RADT Ch. 2: Chest Anatomy, Positioning, & Conditions

3 sections of the chest/thorax:

1. bony thorax

2. respiratory system proper

3. mediastinum

bony thorax

sternum, ribs, and thoracic vertebrae

sternum's 3 sections:

manubrium, body, xiphoid process

vertical prominens

-C7

-used to help determine the CR on a chest PA.

-palpitate base of neck

jugular notch

-felt as deep depression superior to sternum

-used to determine the CR on a chest AP

diaphragm

primary muscle of inspiration

Hemidiaphragm

each half of the diaphragm

how does the diaphragm move during inspiration?

Contracts and pulls down, decreasing pressure in thoracic cavity

pharynx

-throat; passage for food, fluids, air

-3 divisions: nasopharynx, oropharynx, laryngopharynx

nasopharynx

-the area directly posterior to the nose

-oral cavity; contains the hard and soft palates

uvula

-small projection hanging from the back middle edge of the soft palate

-marks boundary between the nasopharynx and oropharynx

oropharynx

-posterior to mouth

-tongue is the anterior wall

-palatine and lingual tonsils

laryngopharynx

above and posterior to the larynx (C3-C6)

thyroid cartilage

anterior cartilage that covers the larynx

laryngeal prominence

-Adam's apple (outer projection of thyroid cartilage)

-C4-C5

cricoid cartilage

-the ring-shaped structure that forms the lower portion of the larynx

-connects to 1st ring of trachea

the larynx is suspended by the _______.

hyoid bone

Epiglottis

-A flap of tissue that seals off the windpipe and prevents food from entering the bronchi

-posterior to larynx and trachea

trachea

-windpipe

-16-20 cartilage rings to prevent collapse

-C6-T4/T5

carina

Point at which the trachea divides into the left and right mainstem bronchi.

3 major endocrine glands associated with the trachea

1. thyroid gland

2. parathyroid gland

3. thymus gland

thyroid gland

-left and right lobes positioned on trachea

-regulate metabolic hormones

-IMPORTANT to shield from radiation

parathyroid glands

-four small glands on the posterior of the thyroid gland

-regulate blood hormones

thymus gland

-anterior and superior to heart

-prominent in infants to build immune system; disappears completely into adulthood.

what does an AP trachea show?

-possbile abnormalities in thymus/thyroid glands

-air-filled trachea

what does a lateral trachea x-ray show?

esophagus and its relation to the trachea/larynx

aortic arch

a curved blood vessel from which arteries branch to the head and neck.

brachiocephalic artery

The first major branch off of the aorta and the major artery to the forelimbs and head.

left common carotid artery

supplies left side of head and neck

left subclavian artery

Third branch of the aortic arch that distributes blood to the left arm

right primary bronchus

-wider, shorter, more open, and more vertical than the left primary bronchus

-easier for foriegn material to enter

how many lobes in the left lung?

2 (superior and inferior) lobes\

2 primary bronchi

oblique fissure

-separates superior and inferior lobes of left lung

-separates middle and inferior lobes of the right lung

How many lobes in the right lung?

3 (superior, middle, inferior)

3 primary bronchi

horizontal fissure

separates the superior and middle lobes of the right lung

lingula

flat, tongue-shaped process on the left lung

cardiac notch

a concave space on the left lung in which the heart lies

the lung tissue is composed of _______

parenchyma; provides elasticity

pleura

double-layered membrane surrounding each lung

parietal pleura

outer layer of pleura lying closer to the ribs and chest wall

visceral (pulmonary) pleura

covers the external lung surface

pleural cavity

space between the pleural layers

pneumothorax

-condition of air/gas in the pleural cavity

-may cause lung to collapse

hemothorax

condition of blood accumulating in the pleural cavity

pleural effusion

refers specifically to the fluid that acculmulates in the pleural cavity

what pulmonary anatomy should be seen on a PA chest x-ray?

-Apices

-Carina

-Base of lungs [rests on diaphragm]

-Costophrenic angles

-Hilum

hilum

depression in an organ where blood vessels and nerves enter and leave

what is uniquely visible during lateral chest x-ray?

the oblique fissure

Mediastinum

-space between the lungs.

-It contains the heart, esophagus, trachea, thymus glands, and great blood vessels.

pericardial sac

surrounds the heart and helps prevent overfilling.

superior vena cava

large vein that returns deoxygenated blood to the heart from the upper body

inferior vena cava

large vein that returns deoxygenated blood to the heart from the lower body

aorta

-The largest artery in the body.

