THORACIC METASTASES OF CANINE MAMMARY GLAND TUMORS

The absence or presence of metastases on thoracic radiographs in 55 female dogs with mammary gland tumors was assessed by comparing the results of a single radiographic examination, using dorsoventral and left lateral views, with clinical and histologic follow-up data. Radiographic abnormalities found in dogs with thoracic metastases were classified as well-defined pulmonary nodules, ill-defined pulmonary nodules, and involvement of pleural effusion. No obvious difference in the effect on the right or left lung lobes was found. The sensitivity, specificity and accuracy for the detection of thoracic metastases were 65%, 97%, and 87%, respectively.     

RADIOGRAPHIC ASPECTS OF Pneumocystis carinii PNEUMONIA IN THE MINIATURE DACHSHUND

The thoracic radiographic changes of Pneumocystis carinii in 7 miniature Dachshunds were reviewed. The dogs were 7–12 months old and presented with polypnea, exercise intolerance and clinical signs suggestive of immune-incompetence. P. carinii pneumonia was diagnosed in all the dogs using transtracheal aspirate cytology and confirmed at postmortem in 3 dogs that died. Radiographically, diffuse pulmonary changes were present and varied from a mild interstitial and bronchial pattern to an alveolar pattern. Radiographic evidence of cor pulmonale was present in 1 dog. The most severe radiographic changes were seen in 2 of the dogs that died.     

家兔胸部X线体层摄影技术的实验研究

选用健康家兔40只,取仰卧位保定,5％戊巴比妥钠溶液麻醉,对家兔胸部体层摄影技术进行了探讨。几何条件:使用直线轨迹时,曝光角度以20°为好;使用区域圆轨迹时,以12°为好。显示支气管的最佳层次()与胸厚(X)的回归方程(?)=0.739X-1.922。物理条件:kVP=胸厚(cm)+40+10(滤线器);mA及s:直线轨迹时100mA,0.3s;区域圆轨迹时20mA,2.8s。并对所拍摄的X线体层照片进行了分析,在显示胸部某一层面的结构上和对肺脏、支气管部位病变的诊断上,体层摄影有明显的优点,而麻醉对改善体层片的质量有一定作用。     

ULTRASONOGRAPHY AS A DIAGNOSTIC AID IN PLEURAL EFFUSION OF HORSES*

Three horses with clinical signs compatible with pleural effusion were examined with diagnostic ultrasound. In one of the three horses, confirmed septic pleural effusion was monitored with ultrasound during a successful treatment regimen. Eficacy of thoracentesis and detection of recurrence of fluid were readily determined. In the second horse, diagnosis of diffuse pleural neoplasia (lymphosarcoma) was made. In the third horse presented for pleural effusion, the effusion was documented and concurrent ascites detected with ultrasound. Carcinomatosis was found at necropsy. Ultrasound examination proved to be a sensitive, noninvasive modality useful in diagnosis and treatment of pleural effusion.     

Outcomes of Heimlich valve drainage in dogs

Objective and design   Retrospective study of the outcomes of Heimlich valve drainage in dogs.
Procedure   Medical records of the past 3 years were retrospectively reviewed. Heimlich valve drainage was used in 34 dogs (median body weight 30 ± 5 kg): lobectomy (n = 15), pneumonectomy (n = 9), intrathoracic oesophageal surgery (n = 2), diaphragmatic hernia repair (n = 1), traumatic open pneumothorax (n = 2), bilobectomy (n = 2), ligation of the thoracic duct (n = 1), and chylothorax and pneumothorax (n = 1 each). Evacuation of air and/or fluid from the pleural cavity was performed with the Heimlich valve following thoracostomy tube insertion. During drainage, the dogs were closely monitored for possible respiratory failure. Termination of Heimlich valve drainage was controlled with underwater seal drainage and assessed with thoracic radiography.
Results   Negative intrathoracic pressure was provided in 29 dogs without any complications. Post pneumonectomy respiratory syncope and post lobectomy massive hemothorax, which did not originate from the Heimlich valve, were the only postoperative complications. Dysfunction of the valve diaphragm, open pneumothorax and intrathoracic localisation of an acute gastric dilatation–volvulus syndrome caused by a left-sided diaphragmatic hernia following pneumonectomy were the Heimlich valve drainage complications.
Conclusions   The Heimlich valve can be used as a continuous drainage device in dogs, but the complications reported here should be considered by veterinary practitioners.     

THE EFFECT OF POSITIONING ON THE RADIOGRAPHIC APPEARANCE OF CAUDODORSAL MEDIASTINAL MASSES IN THE DOG

In this prospective study, the effect of thoracic positioning on the visibility and size of caudal esophageal masses caused by spirocercosis was investigated. Dorsoventral (DV), ventrodorsal (VD) as well as left lateral recumbent (LLR) and right lateral recumbent (RLR) thoracic radiographs of 28 dogs, diagnosed endoscopically with spirocercosis, were evaluated. The radiographic findings were compared with those of esophageal endoscopy. Masses were seen equally well in left vs. right recumbency as well as in DV vs. VD positions but in DV/VD views 86% of masses were detected whereas in lateral views only 50% of masses were identified. In spirocercosis-endemic areas DV and RLR views are advised as they also allow for better visualization of descending aorta aneurysms and to avoid interpreting the potentially normally visible esophagus in LLR in large dogs as a mass.     

