practical cardiac ct - stanford medicine cardiac ct c. damits m. bieler l. molvin ... practical...

PRACTICAL CARDIAC CTPRACTICAL CARDIAC CTPRACTICAL CARDIAC CT

C. DamitsM. Bieler L. Molvin F. AlkhadraW. Earle

C. DamitsC. DamitsM. Bieler M. Bieler L. Molvin L. Molvin F. AlkhadraF. AlkhadraW. Earle W. Earle

ECG-Gated Cardiovascular CT – WorkshopLucas Learning Center – Stanford Radiology

June 6, 2009


June 6, 2009

Stanford Computed Tomography

Stanford CT ScannersStanford CT Scanners

••HOSPITALHOSPITALCT1CT1 GE GE LightSpeedLightSpeed UltraUltra (GE(GE--88))CT3CT3 GEGE LightSpeedLightSpeed 1616 (GE(GE--1616))CT2CT2 GE LightSpeed VCTGE LightSpeed VCT (GE(GE--64)64)

•• Outpatient ScannersOutpatient Scanners

BlakeBlake Siemens Sensation 64Siemens Sensation 64 (S(S--64)64)SMOCSMOC Siemens AS+Siemens AS+ (S(S--AS)AS)SMICSMIC Siemens DualSiemens Dual--SourceSource (S(S--DS)DS)

GE LightSpeed VCTGE LightSpeed VCT (GE(GE--64)64)

'Cardiac scanners'

PRACTICAL CARDIAC CT:

SUH CT2 (GE-VCT)


SUH CT2 (GE-VCT)

Caryn Damits RT R (CT)Caryn Damits RT R (CT)Caryn Damits RT R (CT)

ECG-Gated Cardiovascular CT – WorkshopLucas Learning Center – Stanford RadiologyJune 6, 2009



•Single x-ray tube (100kW, 20-800 mA)

•Detector bank64 0.625 mm [40 mm]

•Gantry rotation: 350 msec ( ~175ms temp.res.)

General Electric VCT(Stanford Hospital, CT2)

64 0.625 mm 64 0.63 mm32 1.25 mm

( total detector width 40 mm )

Coronary CTA ProtocolsGE VCT (SUH CT2)

5.27 SNAPSHOT PULSE SMALL PATIENT 30-74BPM 75-130 LBS PROSPECTIVE

5.28 SNAPSHOT PULSE MEDIUM PATIENT 30-74BPM 131-240 LBS PROSPECTIVE

5.29 SNAPSHOT PULSE LARGE PATIENT 30-74BPM 240+ LBS PROSPECTIVE

5.23 SNAPSHOT SEGMENT SMALL PATIENT 30-74BPM 75-130 LBS RETROGATING

5.24 SNAPSHOT SEGMENT MEDIUM PATIENT 30-74BPM 131-240 LBS RETROGATING

5.25 SNAPSHOT SEGMENT LARGE PATIENT 30-74BPM 240+ LBS RETROGATING

•Scout•Calcium scoring

from carina to apex

•Coronary CTA

GE VCT (CT 2)Step- by- Step Coronary CTA

SmartScore Protocol(prospective)

•Non-contrast calcium scoring•Scanning range:

Carina apex•mA: 300 for small

350 for average450 for large pts.

•DFOV: 25 cm (Do NOT CHANGE)•GIVE NITRO AFTER SmartScore

Use scout and SmartScore images to define scanning range for Coronary CTA

Left coronary artery origin Apex of heart

Coronary CTA Scanning RangeSnapshot Pulse • Snapshot Segment

•20mm above left main coronary artery 20mm below apex of heart (or from 10mm below carina to apex)

•default mA (can be adjusted):small 450 mA average 550 mA large 750 mA

•SmartPrep 8 s diagnostic delay •ROI in ascending aorta, at level where scan starts•40mA; monitoring delay 8s, ISD 2.0; 80 HU

