Positioning - Bony Thorax

• supports wall of pleural cavity & diaphragm

• made to vary the volume of thoracic cavity during respiration

• protects heart & lungs

functions of bony thorax

• sternum

• 12 pairs of ribs

• 12 thoracic vertebrae

bony thorax is formed by:

conical

_____ in shape (narrow at top)

wide

more _____ than deep

longer

ribs are_______ posteriorly than anteriorly

6 inches

sternum is approx. how long?

• manubrium

• body

• xiphoid process

3 parts of sternum

manubrial angles

sternum supports clavicles at ______ - forms sternoclavicular (SC) joints

seven

sternum provides attachment for first _____ pairs of ribs at lateral borders

jugular notch

_______ at superior border of manubrium- palpable landmark

• lies at T2-3 interspace

body (approx. 4 inches)

longest portion of sternum & how long

sternal angle

manubrium joins body of sternum at ________

T4-5 interspace

sternal angle is palpable and lies at ______

xiphoid processes

distal, smallest portion of sternum

T10

xiphoid process lies over ______

12

how many pairs of ribs

ribs

long, narrow, curved bones

• anterior ends lie lower than posterior (vertebral) ends

• slant anteriorly and inferiorly

1st rib

shortest & broadest rib

true ribs

attach directly to sternum

pairs 1-7

true ribs

false ribs

do not attach directly to sternum

pairs 8-12

false ribs

floating ribs

attach only to the vertebrae

pairs 11 & 12

floating ribs

3-5 inches higher

posterior (vertebral) end sits _________ than the anterior (sternal) end

costocondral articulations

• between costal cartilage and sternal end of ribs 1-10

• immovable, cartilaginous, synchondrosis

sternoclavicular joints

• btw the sternal end of clavicle and clavicular notch of manubrium

• freely moveable, synovial, gliding

• only bone articulation btw shoulder girdle and bony thorax

sternocostal joints

• btw costal cartilages of true ribs & sternum

• 1st - immovable, cartilaginous, synchondrosis

• 2-7 - freely moveable, synovial, gliding

interchondral joints

• btw costal cartilages of 6-7, 7-8, 8-9 ribs

• 6-9 - freely moveable, synovial, gliding

• 9-10 - slightly moveable, fibrous, syndesmosis

costotransverse joints

btw tubercle of rib and transverse process of T-spine

• only on ribs 1-10

• freely moveable, synovial, gliding

costovertebral joints

btw head or ribs & facet(s) of the adjacent vertebral body(ies)

• ribs 1, 10, 11, & 12 articulate with only 1 vertebral body

• freely moveable, synovial, gliding

pectus carinatum (pigeon chest)

congenital defect characterized by an anterior protrusion of the lower sternum and xiphoid process

• usually benign condition

• rare cases, could lead to cardiopulmonary complications

pectus excaavatum (funnel chest)

characterized by depressed sternum

• condition rarely interferes with respiration but often is corrected surgically for cosmetic reasons

less

for imaging the sternum, deep chests require _____ rotation

orthostatic breathing

breathing technique for imaging sternum

40”

SID for imaging sternum

RAO and lateral

sternum routine positioning

Patient Positioning

• rotate 15-20 degrees into RAO position

• align long axis of sternum to center IR

Central Ray

• perp to the IR

• entering 1” lateral to the MSP on the elevated side at the level of T7 (midway btw jug notch & xiphoid or inferior border of scapula)

Evaluation Criteria

• entire sternum from jug notch to tip of xiphoid process

• sternum projected over the heart, but free of SI from the T-spine

PA Oblique Sternum (RAO)

Central Ray

• 15-20 mediolateral across the pt from right to left or LPO

trauma PA oblique sternum (RAO)

Patient Positioning

• center sternum to middle of IR

• pt true lateral, sternum perp to plane of IR

• rotate arms/shoulders back (posteriorly), hands clasped

• suspend deep inspiration

Central Ray

• perp to the IR

• entering lateral border of mid-sternum, midway btw jug notch & xiphoid process

Evaluation Criteria

• see sternum in its entirety

• manubrium free of SI by the soft tissue of the shoulders

• sternum free of SI by the ribs

• lower sternum unobscured by breast tissue

lateral sternum positioning

Patient Positioning

• supine on cart

• arms overhead

Central Ray

• horizontal and perp to IR, entering lateral border of mid-sternum

trauma lateral sternum positioning

PA and RAO/LAO

SC joint routine

Patient Positioning

• MSP centered to midline of IR

• both shoulders in same transverse plane

Central Ray

• perp to the IR

• entering MSP at the level of T3 or 3 inches distal to vertebral prominens

Evaluation Criteria

• demonstrate both SC joints without rotation

PA SC joints positioning

Patient Positioning

• DO BOTH OBLIQUES

• pt oblique 10-15 degrees

• both shoulders in the same transverse plane

Central Ray

• (imaging the side closest to the IR)

