Ingeborgh Polis

Ghent University, Gand, Flemish, Belgium

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Publications (127)149.55 Total impact

  • [Show abstract] [Hide abstract] ABSTRACT: Metronomic chemotherapy stimulates the immune response via depletion of regulatory T cells (Tregs) and suppresses angiogenesis by modulating the secretion of thrombospondin-1 (TSP-1) and vascular endothelial growth factor (VEGF). In this study, blood was collected from 10 healthy dogs and from 30 canine cancer patients before and 2 and 4 weeks after treatment with metronomic temozolomide (6.6 mg m(-2) ), cyclophosphamide (12.5 mg m(-2) ) or cyclophosphamide and temozolomide. The percentage of circulating CD25(+) Foxp3(+) CD4(+) Tregs and the plasma levels of TSP-1 and VEGF were measured. There was a significant difference in the percentage of Tregs between cancer patients and healthy dogs. A significant decrease in Tregs was noted in patients treated with metronomic cyclophosphamide and the combination. Treatment with temozolomide had no effect on the percentage of Tregs. TSP-1 and VEGF levels were, respectively, significantly lower and higher in cancer patients than in healthy dogs, but they were not influenced by any of the studied metronomic treatment regimens.
    No preview · Article · Mar 2016 · Veterinary and Comparative Oncology
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    Full-text · Dataset · Feb 2016
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    [Show abstract] [Hide abstract] ABSTRACT: This first-in-dog study evaluates the use of the PET-radioligand [11C]DASB to image the density and availability of the serotonin transporter (SERT) in the canine brain. Imaging the serotonergic system could improve diagnosis and therapy of multiple canine behavioural disorders. Furthermore, as many similarities are reported between several human neuropsychiatric conditions and naturally occurring canine behavioural disorders, making this tracer available for use in dogs also provide researchers an interesting non-primate animal model to investigate human disorders. Five adult beagles underwent a 90 minutes dynamic PET scan and arterial whole blood was sampled throughout the scan. For each ROI, the distribution volume (VT), obtained via the one- and two- tissue compartment model (1-TC, 2-TC) and the Logan Plot, was calculated and the goodness-of-fit was evaluated by the Akaike Information Criterion (AIC). For the preferred compartmental model BPND values were estimated and compared with those derived by four reference tissue models: 4-parameter RTM, SRTM2, MRTM2 and the Logan reference tissue model. The 2-TC model indicated in 61% of the ROIs a better fit compared to the 1-TC model. The Logan plot produced almost identical VT values and can be used as an alternative. Compared with the 2-TC model, all investigated reference tissue models showed high correlations but small underestimations of the BPND-parameter. The highest correlation was achieved with the Logan reference tissue model (Y = 0.9266 x + 0.0257; R2 = 0.9722). Therefore, this model can be put forward as a non-invasive standard model for future PET-experiments with [11C]DASB in dogs.
    Full-text · Article · Feb 2016 · PLoS ONE
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    [Show abstract] [Hide abstract] ABSTRACT: Objective To describe a modified implantation procedure of a vagus nerve stimulation (VNS) device in dogs and to report short- and long-term complications. Study DesignDescriptive, experimental study. AnimalsHealthy, adult Beagle dogs (n=10). MethodsA VNS Therapy((R)) System was implanted in the left cervical region of anesthetized dogs. During and within 48hours after surgery, electrocardiography (ECG) and impedance testing of the system were performed. Dogs were monitored daily and the impedance of the system was determined regularly until VNS devices were surgically removed 3 years after implantation. ResultsThe implantation procedure was successful in all dogs without intraoperative complications. ECG monitoring and impedance tests were within normal limits during and within 48hours after surgery. Postoperative seroma formation was common (70%). One dog developed an irreversible Horner's syndrome leading to removal of the device 5 months after implantation. Another dog developed trauma-induced damage of the lead requiring surgical revision. The device could be safely removed in all dogs; however, electrodes were left in place to avoid nerve damage. At removal, the anchor tether was dislodged in 40% of dogs and the lead was twisted in 50% of dogs. Conclusion Implantation of a VNS Therapy((R)) System is safe and feasible in dogs; however, seroma formation, twisting of the lead, and dislodgement of the anchor tether were common. Practical improvements in the technique include stable device placement, use of a compression bandage, and exercise restriction. Regular evaluation of lead impedance is important, as altered values can indicate serious complications.
