Sternum, SC joints, ribs

Question 1

PA SC joint view description

Answer 1

SID - 100 cm
18x 24 cassette 
Grid
70 kVp
Suspend on expiration for a more uniform density

Positioning-
Prone or standing with MSP parallel to IR.
No rotation of shoulders
T2 - T3 7 cm distal to C7

Critique:
superimposed SC joints of vertebral column and ribs. No rotation via SC equidistant to spinous processes. No shoulder rotation. Lateral aspects of manubrium & medial portions of clavicles visualized lateral to vertebral column

Question 2

Oblique SC joint view description

Answer 2

SID - 100 cm
18x 24 cassette 
Grid
70 kVp
Suspend on expiration for a more uniform density

Position
Rotation patient 10 -15 degrees. Center 3-5 cm laterally to the spinous processes at the level of T2 and T3.

Critique
The manubrium, medial portion of clavicles and sternoclavicular joints are best demonstrated on the downside. The Sc joint on the upside will be foreshortened. No superimposition of the vertebral column or manubrium. As for SC JTs to avoid superimposition of the sternum & vertebral column.

Question 3

Axillary Ribs description

Answer 3

SID - 100 cm whilst 180 cm can be used to minimise magnification of the anatomy
Grid
kVp - above diaphragm 75 - 85
below diaphragm 80- 90
Positioning
Rotate patient 45 degrees p oblique or A oblique, the anterior ribs being xrayed should be away from the IR. Posterior ribs being Xrayed should be touching the IR. The arm on the side of the injured ribs should be elevated above head and the other arm away from the person.

Above diaphragm - 8 to 10 cm below jugular notch = T7
Below diaphragm - midway between xiphoid process and lower rib cage.

upper ribs - inspiration
lower ribs - expiration

Question 4

RAO sternum decription

Answer 4

SID - 100 cm
grid
24x30 portrait
kVp - 70 to 80

using a breathing technique will help to blur out ribs & pulmonary markings
left arm up and right up by your side

15 to 20 degrees towards right side. Big people require less rotation because only sternum needs to get away from spine. IR 4 cm above jugular notch. Cr center of sternum midway between xiphoid and jugular notch.

sternum should be seen on heart shadow. sternum alongside vertebral column with no superimposition by vertebra. No distortion of sternum.

Question 5

Flail chest

Answer 5

Occurs when there are multiple rib #s & a segment of thoracic wall breaks under extreme stress & becomes detached from the rest of the chest wall. This is usually defined as at least two fractures per rib (producing a free segment), in at least two ribs. A segment of the chest wall that is flail is unable to contribute to lung expansion.

Question 6

Pathognomic sign:

Answer 6

a particular sign whose presence means that a particular disease is present beyond any doubt. Labelling a sign or symptom “pathognomonic” represents a marked intensification of a “diagnostic” sign or symptom.

Question 7

Clinical indication for SC joints

Answer 7

• Trauma - contact sports & MVA
  Fractures, dislocations
  Pathological fractures – metastasis
• Osteoporosis
  Depression of body caused by a direct blow
  Often associated w/ haemothorax, lung contusion, ruptured aorta, # ribs and pneumothorax
• Congenital depression
  ‘pectus excavatation’ can simulate cardiomegally on PA CXR

Question 8

Rib 1 (Atypical)

Answer 8

Short, flat & more sharply curved than any of the others.

Has upper & lower surfaces, with outer & inner borders, & on its head there is one articular facet only.

Upper surface has 2 grooves for subclavian artery & vein, separated by scalene tubercle for attachment of scalene anterior muscle.

This rib has very little movement during respiration & serves as a base attachment for the intercostal muscles and the ribs below.

Question 9

A typical rib

Answer 9

Has the following characteristics:
head - articulates w/ bodies of vertebrae
neck
tubercle - articulates w/transverse processes
angle - a point just lateral to tubercle where shaft bends forward;
costal groove -lodges intercostal vessels & nerves

Question 10

What does rib 7 articulate with?

Answer 10

T6 at the inferior costal facet

T7 at the transverse process

Question 11

Ribs clinical indications

Answer 11

Following blunt trauma or Flail Chest
(Several adjacent ribs fx’ed in 2 places bilaterally)
Following strenuous coughing
Suspected secondary CA of breast /Pathological #
#’s particularly common to middle ribs in mid axillary line
Trauma to thoracic or abdominal viscera may be associated with rib injuries
NAI (non-accidental injury) –(shaken baby)
Pagets Disease
SOL