Radiologicaldiagnosisinheartconditionindog

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RADIOLOGICAL DIAGNOSIS
IN HEART CONDITIONS IN THE DOG
Robert Cristian PURDOIU**, PhD Student
Ionel PAPUC*, Professor
Radu LĂCĂTUŞ*, Lecturer
Alexandra Nicoleta PĂVĂLOIU*, PhD Student
Abstract
The examination of the cardiovascular system needs special attention to the history data, on which the whole investigation needs 
to be oriented. In the etiopathology of this system, the degree of selection, exploitation ad effort that the animal is being subjected to 
plays one of the main roles, as well as, in a lesser degree, age, as elements of over-solicitation and implicitly as risk-factors, which 
can favor or create a misbalance in this vital system. A major impact on the cardio vascular system comes from infectious diseases, 
which can, either primarily or secondarily, lead to cardio circulatory symptoms, sometimes characteristic. Chronic respiratory disease, 
nutritional and metabolism misbalances, endocrine disease, renal problems, all are favoring or determining cardiac, vascular and 
sanguine affections. Te examination of the cardio vascular system is performed through: a general functional examination, a physical 
(morphological) examination, a complex blood and hemato-forming organs examination.
Introduction
Out of the specialty literature we have selected and applied the most recommended exposure 
positions in heart conditions in the dog. To evidentiate the cardiac projection area we have used 
the lateral decubitus and exposure; in this case not only the cardiac projection area is evidentiated, 
but also the trajectory of the descending aorta- the thorax portion ad the caudal vena cava- thorax 
portion, the left and right diaphragm pillars, the right atrium and ventricle and the left atrium and 
ventricle (Fig. 1, 2, after Hornof and Koblik, 2011; Burk and Ackerman, 1996).
The pulmonary arterial trunk is difficult to evidentiate if there are no alterations to the heart. 
These changes are more evident in the ventro-dorsal exposure, when the heart is dilated (Thrall, 
2007). Radiography is particularly important in the diagnosis of cardiomyopathy in dogs, in particular 
cardiomegaly and of secondary importance of extracardiac signs, of heart failure include: hepatomegaly, 
splenomegaly, ascitis, suffusions and / or pulmonary edema (Brăslaşu, 2001).
To view the heart mediastinum, a dorsal-ventral position and ventro-dorsal exposure were applied, 
in this case is evidentiating the mediastinal area predominantly occupied by the heart, diaphragm, 
aorta, pulmonary artery, cardiophrenic ligament (Fig 3, 4, Hornof and Koblik, 2011).
* University of Agricultural Science and Veterinary Medicine Cluj Napoca, Faculty of Veterinary Medicine, 
Discipline of Semiology, Ethoology and Veterinary Imagistic Sciences, Str. Mănăştur, nr. 3-5, Cluj Napoca, 
e-mail: robcry999@yahoo.com.
Cluj Veterinary Journal, 1(19)/2011, pp. 32-37
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Fig. 1. Normal topography of the heart in the dog, lateral position, 
lateral exposure (1. Cranial mediastinum; 2. Trachea; 3. Desceding 
aorta; 4. Caudal vena cava; 5. pulmonary cranial artery (pink), left 
cranial pulmonary vein (blue); 6. right pulmonary cranial artery 
(pink), right cranial pulmonary vein (blue); 7. Right atrium; 8. right 
ventricle; 9. Left atrium; 10. Left ventricle; 11. Right diaphragm 
pillar; 12. Left diaphragm pillar; 13. Fat nucleus in the pericardium;
14. Right pulmonary artery; 15. Left pulmonary artery) (after Hornof 
and Koblik)
Fig. 2. Lateral exposure of the thorax in the dog – normal aspect 
(1. Trachea; 2. Carina; 3. Artera aortă; 4. Caudal vena cava;
5. Right diaphragm pillar; 6. left diaphragm pillar; 7. pulmonary 
cranial artery (pink), left cranial pulmonary vein (blue); 8. right 
pulmonary cranial artery (pink), right cranial pulmonary vein (blue); 
9. Cardiac shadow (a. Apex; b. Cranial side of heart; c. Caudal 
side of heart); 10. Costocondral junction; 11. Costal cartilages;
12. Sternebrae; 13. Apex fat deposit; 14. Skin fold) (after Hornof 
and Koblik)
Fig. 3. Dorsal ventral exposure of the thorax in the dog – normal 
aspect (1. Cranial mediastinum; 2. Aorta left lateral margin;
3. Cardiac shadow; 4. Pulmonary artery; 5. Pulmonary vein;
6. Caudal vena cava; 7. cardio phrenic ligament; 8. Diaphragm;
9 Stomach) (after Hornof and Koblik)
Fig. 4. Dorsal ventral exposure of the thorax in the dog – normal aspect 
(1. Cranial mediastinum; 2. Right atrium; 3. Right ventricle; 4. left 
atrium; 5. left ventricle; 6. aorta – lateral margin; 7. Caudal vena cava; 
8. Pulmonary artery; 9. Pulmonary vein; 10. Pulmonary arterial trunk) 
(after Hornof and Koblik)
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Materials and methods
The study was initiated by us in regard to the radiological diagnosis of cardiac changes in dogs 
in their entirety. The biological material was represented by a total of five adult dogs, of different 
sizes, ages and sexes, which were brought in to the radiology clinic for a radiological examination in 
the Faculty of Veterinary Medicine, Cluj-Napoca. The working method we used complied with the 
radiological examination protocol, settling in advance the type of grain of the film and tape, working 
parameters required for exposures (kilovoltage, miliamperage, exposure time and distance), position 
of the animal on the radiology table and exposure position (Papuc et al., 2009). 
