Chest Radiographs

Chapter 4


Chest Radiographs





1. Describe a systematic approach to interpreting a chest radiograph (chest x-ray [CXR]) (Fig. 4-1).



    Common recommendations are to:



2. Identify the major cardiovascular structures that form the silhouette of the mediastinum (Fig. 4-2)




3. How is heart size measured on a chest radiograph?


    Identification of cardiomegaly on a CXR is subjective, but if the heart size is equal to or greater than twice the size of the hemithorax, then it is enlarged. Remember that a film taken during expiration, in a supine position, or by a portable anteroposterior (AP) technique will make the heart appear larger.


4. What factors can affect heart size on the chest radiograph?



image Size of the patient: Obesity decreases lung volumes and enlarges the appearance of the heart.


image Degree of inspiration: Poor inspiration can make the heart appear larger.


image Emphysema: Hyperinflation changes the configuration of the heart, making it appear smaller.


image Contractility: Systole or diastole can make up to a 1.5-cm difference in heart size. In addition, low heart rate and increased cardiac output lead to increased ventricular filling.


image Chest configuration: Pectus excavatum can compress the heart and make it appear larger.


image Patient positioning: The heart appears larger if the film is taken in a supine position.


image Type of examination: On an AP projection, the heart is farther away from the film and closer to the camera. This creates greater beam divergence and the appearance of an increased heart size.


5. What additional items should be reviewed when examining a chest radiograph from the intensive care unit (ICU)?


    On portable coronary care unit (CCU) and ICU radiographs, particular attention should be paid to:



A careful inspection should be made for pneumothorax (Fig. 4-3), subcutaneous emphysema, and other factors that may be related to instrumentation and mechanical ventilation.


Jun 5, 2016 | Posted by in CARDIOLOGY | Comments Off on Chest Radiographs

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