1. Positioning Considerations for Imaging of the Chest and Thorax

2. Evaluation Criteria Structures shown Position/projection
Collimation/central ray
Exposure criteria
Acceptable and unacceptable chest images based on errors i.e.:
Motion
Collimation
Positioning
Exposure factors
Side markers and patient demographic information
RADIATION PROTECTION ON ALL PATIENTS (for chest imaging)
Every time a radiographer completes an image, an evaluation must be made to determine whether the image is diagnostically optimal for the radiologist to provide an accurate diagnosis. A radiologist should NEVER have to return an image for repeat if proper evaluation of the image is done by the radiographer.
Here are five basic criteria for radiographic evaluations and critique. These should be used every time a radiographic image is performed.

3. Heart and Lung Images Upright Recumbent <Images 1 and 2>
When obtaining images of the heart and lungs, the patient is placed in the upright position because this prevents engorgement of the pulmonary vessels. It also allows gravity to depress the diaphragm. When the patient is lying down or in the recumbent position, gravity forces the diaphragm and abdomen to move superior, which compresses the organs in the thorax. This makes it impossible for the patient to take in a big breath and get full expansion of the lungs.
<Habitus.jpg>
Upright or recumbent matters! There isn’t a big change in a patient with a hyposthenic body habitus. However, it makes a big difference in the patient with a hypersthenic body habitus.
Upright
Recumbent

4. PA Chest Basics
<images 5>
Chest radiography is the most common radiographic procedure performed by the radiographer. It is used to visualize the heart, lungs, and thoracic viscera. Chest radiography is used to access disease processes in the lungs, i.e., pneumonia, heart failure, pleurisy, cancer, are common indications for chest radiography. Radiographic positioning and technique are critical in performing a diagnostic chest image.
Example of correct positioning with lead shield and the resultant PA chest image with markers.

5. PA Chest Criteria
Click each button for more information on PA chest imaging.
Technical Considerations
Grid
kVp range:
SID: 72 inches (180 cm)
Patient position
Erect with weight equally distributed on both feet.
Top of IR 1 ½ to 2 inches, 4-5 cm above the shoulders and thorax centered to IR at the level of T6-T7.
Part position
Hands low on the hips, palms facing outward; shoulders relaxed; scapulae rotated forward; chin elevated.
Central Ray
Perpendicular to the IR. (No angle)
Patient Instructions
“Take a deep breath, let it out. Take in another deep breath and hold it. Don’t breathe or move.”
Evaluation Criteria
To demonstrate that the patient is not rotated, SC joints should be equidistant from the vertebral column.
Distance between the vertebral column and the outer margin of the ribs should be symmetrical.
Apices will be demonstrated 1 inch (2 cm) above the clavicles.
Left and right costophrenic angles visible on image.
Scapulae rotated forward and not seen in the lung field.
Mandible elevated and not seen in the lung field.
A minimum of 10 posterior ribs are demonstrated.
Side marker and patient demographics displayed.
Additional information
For patients with a hyposthenic body habitus (short and wide), the IR should be turned crosswise to include both costophrenic angles.
Women with large pendulous breasts should be asked to lift their breasts and pull them to the side. This maneuver will remove overlapping breast shadows on the resultant image.
When a patient presents with a possible pneumothorax, two PA images are taken, one on inhalation and one on exhalation. The exhalation chest image will better demonstrate the pneumothorax.
Guidelines
Evaluation Criteria
Additional Information

6. Knowledge Check Image#2 <Image # 2 Answers on Image 2-1>
Label the following radiographic anatomy:
R lung apex, Clavicle, 4th thoracic vertebra, R scapula, R 3rd anterior rib, R atrium heart, Diaphragm, R costophrenic angle, air filled trachea, L SC joint, L lung, superior manubrium, L 7th posterior rib, aortic arch, Hilum, Heart shadow, L ventricle of the heart.

7. Lateral Chest Basics Example of correct positioning with lead shield
<Image #9>
The lateral chest radiograph is taken erect with the left side against the image receptor. The position reduces heart magnification as compared to the right lateral. A horizontal x-ray beam allows for distinguishing fluid levels in the chest. The importance of the lateral chest radiograph is that it complements the AP or PA radiograph by providing 90-degree views of the chest. Anterior to posterior viewing of both lung fields is demonstrated. The lateral perspective shows structures such as the anterior and posterior mediastinum, medial lung fields, and costophrenic angles, as well as the thoracic spine. Along with the frontal view, the lateral view allows for a more accurate quantification of fluid when present, extent of disease, measurement of pathology (e.g. nodule, mass), and anterior to posterior viewing of the chest.
Example of correct positioning with lead shield

