Evaluation of the feline pancreas using computed tomography and radiolabeled leukocytes

Anatomical and Three-Dimensional Study of the Female Feline Abdominal and Pelvic Vascular System Using Dissections, Computed Tomography Angiography and Magnetic Resonance Angiography

This study describes the anatomical characteristics of the abdominal and pelvic vascular system of two healthy mature female cats via three-dimensional contrast enhanced computed tomography angiography, non-contrast enhanced magnetic resonance angiography and three-dimensional printing. Volume-rendering computed tomography angiography images were acquired from the ventral aspect using RadiAnt, Amira and OsiriX MD Dicom three-dimensional formats, and three-dimensional printing was obtained and compared with the corresponding computed tomography angiography images. Non-contrast enhanced magnetic resonance angiography was made using the time-of-flight imaging in ventral, oblique and lateral views. In addition, three cadavers with colored latex injection were dissected to facilitate the identification of the vascular structures. Three-dimensional computed tomography angiography showed the main vascular structures, whereas with the time-of-flight blood appeared with a high signal intensity compared with associated abdominal and pelvic tissues. Three-dimensional computed tomography angiography images and time-of-flight sequences provided adequate anatomical details of the main arteries and veins that could be used for future feline anatomical and clinical vascular studies of the abdomen and pelvis.

Creation of Three-Dimensional Anatomical Vascular and Biliary Models for the Study of the Feline Liver (Felis silvestris catus L.): A Comparative CT, Volume Rendering (Vr), Cast and 3D Printing Study

In this study, six adult feline cadavers were examined using CTA, 3D printing, and casts injected with epoxy. The aorta, the portal vein, and the gallbladder of 3 feline cadavers were separately injected with a 50% mixture of colored vulcanized latex and hydrated barium sulfate as contrast medium to analyze by CT the arterial, venous and biliary systems. The other three cadavers were injected with a mixture of epoxy resin in the aorta, gallbladder and hepatic veins, separately. After the corrosion and washing process, hepatic vascular and biliary casts were obtained. The images obtained by CT showed the vascular and biliary system using a soft tissue window. For the identification of vascular and biliary structures, the 3D prints together with the 3D reconstructions were analyzed, and the results were compared with the casts obtained with epoxy resin. Each of the arterial, venous and biliary branches associated with each of the liver lobes were identified with the help of the printings. In conclusion, the creation of 3D prototypes of nonpathological feline hepatic parenchyma can be used in the veterinary clinic as a basis for the detection of pathological problems in addition to obtaining future pathological hepatic 3D models.

ACVIM consensus statement on pancreatitis in cats

Background

Pancreatitis in cats, although commonly diagnosed, still presents many diagnostic and management challenges.

Objective

To summarize the current literature as it relates to etiology, pathogenesis, diagnosis, and management of pancreatitis in cats and to arrive at clinically relevant suggestions for veterinary clinicians that are based on evidence, and where such evidence is lacking, based on consensus of experts in the field.

Animals

None.

Methods

A panel of 8 experts in the field (5 internists, 1 radiologist, 1 clinical pathologist, and 1 anatomic pathologist), with support from a librarian, was formed to assess and summarize evidence in the peer reviewed literature and complement it with consensus clinical recommendations.

Results

There was little literature on the etiology and pathogenesis of spontaneous pancreatitis in cats, but there was much in the literature about the disease in humans, along with some experimental evidence in cats and nonfeline species. Most evidence was in the area of diagnosis of pancreatitis in cats, which was summarized carefully. In contrast, there was little evidence on the management of pancreatitis in cats.

Conclusions and Clinical Importance

Pancreatitis is amenable to antemortem diagnosis by integrating all clinical and diagnostic information available, and recognizing that acute pancreatitis is far easier to diagnose than chronic pancreatitis. Although both forms of pancreatitis can be managed successfully in many cats, management measures are far less clearly defined for chronic pancreatitis.

