AAPM 2007 - Multimodality Medical
Imaging - I
Monday, July 28, 2008
Imaging Continuing Education Course
Case History
CE-Imaging: Multimodality Medical Imaging - I
46 year old female with melanoma.
Multimodality Imaging – Clinical
Perspective
PET-CT exam for initial staging.
Michael W. Vannier, M.D.
University of Chicago
Radiological Presentations
Michael W. Vannier - University of
Chicago
Radiological Presentations
AAPM 2007 - Multimodality Medical
Imaging - I
Purpose
(CANADA)
• Challenges in diagnostic imaging technology (2008)
– The “evidence gap”; Overuse
– Economics of diagnostic imaging
– Oncology; Neuroimaging; Cardiovascular; Orthopedic
• Identify trends
– 256-320 channel CT scanners *NEW*
– Applications of high end scanners –
27 June 2008
Doctors often seem to prescribe
CT and MRI scans when they
are of little or no medical use,
perhaps explaining why
Canadians still face hefty delays
to get the tests, a new Ontario
study suggests. Large
percentages of the scans
reviewed by the researchers
either unearthed no medical
problems, or detected
abnormalities that would not
change how the patient was
treated, raising questions about
whether they should have been
ordered in the first place.
• Neuroimaging; Cardiac Imaging; etc.
• 4D angiography; non-gated scanning
– Low end CT scanners:
• Point of Care CT ; DentoMaxilloFacial/ENT
– CT in the cath lab (high end application to PCI)
7/28/2008
5
Sunday, 29 June 2008
Michael W. Vannier - University of
Chicago
AAPM 2007 - Multimodality Medical
Imaging - I
US spends more for healthcare
Medical spending in the United States has
continued to soar, reaching an estimates
$2.25 trillion in 2007. The nation now
spends 50% more on health care per capita
than the next closest industrialized country,
often with no better outcomes for patients.
One reason is overuse of medical
technology.
The New York Times
29 June 2008
Medicare coverage of
cardiac computed tomography angiography
March 2008
Michael W. Vannier - University of
Chicago
Sources: Centers for Medicare and Medicaid Services, U.S. Department
of Health and Human Services, Organization for Economic Cooperation
and Development, New York Times
AAPM 2007 - Multimodality Medical
Imaging - I
Lumbosacral Spine CT
15
Michael W. Vannier - University of
Chicago
http://www.pedrad.org/associations/5364/ig/
AAPM 2007 - Multimodality Medical
Imaging - I
Recommended Protocol Templates in Excel™ Spreadsheets
18
Multirow Detector CT (MDCT) Scanner
128 detector rows; 256 slices (iCT)
Increased Speed, Power, Coverage
• Higher temporal resolution
– 0.27 sec rotation
• Increased Tube Power
– 120 kW / 1,000 mA
– X-Y and Z focal spot modulation
• Greater coverage per rotation
• 8 cm
• 256 slices
Michael W. Vannier - University of
Chicago
Nose to Toe Scan:168 cm in 22sec
AAPM 2007 - Multimodality Medical
Imaging - I
Multi-phase Cardiac
Imaging less than 5 sec
40-64 channels
More detectors
(rows & channels)
Faster gantry
rotation
256 channels
Higher source
brightness
Focal spot
modulation
Larger scanner
aperture
Table weight limit
increased
Lower dose
Michael W. Vannier - University of
Chicago
320 channels
256-320 detector row CT scanners
Enables 4D CT angiography &
Whole organ perfusion exam
AAPM 2007 - Multimodality Medical
Imaging - I
CT Bronchoscopy – Non-Gated Scan
Non-Gated
Chest CT Scan
Excellent coronary visualization
RT=0.33sec
25
Metr
oHea
Large Patient Cardiac CT
132kg
162cm
50 BMI
52 bpm
13 yr old Female
• 4.8 sec scan
• 2D Anti
Anti-Scatter
detector grid improves
contrast resolution
• Smart Focal Spot for
artifact elimination
BMI = 50
28
Michael W. Vannier - University of
Chicago
AAPM 2007 - Multimodality Medical
Imaging - I
Head & Neck
MRI of Cerebral Ischemia
Early DWI/MTT mismatch, lesion growth
FSE T2W
Initial DWI
Initial MTT
DWI 5 days later
78 yo female 3 hrs after onset of aphasia during cardiac cath.
