The Relationship between Brachycephalic Head Features in Modern Persian Cats and Dysmorphologies of the Skull and Internal Hydrocephalus.

BACKGROUND: Cat breeders observed a frequent occurrence of internal hydrocephalus in Persian cats with extreme brachycephalic head morphology. OBJECTIVE: To investigate a possible relationship among the grade of brachycephaly, ventricular dilatation, and skull dysmorphologies in Persian cats. ANIMALS: 92 Persian-, 10 Domestic shorthair cats. METHODS: The grade of brachycephaly was determined on skull models based on CT datasets. Cranial measurements were examined with regard to a possible correlation with relative ventricular volume, and cranial capacity. Persians with high (peke-face Persians) and lower grades of brachycephaly (doll-face Persians) were investigated for the presence of skull dysmorphologies. RESULTS: The mean cranial index of the peke-face Persians (0.97 ± 0.14) was significantly higher than the mean cranial index of doll-face Persians (0.66 ± 0.04; P < 0.001). Peke-face Persians had a lower relative nasal bone length (0.15 ± 0.04) compared to doll-face (0.29 ± 0.08; P < 0.001). The endocranial volume was significantly lower in doll-face than peke-face Persians (89.6 ± 1.27% versus 91.76 ± 2.07%; P < 0.001). The cranial index was significantly correlated with this variable (Spearman's r: 0.7; P < 0.0001). Mean ventricle: Brain ratio of the peke-face group (0.159 ± 0.14) was significantly higher compared to doll-face Persians (0.015 ± 0.01; P < 0.001). CONCLUSION AND CLINICAL RELEVANCE: High grades of brachycephaly are also associated with malformations of the calvarial and facial bones as well as dental malformations. As these dysmorphologies can affect animal welfare, the selection for extreme forms of brachycephaly in Persian cats should be reconsidered.

[Computed tomographic anatomy of the salivary glands in the cat]. / Computertomographische Anatomie der Speicheldrüsen der Katze.

OBJECTIVE: The aim of the study was to define anatomical characteristics of the feline salivary glands in cross-sectional images obtained by unenhanced computed tomography (CT) and to describe landmarks for a reliable identification. MATERIAL AND METHODS: Heads of adult normocephalic cats without indications of cephalic disease were examined. Cats were included in the prospective part of the study when examined no later than 1 hour post mortem (n = 16). In the retrospective part of the study, previous CT-studies were evaluated (n = 25). The results of both groups were evaluated separately. Initially, the possibility of identifying and delineating the salivary glands from the surrounding tissue was assessed. Anatomical structures of the head were then defined as landmarks. Dimensions and density (Hounsfield units, HU) of the salivary glands were determined based on transversal and reconstructed sagittal images. RESULTS: In total, 94.3% of the parotid glands, 90.7% of the mandibular glands and 96.8% of the zygomatic glands could be delineated. The remaining salivary glands could not be identified. Anatomical landmarks, including the external ear canal, the musculus (M.) masseter, the M. pterygoideus medialis and the bulbus oculi facilitated the identification. Comparing the size of the salivary glands of both groups revealed differences (measured lateromedially and rostrocaudally) in size of ≤   2 mm. The definable salivary glands varied significantly in their density. The mean density of the glandula (Gl.) parotis was 65 HU, of the Gl. mandibularis 62 HU and of the Gl. zygomatica 57 HU. The comparisons of densities of both sides of the glands did not show statistically significant differences. CONCLUSIONS: The large salivary glands (Gl. parotis and Gl. mandibularis) and the Gl. zygomatica of the cat can be reliably identified in CT-images. CT landmarks and data regarding the size and density of each gland could be gathered. The remaining minor salivary glands could not be delineated accurately. The difference in depicting the glands can be explained mainly by a lack of contrast with the surrounding tissue.

[Computed tomography with computer-assisted detection of pulmonary nodules in dogs and cats]. / Computertomographische Untersuchungen mit computerassistierter Detektion von pulmonalen Rundherden bei Hund und Katze.

