Lange Review Ultrasonography Examination, 4th Edition

Answers and Explanations

At the end of each explained answer, there is a number combination in parentheses. The first number identifies the reference source; the second number or set of numbers indicates the page or pages on which the relevant information can be found.

1. (B) A fetal echocardiogram should always begin by determining fetal position. Once fetal position is determined, situs (position of the heart and stomach) and cardiac structures can be accurately identified. (Study Guide: 469)

2. (B) In the subcostal four-chamber view, all four chambers can be identified along with the interventricular and interatrial septae. Subcostal four-chamber is the best view to evaluate for ASDs and VSDs, because the septae are perpendicular to the transducer. The long-axis views are important in determining appropriate position of the outflow tracts. (Study Guide: 470)

3. (D) When valves are insufficient, complete closure of the valve does not occur. Blood, therefore, flows back and can be detected with pulsed Doppler proximal to the valve. (Study Guide: 474)

4. (A) A four-chamber heart view does not exclude all anomalies. To increase the chance of identifying abnormalities, outflow tracts must be obtained. Long-axis views of the aorta and pulmonary artery should be seen “criss-crossing.” (Study Guide: 467)

5. (C) Dysrhythmias involve both the atria and ventricle. An atrial beat and a ventricular response can be evaluated if the M-mode cursor is placed through both the atria and ventricle. (Study Guide: 469)

6. (A) Blood flows from the right atrium into the left atrium. The foraminal flap opens into the left atrium. (Study Guide: 474)

7. (D) Complete heart block is associated with mothers who have lupus. Diabetic mothers are more likely to have babies with congenital heart disease, VSD’s double-outlet right ventricle, cardiomyopathies, and truncus arteriosus. Cytomegalovirus is associated with dilated cardiomyopathy. (Study Guide: 467)

8. (B) Trisomies 13 and 18 are associated with heart defects almost 100% of the time. Trisomy 21 has a 40–50% defect rate. (Study Guide: 468)

9. (C) Pulsed and color Doppler and M-mode are essential tools for a fetal echocardiogram. Even though power Doppler can have higher sensitivity, it has increased flash artifact and cannot determine direction of flow. (Study Guide: 467)

10. (D) Congenital heart defects occur in 1/100 live births. (Study Guide: 467)

11. (B) Ventricular septal defects are the most common heart defect, occurring in approximately 20–57% of heart defect cases. (Study Guide: 475)

12. (B) In the subcostal four-chamber view, the septa are perpendicular to the transducer; therefore, it is more likely a defect will be identified. In the apical four-chamber view, the chambers are identified, but the septae is parallel to the transducer. In this position, a pseudodefect is often seen. (Study Guide: 470)

13. (C) A fetal echocardiogram should be performed between 18 and 22 weeks. Before this time, the heart is too small to visualize accurately. After 22 weeks, artifact from bony structures and decreased fluid volume makes evaluation difficult. (Study Guide: 467)

14. (A) The apex of the heart points toward the left. This is termed levocardia. Dextrocardia is when the apex points toward the right. (Study Guide: 469)

15. (B) The heart sits in the chest at an angle approximately 45°. The angle, however, can vary 20° in either direction. (i.e., 25°–65°). (Study Guide: 469)

16. (A) Levocardia is the normal orientation of the fetal heart. Dextrocardia occurs when the heart is in the right chest and the apex points toward the right. When the heart is situated in the midline and the apex points midline, this is termed mesocardia. Dextroposition is when the heart is in the right chest but the apex points toward the left. (Study Guide: 469)

17. (C) The normal fetal heart occupies one-third of the fetal chest. (Study Guide: 469)

18. (B) The apical four-chamber view is obtained with a transverse view of the chest. The heart (apex) is directed toward or away from the transducer. In other words, the interventricular and interatrial septa run parallel to the beam of the transducer. (Study Guide: 469)

19. (D) An apical four-chamber view of the heart allows visualization of all four chambers, the size of the chambers, and the mitral and tricuspid valves. The ventricular septum is not well visualized because the septum is parallel to the transducer. (Study Guide: 469)

20. (D) Once a subcostal four-chamber view is obtained, the transducer can be rotated toward the fetus’s right shoulder. The first view seen will be a long-axis view of the aorta (left ventricular outflow tract). If rotation continues, the long axis of the pulmonary artery will be visualized (right ventricular outflow tract). A short-axis view of the ventricles will be seen next. The short-axis view of the aorta with the pulmonary artery crossing over completes the rotation. (Study Guide: 470)

