prominences, and depressions are very useful to the radiographer in locating anatomic structures that are not visible externally. The fifth thoracic vertebra is at approximately the same level as the sternal angle. The T2-3 interspace is about at the same level as the manubrial (suprasternal) notch. The costal margin is about the same level as L3.
During chest radiography, the act of inspiration
1. raises the ribs.
3. depresses the abdominal viscera.
the diaphragm moves inferiorly and depresses the abdominal viscera. The ribs and sternum are elevated. As the ribs are elevated, their angle is decreased. Radiographic density can vary considerably in appearance depending on the phase of respiration during which the exposure is made.
Tracheotomy and intubation are effective techniques used to restore breathing when there is (are)
A. respiratory pathway obstruction above the larynx.
B. crushed tracheal rings due to trauma.
C. respiratory pathway closure due to inflammation and swelling.
The respiratory passageways include
the nose, pharynx, larynx (upper respiratory structures), trachea, bronchi, and lungs (lower structures). If obstruction of the breathing passageways occurs in the upper respiratory tract, above the larynx (i.e., in the nose or pharynx), tracheotomy may be performed in order to restore breathing. Intubation can be made into the lower structures, larynx and trachea, moving aside any soft obstruction and restoring the breathing passageway.
Place the following anatomic structures in order from anterior to posterior:
Apex of heart, trachea, esophagus
The relationship of these three structures can be appreciated in
a lateral projection of the chest. The heart is seen in the anterior half of the thoracic cavity, with its apex extending inferior and anterior. The air-filled trachea can be seen in about the center of the chest, and the air-filled esophagus just posterior to the trachea
All the following positions may be used to demonstrate the sternoclavicular articulations
may be examined with the patient PA, either bilaterally with the patient's head resting on the chin or unilaterally with the patient's head turned toward the side being examined. The sternoclavicular articulations may also be examined in the oblique position, with either the patient rotated slightly or the central ray angled slightly medialward. Weight-bearing positions are frequently used for evaluation of acromioclavicular joints
Which of the following positions is required to demonstrate small amounts of air in the pleural cavity?
Lateral decubitus, affected side up
Air or fluid levels will be clearly delineated only if
the CR is directed parallel to them. Therefore, to demonstrate air or fluid levels, the erect or decubitus position should be used. Small amounts of fluid within the pleural space are best demonstrated in the lateral decubitus position, affected side down. Small amounts of air within the pleural space are best demonstrated in the lateral decubitus position, affected side up
Aspirated foreign bodies in older children and adults are most likely to lodge in the
right main bronchus
Because the right main bronchus is wider and more vertical,
aspirated foreign bodies are more likely to enter it than the left main bronchus, which is narrower and angles more sharply from the trachea. An aspirated foreign body does not enter the esophagus or the stomach, as they are not respiratory structures, but rather digestive structures.
The patient's chin should be elevated during chest radiography to
avoid superimposition on the apices
Chest positioning must be correct and accurate;
thoracic structures are easily distorted. To avoid superimposition on the upper medial apices, the patient's chin should be sufficiently elevated. Movement of the diaphragm to its lowest position is a function of the erect position and of making the exposure after the second inspiration. The MSP is perpendicular to the IR in the PA projection and parallel to the IR in the lateral projection. The position of the chin has little to do with the MSP.
"Flattening" of the hemidiaphragms is characteristic of which of the following conditions?
Chest radiographs demonstrating emphysema will show
characteristic irreversible trapping of air that gradually increases and overexpands the lungs. This produces the characteristic "flattening" of the hemidiaphragms and widening of the intercostal spaces. The increased air content of the lungs requires a compensating decrease in technical factors. Pneumonia is inflammation of the lungs, usually caused by bacteria, virus, or chemical irritant. Pneumothorax is a collection of air or gas in the pleural cavity (outside the lungs), with an accompanying collapse of the lung. Pleural effusion is excessive fluid between the parietal and visceral layers of pleura
Inspiration and expiration projections of the chest may be performed to demonstrate
2. foreign body.
The phase of respiration is exceedingly important in thoracic radiography,
as lung expansion and the position of the diaphragm strongly influence the appearance of the finished radiograph. Inspiration and expiration radiographs of the chest are taken to demonstrate air in the pleural cavity (pneumothorax), to demonstrate atelectasis (partial or complete collapse of one or more pulmonary lobes) or the degree of diaphragm excursion, or to detect the presence of a foreign body. The expiration image will require a somewhat greater exposure (6 to 8 kV more) to compensate for the diminished quantity of air in the lungs.
