Lawrence N' Tanenbaum, M'D' FACR

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CT Angiographyperipheral vascular

• Lawrence N. Tanenbaum, M.D. FACR
• Seton Hall University NJ Neuroscience Institute
• Edison Imaging JFK Medical Center
• www.drtmasters.com drt_at_drtmasters.com
• Edison, New Jersey

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CT Angiographyaortic and peripheral vascular

• Lawrence N. Tanenbaum, M.D. FACR
• Seton Hall University NJ Neuroscience Institute
• Edison Imaging JFK Medical Center
• www.drtmasters.com drt_at_drtmasters.com
• Edison, New Jersey

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Helical CT scanning

• volumetric data set
• slice position and interval adjustable
• slice shifting
• match or bracket slice location to lesion
• slice overlap
• prospective, retrospective
• superior 3D, multiplanar reformats

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Slice overlap

• helical scan
• 2.5 mm x 2.5 mm
• 30 slices, 75 mm volume
• reconstructed slice overlap
• 2.5 mm x 2 mm
• 38 slices, 75 mm volume
• 2.5 mm x 1.25 mm
• 60 slices, 75 mm volume

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Helical CT scanning
64 ch

• volumetric data set
• slice thickness selection is equal to (or a
  multiple of) the collimation supplying each
  imaging channel
• effective slice thickness related to collimation
  and pitch

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4 channel cluster configurations
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8 channel detector configurations
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LightSpeed16 32 cell matrix detector
16 x 1.25
16 x .625
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Multi-channel detectorvolume CT 64
64 x .625
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Helical scanningdefinitions

• slice pitch
• table movement w/r/t detector collimation
• reflects speed
• beam pitch
• table movement w/r/t dimension of exposed
  detector (beam width)
• reflects slice profile and dose

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Multi-channel SPEED

• 1 channel system
• 1.5 pitch / speed routine
• 4 channel system
• 3 (0.75)
• 6 (1.5)

4 ch
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Multi-channel SPEED

• 8 channel system
• 5 (0.625)
• 7 (0.875)
• 10.8 (1.35)
• 13.4 (1.675)
• 16 channel system
• 9 (.5625)
• 15 (.9375)
• 22 (1.375)
• 28 (1.75)

.625 x 16 channel
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Helical CT scanning
64 ch

• volumetric data set
• slice thickness selection is equal to (or a
  multiple of) the minimum collimation supplying
  each imaging channel
• effective slice thickness related to collimation
  and pitch

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Helical pitch

• extending pitch leads to slice profile broadening
• effective slice thickness gt collimation
• overextending pitch leads to artifacts due to
  undersampling

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Helical pitch

• each channel of helical data contributes to each
  individual slice created
• the more unique data acquired the less slice
  profile broadens with extended pitch
• progressive increase in acceptable table speed
  (slice pitch) as number of imaging channels
  increases

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Helical scanningdefinitions

• slice pitch
• table movement w/r/t detector collimation
• reflects speed
• beam pitch
• table movement w/r/t dimension of exposed
  detector (beam width)
• reflects slice profile and dose

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Multi-channel pitch4 channel system

• distance table travels per tube revolution /
  activated detector dimension
• collimation x number of imaging channels
• 0.75 pitch (3)
• 4 x 5 mm slice, 15 mm table incrementation / rev
• 4 clusters of 4 x 1.25 mm cells
• 150 mm covered in 10 revolutions (5-10 sec)
• 1.5 pitch (6)
• 4 x 3.75 mm slice, 22.5 mm incrementation / rev
• 4 clusters of 3 x 1.25 mm cells
• 225 mm covered in 10 revolutions (5-10 sec)

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Multi-channel pitch8 channel system

• distance table travels per tube revolution /
  activated detector dimension
• collimation x number of imaging channels
• 0.625 pitch (5)
• 0.875 pitch (7)
• 1.350 pitch (10.8)
• 1.675 pitch (13.4)
• 8 x 1.25 mm slice
• 16.75 mm incrementation /revolution
• 1000 mm in 30 sec 60 revolution scan