21. (B) The great vessels should be documented criss-crossing. If the great vessels run parallel, this could indicate transposition of the great vessels. Truncus arteriosus is when one vessel arises from the ventricle. When both vessels arise from the right ventricle, this is termed double outlet right ventricle. (Study Guide: 471)

22. (C) The moderator band is located in the right ventricle. This can be helpful in determining situs, especially with congenitally corrected transposition of the great arteries. (Study Guide: 480)

23. (D) The subcostal four-chamber view, long-axis view of the aorta, and the short-axis view of the ventricles are all useful in determining pathology of the ventricular septum. The short-axis view of the great vessels does not demonstrate the ventricular septum. It is, however, beneficial in determining correct orientation of the great vessels. (Study Guide: 470)

24. (A) In the fetus, the main pulmonary artery bifurcates into the ductus arteriosus and the right pulmonary artery. (Study Guide: 472)

25. (D) The aortic arch does not have the appearance of a hockey stick. The ductal arch is flat and broader, much like a hockey stick. (Study Guide: 473)

26. (B) The majority of coarctations occur just distal to where the ductus arteriosus inserts into the aorta. Aortic valve insufficiency is obtained proximal to the aortic valve. Aortic stenosis occurs at the level of the aortic valve. Pulmonary valve insufficiency would be identified in the right ventricle, proximal to the pulmonary valve. (Study Guide: 477)

27. (C) The ductal arch has a hockey stick appearance. The pulmonary artery, ductus arteriosus, and the descending aorta comprise the ductal arch. (Study Guide: 473)

28. (C) The most common indication for a fetal echocardiogram is family history. The risk for a reoccurring heart defect is highest when the mother has a defect (10–12%). The percentages are lower with other family members. (Study Guide: 467)

29. (D) Suboptimal heart views on a 12-week ultrasound are not an indication for a fetal echocardiogram. At 12 weeks, the fetal heart is small and structures are difficult to visualize. If the heart is suboptimal on an 18-to 20-week ultrasound, a fetal echocardiogram should be performed. (Study Guide: 467)

30. (C) Peak velocities can only be obtained with pulsed Doppler. Color Doppler, however, can help in determining areas of increased velocity or turbulence. (Study Guide: 474)

31. (D) M-mode is not useful in determining direction of flow. Color or pulsed Doppler can be used to determine direction. (Study Guide: 474)

32. (B) In the fetus, oxygenated blood travels from the umbilical veins through the ductus venosus, bypassing the liver. This blood then enters the inferior vena cava. The blood that enters the liver mixes with the portal system. Once the fetus is born, the ductus venosus closes and becomes the ligamentum venosum of the liver. (Study Guide: 474)

33. (A) The pulmonary veins enter the left atrium. Pulsed Doppler is helpful in determining appropriate direction and location of the pulmonary veins. (Study Guide: 474)

34. (D) The Doppler angle should be as close to zero as possible. With a 90° angle, a Doppler signal cannot be obtained. (Study Guide: 474)

35. (D) The Doppler gate should be small to avoid interference of other structures and vessels. (Study Guide: 474)

36. (A) Blood flows from the placenta to the fetus by way of the umbilical vein. The umbilical arteries return blood back to the placenta. The ductus venosum is a shunt that allows blood to bypass the liver. The ductus arteriosus shunts blood from the pulmonary artery to the descending aorta. (Study Guide: 474)

37. (C) Oxygenated blood flows from the placenta through the umbilical vein. Most of this blood bypasses the liver via the ductus venosum and enters the inferior vena cava (IVC). Deoxygenated blood from the lower extremities travels up the IVC and mixes with the oxygenated blood. This oxygenated and deoxygenated blood then enters the right atrium. (Study Guide: 475)

38. (D) The umbilical vein is not considered a shunt. It carries blood from the placenta to the fetus. The ductus venosus allows blood to bypass the liver. It closes shortly after birth and becomes the ligamentum venosum in the liver. The foramen ovale shunts blood from the right atrium to the left atrium. The ductus arteriosus is a shunt between the pulmonary artery and the descending aorta. It also closes shortly after birth and becomes the ligamentum arteriosum. Closure of the ductus arteriosus causes a pressure change in the heart. After birth the pressure is higher in the left side of the heart, causing the foramen ovale to close. (Study Guide: 475)

39. (D) M-mode is not very useful in identifying a ventricular septal defect in the fetus. It is useful in determining heart rate and rhythm, chamber size, and wall thickness. (Study Guide: 474)

40. (A) An atrioventricular septal defect is an abnormal development of the interatrial septum, interventricular septum, and the atrioventricular valves (tricuspid and mitral valves). (Study Guide: 476)