The axillary portion of the ribs is best demonstrated in
a 45° oblique position. The axillary ribs are demonstrated in the AP oblique projection with the affected side adjacent to the IR, and in the PA oblique projection with the affected side away from the IR. Therefore, the right axillary ribs would be demonstrated in the RPO (AP oblique with affected side adjacent to the IR) and LAO (PA oblique with affected side away from the IR) positions.
the space between the lungs that contains the heart, great vessels, trachea, esophagus, and thymus gland. It is bounded anteriorly by the sternum and posteriorly by the vertebral column and extends from the upper thorax to the diaphragm
The ridge that marks the bifurcation of the trachea into the right and left primary bronchi is the
an internal ridge located at the bifurcation of the trachea into right and left primary, or mainstem, bronchi. The epiglottis is a flap of elastic cartilage that functions to prevent fluids and solids from entering the respiratory tract during swallowing. The root of the lung attaches the lung, via dense connective tissue, to the mediastinum. The root of the left lung is at the level of T6, and the root of the right is at T5. The hilus (hilum) is the slitlike opening on the medial aspect of the lung through which arteries, veins, lymphatics, and so forth, enter and exit.
The trachea (windpipe) bifurcates into
left and right mainstem bronchi, each entering its respective lung hilum. The left bronchus divides into two portions, one for each lobe of the left lung. The right bronchus divides into three portions, one for each lobe of the right lung. The lungs are conical in shape, consisting of upper pointed portions, termed the apices (plural of apex), and broad lower portions (or bases). The lungs are enclosed in a double-walled serous membrane called the pleura.
The sternoclavicular joints are best demonstrated with the patient PA and
in a slight oblique position, affected side adjacent to the image receptor
should be performed PA whenever possible to keep the object-to-image receptor distance (OID) to a minimum. The oblique position (about 15°) opens the joint closest to the image receptor. The erect position may be used, but is not required. Weight-bearing images are not recommended for sternoclavicular joints as they often are for acromioclavicular joints.
The right and left main stem (primary) bronchi branch from
the distal trachea; the right branch supplies air to the right lung, and the left branch supplies air to the left lung. The right main stem bronchus is shorter, wider, and more vertical than the left—making it the most likely route for aspirated foreign bodies to enter the right lung
Full or forced expiration is used to elevate the
diaphragm and demonstrate the ribs below the diaphragm to best advantage (with exposure adjustment). Deep inspiration is used to depress the diaphragm and demonstrate as many ribs above the diaphragm as possible. Shallow breathing is occasionally used to visualize the ribs above the diaphragm, while obliterating pulmonary vascular markings.
Which of the following criteria are used to evaluate a PA projection of the chest?
1. Ten posterior ribs should be visualized.
2. Sternoclavicular joints should be symmetrical.
3. The scapulae should be lateral to the lung fields.
To evaluate sufficient inspiration and lung expansion,
10 posterior ribs should be visualized. The sternoclavicular joints should be symmetrical; any loss of symmetry indicates rotation. To visualize maximum lung area, the shoulders are rolled forward to move the scapulae laterally from the lung fields.
The esophagus is
a musculomembranous tube commencing at about the level of the cricoid cartilage, that is, C5-6. It is located posterior to the larynx and trachea and extends to about the level of T11, where it joins with the proximal stomach.
Which of the following positions is required to demonstrate small amounts of fluid in the pleural cavity?
Lateral decubitus, affected side down
Air or fluid levels will be clearly delineated only if
the central ray is directed parallel to them. Therefore, to demonstrate air or fluid levels, the erect or decubitus position should be used. Small amounts of fluid within the pleural space are best demonstrated in the lateral decubitus position, affected side down. Small amounts of air within the pleural space are best demonstrated in the lateral decubitus position, affected side up.
The inhalation of liquid or solid particles into the nose, throat, or lungs is referred to as
nhalation of a foreign substance such as water or food particles into the airway and/or bronchial tree is called
caused by deprivation of oxygen as a result of interference with ventilation, from trauma, electric shock, etc
How should a chest examination to rule out air-fluid levels be obtained on a patient having traumatic injuries?
Include a dorsal decubitus lateral chest projection
One of the most important principles in chest radiography is that it be performed, whenever possible, in the
erect position. It is in this position that the diaphragm can descend to its lowest position during inspiration, and any air-fluid levels can be detected. However, patients having traumatic injuries must frequently be examined in the supine position. An AP supine chest is performed first. If the examination is also being performed to rule out air-fluid levels, this can be determined by performing the lateral projection in the dorsal decubitus position. The patient is lying supine, and a horizontal ("cross-table") x-ray beam is used.
Which of the following will be demonstrated best in the 45-degree right anterior oblique (RAO) position?
Left axillary ribs
The axillary portions of ribs are demonstrated
in a 45-degree oblique position. In order to place the axillary portions parallel to the image receptor (IR), the affected side is away from the IR in the PA oblique (RAO and LAO) positions and toward the IR in the AP oblique (RPO and LPO) positions. Radiography of the sternum, in the slight RAO position, requires greater obliquity for thinner patients and lesser obliquity for thicker patients. The scapular Y position of the shoulder is performed to demonstrate dislocation and requires a rotation of 45-60 degrees, with the affected side closest to the IR.
