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Background: Despite significant advancements in surgical techniques to repair rotator cuff (RC) injuries, failure rates remain high and novel approaches to adequately overcome the natural biological limits of tendon and enthesis regeneration of the RC are required. Small extracellular vesicles (sEVs) derived from the secretome of human multipotent mesenchymal stromal cells (MSCs) have been demonstrated to modulate inflammation and reduce fibrotic adhesions, and therefore their local application could improve outcomes after RC repair. Purpose: In this pilot study, we evaluated the efficacy of clinical-grade human umbilical cord (hUC) MSC-derived sEVs (hUC-MSC-sEVs) loaded onto a type 1 collagen scaffold in an ovine model of acute infraspinatus tendon injury to improve RC healing. Study Design: Controlled laboratory study. Methods: sEVs were enriched from hUC-MSC culture media and were characterized by surface marker profiling. The immunomodulatory capacity was evaluated in vitro by T-cell proliferation assays, and particle count was determined by nanoparticle tracking analysis. Twelve skeletally mature sheep were subjected to partial infraspinatus tenotomy and enthesis debridement. The defects of 6 animals were treated with 2 × 1010 hUC-MSC-sEVs loaded onto a type 1 collagen sponge, whereas 6 animals received only a collagen sponge, serving as controls. Six weeks postoperatively, the healing of the infraspinatus tendon and the enthesis was evaluated by magnetic resonance imaging (MRI) and hard tissue histology. Results: CD3/CD28-stimulated T-cell proliferation was significantly inhibited by hUC-MSC-sEVs ( P = .015) that displayed the typical surface marker profile, including the presence of the MSC marker proteins CD44 and melanoma-associated chondroitin sulfate proteoglycan. The local application of hUC-MSC-sEVs did not result in any marked systemic adverse events. Histologically, significantly improved Watkins scores ( P = .031) indicated improved tendon and tendon-to-bone insertion repair after sEV treatment and lower postcontrast signal of the tendon and adjacent structures on MRI suggested less residual inflammation at the defect area. Furthermore, the formation of osteophytes at the injury site was significantly attenuated ( P = .037). Conclusion: A local, single-dose application of hUC-MSC-sEVs promoted tendon and enthesis healing in an ovine model of acute RC injury. Clinical Relevance: Surgical repair of RC tears generally results in a clinical benefit for the patient; however, considerable rerupture rates have been reported. sEVs have potential as a cell-free biotherapeutic to improve healing outcomes after RC injury.

Adrenal computed tomography characteristics (aCTc) in healthy cats are known, but reference intervals for diseased cats are lacking. aCTc of cats without evidence of adrenal disease (NAD group) were compared to parameters of cats with possible concurrent adrenal disease (PAD group). The PAD group was assessed for adrenal masses or other morphological deviations using the NAD group as reference. Associations of aCTc with patient variables were explored, and all results were compared with published aCTc of healthy cats. No incidental adrenal masses were identified in the PAD group (n = 92), and only few aCTc differed compared to the NAD group (n = 30). The NAD group showed similar associations of patient variables and aCTc as length (right: 11.5 ± 2.2 mm, left: 11.8 ± 1.7 mm), width (right: 6.4 ± 1.2 mm, left: 5.4 ± 0.8 mm), height (right: 4.5 ± 0.9 mm, left: 4.5 ± 0.8 mm), attenuation (right: 33.1 ± 5.0 Hounsfield units, left: 32.5 ± 5.3 Hounsfield units) and position, but markedly more mineralization (right: 10%, left: 13.3%) than reported in healthy cats. This study provides references of aCTc for diseased cats without evidence of adrenal disease. The result suggests that adrenal incidentalomas seem to be rare in cats.

Different measuring techniques have been used to objectify the classification of hoof shape. The MicroScribe® is a novel tool that might prove useful for measuring hooves without prior reconstruction or compensation of projection artefacts. The aim of this study was to compare biometric data of the equine hoof collected by the MicroScribe® tool and measurements collected directly from hooves, scaled photographs and radiographs, from photogrammetry models and computed tomography (CT) datasets. The suitability of MicroScribe® generated data to differentiate individual hoof conformations was tested. A total of 62 measures were recorded from 16 forehooves. 21 linear and nine angular measures were collected by at least four methods each, and subjected to further analysis by ANOVA and MANOVA. Ratios and differences of these measures were calculated as suitable for the definition of hoof shapes and analysed as well. Absolute equivalency of methods was detected for five linear and none of the angular measurements. The precision of the tested measurement methods was comparable. In some cases, different methods measure different structures. Radiographs tended to overestimate, while CT slides to underestimate distances. Photogrammetry and scaled photographs were less suitable for measuring hoof angles. The MicroScribe® tool can readily be used for hoof measurements. Its values for linear measures showed good equivalency with other methods based on real hooves. For angular measurements, the uneven hoof surface might introduce imprecision. Not all hoof conformations could be detected based on measuring results alone. Diagnosis by a skilled veterinarian is still essential.