COMPARISON OF THORACIC ULTRASONOGRAPHY AND RADIOGRAPHY FOR THE DETECTION OF INDUCED SMALL VOLUME PNEUMOTHORAX IN THE HORSE

Small volume pneumothorax can be challenging to diagnose in horses. The current standard method for diagnosis is standing thoracic radiography. We hypothesized that thoracic ultrasonography would be more sensitive. Objectives of this prospective, experimental study were to describe a thoracic ultrasound method for detection of small volume pneumothorax in horses and to compare results of radiography and ultrasound in a sample of horses with induced small volume pneumothorax. Six mature healthy horses were recruited for this study. For each horse, five 50 ml air boluses were sequentially introduced via a teat cannula into the pleural space. Lateral thoracic radiographs and standardized ultrasound (2D and M‐mode) examinations of both hemithoraces were performed following administration of each 50 ml air bolus. Radiographs and ultrasound images/videos were analyzed for detection of pneumothorax by four independent investigators who were unaware of treatment status. Sensitivity, specificity, positive predictive values, negative predictive values, and agreement among investigators (Kappa test, κ) were calculated for radiography, 2D and M‐mode ultrasound. Comparisons were made using a chi‐squared exact test with significance set at P < 0.05. Two‐dimensional (84%) and M‐mode (80%) ultrasound were more sensitive than radiography (48%) for pneumothorax detection (P = 0.02 and P = 0.04, respectively). Specificity and positive predictive values were similar for all three imaging modalities (P = 1). Agreement between investigators for pneumothorax detection was excellent for 2D ultrasound (κ = 1), very good for M‐mode ultrasound (κ = 0.87), and good for radiography (κ = 0.79). Findings from this experimental study supported the use of thoracic ultrasonography as a diagnostic method for detecting pneumothorax in horses.     

NON-CARDIAC THORACIC ULTRASOUND IN 75 FELINE AND CANINE PATIENTS

The purpose of this study was to describe the ultrasonographic appearance of non-cardiac diseases of the small animal thorax. Ultrasound images from a total of 75 animals (26 cats and 49 dogs) were compared to cytologic, histopathologic, and necropsy findings. Clinical diagnoses included neoplasia of the mediastinum, pleura, or lungs (43); idiopathic mediastinal cyst (3); diaphragmatic or peritoneopericardial hernia (4); lung lobe torsion (1); pulmonary eosinophilic infiltrates (1); and idiopathic, chylous, congestive heart failure, or lymphangiectasia associated pleural effusion (14). In the remaining 9 patients, a definitive diagnosis was not obtained. Ultrasound-guided fine needle aspirate was performed in 56 patients; 1 of these also had an ultrasound-guided tissue core biopsy. Of the fine needle aspirates, 51 (91%) were diagnostic. Ultrasound examination, particularly when accompanied by guided tissue sampling, can be a valuable tool in the diagnosis of non-cardiac intrathoracic lesions.     

Dogs with acute myeloid leukemia or lymphoid neoplasms (large cell lymphoma or acute lymphoblastic leukemia) may have indistinguishable mediastinal masses on radiographs

Acute myeloid leukemia is an uncommon hematopoietic neoplasm of dogs that should be differentiated from lymphoid neoplasms, such as lymphoma, because of different treatment protocols and a worse prognosis. Thoracic radiography is performed frequently in dogs with suspected hematopoietic neoplasia, and detecting a mediastinal mass often prioritizes lymphoma as the most likely diagnosis. However, we have observed a mediastinal mass in several dogs with acute myeloid leukemia and hypothesized that (1) the frequency of a mediastinal mass was higher and (2) the size of the mass was larger in dogs with acute myeloid leukemia compared to dogs with lymphoid neoplasms. In this analytical study (observational, retrospective, and cross‐sectional), the sample population included 238 dogs with hematopoietic neoplasia. These dogs were divided into lymphoid (large cell lymphoma, acute lymphoblastic leukemia) and myeloid groups based on standard phenotyping tests. A mediastinal mass was detected during thoracic radiography in 73/218 (33%) and nine of 20 (45%) dogs in the lymphoid and myeloid groups (P = 0.21), respectively. The median size ratio of mediastinal mass to cardiac silhouette was 0.20 and 0.23 in the lymphoid and myeloid groups (P = 0.96), respectively. Additionally, we observed normal thoracic radiographs in 111/218 (51%) dogs in the lymphoid group and nine of 20 (45%) dogs in the myeloid group. In conclusion, acute myeloid leukemia should be considered when a mediastinal mass is detected during radiography in dogs with suspected hematopoietic neoplasia—but the presence or size of a mediastinal mass does not differentiate between myeloid and lymphoid neoplasms.     

IMAGING CHARACTERISTICS OF INTRATHORACIC HISTIOCYTIC SARCOMA IN DOGS

In this retrospective study, two observers independently reviewed thoracic imaging studies of 39 dogs with confirmed histiocytic sarcoma. The most common findings were intrathoracic lymphadenopathy, identified by the first and second observers in 82.1% and 87.2% of dogs, respectively, and pulmonary masses (74.4% and 82.1%). Right middle lung lobe masses were significantly more common than masses in any other lung lobe (P<0.0013), with the majority having a ventral distribution. Sternal and tracheobronchial lymphadenopathy were significantly more common than cranial mediastinal lymphadenopathy (P‐values of 0.0002 and 0.012, respectively). Interobserver agreement regarding distribution of lymphadenopathy and pulmonary masses was good (κ=0.64 and 0.75, respectively). Other findings included pulmonary nodules, pleural effusion, and abnormal pulmonary patterns. In patients with CT examinations, the majority of masses were mildly to moderately enhancing and heterogeneous, poorly marginated, and bronchocentric. Lymphadenopathy and pulmonary masses are the most common intrathoracic findings in dogs with histiocytic sarcoma, and the strong predilection for the ventral aspect of the right middle lung lube may help to differentiate it from other types of neoplasia.