Procedures I Ch 2 positioning & problem solving
Are grids recommended for an LPO projection of the adult chest?
yes
To prevent the clavicles from obscuring the apices on an AP projection of the chest, the CR should be angled _____ _____ so that it is perpendicular to the _____.
~ 5 degrees caudad; sternum
A radiograph of a PA and a left lateral projection of the chest show the mediastinum of the chest is underpenetrated. The technologist used the following factors for the radiograph: a 72" SID, an upright bucky, a full-inspiration exposure, 75-kV and 600 mA, and 1/60-second exposure time. Which of these factors is the most likely cause of the problem? How can the tech improve the image when making the repeat exposure?
• The 78 kV is too low. The recommended kV range is 110-125 • Increase the kV and reduce the mAs for the repeat exposure
A patient with a history of pleurisy comes to the radiology department. What radiographic series should be performed?
Erect PA and lateral
How much separation of the posterior ribs on a lateral chest projection indicates excessive rotation from a true lateral position?
Greater than 1/2"-3/4"; less separation than this is caused by the divergent x-rays
An erect chest PA radiograph aids the patient to achieve full inspiration and helps to prevent ___ and ____ of the pulmonary vessels.
engorgement; hyperemia
For certain studies of the heart, the _____ (R or L) anterior oblique requires a rotation of
left; 60 degrees
What positioning/projection would be used for a patient who is too ill or weak to stand for an AP lordotic projection?
AP semiaxial projection, CR 15-20 degrees cephalad
A young child enters the ER with a possible foreign body in one of the bronchi of the lung. The foreign body, a peanut, cannot be seen on the PA and lateral projection of the chest projection. Which additional projection(s) could the tech perform to locate the foreign body?
AP and lateral upper airway projections
A routine chest series indicates a possible mass beneath a patient's right clavicle. The PA and lateral projections are inconclusive. What additional projection(s) could be taken to rule out this condition?
AP lordotic
What chest projections/positions is recommended to detect calcifications or cavitations within the upper lung region beneath the clavicles?
AP lordotic
A patient has a possible small possible neolplasm in the right lung apex comes to the radiology department for a chest examination. The PA and lateral projections do not clearly demonstrate the neoplasm because of superimposition of the clavicle over the apex. The patient is unable to sit or stand erect. Which additional projection can be taken to demonstrate the neoplasm clearly and to eliminate the superimposition of the clavicle and the left lung apex?
AP semiaxial projection; CR is angles 15-20 degrees cephalad to project the clavicles above the apices and to demonstrate clearly the possible tumor
PA and left lateral projections demonstrate a suspicious region in the left lung. The radiologist orders an oblique projection that will best demonstrate or "elongate" the left lung. Which specific oblique projections will best elongate the left lung?
Both the LPO and RAO oblique positions will best demonstrate or elongate the left lung
Where is the CR placed for a lateral upper airway?
C6-C7, midway between thyroid cartilage & jugular notch
A radiograph of a PA projection of the chest shows the top of the apices is cut off and a wide collimation border can be seen below the diaphragm. In what way can this be corrected during the repeat radioghraph?
Center the CR higher (T7), which will be found 7-8" below the vertebra prominens. Make sure the IR is centered to the CR and the top collimation light border is at the vertebra prominens.
A patient with a clinical history of advanced emphysema comes to the radiology department for a chest x-ray. AEC will not be used. How should the tech alter the manual exposure setting for this patient?
Decrease the kV moderately
A radiograph of a lateral projection of the chest shows the posterior ribs and costophrenic angles are separated more than 1/2", or 1 cm, indicating excessive rotation. Describe a possible method for determining the direction of rotation.
Determine which hemidiaphragm (R or L) is more posterior or more anterior. The left hemidiaphragm can frequently be identified by visualization of the gastric air bubble or the inferior heart shadow, both of which are associated with the left hemidiaphragm.
A patient comes to the radiology department for a presurgical chest examination. The clinical history indicates a possible situs inversus of the thorax (transposition of structures within the thorax). Which positioning step or action must be taken to perform a successful chest examination?
Ensure placement of the correct right or left anatomic side marker on the IR because the heart and other thoracic structures may be transposed from right to left.
A patient with severe pleural effusion comes to the radiology department for a chest x-ray automatic exposure control (AEC) will not be used. How should the tech alter the manual exposure settings for this patient?
Increase the kV slightly
A patient has a possible small pneumothorax. Routine chest projections fail to show the pneumothorax conclusively. Which additional projections could be taken to rule out this condition?
Inspiration and expiration PA projections and / or lateral decubitus AP chest with affected side upk
Why should a left lateral be performed unless departmental protocol indicates otherwise?
It better demonstrates the heart region
Which posterior oblique projection would best demonstrate the left lung? right anterior oblique (RAO) or left anterior oblique (LAO)
LPO
What are the recommended patient instructions when performing an erect PA chest on a female patient with large pendulous breasts?
Lift the breasts up & outward & then remove her hands as she leans against the bucky to keep them in position.
Why is a PA chest preferred to an AP projection?
Places the heart closer to the image receptor to reduce magnification of the heart
Which anterior oblique projection would best demonstrate the left lung---right anterior oblique (RAO) or left anterior oblique (LAO)
RAO
A patient enters the ER with a possible hemothorax in the right lung caused by a motor vehicle accident. The patient is unable to stand or sit erect. Which specific projection would best demonstrate this condition, and why?
Right lateral decubitus; in a patient with hemothorax (fluid), the side of interest should be down
A radiograph of a PA view of the chest shows that the sternoclavicular (SC) joints are not the same distance from the spine. The right SC joint is closer to the midline than is the left SC joint. What is the positioning error?
Rotation. The patient is rotated into a slight RAO position.
What circumstances or clinical indications suggest that an AP lordotic projection should be ordered?
Rule out calcifications or masses beneath the clavicles
The CR is placed at the level of the _____ vertebra for a PA chest projection.
T7
A radiograph of a PA projection of the chest shows only seven posterior ribs above the diaphragm. What caused this problem, and how could it be prevented on the repeat exposures?
The lungs are underinflated. Explain to the patient the need for a deep inspiration, and take the exposure on the second deep inspiration.
Which specific position would be used if a patient were unable to stand but the physician suspected that the patient had fluid in the left lung
left lateral decubitus,
What is the name of the condition characterized by fluid entering the pleural cavity?
pleural effusion
What is the name of the condition characterized by free air entering the pleural cavity?
pneumothorax
Which specific position would be used if the patient were unable to stand but the physician suspected that the patient had free air in the left pleural cavity?
right lateral decubitus (affected side up)
The shoulders need to be rolled forward for the PA projection to allow the _____ to move laterally and be clear of the lung fields
scapulae
Careful collimation during a chest radiograph will improve image quality by decreasing _____ radiation to the IR.
scatter