The aim of this review is to describe the steps of constructing exposure tables for use of digital detector systems (DRx) in equine practice. Introductory, selected underlying technical aspects of digital radiography are illustrated. Unlike screen film radiography (SFR), DRx have a uniform signal response of the detector over a large dose range. This enables generation of diagnostic images from exposures that were previously non-diagnostic on SFR, thus reducing retakes. However, with decreasing detector entrance dose, image noise increasingly hampers the image quality. Conversely, unlike the blackening observed on SFR, overexposures can go visibly undetected by the observer. In DRx the numeric exposure indicator value is the only dose-control tool. In digital radiography the challenge is to reduce the dose and reduce the radiation risk to staff whilst maintaining diagnostic image quality. We provide a stepwise method of developing exposure tables as tools for controlling exposure levels. The identified kVp - mAs combinations in the table are derived from the pre-defined exposure indicator values of the detector system. Further recommendations are given as to how the exposure indicator can be integrated into routine workflow for re-checking the reliability of the formerly identified settings and how these tables might serve a basis for further reduction of the exposure level. Detector-quantum efficiency (DQE) is an important parameter of assessing performance of an imaging system. Detectors with higher DQE can generate diagnostic images with a lower dose, thus having a greater potential for dose reduction than detectors with low DQE.

This method comparison study used radiographs of 20 mice and 20 budgerigars to investigate comparability between computed radiography (CR) and high-resolution screen-film systems and study the effects of reduced radiation doses on image quality of digital radiographs of small patients. Exposure settings used with the mammography screen-film system (SF) were taken as baseline settings. A powder-based storage-phosphor system (CRP) and a needle-based storage-phosphor system (CRN) were used with the same settings (D/100%) and half the detector dose (D/50%). Using a scoring system four reviewers assessed five criteria per species covering soft tissue and bone structures. Results were evaluated for differences between reviewers (interobserver variability), systems and settings (intersystem variability, using visual grading characteristic analysis). Correlations were significant (p ≤ 0.05) for interobserver variability in 86.7% of the cases. Correlation coefficients ranged from 0.206 to 0.772. For mice and budgerigars, the CRN system was rated as superior to the SF and CRP system for most criteria, being significant in two cases each. Comparing the SF and CRP system, the conventional method scored higher for all criteria, in one case significantly. For both species and both digital systems, dose reduction to 50% resulted in significantly worse scores for most criteria. In summary, the needle-based storage-phosphor technique proved to be superior compared to the conventional storage-phosphor and mammography screen-film system. Needle-based detector systems are suitable substitutes for high-resolution screen–film systems when performing diagnostic imaging of small patients. Dose reduction to 50% of the corresponding dose needed in high-resolution film-screen systems cannot be recommended.

Volume definition is a delicate step within the radiation treatment planning process and the precision of defining the volumes to irradiate is important for the success of the radiation treatment. Traditionally, radiation plans are created using computed tomography (CT) studies. Due to its different mechanism of action, magnetic resonance imaging (MRI) is more sensitive for detection of brain lesions. Therefore, using fused images of both imaging modalities should result in a more precise definition of the volumes to irradiate. The feasibility to fuse CT and MRI studies performed at different institutions was tested to subsequently analyse the influence of the fused images on target volume definition.Fourteen dogs and four cats with brain lesions having MR- and CT-imaging were included. Contrast-enhanced radiotherapy planning CT scans were fused to T1-weighted post-contrast and T2-weighted MRI scans. The gross tumor volume (GTV), the clinical tumor volume (CTV) and the planning target volume (PTV) were delineated on CT- and MRI studies. CT and MRI volumes were compared with regard to volumetric and spatial differences.The mean GTV was larger on MRI than on CT (2.15 vs.1.54 cmCT-MRI fusion was feasible especially when defined, reliable, and consistent anatomic landmarks were used as registration points. Volumetric differences between CT and MRI were insignificant. In general, GTV and CTV were easier identified on MRI.Die Präzision, mit der die Bestrahlungsvolumina und damit die Grenzen der Strahlenfelder definiert werden, entscheidet wesentlich über den Erfolg einer Strahlentherapie. Traditionell basiert die Planung auf Datensätzen einer zuvor durchgeführten computertomographischen Untersuchung. Aufgrund anderer Abbildungseigenschaften ist die Magnetresonanztomographie (MRT) der Computertomographie (CT) bei der Darstellung zerebraler Läsionen überlegen. Es ist davon auszugehen, dass durch die Fusion der Daten von CT- und MRT-Studien die Definition der Bestrahlungsvolumina präziser erfolgen kann. Ziel der Untersuchungen war, die Durchführbarkeit der Fusion von Bilddatensätzen aus unterschiedlichen Einrichtungen zu testen, um in der Folge den Einfluss fusionierter Bilder auf die Darstellung der Zielvolumina zu untersuchen.In die Studie wurden 14 Hunde und vier Katzen mit Hirnläsionen, bei denen MRT- und CT-Studien vorlagen, eingeschlossen. Fusioniert wurden Datensätze von CTs zur Strahlentherapieplanung nach Kontrastmittelgabe mit T1-gewichteten MRT-Serien nach Kontrastmittelapplikation und mit T2-gewichteten MRT-Serien. Das makroskopische Tumorvolumen (GTV), das klinische Tumorvolumen (CTV) und das Planungszielvolumen (PTV) wurden auf den CT- und MRT-Studien eingezeichnet. CT- und MRT-Volumina wurden bezüglich volumetrischer und räumlicher Unterschiede verglichen.Der Mittelwert des GTV war in den MRT-Aufnahmen größer als in den CT-Aufnahmen (2,15 vs.1,54 cmDie CT-MRT-Fusion war vor allem durch die Verwendung von definierten, verlässlichen und übereinstimmenden anatomischen Orientierungshilfen als Registrierungspunkte durchführbar. Volumetrische Unterschiede zwischen den beiden Studien waren nicht signifikant. Generell konnten GTV und CTV einfacher mit den MRT-Serien identifiziert werden.

