Radiography

Question 1

What is the effect of using a grid?

Answer 1

reduce the amount of scattered radiation reaching the cassette, but will necessitate increasing the exposures roughly three-fold

Question 2

What does using a low mA mean?

Answer 2

long exposure times are required, resulting in an increasing likelihood of movement blur in the conscious patient

Question 3

What should you ask before using a radiograph for diagnosis?

Answer 3

■■ Are they well positioned?
■■ Could the overlying forelimbs be hiding any cranial
thoracic pathology?
■■ Are the exposure factors optimal?
■■ Are the lungs adequately inflated?
■■ Is there good symmetry of the heart and lung fields
on the dorsoventral/ventrodorsal view?
■■ Could any of the changes seen be artifact?
■■ Do the changes explain the clinical signs?
■■ If the radiograph, or radiographs, are normal, are
there any further views that should be taken?
■■ Could there be disease elsewhere that would
explain the clinical signs?
■■ Could there be a thoracic disease that explains the
clinical signs that may not be visible on thoracic
radiographs?

Question 4

What do you need to ensure you assess in a chest x-ray?

Answer 4

heart → pulmonary vessels → lung fields → trachea →
ribs → thoracic vertebrae → mediastinum → cranial
abdomen),

Question 5

What are the types of lung atelectasis?

Answer 5

relaxing, obstructive, adhesive, and cicatrizing

The different types relate to the mechanism for which the lungs cannot inflate

Question 6

What is relaxation atelectasis?

Answer 6

due to the unopposed tendency of the lung to collapse due to inherent elasticity.
Diseases that may produce this type of atelectasis are pneumothorax, pleural fluid, space-occupying lesion, and gravity-dependent and shallow breathing

Question 7

What is obstructive atelectasis?

Answer 7

due to absorption of alveolar gas without replacement due to airway obstruction.
The differential diagnosis includes neoplasm, foreign body, mucous plugging (eg, asthma), infectious bronchitis or pneumonia
Whereas pneumonia typically produces lung consolidation, atelectasis may occur when the lung lobe is not completely filled with pus and exudates obstruct some of the airways, preventing refilling of alveolar gas.

Question 8

What is adhesive atelectasis?

Answer 8

due to lumen surfaces of alveoli sticking together due to surfactant abnormality. Diseases include neonatal respiratory distress syndrome, acute respiratory distress syndrome, and pulmonary thrombosis

Question 9

What is cicatrizing atelectasis?

Answer 9

occurs when the lungs do not increase in volume under normal respiration because of reduced compliance due to such things as chronic idiopathic fibrosis, chronic immune-mediated lung disease, chronic pneumonia, and radiation pneumonitis

Question 10

What is atelectasis?

Answer 10

An incompletely expanded lung that has an increased opacity that completely or partially obscures the margins of pulmonary blood vessels and airway walls is called collapse or atelectasis.
Atelectasis is reduced inflation of all or part of the lung.

Question 11

What are the radiographic signs of atelectasis?

Answer 11

a mediastinal shift toward the abnormal appearing lung, crowding and reorientation of pulmonary blood vessels, crowding of ribs, compensatory hyperinflation of other lung lobes, bronchial rearrangement, cardiac rotation, displacement of interlobar fissures, displacement of the diaphragm, change in location of abnormal structures, and rounded pulmonary margins. Not all need to be present to recognize atelectasis

Question 12

What does a regional atelectasis suggest?

Answer 12

might suggest a local problem such as a foreign body, radiation pneumonitis, or recumbency.

Question 13

What is consolidation?

Answer 13

A fully expanded lung that has a homogeneous increased opacity that obscures the margins of pulmonary blood vessels and airway walls
May or may not be air bronchograms
Consolidation is not an end-point diagnosis but rather refers to a condition where an exudate or other product of disease replaces alveolar air, rendering the lung solid

Question 14

What is ground glass opacity?