OBJECTIVE: The aim of this study was to assess the potential benefit of computer-assisted detection (CAD) of pulmonary nodules in veterinary medicine. Therefore, the CAD rate was compared to the detection rates of two individual examiners in terms of its sensitivity and false-positive findings. MATERIALS AND METHODS: We included 51 dogs and 16 cats with pulmonary nodules previously diagnosed by computed tomography. First, the number of nodules ≥ 3 mm was recorded for each patient by two independent examiners. Subsequently, each examiner used the CAD software for automated nodule detection. With the knowledge of the CAD results, a final consensus decision on the number of nodules was achieved. The software used was a commercially available CAD program. RESULTS: The sensitivity of examiner 1 was 89.2%, while that of examiner 2 reached 87.4%. CAD had a sensitivity of 69.4%. With CAD, the sensitivity of examiner 1 increased to 94.7% and that of examiner 2 to 90.8%. CONCLUSION AND CLINICAL RELEVANCE: The CAD-system, which we used in our study, had a moderate sensitivity of 69.4%. Despite its severe limitations, with a high level of false-positive and false-negative results, CAD increased the examiners' sensitivity. Therefore, its supportive role in diagnostics appears to be evident.

Colonic cyst in a cat presenting recurrent constipation and abdominal pain.

A 5-year-old domestic short-haired spayed female cat was presented for abdominal pain and suspended defecation. Abdominal radiographs confirmed constipation; abdominal ultrasonography showed a cystic oval structure attached to the colon. The structure exhibited a well-defined wall, composed of three layers. Its content was mildly echogenic and inhomogeneous. Laparotomy was performed and complete resection of the structure, and of part of the colon, was required (end-to-end anastomosis). Histopathology confirmed the structure to be a cystic formation of the colon with some areas of mucosal metaplasia. However the question whether the cystic structure was consistent with an intestinal duplication cyst - which is the most likely type of cyst in this particular case - a Meckel's diverticulum remnant, a vitelline duct cyst or a cystic diverticulum of the colon could not be resolved. Postoperatively, no further other episode of constipation occurred.

[Options for the reduction of magnetic susceptibility artifacts caused by implanted microchips in 0.5 Tesla magnetic resonance imaging]. / Möglichkeiten zur Reduktion von Suszeptibilitätsartefakten durch Mikrochips bei Untersuchungen im 0,5-Tesla-Magnetresonanztomographen.

OBJECTIVE: Microchips contain ferromagnetic materials, which lead to severe focal image interferences when performing magnetic resonance imaging (MRI). Very small animals are particularly prone to these susceptibility artifacts, which may hinder analysis of the neck-region MRI image. We investigated the impact of sequence type on the artifact's size and determined the optimal imaging parameters to minimize these artifacts. Furthermore, the minimum distance between the microchip and the spinal canal required to assess the spinal structures should be determined. MATERIAL AND METHODS: Investigations were performed on the cadavers of 26 cats and two dogs using a low-field MRI System (field strength 0.5 Tesla). To quantify susceptibility artifacts, several sequence types (spin echo, turbo-spin echo (TSE), gradient echo) and imaging parameters (echo time (TE), voxel volume, frequency direction) were systematically varied. Additionally, computed tomography imaging was performed to determine the distance between the microchip and the spinal canal. RESULTS: The size of the artifact was smallest with T1-weighted TSE sequences. A short TE (10 ms) and a small voxel size (acquisition matrix 256 x 256 pixels, field of view 160 mm, slice thickness 2 mm) significantly reduced artifact size. Furthermore, it could be shown that by changing the frequency- and phase-encoding direction, the shape and orientation of the maximum dimension of the artifact could be influenced. Even when using an optimized T1-weighted TSE sequence, it was impossible to evaluate the spinal cord when the distance between the microchip and the center of the spinal canal was < 19  mm. CONCLUSION AND CLINICAL RELEVANCE: In MR studies of the cervical spine of small dogs and cats, microchips can cause severe susceptibility artifacts. Because of the small distance between the microchip and the spinal structures, spinal evaluation may be limited or impossible. The investigations demonstrated that the adjustment of sequence parameters helps to significantly minimize artifact size and shape. The greatest reduction in artifact size was achieved by using a T1-weighted TSE sequence.

Morphometrical analysis of the thoracolumbar dural sac in sheep using computed assisted myelography.

