tailieunhanh - Ebook Veterinary diagnostic imaging, the dog and cat (Vol 1): Part 3

Part 3 book "Veterinary diagnostic imaging, the dog and cat" includes content: Lung edema (pulmonary edema), airway disease, mediastinal disease, disorders of the thoracic esophagus, diaphragmatic hernia, heart and circulatory variations and radiographic disease indicators, cardiac silhouette analysis, angiography and angiocardiography, congenital heart disease, acquired heart disease, and other contents. | C h a p t e r 4 3 Lung Edema Pulmonary Edema FIRST DECISION CARDIAC should be made with caution and noncardiac possi- OR NONCARDIAC bilities should be seriously considered. Numerous examples of cardiac edema are found in the cardiol- Cardiac Edema ogy chapters. Cardiac edema with rare exception typically occurs in the context of cardiomegaly and pulmonary hyper- Noncardiac Edema emia. Cardiac edema is often unevenly distributed and In my experience many myths surround noncardiac almost never features the bat-wing sign that is com- pulmonary edema in dogs and cats. The greatest of monly shown in human radiology textbooks. In my these asserts that the edema usually is located in the experience about 5 percent of dogs in heart failure dorsal portions of the caudal lobes. Although this may present with unilateral lung edema a finding that can be true in some animals Figure 43-1 it is not a con- be confused with contusions or pneumonia. When sistent finding Figures 43-2 and 43-3 . increased lung density is not accompanied by heart Table 43-1 lists causes of noncardiac edema in dogs and vascular enlargement a diagnosis of heart failure and 2 A B Figure 43-1 Lateral A and ventrodorsal B views of the thorax of a dog that was recently electrocuted shows poorly outlined dorsal lobe consolidation. The seemingly straightened bronchi are an illusion the result of inadvertent oblique positioning related the dog s dyspnea. 433 434 SECTION V The Throat Neck and Thorax A B Figure 43-2 Full ventrodorsal A and close-up views B of the lung of a dog suffering from severe heatstroke shows a vague granular form of pulmonary edema surrounding a Y-shaped bronchogram B emphasis zone . A B Figure 43-3 Lateral thoracic radiographs of a cat with acute progressive pulmonary edema on admission A and 24-hours later B . As the amount of edema increases the lung turns a lighter shade of gray but more importantly its tissue density increases causing greater x-ray absorption. The result is a .