Thorax 1 - Views, Vessels, Nodules

What structure is highlighted?

Cranioventral mediastinal reflection

What structure is shown in this image?

Cranioventral mediastinal reflection

What structure is highlighted?

Caudal mediastinal reflection

What view is this?

VD

What view is this?

DV

What structures can be see on a thorax VD?

• Diaphragm cupula

• Left hemidiaphragm

• Right hemidiaphragm

What structures can be seen on a thorax DV?

• Cupula

• Caudodorsal vessels

Positioning VD/DV thorax

• Roughly equal thorax space each side of the spine

• Sternum over spine

• Spinous process straight (end-on tear drop shape)

Positioning laterals Thorax

• Rib heads superimposed

• Rib curvature should match

• Pull limbs out of image - minimize bone & soft tissue on top of lungs

Veins are ______ and _____ to bronchus

Ventral and Central

What is being shown on this image?

Artery, bronchus, & vein - lateral projection

What structures are shown in this image?

Artery, bronchus & veins - VD/DV projection

Normal vasculature - lateral projection

• Arteries & veins equal in size

Normal vasculature - DV or VD

• Arteries & veins equal in size

• No larger than 9th ribs where they cross

____ arteries and ____ veins

Big, Big (“vascular pattern”)

____ arteries and ____ veins

Small, small

____ arteries, _____ veins

Big, normal

_____ veins, _____ arteries

Big, normal

Causes of Big arteries and veins

• L —> R cardiac shunt

  • Patent Ductus Arteriosus (PDA)

  • Ventricular Septal Defect (VSD)

  • Atrial Septal Defect (ASD)

• Iatrogenic IV fluid overload

Causes of small arteries and veins

• Hypovolemia

• Shock

• Addison’s disease

• Severe pulmonic stenosis

• R —> L cardiac shunt

  • Tetralogy of Fallot

  • Any L —> R shunt that reversed direction due to high R heart pressure (aka Eisenmenger syndrome)

Causes of Big arteries, normal veins

• Pulmonary Hypertension

• Heartworm disease

• Thromboembolism (rare)

Causes of Big veins, normal arteries

• Venous congestion due to:

  • L-sided heart congestion

    • Mitral valve degeneration

    • Cardiomyopathy (Dilated, hypertrophic)

  • Rare

    • Mitral valve dysplasia (congenital)

    • L atrial obstruction

      • Mass at heart base

      • Thrombosis

      • Cor triatriatum sinister (congenital)

Radiographic appearances of pulmonary Nodules

• Soft tissue opaque

• Round

Radiographic appearance of pulmonary Masses

• Soft tissue opaque

• Round or irregularly shaped

• Can have ill-defined margins

• Can have air bronchograms

Causes of Multiple pulmonary nodules/masses

• Metastatic neoplasia

• Granuloma

  • Fungal disease

  • Feline asthma

  • Certain inflammatory disease

• Hematogenous pneumonia (rare)

Causes of Solitary pulmonary nodule/masses

• Primary lung tumor

• Early metastatic neoplasia (1 small nodule)

• Granuloma (uncommon)

Causes of weird stuff pulmonary nodules/masses

• Bulla (uncommon)

• Cavitation nodule (rare)

• Hematocele (rare)

• Abscess (rare)

What cause of pulmonary nodules/masses is this image showing?

Metastatic neoplasia

Things that mimic pulmonary nodules

• Pulmonary osteomas

• End-on vessels

• Dermal structures

  • Dermal nodules/masses

  • Nipples

• Costochondral junction remodeling

What is being highlighted?

Pulmonary osteomas

Pulmonary osteomas

• mineral opaque

• Visible at smaller size

• Sharp edges or weird shapes

Appearance of Pulmonary nodules on rads

• round, smooth

• Similar opacity as similar size vessel

End-on vessels

• in vessel’s path - same size as vessel

• More opaque than a same-size soft tissue nodule

What structure is highlighted?

End-on vessel

What structure is highlighted?

Cutaneous nodules/nipples

Appearance of Costochondral junction remodeling on radiographs

• between bone & cartilage w/in a rib

• Mineral opaque

• Usually irregular, can be smooth/round

Humanoid projection

• move scapulae & soft tissues away from cranial lung lobes

• Thoracic limbs pulled caudally

What structure is this image showing?

Bulla

Bulla

• gas-filled round structure w/ very thin soft tissue opaque rim

What structure is highlighted?

Cavitation lesions

What do Cavitary lesions look like on radiographs?

• thicker more irregular soft tissue opaque outer tissue (compared to bulla)

• Gas-filled center

What structure is highlighted?

Abscess

What do Abscess look like on radiographs?

Gas bubbles in soft tissue mass