Computed tomographic characteristics of confirmed and presumed noncutaneous pythiosis in 25 dogs

Pythium insidiosum is an aquatic oomycete that causes granulomatous infection in dogs, most commonly cutaneous and gastrointestinal. Ultrasonographic characteristics of gastrointestinal pythiosis have been described; occasionally, CT is utilized in the clinical setting, and CT features of pythiosis have not been published. The purpose of this retrospective, multicenter, descriptive study is to describe CT characteristics of noncutaneous canine pythiosis. The following CT parameters were recorded: lesion anatomic location, number, shape, margination, size, attenuation pre- and postcontrast, enhancement pattern, lymph nodes affected, other lesions identified, and presence of peritoneal effusion or steatitis. Descriptive statistics demonstrating the frequency of lesion appearances were performed. Twenty-five dogs with noncutaneous pythiosis lesions that underwent CT were included; 19 had primarily gastrointestinal infections, four primarily arterial infections, one intrathoracic and intra-abdominal infection, and one primary pulmonary infection. In dogs with primary gastrointestinal infection, lesions were most common at the ileocolic junction and were most frequently focal, well-defined, moderate to marked circumferential wall thickening that was homogeneous and smoothly marginated precontrast, with moderate heterogeneous contrast enhancement. Most dogs had involvement of multiple gastrointestinal regions. Of four dogs with primary arterial involvement, three had large aneurysmal dilatations of the cranial mesenteric artery with severe mural thickening. All dogs had regional lymphadenopathy, which was variable but generally mild. Nine dogs had peritoneal effusion; six dogs had steatitis. CT features of pythiosis can overlap with neoplasia, but pythiosis should be considered as a differential, especially in young dogs. Findings supported using CT as an adjunct imaging test for increasing clinical suspicion of noncutaneous pythiosis.

Correlation between computed tomography and histological evaluation of nodal metastasis in dogs with mast cell tumours

Early diagnosis of nodal metastasis has been shown to impact prognosis for dogs with mast cell tumours (MCT). The objective of this retrospective study was to determine the correlation between computed tomographic characteristics of lymph nodes and histologic nodal metastasis using the HN classification system, in dogs with cutaneous or subcutaneous MCT and regional lymph node(s) removal. Dogs that had removal of MCT and regional lymphadenectomy within 31 days of the initial staging computed tomography (CT) were enrolled. Subjective lymph node characteristics used included margination, loss of fat at hilus, shape of margin, perinodal fat pattern, increase in number of nodes, and pre- and post-contrast heterogeneity. Enhancement, heterogeneity, and short-long axis ratio were calculated. Seventy-one lymph nodes from 37 dogs were included. Generalised linear mixed model of assessment of lymph node was performed twice, with binary outcome [non-metastatic (HN0/1) versus metastatic (HN2/3)] and 4-point scales (HN0-HN3). After blind assessment of 7 characteristics described above, a final subjective interpretation of each lymph node as non-metastatic or metastatic was assigned. A significant correlation was found between final interpretation and prediction of metastasis. Higher HN classification was also significantly correlated with the increased number of nodes and pre- and post-contrast heterogeneity. No correlation was found in short-long axis ratio, calculated heterogeneity, or degree of enhancement. Sensitivity of CT was 35.7%, specificity was 96.6%, and accuracy was 60.5% for nodal metastasis. CT alone cannot be recommended for assessment of metastasis. The use of multiple computed tomographic characteristics may increase accuracy of nodal metastasis detection.

Computed tomographic findings may be useful for differentiating small intestinal adenocarcinomas, lymphomas, and spindle cell sarcomas in dogs

