Role of mdc tin coronary artery part 3 (manifestation of coronary artery diseases in mscta) dr ahmed esawy Magnetic Resonance Imaging in Coronary Artery Disease MULTISCLICE CTcoronary artery angiography Coronary artery segments Coronary artery anatomy Coronary artery stenosis Coronary artery calcification score Coronary artery stricture Coronary artery aneurysm Coronary artery pos operative changes Coronary artery by pass Coronary artery stent Coronary artery bridge Artifacts recognition and management 1/ Fundamental CT artifacts Scanner hardware failure Partial volume artifacts Beam hardening artifacts Metal related artifacts Coronary artery angiography pitfalls Artifact Cardiac motion Pulmonary motion Body motion Beam hardening Metallic object A Artifacts recognition and management 1/ Fundamental CT artifacts Scanner hardware failure Partial volume artifacts Beam hardening artifacts Metal related artifacts rtifacts recognition and management 1/ Fundamental CT artifacts Scanner hardware failure Partial volume artifacts Beam hardening artifacts Metal related artifacts 2/ Artifacts specific to cardiac CT Slab misalignment Tube modulation artifacts Cardiac motion Patient motion

1. Manifestation of
coronary artery diseases
in Multi-Slice CT
Coronary angiography
Dr/AHMED ESAWY

2. Dr. Ahmed Esawy
MBBS M.Sc. MD
Dr/AHMED ESAWY

3. Manifestation of CAD
• CORONARY PLAQUE
• CORONARY ARTERY CALCIFICATION
• CORONARY ARTERY STENOSIS
• POSTOPERATIVE EVALUATION OF
CORONARY ARTERY
• ANOMALOUS CORONARY ARTERIES
• Non-atherosclerotic coronary abnormalities
1/ M. Kawasaki
2/ Myocardial bridging
3/ External compression
4/ Coronary dissection
Dr/AHMED ESAWY

4. CORONARY
PLAQUE
Dr/AHMED ESAWY

5. Atherosclerosis
• it was defined as slight to moderate wall
change, without substantial narrowing of the
vessel.
• Most acute coronary syndromes are initiated
by sudden disruption of atherosclerotic
plaques that are not causing significant
stenosis.
• Those non stenotic plaques are associated
with high lipid content.
• Calcium content, on the other hand, has been
associated with plaque stability.
Dr/AHMED ESAWY

6. Atherosclerosis
• Lipid-rich plaque in
mid LAD artery at
• A) MSCT coronary
angiography and
• B) Corresponding
histopathologic
section with a large
extra cellular lipid
pool
Dr/AHMED ESAWY

7. Vulnerable Plaque
Increased risk for erosion or rupture
Associated with acute coronary ischemic events
Dr/AHMED ESAWY

8. Calcified Plaque
CT attenuation of > 130 HU,
separated from the contrast-
enhanced lumen
> 2 independent planes
Non-Calcified Plaque
CT attenuation below contrast-
enhanced lumen but above the
surrounding tissue/epicardial fat
> 2 independent planes
Mixed Plaque
Calcified and Non-calcified Plaque
per segment
Methods - Definition of Plaque by
MDCT
Dr/AHMED ESAWY

9. 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
Dr/AHMED ESAWY

10. The LAD shows few small calcific and mixed plaques at its proximal one
third causing no significant stenotic lesions, its middle and distal one
thirds are seen patent with no lesions. It supplies early sizable single
patent diagonal branch .
Dr/AHMED ESAWY

11. 41 year old asymptomatic man with normal stress thalium:
Cardiac CT angiography shows ulcerated soft plaque in the proximal
LAD (red boxes)
Dr/AHMED ESAWY

12. Detection of Coronary Plaques
by CTA
Sensitivity Specificity
Calcified plaque 94% 94%
Non calcified plaque 78% 87%
Dr/AHMED ESAWY

13. Limitation of CT Plaque Imaging
Inadequate spatial resolution
Density measurement highly dependant on slice
width and surrounding contrast enhancement
No activity or functional information
Dr/AHMED ESAWY