Background The aim of this study is to evaluate additional findings which can be detected by post-contrast computed tomography (CCT) in relation to plain CT (PCT) findings in patients presented with head trauma. Medical records of canine patients with the history of head trauma from three institutions were reviewed. PCT- and CCT-anonymized images were evaluated by a veterinary radiologist separately. From the categorized findings the following conclusions were drawn as: abnormalities were identified on (A) PCT but missed on CCT, (B) CCT but missed on PCT, (C) both PCT and CCT. Results Thirty-two patients were included. The results showed that findings identified on CCT or PCT (category A and B) but missed on the other series were limited to mild soft tissue and sinus changes. Overall, 61 different fracture areas, 6 injuries of the temporomandibular joint (TMJ), 4 orbital injuries, 14 nasal cavities with soft tissue density filling, 13 areas of emphysema, 4 symphysis separations, 12 intracranial hemorrhages, 6 cerebral edema, 5 cerebral midline shifts, 3 intracranial aeroceles, 3 brain herniations and 6 intraparenchymal foreign bodies (defined as an abnormal structure located within the brain: e.g. bony fragments, bullet, teeth,..) were identified on both PCT and CCT separately (category C). Severity grading was different in 50% (3/6) of the reported cerebral edema using PCT and CCT images. Conclusion The results showed that PCT is valuable to identify the presence of intracranial traumatic injuries and CCT is not always essential to evaluate vital traumatic changes.

The aim of this study was to investigate the variability of the slope of the pelvis in different dog breeds and the correlation between pelvic slope and femoral subluxation. The sacrum–pelvis angle (SPA), the angulation between the sacrum and the axis of the ilium was created to represent the differences in the slope of the pelvis on lateral pelvic radiographs. The Norberg angle (NA) was used to quantify the femoral subluxation on hip-extended radiographs. Archived standard ventrodorsal hip radiographs and lateral lumbosacral radiographs of the same dogs were retrieved and a single observer measured the SPA and the NA in each case. A total of 180 dogs from six different breeds were sampled. The SPA varied between 40° and 71.5° and the NA between 71.2° and 113.9°. The findings indicated that there are significant individual and interbreed variations in the slope of the pelvis. However, no significant relationship between the slope of the pelvis and femoral subluxation could be identified.

Stereotaxic systems and automatic tissue segmentation routines enable neuronavigation as well as reproducible processing of neuroimage datasets. Such systems have been developed for humans, non-human-primates, sheep, and rodents, but not for dogs. Although dogs share important neurofunctional and -anatomical features with humans, and in spite of their importance in translational neuroscience, little is known about the variability of the canine brain morphology and, possibly related, function. Moreover, we lack templates, tissue probability maps (TPM), and stereotaxic brain labels for implementation in standard software utilities such as Statistical Parametric Mapping (SPM). Hence, objective and reproducible, image-based investigations are currently impeded in dogs. We have created a detailed stereotaxic reference frame for dogs including TPM and tissue labels, enabling inter-individual and cross-study neuroimage analysis. T2w datasets were acquired from 16 neurologically inconspicuous dogs of different breeds by 3T MRI. The datasets were averaged after initial preprocessing using linear and nonlinear registration algorithms as implemented in SPM8. TPM for gray (GM) and white matter (WM) as well as cerebrospinal fluid (CSF) were created. Different cortical, subcortical, medullary, and CSF regions were manually labeled to create a spatial binary atlas being aligned with the template. A proof-of-concept for automatic determination of morphological and volumetrical characteristics was performed using additional canine datasets (n = 64) including a subgroup of laboratory beagles (n = 24). Overall, 21 brain regions were labeled using the segmented tissue classes of the brain template. The proof-of-concept trial revealed excellent suitability of the created tools for image processing and subsequent analysis. There was high intra-breed variability in frontal lobe and hippocampus volumes, and noticeable inter-breed corpus callosum volume variation. The T2w brain template provides important, breed-averaged canine brain anatomy features in a spatial standard coordinate system. TPM allows automatic tissue segmentation using SPM and enables unbiased automatic image processing or morphological characterization in different canine breeds. The reported volumetric and morphometric results may serve as a starting point for further research aimed at in vivo analysis of canine brain anatomy and function.