An improved understanding of the CT characteristics for histologically confirmed primary intestinal tumors would be helpful for guiding prognosis and treatment plans in affected dogs. This retrospective, multi-center, analytical study aimed to evaluate the CT characteristics for the differentiation of adenocarcinoma, lymphoma, and spindle cell sarcoma (SCS) in dogs. Thirty-seven dogs who underwent contrast CT and histopathological examinations were included (adenocarcinomas, n = 11; lymphomas, n = 12; SCS, n = 14). Quantitative and qualitative CT parameters, including tumor morphology, contrast enhancement pattern, Hounsfield unit (HU) value, and presence or absence of intraabdominal lymphadenopathy, were evaluated for each included small intestine tumor CT case. Adenocarcinomas tended to show endophytic growth, intestinal obstruction, and a heterogeneous enhancement pattern. Lymphomas tended to show exophytic growth, contrast enhancement of the intestinal tumor mucosal layer, a homogeneous enhancement pattern, and the presence of lymphadenopathies in the abdominal cavity. SCSs tended to show lobulated growth, a large cystic portion within the tumor, a heterogeneous enhancement pattern, a large size with fat stranding sign, and lower HU values in postcontrast images. Cut-off values of the minimum diameter/fifth lumbar vertebral mid-body height (≥5.80; area under the curve [AUC] = 0.97, P < 0.001) and minimum HU value/HU value of the aorta (≤0.26; AUC = 0.96, P < 0.001) were derived to discriminate SCS from the two other tumor types. In conclusion, contrast CT characteristics may be useful in differentiating small intestinal adenocarcinomas, lymphomas, and SCSs in dogs.

Contrast-enhanced CT features of pyloric lesions in 17 dogs: Case series

Pyloric outflow obstructions can be caused by several types of lesions. When a thickened gastric wall and pyloric mass are detected, malignant neoplasia must be differentiated from chronic hypertrophic pyloric gastropathy. CT can characterize gastric tumors. However, based on the authors' review of the literature, there is limited information about the CT findings of pyloric lesions. The purpose of this retrospective case series study was to assess the CT findings of canine pyloric lesions. The following CT parameters were recorded: anatomical area, involved area, lesion shape, growth patterns of wall thickening lesions, enhancement pattern of the lesion in the early and delayed phases, lymphomegaly, and pulmonary metastasis. Seventeen dogs were included in this study and had the following final diagnoses: hyperplasia (five dogs), adenoma (five dogs), adenocarcinoma (three dogs), gastrointestinal stromal tumor (GIST; two dogs), polyposis (one dog), and pyogenic granuloma (one dog). Hyperplasia, adenoma, and polyposis formed mass lesions that involved the mucosal layer. Lymphomegaly was detected in two Jack Russell terriers with hyperplasia; however, the causes were unknown because we did not perform biopsies. All adenocarcinomas formed wall-thickened lesion that involved the outer layer, with lymphomegaly. All GISTs formed mass lesion that involved the outer layer. The pyogenic granulomas formed symmetric wall-thickened lesion that involved the mucosal and outer layers. CT facilitated the characterization of canine pyloric lesions using contrast enhancement, based on the involved area and lesion shape. However, polyposis may require caution in diagnosis based on CT findings alone.

Comparison of sonographic and CT findings for the identification of renal nodules in dogs and cats

Ultrasonography (US) and computed tomography (CT) are used to diagnose neoplastic and non-neoplastic focal renal lesions in dogs and cats; however, comparative studies between these two diagnostic tools are lacking. The aim of this retrospective, methods comparison study was to evaluate and compare the performance of US compared to CT in identifying at least one renal nodule in animals with confirmed focal renal lesions. Imaging studies of animals with uni- or bilateral renal nodules smaller than 3 cm that underwent both US and CT and that had a pathologically confirmed diagnosis were reviewed. Animals with renal cysts and infarcts were excluded. Recorded features for both modalities included the following: shape, size, number, localization, margins, renal profile. For CT only, recorded features also included attenuation (HU) and pattern of enhancement.  For US only, recorded features also included echogenicity, echostructure, and rate of visibility. Final diagnosis was obtained by cytology or histopathology. Using CT, lesions were identified in all 39 (100%) kidneys of 18 dogs and seven cats. Most lesions were multiple, cortical, well-defined, iso-attenuating (precontrast), hypo-attenuating, and moderately enhancing (postcontrast). Using US, lesions were identified in 29 of 39 (74%) kidneys. Overall, nine (31%) lesions were poorly visible; 10 (26%) kidneys appeared normal; in 17 (59%) organs, lesions' number was underestimated. Isoechoic, non-protruding lesions were difficult to identify by US. Ultrasonography underestimated renal lesions compared to CT in 59% of the kidneys (P = 0.001). Final diagnoses included metastatic disease (n = 16), infiltration by feline lymphoma (n = 4), primary neoplasia (n = 3), and non-neoplastic benign lesions (n = 2).

