LECT2 ANGI PDF

Introduction Definition : Angiography refers to the radiographic examination of vessels after injection of contrast media. Because of the relative densities of the soft tissues of the body, contrast media must be added to visualize the circulatory system. For example, the routine lat...

Introduction Definition : Angiography refers to the radiographic examination of vessels after injection of contrast media. Because of the relative densities of the soft tissues of the body, contrast media must be added to visualize the circulatory system. For example, the routine lateral skull radiograph in Fig. 17-1 demonstrates none of the vessels of the cranial circulatory system, whereas the lateral carotid arteriogram in Fig. 17-2 clearly differentiates between the brain and blood vessels. This is also true for the circulatory system of other body regions, such as the thorax, abdomen, and upper and lower limbs (peripheral). A good understanding of the vascular anatomy, is essential for performing angiography. Divisions or components of the circulatory system : The circulatory system consists of the cardiovascular and lymphatic components. The cardiovascular portion includes the heart, blood, and vessels that transport the blood. the liquid portion of the blood, consists of 92% water and about 7% plasma protein and salts, nutrients, and oxygen The lymphatic component of the circulatory system is composed of a clear, watery fluid called lymph, lymphatic vessels, and lymphatic nodes. The cardiovascular and lymphatic components differ in their function and method of transporting their respective fluids within the vessels. The cardiovascular, or blood circulatory, division may be divided further into the cardio (circulation within the heart) and vascular (blood vessel) components. The vascular or vessel component is divided into pulmonary (heart to lungs and back) and general, or systemic (throughout the body). cardiovascular system : The heart is the major organ of the cardiovascular system; it functions as a pump to maintain circulation of blood throughout the body. The vascular component comprises a network of blood vessels that carry blood from the heart to body tissues and back to the heart again. Functions of the cardiovascular system include the following: 1. Transportation of oxygen, nutrients, hormones, and chemicals necessary for normal body activity 2. Removal of waste products through the kidneys and lungs 3. Maintenance of body temperature and water and electrolyte balance. These functions are performed by the following blood components: red blood cells, white blood cells, and platelets suspended in plasma. Blood Components Red blood cells, or erythrocytes, are produced in the red marrow of certain bones and transport oxygen by the protein hemoglobin to body tissues. White blood cells, or leukocytes, are formed in bone marrow and lymph tissue and defend the body against infection and disease. platelets, also originating from bone marrow, repair tears in blood vessel walls and promote blood clotting. plasma  Pulmonary Circulation The elements of the blood vessel circuit (veins, venules, capillaries, arterioles, and arteries) that supply blood to the lungs and back make up the pulmonary circulation component of the cardiovascular system. As previously noted, arteries generally carry oxygenated blood away from the heart to the capillaries. Exceptions are the pulmonary arteries, which carry deoxygenated blood to the lungs that has been returned to the heart through the superior and inferior venae cavae. The superior and inferior venae cavae (singular, vena cava) empty the returning deoxygenated blood into the right atrium of the heart The heart pumps this deoxygenated blood from the right ventricle through the pulmonary arteries to the lungs, where oxygen and carbon dioxide (CO2) are exchanged through the small air sacs or alveoli of the lungs. The oxygenated blood returns through the pulmonary veins to the left atrium of the heart (Fig. 17-4) General Systemic circulation heart The heart is a muscular organ that pumps blood throughout the body. Anatomically, the heart lies within the mediastinum and rests on the diaphragm (Fig. 17-5).  Cardiac tissue differs from other muscle tissues of the body in its construction and is termed myocardium. The left side of the heart is responsible for the extensive systemic circulation; the left muscle wall is about three times as thick as the right side. The heart is divided into four chambers: the right and left atria and the right and left ventricles. Each chamber functions to receive or pump blood. The blood circulation is a closed system by which unoxygenated blood enters the right atrium from all parts of the body, is reoxygenated in the lungs, and is returned to the body by the left ventricle. Blood returning to the heart enters the right atrium through the superior and inferior venae cavae (Fig. 17-6). Blood in the superior vena cava originates from the head, chest, and upper limbs. The inferior vena cava (IVC) delivers blood into the right atrium from the abdomen and lower limbs i. From the right atrium, blood is pumped through the tricuspid (right atrioventricular) valve to the right ventricle. ii. The right