Transcript MDCT COMPLEMENTARY TO CORONARY ANGIOGRAPHY

MDCT COMPLEMENTARY
TO CORONARY
ANGIOGRAPHY
Radiology departement
La rabta hospital
INTRODUCTION
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The possibility to perform cardiac and coronary imaging was a major driving force
behind an ongoing, rapid evolution of scanner technology, accompanied by
improvements of software and post-processing tools.
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The most recent generations of MDCT with the ability to acquire 64 slices
simultaneously allow relatively robust morphological and functional imaging of
the heart.
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Although initially, clinical applications were restricted to the detection of coronary
calcium, visualization of the coronary artery lumen (non-invasive coronary
angiography) has now become the major focus of cardiac MDCT.
PATIENTS AND METHODS
• Analytical descriptive and prospective study about
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patients who subsequently received a computed tomographic coronary
angiography in addition to exploration with coronary angiography when it could not
be formally conclusive.
=> The results and limitations of MDCT were evaluated according to different clinical
and anatomical situations.
• Patients explored with usual MDCT coronary angiography technique.
• Use of beta blockers when heart rate above 65 b / min
RESULTS
1.
DEMOGRAPHIC AND CLINICAL DATA:
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The average age of our patients was 60,1 years, from to years.
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There were women and men with sex ratio 2.7/1.
INDICATIONS OF CORONARY ANGIOGRAPHY:
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Coronary angiography was performed after an acute coronary syndrome or chest pain 91% of cases.
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2 patients were admitted to investigate a dilated cardiomyopathy (n =2).
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One patient was admitted for congestive heart failure revealing an aortic coarctation associated with
an atrial septal defect
MDCT INDICATIONS:
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Further study of congenital anomalies of the coronary arteries (n=7).
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Not visualized coronary artery bypass grafts (n=11).
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Exploration of ostial coronary lesions (n = 14).
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Not catheterized coronary (n = 2).
2. STUDY OF CONGENITAL ANOMALIES OF THE CORONARY
ARTERIES
• 7 patients.
• Indications were:
• Further study of the origin or path of an abnormal origin of a
coronary artery from the contralateral sinus of Valsalva side.(n=)
• Suspicion of a single coronary artery(n=)
• Exploration of a coronary – pulmonary fistula (n=)
Case 1
• 48 years old man
• Having already received a right coronary stenting.
• Currently admitted for a recurrence of chest pain on optimal medical therapy.
Coronary angiography:
ooccluded right coronary artery from its origin back through the network contralateral side.
oleft anterior descending arising from right anterior sinus.
The data of coronary angiography could not formally identify the pre, retro or inter aorto pulmonary
course
IVA arising from right anterior sinus. incidence in cranial and anterior right oblique, note the recovery of right coronary system
The patient underwent a multidetector CT which
confirmed the presence of an abnormal origin of the left anterior artery arising from
the right coronary artery,
with inter aortopulmonary course.
3D MDCT reconstructions (left), volume rendering mode and 2D curvilinear (right): The IVA artery arises from the
segment I of the right coronary artery, describing a inter aorto-pulmonary course before being in the interventricular furrow.
Case 2
• Female, 55 years old, diabetic, hypertensive and obese.
• Admitted to explore a dilated cardiomyopathy.
Coronary angiography failed to opacify the left coronary system, but described a large
dominant right coronary artery with a posterior descending artery giving back into a semblance
left anterior descending.
Coronary angiography: left profile, right coronary dominant giving PDA which seems to extend through an LAD
The MDCT revealed:
The right coronary artery gives an PDA repeating in part the territory of the LAD
Reverse left ventricular territory includes part of the marginal
=> Confirming the fact whether a single coronary artery
Reconstruction 3D Volume rendering: Lack of individualization of a left coronary artery, the coronary
system can be summarized in a single large right coronary artery.
Case 3
• Man aged 32, Type I diabetic, and hypothyroid,
• Admitted for exploration of dilated cardiomyopathy.
Coronary angiography:
o has not objectified atheromatous lesion.
oaffirmed the existence of an artery emerging from a common core with undetermined irrigation
Coronary angiography: catheterization of the left coronary shows the arising of a vessel from the common
core that seems to irrigate an undetermined structure.
• The CT scan examination was performed with biphasic injection of contrast whose goal is
to get on the acquisition of a significant enhancement in the left cavities contrasting with
little opacified right cavities.
