bony thorax-sternum and ribs

true ribs

ribs 1-7

false ribs

ribs 8-12

floating ribs

11 and 12

what makes a true rib?

they’re connected directly to the sternum with costal cartilage

what makes a false rib?

they’re all connected to the costal cartilage that comes together at rib 7. not directly connected to the sternum.

what makes a floating rib?

11 and 12 do not have costal cartilage and do not connect to the sternum, therefore are “floating”

at what age is the body of the sternum fully unified?

25

what age does the xiphoid process fully ossify?

40

which ribs have the sharpest angle?

1st ribs

which ribs create the widest part of the rib cage?

8th and 9th ribs

which part of the sternum is the most superior?

the manubrium

which part of the sternum separates the manubrium from the body?

sternal angle

which part of the sternum is the shortest and how long is it?

manubrium, 2 in

which part of the sternum is the longest and how long is it?

body, 4 in

how many parts is the body divided into before age 25?

4

most inferior portion of the sternum

xiphoid process

the sternum is a ___ bone.

thin, narrow, flat bone

how does the clavicle articulate with the manubrium?

medially with the 1st rib sitting posteriorly behind

where is the facet for the 1st costocartilage?

on the manubrium

which end of the ribs attach to the costocartilage?

the sternal end, anteriorly.

how much lower is the sternal end from the vertebral end on a rib?

3-5 inches

which ribs have the widest diameter?

8th and 9th

costotransverse joint

kind of where tubercle is, found on 1st-10th ribs

costovertebral joint

where head connects to vertebrae, all 12 ribs have this

why do we have to do RAO to visualize the sternum?

to move the sternum out of the thoracic vertebrae and into the heart shadow for better visualization

what’s the degree of obliquity for a large, barrel chested thorax?

15°

what’s the degree of obliquity for a thin-chested thorax?

20°

the xiphoid process does not become totally ossified until the age of ___.

40

true or false: the anterior ends of the ribs do not attach directly to the sternum.

true

which ribs are classified as floating ribs?

11th and 12th

the inside margin of the rib, containing the blood vessels and nerves, is called the ___.

costal groove

breathing technique for sternum radiograph

orthostatic, 2-3 seconds

kVp range for sternum radiographs

70-80 kVp

SID for sternum radiographs

40 in

technical considerations for visualization of ribs above the diaphragm

on inspiration, 75-85 kVp, erect if possible

technical considerations for visualization of ribs below the diaphragm

on expiration, 80-90 kVp, recumbent

will you do PA or AP for first image on pt complaining of anterior left rib pain?

PA bc we want to visualize their anterior side

PA or AP for posterior upper right rib pain?

AP to visualize posterior side

should you shield for rib x-rays?

every time

which marker should you use for posterior upper left rib pain?

left marker on left side.

for anterior right rib pain, what two views will be demonstrated?

PA and LAO

for left posterior rib pain, what two views will be demonstrated?

AP and LPO

how much rotation is necessary for oblique rib radiographs?

45°

what is the correct SID for a lateral sternum radiograph?

60-72 in

what pt positioning is used for lateral sternum radiographs?

pt locks hands behind their back and puffs chest as much as possible

where is the CR directed for PA SC joints radiograph?

T2-T3 (3 in distal to vertebrae prominens)

anterior oblique SC joint radiographs should have:

10°-15° rotation, CR to T2-T3, left would be LAO, right would be RAO

what should be included in an RAO of SC joints

open right SC joint shifted away from spine, manubrium and medial clavicle visible, often do both sides to compare the spacing

true or false: a hypersthenic pt requires greater rotation of the sternum for the RAO projection as compared with a sthenic pt.

false

where is the CR centered for a PA projection of the SC joints?

level of T2-T3

true or false: the ideal, general position for a study of the ribs below the diaphragm is recumbent

true

which of the following technical considerations do not apply to a rib study for an injury to the left, upper anterior ribs?

Exposure upon expiration

rib fractures

most commonly caused by trauma or underlying pathology, ANY rib fracture may cause injury to adjacent lung or cardiovascular structures. fractures to first ribs often associated with injury to the underlying arteries/veins, fractures to lower ribs (9-12) associated with injury to the spleen, liver, or kidney

rib/flail chest fractures on an xray

disruption of bony cortex of rib, linear lucency through rib

flail chest

when ribs are fractured in 2 or more places on multiple adjacent ribs creating a segment of ribs that are unattached to the bony thorax, can lead to instability of chest wall and create paradoxical chest movement during breathing, result of severe trauma/blunt trauma, must perform rib studies erect if possible

sternum fracture

caused by blunt trauma, associated with underlying cardiac injury

sternum fracture on xray

disruption of bony cortex of sternum, linear lucency or displaced sternal segment

congenital anomalies

conditions present from birth that may become more evident as a child grows, ex: pectus carinatum (pigeon breast) and pectus excavatum (funnel chest)

pectus carinatum (pigeon breast)

anterior protrusion of lower sternum and xiphoid process, usually benign condition but could lead to cardiopulmonary complications in rare cases.

pigeon breast on xray

anterior protrusion of lower sternum

pectus excavatum (funnel chest)

characterized by depressed sternum, rarely interferes with respiration but often corrected surgically for cosmetic reasons

funnel chest on xray

depressed sternum

metastases

primary malignant neoplasms spread to distant sites via blood and lymphatics, ribs are common site of metastatic lesions

osteolytic metastases on xray

irregular margins and decreased density

osteoblastic metastases on xray

increased density

combination metastases on xray

moth eaten appearance

3 characterizations of metastases of ribs

osteolytic, osteoblastic, combination

osteolytic

destructive lesions with irregular margins, decrease exposure factors

osteoblastic

proliferative bony lesions of increased density, increase exposure factors

combination osteolytic and osteoblastic

moth-eaten appearance of bone resulting from the mix of destructive and blastic lesions, no change

osteomyelitis

localized/generalized infection of bone and marrow can be associated with postoperative complications of open heart surgery, which requires sternum to be split, most common cause is bacterial infection

osteomyelitis on xray

erosion of bony margins