Mediastinal lymphoma in dogs is homogeneous compared to thymic epithelial neoplasia and is more likely to envelop the cranial vena cava in CT images.

In order to identify CT signs that could be used to distinguish cranial mediastinal lymphoma and thymic epithelial neoplasia, a retrospective case-control study was done. Associations between CT signs and diagnosis were tested using binary logistic regression and results expressed as odds ratio and 95% confidence interval. Sixty-two dogs that had thoracic CT and confirmed diagnosis of lymphoma (n = 33) or thymic neoplasia (n = 29) were sampled. Thymic neoplasms included 24 thymomas and five thymic carcinomas. Dogs with thymic epithelial neoplasia were significantly older than dogs with lymphoma (median age 8.6 years versus 6.0 years, P = .007), but there were no significant differences in prevalence of clinical signs. Diagnosis of thymic epithelial neoplasia was associated with heterogeneous attenuation in pre- (odds ratio 23.3, 95% confidence interval, 4.5-121.1) and post-contrast (odds ratio 30.7, 95% confidence interval, 3.6-265.0) images. Conversely, envelopment of the cranial vena cava by the mass was less likely with thymic epithelial neoplasia than lymphoma (odds ratio 0.07, 95% confidence interval, 0.007-0.66). Greater standard deviation of Hounsfield unit values in post-contrast images was associated with thymic epithelial neoplasia (P = .005). Based on ROC analysis, SD > 17HU of the mass in post-contrast images had a sensitivity of 72% and specificity of 79% for thymic epithelial neoplasia. There were no significant differences in morphology, prevalence of calcification, mediastinal lymphadenopathy, cranial vena cava invasion, collateral vessels, or pleural fluid associated with these tumors. Thymic epithelial neoplasms tended to occur in older dogs and were heterogeneous in CT images, whereas mediastinal lymphoma was more homogeneous and more likely to envelop the cranial vena cava.

Variations in surgical technique for adrenalectomy with caudal vena cava venotomy in 19 dogs.

OBJECTIVE: To describe surgical techniques, caval occlusion times, and short-term outcomes in dogs undergoing adrenalectomy with caval venotomy. STUDY DESIGN: Retrospective case series. ANIMALS: Dogs undergoing adrenalectomy with caval venotomy between October 1, 2010 and May 31, 2018. METHODS: Medical records of dogs undergoing adrenalectomy with caval venotomy were reviewed for signalment, perioperative management, surgical details, perioperative complications, mortality, and histopathology. Computed tomography images were reviewed to describe tumor morphology and signs of thrombus extension. RESULTS: Nineteen dogs had adrenal tumor thrombi extending into the prehepatic (14 dogs, 74%), hepatic (3 dogs, 16%), and posthepatic (2 dogs, 11%) caudal vena cava. Tumors occurred in left (11) and right (8) adrenal glands. Median caval occlusion was 6.5 minutes (range, 2-25). Two to six vascular tourniquets were used. Venotomy closure was performed under full caval occlusion in 11 dogs and by using a partial occlusion clamp in 8 dogs. Left ureteronephrectomy was performed in 5 dogs. Perioperative mortality rate was 21% (4 dogs). CONCLUSION: Extension of caval tumor thrombus beyond the hepatic hilus did not preclude a good outcome. Longer caval occlusion than has been previously reported was tolerated in some cases. Number of vascular tourniquets used reflected the location of phrenicoabdominal vein insertion on the cava and length of the caval tumor thrombus. Venotomy closure under full occlusion was often required for right adrenal tumors. When required, ureteronephrectomy was left sided. CLINICAL SIGNIFICANCE: Dogs with adrenal tumors extending beyond the hepatic hilus and those requiring a long caval occlusion time can survive adrenalectomy.

Prevalence of pulmonary nodules in dogs with malignant neoplasia as determined by CT.

