Recipient Organization
UNIVERSITY OF TENNESSEE
2621 MORGAN CIR
KNOXVILLE,TN 37996-4540
Performing Department
Small Animal Clinical Sciences
Non Technical Summary
The use of magnetic resonance imaging in human medicine to evaluate specific abdominal organ pathology has increased in recent years. The advantages of MRI over other imaging modalities include superior soft tissue contrast, lack of ionizing radiation, and the option of multiplanar imaging. Because of these advantages, new studies characterizing various image acquisition techniques and new contrast media have been investigated. The liver is an organ that is frequently affected by various disease processes making diagnostic imaging an integral part of the clinical diagnostic process. Many studies in humans have proved the usefulness of Eovist in the characterization of both focal and diffuse liver disease. The most common reason to image the liver in human medicine is for the detection of neoplastic processes, both primary and metastatic. Tissue specific contrast agents such as Eovist allow differentiation between liver parenchyma and metastases, thus improving lesion detection and characterizatio. Like in humans, liver disease is commonly diagnosed in veterinary patients. Various imaging modalities such as abdominal ultrasound and computed tomography have proved to be useful methods of imaging the liver in animals. With increasing availability of MRI and the development of newer and faster imaging sequences, it seems that investigating the usefulness of MRI in detecting lesions in the abdomen, specifically the liver, is logical. The goal of this study is to establish an MRI protocol for the investigation of the canine liver using Eovist and characterize the liver of healthy dogs. The results of this study will be used as a baseline for future clinical studies that involve patients with liver disease.
Animal Health Component
(N/A)
Research Effort Categories
Basic
(N/A)
Applied
(N/A)
Developmental
(N/A)
Goals / Objectives
The purpose of this study is to develop a protocol for the use of Eovist in dogs and characterize normal liver magnetic resonance images before and after administration of Eovist in healthy dogs. This study will provide a baseline for future studies in dogs with liver disease.
Project Methods
Eight healthy dogs were included in the study. Dogs were deemed healthy based on the results of a complete blood count (CBC), serum biochemistry profile, urinalysis, two view abdominal radiographs (right lateral and ventrodorsal views), two view thoracic radiographs (right lateral and ventrodorsal views) and abdominal ultrasound. Radiographs were reviewed and the ultrasound was performed by a radiology resident under supervision of a board-certified radiologist, and all blood work results were reviewed by a board certified internist. Included patients were pre-medicated and anesthetized by a staff anesthesiologist. The MRI examination was performed using a 1.0 Tesla magnet operated by a MRI technologist and supervised by a radiology resident and a board-certified veterinary radiologist. Pre-contrast sequences performed on all dogs included dorsal and transverse T1-weighted spin echo (T1-W SE) and T2-weighted fast spin echo (T2-W FSE), and transverse volume-interpolated body examination (VIBE; T1-W fat suppressed GRE sequence). Dogs 1, 3, 5, and 7 received one 0.05mL/kg (0.0125mmol/kg) dose of Eovist and dogs 2, 4, 6, and 8 received one 0.1mL/kg (0.025mmol/kg) dose of Eovist. The post-contrast sequences of dogs 1, 2, 3, and 4 were transverse VIBE initiated immediately after contrast medium administration followed by transverse VIBE acquired every 5 minutes for 40 minutes, and transverse and dorsal T1-W SE acquired after 40 minutes. The post-contrast sequences of dogs 5, 6, 7, and 8 were transverse T1-W SE acquired immediately and then every 5 minutes for 40 minutes, and transverse and dorsal VIBE acquired after 40 minutes. Images were stored on a PACS system and evaluated on grayscale monitors by a radiology resident and a board certified radiologist. Images were subjectively assessed for image quality and for the presence or absence of artifacts. The hepatic parenchyma was assessed for homogeneity of contrast uptake. Signal intensity ratios (SIR) of post-contrast T1-W SE and VIBE, and SIR between the two dose groups were evaluated using a student's t-test. A p-value of <0.05 was considered significant.