OBJECTIVES: Sheep are frequently used as animal models in experimental spinal injury studies. Therefore, extensive knowledge of ovine spinal dimensions is essential for experimental design and interpretation of results obtained in these trials. This study aimed to obtain quantitative morphometrical data of the thoracolumbar dural sac in sheep and determine the anatomical relationship between the dural sac and the vertebral canal. METHODS: Computed assisted myelography imaging was carried out in five adult German Black-Headed Mutton sheep under general anaesthesia. Transverse images were acquired with 2 mm slice thickness from the first thoracic to the sixth lumbar vertebrae. Sagittal and transverse diameters and the cross-sectional area of the dural sac and vertebral canal were measured. To determine the anatomical relationship between the dural sac and vertebral canal, the pedicle-dural sac distance (PPSD) and the epidural space as well as the SAC (available space for the dural sac) were calculated. RESULTS: Sagittal diameters of the dural sac ranged from 5.1 to 12.0 mm. Transverse diameters ranged from 5.6 to 12.2 mm. The dural sac area covered 45.9% and 49.0% of the thoracic and lumbar vertebral canal area. The PDSD in the lumbar vertebrae was up to 15.8% larger than in the thoracic ones. The dural sac area was significantly positively correlated with the transverse diameter and area of the vertebral canal. CLINICAL SIGNIFICANCE: The lumbar vertebral canal contained more space for the dural sac, which seems to be safer for testing spinal implants.

[Comparison of projection radiography and computed tomography for the detection of pulmonary nodules in the dog and cat]. / Vergleich von Projektionsradiographie und Computertomographie zur Detektion pulmonaler Rundherde bei Hund und Katze.

OBJECTIVE: The aim of our study was to evaluate the value of projection radiography as a standard screening method for the detection of lung nodules compared to computed tomography (CT). Furthermore, we attempted to describe the reasons that might lead to a failed detection of pulmonary nodules in radiography. MATERIALS AND METHODS: From dogs and cats which were diagnosed in CT (multislice CT) with nodular changes in the lung pattern we selected radiographs (projection radiography with soft copy reading) in at least two projection planes produced in the same timeframe as the CT images. Exclusion criteria were nodules > 3 cm and homogenously calcified nodules (osteomata). A total of 70 animals (50 dogs and 20 cats) met the inclusion criteria. RESULTS: In 43 animals (61%), nodular changes had already been detected using radiography and were then confirmed by the results of the computed tomography. In detail, 32 of 50 dogs (64%) and 11 of 20 cats (55%) showed nodular lesions in the radiographs. In cats, undetected nodules were often accompanied by highly changed lung opacities, resulting in a poor contrast of the lung. In dogs the reasons for a failed detection of lung nodules were relatively equally distributed to several causes. Interestingly, small nodule size itself was not the predominant reason for missing the nodules in radiographs. CONCLUSION AND CLINICAL RELEVANCE: In general, radiography still plays an important role as a screening method for the detection of nodular lung lesions. However, one needs to be aware, that a quite high percentage of nodular lung changes can be missed in radiographs. The overall detection rate in this study was 61%. Furthermore, we showed that plane radiographs are of poor diagnostic value when concurrent problems exist which lead to increased lung opacity.

Magnetic resonance imaging of plantar soft tissue structures of the tarsus and proximal metatarsus in foals and adult horses.

OBJECTIVES: The object of this study was to describe previously defined soft tissue structures by using spin and gradient sequences in a 0.5 Tesla magnetic resonance system in order to improve the characterisation of tendon and ligaments at the plantar region of the equine tarsus and metatarsus while considering possible age-related variations. METHODS: Cadaveric hindlimbs from twenty-two Warmblood horses with an age range from one month to twenty-five years were examined in spin and gradient echoes. The proximal suspensory ligament from six limbs was dissected to assign the signal intensities histologically. For statistical analysis, horses were divided into two groups (≤3 years and >3 years) for evaluating signal intensity and homogeneity of the plantar tendons and ligaments. RESULTS: Focal increase of the signal intensity within the deep digital flexor tendon was significantly more present in horses older than three years. Signal alterations of the long plantar ligament were seen without a significant dependency to age. The accessory ligament of the deep digital flexor tendon could not be visualized on all images within the region of interest. The morphology of the proximal suspensory ligament was not affected by age-related changes. CLINICAL RELEVANCE: Spin and gradient echoes in MRI were suitable to identify and assess soft tissue structures at the plantar aspect of the equine tarsus and proximal metatarsus. Age-related appearance must be considered when interpreting magnetic resonance images.