ventricle contracts, moving the blood through the pulmonary (pulmonary semilunar) valve to the pulmonary arteries and on to the lungs. While in the lungs, the blood is oxygenated and then is returned to the left atrium of the heart by the pulmonary veins. iii. As the left atrium contracts, blood is transported through the mitral (left atrioventricular or bicuspid) valve to the left ventricle. iv. When the left ventricle contracts, the oxygenated blood exits the chamber by the aortic (aortic semilunar) valve, flows through the aorta, and is delivered to various body tissues. coronary arteries : The coronary arteries are the vessels that deliver blood to the heart muscle. The two coronary arteries are called the right and the left. Both coronary arteries originate from the aortic bulb (root). i. The right coronary artery arises from the right (anterior) sinuses of the aortic bulb, and the left coronary artery originates from the left (posterior) aortic bulb sinus. ii. The right coronary artery supplies much of the right atrium and the right ventricle of the heart. iii. The left coronary artery supplies blood to both ventricles and the left atrium of the heart. iv. Many interconnections or anastomoses exist between the left and right coronary arteries. Blood returns to the right atrium of the heart via the coronary veins. coronary veins The coronary sinus system returns blood to the right atrium for recirculation. The coronary sinus is a large vein on the posterior side of the heart between the atria and ventricles. The coronary sinus has three major branches: the great, middle, and small cardiac veins. The great cardiac vein receives blood from both ventricles and the left atrium. The middle cardiac vein drains blood from the right ventricle, right atrium, and part of the left ventricle. The small cardiac vein returns blood from the right ventricle. The coronary sinus drains most of the blood from the heart. Some small veins drain directly into both atria. Cerebral Arteries Blood supply to brain: The brain is supplied with blood by major arteries of the systemic circulation. The four major arteries that supply the brain are as follows (Fig. 17-9): 1. Right common carotid artery 2. Left common carotid artery 3. Right vertebral artery 4. Left vertebral artery Major branches of the two common carotid arteries supply the anterior circulation of the brain, and the two vertebral arteries supply the posterior circulation. Radiographic examination of the neck vessels and the entire brain circulation is referred to as a four vessel angiogram because these four vessels are collectively and selectively injected with contrast media. Another common series is the three-vessel angiogram, in which the two carotids and only one vertebral artery are studied. Branches of aortic arch : The aorta is the major artery leaving the left ventricle of the heart. Three major branches arise from the arch of the aorta as follows (Fig. 17-10): 1. Brachiocephalic artery 2. Left common carotid artery 3. Left subclavian artery The brachiocephalic trunk is a short vessel that bifurcates into the right common carotid artery and the right subclavian artery. This bifurcation occurs directly posterior to the right sternoclavicular joint. The right and left vertebral arteries are branches of the subclavian arteries on each side as described earlier (see Fig. 17-9). Because the left common carotid artery rises directly from the arch of the aorta, it is slightly longer than the right common carotid artery.  In the cervical region, the two common carotid arteries resemble one another. Each common carotid artery passes cephalad from its origin along either side of the trachea and larynx to the level of the upper border of the thyroid cartilage. Each common carotid artery divides here into external and internal carotid arteries. The site of bifurcation for each common carotid artery is at the approximate level of the fourth cervical vertebra.  Neck and head arteries: The major arteries supplying the head, as seen from the right side of the neck, are shown in Fig. 17-11 (only right-side vessels are identified on this drawing). The brachiocephalic trunk artery bifurcates into the right common carotid artery and the right subclavian artery. The right common carotid artery ascends to the level of the fourth cervical vertebra to branch into the external carotid artery and internal carotid artery, also described earlier. Each external carotid artery primarily supplies the anterior neck, the face, and the greater part of the scalp and meninges (brain coverings). Each internal carotid artery supplies the cerebral hemispheres, the pituitary gland, the orbital structures, the external nose, and the anterior portion of the brain  The right vertebral artery arises from the right subclavian artery to pass through the transverse foramina of C6 through C1. Each vertebral artery passes posteriorly along the superior border of C1 before angling upward through the foramen magnum to enter the cranium. A common carotid arteriogram is shown on the right visualizing the right internal carotid artery (A), right external carotid artery (B), right common carotid artery (c). External carotid artery branches the four major branches of the external carotid artery include the following: 1. Facial artery 2. Maxillary artery 3. Superficial temporal artery 4. Occipital artery these arteries do not play a significant role in angiography and are not shown on drawings. internal carotid artery Each internal carotid artery ascends to enter the carotid canal in the petrous portion of the temporal bone. The S-shaped portion of each internal carotid artery is termed the carotid siphon and is studied carefully by the radiologist. anterior cerebral artery the two end branches of each internal carotid artery are the anterior cerebral (Fig. 17-12) and the middle cerebral arteries (Fig. 17-13).  