Feline pancreatic ducts are consistently identified on CT and more likely to be dilated in the body of pancreas in cats with elevated feline pancreatic lipase immunoreactivity.

Feline pancreatitis is a challenge to diagnose and no previously published study has described the CT characteristics of the pancreatic duct (PD) in cats. The current prospective analytical study was performed to identify and describe the CT characteristics of the PD in normal cats and to compare that to those cats with an elevated feline pancreatic lipase immunoreactivity (fPLI). Contrast-enhanced CT was performed in 16 normal cats and 13 cats with an elevated fPLI. Two ACVR-certified radiologists blinded to the fPLI status assessed whether or not the PD could be identified, contrast phase during which the PD was most conspicuous, and PD shape in the body, right and left lobes. A second-year radiology resident blinded to the fPLI status measured maximum PD diameter and PD:parenchyma. The PD was identified in 84 of 87 pancreatic segments, which was most conspicuous in the portal phase in 28 of 29 cats. The PD shape was tubular (48/84), tapered (34/84), or beaded (2/84) with no significant difference (P = 1.0 to .1615) between groups. Mean maximal PD diameters of normal cats were 1.5-1.7 mm, which was significantly larger in the body of the pancreas in cats with an elevated fPLI (2.4 mm, P = .0313). Mean PD:parenchyma was not significantly different between groups (P = .2001 to .949). In conclusion, the feline PD can be consistently identified on CT, for which the portal phase is preferred. Cats with an elevated fPLI are more likely to exhibit dilation of the PD in the body of the pancreas on CT.

IMAGING DIAGNOSIS--RADIOGRAPHIC, ULTRASONOGRAPHIC, COMPUTED TOMOGRAPHIC, AND FLUOROSCOPIC APPEARANCE OF A DISTAL PELVIC LIMB ARTERIOVENOUS MALFORMATION IN A YOUNG GERMAN SHEPHERD DOG.

A German shepherd puppy presented for evaluation of a suspected arteriovenous fistula on the distal aspect of the right pelvic limb. Radiographs demonstrated expansion and resorption of the tarsal and metatarsal bones, and ultrasound detected a vascular abnormality. Using computed tomographic angiography, a complex arteriovenous malformation (AVM) involving the distal tibia, tarsus, and the metatarsus and an osteochondritis dissecans (OCD) lesion of the talus were identified. Based on these findings, therapeutic limb amputation was performed. Fluoroscopic angiography, vascular casting, and dissection were then used to further characterize features of this previously unreported AVM with concurrent bony lesions and OCD.

Determination of the cause of selected canine urolith formation by advanced analytical methods.

OBJECTIVE: The goal of this study was to determine the cause of selected canine urolith formation using less conventional but more advanced analytical methods. METHODS: A routine laboratory specialising in urinary calculi analysis noticed a special type of core zone in some canine uroliths, which was typically made up of cylindrical holes. Of 4028 canine samples analysed, non-absorbable suture material was detected in 9 (0·22%) cases. A hollow cylindrical central area was found in a further 13 (0·32%) samples. X-ray microtomography (µCT) was utilised in order to reveal the channel structure inside this urolith sample. Matrix-assisted laser desorption-ionisation - time of flight mass spectrometry was used in order to assess the cause of this urinary stone formation. RESULTS: The diameter of the channel structure corresponded with the diameter of the previously utilised suture material and indicated that this urolith was formed around residual suture material. Further confirmation was provided by the comparative matrix-assisted laser desorption-ionisation - time of flight mass spectrometry chemical analysis. This channel structure is formed by a surgical thread that serves as a base for the urolith growth. CLINICAL SIGNIFICANCE: Results of this study confirm the causative role of absorbable suture material in the pathogenesis of hollow channel structures in some canine compound uroliths.

Evaluation of radiographic, computed tomographic, and cadaveric anatomy of the head of boa constrictors.