In which of the following examinations is exposure on full expiration required?
Below diaphragm ribs
Full or forced expiration is used to
elevate the diaphragm and demonstrate the ribs below the diaphragm to best advantage. Deep inspiration is used to depress the diaphragm and demonstrate as many ribs above the diaphragm as possible. Shallow breathing is used occasionally to visualize the ribs above the diaphragm while obliterating pulmonary vascular markings. Shallow breathing is also used during exposure of the lateral thoracic spine and functions to blur prominent vascular markings. Posteroanterior (PA) and apical lordotic chest radiographs require full inspiration.
To better demonstrate the ribs below the diaphragm,
1. suspend respiration at the end of full exhalation.
2. perform the examination in the recumbent position.
The ribs below the diaphragm are best demonstrated
with the diaphragm elevated. This is accomplished by placing the patient in a recumbent position and by taking the exposure at the end of exhalation. Conversely, the ribs above the diaphragm are best demonstrated with the diaphragm depressed. Placing the patient in the erect position and taking the exposure at the end of deep inspiration accomplishes this.
The laryngeal prominence,
or "Adam's Apple," is formed by the thyroid cartilage—the principal cartilage of the larynx. The thyroid gland, one of the endocrine glands, is lateral and inferior to the thyroid cartilage. The vocal cords are within the laryngeal cavity. Portions of the pharynx serve as passage for both air and food.
RAO position of the sternum
The sternum is projected to the left side of the thorax, over the heart and other mediastinal structures, in the RAO position, thus promoting more uniform density, The central ray should be directed midway between the jugular (manubrial) notch and the xiphoid process
The bony thorax consists of
12 pairs of ribs and the structures to which they are attached anteriorly and posteriorly: the sternum and the thoracic vertebrae. These structures form a bony cage that surrounds and protects the vital organs within (the heart, lungs, and great vessels). The scapulae, together with the clavicles, form the shoulder (pectoral) girdle of the upper extremity.
What are the positions most commonly employed for a radiographic examination of the sternum?
Because the sternum and vertebrae would be superimposed in a direct PA or AP projection
a slight oblique (just enough to separate the sternum from superimposition on the vertebrae) is used instead of a direct frontal projection. In the RAO position, the heart superimposes a homogeneous density over the sternum, thereby providing clearer radiographic visualization of its bony structure. If the LAO position were used to project the sternum to the right of the thoracic vertebrae, the posterior ribs and pulmonary markings would cast confusing shadows over the sternum because of their differing densities. The lateral projection requires that the shoulders be rolled back sufficiently to project the sternum completely anterior to the ribs. Prominent pulmonary vascular markings can be obliterated using a "breathing technique," that is, using an exposure time long enough (with appropriately low milliamperage) to equal at least a few respirations.
To demonstrate the pulmonary apices with the patient in the AP position, the
central ray is directed 15° to 20° cephalad
When the shoulders are relaxed, the clavicles are usually
carried below the pulmonary apices. To examine the portions of the lungs lying behind the clavicles, the central ray is directed cephalad 15° to 20° to project the clavicles above the apices when the patient is examined in the AP position.
The expectoration of blood from the larynx, trachea, bronchi, or lungs is termed
hemoptysis. Hemoptysis can occur in several diseases, including pneumonia, bronchitis, pulmonary tuberculosis, and others. Hematemesis is vomiting of blood—this can occur with gastric ulcers, gastritis, esophageal varices, and other conditions.
Which of the following is (are) recommended when positioning the patient for a lateral projection of the chest?
The patient should be examined upright
The chest should be examined in the
upright position whenever possible to demonstrate any air-fluid levels. For the lateral projection, the patient elevates the arms and flexes and grasps the elbows. The midsagittal and midcoronal planes must remain vertical to avoid distortion of the heart. In the PA projection, the shoulders should be relaxed and depressed to move the clavicles below the lung apices, and the shoulders should be rolled forward to move the scapulae out of the lung fields
Which of the following statements is (are) correct with respect to evaluation criteria for a PA projection of the chest for lungs?
The sternoclavicular joints should be symmetrical
In the PA projection of the chest,
there should be no rotation, as evidenced by symmetrical sternoclavicular joints. The shoulders are rolled forward to remove the scapulae from the lung fields. Inspiration should be adequate to demonstrate 10 posterior ribs above the diaphragm (the anterior ribs angle downward; the tenth anterior rib is the last attached to the sternum and is very unlikely to be imaged on inspiration). The sternum should be seen lateral without rotation in the lateral position of the chest.