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Flashcards in Imaging and modalities Deck (11)

Radiography (plain x-rays)

noninvasive imaging used to identify and screen for bone and joint injuries, lung or heart disease, foreign objects, etc

use ABCS to interpret:
-Alignment with adjacent bones, contours
-Bone density and texture of bone (>density=whiter)
-Cartilage spaces: joint space width, presence of subchondral bone, epiphyseal plates

Advantages: convenient, inexpensive, quick

Disadvantages: exposure to ionizing radiation, poor for visualizing subtle fractures and soft tissue injuries


Magnetic resonance imaging (MRI)

T1 vs. T2

noninvasive test used to provide visualization of soft tissues; uses magnetic fields rather than radiation

sectional images can be configured into 3D

utilizes 2 types of images:
-T1 demos fat within the tissues and typically used to asses bony anatomy
-T2 suppresses fat and demos tissues with high water content; used to assess soft tissue structures

Advantages: high quality imaging of almost any body structure

Disadvantages: relatively expensive, time-consuming, can't be used if patient has any implanted metal device, claustrophobic environment


Computed tomography (CT) or CAT scan

noninvasive test that provides sectional imaging of bone and most soft tissues

used plain film lives that are enhanced y a computer to improve evolution; multiplayer so can image in any plane

especially useful for chest and abdomen

typically used to assess complex fractures as well as facet dysfunction, disc disease or spinal stenosis

Advantages: fast; provides high quality imaging of bone, soft tissue and blood vessels all at the same time

Disadvantages: large amounts of radiation; not as high quality as MRI for soft tissues; relatively expensive.


Bone scan or bone scintigraphy

uses a radio nucleotide injected intravenously to visualize areas of increased metabolic activity in bone (remodeling)- isotope settles in areas of high activity ("hot spots")

helpful for identifying stress fractures and tumors that are not detected by x-ray; also used for RA, bone cancer, bone infection

Advantages: small amounts of radiation; ability to visualize metabolic activity in bone

Disadvantages: slow procedure (1 hour scan + time for contrast to circulate after injection); potential adverse reaction to contrast



an invasive procedure in which a catheter and contrast material are used in conjunction with x-rays, CT or MRI to visualize blood vessels throughout the body



radiography of a joint after injection of opaque contrast material

typically used to identify abnormalities within joints (tendon ruptures)

expensive and carries invasive risks


Bone density scan or dual energy x-ray absorptiometry (DEXA)

gold standard for measuring bone mineral density

delineates osteopenia from osteoporosis


Diagnostic Ultrasound

clinically convenient, noninvasive procedure for helping diagnose partial tendon tears, soft tissue lesions, and swelling.

Utilizes transmission of high frequency sound waves; limited by contrast resolution, small viewing field, depth penetration and poor penetration of bone. Interpretation of data is subjective, so results depend on operator skill.

Can also be used as biofeedback to facilitate muscle activation (rehab US)


Positron emission tomography (PET) scan

used to detect non perfusing areas of the heart or to evaluate the brain in suspected cases of dementia, stroke, seizures and tumors.



radipaque dye is injected into the disc to identify abnormalities within the disc (annulus or nucleus). The needle is inserted into the disc with the assistance of radiography (fluoroscopy).

not commonly used. requires high level of skill and proper equipment.

Fairly specific technique to identify internal disc disruptions of the nucleus and/or annulus

expensive, may be painful, and risk of infection since invasive



invasive technique using water-soluble dye. Dye is visualized as it passes through vertebral canal to observe anatomy within region.

rarely used due to side effects vs. MRI or CT scan; very expensive

traditionally used for discs and stenosis