CT features of feline cystic bronchiectasis forming mass lesions.

Case series summary: Cystic bronchiectasis was diagnosed in three cats with known histories of chronic coughing using CT and histopathology. CT of the lungs revealed large space-occupying lesions that compressed and displaced unaffected pulmonary parenchyma and vessels. The masses were soft tissue attenuating in two cases and gas-cavitated with areas of dependent fluid in one case. All three cats were found to have mineral attenuating material in lesions and in other dilatated airways. Generalized bronchial wall thickening was also present and indicative of chronic lower airway disease. These findings were supported by histopathology showing inflammatory changes and dilatated airways in the collected tissues. In the two cases in which post-contrast CT series were acquired, the lesions had rim-enhancement. Relevance and novel information: Cystic bronchiectasis is a rare presentation of bronchiectasis in cats and may mimic a pulmonary mass lesion, which could be mistaken for neoplasia or abscessation. The lack of central enhancement or presence of gas cavitation on CT, concurrent presence of diffuse bronchial wall thickening, other areas of bronchiectasis and the presence of broncholithiasis may alert the clinician to the possibility of cystic bronchiectasis related to chronic lower airway disease.

Diagnostic imaging and histopathologic features of rounded atelectasis in four cats and one dog: A descriptive case series study.

In humans, rounded atelectasis is defined as focal lung collapse that radiologically appears as a round mass-like lesion in the periphery of the lung. In general, human patients with rounded atelectasis have a history of pleural effusion and abnormal pleura and characteristic CT findings help to distinguish rounded atelectasis from pulmonary neoplasia without the need for invasive surgical biopsy. This retrospective multi-center case series describes rounded atelectasis in four cats and one dog. Chylothorax was seen in four patients and an eosinophilic and lymphoplasmacytic effusion was seen in one patient. All patients had solitary or multifocal subpleural pulmonary masses (26 masses total in 5 patients) with diffuse, multifocal, or focal visceral and parietal pleural thickening. All the masses but one were broad-based towards the visceral pleura. Masses were most common in the ventral or lateral aspect of the lungs. Indistinctness at the hilar aspect of the lesion was seen in all masses; a "comet tail" sign was seen in 14 of 26 masses. On postcontrast images, the lesions were homogeneously enhanced in 24 of 26 masses and heterogeneous in two of 26 masses. Other findings include ground glass opacities (n = 5), parenchymal bands (n = 4), mild to moderate lymphadenopathy (n = 4), and compensatory hyperinflation of the lung lobes not affected by atelectasis (n = 2). Histopathology of four cases revealed atelectasis with fixed pleural folds, chronic pleuritis, and mild to moderate pleural fibrosis. Awareness of rounded atelectasis in veterinary species will enable inclusion of a benign etiology into the differential diagnosis for subpleural masses in cases with pleural abnormalities.

Severity of nasopharyngeal collapse before and after corrective upper airway surgery in brachycephalic dogs.

OBJECTIVE: To determine the severity of nasopharyngeal collapse in brachycephalic dogs before and after corrective airway surgery. ANIMALS: Twenty-three brachycephalic dogs (21 with clinical signs referrable to the upper airway) and nine clinically normal nonbrachycephalic dogs (controls). METHODS: Dogs were evaluated with fluoroscopy awake and standing with the head in a neutral position. The magnitude of nasopharyngeal collapse was measured as the maximum reduction in the dorsoventral dimension of the nasopharynx during respiration and expressed as a percentage. Brachycephalic dogs were anesthetized, the airway evaluated, and corrective upper airway surgery (alaplasty, staphylectomy, sacculectomy, tonsillectomy) was performed. A cohort (n = 11) of the surgically treated brachycephalic dogs had fluoroscopy repeated a minimum of 6 weeks after surgery. RESULTS: Median preoperative reduction in the dorsoventral dimensions of the nasopharynx was greater in brachycephalic dogs (65%; range: 8-100%) than in controls (10%; range: 1-24%, p = .0001). Surgery did not improve the reduction in dorsoventral diameter of the nasopharynx during respiration in brachycephalic dogs (n = 11) postoperatively (p = .0505). CONCLUSION AND CLINICAL SIGNIFICANCE: Nasopharyngeal collapse was a common and sometimes severe component of brachycephalic airway obstruction syndrome in the cohort of dogs evaluated. The lack of significant postoperative improvement may represent a type II error, a failure to adequately address anatomical abnormalities that increase resistance to airflow, or inadequate upper airway dilator muscle function in some brachycephalic dogs.