OBJECTIVE: To evaluate the radiographic, computed tomographic (CT), and cadaveric anatomy of the head of boa constrictors. ANIMALS: 4 Boa constrictor imperator cadavers. PROCEDURES: Cadavers weighed 3.4 to 5.6 kg and had a body length ranging from 189 to 221 cm. Radiographic and CT images were obtained with a high-detail screen-film combination, and conventional CT was performed with a slice thickness of 1.5 mm. Radiographic images were obtained in ventrodorsal, dorsoventral, and left and right laterolateral recumbency; CT images were obtained with the animals positioned in ventral recumbency directly laying on a plastic support. At the end of the radiographic and CT imaging session, 2 heads were sectioned following a stratigraphic approach; the other 2, carefully maintained in the same position on the plastic support, were moved into a freezer (-20°C) until completely frozen and then sectioned into 3-mm slices, respecting the imaging protocol. The frozen sections were cleaned and then photographed on each side. Anatomic structures were identified and labeled on gross anatomic images and on the corresponding CT or radiographic image with the aid of available literature. RESULTS: Radiographic and CT images provided high detail for visualization of bony structures; soft tissues were not easily identified on radiographic and CT images. CONCLUSIONS AND CLINICAL RELEVANCE: Results provide an atlas of stratigraphic and cross-sectional gross anatomy and radiographic and CT anatomy of the heads of boa constrictors that might be useful in the interpretation of any imaging modality in this species.

Effect of contrast medium injection duration on peak enhancement and time to peak enhancement of canine pulmonary arteries.

Our goal was to investigate the effect of contrast medium injection duration on pulmonary artery peak enhancement and time to peak enhancement. Fourteen dogs were allocated into one of seven predefined weight categories, each category contained two dogs. Dogs in each weight category were assigned to group A or B. Animals in each group received a different contrast medium injection protocol. In group A, a fixed injection rate of 5 ml/s was used. In group B, the contrast injection rate was calculated as follows: flow rate= contrast volume/scan duration + 10s. Time to peak enhancement and peak enhancement of the main left and right pulmonary arteries were measured on single-level, dynamic CT images for a fixed time of 30s. Rank correlation (Spearman's) coefficients between injection duration and time to peak enhancement and between body weight and peak enhancement were calculated. For group A, there was a significant negative correlation between peak enhancement and weight (r = -0.94; P = 0.005), while for group B, there was no significant correlation (r = -0.64 and P = 0.18). There was a significant correlation between time to peak enhancement and injection duration in both groups (group A: r = 0.99; P = 0.006 and group B: r = 0.85; P = 0.02). In conclusion, injection duration is a key feature in a CT angiography injection protocol. A protocol with an injection duration adjusted to the scan duration seems to be particularly suitable for veterinary applications where a population with great weight variability is studied.

Virtopsy in a red kangaroo with oral osteomyelitis.

This report describes the use of computed tomography (CT) in a nondomestic species. Postmortem CT was performed on a red kangaroo (Macropus rufus) and a diagnosis of oral osteomyelitis was made. CT examination revealed bony remodeling of the right mandible, an intraosseous lesion of the right temporal bone, muscle necrosis around the right mandible, and the absence of the right, first, upper molar tooth. Cardiac and intrahepatic gas and a distended intestine due to postmortem gas accumulation were also seen. All the lesions identified with CT were also identified by conventional necropsy, except the cardiac and intrahepatic gases. Virtopsy may be a useful procedure for the noninvasive identification of cause of death and as a guide for necropsy in animals.

Simultaneous acquisition of dual analyser-based phase contrast X-ray images for small animal imaging.

Analyser-based phase contrast X-ray imaging can provide high-contrast images of biological tissues with exquisite sensitivity to the boundaries between tissues. The phase and absorption information can be extracted by processing multiple images acquired at different analyser orientations. Recording both the transmitted and diffracted beams from a thin Laue analyser crystal can make phase retrieval possible for dynamic systems by allowing full field imaging. This technique was used to image the thorax of a mechanically ventilated newborn rabbit pup using a 25 keV beam from the SPring-8 synchrotron radiation facility. The diffracted image was produced from the (111) planes of a 50 mm x 40 mm, 100 microm thick Si analyser crystal in the Laue geometry. The beam and analyser were large enough to image the entire chest, making it possible to observe changes in anatomy with high contrast and spatial resolution.

A case of adrenal gland dependent hyperadrenocorticism with mitotane therapy in a Yorkshire terrier dog.

