived radioactive
  tracer isotope, which decays by emitting a
  positron, which also has been chemically
  incorporated into a metabolically active
  molecule, is injected into the living subject
  (usually into blood circulation).
• The data set collected in PET is much poorer than
  CT, so reconstruction techniques are more
  difficult (see section below on image
  reconstruction of PET).

PET Animation Pet Animation Atoms
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Computed tomography (CT), originally known as
computed axial tomography (CAT or CT scan) and
body section roentgenography, is a medical
imaging method employing tomography where digital
geometry processing is used to generate a
three-dimensional image of the internals of an
object from a large series of two-dimensional
X-ray images taken around a single axis of
rotation
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Medical Imaging Body Region, Organ, Tissue,
Cell, Gene Diseases What you want to detect,
to see, or to diagnosis? Energy sources
Detectors Image formation Display User
Interface Connection to other Systems
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• Anatomy to Physiology
• Anatomy Body regions, organs, blood
• vessels, etc.
• Can we see smaller anatomy? How small is
• small?
• Static vs. Dynamics how fast can we detect
• and record?
• Physiology Functions, metabolism, oxygen
• concentration, blood flow, etc.
• How fast can we detect and record?
• Can we combine anatomy and physiology?
• Can we see the dynamic?

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Medical Images One-dimensional Signals
Two-dimensional Images Three-Dimensional
Images Four-Dimensional Images Five- or
Higher-Dimensional ?
Rotating Tesseract The four-dimensional
equivalent of a cube.
The fourth dimension and orthogonality A right
angle is defined as one quarter of a revolution.
Cartesian geometry arbitrarily chooses orthogonal
directions through space, which means that they
are at right angles to one another. The
orthogonal directions of three-dimensional space
are known as the length, width and height. The
fourth dimension is therefore the direction in
space that is at right angles to these three
observable directions.
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X-Ray
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MRI Scan
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MRI Scan with injected isotopes
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MRI Scan with injected isotopes
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One 256-Slice CT Scan 256 x 0.5 MB 178 MB
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Medical Imaging Body Region, Organ, Tissue,
Cell Diseases What you want to detect to see,
or diagnosis? Energy sources Detectors
Image formation Display User Interface
Connection to another Systems
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Imaging Informatics Computer Software
Technology Mathematical Modeling Patient
Information History PACS and other medical
Image Data Infrastructure Networking
knowledge base Visualization and Presentation
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One Approach to Image Storage Picture Archiving
and Communication System ( PACS)
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CAD (Computer Aided Diagnosis/ (Detection))
CADx CA Diagnosis Provide computer output to
assist human (radiologist) in image
interpretation One of the major research
subjects in medical imaging and diagnostic
radiology during the past 5 years Being
applied in clinical practice
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Effect of CAD on Ambulatory Care and Emergency
Physicians

• The automated assist and diagnosis software is
  approaching the quality of human experts that
  evaluate images

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• The unaided scan on left was enhanced and
  evaluated using the CAD-diagnosis software and
  the picture on the right color coded the
  abnormality and displayed a message.

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CAD-PACS (Computer Aided Diagnostics Picture
Archiving and Communications System)
Integration Using DICOM IHE (Data Integration
and Communications)
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Combined Diagnosis with Treatment
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• Ultrasound-guided Endoscopy Imagine
• Traditional endoscopy Use fiber optic with
  visible light
• Ultrasound endoscopy Small transducer at the end
  of endoscopic tube
• Two possible types of images Circumferential
  image of lumen Planar image of lumen
• Source Barrets Foundation

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Ultrasound-guided Endoscopy Example

• Ultrasound endoscopy for upper GI tract
• Two transducers at tip of endoscope Low
  frequency Imaging
• High frequencytreatment
• Source Penn Center

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Ultrasound-guided Endoscopy Treatment

• Tumor detection with ultrasound
• Heating and killing tumor cells with high
  intensity focused ultrasound (HIFU)
• Effective hyperthermia above 70C Mechanical
  result tissue disruption
• Focus possible single transducer to send both
  imaging and therapeutic frequencies

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