Evaluation of Presumptive Normal Feline Tonsils with Low-Field Magnetic Resonance Imaging: A Preliminary Retrospective Study.

Palatine tonsils are lymphoid organs, whose anatomic localization gives them a role against antigens entering the body during feeding and breathing. In human medicine, MRI is used to investigate tonsillar diseases. In veterinary medicine, a recent study on healthy dogs described the MRI appearance of canine palatine tonsils, with no available reports about feline ones. Due to the similarities between animals and humans, and based on the study on canine tonsils, the authors aimed to evaluate the feasibility of low-field MRI to detect and describe presumed normal features of feline palatine tonsils, assessing the finding's reproducibility. Low-field MRI of the heads of 14 cats was reviewed, and qualitative findings (visualization, shape, margins, signal intensity, and pattern) and size of each tonsil were recorded. Each observer recorded 71% of the expected tonsils. Most of them were classified as oval, ill-defined, and hyperintense structures with both homogeneous and heterogeneous signal patterns; the overall agreement was considered good. Low-field MRI is potentially a useful imaging modality to visualize palatine tonsils in cats, and their normal appearance has been described for the first time. The authors recommend the evaluation of tonsils in the transverse plane and consider the most accurate estimation of the short axis.

Ultrasonography and Sonoelastography Characteristics of Benign vs. Malignant Mesenteric Lymph Nodes in Cats: An Update.

(1) Background: Strain elastography (SE) is an ultrasound-based technique able to non-invasively assess tissue elasticity, with malignant tissues being stiffer than normal tissues. The purpose of the study was to evaluate the diagnostic performance of SE to differentiate feline mesenteric benign and malignant lymph nodes (LNs) using a multivariate approach including both SE results and B-mode ultrasound and color Doppler findings. (2) Methods: Feline enlarged mesenteric LNs were evaluated using B-mode ultrasound, color Doppler ultrasonography, and SE. Short-to-long axis ratios, borders, echogenicity, hilum, vascular flow distribution, elastographic patterns, and strain ratios were recorded. Histological and/or cytological diagnosis was available for each LN. (3) Results: A total of 88 LNs were included, 46 (52.3%) benign and 42 (47.7%) malignant; in the benign group, 40 LNs had a diagnosis of reactive hyperplasia (group A) and 6 eosinophilic sclerosing lymphadenitis (group B), while in the malignant group 42 had a diagnosis of lymphoma (group C). The principal component analysis approach showed evidence that by combining B-mode- and color Doppler-based scores with SE scores, the three groups of LNs can be accurately distinguished. (4) Conclusions: Our results demonstrate that a multivariate sonographic approach combining B-mode ultrasound, color Doppler ultrasonography, and SE can accurately distinguish benign from malignant LNs, thus helping in the clinical advice of feline patients.

Canine prostatic serum esterase and strain and 2D-shear wave sonoelastography for evaluation of normal prostate in dogs: Preliminary results.

Canine prostatic serum esterase (CPSE) is considered a useful tool to identify prostate disorders in dogs, with increasing interest in ultrasound (US)-based sonoelastography to non-invasively detect prostate disorders. Since no report is available about a possible correlation between these diagnostic tools, we aimed to investigate a possible correlation between strain elastography (SE) and 2D-shear wave elastography (SWE) and CPSE. Twenty-one dogs were included and, on each animal, CPSE was evaluated followed by a complete US examination and SE and 2D-SWE application. Healthy dogs were identified based on the CPSE results. All the dogs included were characterized by normal CPSE values (<52.3 ng/mL) and normal US prostate appearance. The prostate was characterized by intermediate stiffness with SE (pattern III - 84.7% for the left lobe and 79.27% for the right lobe) and softer than the abdominal wall (SR 0.6 for the left lobe and 0.56 for the right lobe), with low values for both m/s and kilopascals (kPa) for 2D-SWE, pointing that the healthy tissue is not hard. 2D-SWE results were, respectively, 13.51 ± 5.55 kPa and 2.31 ± 0.42 m/s for the left lobe and 18.05 ± 6.47 kPa and 2.39 ± 0.43 m/s for the right lobe. The significant difference between the right and left measurements expressed with kPa, not evidenced with m/s, can be considered indicative of m/s as the most reliable measurement to be considered regarding the prostate parenchyma. Even though no linear correlation was detected between CPSE and elastography values, these preliminary results evidence that the healthy prostates were characterized by a similar elastographic pattern, thus pointing that these techniques can be potentially useful to be applied in case of prostatic disorders to improve the accuracy of the final diagnosis in a non-invasive way.