• This biphasic injection helped to reveal the coronary pulmonary fistula.
MDCT in axial and sagittal reconstruction. The vessel described above comes into contact with the anterior trunk of the left
pulmonary artery with evidence of passage of contrast in the pulmonary artery, confirming coronary pulmonary fistula
3. CORONARY ARTERY BYPASS GRAFTS:
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11 coronary patients, having already undergone coronary artery bypass grafting
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10 men and one woman.
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Average age of 63.5 years
• These patients accounted for 26 bridges to analyze which types were:
o Saphenous vein grafts in 14 cases
o Internal mammary graft in 10 cases
o Radial graft in 2 cases.
• The anastomoses were on:
o LAD in 9 cases
o the marginal artery in 9 cases
o the diagonal artery in 4 cases
o the right coronary artery in 6 cases
CORONAY ANGIOGRAPHY DATA:
• 6 of 10 internal mammary grafts were patent, four were not opacified.
• 6 of 15 venous grafts were patent, the grafts were not opacified in eight
cases, one was thrombosed.
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The two radial graftss were not opacified.
MDCT DATA:
• All not opacified grafts were studied on CT :
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the four non-opacified internal mammary grafts:
o 2 were patent.
o one was thrombosed.
o One was analyzed only in part, the distal anastomosis could not be
studied because of the occurrence of tachycardia.
the 8 non-opacified venous grafts:
o 5 were thrombosed
o two were patent
o one was the site of a distal anastomotic stricture
o The two radial graftss were occluded.
• For segments opacified by both methods, the findings of
the scanner were identical to those of coronary
angiography.
• Functional grafts studied with coronary angiography were
also permeable on CT.
Case 4
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Man, 63 years old, smoking and diabetes
Background:
double angioplasty of the circumflex and right coronary six years earlier
then triple coronary artery bypass grafting
LAD/LIMA
Second-diagonal /ISV
First-Side / ISV
This patient was admitted for treatment of chest pain
coronary angiography:
Graft ISV/2 nd diagonal permeable and of good size
ISV / 1 st lateral permeable good caliber
The bypass LIMA / LAD was impossible to opacify.
• Coronary Computed tomography described
• A graft on the left internal mammary /LAD
permeable.
• The analysis of the rest of the thoracic led to the
discovery of a highly suspicious apical left mass
without associated signs of mediastinal
extension.
4. EXPLORATION OF OSTIAL CORONARY LESIONS :
• 14 patients with mean age of 57.75 years (41-74 years).
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/ patients were investigated after a confirmed acute coronary syndrom or
suspected chest pain.
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X patient has been explored in the context of dilated cardiomyopathy.
• The ostial lesions:
o Lesions of the left main trunk (n = )
o Ostial lesion of the right coronary (n = )
o Ostial stenosis of the LAD
• Computed tomography coronary helped give a useful answer to the
diagnostic management and / or therapeutic clinical situations in /14
• The ostial lesions:
o Lesions of the left main trunk (n = )
o Ostial lesion of the right coronary (n = )
o Ostial stenosis of the LAD
• Computed tomography coronary helped give a useful
answer to the diagnostic management and / or therapeutic
clinical situations in /14
Case 5
• Male 65 years old, smoking hypertension, diabetes
• Admitted for acute coronary syndromes without ST segment above.
• The ECG and ultrasound trans chest were unremarkable.
Coronary angiography was suspected without affirming, ostial stenosis of the left coronary
artery.
The LAD was infiltrated without significant stenosis and right coronary artery was small and
dominated.
caudal LAO coronary incidence. : Ostial stenosis of the left coronary artery, difficult to quantify
• Computed tomography of the coronary arteries showed:
the presence of a hypodense ostial plaque in left coronary trunk responsible for stenosis
with a minimum area of 3.6 mm2 to planimetry.
This patient underwent a double bypass of the LAD by the left internal mammary artery
and lateral saphenous vein.
MDCT-Reconstruction curvilinear and cross section for measuring the flatness of the core and confirming the closeness
of the stenosis.
Stenosis hypodense non-calcified plaque.
Case 6
• Patient aged 59 years, smoking
• Admitted for acute coronary syndrome.
Coronary angiography has described a right coronary ostial calcified stenosis whose severity
is poorly quantified, the rest of the tree was healthy.
