| Chest Positioning |
Answers |
| Why is the patient placed in an upright position when x-raying the heart and lungs? | To prevent engorgement of the pulmonary vessels and to allow gravity to depress diaphragm. |
| Which lateral chest image (left or right) is most commonly used? | Left |
| In a PA projection of the chest, the central ray is directed to what level? | T7 |
| During x-ray of the lungs, the diaphragm moves to its lowest position when? | Erect inspiration |
| Rotation on a PA chest x-ray can be detected by evaluating what? | Sternoclavicular joints |
| How many ribs should be seen on an adult chest x-ray? | 10 |
| When performing a frontal projection of the chest, why is the PA projection preferred? | It places the heart closest to the IR |
| Why is the right side of the lung base higher than the left? | Because of the presence of the liver. |
| Is the posterior aspect of the ribs higher than the anterior aspect? | Yes |
| How many degrees should a patient be rotated for a PA oblique projection of the chest evaluating the lungs? | 45 degrees |
| Where should the CR be directed/centered for a lateral projection? | Perpendicular to the midline of the IR, at the level of T7. |
| Where is the midsagittal plane placed for a lateral projection? | The MSP should be parallel with the plane of the IR. |
| What body plane should be perpendicular and centered to the midline of the IR? | Midcoronal |
| With a PA Oblique projection, which side (the one closer or farther) is generally the side of interest? | The one farthest from the IR. |
| Which side of the chest (left or right) is of primary interest with the PA oblique projection, RAO? | Left side |
| When performing the PA oblique projection, RAO position, how many degrees should the patient be rotated? | 45 degrees |
| When performing the PA oblique projection, LAO position, how many degrees should the patient be rotated? | 55 to 60 degrees |
| Which AP oblique projection produces an image similar to that produced by the PA oblique projection, RAO position? | AP oblique projection, LPO position |
| In a AP Axial (Lordotic) projection, which portion of the lung is generally the area of interest? | Apex |
| In a AP Axial (Lordotic) projection, where should the CR enter the patient? | Midsagittal plane, on the midsternum. |
| What is the general purpose for using a lateral decubitus position? | To demonstrate air or fluid levels in the thorax. |
| If a patient has fluid on right side of thorax, which lateral decubitus position should be used? | Right lateral recumbent |
| Which side of the thorax will best demonstrate free air when the patient is in the left lateral decubitus position? | Right |
| What positions are used to demonstrate air and fluid levels in a supine or prone position? | Ventral and dorsal decubitus |
| For a dorsal decubitus position projection, what position is the patient placed in? | Supine |
| For a ventral decubitus position projection, what position should the patient be placed in? | Prone |
| Where is the CR entered on a patient for the dorsal decubitus projection? | Midcoronal plane, approximately 3-4 inches distal to jugular notch |
| Where is the CR entered on a patient for the ventral decubitus projection? | Midcoronal plane at level of T7 |
| Which structure is not demonstrated within the mediastinum in PA projections of the chest? | Diaphragm |
| Why should chest x-rays be performed with a 72-inch SID? | To minimize magnification of the heart. |
| Why should chest x-rays be performed after the patient has suspended respiration after the second inspiration? | To better expand the lungs. |
| With reference to the IR, how are the MSP and the MCP positioned for a chest PA projection? | MSP: perpendicular; MCP: parallel |
| For a chest PA projection, what maneuver should be performed to remove scapulae from lung fields? | Rotate the shoulders forward |
| For which chest projection should the MSP be parallel with the IR? | Lateral projection |
| Regarding the IR, how are the MCP and MSP positioned for the lateral projection of the chest? | MCP: perpendicular; MSP: parallel |
| Which chest projection demonstrates lung apices free from superimposition with the clavicles? | AP axial projection, lordotic position (Lindblom method) |
| How many degrees should patient be rotated for PA oblique projections of the chest to evaluate the lungs? | RAO: 45 degrees; LAO: 45 degrees |
| Using the lateral decubitus position for patients unable to stand best demonstrates which pathologic condition of the chest? | Air or fluid levels |
| Regarding IR, how are the MSP and the MCP positioned for the AP chest (left lateral decubitus position)? | Midsagittal: perpendicular; midcoronal; parallel |
| Which pathologic condition of the lungs is best demonstrated with the AP chest, right lateral decubitus position? | Free air in the left side or fluid levels in the right side? |
| Which pathologic condition of the lungs is best demonstrated with the AP chest, right lateral decubitus position? | Free air in the left side or fluid levels in the right side. |
| Which x-ray position requires that the patient be placed prone? | Ventral decubitus |
| Which evaluation criterion pertains to the AP axial projections, lordotic position radiograph of the chest? | The clavicles should lie superior to the apices. |
| Which decubitus would be performed for a patient with fluid on the left side? | Left lateral decubitus |
| Which x-ray position requires the patient to be placed supine? | Dorsal Decubitus |
| To demonstrate free air in the thoracic cavity on patient's left side, what position is used? | Right Lateral decubitus |
| During an upright PA chest x-ray, why is the patient asked to flex their arms and rest the back of their hands on the hips? | To rotate the scapulae laterally, avoiding superimposing the lungs. |