Thoracoscopic Assisted PleuralPortTM Application in Seven Dogs Affected by Chronic Pleural Effusion.

Chronic non-septic pleural effusion is a condition that frequently may occur because of lung or pleural neoplasia, or chylothorax refractory to surgical treatment, in dogs. Effusion management can be performed with multiple pleurocenteses or the application of chest drains. New modified vascular devices have been used for patients with chronic diseases; they offer the advantage of allowing home management and do not require hospitalization. Eight PleuralPortTM devices were applied in seven dogs during thoracoscopic exploration and biopsy procedures; five were affected by mesothelioma; one by lung metastases from a mammary carcinoma; and one by chronic chylothorax. The median time of surgical procedure was 51 min; one developed pneumothorax post-operatively that resolved within 12 h after repeated drainage; one device was obstructed after 45 days and was successfully managed by flushing. All patients were discharged after 24 h. The median duration of port insertion in cancer patients was 5 months and those dogs were euthanized because of tumor progression; in the dog with chylothorax, the device was removed after 1 year when the effusion had resolved.

A Comparison of the Intrarectal and Intramuscular Effects of a Dexmedetomidine, Ketamine and Midazolam Mixture on Tear Production in Cats: A Randomized Controlled Trial.

Cats are often easily stressed and uncooperative. The use of sedative agents in the feline species is widely used to perform even minor clinical and diagnostic procedures. The aim of this study is to assess the impact on tear film production of the intrarectal route (IR) administration of a mixture of dexmedetomidine, ketamine and midazolam in comparison with the intramuscular (IM) one. A group of twenty cats were involved in a randomized and blinded clinical trial. A clinical and ophthalmological examination was conducted on the cats. The IR group received dexmedetomidine 0.003 mg kg-1, ketamine 4 mg kg-1 and midazolam 0.4 mg kg-1; the IM group received dexmedetomidine 0.003 mg kg-1, ketamine 2 mg kg-1 and midazolam 0.2 mg kg-1. A Shirmer tear test I (STT- I) was conducted 1 h before sedation and 2', 10', 20', 30', 40', and 80' post drug administration. The reaction to STT-I administration was also evaluated. The IM group has a lower mean tear production than the IR group for all time points evaluated. Cats in the IM group showed less reaction to STT-I administration. This study may suggest that the effect of sedative agents administered by the IR route has a lower incidence on tear production than the IM one. The use of eye lubricant is recommended in any case.

Volumetric assessment and longitudinal changes of subcortical structures in formalinized Beagle brains.

High field MRI is an advanced technique for diagnostic and research purposes on animal models, such as the Beagle dog. In this context, studies on neuroscience applications, e.g. aging and neuro-pathologies, are currently increasing. This led to a need for reference values, in terms of volumetric assessment, for the structures typically involved. Nowadays, several canine brain MRI atlases have been provided. However, no reports are available regarding the measurements' reproducibility and little is known about the effect of formalin on MRI segmentation. Here, we assessed the segmentation variability of selected structures among operators (two operators segmented the same data) in a sample of 11 Beagle dogs. Then, we analyzed, for one Beagle dog, the longitudinal volumetric changes of these structures. We considered four conditions: in vivo, post mortem (after euthanasia), ex vivo (brain extracted and studied after 1 month in formalin, and after 12 months). The MRI data were collected with a 3 T scanner. Our findings suggest that the segmentation procedure was overall reproducible since only slight statistical differences were detected. In the post mortem/ ex vivo comparison, most structures showed a higher contrast, thereby leading to greater reproducibility between operators. We observed a net increase in the volume of the studied structures. This could be justified by the intrinsic relaxation time changes observed because of the formalin fixation. This led to an improvement in brain structure visualization and segmentation. To conclude, MRI-based segmentation seems to be a useful and accurate tool that allows longitudinal studies on formalin-fixed brains.