Answer 14

A fully expanded lung that has a hazy increased opacity that only partially obscures the margins of pulmonary blood vessels and airway walls is called ground-glass opacity. This finding is caused by partial filling of air spaces, interstitial thickening (due to fluid, cells, or fibrosis), increased capillary blood volume, or a combination of these, the common factor being displacement of air.

Question 15

What are the ddx for increased opacity in a fully expanded lung

Answer 15

pneumonia, neoplasia, hemorrhage, pulmonary edema, and immune-mediated diseases

Question 16

What are the possible locations for lesions within the lungs?

Answer 16

cranioventral, caudodorsal, diffuse, lobar, focal, locally extensive, multifocal, and asymmetric.

Question 17

What may locally extensive increased opacity that contains innumerable, small, gas bubbles suggest?

Answer 17

lung-lobe torsion with lung necrosis

Question 18

When assessing the lungs, what should you assess?

Answer 18

■ Change in lung volume;
■ Location of pathology;
■ Bronchi and peribronchial tissue (bronchial pattern);
■ Number, size and course of blood vessels (vascular
pattern);
■ Increased opacity of the lungs (poor inflation, technical factors, alveolar or interstitial patterns);
■ Nodules and masses;
■ Mineralisation;
■ Decreased opacity of the lungs

Question 19

How do the vessels appear in the lung?

Answer 19

The most visible structures in the lungs of normal, younger animals are the pulmonary blood vessels, but bronchial walls can also be identified in the central area.
A faint meshwork-like background opacity is created by
small vessels and airways that cannot be identified individually.
The arteries and veins run on either side of the corresponding bronchus

Question 20

How do you assess sizes of vessels?

Answer 20

The maximum vessel diameter does not usually exceed the width of the proximal part of the fourth rib
For the orthogonal view, the DV projection is preferred
to the VD for the assessment of vessel size, and caudal
lobe vessels are compared with the ninth rib where they cross; similar normal size ranges apply.

Question 21

What may be suggestive of air trapping?

Answer 21

If the lungs are well expanded without manual inflation on repeated radiographs, generalised air-trapping may be present. In such cases, the diaphragm will be flattened and displaced caudally and, in cats, the diaphragmatic attachments to the ribs may be evident on the DV/VD view, giving the diaphragm a ‘Christmas tree’ shape

Question 22

What may a wide trachea suggest?

Answer 22

This indicates respiratory effort or significant lumenal

pressure during manual inflation.

Question 23

What can cause increased pulmonary volume?

Answer 23

Deep inspiration
Iatrogenic overinflation
Dyspnoea
Compensatory hyperinflation
Air-trapping due to bronchospasm
Emphysema (congenital/acquired)
Pulmonary mass

Question 24

What can cause decreased pulmonary volume?

Answer 24

Expiration
Occlusion of airway due to:
– Mucous plugs
– Tumour in, or compressing, the bronchus
– Foreign body
– Endotracheal tube
– Bronchospasm and air absorption
Atelectasis under general anaesthesia
Compression by expanded lung lobe(s)

Question 25

What does Increased opacity of a lung lobe without a | change in volume suggest?

Answer 25

Consolidation

Question 26

Which diseases are normally cranial and ventral?

Answer 26

``` Bronchopneumonia, lobar pneumonia, aspiration pneumonia, haemorrhage atelectasis ```

Question 27

Which diseases are caudal and dorsal normally?

Answer 27

``` Cardiogenic oedema (especially hilar area in dogs), non-cardiogenic oedema, interstitial pneumonia, infarct due to pulmonary thromboembolus, haemorrhage, atelectasis ```

Question 28

Which diseases are normally diffuse?

Answer 28

``` Acute cardiogenic and non-cardiogenic oedema, fibrosis, bronchitis, miliary metastases, haemorrhage atelectasis*, primary neoplasia in cats ```

Question 29

Which diseases are normally unifocal?

Answer 29

``` Primary neoplasm, solitary metastasis, abscess, granuloma, bulla, cyst, infarct due to pulmonary thromboembolus, lobe torsion, lobe consolidation, atelectasis* (especially right middle lobe) ```

Question 30

Which diseases are normally multifocal?

