# Projection Flashcards

AP projection (anteroposterior)

A perpendicular central ray enters the anterior body surface and exits the posterior body surface. In a true AP projection without rotation, the CR is perpendicular to the coronal plane and parallel to the MSP

What does projection refer to?

The path of the central ray.

An AP projection of the foot is also called:

a dorsoplantar projection

PA projection (posteroanterior)

A perpendicular central ray enters the posterior surface of the body and exits the anterior body surface.

AP oblique projection

During an oblique projection the CR enters the body or body part from a side angle following an oblique plane. An AP oblique projection enters the anterior surface. An AP oblique projection of the upper or lower limbs must also include a qualifying term indicating which way it is rotated such as medial or lateral.

PA oblique projection

During an oblique projection the CR enters the body or body part from a side angle following an oblique angle. A PA projection enters the posterior surface. A PA oblique projection of the upper or lower limbs must also include a qualifying term indicating which way it is rotated such as medial or lateral.

Mediolateral and lateromedial projections

A lateral projection is described by the path of the CR. A Mediolateral projection enters the medial side and exits the lateral side. A lateromedial projection enters the lateral and exits the medial. (used with limbs)

An AP projection of the foot is also called:

Dorsoplantar

What three positions can PA projections be achieved in?

Seated, prone and lateral decubitus

Axial projection

In an axial projection, there is longitudinal angulation of the central ray with the long axis of the body OR a specific body part. The angle must be greater than ten degrees.

How can an axial projection be achieved when keeping a perpendicular central ray?

By angling the entire body or body part.

Tangential Projection:

- Means touching a curve or surface at only one point.
- Describes a projection that merely skims a body part to project that part into profile and away from other body structures.

Lordotic position - AP axial projection

Demonstrates the apices of the lungs. The long axis of the body is angled rather then the CR.

Transthoracic lateral projection

A unique lateral projection through the thorax used for shoulder radiography. Requires a positioning term (right or left lateral position) to indicate which shoulder is closest to the IR & is being examined.

Dorsoplantar and plantodorsal projections

Dorsoplantar (DP) describes the path of the CR from the dorsal surface to the plantar surface.

A special plantodorsal projection of the heel bone (calcaneus) is called an axial plantodorsal projection because the angled CR enters the plantar surface of the foot & exits the dorsal surface.