In order to estimate the prevalence of pulmonary nodules in dogs with nonpulmonary malignant neoplasia, medical record descriptions of CT findings in dogs diagnosed with nonpulmonary malignant neoplasia were reviewed retrospectively. A total of 536 dogs were sampled from a single hospital. For malignant neoplasms with >10 affected individuals, prevalence of multiple pulmonary nodules at first CT was hemangiosarcoma 24 of 58 (41%), osteosarcoma 14 of 55 (26%), carcinoma 20 of 80 (25%), histiocytic sarcoma five of twenty-one (24%), soft tissue sarcoma 13 of 57 (23%), adenocarcinoma 11 of 60 (18%), melanoma five of thirty-seven (14%), lymphoma 10 of 76 (13%), mast cell tumor two of forty-seven (4%), and squamous cell carcinoma zero of seventeen (0%). A solitary pulmonary nodule was identified at first CT in 33 (6%) dogs. Of these, nine had follow-up CT, including two dogs in which the nodule disappeared, three dogs in which the size of the nodule did not change, and four dogs in which the nodule enlarged and additional pulmonary nodules appeared. Dogs with hemangiosarcoma were most likely to have signs of pulmonary metastasis at first CT, whereas dogs with mast cell tumor were infrequently affected, and no dog with squamous cell carcinoma had signs of pulmonary metastasis. A solitary pulmonary nodule at first CT was an indeterminate finding, potentially unassociated with neoplasia.

IMAGING DIAGNOSIS-IMAGING AND HISTOPATHOLOGIC CHARACTERISTICS OF A VERTEBRAL HAMARTOMA IN A CAT.

A 9-month-old domestic shorthair cat had progressive ambulatory paraparesis, proprioceptive ataxia, and thoracolumbar hyperesthesia. An extradural mass affecting the left pedicle and lamina of the second lumbar vertebra (L2) causing marked spinal cord impingement was identified in magnetic resonance (MR) images. The mass was predominantly calcified in computed tomographic (CT) images. A hemilaminectomy was performed to resect the mass. Clinical signs were greatly improved at 12-month follow-up. The histopathologic diagnosis was vascular hamartoma. To our knowledge, this is the first report describing the MR characteristics of a vascular hamartoma associated with the vertebral column.

Does the computed tomographic appearance of the lung differ between young and old dogs?

In computed tomographic (CT) images of humans, decreased lung attenuation, bronchial dilation, and/or thickening, air trapping, cysts, and thickened interlobular septa have been associated with increasing age. To determine if there are differences in the CT appearance of the lungs of young and old dogs that could affect interpretation of diagnostic studies, pulmonary CT images of dogs with conditions unrelated to the thorax were reviewed retrospectively in a case-control study. Computed tomography studies of 42 young dogs (range 0.3-4.8 years) and 47 old dogs (range 9-15.1 years) were jumbled and reviewed by an observer blinded to dog age. Computed tomography was performed under sedation in 62 (70%) dogs and under general anesthesia in 27 (30%). Heterotopic bone was more prevalent (62% vs. 14%) in old dogs. Lung collapse was significantly associated with old age, greater body weight, and anesthesia. There were no significant differences in median lung attenuation or occurrence of ground glass pattern, cysts, bronchial thickening, bronchial dilation, or degree of tracheal calcification. No examples of reticular pattern, emphysema, pleural thickening, or septal thickening were observed in any dog. Despite previous studies describing age-related changes in the radiographic appearance of the lungs of old dogs, it appears that there are minimal observable differences in CT images. Old dogs are more likely to have visible foci of heterotopic bone and may be more prone to lung lobe collapse than young dogs, but neither of these differences should contribute to misdiagnosis of pulmonary disease.

IMAGING DIAGNOSIS-COMPUTED TOMOGRAPHY OF TRACTION BRONCHIECTASIS SECONDARY TO PULMONARY FIBROSIS IN A PATTERDALE TERRIER.