High-field MRI using standard pulse sequences has moderate to substantial interobserver agreement and good accuracy for differentiation between intracranial extra-axial histiocytic sarcoma and meningioma in dogs.

Intracranial extra-axial histiocytic sarcoma shares common MRI features with meningioma. As histiocytic sarcoma carries a generally worse prognosis than meningioma, the ability to differentiate between these two neoplasms is of clinical value. The aim of this retrospective diagnostic accuracy and observer agreement study was to evaluate the accuracy and reliability of high-field MRI to differentiate between these two tumors, using standard pulse sequences and published MRI features. A total of 51 dogs were included (26 meningiomas and 25 histiocytic sarcomas). Magnetic resonance imaging examinations were independently assessed by three experienced board-certified radiologists, evaluating 18 imaging features. They were asked to assign each case to one of three categories (meningioma, histiocytic sarcoma, and undetermined). Agreement for the MRI diagnosis across all three reviewers was moderate (κ 0.54) while paired interobserver agreement ranged from moderate to substantial (κ 0.58-0.74) with percent agreement ranging between 86.1% and 87.7%. Overall, the probability of correctly diagnosing meningioma in a dog with this tumor ranged between 79.2% and 94.4%, and the probability of correctly diagnosing histiocytic sarcoma in a dog with this tumor ranged between 76.0% and 92.3%. The overall probability to diagnose the correct tumor, irrespective of type, ranged between 79.2% and 89.7%. Histiocytic sarcomas tended to have more extensive edema and more often had combined perilesional and distant meningeal enhancement affecting both pachy- and leptomeninges, while for meningiomas, meningeal enhancement tended to more commonly be perilesional and pachymeningeal. Imaging features that seemed more useful to make a correct diagnosis included "location/type of meningeal enhancement," "osseous changes in the adjacent neurocranium," "cystic changes," and "herniation severity."

Radiation exposure of dogs and cats undergoing fluoroscopic procedures and for operators performing those procedures.

OBJECTIVE: To evaluate radiation exposure of dogs and cats undergoing procedures requiring intraoperative fluoroscopy and for operators performing those procedures. SAMPLE: 360 fluoroscopic procedures performed at 2 academic institutions between 2012 and 2015. PROCEDURES: Fluoroscopic procedures were classified as vascular, urinary, respiratory, cardiac, gastrointestinal, and orthopedic. Fluoroscopy operators were classified as interventional radiology-trained clinicians, orthopedic surgeons, soft tissue surgeons, internists, and cardiologists. Total radiation exposure in milligrays and total fluoroscopy time in minutes were obtained from dose reports for 4 C-arm units. Kruskal-Wallis equality of populations rank tests and Dunn pairwise comparisons were used to compare differences in time and exposure among procedures and operators. RESULTS: Fluoroscopy time (median, 35.80 minutes; range, 0.60 to 84.70 minutes) was significantly greater and radiation exposure (median, 137.00 mGy; range, 3.00 to 617.51 mGy) was significantly higher for vascular procedures than for other procedures. Median total radiation exposure was significantly higher for procedures performed by interventional radiology-trained clinicians (16.10 mGy; range, 0.44 to 617.50 mGy), cardiologists (25.82 mGy; range, 0.33 to 287.45 mGy), and internists (25.24 mGy; range, 3.58 to 185.79 mGy). CONCLUSIONS AND CLINICAL RELEVANCE: Vascular fluoroscopic procedures were associated with significantly longer fluoroscopy time and higher radiation exposure than were other evaluated fluoroscopic procedures. Future studies should focus on quantitative radiation monitoring for patients and operators, importance of operator training, intraoperative safety measures, and protocols for postoperative monitoring of patients.

