Contrast-enhanced ultrasound complements two-dimensional ultrasonography in diagnosing gallbladder diseases in dogs.

Gall-bladder diseases are common in dogs and two-dimensional ultrasonography is a current standard method for diagnosis and treatment planning. However, findings from this modality can be nonspecific. The aim of this retrospective, case series study was to describe conventional and contrast-enhanced ultrasound (using SonoVue® ) findings in a group of dogs with histologically confirmed gall bladder disease. A total of 65 dogs were included. Branchlike, heterogeneous, and homogeneous contrast enhancement of echogenic intraluminal mass-forming lesions was a contrast-enhanced ultrasound characteristic of polypoid lesions due to cystic mucosal hyperplasia of the gallbladder and/or tumor, which had different wash-in and washout characteristics. In dogs with mobile or immobile biliary sludge or mucocele, the echogenic intraluminal masses remained unenhanced. A double rim mark or enhancement defect in the gallbladder wall was a characteristic of edema or necrosis/rupture of the wall, respectively. Conventional ultrasonography correctly identified biliary sludge or mucocele in 36/37 dogs, cholecystitis/edema in 44/47 dogs, necrosis/rupture in 19/25 dogs, and gallbladder neoplasia in three of three dogs with these pathologies. It falsely identified biliary sludge or mucocele in eight of 28 dogs, cholecystitis/edema in three of 15 dogs, necrosis/rupture in 13/37 dogs, and gall-bladder neoplasia in 20/59 dogs that did not have these pathologies. Contrast-enhanced ultrasound correctly identified cholecystitis/edema in 42/47 dogs, but falsely identified cholecystitis/edema in three of 18 dogs. It correctly identified necrosis/rupture, benign polypoid lesions, and gallbladder neoplasia in all dogs with no false-positive results. Findings supported contrast-enhanced ultrasound as a complement to conventional ultrasonography for dogs with suspected gallbladder pathologies such as edema, necrosis, and rupture.

EVALUATION OF CONTRAST-ENHANCED ULTRASONOGRAPHY AS A METHOD FOR DETECTING GALLBLADDER NECROSIS OR RUPTURE IN DOGS.

Gall bladder necrosis and rupture are life-threatening conditions in dogs requiring surgical intervention and early diagnosis is essential. Human patients with suspected gall bladder necrosis/rupture are commonly evaluated with contrast-enhanced ultrasonography (CEUS), however this procedure has not been described in dogs with suspected gall bladder necrosis/rupture. In a prospective diagnostic cohort study, CEUS (using SonoVue contrast medium) was performed in 93 dogs with gallbladder lesions identified by abdominal conventional ultrasonography. Necrosis/rupture was identified by CEUS as a focal lack of enhancement of the gallbladder wall. Dogs with positive CEUS finding for necrosis/rupture (complete lack of regional wall enhancement) underwent immediate surgery as did dogs with other biliary disorders requiring surgery. Dogs with negative CEUS findings or those not requiring surgery were managed medically. In cases undergoing surgery, necrosis/rupture was confirmed intraoperatively (and via histopathology). Absence of necrosis/rupture was confirmed either intraoperatively (via histopathology) or was assumed to be absent by complete recovery with medical management. Forty-nine dogs underwent surgery and cholecystectomy: 24 had necrosis/rupture. CEUS was more accurate (100% sensitive and specific) in diagnosing gallbladder wall necrosis/rupture than conventional ultrasonography (75% sensitive and 81% specific) (P < 0.03). In conclusion, CEUS provides accurate characterization of gallbladder wall integrity that can impact decisions regarding clinical management, either surgical or medical.

Contrast-enhanced ultrasonographic characteristics of adrenal glands in dogs with pituitary-dependent hyperadrenocorticism.