• perp to IR

• entering level of T2-3 or 3 inches distal to vertebral prominens, and 1-2 inches lateral from MSP on upside

Evaluation Criteria

• open SC joint space

• SC joint of interest centered and adjacent to vertebral column

• includes manubrium and medial end of clavicle

RAO/LAO SC joint oblique positioning

• SID - 40” or 72”

• done upright if possible

  • allows gravity to assist in lower diaphragm, allowing a deeper inspiration, depresses diaphragm to its lowest point

• painful to lie on xray table

• suspend respiration and expose on deep inspiration

• kVp 75-85

rib pain above diaphragm

• SID - 40”

• done recumbent if possible

  • allows diaphragm to rise to its highest point resulting in a less thick abdomen

• abdomen flattens when recumbent allowing better visualization of lower ribs through abdominal structures

• suspend respiration and expose in expiration

• kVp 75-85

• See ribs 8-12

rib pain below diaphragm

Patient Positioning

• upright

• suspend inspiration

Central Ray

• SID - 40” or 72” (72 for upright)

• perp to the IR

• centered midway btw MSP and outer margin of thorax at level of T7 (3-4 inches below jug. notch)

Evaluation Criteria

• visualize ribs 1-10

• no rotation of thorax

AP or PA rib positioning above diaphragm

Patient Positioning

• patient recumbent

• suspend expiration

Central Ray

• SID - 40”

• perp to IR

• centered midway btw MSP and outer margin of thorax midway btw xiphoid process and lower rib margin

Evaluation Criteria

• visualize ribs 8-12

• no rotation of thorax

AP ribs below diaphragm

Patient Positioning

• rotate pt into 45 degree oblique

• abduct arm of affected side

Central Ray

• perp to the IR

• centered midway btw MSP (spine) and outer margin of thorax of affected side

• Above diaphragm

  • enter 3-4 inches below jug notch

• Below diaphragm

  • midway btw xiphoid process and lower rib margin

Evaluation Criteria

• axillary ribs free of SI with thoracic spine with the spine rotated away from the area of interest

• no motion

• above diaphragm - ribs 1-10

• below diaphragm - ribs 8-12

Oblique Rib Positioning

Trauma (injury)

• upright chest AP or PA - if not done since injury or within last 24 hrs

• MUST image all 12 ribs on affected side (may need to do 2 separate exposures)

non-trauma (no injury)

• image ribs either above or below diaphragm

also protocol to do BOTH obliques (RPO & LPO or RAO & LAO) centered on the affected side

• additional oblique is done to visualize the small portion of the rib closest to the spine (vertebral end) and foreshortens the axillary ribs

Trinity rib routines

soft tissue neck

used to demonstrate foreign bodies, swelling, masses, and fractures of the larynx and hyoid bone

Patient Positioning

• upright

• MSP perp to IR

• shoulders in same plane

• extend neck slightly to place AML perp to IR

Central Ray

• upper airway - MSP at level of laryngeal prominence (Adam’s apple)

• larynx and superior mediastinum - MSP at level of jugular notch

• expose during SLOW inspiration

Evaluation Criteria

• air filled upper airway

• no rotation, with spinous process equidistant to pedicles and aligned with midline of cervical bodies

• proximal larynx not well visualized bc of SI of base of skull and mandible

AP soft tissue neck positioning

Patient Positioning

• true lateral

• rotate shoulders back/posteriorly with hands clasped behind body

• MSP parallel to IR, AML parallel to floor

Central Ray

• perp to IR

• Upper airway - MCP at level of Adam’s apple

• Trachea & superior mediastinum - level of jug notch, at point midway btw jug notch and MCP

Evaluation Criteria

• air filled upper airway

• no rotation or tilt of cervical spine

• SI zygapophyseal joints, open intervertebral joints, and SI or nearly SI mandibular rami

Lateral soft tissue neck positioning

Patient Positioning

• lateral

• upright or x-table

• SID - 72’’

• AML parallel to floor

Central Ray

• collimate from nasion (including complete nasal passage) to thoracic inlet (approx. jugular notch), including the entire C-spine

Evaluation Criteria

• set manual technique, dont use AEC

ST neck - adenoid protocol