- •Chest Imaging
- •Foreword
- •Preface
- •Educational Support and Funding
- •Acknowledgments
- •Contents
- •Fundamentals > Chest Primer Presentation
- •Chest X-Ray Interpretation Self-Study Instructions
- •Using the RoboChest Website
- •Decision Tree Algorithms to Help Solidify Concepts
- •References
- •Comprehensive Review of Search Patterns
- •Search Pattern Mnemonic
- •Interpretive Approach to CXR
- •Applying the Mnemonic to the Search Pattern
- •Chest Primer Presentation
- •References
- •Introduction and Terminology
- •Chest Imaging Terminology
- •Mach Effect on CXR
- •Trachea and Lungs on CXR
- •Mediastinal Anatomy on CXR
- •The Hilum (Plural: Hila)
- •Pulmonary Arteries and Veins
- •Normal Lung Markings
- •Vessel Size
- •Quiz Yourself: Mediastinum Lines, Edges
- •Shoulder Anatomy
- •Reference
- •Abnormal Lung Parenchyma
- •Mass
- •Mass Considerations
- •Size
- •Mass Characteristics
- •Malignancy
- •Case 4.1
- •Metastatic
- •Case 4.2
- •Bronchial Carcinoid
- •Radiological Signs
- •Case 4.3
- •Granulomatous Disease
- •Infectious Granulomatous Disease
- •Case 4.4
- •Non-infectious Granulomatous Disease
- •Benign Neoplasm
- •Hamartoma
- •Case 4.6
- •Congenital Abnormality
- •Pulmonary Arteriovenous Malformations
- •Case 4.7
- •Consolidation
- •Consolidative Radiological Findings/Distribution
- •Consolidative Model
- •Blood (Hemorrhage)
- •Case 4.8
- •Pus (Exudate)
- •Case 4.9
- •Case 4.10
- •Water (Transudate)
- •Pulmonary Edema
- •Case 4.11
- •Case 4.12
- •Protein (Secretions)
- •Case 4.13 (see Figs. 4.38 and 4.39)
- •Cells (Malignancy)
- •Interstitial
- •Radiological Signs
- •Linear Form: Lines
- •Case 4.14
- •Nodular Form: Dots
- •Case 4.15
- •Reticulo-Nodular Form
- •Pneumoconiosis
- •Case 4.16
- •Case 4.17
- •Destructive Fibrotic Lung
- •Case 4.18
- •Langerhans Cell Histiocytosis
- •Case 4.19
- •Vascular Pattern
- •Normal Pulmonary Vascular Anatomic Review
- •Radiological Signs in the Vascular Pattern
- •Mechanism
- •Vascular Examples
- •Pulmonary Arterial Hypertension (PAH)
- •Case 4.20
- •Pulmonary Venous Congestion
- •Pulmonary Venous Congestion: Edema
- •Emphysema
- •Airway (Bronchial) Patterns
- •Complete Obstruction
- •Lobar Atelectasis (Collapse)
- •Signs
- •Lobar Atelectasis Patterns
- •Complete Obstruction: Case Study
- •Partial Obstruction
- •Radiological Signs
- •Bronchial Wall Thickening
- •Bronchial Wall Thickening Causes
- •Bronchial Wall Thickening Model
- •Bronchiolar
- •Case 4.21
- •References
- •Pleural Effusion
- •Case 5.1
- •Technique and Positioning Revisited
- •Case 5.2
- •Comparison of Effusions over Time
- •Loculated Fluid/Pseudotumor
- •Case 5.3
- •Case 5.4
- •Thickening
- •Pneumothorax
- •Fluid and Air
- •Analogous Model
- •References
- •Anterior Mediastinal Mass
- •Case 6.1
- •Middle Mediastinal Mass
- •Posterior Mediastinal Mass
- •Case 6.2
- •Mediastinal Enlargement
- •Case 6.3
- •Reference
- •Case 7.1
- •Lines and Tubes
- •References
- •Appendix
- •Appendix 1: Glossary and Abbreviations
- •Appendix 2: Sources and Additional References
- •Text Sources
- •Image Sources
- •Additional References
- •Chest Imaging References
- •Chest Imaging Online References
- •Index
18 |
3 Normal Chest X-Ray, Terminology and Radiographic Anatomy |
Obliterated: Obscured structure that should otherwise be seen. Other descriptions include “masked,” “not seen” or “not well discerned”.
Projection: the path of the X-Ray beam, can be a frontal projection (either PA or AP), lateral, decube, or upright (erect) etc.
Shadow: Anything visible on an image; hence, any specific density or lucency.
Silhouette: Synonym for edge. Loss of an edge constitutes the “silhouette sign.” This occurs by adjacent structures masking others; such as how a right middle lobe (RML) consolidation obliterates the right atrial edge.
Stripe: Either an edge or a line.
Summation Shadow: Anatomic noise of overlapping structures. This often happens with posterior ribs overlapping vessels and anterior ribs; mimicking an infiltrate.
Tram tracks: Parallel lines that look like tram (or train) tracks due to their outlining bronchi in bronchiectasis.
There are many important elements in the description of a finding. They include the following.
•Anatomic location: such as distribution, lobar, diffuse, central
•Proximity: for example adjacent to, surrounded by (think 2D image of 3D anatomy).
•Pattern: examples include mass, consolidate, etc.
•Orientation: such as en-face (face-on), profile (opposite of en-face)
•Angle of approximation: obtuse vs. acute angle
See Fig. 3.3 that demonstrates a fluid-fluid level along with a few other terms described. This is a radiograph of a syringe oriented vertically with immiscible contrast (more dense and dependent) and water (less dense on top) showing an edge at the interface. Note that the needle represents a line (which is thinner than an edge).
Mach Effect on CXR
The following series of images shows the Mach effect, a very common phenomenon seen on chest X-Rays [1].
In Fig. 3.4, the apparent lucency next to the edge (of skin) in the right lung field is actually a Mach band. The skin fold is not uncommon in portable CXRs in that the plate is sometimes moved up to get the apicies, pulling exposed skin up. This creates an edge with associated lucency (Fig. 3.5), which actually represents the Mach effect. Figures 3.6 and 3.7 show close-ups of the Mach effect.
Trachea and Lungs on CXR
Figures 3.8–3.11 highlight the appearance of the trachea and lungs on a normal CXR.