CT features of divisional bile ducts in healthy Labrador Retrievers

Computed tomography (CT) is increasingly being used for the study of gallbladder and bile duct diseases. The first step in interpreting CT findings is understanding the cross-sectional anatomy of the structures involved, but there are no published studies describing the CT features of the divisional bile ducts. In dogs, anatomic studies report two common patterns including three or four divisional bile ducts. The aim of this retrospective, descriptive, anatomical study was to describe the size and pattern of the visible divisional bile ducts, based on their location and extension, using contrast-enhanced CT in a group of Labrador Retrievers without evidence of hepatobiliary diseases. The correlation between the biliary duct number and dimensions, and the visceral fat area percentage (VFA%) was also evaluated. The right lateral divisional duct (RLD) was visualized in four of 40 dogs, the left lateral divisional duct (LLD) in nine of 40 dogs, and in 17 of 40 dogs, both were simultaneously visualized. In 10 of 40 dogs, the RLD and LLD were not highlighted. When visible, the RLD has a median diameter of 0.23 cm and a median length of 0.82 cm. The LLD has a median diameter of 0.23 cm and a median length of 2.72 cm. The median diameter of the common bile duct before and after the insertion of divisional bile ducts was 0.23 and 0.25 cm, respectively. No correlation with the VFA% was found. At least one of the divisional bile ducts could be visualized using contrast-enhanced CT in the majority of sampled dogs (75%) .

Anatomic, computed tomographic, and ultrasonographic assessment of the lymph nodes in presumed healthy adult cats: the abdomen, pelvis, and hindlimb

Background

The computed tomography (CT) and ultrasonography (US) features of lymph nodes of the abdomen, pelvis, and hindlimb in healthy cats are poorly described in the current literature. A prospective anatomic and reference interval study was therefore performed. The lymph nodes of six feline cadavers were identified, and dimensions were measured (length, width, and height). The lymph nodes from 30 healthy adult cats were identified and measured using CT (pre- and postcontrast) and US. The identification and dimensions of the separate lymph nodes were compared between imaging techniques and the anatomic study.

Results

The identification of lymph nodes was most frequent in CT, and the dimensions were overall larger than those identified and measured in US and the anatomic study. The caudal epigastric and sacral lymph nodes were not identified in the anatomic study. The ischiatic, lumbar aortic, internal iliac, and caudal epigastric lymph nodes were not visualized in US. The height presented the main statistical differences among techniques. The lymph nodes were mainly homogeneous in pre- and postcontrast CT and US images. Some lymph nodes showed a hyperattenuating periphery with a hypoattenuating center (on pre- and postcontrast images) and a hypo-/isoechoic periphery with a hyperechoic center, representing the hilar fat. The lymph nodes were commonly elongated and rounded except for the jejunal lymph nodes, which had an irregular shape.

Conclusions

The assessment of most of the abdominal, pelvic, and hindlimb lymph nodes in the cat is feasible using CT and US, with CT performing best. Factors like the amount of adipose tissue and contrast administration subjectively improved the lymph node visualization and assessment. The measurements and features reported are proposed as reference values.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13028-022-00638-x.

Computed tomographic staging of dogs with anal sac adenocarcinoma

OBJECTIVES

To describe the CT appearance of anal sac adenocarcinoma lesions in a population of dogs including the relations between primary tumour, and locoregional and distant metastasis.

MATERIALS AND METHODS

Retrospective review of dogs with confirmed anal sac adenocarcinoma and available CT images of the thorax, abdomen and pelvis.

RESULTS

A population of 70 dogs were included in the study. No association was found between anal sac mass size and presence or absence of iliosacral lymph node enlargement. The prevalence of local metastatic disease characterised by iliosacral lymphadenomegaly in this study was 71%, with pulmonary metastases identified in 11% of cases. There were no cases of distant pulmonary metastasis without concurrent locoregional lymphadenomegaly.

CLINICAL SIGNIFICANCE

In our population of dogs local metastatic spread of anal sac adenocarcinoma was common, with a relatively low prevalence of pulmonary metastasis. The study demonstrates the importance of thorough rectal examination and/or imaging to assess the iliosacral lymph centre in this disease irrespective of the size of the anal sac mass.