Ability of ultrasonography to predict the presence and location of histologic lesions in the small intestine of cats.

BACKGROUND: Diagnosis of infiltrative small intestinal (SI) disease in cats is challenging, and debate continues regarding optimal biopsy techniques. Ultrasonography may facilitate selection of biopsy type and location. HYPOTHESIS/OBJECTIVES: Assess ability of ultrasonography to predict histologic lesions by SI segment and tissue layer. ANIMALS: One-hundred sixty-nine cats that had abdominal ultrasonography and full-thickness SI biopsies performed. METHODS: Ultrasonographic images and full-thickness biopsy samples were retrospectively reviewed, and each SI wall layer evaluated for lesions according to published standards. RESULTS: Ultrasonographic SI lesions were present in 132 cats (63 duodenum; 115 jejunum; 71 ileum). Samples were obtained at laparotomy (60) or necropsy (109). Ultrasonographic abnormalities had high positive predictive value (PPV) for histologic lesions (duodenum, 82.0%; 95% confidence interval [CI], 68.6-91.4; jejunum, 91.0%; 95% CI, 81.5-96.6; ileum, 88.1%; 95% CI, 74.4-96.0), but poor negative predictive value (duodenum, 27.1%; 95% CI, 17.2-39.1; jejunum, 27.3%; 95% CI, 10.7-50.2; ileum, 40.4%; 95% CI, 26.4-55.7). The ability of ultrasonography to predict histologic lesions in this population, which had high disease prevalence (SI histologic lesions in 78.1% of cats) was high for mucosal lesions (PPV, 72.7%-100%) but low for submucosal or muscularis lesions (PPV, 18.9%-57.1%). CONCLUSIONS AND CLINICAL IMPORTANCE: In a population with high disease prevalence, most cats with SI mucosal ultrasonographic lesions will have mucosal histologic lesions. Small intestinal submucosal and muscularis ultrasonographic lesions are not predictive of histologic disease in those layers, suggesting that full-thickness biopsy may not be essential in these cats. Ultrasonography may help guide decisions about biopsy type in individual cats.

Nodules and masses are associated with malignant pleural effusion in dogs and cats but many other intrathoracic CT features are poor predictors of the effusion type.

Thoracic CT may be used in the workup of patients with pleural effusion. In humans, certain pleural features on CT aid in diagnosing an underlying cause for pleural effusion, whereas this is not well studied in veterinary medicine. This retrospective cross-sectional analytical study assessed pleural and other intrathoracic abnormalities on CT in dogs and cats with pleural effusion and explored potential discriminatory features between effusion types. Eighty-nine dogs and 32 cats with pleural cytology and/or histopathology were categorized into malignant pleural disease (15 dogs and 11 cats), pyothorax (34 dogs and 7 cats), chylothorax (20 dogs and 11 cats), transudative (11 dogs and 2 cats), and hemorrhagic effusion (9 dogs and 1 cat). Multivariable logistic regression analysis comparing malignancy to other effusions found that older patient age (dogs: odds ratio 1.28, P = 0.015; cats: odds ratio 1.53, P = 0.005), nodular diaphragmatic pleural thickening (dogs: odds ratio 7.64, P = 0.021; cats: odds ratio 13.67, P = 0.031), costal pleural masses (dogs: odds ratio 21.50, P = 0.018; cats: odds ratio 32.74, P = 0.019), and pulmonary masses (dogs: odds ratio 44.67, P = 0.002; cats: odds ratio 18.26, P = 0.077) were associated with malignancy. In dogs, any costal pleural abnormality (odds ratio 47.55, P = 0.002) and pulmonary masses (odds ratio 10.05, P = 0.004) were associated with malignancy/pyothorax, whereas any costal pleural abnormality (odds ratio 0.14, P = 0.006) and sternal lymphadenopathy (odds ratio 0.22, P = 0.040) were inversely associated with transudates. There were, however, many overlapping abnormalities between effusion types, so further diagnostic testing remains important for diagnosis.