An 8-year-old, Patterdale terrier was referred for evaluation of tachypnoea, exercise intolerance, and weight loss. Computed tomographic images showed pneumomediastinum, diffuse pulmonary ground glass opacity, and marked dilatation of peripheral bronchi, but no evidence of thickened bronchial walls. The histopathologic diagnosis was diffuse pulmonary interstitial fibrosis, type II pneumocyte hyperplasia, and bronchiectasis. The lack of evidence of primary bronchitis supported a diagnosis of traction bronchiectasis. Traction bronchiectasis can occur as a sequela to pulmonary fibrosis in dogs.

Can malignant and inflammatory pleural effusions in dogs be distinguished using computed tomography?

Computed tomography (CT) is the primary imaging modality used to investigate human patients with suspected malignant or inflammatory pleural effusion, but there is a lack of information about the clinical use of this test in dogs. To identify CT signs that could be used to distinguish pleural malignant neoplasia from pleuritis, a retrospective case-control study was done based on dogs that had pleural effusion, pre- and postcontrast thoracic CT images, and cytological or histopathological diagnosis of malignant or inflammatory pleural effusion. There were 20 dogs with malignant pleural effusion (13 mesothelioma, 6 carcinoma; 1 lymphoma), and 32 dogs with pleuritis (18 pyothorax; 14 chylothorax). Compared to dogs with pleuritis, dogs with malignant pleural effusions were significantly older (median 8.5 years vs. 4.9 years, P = 0.001), more frequently had CT signs of pleural thickening (75% vs.44%, P = 0.04), tended to have thickening of the parietal pleura only (65% vs. 13%, P = 0.01) and had more marked pleural thickening (median 3 mm vs. 0 mm, P = 0.01). Computed tomography signs of thoracic wall invasion were observed only in dogs with malignant pleural effusions (P = 0.05). There were no significant differences in pleural fluid volume, distribution or attenuation, degree of pleural contrast accumulation, amount of pannus, or prevalence of mediastinal adenopathy. Although there was considerable overlap in findings in dogs with malignant pleural effusion and pleuritis, marked thickening affecting the parietal pleural alone and signs of thoracic wall invasion on CT support diagnosis of pleural malignant neoplasia, and may help prioritize further diagnostic testing.

RESULTS OF COMPUTED TOMOGRAPHY IN DOGS WITH SUSPECTED WOODEN FOREIGN BODIES.

Detection of wooden foreign bodies in dogs can be challenging. A retrospective, cross-sectional study was done to describe computed tomographic (CT) signs associated with wooden foreign bodies, and to estimate the accuracy of CT for detection of wooden foreign bodies. Patient records and CT images were reviewed for 72 dogs that had a history of suspected stick injury and CT of the affected body part, or possible wooden foreign object reported on CT, and had surgical exploration during the same period of hospitalization. Duration of clinical signs was acute in 48 (67%) dogs and chronic in 24 (33%). Wood was removed from 55 dogs, including a piece of a tree or shrub in 33 (60%) instances, kebab stick in 8 (15%), piece of bamboo garden cane in 2 (4%), cocktail stick in 2 (4%), thorn in 1 (2%), and unidentified wood in the remaining nine instances. Based on review of CT images with knowledge of the surgical findings, sensitivity of CT for wooden foreign bodies was 79% (95% CI 65%-89%), specificity 93% (78%-98%), positive likelihood ratio 11.5 (2.9-44.1), and negative likelihood ratio 0.23 (0.13-0.41). Wooden foreign bodies were predominantly rectangular or linear, with median length 48 mm (range 2-270 mm), median thickness 3 mm (range 1-22 mm), and median attenuation 111 HU (range -344 to +640 HU). A CT finding of gas in soft tissues was significantly associated with acute cases, whereas suspected foreign material, cavitary lesions, fat stranding, and periosteal reaction on adjacent bones were associated with chronic cases.

MAGNETIC RESONANCE IMAGING OF INTRACRANIAL INFLAMMATORY CONDITIONS IN DOGS: SENSITIVITY OF SUBTRACTION IMAGES VERSUS PRE- AND POST-GADOLINIUM T1-WEIGHTED IMAGE PAIRS.