Coronary angiography: left anterior oblique Incidence showing a calcified ostial stenosis of the right coronary artery
The MDCT confirmed the presence of a large eccentric calcified plaque in right
coronary ostial responsible for a severe stenosis.
Coronary MDCT: 3D MIP and curvilinear reconstruction of the right coronary artery:
partially calcified ostial plaque responsible for a sub-occlusive stenosis
5. NOT CATHETERIZED CORONARY :
• 60 years old female patient, hypertensive since 30 years.
• Admitted for congestive heart failure revealing a tight aortic
coarctation associated with atrial septal defect (veinosus sinus).
• Preoperative coronary angiography through the radial approach
could not be achieved, for failure to advance the probe of the
ascending aorta due to a strong collaterally with tortuosity of the
brachiocephalic trunk.
• The MDCTA :
o confirmed coarctation of the aorta.
o studied the collateral circulation.
o studied the coronary system which was free of lesions.
CT angiography: sagittal reconstruction : isthmic coarctation of the aorta
DISCUSSION
• Recent technological developments have enabled the cardiac CT to
fit into the diagnostic of coronary disease.
• Coronary angiography remains the standard protocol in acute
coronary syndromes with electrical and / or enzymatic
modifications, and symptomatic patients with high likelihood of
coronary disease.
• The detection of coronary artery disease is the main indication of
cardiac CT retained due to its negative predictive value close to
100%
ADVANTAGES AND LIMITATION OF MDCT
ADVANTAGES:
• The introduction of multi-detector row computed tomography
(MDCT) led to a significant improvement in the temporal and
spatial resolution of CT, which permitted substantial expansion of
potential indications for CT imaging. Small and rapidly moving
anatomic structures could be visualized with good image quality.
• Coronary CT angiography investigation allows for the accurate
detection of coronary artery stenoses. Especially, the negative
predictive value has uniformly been found to be high, indicating
that the technique may be most suitable as a non-invasive tool to
rule out the presence of obstructive coronary lesions.
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3D imaging provides a real coronary mapping mode using the 3D
volume rendering and MIP.
• CT allows by the measurement of density, to distinguish plaques with
high lipid component called vulnerable, with high risk of erosion.
• Besides the detection of coronary stenoses, cardiac CT has the potential
to visualize earlier stages of coronary atherosclerosis
• Besides the assessment of the coronary arteries, CT provides for
accurate assessment of general cardiac morphology.
• This can be particularly useful in the context of electrophysiology when
detailed anatomic information (e.g. the pulmonary veins and left atrium
prior to ablation procedures or coronary veins in CRT for left ventricular
lead placement) is needed.
• Similarly, CT imaging can be useful in patients with
congenital heart disease or other structural cardiac
disease.
• Exploration concomitant lung parenchyma; according
to Haller, 5% of coronary CT examinations are an
opportunity to discover an extracardiac disease (lung
cancer, pulmonary embolism, benign mass,
pneumonia)
LIMITATIONS:
• Several situations currently pose challenges for reliable CT imaging these
include
• The patient should be cooperative , able to do a few seconds apnea, to
withstand the supine position for ten minutes, arms above the head
• patients with arrhythmias,
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patients with advanced CAD and pronounced coronary calcifications,
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and patients with coronary artery stents, which are often difficult to evaluate.
Similarly, although CABGs can be assessed with very high diagnostic accuracy,
detection of stenoses at the site of anastomosis and in the native coronary
arteries of patients after CABG has reduced accuracy.
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Coronary CT angiography is not routinely recommendable in these situations.
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Patients with coronary artery stents, which are often difficult to evaluate.
Similarly, although CABGs can be assessed with very high diagnostic accuracy,
detection of stenoses at the site of anastomosis and in the native coronary
arteries of patients after CABG has reduced accuracy.
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Obesity is a factor of degradation of the quality of the examination due to the
attenuation of X-ray
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One limitation technique is the spatial resolution is lower than that of
conventional angiography makes the exploration of the distal (septal, diagonal,
marginal) difficult.
RISKS OF MDCT
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The usual risks of the injection of iodinated contrast agents (allergic risk, renal
failure)
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The X-ray dose delivered remains significant.
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A coronary MDCT strips is currently two times more radiant than coronary
angiography although the values recorded are well below accepted standards.
STUDY OF CONGENITAL OF THE CORONARY ARTERIES ANOMALIES
• Although coronary anomalies are rare conditions, possible consequences
include myocardial infarction and sudden death.