Each anterior cerebral artery and branches supply much of the forebrain near the midline. The anterior cerebral arteries curve around the corpus callosum, giving off several branches to the midportions of the cerebral hemisphere. Each anterior cerebral artery connects to the opposite one and to the posterior brain circulation. Middle cerebral artery the middle cerebral artery is the largest branch of each internal carotid artery. This artery supplies the lateral aspects of the anterior cerebral circulation (Fig. 17-13). As the middle cerebral artery courses toward the periphery of the brain, branches extend upward along the lateral portion of the insula or central lobe of the brain.  Vertebro basilar arteries the two vertebral arteries enter the cranium through the foramen magnum and unite to form the single basilar artery. The vertebral arteries and the basilar artery and their branches form the vertebrobasilar system. these arteries are shown along the base of the skull. Several arteries arise from each vertebral artery before their point of convergence to form the basilar artery. These branches supply the spinal cord and the hindbrain. The basilar artery rests on the clivus, a portion of the sphenoid bone, arterial circle (circle of willis) The blood to the brain is supplied by the internal carotid and vertebral arteries. The posterior brain circulation communicates with the anterior circulation along the base of the brain in the arterial circle or circle of Willis (Fig. 17-16). The five arteries or branches that make up the arterial circle are (1) The anterior communicating artery, (2) The anterior cerebral arteries, (3) Branches of the internal carotid arteries, (4) The posterior communicating artery, (5) The posterior cerebral arteries The posterior cerebral arteries are two of the larger branches. Certain aneurysms may occur in these vessels that make up the arterial circle, and they need to be well demonstrated on cerebral angiographic studies. 1. The important “master” gland, the hypophysis (pituitary gland), and its surrounding bony structure, the sella turcica, are located within the arterial circle. See Fig. 17-15 for the location of the basilar artery resting on the clivus and the relationship of these structures to the dorsum sellae. 2. vertebrobasilar arteriogram A standard vertebrobasilar arteriogram appears similar to the simplified drawing in Fig. 17-17. The vertebral arteries, basilar artery, and posterior cerebral arteries can be seen. Several branches to the cerebellum have not been labeled on this drawing. cerebral veins great veins of neck The three pairs of major veins that drain the head, face, and neck region (shown in Fig. 17-18) include the following: 1. Right and left internal jugular veins 2. Right and left external jugular veins 3. Right and left vertebral veins Each internal jugular vein drains the meninges and brain The right and left brachiocephalic veins join to form the superior vena cava, which returns blood to the right atrium of the heart. The two external jugular veins are more superficial trunks that drain the scalp and much of the face and neck. Thoracic Circulatory System thoracic arteries the aorta and pulmonary arteries are the major arteries located within the chest. the pulmonary arteries supply the lungs with deoxygenated blood (as shown earlier in Fig. 17-4). The aorta extends from the heart to about the fourth lumbar vertebra and is divided into thoracic and abdominal sections. The thoracic section is subdivided into the following four segments (Fig. 17-21): Aortic bulb (root) Ascending aorta Aortic arch Descending aorta The bulb, or root portion, is at the proximal end of the aorta and is the area from which the coronary arteries originate. Extending from the bulb is the ascending portion of the aorta, which terminates at approximately the second sterno- costal joint and becomes the arch. The arch is unique from the other segments of the thoracic aorta because three arterial branches arise from it: i. the brachiocephalic artery ii. left common carotid artery iii. left subclavian artery. (This is also shown in Fig. 17-10.) Many variations of the aortic arch exist. Three more common variations sometimes seen in angiography include the following (Fig. 17-22): A. left circumflex aorta (normal arch with the descending aorta downward and arched to the left) B. Inverse aorta (arch is arched to the right) C. pseudocoarctation (arched descending aorta) At its distal end, the arch becomes the descending aorta (see Fig. 17-21). The descending aorta extends from the isthmus to the level