Imaging of the Heart and Great Vessels

1. Imaging of the Heart and Great Vessels

3. Imaging Tests for Heart, Great Vessels, and Pericardium Conventional radiographs   Echocardiography   Radionuclide imaging   Computed tomography Magnetic resonance imaging Angiography  

4. Conventional radiographs --PA , Lateral, AP view Echocardiography --Transthoracic , Transesophageal Radionuclide imaging --Positron emission tomography Computed tomography Magnetic resonance imaging Angiography --Coronary arteriography , Aortography , Pulmonary arteriography

5. Conventional Radiographs Most common are PA and left lateral (LAT) projections. The examination is ideally performed with the patient at maximal inspiration. A good rule of thumb for estimating adequate inspiration is to be able to count 9 to 10 posterior ribs or 5 to 6 anterior ribs from the lung apices to the hemidiaphragms through the aerated lungs. When a chest radiograph is taken in the expiratory phase of respiration, the patient may appear to have cardiomegaly, vascular congestion, and even pulmonary edema.

6. PA view of normal chest. RA = right atrium, RDPA = right descending pulmonary artery, RPA = right main pulmonary artery, SVC = superior vena cava, AA = aortic arch, DA = proximal descending thoracic aorta, LPA= left pulmonary artery, RV = right ventricle.

7. Lateral view of normal chest. RV = right ventricle, RSS = retrosternal clear space, AA = ascending aorta, LPA = left pulmonary artery, RPA = right pulmonary artery en face, IVC = inferior vena cava, LA = left atrium, and LV = left ventricle.

8. Expiratory phase of a respiration chest radio-graph shows low lung volumes, crowded bronchovascular markings, and apparent increased heart size. If the degree of inspiration is not noted, the interpreter may incorrectly diagnose disease.

9. AP view Indications Severely ill, debilitated patients Patients in the intensive care unit (ICU) who are undergoing mechanical ventilation. Disadvantages heart may appear enlarged. Prominent bronchovascular markings.

10. Supine AP chest radiograph showing apparent increase in heart size and prominent bronchovascular markings (arrows).

11. The chest radiograph should always be the initial screening examination in the evaluation of the cardiovascular system. Chest x-ray must be correlated with the clinical symptoms and physical examination.

12. Normal cardiac silhouette size determined by the cardiothoracic ratio (CT ratio), a measurement obtained from the PA view. This ratio is calculated by dividing the transverse cardiac diameter (measured from each side) by the widest diameter of the chest (measured from the inner aspect of the right and left lung fields near the hemidiaphragms). The average normal value for this ratio in adults is 0.50, although up to 60% may be normal. Any measurement greater than 50% is usually considered abnormal in an upright inspiratory-phase PA film. This CT ratio cannot be reliably used for the AP projection of the chest since the heart is magnified .

13. Upright PA chest radiograph in a patient with leukemia shows normal cardio- (C) thoracic (T) ratio and how it is measured. Incidentally noted is the tip of an internal jugular triple-lumen catheter in the superior vena cava (arrow).

14. In PA view Heart, great vessels, the spine, ribs, adjacent soft tissues, and upper abdominal contents should all be scrutinized. lateral view -- Just behind the sternum there is normally a radiolucent area called the retrosternal clear space (RSS). This region represents lung interposed between the chest wall and the anterior margin of the ascending aorta. Any density present within the RSS may be due to anterior mediastinal mass or postsurgical changes.

15. Echocardiography Echocardiography uses high-frequency ultrasound to evaluate the heart and great vessels. Transthoracic Transesophageal

16. Major Indications for Echocardiography Ventricular function Congenital heart disease Valvular heart disease Cardiomyopathy Pericardial effusion Suspected cardiac masses Aortic disease (proximally)

17. recently, echocardiography has been combined with stress-testing modalities to assess inducible myocardial ischemia using wall motion analysis of left ventricular function.

18. Normal transthoracic echocardiogram from a healthy subject. Views are taken from the left midparasternal region through an intercostal space. The structure closest to the apex of the screen is the chest wall. The mitral valve, separating the left atrium and left ventricle, is partially open in this image from early systole.A = aorta, LA = left atrium, LV = left ventricle, and RV=right ventricle.