Ante mortem diagnosis of canine meningoencephalitis is usually based on the results of neurologic examination, cerebrospinal fluid analysis and magnetic resonance (MR) imaging. It has been hypothesized that subtraction MR imaging may increase the sensitivity of MR for intracranial inflammatory lesions compared to conventional post-gadolinium T1-weighted imaging. Sensitivity of pre- and post-gadolinium (C-/C+) image pairs and dynamic subtraction (DS) images was compared in a retrospective diagnostic accuracy study of 52 dogs with inflammatory cerebrospinal fluid and 67 dogs with idiopathic epilepsy. Series of transverse C-/C+ and DS images were reviewed independently for signs of abnormal enhancement affecting the pachymeninges, leptomeninges or intra-axial structures. Sensitivity of C-/C+ image pairs and DS images was 48% (95% CI: 35-61%) and 65% (95% CI: 52-77%), respectively (P = 0.01). Intra-axial lesions were observed more frequently than meningeal lesions in both C-/C+ (43% vs. 31%) and DS images (61% vs. 22%). The difference in sensitivities of C-/C+ and DS series was entirely due to increased sensitivity of DS images for intra-axial lesions. Eight (12%) dogs with epilepsy had evidence of intra-axial gadolinium accumulation affecting the cerebral cortex in DS images. This finding may represent a false-positive result or a true sign of pathology, possibly associated with a leaky blood-brain barrier in areas of the brain affected by neovascularization secondary to repeated seizures. Results suggest that DS imaging has higher sensitivity than comparison of pre- and post-gadolinium image pairs for inflammatory intra-axial lesions.

TRUNCATION ARTIFACT IN MAGNETIC RESONANCE IMAGES OF THE CANINE SPINAL CORD.

The truncation artifact in magnetic resonance (MR) images is a line of abnormal signal intensity that occurs parallel to an interface between tissues of markedly different signal intensity. In order to demonstrate the truncation artifact in sagittal images of the canine spinal cord and the effect of changing spatial resolution, we conducted an experimental in vitro study. A section of fixed canine spinal cord was imaged using a 1.5T magnet. Spatial resolution was increased by increasing the acquisition matrix and reconstruction matrix, producing series of T2-weighted (T2w) images with the following pixel sizes: A, 1.6 (vertical) × 2.2 mm2 (horizontal); B, 1.2 × 1.7 mm2 ; C, 0.8 × 1.1 mm2 ; D, 0.4 × 0. 6 mm2 . Plots of mean pixel value across the cord showed variations in signal intensity compatible with truncation artifact, which appeared as a single, wide central hyperintense zone in low-resolution images and as multiple narrower zones in high spatial resolution images. Even in images obtained using the highest spatial resolution available for the MR system, the edge of the spinal cord was not accurately defined and the central canal was not visible. The experiment was repeated using an unfixed spinal cord specimen with focal compression applied to mimic a pathologic lesion. Slight hyperintensity was observed within the spinal cord at the site of compression although the cord was normal histologically. Results of this study suggest that caution should be applied when interpreting hyperintensity affecting the spinal cord in T2w sagittal images of clinical patients because of the possibility that the abnormal signal could represent a truncation artifact.

PATHOLOGIC BASIS FOR RIM ENHANCEMENT OBSERVED IN COMPUTED TOMOGRAPHIC IMAGES OF FELINE NASOPHARYNGEAL POLYPS.

