Атлас по рентгенологии травмированных собак и кошек / an-atlas-of-radiology-of-the-traumatized-dog-and-cat

32 Radiology of Thoracic Trauma

Case 2.7

2

Signalment/History: “Grenigo” was a 2-year-old, male

DLH cat who had been hit by a car 12 hours earlier.

Physical examination: The cat was dyspneic and unable to stand. He did not seem to be able to move his pelvic limbs. Deep pain was evident in the pelvic limbs.

Radiographic procedure: Radiographs were made of the thorax and of the lumbar spine and pelvis.

Radiographic diagnosis (thorax): Extensive subcutaneous emphysema was located primarily on the left. The 5th rib on the left was fractured and the separation of the ribs indicated intercostal muscle tearing (white arrows). Widening of the space between sternebrae 3 and 4 suggested a luxation. Extensive pulmonary contusion was most severe on the right, but also affected the left cranial lobe. Pneumothorax was principally on the left and minimal. Signs of pneumomediastinum were prominent.

Thorax wall injury 33

2

Radiographic diagnosis (lumbar spine): A compression fracture involved the body of L6 with collapse of the L5– 6 disc space (arrow). Bony fragments appeared to be driven dorsally into the spinal canal. Both hip joints were unstable probably due to hip dysplasia.

Treatment/Management: “Grenigo” was treated conservatively. The pulmonary contusion regressed rather quickly. By maintaining a strict control on movement, the vertebral fracture healed in two weeks permitting him to eventually walk almost normally.

34 Radiology of Thoracic Trauma

Case 2.8

2

	Thorax wall injury 35
Signalment/History: “Asta”, a 6-month-old, female Ger-	Treatment/Management: Both a brachial plexus injury and
man Shepherd puppy, had been struck by a car one hour pri-	pelvic injury were suspected. The cervico-thoracic injury was
or to presentation for treatment.	partially confirmed by identification of the rib fracture. Addi-
	tional radiographic studies of the thoracic inlet region were
Physical examination: She was unable to rise to a standing	made using a more penetrating x-ray beam, but added no new
position. She had no pain sensation in the right forelimb and	information. Pelvic radiographs were made and showed only a		2
minimal voluntary movements in the left forelimb.	developmental transitional lumbosacral segment with an asso-
	ciated malposition of the pelvis and did not indicate a recent
Radiographic procedure: Radiographs were made of the	fracture.
thorax as a part of a clinical work-up for a trauma patient.	“Asta” was diagnosed with an avulsion type injury to the
Radiographic diagnosis: An increase in fluid density was	brachial plexus and did not recover the use of her forelimb.
noted in the cranial lung lobes. It was more prominent on the	Comments: Cranial mediastinal width is difficult to detect in
right side, probably indicating pulmonary contusion. It was
difficult to evaluate the width of the mediastinum on the VD	a case such as this and mediastinal hemorrhage was not con-
view, but the presence of mediastinal thickening due to hem-	firmed.
orrhage was considered. A fracture of the first rib on the left	Because of the large size of the dog, an error was made in not
was identified. Air-bronchograms in the left cranial lobe
(arrow) indicated injury to that lung also.	including the entire diaphragm on the DV radiograph. The
	marked caudal displacement of the left hemidiaphragm was
The injury in the axillary region in a patient with neurologic	only suspected on the DV view. On the lateral view, the shad-
deficits in a forelimb suggested that the soft tissue injury was	ow of the dorsal crura on the left was positioned caudally.
more important than the minimal lung and rib lesions.

36 Radiology of Thoracic Trauma

Case 2.9

2

Day 1

Signalment/History: “Ginger” was an obese, 10-year-old, female Golden Retriever, who had been hit by a car several hours earlier and was presented with a flail chest.

Physical examination: Palpation of the thorax indicated severe injury to the ribs on the right. A soft tissue mass was evident in the inguinal region, but this was not thought important at the time.

Radiographic procedure: Initially on day 1, only thoracic radiographs were made due to the condition of the patient. But because of the caudal location of the thoracic trauma, injury to the liver, pancreas, and gall bladder needed to be considered and abdominal studies were made as soon as the patient was stabilized.