• The identification of the origin and course of aberrant coronary arteries
by invasive angiography can be difficult. Because of the threedimensional nature of the data set, MDCT is very well suited to detect
and define the anatomic course of coronary artery anomalies and their
relationship to other cardiac and non-cardiac structures
• Numerous case reports and several research papers have demonstrated
that the CT analysis of coronary anatomy in these patients is
straightforward and very reliable with an accuracy close to 100%.
=>The robust visualization and classification of anomalous coronary
arteries make CT angiography a first-choice imaging modality for the
investigation of known or suspected coronary artery anomalies.
Radiation dose must be considered often in the young patients, and
measures to keep dose as low as possible must be employed.
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In our series, angiography and multidetector CT were
complementary.
• In fact, coronary angiography was performed to explore an acute
coronary syndrome whereas CT coronary was requested further
study of the origin or path of an abnormal origin of from a coronary
sinus of Valsalva in contralateral side.
MDCT ON COMPLEX CORONARY-PULMONARY ARTERY FISTULA
• Coronary-pulmonary artery fistula is usually detected in 0.1% to
0.2% of coronary angiograms .
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Although not all coronary-pulmonary artery fistulas are clinically
or hemodynamically significant, some can result in serious
consequences including myocardial ischemia, myocardial
infarction, or sudden death.
• When complex anatomy or intervention is contemplated, coronary
angiography may not be sufficient. An ideal investigation
technique should be noninvasive and provide a quality anatomic
description of the fistula.
• The diagnostic value of coronary angiography is limited by its
planar imaging nature, restricted angle of angiographic
projections, and concern for the contrast load.
• The 3D reconstruction with viewing at an unlimited angle allows:
o to demonstrate a lesion such as a fistula at its best projection
o without subjecting the patient to repeated radiation exposure and
an additional contrast load.
o makes assessment of the size and exact location of the lesion
feasible.
o quantitative cardiac function analysis.
• This could be helpful for planning future cardiovascular
intervention.
CORONARY ARTERY BYPASS GRAFTS
• Coronary artery bypass grafts (CABGs) move less rapidly and
particularly venous grafts have relatively large diameters
compared with native coronary arteries .
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Occluded grafts and stenoses in the body of bypass conduits can
therefore be detected with very high diagnostic accuracy.
• Accurate assessment of the native coronary arteries by cardiac CT
in patients after CABG is often challenging and image quality
impaired because of advanced CAD and pronounced coronary
calcifications.
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Consequently, the studies that have investigated the accuracy of
CT angiography to evaluate the native arteries in patients with
bypass grafts have reported low accuracies.
• The possibility of a 3-dimensional volumetric study allows easy
viewing of the path of bridges in MDCT , this is crucial before any
redux surgery.
• => Although the clinical application of CT angiography may be
useful in very selected patients in whom only bypass graft
assessment is necessary (e.g. failed visualization of a graft in
invasive angiography), the inability to reliably visualize the native
coronary arteries in patients post-CABG poses severe restrictions
to the general use of CT angiography in post-bypass patients.
EXPLORATION OF OSTIAL CORONARY LESIONS
• The exploration of the ostium and the first centimeter of the
arteries on coronary angiography is sometimes delicate. Ostial
stenosis may be overlooked, often hidden or difficult to identify.
• Luminographie planimetry of the core curriculum is accessible to
the scanner.
• Caussin, reports that the 64 slice CT has a sensitivity and specificity
of 87% and 72% in the diagnosis of significant stenoses of the core
compared to IVUS.
• Several authors have also reported the interest of the scanner in
the evaluation of ostial stenosis of the right coronary.
• The MDCT is as a complementary tool in the
exploration of coronary ostial stenosis of the
core and the right coronary artery.
• It confirms and quantifies stenosis, precise
topography, approach the nature of the
plaque and guide therapeutic decisions.
NOT CATHETERIZED CORONARY
• The noninvasive nature of CT coronary
imaging has allowed a coronary artery
exploration when it is technically impossible
by coronary angiography.
CONCLUSION
• Although coronary angiography remains the
gold standard investigation for the evaluation of
suspected coronary artery disease. Newer, less
invasive, modalities have been developed that
may complement this. CT coronary angiography
offers high sensitivity and specificity in the
identification of coronary lesions.