Imaging Technology:
The inside story
Benjamin M. Ellingson, Ph.D., M.Sc.
Assistant Professor of Radiology
Department of Radiological Sciences
David Geffen School of Medicine at UCLA
Imaging Technology
The x-ray was discovered [accidentally] in
1895 by Wilhelm Roentgen
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
Imaging Technology
The x-ray was discovered [accidentally] in
1895 by Wilhelm Roentgen
Two weeks later, he took an x-ray of his wife’s
hand
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
Imaging Technology
The x-ray was discovered [accidentally] in
1895 by Wilhelm Roentgen
Two weeks later, he took an x-ray of his wife’s
hand
Immediately used to as a diagnostic tool
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
Imaging Technology
The x-ray was discovered [accidentally] in
1895 by Wilhelm Roentgen
Two weeks later, he took an x-ray of his wife’s
hand
Immediately used to as a diagnostic tool
Tropical Fish
Also used as a research tool
Newborn Rabbit
Eder & Valenta, 1896
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
Eder & Valenta, 1896
Imaging Technology
The x-ray was discovered [accidentally] in
1895 by Wilhelm Roentgen
Two weeks later, he took an x-ray of his wife’s
hand
Immediately used to as a diagnostic tool
Also used as a research tool
Also used as a new “picture” device
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
Imaging Technology
The x-ray was discovered [accidentally] in
1895 by Wilhelm Roentgen
Two weeks later, he took an x-ray of his wife’s
hand
Immediately used to as a diagnostic tool
Also used as a research tool
Also used as a new “picture” device
Changed medicine forever!
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
Imaging Technology
With the discovery of x-rays came a new area
of medicine: Radiology
X-rays were routinely used to find bullets and
shrapnel in soldiers
Routinely used to image the lungs (cancer,
pneumonia) and the abdomen (intestinal
obstructions, gall/kidney stones)
X-rays are still the most common diagnostic
imaging modality
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
“Flavors” of Imaging Technology
X-Ray
CT/CAT Scan
PET
MRI
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
“Flavors” of Imaging Technology
X-Ray
CT/CAT Scan
PET
MRI
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
Standard X-Ray Scan
Like a regular camera, but instead of
visible light it uses x-rays and film
X-rays are generated by an “emitter”
and the film acts as a “detector” (now
digital)
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
Standard X-Ray Scans
X-Ray Emitter (Source)
X-Ray Detector
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
Standard X-Ray Scans
A filament causes emission of high energy electrons (like a light bulb)
High energy electrons smash into a metal (Tungsten) target
X-rays are emitted!
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
Standard X-Ray Scans
Bones, fat, muscle, tumors, etc., absorb the xrays, causing no exposure of the film in these
locations
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
Standard X-Ray Scans
Current systems are mostly digital
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
“Flavors” of Imaging Technology
X-Ray
CT/CAT Scan
PET
MRI
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
“Flavors” of Imaging Technology
X-Ray
CT/CAT Scan
PET
MRI
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
Computed Tomography
CT = Computed Tomography
CAT = Computed Axial Tomography
A series of x-rays from different
directions to create a 3D image
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
Computed Tomography
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
Computed Tomography
Mathematics
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
Computed Tomography
Normal CT
Spiral CT
Cancer.gov
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
Computed Tomography
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
Computed Tomography
Siemens Healthcare
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
Computed Tomography
Meditech Visual Aids
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
Computed Tomography
Wikipedia.org
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
“Flavors” of Imaging Technology
X-Ray
CT/CAT Scan
PET
MRI
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
“Flavors” of Imaging Technology
X-Ray
CT/CAT Scan
PET
MRI
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
Positron Emission Tomography (PET)
Uses small amounts of radioactive material to
diagnose cancers and other abnormalities
Radioactive Tracer:
Radioactive tracer that mimics substances
found in the body
Provide a “light source” to identify where the
chemicals are accumulating
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
Positron Emission Tomography (PET)
“Marvel of Quantum Physics”
Uses “anti-matter”
“Positron” + “Electron”
Radioactive Energy
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
Positron Emission Tomography (PET)
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
Positron Emission Tomography (PET)
PET / CT
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
Positron Emission Tomography (PET)
T2-Weighted MRI
18F-FDG
PET (Blood Glucose)
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
Positron Emission Tomography (PET)
FLAIR MRI
18F-FDOPA
PET (Dopamine)
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
Positron Emission Tomography (PET)
T2-Weighted MRI
18F-FDOPA
PET (Dopamine)
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
Positron Emission Tomography (PET)
18F-FDG
Normal, Resting
PET (Blood Glucose)
During Seizure - Hypometabolic
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
Positron Emission Tomography (PET)
Na18F PET
Bridges, 2007
Bridges, 2007
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
“Flavors” of Imaging Technology
X-Ray
CT/CAT Scan
PET
MRI
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
“Flavors” of Imaging Technology
X-Ray
CT/CAT Scan
PET
MRI
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
Magnetic Resonance Imaging (MRI)
