Anatomy and Positioning of theBony Thorax, Sternum and Ribs
ribs attach between vertebral bodies via demifacets
2nd - 9th
Floating ribs
False ribs 11 and 12 Anterior ends do NOT articulate with sternum or costal cartilage of rib above
Neck of Rib
"Skinny" portion of the rib; lateral to head; located between head and tubercle
Sternoclavicular
(between sternum and clavicle) Diarthroidal gliding
Costal groove of Rib
On inner surface of body inferiorly; "protection" for nerves, veins, and arteries
AP RibsBelow Diaphragm positioning
Place bottom of cassette 1" below iliac crests CR perpendicular to midpoint of cassette Expose on expiration Ninth to twelfth ribs visualized
AP Oblique RibsBelow Diaphragm
Place bottom of cassette at iliac crests CR perpendicular to midpoint of cassette Make exposure on suspended deep expiration
AP Oblique RibsAbove Diaphragm
Place top of cassette 1.5" - 2" above shoulder CR perpendicular to midpoint of cassette Make exposure on suspended deep inspiration
Tubercle of Rib
Projection lateral and posteroinferior to neck; articulates with vertebra's transverse process; forms costotransverse joint
Sternal extremity is on which end of the rib
is on anterior end of rib. Attached anteriorly to sternum via costal cartilage (not directly attached to sternum)
Ribs
12 pair Flat bones, curving anteriorly & inferiorly Connect sternum to thoracic vertebrae (around and down)
RAO Sternum Positioning
15°- 20° RAO (separates sternum from spine) CR to center of sternum (1" to left of midline and midway between jugular notch and xiphoid process) Trauma alternative: 15°-20° cross angle, grid crosswise
ribs attach directly to a single vertebral body via one facet
1st and 10th - 12th
where do the ribs become shorter again
7th rib
Where are the Ribs the widest
8th and 9th ribs
What does the sternum articulate with
Articulates with ribs (facets) and clavicle (top)
Head of Rib
At posteromedial end; articulates with demifacets of adjacent vertebral bodies to form costovertebral joint
Sternocostal joint -
Connect costal cartilages to sternum
Costovertebral joint -
Between rib and vertebra occurring between the head and facet of the vertebral body; ONLY ONE VERTEBRA ARTICULATES WITH RIBS 1, 11, AND 12.
Costotransverse joint -
Between rib tubercle and facet on anterior surface of transverse process
Costochondral Joints
Between sternal end of rib and costal cartilage No motion (synarthroidal) Ten of these, with no anterior attachment to ribs 11 and 12
Costochondral joint -
Between sternal end of rib and costal cartilage (no movement)
AP Above Diaphragm positioning
CR 3" - 4" below jugular notch Place top of cassette 1.5" - 2" above the shoulder CR perpendicular to midpoint of cassette Make exposure on suspended deep inspiration
Costal cartilage -
Cartilage at rib's MEDIAL end
only connection to shoulder girdle from bony thorax; connects to sternum above first rib
Clavicle
Ribs 1 - 10 Articulations
Costotransverse and costochondral joints
All ribs (12) Articulation
Costovertebral joints
STERNOCOSTAL JOINTS:
First sternocostal joint has no motion (synarthroidal) Second - seventh have their own cartilage and are diarthroidal (gliding)
Rib Oblique above / below diaphragm
For anterior obliques, side of interest will be AWAY from IR For posterior obliques, side of interest will be closest to IR
Ribs 6 - 10 -articulation
Interchondral joints
LPO / RAO Ribs
Left axillary ribs Right vertebral ribs
Sternum has three components:
Manubrium (approx. 2") Body (gladiolus) Xiphoid process or xiphoid tip (the "end"; begins as cartilage and ossifies in the 40s)
Angle of the Rib
Most posterior portion; lateral to tubercle
True ribs
Rib pairs 1 - 7 Attach directly to sternum via costal cartilage
False ribs
Ribs 8 - 12 - Ribs 8 - 10 articulate via costal cartilages with 7th rib's costal cartilage; ribs 11 and 12 are not connected anteriorly
RPO / LAO Ribs
Right axillary ribs Left vertebral ribs
PA Oblique SC Joints positioning
Rotate 10° -15° with side of interest down Center joint of interest to midline of table CR perpendicular to level of jugular notch Center film to CR Expose on suspended expiration Obtain both sides for comparison
AP Oblique Ribs positioning
Rotate patient to 45° RPO or LPO with affected side down Raise the arm on the side down to remove scapula
joints are above first rib
SC (sternoclavicular)
Body of the Rib
Shaft of rib; the longest part
Intercostal space -
Space between ribs
RAO SternumEvaluation Criteria
Sternal ends of clavicles and entire sternum included Sternum separated from vertebral column Sternum superimposed on heart
Lateral SternumEvaluation Criteria
Sternal ends of clavicles superimposed Sternum separated from ribs and shoulders
Ribs 1 - 7 articulation
Sternocostal joints
Bony Thorax Comprised of:
Sternum anteriorly Thoracic vertebrae posteriorly Twelve pairs of ribs
Lateral Sternum positioning
Top of cassette 1.5" above jugular notch CR perpendicular to center of film 72" SID Expose on suspended deep inspiration
PA Sternoclavicular Joints
True PA CR perpendicular to T2 - T3 (3" distal to vertebra prominens)
INTERCHONDRAL JOINTS:
between the cartilages of ribs 8 - 10 and the 7th. They are diarthroidal/gliding joints and involved in the breathing process.
Functions of the Bony Thorax
expand and contract during breathing
First ribs are
short and broad
A source of red bone marrow found in
sternum