7/28/2008
31
Greg Sorensen, Massachusetts General Hospital
Michael W. Vannier - University of
Chicago
7/28/2008
32
Bernhard Preim, Visualization Research Group, University of Magdeburg, Germany
AAPM 2007 - Multimodality Medical
Imaging - I
Perfusion
CTP
T2
DWI
MRP
MTT
STROKE
IMAGING
Non-contrast CT
CT vs. MRI
MRI
vs. xenon CT vs. PET vs. SPECT
7/28/2008
33
7/28/2008
34
Megan Strother, M.D., Vanderbilt University
Imaging Ischemia--Vascular
Megan Strother, M.D., Vanderbilt University
Imaging Ischemia- Parenchyma
Angiogram
1950-60’s (pre-CT era)
Head CT
Vascular occlusion
<1/3 MCA
territory
No ICH
24 hours
Thrombolysis
<3 hours
Recanalization =
Clinical improvement
7/28/2008
IV Thrombolysis
35
Megan Strother, M.D., Vanderbilt University
Michael W. Vannier - University of
Chicago
7/28/2008
36
Megan Strother, M.D., Vanderbilt University
AAPM 2007 - Multimodality Medical
Imaging - I
MR vs. CT
A
d
v
a
n
t
a
g
e
Wall Clock
Vascular Occlusion
Parenchymal changes
on non-contrast CT
CT
MR
Tissue Clock
CBF
MTT
CBV
• No radiation
• Better contrast
.
7/28/2008
37
M
R 38
7/28/2008
Megan Strother, M.D., Vanderbilt University
A
d
v
a
n
t
a
g
e
CT
MR
• Diffusion = Infarct
• MR = 94% sensitive and 96%
specific for infarct
• Non-contrast CT = 50%
accurate for acute infarct
M
R 39
7/28/2008
Megan Strother, M.D., Vanderbilt University
Michael W. Vannier - University of
Chicago
Megan Strother, M.D., Vanderbilt University
CT
MR
• MR = whole-brain coverage
• CT limited by scanner (10-40 mm max)
• Post fossa obscured on CT by beamhardening artifact
7/28/2008
A
d
v
a
n
t
a
g
e
M
R 40
Megan Strother, M.D., Vanderbilt University
AAPM 2007 - Multimodality Medical
Imaging - I
A
d
v
a
n
t
a
g
e
MR
CT
• Speed
• Accessibility
• Spatial Resolution on CTA
C
T
7/28/2008
A
d
v
a
n
t
a
g
e
MR
CT
– Quantifiable
• MR relies on indirect T2* effects on tissue
from gad, therefore not quantifiable
41
7/28/2008
Megan Strother, M.D., Vanderbilt University
C
T
42
Megan Strother, M.D., Vanderbilt University
CT Scan
Protocol
1st
Non-contrast
Head CT
quantifiable
whole-brain coverage
CTA vascular detail
accessible
2nd
no radiation
cheap
STROKE
IMAGING
CT Perfusion
diffusion
fast
CTP
MRP
7/28/2008
3rd
43
Megan Strother, M.D., Vanderbilt University
Michael W. Vannier - University of
Chicago
7/28/2008
CT angiogram
44
AAPM 2007 - Multimodality Medical
Imaging - I
Head & Neck
7/28/2008
45
CT Scanning Protocol – 320 Channel
Michael W. Vannier - University of
Chicago
Whole Head Dynamic CTA (Multiple Phases) (16 cm z-axis coverage)
AAPM 2007 - Multimodality Medical
Imaging - I
Whole Brain Perfusion (16 cm z-coverage)
256 to 320 Channel MDCT Scanner (2008)
• 8-16 cm zz-axis coverage is well suited to evaluation of
cerebrovascular disease, in stroke (arterial & venous)
• Whole brain perfusion examination is new
• Dynamic wholewhole-head CT angiography with high
temporal resolution
• Bone subtraction – petrous ICA, V4, stents
• Single 50 ml IV contrast material bolus injection
• Combined with CTA of the suprasupra-aortic vessels
Michael W. Vannier - University of
Chicago
Whole Brain Perfusion
Renal CT Angiography (CTA)
Renal artery stenosis, trauma,
transplant donor, neoplasm
But NOT renal function
AAPM 2007 - Multimodality Medical
Imaging - I
Michael W. Vannier - University of
Chicago
AAPM 2007 - Multimodality Medical
Imaging - I
CT of the kidneys: current status
• Highest spatial resolution (0.5 mm)
(Coppenrath EM et al. Eur Radiol 2006; 16: 2603 – 2611)
• Bi-/tri-phasic imaging - high sensitivity for neoplasia
(Walter C et al. Br J Radiol 2003; 76: 696 – 703)
• CT urography - replacing conventional urograms
(Jung DC et al. Radiographics 2006; 26: 1827 -1836)
Challenges:
• Renal function (perfusion, clearance)?