    Full-text · Article · Jan 2016 · Veterinary Surgery
  • [Show abstract] [Hide abstract] ABSTRACT: Two male Golden retrievers, each one about ten years old, were presented with a visible mass in the nose, showing symptoms of sneezing and epistaxis. The histopathological examination of biopsies indicated that both dogs were affected by a squamous cell carcinoma. Further staging did not reveal any indications for metastases. Surgical removal of the tumor through a planectomy or nosectomy was proposed. Since the classical removal of the nose was cosmetically unacceptable for the owners of both dogs, a rostral nose reconstruction was opted for in both cases. As the tumor in the first dog was rather superficial, resection of the cartilaginous part of the nose (planectomy) turned out to be sufficient. In the second dog however, there was also evidence of bony involvement. Therefore, not only the nose but also the os incisiva was removed (nosectomy). In both cases, remission of the tumor was obtained after a 35 and 29 months follow-up, respectively, accompanied by an excellent cosmetic result.
    No preview · Article · Jan 2016
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    [Show abstract] [Hide abstract] ABSTRACT: [ 11 C]-3-amino-4-(2-dimethylaminomethyl-phenylsulfanyl)-benzonitrile ([ 11 C]DASB) is currently the mostly used radiotracer for positron emission tomography (PET) quantitative studies of the serotonin transporter (SERT) in the human brain but has never been validated in dogs. The first objective was therefore to evaluate normal [ 11 C]DASB distribution in different brain regions of healthy dogs using PET. The second objective was to provide less invasive and more convenient alternative methods to the arterial sampling-based kinetic analysis. A dynamic acquisition of the brain was performed during 90 min. The PET images were coregistered with the magnetic resonance images taken prior to the study in order to manually drawn 20 regions of interest (ROIs). The highest radioactivity concentration of [ 11 C]DASB was observed in the hypothalamus, raphe nuclei and thalamus and lowest levels in the parietal cortex, occipital cortex and cerebellum. The regional radioactivity in those 20 ROIs was quantified using the multilinear reference tissue model 2 (MRTM2) and a semi-quantitative method. The values showed least variability between 40 and 60 min and this time interval was set as the optimal time interval for [ 11 C]DASB quantification in the canine brain. The correlation (R 2 ) between the MRTM2 and the semi-quantitative method using the data between 40 and 60 min was 99.3 % (two-tailed p-value < 0.01). The reference tissue models and semi-quantitative method provide a more convenient alternative to invasive arterial sampling models in the evaluation of the SERT of the normal canine brain. The optimal time interval for static scanning is set at 40 to 60 min after tracer injection.
    Full-text · Article · Dec 2015 · BMC Veterinary Research
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    [Show abstract] [Hide abstract] ABSTRACT: Cell-penetrating peptides (CPPs) are a group of peptides, which have the ability to cross cell membrane bilayers. CPPs themselves can exert biological activity and can be formed endogenously. Fragmentary studies demonstrate their ability to enhance transport of different cargoes across the blood-brain barrier (BBB). However, comparative, quantitative data on the BBB permeability of different CPPs are currently lacking. Therefore, the in vivo BBB transport characteristics of five chemically diverse CPPs, i.e. pVEC, SynB3, Tat 47–57, transportan 10 (TP10) and TP10-2, were determined. The results of the multiple time regression (MTR) analysis revealed that CPPs show divergent BBB influx properties: Tat 47–57, SynB3, and especially pVEC showed very high unidirectional influx rates of 4.73 μl/ (g × min), 5.63 μl/(g × min) and 6.02 μl/(g × min), respectively, while the transportan analogs showed a negligible to low brain influx. Using capillary depletion, it was found that 80% of the influxed peptides effectively reached the brain parenchyma. Except for pVEC, all pep-tides showed a significant efflux out of the brain. Co-injection of pVEC with radioiodinated bovine serum albumin (BSA) did not enhance the brain influx of radiodionated BSA, indicating that pVEC does not itself significantly alter the BBB properties. A saturable mechanism could not be demonstrated by co-injecting an excess dose of non-radiolabeled CPP. No significant regional differences in brain influx were observed, with the exception for pVEC, for which the regional variations were only marginal. The observed BBB influx transport properties cannot be correlated with their cell-penetrating ability, and therefore, good CPP properties do not imply efficient brain influx.