Morphological assessment of cat kidneys using computed tomography

There are numerous publications about feline renal imaging information; however, none have established reference values for kidney size using computed tomography (CT). This study aimed to determine renal size and shape as well as the morphology of renal-related structures in clinically normal cats (Felis catus) that underwent CT. Twenty-seven healthy cats underwent pre- and post-iodinated contrast-enhanced CT. Most cat (59%) kidneys were located at the same level. The average pre-contrast dimensions of the left kidney included a width of 2.46 ± 0.28 cm, a length of 3.52 ± 0.44 cm and a height 2.19 ± 0.31 cm, whereas those of the right kidneys were 2.45 ± 0.27 cm, 3.54 ± 0.46 cm and 2.05 ± 0.23 cm, respectively. After contrast enhancement, kidneys were slightly enlarged though not significantly. Additionally, renal length (LK or RK) was compared with second lumbar vertebra (L2) length and abdominal aorta diameter (AO). AO was significantly larger in male cats whereas L2 length appeared longer in male cats, but was not statistically different from the female cats. The LK/L2 and RK/L2 ratios were 2.29 ± 0.23 and 2.36 ± 0.20, respectively, and the LK/AO and RK/AO were 11.72 ± 1.37 and 12.05 ± 1.47, respectively. Renal vessels were examined. The renal vein was obviously larger than the renal artery, and paired renal veins were observed periodically. This study provides CT information about the feline kidney, which may help to establish reference values and information regarding renal structure prior to surgery in practice.

Computed tomographic appearance of abdominal lymph nodes in healthy cats

Background

Computed tomography (CT) is commonly used in veterinary medicine and plays an important role in disease identification and cancer staging. Identification of abnormal abdominal lymph nodes is important for clinical, therapeutic, and prognostic decision making. No published study describes the CT appearance of abdominal lymph nodes in healthy cats.

Hypothesis/Objectives

All abdominal lymph centers will be identified on CT with the majority of lymph nodes being elongated and homogenously contrast enhancing.

Animals

Sixteen healthy cats without clinical or biochemical evidence of disease.

Methods

Precontrast and postcontrast CT images of sedated healthy cats were used to identify the presence and descriptive characteristics of intra‐abdominal lymph nodes. These assessments then were compared with patient characteristics to identify possible correlations.

Results

Abdominal lymph nodes were readily identified on CT with caudal mesenteric, colic, hepatic, inguinal, and pancreaticoduodenal lymph nodes identified in 16/16 cats. Lymph node size and shape varied among lymph centers with nearly all lymph nodes homogeneously contrast enhancing in 515/525. Significant negative correlations were identified between age and length (P = .0166) and width (P = .0387) of abdominal lymph nodes as well as age and number of sacral lymph nodes (P = .0493). Intranodal fat was present in 18/525 lymph nodes.

Conclusions and Clinical Importance

CT readily permitted identification and characterization of feline abdominal lymph nodes. This study provides subjective and objective data on the CT characteristics of abdominal lymph nodes in 16 healthy cats, with younger cats having larger abdominal lymph nodes and a higher number of sacral lymph nodes.

Triple phase computed tomography of the pancreas in healthy cats

While the availability and use of computed tomography (CT) continues to grow, no study has described the size and multiphase CT appearance of the normal feline pancreas. This information is important to not only allow more accurate identification and differentiation of disease, but it may also be useful in assessing pancreatic function. In this prospective analytical study, we described a triple phase CT protocol of the pancreas for use in sedated cats and the attenuation, enhancement pattern, size, and volume of the pancreas for a group of healthy cats. Fifteen healthy cats were enrolled in the study and a standardized protocol for acquiring arterial, portal, and delayed phase CT images of the pancreas was developed and described. The pancreas was hypo to isoattenuating to both the liver and spleen in all phases in the majority of cats with a homogenous enhancement pattern noted in all 15. Mean pancreatic attenuation was 48, 79, 166, and 126 Hounsfield units (HU) respectively on precontrast, arterial, portal, and delayed phase images. In addition, mean height, length, and width of the left lobe of the pancreas were larger than the right lobe in all 15 cats. There were no associations between volume and volume: body weight ratio with age (P = 0.6518, P = 0.6968) or sex (P = 0.7013, P = 0.2043). This baseline information may be beneficial for use in future studies characterizing pancreatic disease in cats as well as future research studies evaluating pancreatic endocrine function.

Perspectives in molecular imaging through translational research, human medicine, and veterinary medicine

The concept of molecular imaging has taken off over the past 15 years to the point of the renaming of the Society of Nuclear Medicine (Society of Nuclear Medicine and Molecular Imaging) and Journals (European Journal of Nuclear Medicine and Molecular Imaging) and offering of medical fellowships specific to this area of study. Molecular imaging has always been at the core of functional imaging related to nuclear medicine. Even before the phrase molecular imaging came into vogue, radionuclides and radiopharmaceuticals were developed that targeted select physiological processes, proteins, receptor analogs, antibody-antigen interactions, metabolites and specific metabolic pathways. In addition, with the advent of genomic imaging, targeted genomic therapy, and theranostics, a number of novel radiopharmaceuticals for the detection and therapy of specific tumor types based on unique biological and cellular properties of the tumor itself have been realized. However, molecular imaging and therapeutics as well as the concept of theranostics are yet to be fully realized. The purpose of this review article is to present an overview of the translational approaches to targeted molecular imaging with application to some naturally occurring animal models of human disease.