Radiographic distribution of ureteral stones in 78 cats.

OBJECTIVE: To document the distribution of ureteral stones in cats. STUDY DESIGN: Retrospective case series. ANIMALS: Seventy-eight cats. METHODS: Abdominal radiographs with ureteral stones were reviewed. The location of stones was categorized as proximal ureter (PU), midureter (MU), or ureterovesicular junction (UVJ). The number, size, and location of stones were recorded by using the kidneys and vertebral bodies as landmarks. Stone location in cats with 1 versus multiple stones was assessed. Descriptive statistics were used to describe the incidence of ureteral stone location. RESULTS: Among cats with a single stone (44%, 34/78), 44% (15/34) had a stone in the PU, 41% (14/34) had a stone in the MU, and 15% (5/34) had a stone at the UVJ. When multiple stones were present, 61% (27/44) of cats had at least 1 stone located in the PU, 70% (31/44) had at least 1 stone located in the MU, and 34% (15/44) had at least 1 stone located at the UVJ. The L4 vertebral body most commonly marked stone location in cats with 1 stone and the most distal stone in cats with multiple stones. Stones located at the UVJ site were more common in male (37%) than in female (12%) cats (P = 0.004). Larger stone size was associated with a more proximal location (P = 0.04). CONCLUSION: Ureteral stones were more commonly located in the PU and the MU than in the UVJ. UVJ stones were more common in male than in female cats, and larger stones had a more proximal location. CLINICAL SIGNIFICANCE: This study enhances our understanding of feline ureteral stone location and identifies a correlation between stone location and stone size.

Diagnostic Accuracy of Ultrasound to Predict the Location of Solitary Hepatic Masses in Dogs.

OBJECTIVE: To determine the sensitivity, specificity, and predictive value of ultrasonography for localizing hepatic masses in dogs and to identify patient factors associated with diagnostic accuracy. STUDY DESIGN: Retrospective cross-sectional study. ANIMALS: Client-owned dogs (n = 137). METHODS: Medical records of dogs diagnosed with a solitary hepatic mass on abdominal ultrasound and confirmed by laparotomy or laparoscopy were reviewed. Location of the mass predicted by ultrasound was compared to mass location identified at surgery. Ultrasound exams were performed by or under the supervision of a board certified radiologist. Sensitivity, specificity, and positive predictive values were calculated. Patient factors associated with accurate localization were identified using logistic regression. RESULTS: Ultrasound correctly localized liver masses in 71/137 dogs (51.8%). The sensitivity of ultrasound localization was 55% for left and right division masses and 29% for central division masses. The specificity was 98% for left division masses, 87% for central division masses, and 89% for right division masses. Correct localization was 3.2 times more likely when the mass arose from the right or left division compared to the central division (odds ratio [OR] 3.2; 95% confidence intervals [CI] 1.1, 9.0; P = .030). Correct localization was significantly less likely when diffuse or multifocal hepatic disease was present (OR 0.32; 95% CI 0.15, 0.70; P = .004). CONCLUSION: Ultrasound was specific but not sensitive for localizing hepatic masses, and localization accuracy was influenced by mass location and the presence of concurrent liver pathology. These findings should be taken into consideration by veterinary surgeons using ultrasound examination to guide patient treatment and surgical planning.

Computed tomographic findings in 57 cats with primary pulmonary neoplasia.