Low-field magnetic resonance imaging characteristics of multifocal vertebral lesions in dogs

BACKGROUND

There is a lack of information regarding magnetic resonance imaging (MRI) features of polyostotic vertebral lesions in dogs. The aim of this retrospective study was to identify and differenciate low-field MRI features of aggressive versus benign multifocal vertebral diseases in dogs.

METHODS

MRI examinations from 49 dogs with polyostotic vertebral lesions were reviewed. Images were evaluated for vertebral intensity changes, expansile lesions, new bone formation, cortical bone interruption, paravertebral musculature changes, lymphadenomegaly, spinal cord compression and spinal cord signal changes.

RESULTS

Twenty-nine dogs with non-aggressive bone lesions and 20 dogs with aggressive vertebral lesions were included. Non-aggressive lesions had variable T2-weighted fast spin-echo (T2W) signal intensity and the majority displayed low signal intensity on short tau inversion recovery (STIR). Aggressive lesions predominantly had high T2W and STIR signal intensity, with variable signal intensity on T1-weighted spin-echo and contrast enhancement. Aggressive lesions were associated with spinal pain (p < 0.01), new bone formation (p = 0.02), spinal cord compression (p < 0.01) and lymphadenomegaly (p < 0.01). Cortical interruption (p < 0.01) and paravertebral musculature changes (p < 0.01) were the strongest indicative imaging features for aggressive lesions.

CONCLUSION

Spinal pain, spinal cord compression, new bone formation, lymphadenomegaly and especially cortical interruption and paravertebral musculature signal intensity changes were the best discriminators for differentiating malignant from benign vertebral lesions.

Comparison of the clinical, ultrasound, and CT findings in 13 dogs with gastric neoplasia

Diagnosis of gastric tumors in dogs is difficult and is often obtained by biopsy following identification of a mass through ultrasound (US) or endoscopy. In human medicine, modalities such as CT and endoscopy are standard of care in the diagnosis and staging of gastric tumors. Although one veterinary study has described CT findings of gastric tumors in dogs using iatrogenic gas dilation, there are no veterinary studies that have directly compared the usefulness of US versus CT in the diagnosis and staging of these tumors. This retrospective, descriptive study evaluated US and CT images from 13 dogs. Gastric tumor diagnoses included leiomyoma (n = 4), adenocarcinoma (n = 3), leiomyosarcoma (n = 3), gastrointestinal stromal tumor (n = 2), and lymphoma (n = 1). Computed tomography was successful in identification of 92% of gastric tumors, while US identified only 69%. Computed tomography identified more locations of lymphadenopathy and correctly identified the location of gastric tumors more frequently than US when compared to the surgical, endoscopic, or necropsy reports. Most features seen on US and CT overlapped between the different tumor types. Lymphoma had a lower mean attenuation in CT than the other gastric tumors and was the only gastric tumor to not have complete loss of the gastric wall layering on US. As expected, adenocarcinoma appeared as gastric wall thickening with regional lymphadenopathy. Findings supported using CT as an ancillary diagnostic test for characterizing and staging gastric tumors in dogs and assisting in the selection of surgical candidates.

Anatomic, computed tomographic, and ultrasonographic assessment of the lymph nodes in presumed healthy adult cats: The head, neck, thorax, and forelimb

Assessment of the lymph nodes is key in staging cancer patients. Descriptions of normal features of the feline lymph nodes using computed tomography (CT) and ultrasound (US) are limited. A prospective anatomic and comparative imaging study was performed. The frequency of identification and the size of the lymph nodes during gross pathology from 6 feline cadavers were compared to the images of lymph nodes from 30 presumed healthy adult cats obtained by CT and US. Measurements (length, width, and height) were compared among techniques. The CT and US features of the identified lymph nodes were also recorded. The frequency of identification of the lymph centers varied among techniques and individually. The mandibular lymph nodes were identified in 100% of the cadavers and in 100% of the healthy cats using CT and US. The medial retropharyngeal lymph nodes were identified in 100% of the cats using CT and US. The deep cervical lymph nodes were not visualized in the cadavers. The cranial mediastinal and tracheobronchial lymph nodes were not visualized using US. Lymph nodes showed a higher length on CT and higher width on US. The height was the most statistically significant variable measurement among techniques. On CT, lymph nodes were most frequently isoattenuating or slightly hypoattenuating to surrounding musculature, with homogeneous contrast enhancement. On US, most lymph nodes were isoechoic or hypoechoic to surrounding fat tissue. The lymph nodes were most frequently elongated or rounded.

