Question 1

A patient enters the emergency department (ED) with a possible pneumothorax of the right lung.The patient is unable to stand or sit erect.Which specific position should be performed to diagnose this condition?

Accepted Answer

The left lateral decubitus position is the best choice for diagnosing a possible pneumothorax of the right lung. This position allows the air to rise to the uppermost part of the thorax, making it easier to detect any abnormal pockets of air. In addition, the patient's weight is not resting on the affected side, which can cause discomfort or compromise the diagnostic findings.

Question 2

A patient enters the ED with a possible shoulder dislocation.Because of his multiple injuries, the patient is unable to stand or sit erect.Which of the following routines best demonstrates the dislocation?

Accepted Answer

The AP and horizontal beam transthoracic lateral projections are suitable for patients who cannot stand or sit erect, as they allow for imaging in a supine position.

Question 3

What is the primary disadvantage of performing a PA thumb over an AP projection?

Accepted Answer

The primary disadvantage of performing a Posteroanterior (PA) thumb over an Anteroposterior (AP) projection is that it results in an increase in object image receptor distance (OID). This can lead to a decrease in image sharpness due to increased magnification and potential distortion of the thumb's anatomy.

Question 4

A patient enters the ED with severe trauma to the abdomen.The ED physician is concerned about bleeding in the abdomen with associated possible free intra-abdominal air.The patient is unable to stand or sit erect.Which position best demonstrates the condition?

Accepted Answer

The lateral decubitus position is the best position for assessing free intra-abdominal air and identifying bleeding in the abdomen. This position allows the fluid or air to accumulate in the dependent part of the abdomen and is useful for identifying small quantities of fluid or air that may not be visible in other positions. The supine, dorsal decubitus, and ventral decubitus positions are not as useful for this purpose.

Question 5

A 30° tilt of the C-arm x-ray tube from the vertical position will increase radiation exposure to the face and neck region of the operator standing next to the C-arm by approximately a factor of:

Accepted Answer

When the C-arm x-ray tube is tilted at a 30° angle from the vertical position, the cosine of the angle (cos 30° = 0.866) increases the radiation exposure to the operator's face and neck region by a factor of approximately 4. Therefore, the correct choice is option C.

Question 6

A patient enters the ED with a possible fractured sternum.The patient is supine and unable to lie prone.Which of the following routines best demonstrates the sternum?

Accepted Answer

The LPO position allows for the sternum to be projected over the heart shadow for better visualization, and the horizontal beam lateral is suitable for patients who cannot lie prone.

Question 7

What type of "holding breath" instructions should be given for an AP projection (patient supine) of the ribs located above the diaphragm?

Accepted Answer

Exposing upon inspiration is correct for imaging ribs located above the diaphragm because it allows the diaphragm to move downward and the lungs to expand, providing a clearer view of the ribcage without the interference of overlying diaphragmatic tissue.

Question 8

Which of the following positions or projections best demonstrates free intra-abdominal air on the patient who cannot stand or sit erect?

Accepted Answer

The left lateral decubitus position is best for demonstrating free intra-abdominal air in patients who cannot stand or sit erect because it allows air to rise and be visualized against the liver on the right side.

Question 9

A radiographer receives 400 mR/hr standing 1 foot from a C-arm fluoroscopy unit.What is the exposure rate if the radiographer moves to 3 feet?

Accepted Answer

The exposure rate decreases as the distance from the source increases. The inverse-square law states that the intensity of radiation is inversely proportional to the square of the distance from the source. Therefore, if the radiographer moves to 3 feet, the exposure rate would be approximately 25 to 50 mR/hr (400 mR/hr divided by 9). Choices A and B overestimate the exposure rate while choice D underestimates it.

Question 10

A patient enters the ED with a fractured forearm.The physician reduces the fracture and places a fiberglass cast on the forearm.The initial analog technique was 55 kV and 5 mAs.Which of the following technical factors is best for the postreduction study?

Accepted Answer

The answer of A patient enters the ED with a...

Question 11

Beyond the AP projection, what other projection should be taken if the patient is unable to stand for a possible proximal humeral dislocation?

Accepted Answer

The AP oblique-scapular Y projection is recommended for patients who are unable to stand when a proximal humeral dislocation is suspected. This projection provides a clear view of the humeral head in relation to the glenoid, helping in the diagnosis of dislocations.

Question 12

How much rotation is required for an AP oblique projection of the sternum on a hypersthenic patient?

Accepted Answer

A hypersthenic patient requires less rotation, around 15°, for an AP oblique projection of the sternum due to their broader thorax.

Question 13

How much CR angulation should be used for an AP axial projection of the clavicle on an asthenic patient?

Accepted Answer

Asthenic patients are typically slender and have a longer clavicle. Therefore, a higher CR angle of 30° cephalad will help open up the acromioclavicular joint space and project the clavicle out of the superimposed shoulder structures.

Question 14

Where should the operator (or surgeon) stand when using a C-arm fluoroscopy unit in a horizontal central ray (CR) position?

Accepted Answer

The operator should stand at the intensifier end of the C-arm to minimize radiation exposure, as the intensity of scattered radiation is significantly lower on this side compared to the x-ray tube side.

Question 15

A patient enters the ED on a backboard with multiple injuries, including an injury to the knee region with a possible stellate fracture noted on the examination requisition.Which of the following routines best demonstrates this injury safely?

Accepted Answer

The horizontal beam lateral projection is the safest and most effective way to image a patient with a suspected stellate fracture of the knee who is on a backboard, as it requires minimal movement of the injured limb, reducing the risk of further injury. This method also allows for a clear view of the knee and patella without the need for knee flexion, which could be painful or harmful given the patient's condition.

Question 16

A patient's lower leg is in traction in the hospital bed.The orthopedic surgeon orders an AP mortise projection of the ankle.Because of the traction, the lower leg cannot be rotated.The leg is in a straight "foot up" position.What can the radiographer do to achieve this AP mortise projection?

Accepted Answer

To achieve an AP mortise projection without rotating the lower leg, the radiographer can angle the central ray (CR) 15° to 20° lateromedial. This compensates for the inability to rotate the leg by angling the x-ray beam instead.

Question 17

A patient comes to the ED with a possible abdominal aortic aneurysm.Which of the following projections of the abdomen best demonstrates it?

Accepted Answer

The dorsal decubitus position allows for a lateral view of the abdomen, which is useful in visualizing the abdominal aorta and any potential aneurysms.

Question 18

How should the CR be aligned for a trauma PA projection of the elbow?

Accepted Answer

The CR should be perpendicular to the interepicondylar plane for a trauma PA projection of the elbow. This plane is formed by a line connecting the medial and lateral epicondyles of the humerus.

Question 19

How should the CR be aligned for an AP projection of the chest?

Accepted Answer

To obtain an AP projection of the chest, the CR should be aligned perpendicular to the long axis of the sternum. This will ensure that the heart and lungs are visualized in their proper anatomical position. The other options (B, C, D) are incorrect because they do not correspond with the proper alignment for an AP projection of the chest.

Question 20

A patient enters the ED with a possible fractured scapula.Because of her multiple injuries, the patient is on a backboard.Which of the following techniques is most helpful in providing a lateral view of the scapula if the patient is unable to rotate the affected shoulder adequately?

Accepted Answer

Angling the CR lateromedial and parallel to the scapular body allows for a lateral view of the scapula without requiring the patient to rotate the shoulder.

Quiz 15: Trauma, Mobile, and Surgical Radiography