Primary pulmonary neoplasia is relatively uncommon in cats and generally has a poor prognosis. In this multicenter, retrospective study of 57 cats with pulmonary neoplasia, the most frequent presenting signs were anorexia/inappetence (39%) and cough (37%). The pulmonary tumors were considered to be incidental findings in 9% cats. In computed tomographic (CT) images, primary pulmonary tumors appeared as a pulmonary mass in 55 (96%) cats and as a disseminated pulmonary lesion without a defined mass in two (4%) cats. Most pulmonary tumors were in the caudal lobes, with 28 (49%) in the right caudal lobe and 17 (30%) in the left caudal lobe. CT features associated with pulmonary tumors included mass in contact with visceral pleura (96%), irregular margins (83%), well-defined borders (79%), bronchial compression (74%), gas-containing cavities (63%), foci of mineral attenuation (56%), and bronchial invasion (19%). The mean (range) maximal dimension of the pulmonary masses was 3.5 cm (1.1-11.5 cm). Additional foci of pulmonary disease compatible with metastasis were observed in 53% cats. Pleural fluid was evident in 30% cats and pulmonary thrombosis in 12% cats. The histologic diagnoses were 47 (82%) adenocarcinomas, six (11%) tumors of bronchial origin, three (5%) adenosquamous cell carcinomas, and one (2%) squamous cell carcinoma. In this series, adenocarcinoma was the predominant tumor type, but shared many features with less common tumor types. No associations were identified between tumor type and CT features. Prevalence of suspected intrapulmonary metastasis was higher than in previous radiographic studies of cats with lung tumors.

Suspected hypertrophic osteopathy in an ancient canid: Differential diagnosis of possible etiologies.

Hypertrophic osteopathy (HO) has been reported in numerous mammalian species, but no reports address the range of conditions that can lead to HO, or the implications of those conditions, for archaeological diagnosis. We describe suspected HO from skeletal remains of an ancient large domestic dog recovered in Iowa, USA, at the Cherokee Sewer site. Canid remains from this site date 7430-7020calBP. The site is believed to have been a temporary, low-intensity campsite where bison were procured. Over 100 specimens from two small dogs, two large dogs, and a coyote, are present in the archaeofaunal assemblage. We document five pathological metapodials; an affected left ulna, radius, tuber calcaneus, accessory carpal, radial carpal; and an affected right central, second, and third tarsal within in a proliferative mass. HO was suspected based on gross morphology, radiography, and computed tomography. HO is a paraneoplastic syndrome with undetermined underlying pathogenesis; neuroendocrine complication of a number of neoplastic and non-neoplastic diseases is suspected. We review known disease associations of HO to provide a balanced field for considering differential diagnosis of suspect archaeological specimens, and suggest that definitive diagnosis of HO, or suspected HO, may be impossible in many instances where only skeletal remains are available for study.

Computed tomographic characteristics of odontogenic neoplasms in dogs.

Odontogenic neoplasms are locally invasive oral tumors in dogs. The purpose of this retrospective study was to describe CT characteristics for varying histopathologic types of canine odontogenic neoplasms. A board-certified veterinary radiologist who was unaware of histologic findings reviewed and scored imaging studies. A total of 29 dogs were included in the study. Twenty-three of these dogs had concurrent dental radiographs. The most common CT characteristics for all tumor types were a direct association with or in the region of multiple teeth in 96.4% (27/28), contrast enhancement in 96.3% (26/27), alveolar bone lysis in 93.1% (27/29), and mass-associated tooth displacement in 85.2% (23/27). Mass-associated cyst-like structures were identified in 53.6% (15/28) and were only present in tumors containing odontogenic epithelium. Canine acanthomatous ameloblastomas (n = 15) appeared as extra-osseous (10/15) or intra-osseous (5/15) masses. Intra-osseous canine acanthomatous ameloblastomas were more likely to have mass-associated cyst-like structures and were subjectively more aggressive when compared with extra-osseous canine acanthomatous ameloblastomas. Amyloid-producing odontogenic tumors (n = 3) had subjectively uniform CT imaging characteristics and consisted of round soft tissue and mineral attenuating masses with multiple associated cyst-like structures. Fibromatous epulides of periodontal ligament origin (n = 4) were contrast enhancing extra-osseous masses that were rarely referred for CT examinations and 25% (1/4) were not visible with CT. Other odontogenic tumors were less represented or had more variable CT imaging characteristics. Mass-associated tooth destruction was appreciated more often with dental radiographs and extra-oral tumor extension was identified more often with CT.

