Normal Lung Markings |
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a |
b |
Fig. 3.20 (a) Pulmonary angiogram in the arterial phase; (b) Pulmonary angiogram in the venous phase; showing the more inferior location of the pulmon ary veins
Pulmonary Arteries and Veins
See (Figs. 3.20 a-d) for pulmonary angiogram images, obtained after the administration of a contrast injection into the pulmonary arteries directly (note the catheter). Note how the main pulmonary arteries (left image) are more superior than the major veins (right image, taken about 20 s after first image). The confluence of the pulmonary veins are inferior and posterior to origin of the pulmonary arteries. See Fig. 3.21 showing approximate location of pulmonary veins on PA view.
Normal Lung Markings
The only normal densities within the lungs are the pulmonary vessels when filled with blood and fissures. Where they are seen, they are densities, not lucencies.
Vessel Size
Vessels in the lungs may appear as small nodules. The following helps differentiate normal vessels from nodules.
Vessels on-end should be the same size as similarly distributed vessels in profile: i.e., expected size/compared size. In the following image, note that the vessel onend (circled) is about the same size as the vessel seen leading to it (between lines, below the circled vessel).
Normal pulmonary markings (vessels) can be followed from the hilum toward the lung periphery in all directions. They branch at acute angles, taper and diverge toward the periphery.
Abnormal pulmonary markings are any shadows in the area of lungs that are IN ADDITION to the normal markings (fissures, vessels).
Many such shadows obscure the normal markings or displace them.
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3 Normal Chest X-Ray, Terminology and Radiographic Anatomy |
Fig. 3.21 Pulmonary veins colored blue here. Note these are inferior to the pulmonary arteries
a |
b |
Fig. 3.22 Comparing vessel size on end to differentiate from nodules. The expected vessel size on end (circle) should be the same as the visible vessel (two lines). When larger, the density may represent a nodule. Figure b has the annotations for figure a
Normal Lung Markings |
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Fig. 3.23 Azygoesophageal edge
Fig. 3.24 PA chest with lines outlining mediastinal structures. Match with the list of structures before looking at answers on following page