    Full-text · Article · Oct 2015 · PLoS ONE
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    [Show abstract] [Hide abstract] ABSTRACT: ABSTRACT In this study, female canines referred with clinical signs consistent with pyometra were prospectively evaluated. Signalment, clinical signs, laboratory findings and surgical findings were compared between dogs with and without bacterial isolation based on aerobic techniques. Patients with positive bacterial isolation were placed in the pyometra group, whereas patients with negative bacterial isolation were grouped as mucometra. A total of 140 dogs (118 with pyometra and 22 with mucometra) met the inclusion criteria. Prereferral antibiotic administration was associated with a prolonged duration of clinical signs in the patients of the pyometra group (12 ± 2 days versus 7 ± 1 days; P=0.006). In the pyo-metra patients, clinical signs, like pyrexia, anorexia and discomfort on abdominal palpation, were observed more commonly than in the mucometra group. The total leukocyte count was the only parameter that differed significantly between the two groups (P=0.01). Although no difference in color and consistency of the uterine fluid was noted, the uteri of the pyometra group were heavier (851.80 ± 800.30 g compared to 263.50 ± 297.10 g). E. coli was the most commonly isolated bacterium (92/123). SAMENVATTING In deze studie werden vrouwelijke honden met klinische klachten verenigbaar met pyometra prospectief geëvalueerd. Het signalement, de klinische symptomen, laboratoriumresultaten en chirur-gische bevindingen werden vergeleken tussen honden met en zonder bacteriële isolatie op basis van aërobe technieken. Patiënten met een positieve bacteriële isolatie werden in de pyometragroep ge-klasseerd, terwijl patiënten met een negatieve bacteriële isolatie als honden met mucometra werden gegroepeerd. Honderdveertig honden (118 met pyometra en 22 met mucometra) voldeden aan de in-clusiecriteria. De toediening van een antibioticum vooraleer door te verwijzen was geassocieerd met verlengde klinische symptomen bij de patiënten van de pyometragroep (12 ± 2 dagen versus 7 ± 1 dagen; P = 0,006). Bij de pyometrapatiënten werden klinische symptomen, zoals koorts, anorexia en ongemak bij abdominale palpatie vaker waargenomen dan bij de mucometrapatiënten. Het totale aantal leukocyten was de enige parameter die significant verschilde (P=0,01). Hoewel er tussen de twee groepen geen verschil in kleur en consistentie van de baarmoedervloeistof werd opgemerkt, was de baarmoeder van de honden met pyometra zwaarder dan bij de honden met mucometra (851,80 ± 800,30 g versus 263,50 ± 297,10 g). E. coli was de vaakst geïsoleerde bacterie (92/123).
    Full-text · Article · Sep 2015 · Vlaams Diergeneeskundig Tijdschrift
  • [Show abstract] [Hide abstract] ABSTRACT: Syringomyelia (SM) is defined as the presence of fluid-containing cavities within the parenchyma of the spinal cord. Sagittal magnetic resonance (MR) images have been described as the preferred technique for visualizing SM in dogs and humans. To investigate whether computed tomography (CT) can be used to diagnose SM. Thirty-two client-owned dogs referred for investigation of the cervical spine on magnetic resonance imaging (MRI) and CT. Two reviewers retrospectively analyzed sagittal and transverse T1-weighted spin echo (T1WSE) MR images and CT images from each dog for the presence of SM and, if SM was present, the width (mm, syrinx width [SW]) was measured. The results were analyzed statistically. For the presence of SM there was a moderate interobserver agreement for MR (81%, κ = 0.54) and almost perfect agreement for CT (94%, κ = 0.87). There was a moderate intramodality agreement for both observers (observer 1 81%, κ = 0.59; observer 2 81%, κ = 0.57). For measurement of SW the repeatability was the best on the midsagittal T1WSE images (95% repeatability coefficient <0.52 mm) and the reproducibility was the best on midsagittal images in both modalities (95% limits of agreement -0.55-0.45; P = 0.002). Both techniques can be used to detect SM. Midsagittal MR and CT images are best used for measuring SW. Computed tomography can be used as a diagnostic tool for SM when MRI is not available, but CT cannot replace MRI as the standard screening technique for the detection of SM in Cavalier King Charles Spaniel for breeding purposes. Copyright © 2015 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.
