CT CHARACTERISTICS OF PRIMARY HEPATIC MASS LESIONS IN DOGS

Abstract

Little information is available on the relationship between computed tomography (CT) imaging findings and the pathologic diagnosis of canine hepatic tumors. Our purpose was to clarify the characteristic features of CT findings in liver tumors in dogs. Data from 33 dogs with either a hepatocellular carcinoma, n = 14, hepatocellular adenoma, n = 14, or nodular hyperplasia, n = 5 were summarized from medical records. CT features for each histologic diagnosis were characterized and analyzed statistically. Common findings in hepatocellular carcinoma included central (79%, P = 0.0030) and marginal enhancement (93%, P = 0.00043) in the arterial phase, cyst-like lesions (93%), capsule formation (93%), and hypoattenuation in the portal (86%), and equilibrium phases (93%). Hepatic adenoma was characterized by a characteristic diffuse enhancement pattern during the arterial phase (57%, P = 0.013), which was also found in nodular hyperplasia (60%), but never in hepatocellular carcinoma. Nodular hyperplasia was less likely to have a capsule structure (20%, P = 0.0087). Mass size was significantly smaller in nodular hyperplasia than in hepatocellular carcinoma and hepatic adenoma (P = 0.0033 and 0.038, respectively). Hyperattenuation in the arterial and the portal phase i.e. contrast retention, was more frequent in hepatic adenoma than in the other groups (P = 0.037 and 0.037, respectively). Nodular hyperplasia was more frequently isoattenuating in the equilibrium phase (P = 0.043).

Diagnostic Accuracy of Ultrasound to Predict the Location of Solitary Hepatic Masses in Dogs

“…Currently, MRI and CT have surpassed ultrasound as the diagnostic imaging modalities of choice for evaluation of human patients with focal hepatic lesions . Although these imaging methods are less commonly used in veterinary patients given their more limited availability and increased cost relative to unenhanced ultrasonography, their use has been reported in the veterinary literature with benefits including improved lesion detection and possible differentiation between benign and malignant disease processes . Future studies that compare the sensitivity of these imaging modalities to unenhanced ultrasonography would be useful for veterinary surgeons deciding on the most appropriate imaging technique to use for preoperative staging.…”

What Is Your Diagnosis?

“…7 Visualization of a mass on preoperative imaging allowed identification of a potential source of chronic inflammation and the opportunity to target treatment. Preoperative imaging additionally proved essential in the dog of the present report as the thick adhesions surrounding the abdominal contents would have made identification of the mass during surgery much more difficult.…”

Associations Between Dual‐phase Computed Tomography Features and Histopathologic Diagnoses in 52 Dogs With Hepatic or Splenic Masses

“…Dogs with hepatic masses have not been investigated using dual‐phase CT. Instead, triple‐phase CT studies have been described, with images acquired at 13–20 s (hepatic arterial phase), 30–40 s (early portal venous phase), and 120 s (equilibrium or delayed phase) following contrast administration . These studies found evidence of associations between the pattern and degree of postcontrast enhancement and the pathologic diagnosis of hepatic masses, although there was substantial overlap .…”

“…Instead, triple‐phase CT studies have been described, with images acquired at 13–20 s (hepatic arterial phase), 30–40 s (early portal venous phase), and 120 s (equilibrium or delayed phase) following contrast administration . These studies found evidence of associations between the pattern and degree of postcontrast enhancement and the pathologic diagnosis of hepatic masses, although there was substantial overlap . Most hepatocellular carcinomas showed heterogeneous enhancement in hepatic arterial phase, portal venous phase and delayed phase images, often had a central zone of hypoattenuation, and were hypoattenuating compared to the liver in portal and delayed phase images .…”