Sensitivity, positive predictive value, and interobserver variability of computed tomography in the diagnosis of bullae associated with spontaneous pneumothorax in dogs: 19 cases (2003-2012).

OBJECTIVE: To determine the sensitivity, positive predictive value, and interobserver variability of CT in the detection of bullae associated with spontaneous pneumothorax in dogs. DESIGN: Retrospective case series. ANIMALS: 19 dogs with spontaneous pneumothorax caused by rupture of bullae. PROCEDURES: Dogs that had CT for spontaneous pneumothorax caused by rupture of bullae confirmed at surgery (median sternotomy) or necropsy were included. Patient signalment, CT protocols, and bulla location, size, and number were obtained from the medical records. Computed tomographic images were reviewed by 3 board-certified radiologists who reported on the location, size, and number of bullae as well as the subjective severity of pneumothorax. RESULTS: Sensitivities of the 3 readers for bulla detection were 42.3%, 57.7%, and 57.7%, with positive predictive values of 52.4%, 14.2%, and 8.4%, respectively, with the latter 2 readers having a high rate of false-positive diagnoses. There was good interobserver agreement (κ = 0.640) for correct identification of bullae. Increasing size of the bulla was significantly associated with a correct CT diagnosis in 1 reader but not in the other 2 readers. Correct diagnosis was not associated with slice thickness, ventilation protocol, or degree of pneumothorax. CONCLUSIONS AND CLINICAL RELEVANCE: Sensitivity and positive predictive value of CT for bulla detection were low. Results suggested that CT is potentially an ineffective preoperative diagnostic technique in dogs with spontaneous pneumothorax caused by bulla rupture because lesions can be missed or incorrectly diagnosed. Bulla size may affect visibility on CT.

CT features of pleural masses and nodules.

Pleural space masses and nodules are rarely described on computed tomography (CT) in veterinary medicine and have only been described in patients with neoplasia. Our purpose was to describe the CT findings and diagnoses in seven patients with pleural masses and nodules. Two patients had broad-based, plaque-like pleural masses, both of which were due to neoplasia (primary pleural carcinoma, metastatic thymoma). Two patients had well-defined pleural nodules and nodular pleural thickening, one of which had mesothelial hypertrophy, and another of which had metastatic hemangiosarcoma. Three patients had ill-defined pleural nodules to nodular pleural thickening, one of which had metastatic pulmonary carcinoma, while the other two had bacterial infection with mesothelial proliferation (n = 2), fibrinous pleuritis (n = 1), and severe mediastinal pleuritis/mediastinitis (n = 2). Five of the seven patients had focal, multifocal or diffuse smooth, and/or irregular pleural thickening. Five of seven patients had pleural effusion, and postcontrast CT was useful in several patients for delineating the pleural lesions from the effusion. All patients except one had additional lesions identified on CT besides those in the pleural space. CT is useful in identifying and characterizing pleural space lesions and could be used to guide further diagnostic procedures such as thoracoscopy or exploratory thoracotomy. Both neoplastic and nonneoplastic diseases should be considered in the differential diagnoses for pleural space masses and nodules found on CT.

Acute biological effects of simulating the whole-body radiation dose distribution from a solar particle event using a porcine model.