    No preview · Article · Aug 2015 · Journal of Veterinary Internal Medicine
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    Full-text · Dataset · Jul 2015
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    [Show abstract] [Hide abstract] ABSTRACT: In this study, female canines referred with clinical signs consistent with pyometra were prospectively evaluated. Signalment, clinical signs, laboratory findings and surgical findings were compared between dogs with and without bacterial isolation based on aerobic techniques. Patients with positive bacterial isolation were placed in the pyometra group, whereas patients with negative bacterial isolation were grouped as mucometra. A total of 140 dogs (118 with pyometra and 22 with mucometra) met the inclusion criteria. Prereferral antibiotic administration was associated with a prolonged duration of clinical signs in the patients of the pyometra group (12 +/- 2 days versus 7 +/- 1 days; P=0.006). In the pyometra patients, clinical signs, like pyrexia, anorexia and discomfort on abdominal palpation, were observed more commonly than in the mucometra group. The total leukocyte count was the only parameter that differed significantly between the two groups (P=0.01). Although no difference in color and consistency of the uterine fluid was noted, the uteri of the pyometra group were heavier (851.80 +/- 800.30 g compared to 263.50 +/- 297.10 g). E. coil was the most commonly isolated bacterium (92/123).
    Full-text · Article · Jul 2015 · Vlaams Diergeneeskundig Tijdschrift
  • [Show abstract] [Hide abstract] ABSTRACT: The aim of this study was to investigate the effect of epinephrine-enhanced computed tomographic arthrography (CTA) on the image sharpness of the lateral and medial glenohumeral ligaments (LGHL and MGHL, respectively), biceps tendon (BT) and joint cartilage (JC) in the canine shoulder.The shoulders of eight normal dogs were examined using a 4-slice helical CT scanner. The right shoulders were injected with Iohexol and the left shoulders with a mixture of Iohexol and epinephrine. CTA images were obtained after 1, 3, 5, 9, 13, 20 and 30. min and the image sharpness of the intra-articular structures in both shoulders was graded for visibility. The attenuation values were measured to examine the persistence of contrast appearance. Admixture of epinephrine and Iohexol significantly improved the image sharpness of the LGHL and the BT, especially on delayed CTA images. The use of epinephrine did not negatively affect post-CTA recovery.
    No preview · Article · Jun 2015 · Research in Veterinary Science
  • [Show abstract] [Hide abstract] ABSTRACT: Ketamine, a dissociative anesthetic frequently used in veterinary medicine, possesses rapid-acting antidepressant effects in humans possibly indicating an interaction with the cerebral perfusion or with the serotonergic system. In this single-photon emission computed tomography study, 7 healthy dogs were used to investigate the influence of ketamine on the regional cerebral blood flow using technetium-99m-ethyl cysteinate dimer and on the binding of the 5-hydroxytryptamine 2A receptor radioligand iodine-123 labeled R91150 in the canine brain. Ketamine increased the regional perfusion in the left frontal cortex and right parietal cortex. Significant changes in the distribution of iodine-123 labeled R91150 were not observed. This study demonstrated an acute effect of ketamine on the regional brain perfusion but not on the 5-hydroxytryptamine 2A receptors in the canine brain in the dose used in this study.