Answer 30

``` Metastases, abscesses, granulomata, bullae, parasitic cysts, cardiogenic oedema in cats, primary neoplasia in cats ```

Question 31

What can cause bronchial wall disease?

Answer 31

This is due to mucosal or submucosal hypertrophy and submucosal glandular hypertrophy, often in the presence of lumenal discharge. These diseases cause chronic bronchitis; radiographic evidence of acute bronchitis is rare. Congenital and acquired bronchiectasis will produce similar changes. Chronic bronchitis may be caused by infection (bacterial, postviral, fungal or protozoal), sterile inflammation, allergy (eg, feline asthma), parasites (especially Aelurostrongylus abstrusus in cats and Crenosoma vulpis in dogs) and irritants;

Question 32

What three things can cause a bronchial pattern?

Answer 32

Bronchial wall disease Bronchial calcification Peribronchial infiltrate with fluid or cells

Question 33

Outline bronchial calcification

Answer 33

This occurs as a natural ageing process, especially in chondrodystrophic breeds, and accounts for the increased bronchial pattern that is visible in many middle-aged and older patients. It may also be the result of previous, healed bronchial disease, naturally occurring or iatrogenic hyperadrenocorticsm and chronic kidney disease

Question 34

Outline peribronchial infiltrate of fluid of cells as a cause of a bronchial pattern

Answer 34

In cases of pulmonary oedema, fibrosis, eosinophilic infiltrate (eg, pulmonary infiltrate with eosinophils [PIE]) and neoplasia (eg, lymphoma or, occasionally, diffuse metastasis), the primary disease is not bronchial in origin

Question 35

Outline the appearance of a bronchial pattern (SIMPLE VERSION)

Answer 35

The bronchial markings are thickened and/or more radiopaque than normal, producing ‘tramlines’, ‘doughnuts’ and ‘signet rings’

Question 36

What are all of the signs of a bronchial patter

Answer 36

■ ‘Tramlines’ (non-vascular linear markings) corresponding to bronchial walls are seen longitudinally. Tracing the lines peripherally helps to differentiate a tramline from parallel blood vessels, which follow a similar course. Tramlines stay the same size and converge, while blood vessels taper and diverge; ■ ‘Doughnuts’ (ring markings) corresponding to bronchi are seen in cross-section, often with an adjacent end-on blood vessel, creating a ‘signet ring’ sign; ■ Airways containing significant amounts of debris may appear as apparent nodules when seen in cross-section; ■ Bronchial markings extend more peripherally than normal, creating a ‘scruffy’ or ‘busy’ lung field even though individual bronchioles cannot be identified; ■ Ill-defined bronchial markings suggest peribronchial infiltrate. Well-defined markings occur with chronic disease and bronchial calcification produces very fine but highly radiopaque markings; ■ Blood vessels are less distinct than normal as they are partly obscured by the bronchial pattern; ■ Lung volume may be increased if bronchospasm causes air-trapping, or may be reduced if mucous plugs obstruct the airways (the right middle lobe is usually affected); ■ A background interstitial pattern often coexists when chronic airway disease is present, and a concomitant alveolar pattern is present with bronchopneumonia.

Question 37

What can cause a hyper-vascular pattern?

Answer 37

