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

42 Radiology of Thoracic Trauma

Case 2.12

2

Referral radiographs

Signalment/History: “Sandy”, a 5-year-old, male Queensland Heeler, had been hit by a car 24 hours earlier.

Physical examination: The examination was difficult because of the obtunded status of the dog. Abnormalities in the left chest wall could be palpated.

Radiographic diagnosis (referral radiographs): Referral radiographs showed a massive pneumothorax with extensive separation of the cardiac silhouette away from the sternum. The lung lobes on the right and the cranial lobe on the left showed pulmonary contusion. Rib fractures were present on the left. A pneumoperitoneum was suspected. The status of the diaphragm was uncertain, especially in the region of the esophageal hiatus. Metallic shotgun pellets were noted, but were thought to be incidental.

Thorax wall injury 43

2

Day 2

Radiographic diagnosis (day 2): The pneumothorax was persistent, however, the pulmonary contusion/atelectasis was less than in the referral radiographs. Pneumomediastinum could now be seen. The subcutaneous emphysema on the left was still evident. The fractured ribs showed further separation between the 5th and 6th ribs on the left. The diaphragm appeared intact on this study. The tip of a thoracic tube on the

right lay at the level of the 9th rib (DV view, arrow).

44 Radiology of Thoracic Trauma

2

Day 4

Radiographic diagnosis (day 4): The status of the patient improved after being on the pleura-vac for two days. The pneumothorax decreased and the right lung re-inflated. The pneumomediastinum was still evident and the chest wall injury remained unchanged. A chest tube remained in position on the left side.

Treatment/Management: The pneumothorax recurred following removal of the thoracic tube on day 4, thereby delaying recovery. The appearance of the lungs and the extensive pneumothorax suggested little functional lung tissue at the time of the first study. The radiographic appearance is a warning that the lung injury was more severe than normally seen with the usual blunt trauma. The pneumomediastinum was probably present on the first study as indicated by the gas within the soft tissues at the thoracic inlet. This also is a possible indication of injury to either a main stem bronchus or the trachea and is indicative of a probably prolonged recovery.

Thorax wall injury 45

Case 2.13
Signalment/History: “Tom” was a 1-year-old, male DLH
cat with a malformed thoracic cavity thought to have oc-
curred following an accident. The owner was concerned be-	2
cause of the “strange shape of the chest”.

Physical examination: The abnormality in the sternum was easily palpated; however, no pain or soft tissue swelling was noted. Heart sounds were much more prominent on the left side.

Radiographic procedure: Radiographs were made of the thorax.

Radiographic diagnosis: A congenital anomaly of the sternum had caused the xiphoid process to be angled dorsally and to the right (arrows). As a result, the apex of the heart was shifted to the left against the thoracic wall. The lung fields were normal. The diaphragm was intact, but was shifted caudally. The liver shadow was shifted ventrally and caudally.

Treatment/Management: The congenital anomaly had caused marked changes in the conformation of the thorax without markedly affecting the function of either the lungs or heart. As a consequence, no treatment was considered.

46 Radiology of Thoracic Trauma

2.2.2Paracostal hernia

Case 2.14

2

Day 1

Signalment/History: “Baby” was a 7-month-old, male DSH cat who had been missing from home for several days.

Physical examination: He was depressed, dyspneic, and in shock.

Radiographic procedure: Lateral views of the whole body were made.

Radiographic diagnosis (day 1, whole body, lateral view): A large soft tissue mass lay ventral to the xiphoid process on the right side. It contained air-filled bowel loops plus disseminated air indicative of subcutaneous emphysema. The abdominal wall and ventral liver border could not be identified suggesting the presence of peritoneal fluid. Adjacent to the diaphragm was an area of increased fluid density within the dorsal part of the caudal lung lobes possibly due to either a pulmonary lesion such as hemorrhage or even a lesion affecting the gastroesophageal junction.