14. Thin-slab MIP image across LAD plane shows large noncalcified plaque causing moderate (0%–
30%) luminal obstruction in proximal LAD segment.
Complex mixed coronary atherosclerotic plaque in middle LAD segment consists of both
calcified plaque and noncalcified plaque, causing highly significant luminal narrowing. (C) 3-
Dimensional volume-rendered CT image
Dr/AHMED ESAWY

15. CORONARY ARTERY
CALCIFICATION
Dr/AHMED ESAWY

16. Coronary artery calcification-
What do we know?
Coronary artery calcification is a reliable sign of
chronic atherosclerotic changes
Calcified coronary plaque = coronary atherosclerosis
Calcium is absent in normal vessel walls
Calcium seen in arterial wall from 20 years of age
Calcification increases with age and with extent of disease
Dr/AHMED ESAWY

17. Coronary Calcification
Dr/AHMED ESAWY

18. Coronary Calcification
Dr/AHMED ESAWY

19. Calcium or Agatston Score
Agatston score based on the maximum CT
number and the area of calcium deposit in
each lesion.
The score of each single lesion on each image is
the product of its area multiplied by a cofactor
reflecting calcium density in each lesion.
Agatston score is not a linear measurement and
is complex to calculate.
Threshold set is > 130 Hu
Dr/AHMED ESAWY

20. Cardiac Calcium Scoring
Addition of CACS to a prediction model based on
traditional risk factors significantly improved the
classification of risk
Calcium Score Presence of CAD
0 No evidence of CAD
1-10 Minimal evidence of CAD
11-100 Mild evidence of CAD
101-400 Moderate evidence of CAD
Over 400 Extensive evidence of CAD
Dr/AHMED ESAWY

21. Hn x-factor
(Agatston Scoring)
130-199 1
200-299 2
300-399 3
>400 4
Area = 15 mm2
Peak CT = 450
Score = 15 x 4 = 60
Area = 8 mm2
Peak CT = 290
Score = 8 x 2 = 16
Total Score = S
Calcium Volume Scoring
Dr/AHMED ESAWY

22. Who should be screened using CT for calcium scoring ?
- Patient with risk factors for CAD (high cholesterol, DM, HTN,
Smoker, obese, FH of CAD)
What are the limitations of Cardiac CT for Calcium Scoring?
- weight limit, CAD can still be present without calcium even
if your calcium score is low, HR > 90, insurance coverage
- Calcium score correlates directly with risk of events and
likelihood of obstructive CAD
Dr/AHMED ESAWY

23. Predictive Value of Coronary Calcium for
cardiac events
Calcium scores have predictive value for future
coronary events.
Calcium score > 100 : medium risk
Calcium score > 400 : high risk
Calcium score > 1000 : very high risk (events in
the short term (1-2 years)
Dr/AHMED ESAWY

24. Prognostic Value of Calcium Scoring
Calcium score > 100.
10 times high risk of a cardiac event than those with
lower score
Cardiac events occurred earlier and more
frequently in patients with scores > 1000.
Dr/AHMED ESAWY

25. Coronary Calcium Quantification
• A 55-year-old male
with calcification in
LAD artery. Agatston
score was 318.
Dr/AHMED ESAWY

26. (A) Axial image obtained at level of origin of
left main artery, showing extensive
calcification in left anterior descending
coronary artery. Aortic mechanical
prosthetic valve is visualized (arrow).
(B) Maximum-intensity projection image
obtained from patient with ‘‘kissing’’ stents in
left anterior descending coronary artery and
first diagonal branch. In this case, it is difficult
to evaluate lumen because of metallic
artifacts. Vessels distal to stents are widely
patent
Dr/AHMED ESAWY

27. Ultra fast multislice computer tomography of coronary arteries.
Calcification of coronary, score 9.8 Agatston,80 75th percentile for age and gender
Dr/AHMED ESAWY

28. Axial image at level of left main coronary artery ostium and heavily calcified proximal and
middle left anterior descending coronary artery.
Cross-sectional view at level of proximal left anterior descending coronary artery. Note
blooming artifact (arrowhead) caused by vessel calcification, which precludes
exclusion of significant coronary artery stenosis.
Dr/AHMED ESAWY