Objective To evaluate airway obstruction due to abnormal intranasal anatomy in 3 brachycephalic dog breeds using computed tomography and rhinoscopy. Study Design Prospective clinical study. Animals A total of 132 brachycephalic dogs (66 Pugs, 55 French Bulldogs, and 11 English Bulldogs) with severe respiratory distress due to brachycephalic syndrome. Methods Computed tomography and anterior and posterior rhinoscopy were performed to evaluate endonasal obstruction. Results All dogs had abnormal conchal growth that obstructed the intranasal airways. Rostral aberrant turbinates (RAT) were common in Pugs (90.9%) but less frequent in French (56.4%) and English (36.4%) Bulldogs. Caudal aberrant turbinates (CAT) obstructing the nasopharyngeal meatus were commonly found in all breeds (66.7%). Deviation of the nasal septum was an almost consistent finding in Pugs (98.5%) but was less common in bulldogs. Obstructing turbinates had multiple points of mucosal contact responsible for obstruction of the intranasal airway. Interconchal and intraconchal mucosal contacts were evident in 91.7% of dogs. Conclusion Selective breeding for short head conformation reduces the size of the nasal cavities to such an extent that intranasal structures grow aberrantly and malformed, leading to obstructed air conducting spaces. Intranasal airway obstruction of brachycephalic dogs may contribute to their exercise and heat intolerance because of impaired pulmonary ventilation and compromised thermoregulatory functions of the canine nose. Failure to address intranasal obstruction might be an explanation for lack of therapeutic success after conventional surgery for brachycephalic syndrome. Future consideration should be given to the diagnosis, management, and treatment of this newly described aspect of airway obstruction.

Zusammenfassung Gegenstand und Ziel: Im computertomographischen Nativbild sollten anatomische Schnittbildmerkmale für die Speicheldrüsen der Katze definiert und Landmarken für eine sichere Identifikation beschrieben werden. Material und Methoden: Untersucht wurden die Köpfe ausgewachsener normozephaler Katzen ohne Hinweis auf Erkrankungen des Kopfes. Im prospektiven Anteil der Studie fand die Untersuchung bei 16 Katzen innerhalb der ersten Stunde post mortem statt, im retrospektiven Teil gelangten vorhandene computertomographische Datensätze zur Beurteilung (n = 25). Die Auswertung der Ergebnisse beider Gruppen erfolgte getrennt. Zunächst wurde die Möglichkeit der Identifizierung und Abgrenzbarkeit der Speicheldrüsen gegenüber dem umliegenden Gewebe beurteilt. Als Landmarken wurden anatomische Strukturen im Bereich des Kopfes beschrieben. Am Transversal- und Sagittalschnitt wurden Größe und Dichtewerte (Hounsfield Units, HU) bestimmt. Ergebnisse: 94,3% der Glandulae parotideae, 90,7% der Glandulae mandibulares sowie 96,8% der Glandulae zygomaticae konnten abgegrenzt werden. Weitere Speicheldrüsen ließen sich nicht identifizieren. Anatomische Landmarken wie äußerer Gehörgang, M. masseter, M. pterygoideus medialis und Bulbus oculi ermöglichten die Zuordnung. Im Größenvergleich der Speicheldrüsen beider Gruppen ergaben sich bei der lateromedialen und rostrokaudalen Messung Unterschiede von maximal 2 mm. Die abgrenzbaren Speicheldrüsen unterschieden sich in ihrer Dichte signifikant. Die mittleren Dichtewerte lagen für die Glandula (Gl.) parotis bei 65 HU, für die (Gl.) mandibularis bei 62 HU und für die (Gl.) zygomatica bei 57 HU. Beim Seitenvergleich der Dichtewerte zeigte sich kein signifikanter Unterschied. Schlussfolgerungen: Die großen Speicheldrüsen (Gl. parotis, Gl. mandibularis) und die Gl. zygomatica der Katze sind computertomographisch sicher identifizierbar. Es konnten Landmarken und Angaben über die Größe und Dichte der einzelnen Drüsen beschrieben werden. Die kleinen Speicheldrüsen lassen sich im Nativbild nicht abgrenzen. Die unterschiedliche Darstellbarkeit beruht vor allem auf dem fehlenden Kontrast der Drüsen zum umliegenden Gewebe.