Paracostal hernia 47

2

Day 2

Radiographic diagnosis (day 2, DV and lateral views):

Radiographs made two days later continued to show the ex- tra-thoracic mass, but without the presence of air-filled bowel loops. Diffuse air again suggested subcutaneous emphysema from a puncture wound in the skin. The DV view confirmed a pulmonary lesion and located it in the caudal lobe on the right. The continued presence of the pulmonary lesions suggested the cause was more than just a contusion. Disruption of the 10th and 11th ribs on the left indicated the nature of the injury as a probable bite wound with injury on both sides of the thorax. Pleural fluid pocketed around the dorsal segment of the right caudal lobe suggested a failure of that lobe to fully inflate. The possibility of peritoneal fluid remained. The absence of bowel loops in the hernial sac provided an excuse to postpone surgery.

Treatment/Management: After three days in the clinic during which antibiotics were used to treat the unknown cause of an elevated WBC count, “Baby” collapsed and emergency surgery identified rents in the stomach and a bruised ileum. A tear in the dorsal diaphragm was identified without herniation of abdominal contents. Necrotic omentum was noted in the paracostal hernia. Peritonitis and pneumonia were evident at necropsy two days later.

Comments: It was thought that this patient had been treated rather too conservatively in the face of the radiographic and clinical findings, which suggested the presence of a more severe clinical situation.

48 Radiology of Thoracic Trauma

Case 2.15

2

Paracostal hernia 49

Signalment/History: A male, mixed-breed puppy was found lying by the roadside and was brought to the clinic for treatment.

Physical examination: A soft tissue mass was palpable on the right abdominal wall. The physical examination was limited.

Radiographic procedure: Abdominal radiographs were made.

Radiographic diagnosis: Air-filled small bowel loops were displaced laterally into a soft tissue pocket along the right abdominal wall. The bowel loops within the hernia did not appear distended. The 11th and 12th ribs on the right were fractured. An increase in fluid density of the caudal lung lobes was noted as well as a pneumothorax, which had resulted in sepa-

ration of the cardiac silhouette from the sternum. Subcutaneous emphysema was present over the caudal abdomen. Endplate fractures of the bodies of T13 and L2 helped to explain the extreme pain exhibited by the puppy.

Treatment/Management: A major problem in diagnosis in

this puppy was to distinguish whether the air pockets located 2 in the hernial sac were within bowel loops or represented free subcutaneous air that had pocketed. The tendency for the air

to be defined into well-marginated patterns suggested that it was more likely to be lying within bowel loops.

The hernia was repaired, the bowel loops replaced within the peritoneal cavity, and the puppy closely confined until the fractures had healed.

50 Radiology of Thoracic Trauma

Case 2.16

2

	Paracostal hernia 51
Signalment/History: A young, male Chihuahua had been	The small bowel loops were air-filled and distended suggest-
found by a friend of the owner laying on its side and breath-	ing a paralytic ileus.
ing with great difficulty after being attacked by larger dogs.	The displaced gastric shadow had the pylorus on the left side.
He was brought to the clinic.
	Although the fundus was displaced cranially, it was thought
Physical examination: A large soft tissue mass could be pal-	not to be herniated through a diaphragmatic tear. Uniform		2
pated on the left body wall.	fluid density within the cranial abdomen suggested a focal
Radiographic procedure: Radiographs were made of the	peritoneal hemorrhage or peritonitis.
	Note that the trauma did not affect the underlying lungs and
caudal portion of the body.
	had not caused a generalized peritoneal hemorrhage or peri-
Radiographic diagnosis: Incomplete fractures of the last	tonitis. The distention of the stomach with air suggested a py-
ribs on the left were noted with a costovertebral luxation of	loric stenosis.
the last two ribs. The underlying lungs appeared normal. Her-	Treatment/Management: At surgery, the gut was partially
niation of air-filled bowel loops, spleen, mesenteric fat, and a
part of the stomach filled the paracostal hernial sac on the left.	twisted on its mesentery with secondary necrosis. No tear in
A soft tissue mass just cranial to the bowel loops had an uneven	the diaphragm could be found. The dog was discharged after
fluid density and was thought to be hemorrhage (hematoma).	surgery.