Computed Tomography Evaluation of Normal Canine Abdominal Lymph Nodes: Retrospective Study of Size and Morphology According to Body Weight and Age in 45 Dogs

The morphological characteristics of the largest lymphatic vessels and lymph nodes of the body have been described through ultrasonography, although food and gas in the gastrointestinal tract can often have negative effects on the response of small abdominal structures. The aim of the study was to describe the size of normal abdominal lymph nodes (ALs) in dogs affected by disease, not including lymphadenomegaly or lymphadenopathy, and divided according to body weight and age. The ALs studied included the jejunal, medial iliac, portal, gastric, splenic, and pancreaticoduodenal lymph nodes. Statistical correlation considering body weight and age as continuous variables showed that all measurements of the ALs increased according to body weight changes (p < 0.01). The most reliable values were the volume measurements (p < 0.001) compared to the length, thickness, and width. Mixed results emerged from a comparison of weight categories and age; only the jejunal lymph nodes showed a significant correlation (p < 0.05). Other characteristics (shape, attenuation, and enhancement) are subsequently reported. The resulting data can be used to categorize CT measurements of normal ALs displayed based on the body weight and age of the subjects. This study aimed to propose a new parameter of normalcy that may serve as a reference for the evaluation of infectious or neoplastic events.

Multi-factorial considerations for intra-thoracic lymph node evaluations of healthy cats on computed tomographic images

Background

It is difficult to examine mild to moderate feline intra-thoracic lymphadenopathy via and thoracic radiography. Despite previous information from computed tomographic (CT) images of intra-thoracic lymph nodes, some factors from animals and CT setting were less elucidated. Therefore, this study aimed to investigate the effect of internal factors from animals and external factors from the CT procedure on the feasibility to detect the intra-thoracic lymph nodes. Twenty-four, client-owned, clinically healthy cats were categorized into three groups according to age. They underwent pre- and post-contrast enhanced CT for whole thorax followed by inter-group evaluation and comparison of sternal, cranial mediastinal, and tracheobronchial lymph nodes.

Results

Post contrast-enhanced CT appearances revealed that intra-thoracic lymph nodes of kittens were invisible, whereas the sternal, cranial mediastinal, and tracheobronchial nodes of cats aged over 7 months old were detected (6/24, 9/24 and 7/24, respectively). Maximum width of these lymph nodes were 3.93 ± 0.74 mm, 4.02 ± 0.65 mm, and 3.51 ± 0.62 mm, respectively. By age, lymph node sizes of these cats were not significantly different. Transverse lymph node width of males was larger than that of females (P = 0.0425). Besides, the detection score of lymph nodes was affected by slice thickness (P < 0.01) and lymph node width (P = 0.0049). Furthermore, an irregular, soft tissue structure, possibly the thymus, was detected in all juvenile cats and three mature cats.

Conclusions

Despite additional information on intra-thoracic lymph nodes in CT images, which can be used to investigate lymphatic-related abnormalities, age, sex, and slice thickness of CT images must be also considered.

Clinical, CT, and ultrasonographic features of canine and feline pleural and peritoneal carcinomatosis and sarcomatosis

Carcinomatosis and sarcomatosis describe the widespread dissemination of metastatic neoplastic cells throughout the body. Studies describing their clinical and imaging features in veterinary patients are limited. The objective of this retrospective, multicenter, cross-sectional study is to describe the clinical, ultrasonographic, and CT features of pleural and peritoneal carcinomatosis and sarcomatosis in dogs and cats to aid detection and differentiation of these lesions. Medical records and CT and ultrasonographic images were reviewed. Although a large degree of overlap was observed between the imaging features and clinical signs of canine and feline carcinomatosis and sarcomatosis, some distinguishing features were observed. Dogs were significantly more likely to present with abdominal pain compared to cats (P = .022), whereas cats more commonly presented with inappetence (P = .019). Dogs with sarcomatosis had a significantly heavier bodyweight than dogs with carcinomatosis (P = .005), largely due to a higher prevalence of splenic hemangiosarcoma in this patient cohort. Peritoneal effusion was more frequently observed in dogs with carcinomatosis compared to dogs with sarcomatosis (P = .021). Imaging and clinical features observed in this study may help to distinguish sarcomatosis and carcinomatosis lesions. Due to the large degree of overlap observed, cytological or histopathological analysis is recommended for definitive diagnosis.

