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

172 Radiology of Thoracic Trauma

Case 2.88

2

Signalment/History: “George” was an 11-year-old, male DSH cat with a four-week history of coughing, wheezing, and dyspnea. These symptoms were partially responsive to prednisone therapy. Previous endoscopy had shown an edematous larynx and biopsy revealed a laryngeal polyp.

Physical examination: Increased respiratory stridor was noted on physical examination with an increased expiratory effort. Palpation of the trachea and larynx, as well as an oral examination were unremarkable. An intrathoracic obstructive lesion was suspected.

Radiographic procedure: Lateral views were made of the cervical region and a complete study of the thorax.

Radiographic diagnosis: Indistinct shadows in the terminal trachea and carina suggested a tracheal foreign body or mass (arrows). The mediastinum had a greater fluid density over the base of the heart. The diameter of both the extrathoracic and intrathoracic trachea was small. The lungs were hyperinflated without infiltrative or pulmonary mass lesions. The minimal peribronchial shadows were compatible with the age of the patient. The diaphragm was caudal and flattened. The patient was noted to be obese. The spondylosis deformans present was compatible with the cat’s age. A metallic air-gun pellet lay in the soft tissues ventral and to the left of the rib cage.

Treatment/Management: Bronchoscopy revealed a small (0.5 x 1.0 cm), flat rock covered with casseous exudate at the level of the carina. Following removal of the foreign body, “George” was placed on Clavamox for 10 days to prevent extension of the secondary bacterial infection. He was then discharged with resolution of his dyspnea.

Comments: It is considered poor medical practice to treat a patient with a history of respiratory distress for four weeks without making a radiographic study of the thorax.

Tracheal/bronchial foreign bodies 173

2

174 Radiology of Thoracic Trauma

Case 2.89

2

Day 1

Signalment/History: “Smoochy”, a 7-year-old, female DSH cat, was presented with a history of having had a bronchoscopy examination two weeks previously in search of a tooth that was thought to have been inhaled.

Radiographic procedure: The radiographic examination was a search for the missing tooth.

Radiographic diagnosis (day 1): A radiopaque foreign body was located in the right, main-stem bronchus to the caudal lung lobe and had the appearance of a tooth. Minimal lung congestion with the appearance of a plate-like atelectasis was evident distal to the obstruction. The minimal mediastinal shift to the right was probably due to the atelectasis. The remaining lung fields were normal.

Tracheal/bronchial foreign bodies 175

2

Day 2

Radiographic diagnosis (day 2): The previously identified radiopaque foreign body had been removed. The lung congestion distal to the site of the foreign body was less prominent. A static left-sided cardiomegaly was evident.

Comments: The foreign body appeared to be slightly obstructive causing atelectasis of the right lung and compensatory hyperinflation of the left lung. This imbalance had been corrected by the time of the second study.

176 Radiology of Thoracic Trauma

Case 2.90

2

Day 1

Signalment/History: “Bruce” was a 1-year-old, male DSH cat with an acute onset of “gagging”.

Physical examination: The rate of respiration was increased and a marked expiratory effort was noted.

Radiographic procedure: Routine studies were made of the thorax.

Radiographic diagnosis (day 1): An increase in fluid density within the left caudal lung lobe was associated with a mediastinal shift to the left. This appeared to be an obstructive atelectasis and could have been associated with a bronchial foreign body. The air-filled trachea was truncated at the hilar region as seen on the lateral view. The failure to see the normal air-filled carina supported the diagnosis of an intratracheal foreign body.

Treatment/Management: The foreign body was a plant head and it was removed from the left main-stem bronchus using a bronchoscope.

Tracheal/bronchial foreign bodies 177

2

Day 2, post surgery

Radiographic diagnosis (day 2, post surgery): The reinflation of the obstructed lobe had occurred in the previous two days. The mediastinal shift was no longer present, and the appearance of the hilar region was normal.

178 Radiology of Thoracic Trauma

2.2.14 Tracheal injury

Case 2.91

2

Day 1

Day 8

Tracheal injury 179

2

Day 23

Signalment/History: “Tina” was a 2-year-old, female Pit Bull Terrier mixed breed with a history of having been in a fight with another dog one month earlier. She had difficulty in swallowing, which had begun at the time of the fight and she had vomited partially digested food at times since then, unassociated with eating. Her breathing was difficult.

The radiographic interpretation of the thorax one month previously showed the lungs to be poorly inflated resulting in an increase in both interstitial and peribronchial density.

Radiographic procedure: Because of the history of a bite wound to the neck, the radiographic study was directed toward that region.

Radiographic diagnosis (day 1, cervical region): The tracheal stenosis was 1 cm in length and involved 5 or 6 tracheal rings at the level of C5. The lesion was probably posttraumatic.

Radiographic diagnosis (day 8 post surgery, cervical region): The lumen of the stenotic segment was wider and

was almost 2/3 of its normal diameter. A ring of soft tissue protruded into the tracheal lumen at the level of C5. The ventral soft tissue edema was probably postsurgical.

Radiographic diagnosis (day 23, cervical region): The diameter of the post-traumatic tracheal stenosis was almost normal and the ring of intraluminal soft tissue at level of C5 had almost completely regressed.

Treatment/Management: The surgical biopsy revealed fractured tracheal rings with one ring protruding into the lumen being the primary cause for the stricture. The broken rings were calcified forming a cartilaginous callus around the trachea.

It is interesting that the clinical signs had suggested a problem with swallowing; however, the immediate treatment was directed toward the tracheal stenosis. The possibility of adjacent esophageal injury would indicate the need for study of that organ as well.

180 Radiology of Thoracic Trauma

2.2.15 Esophageal foreign bodies

Case 2.92

2

Noncontrast

Esophageal foreign bodies 181

2

Barium swallow

Signalment/History: “Tina Maria” was a 14-year-old, female Miniature Poodle with a clinical history suggestive of an esophageal foreign body for the previous three weeks.

Physical examination: The dog was alert but thin with almost no body fat.

Radiographic procedure: Both non-contrast and contrast studies were performed in an evaluation of the esophagus.

Radiographic diagnosis: A radiodense esophageal foreign body with the marginal features and density of a bone was located just dorsocranial to the heart (arrow). No air or fluid was noted within the mediastinum as would have been expected if the esophageal wall had been punctured. Tracheal elevation was associated with bilateral cardiomegaly.

The barium sulfate swallow confirmed the location of the foreign body and showed no leakage of the contrast agent. The foreign body was not obstructing and permitted fluid to pass, thus enabling the patient to survive during the previous three weeks.

Treatment/Management: The bone was removed surgically; however, the patient died one day later. At necropsy, the esophagus had a single perforation 1 mm in diameter at the site of the foreign body. The trachea also had a 1 mm in diameter hole in the center of the inflammatory response at the same location. These findings support the clinical history of the foreign body having been present for three weeks and indicate the nature of the secondary changes that can occur in the event of failure to remove a foreign body promptly, especially if it has sharply protruding parts that can penetrate the esophageal wall.

Comments: Unfortunately, a focal mediastinitis cannot usually be identified on a radiographic study of the esophagus, with or without contrast agent, because the pocket of inflammation closes the sites of penetration and does not alter the appearance of the esophagus, trachea, or surrounding mediastinum. Even if air should escape through the site of penetration, the amount is usually so minimal that it cannot be recognized on a radiograph.