CT ANGIOGRAPHY EDocFind com

POWER INJECTOR PARAMETERS VOLUME OF CONTRAST-ml RATE ml/sec TIME OF INJECTION – sec SCAN DELAY TIME - sec... CONTRAST ADMINISTRATION AND SCANNING METHODS• BOLUS TRACKING • BOLUS TIMING •

CT ANGIOGRAPHY

CT IMAGE OF THE BLOOD

VESSEL OPACIFIED BY

CONTRAST

REQUIREMENTS FOR CTA

PATIENT PREP.

INFORMED CONSENT

PATIENT PREP.

• BUN 7-20 mg/dl

• CREAT.- 0.6 –1.2 mg/dl

• IODINE ALLERGY- STEROID THERAPY

• HYPERVENTILATION BEFORE EXAM FOR BETTER BREATHOLD

UTILIZED

GAUGE SUITABLE FOR CTA

18 OR 20

CONTRAST ADMINISTERED

WITH POWER INJECTOR

ACQUSITION PARAMETERS

• USUALLY ROUTINE CT PRECEDES A CTA EXAM THE ROUTINE EXAM IS USED AS A REFERENCE SCAN

HELPING TO DETERMING THE

SCANNING RANGE IN CTA

SLICE THICKNESS

• SLICE

THICKNESS

• SPATIAL RESOLUTION

SPIRAL PITCH

RESOLUTION

SPIRAL PITCH

• UP TO 2

kVp, mA, TIME

• SIMILAR TO NON- CTA EXAM OF THE SAME BODY PART

RECONSTRUCTION

INTERVAL

• 50% OF OVERLAP

CONTRAST ADMINISTRATION

POWER INJECTOR

POWER INJECTOR

PARAMETERS

VOLUME OF CONTRAST-ml

RATE ml/sec TIME OF INJECTION – sec

SCAN DELAY TIME - sec

CONTRAST WARMER

WHY???

RATE OF INJECTION

3-5 ml/sec

ORAL CONTRAST????

WATER NEGATIVE CONTRAST

CONTRAST ADMINISTRATION AND SCANNING METHODS

• BOLUS TRACKING

• BOLUS TIMING

• MANUAL PRESET TIME

CARE BOLUS

SMART PREP

SURE START

Bolus tracking- PE

PE?

Tracking slice

Bolus tracking- Carotids and

Circle of Willis

Circle of Willis

Circle of Willis?!

40 SEC

Renal arteries 25-30 sec.

ABDOMINAL AND FEMORAL RUNOFF

CARDIAC CT

TWO TECHNIQUES TO REDUCE MOTION ARTIFACTS IN CARDIAC

CT

• PROSPECTIVE TRIGGERING

• RETROSPECTIVE GATING

Prospectively ECG-Triggered Sequential

Scanning

Cardiac CT applications require the

synchronization of data acquisition to the cardiac cycle, i.e to the movement of the heart For

sequential imaging, a prospective trigger is

derived from the ECG-trace to initiate the CT-scan with a certain delay time after the R-wave The

true delay time is calculated from a given phase parameter (e.g a percentage of the RR-interval time) for each cardiac cycle individually based on

a prospective estimation of the RR-intervals

Usually, the delay is defined such that the scans are acquired during the diastolic phase of the

heart

Retrospectively ECG-Gated Spiral Scanning

For "retrospectively ECG-gated spiral scanning" a continuous spiral scan is acquired with the ECG-

signal recorded simultaneously The acquired scan data is selected for image reconstruction with

respect to a pre-defined cardiac phase Similar to ECG-triggered sequential scanning a certain R-wave delay time defines the start point of data that is

used for image reconstruction ECG-gated spiral

scanning has several advantages over

ECG-triggered sequential scanning The continuous

acquisition allows for reconstruction of overlapping slices Due to the retrospective analysis of the ECG, the technique is less sensitive to arrhythmia.

BOTH METHODS REQUIRE

ECG MONITORING

DIASTOLIC PHASE

SCANNING DURING

RR INTERVAL

Retrospective ECG-Gating

CARDIAC CT PROCEDURES

• CARDIAC ANGIOGRAM

• CALCIUM SCORING

CALCIUM SCORING

NO IV CONTRAST USED

CARDIAC ANGIOGRAM

CALCIUM SCORING

CARDIAC ANGIOGRAM

CTA - MPR

PLANE?

PLANE?

MIP - CTA

SSD -CTA

VR - CTA

CINE CTA

• INACCURATE

• EDITING REQUIRED

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