The working parameters of the roentgen diagnostic equipment used in latero-lateral exposure have 
ranged from 50-66 kV and 8-15 mA, and in ventro-dorsal exposures they have ranged from 55-66 kV
and 10-25 mA depending on the size of the animal. Also, for each patient, the exposure dose of 
radiation received was monitored. 
Results and discussions
In the latero-lateral exposure it was possible to visualize the right ventricle, and to perform 
measurements of cardiac performance in relation to the rib cage. Under normal conditions, the heart 
height represents 2/3 of chest height and the width is still 2/3 compared to the width of the thoracic 
cavity, with a slope at an angle of about 30°, this ratio is changed if cardiac dilation appears (Fig. 5, 
Fig. 6).
The right ventricle may undergo changes in shape and volume due to heart hypertrophy or 
cardiac dilation. The most common causes of right ventricular dilation, with the possibility of 
radiological diagnosing are intracardiac parasites and pulmonary stenosis. Radiological diagnosis of 
right ventricular dilation is much more easily determined than left ventricular dilation, this is due to 
right ventricular wall thickness, which is much thinner than the left ventricular wall, which allows 
for the change in shape and volume. Because the topography of the right ventricle is normally close 
to the sternum, right ventricular dilation will increase the contact surface of the heart to the sternum. 
In healthy dogs, contact of the heart with the sternum is visible on 2-3 intercostal spaces (Fig. 1). A 
contact area of more than three intercostal spaces indicates a right ventricular dilatation. In cases of 
Fig. 5. Lateral exposure 66 kV, 20 mA – cardiac dilation (A- thorax 
height; B- heart height; C- cardiac axis; D-heart width; E- angle of 
cardiac axis, F- pulmonary densificatios) 
Fig. 6. Ventro-dorsal exposure 66 kV, 25 mA – cardiac dilation
(A- thorax width; B- heart width)
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severe right ventricular dilatation, the apex amends its position to the sternum, the cardiac shadow 
becomes almost spherical (globular – Fig 8, Fig. 9), heart topography is altered, mainly occupying 
the right hemithorax, which is highlighted on the X-ray, in ventro-dorsal exposure, in terms of a 
turned letter D.
The left ventricle has a ventricular wall three 
times thicker than the right ventricular wall, so it 
does not have the same flexibility as its congener, 
expansion in this level being diagnosed more 
infrequently. Left heart dilation appears in the 
global dilation of the heart, in this case, with the 
exposure in latero-lateral position, the heart has 
a spherical appearance. Diagnosisof left heart 
dilatation may be provided the easiest through 
ventro-dorsal exposure. In this case the heart is 
highlighted in both the right mediastinum and the 
left mediastinum. The edge of the left heart wall, 
which normally is relatively straight, becomes 
convex in left heart dilation (Fig. 8, 9).
The pulmonary arterial trunk, from a radio-
logical point of view, is very difficult to identify 
as a well defined structure, but if it is dilated, it 
may act as a densification in the heart (1 o’clock 
direction), but only the ventro-dorsal exposure 
(Fig. 8), in latero-lateral exposure, the diagnosis 
is difficult to determine.
