Riccardo Orlandi

Doppler evaluation of maternal and fetal vessels during normal gestation in rabbits

The aim of this work is to evaluate the haemodynamic characteristics of maternal and foetal vessels during normal pregnancy in queens, using colour Doppler and pulsed wave Doppler ultrasonography, in order to obtain information about maternal and foetal circulation. The blood waveforms of the uteroplacental arteries, aorta, caudal cava vein and umbilical cord of the fetuses were recorded weekly in seven healthy pregnant queens. Also, the measurements of peak systolic, end diastolic velocities, resistance and pulsatility indices were carried out. Uteroplacental blood flow was biphasic while the ones of the umbilical artery and aorta were first systolic and then diastolic. The caudal cava vein showed a typical waveform of venous vessels. During gestation the EDV and PSV of foetal vessels increased (alpha<0.05) while the PI and RI of all vessels examined decreased (alpha<0.05) except for the IP of the aorta. The Doppler ultrasonography, also in queens, can be used to evaluate the characteristics of maternal and foetal vessel flow and their progressive changes during pregnancy. This study can be considered the basis for further contribution in diagnosing and monitoring high-risk pregnancies in Veterinary Medicine.

Aglepristone (RU534) administration to non-pregnant bitches in the mid-luteal phase induces early luteal regression

The effect of the antiprogestagen aglepristone (10 mg/kg bw), administered at days 29 and 30 following the estimated day of LH surge (day 0), on corpora lutea (CL) function was examined during the diestrus phase of non-pregnant bitches. Aglepristone shortened (P < 0.01) the luteal phase and complete luteolysis (progesterone <2 ng/mL) was observed at days 40.8 +/- 3.5 and 71.5 +/- 4.6 (means +/- SD; n = 9/group) in treated and control bitches, respectively. Peripheral estradiol-17beta concentrations declined from 91.5 +/- 14.3 pg/mL at day 9 to 50 pg/mL at day 18, remaining at approximately the same levels thereafter in both treated and control bitches. Intraluteal in vitro synthesis of progesterone and estradiol-17beta released by CL explanted at day 38 from control bitches (511.9 +/- 285.6 and 40.7 +/- 17.2 pg/mg protein, respectively) did not differ from that of treated. From day 38, intraovarian hemodynamic variables (arterial blood flow, systolic peak, and end-diastolic velocities), monitored by color-coded and pulsed Doppler, decreased more steeply (P < 0.01) in aglepristone-treated (n = 4) than in control (n = 4) bitches, whereas the resistance index increased (P < 0.01) in treated animals. All the blood flow parameters were undetectable at 60 +/- 3.6 and 68 +/- 2.0 days (medians +/- SD) after LH peak in treated and control bitches, respectively. In conclusion, aglepristone administration to dogs during the mid-luteal phase markedly accelerates the luteolytic process which is accompanied by a parallel decline in ovarian blood flow supply with a shift from approximately 8 to 10 days.

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.

Power and pulsed Doppler evaluation of ovarian hemodynamic changes during diestrus in pregnant and nonpregnant bitches

The aim of the study was to further characterize the relationship between hemodynamic changes in the ovary and luteal function in pregnant and nonpregnant bitches. Fourteen German Shepherd bitches were monitored three times a week from the first day of cytological diestrus (D1) until parturition or the end of diestrus (progesterone <2 ng/mL) by color Doppler, pulsed wave spectral Doppler, and power Doppler (PD) ultrasonography. By means of PD the total number of color pixels were calculated. The Doppler parameters evaluated were: peak systolic velocity (PSV), end diastolic velocity (EDV), and both resistive and pulsatility indices. Blood samples were collected three times a week throughout the experiment to determine progesterone (P4) concentrations. The length of diestrus in pregnant versus nonpregnant group was significantly shorter (P < 0.01; 57 ± 1 vs. 63 ± 1, respectively). By means of pulsed wave spectral Doppler the waveform showed a typical pattern of a low-resistive vessel characterized by a rapid systolic peak followed by a slow telediastolic decrease with a relatively high end-diastolic velocity. Blood flow parameters did not differ between left and right ovary. In both groups PSV and EDV showed a gradual decrease with the progress of diestrus; however, the values of PSV and EDV were significantly higher (P < 0.05) in the pregnant group versus nonpregnant group from D31 to D61 and from D49 to D58 respectively. Moreover, a significantly decrease (P < 0.05) of PSV and EDV in the pregnant group was observed from D46 to D58 and from D49 to D55, respectively. The resistive and pulsatility indices showed an increase during diestrus and the values were significantly lower (P < 0.05) in the pregnant group from D49 to D61. By means of PD, the pixel number was significantly higher (P < 0.05) in the pregnant versus nonpregnant group from D40 to D61. In particular, a significant decrease (P < 0.05) in the pixel number in the pregnant group was observed from D46 to D61. The comparison of the P4 values with the ovarian pixel number in the pregnant and nonpregnant group showed a direct correlation (r = 0.792, N = 59 and r = 0.774, N = 59, respectively). In particular, the P4 values were higher (P < 0.05) in the pregnant than in the nonpregnant group from D37 to D52. In conclusion, significant physiological differences between pregnant and nonpregnant bitches in terms of P4 and ovarian blood supply are reported. In addition it was possible to define that blood flow pattern during diestrus in pregnant bitches is not always closely related with P4 production.

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.

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 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.