Chapter 14: Cardiac Radiography
Radiographic assessment of the lung can often reflect the underlying pathophysiology of diseases of the heart. Which of the following statements regarding the normal radiographic appearance of the pulmonary vasculature of an upright human being is false?
A. The pressure differential between the apex and the base of the lung is approximately 22 mm Hg in adult men
B. The number of vessels and their length are more important than their caliber
C. Pulmonary blood volume can be assessed by comparing the size of the pulmonary artery with that of the accompanying bronchus
D. There is caudalization of the pulmonary vascularity because of gravity
The answer is B. (Hurst’s The Heart, 14th Edition, Chap. 14). In the evaluation of pulmonary vasculature, the caliber of the vessels is more important than the length or the number (option B). As long as the pulmonary blood flow pattern remains normal, with a greater amount of flow to the bases than to the apices, the volume of the flow is proportional to the caliber of the pulmonary arteries. Options A, C, and D are correct.
A 55-year-old man, with no prior cardiac history, presented to the emergency department complaining of acute dypsnea. His chest x-ray revealed cephalad redistribution of the pulmonary vascularity. In which of the following conditions does cephalization not occur?
B. Pulmonic stenosis associated with ventricular septal defect
D. Left ventricular (LV) failure
E. Severe mitral regurgitation (MR)
The answer is B. (Hurst’s The Heart, 14th Edition, Chap. 14). Patients with pulmonic stenosis and associated ventricular septal defect (VSD) often show decreased pulmonary vascularity with smaller and shorter pulmonary arteries and veins and more radiolucent lungs. Cephalization tends to occur instead in (1) left-sided obstructive lesions—for example, mitral valvular or aortic valvular stenosis (options A and C); (2) LV failure (option D)—for example, coronary heart disease or cardiomyopathies; and (3) severe MR even before pump failure of the LV occurs (option E).1 Option B is therefore the correct answer.
A 25-year-old immigrant, with no prior medical history, is referred to your clinic for further evaluation of an abnormal chest radiography, which was discovered incidentally after a positive tuberculin skin test (Mantoux test). Otherwise she had no chest pain, dyspnea, or other specific signs or symptoms. Her ...