Each hydrogen atom has magnetic properties,
much like a small bar magnet
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
Magnetic Resonance Imaging (MRI)
Each hydrogen atom has magnetic properties,
much like a small bar magnet
m
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
Magnetic Resonance Imaging (MRI)
Magnetic Field
When put into a strong magnetic field, the bar
magnet aligns with the external magnetic field
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
m
Magnetic Resonance Imaging (MRI)
Magnetic Field
When put into a strong magnetic field, the bar
magnet aligns with the external magnetic field
m
Like Magnets Repel
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
Magnetic Resonance Imaging (MRI)
Magnetic Field
When put into a strong magnetic field, the bar
magnet aligns with the external magnetic field
m
Opposites Attract
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
Magnetic Resonance Imaging (MRI)
Magnetic Field
When put into a strong magnetic field, the bar
magnet aligns with the external magnetic field
High Potential Energy
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
m
Magnetic Resonance Imaging (MRI)
Magnetic Field
When put into a strong magnetic field, the bar
magnet aligns with the external magnetic field
Low Potential Energy
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
m
Magnetic Resonance Imaging (MRI)
When put into a strong magnetic field, the bar
magnet aligns with the external magnetic field
Magnetic Field
Based on quantum mechanical properties, we
can “excite” the bar magnet using radiowaves,
causing the bar magnet to “flip” to high energy
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
m
Magnetic Resonance Imaging (MRI)
When put into a strong magnetic field, the bar
magnet aligns with the external magnetic field
Magnetic Field
Based on quantum mechanical properties, we
can “excite” the bar magnet using radiowaves,
causing the bar magnet to “flip” to high energy
“Magnetic Resonance”
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
m
Non-ionizing
Radiowaves
MR “Coil”
Magnetic Resonance Imaging (MRI)
When put into a strong magnetic field, the bar
magnet aligns with the external magnetic field
Magnetic Field
Based on quantum mechanical properties, we
can “excite” the bar magnet using radiowaves,
causing the bar magnet to “flip” to high energy
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
m
Magnetic Resonance Imaging (MRI)
When put into a strong magnetic field, the bar
magnet aligns with the external magnetic field
Based on quantum mechanical properties, we
can “excite” the bar magnet using radiowaves,
causing the bar magnet to “flip” to high energy
Magnetic Field
Each proton then releases this potential energy
in the form of radiowaves depending on the
tissue type
m
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
Magnetic Resonance Imaging (MRI)
When put into a strong magnetic field, the bar
magnet aligns with the external magnetic field
Based on quantum mechanical properties, we
can “excite” the bar magnet using radiowaves,
causing the bar magnet to “flip” to high energy
Magnetic Field
Each proton then releases this potential energy
in the form of radiowaves depending on the
tissue type
m
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
Magnetic Resonance Imaging (MRI)
When put into a strong magnetic field, the bar
magnet aligns with the external magnetic field
Based on quantum mechanical properties, we
can “excite” the bar magnet using radiowaves,
causing the bar magnet to “flip” to high energy
Magnetic Field
Each proton then releases this potential energy
in the form of radiowaves depending on the
tissue type
Radiowaves
m
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
Magnetic Resonance Imaging (MRI)
97% of the body is water
Water has two hydrogen atoms H2O
MRI images the water in the body
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
Magnetic Resonance Imaging (MRI)
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
Magnetic Resonance Imaging (MRI)
Different “excitation” and “listening” techniques
result in different types of MRI images
MRI is the most flexible imaging modality
T1 weighted images
T2 weighted images
Contrast-Enhanced
Diffusion
Perfusion
Functional MRI
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
Magnetic Resonance Imaging (MRI)
T1 weighted images = How fast hydrogen goes from
“high energy” to “low energy” (spin-lattice)
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
Magnetic Resonance Imaging (MRI)
T2 weighted images = How much hydrogen
molecules interact with each other (spin-spin)
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
Magnetic Resonance Imaging (MRI)
Contrast agents change tissue T1
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
Magnetic Resonance Imaging (MRI)
Diffusion MRI = Axons
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
Magnetic Resonance Imaging (MRI)
Diffusion MRI = Tumor Cellularity & Dynamics
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
Magnetic Resonance Imaging (MRI)
Perfusion MRI = Blood flow & blood volume
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
Magnetic Resonance Imaging (MRI)
Functional MRI = Change in MRI signal resulting
from a “task”
Beauchamp, Fronteirs in Systems Neuroscience, 2010
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
“Flavors” of Imaging Technology
X-Ray
CT/CAT Scan
PET
MRI
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
“Flavors” of Imaging Technology
X-Ray
CT/CAT Scan
PET
MRI
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
“Flavors” of Imaging Technology
X-Ray
CT/CAT Scan
PET
MRI
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
“Flavors” of Imaging Technology
X-Ray
CT/CAT Scan
PET
MRI
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
“Flavors” of Imaging Technology
X-Ray
CT/CAT Scan
PET
MRI
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011
Questions?
Benjamin M. Ellingson, Ph.D., Dept. of Radiological Sciences, David Geffen School of Medicine at UCLA, 2011