A noninvasive method for quantifying adrenal gland vascular patterns could be helpful for improving detection of adrenal gland disease in dogs. The purpose of this retrospective study was to compare the contrast-enhanced ultrasound (CEUS) characteristics of adrenal glands in 18 dogs with pituitary-dependent hyperadrenocorticism (PDH) vs. four clinically healthy dogs. Each dog received a bolus of the contrast agent (SonoVue®, 0.03 ml/kg of body weight) into the cephalic vein, immediately followed by a 5 ml saline flush. Dynamic contrast enhancement was analyzed using time-intensity curves in two regions of interest drawn manually in the caudal part of the adrenal cortex and medulla, respectively. In healthy dogs, contrast enhancement distribution was homogeneous and exhibited increased intensity from the medulla to the cortex. In the washout phase, there was a gradual and homogeneous decrease of enhancement of the adrenal gland. For all dogs with PDH, there was rapid, chaotic, and simultaneous contrast enhancement in both the medulla and cortex. Three distinct perfusion patterns were observed. Peak perfusion intensity was approximately twice as high (P < 0.05) in dogs with PDH compared with that of healthy dogs (28.90 ± 10.36 vs. 48.47 ± 15.28, respectively). In dogs with PDH, adrenal blood flow and blood volume values were approximately two- to fourfold (P < 0.05) greater than those of controls. Findings from the present study support the use of CEUS as a clinical tool for characterizing canine adrenal gland disease based on changes in vascular patterns.

Contrast-enhanced ultrasound features of adrenal lesions in dogs.

BACKGROUND: The contrast-enhanced ultrasound (CEUS) features of adrenal lesions are poorly reported in veterinary literature. METHODS: Qualitative and quantitative B-mode ultrasound and CEUS features of 186 benign (adenoma) and malignant (adenocarcinoma and pheochromocytoma) adrenal lesions were evaluated. RESULTS: Adenocarcinomas (n = 72) and pheochromocytomas (n = 32) had mixed echogenicity with B-mode, and a non-homogeneous aspect with a diffused or peripheral enhancement pattern, hypoperfused areas, intralesional microcirculation and non-homogeneous wash-out with CEUS. Adenomas (n = 82) had mixed echogenicity, isoechogenicity or hypoechogenicity with B-mode, and a homogeneous or non-homogeneous aspect with a diffused enhancement pattern, hypoperfused areas, intralesional microcirculation and homogeneous wash-out with CEUS. With CEUS, a non-homogeneous aspect and the presence of hypoperfused areas and intralesional microcirculation can be used to distinguish between malignant (adenocarcinoma and pheochromocytoma) and benign (adenoma) adrenal lesions. LIMITATIONS: Lesions were characterised only by means of cytology. CONCLUSIONS: CEUS examination is a valuable tool for distinction between benign and malignant adrenal lesions and can potentially differentiate pheochromocytomas from adenocarcinomas and adenomas. However, cytology and histology are necessary to obtain the final diagnosis.

Contrast-Enhanced Ultrasonography (CEUS) in Imaging of the Reproductive System in Dogs: A Literature Review.

The use of contrast-enhanced ultrasound (CEUS) has been widely reported for reproductive imaging in humans and animals. This review aims to analyze the utility of CEUS in characterizing canine reproductive physiology and pathologies. In September 2022, a search for articles about CEUS in canine testicles, prostate, uterus, placenta, and mammary glands was conducted on PubMed and Scopus from 1990 to 2022, showing 36 total results. CEUS differentiated testicular abnormalities and neoplastic lesions, but it could not characterize tumors. In prostatic diseases, CEUS in dogs was widely studied in animal models for prostatic cancer treatment. In veterinary medicine, this diagnostic tool could distinguish prostatic adenocarcinomas. In ovaries, CEUS differentiated the follicular phases. In CEH-pyometra syndrome, it showed a different enhancement between endometrium and cysts, and highlighted angiogenesis. CEUS was shown to be safe in pregnant dogs and was able to assess normal and abnormal fetal-maternal blood flow and placental dysfunction. In normal mammary glands, CEUS showed vascularization only in diestrus, with differences between mammary glands. CEUS was not specific for neoplastic versus non-neoplastic masses and for benign tumors, except for complex carcinomas and neoplastic vascularization. Works on CEUS showed its usefulness in a wide spectrum of pathologies of this non-invasive, reliable diagnostic procedure.

Characterization of Testicular Tumor Lesions in Dogs by Different Ultrasound Techniques.