Latero-lateral exposure of the chest, in a dog 
with right heart dilatation, highlights the increased 
area of contact between the right ventricle and 
sternum (Fig. 7-D), these are occupying 4-5 inter-
costal spaces. Densification outbreaks are also 
evident in the tracheal bifurcation (Fig. 7-B) and 
Fig. 7. Lateral thorax exposure, right lateral position (dog), 66 kV,
25 mA (A- Aortic curve; B- Carina densification focus; C- Left ventricle 
densification focal spots)
Fig. 8. Ventro-dorsal exposure 60 kV, 20 mA – bilateral heart dilation 
(A- pulmonary arterial trunk, B- pulmonary artery, C- dense formation 
in the pulmonary parenchyma)
Fig. 9. Global cardiac dilation, ventro dorsal exposure, 66 kV, 25 mA
Fig. 10. Lateral exposure (dog), lateral left position 66 kV, 25 mA 
(A- Descending aorta; B- Lung densification focal spot; C- left atrium 
densification focal spots; D- right atrium densification focal spots; 
E- position of the cardiac apex compared to the sternum)
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in the lung lobes (Fig. 10-B, 8-C), indicating a possible fibrosis found in of the lung migration of 
parasites larvae or in the case of lung tumors (Fig. 10-B) (Fig. 8-C). The focus of densification of the 
left ventricle (Fig. 7 C) indicates damage to the myocardium, the general problem in the case of an 
infarction. The apex of the heart in right heart dilation comes into direct contact with the sternum 
(Fig. 10-E), being oriented cranio-caudally and altering the heart axis angle (Fig. 5-E). All of these 
topographic changes are diagnosed in right heart dilation and in irritating agents in the cardio-
pulmonary area.
To determine an exact diagnosis of left or right ventricular dilatation, a dorsal-ventral exposure and 
ventro-dorsal one were necessary. These complimentary exposures underline the slightly spherical 
shape of the heart shadow - for right heart dilation and appearance of a globular heart with visibility 
both in the left and right mediastinum – in left heart dilation and the fact that it occupies mainly 
the left hemithorax – in right heart dilation, or the entire chest cavity if it is a left cardiac dilation or 
global heart dilation. The radiological examination can also diagnose radioopaque nodules located 
in the left myocardium (Fig. 11-E, Fig. 12-A). Right ventricular dilation on the radiological picture 
looks like the letter D, and dilation of the right atrium looks like an area of rarefaction (Fig. 11-B). 
On the side of the thoracic spine, on the right side, the arterial pulmonary trunk may be evidenced 
by radiological means (Fig. 11-C, Fig. 12-C), in terms of a well circumscribed radioopaque formation, 
and to the left aide, the aorta, abdominal segment.
Conclusions
Certainty in the diagnosis of heart disorders in dogs is determined by typical, general and organ 
signs, obtained in the clinical examination, in conjunction with data provided by radiological 
examination. Based on data we obtained, several conclusions can be drawn.
1. Radiography as a paraclinical examination, in the cardiac disorders in dogs, can provide data 
for establishing a diagnosis in: right ventricular dilation, dilation of the right atrium, pulmonary 
artery trunk and aorta wall clouding, focal sites of densification with a tortuous appearance on the 
cardiac lung lobes, the presence of the radioopaque nodules or outbreaks of myocardial fibrosis.
Fig. 11. Dorso-ventral position, ventro-dorsal exposure of the 
thorax in a dog with suspected dirofilariosis 66 kV, 25 mA (A- Right 
ventricle; B- right atrium; C- Pulmonary arterial trunk; D- Pulmonary 
densification tortuous lines; E- radioopaque nodules in the left 
ventricle myocardium 
Fig. 12. Dorso-ventral position, ventro-dorsal exposure of the 
thorax in a dog with suspected dirofilariosis 66 kV, 25 mA (A- 
radioopaque nodules in the left ventricle myocardium; B- Aorta trunk; 
C- Pulmonary arterial trunk; D- Pulmonary densification tortuous 
lines on the cardiac side of the lung lobes)
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2. Quality radiological images were obtained at working parameters of 66 kV, 25 mA and an exposure 
time of 0.02 seconds.
3. During the radiological examination the X-ray dose was monitored by means of a DAP-meter, taking 
into account the limitation of the amount of radiation received by a patient. Received radiation 
dose per patient / 2 exposures was between 44,42 μGy m2 and 85,28 μGy m.
4. To diagnose right ventricular, left ventricular and pulmonary arterial trunk dilation, a ventro-dorsal 
exposure is recommended.
5. The changing topography in the left heart cardiac dilation is much more evident compared with 
right heart dilation.
6. Right heart dilation is commonly diagnosed in parasitic infestation cardio-pulmonary parasitic 
infestation or pulmonary arterial trunk fibrosis and left heart dilation in focal points of densification 
in the myocardium or chronic systemic disorders such as hepatomegaly, splenomegaly, ascites..
References
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Saunders Company. P23-211, 1996.
3. Donald E. Thrall, Textbook of Veterinary Diagnostic Radiology, Saunders Elsevier, Ed. Elsevier Inc., 2007.
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veterinar, Ed. Accent, Cluj Napoca, pp. 358-359, 2009.
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