    No preview · Article · Apr 2015 · Journal of Veterinary Behavior Clinical Applications and Research
  • [Show abstract] [Hide abstract] ABSTRACT: Prepubertal gonadectomy (PPG) is promoted as a way of managing overpopulation in cats, but concerns about PPG and potential health issues still exist. The objective of the present study was to evaluate short-term and long-term health problems in cats subjected to PPG in comparison to gonadectomy at traditional age (TAG). In a prospective clinical trial, 800 shelter kittens aged between approximately 8 weeks and 12 weeks were recruited before adoption and randomly assigned to either the PPG group (gonadectomy performed immediately) or the TAG group (gonadectomy delayed until six months to eight months of age). Short-term health issues included mortality between when kittens arrived at the clinic and up to seven days after they returned to the shelter, as well as the occurrence of various other health issues arising in the first month following adoption. Kittens were followed-up until 24 months of age specifically for feline lower urinary tract disease, urethral obstruction (male cats), lameness, fractures and hypersensitivity disorders with dermatological presentation. In the short term, there were no significant differences between health problems in PPG and TAG kittens. Similarly, no significant differences were observed between treatment groups in terms of the type or number of health issues in the long term. In conclusion, there are no health-related contraindications to advocating PPG strategies in shelter cats. Ideally, PPG should be performed at the shelter facility itself as long as excellent infectious disease control and postoperative clinical observation before adoption are guaranteed. British Veterinary Association.
    No preview · Article · Mar 2015
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    [Show abstract] [Hide abstract] ABSTRACT: A young Labrador Retriever was presented for treatment of severe distal hindlimb necrosis caused by bandage ischemia. During digit amputation at the metatarsophalangeal joints, the third and fourth digital pads were salvaged and transferred to the metatarsal stump to create a weight-bearing surface. Negative pressure wound therapy (NPWT) was utilized for flap immobilization and to promote granulation tissue in the remaining wound defect. Sturdy adherence of the digital pads was achieved after only four days. The skin defect healed completely by second intention and the stump was epithelialized with a thin pad after three months. At the nine month follow-up examination, the stump had a thick hyperkeratinized pad. The dog walked and ran without any apparent signs of discomfort and compensated for the loss of limb length by extending the stifle and tarsocrural joints. Despite a challenging wound in a difficult anatomical location, digital pad flap transfer and NPWT proved successful in restoring long-term ambulation in an active large breed dog.
    Full-text · Article · Dec 2014 · Veterinary and Comparative Orthopaedics and Traumatology
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    Sanne M Melis · Hilde de Rooster · Tim Waelbers · Ingeborgh Polis
    Full-text · Article · Dec 2014 · Journal of the American Veterinary Medical Association
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    [Show abstract] [Hide abstract] ABSTRACT: Background Cavalier King Charles Spaniels (CKCS) have a high prevalence of Chiari-like malformation (CM). Herniation of the cerebellum into the foramen magnum is a key diagnostic feature for CM. Midsagittal MR images are the preferred technique for visualizing cerebellar herniation (CH).Objective To investigate whether CT can be used to diagnose CH.AnimalsFifteen client-owned CKCS dogs referred for investigation of the brain and cranial cervical spine on MRI and CT.Methods Two reviewers retrospectively analyzed midsagittal T1WSE and T2WSE MR images and midsagittal pre- and postcontrast 2D multiplanar reformatted CT images from each dog for the presence of CH. And, if present, the length (mm, CHL) of the herniation was measured. The results were analyzed statistically.ResultsThere was no significant difference between the different observers and techniques for the detection of CH and measurement of CHL. Overall, the CHL was longer on the CT images.Conclusion and Clinical ImportanceBoth techniques are useful for detecting CH and measuring CHL. Because CHL does not have a known direct impact on the clinical presentation of CM, CT can be used as a diagnostic tool in a routine clinical practice for CM in CKCS when MRI is not available. We emphasize that MRI is the standard screening technique in CKCS for breeding purposes to detect the presence of CM and SM and, at the current time, CT cannot replace MRI.