In this retrospective study, we assessed the accuracy of different blood flow imaging in diagnosing testicular tumor types in dogs. We recruited 27 dogs with leydigomas (14), seminomas (eight), sertoliomas (six), and mixed cells (five) confirmed histopathologically. In intact dogs, Pampiniform plexus and marginal arteries were scanned through pulsed Doppler. Blood flow and presence of intralesional/perilesional arteries were assessed by color and power Doppler, B-flow, and contrast-enhanced ultrasound. Tumor types did not differ by B-Mode ultrasonography characters. Pampiniform and testicular arteries of sertoliomas had higher (p < 0.05) pulsatility and resistive indexes. The proportion of leydigomas with a perilesional and/or perilesional/intralesional blood flow pattern detected by color and pulsed Doppler and B-flow was higher (p < 0.05) than that of the other tumors counted together. This resulted in a sensitivity of 81.8%, 83.3%, and 85.7%, a specificity of 76.5%, 56.3%, and 73.7%, and a correct classification rate of 78.6%, 67.9%, and 78.8%, respectively. While contrast enhanced ultrasound was highly effective in detecting all tumors, qualitative and quantitative parameters did not contribute to their differential diagnosis. In conclusion, results indicate that different testicular tumor types of dogs have subtly different vascular patterns, a condition that could help in identifying leydigomas.

Contrast-enhanced ultrasound features of focal pancreatic lesions in dogs.

BACKGROUND: Contrast-enhanced ultrasound (CEUS) features of pancreatic lesions are poorly reported in veterinary literature. METHODS: Qualitative and quantitative features of pancreatic benign (nodular hyperplasia [NH], cyst and abscess) and malignant (adenocarcinoma and insulinoma) lesions during B-mode and CEUS examinations are described in 75 dogs. RESULTS: Adenocarcinomas (n = 23) had mixed echogenicity at B-mode, and they were hypoenhancing or non-enhancing at CEUS, with a non-homogeneous and cystic enhancement pattern. Insulinomas (n = 23) appeared as hypoechoic lesions at B-mode, and as hyperenhancing, homogeneous and solid lesions at CEUS. NH (n = 17) had an constant appearance, being hypoechoic at ultrasound (US) and isoenhancing at CEUS. Cysts (n = 7) were all anechoic, with acoustic enhancement clearly detectable at US, but were non-enhancing at CEUS. Lastly, abscesses (n = 5) had mixed echogenicity, and they showed both hyperenhancement and non-enhancement at CEUS. Hypoenhancement and non-homogeneous appearance had a moderate diagnostic accuracy in the detection of adenocarcinomas. In particular, hyperenhancement was evident only in malignant lesions (adenocarcinomas and insulinomas). CONCLUSION: CEUS, in combination with B-mode US features, is a valuable tool for distinction of benign and malignant abnormalities of the pancreas and can potentially differentiate insulinomas from adenocarcinomas.

Contrast-enhanced ultrasound features of focal pancreatic lesions in cats.

A large overlap in the ultrasound (US) features of focal pancreatic lesions (FPLs) in cats is reported. Furthermore, only a small number of studies describing the contrast-enhanced ultrasound (CEUS) features of FPLs in cats have been conducted today. The aim of this study is to describe the B-mode US and CEUS features of FPLs in cats. Ninety-eight cats cytologically diagnosed with FPL were included. The lesions were classified as adenocarcinoma (n = 40), lymphoma (n = 11), nodular hyperplasia (n = 17), other benign lesion (OBL) (n = 20), cyst (n = 4) or other malignant lesion (OML) (n = 6). Several qualitative and quantitative B-mode and CEUS features were described in each case. OMLs and cysts were not included in the statistical analysis. A decision tree to classify the lesions based on their B-mode and CEUS features was developed. The overall accuracy of the cross-validation of the decision tree was 0.74 (95% CI: 0.63-0.83). The developed decision tree had a very high sensitivity and specificity for nodular hyperplasia (1 and 0.94, respectively) as well as good sensitivity and specificity for both adenocarcinomas (0.85 and 0.77, respectively) and OBLs also (0.70 and 0.93, respectively). The algorithm was unable to detect any specific feature for classifying lymphomas, and almost all the lymphomas were classified as adenocarcinomas. The combination between CEUS and B-mode US is very accurate in the classification of some FPLs, especially nodular hyperplasia and adenocarcinomas. Cytopathology and or histopathology is still a fundamental step FPL diagnostic workflow.

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.

Contrast-enhanced ultrasound features of malignant focal liver masses in dogs.