-Carries oxygenated blood from the left ventricle to the rest of the body.

ascending aorta

Branches off the left ventricle; carries oxygen rich blood to parts of the body above the heart

arch of aorta

The most superior portion of the aorta, lying between the ascending and descending segments of the aorta.

descending aorta

the descending part of the aorta that branches into the thoracic and abdominal aortae

pulmonary arteries & veins

supply blood and return blood to and from all segments of the lungs

body habitus

general appearance/state of a person's body

asthenic

very slender (10%) build

-narrow thorax/chest

-long vertically

hyposthenic

slender (35%)

sthenic

Average body habitus (50%)

hypersthenic

broad frame (5%)

what three dimensions does the thoracic cavity increase with inspiration?

1. vertical diameter

2. transverse diameter

3. anteroposterior diameter

-> returns to normal size with expiration

vertical diameter

increases volume by contraction and downward movement of the diaphragm

transverse diameter

ribs swing outward and upward

anteroposterior diameter

raise ribs, specifical 2nd-6th ribs

a minimum of ____ in posterior x-ray

10-11 ribs visible

chest x-ray uses ____ contrast

low

kVp of chest x-ray

-adult: 110-125

-pediatric: 70-80

situs inversus/visceral inversion

major organs of the body are on the opposite side

how do you position a newborn for a chest x-ray?

-AP: supine OR PA with Pigg-O-Stat

-Lateral supine or Pigg-O-Stat

Geriatric CR location

some geriatric patients have a smaller lung field; may need to adjust CR to T6-T7

why are chest x-rays done standing?

1. diaphragm moves down farther

2. air and fluid levels can be properly visualized

3. prevents engorgement and hyperemia

engorgement

swollen with fluid

hyperemia

excess of blood in an area of the body

evaluation criteria for PA chest x-ray

-no rotation

-extended chin

evaluation criteria for lateral chest x-ray

-left [unless ordered otherwise]

-no rotation

-no tilt

-raise arms/no superimposition

chest x-ray collimation

1.5-2 inches above vertebra prominens

SID for chest radiography

72 inches

patient positioning for PA chest X-ray

-even footing

-chest towards wall IR

-shoulders rolled forward

-chin up

Patient Positioning for Lateral Chest X-ray

-left side towards wall iR

-straight back

-arms raised away from sides

Positioning AP semierect

Positioning AP supine

AP lateral decubitus

AP Lordotic Chest

-CR- perpendicular to mid sternum, with pt standing at a foot away from the IR leaning back

-Back and head against IR

-If pt cannot stand direct CR 15-20 degrees cephalic

left anterior oblique (LAO)

angle that places left anterior portion of the body closest to the image receptor; usually 45 degree angle

right anterior oblique

angle that places right anterior portion of the body closest to the image receptor; usually 45 degree angle

Lateral Upper Airway X-Ray Stats

-CR: C6-C7

-SID: 72"

-10 x 12 inch cassette

-Grid

-kVp: 75-85

AP Upper Airway X-Ray Stats

-CR: T1-T2

-SID: 40"

-10 x 12 inch cassette

-Grid

-kVp: 75-85

-raise chin

aspiration

-mechanical obstruction, usually when foreign objects are swallowed into bronchial tree

-AP + Lateral Chest, AP + Lateral upper airway X-Rays

Atelectasis

-condition involving a collapsed lung

-collapsed portion appears lighter (more "radiodense") sense there is less air in the lung

mediastinal shift

shift of central thoracic structures toward one side

Bronchiectasis

abnormal dilation of the bronchi with accumulation of mucus

chronic obstructive pulmonary disease (COPD)

-a disease that results in a gradual loss of lung function; increasingly difficult to empty air from the lungs

-only present on x-ray if severe

cystic fibrosis (CF)

-hereditary; causes excessive mucus to clog the bronchioles

-x-ray may show hyperinflated (large) lungs and lots of radiodensity

Emphysema (COPD)

-progressive destruction of the alveoli in the lungs; trouble expelling air

-x-rays show increased lung dimension, very radiolucent (dark), depressed diaphragm, and elongated heart shadow

Epiglottitis

-inflammation of the epiglottis

-can be fatal in children 2-5

lung neoplasm

new growth or tumor;

may be benign or malignant

Hamartoma

benign peripheral pulmonary mass

empyema

pus in the pleural cavity