INJECTION PROTOCOL

• CONTRAST: (Isovue 370 ) • Injection (~1.1 mL/kgBW in 15s) + Saline Flush • Scan Time: approx. 5 seconds [or 7s for 4 heart beats]

<121 lbs (<55 kg) 60 [70] mL @ 4.0 mL/s121-143 (<65 kg) 65 [75] mL @ 4.5 mL/s143-187 (~75 kg) 75 [85] mL @ 5.0 mL/s187-209 (>85 kg) 85 [95] mL @ 5.5 mL/s>209 lbs (>95 kg) 90 [100]mL @ 6.0 mL/s> XXL 110 mL [120] @ 6.0/s

and increase. diag. delay to 11s

Prospective GatingCoronary CTA

••StepStep--andand--Shoot (every other heart beat)Shoot (every other heart beat)-- 3 scans (~12cm): 5 heartbeats 3 scans (~12cm): 5 heartbeats ~5 sec~5 sec-- 4 scans4 scans (~16cm): 7 heartbeats (~16cm): 7 heartbeats ~7 sec~7 sec

••Sequential Acquisition as fast as helical Sequential Acquisition as fast as helical ••Substantially less radiation dose (~5mSv) Substantially less radiation dose (~5mSv)

(1/3(1/3rd rd to 1/4to 1/4th th ))••ECG Triggers the scan ~ every other heat beatECG Triggers the scan ~ every other heat beat••Need a low and steady heart rate !! Need a low and steady heart rate !!

(for GE(for GE--VCT: <60; VCT: <60; 5)5)••No dynamic information (no 4D)No dynamic information (no 4D)

GE- VCT 'PADDING'

GE VCT (CT 2)Coronary CTA Image Reconstruction

PROSPECTIVE:• Default: 75% (diastolic)• additional: ~65% - 85% (in 3% intervals, depends on

padding)

56 yo man with chest pain (ER)

Prospectively Gated Coronary CTAProspectively Gated Coronary CTA(betablocker, HR 62 bpm)(betablocker, HR 62 bpm)

33 yo man with atypical chest 33 yo man with atypical chest pain (ER)pain (ER)

CORONARY CTA RETROSPECTIVE GATINGSNAPSHOT SEGMENT

••HelicalHelical AcquisitionAcquisition••Low Pitch, redundant scanningLow Pitch, redundant scanning••ECG signal is recorded, does not trigger scanECG signal is recorded, does not trigger scan••Can Reconstruct 10 phases (0%Can Reconstruct 10 phases (0%--90%)90%)••Robust for faster Heart RatesRobust for faster Heart Rates••> 65 bpm> 65 bpm••More Radiation DoseMore Radiation Dose

59 yo womanhx of MI, LAD sten.

HR: 91 bpm retrosp. gating

myo

c. t

hin

nin

g

RCA LAD

RCA

3-chamber view (10 phases [0-90% RR])



RCA

3-chamber view (10 phases [0-90% RR])



Comparison / Range of Radiation Doses

Recent Example:Low dose prospectively gated CTA-- 100kVp (slim patient)100kVp (slim patient)-- 3 seq.scans at 650mA3 seq.scans at 650mA-- CTDICTDIvolvol: : 18.8 mGy (DLP 225 mGy*cm)18.8 mGy (DLP 225 mGy*cm)~ ~ 3.8 mSv3.8 mSv effective doseeffective dose

What was the radiation dose in this case ?Retrospective Gating:-- 120kVp120kVp-- CTDICTDIvolvol: : 51.7 mGy (DLP 879 mGy*cm)51.7 mGy (DLP 879 mGy*cm)~ ~ 14 mSv14 mSv effective doseeffective dose

Patient Preparation

•Patient into Gown, Proper IV access•Oral Beta blocker 1-3 hours before scan •Keep Patient in Quiet environment