In postcontrast computed tomographic (CT) images, feline nasopharyngeal polyps typically demonstrate enhancement of the peripheral rim. Computed tomographic images and histologic specimens of a case series of 22 cats with surgically removed nasopharyngeal polyps were reviewed retrospectively in an attempt to elucidate the origin of rim enhancement. Polyps were present in the tympanic cavity in 15 (68%) cats (three with extension into the nasopharynx), only in the nasopharynx in four (18%) cats, and only in the external ear canal in the remaining three (14%) cats. All polyps had variable degrees of epithelial injury. Hemorrhage and inflammatory infiltration were significantly more marked in the superficial stroma whereas edema was significantly more marked in the core stroma. In noncontrast CT images (n = 22), the tympanic bulla was thickened in all 15 cats with a polyp in the tympanic cavity and enlarged in eight (53%) of these cats. In postcontrast CT images (n = 15), an outer zone of relatively increased attenuation compatible with a rim was observed in 11 (73%) polyps. The magnitude and extent of rim enhancement in CT images was positively correlated with the histologic grade of inflammation in the superficial stroma and negatively correlated with the grade of edema in the superficial stroma. It appears that inflammation is the major determinant of contrast medium accumulation in feline nasopharyngeal polyps, and the tendency for inflammation to affect predominantly the superficial layers explains the frequent observation of a rim in postcontrast CT images.

ASSOCIATIONS BETWEEN DUAL-PHASE COMPUTED TOMOGRAPHY FEATURES AND HISTOPATHOLOGIC DIAGNOSES IN 52 DOGS WITH HEPATIC OR SPLENIC MASSES.

Ability to noninvasively differentiate malignant from nonmalignant abdominal masses would aid clinical decision making. The aim of this retrospective, cross-sectional study was to identify features in dual-phase computed tomographic (CT) studies that could be used to distinguish malignant from nonmalignant hepatic and splenic masses in dogs. Medical records were searched for dogs that had an abdominal dual-phase CT examination, a hepatic or splenic mass, and subsequent histopathologic diagnosis. Computed tomographic images for all included dogs were acquired prior to and <30 s (early phase) and >60 s (delayed phase) after intravenous contrast administration. Fifty-two dogs with 55 masses were studied: 24 hepatic, including 14 (58%) malignant and 10 (42%) non-malignant; 31 splenic, including 18 (58%) malignant and 13 (42%) nonmalignant. There was substantial overlap in the pre- and postcontrast CT features of malignant and nonmalignant hepatic and splenic masses. Regardless of histologic diagnosis, hepatic masses most frequently showed marked, generalized enhancement in early phase images that persisted in the delayed phase. Splenic hemangiosarcoma and nodular hyperplastic lesions most frequently showed marked, generalized enhancement in early phase images that persisted in delayed images whereas most splenic hematomas had slight enhancement in early phase images. All splenic hematomas and 77% of the hemangiosarcomas had contrast accumulation compatible with active hemorrhage. There were no other significant differences in quantitative or categorical CT data between malignant and nonmalignant hepatic or splenic masses. Dual-phase CT of dogs with hepatic or splenic masses provides limited specific diagnostic information.

Differentiation between inflammatory and neoplastic orbital conditions based on computed tomographic signs.

OBJECTIVE: To identify computed tomographic (CT) signs that could be used to differentiate inflammatory from neoplastic orbital conditions in small animals. ANIMAL STUDIED: Fifty-two animals (25 cats, 21 dogs, 4 rabbits, and 2 rodents). PROCEDURE: Case-control study in which CT images of animals with histopathologic diagnosis of inflammatory (n = 11), neoplastic orbital conditions (n = 31), or normal control animals (n = 10) were reviewed independently by five observers without the knowledge of the history or diagnosis. Observers recorded their observations regarding specific anatomical structures within the orbit using an itemized form containing the following characteristics: definitely normal; probably normal; equivocal; probably abnormal; and definitely abnormal. Results were statistically analyzed using Fleiss' kappa and logistic regression analyses. RESULTS: The overall level of agreement between observers about the presence or absence of abnormal CT signs in animals with orbital disease was poor to moderate, but was highest for observations concerning orbital bones (κ = 0.62) and involvement of the posterior segment (κ = 0.52). Significant associations between abnormalities and diagnosis were found for four structures: Abnormalities affecting orbital bones (odds ratio [OR], 1.7) and anterior ocular structures (OR, 1.5) were predictive of neoplasia, while abnormalities affecting extraconal fat (OR, 1.7) and skin (OR, 1.4) were predictive of inflammatory conditions. CONCLUSIONS: Orbital CT is an imaging test with high specificity. Fat stranding, a CT sign not previously emphasized in veterinary medicine, was significantly associated with inflammatory conditions. Low observer agreement probably reflects the limited resolution of CT for small orbital structures.