In a solar particle event (SPE), an unshielded astronaut would receive proton radiation with an energy profile that produces a highly inhomogeneous dose distribution (skin receiving a greater dose than internal organs). The novel concept of using megavoltage electron-beam radiation to more accurately reproduce both the total dose and the dose distribution of SPE protons and make meaningful RBE comparisons between protons and conventional radiation has been described previously. Here, Yucatan minipigs were used to determine the effects of a superficial, SPE-like proton dose distribution using megavoltage electrons. In these experiments, dose-dependent increases in skin pigmentation, ulceration, keratinocyte necrosis and pigment incontinence were observed. Five of 18 animals (one each exposed to 7.5 Gy and 12.5 Gy radiation and three exposed to 25 Gy radiation) developed symptomatic, radiation-associated pneumonopathy approximately 90 days postirradiation. The three animals from the highest dose group showed evidence of mycoplasmal pneumonia along with radiation pneumonitis. Moreover, delayed-type hypersensitivity was found to be altered, suggesting that superficial irradiation of the skin with ionizing radiation might cause immune dysfunction or dysregulation. In conclusion, using total doses, patterns of dose distribution, and dose rates that are compatible with potential astronaut exposure to SPE radiation, animals experienced significant toxicities that were qualitatively different from toxicities previously reported in pigs for homogeneously delivered radiation at similar doses.

Computed tomographic features of oral squamous cell carcinoma in cats: 18 cases (2002-2008).

OBJECTIVE: To describe the computed tomographic features of oral squamous cell carcinoma (SCC) in cats and identify imaging characteristics associated with survival time. DESIGN: Retrospective case series. ANIMALS: 18 cats with a diagnosis of oral SCC. PROCEDURES: Information on history; clinical, laboratory, and diagnostic imaging findings; treatment; and survival time was obtained from medical records of 18 cats with oral SCC. Computed tomography (CT) studies were examined to identify features associated with oral SCC. The association of CT features with survival time was evaluated. RESULTS: On CT images, SCC was centered at the following sites: sublingual or lingual region (n = 7), maxilla (5), buccal mucosa (4), mandible (4), pharyngeal mucosa (2), soft palate mucosa (1), and lip (1). These results were in agreement with the results of oral examination for all sites, except the soft palate (CT, 1 cat; oral examination, 4 cats). On CT images, extension of maxillary masses was most often observed to affect the orbit (5 cats). Heterogeneous contrast enhancement was most commonly identified (8/18). Osteolytic mass lesions were identified on CT images in 9 cats. None of the quantitative CT features that were identified, including mass size, attenuation, or lymph node width, were correlated with survival time. CONCLUSIONS AND CLINICAL RELEVANCE: Common CT features of oral SCC in cats included sublingual and maxillary locations, marked heterogeneous contrast enhancement, and osteolysis. Computed tomography may be used to determine mass extension and lymph node enlargement, but results did not correlate with survival time.

Computed tomographic evaluation of anatomic and pathologic variations in the feline nasal septum and paranasal sinuses.

The purpose of this study was to compare the prevalence of nasal septal deviation and variations of the paranasal sinuses in normal and diseased cats. Prevalence of nasal septal deviation was 86.7%, 68.4%, and 71.4% in cats with rhinitis, neoplasia, and normal cats, respectively, with no statistically significant difference (P = 0.244). There was a statistically significant difference (P = 0.01) in the magnitude of nasal septal deviation between cats with and cats without nasal disease, using a cutoff value of 1 mm for maximum distance of deviation from midline. There was a statistically significant difference (P = 0.019) between cats with rhinitis and neoplasia when comparing the presence of a mass (7.7% and 53.8%, respectively), but not when comparing for lysis of the septum. Deviation of the frontal sinus septum occurred in 27.7% of all cats, while the sphenoid septum was oblique and eccentric in 96.6% of all cats. The mean length of the frontal sinus was longer in male cats than female cats. The presence of nasal septal deviation alone cannot be used as a criterion to diagnose nasal disease, but cats with rhinitis or neoplasia have more marked deviation than normal cats. The presence of a mass and lysis of the septum were only seen in cats with nasal disease and a mass is more likely to be seen with neoplasia than rhinitis. Male cats have a longer frontal sinus than female cats. Almost all cats have an oblique, eccentric sphenoid septum.