A Magnetic Resonance-Relaxometry-Based Technique to Identify Blood Products in Brain Parenchyma: An Experimental Study on a Rabbit Model.

Magnetic resonance relaxometry is a quantitative technique that estimates T1/T2 tissue relaxation times. This has been proven to increase MRI diagnostic accuracy of brain disorders in human medicine. However, literature in the veterinary field is scarce. In this work, a T1 and T2-based relaxometry approach has been developed. The aim is to investigate its performance in characterizing subtle brain lesions obtained with autologous blood injections in rabbits. This study was performed with a low-field scanner, typically present in veterinary clinics. The approach consisted of a semi-automatic hierarchical classification of different regions, selected from a T2 map. The classification was driven according to the relaxometry properties extracted from a set of regions selected by the radiologist to compare the suspected lesion with the healthy parenchyma. Histopathological analyses were performed to estimate the performance of the proposed classifier through receiver operating characteristic curve analyses. The classifier resulted in moderate accuracy in terms of lesion characterization.

Ultrasound Examination of Unilateral Seminoma in a Salernitano Stallion.

An 18-year-old Salernitano stallion developed a progressive enlargement of the left testicle over eight months. An ultrasound evaluation was performed, along with a hormonal profile. A histopathological evaluation of the testis was performed after unilateral orchiectomy. On B-mode ultrasound examination, testicular parenchyma was characterized by the loss of internal structure, with the presence of multiple coalescing, nodular, well-defined and heterogeneous lesions with capsule deformity, appearing with an irregular profile. On dissection, the testicular parenchyma bulged over the cut section, confirming the increase in size. Microscopically, the lesion consisted mainly of large, densely packed, polygonal-to-round-shaped neoplastic cells. Mitotic figures were plentiful and frequently atypical; further microscopic features included apoptosis and necrosis. At immunohistochemistry, the entire neoplasm showed strong and diffuse immunolabeling for vimentin, while CD117-specific immunoreactivity was only observed in scattered clusters of neoplastic cells. Based on the gross, microscopic and IHC findings, a diagnosis of diffuse seminoma was made. Three months later, a follow-up examination showed no evidence of recurrence and the preservation of reproductive abilities. The case presented shows an unusual ultrasonographic pattern for seminoma and the basis of the correlation between the characteristics of the sonoelastographic examination and histological diagnosis.

B-Mode and Contrast Enhanced Ultrasonography Features of Gastric Inflammatory and Neoplastic Diseases in Dogs.

Canine gastric disorders are common in veterinary clinical practice and among these neoplasms require rapid identification and characterization. Standard ultrasound (US) is the imaging modality of choice for gastric wall assessment. The aim of this prospective study is to describe the specific B-mode and contrast enhanced US (CEUS) features of normal, inflammatory, and neoplastic gastric wall in dogs. B-mode US and CEUS of the stomach were performed in anesthetized dogs with or without gastric disorders. Gastric wall qualitative and quantitative parameters were evaluated on B-mode US and CEUS examination. A total of 41 dogs were included: 6 healthy (HEA) as the control group; 9 gastritis (INF); 8 adenocarcinoma (AC); 8 alimentary lymphoma (AL); 4 leiomyosarcoma (LEIS); 2 gastrointestinal stromal tumor (GIST); 2 leiomyoma; 1 undifferentiated sarcoma; 1 metastatic gastric hemangiosarcoma. Gastric tumors appear as a marked wall thickness with absent layers definition and possible regional lymphadenopathy (AC and AL) and steatitis (AC) while gastritis generally shows no/mild thickening and no other alterations on B-mode US. On CEUS, neoplasm shows a higher and faster wash in if compared to that of gastritis. B-mode and CEUS assessment may be useful in the evaluation of canine gastric disorders in the distinction between gastritis and gastric neoplasms, even if there are no specific features able to discriminate between the different tumor histotypes.