of the twelfth dorsal vertebra. These arteries transport blood to the organs for which they are named. Thoracic veins The major veins within the chest are The superior vena cava, azygos, and pulmonary arteries. The superior vena cava returns the blood transported from the thorax to the right atrium. The azygos vein is the major tributary that returns blood from the posterior thoracic wall to the superior vena cava (Fig. 17-23). The azygos vein enters the superior vena cava posteriorly. Blood from the chest enters the azygos vein from the intercostal, bronchial, esophageal, and phrenic veins. A section of the vena cava has been removed on this drawing to visualize the azygos and intercostal veins better. Blood from the right ventricle of the heart is carried to lungs by pulmonary arteries. The superior and inferior pulmonary veins return oxygenated blood from the lungs to the left atrium, as previously shown. The IVc returns blood from the abdomen and lower limbs to the right atrium (see Figs. 17-4 and 17-6). The abdominal aorta is the continuation of the thoracicabdominal circulatory system abdominal arteries aorta. The abdominal aorta is anterior to the vertebrae and extends from the diaphragm to approximately L4, where it bifurcates into the right and left common iliac arteries. Five major branches of the abdominal aorta exist that are of greatest interest in angiography. Any one of these branches may be selectively catheterized for study of a specific organ. These are shown in Fig. 17-24 as follows: 1. celiac artery 2. Superior mesenteric artery 3. Left renal artery 4. Right renal artery 5. Inferior mesenteric artery The trunk of the celiac artery arises from the anterior aspect of the aorta just below the diaphragm and about 1.5 cm above the origin of the superior mesenteric artery.  Organs supplied with blood by the three large branches of the celiac trunk are the liver, spleen, and stomach. The superior mesenteric artery supplies blood to the pancreas, most of the small intestine, and portions of the right side of the large intestine (cecum, ascending colon, and about one half of the transverse colon). It originates from the anterior surface of the aorta at the level of the first lumbar vertebra about 1.5 cm below the celiac artery. The inferior mesenteric artery originates from the aorta at about the third lumbar vertebra (3 or 4 cm above the level of the bifurcation of the common iliac arteries). Blood is supplied to portions of the large intestine (left half of transverse colon, descending colon, sigmoid colon, and most of the rectum) by the inferior mesenteric artery. The right and left renal arteries supplying blood to the kidneys originate on each side of the aorta just below the superior mesenteric artery at the level of the disk between the first and second lumbar vertebrae. The distal portion of the abdominal aorta bifurcates at the level of the fourth lumbar vertebra into the right and left common iliac arteries. 1. Each common iliac artery divides into the internal and external iliac arteries. The internal iliac arteries supply the pelvic organs (urinary bladder, rectum, reproductive organs, and pelvic muscles) with blood. The lower limbs receive blood from the external iliac arteries. The external iliac artery is significant in angiography and is used to study each lower limb. Abdominal veins blood is returned from structures below the diaphragm (the trunk and lower limbs) to the right atrium of the heart by the IVc. Several radiographically important tributaries to the IVC exist. These veins include 1. The right and left common iliacs, 2. Internal iliacs, external iliacs, renal veins (Fig. 17-25), and 3. Hepatic portal system (Fig. 17-26). The iliac veins drain the pelvic area and lower limbs, and the renal veins return blood from the kidneys. The superior and inferior mesenteric veins return blood from the small and large intestine through the hepatic portal vein and the hepatic veins and into the IVc. This is best shown in Fig. 17-26 on the next page.  Hepatic portal system (hepatoportal system) the hepatic portal system includes all veins that drain blood from the abdominal digestive tract and from the spleen, colon, and small intestine. From these organs, this blood is conveyed to the liver through the hepatic portal vein. While in the liver, this blood is “filtered” and is returned to the IVC by the hepatic veins. Several major tributaries to the hepatic veins exist (Fig. 17-26). The splenic vein is a large vein with its own tributaries, which return blood from the spleen. The inferior mesenteric vein, which returns blood from the rectum and from parts of the large intestine, usually opens into the splenic vein, but in about 10% of cases, it ends at the angle of union of the splenic and superior mesenteric veins. The superior mesenteric vein returns blood from the small intestine and parts of the large intestine. It unites with the splenic vein to form the portal vein. Peripheral Circulatory System upper limb arteries : The arterial circulation of the upper limb is generally considered to begin at the subclavian artery. The origin of the subclavian artery differs from the right side to the left side. On the right side, the subclavian arises from the brachiocephalic artery, whereas the left subclavian originates directly from the aortic arch. The subclavian continues to become the axillary artery, which gives rise to the brachial artery. The brachial artery bifurcates into the ulnar and radial arteries at approximately the level of the neck of the radius. The radial and ulnar arteries continue to branch until they join together to form two palmar arches (deep and superficial). Branches of these arches supply the hand and fingers with blood.  