Cardiac ct ccta

1. Cardiac CT-CCTA
Dr.Sahar Gamal El-Din,CBCCTDr.Sahar Gamal El-Din,CBCCT
National Heart InstituteNational Heart Institute

2. AgendaAgenda
• IntroductionIntroduction
• Historical backgroundHistorical background
• IndicationsIndications
• ContraindicationsContraindications
• LimitationsLimitations

3. IntroductionIntroduction

4. • Cardiac CT and CCTA has emerged asCardiac CT and CCTA has emerged as
promising noninvasive imagingpromising noninvasive imaging
modality for coronary artery and cardiacmodality for coronary artery and cardiac
structural and functional evaluation.structural and functional evaluation.
• In order to gain high diagnostic accuracy,In order to gain high diagnostic accuracy,
the CT scanner system should providethe CT scanner system should provide
high temporal and spatial resolutionshigh temporal and spatial resolutions

5. • Temporal resolution (TR):Temporal resolution (TR):
• The duration of time for acquisation of aThe duration of time for acquisation of a
single frame of a dynamic process.single frame of a dynamic process.
• TR=TR=TimeTime to repetition .to repetition .
• Temporal resolution in the region of 100 msTemporal resolution in the region of 100 ms
is required to create relatively motionlessis required to create relatively motionless
images of the beating heartimages of the beating heart

6. •Spatial resolution (SR):
 The ability to distinguish two points as
separate in space .
 The higher the spatial resolution ,the smaller
the distance which can be distinguished

7. Historical backgroundHistorical background

8. CT was first introduced by Sir Godfrey
Hounsfield in the 1970 & 1st
commercial
scanner at 1972.
Sir Godfrey N.
Hounsfield, the father of
computed tomography.

9. 4.5 min/image 1972 2.5 min/image 1972
18s/image 1976 2s/image 1978

10. In the early 1980s, an important advance moved CT
into the top of cardiac imaging. This was the
introduction of the electron beam technology concept
by Dr. Douglas Boyd .
Arch Intern Med 2001;161:833–838.

11. • This technology decreased scan times to 50–100
ms, which essentially froze cardiac motion and
thus dramatically changed our ability to image
the beating heart. For the first time it was
possible to view cardiac contractions and to
visualize small structures such as calcium
deposits within the walls of the coronary
artery.
• An additional major advance in CT imaging
came in the early 1990s with the introduction of
helical/spiral CT imaging and its slip-ring
technology

12. • With these advances, the X-ray beam was able to
continuously rotate around the patient as the
patient moved through the scanner gantry. These
innovations decreased scan times to approx 500–
1000 ms and ultimately produced data sets with
spatial resolutions as small as 0.5 mm.
Radiology 2013;226:145–152.

13. • Dual Source Multi Slice CT 1991-1992.
(sensitivity: 86% - specificity: 81%).
• 8 slice scanners Dual Source CT 2000.
(sensitivity: 86% - specificity : 81%).
• 16 slice scanners Dual Source CT 2002.
(sensitivity: 96% - specificity : 83%).
• 64 slice scanners Dual Source CT 2004- 2005.

15. Dual Source CT (DSCT)Dual Source CT (DSCT)
• Two X ray tubes positionedTwo X ray tubes positioned
at right angleat right angle
• Two detector arrays oppositeTwo detector arrays opposite
to X ray tubesto X ray tubes
• Temporal resolutions of 100Temporal resolutions of 100
ms is possible by combiningms is possible by combining
data from one-fourth of datadata from one-fourth of data
acquired by two detectorsacquired by two detectors
*Siemens ‘Definition’ at Johns Hopkins, 2006
Tube
A
Tube
B

16. Indications

17. Indications:
A.Exclusion of CAD in patients at low toin patients at low to
intermediate pretest probability of CAD &intermediate pretest probability of CAD &
detection of CAD when inconclusive stress testdetection of CAD when inconclusive stress test
or persistent symptoms despite – ve stress testor persistent symptoms despite – ve stress test..
Likelihood (in %) of CAD according to sex, age, and symptomsLikelihood (in %) of CAD according to sex, age, and symptoms
WomenWomen MenMen
AgeAge
(years)(years)
NonanginalNonanginal
chest painchest pain
AtypicalAtypical
anginaangina
TypicalTypical
anginaangina
AgeAge
(years)(years)
NonanginalNonanginal
chest painchest pain
AtypicalAtypical
anginaangina
TypicalTypical
anginaangina
3030––3939 0.80.8 44 2626 3030––3939 55 2222 7070
40–4940–49 33 1313 5555 40–4940–49 1414 4646 9090
50–5950–59 88 3232 7979 50–5950–59 2222 5959 9292
60–6960–69 1919 5454 9191 60–6960–69 2828 6767 9494
High: 90% pretest probability; intermediate: between 10% and 90% pretest probability;High: 90% pretest probability; intermediate: between 10% and 90% pretest probability;
low: between 5% and 10% pretest probability; and very low: 5% pretest probability.low: between 5% and 10% pretest probability; and very low: 5% pretest probability.