Feasibility of endoscopic retrograde cholangiopancreatography in healthy cats

Cats are predisposed to diseases of the biliary tract and the exocrine pancreas and these can be challenging to diagnose. In humans and dogs > 10 kg, endoscopic retrograde cholangiopancreatography (ERCP) has been successfully used to diagnose some of these disorders. The purpose of our study was to determine whether ERCP would also be feasible in cats using a pediatric duodenoscope. Four purpose-bred, clinically healthy, castrated domestic shorthair cats participated in two studies. Study 1 compared standard white light endoscopy with chromoendoscopy for localizing the major duodenal papilla. In Study 2 ERCP was performed. Repeated clinical examinations and measurements of serum feline pancreatic lipase immunoreactivity (fPLI) were performed before and up to 18 hours after interventions on all cats. Chromoendoscopy was subjectively judged to be superior for localizing the major papilla. Insertion of the ERCP catheter was best accomplished when cats were in dorsal recumbency. Complete ERCP was successful in two cats. In the other cats, either retrograde cholangiography or pancreatography was possible. Serum fPLI concentrations increased temporarily in two cats during Study 2 when measured immediately, 2, 4, and 18 h after ERCP. Peak fPLI concentrations were detected either immediately after ERCP or 2 h later. No clinical signs of complications were observed within 18 h after the procedures. Findings indicated that ERCP is technically demanding but feasible in healthy cats. Future studies need to determine whether the temporary increases in serum fPLI concentrations are clinically important and to investigate the utility of ERCP in feline patients.

Computed tomography in small animals – Basic principles and state of the art applications

Since its clinical introduction, computed tomography (CT) has revolutionized veterinary medicine and is considered to be one of the most valuable tools for the imaging work-up of neurological, oncological and orthopaedic canine and feline patients. In small animals with acute trauma, particularly those involving complex anatomic areas such as the head, spine or pelvis, CT has been established as a standard imaging method. With the increasing availability of radiation therapy in veterinary medicine, CT has also become the principal tool to stage a tumour, assess response, and guide radiation therapy. The increasing availability of helical CT in veterinary medicine has allowed novel techniques such as spiral CT angiography and high-resolution CT. This review provides a brief overview of the historical and technical development of CT and literature reviews of the major clinical CT applications in small animals such as intracranial and extracranial lesions, the spine, the appendicular skeleton, and abdominal and thoracic diseases.

USE OF COMPUTED TOMOGRAPHY AND RADIOLABELED LEUKOCYTES IN A CAT WITH PANCREATITIS

The normal feline pancreas has been evaluated using radiolabeled leukocytes (99mTc-HMPAO) and computed tomography. The purpose of this report is to describe a clinical case where both modalities were utilized to assess the inflamed feline pancreas. A nine year old female cat presented with anorexia, depression and some vomiting. Blood values were unremarkable. Radiographs and ultrasound were suggestive of pancreatitis. The cat's leukocytes were separated and labeled according to an established protocol. Whole body images were acquired immediately, at 5 and 30 min, and at 1, 2, 4, and 17 hours post injection. Approximately 48 h later, the animal was anesthetized and computed tomography of the abdomen was preformed both pre and post contrast. Surgical biopsies were taken. The distribution of the WBCs was similar to that documented in normal animals, however, at 2 h there was faint uptake seen in the region of the pancreas. This uptake became more intense at 4 h and persisted at 17 h. Computed tomography showed irregular margination of the pancreas, it was larger than normal and inhomogeneous. Contrast enhancement was inhomogeneous and its peak enhancement was not reached until 10 min post injection; normal feline pancreas enhances homogeneously and peaks immediately. Histopathology confirmed pancreatitis with lymphocytic, plasmacytic, neutrophilic and eosinophilic inflammation and fibrosis. Radiolabeled leukocytes can be used to document pancreatic inflammation and this is best seen 4 h after injection. Computed tomography allows superior visualization of the pancreas. Both the appearance and contrast enhancement pattern of the inflamed pancreas differ from normal.