Hyperadrenocorticism, a disorder characterized by excessive production of cortisol by the adrenal cortex, is well-recognized in dogs. A 10-year-old, intact male, Yorkshire terrier dog was evaluated because of corneal ulceration and generalized alopecia. Diagnosis was made based on history taking, clinical signs, physical examination, and results of routine laboratory testing (complete blood count, serum biochemical analysis, and urinalysis). In addition, adrenocorticotropic hormone (ACTH) stimulation test and abdominal ultrasonography were also used to diagnose this case. The patient was diagnosed as adrenal gland neoplasia and medical therapy using the adrenocorticolytic agent, mitotane, was initiated. An ACTH stimulation test was performed after initial therapy. After successful induction was obtained, maintenance therapy with mitotane still continued.

A case of adrenal gland dependent hyperadrenocorticism with mitotane therapy in a Yorkshire terrier dog

Hyperadrenocorticism, a disorder characterized by excessive production of cortisol by the adrenal cortex, is wellrecognized in dogs. A 10-year-old, intact male, Yorkshire terrier dog was evaluated because of corneal ulceration and generalized alopecia. Diagnosis was made based on history taking, clinical signs, physical examination, and results of routine laboratory testing (complete blood count, serum biochemical analysis, and urinalysis). In addition, adrenocorticotropic hormone (ACTH) stimulation test and abdominal ultrasonography were also used to diagnose this case. The patient was diagnosed as adrenal gland neoplasia and medical therapy using the adrenocorticolytic agent, mitotane, was initiated. An ACTH stimulation test was performed after initial therapy. After successful induction was obtained, maintenance therapy with mitotane still continued.

[Sacral osteochondrosis dissecans in a Bernese Mountain Dog: diagnosis and treatment]. / Osteochondrosis dissecans am Sakrum einer Berner Sennenhündin: Diagnostische und therapeutische Aspekte.

A 18-month-old female Bernese Mountain Dog with chronic pain at jumping, extension of the right hind leg and paresis of the tail was referred to the Neurological Service of the Veterinary Hospital of the University of Zurich. Upon radiological examination a mineralised fragment at the dorsal aspect of the endplate of S1 was detected. The diagnosis of Osteochondrosis dissecans was confirmed by linear and computed tomography as well as histologic examination of the fragment, which was surgically removed. Preoperative imaging allowed a minimal surgical approach using a unilateral, modified dorsal laminectomy. Outcome was evaluated by neurological reevaluation and a CT scan performed 6 months after surgery.

Elbow dysplasia in the dog: pathophysiology, diagnosis and control.

Elbow dysplasia is a non-specific term denoting abnormal development of the elbow. Elbow dysplasia encompasses the clinical and radiographic manifestation of ununited anconeal process, fragmented medical coronoid process, osteochondritis dissecans, erosive cartilage lesions and elbow incongruity. The net result is elbow arthrosis, which may be clinically inapparent or result in marked lameness. These conditions may be diagnosed by means of routine or special radiographic views and other imaging modalities, or the precise cause of the arthrosis or lameness may remain undetermined. Breeds most commonly affected are the rottweiler, Bernese mountain dog, Labrador and golden retriever and the German shepherd dog. Certain breeds are more susceptible to a particular form of elbow dysplasia and more than 1 component may occur simultaneously. The various conditions are thought to result from osteochondrosis of the articular or physeal cartilage that results in disparate growth of the radius and ulna. Heritability has been proven for this polygenic condition and screening programmes to select suitable breeding stock have been initiated in several countries and have decreased the incidence of elbow dysplasia.

Comparison of radiologic imaging techniques for diagnosis of fragmented medial coronoid process of the cubital joint in dogs.

Thirty cubital joints from 16 dogs suspected of having a fragmented medial coronoid process were examined. Four breeds accounted for 87.5% of the cases: German Shepherd Dog (25%), Labrador Retriever (25%), Rottweiler (18.75%), and Golden Retriever (18.75%). Seventy-five percent of the dogs were male. Mean age of affected dogs was 13.6 months. Plain-film radiography, xeroradiography, linear tomography, arthrography, and computed tomography were performed on each cubital joint prior to surgical exploration of the joint. Three reviewers evaluated each diagnostic study and independently determined whether a fragment from the medial coronoid process could be seen. The consensus opinion was compared with the finding at surgery. Abnormalities of the medial coronoid process were detected in 25 of 30 joints at surgery. Fragmented coronoid process was found in 17 of 30 joints, and wear lesions were observed in 8 of 30 joints. Computed tomography had the highest accuracy (86.7%), sensitivity (88.2%), and negative-predictive value (84.6%) of the 5 imaging modalities evaluated (P < 0.05). Specificity and positive-predictive value of all imaging techniques were high. There was no significant difference between the diagnostic ability of plain-film radiography, xeroradiography, or linear tomography of the cubital joint. The combination of plain-film radiography and linear tomography provided an improvement in accuracy, approaching that of computed tomography.

