APPEARANCE OF THE SACROILIAC JOINT IN VENTRODORSAL RADIOGRAPHS OF THE NORMAL CANINE PELVIS

Radiology of the canine sacroiliac (SI) joint was investigated by obtaining ventrodorsal radiographs of cadaveric pelves and bone specimens (n = 40) marked with solder wire or radiopaque paint to demonstrate the orientation of the sacroiliac joint in various radiographic views. In the following retrospective radiographic study (n = 94 survey sacroiliac joint radiographs), central projections of the sacrum were noted to ease identification of the dorsal, middle and ventral joint components, whereas angled projections of the sacrum had advantages when assessing the cranial joint components. Radiographic assessment was already successful in juvenile dogs older than 5 months. Failure in tracing the outlines of the joint space of the sacroiliac joints is not consistent with alteration of the SI joint. Rather, it was felt that alterations would have assisted in identifying the contours of the SI joints because of an increase in mineralization.     

EMPHYSEMATOUS PYOMETRA IN A DOG

An 8-year-old intact female West Highland White Terrier was examined for anorexia, vomiting, abdominal distension, and mild purulent vulvar discharge. The results of physical examination, laboratory testing, and radiography are presented. Emphysematous pyometra was suspected and confirmed at surgery. Clostridium perfringens was isolated from the uterine lumen. A brief discussion of emphysematous pyometra is presented.     

CRANIAL MEDIASTINAL CYSTS IN NINE CATS

Nine cats, from 11 to 17 years of age (mean 13.6 years of age), were diagnosed with a cranial mediastinal cyst. Thoracic radiographs in all cats were characterized by an increased soft tissue opacity in the cranial mediastinum confirmed to be a cyst by ultrasonography or necropsy. Ultrasonographically cysts appeared as an anechoic mass. A low-cellularity clear fluid was obtained on aspiration. The majority of the cats (n = 8) presented for unrelated conditions with no signs of respiratory distress. No treatment for the cyst was pursued except for drainage during ultrasonographic-guided aspiration in several cats. On follow-up of eight cats, none were symptomatic for the cyst from 3-45 months after diagnosis. Mediastinal cyst should be considered when a cranial mediastinal mass is evident radiographically in an older cat. The majority of feline cranial mediastinal cysts are benign with no need for treatment.     

Cone beam computed tomography and intraoral radiography for diagnosis of dental abnormalities in dogs and cats

The development of veterinary dentistry has substantially improved the ability to diagnose canine and feline dental abnormalities. Consequently, examinations previously performed only on humans are now available for small animals, thus improving the diagnostic quality. This has increased the need for technical qualification of veterinary professionals and increased technological investments. This study evaluated the use of cone beam computed tomography and intraoral radiography as complementary exams for diagnosing dental abnormalities in dogs and cats. Cone beam computed tomography was provided faster image acquisition with high image quality, was associated with low ionizing radiation levels, enabled image editing, and reduced the exam duration. Our results showed that radiography was an effective method for dental radiographic examination with low cost and fast execution times, and can be performed during surgical procedures.     

PSITTACINE SKULL RADIOGRAPHY

The psittacine skull is a complex anatomic structure, frequently traumatized but difficult to adequately image with standard radiographic procedures. Multiple views including a ventrodorsal, a lateral, and complementary oblique projections are necessary to fully evaluate potential skull fractures in the avian patient. Magnification radiography is a relatively easy procedure that aids the review of small osseous structures. Familiarity with psittacine skull anatomy greatly facilitates radiographic interpretation of cranial trauma.     

EVALUATION OF THE VARIABLY OSSIFIED COLLATERAL CARTILAGES OF THE DISTAL PHALANX AND ADJACENT ANATOMIC STRUCTURES IN THE FINNHORSE WITH COMPUTED TOMOGRAPHY AND MAGNETIC RESONANCE IMAGING

Six Finnhorse cadaver forefeet were selected to represent radiographically different types and grades of ossification of the collateral cartilages of the distal phalanx. These cartilages and adjacent tissues were evaluated with computed tomography (CT) and high field magnetic resonance imaging (MRI). In CT the internal structure of the cartilages was consistent, but in MRI some differences were noted. The shape of the collateral cartilages and their ligamentous attachments varied. The border between ossified and non-ossified cartilage appeared distinct, with considerable variation in the extent of the ossified area in regard to the cross-sectional area of the cartilage. Ossification originating from the palmar processes and extending in the proximaVpalmaroproximal direction, without separate centers of ossification, generally appeared smooth and inactive. Palmar ossification followed the irregular shape of the cartilage. Separate centers of ossification had a medullary cavity or were sclerotic. Presence ofamedullary cavity or sclerosis were also found at the base of the cartilages. The incomplete fusion lines between separate centres of ossification and the ossified base of the cartilage varied from congruent and inactive to reactive with marked sclerosis, flared margins and parachondral changes. Incomplete fusion may be clinically significant. Local conformational adaptations of the hoof were also documented with extensive ossification of the collateral cartilage.     

