how x rays produce images and why bones appear white
dense objects such as bones absorb more in x ray preventing penetration making them appear white
what happens when fasgt moving electrons collide with matter
x rays are produced
why do dense objects show up differently than less dense tissue on Xray
dense objects absorb more xray while less dense tissue allow more x ray to pass through creating varying images shades
describe the position for PA chest radiograph
-stand or sit upright
-lungs at full inspirtation
-anterior chest against film
preferred: most accurate and less distorted images
what circumstance would AP chest radiograph be used and disadvantage
- pt is debilitated, immobilized or too young
disadvantage: less resolution and more distortion
how is lateral chest radiograph performed and primary purpose
lateral view: pt stands with side against side cassette, arms raised
used to complement PA view and provide more indepth
what is lateral decubitus view, how is it named and what condition is it most helpful in diagnosing
-pt lies on left or right side,
-names after the side that is down
-detects fluid movement
what are 3 steps in evaluating technical quality of chest xray
-position
-exposure quality
-inspiration level
how do you determine if the exposure quality is appropriate
adequate if spinal processes are visible to T5-T6
at full inspiration, where should diaphragm be located in relation to the ribs
posterior 9th-11th ribs
what structures are assessed in the “inside out” approach to reading a chest x ray
-mediastinum
-trachea
-heart
-hilar region
-lung parenchym
-pleura
-diaphragm
-gastric air bubble
-bony thorax
-extra thoracic soft tissue
what is the normal cardothoracic ratio on PA chest x ray
less than 1:2
what is the normal vertebral column should show a small portion of the heart on a normal PA CXR
right side
give 1 ex of condition that can pull the trachea to one side
left upper lobe: atelectasis, TB, Fibrosis
give ex of condition that can push trachea to one side
large pleural effusion
what condition can cause the left diaphragm to shift upward
left lower lobe- atelectasis or fibrosis
what condition can cause the left lung to shift rightward
left sided tension pneumothorax
what is the typical chest x ray appearance of ARDS
-ground glass appearance-frost glass
-airbronchograms
-alveolar collapse
what are the CXR findings in Obstructive lung disease
-hyperinflated lungs
-flatten diaphragm
-enlonged heart
describe the appearance of pulmonary fibrosis on a CXR
-net like shadowing
-more prominent at the lungs
-indistinct contours of heart boarders
what CXR pattern is classic for pulmonary edema
-enlarged heart
-thickened fissures
-batwing airspace opacities
-possible air bronchograms
what view is best for detecting small pleural effusions
later decubitus
what advantages does a CT scan have over a standard CXR
-cross sectional images
-detect small lesions,nodules,pulmonary embolism,pleural effusion,. mediastinal masses
what is the main purpose of a PET scan in chest imaging
detect metabolic activity and early malignancies