ZusammenfassungGegenstand und Ziel: Mit magnetresonanztomographischen Untersuchungen sollten anatomische Merkmale der Speicheldrüsen der Katze und Landmarken für eine sichere Identifikation beschrieben werden. Material und Methoden: Untersucht wurden MRT-Aufnahmen des Kopfes von 37 adulten Katzen ohne anamnestische oder klini sche Hinweise auf Erkrankungen der Speicheldrüsen. Die Studie bestand aus zwei Teilen. Die in den prospektiven Teil eingegangenen Tiere wurden maximal eine Stunde nach der Euthanasie untersucht (n = 16). Im zweiten Teil erfolgte eine retrospektive Auswertung von MRT-Datensätzen (n = 21). Das standardisierte Untersuchungsprotokoll umfasste im prospektiven Untersuchungsabschnitt die Sequenzen T2W TSE, T2W TSE fettunterdrückt und PDW TSE im transversalen Schnitt sowie T1W FFE im transversalen, sagittalen und dorsalen Schnitt. Für die retrospektive Auswertung lagen mit den Sequenzen T2W TSE und T1W TSE vor und nach Kontrastmittelgabe erstellte transversale Schnittbilder vor. Die Möglichkeiten zur Identifikation und Abgrenzbarkeit der Speicheldrüsen wurden untersucht und anatomische Strukturen des Kopfes als Landmarken definiert. Die Größe der Speicheldrüsen wurde gemessen (Sequenz T2W TSE) und in allen Sequenzen das Signalverhalten im Vergleich zum Fett und zur umliegenden Muskultur beschrieben. Ergebnisse: Die Glandula (Gl.) parotis konnte in den T2-gewichteten TSE- und den T1-gewichteten TSE- und FFE-Sequenzen zu 95,9% identifiziert werden, die Gl. mandibularis in beiden Sequenzen zu 100% und die Gl. zygomatica im T2-gewichteten TSE-Bild zu 93,3% und im T1-gewichteten TSE- und FFE-Bild zu 82,5%. Die Gl. buccalis ventralis ließ sich in einem Teil der Untersuchungen (T2W TSE: 51,4%, T1W TSE und FFE: 18,9%) abgrenzen. Die anatomischen Landmarken erleichterten die Identifikation der Drüsen. Bei der Größenmessung der Drüsen ergaben sich zwischen beiden Gruppen Unterschiede von maximal 2 mm. Schlussfolgerung: Die großen Speicheldrüsen (Gl. parotis und Gl. mandibularis) sowie die kleinen Speicheldrüsen (Gl. zygomatica und Gl. buccalis ventralis) der Katze können im Niederfeld-MRT sicher identifiziert werden.

ZusammenfassungEine 5-jährige, weiblich-kastrierte Europäisch-Kurzhaar-Katze wurde mit abdominalen Schmerzen und fehlendem Kotabsatz vorgestellt. Die Röntgenaufnahmen zeigten eine Kolonkonstipation. In der Ultraschalluntersuchung konnte eine ovale zystische Struktur in unmittelbarer Nachbarschaft des Kolons dargestellt werden. Die Struktur wies eine aus drei Schichten bestehende Wand auf. Der Inhalt präsentierte sich inhomogen hypoechogen. Über eine Laparotomie wurde die Struktur vollständig entfernt. Dazu musste ein Teil des Kolons reseziert werden. Die Adaptation erfolgte mit einer End-zu-End-Anastomose. Histopathologisch wurden in verschiedenen Lokalisationen der Zystenwand Metaplasien der Schleimhaut nachgewiesen. Eine sichere Einordnung der Zyste als intestinale Duplikationszyste, die im vorliegenden Fall als sehr wahrscheinlich anzusehen ist, als Rudiment des Meckel-Divertikels, als Vitellingang-Zyste oder als zystisches Kolondivertikel war jedoch nicht möglich. Nach dem operativen Eingriff normalisierte sich der Kotabsatz.

ZusammenfassungZiel war, den diagnostischen Wert der computerassistierten Detektion (CAD) von pulmonalen Rundherden in der Tiermedizin zu überprüfen. Hierzu wurde die Detektionsrate der computerassistierten Methode mit der Detektionsrate zweier unabhängiger Untersucher in Bezug auf die Sensitivität und die Rate falsch positiver Befunde verglichen. Material und Methoden: In die Studie wurden 51 Hunde und 16 Katzen einbezogen, bei denen zuvor mittels computertomographischer Untersuchung pulmonale Rundherde diagnostiziert worden waren. Zwei unabhängige Untersucher erfassten bei jedem Patienten die Anzahl der Rundherde ≥ 3 mm und setzten anschließend das Programm zur automatischen Rundherddetektion ein. Im letzten Schritt wurde ein Konsensus der beiden Untersucher unter Kenntnis der CAD-Ergebnisse getroffen. Zur Rundherdauswertung diente ein kommerziell erhältliches Programm zur computerassistierten Detektion. Ergebnisse: Insgesamt wurden 586 pulmonale Rundherde diagnostiziert. Für Untersucher 1 ergab sich eine Sensitivität von 89,2%, für Untersucher 2 betrug sie 87,4%. Die CAD erreichte eine Sensitivität von 69,4%. Mithilfe der CAD ließ die Sensitivität von Untersucher 1 auf 94,7% und die Sensitivität von Untersucher 2 auf 90,8% steigern. Schlussfolgerung und klinische Relevanz: Das verwendete CAD-System wies eine moderate Sensitivität von 69,4% auf. Trotz gewichtiger Limitationen wie einer hohen Anzahl an falsch positiven und falsch negativen Befunden konnte die CAD die Sensitivität beider Untersucher erhöhen, sodass sie zumindest eine unterstützende Funktion besitzt.

A 13-year-old male spur-thighed tortoise (Testudo graeca) was presented with anorexia, apathy, and prolapse of penile tissue. Ultrasonography revealed a large heterogeneous mass in the coelomic cavity, and fine-needle aspiration demonstrated sperm. Magnetic resonance imaging showed a sharply defined mass originating from the left testis. Appearance and signal intensities were similar to those reported in testicular neoplasms in humans, in particular sharing similarities with seminomas. Necropsy results and histopathological findings were consistent with a seminoma. To the authors' knowledge this is the first report of the diagnosis of testicular neoplasia in a reptile using imaging techniques.

