RADR 2401, Chapter 15, Unit 1

What are the 3 positioning principles for mobile or trauma radiography?

(1)Min 2 projections, 90 degrees; IR & CR are perpendicular, (2)entire structure or trauma area on IR, (3)Maintain safety of the pt. (pg.570-571)

Smith's fx

(reverse Colles' fx) This is a fracture of the wrist with the distal fragment of the radius displace anteriorly rather than posteriorly, as in a Colles' fracture. It commonly results from a backward fall on an outstretched arm.

When looking for air/fluid levels with the decubitus chest/abdomen technique, which side should be down? How long should the pt be in position to allow fluid or air to settle?

*Fluid levels* best imaged with affected side down *Air levels* seen best with unaffected side down Patient should be in position *5 minutes* before exposure to allow fluid or air to settle

Greenstick fx (hickory or willow stick fx)

*Fracture is on one side only*. The cortex on one side of the bone is broken and the other side is bent. When the bone straightens, a faint fracture line in the cortex may be seen on one side of the bone and a slight bulging or wrinkle-like defect is seen on the opposite side.

When doing trauma femur projections using mobile radiography, which projection is preferred: lateromedial or mediolateral and why?

*Mediolateral* projection preferred because it provides *more visualization of proximal femur*

AP/PA Chest Lateral Decubitus Position

*Part position* Ensure lateral position without rotation Vertical IR top 2′′ (5 cm) above relaxed shoulders *CR* Horizontal and perpendicular to IR Enters about 3′′ (7.6 cm) below jugular notch at level of T7

Advantages of the capacitor-discharge mobile unit

-Smaller and easier to maneuver -Do not require much time to charge for each exposure (much less time than batteries to recharge)

Disadvantages of the capacitor-discharge mobile unit

-kVp drops constantly during exposure -Drop can cause inadequate penetration of thick body parts -Must be plugged into outlet

Three important technical factors must be clearly understood to perform optimum mobile examinations:

1. Grid 2. Anode-heel effect 3. Source-to-image receptor (SID)

Where should the tech stand? How far away?

90 degree angle from pt and primary beam 6 ft away

Define "open reduction"

A *surgical procedure*. The fracture site is exposed and screws, plates, or rods are installed as needed to maintain alignment of the bony fragments until new bone growth can take place. This is called an *open reduction with internal fixation (ORIF)*.

Splintered fx

A comminuted fracture in which the bone is splintered into thin sharp fragments.

Butterfly fx

A comminuted fracture with two fragments on each side of a main, wedge-shaped separate fragment; it has some resemblance to the wing of a butterfly.

Compound (open) fx

A fracture in which a portion of the bone (usually the fragmented end) protrudes through the skin.

Simple (closed) fx

A fracture in which the bone *does not break through the skin)

Bayonet apposition

A fracture wherein the fragments overlap and the shafts make contact, but not at the fracture ends.

Segmental fx

A type of double fracture in which two fracture lines isolate a distinct segment of bone; the bone is broken into three pieces, with the middle fragment fractured at both ends.

What is an important consideration when using grids in mobile radiography?

Align correctly to avoid grid cutoff Technical factors need to increase

Anatomic apposition

Anatomic alignment of ends of fractured bone fragments, wherein the ends of the fragments make end-to-end contact.

What are the 2 primary types of mobile x-ray units?

Battery & capacitor discharge

Describe the Capacitor-discharge mobile unit

Capacitor is a device that stores electrical energy Radiation is generated when an electrical discharge is sent across the x-ray tube electrodes from a bank of high-voltage capacitors Capacitor has to be plugged in to an electrical outlet to charge before each exposure

Advantages of the battery-operated mobile units

Cordless Provide constant kVp and mAs

How should IR be placed for average to large patient on portable AP chest? SID? Kv range? (CW, min 60 -72, 90-100

Crosswise Minimum of 60-72 inches SID 90-100 kVp

In fracture alignment terminology, *Angulation* refers to what?

Describes loss of alignment of the fracture; apex is the direction of the angulation and is opposite in relation to the distal part of the fracture fragments.

Apex angulation

Describes the direction or angle of the apex of the fracture, such as a medial or lateral apex, wherein the point of apex of the fracture points medially or laterally.

What is the most effective radiation protection measure?

Distance

Define "closed reduction"

Fracture fragments are realigned by manipulation and are immobilized by a cast or splint. It is a *nonsurgical procedure*

Transverse fx

Fracture is transverse at a *near right angle* to the long axis of the bone.

*Lateral Cervical Spine* LW or CW? Top of IR? CR? Pt position? SID? Breathing instructions?

IR *lengthwise* on right or left side, parallel to neck Top of *IR about 1′′* (2.5 cm) *above EAM* (TEA) *CR* centered to *C4* Raise chin slightly, if not contraindicated Relax shoulders and reach for feet, if possible *60′′ to 72′′* (158 to 183 cm) *to help demonstrate C7* Exposure made upon *full expiration* to maximize shoulder depression

Depressed fx (sometimes called a ping-pong fx)

In this *fracture of the skull*, a fragment is depressed. The appearance is similar to a ping-pong ball that has been pressed in by the finger, but if the indentation can be elevated again, it can assume it's near-original position.

In fracture alignment terminology, *Complete fx* refers to what?

In this fracture the *break is complete* and includes the cross-section of bone. The bone is *broken into two pieces*. There are three major types of complete fractures: 1. Transverse fx 2. Oblique fx 3. Spiral fx

Impacted fx

In this fracture, *one fragment is firmly driven into the other*, such as the shaft of the bone being driven into the head or end segment. These most commonly occur at distal or proximal ends of the femur, humerus, or radius.

