Cholangitis is a common inflammatory disorder of the biliary system in cats. There are two major forms based on the predominate type of inflammatory cell infiltrates: lymphocytic or neutrophilic. Ultrasound is a common imaging modality used in these patients. This retrospective study evaluated the ultrasound examinations of 26 cats with a histologic diagnosis of cholangitis. Most cats with cholangitis had sonographically normal liver size, echogenicity, and normal biliary systems. Statistically significant sonographic changes for cats with cholangitis included hyperechoic liver parenchyma, hyperechoic gallbladder contents, and increased pancreatic size. No statistically significant changes were noted to distinguish lymphocytic and neutrophilic forms of cholangitis. Cats with the sonographic features of diffuse liver hyperechogenicity, gallbladder contents and enlarged pancreas may suggest cholangitis.

Ultrasonographic findings of feline cholangitis.

Cholangiohepatitis/cholangitis is second only to hepatic lipidosis as the most common liver disease in cats and is often associated with concurrent pancreatitis. Magnetic resonance imaging (MRI) and MR cholangiopancreatography (MRCP) have developed into an accurate, highly sensitive and specific imaging tool for the diagnosis of biliary and pancreatic duct disorders in humans. In this prospective case series, 10 cats with suspected cholangitis and/or pancreatitis were enrolled based on clinical history, physical examination and appropriate diagnostic test results. MRI and MRCP sequences with secretin stimulation of the cranial abdomen were performed, and sonography and laparoscopic biopsies for histologic diagnosis were obtained for comparison. MRI detected pancreatic abnormalities in cats suspected of pancreatitis, including T1 pre-contrast hypointense and T2 hyperintense pancreatic parenchyma and a dilated pancreatic duct. The MRI findings of the liver were non-specific. Nine of 10 cats had biliary abnormalities, including gall bladder wall thickening, gall bladder wall moderate contrast enhancement and/or gall bladder debris. Eight of 10 cats had histologic evidence of pancreatitis, as well as hepatitis or cholangitis, with one cat diagnosed with hepatic lymphoma. The advantages of MRI/MRCP over sonography of these cats included the striking pancreatic signal changes associated with pancreatitis and the ability to comprehensibly assess and measure the pancreas and hepatobiliary structures without operator dependence or interference from bowel gas. MRI/MRCP imaging of the feline abdomen may be beneficial in cases with equivocal ultrasound imaging findings.

Magnetic resonance (MR) imaging and MR cholangiopancreatography findings in cats with cholangitis and pancreatitis.

The purposes of this retrospective study were to assess the prevalence of gallbladder sludge (GBS) in a population of cats presented for abdominal ultrasound in a teaching hospital and to determine its association with increased serum alanine aminotransferase (ALT), alkaline phosphatase (ALP), and total bilirubin (TB). Gallbladder sludge was detected in 152 (14%) of the cats undergoing abdominal ultrasound between 2004 and 2008. This population was compared to a control group of 32 cats without GBS. Alanine aminotransferase, ALP, and TB mean values were significantly higher in cats with GBS than in controls (P ≤ 0.0005) and odds for increased values in cats with GBS were 4.2 [95% confidence interval (CI): 1.6 to 11.0], 9.5 (95% CI: 2.2 to 41.7), and 4.1 (95% CI: 1.5 to 11.5), respectively (P ≤ 0.007). In conclusion, GBS is an uncommon ultrasonographic finding in cats that is predictive of increased liver enzymes and TB. More studies are needed to establish potential links between GBS and hepatobiliary disease in cats.

Gallbladder sludge on ultrasound is predictive of increased liver enzymes and total bilirubin in cats

We quantified gallbladder volume in 30 clinically healthy, fasted, cats, using an ellipsoid formula. All cats had a complete blood count and serum chemistry profile performed. Fasting times before sonography ranged from 12 to 16 h. The median gallbladder volume was 2.42 ml, with a range of 0.84-4.50 ml. The mean gallbladder volume was 2.41 ml. This reference range will assist clinicians when evaluating cats with hepatobiliary disease or suspected extrahepatic biliary obstruction.

Sonographic assessment of gallbladder volume in normal cats

Magnetic resonance (MR) cholangiopancreatography is useful in humans to diagnose biliary and pancreatic diseases. Some of these protocols incorporate the use of secretin, which stimulates the exocrine pancreas to release bicarbonate with secondary dilation of the pancreatic duct. We compared the utility and quality of multiple hepatic-pancreaticobiliary MR imaging sequences before and after secretin stimulation of the pancreatic duct in five healthy cats. Multiple MR sequences were evaluated, including fast Spoiled Gradient Recalled in- and out-of-phase, Single Shot Fast Spin Echo (SSFSE), T2 Fast Spin Echo, MR cholangiopancreatography (pre- and postsecretin administration), and Fast Acquisition with Multiphase Efgre (FAME) (postsecretin and before and after gadolinium administration). The MR cholangiopancreatography protocol with secretin stimulation was feasible and yielded high-contrast maps of the biliary ductal anatomy but the pancreactic duct was seen inconsistently. The FAME series most consistently provided visualization of biliary and postsecretin pancreatic ductal anatomy, combined with very good depiction of the liver and pancreas. The remaining sequences each had satisfactory utility and diagnostic quality, with the exception of the SSFSE sequences. Secretin improved the conspicuity of the pancreatic duct.

Clifford Berry

Papers

Liver imaging in the cat.