19. Transthoracic echocardiogram, left parasternal view, from a patient with a moderate-sized posterior pericardial effusion (PE), visualized as a sonolucent space between the epicardium and pericardium. RV = right ventricle, LV = left ventricle, and LA = left atrium.

20. Transthoracic spectral Doppler tracing taken from an intercostal space over the cardiac apex. The Doppler sample is placed in line with the left ventricular outflow and aorta (shown in miniature echocardiogram image at top right). Velocity of flow is denoted along the left edge of the tracing in centimeters per second. The Doppler tracing shows that aortic peak velocity (a) is normal (140 cm/sec). This technique can reliably assess the presence of and quantitate the severity of aortic stenosis.

21. Radionuclide Imaging (Nuclear Medicine) primarily used for the patient with suspected myocardial ischemia or infarction requires an intravenous injection of radioactively labeled compounds (Thallium) that have an affinity for the myocardium. These tests are most commonly used in the evaluation of patients with angina and atypical chest pain. Positron emission tomography (PET) is useful in assessing myocardial viability in patients with known coronary artery disease who represent a therapeutic dilemma after they are evaluated with other imaging modalities .

22. Computed Tomography The major indications for CT are to characterize or confirm a suspected mediastinal or pulmonary mass seen on PA and lateral chest radiographs to evaluate patients suspected of having an aortic abnormality, or to assess for pulmonary embolism.

23. CT Contrast abnormalities of the thoracic aorta such as dissection for evaluation of the pulmonary arteries for pulmonary embolism.

24. Axial CT images A, B, C in the superior-to-inferior direction show the superior vena cava (s), ascending aorta (a), descending aorta (d), right ventricle (rv), right atrium (ra), left atrium (la), and left ventricle (lv).

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27. Magnetic Resonance Imaging The major indications for MR imaging congenital heart disease suspected intracardiac masses valvular dysfunction aortic abnormality (eg., aortic dissection).

28. Normal coronal MR image shows the right atrium (ra), ascending aorta (aa), pulmonary artery (pa), and left ventricle (lv). Note how well the thickness of the myocardium in the left ventricle is depicted with MR imaging (arrows).

29. Normal axial MR image shows the right ventricle (rv), left ventricle (lv), and descending aorta (a). MR imaging is an excellent way to noninvasively visualize the cardiac and great vessel structures.

30. Angiography Coronary angiography is one of the most commonly performed imaging tests for evaluating the heart and great vessels. Types coronary arteriography (coronary arteries), aortography (aorta), and pulmonary angiography (pulmonary arteries and lungs).

31. coronary arteriography (coronary arteries), The purpose of coronary arteriography is to define the degree of coronary artery obstruction, usually caused by atherosclerosis. Coronary angiography can also be performed in the acute setting of suspected coronary occlusion, and a balloon catheter or thrombolytic agent can be placed through the catheter in an attempt to relieve the coronary artery obstruction.

32. Coronary arteriogram. Images were obtained from the left lateral projection with contrast injection into the left main coronary artery. The left anterior descending (L), left circumflex (CX), and first obtuse marginal (O) branches are visualized. Severe stenosis is seen in the mid portion of the left anterior descending artery (arrow) in this patient, who had unstable angina pectoris.

33. Coronary arteriogram, same projection and patient as in A, obtained 1 day later. The stenosis in the left anterior descending coronary artery (arrow) has been reduced after percutaneous balloon angioplasty.

34. Aortography Aortography is used primarily to evaluate suspected aortic disease. Although aortography remains the standard for traumatic injury, CT has largely replaced aortography.

35. pulmonary angiography pulmonary angiography is to treat massive pulmonary embolism with thrombolytic therapy or treat arteriovenous malformations. Pulmonary artery catheterization is also used to measure the pulmonary artery pressures in patients suspected of having pulmonary arterial hypertension.

36. Normal aortogram in patient suspected of having traumatic aortic injury. Note the normal origins of "take-offs" of the right brachiocephalic artery (a), left common carotid artery (b), and left subclavian artery (c) from the arch of the aorta.