•Sublingual Nitroglycerine ~3-5 min before CTA

Communicate with your patient

Explain Answer Questions

BREATHING INSTRUCTIONS

•Inspiration: BREATHING instructions: ('stop breathing‘

• “Take in a breath, STOP BREATHING”• Importance of “Not Bearing Down”•Coach the Patient a few times before scan

Wrong way to attach leads

Proper way to attach Leads

CHECK ECG TRACE (quality, readjust leads if necessary, wipe skin before placing leads etc, check heart rate and heart rate variability

GE VCT (CT 2)Tips and Tricks

Make the patient comfortableCreate a quiet environment

Keep the lights low, decrease background noise

GE VCT (CT 2)Tips and Tricks

THANK YOU ….THANK YOU ….




11


Siemens Sensation 64


Siemens Sensation 64

Mark BielerMark BielerMark Bieler


June 6, 2009


June 6, 2009


Siemens Sensation 64Siemens Sensation 64(Blake Wilbur)(Blake Wilbur)

••xx--ray Tube: single tube ray Tube: single tube (85kW, 665mA)(85kW, 665mA)

••gantry rotation: 330 msec gantry rotation: 330 msec (temp.res.~175ms)(temp.res.~175ms)

••Detector bank Detector bank (for coronaries)(for coronaries)32 rows 32 rows 0.6 mm0.6 mm thickness [19.2 mm]thickness [19.2 mm]but it's still a but it's still a 6464--sliceslice scanner !scanner !

ECG gating:ECG gating:••retrospective, tube current modulation retrospective, tube current modulation ••(no prospective)(no prospective)

Matrix Detector

Hybrid Detector

64 0.625 mm

GE LightSpeed VCTGE LightSpeed VCT

(Siemens Sensation 64)

z

32 0.6 mm

4 1.2 mm 4 1.2 mm

64 64 –– Channel (Slice) CT SystemsChannel (Slice) CT Systems

64 0.6 mm channels

( total detector width 40 mm )

| total detector width 28.8 mm (24x1.2mm) |

Gantry rot: 350ms, z-Resolution ~0.625

Gantry rot: 330ms, z-Resolution ~0.4

| detector width 19.2 mm |

(Siemens Sensation 64)

z32 0.6 mm

4 1.2 mm 4 1.2 mm

Dual Focal Spot: Electromagnetic field deflects electron-beam and thus allows two focal spot positions on tube anode in z-direction (4640 shifts/s)

Gantry rot: 330ms

z-resolution: 0.4 mm

New Straton Tube (580mA)

integrated scanning integrated scanning and injection and injection protocols for 64protocols for 64--channel CTchannel CT

Stanford CTAStanford CTA ProtocolsProtocols(Siemens Sensation 64, Blake Wilbur)(Siemens Sensation 64, Blake Wilbur)

22

Calcium Score PhantomCalcium Score PhantomCalcium Scoring and Coronary CTACalcium Scoring and Coronary CTA

Siemens Sensation Siemens Sensation 64 (Blake64 (Blake Wilbur)Wilbur)

Tips and TricksTips and Tricks

••ECG lead placement ECG lead placement on table /w arms on table /w arms above headabove head

••Check ECG tracingCheck ECG tracing••Hairy ChestHairy Chest••Practice breathingPractice breathing••Shoulder positionShoulder position

Coronary CTA ProtocolCoronary CTA Protocol

Continued…Continued…

64 x 0.6mm64 x 0.6mm12s scan12s scan--timetime

100mg 100mg atenololatenololsublingual nitrosublingual nitroHR: 55 HR: 55 bpmbpm

48 y/o business48 y/o business--executive w equivocal stressexecutive w equivocal stress--echo echo (posteroinf. wall(posteroinf. wall--motion abnormality?)motion abnormality?)

100mL CM, 100mL CM, 5mL / s (20s)5mL / s (20s)Delay: Delay: ttCMTCMT+8 +8

(Care(Care--bolus)bolus)

33

TroubleshootingTroubleshooting

••Use own judgement to assess patient: Use own judgement to assess patient: weight, age, general health, …. weight, age, general health, …. (general (general protocol applicable? i.e. test bolus vs. tracking?)protocol applicable? i.e. test bolus vs. tracking?)