■ PULMONARY CONGESTION DUE TO HEART DISEASE. For example, mitral insufficiency, cardiomyopathy and other causes of left-sided heart failure; ■ LARGE LEFT-TO-RIGHT SHUNT. Extracardiac shunts, such as a patent ductus arteriosus (PDA), cause more pronounced hypervascularity than intracardiac shunts, such as a ventricular septal defect (VSD); ■ IATROGENIC FLUID OVERLOAD; ■ VERMINOUS ARTERITIS. In the case of dirofilariosis and angiostrongylosis, the physical presence of the worms in the arteries causes distension. In the case of feline aelurostrongylosis, hypervascularity is due to arteritis and arterial hyperplasia. Changes are most dramatic with Dirofilaria species infection; ■ PULMONARY HYPERTENSION. This is due to severe, chronic lung disease; ■ PERIPHERAL ARTERIOVENOUS FISTULA; ■ SEVERE, CHRONIC ANAEMIA; ■ PULMONARY THROMBUS OR EMBOLUS. For example, secondary to cardiac disease, heartworm, disseminated intravascular coagulation (DIC), trauma, renal disease, septicaemia, pancreatitis, hyperadrenocorticism and following surgery

Question 38

Do veins or arteries distend in a vascular pattern?

Answer 38

Depending on the cause, both the arteries and veins may be distended or one set of vessels may be larger. However, veins distend more readily than arteries due to their thinner walls.

Question 39

What are the general signs of a hyper vascular pattern

Answer 39

■ Increased vessel size (arteries and/or veins); ■ End-on vessels mimicking nodules; ■ Enlarged vessels becoming slightly tortuous; ■ Vessels extending further to the periphery of the lung field than normal; ■ Overall increase in lung opacity; ■ Loss of clarity of vessel outline in the presence of early pulmonary oedema; ■ Associated changes in the heart, caudal vena cava, abdomen, and so on, depending on the cause

Question 40

What can cause a hypovascular pattern?

Answer 40

■ COMPRESSION OF VESSELS. Due to hyperinflation of the lungs (air-trapping, overzealous manual inflation); ■ HYPOVOLAEMIA. Due to dehydration or blood loss; ■ SHOCK; ■ HYPOADRENOCORTICISM (Addison’s disease); ■ SEVERE PULMONIC STENOSIS; ■ RIGHT-TO-LEFT SHUNTS. For example, tetralogy of Fallot and reverse-shunting PDA; ■ FORWARD RIGHT-SIDED HEART FAILURE. Due to pericardial effusion and cardiac tamponade, restrictive pericarditis or severe tricuspid regurgitation.

Question 41

What are the general signs of a hypovascular pattern?

Answer 41

■ Hyperlucency of the lungs due to a reduction in the volume of circulating blood, which is of soft tissue opacity; ■ Thin and thread-like vessels, which do not extend to the periphery; ■ Changes in heart size depending on the cause. Reduction in the size with circulatory problems and hyperinflation, and changes in size and shape with cardiac disease; ■ Reduction in the size of the caudal vena cava and sometimes also the aorta with circulatory problems and hyperinflation.

Question 42

Compare the fundamentals between alveolar and interstitial patterns

Answer 42

alveolar pattern - where fluid or cells replace alveolar air | interstitial pattern - where fluid or cells infiltrate alveolar septa and other areas of the interstitium

Question 43

What can air in the alveoli be replaced with?

Answer 43

oedema, haemorrhage, exudate or cells, or lost due to lung collapse. The various types of infiltrate cannot be differentiated radiographically, but may be intimated by the presence of certain ‘clues’ such as left atrial dilation (suggesting cardiogenic oedema), fractured ribs (suggesting pulmonary contusion), distribution of pathology and the presence of other lung patterns.

Question 44

What are the possible causes of pulmonary oedema?

Answer 44

■ Pulmonary oedema due to many processes, both cardiogenic and non-cardiogenic. Non-cardiogenic oedema may be caused by direct alveolar inflammation, systemic disease, neurogenic causes, upper respiratory tract obstruction and late acute respiratory distress syndrome (ARDS). ■ Haemorrhage resulting from congenital or acquired coagulopathy, trauma or a rapid proliferation of miliary metastases. ■ Exudate occurring as a result of various forms of pneumonia. ■ Other fluids, which have been aspirated accidentally. ■ Cellular infiltrate, which is less common but may be neoplastic (especially in cats) or part of pulmonary infiltrate with eosinophils (PIE). ■ Atelectasis, which can occur for a variety of reasons and often arises in the dependent middle lung lobe of anaesthetised dogs due to compression by the overlying heart. This may both mimic and mask pathology. If it is due to anaesthesia, radiographs can be repeated after repositioning and several minutes of ventilation.