Diagnostic accuracy of tests based on radiologic measurements of dogs and cats: a systematic review.

A systematic review of diagnostic tests based on radiologic measurements of structures in dogs and cats was done in order to reach generalizable conclusions about the value of making such measurements. Literature search was done using the ISI Web of Knowledge(SM) for studies in the subject category Veterinary sciences. Studies were eligible for inclusion that employed length, angle, area or volume measurements from radiographic, ultrasonographic, CT or MR images of dogs or cats as a diagnostic test for a naturally occurring condition, compared the results of imaging with a reference standard, included at least 10 subjects, and sufficient data that a 2 × 2 table of results could be constructed. Quality of studies was assessed using the QUADAS-2 tool. Twenty-six studies were found describing 40 tests that satisfied the inclusion criteria. Tests were radiographic in 22 (55%) instances and ultrasonographic in 18 (45%). Quality of studies was generally low, with a risk of bias in patient selection in 92% studies, performance of the index test in 73% studies, and patient flow in 42% studies. Median (range) number of subjects was 64 (20-305), sensitivity was 77% (38-99%), specificity was 82% (50-99%), positive likelihood ratio was 4.1 (1-103), and negative likelihood ratio was 0.29 (0.01-1). Two studies that compared accuracy of radiographic measurements to subjective image interpretation alone found no difference. Evidence is weak that radiologic measurements of structures in dogs and cats are useful for diagnosis, hence measurements should not be emphasized as a basis for diagnosis in either teaching or clinical imaging reports.

Acceptance rate and reasons for rejection of manuscripts submitted to Veterinary Radiology & Ultrasound during 2012.

Better understanding of the reasons why manuscripts are rejected, and recognition of the most frequent manuscript flaws identified by reviewers, should help submitting authors to avoid these pitfalls. Of 219 manuscripts submitted to Veterinary Radiology & Ultrasound in 2012, none (0%) was accepted without revision, four (2%) were withdrawn by the authors, 99 (45%) were accepted after revision, and 116 (53%) were rejected. All manuscripts for which minor revision was requested, and 73/86 (85%) manuscripts for which major revision was requested, were ultimately accepted. Acceptance rate was greater for retrospective studies and for manuscripts submitted from countries in which English was the primary language. The prevalences of flaws in manuscripts were poor writing (62%), deficiencies in data (60%), logical or methodological errors (28%), content not suitable for Veterinary Radiology & Ultrasound (26%), and lack of new or useful knowledge (25%). Likelihood of manuscript rejection was greater for lack of new or useful knowledge and content not suitable than for other manuscript flaws. The lower acceptance rate for manuscripts from countries in which English was not the primary language was associated with content not suitable and not poor writing. Submitting authors are encouraged to do more to recognize and address manuscript flaws before submission, for example by internal review. Specifically, submitting authors should express clearly the potential added value of their study in the introduction section of their manuscript, describe completely their methods and results, and consult the Editor-in-Chief if they are uncertain whether their subject matter would be suitable for the journal.

Computed tomographic findings in 15 dogs with eosinophilic bronchopneumopathy.

Eosinophilic bronchopneumopathy is a disease characterized by the infiltration of the lung and bronchial mucosa by eosinophils. The aim of the present study was to describe the CT findings in a large series of dogs with confirmed diagnosis of eosinophilic bronchopneumopathy. Computed tomographic scans of 15 dogs with confirmed diagnosis of eosinophilic bronchopneumopathy were evaluated retrospectively by two boarded radiologists who reached a consensus. Abnormalities were identified in 14/15 (93%) dogs, including pulmonary parenchymal abnormalities in 14/15 (93%) dogs, bronchial wall thickening in 13 (87%) dogs, which was considered marked in eight (53%), plugging of the bronchial lumen by mucus/debris in 11 (73%) dogs, and bronchiectasis in nine (60%) dogs. Pulmonary nodules were identified in 5/15 (33%) dogs including one dog with a mass. All dogs with a nodular lung pattern had additional abnormalities. Lymphadenopathy was present in 10 dogs (67%). Lesions associated with eosinophilic bronchopneumopathy are variable and heterogeneous and encompass a wider variety of computed tomographic features than reported previously. Computed tomographic images were abnormal in the majority of affected dogs, hence CT is a useful modality to characterize the nature and distribution of thoracic lesions in dogs with eosinophilic bronchopneumopathy.