41. (A) With hypoplastic left heart syndrome (HLHS), there is a decrease in the blood flow coming in or out of the ventricle. The decrease in flow results in underdevelopment of the ventricle. (Study Guide: 476)

42. (D) Because HLHS affects the left heart, the mitral and aortic valves can be abnormal. (Study Guide: 476)

43. (A) With HLHS, the flow through the ascending aorta may be absent or reversed. This is caused by the blood flowing back through the ductus arteriosus into the ascending aorta. (Study Guide: 476)

44. (C) Atrioventricular septal defects are associated with polysplenia approximately 30% of the time. (Study Guide: 476)

45. (C) Approximately 78% of AVSDs are associated with Down syndrome (trisomy 21). (Study Guide: 476)

46. (B) An isolated ventricular septal defect has the best prognosis. With Ebstein anomaly, the displacement of the tricuspid valve can lead to an enlarged right atrium, pulmonary atresia or stenosis, and cardiomegaly. Truncus arteriosus has a poor prognosis when left untreated. When treated, there is still mixing of oxygenated and deoxygenated blood. If a Coarctation of the Aorta is untreated it can be fatal. (Study Guide: 475)

47. (A) Hypoplastic left heart syndrome has the poorest prognosis. If left untreated, it is uniformly fatal. The poor prognosis is because of the small left heart, hypoplastic mitral valve, and ascending aorta. Hypoplastic right heart syndrome, however, has a better prognosis with a survival rate of approximately 25%. A mild aortic stenosis and an isolated atrial septal defect are treatable and have a good prognosis. (Study Guide: 476)

48. (B) With hypoplastic right heart syndrome, the pulmonary artery and valve can be small or atretic. The aorta and pulmonary veins are not affected by hypoplastic right heart syndrome since they are left-sided structures. (Study Guide: 477)

49. (D) When a valve is stenotic, the velocity will be increased distal to the valve. The sample gate can be placed proximal to the valve to determine valvular regurgitation. (Study Guide: 474)

50. (C) With the decrease of size and flow through the right side of the heart, there is decreased flow through the pulmonary artery. (Study Guide: 477)

51. (A) A univentricular heart has two atria and one ventricle. Often, when a univentricular heart is present, there is transposition of the great vessels coming off this one ventricle. (Study Guide: 477)

52. (A) With a univentricular heart, two atrioventricular valves may be seen. One, however, is usually atretic, indicating tricuspid or mitral atresia. This atresia is not related to the univentricular heart but is considered a separate pathology. Pulmonary stenosis, asplenia, and polysplenia are all associated with a univentricular heart. (Study Guide: 477)

53. (C) Coarctation is a narrowing of the aorta. Coarctation is often difficult to diagnosis in utero(Study Guide: 477)

54. (D) Approximately 98% of coarctations occur between the left subclavian artery and the ductus arteriosus. (Study Guide: 477)

55. (B) Coarctation of the Aorta is often difficult to visualize in utero. A narrowing of the aorta or increased velocities in the aorta can help to confirm the diagnosis. A large right ventricle may be a secondary sign of a coarctation. (Study Guide: 477)

56. (A) Coarctation of the Aorta is most commonly seen with Turner syndrome. (Study Guide: 477)

57. (C) Ebstein anomaly is a right-sided heart anomaly. The tricuspid valve is displaced inferiorly. (Study Guide: 478)

58. (A) Maternal use of lithium has been associated with Ebstein anomaly. (Study Guide: 478)

59. (D) The four criteria for tetralogy of Fallot are a ventricular septal defect, overriding aorta, pulmonary stenosis, and right ventricular hypertrophy. (Study Guide: 478)

60. (C) Right ventricular hypertrophy may not be seen in utero because of the presence of fetal shunts. An atrial septal defect is not a defect associated with tetralogy of Fallot. (Study Guide: 478)

61. (D) Ventricular septal defects are present with truncus arteriosus. The single vessel overrides this defect. (Study Guide: 479)

62. (A) With truncus arteriosus, a single vessel arises from the heart. The pulmonary arteries then branch off this single vessel. (Study Guide: 479)

63. (B) Congenitally corrected transposition of the great vessels occurs when ventricles are switched. The aorta arises from the left-sided right ventricle and follows the normal course toward the left side. With truncus arteriosus, a right-sided aortic arch is seen in approximately 15–30% of cases. Tetralogy of Fallot has a right side aortic arch in 25% of cases. With situs inversus of the chest, all anatomy above the diaphragm would be transposed. (Study Guide: 478–480)