••PostPost Processing ECG Editing and Sync Processing ECG Editing and Sync AdaptationAdaptation

44

THANK YOU ..THANK YOU ..


June 6, 2009


June 6, 2009



Siemens Definition (DualSource)


Siemens Definition (DualSource)

Molvin, LAlkhadra, FMolvin, LMolvin, LAlkhadra, FAlkhadra, F


June 6, 2009


June 6, 2009


Siemens Definition (DualSiemens Definition (Dual-- Source)Source)(Stanford Medicine Imaging Center (Stanford Medicine Imaging Center -- SMOC)SMOC)

••Two xTwo x--ray Tubes ray Tubes (2(2100kW, 20100kW, 20--800 mA)800 mA)

••Two detector banks Two detector banks (each bank same as Blake)(each bank same as Blake)2 2 32320.6mm [19.8 mm]0.6mm [19.8 mm](2 (2 64 channels)64 channels)



••Two detector banks Two detector banks (each bank same as Blake)(each bank same as Blake)2 2 32320.6mm [19.8 mm]0.6mm [19.8 mm](2 (2 64 channels)64 channels)



••Detector banks Detector banks (each bank same as Blake)(each bank same as Blake)2 2 32320.6mm [19.8 mm]0.6mm [19.8 mm](2 (2 64 channels)64 channels)

••gantry rotation: gantry rotation: 330 msec330 msec••temporal resolution:temporal resolution: (not 330/2 = 175ms)(not 330/2 = 175ms)

but 330/4 = 85msbut 330/4 = 85ms

Coronary CTA ProtocolsCoronary CTA Protocols(Siemens Definition (Siemens Definition –– DualSource, SMIC)DualSource, SMIC)

••(Prospective gating)(Prospective gating)detector smaller than GEdetector smaller than GE--VCT or VCT or Siemens AS+ (SMOC)Siemens AS+ (SMOC)

••Retrospective ProtocolsRetrospective Protocols-- Small (100kV)Small (100kV)-- MediumMedium-- Large (more mA for less temp.res)Large (more mA for less temp.res)

ECG tube current modulat. ECG tube current modulat. based on heart ratebased on heart rate minmin--dose, 70% of RR onlydose, 70% of RR only minmin--dose, 30dose, 30--70% of RR70% of RR

55

••at low heart rate (<65 bpm) reliable still at low heart rate (<65 bpm) reliable still phase during diastolic phase of heart phase during diastolic phase of heart (diastolic: 70% or RR interval (diastolic: 70% or RR interval [65[65--75]75])) full dose only at full dose only at 7070% % of RRof RR intervalinterval

••at higher heart rates (>65 bpm) need end at higher heart rates (>65 bpm) need end systolic (30%RR) through diastolic (70%RR)systolic (30%RR) through diastolic (70%RR) full dose from full dose from 30%30%--70% RR70% RR

downdown--modulate mA to 4% during nonmodulate mA to 4% during non--diagnostic phases of cardiac cycle diagnostic phases of cardiac cycle (minDose)(minDose)

Retrospectively Gated Coronary CTARetrospectively Gated Coronary CTA(Siemens Definition (Siemens Definition –– DualSource, SMIC)DualSource, SMIC)

100% 100% --

20% 20% --

100%100% --

100% 100% --

4% 4% --

No ModulationNo Modulation

max.mAmax.mA: full RR: full RRmin.mAmin.mA: 100%: 100%

EKG ModulationEKG Modulation

max.mAmax.mA: 30: 30--70%RR70%RRmax.mAmax.mA: 70%RR: 70%RR

min.mAmin.mA: 20%: 20%

'Min.'Min.--Dose' ModulationDose' Modulationmax.mAmax.mA: 30: 30--70%RR70%RR

max.mAmax.mA: 70%RR: 70%RR


end

syst

.en

d sy

st.