    Full-text · Article · Nov 2014 · Journal of Veterinary Internal Medicine
  • [Show abstract] [Hide abstract] ABSTRACT: The Sterycat project is a scientific study financed by the Federal Public Service of Public Health, Food Chain Safety and Environment, in which the Faculty of Veterinary Medicine collaborated with seventeen Flemish animal shelters, to investigate the effect of prepubertal gonadectomy on the health and behavior of cats. To be able to efficiently integrate prepubertal gonadectomy of shelter cats in governmental policy, it is important to know the opinion on this topic of people in the field. For this purpose, at the end of the Sterycat project, a survey (16 questions, 70 copies in total) was distributed among shelter veterinarians and staff workers of the participating shelters. Thirty-five individuals completed the survey (10 shelter veterinarians, 25 staff workers). The majority of them (85%) were in favor of continuing prepubertal gonadectomy in shelter cats after the Sterycat project had ended. However, some respondents were concerned about potential complications due to the procedure (58%) and about viral disease outbreaks (72%). Whether prepubertal gonadectomy could be implemented successfully seemed to be dependent upon the financial feasibility and the development of a framework to prevent income loss for non-shelter veterinarians. Furthermore, to efficiently reduce the overpopulation of cats, private cat owners and municipalities would have to assume responsibility to prevent reproduction in cats. A positive perception of the feasibility of prepubertal gonadectomy and microchipping in cats was associated with the enthusiasm of the veterinarian, the increased chances of adoption of the kittens and with the fact that both procedures contributed to the decrease in cat population numbers. In turn, the degree with which prepubertal gonadectomy was considered important was associated with the type of shelter and the expectation of a better return for the shelter. These results indicate that most surveyed shelter veterinarians and staff workers support the idea of continuing prepubertal gonadectomy at their shelter, on the condition that the financial aspect of the procedure and the responsibility of others (private cat owners and municipalities) are taken into account.
    No preview · Article · Nov 2014 · Vlaams Diergeneeskundig Tijdschrift
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    [Show abstract] [Hide abstract] ABSTRACT: Enkephalins are active in regulation of nociception in the body and are key in development of new synthetic peptide analogs that target centrally located opioid receptors. In this study, we investigated the in vivo blood–brain barrier (BBB) penetration behavior and antinociceptive activity of two cyclic enkephalin analogs with a thiourea (CycS) or a N-methyl-guanidine bridge (CycNMe), and their linear counterparts (LinS and LinNMe) in mice, as well as their in vitro metabolic stability. 125I-LinS had the highest blood–brain clearance (K1 = 3.46 μL/g min), followed by 125I-LinNMe, 125I-CycNMe, and 125I-CycS (K1 = 1.64, 0.31, and 0.11 μL/g min, respectively). Also, these peptides had a high metabolic stability (t1/2 > 1 h) in mouse serum and brain homogenate, and half-inhibition constant (Ki) values in the nanomolar range with predominantly μ-opioid receptor selectivity. The positively charged NMe-enkephalins showed a higher antinociceptive activity (LinNMe: 298% and CycNMe: 205%), expressed as molar-dose normalized area under the curve (AUC) relative to morphine, than the neutral S-enkephalins (CycS: 122% and LinS: 130%).
    Full-text · Article · Nov 2014 · Peptides
  • [Show abstract] [Hide abstract] ABSTRACT: Contrast-enhanced ultrasonography of the left kidney was performed using a commercial contrast agent in six healthy adult purpose-bred cats. A cross-over design was used to compare three protocols: (1) awake, (2) butorphanol (0.4 mg/kg IM), and (3) propofol (3.5-7.7 mg/kg IV boluses to effect). Time-intensity curves were created from two regions-of-interest drawn in the renal cortex. The curves were analyzed for blood flow parameters representing blood volume (base intensity, peak intensity, area-under-curve) and blood velocity (arrival time, time-to-peak, wash-in/out). There was no difference in the subjective enhancement pattern between the three protocols. No significant effect of butorphanol was observed in any of the perfusion parameters (P > 0.05). Propofol did not influence the most important perfusion parameter, area-under-the-curve, and is adequate for use in contrast-enhanced ultrasound studies.
    No preview · Article · Oct 2014 · The Veterinary Journal