Contrast Harmonic Ultrasound of Spontaneous Liver Nodules in 32 Dogs

Abstract

Thirty-two dogs with spontaneous hepatic nodules were given intravenous ultrasound contrast medium (Definity or Sonovue) and imaged with contrast harmonic software on a conventional ultrasound machine system. Digital video images were initially reviewed to describe the perfusion pattern of malignant nodules. The images were reviewed again to test this pattern against all individual nodules. Subjectively, there was improved conspicuity of malignant nodules after contrast enhancement compared with conventional imaging and increased numbers of malignant nodules were often noted. There was decreased conspicuity of benign nodules and no additional nodules were seen after contrast enhancement. There was a highly significant (P < 0.0001) association of malignancy with a hypoechoic nodule at surrounding normal liver peak contrast enhancement. Benign nodules were isoechoic to the surrounding normal liver at peak contrast enhancement. Only one benign nodule (hepatoma) had regions of hypoechogenicity compared with the surrounding normal liver at peak liver contrast enhancement. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were highly significant (P < 0.0001) (100%, 94.1%, 93.8%, 100%, and 96.9%, respectively). No complications or morbidity was noted throughout the course of the study. Contrast harmonic ultrasound appears to be accurate at discriminating between naturally occurring benign and malignant nodules in the liver of dogs.

Contrast Harmonic Imaging of Canine Hepatic Tumors

“…In addition, Levovist was shown to have hepatic parenchymal echo enhancement for a duration of over 7 min, whereas Definity was demonstrated to have hardly hepatic parenchymal echo enhancement [8]. In the previous report that used Definity, the post vascular phase was not observed [10]. In our study using Levovist, the contrast pattern that showed a defect in the complete tumor and an enhancement of the surrounding hepatic tissues in the post vascular phase were demonstrated in 7 of the 8 dogs, and their contrast patterns were similar to those in humans.…”

“…To our knowledge, there is only one veterinary study that is reported in literature that has demonstrated CHI findings in 1 dog with HCC and in 3 dogs with metastatic hepatic HSA [10]. In the previous report, Definity was used as the contrast medium.…”

“…From 5 min after the injection of Levovist, the CHI recording in the same plane was continued for 1 min in order to determine the characterization of CHI in the post vascular phase. The start of the post vascular phase used in this series, 5 min after the injection of Levovist, was extrapolated from that fixed in human hepatic CHI methodology [10]. All CHI data were recorded at a rate of frames per second by means of the flush echo imaging technique.…”

“…However, to the best of our knowledge, a limited number of veterinary studies on canine CHI have been published [10,12,17]. We believe that CHI is of value in small animal medicine, similar to humans, considering that it is a convenient and noninvasive method that does not involve sedation/anesthesia for the differential diagnosis of hepatic malignant tumors.…”

Contrast-enhanced ultrasonography (CEUS) in canine liver examination

“…Namely, during the peak of parenchymal enhancement all malignant focal lesions were hypoechogenic. This occurrence (O'Brien et al 2004) correlates with the malignancy with a very high sensitivity, specificity, positive predictive value, negative predictive and accuracy (100%, 94.1%, 93.8%, 100% and 96.9%, respectively). (n=1) 1…”