A total of 185 cases (150 retrospectively and 35 prospectively) of malignant liver masses were collected. In the retrospectively collected cases hyperenhancement during wash-in was the most common feature in HCCs but there was a high percentage of cases showing no enhancement or hypo/isoenhancement. ICCs displayed a large variety of contrast enhancement patterns and, although statically significant differences between ICCs and HCCs were evident, no clear distinction between these two pathologies was possible based only on their CEUS appearance. Sarcomas displayed all the possible degrees of wash-in enhancement with non-enhancing being the most common appearance. Metastases displayed all the possible contrast-enhancement patterns, with the most common being hyperenhancement in the wash-in phase followed by hypoenhancement in the wash-out phase. A decision tree was developed based on the features of the retrospectively selected cases. Based on the developed decision tree 27/35 prospectively collected cases were correctly classified. Even if some significant differences among groups were evident, all the histotypes displayed all the possible patterns of contrast enhancement, and, therefore, the differentiation of liver masses in dogs based only on their CEUS features is not feasible and, therefore, cytology or histopathology is required.

Contrast-enhanced ultrasonography features of hepatobiliary neoplasms in cats.

BACKGROUND: Contrast-enhanced ultrasonography (CEUS) features of primary hepatobiliary neoplasms have been reported in dogs but no information is available in cats. METHODS: Qualitative and quantitative features of bile duct adenomas (BDAs, n=20), bile duct carcinomas (BDCs, n=16), and hepatocellular carcinomas (HCCs, n=8) are described in 44 cats. RESULTS: There was an overlap in CEUS qualitative features between different histotypes, both in wash-in and wash-out phases. Distinction between different neoplasms based only on the CEUS qualitative features was not possible. At peak of enhancement, the BDAs, BDCs and HCCs showed a large range of echogenicities, from hypoenhancement to hyperenhancement, in comparison to the liver parenchyma. Eight of 20 BDAs showed inhomogeneous hyperenhancement during wash-in, which is a feature reported as typical of malignant lesions in dogs. BDC had a significantly faster wash-in compared with both BDA and HCC but the diagnostic accuracy of all the included quantitative variables was only moderate. No significant differences in the wash-out quantitative features of BDA and BDC were evident. CONCLUSION: There is poor evidence that CEUS may be used to distinguish between different primary hepatobiliary neoplasms in cats.

Contrast-enhanced ultrasound features of hepatocellular carcinoma in dogs.

BACKGROUND: This study aimed to describe the contrast-enhanced ultrasound (CEUS) features of canine hepatocellular carcinoma (HCC) in relation to cellular differentiation and lesion size. METHODS: Sixty dogs with a cytological diagnosis of HCC and that underwent a CEUS examination were retrospectively selected. The wash-in and wash-out patterns of contrast enhancement, along with the time to wash-in and the time to wash-out, of each lesion were recorded. A dimensional cut-off value of 3 cm was adopted for classification. RESULTS: Cellular differentiation had a significant influence on both wash-in (chi-squared=16.99; P<0.001) and wash-out (chi-squared=10.9; P=0.004) patterns of contrast enhancement. Lesion size had a lower, but still significant, influence on both wash-in (chi-squared=12.7; P=0.005) and wash-out (chi-squared=7.42; P=0.024) patterns. A homogeneous hyperenhancement in the arterial phase followed by homogeneous wash-out were suggestive of a well-differentiated HCC. The cellular differentiation of lesions with inhomogeneous hyperenhancement or hypoenhancement/no enhancement as well as an inhomogeneous wash-out or no wash-out could not be inferred. CONCLUSIONS: No significant difference in the time to wash-in and the time to wash-out in relation to cellular differentiation or lesion size was evident. CEUS has the potential to improve efficiency in the diagnosis of HCCs in dogs.

Contrast-enhanced ultrasonography of maternal and fetal blood flows in pregnant bitches.