Im Gegensatz zum Menschen, bei dem ein erworbener portosystemischer Shunt meist nur sekundar durch Erkrankungen der Leber auftritt, kommt der portosystemische Shunt beim Hund ofter angeboren als erworben vor. Die Haufigkeit der Erkrankung wird kritisch diskutiert. Man geht jedoch von einer erheblichen Dunkelziffer aus, insbesondere weil die Symptome mannigfaltig sind und die Auspragung sehr unterschiedlich ist. Die Erkrankung zahlt zu den beim Hund beschriebenen Erbkrankheiten.

Die Rontgendiagnostik gehort zu den Routineuntersuchungen in der tierarztlichen Praxis. Aufnahmen des Thorax stellen dabei besonders hohe Anforderungen an die technische Durchfuhrung und die interpretatorischen Fertigkeiten des Untersuchers.

SummaryObjectives: 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.

To evaluate airway obstruction due to abnormal intranasal anatomy in 3 brachycephalic dog breeds using computed tomography and rhinoscopy.Prospective clinical study.A total of 132 brachycephalic dogs (66 Pugs, 55 French Bulldogs, and 11 English Bulldogs) with severe respiratory distress due to brachycephalic syndrome.Computed tomography and anterior and posterior rhinoscopy were performed to evaluate endonasal obstruction.All dogs had abnormal conchal growth that obstructed the intranasal airways. Rostral aberrant turbinates (RAT) were common in Pugs (90.9%) but less frequent in French (56.4%) and English (36.4%) Bulldogs. Caudal aberrant turbinates (CAT) obstructing the nasopharyngeal meatus were commonly found in all breeds (66.7%). Deviation of the nasal septum was an almost consistent finding in Pugs (98.5%) but was less common in bulldogs. Obstructing turbinates had multiple points of mucosal contact responsible for obstruction of the intranasal airway. Interconchal and intraconchal mucosal contacts were evident in 91.7% of dogs.Selective breeding for short head conformation reduces the size of the nasal cavities to such an extent that intranasal structures grow aberrantly and malformed, leading to obstructed air conducting spaces. Intranasal airway obstruction of brachycephalic dogs may contribute to their exercise and heat intolerance because of impaired pulmonary ventilation and compromised thermoregulatory functions of the canine nose. Failure to address intranasal obstruction might be an explanation for lack of therapeutic success after conventional surgery for brachycephalic syndrome. Future consideration should be given to the diagnosis, management, and treatment of this newly described aspect of airway obstruction.

Radiography is an excellent tool to generate diagnostic information in cases where either a skeletal lesion or systemic disease with skeletal manifestation is suspected. The fact that radiographic equipment is available in almost all veterinary practices makes it the imaging method most often used initially to detect and characterize lesions of bones and joints. This chapter covers radiography techniques and the basics of musculoskeletal radiography.

A retrospective analysis of 619 upper and lower cheek teeth from 62 horses was performed. Based on clinical findings, as well as radiographic and magnetic resonance (MR) imaging findings, the teeth were classified into five groups. There were 20 teeth with abnormal MR imaging signals as well as clinical alterations and 599 healthy teeth. Using MR imaging, the appearance of pulp in diseased and disease-free teeth was compared, and the appearance of abnormal pulp was studied. Subsequently, the ability of MR imaging to diagnose pulpitis and pulp necrosis in teeth with normal external appearance was investigated. In horses with clinically verified dental disease, abnormal MR imaging findings were confirmed in the pulp of all affected teeth. An enlarged blurred pulp image with a lower signal intensity was observed only in clinically diseased teeth and was a reliable criterion for diagnosing dental disease on MR imaging. On the other hand, partial or complete absence of pulp in all MR imaging sequences was observed in both diseased and nondiseased teeth. These data demonstrate that pulp changes in equine cheek teeth can be evaluated using MR imaging.

Low-field MRI (lfMRI) has become increasingly accepted as a method for diagnosing canine meniscal tears in clinical practice. However, observer effects on diagnostic accuracy have not been previously reported. In this study, 50 consecutive stifle joints with clinical and radiologic evidence of cranial cruciate ligament insufficiency were investigated by lfMRI and arthroscopy. Fifteen observers who had varying levels of experience and who were unaware of arthroscopic findings independently reviewed lfMRI studies and recorded whether lateral and medial meniscal tears were present. Diagnostic accuracy (sensitivity, specificity, positive (PPV) and negative predictive value (NPV)) was determined for each observer and median values were calculated for all observers, using arthroscopy as the reference standard. Interrater agreement was determined based on intraclass correlation coefficient (ICC) analysis. Observer level of experience was compared with diagnostic sensitivity and specificity using correlation analysis. Based on pooled data for all observers, median sensitivity, specificity, PPV, and NPV for lfMRI diagnosis of lateral meniscal tears were 0.00, 0.94, 0.05, and 0.94, respectively. Median sensitivity, specificity, PPV, and NPV for medial meniscal tears were 0.74, 0.89, 0.83, and 0.79, respectively. Interrater agreement for all menisci was fair (0.51). Menisci were less consistently scored as having no tears (ICC = 0.13) than those scored as having tears (ICC = 0.50). No significant correlations between observer experience and diagnostic sensitivity/specificity were identified. Findings indicated that the accuracy of lfMRI for diagnosing canine meniscal tears was poor to fair and observer-dependent. Future studies are needed to develop standardized and widely accepted lfMRI criteria for diagnosing meniscal tears.