dias

tole

dias

tole

% max. % max. mAmA

Retrospectively gated cardiac CTRetrospectively gated cardiac CT

EKG Modulation of Tube CurrentEKG Modulation of Tube Current

100% 100% --

20% 20% --

100%100% --

100% 100% --

4% 4% --

No ModulationNo Modulation

max.mAmax.mA: full RR: full RRmin.mAmin.mA: 100%: 100%

EKG ModulationEKG Modulation

max.mAmax.mA: 30: 30--70%RR70%RRmax.mAmax.mA: 70%RR: 70%RR


'Min.'Min.--Dose' ModulationDose' Modulationmax.mAmax.mA: 30: 30--70%RR70%RR

max.mAmax.mA: 70%RR: 70%RR


end

syst

.en

d sy

st.

dias

tole

dias

tole

% max. % max. mAmA

Retrospectively gated cardiac CTRetrospectively gated cardiac CT

EKG Modulation of Tube CurrentEKG Modulation of Tube Current 3030-- 70% Phase 70% Phase MindoseMindose Dose ModulationDose Modulation50% Dose Reduction50% Dose Reduction

70% Phase Gated Chest CTA70% Phase Gated Chest CTA75% dose Reduction75% dose Reduction

Image ReconstructionImage Reconstruction

High HR (>65%) (30High HR (>65%) (30--70%RR):70%RR):••Recon 1:Recon 1: 'BestDiast' 'BestDiast' ••Recon 2: Recon 2: 'BestSyst''BestSyst'••Recon 3:Recon 3: 00--90% (10phases)90% (10phases)

Low Heart rate (<65%) (70% RR)Low Heart rate (<65%) (70% RR)••Recon 1: Recon 1: 'BestDisat''BestDisat'••Recon 2:Recon 2: 00--95% RR (20ph.) functional matrix95% RR (20ph.) functional matrix

66

EKGEKG Troubleshooting: Manual EditingTroubleshooting: Manual Editing

recon @ 65% of RR intervalrecon @ 65% of RR interval recon @ 39% of RR intervalrecon @ 39% of RR interval

Image ReconstructionImage Reconstruction

High HR (>65%) (30High HR (>65%) (30--70%RR):70%RR):••Recon 1:Recon 1: 'BestDiast' 'BestDiast' ••Recon 2: Recon 2: 'BestSyst''BestSyst'••Recon 3:Recon 3: 00--90% (10phases)90% (10phases)

Low Heart rate (<65%) (70% RR)Low Heart rate (<65%) (70% RR)••Recon 1: Recon 1: 'BestDisat''BestDisat'••Recon 2:Recon 2: 00--95% RR (20ph.) functional matrix95% RR (20ph.) functional matrix

Reconstruction: 'Functional Matrix'Reconstruction: 'Functional Matrix'(256x256, 2mm STh, 20 phases)(256x256, 2mm STh, 20 phases)

77

retrosp., mindose 70retrosp., mindose 70-- 70, 100kV: 70, 100kV: 11.49 mGy, 192 mGy*cm [3.26 mSv]11.49 mGy, 192 mGy*cm [3.26 mSv]

75 %75 %

25

6*2

56

matr

ix,

2m

m S

Th

25

6*2

56

matr

ix,

2m

m S

Th

retrosp., mindose 70retrosp., mindose 70-- 70, 100kV: 70, 100kV: 11.49 mGy, 192 mGy*cm [3.26 mSv]11.49 mGy, 192 mGy*cm [3.26 mSv]

25

6*2

56

matr

ix,

2m

m S

Th

25

6*2

56

matr

ix,

2m

m S

Th

THANK YOU …THANK YOU …


June 6, 2009


June 6, 2009


PRACTICAL GATED CT:

Siemens Definition AS+

PRACTICAL GATED CT:

Siemens Definition AS+


June 6, 2009


June 6, 2009


Wendy Earle, RTWendy Earle, RTWendy Earle, RT

(SMOC (SMOC –– Stanford Medicine Stanford Medicine Outpatient Clinic) Outpatient Clinic)

thx

Dave

!