Question 45

What are the radiographic signs of an alveolar pattern?

Answer 45

■ Patchy, ill-defined areas of increased lung opacity, often described as ‘fluffy’ or ‘cotton wool-like’. ■ Increased lung opacity, which is least peripherally where the lung is thinner and from where labile fluid may be ‘massaged’ out by respiratory motion. ■ Blood vessels and bronchial walls are unclear due to border effacement by the adjacent alveolar opacity. In severe cases, the cardiac and diaphragmatic margins may also be ill-defined. Blood vessels are most clearly seen in the least-affected lobe(s). ■ Lobar margins appear obvious due to differences in the severity of the alveolar pattern in adjacent lobes. ■ Air bronchograms are evident as the patches of alveolar filling become larger or confluent; these are linear or cross-sectional bronchi appearing radiolucent because air is highlighted against consolidated lung. Adjacent blood vessels are completely obscured. Care must be taken not to misdiagnose the air-filled lumen of a bronchial marking or the space between parallel blood vessels as an air bronchogram. Although air bronchograms are a characteristic sign of an alveolar pattern, they are only present when the lung infiltrate is severe, and they are unusual in cats.

Question 46

Why may there be poor correlation between interstitial changes and clinical signs?

Answer 46

interstitial changes often reflect ageing or previous disease that has healed, and bronchoalveolar lavage is much less likely to be reward

Question 47

What can cause a diffuse reticular interstitial pattern?

Answer 47

■ Artefacts due to underexposure, underdevelopment or poor lung inflation. ■ Pulmonary fibrosis due to ageing changes – so-called ‘old dog lungs’. ■ Increased pulmonary water content in young animals. ■ Chronic respiratory disease. ■ Idiopathic pulmonary fibrosis, especially in West Highland white terriers. ■ Neoplasia – most commonly lymphoma, but also diffuse metastasis from scirrhous mammary carcinomas and feline bronchoalveolar carcinomas. ■ Interstitial pneumonia due to viral (mainly distemper), fungal, parasitic or metabolic pathology, or inhaled irritants such as smoke. ■ Paraquat poisoning. ■ PIE. ■ Late hyperadrenocorticism with alveolar microlithiasis. ■ Early ARDS. ■ Feline infectious peritonitis.

Question 48

What can cause a focal interstitial pattern?

Answer 48

■ Bronchial foreign bodies; ■ Pulmonary thromboembolism; ■ Contusion from blunt trauma.

Question 49

What are the main differences between an interstitial and alveolar pattern?

Answer 49

the homogeneity of the interstitial pattern and the fact that with interstitial the increased opacity extends to the periphery of the lungs.

Question 50

What are the radiographic signs of a generalised reticular interstitial pattern?

Answer 50

■ Overall increase in lung opacity, extending to the periphery. The pattern is often described as being ‘honeycomb’ or ‘chicken wire’ in appearance. ■ Widespread pattern affecting all lobes equally. ■ Loss of clarity of blood vessels without overt border effacement, and reduced contrast within the lungs. ■ Faint air bronchograms in severe cases, but much less obvious than with an alveolar pattern. ■ Exacerbation of the reticular pattern by small areas of emphysema in some cases.