The vacuum phenomenon in intervertebral disc disease of dogs based on computed tomography images.

OBJECTIVES: Vacuum phenomenon is suspected to be indicative of disc degeneration and subsequent herniation. The objective of this study was to assess the reliability of vacuum phenomenon for identification of herniated discs causing neurological signs. Prevalence of vacuum phenomenon and influencing factors in dogs with disc herniation were determined. METHODS: Retrospective review of computed tomography scans from dogs with suspected disc herniation for the presence of gas within intervertebral disc space with subsequent comparison of vacuum phenomenon and herniated disc as confirmed by surgery. Subgroups were created (chondrodystrophic, non-chondrodystrophic and unknown classification) to analyse prevalence and influencing factors (age, breed and gender) for vacuum phenomenon and agreement with herniated disc. RESULTS: Prevalence of vacuum phenomenon in all dogs, chondrodystrophic, non-chondrodystrophic dogs and those with unknown classification was 19·8, 14·9, 35·7 and 24·5%, respectively. Corresponding correlation rate between vacuum phenomenon and herniated disc was 64, 67, 40 and 82%. Prevalence of vacuum phenomenon was significantly higher in nonchondrodystrophic dogs (P=0·04). Age was the only factor influencing prevalence of vacuum phenomenon (P=0·04). CLINICAL SIGNIFICANCE: In dogs with intervertebral disc disease, vacuum phenomenon is a frequent but inconsistent finding. Although helpful to identify degenerated discs, it is not suitable to identify currently herniated disc with sufficient accuracy.

[Multiphasic contrast-enhanced CT: correlation of the peak attenuation in the aorta abdominalis and portal vein with easily detectable clinical parameters]. / Multiphasen-Kontrastcomputertomographie: Korrelation der Anreicherungskurven in Aorta abdominalis und Vena portae mit einfach klinisch messbaren Parametern.

OBJECTIVE: The diagnostic value of a multiphase CT strongly depends on the correct timepoints of analysis. Therefore, we investigated whether the peak attenuation time in the aorta and portal vein are predictable using easily detectable clinical parameters. Regression equations were developed that enable an approximate prediction of these scan times. MATERIAL AND METHODS: Contrast dynamic CT was performed in 39 anaesthetised dogs of different breeds. The heart rate at the onset of the examination, the age and the body weight were documented. The contrast agent Imeron 300® was injected into a cephalic vein at 3 ml/s with 600 mg iodine/kg body weight using an automatic injector and a dynamic axial CT was started at the same time. The peak enhancement time in the aorta (pETA) and portal vein (pETP) were measured. RESULTS: The mean pETA was 24.5 ± 8.6 seconds and the mean pETP was 43.6 ± 13.4 seconds. There was a strong correlation (r = 0.92) between pETA and body weight in combination with the heart rate, and a moderate correlation (r = 0.66) between pETP and body weight in combination with the age. The regression equation was: pETA = 12.23 + 0.61 body weight - 0.07 heart rate. The time between pETA and pETP was 8-24 seconds in 34 animals. CONCLUSION: To plan the arterial peak the authors recommend the use of the established regression equations based on the statistical results or alternatively bolus tracking to plan the arterial peak. When it is planned to examine the portal venous peak, an interscan duration of 8-14 seconds is recommended.

[Magnetic resonance imaging of the temporomandibular joint in dogs and cats. Effect of different coils on image quality]. / Magnetresonanztomographische Untersuchung des Kiefergelenks von Hund und Katze. Einfluss unterschiedlicher Spulen auf die Bildqualität.