(Daghini E et al. Radiology 2007; 243: 405 – 412)
C
H A RITE’
CONE BEAM CT
Hitachi MercuRay
NewTom QR 2000
7/28/2008
7/28/2008
J. Morita 3DX Accuitomo
Xoran/ISI
Xoran/ISI DentoCAT,
DentoCAT, Ann Arbor, MI
59
Michael W. Vannier - University of
Chicago
60
AAPM 2007 - Multimodality Medical
Imaging - I
Diagnostic Imaging
Facial to Palatal
Distal to Anterior
Distal to Anterior
Facial to Palatal
7/28/2008
7/28/2008
61
62
Dentomaxillofacial Images
Sagittal MPR
Panoramic
Michael W. Vannier - University of
Chicago
63
64
AAPM 2007 - Multimodality Medical
Imaging - I
8-Slice Portable CT Scanner
• Compact, lightweight, mobile, high speed, battery and line powered
multi-slice CT scanner
• 25 cm field of view, primarily head and neck.
• Up to 8 slices per revolution
• Wireless image transfer system (WITS)
• Non-contrast head CT; CTA; CTP
7/28/2008
7/28/2008
65
Radiation Data
8-Slice Portable CT Scanner
7/28/2008
7/28/2008
67
Michael W. Vannier - University of
Chicago
66
68
AAPM 2007 - Multimodality Medical
Imaging - I
CT Scanner for ENT Office / Clinic
Manufacturer claims -
7/28/2008
7/28/2008
70
69
Follow-up to surgery
Low X-Ray Radiation Dose
R
L
Sinus CT with a full-body scanner
• Adult: 1.0-2.0 mSv
• Child: 1.0-2.0 mSv
Sinus CT with the MiniCAT™ low-dose scanner
BUC
R
7/28/2008
LING
• Adult: 0.13 mSv (7-15 x lower radiation dose)
• Child: 0.07 mSv (14-28 x lower radiation dose)
L
71
Michael W. Vannier - University of
Chicago
7/28/2008
72
AAPM 2007 - Multimodality Medical
Imaging - I
Another Clinical Example….
This is the same pt
scanned within 24
hours using the
Ceretom portable
scanner and then
our GE stationary
scanner…
Ceretom
Patient
500lb 38 year old
African American
male
Symptoms
Aphasia and right
sided hemiparesis.
GE
Issues
No hospital in NYC
willing to scan a
patient over 400lbs.
Patient went 5 days
without a CT scan.
Which
do you
prefer?
Ceretom
Imaging
Large MCA infarct
with mass effect &
midline shift.
GE
Cerebrovascular Evaluation
CBF
CBV
CTA
MTT
CT Perfusion (CTP)
•axial, 1 cm slice, 1 slice/second,
•acquisition time is user defined (30-40 seconds)
•reconstruction on the scanner in real time
Michael W. Vannier - University of
Chicago
Direct coronal imaging
Direct coronals
AAPM 2007 - Multimodality Medical
Imaging - I
Direct Coronal Facial CT
4 months apart, same Pt, same dose, same recon settings
Summary
Advantages of Portable CT Imaging
• Mobile and easy to move (unlike the patient!)