The future of radiography will be digital. In exotic pet radiography, where some of the animals have a very low body weight and anatomic structures can be small, detail rendition plays an important feature in image quality. Veterinarians should be familiar with the technical principles, image quality criteria, and radiation exposure issues associated with the various types of digital systems currently available. This article discusses basic principles of digital radiography, technical solutions, and selected parameters characterizing detectors, processing, and monitors. An overview of reported experiences is given, and results from experimental clinical studies are reviewed to evaluate the current options and limitations in applying digital radiography to exotic pet medicine.

A 7 yr old mixed-breed dog was presented with a choroidal melanoma of the left eye that had penetrated the sclera, producing an orbital mass. Bradycardia was detected on auscultation. The bradycardia resolved after exenteration of the orbit and was therefore presumed to be associated with the oculocardiac reflex.

The aim of the study was to define anatomical characteristics of feline salivary glands using magnetic resonance imaging (MRI) and to describe landmarks for their reliable identification.Heads of 37 adult cats without signs of diseased salivary glands on clinical examination or history were examined. In cats included in the prospective part of the study, the MRI study was completed within one hour after euthanasia (n = 16). In the retrospective part, previously performed MRI studies were evaluated (n = 21). The prospective part of the study included the following standardized sequences: T2-weighted (T2W) turbo spin echo (TSE), T2W fat-suppressed TSE and proton density weighted (PDW) TSE images in a transverse plane as well as T1-weighted (T1W) fast field echo (FFE) in the transverse, sagittal and dorsal planes. In the retrospective part, T2W TSE and T1W TSE transverse images pre- and post-contrast were analyzed. Initially, identification and delineation of the salivary glands from surrounding tissue was assessed. Anatomical structures of the head were then identified and defined as landmarks. The dimensions of the glands were measured on T2W TSE images and the signal intensity in relation to that of fat and muscle was described using all sequences.In total, 95.9% of the parotid glands and 100% of the mandibular glands could be visualized on T1W TSE and FFE images and on T2W TSE images. Additionally, 93.3% of the zygomatic glands were identified on T2W TSE sequences and 82.5% on T1W TSE and FFE images. The ventral buccal glands could be demarcated in some sequences (T2W TSE: 51.4%, T1W TSE and FFE: 18.9%). Anatomical landmarks facilitated gland identification. Comparing the size of the salivary glands of both groups revealed differences of up to 2 mm.Both the large salivary glands (Glandula [Gl.]. parotis and Gl. mandibularis) and the small salivary glands (Gl. zygomatica and Gl. buccalis ventralis) of the cat can be reliably identified on MRI images.

Case summary This report describes the clinical and parasitological findings in a domestic shorthair cat with isolated thoracic tetrathyridiosis. The cat was a stray from Malta that had lived in Germany for several years since as an indoor-only cat. Therefore, the process of infection remains very unusual. In this case it must be considered that the cat had been infected years previously while in Malta, and had lived at least 4 years without any clinical signs. It was possible to diagnose this uncommon disease and initiate an effective treatment with fenbendazole, praziquantel and supportive care. Clinical signs, as well as radiographic findings, were regressive with this treatment. Relevance and novel information Tetrathyridiosis is a rare finding in cats, especially in Germany, but it seems to be a potential differential diagnosis of pleural effusion. Mesocestoides corti, which was the causative parasite in this case, has not previously been isolated in Germany. Because tetrathyridiosis is only diagnosed post mortem in most cases, little is known about effective therapeutic options. Furthermore, clinical signs of this disease can be absent for several years and can potentially be triggered by neoplastic conditions or immunosuppression. Tetrathyridiosis seems to be a treatable disease that can be controlled by adequate antiparasitic therapy.

Die Diagnostik von Erkrankungen des Mittel- und Innenohres erfordert fast immer den Einsatz bildgebender Verfahren. Rontgenuntersuchungen konnen wertvolle Informationen liefern und dazu beitragen, Ohrerkrankungen nachzuweisen und zu differenzieren. Welche das sind und wie die Untersuchung durchgefuhrt werden muss, soll in diesem Artikel besprochen werden.

The aims of the study were (1) to quantify the influence of selected imaging parameters on the image quality (slice thickness, mAs, and beam orientation) defining optimal conditions for scan protocols and (2) to evaluate the benefits of the 3D reconstruction techniques for visualization of NDS structures in dogs. CT-DCG was performed bilaterally in 32 heads of dogs. CT transverse images were obtained using a combination of two slice thickness values (0.8 mm and 2 mm) and two mAs values (50 mAs and 300 mAs). Two beam projection orientations were also tested: transverse plane (perpendicular to the hard palate) and oblique to the hard palate. Three-dimensional images were obtained using Volume Rendering (VR). Transverse beam projection proved to be superior for the assessment of the inferior and superior lacrimal canaliculi and lacrimal sac. In this study, there was no statistical difference regarding mAs values (50 mAs and 300 mAs) and slice thickness values (0.8 mm and 2 mm). Three-dimensional images were helpful for the assessment of topographic relationship between nasolacrimal structures and cranial landmarks.