OBJECTIVE: In magnetic resonance imaging (MRI) the image quality is considerably affected by the coil used, particularly when small structures are examined. The purpose of this study was to determine which coil provides the best scanning results for imaging of the temporomandibular joint (TMJ) of dogs and cats. MATERIAL AND METHODS: MRI investigations were performed using a standard human knee coil and an 8-cm-diameter surface coil with a low-field MRI-system (field strength 0.5 T). TMJs of two dogs and two cats were examined. The scan protocol consisted of T1-weighted spin echo (T1W/SE), T2-weighted turbo spin echo (T2W/TSE), a proton density-weighted sequence (PDW) (slice thickness: 3 mm each), and gradient echo sequences (slice thickness: 1-1.5 mm) in the sagittal plane. Three observers independently compared the features "contrast resolution", "bone structure", "spatial resolution", and "signal-to-noise ratio" (SNR) using a 5-point scale. Investigators were blinded with respect to the coils used. RESULTS: Approximately 50% of the images obtained by the use of the surface coil were rated superior in comparison with the knee coil in terms of the features "contrast resolution", "bone structure", and "spatial resolution". In approximately 50% of the MRI-images no differences in the ratings were seen. With respect to the criterion "signal-to-noise ratio" 90% of the images acquired with the surface coil were rated better. In 5% of the images an identical quality was recorded. The surface coil proved to be superior both in dogs and cats. CONCLUSIONS AND CLINICAL RELEVANCE: Display quality of small structures of the TMJ is dependent on the spatial resolution of the MR images. Therefore, a dedicated coil and a small field of view (FOV) should be used. Results reveal that low-field MRI is able to display subtle anatomic structures of the TMJ in dogs and cats. In principle, the results can be transmitted to other MRI-systems. However, to generate valid scan protocols it is necessary to adapt scan parameters and coil selection specifically.

[Computed tomography imaging of the temporomandibular joint in dogs and cats. Effects of different scan parameters on image quality]. / Computertomographische Darstellung des Kiefergelenks von Hund und Katze. Beeinflussung der Bildqualität durch unterschiedliche Aufnahmeparameter.

OBJECTIVE: Temporomandibular joints (TMJs) of dogs and cats were examined with multislice computed tomography (MSCT) using different technical scan parameters in order to investigate their impact on image quality. Another aspect was to analyze whether size differences of the TMJ affect the display of small joint structures. MATERIAL AND METHODS: The TMJs of two dogs and two cats were examined using MSCT. Scan parameters were varied including tube current, scan matrix, resolution mode, slice thickness, and reconstruction increment. Three observers being blinded with respect to the used scan parameters independently assessed the image quality in terms of "contrast resolution", "bone structure", "spatial resolution", "evaluation of the joint space", and "artefacts" according to a 4-point scale. RESULTS: The criteria "spatial resolution" and "evaluation of the joint space" emphasize the influence of the size of the TMJ. The image quality of the TMJ of the dogs was evaluated superior (by 0.5 to 1.5 points higher graded) compared to the smaller ones of the cats. In terms of "spatial resolution" and "bone structure" the images of an ultra high resolution technique achieved a higher evaluation level (scoring one point superior) compared to the images created by a high resolution protocol. The tube current did not significantly influence the image quality in any of the pictures. CONCLUSIONS AND CLINICAL RELEVANCE: The display quality of small structures of the TMJ is dependent on the spatial resolution of the CT images. Therefore, a thin slice collimation, a small field of view, and a high resolution reconstruction matrix should be used. Under those aspects subtle alterations of bone structure of the TMJ can be reliably detected. The soft tissue structures of the TMJ can not be visualized with MSCT in small animals. In principle, the results can be applied to any other MSCT-scanner. However, adjustments of the technical parameters may be still necessary.

[Comparison of the image quality of conventional and digital radiography in lizards. Mammography technique versus digital detector system]. / Vergleich der Bildqualität konventioneller und digitaler Radiographie bei Echsen. Mammographietechnik vs. digitales Detektorsystem.

OBJECTIVE: A conventional high-resolution screen-film system (Film Kodak MIN-R S, Kodak MIN-R 2000) was compared with an indirect digital detector system (Varian PaxScan 4030E) for use in radiography of lizards. MATERIAL AND METHODS: A total of 20 bearded dragons (Pogona vitticeps ) with body masses between 123 g and 487 g were investigated by using conventional and digital image acquisition techniques. The digital image was taken with the same dose as well as half the dose of the conventional radiograph. The study was conducted semi-blinded as the x-ray images were encoded and randomised. Five veterinarians with clinical experience in reptile medicine served as observers. Exactly defined structures in three anatomical regions were assessed using a three-step scale. Furthermore, the overall quality of the respective region was evaluated using a five-step scale. Evaluation of the data was done by visual grading analysis. RESULTS: None of the structures examined was assessed to be of significantly inferior quality on the digital images in comparison to the conventional radiographs. The majority of the results demonstrated an equal quality of both systems. For assessment of the lung tissue and the pulmonary vessels as well as the overall assessment of the lung, the digital radiographs with full dose were rated to be significantly superior in comparison to the film-screen system. Furthermore, the joint contours of the shoulder and cubital joints and the overall assessments of the humerus and the caudal coelomic cavity were rated significantly better on digital images with full dose compared to those with reduced dose. CONCLUSIONS: The digital flat panel detector technique examined in this study is equal or superior to the conventional high-resolution screen-film system used. Nevertheless, the practicability of a dose reduction is limited in bearded dragons. CLINICAL RELEVANCE: Digital imaging systems are progressively being used in veterinary practice. The results of the study demonstrate the useful application of the digital detector systems in lizards.