Radiographic diagnosis (day 1, thorax): Multiple fractures of the 9th–12th ribs on the right were noted with fragment displacement (flail chest), causing a marked deformity of the caudal portion of the right thoracic wall. Loculated pleural fluid, probably a hemothorax, was present in the caudal right hemithorax. This was associated with a volume loss caused by the caudal lobe atelectasis. The pulmonary vessels were small indicating shock. The apparent slight mediastinal shift to the left was thought to be the result of spinal curvature due to positioning and not due to trauma. A pneumothorax was expected in association with the chest wall injury, but a pattern of pleural air was difficult to identify. A small pattern of air separated the left caudal lung lobe from the chest wall and the diaphragm, but the volume was much less than antic-

Thorax wall injury 37

2

Day 3

ipated considering the nature of the injury. The diaphragm was intact with the ventral portion more cranial in position than normal. A minimal amount of peritoneal fluid, probably hemorrhage, caused a reduced contrast in the abdomen.

Radiographic diagnosis (day 3, abdomen): Intestinal loops were noted within a right inguinal hernia. Loss of peritoneal shadows suggested the presence of peritoneal fluid. Liver, gastric gas bubble, and spleen were identified in their normal positions. The diaphragm was intact. Failure to identify the urinary bladder was thought to be an important finding.

Differential diagnosis: The distention of the single small bowel loop could mean: (1) an obstructive lesion associated with the hernia, (2) a paralytic ileus associated with damage to

the blood supply to a solitary loop, or (3) a paralytic ileus associated with spillage of urine into the peritoneal cavity. This question was resolved at the time of abdominal surgery.

Treatment/Management: The inguinal hernia was repaired. The associated bowel loop was found to have a good blood supply and not to be torsed. “Ginger” was discharged with a persistent chest wall deformity and the possibility of being a “chronic respiratory cripple”.

Comments: “Ginger” is an example of the importance of making both thoracic and abdominal radiographic studies recognizing that this technique can be of immediate value in the evaluation of the entire patient.

38 Radiology of Thoracic Trauma

2

Case 2.10

Signalment/History: “Buster” was a 1-year-old, male Golden Retriever with a history of chronic cough.

Physical examination: The examination did not contribute to an understanding of the clinical signs. There was no history of trauma that might have preceded the cough.

Radiographic procedure: Multiple views were made of the thorax.

Radiographic diagnosis: The injury to the right thoracic wall was long-standing with malunion rib fractures and thickened pleural shadows indicative of pleural scaring. The cardiac shift toward the site of injury suggested pleural adhesions with atelectasis. The lesion was not identified on the lateral view.

Treatment/Management: The post-traumatic changes caused a failure of normal expansion of the right middle lobe, a probable defect in the ciliary clearing mechanism, and a possible chronic pneumonia. Three separate DV radiographs were made to insure that the apparent shift in position of the mediastinum was not due to improper positioning of the patient during radiography. The apparent cardiomegaly may have been real or the result of the heart’s malposition.

Treatment was limited to the purely symptomatic.

Thorax wall injury 39

2

40 Radiology of Thoracic Trauma

Case 2.11

Signalment/History: “Quake” was an 8-year-old, male Schnauzer mixed-breed with a history of a left-sided thoracic

mass thought to be secondary to a bite wound.

2

Physical examination: No evidence of soft tissue injury was noted. The soft tissue mass was firm, not warm, and not fluctuant.

Radiographic procedure: The intensity of the radiographic beam used for the thoracic studies was increased to permit a better evaluation of the thoracic wall.

Radiographic diagnosis: A concave defect in the thoracic wall on the left (arrows) was associated with an increase in the width of the extra-thoracic musculature. Focal pleural thickening or trapped pleural fluid lay adjacent to the defect. No rib fractures were noted. The cardiac and pulmonary structures were normal. The lateral view did not contribute to the evaluation of the thoracic wall lesion.

Differential diagnosis: The differential diagnosis of a flattened, focal, pleural thickening in the absence of rib lesions includes: (1) inflammatory pleuritis that can be acute or chronic, and active or quiescent, (2) a soft tissue tumor invading from the extra thoracic region such as a fibrosarcoma, (3) a pleural tumor such as a mesothelioma, or (4) chronic chest wall injury.

At presentation

Thorax wall injury 41

Treatment/Management: Surgical exploration resulted in the removal of a plant awn that had partially penetrated into the thoracic cavity. A follow-up study made three months later showed only a persistent pleural thickening as a consequence of the infection and the surgery.

2

Month 3