7/27/2019 SA Anatomy Thorax
1/22
Introduction to Thoracic
Radiology
Dr. LeeAnn Pack
Dipl. ACVR
7/27/2019 SA Anatomy Thorax
2/22
Indications
Coughing
Dyspnea/ Tachypnea
Heart Murmur, Collapse
Primary or Secondary Neoplasia
Check for metastasis
Thoracic Trauma Chest Wall Mass
Exercise Intolerance, Weight Loss
7/27/2019 SA Anatomy Thorax
3/22
Technical Factors
Potential for Movement Decrease mAs
High inherent contrast
area High kVp
Collimation
Centering caudal
scapula Thoracic inlet to
diaphragm
Pull forelimbs forward
7/27/2019 SA Anatomy Thorax
4/22
Determining the Phase of
Respiration Always expose at peak inspiration
Maximizes lung contrast
Inspiratory lateral view Caudodorsal aspect of lung caudal to T12
Increased aeration of accessory lung lobe
Separation of heart silhouette and diaphragm
Inspiratory VD/DV view Diaphragmatic cupola caudal to mid T8
Lung tips caudal to T10
7/27/2019 SA Anatomy Thorax
5/22
Inspiratory vs. Expiratory Lateral
Note the space inside thetriangle
7/27/2019 SA Anatomy Thorax
6/22
Inspiratory vs. Expiratory VD
Easy to see the difference in wellvisualized lung
7/27/2019 SA Anatomy Thorax
7/22
DV vs. VD
DV Less stressful, better for heart
Diaphragm rounded
Caudal pulmonary vessels better visualized Better to see small amount of pleural air
VD Better for lungs
Hear appears elongated Flat diaphragm Mickey Mouse ears
Better to see small amount of pleural fluid
7/27/2019 SA Anatomy Thorax
8/22
DV vs. VD
7/27/2019 SA Anatomy Thorax
9/22
Right vs. Left Lateral etal.
Right Lateral
Better cardiac detail
R crus forward
See Cava go into it
Left Lateral
Heart appears round
L crus forward
See Cava go past
Anesthesia
Breed Differences
7/27/2019 SA Anatomy Thorax
10/22
The Effects of Lateral
Recumbency Lung lesions (mass, nodule, infiltrate)
may only be seen on 1 view!!!
Only the non-dependent (up) lung canbe critically evaluated
Dependent lung loses aeration
(atelectasis) Increases in opacity
Silhouettes with lesions
7/27/2019 SA Anatomy Thorax
11/22
Interpretation of Thoracic
Radiographs Heart
Lungs
Mediastinum
Pleural space
Chest wall Bones, Abdomen,Neck
7/27/2019 SA Anatomy Thorax
12/22
Normal Cardiac Silhouette
Subjective
Dog = 2 - 3 intercostal spaces
Cat = 2 2 intercostal spaces
65% or less on VD/DV view
Objective
Buchanan method
7/27/2019 SA Anatomy Thorax
13/22
Clock Face
11-1 Aortic Arch
1-2 Main Pulmonary Trunk
2-3 Left Auricle 2-5 Left Ventricle
5-9 Right Ventricle
9-11 Right Atrium Centrally Left Atrium
7/27/2019 SA Anatomy Thorax
14/22
Lateral View
Make a Plus sign
Bermuda triangle
Left atrium
Left Ventricle
Right Ventricle
7/27/2019 SA Anatomy Thorax
15/22
Thoracic and Pulmonary
Vessels Aorta
Caudal Vena Cava
Cranial pulmonaryvessels
Proximal third rib
Caudal pulmonary
vessels
9th rib where crosses
Veins are ventral and
central
7/27/2019 SA Anatomy Thorax
16/22
Trachea, Bronchial Tree
Carina then splits to the main stem
bronchi then lobar bronchi
Tracheal rings can mineralize
Decreased tracheal diameter
Tracheal narrowing (stenosis, extramural
compression), Tracheal hypoplasia,Tracheal collapse
7/27/2019 SA Anatomy Thorax
17/22
Lungs
Normal anatomy
Left
Cranial (cranial
subsegment) Cranial (caudal
subsegment)
Caudal
Right
Cranial Middle
Caudal
Accessory
7/27/2019 SA Anatomy Thorax
18/22
The Mediastinum
Cranial, middle, caudal compartments
Routinely visible structures:
Heart, trachea, cvc, aorta, +/- thymus, +/-
esophagus
Cranioventral mediastinal reflection
Caudoventral mediastinal reflection Aka phrenopericardiac ligament
7/27/2019 SA Anatomy Thorax
19/22
Mediastinal reflections
7/27/2019 SA Anatomy Thorax
20/22
Extrathoracic Structures
Sternum
Vertebrae
Ribs Adjacent soft
tissues
Diaphragm
7/27/2019 SA Anatomy Thorax
21/22
The Diaphragm
Cupola
Cranioventral convex
portion
Right and left crura Attach to cranioventral
border of L3 and body of
L4
May cause irregularity on
these surfaces Appearance depends on
centering of X-ray beam
7/27/2019 SA Anatomy Thorax
22/22
The Diaphragm