Computed tomography of thoracic lymph nodes in 100 dogs with no abnormalities in the dominated area

In dogs, reports on thoracic lymph nodes are lacking compared to abdominal lymph nodes. This report analyzed the position, number, size, shape, and homogeneity of thoracic lymph nodes (cranial sternal, cranial mediastinal, tracheobronchial, aortic thoracic, and pulmonary lymph nodes) using thoracic computed tomography (CT) images of 100 dogs without any lesions in the dominated areas of thoracic lymph nodes. The position and number of intrathoracic lymph nodes could be observed in CT, consistent with macroscopic anatomical studies. It was difficult to set a clinical index associated with size using CT scans. Image findings that indicated abnormalities, such as circular shapes and non-uniform, may be routinely found in dogs and may not be considered abnormal on CT scans.

Contrast-enhanced computed tomography findings of canine primary renal tumors including renal cell carcinoma, lymphoma, and hemangiosarcoma

In veterinary medicine, abdominal ultrasonography is used to rank the differential diagnosis of renal lesions. However, a conventional sonographic examination may show nonspecific findings. The purpose of this study was to assess the computed tomography (CT) findings of canine renal tumors, including renal cell carcinoma (RCC), lymphoma, and hemangiosarcoma (HSA). In this retrospective study, the following CT parameters were recorded for each dog: 1) extent of renal involvement of tumors, 2) enhancement pattern, 3) number of renal tumors, 4) renal tumor vessel enhancement in the corticomedullary phase, 5) presence of lymphadenopathy and lung metastasis, and 6) attenuation values of the renal tumors on the pre- and post-contrast corticomedullary, nephrographic, and excretory phase images. Fifteen dogs met the inclusion criteria, of which nine had RCCs, four had lymphomas, and two had HSAs. RCCs tended to show heterogeneous enhancement and unilateral renal involvement, and vessel enhancement was detected in the corticomedullary phase in dogs with RCC. Conversely, renal lymphomas showed homogeneous enhancement, bilateral renal involvement, and multiple masses; in these dogs, no vessel enhancement was detected in the corticomedullary phase, and the incidence of lymphadenopathy was low. However, in dogs with lymphadenopathy, the renal lymphoma was associated with regionally severe lymphadenopathy. Finally, renal HSAs tended to show heterogeneous enhancement with a non-enhanced area and unilateral renal involvement; in these dogs, vessel enhancement was detected in the nephrographic phase, with the enhancement expanding around the vessel. These findings had no significant differences. Further studies with a larger sample size are required to examine the association between CT and histopathological findings.

CT angiographic changes in dogs with acute pancreatitis: A prospective longitudinal study

Computed tomographic angiography (CTA) has recently been shown to be a useful tool in the diagnosis of acute canine pancreatitis, the identification of pancreatic necrosis, and the detection of sequelae. Evidence of pancreatic necrosis on CTA has been shown to be correlated with a poorer outcome in both humans and dogs and early diagnosis and intervention may improve outcomes. In humans, pancreatic necrosis is typically evident on CTA within 48 h of clinical signs, thus, repeat CTA examinations are often performed to identify pancreatic necrosis that may not have been evident on CTA examinations performed early in the course of disease. Published information investigating the timing of CTA examinations and the use of serial CTA in dogs with acute pancreatitis is lacking. In this prospective, longitudinal study, CTA examinations were performed at the time of hospitalization and repeated 3-5 days later in 11 dogs suffering from acute canine pancreatitis to determine if pancreatic necrosis or sequelae are under diagnosed on examinations performed at the time of hospitalization. Computed tomographic angiography studies were evaluated for changes in pancreatic size, pancreatic contrast enhancement, and peri-pancreatic tissues and vessels. The only statistically significant difference between the initial and repeat CTA examinations was the improvement of fat stranding on the repeat CTA examinations (P < .045). Based on these results, CTA performed at the time of admission is likely adequate in the diagnosis and evaluation of dogs with acute pancreatitis. Repeat CTA examinations are unlikely to add additional information in the absence of worsening clinical signs.