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Multi-channel pitch16 channel system

• distance table travels per tube revolution /
  activated detector dimension
• collimation x number of imaging channels
• 0.5625 pitch (9)
• 0.9375 pitch (15)
• 1.375 pitch (22)
• 1.75 pitch (28)
• 16 x 1.25 mm slice
• 33.5 mm incrementation /revolution
• 1000 mm in 15 sec 60 revolution scan

16 x .625
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16 channel
4 x 1.25 mm
.625 mm
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4 channel 2.5
16 channel .625
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1.25/1.0
2.5/1.25
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.625
2.5
1.25
3.75
25
1.25
3.75
.625
2.5
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CT angiographyclinical applications

• aortic disease
• aneurysm, dissection
• renal artery stenosis
• celiac, SMA ASVD
• runoff
• pulmonary emboli
• carotid ASVD
• arch to circle of Willis
• intracranial
• ASVD, aneurysm
• coronary

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CT Angiography Aorta-runoff 4 channel

• 2.5 mm cuts
• pitch 1.5 (6)
• HS, 2.5 mm / 15 mm/rev
• overlap q 2 mm
• 140 kV 380 mA 0.5 sec
• SmartPrep left heart
• 20 sec prep delay

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CT Angiography Aorta-runoff
8 channel

• 1.25 mm cuts
• pitch 1.675 (13.4)
• 1.25 mm / 16.75 mm/rev
• overlap q .8 mm
• 140 kV 380 mA 0.5 sec
• SmartPrep left heart
• 20 sec prep delay

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CT Angiography Aorta-runoff
16 channel

• .625 mm cuts
• pitch 1.75(28)
• .625 mm / 17.5 mm/rev
• overlap q .55
• 140 kV 380 mA 0.5 sec
• SmartPrep left heart
• 20 sec prep delay

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CT Angiography Aorta-runoff
64 channel

• .625 mm cuts
• pitch .984
• .625 mm / 39 mm/rev
• overlap q .6
• 120 kV 300-800 mA (NI 15)
• 0.4 sec
• SmartPrep abdominal aorta

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Multi-channel SPEEDvolume CT
64 x .625
4 x the table speed of 16 channel at the same
pitch / slice profile
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total body CTA 100 cc 2.5 cc/sec
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Intravenous contrast

• Chest 18 grams
• Abdomen-pelvis 37 grams
• Pelvis 23 grams
• Head (standard dose) 40 grams
• Neck, orbit 23 grams
• CT angiography 18-37 gms

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CT Angiographyhigh concentration

• Brain or neck 40-50 cc 15-18 grams
• Full neuro 50-75 cc 18-28 grams
• Aorto-iliac 50-75 cc 18-28 grams
• Runoff to feet 75-100 cc -28-37 grams
• Pulmonary 75-100 cc -28-37 grams
• Coronary 80-100 cc -30-37 grams

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64 channel 50 cc 370
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CT Angiography
SmartPrep
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runoff CT angiography .625 mm 64 channel
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Runoff CTA
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4 channel
occlusive disease
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aortic occlusion
failed conventional angiography
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aortic occlusion 64 channel .625 mm 50 cc 370
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MIP
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64 channel
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16 x .625
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64 channel
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64 ch .625 .9 pitch .4 sec
16 ch .625 mm 1.375 pitch 0.5 sec
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16 ch .625 mm 1.375 pitch 0.5 sec
64 ch .625 .9 pitch .4 sec
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VCT 64
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64 channel
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370 / 100 cc
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16 channel CTA runoff 370 / 100 cc
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VCT 64
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VCT 64
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CT angiographypitfalls

• timing
• pulsation artifacts
• Ca
• stent
• single vs multiphase assessment
• iodinated contrast / radiation
• data load
• reimbursement

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CT angiographypitfalls

• timing
• pulsation artifacts
• Ca
• stents
• single vs multiphase assessment
• iodinated contrast / radiation
• data load
• reimbursement

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3D elliptical centric TRICKS 10 -15 cc Gd
retrograde flow
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www.drtmasters.com
JFK Medical Center