Sonographic Evaluation of Medial Iliac Lymph Nodes-to-Aorta Ratio in Dogs

Ultrasonographic measurement of the prostatic dimension-to-aortic luminal diameter in healthy intact male dogs and dogs with benign prostatic hyperplasia

OBJECTIVES

To establish ultrasonographic measurements of the prostatic dimension-to-aortic luminal diameter ratios including the prostatic volume-to-aortic luminal diameter ratio in healthy, intact male dogs and compare these ratios between healthy dogs and dogs affected by benign prostatic hyperplasia.

MATERIALS AND METHODS

Healthy dogs (n = 75) and dogs affected by benign prostatic hyperplasia (n = 104) were included in the study. Prostate length, width, average height and aortic luminal diameter were measured from ultrasonographic images. In addition, prostatic volume was calculated, and prostatic volume-to-aortic luminal diameter were also compared.

RESULTS

In healthy dogs, aortic luminal diameter was significantly associated with bodyweight and the prostatic width while body condition scores, prostate length and prostatic average height were not associated. Prostatic dimension-to-aortic luminal diameter ratios and prostatic volume-to-aortic luminal diameter ratio was not significantly different among dogs with different body condition scores either in healthy dogs or dogs affected by benign prostatic hyperplasia, except prostatic volume-to-aortic luminal diameter ratio in benign prostatic hyperplasia. Prostatic dimension-to-aortic luminal diameter ratios were significantly higher in benign prostatic hyperplasia while prostatic volume-to-aortic luminal diameter ratio significantly higher in healthy dogs. Prostatic dimension-to-aortic luminal diameter ratios demonstrated medium to high sensitivity and specificity when distinguishing between healthy dogs and dogs affected by benign prostatic hyperplasia. Prostatomegaly, should be considered when the prostatic dimension-to-aortic luminal diameter ratios increase. The calculated cut-off values were 3.68, 4.46 and 3.06 for prostate length-to-aortic luminal diameter, prostatic width- to-aortic luminal diameter and prostatic average height-to-aortic luminal diameter, respectively.

CLINICAL SIGNIFICANCE

The prostatic dimension-to-aortic luminal diameter ratios could be useful to evaluate the size of the prostate in dogs, as it is unaffected by the body condition scores.

Digital postprocessing analysis of prostatic perfusion in neutered dogs

B-mode ultrasound is routinely performed to evaluate the prostate gland in neutered dogs, although, the detection of malignancies may be challenging. Contrast-enhanced ultrasound (CEUS) has shown to be useful for the assessment of prostatic perfusion in normal and diseased dogs, although the interpretation of contrast ultrasonographic features may still be subjective. A quantitative tool for evaluating prostatic perfusion might improve the reliability of the results in terms of early detection of prostate neoplasia in neutered dogs. The present study aimed to evaluate the applicability of a postprocessing analysis tool to CEUS of the prostate in healthy neutered dogs, to provide quantitative measurements, and to study the influence of individual characteristics on prostatic regression. Twenty-three neutered dogs underwent a B-mode and CEUS examination of the prostate to acquire data about prostatic morphology and microcirculation. The prostate was imaged using a 5-7.5 MHz linear transducer and contrast was administered intravenously. Videoclips were analyzed by using Qontrast software and a postprocessing digital analysis tool (ImageJ) to measure perfusion peak intensity, time to peak, and vascularization ratio at the moment of the peak, which were then related to body weight, age, and time elapsed since orchiectomy. Correlation tests revealed higher vascularization in younger compared with older dogs (P < .05) and in smaller compared with larger dogs (P < .05). Time elapsed since orchiectomy (P > .05) did not affect prostatic perfusion. Contrast-enhanced ultrasound and the postprocessing analysis tool ImageJ allowed analysis of vascular perfusion in all dogs and have the potential to improve the diagnostic possibilities for andrological examination.

The use of ultrasonographic adrenal dimensions and the adrenal dimension-to-aorta ratio in the diagnosis of benign and malignant adrenal diseases in dogs

Background and Aim

Ultrasound (US) is a useful tool for detecting adrenal abnormalities. However, a definite reference range differentiating normal and diseased adrenal glands in dogs of varying body sizes is still lacking. The organ dimension-to-aorta (Ao) ratio of the dogs is correlated with their body weight (BW). Therefore, this study aimed to investigate the adrenal dimensions, including adrenal pole thickness and adrenal length, as well as the adrenal dimension-to-Ao ratio, to differentiate between dogs with normal, benign lesions such as pituitary-dependent hyperadrenocorticism (PDH) and malignant invasive adrenal tumors.

Materials and Methods

The medical records and US images of 39 dogs that were either normal (normal) (n = 15) or affected by PDH (n = 15) or malignant invasive adrenal tumors (tumor) (n = 9) were retrieved in this study. All the dogs had a transabdominal US on the sagittal plane. The adrenal dimensions and luminal Ao diameter at the peak of the systolic phase were recorded. The average adrenal dimensions, including the adrenal dimension-to-Ao ratio, were compared among the groups.

Results

Most of the dogs in each group were small-breed dogs with comparable ages, BW, and Ao values. Both adrenal dimensions and the adrenal dimension-to-Ao ratio were significantly lower in the normal group than in the PDH and tumor groups. To differentiate the PDH group from the tumor group, adrenal dimensions of pole thickness and length were more appropriate than the adrenal dimension-to-Ao ratio.

Conclusion

Adrenal dimensions and the adrenal dimension-to-Ao ratio can be used to diagnose adrenal diseases. However, in small-breed dogs, adrenal dimensions are suitable for differentiating PDH from tumor groups. Further research is required with a larger sample size and a wider range of canine body sizes.

Canine anal sac gland carcinoma with regional lymph node metastases treated with sacculectomy and lymphadenectomy: Outcome and possible prognostic factors

The staging system commonly used in canine anal sac gland carcinoma (ASGC) is a revised Tumour-Node-Metastasis (TNM) system published in 2007. This staging system consists in four stages and, for dogs with nodal metastases, the size of the metastatic lymph node (mLN) defines the N stage. However, we hypothesise that (1) the mLN size has no prognostic significance when the mLN can be excised, (2) a high number of mLNs is associated with poorer prognosis and (3) the measurement of the mLN on imaging is not reproducible. To investigate these hypotheses, medical records and diagnostic images of dogs with ASGC and mLN, treated with sacculectomy and lymphadenectomy, with or without chemotherapy, were reviewed. Interobserver variability for mLN measurement was assessed. Prognostic factors including mLN size and number were investigated. Time to documented progression (TDP) and disease-specific survival (DSS) were evaluated. Progression-free interval (PFI) was analysed with interval-censored data analysis. Fifty-seven dogs were included. The median PFI, TDP and DSS were 110 (95%CI 61.5-185.5), 196 (95%CI 162-283) and 340 days (95%CI 321-471), respectively. For measurement of the largest mLN, interobserver agreement was excellent but limits of agreement reached 39.7%. Neither the size of the largest mLN nor the use of adjuvant chemotherapy were associated with outcome. The number of mLNs was associated with outcome and having more than four mLNs was associated with shorter PFI (p < .001), TDP (p = .004) and DSS (p < .001). While mLN size measurement was not consistently reproducible and did not influence outcome in our cohort, number of mLNs did. Further studies are required for development of a revised staging system.