RESUMEN
Magnetic resonance cholangiography (MRC) is an established diagnostic tool for noninvasive assessment of the biliary tract in humans. It has also been found to be feasible in companion animals, but no published studies have compared MRC sequences in veterinary medicine. The present study is part of a prospective, observational, analytical investigation on MR cholangiopancreatography performed on the donated bodies of 12 cats and eight dogs. The main aim of this study was to compare the images of 2D-SSh-TSE-MRC and 3D-TSE-MRC sequences for visualization and image quality of the feline and canine biliary tract. Both sequences are T2-weighted and noncontrast. Three independent readers scored the visibility of four segments of the biliary tract, namely the gallbladder (GB), cystic duct, common bile duct (CBD), and extrahepatic ducts, and the image quality of the two MRC sequences using five-point Likert scales. Wilcoxon signed-rank test was used to compare the scores between the MRC sequences separately for cats and dogs. Inter- and intraobserver agreements were measured using Gwet's AC2 with linear weighting. The 3D-TSE-MRC images were scored significantly higher than the 2D-SSh-TSE-MRC for both visibility and image quality (P < .001-.016 for cats, P = .008-.031 for dogs); the only exception was GB in dogs. In both cats and dogs, interobserver agreement for segment visibility and image quality ranged from slight to substantial in 2D-SSh-TSE-MRC and from poor to almost perfect in 3D-TSE-MRC. Most of the assessments (73% for segment visibility and 66% for image quality) had substantial to almost perfect intraobserver agreement. Findings from the current study support the use of 3D-TSE-MRC over 2D-SSh-TSE-MRC for evaluation of the feline and canine biliary tract, but further studies on live animals are warranted.
Asunto(s)
Sistema Biliar , Pancreatocolangiografía por Resonancia Magnética , Imagenología Tridimensional , Animales , Perros , Gatos , Pancreatocolangiografía por Resonancia Magnética/veterinaria , Pancreatocolangiografía por Resonancia Magnética/métodos , Imagenología Tridimensional/veterinaria , Imagenología Tridimensional/métodos , Estudios Prospectivos , Sistema Biliar/diagnóstico por imagen , Enfermedades de los Gatos/diagnóstico por imagen , Femenino , Masculino , Enfermedades de los Perros/diagnóstico por imagen , Enfermedades de las Vías Biliares/veterinaria , Enfermedades de las Vías Biliares/diagnóstico por imagenRESUMEN
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.
Asunto(s)
Enfermedades de los Gatos/diagnóstico , Colangiopancreatografia Retrógrada Endoscópica/veterinaria , Pancreatocolangiografía por Resonancia Magnética/veterinaria , Colangitis/veterinaria , Pancreatitis/veterinaria , Animales , Gatos , Colangitis/diagnóstico , Endosonografía/veterinaria , Femenino , Masculino , Pancreatitis/diagnóstico , Reproducibilidad de los Resultados , Sensibilidad y EspecificidadRESUMEN
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.