Question 51

What are the causes of miliary interstitial pattern?

Answer 51

■ Miliary metastatic neoplasia. ■ Pulmonary lymphoma. ■ Miliary granulomata (eg, fungal [not endemic in the UK] or tuberculous). ■ Disseminated form of primary alveolar cell carcinomas. ■ Granulomatous form of PIE. ■ Multiple small airways plugged with mucus. ■ Aelurostrongylosis in cats, although this is due to arteritis and small bronchial markings rather than true miliary disease. These conditions involve widespread dissemination of neoplastic or inflammatory cells via haematogenous or lymphatic routes and, hence, radiographic changes are usually generalised and affect all lung lobes

Question 52

What are the radiographic signs of a nodular interstitial pattern?

Answer 52

■ Granular or nodular increase in lung opacity (often due to summation – the so-called ‘bunch of grapes’ effect). ■ Increased opacity extending to the periphery, which is unlike alveolar patterns, in which the margins of the lungs are often least affected. ■ Larger nodules remain distinct and do not coalesce, unlike alveolar patterns. ■ Lobar margins may become visible. ■ The distinct nodular pattern may be blurred by movement artefact (short exposure times are necessary, especially in dyspnoeic patients) or superimposed alveolar disease. ■ Mediastinal lymphadenopathy may be visible

Question 53

How is a miliary pattern different to end on blood vessels?

Answer 53

End-on blood vessels are more radiopaque for their size than spherical soft tissue nodules of the same diameter. They are close to blood vessels of similar size seen side-on, and therefore are largest and most numerous centrally and smaller and scarcer peripherally.

Question 54

How can you tell the difference between calcification and a miliary pattern?

Answer 54

With calcification, despite their small size, their marked radiopacity shows that they are mineralised rather than soft tissue nodules

Question 55

What can cause a nodule/ mass in the lung?

Answer 55

■ Solitary primary lung tumour (which may take on a lobar shape due to bronchial occlusion with distal consolidation or collapse). ■ Metastatic lung disease (usually multiple). ■ Histiocytosis ■ Abscess (eg, following foreign body aspiration). ■ Granuloma (fungal, parasitic, eosinophilic, tuberculous). ■ Haematoma. ■ Traumatic, fluid-filled bulla. ■ Bronchogenic cyst. ■ Enlarged, mucus-filled bronchus seen end-on (eg, bronchiectasis).

Question 56

How can you tell if a mass on a radiography is solid?

Answer 56

The mass may be fluid-filled or necrotic in the centre, although this cannot be detected radiographically as the radiopacity remains the same. However, peripheral lesions may be amenable to ultrasonographic examination, which enables the detection of fluid-filled areas.

Question 57

What can cause a decrease in the opacity of the lungs?

Answer 57

Mostly artefact. iatrogenic overdistension of the lungs when manual lung inflation is used, or may be apparent in emaciated animals or those with pneumothorax. Genuine hyperlucency of the lung field may be due to a reduced amount of blood circulating in the lungs (hypoperfusion), an increase in the volume of air contained (hyperinflation) or a combination of both processes. While usually generalised, lobar and focal changes are sometimes seen.

Question 58

What are signs of hyperinflation?

Answer 58

■ Darker lungs than normal on technically correct radiographs; ■ Diaphragm displaced caudally, flattened and ‘tented’ on the dorsoventral/ventrodorsal projection; ■ Ribs perpendicular to the spine on the dorsoventral/ ventrodorsal projection; ■ Small heart and vessels due to compression.

Question 59

What are the benefits of CT?

Answer 59

