The document discusses how chest X-rays work and what they can show. Different tissues absorb X-rays at different rates, with bone appearing white, soft tissue grey, and air black. A PA view has X-rays enter through the back while an AP view is from the front. Proper exposure level is needed to see details in the lungs and heart without being over or under penetrated. Positioning is important to evaluate symmetry and check for abnormalities in soft tissues and bones like the ribs, spine, diaphragm and heart. Lung fields and costophrenic angles should have sharp margins and be checked for issues like infiltrates or masses.

1. Chest Xray

2. Different tissues in body absorb X-rays at
different extents:
• Bone- high absorption (white)
• Tissue- somewhere in the middle absorption (grey)
• Air- low absorption (black)

4. CXR - PA Vs AP view.
PA- the x-rays penetrate through the back of the
patient on to the film
AP-the x-rays penetrate through the front of the
patient on to the film.

6. Penetration / Exposure
 Able to see ribs
through the heart
 Barely see the
spine through the
heart
 Pulmonary vessels
can be traced
nearly to the edges
of the lungs

7. Underpenetrated Film
Hemi diaphragms are obscured
Pulmonary markings more prominent than they actually

8. Over penetrated Film
 Lung fields darker than
normal—may obscure subtle
pathologies
• See spine well beyond the
diaphragms
• Inadequate lung detail

9. Positioning / Rotation
Does the thoracic spine align in the center of the
sternum and between the clavicles?
Clavicles – equidistant from spine

11. Determine side – ? L/R
 Gastric bubble should be on the left ( normally )

12. Look at
 Soft tissue
 Bony cage

13. Soft tissue and bony structures
 Check for
 Symmetry
 Deformities
 Fractures
 Masses
 Calcifications
 Lytic lesions

17. Look at the diaphram:
-Tenting
-free air
-abnormal elevation
 Margins should be
sharp
(the right hemidiaphram is
usually slightly higher than
the left)

18. Heart
 Size
 Shape
 Silhouette-margins should be sharp
 Diameter (>1/2 thoracic diameter is
enlarged heart)
 AP views make heart appear larger than it
actually is.

20. Costo-phrenic / cardiophrenic angles
Margins should
be sharp

21. Lung fields
 Infiltrates
 Increased interstitial markings
 Masses
 Absence of normal margins
 Air bronchograms
 Increased vascularity

34. Cannon ball appearance- DDS
Osteogenic sarcoma
Thyroid (follicular)
Testicular carcinoma
Kidney
Choriocarcinoma
Prostate
Malignant melanoma, Some GI, Some very
advanced nasopharyngeal, and pharyngeal
carcinomas
Breast
Lymphangitis carcinomatosa