Comparison of computed tomographic and cytological results in evaluation of normal prostate, prostatitis and benign prostatic hyperplasia in dogs

Prostate gland can be structurally evaluated by computed tomography (CT) with taking advantages of tomographic feature and post-contrast parenchymal changes. The current examination initiated to determine association between computed tomographic and cytological results in evaluation of canine prostate. Thirty mature male dogs were included and under gone by both CT and fine needle sampling of prostate. The cytology and CT examination results showed 18/30 (60.00%) and 15/30 (50.00%) normal prostate, 5/30 (16.66%) and 4/30 (13.33%) prostatitis and 7/30 (23.33%) and 11/30 (36.66%) benign prostatic hyperplasia, respectively. Moderate agreement has been found between cytology and final diagnosis based on pre-contrast CT images, however fair agreement was existed between cytological diagnosis and final CT interpretation according to post-contrast and both pre- and post- contrast CT series. Additionally, the internal iliac lymph node length showed statistically significant difference in prostatitis compared to normal and benign hyperplastic prostates in this study. In conclusion, the fair and moderate associations between cytology and final diagnosis based on CT images should be considered and they can be used in further investigations and clinical examinations. Also, using internal iliac lymph node length to differentiate prostatitis with normal and benign hyperplastic prostates can be used efficiently in diagnosis to choose the best method of management and have a proper follow up and prognosis.

Computed tomographic angiography and ultrasonography in the diagnosis and evaluation of acute pancreatitis in dogs

Background

Acute pancreatitis in dogs is an under‐diagnosed disease. Current diagnostic methods are insufficient at identifying sequelae and lack prognostic capability. Computed tomographic angiography (CTA) is accurate for diagnosis and prognostication of pancreatitis in humans.

Objectives

In comparison to ultrasound (US), CTA will (1) better diagnose more severe pancreatitis and sequelae and (2) provide assessment of patient outcome by identification of pancreatic contrast enhancement patterns.

Animals

Twenty‐six client‐owned dogs suspected to have acute pancreatitis.

Methods

US and CTA examinations performed at time of admission were compared to determine the detection of pancreatic changes and sequelae. CTA findings also were compared to outcome indicators for prognosis of dogs with acute pancreatitis. Specific canine pancreatic lipase (cPL) samples were obtained and compared with CTA findings.

Results

Ten of 26 dogs had heterogeneous contrast enhancement of the pancreas. Compared to US, CTA better identified portal vein thrombosis (P = .003). Patients with heterogeneous contrast enhancement had longer hospitalization (P = .01), including hospital stays for >5 days (P = .02), had more relapses, and were more likely to have portal vein thrombosis (P = .002). Patients with heterogeneous contrast enhancement had increased spec cPL (P = .006).

Conclusions and Clinical Importance

In comparison to US, CTA better identified dogs with more severe acute pancreatitis and those with portal vein thrombosis, factors that may predict longer hospitalization and increased risk of relapse. The presence of heterogeneous contrast enhancement and portal vein thrombosis may change therapy for patients with acute pancreatitis.

Computed tomographic appearance of abdominal lymph nodes in healthy cats

Background

Computed tomography (CT) is commonly used in veterinary medicine and plays an important role in disease identification and cancer staging. Identification of abnormal abdominal lymph nodes is important for clinical, therapeutic, and prognostic decision making. No published study describes the CT appearance of abdominal lymph nodes in healthy cats.

Hypothesis/Objectives

All abdominal lymph centers will be identified on CT with the majority of lymph nodes being elongated and homogenously contrast enhancing.

Animals

Sixteen healthy cats without clinical or biochemical evidence of disease.

Methods

Precontrast and postcontrast CT images of sedated healthy cats were used to identify the presence and descriptive characteristics of intra‐abdominal lymph nodes. These assessments then were compared with patient characteristics to identify possible correlations.

