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ENGINEERING AND MEDICINE
BY
Mark H. Bechtel, M.D.
My Story
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No inclination into medicine originally
Mother and wife are nurses, Wife also CRNA
1st hand experience with hospitalization
Wanted Change
Career Counseling
Decided on Medicine in 1993
Prerequisites by 1994 and started Med School.
Introduction
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Moscow High School
BSEE, University of Idaho 1989
Internships at Varian and Chevron during EE training.
Test Engineering at IBM, 1989-1991
VLSI Design at AHA, 1991-1994
MD at University of Washington 1994-1998
Internship in Spokane, Washington 1999
Radiology Residency at University of Wisconsin, 1999-2003
General Radiologist in Brainerd, MN 2003-2004
Musculoskeletal Fellowship at Penn State Hershey, 2004
General Radiologist, MSK Specialist, Yankton, SD, 2005-2006
General Radiologist, MSK Specialist, Moscow, ID, 2006-present
Main Points
• Engineers as Physicians
• Engineers as Information System Experts
• Biomedical Engineering
• Electrical Design in Medicine
Physician Engineers
• Engineering is an excellent base for
medicine
• High percentage of radiologists are
engineers
• Engineering teaches a method of thinking
that is not taught in other undergrad
degrees
Medical School
• 4 Years
• Easier conceptually than engineering
• More time than engineering
– Engineering: if understand the concept then studying
is over.
– Medicine: Doesn’t matter if understand the concept.
Human body is dynamic and the patient is still sick.
Learning is constant and there is no definite endpoint.
• Much more memorization
Internship
• Most Physicians have internships
• One year general training
• Interview and selection process
Residency
• Three to Six years
– Radiology (4 years)
Fellowship
• Further specialization
• 1-2 years for radiology
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Engineers as Information System
Specialist
• Radiology is highly Technology Dependent
• PACS systems
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Large storage system
Single CT can have 2000 images at 500Kbyte each
Need to interface with different equipment
Need to be able to send entire studies many miles
away
– NightHawk
Biomedical Engineering
• Designing equipment for medical use
• Ie: Insulin pump and detector
– Pacemaker/defibrillator
– Digital Subtraction Angiography
– Stents
– Intravascular work
Pacemaker
• Earl Bakken
Pacemaker
• Bakken’s orignal schematic
Pacemaker
• Newer Devices
Pacemaker
• Chest Xray
Pacemaker
• Conduction system
Ultrasound Images
Magnetic Resonance Imaging
MRI Images
• Enhancement characteristics
MRI Images
• Diffusion Tensor Imaging
MRI Images
• MRA
MRI Images
• Fat saturation
MRI Images
• Spectroscopy
MRI Images
• Cardiac Imaging
MRI Images
• K-Space
MRI Physics
CT
• See other lecture
Conclusion
• Engineering is an excellent base for
medicine as a researcher, designer,
information specialist, or as a physician.
Multidetector CT
Mark Bechtel, M.D.
Education
• Medical School: University of Washington
• Radiology Residency: University of
Wisconsin
• Musculoskeletal Fellowship: Penn State
University, Milton S. Hershey Medical
Center
Chronological Developments in
Multisclice CT
• 1971 CT invented by Godfrey Hounsfeld of EMI and independently by Allan Cormack
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of Tufts University, Massachusetts.
1974-1976 First Commercial CT scanners (for head CT only)
1976 Whole body CT now available.
1980 CT now widely available.
1989 Introduction of Helical CT by Siemens, Germany
1991 Launch of Dual Slice CT by Elscint, Haifa, Israel
1999 Launch of 4 Slice Scanners
2002 Launch of 16 Slice Scanners
2003 Prototype 32 Slicers developed
2003 Prototype 256 Slicers developed (Toshiba) 4D CT
2003 Research in Flat Panet Detectors
2003 Research in Faster scanning (<0.4 s rotation time)
2003 Research in Cone Beam CT
Multislice CT : A Quantum Leap in Whole Body Imaging
IK indrajit, mn shreeram, jd d’souza
Ind J Radiol Imag 2004 14:2:209-216
• 16 Slice is new standard
• 32 and 64 slice models for cardiac
scanning
• New method of use is 3D evaluation
versus axial imaging
Evaluation of a Mandibular Lesion
• Left mandibular lesion was scanned in the
axial and coronal planes.
• Sagittal, oblique Sagittal and 3D images
were reformated.
Mandibular Mass/Abscess
Mandibular Mass/Abscess 3D
Mandibular Mass/Abscess 3D
Comparison of Reconstructions
• Comparing lumbar spine reconstructions
from usual abdominal CT data sets from a
single slice CT scanner and from a 16 slice
multidetector CT.
Comparison of L-Spine Recons
3D Reconstruction of Bones and
Fractures
• Multiplanar reconstructions are possible
• Allows better visualization of orientation of
certain types of fractures.
• Experienced readers often prefer 2D
reconstructions
3D Hind/Mid Foot
Clavicle Fracture missed on plain
film
Clavicle Fracture missed on plain
film
Clavicle Fracture missed on plain
film
Clavicle Fracture missed on plain
film
CTA of the Lower Extremities
• Fast scanning abilities allows scanning of
the lower extremities for vascular disease.
• Makes conventional diagnostic
angiography almost obsolete.
• Can be used for surgical planning.
Mesenteric CTA
Carotid and Intracranial Evaluation
• CTA is less prone to overestimating
stenosis than MRA.
• CTA has replaced conventional diagnostic
angiography for evaluation of carotid
arteries in many locations.
• CTA is excellent for evaluation of
intracranial vessels. It may be as good as
3D conventional, diagnostic angiography.
CTA Intracranial Arteries
Multidetector CT in Sinus
Evaluation
• Only need to scan in one plane. All other
planes can be reconstructed.
Sinus CT
Scanned axially
Reconstruction
Routine Cross Sectional Imaging
• Tube heating is not a problem.
• Patient can be scanned from head to toes
in less than 30 seconds making trauma
evaluations with contrast possible.
• Multiple phases of contrast enhancement
can be obtained with single contrast
administration.
• Multiplanar reconstructions of most scans
is possible.
Pulmonary Embolism Evaluation
• Standard of care for evaluation of PE.
• Much higher resolution than single slice
scanners. (faster scan times, single
breath-hold)
• Bolus timing still very important.
Future Exams
• Coronary CT Angiograms
• Whole Body Trauma Imaging
• Brain Perfusion Imaging
• 3D Fracture reconstructions
Warnings
• Excessive Radiation from Scanning too
much.
• CT is still not MRI for evaluation of soft
tissue (ie: disk pathology)
Conclusion
• 16 slice, multidector CT is very powerful
and can greatly increase our diagnostic
abilities.
• New possibilities with CT angiography are
now within reach.
• There is a learning curve.
• Don’t overscan.