29. CORONARY ARTERY
STENOSIS
Dr/AHMED ESAWY

30. Coronary Artery Stenosis
• Hemodynamically relevant stenosis was
defined as substantial wall irregularity, with
more than 50% vascular narrowing.
• The degree of stenosis was measured on
transverse scans and MPRs by using an
automated distance-measuring tool.
Dr/AHMED ESAWY

31. Dr/AHMED ESAWY

32. Schematic illustrations of coronary artery stenosis. A–D, Illustrations show progressive
narrowing of lumen (L) resulting in mild (A), moderate (B), severe (C), and complete
(D) stenosis. (Quoted from Sundaram et al., 2009).
Dr/AHMED ESAWY

33. • Also there is growing evidence that the presence, amount, and
composition of noncalcified coronary atherosclerotic plaque and the
degree of coronary remodeling in proximal segments can be
assessed by MDCT with a good correlation to intravascular
ultrasound.
Visualization of the Coronary Artery Lumen
Dr/AHMED ESAWY

34. Coronary Artery Stenosis
• CT coronary angiography and conventional angiography of a
non calcified lesion corresponding to a significant stenosis in
the Proximal LAD artery.
Dr/AHMED ESAWY

35. LAD stenosis
Dr/AHMED ESAWY

36. • old male with severely stenotic mid-LAD lesion
shown by 3D volume rendered CT coronary
angiography and confirmed by the catheter
angiogram.
Dr/AHMED ESAWY

37. • old male with chest pain and dyspnea. The CT
coronary angiography shows a proximal LAD
occlusion with distal filling through collaterals.
Dr/AHMED ESAWY

38.  old male with dyspnea and abnormal
triglyceride level. The CT angiography shows a
soft-plaque causing non-significant stenosis of
the distal Left main coronary and proximal LAD.
Dr/AHMED ESAWY

39. Oblique coronal image obtained from patient with anginal symptoms and indeterminate
stress test results, showing severe stenosis of ostium of left main coronary artery (arrow).Dr/AHMED ESAWY

40. invasive coronary angiography
stenosis OF LAD
Dr/AHMED ESAWY

41. CT shows long-segment irregular mild luminal narrowing(36% stenosis) with myointimal
thickening in the middle RCA, whereas MR overestimates the stenosis degree
in corresponding segment
Dr/AHMED ESAWY

42. POSTOPERATIVE
EVALUATION OF
CORONARY ARTERY
BY PASS
Dr/AHMED ESAWY

43. Postoperative evaluation of Coronary Artery
• Coronary artery bypass graft surgery
Patency or occlusion of grafts can be established
by the presence or absence of contrast
enhancement, respectively.
However, artifacts from metallic surgical clips may
obscure the adjacent portion of a coronary graft.
Dr/AHMED ESAWY

44. By passes
Accuracy of about 90%
Excellent depiction of distal anastomoses
Dr/AHMED ESAWY

45. Postoperative evaluation of Coronary
Artery
• Coronary artery bypass graft
status at MSCT coronary
angiography. Axial images
demonstrate occlusion of a
dilated aorto coronary venous
graft (large arrows) to the Lcx,
while another aorto coronary
venous graft (small arrows)
communicating with the RCA is
patent. Left IMA graft
(arrowheads) to the LAD
coronary artery is also patent
Dr/AHMED ESAWY

46. Assessment of coronary artery bypass graft (CABG)
Curved axial multiplanar reformation image of the SVG shows a stent (arrowhead) and a
thrombosed segment partly occluding the lumen (arrow)
Dr/AHMED ESAWY

47. Three-dimensional volume-rendered oblique sagittal view obtained from patient with
previous bypass surgery.Arrow indicates distal anastomosis of aortocoronary bypass
graft to left anterior descending artery.
Dr/AHMED ESAWY

48. 3-Dimensional volumerendered
image of patient showing status
after left internal mammary graft to middle
segment of left anterior descending
coronary artery (arrowheads). Operative
clips are visualized parallel to course of
graft. In addition, venous coronary bypass
graft can be seen between aorta
and left circumflex coronary artery (arrows)
Dr/AHMED ESAWY

49. 68 year old male with
atypical chest pain,
submitted to
revascularization
surgery: bypass from left
internal mamary to
anterior descending
artery, saphen vein
to right coronary artery
and saphen vein to
circunflex artery. Native
coronary artery
assessment was
impossible due to calcified
plaques , possibly with
multiple critical
stenosis Dr/AHMED ESAWY