Results

Abdominal lymph nodes were readily identified on CT with caudal mesenteric, colic, hepatic, inguinal, and pancreaticoduodenal lymph nodes identified in 16/16 cats. Lymph node size and shape varied among lymph centers with nearly all lymph nodes homogeneously contrast enhancing in 515/525. Significant negative correlations were identified between age and length (P = .0166) and width (P = .0387) of abdominal lymph nodes as well as age and number of sacral lymph nodes (P = .0493). Intranodal fat was present in 18/525 lymph nodes.

Conclusions and Clinical Importance

CT readily permitted identification and characterization of feline abdominal lymph nodes. This study provides subjective and objective data on the CT characteristics of abdominal lymph nodes in 16 healthy cats, with younger cats having larger abdominal lymph nodes and a higher number of sacral lymph nodes.

Radiographic and ultrasonographic findings of the spleen and abdominal lymph nodes in healthy domestic ferrets

Objective

To describe the radiographic and ultrasonographic characteristics of the spleen and abdominal lymph nodes in clinically healthy ferrets.

Materials and Methods

Fifty‐five clinically healthy ferrets were prospectively recruited for this cross‐sectional study. Three‐view whole body radiographs and abdominal ultrasonography were performed on awake (23 out of 55) or sedated (32 out of 55) ferrets. On radiographs splenic and abdominal lymph node visibility was assessed. Splenic thickness and echogenicity and lymph node length, thickness, echogenicity, number and presence of cyst‐like changes were recorded.

Results

The spleen was radiographically detectable in all ferrets. On ultrasound the spleen was hyperechoic to the liver (55 out of 55) and mildly hyperechoic (28 out of 55), isoechoic (15 out of 55) or mildly hypoechoic (12 out of 55) to the renal cortices. Mean splenic thickness was 11.80 ±0.34 mm. Lymph nodes were radiographically discernible in 28 out of 55 ferrets and included caudal mesenteric and sublumbar nodes. An average of 9 ±2 lymph nodes (mean± standard deviation; mode 10) were identified in each ferret using ultrasound. A single large jejunal lymph node was identified in all ferrets and had a mean thickness of 5.28 ± 1.66 mm. For other lymph nodes the mean thickness measurements plus one standard deviation were less than 4.4 mm (95% confidence interval: ≤ 3.72 mm).

Clinical Significance

The information provided in this study may act as a baseline for evaluation of the spleen and lymph nodes in ferrets.

Utility of Computed Tomography versus Abdominal Ultrasound Examination to Identify Iliosacral Lymphadenomegaly in Dogs with Apocrine Gland Adenocarcinoma of the Anal Sac

Background

Apocrine gland adenocarcinoma of the anal sac (AGAAS) is associated with high rates of iliosacral lymph node metastasis, which may influence treatment and prognosis. Magnetic resonance imaging (MRI) recently has been shown to be more sensitive than abdominal ultrasound examination (AUS) in affected patients.

Objective

To compare the rate of detection of iliosacral lymphadenomegaly between AUS and computed tomography (CT) in dogs with AGAAS.

Animals

Cohort A: A total of 30 presumed normal dogs. Cohort B: A total of 20 dogs with AGAAS that underwent AUS and CT.

Methods

Using cohort A, mean normalized lymph node : aorta (LN : AO) ratios were established for medial iliac, internal iliac, and sacral lymph nodes. The CT images in cohort B then were reviewed retrospectively and considered enlarged if their LN : AO ratio measured 2 standard deviations above the mean normalized ratio for that particular node in cohort A. Classification and visibility of lymph nodes identified on AUS were compared to corresponding measurements obtained on CT.

Results

Computed tomography identified lymphadenomegaly in 13 of 20 AGAAS dogs. Of these 13 dogs, AUS correctly identified and detected all enlarged nodes in only 30.8%, and either misidentified or failed to detect additional enlarged nodes in the remaining dogs. Despite limitations in identifying enlargement in all affected lymph nodes, AUS identified at least 1 enlarged node in 100% of affected dogs.

Conclusion and Clinical Importance

Abdominal ultrasound examination is an effective screening test for lymphadenomegaly in dogs with AGAAS, but CT should be considered in any patient in which an additional metastatic site would impact therapeutic planning.