[Comparison of the image quality of a storage phospor system and a flat-panel detector in feline thoracic radiography]. / Vergleich der Bildqualität eines Speicherfoliensystems und eines Flachbilddetektors bei Thoraxröntgenaufnahmen von Katzen.

OBJECTIVE: The aim of the study was to compare the image quality of radiographs obtained with a storage phosphor (SP) system and a flat-panel detector (FD). Furthermore, the influence of different exposure settings was investigated. MATERIAL AND METHODS: In a prospective study a series of lateral thoracic radiographs of 45 normal cats were acquired by use of a standard SP-system and an opto-direct FD. From each animal four radiographs were taken with exposure settings adjusted to achieve sensitivity (S)-values of the system-specific dose indicator of S180 and S360. In a blind study, five observers rated the presentation of anatomical structures (trachea, cranial lung field, sternum, cardiac silhouette, caudal thoracic field) by use of a four-point scale (1 - excellent; 4 - insufficient). RESULTS: Independent of the detector-type and the exposure level applied the mean values of the ratings of the respective image criteria ranged from 1.14 to 1.67. In both systems higher doses related to better rating results. While comparing the detectors on the basis of identical exposure settings the FD demonstrated superior performance. CONCLUSION AND CLINICAL RELEVANCE: At the dose levels investigated both detectors reveal an image quality sufficient for the depiction of subtle, low-contrast thoracic structures in cats. Therefore, the detectors can be recommended for practical use in small animal radiology. In both systems a dose reduction of 50% in comparison to the original level (S180) is possible without a substantial loss of information. Because of the superior quantum efficiency the dose saving potential of the FD might be even higher. Alternatively, the higher dose efficiency can be utilised to improve image quality in comparison to the SP-system with identical exposure settings.

[Assessment of clinical image quality in feline chest radiography with a needle-image plate (NIP) storage phosphor system--an approach to the evaluation of image quality in neonatal radiography]. / Untersuchungen zur Qualität von Thoraxaufnahmen bei Katzen mit einem auf einer Nadelstruktur basierenden Speicherfoliensystem - Modelluntersuchungen zur Bewertung der Bildqualität bei Neugeborenen.

PURPOSE: Is the image quality of thoracic radiographs of cats obtained with a needle-based storage phosphor (NIP) system superior to conventional (PIP) storage phosphor radiography? Is it possible to decrease the mAs by 50 % with the NIP system without significant loss of information? MATERIALS AND METHODS: From each of the 20 animals, three lateral radiographs were acquired. The assessment of the exposure level was based on the generated lgM-values. Images were acquired 1. with the NIP system and exposure settings equivalent to an lgM of 1.9, 2. with the PIP system and identical settings, and 3. with the NIP system and 50 % of the mAs. Six blinded readers used a 5-step scale to assess the reproducibility of five anatomical structures and image noise sensation. Data were analysed using Visual Grading Characteristics Analysis (VGC). RESULTS: While applying identical exposure values the NIP system for all features revealed superior ratings to those of the PIP system (AUC (VGC) values ranged from 0.81 for "cardiac silhouette" to 0.92 for "trachea"). Even when reducing mAs by 50 % in the NIP images all features were rated better compared with the PIP images and original settings (AUC (VGC) values ranged from 0.60 for "cardiac silhouette" to 0.74 for "trachea" and "caudal thoracic field"). CONCLUSION: The NIP system demonstrates clearly better image quality compared to the reference PIP system. A dose reduction of 50 % seems to be possible without relevant detraction from image quality. The results obtained in the animal model are valid for simulating conditions in neonatal radiological practise.

