Multi slice tomography angiography 9 15 EDocFind com

Multi-Slice CT for
Coronary Calcium Scoring
and Coronary Angiography
John D. Symanski, M.D., F.A.C.C

The Sanger Clinic, PA and
Carolinas Medical Center
No Disclosures




Objectives
• Show lots of pretty pictures
• Overview fundamental principles of
MSCT technology
• Review strengths and limitations of MSCT
• Raise awareness of current indications
and clinical scenarios for which to
consider CT angiography


Case Presentation
• 64-year-old female with stage 1 CLL
• Dyslipidemia (untreated); No HTN,
diabetes, or tobacco use
• Negative stress echo previously
• Atypical chest pain
• Stress echo: septal hypokinesis at rest,
LVEF: 50%
• Referred for calcium scoring and CTA

CT Angiogram Interpretation
• Calcium Volume Score: ZERO
• CT angiography:
– Left Main, Circumflex, and Right
coronary arteries: normal
– LAD: eccentric, soft plaque adjacent to
origin of first diagonal (~60% stenosis)
• Correlation recommended




Summary
Cardiovascular Imaging - State of the Art
• Multi-slice CT (MSCT) not likely to
replace conventional angiography
• Post-processing of images for MSCT
angiography time & labor intensive
• Major strength of CTA is its high
negative predictive value
• CMR to become the preferred cardiac
imaging modality in the future

Which Test for Which Patient?
• All modalities are improving
• No single modality fits all
applications and all patients
• Choice of initial test depends on the
specific clinical question in
individual patient


Cardiac Magnetic Resonance


Viability Assessment
CMR Delayed Hyper-Enhancement


Hazards of MRI
Magnet-Seeking Projectiles


First whole-body CT cross-section through a human thorax,
generated by Ledley et al in 1974 (Science 1974;186:207)



The Examination


Current Generation Scanners

• Spatial resolution 0.4 mm - conventional
coronary angiography 0.15-0.25 mm
• Temporal resolution (shutter speed)
improved to 166 msec with faster gantry
rotation (330 msec) – conventional
angiography 6 msec
• Up to 64 slices in one rotation


4 to 64 Slice Scans
Five Heart Beats
10 mm detector
Pitch ~0.25

20 mm detector
Pitch ~0.25

40 mm detector
Pitch ~0.25

3 cm in 5 sec

6.2 cm in 5 sec

12.5 cm in 5 sec


64-Slice CT Scanner
• More coverage (volume) with each
heart beat

• Entire heart imaged in 5-15 seconds
• Less contrast required
• No increase in rotation speed, but with
overlapping slices, can use segments
from different heart beats to improve
temporal resolution


3-D Volume Rendered Image