Clinical Value of CT-Guided Fine Needle Aspiration and Tissue-Core Biopsy of Thoracic Masses in the Dog and Cat.

Diagnosis of thoracic lesions on the basis of history and physical examination is often challenging. Diagnostic imaging is therefore of paramount importance in this field. Radiology has traditionally been considered the diagnostic procedure of choice for these diseases. Nevertheless, it is often not possible to differentiate inflammatory/infectious lesions from neoplastic diseases. A correct cytological and histopathologic diagnosis is therefore needed for an accurate diagnosis and subsequent prognostic and therapeutic approach. In human medicine, Computed Tomography (CT) and CT-guided biopsy are used in the presence of lesions which are not adequately diagnosed with other procedures. In the present study, thoracic lesions from 52 dogs and 10 cats of different sex, breed and size underwent both CT-guided fine-needle aspiration (FNAB) and tissue-core biopsy (TCB). Clinical examination, hematobiochemical analysis and chest radiography were performed on all animals. In this study, 59 of 62 histopathological samples were diagnostic (95.2%). Cytology was diagnostic in 43 of 62 samples (69.4%). General sensitivity, accuracy and PPV for FNAB and TCB were 67.7%, 67.7% and 100% and 96.7%, 95.2% and 98.3%, respectively. Combining the two techniques, the overall mean accuracy for diagnosis was 98.4%. Nineteen of 62 cases showed complications (30.6%). Mild pneumothorax was seen in 16 cases, whereas mild hemorrhage occurred in three cases. No major complications were encountered. CT-guided FNAB cytology can be considered a useful and reliable technique, especially for small lesions or lesions located close to vital organs and therefore dangerous to biopsy in other way.

Lymphatic Drainage Mapping with Indirect Lymphography for Canine Mammary Tumors.

Mammary gland tumors are the most common canine neoplasms. They account for 25-50% of all tumors diagnosed in bitches. Metastases and recurrences develop in about 35-70% of bitches following excision. The presence of regional lymph node metastases is a relevant factor affecting prognosis and treatment in cases of mammary gland tumors. The sentinel lymph node (SLN) is the first lymph node (or nodes) in the regional lymphatic basin that receives lymphatic flow from the primary neoplasm. The aim of this study is to investigate the SLN with indirect lymphography for a mammary tumor in dogs. The knowledge of the precise drainage pattern and SLN of the neoplastic mammary glands would provide clinically relevant information to the surgeon and to the oncologist, and it would be of high importance for the surgeon not only for performing the most adequate surgical excision but also for determining an accurate post-surgical prognosis.

Sonoelastography of Normal Canine Common Calcaneal Tendon: Preliminary Results.

Shear wave elastography (SWE) is a feasible and newly developed ultrasonographic technique which is able to assess elasticity of tissues. The aim of this work was to assess the feasibility of SWE on the normal canine common calcaneal tendon (CCT) evaluating the intra-operator repeatability and reproducibility of single measurements and stiffness of different anatomic CCT portions was examined. Tendons were first evaluated with B-mode ultrasound with a linear probe 8.5 to 10 MHz in longitudinal section with slight flexed tarsocrural joint and a gel-pad. Common calcaneal tendon was divided into three different anatomical regions. Shear wave elastography was performed in each region by two operators and quantitative evaluation (m/s and kPa) was performed on the most representative images. Region of interest (0.15 cm) was settled. Intraclass correlation coefficient (ICC) results were classified using the following scale: 0.00 to 0.20 = poor; 0.20 to 0.40 = fair; 0.40 to 075 = good; >0.75 = excellent. Ten adult dogs were enrolled. Intra-operator ICC values were >0.75 for both operators in every tendon portion. Inter-operator SWE ICC values for m/s measurements were 0.3, 0.61 and 0.61 for the enthesis, intermediate portion and the myotendinous junction respectively; for kPa measurements, values were respectively 0.3, 0.7 and 0.81. The three CCT portions were significantly different in stiffness (p-value < 0.001 for both m/s and kPa measurements). These preliminary results provide evidence that SWE is potentially appliable to assess mechanical properties of canine CCT affected by tendinopathies.