37. Aortogram in a patient with acute traumatic aortic injury. The site of injury is the focal outpouching at the insertion of the ductus arteriosus (arrow).

38. Technique Selection After a thorough history and physical exam, the initial screening study should always be a chest radiograph. Ideally the PA and lateral views should be obtained with maximum inspiration. This study gives important information about the cardiac contour and the status of the lungs.

39. Echocardiography is a good screening test to assess cardiac and great vessel valvular motion and structural abnormalities, cardiac chamber morphology, and flow. Angiography delineates the structural status of the coronary arteries. It is also used to guide interventions such as stent placement in the coronary arteries. Because of its inherent risks, coronary angiography is usually reserved for patients with signs and symptoms of myocardial ischemia or infarction either on the basis of history or results of electrocardiography, echocardiography, or radionuclide myocardial imaging.

40. In patients with suspected pulmonary emboli, helical CT is the most appropriate test in the setting of an abnormal chest x-ray . The ventilation-perfusion (V/Q) scan can be performed if the chest radio-graph is normal. Both of these tests can confirm the clinically suspected diagnosis of pulmonary embolic disease.

41. Axial A and coronal B CT images show filling defect (arrowheads) in right upper lobe artery from pulmonary embolism.

43. Echocardiography, MR imaging may be selected for patients with suspected congenital heart disease. MR imaging is the preferred imaging test in the pediatric population.

44. Suspected aortic dissection (either atherosclerotic or traumatic in origin) can be evaluated by helical CT, TEE, aortography, or MR imaging. Helical CT is the imaging modality of choice for acute dissection due to its accuracy and availability .

45. Axial A and coronal B CT images show intimal flap of type A dissection (arrows).

47. Radiology of the Chest Most common are PA and left lateral (LAT) projections. The examination is ideally performed with the patient at maximal inspiration. lateral decubitus films taken with the patient lying on one side.

48. AP view Indications Severely ill, debilitated patients Patients in the intensive care unit (ICU) who are undergoing mechanical ventilation. Disadvantages heart may appear enlarged. Prominent bronchovascular markings.

50. Normal radiographic anatomy. Lateral chest radiographs.

52. Computed Tomography of the Chest For CT chest, iv contrast material is frequently administered for opacification of arteries and veins and to facilitate the recognition of abnormal masses or lymph nodes. Anatomic features of the chest that are readily identifiable on CT scans

53. Indications for CT of the Chest Clarification of abnormal chest radiograph findings Staging of lung cancer and esophageal cancer Evaluation of a solitary pulmonary nodule Suspected mediastinal or hilar mass Suspected pulmonary embolism Evaluation of chronic pulmonary disease (thin-section or high-resolution CT) Suspected pleural tumor or empyema Determining source of hemoptysis (e.g., bronchiectasis) CT-guided percutaneous needle aspiration of lung and mediastinal masses CT-guided pleural drainage

54. Ultrasonography of the Chest typically performed to evaluate fluid collections within the pleural space. Ultrasound may be used to guide thoracentesis, especially when the fluid collection is small or loculated.

55. Nuclear Medicine--Indications ventilation-perfusion (V/Q) scanning -- imaging study of choice for a patient with suspected pulmonary thromboembolism. scanning for sites of inflammation-- sarcoidosis, radiation pneumonitis, and idiopathic pulmonary fibrosis, as well as in pneumonia and lung abscess. Infrequently obtained for pulmonary disease, because CT almost always localizes abnormalities precisely, and fiber-optic bronchoscopy is very effective for diagnosis of pulmonary abnormalities. scanning with tumor-seeking radiopharmaceuticals for tumor staging.