8. Lateral Chest Criteria
Technical Considerations
Grid
kVp range:
SID: 72 inches (180 cm)
Patient Position
Erect with weight equally distributed on both feet; top of IR 1 ½ inches 4-5 cm above the shoulder, CR perpendicular to IR at the level of T6-T7.
Part Position
Feet, hips, and shoulders in true lateral position; arms raised over the head with each hand grasping opposite elbows or grasping bar positioned in front of and over the patient’s head; chin elevated; midcoronal plane centered to the IR.
Central Ray (CR)
Perpendicular to the IR.
Patient Instructions
“Take a deep breath, let it out. Take in another deep breath and hold it. Don’t breathe or move.”
Evaluation Criteria:
Posterior aspect of the ribs and lungs should be superimposed.
Intervertebral joint spaces of the thoracic spine should be clearly visible.
Sternum should be in lateral position.
Apices and costophrenic angles should be included and on the image.
Hilum should be near the center of the image.
Midsagittal plane of the patient should be vertical—the patient should not be leaning forward or backward.
Side markers and patient demographics displayed
Additional Information
Mark the side closest to the Image receptor
Left lateral chest is with the left side against the IR
Always include the lateral chest image with the AP or PA chest when possible.
Click each button for more information on lateral chest imaging.
Guidelines
Evaluation Criteria
Additional Information

9. Knowledge Check Image #9-2
<Image #9-2 answers image #9-1 Label the anatomy on this Left Lateral Chest Image, Lung apex, Scapulae, Thoracic vertebrae, Posterior ribs, Costophrenic angles, Trachea, Esophagus, Hila, Sternum, Heart, Diaphragm, Nipple piercing.

10. Lateral Decubitus Chest Basics
<images 28 and 29>
The word “decubitus” means lying down. This position is used to evaluate or demonstrate small amounts of fluid or air in the pleural cavity. To demonstrate fluid in the pleural cavity the patient lies on the affected side. To demonstrate air in the pleural cavity the patient lies on the unaffected side.
Left shows a patient in position for a right lateral decubitus position.   The right is an example of a decubitus film in this case
showing a mobile pleural effusion (arrows).

11. Lateral Decubitus Chest Criteria
Technical Considerations
Grid
kVp range:
SID: 72 inches (180 cm)
Patient Position
Lateral recumbent position; both arms raised over the head; ankles and knees on top of one another and the knees flexed for support.
Part Position
Fix pelvis and shoulder parallel to the IR; fix the center of the IR holder to the midsagittal plane, and place the top of the IR 2 inches (5 cm) above the shoulder.
Central Ray (CR)
Horizontal perpendicular to the IR holder; center x-ray tube to IR at the level of T6-T7.
Patient Instructions
“Take a deep breath, let it out. Take in another deep breath and hold it. Don’t breathe or move.”
Evaluation Criteria
SC joints equidistant from the vertebral column.
Distance between the vertebral column and the outer margin of the ribs should be symmetrical on each side.
Apices will be demonstrated 1 inch (2 cm) above the clavicles.
Left and right costophrenic angles seen on the image.
Affected side must be included on the image and should not be superimposed by the support.
Patient’s arms should not superimpose the upper lung field.
Additional Information
Marker placement is very important. A left or right marker can be used and must be placed on the correct side of the patient.
If demonstrating fluid levels, the patient should be placed on a radiolucent support to elevate the dependent side enough for the entire side to be demonstrated on the image.
The word “decubitus” means lying down. To describe the position of the patient you say, the patient is lying in the “left lateral decubitus position” meaning the patient is lying on the left side in the lateral position with the CR directed horizontal. Or you say, “The patient is lying in the dorsal decubitus position, meaning the patient is lying on his/her back and the CR is directed horizontal.
Click each button for more information on lateral decubitus chest imaging.
Guidelines
Evaluation Criteria
Additional Information

12. Knowledge Check <image 14> What is this position?
Right lateral decubitus
Right dorsal decubitus
Left lateral decubitus
Left dorsal decubitus

13. AP Lordotic Chest Basics
<images 16 and 17>
The AP lordotic position of the chest is performed to demonstrate the apices free from superimposition of the clavicles. This position will also demonstrate a right middle lobe pneumothorax. Images used to rule out pathologies in the lung apices such as tuberculosis.

14. AP Lordotic Position Criteria
Technical Considerations
Grid
kVp range:
SID: 72 inches (180 cm)
Patient position
The patient is erect; with the top of the IR approximately 3-4 inches (8-9 cm) above the shoulders
Part position
Standing approximately 1 foot from the IR, facing forward toward the x-ray tube and leaning back so the top of the shoulders, neck, and head are against the IR holder;
Hands on hips and shoulders rotated forward;
Midsagittal plane centered to the IR holder.
Central Ray (CR)
Perpendicular to the IR holder and centered mid-sternum, 3-4 inches (8-10 cm) inferior to the suprasternal notch.
Patient Instructions
“Take a deep breath, let it out. Take in another deep breath and hold it. Don’t breathe or move.”
Evaluation Criteria
Clavicles will have a horizontal appearance above the apices.
SC joints equidistant from the vertebral column.
Distance between the vertebral column and the outer margin of the ribs should be symmetrical on each side.
Proper exposure factors will demonstrate lung marking throughout the lung field, especially in the apices.
Ribs will have an appearance of distortion with the anterior and posterior ribs mostly superimposed.
Additional information
Always help the patient in an out of this position.
A patient who cannot stand can be placed on a stool (without wheels) and the same procedure can be followed in the sitting position.
A patient who cannot sit or stand can lie on the imaging table or stretcher with the CR angled degrees cephalad centered to the mid sternum. (AP axial lordotic projection)
Click each button for more information on lordotic position chest imaging.
Guidelines
Evaluation Criteria
Additional Information