50. 71 year old patient
submitted to
coronary artery by-
pass surgery.
Curved MPR
may show less beam-
hardening than axial
section
Dr/AHMED ESAWY

51. 76 year old male patient, submitted to coronary-bypass: saphen to right
coronary, saphen to 1st marginal obtuse and left internal mamary artery to
descending anterior artery.
Dr/AHMED ESAWY

52. 84 year old patient with previous coronary by-pass: saphen to left marginal artery, occluded
Dr/AHMED ESAWY

53. Looking at the MDCT:Surgery
• Overview anastomisis (start by the 3D)
• Evalute grafts in axial and orhogonal MPR planes
• Evaluate anastomosis and run-off
• Evaluate aorta and left-ventricle size
• It is essential that the whole graft is included in the acquisition.
• The most common cause of saphenous graft failure is thrombosis in
the first year and after that atherosclerotic changes ensue.
• Arterial grafts usually have longer life span.
• MDCT, unlike angiography, allows assessment of occluded grafts
Dr/AHMED ESAWY

54. POSTOPERATIVE
EVALUATION OF
CORONARY ARTERY
STENT
Dr/AHMED ESAWY

55. Postoperative evaluation of Coronary Artery
Coronary artery stent
Evaluation of stent patency is by demonstration of
contrast enhancement at the leading and trailing
ends of a stent.
Dr/AHMED ESAWY

56. Evaluation of the patency of coronary
vessels after intervention
MDCT is limited in its ability to visualize lumen
within intracoronary stents because of metal
artifacts  making the detection of intrastent
stenosis difficult.
The accuracy of stent evaluation may depend
upon stent diameter
< 3mm  inaccessible.
Dr/AHMED ESAWY

57. Successful (LAD; 3.5 mm)
Dr/AHMED ESAWY

58. Limited (LAD; 4.0 mm)
Dr/AHMED ESAWY

59. Stents
Accuracy of about 70-80%
Only BIG stents (≥ 3.5 mm)
Only 50% of the small guy2
Dr/AHMED ESAWY

60. Dr/AHMED ESAWY

61. Postoperative evaluation of Coronary
Artery
• Coronary artery stent
patency at MSCT coronary
angiography. demonstrate
stent (large arrows) within
the middle LAD coronary
artery. Stent patency is
supported by adequate flow
to distal segments of the
artery. Arterial stenosis is
noted at the leading end of
a stent (small arrow).
Dr/AHMED ESAWY

62. A patient being evaluated after intra coronary stent placement. CT
coronary angiography and catheter angiogram reveal patency of the
stent.
Dr/AHMED ESAWY

63. Imaging of coronary stents
In-stent occlusion ,two stents in the right
coronary artery. CT was performed after
conventional angiography failed to depict the
right coronary artery. Multiplanar reformatted
image shows lower attenuation inside the
stent lumina than in the proximal untreated
tract of the right coronary artery.
Dr/AHMED ESAWY

64. 55-year-old man with history of coronary
artery stent insertion for focal severe luminal
stenosis
widely patent coronary stent (curved arrows)
and excluded origin of marginal branch
(straight arrows)
67-year-old man with history of coronary stent
insertion in left anterior descending artery
(LAD)
LAD shows in-stent thrombosis (arrow)
resulting in mild diffuse luminal disease
Dr/AHMED ESAWY

65. LCA stent
Dr/AHMED ESAWY

66. Curved MPR image with sharp image filter reconstruction of right coronary artery in patient with
percutaneous stent placement (arrowhead). Lumen of stent (3.5-mm diameter) is patent. There
is no evidence of in-stent restenosis or neointimal hyperplasia. In addition, this patient has large
noncalcified plaque that protrudes into lumen of proximal right coronary artery, causing
significant stenosis (arrow).
Dr/AHMED ESAWY

67. non contrast study showing stent
VRT reconstruction of the coronary tree
Contrast-enhanced showing stent
Oblique MPR of the left descending artery
showing a mixed softtissue
and calcified plaque causing 50% stenosis
59 year old patient with
stent in right coronary
artery. No stenosis was
found in the stent.
Anterior descending
coronary artery
presented partially
calcified plaque
which caused stenosis
of circa 50%.
Dr/AHMED ESAWY