56. Indications for Nuclear Medicine Imaging of the Chest Suspected pulmonary thromboembolism (V/Q scan) Staging of inflammatory disease (e.g., sarcoidosis) (gallium scan) Detecting recurrence of lymphoma (gallium scan) Detecting infection (indium-111–labeled WBC scan) Differentiation of benign and malignant pulmonary nodule (PET) Detecting recurrent or metastatic tumor (PET)

57. Indications for Mr Imaging of the Chest Evaluation of a mediastinal mass Suspected Pancoast's (superior sulcus) tumor Superior vena cava syndrome Staging of lung cancer, when CT suggests invasion of the heart, great vessel, chest wall, diaphragm Suspected aortic dissection Congenital and acquired heart disease

58. Radiology of the Breast: Introduction screening mammography—mammography when used in asymptomatic patients. When imaging is targeted to patients with signs or symptoms of breast cancer, it is referred to as diagnostic breast imaging. The primary purpose of breast imaging is to detect breast carcinoma.

59. breast ultrasonography -- most often used adjunctive technique. It is effective in distinguishing cystic lesions from solid masses. Magnetic resonance (MR) imaging of the breast can be used in selected patients. Image-guided needle biopsy of the breast is used for diagnosis of indeterminate lesions of the breast. Contrast injection studies (ductography) are occasionally used under special circumstances with specific indications.

60. Film-Screen and Digital Radiography (Radiomammography) Limitations Sensitivity is limited by three factors: the nature of breast parenchyma --very dense breast tissue may obscure masses the difficulty in positioning the organ for imaging -- requires both a cooperative patient and a skilled technologist. the nature of breast carcinoma– well-defined, rounded masses or tiny, but bright, calcifications, are easily detected. poorly defined and irregular, mimicking normal breast tissue are hard to detect.

61. Screening Mammography The standard mammogram (along with appropriate history-taking) makes up the entire screening mammogram. The indication for this examination is the search for occult carcinoma in an asymptomatic patient. Physical examination by the patient's physician, known as the clinical breast examination (CBE), and breast self-examination (BSE) are the other two indispensable elements in complete breast screening.

62. American Cancer Society Recommendations for Breast Cancer Detection in Asymptomatic Women

63. Diagnostic Mammography Indications for diagnostic mammography are a palpable mass or other symptom or sign (e.g., skin dimpling, nipple retraction, or nipple discharge that is clear or bloody) a radiographic abnormality on a screening mammogram. patients with a personal history of breast cancer.

64. Ultrasonography The indications for ultrasonography are a mammographically detected mass, the nature of which is indeterminate; a palpable mass that is not seen on mammography; a palpable mass in a patient below the age recommended for routine mammography; As a guidance for intervention. Ultrasonography is a highly reliable technique for differentiating cystic from solid masses. A limitation of ultrasonography is that it is very operator dependent.

65. Magnetic Resonance Imaging MRI is used to evaluate the integrity of breast implants. Other applications include staging of tumor in the breast, search for a primary tumor in patients with cancerous axillary lymph nodes, evaluation of tumor response to neoadjuvant chemotherapy, and differentiation of dense breast tissue or fibrosis from tumor. MR imaging of the breast is not widely used routinely.

66. Ductography Ductography, or galactography, uses mammographic imaging with contrast injection into the breast ducts. Indication is a profuse, spontaneous, non- milky nipple discharge from a single duct orifice.

67. Image-Guided Needle Aspiration and Biopsy Guidance for needle biopsy can be accomplished with mammography, ultrasound, and MR. Ultrasound is most commonly used. Indications aspiration of cystic lesions to confirm diagnosis, to relieve pain, or both. Nonpalpable cysts require guidance with either ultrasound or mammography. The cystic fluid is not routinely sent for cytology unless it is bloody. 2. solid lesions.-needle biopsy

68. Needle biopsy is used in solid lesions to confirm benignity of a lesion carrying a low suspicion of malignancy mammographically, to confirm malignancy in a highly suspicious lesion prior to initiating further surgical planning and treatment, evaluate any other relevant mammographic lesion for which either follow-up imaging or surgical excision is a less desirable option for further evaluation.

69. Technique Selection Asymptomatic patients. these patients will benefit from routine screening mammography performed according to published national guidelines. Symptomatic patients. These are women who have any of the following signs or symptoms: a new or enlarging breast lump, skin changes (primarily dimpling), nipple retraction, eczematoid nipple changes, bloody or serous nipple discharge, and focal pain or tenderness. Diagnostic mammography is indicated in these patients.