01 Principles of Radiograph

RADIOGRAPH

a 2-dimensional representation of a 3-dimensional structure where the imaged produced is made up of multiple overlying structures

What are the advantages of a radiograph?

Being readily available

Being relatively cheap

Provides good anatomic resolution

What are the disadvantages of a radiograph?

Does expose the patient to radiation

It offers poor differentiation of soft-tissue structures

Not sensitive to subtle pathology

Enumerate rules to minimize errors when taking xrays

If possible, the patient should be awake

The X-ray beam must be perpendicular to the anatomic region being examined

The x-ray source should be the farthest possible distance from the region being examined (min distance: 2.75 m)

T

T/F: The greater the density of the tissue, the less penetration of x-rays there is and the whiter its image appears on the film

T

Xrays are based on the principle that different tissues have different densities and produce images in different shades of gray

XRAY

Part of the electromagnetic spectrum and have the ability to penetrate tissue to varying degrees

Radiographic density: foreign bodies (e.g., metals)

solid white

Radiographic density: contrast media

brigh white outline

Radiographic density: bones

white

Radiographic density: soft tissues, water

gray

Radiographic density: fat

gray-black

Radiographic density: air or gas

black

What are the pitfalls of image interpretation?

Errors of observation, errors of interpretation

F

T/F: Non-radiologist cannot offer expertise from her or his own area of clinical specialty nor collaborate with the radiologist and others involved in the patient’s care.

SCLEROTIC

increased bone density

LYTIC

bone destruction

CORTEX

compact (dense) bone forming the bone surface

MEDULLA

trabecular bone in the bone marrow

ARTICULAR

refers to a joint (an articulation)

DEMINERALIZATION

decreased bone density (as occurs with osteomalacia/osteopenia/ osteoporosis)

ANKYLOSIS

fusion

OSTEO

prefix meaning bony

CHONDRO

prefix meaning cartilaginous

FIBRO

prefix meaning fibrous

ARTHRO

prefix meaning joint

SPONDYLO

prefix meaning spinal

DACTYL

prefix meaning digit

What does ABCS stands for in searching patterns for radiologic image interpretation?

Alignment, Bone desity, Cartilage space, Soft tissues

PAGET’S DSE

POLYDACTYLY

CONGENITAL ANOMALY - CERVICAL RIB

CONGENITAL DEFORMITY

CLEIDOCRANIAL DYSOSTOSIS

DEVELOPMENTAL DEFORMITY - SCOLIOSIS

T

T/F: The cortical outline of each bone should be smooth and continuous.

HEEL SPUR

IMPACTION

AVULSION FRACTURE

ANT DISLOCATION OF GH JOINT

RA OF THE HANDS

OSTEOPOIKILOSIS

overall increase in skeletal density

OSTEOMALACIA

overall decrease in skeletal density

OSTEOPOROSIS

FLUFF TRABECULAE

random proliferation of both osteoblastic and osteoclastic activity; seen in the skull of a patient with Paget’s disease and in hyperparathyroidism

HYPERTHYROIDISM

SMUDGED AND INDISTINCT TRABECULAE

a characteristic of osteomalacia

COARSENING OF TRABECULAE

often seen in patients with chronic renal failure and osteoporosis

LACY, DELICATE APPEARANCE OF TRABECULAE

secondary to thalassemia (Cooley’s anemia)

COOLEY’S ANEMIA OR THALASSEMIA

SCLEROSIS

normal local increases in bone density seen in areas subjected to increased physical stress, such as the weight-bearing areas of joints; actually signs of repair-extra bone is deposited to fortify bony architecture to withstand the forces of weight-bearing

EXCESSIVE SCLEROSIS

evident in normal conditions: at the site of a healing fracture as callus is formed and new bone is remodeled
may also be seen in abnormal conditions: degeneration of an osteoarthritic joint

DJD OF THE KNEE

REACTIVE SCLEROSIS

present when the body acts to surround and contain a diseased area, such as a tumor or infection

OSTEOMYELITIS

F, should be decreased

T/F: An increased joint space implies that the cartilage or disk is thinned down as a result of degenerative processes.

DEGENERATIVE DISK DISEASE

T

T/F: In the inflammatory arthritides such as rheumatoid arthritis or gout, no reparative sclerosis is seen in the subchondral bone. Rather, erosions of the subchondral bone form radiolucencies at the joint margins.

GOUT AT IP JOINT

GROSS MUSCLE WASTING

may suggest a primary muscle disease, paralysis, inanition associated with severe illnesses, or disuse atrophy secondary to trauma

DISUSE ATROPHY OF QUADS

GROSS SWELLING OF MUSCLES AND SOFT TISSUES

may be indicative of inflammation, edema, hemorrhage, or tumor

RA OF THE HAND

T

T/F: Loss or displacement of fat pads and lines is usually due to swelling and is a clue to an adjacent abnormality.

F, should be pronator quadratus

T/F: Displacement of the pronator teres fat line at the wrist usually indicates a wrist fracture.

T

T/F: Displacement of the fat pads at the elbow (from the olecranon fossa posteriorly and from the coronoid and radial fossa anteriorly) often indicated hemarthrosis associated with fracture.

POSITIVE FAT PAD SIGN OR SAIL SIGN

SOLID

This reaction indicates an indolent (slow-growing) process; seen in fracture healing and chronic osteomyelitis.

LAMINATED OR ONIONSKIN

This reaction indicates repetitive injury, as in the battered child syndrome. It is also associated with sarcomas such as Ewing’s sarcoma.

SPICULATED OR SUNBURST

This reaction is almost always associated with malignant bone lesions, such as osteogenic sarcomas, and is less frequently seen in metastatic squamous cell tumors.

CODMAN’S TRIANGLE

A piece of periosteum elevated by abnormal conditions ossifies in a triangular shape. This may be present in a variety of conditions, including tumor, subperiosteal hemorrhage, and battered child syndrome.

GAS IN SOFT TISSUES

in soft tissues, this is an indication of gas-forming organisms,as in gangrene or trauma

CALCIFICATION

may be the result of trauma whereby hemorrhage has coagulated and calcified

MYOSITIS OSSIFICANS