A COMPARISON OF RADIOGRAPHY, COMPUTED TOMOGRAPHY, AND MAGNETIC RESONANCE IMAGING FOR THE DIAGNOSIS OF PALMAR PROCESS FRACTURES IN FOALS

The relative sensitivity of radiography, computed tomography, and magnetic resonance imaging for detecting palmar process fractures of the distal phalanx in foals was determined and the imaging findings were compared with histomorphologic evaluations of the palmar processes. Compared to radiography, computed tomography and magnetic resonance imaging did not improve the sensitivity for detection of palmar process fractures. Statistical agreement for palmar process fracture diagnosis was excellent among the three imaging modalities. Histomorphologic evaluations were more sensitive for diagnosis of palmar process fracture than any of the imaging modalities. Three-dimensional image reconstructions and volume measurements of distal phalanges and palmar process fracture fragments from computed tomography studies provided more complete anatomical information than radiography. Magnetic resonance imaging confirmed that the deep digital flexor tendon insertion on the distal phalanx is immediately axial to the site where palmar process fractures occur, and differentiated cartilage, bone, and soft tissue structures of the hoof.     

ACCURACY OF SURVEY RADIOGRAPHIC DIAGNOSIS OF INTERVERTEBRAL DISC PROTRUSION IN DOGS

To assess the diagnostic accuracy of survey radiography for canine thoracolumbar intervertebral disc protrusion, survey radiographs (lateral and ventrodorsal) of 64 dogs with surgically-confirmed thoracolumbar intervertebral disc protrusion, 51 dogs with negative myelograms and 29 dogs with various spinal conditions other than disc protrusion were reviewed by three independent observers who were unaware of any clinical information. There were marked differences in observer performance for diagnosis of intervertebral disc protrusion, although there were no significant differences in intraobserver diagnostic accuracy for small vs. large dogs. Accuracy of observers for determining sites of intervertebral disc protrusion using survey radiography was in the range 51-61%. All observers had low accuracy for identification of second sites of intervertebral disc protrusion. The most useful radiographic sign, narrowed intervertebral space, had only moderate sensitivity (range 64-69%) and moderate predictive value (range 63-71%) for intervertebral disc protrusion. Vacuum phenomenon was an infrequent but accurate sign of intervertebral disc protrusion. Recognition of multiple radiographic signs of intervertebral disc protrusion at one site was associated with increased accuracy of diagnosis. No observer was accurate enough to justify attempting targeted surgical treatment of intervertebral disc protrusion without myelography.     

CEREBRAL SINUS VENOGRAPHY IN THE DOG: A NEW TECHNIQUE

A new of performing cerebral sinus venography was developed that opacivies both the ventral and most of the dorsal venous sinus systems. A pediatric angiographic catheter was introduced into the external jugular vein and advanced to the level of the temporal sinus. Iodinated contrast medium was injected manually and radiographs were made. Subtraction radiography was used to visualize vessels field wit contast medium. Venography was simple and relatively non-invasive and was considered safe. The technique was used to confirm occlusion of the transverse venous sinus in healthy dogs that had undergone radical craniectomies.     

Role of navicular bone shape in the pathogenesis of navicular disease: a radiological study

From progeny lists of 30 Dutch Warmblood sires, 586 3-year-old females by these stallions were randomly selected, each progeny group aimed at 20 animals for statistical reasons. The front feet of the sires and female progeny were examined radiographically using lateromedial and dorsopalmar upright pedal projections. The radiological features associated with navicular disease were classified 0–4 using a standardised classification, grades 3 and 4 representing the more severe changes. The shape of the proximal articular border of the navicular bone outlined on the dorsopalmar view was classified 1–4: l=concave; 2=undulating; 3=straight; 4=convex. A significant shape-grade association was found, the highest grades 3 and 4 incidence associated with shape 1 and the lowest grades 3 and 4 incidence demonstrated by shape 4. In shapes 1 and 2, navicular bones grades 3 and 4 features were mainly characterised by inverted flask-shaped channels. In shape 3, navicular bones grades 3 and 4 were dominated by enthesiophytes. These findings indicate an apparent shape predisposition to radiological changes associated with navicular disease. The shape of the navicular bone in the offspring was on average the same as the sire, indicating an hereditary element in navicular bone shape.