Magnetic resonance imaging diagnosis: incomplete ossification of the humeral condyle in a German shepherd dog.

Clinical signs, radiological, arthroscopic findings and magnetic resonance imaging features of a male German shepherd dog with incomplete ossification of the humeral condyle are described. The dog showed recurrent left forelimb lameness and pain on elbow palpation. In routine radiographs, the lesion was obscured. In oblique radiographs, a radiolucent line was detected, and magnetic resonance imaging clearly demonstrated a defect in the humeral condyle. However, arthroscopy showed no changes or discontinuity of the humeral cartilage. Incomplete ossification of the humeral condyle may be underrepresented in conventional, routine studies because if there is concurrent additional elbow pathology (for example fragmented coronoid process), treatment may lead to clinical improvement and further diagnostic techniques may not be performed. The benefit of magnetic resonance imaging in this case is demonstrated.

High-dose-rate brachytherapy for intranasal tumours in dogs: results of a pilot study.

This prospective study describes the feasibility and toxicity of (192)Iridium high-dose-rate (HDR) brachytherapy as an alternative strategy for the treatment of canine intranasal tumours. Fifteen dogs with malignant intranasal tumours were treated twice weekly using a hypofractionated protocol with eight fractions, 5 Gy per fraction, resulting in a total dose of 40 Gy. Acute and chronic adverse side-effects appeared to be rare. Only 7% of the acute side-effects and 5% of the chronic were classified as severe (grade 3). Eight dogs showed clinical complete remission, and five dogs had partial remission, with a resolution of tumour-related symptoms. Magnetic resonance imaging showed a reduced tumour mass in 12 cases. Median survival time was 17 months (range 4-48 months), with four dogs (three without disease) still alive. Median time to recurrence of these dogs was 14 months. In nine dogs, progression or recurrence of the tumour was the cause of death. This study suggests that HDR brachytherapy is feasible and well tolerated.

[The effects of low-dose Co-60 irradiation on the course of aseptic arthritis in a rabbit knee joint]. / Effekte einer niedrig dosierten Co-60-Bestrahlung auf den Verlauf einer aseptischen Arthritis am Kniegelenk des Kaninchens.

PURPOSE: Numerous clinical observations demonstrate the efficacy of low radiation doses in the treatment of painful osteoarthritis. Experimental investigations remain scarce. We investigated the effects of locally daily 5 times 1.0 Gy 60-Co irradiation on an artificially induced aseptic gonarthritis in rabbits. MATERIAL AND METHODS: Three separate experiments (EV) were performed (10 rabbits per experiment, 5 treated/5 controls; duration: EV1: 18 days; EV2: 6 days; EV3: 29 days). An aseptic arthritis in the right knee joint of rabbits was induced by intraarticular injection of 0.5 ml papain solution (3%, 30,000 USP/mg) on day 0. The arthritic knee joint of the anesthesized animals was irradiated daily from day 1 to 5 with 5 times 1.0 Gy. The controls were sham-irradiated under the same conditions. The time course of arthritis in treated animals and sham-treated controls was evaluated by clinical, laboratory-chemical and histological criteria. The clinical investigation was performed daily, the puncture of the knee-joints was carried out several times in EV1, and at the end of experiments in EV2 and EV3. At the end of the observation period, animals were killed and the knee joints excised for histological analysis. RESULTS: The intraarticular injection of papain caused a peracute inflammatory response in all animals. After 1 week the chronic stage was reached, and the experimental arthritis resolved slowly within several weeks. Local irradiation accelerated the decrease of inflammatory joint swelling, being significant by day 4. On day 6 the volume of synovial fluid in irradiated knee-joints was significantly smaller. The morphometric data indicated a reduction in thickness of synovial membrane, a decrease in number of synovial cell layers, and a decrease in distance between capillaries and the synovial membrane surface following irradiation of arthritic joints. Due to considerable individual variability, the morphometric data partially did not reach statistically significance. CONCLUSION: The experiments provide evidence for an antiphlogistic effect of irradiation with 5 times 1.0 Gy in vivo. They support the clinical observations of the efficacy of anti-inflammatory radiotherapy.