Siemens Definition AS+Siemens Definition AS+

•• Single XSingle X-- Ray Tube:Ray Tube: 100 100 kW;kW; 2020--800 800 mAmA

•• Gantry Rotation: 300 Gantry Rotation: 300 msecmsec temporaltemporal Resolution: 150 Resolution: 150 msecmsec

•• Detector Bank:Detector Bank:•• 64 64 rowsrows xx 0.6 mm 0.6 mm (total width: 38.4(total width: 38.4 mm)mm) double focal spot: double focal spot: 128 channel128 channel scannerscanner

88

Matrix Detector

64 0.6 mm


( total detector width 38.4 mm )

Siemens Flying Focal Spot:Siemens Flying Focal Spot: '2 Scans per Rotation'

128 0.6 mmChannels


•• Single XSingle X-- Ray Tube:Ray Tube: 100 100 kW;kW; 2020--800 800 mAmA

•• Gantry Rotation: 300 Gantry Rotation: 300 msecmsec temporaltemporal Resolution: 150 Resolution: 150 msecmsec

•• Detector Bank:Detector Bank:•• 64 rows x 0.6 mm (total width: 38.4 mm)64 rows x 0.6 mm (total width: 38.4 mm) double focal spot: 128 channel scannerdouble focal spot: 128 channel scanner

•• Gantry Aperture:Gantry Aperture: 78 78 cm !!cm !!

•• Weight Limit: 480 lbsWeight Limit: 480 lbs•• with with bariactricbariactric tabletable--top: 660 lbstop: 660 lbs


ECG GatingECG Gating

••Prospective:Prospective:SequentialSequentialRR--peak triggers scanpeak triggers scan

••Retrospective:Retrospective:SpiralSpiralTube Current ModulationTube Current Modulation

What is the difference between a What is the difference between a coronary CTA and a gated Chest ?coronary CTA and a gated Chest ?

••Coverage: entire chest Coverage: entire chest A/PA/P••Main focus: aortic root (not Main focus: aortic root (not

coronaries)coronaries)••need to see aortic valve open, need to see aortic valve open,

closed, and in between (throughout closed, and in between (throughout cardiac cycle)cardiac cycle)

••WHICH GATING TECHNIQUE CAN DO WHICH GATING TECHNIQUE CAN DO THIS ??THIS ??


Setting the Pulsing RangeSetting the Pulsing Range

Points to Consider:Points to Consider:••The range from one RThe range from one R--peak to the next is peak to the next is

100%100%••Diastole usually occurs within 65 to 75%Diastole usually occurs within 65 to 75%••Systole usually occurs within 30 to 40 %Systole usually occurs within 30 to 40 %••A Range of 30 to 70% includes both Diastole A Range of 30 to 70% includes both Diastole

and Systoleand Systole

99

ECG Tube Current ModulationECG Tube Current Modulation“Pulsing”“Pulsing”

••AutoAuto•• 20% residual dose; scanner 20% residual dose; scanner selects RRselects RR rangerange

••ManualManual•• 20% residual dose; technologist selects range20% residual dose; technologist selects range

••MinDose MinDose –– AutoAuto•• 4% residual dose; scanner selects 4% residual dose; scanner selects RR rangeRR range

••MinDose MinDose -- ManualManual•• 4% residual dose; technologist selects 4% residual dose; technologist selects RR rangeRR range

••Pulsing OffPulsing Off•• 100% dose100% dose

3030--70% RR70% RR


Gated Chest Image ReconstructionsGated Chest Image Reconstructions

••Best PhaseBest Phase••Best Diastole for HR< Best Diastole for HR< 6060 bpmbpm••Best Systole for HR > 80 Best Systole for HR > 80 bpmbpm

