MDCT COMPLEMENTARY TO CORONARY ANGIOGRAPHY

1. MDCT COMPLEMENTARY TO CORONARY ANGIOGRAPHY Radiologydepartement La rabtahospital

2. INTRODUCTION • 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. • The most recent generations of MDCT with the ability to acquire 64 slices simultaneously allow relatively robust morphological and functional imaging of the heart. • 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.

3. PATIENTS AND METHODS • Analytical descriptive and prospective study about 37 patients who subsequently received a computedtomographiccoronaryangiography 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

4. RESULTS • DEMOGRAPHIC AND CLINICAL DATA: • The averageage of our patients was 60,1 years, from to years. • There werewomen and men withsex ratio 2.7/1. INDICATIONS OF CORONARY ANGIOGRAPHY: • Coronaryangiographywasperformedafter an acute coronary syndrome or chest pain 91% of cases. • 2 patients wereadmitted to investigate a dilatedcardiomyopathy (n =2). • One patient was admitted for congestive heart failure revealing an aortic coarctation associated with an atrial septaldefect MDCT INDICATIONS: • Further study of congenital anomalies of the coronary arteries (n=7). • Not visualized coronary artery bypass grafts (n=11). • Exploration of ostialcoronarylesions (n = 14). • Not catheterizedcoronary (n = 2).

5. 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=)

6. Case 1 • 48 yearsold man • Having already received a right coronary stenting. • Currently admitted for a recurrence of chest pain on optimal medical therapy. • Coronaryangiography: • occluded right coronary artery from its origin back through the network contralateral side. • leftanteriordescendingarising 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

7. 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 inter-ventricular furrow.

8. 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 leftanteriordescending. Coronary angiography: left profile, right coronary dominant giving PDA which seems to extend through an LAD

9. 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.

10. Case 3 • Man aged 32, Type I diabetic, and hypothyroid, • Admitted for exploration of dilated cardiomyopathy. • Coronary angiography: • has not objectified atheromatous lesion. • affirmed the existence of an artery emerging from a common core with undeterminedirrigation Coronary angiography: catheterization of the left coronary shows the arising of a vessel from the common core that seems to irrigate an undetermined structure.

11. 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

12. 3. CORONARY ARTERY BYPASS GRAFTS: • 11 coronary patients, having already undergone coronary artery bypass grafting • 10 men and one woman. • Average age of 63.5 years • These patients accounted for 26 bridges to analyze which types were: • Saphenous vein grafts in 14 cases • Internal mammary graft in 10 cases • Radial graft in 2 cases. • The anastomoses were on: • LAD in 9 cases • the marginal artery in 9 cases • the diagonal artery in 4 cases • the right coronary artery in 6 cases

13. 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. • The two radial graftsswere not opacified. MDCT DATA: • All not opacified grafts were studied on CT : • the four non-opacified internal mammary grafts: • 2 were patent. • one was thrombosed. • One was analyzed only in part, the distal anastomosis could not be studied because of the occurrence of tachycardia.

14. the 8 non-opacified venous grafts: • 5 were thrombosed • two were patent • one was the site of a distal anastomotic stricture • The two radial graftsswere 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.

15. Case 4 • 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.

16. 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 mediastinalextension.

17. 4. EXPLORATION OF OSTIAL CORONARY LESIONS : • 14 patients with mean age of 57.75 years (41-74 years). • / patients were investigated after a confirmed acute coronary syndrom or suspected chest pain. • X patient has been explored in the context of dilated cardiomyopathy. • The ostial lesions: • Lesions of the left main trunk (n = ) • Ostial lesion of the right coronary (n = ) • Ostial stenosis of the LAD • Computed tomography coronary helped give a useful answer to the diagnostic management and / or therapeutic clinical situations in /14

18. The ostiallesions: • Lesions of the left main trunk (n = ) • Ostiallesion of the right coronary (n = ) • Ostialstenosis of the LAD • Computed tomography coronary helped give a useful answer to the diagnostic management and / or therapeutic clinical situations in /14

19. 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. : Ostialstenosis of the left coronary artery, difficult to quantify

20. Computed tomography of the coronary arteries showed: • the presence of a hypodenseostial 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.

21. 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

22. 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 ostialplaque responsible for a sub-occlusive stenosis

23. 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 septaldefect (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 : • confirmed coarctation of the aorta. • studied the collateral circulation. • studied the coronary system which was free of lesions.

24. CT angiography: sagittal reconstruction : isthmic coarctation of the aorta

25. 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%

26. 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.

27. 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.

28. Similarly, CT imaging can be useful in patients with congenital heart disease or other structural cardiac disease. • Exploration concomitant lungparenchyma; according to Haller, 5% of coronary CT examinations are an opportunity to discover an extracardiac disease (lung cancer, pulmonary embolism, benign mass, pneumonia)

29. 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, • patients with advanced CAD and pronounced coronary calcifications, • 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. • Coronary CT angiography is not routinely recommendable in these situations.

30. 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. • Obesity is a factor of degradation of the quality of the examination due to the attenuation of X-ray • 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 • The usual risks of the injection of iodinated contrast agents (allergic risk, renal failure) • The X-ray dose delivered remains significant. • A coronary MDCT strips is currently two times more radiant than coronary angiography although the values recorded are well below accepted standards.

31. 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 three-dimensional 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%.

32. =>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. • 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.

33. MDCT ON COMPLEX CORONARY-PULMONARY ARTERY FISTULA • Coronary-pulmonary artery fistula is usually detected in 0.1% to 0.2% of coronary angiograms . • 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.

34. The 3D reconstruction with viewing at an unlimited angle allows: • to demonstrate a lesion such as a fistula at its best projection • without subjecting the patient to repeated radiation exposure and an additional contrast load. • makes assessment of the size and exact location of the lesion feasible. • quantitative cardiac function analysis. • This could be helpful for planning future cardiovascular intervention.

35. 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 . • 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. • 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.

36. 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.

37. 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. • Luminographieplanimetry 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.

38. 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.

39. NOT CATHETERIZED CORONARY • The noninvasive nature of CT coronary imaging has allowed a coronary artery exploration when it is technically impossible by coronary angiography.

40. CONCLUSION • Althoughcoronaryangiographyremains the gold standard investigation for the evaluation of suspectedcoronaryarterydisease. Newer, less invasive, modalities have been developedthatmaycomplementthis. CT coronaryangiographyoffershighsensitivity and specificity in the identification of coronarylesions.