Stellate fx

In this fracture, ,the *fracture lines radiate from a central point* of injury with a starlike pattern. The most common example of this type of fracture occurs at the patella and is often cause by knees hitting the dashboard in a mva.

Spiral fx

In this fracture, the bone has been twisted apart and the fracture *spirals* around the long axis.

Comminuted fx

In this fracture, the bone is *splintered or crushed* at the site of impact, resulting in *two or more fragments*. Three types of comminuted fractures have specific implications for treatment and prognosis because of the possible substantial disruption of blood flow: 1. *Segmental fx* 2. *Butterfly fx* 3. *Splintered fx*

How is the CR centered and aligned in relationship to the sternum for an AP portable projection of the chest?

Perpendicular to the sternum

What produces the most occupation dose for the technologist?

Scatter

Varus deformity

The distal fragment ends are angled *toward the midline* of the body and results in a lateral apex that points away from the midline.

Lack of apposition (distraction)

The ends of fragments are aligned but pulled apart and are not making contact with each other.

Chip fx

The fracture involves an *isolated bone fragment;* however, this is not the same as an avulsion fracture because this fracture is not caused by tendon or ligament stress.

Oblique fx

The fracture passes through bone at an *oblique angle.*

Boxer's fx

The fracture usually involves the distal fifth metacarpal, with an apex posterior angulation best demonstrated on the lateral view. It results from punching someone or something.

Barton's fx

The in an intra-articular fracture of the *posterior lip of the distal radius*

Valgus deformity

The opposite of varus; the distal fragment ends are *angled away fro the midline* and the apex is pointed toward the midline.

Pathologic fx

These fractures are due to *disease process within the bone*, such as osteoporosis, neoplasia, or other bone diseases.

Blowout and/or tripod fx

These fractures, which result from a *direct blow to the orbit* and/or maxilla and zygoma, create fractures to the orbital floor and lateral orbital margins, respectively, and are described and illustrated in Chapter 11.

Tuft or burst fx

This *comminuted fracture of the distal phalanx* may be caused by a crushing blow to the distal finger or thumb.

Torus fx

This buckle of the cortex (outer portion of the bone) is characterized by localized expansion or torus of the cortex, possibly with little or no displacement, and *no complete break in the cortex.*

Incomplete (partial) fx

This fracture *does not traverse through the entire bone*. The bone is not broken in two pieces. It is most common in children.

Hangman's fx

This fracture occurs through the pedicles of the axis (C2), with or without displacement of C2 or C3.

Monteggia's fx (mon-tej'-ahz)

This fracture of the *proximal half of the ulna*, along with *dislocation of the radial head*, may result from defending against blows with the raised forearm.

Trimalleolar fx

This fracture of the ankle joint involves the medial and lateral malleoli as well as the posterior lip of the distal tibia.

Baseball (mallet) fx

This fracture of the distal phalanx is caused by a ball striking the end of an extended finger. The distal interphalangeal (DIP) joint is partially flexed and an avulsion fracture is frequently present at the posterior base of the distal phalanx.

Colles' fx

This fracture of the wrist in which the distal radius is fractured with the distal fragment *displaced posteriorly*, may result from a forward fall on an outstretched arm.

Avulsion fx

This fracture results from severe stress to a tendon or ligament in a joint region. A *fragment of bone is separated or pulled away* by the attached tendon or ligament.

Epiphyseal fx

This is a fracture *through the epiphyseal plate*, the point of union of the epiphysis and shaft of a bone. It is one of the most easily fractures sites in long bones of children. Radiologists commonly use the *Salter-Harris classification* (Salter 1 to 5, with Salter 5 indicating the most complex) to describe the severity and reasonable indication of prognosis of these fractures.

Hutchinson's (chauffeur's) fx

This is an intra-articular fracture of the radial styloid process. (The name originates from the time when hand-cranked cars would backfire, with the crank striking the lateral side of the distal forearm.)

Bennett's fx

This longitudinal fracture, which occurs at the *base of the first metacarpal* with the fracture line entering the *carpometacarpal joint* generally includes a posterior dislocation or subluxation.

Pott's fx

This term is used to describe a complete fracture of the *distal fibula* with major injury to the ankle joint, including ligament damage and *frequent fracture of the distal tibia or medial malleolus*.

Stress or fatigue fx (sometimes called a *march* fx)

This type of fracture is *nontraumatic in origin*. It results from repeated stress on a bone, such as from marching or running. If caused by marching, these fractures usually occur in the midshafts of metatarsals; if caused by running, they are in the distal shaft of the tibia. Stress fractures are frequently difficult to demonstrate radiographically and may be visible only through subsequent callus formation at the fracture site or on a nuclear medicine bone scan.

Compression fx

This vertebral fracture is caused by compression-type injury. The vertebral body collapses or is compressed. Generally, it is most evident radiographically by a decreased vertical dimension of the *anterior vertebral body*.

Describe the Battery-operated mobile unit

Uses two different sets of batteries -One set used to control x-ray power output -Second set powers the self-propelled driving capability Fully charged batteries can make 10 to 15 exposures and be driven reasonable distances around the institution.

Who should be shielded during mobile radiography?

You and the patient, and anyone assisting with exam.

In fracture alignment terminology, *Apposition* refers to what?

describes the manner in which the fragmented ends of the bone make contact with each other. There are 3 types of apposition: 1. Anatomic apposition 2. Lack of apposition (distraction) 3. Bayonet apposition