(either for (either for HRsHRs in the 70’s)in the 70’s)••MultiphaseMultiphase

••0 0 –– 90% 90%


Gated Chest ProtocolsGated Chest Protocols

••RoutineRoutine••Gated Chest with Gated Chest with Abd/PelAbd/Pel CTACTA••Gated Chest with Routine Gated Chest with Routine Abd/PelAbd/Pel


Routine Gated Chest Injection ProtocolRoutine Gated Chest Injection Protocol

VolumeVolume CalculationCalculationFlowFlow RateRateBodyBody WeightWeight

6.06.0

5.55.5

5.05.0

4.54.5

4.04.0

(scant time + 8) x 6.0(scant time + 8) x 6.0> 209 lbs> 209 lbs

(scant time + 8) x 5.5(scant time + 8) x 5.5187 187 -- 209209



(scant time + 8) x 4.0(scant time + 8) x 4.0<121 lbs<121 lbs

Bolus triggering, 8s DelayBolus triggering, 8s Delay


Gated Chest with Gated Chest with Abd/PelAbd/Pel CTACTA

••Two Scan Ranges:Two Scan Ranges:••Both ranges have 0.3 rotation timeBoth ranges have 0.3 rotation time••Same FOV for bothSame FOV for both••Minimal time gap between rangesMinimal time gap between ranges••Single Single breathholdbreathhold

••Abd/PelAbd/Pel CTA:CTA:••Begin scan 0.7 mm below end of chest Begin scan 0.7 mm below end of chest ••6 second scan time6 second scan time


Gated Chest with A/P CTA Injection Gated Chest with A/P CTA Injection ProtocolProtocolBIPHASIC INJECTIONBIPHASIC INJECTION

PhasePhase IIIIPhasePhase IIBodyBody WeightWeight

30 ml @ 6.030 ml @ 6.0

28 ml @ 5.528 ml @ 5.5

25 ml @ 5.025 ml @ 5.0

23 ml @ 4.523 ml @ 4.5

20 ml @ 4.020 ml @ 4.0

(scan(scan time + 5) x 4.8time + 5) x 4.8> 209 lbs> 209 lbs

(scan(scan time + 5) x 4.4time + 5) x 4.4187 187 -- 209209



(scan(scan time + 5) x 3.2time + 5) x 3.2<121 lbs<121 lbs

Injection duration = scanInjection duration = scan--time+10s; Bolus triggering, 5s Delaytime+10s; Bolus triggering, 5s Delay

1010


Gated Chest with Routine Gated Chest with Routine Abd/PelAbd/Pel

••Two Scan Ranges with the Same FOVTwo Scan Ranges with the Same FOV

••Gated Chest:Gated Chest:••0.3 rotation time0.3 rotation time

••Routine Routine Abd/PelAbd/Pel::••0.5 rotation time 0.5 rotation time ••Begin scan above dome of liverBegin scan above dome of liver••Calculate delay to begin scan 70 seconds Calculate delay to begin scan 70 seconds

following injectionfollowing injection


Gated Chest with Routine A/P Injection ProtocolGated Chest with Routine A/P Injection Protocol

Volume@FlowVolume@Flow RateRateBody WeightBody Weight

150 @ 6.0150 @ 6.0

135 @ 5.5135 @ 5.5

120 @ 5.0120 @ 5.0

105 @ 4.5105 @ 4.5

90 @ 4.090 @ 4.0

> 209 lbs> 209 lbs

187 187 -- 209209

143 143 -- 187187

121 121 -- 143143

<121 lbs<121 lbs

Bolus triggering, 8s Delay, A/P ~40s DelayBolus triggering, 8s Delay, A/P ~40s Delay

63 y/o man63 y/o mangated chest + routine APgated chest + routine AP

THANK YOU ….THANK YOU ….


June 6, 2009


June 6, 2009


practical cardiac ct - stanford medicine cardiac ct c. damits m. bieler l. molvin ... practical...

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