Nephrotomography and ultrasonography for the localization of hyperfunctioning adrenocortical tumors in dogs.

Nephrotomography and ultrasonography were used in 11 dogs with hyperadrenocroticism to assess the value of these techniques for the localization of biochemically diagnosed hyperfunctioning adrenocortical tumors. Both techniques enabled accurate localization of a unilateral adrenal mass in each of the dogs. Cross-sectional diameters of the masses ranged from 1 to 4 cm. In 1 dog, expansion of tumor into the caudal vena cava was revealed by caudal venacavography and ultrasonography. Mineralization in the tumor mass in 2 dogs was easily recognized by nephrotomography, but not by ultrasonography. Paracostal laparotomy confirmed the presence of an adrenocortical tumor in each dog, and expansion of tumor into the caudal vena cava in 1 dog. Cross-sectional diameters of the tumors ranged from 1.2 to 4.5 cm and corresponded well with cross-sectional measurements by nephrotomography and ultrasonography. It was concluded that nephrotomography and ultrasonography have similar diagnostic accuracies for the detection and localization of hyperfunctioning adrenocortical tumors.

X-ray-computed tomography, nephrotomography, and ultrasonography of the adrenal glands of healthy dogs.

X-ray-computed tomography (CT), nephrotomography, and ultrasonography were performed in 10 clinically healthy dogs (weighing 14 to 33 kg) to visualize the adrenal glands. In all 10 dogs, CT enabled visualization of both adrenal glands. Cross-sectional diameter was measured accurately. The size and shape of CT sections of the adrenal glands varied widely because of individual differences in the actual size and shape of the adrenal glands and because of their position in the plane of the CT scans. In 5 dogs, nephrotomography enabled visualization of 1 or both adrenal glands as oblong craniocaudal-directed densities in the craniodorsal portion of the abdomen. In 7 dogs, transverse ultrasonography enabled visualization of 1 or both adrenal glands as round or oval hypoechoic structures in the surrounding hyperechoic fat.

The effect of partial rostral hemimandibulectomy on mandibular mobility and temporomandibular joint morphology in the dog.

Partial rostral hemimandibulectomy was performed in 10 adult dogs. The temporomandibular joints (TMJs) were examined radiographically and tomographically before surgery, and mandibular stability was evaluated before and immediately after surgery. Radiographic, tomographic, and hemimandibular mobility assessments were made again at months 3 and 6. The TMJs were examined grossly and histologically in five dogs euthanatized at month 3 and in five dogs euthanatized at month 6. Statistically significant hemimandibular instability (p less than 0.05) persisted in all subjects throughout the study. The radiographic appearance of the joints remained unaltered; however, space asymmetry was identified in postoperative tomograms of three dogs at month 3 and four dogs at month 6. The TMJs were grossly normal at necropsy. Histologically, there were degenerative changes in articular cartilage and subchondral bone in all of the joints. The authors conclude that partial rostral hemimandibulectomy causes TMJ degeneration, as a consequence of hemimandibular instability or abnormal loading, or both.

[Tomography in veterinary medicine. Possibilities for the application of this x-ray technic demonstrated on the spinal column of a dog]. / Tomographie in der Veterinärmedizin. Anwendungsmöglichkeiten dieser Röntgentechnik am Beispiel der Wirbelsäule des Hundes.

After a short introduction of theoretical principles of tomography, the advantages of this technique--especially the representation of the dog's spinal column--are discussed with five case histories. This technique allows to produce isolated pictures of special parts of the spinal column which may be superpositioned by other body parts like: atlantooccipitalregion (especially dens axis), caudal cervical spine, thoracical spine and lumbosacral region. Particularly the evaluation of the intervertebral spaces, the small vertebral joints and the contours and structures of the vertebrae is enhanced, which is important in tumorous and infectious processes, as well as in fractures and luxations of the vertebrae. Besides the spatial association of certain structures is possible if their localization with conventional x-ray methods and even with exposures in two planes is unsuccessful.