RADPOS 2 - Finals

It allows imaging to be performed directly at the patient's location.

What is the primary advantage of mobile radiography?

kVp and mAs

Which settings can you control on most mobile x-ray units?

15–25 kW

What is the typical power range for a mobile x-ray machine?

kVp: 40–130; mAs: 0.04–320

What are the typical kVp and mAs ranges found on mobile x-ray machines?

Position patient and equipment carefully for diagnostic quality

What is a recommended principle for using mobile x-ray equipment?

Stationary units have more power and are used only in radiology rooms.

How does a stationary radiography machine typically compare to a mobile unit?

Reduce scatter radiation and improve image quality

What is the main purpose of using a grid in mobile radiography with CR or DR systems?

Grid cutoff resulting in reduced image density or distortion

What may occur if a grid is tilted or if the central ray is not centered on the grid?

6:1 or 8:1

Which grid ratio is most commonly used in mobile radiography?

Image density is lower under the anode side, especially with short SID and large field sizes

How does the anode heel effect impact mobile radiography exposures?

It compensates for decreased intensity under the anode (heel effect)

Why should the cathode side of the x-ray tube be positioned over thicker anatomy during a mobile exam?

40 inches (102 cm)

What is the recommended standard SID for most mobile radiographic examinations?

For larger body parts, though it requires increased mAs and longer exposure time

When is a longer SID (40−48 inches) sometimes used in mobile radiography?

Caliper

What tool is important for determining technique factors in mobile radiography based on patient thickness?

6 feet (2 meters)

What is the minimum safe distance a radiographer should maintain from the x-ray source and patient during mobile radiography?

At a 90° angle to the beam

Where should a radiographer stand in relation to the primary beam to receive the least amount of scatter radiation?

12 inches (30 cm)

What is the federally mandated minimum source-to-skin distance (SSD) for mobile radiography?

To protect the patient from outside microorganisms

What is the primary purpose of reverse isolation in mobile radiography?

To protect the IR and patient from possible body fluid contamination

Why should image receptors (IRs) be placed in a clean, impermeable cover for some isolation procedures?

To maintain a clean/dirty barrier—one handles the patient, the other the equipment

In strict isolation procedures, why might two radiographers be used?

Toward the middle of the bed

When positioning the mobile unit, how should the machine base be placed for a supine patient?

Ask the patient's permission or check with staff

Before moving any part of a patient's body, what MUST the radiographer do?

Adjust the position of the IR or the central ray

If medical devices (e.g., tubes, traction frames) cannot be moved out of the x-ray beam, what should the radiographer do?

2 inches above the shoulders

In the AP chest projection, where should the top edge of the image receptor (IR) be placed in relation to the patient's relaxed shoulders?

To move the scapulae out of the lung fields

Why should the patient's arms be internally rotated for a chest AP projection, if not contraindicated?

3 inches below the jugular notch at the level of T7

Where should the central ray (CR) enter for an AP chest projection to ensure proper centering?

Expose during full inspiration

Which technique ensures optimal visualization of the lung fields during a mobile chest AP projection?

Grid

During mobile CR chest radiography with a technique over 90 kVp, what additional equipment must be used?

To avoid excess shadow of the shoulders above the IR

Why is proper patient alignment critical for AP chest imaging, especially regarding the position of the shoulders?

To reveal air or fluid levels in the pleural cavity

What is the primary purpose of the lateral decubitus chest projection?

Lateral recumbent on a firm pad, knees flexed, and arms above the head

How is the patient positioned for a lateral decubitus chest x-ray?

To prevent the patient from sinking into the mattress

Why should a firm pad be placed under the patient in this projection?

Place the IR behind the patient, below the support, grid extends 2 inches above the shoulders, IR upright

How should the image receptor (IR) and grid be positioned for a lateral decubitus chest projection?

Affected side down

Which side should be positioned down to best visualize pleural fluid in a lateral decubitus chest exam?

At least 5 minutes to let air rise and fluid settle

How long should the patient remain in position before making the exposure and why?

On full inspiration

On which respiration phase should the exposure be taken for a lateral decubitus chest projection?

Both lung fields and any air/fluid levels in the pleural cavity

What structures are demonstrated in a lateral decubitus chest projection?

Supine

What is the recommended patient position for the AP projection of the abdomen in mobile radiography?

At the iliac crests

Where should the grid be centered for a general AP abdomen projection?

Suspended expiration

What is the preferred respiration phase for an AP abdominal image?

Two crosswise projections

For hypersthenic patients (with a broad abdomen), what adaptation may be required for a complete survey?

To avoid grid tipping and cutoff

Why is it important to stabilize the grid when positioned under the patient for a mobile AP abdomen radiograph?

Left lateral recumbent

Which patient position is typically used for detecting air or fluid levels in the abdominal cavity using the left lateral decubitus projection?

Both arms raised away from abdomen

How should the patient's arms be positioned during the left lateral decubitus projection for the abdomen?

2 inches (5 cm) above the iliac crests

Where should the grid be centered for the left lateral decubitus abdominal projection?