15. Knowledge Check Image #26 <Image 26>
1. What would you change about this apical lordotic image?
The positioning is not correct
CR is angled caudal
Image is overexposed
There are snaps on the image
Image #26

16. Oblique Chest Basics <Images 20 and 27>
The oblique position is performed to demonstrate the trachea, right and left bronchial trees, heart, and aorta free from superimposition of the vertebral column. Either right or left oblique positions or both may be indicated in the physician’s order. The side furthest from the IR is demonstrated. The LAO (left anterior oblique) will demonstrate the right lung. The RAO (right anterior oblique) will demonstrate the left lung.

17. Oblique Chest Position Criteria
Technical considerations
Grid
kVp range:
SID: 72 inches (180 cm)
Patient position
Patient is erect; weight equally distributed on both feet;
Top of IR 1 ½ to 2 inches (4-5 cm) above the shoulders.
CR directed to the level of T6-T7.
Part position
Rotate the patient 45 degrees from the PA position with either the left (LAO) or right (RAO) shoulder and chest against the IR holder
Hand closest to the IR is on the waist and the opposite hand is raised over the patient’s head resting on the IR holder
Elevate the chin
Patient is positioned so both sides of the chest are included on the image
Central Ray
The CR is perpendicular to the IR.
Patient Instructions
“Take a deep breath, let it out. Take in another deep breath and hold it. Don’t breathe or move.”
Evaluation Criteria
The side away from the IR will be approximately 2 times the size of the side closest to the IR.
Apices and both costophrenic angles should be visible on the image.
Additional Information
According to the patient pathology the degree of obliquity will vary on this position.
A 60 degree LAO may be used to separate the aorta from the thoracic spine.
AP obliques may be performed if the patient is unable to stand upright or lie prone. AP obliques demonstrate the side closest to the IR.
RPO will demonstrate the same structures as the LAO, and the LPO will demonstrate the same structures as the RAO.
Click each button for more information on oblique chest imaging.
Guidelines
Evaluation Criteria
Additional Information

18. Knowledge Check <Image #19 and 21>
What is the position of the patient and image?
A. RAO
B. LAO
C. RPO
D. LPO

19. Knowledge Check <Image #18 and Image #27 (answers)>
2. Label the following radiographic anatomy:
Right lung, trachea, Left bronchus, Carina, Vertebral column, Heart, Left lung, Diaphragm, Right costophrenic angle

20. Dorsal Decubitus Chest Basics
<images 22 and 23>
This image of the chest is performed for the purpose of demonstrating fluid levels from a lateral perspective.

21. Dorsal Decubitus Chest Position Criteria
Technical Considerations
Grid
kVp range:
FFD or SID: 72 inches (180 cm)
Patient position
Patient is recumbent in the supine position, lying on a radiolucent support of 2-3 inches (5-8 cm)
Knees flexed for patient comfort and support;
IR is placed 1 ½ to 2 inches (4-5 cm) above the patient’s shoulders and centered to the midaxiallary line at the level of T6-T7.
Part position
Patient’s arms are extended over the head
IR holder is adjusted to the midaxillary line.
Central Ray (CR)
Perpendicular to the IR (the x-ray tube must be horizontal to demonstrate air/fluid levels in the chest)
Patient instructions
“Take a deep breath, let it out. Take in another deep breath and hold it. Don’t breathe or move.”
Evaluation Criteria
Posterior aspect of the ribs and lungs should be superimposed.
Intervertebral joint spaces of the thoracic spine should be clearly visible.
Sternum should be in lateral position.
Apices and costophrenic angles should be included and on the image.
Hilum should be near the center of the image.
Anatomy should NOT be superimposed by the support.
Additional information
Should the patient NOT be able to lie in the supine position; a ventral decubitus may be done.
Click each button for more information on dorsal decubitus chest imaging.
Technical Considerations
Evaluation Criteria
Additional Information

22. Knowledge Check <Image #24>
The PA chest image demonstrates a fluid level in the base of the left lung, which chest image should be performed next?
Ventral decubitus
Dorsal decubitus
Right lateral decubitus
Left lateral decubitus

23. Summary
Chest imaging seems simple and easy. However, chest imaging is one of the most important radiographs the radiographer performs. Chest imaging comprises about 75% of the radiographs the radiographer will do. Positioning is important because the routine PA and lateral chest radiographic provide diagnostic information for many disease processes.