Triple-Phase Multidetector Computed Tomography in Distinguishing Canine Hepatic Lesions.

The liver has a unique vascular supply, and triple-phase contrast-enhanced computed tomography examinations are being performed in order to characterize liver lesions. This study aimed to look for any associations between the attenuation values of liver lesions and their histological classification. The inclusion criteria for this retrospective study were focal or multifocal liver lesions and histological diagnosis. All of the dogs underwent pre-contrast and triple-phase postcontrast computed tomography (CT) examinations with identical timings of the postcontrast series. Thirty-one dogs were included in the study, and various benign and malignant pathologies were identified. The results did not identify any significant differences between the benign and malignant liver lesions, nor between the individual histological diagnoses. Inflammatory lesions were significantly different compared to the normal liver parenchyma, and significant hypoattenuation was found in the portal and delayed venous phases. Hemangiosarcomas were significantly hypoattenuating to the normal liver parenchyma in the pre-contrast and arterial phases, and also to all of the benign lesions in the arterial phase. The other pathologies showed variable attenuation patterns in the different postcontrast phases, and differentiation was not possible. On the basis of this study, triple-phase contrast-enhanced computed tomography cannot differentiate between benign and malignant liver lesions, and biopsy and further histological analysis are necessary.

B-Mode and Contrast Enhanced Ultrasonography Features of Gastric Inflammatory and Neoplastic Diseases in Cats.

Alimentary lymphoma (AL) is the most common malignancy of the feline gastrointestinal tract and may cause variable mild to severe alteration of the gastric wall on ultrasonography (US) that can be very similar to those caused by inflammation (INF). The aim of this prospective study is to establish the value of B-mode and contrast-enhanced US (CEUS) in describing specific features of normal, inflammatory, and neoplastic gastric diseases in feline species. B-mode US and CEUS of the stomach were performed in anesthetized cats with or without gastric disorders. Gastric wall qualitative and quantitative parameters were evaluated on B-mode US and CEUS examination. A total of 29 cats were included: six healthy (HEA) cats as the control group; nine INF; three low-grade lymphoma (LGAL); 10 high-grade lymphoma (HGAL). On B-mode US, there were significant differences in thickness, the wall's layer definition and echogenicity between HGAL and all the other groups (<0.001). For CEUS, statistical differences between groups were found in the following: HGAL vs. HEA, HGAL vs. INF; HGAL vs. LGAL; INF vs. HEA. Diagnostic accuracy (AUC) and cut-off value were calculated and found to be significant for thickness (3.8 mm) for INF vs. LGAL (AUC > 0.70) and "benign" vs. "malignant" (AUC > 0.90) as well as peak enhancement (34.87 dB) for "benign" vs. "malignant" (AUC > 0.70). INF and LGAL showed an overlap of qualitative and quantitative parameters both on B-mode and CEUS, while HGAL usually appears as a severe wall thickening with absent layer definition, high-contrast uptake, a specific enhancement pattern, regional lymphadenopathy and local steatitis. Thickness and peak enhancement can be useful parameters in the characterization of gastric infiltrates in cats.

Evaluation of the Spirotome Device for Nasal Tumors Biopsy in Eleven Dogs.

This study evaluated the accuracy and diagnostic quality of histological samples obtained with the Spirotome device on biopsies from dogs affected by canine nasal tumors. Eleven dogs were included in this study. The mean age was 10 years. All biopsies were successfully performed within 15 minutes. All dogs showed nasal bleeding after the biopsies, which was quickly managed by applying intranasal compression with sterile cotton swabs. Bleeding stopped within 10 minutes after sampling. All biopsy samples were considered satisfactory by the pathologist, allowing a proper histological assessment.