Right border

Which abdominal border must be visualized in the left lateral decubitus projection?

14 × 17 inches

Which technical factor is correct for collimation in the left lateral decubitus abdominal projection?

To ensure the entire abdominal area is visualized

Why might hypersthenic or tall patients require two projections for the left lateral decubitus abdomen examination?

Vertically in front of the patient

For a PA projection in the left lateral decubitus position, where is the grid placed?

Midway between the anterior superior iliac spine (ASIS) and pubic symphysis

When performing a mobile AP pelvis projection, where should the grid be centered?

Rotated medially about 15°

For optimal visualization in the AP pelvis projection, how should the patient's legs be positioned (unless contraindicated)?

Angle the x-ray tube caudally

What is a common technical adjustment needed if the patient's weight causes the grid to tilt upward at the bottom?

Hip bones, sacrum, coccyx, and proximal femora

Which structures are primarily visualized in a proper AP pelvis radiograph as described?

14 × 17 inches

What is the suggested field size (collimation) for a mobile AP pelvis x-ray?

Supine

How should the patient be positioned for a mobile AP femur radiograph?

Place grid lengthwise under femur, with distal edge low enough to include fracture and knee joint.

Which of the following best describes correct grid placement for the AP femur projection?

Top at ASIS for hip, bottom at tibial tuberosity for knee, sides 1 inch beyond femur shadow, length 17 inches (43 cm)

How should collimation borders be set for a mobile AP femur projection?

Measure the thickest part of the femur and choose a kVp high enough to penetrate it.

What adjustment should be made for digital imaging to ensure visualization of the proximal femur?

Over the proximal femur

To improve CR image quality for the proximal femur, where should the cathode be positioned?

Distal two thirds of the femur including the knee joint

What anatomical region is visualized in most mobile AP femur radiographs?

Vertically alongside the lateral side of the femur

In the mediolateral lateral projection of the femur for mobile radiography, where should the grid be placed?

Top at ASIS for hip, bottom at tibial tuberosity for knee, 1 inch beyond femur shadow, length 17 inches

Which of the following best describes the collimation field for a lateral femur mobile projection?

Measure the thickest section (proximal femur) and select sufficient kVp for penetration

What is the most important technical consideration for exposure in digital radiography of the femur?

The distal two thirds of the femur and the knee joint, without superimposed opposite thigh

Which anatomical region is best visualized with the mediolateral projection of the femur?

Grid and central ray must be perfectly aligned and centered to the femur

To avoid grid cutoff when imaging the lateral femur, what must always be ensured?

1 inch (2.5 cm) above the external acoustic meatus (EAM)

Where should the top of the grid be positioned for a lateral cervical spine radiograph?

To minimize magnification from large object-to-image distance (OID)

Why is the SID recommended to be 60–72 inches (158–183 cm) for a lateral cervical spine projection?

Have the patient relax shoulders and reach for feet, if possible

How should the radiographer manage the patient's shoulders to visualize C6 and C7?

Consult the nurse or physician before elevating the chin

When imaging a trauma patient with possible cervical fracture, what must you do before moving the chin?

Align the central ray horizontally and perpendicular to the grid

How is grid cutoff prevented in mobile lateral cervical spine imaging?

Swimmer's (Twining) view

If a standard lateral projection does not adequately show C6 and C7, what method is recommended?

Base of the skull, C1–C7, and soft tissues of the neck

Which anatomical structures should always be included in a lateral cervical spine projection?

To penetrate the lower cervical vertebrae, especially C7

Why must kVp be set high enough when using digital radiography for this projection?

Supine

What is the preferred patient position for the AP projection of the chest and abdomen in a neonate?

Arms away from body or above head, legs down and away from abdomen

How should the neonate's arms and legs be positioned during this exam?

Leave the head in the usual (routine) position

What is the correct approach regarding the neonate's head position when an endotracheal tube is in place?

Top 1 inch above shoulders, bottom at pubic symphysis, 1 inch on sides

Which of the following best describes the collimation boundaries for a combined chest and abdomen image in a neonate?

To keep the IR warm and comfortable for the neonate

Why is it recommended to cover the IR with a soft, warm blanket for this exam?

Aim for exposure on inspiration, timing as best as possible

How should respiration be managed during neonatal chest and abdomen x-rays?

Entire chest, airways, lung fields, heart, and abdominal organs

Which anatomical structures should be shown on a neonate combined chest and abdomen AP x-ray?

Neonates cannot be turned or placed upright safely

Why is the dorsal decubitus position used for lateral chest and abdomen radiography in neonates?

Lengthwise and vertical, beside the infant

How should the image receptor (IR) be positioned for a lateral projection in a neonate?

Horizontally and perpendicular to the midcoronal plane at the midpoint of the chest and abdomen

Where should the central ray be directed in a lateral neonate chest/abdomen projection?

Entire chest and abdomen, including costophrenic angles and air/fluid levels

Which anatomical structures should be fully visualized in a successful lateral chest and abdomen neonate radiograph?