64. (B) Truncus arteriosus and tetralogy of Fallot appear similar sonographically. Both pathologies have a single vessel overriding a ventricular septal defect. Truncus arteriosus, however, occurs when the pulmonary arteries arise from this single vessel; where with tetralogy of Fallot, the pulmonary artery arises from the right ventricle. A univentricular heart’s vessels are often transposed. (Study Guide: 478, 479)

65. (C) With complete transposition of the great vessels, the great arteries arise from the heart in a parallel fashion; therefore, a normal short-axis view of the great vessels cannot be obtained. A normal four-chamber heart can be identified. This stresses the point of why outflow tracts should always be obtained. (Study Guide: 479)

66. (A) With complete transposition of the great vessels, the atria, ventricles, and valves are in the appropriate location. The aorta arises from the right ventricle, and the pulmonary artery arises from the left ventricle. This differs from congenitally corrected transposition of the great vessels. With congenitally corrected transposition, the right atrium and left ventricle are connected, and the left atrium and right ventricle are connected. The aorta arises from the left-sided right ventricle, and the pulmonary artery arises from the right-sided left ventricle. Identification of the moderator band in the right ventricle is helpful in the diagnosis of congenitally corrected transposition of the great vessels. (Study Guide: 479)

67. (D) The moderator band will always be located in the right ventricle. In congenitally corrected transposition of the great vessels, the right ventricle is located on the left side of the chest. (Study Guide: 480)

68. (D) With congenitally corrected transposition, the right atrium and left ventricle are connected, and the left atrium and right ventricle are connected. The aorta arises from the left-sided right ventricle, and the pulmonary artery arises from the right-sided left ventricle. Identification of the moderator band in the right ventricle is helpful in the diagnosis of congenitally corrected transposition of the great vessels. With complete transposition of the great vessels, the atria, ventricles and valves are in the appropriate location. The aorta arises from the right ventricle, and the pulmonary artery arises from the left ventricle. (Study Guide: 480)

69. (A) When the long-axis views of the aorta and pulmonary artery are obtained, both great arteries would be visualized arising from the right ventricle. Four-chamber views of the heart will not demonstrate double outlet right ventricle. (Study Guide: 480)

70. (C) Double outlet right ventricle occurs when both great arteries arise from the right ventricle running parallel. (Study Guide: 480)

71. (C) The pulmonary veins normally drain into the left atrium. When total anomalous pulmonary venous connection is present, all four pulmonary veins will drain into the right atrium, or other venous structures. (Study Guide: 480)

72. (D) Of the choices listed, hypoplastic left heart syndrome would be the most likely diagnosed in utero when only a four-chamber heart view is visualized. All of the other pathologies listed can be diagnosed with careful interrogation of the outflow tracts. (Study Guide: 476)

73. (B) Severe levocardia is defined as the heart’s apex pointing toward the left at an angle greater than the normal 45° ± 20°. Severe levocardia is commonly seen with Ebstein anomaly, or other cardiac lesions that cause right-sided enlargement. (Study Guide: 481)

74. (C) Dextrocardia is when the heart is in the right chest, and the apex of the heart is pointed toward the right. Levocardia is the normal position of the heart. Severe levocardia is defined as the heart’s apex pointing toward the left at an angle greater than the normal 45° ± 20°. Dextroposition is when the heart’s apex points toward the left, but the heart is in the right chest. (Study Guide: 481)

75. (A) A diaphragmatic hernia and cystic adenomatoid malformation can push the heart into the right chest. Hypoplastic right lung causes a potential space on the right side that the heart can move into. Tricuspid insufficiency will not cause abnormal cardiac axis or position. (Study Guide: 481)

76. (D) The most common dysrhythmia is premature atrial contractions (PACs). PACs can be caused by maternal use of caffeine, cigarettes or alcohol, or by a redundant foraminal flap. The majority of PACs resolve by delivery. (Study Guide: 482)

77. (D) Supraventricular tachycardia occurs when the fetal heart rate is 180–280 bpm, and there is also atrial–ventricular concordance. If SVT remains throughout pregnancy, fetal hydrops or death can occur. (Study Guide: 482)

78. (C) Transducer pressure can lead to bradycardia. When pressure is released, normal rate returns. (Study Guide: 482)

79. (B) A second-degree heart block of 3:1 occurs when there are three atrial contractions for every one ventricular contraction. (Study Guide: 482)

80. (A) Atrial septal defects, cardiac tumors, and polysplenia are all associated with complete heart block. Chordae tendineae are cord-like tendons that connect the papillary muscles to the tricuspid valve. (Study Guide: 482)