(Chest Radiography, CXR)
What is a chest X-ray?
Chest X-rays may provide important information regarding the size, shape, contour, and anatomic location of the heart, lungs, bronchi, great vessels (aorta, aortic arch, pulmonary arteries), mediastinum (an area in the middle of the chest separating the lungs), and the bones (cervical and thoracic spine, clavicles, shoulder girdle, and ribs). Changes in the normal structure of the heart, lungs, and/or lung vessels may indicate disease or other conditions.
What are X-rays?
X-rays use invisible electromagnetic energy beams to produce images of internal tissues, bones, and organs on film. X-rays are made by using external radiation to produce images of the body, its organs and other internal structures for diagnostic purposes. X-rays pass through body tissues onto specially treated plates (similar to camera film) and a “negative” type picture is made (the more solid a structure is, the whiter it appears on the film). X-rays are often created digitally now for analysis on computers rather than x-ray film.
Depending on the results of the chest X-ray, additional tests or procedures may be requested by your doctor for further diagnostic information.
Other related procedures that may be used to diagnose problems of the chest and respiratory tract include chest fluoroscopy, chest ultrasound, computed tomography (CT scan) of the chest, lung biopsy, lung scans, mediastinoscopy, positron emission tomography (PET scan) of the chest, pleural biopsy, thoracentesis, sinus X-rays, pulmonary angiogram, bronchoscopy, and bronchography. Please see these procedures for additional information.
Anatomy of the respiratory system
The respiratory system is made up of the organs involved in the interchanges of gases, and consists of the upper and lower respiratory tracts.
The upper respiratory tract includes the:
Ethmoidal air cells
The lower respiratory tract includes the:
What are the functions of the lungs?
The lungs take in oxygen, which cells need to live and carry out their normal functions. The lungs also get rid of carbon dioxide, a waste product of the body's cells.
The lungs are a pair of cone-shaped organs made up of spongy, pinkish-gray tissue. They take up most of the space in the chest, or the thorax (the part of the body between the base of the neck and diaphragm).
The lungs are enveloped in a membrane called the pleura.
The lungs are separated from each other by the mediastinum, an area that contains the following:
The right lung has three sections, called lobes. The left lung has two lobes. When you breathe, the air enters the body through the nose or the mouth. It then travels down the throat through the larynx (voice box) and trachea (windpipe) and goes into the lungs through tubes called main-stem bronchi.
One main-stem bronchus leads to the right lung and one to the left lung. In the lungs, the main-stem bronchi divide into smaller bronchi and then into even smaller tubes called bronchioles. Bronchioles end in tiny air sacs called alveoli. The alveoli are where the absorption of oxygen and exchange of carbon dioxide occur.
Reasons for the procedure
Chest X-rays may be used to assess heart, ribs, and lungs. Changes in the normal structure of the heart, lungs, and/or lung vessels may indicate disease or other conditions.
Conditions that may be assessed with a chest X-ray include, but are not limited to, the following:
Heart enlargement (which can occur with congestive heart failure, congenital heart defects, or cardiomyopathy)
Pericardial effusion. A buildup of excess fluid in between the heart and the membrane that surrounds it, often due to inflammation
Pleural effusion. A collection of blood or fluid around the lung
Pneumothorax (collapsed lung) and hemothorax (blood in the lung cavity)
Pneumonia, persistent cough, and other lung conditions
Aneurysms. Ballooning of the walls of the great blood vessels, such as the aorta
Calcification of heart structures (such as heart valves or aorta)
Tumors or cancer
Granulomas found in diseases such as tuberculosis and sarcoidosis
Herniation (a hole) or elevation (movement out of position) of the diaphragm (the breathing muscle)
Pulmonary edema (“fluid in the lungs,” which can occur with congestive heart failure or congenital heart defects)
Other reasons for performing a chest X-ray may include:
As part of the physical assessment before hospitalization and/or surgery or as part of a complete physical examination
To assess symptoms of conditions related to the heart or lungs
To assess progression of a condition and/or effectiveness of treatments
To check the position of implanted pacemaker wires and other internal devices, such as central venous catheters, endotracheal tubes, chest tubes, or nasogastric tubes
To check status of lungs and chest cavity after surgery
To check for rib fractures or bone abnormalities
There may be other reasons for your doctor to recommend a chest X-ray.
Risks of the procedure
You may want to ask your doctor about the amount of radiation used during the procedure and the risks related to your particular situation. It is a good idea to keep a record of your past history of radiation exposure, such as previous scans and other types of X-rays, so that you can inform your doctor. Risks associated with radiation exposure may be related to the cumulative number of X-ray examinations and/or treatments over a long period of time. The amount of radiation from a chest x-ray is very small and equal to about the amount of natural radiation you receive over 10 days.
If you are pregnant or suspect that you may be pregnant, you should notify your doctor. Radiation exposure during pregnancy may lead to birth defects.
There may be other risks depending on your specific medical condition. Be sure to discuss any concerns with your doctor prior to the procedure.
Before the procedure
The doctor will explain the procedure to you and offer you the opportunity to ask any questions that you might have about the procedure.
Generally, no prior preparation, such as fasting or sedation, is required.
Notify the radiologic technologist if you are pregnant or suspect that you may be pregnant.
Dress in clothes that permit access to the area to be tested or that are easily removed.
Notify the radiologic technologist if you have any body piercing on your chest or prior surgery on your chest.
Based on your medical condition, your doctor may request other specific preparation.
During the procedure
A chest X-ray may be performed on an outpatient basis or as part of your stay in a hospital. Procedures may vary depending on your condition and your doctor's practices.
Generally, a chest X-ray follows this process:
You will be asked to remove any clothing, jewelry, or other objects that may interfere with the procedure.
If you do not remove your clothing, let the technologist know if you have anything in your shirt pocket. If you need to remove your clothing, you will be given a gown to wear.
The particular view that the doctor orders will determine how you are positioned for the X-ray, such as lying, sitting, or standing. You will be positioned carefully so that the desired view of the chest is obtained. The doctor will also specify the number of films to be made.
For a standing or sitting image, you will stand or sit in front of the X-ray plate. You will be asked to roll your shoulders forward, take in a deep breath, and hold it until the X-ray exposure is made. For patients who are unable to hold their breath, the radiologic technologist will take the picture at the appropriate time by watching the breathing pattern.
It will be important for you to remain still during the exposure, as any movement will blur the film.
For a side-angle view of the chest, you will be asked to turn to your side and raise your arms above your head. You will be instructed to take in a deep breath and hold it as the X-ray exposure is made.
The radiologic technologist will step behind a protective window while the images are being made.
While the X-ray procedure itself causes no pain, the manipulation of the body part being examined may cause some discomfort or pain, particularly in the case of a recent injury or invasive procedure, such as surgery. The radiologic technologist will use all possible comfort measures and complete the procedure as quickly as possible to minimize any discomfort or pain.
After the procedure
Generally, there is no special type of care after a chest X-ray. However, your doctor may give you additional or alternate instructions after the procedure, depending on your particular situation.