Upper limb veins The venous system of the upper limb may be divided into two sets: deep and superficial veins (Fig. 17-28). They communicate with each other at frequent sites and form two parallel drainage channels from any single region. The cephalic and basilic veins are the primary tributaries of the superficial venous system. Both veins originate in the arch of the hand. Anterior to the elbow joint is the median cubital vein (the vein most commonly used to draw blood), which connects the superficial drainage systems of the forearm. The upper basilic vein empties into the large axillary vein, which flows into the subclavian and eventually the superior vena cava. The lower basilic vein joins the median cubital vein, continuing to the upper basilic vein. The deep veins include the two brachial veins that drain the radial vein, ulnar vein, and palmar arches. The deep brachial veins join the superficial basilic vein to form the axillary vein, which empties into the subclavian and finally into the superior vena cava. Lower limb arteries the arterial circulation of the lower limb begins at the external iliac artery and ends at the arteries of the foot The first artery to enter the lower limb is the common femoral artery. The common femoral artery divides into the femoral and deep femoral arteries  Arteries External iliac becomes……. – Femoral Once passes the inguinal ligament Lower limb Branches into profunda femoris artery or deep femoral artery – Adductors, hamstrings, quadriceps – Branches into Medial/lateral femoral circumflex » Head and neck of femur Femoral becomes…… – Popliteal (continuation of femoral) Branches into: – Geniculars » Knee Splits into: – Anterior Tibial » Anterior leg muscles, further branches to feet – Posterior Tibial » Flexor muscles, plantar arch,  Veins Deep Veins: Mostly share names of arteries – Ultimately empty into Inferior Vena Cava Plantar Tibial Fibular Popliteal Femoral External/internal iliac Common iliac Superficial Veins – Dorsal venous arch (foot) – Great saphenous (empties into femoral) – Small saphenous (empties into popliteal)  External Iliac Artery Inguinal Ligament Common Femoral Artery Profunda Femoris Artery Superficial Femoral Artery Profunda Femoris Lateral Circumflex Perforating arteries  Adductor Brevis Adductor Magnus Superficial Femoral Vastus Medialis Sartorius Lateral Superior Genicular Artery Popliteal Artery Popliteal Artery Inferior Lateral Genicular Artery Anterior Tibial Artery Tibioperoneal Trunk Peroneal Artery Posterior Tibial Artery  Peroneal Artery Calcaneal Branch of Peroneal artery  Lymphatic system lymph drainage The lymphatic system drains interstitial fluid (fluid in the spaces between the cells) and returns it to the venous system. The fluid from the left side of the body, lower limbs, pelvis, and abdomen enters the venous system by the thoracic duct (largest lymph vessel in the body), which drains into the left subclavian vein near its junction with the left jugular vein. The upper right side of the body, upper limb, and head and neck region drain lymph fluid into the venous system at the junction of the right jugular and right subclavian veins by the right lymph duct (Figs. 17-31 and 17-32). Functions of the lymphatic portion of the circulatory system are as follows: 1. Fights disease by producing lymphocytes and macrophages 2. Returns proteins and other substances to the blood 3. Filters the lymph in the lymph nodes 4. Transfers fats from the intestine to the thoracic duct and to the blood The lymphatic system has no heart pressure to pump lymph fluid to its destination. Rather, fluid is transported by diffusion, peristalsis, respiratory movements, cardiac activities, massage, and muscular activity. The transportation of lymphatic fluid occurs in one direction only—away from the tissues. The sequence of fluid movement is from lymphatic capillaries to the various lymph vessels, where fluid enters the lymph nodes and is returned to the venous system by efferent lymphatic vessels. Lymph nodes tend to form in clusters, although they may appear singularly. Thousands of nodes exist throughout the body, some of which are identified in Fig. 17-32. The major collections of nodes that are seen radiographically are in the thoracic, abdominal, pelvic, and inguinal regions. Lymphography (lim-fog′-rah-fe) is the general term used to describe radiographic examination of the lymphatic vessels and nodes after injection of contrast media. Although the lymphatic system can be demonstrated radiographically through the injection of iodinated contrast media, this examination is rarely performed today. CT (computed tomography), with its superior contrast resolution, provides excellent visualization of lymph nodes.