``` Avoids superimposition Can see smaller lesions More descriptive Better at identifying location Very good for interstitial lung diseaase V useful in oncology ``` BUT can add noise

Question 60

What is the best way to radiograph the chest?

Answer 60

patients should be kept in sternal recumbency and have sedation/anaesthetic time kept to a minimum before an image is acquired. Three radiographic projections should ideally be obtained, starting with a dorsoventral (DV)/ventrodorsal (VD) view and then both lateral views. Inflated views under general anaesthesia are also preferable to prevent atelectasis and expand the parenchyma

Question 61

How do mediastinal masses appear?

Answer 61

typically as rounded, soft tissue opacity structures, often with ill-defined margins due to adjacent soft tissue structures (compared with pulmonary masses). They should lie on or very close to the midline of the thorax (best assessed on the DV view Secondary displacement of other mediastinal structures may occur; for instance, cranioventral masses can cause caudal displacement of the heart or dorsal displacement of the trachea and oesophagus. Compression and/or displacement of adjacent lung lobes may also occur.

Question 62

What are the most common masses in the mediastinum?

Answer 62

The most common masses are located in the cranioventral quadrant of the mediastinum. Lymphoma is the most common tumour here and is typically multicentric; enlargement of the tracheobronchial lymph nodes may also be seen, together with abdominal and/or peripheral lymphadenopathy. Thymomas appear as single encapsulated masses. Megaoesophagus is reported in approximately 40 per cent of thymoma cases due to paraneoplastic-acquired myasthenia gravis

Question 63

What are the divisions of the lungs?

Answer 63

comprise four right-sided lobes (cranial, middle, caudal and accessory) and two left-sided lobes (cranial [subdivided into cranial and caudal portions] and caudal)

Question 64

How do primary pulmonary neoplasms appear?

Answer 64

tend to be solitary, well-defined lesions and are slightly more common in the caudal lung lobes

Question 65

Outline histiocytic sarcomas of the lung

Answer 65

Histiocytic sarcomas can present as a primary pulmonary mass or as metastatic disease, with both Bernese mountain dogs and rottweilers being over-represented. This mass is commonly seen in the right middle or left cranial lobes and tends to be ventrally located or affecting the whole lobe Unlike primary carcinomas, air bronchograms may be seen with histiocytic sarcomas, which can create a similar appearance and distribution to aspiration pneumonia

Question 66

Outline the difficulty with accessory lung lobe masses

Answer 66

diagnostically challenging as they are located on the midline and may mimic a mediastinal lesion. Radiographically it may not be possible to differentiate these two types of mass so CT is indicated in such cases

Question 67

How do metastatic neoplasms present in the lung and what are they?

Answer 67

The majority of these neoplasms are carcinomas (eg, mammary, prostatic, urinary tract transitional cell, thyroid), and while the imaging characteristics are non-specific they tend to present as numerous, diffuse, small, sometimes ill-defined nodules. Mesenchymal tumour (sarcoma) metastases are typically fewer in number, larger and more well-defined. . One exception is haemangiosarcoma, where numerous small nodules can be seen with variable margin definition due to local haemorrhage.

Question 68

How does pulmonary lymphoma present?

Answer 68

typically presents as a diffuse interstitial pattern; however, it has been reported to form mass lesions and a nodular pattern if a peripheral and/or thoracic lymphadenomegaly is present, this should be considered more likely.

Question 69

What eosinophilc condition can appear as a neoplastic lesion?

Answer 69

Eosinophilic bronchopneumopathy is an inflammatory disorder typically affecting young adult dogs (more commonly female and medium/ large breeds) in which eosinophilic infiltrates occasionally cause a nodular pattern and, less commonly, a larger mass

Question 70

Outline primary rib tumours

Answer 70

Primary rib tumours are typically mesenchymal in origin (with osteosarcomas and chondrosarcomas being the most common) and are generally located distally, near the costochondral junction. Intrathoracic extension of the tumour often occurs to a greater extent than peripheral extension, which can result in late diagnosis of the disease and very large masses may be present despite relatively mild clinical signs. Concurrent pleural effusion is often present and causes radiographic effacement of the mass; thoracocentesis with either repeat radiography or CT is indicated in such cases. Benign masses are rare but include chondromas, fibromas, multiple cartilaginous exostoses and calcinosis circumscripta

Question 71

Outline mets to the ribs

Answer 71

seen with several neoplastic conditions (notably canine osteosarcoma) and therefore careful scrutiny of the entire ribcage is essential with any thoracic radiograph. In contrast to primary tumours, they are typically found in the proximal third of the rib shaft and are often subtle, with only a small degree of lysis or periosteal reaction, but can significantly change the diagnostic and therapeutic course of the patient concerned Can get multiple myeloma