18. B.B. Suspicion of coronary artery anomalies.Suspicion of coronary artery anomalies.
MDCT has very high sensitivity and specificityMDCT has very high sensitivity and specificity
for coronary anomaliesfor coronary anomalies..

19. C.C. Assessment of anatomy in complexAssessment of anatomy in complex
congenital heart diseasecongenital heart disease..

20. D. Assessment of CABG.D. Assessment of CABG.

21. E.E. Assessment of Coronary Artery Stents?Assessment of Coronary Artery Stents?
Material/Design/size dependentMaterial/Design/size dependent

24. `
F. Evaluation of aortic disease. MDCT is the
test of choice for evaluating aortic aneurysm
and suspected aortic dissection.

26. Maximal intensity projection of the abdominal aorta,Maximal intensity projection of the abdominal aorta,
demonstrating severe calcifications at the iliac bifurcationdemonstrating severe calcifications at the iliac bifurcation
G. Evaluation of PADG. Evaluation of PAD..

27. H. Evaluation of suspected pulmonary embolismH. Evaluation of suspected pulmonary embolism

28. I. Pulmonary vein evaluationI. Pulmonary vein evaluation can be performed,can be performed,
often before or after pulmonary vein isolation foroften before or after pulmonary vein isolation for
atrial fibrillation.atrial fibrillation.

29. Fusion of MDCT and Electroanatomical MappingFusion of MDCT and Electroanatomical Mapping

30. K. Preoperative Coronary AssessmentPreoperative Coronary Assessment Prior
to non coronary Cardiac Surgery
L. Complimentary to coronary cath.L. Complimentary to coronary cath.
M. Evaluation of chest painM. Evaluation of chest pain (Triple rule out)(Triple rule out)

31. 3-D volume rendered image demonstrating visualization of the coronary3-D volume rendered image demonstrating visualization of the coronary
venous system including the coronary sinus (venous system including the coronary sinus (double white arrow), a middledouble white arrow), a middle
cardiac vein (black arrow), andcardiac vein (black arrow), and a posterolateral vein (a posterolateral vein (single white arrow).single white arrow).
J. Coronary vein mappingCoronary vein mapping prior to placement of CRT

32. K. Triple rule outK. Triple rule out

33. N. New-Onset or Newly Diagnosed ClinicalN. New-Onset or Newly Diagnosed Clinical
HF and No Prior CAD.HF and No Prior CAD.
O.O. Evaluation of cardiac masses &Evaluation of cardiac masses &
pericardial diseasepericardial disease when other modalitieswhen other modalities
such as TTE, TEE, or MRI are unrevealing.such as TTE, TEE, or MRI are unrevealing.
P. Evaluation of Cardiac Structure &P. Evaluation of Cardiac Structure &
FunctionFunction (Inadequate images from other(Inadequate images from other
noninvasive methods).noninvasive methods).
Q. Assessment of TAVI.Assessment of TAVI.

39. Contraindications:
•Absolute contraindications :
A. Renal insufficiency. Given the potential for
contrast nephropathy, patients with significant
renal insufficiency (i.e., Cr > 1.5 mg/dL) should not
undergo contrast-enhanced CT unless the
information from the scan is critical and the
risks/benefits are discussed with the patient.
B. Known history of anaphylactic contrast reactions
C. Pregnancy
D. Clinical instability

40. •Relative contraindications
A. Contrast (iodine) allergy. Patients with allergic
reactions to contrast should be pretreated with
diphenhydramine and steroids before contrast
administration.
B. Recent intravenous iodinated contrast
administration. Patients who have received an IV
dose of iodinated contrast should avoid contrast-
enhanced CT scanning for 24 hours to reduce the
risk of contrast nephropathy.

41. C. Hyperthyroidism. Iodinated contrast is
contraindicated in the setting of uncontrolled
hyperthyroidism due to possible precipitation of
thyrotoxicosis.
D. Atrial fibrillation or any irregular heart rhythm,
is a contraindication to coronary CT angiography
due to image degradation from suboptimal ECG
gating.
E. Inability to breath hold for at least 10 seconds.
Image quality will be significantly reduced due
to respiratory motion artifact if the patient
cannot comply with breath hold instructions.

42. F. Morbid obesity.
G. Severe coronary calcium .
H. Metallic interference (e,g: pacemaker,
defibrillator wires)

43. CCT LimitationsCCT Limitations

44. • LimitationsLimitations
• Rapid (>80 bpm) and irregular HRRapid (>80 bpm) and irregular HR
• High calcium scores (>800-1000)High calcium scores (>800-1000)
• StentsStents
• Contrast requirements (Cr > 1.5 mg/dl)Contrast requirements (Cr > 1.5 mg/dl)
• Small vessels (<1.5 mm) and collateralsSmall vessels (<1.5 mm) and collaterals
• Obese and uncooperative patientsObese and uncooperative patients
• RADIATION EXPOSURERADIATION EXPOSURE

45. Heart Rate
5050 7777 8585

46. Impact of Breathing

47. Impact of Breathing