68. 3D reconstruction of the
coronary artery, showing stent
localtion
Curved MPR of the descending
coronary artery showing a
plaque distal to the stent
Center: Coronal MPR showing
stent permeability
5 year old female patient with percutaneous stent placement in the anterior
descending artery. Perfusion cyntigraphy with 99-TCm showed apical perfusion deffect
in the 17th segment (left anterior descending artery). Although the stent was
apparently permeable, distal to it there is na atherosclerotic plaque which conditions a
significant stenosis.
Dr/AHMED ESAWY

69. Significant restenosis of a 3.0 mm diameter bare-metal stent in the proximal left anterior
descending coronary artery (LAD) in a 63-year-old male with typical angina pectoris.
Coronary CT angiography suggested occlusion of this stent (arrowsDr/AHMED ESAWY

70. Prestent stenosis in a 45-year-old male patient without symptoms. Curved multiplanar
reformation of CT demonstrates a 30% diameter reduction in the lumen immediately
proximal to the stent, resulting from a noncalcified plaque (arrow in Panel A). Significant
in-stent restenosis was excluded using stent kernel curved multiplanar reformations
(not shown). Conventional angiography also demonstrated the 30% prestent stenosis
(arrow in Panel B). Angiographic emulation of coronary CT angiography nicely
demonstrated the stenosis
Dr/AHMED ESAWY

71. Images of three stents in venous coronary bypass grafts obtained by using 64-slice MDCT.
The stent lumen appears to be clearly visualized, with no apparent restenosis.The stent
diameter is 4.0–4.5 mm.A surgical metal clip causes some beam hardening artifacts,
whereas the stents themselves cause few visual artifactsDr/AHMED ESAWY

72. Coronary Stent Fracture
Dr/AHMED ESAWY

73. What to state on the examination?
• Is the in-stent portion diagnostic quality?
• Is there stenosis inside the stent
• Looking at the MDCT:Stents
1. Multiplanar reconstructions
2. Used curved MPR
3. If artifacts cannot be excluded then lumen is nondiagnostic.
• Presence of distal contrast does not exclude in-stent stenosis.
• Major complications are stent-thrombosis and restenosis.
Dr/AHMED ESAWY

74. Coronary Stent Fracture
Relatively High Incidence
• Incidence of stent fracture : 1.7–29%
• Potential Cause of in-stent restenosis (ISR)
• 20% of the patients with DES ISR have stent fractures
Dr/AHMED ESAWY

75. Longitudinal Compression
Definition
• Distortion or shortening of a stent in the longitudinal
axis following successful stent
• New generation drug-eluting stents (DES)
• Lower longitudinal strength due to thin strut
Dr/AHMED ESAWY

76. Coronary CTA Imaging Criteria
Stent fracture - Partial or circumferential separation of the stent on
visual inspection of CT image using Maximal intensity projection
(MIP) or curved planar reformation technique (CPR) - Absence of a
metallic strut on cross-sectional image
Dr/AHMED ESAWY

77. Coronary CTA Imaging Criteria
Longitudinal compression - Uneven distortion or shortening
of a stent in the longitudinal axis - Increased density of a
strut in a shorted area
Dr/AHMED ESAWY

78. Stent Fracture and ISR
58 yrs/M with chest pain
Stent fracture causing total occlusion
Sudden loss of stent strut
Low density filling defect in
stent
Total occlusion of pRCA stent was
confirmed by angiography
Dr/AHMED ESAWY

79. Longitudinal compression
Uneven distortion or shortening of stent in
longitudinal axis _Increased density of strut in
shorted area
Dr/AHMED ESAWY

80. Single heart beat 320
RCA with a stent (arrowhead) in segment
RCA showing a patent stent (arrowhead)
Dr/AHMED ESAWY

81. Single heart beat 320
Curved multiplanar reconstruction using a
sharp convolution kernel. In the upper right-
hand corner, transverse sections of the stent
and both stent edges (arrows) help confirm the
absence of in-stent hyperplasia.
An invasive coronary angiogram in D confirmed
the observation
Dr/AHMED ESAWY