We evaluated the potential usefulness of CEUS to assess fetal-maternal circulation during pregnancy in dogs. Nine bitches were examined at 23, 30, and 45 days of gestation using an ultrasound machine (LOGIQ E9) and SonoVue® contrast media as echo-signal enhancer. Qualitative and quantitative evaluation of contrast enhancement patterns of uterine artery and utero/placental vessels were performed on recorded images. Independently of the gestational periods, the qualitative evaluation showed the initial wash-in phase from the first appearance of the uterine artery to the rapid distribution in embryonic vesicles or placenta to the progressive washout, whilst there was no enhancement of either embryos or fetuses in any bitch. Independent of gestational age, parameters derived from quantitative analysis of time intensity-curves of contrast enhancement (peak intensity, time to peak, rise time, washout) did not vary between proximal placenta, distal placenta, and uterine artery. With the progression of gestation, AUC values did not change in both proximal and distal placenta, but in the uterine artery it was lower (P ≤ 0.05) at day 30 than at day 23 (464.8 ±â€¯16.1 vs.596.4 ±â€¯28.1, respectively). In conclusion, CEUS appears to safely permit evaluation of the maternal and fetal vessels in the first two third of gestation, without any clinically relevant adverse effects. Further studies in a larger number of bitches in different stages of pregnancy are needed to establish standard parameters for normal pregnancies that can be used to detect abnormalities of pregnancy.

Use of Contrast-Enhanced Ultrasound in the Differential Diagnosis of Adrenal Tumors in Dogs.

We evaluated the diagnostic accuracy of the contrast-enhanced ultrasonography (CEUS), using a second-generation microbubble contrast agent, in differentiating the different types of adrenal mass lesions in 24 dogs. At B-mode ultrasound, 9 lesions involved the right adrenal gland, 14 the left, and 1 was bilateral. Each dog received a bolus of the contrast agent into the cephalic vein, immediately followed by a 5-mL saline flush. The first contrast enhancement of each adrenal lesion was evaluated qualitatively to assess the degree of enhancement and its distribution during the wash-in and wash-out phases, as well as the presence of non-vascularized areas and specific vascular patterns. Pathological diagnoses were determined in all dogs by histopathology or by cytology. Combining enhancement degree and vascularity resulted in the best predictive model, allowing CEUS to differentiate adrenocortical adenoma (n=10), adenocarcinoma (n=7), and pheochromocytoma (n=7) with an accuracy of 91.7% (P < 0.001). Combining enhancement degree and vascularity, CEUS can discriminate malignant versus benign adrenal lesions with a sensitivity of 100.0%, a specificity of 80.0%, and an accuracy of 91.7% (P < 0.001). In conclusion, results of this study confirm that CEUS is useful for differentiating between the different types of adrenal tumors in dogs.

Contrast-enhanced ultrasonographic characteristics of the diseased canine prostate gland.

The work was carried out on a total of 26 male dogs that on the basis of clinical examination, prostate ultrasound and prostate biopsy, were divided prospectively into four groups: (1) normal dogs (control group; n = 8); (2) dogs with benign prostatic hyperplasia (group BPH; n = 8); (3) dogs suffering from prostatitis (group prostatitis; n = 4); (4) dogs with prostatic tumors (group tumors; n = 6). The examination of the prostate by means of contrast medium and dedicated ultrasound system allowed a detailed qualitative and quantitative analysis of prostatic vessels in normal and diseased conditions, enabling the detection and characterization of different disease states, and quantification of parameters such as peak intensity of perfusion (%), arrival time of the contrast medium to its maximum value of video intensity (time to peak [TTP; seconds]), regional blood volume, regional blood flow, and mean transit time (MTT [seconds]). The hemodynamic indices TTP (P < 0.01) and MTT (P < 0.001) of diseased prostate groups were significantly lower than those in the normal prostate group although there were no differences among diseases. Optimal cutoff values were 31 seconds (Sensitivity: 72%; Specificity: 88%) and 47 seconds (Sensitivity: 100%; Specificity: 88%) while area under receiver operating characteristic curves were 0.86 (P < 0.01) and 0.97 (P < 0.01) for TTP and MTT, respectively. The qualitative evaluation of vascular patterns showed differences between normal and diseased prostate glands. The latter were characterized by an alteration of the normal vascular appearance consisting of loss of the subcapsular arterioles and lack of a centripetal vascular pattern. The qualitative aspect of the study highlighted the different vascular architecture between BPH, prostatitis, adenocarcinoma, and lymphoma. This study shows how contrast-enhanced ultrasound represents a valid and noninvasive method for highlighting and characterizing prostatic vasculature. Furthermore, it allows the operator to obtain qualitative and quantitative data that are useful for the diagnosis of selected prostatic diseases. In conclusion, contrast-enhanced ultrasound can be a valuable noninvasive diagnostic tool to improve the diagnostic accuracy of prostate diseases in the dog.