• Easy to operate for hospital & office personnel
• Plugs into 120v wall power outlet; or battery
• Compact & does not require room shielding
• Performs axial and coronal images; can
•
CereTom
provide sagittal reconstructions if needed;
can provide CTA and 3D images.
Compatible with surgical navigation units.
GE Lightspeed
Medical Imaging Workstations
7/28/2008
79
Michael W. Vannier - University of
Chicago
Thick Client – expensive, with substantial
local processing capability
Thin Client – small, portable
80
Accessible throughout enterprise
AAPM 2007 - Multimodality Medical
Imaging - I
Revolution in thin-client solutions
Thin Client Solutions
Adding applications and 3D to viewing
CT viewing plus
• Comprehensive Cardiac Analysis
PACS
• Brain perfusion-summary maps
Tech
at scanner
• CT Angiography Applications
Department Workstations
CT Scan
Room
CT Control
Room
- AVA Stenosis and Stent Planning
• Lung Nodule Assessment
Workspace
Portal
All
Key
Clinical
Applications
• Virtual Colonography
Cath or EP Lab
3D Tech
at Workstation
7/28/2008
3D Lab
Any chair of
your choice
7/28/2008
Home
81
82
Integrating CT into the Cath Lab—
Current and Future Applications
7/28/2008
83
7/28/2008
84
John C. Messenger, MD, FACC
Michael W. Vannier - University of
Chicago
AAPM 2007 - Multimodality Medical
Imaging - I
A New Paradigm for Coronary Intervention
3-D Features of a Coronary Tree
Perform PCI
Derived from CTA or 2-D Projection Images
3-D Model
Proximal RCA
Radius of curvature=34.4°
Length=4.27 cm
Mid RCA
Radius of curvature=30.8°
Length=3.90 cm
Distal RCA
Radius of curvature=22.0°
Length=2.62 cm
Complete
Diagnostic
Imaging
Study (CTA)
Showing
Need for PCI
Analyze 3-D
Coronary
Artery Tree
Messenger, Chen, Carroll,
Burchenal, Kioussopoulos, Groves.
3-D coronary reconstruction from
routine single-plane coronary
angiograms: Clinical validation and
quantitative analysis of the right
coronary artery in 100 patients.
International. J. Cardiac Imaging
2001.
7/28/2008
Case Specific Selection
of Equipment and
Working Views
Predict PCI
Difficulty and
Patient Risks
85
7/28/2008
86
87
7/28/2008
88
Use of 3D coronary analysis for
procedural planning of PCI
7/28/2008
Michael W. Vannier - University of
Chicago
AAPM 2007 - Multimodality Medical
Imaging - I
51 Y/O, 180 lb female with newly diagnosed infiltrating
ductal carcinoma of the right breast and one positive
lymph node. ER (+), PR(+).
7/28/2008
7/28/2008
89
J. Boone, UC Davis
7/28/2008
91
Bernhard Preim, Visualization Research Group, University of Magdeburg, Germany
Michael W. Vannier - University of
Chicago
90
7/28/2008
92
Bernhard Preim, Visualization Research Group, University of Magdeburg, Germany
AAPM 2007 - Multimodality Medical
Imaging - I
Conclusion
Acknowledgments
• Diagnostic imaging is subject to overuse with
limited evidence for a beneficial effect on
outcomes in some applications (e.g., cardiac)
• Imaging modalities (e.g., CT scanners) are
becoming both more and less expensive
• Low end scanners are available at the Point of
Care
• High end specialty imaging (e.g., CT in the cath
lab) is in development
7/28/2008
Michael W. Vannier - University of
Chicago
•
•
•
•
•
•
•
•
•
•
•
93
John Steidley, Ph.D., Philips Medical Systems
GE Healthcare, Inc.
Siemens Medical Solutions, Inc.
Diego Ruiz, Johns Hopkins Hospital
Predrag (“Pedja”) Sukovic, Xoran Technologies, Inc.
Bernhard Preim, University of Magdeburg, Germany
John C. Messenger, MD, FACC, University of Colorado
Megan Strother, MD, Vanderbilt University
Patrik Rogalla, MD, Charite’ Berlin
Alisa Gean, MD, UCSF Radiology
David Rosenblum, DO, Case Western Reserve Univ.
7/28/2008
94