Comparison of computed tomographic and pathologic findings in 17 dogs with primary adrenal neoplasia.

The CT appearance of canine adrenal masses has been reported, but associations between imaging features and pathologic features of these lesions have not been investigated in detail. The purpose of this study was to test associations between different types of adrenal neoplasia and their CT and pathologic features. A retrospective cross-sectional study was performed and inclusion criteria were histologic diagnosis of primary adrenal neoplasia, contrast-enhanced CT examination of the abdomen and surgical resection of the mass or necropsy examination. For all included dogs, CT images and histopathologic specimens were reviewed independently by two veterinary radiologists and a veterinary pathologist, respectively. Seventeen dogs met inclusion criteria. Diagnoses were adenocarcinoma in nine (53%) dogs, pheochromocytoma in five (29%) dogs, and adenoma in three (18%) dogs. Pheochromocytoma was associated with CT signs of vascular invasion (likelihood ratio = 4.8, 95% CI = 1.3-18.3, P = 0.03) and macroscopic vascular invasion (likelihood ratio = 9.6, 95% CI = 1.4-65.9, P = 0.02). There was excellent agreement between signs of vascular invasion in CT images and vascular invasion at surgery or necropsy (kappa = 0.86, P = 0.001). A peripheral contrast-enhancing rim in delayed postcontrast CT images was associated with fibrous encapsulation of the tumor (kappa = 0.53, P = 0.05), and a heterogeneous pattern of contrast distribution in delayed postcontrast CT images was associated with adrenal hemorrhage or infarction on histological examination (kappa = 0.45, P = 0.05). Findings indicated that CT enabled assessment of adrenal neoplasia features that reflected their biological behavior and pathological findings, however overlapping characteristics between tumor types limited the potential for reliably distinguishing them based on CT alone.

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.

X-ray attenuation of the liver and kidney in cats considered at varying risk of hepatic lipidosis.

X-ray attenuation of the liver has been measured using computed tomography (CT) and reported to decrease in cats with experimentally induced hepatic lipidosis. To assess the clinical utility of this technique, medical records and noncontrast CT scans of a series of cats were retrospectively reviewed. A total of 112 cats met inclusion criteria and were stratified into three hepatic lipidosis risk groups. Group 1 cats were considered low-risk based on no history of inappetence or weight loss, and normal serum chemistry values; Group 2 cats were considered intermediate risk based on weight loss, serum hepatic enzymes above normal limits, or reasonably controlled diabetes mellitus; and Group 3 cats were considered high risk based on poorly controlled diabetes mellitus due to hypersomatotropism. Mean CT attenuation values (Hounsfield units, HU) were measured using regions of interest placed within the liver and cranial pole of the right kidney. Hepatic and renal attenuation were weakly positively correlated with each other (r = 0.2, P = 0.03) and weakly negatively correlated with body weight (r = -0.21, P = 0.05, and r = -0.34, P = 0.001, respectively). Mean (SD) hepatic and renal cortical attenuation values were 70.7 (8.7) HU and 49.6 (9.2) HU for Group 1 cats, 71.4 (7.9) HU and 48.6 (9.1) HU for Group 2, and 68.9 (7.6) HU and 47.6 (7.2) HU for Group 3. There were no significant differences in hepatic or renal attenuation among groups. Findings indicated that CT measures of X-ray attenuation in the liver and kidney may not be accurate predictors of naturally occurring hepatic lipidosis in cats.