A conventional high-resolution screen–film system was compared with a digital detector system. A total of 20 birds (14 pigeons and six psittacine birds) with an average body mass of 533 g were examined in dorsoventral as well as lateral projections. Digital radiographs were acquired with the same mAs as well as half the mAs used for the conventional radiographs. Three criteria and one overall assessment were defined for each of four anatomic regions and assessed by five veterinarians using a score system. Comparison of the ratings was done by visual grading analysis. For the majority of criteria, there was no significant difference regarding image quality between the digital and screen–film projections. However, for certain criteria the quality of the digital images was significantly superior. Using the same mAs as for the conventional radiographs, the humeral joint surfaces and the honeycomb structure of the lung were assessed as superior with the digital imaging system. The tracheal rings and the delineation of the trachea from the surrounding tissue were also superior with the digital system. Assessment of the trabecular structure of the humerus was superior when the full mAs was used compared with the reduced mAs. In conclusion the digital technique is equal or superior to the conventional screen–film high-resolution system for pet birds of a medium size. With some limitations, a dose reduction is possible with the digital system.

Rontgenologische Darstellung entzundlicher und neoplastischer Veranderungen der Wirbelsaule bei Hund und Katze

Objective: To report slot morphometry, degree of spinal decompression, and factors influencing decompression after partial lateral corpectomy (PLC) of the thoracolumbar spine in dogs with intervertebral disc disease. Study Design: Case series. Animals: Dogs (n=51) with predominantly ventrally located spinal cord compression. Methods: PLC (n=60) were performed. Spinal cord compression was determined by computed tomographic (CT) myelography (n=46), myelography (n=2) or magnetic resonance imaging (n=3). Postsurgical CT images were used to evaluate slot dimensions and orientation, and spinal cord decompression. The influence of age, body weight, breed, breed type (chondrodystrophic, nonchondrodystrophic), disc location, lateralization and mineralization, presurgical compression, slot morphometry, and surgeon on degree of decompression were evaluated. Results: Mean slot depth was 64.1% of vertebral body width; mean height, 43.0% of vertebral body height; mean cranial extension, 29.5%; median caudal extension, 22.0% vertebral body length; mean angulation from horizontal, 6.3°. Decompression was satisfactory in 90% of sites after PLC (58% complete, 32% good). None of the analyzed factors significantly influenced decompression. All lumbar spine PLC resulted in complete or good decompression compared with 83% after thoracic PLC (P=.052). Deeper slots tended to allow more complete decompression (P=.058). Conclusions: Thoracolumbar PLC results in satisfactory decompression in most cases with a better outcome in the lumbar spine than the thoracic spine. Achieving a slot depth equal to 2/3 of vertebral body width might facilitate complete decompression.

Zusammenfassung Gegenstand und Ziel: Verglichen wurde die Qualität von Röntgenaufnahmen, die mit einem Speicherfolien-(SF-)System und einem Flachbilddetektor (FD) aufgenommen wurden. Weiterhin wurde geprüft, ob unterschiedliche Aufnahmedosen das Ergebnis beeinflussen. Material und Methode: In einer prospektiven Untersuchung wurden seitliche Thoraxaufnahmen von 45 gesunden Katzen mit einem konventionellen SF-System und einem optodirekten FD angefertigt. Die Belichtungsdaten orientierten sich an den S-Werten (Sensitivity Value) des Dosisindikators. Die gewählten Einstellungen korrelierten bei beiden Detektoren mit S-Werten von S180 und S360. In einer Blindstudie bewerteten fünf Untersucher anatomische Bildmerkmale (Trachea, kraniales Lungenfeld, Sternum, Herzsilhouette, kaudales Thoraxfeld) anhand einer vier-stufigen Bewertungsskala (1 – sehr gut; 4 – unzureichend). Ergebnisse: Die Mittelwerte der Benotungen für die jeweiligen Bildmerkmale lagen unabhängig vom Detektor und der Aufnahmedosis zwischen 1,14 und 1,67. Höhere Aufnahmedosen gingen bei beiden Systemen mit besseren Bewertungen der Bildgüte einher. Beim Vergleich auf der Basis identischer Belichtungsparameter zeigte der FD überlegene Abbildungseigenschaften. Schlussfolgerung und klinische Relevanz: Auf beiden Belichtungsniveaus erreichen die Detektoren eine Bildqualität, die es ermöglicht, subtile thorakale Veränderungen bei Katzen zu erkennen. Sie können deshalb für den Einsatz in der Kleintierpraxis empfohlen werden. Bei beiden Detektoren kann die Dosis gegenüber dem Ausgangsniveau (S180) um 50% verringert werden, ohne dass es zu einem relevanten Verlust an Bildinformation kommt. Aufgrund des höheren Quantenwirkungsgrades ist das Potenzial des FDs zur Dosisreduktion größer. Alternativ kann die höhere Dosiseffizienz genutzt werden, um bei Verwendung identischer Belichtungsdaten eine bessere Bildqualität gegenüber dem SF-System zu erreichen.