Avaliação da epífora de cães usando dacriocistografia e tomografia computadorizada / Epiphora assessment of dogs with dacryocystography and computed tomography

A avaliação da epífora pode ser feita por exames clínicos, testes de excreção lacrimal, exames contrastados, como avaliação radiológica e estudo tomográfico; estes dois últimos permitem análise minuciosa das estruturas. O presente estudo teve como objetivo avaliar a via lacrimal excretora com uso de radiografia e tomografia computadorizada contrastadas, feitas em animais com epífora, comparando-se com animais sadios, sem essa afecção. Foram utilizados 20 cães, de raças e pelagens variadas, machos e fêmeas, com peso de 1 a 20 kg, com 0,7 a 8 anos de idade, apresentando epífora (grupo epífora - GE). Como grupo de controle (GC), foram utilizados 15 cães, sem alterações clínicas de drenagem do sistema lacrimonasal de raças e pelagens variadas, machos e fêmeas, pesando 1 a 20 kg, com 0,7 a 8 anos. Foi proposta a divisão do sistema de drenagem lacrimal em quatro regiões. Na região 1, o GE teve 29 (76,3%) animais com dilatação visibilizada pelo R-X e 32 (84,2%) pela TC; no GC, 4 (12,5%) no R-X e 1 (3,1%) na TC demonstraram dilatação. Na região 3, 13 (34,2%) cães evidenciaram dilatação do DLN no R-X e 14 (36,8%) na TC; e 21 (55,3%) comunicação do ducto lacrimonasal com o seio nasal pelo R-X e 28 (73,7%) pela TC. Já no GC, 15 (46,9%) pelo R-X e 22 (68,7%) pela TC possuíam comunicação do ducto lacrimonasal com o seio nasal. Concluiu-se que: dilatações também podem ser observadas em alguns cães sem sinal clínico da afecção; comunicação do ducto lacrimonasal com o seio nasal não indica alteração causadora de epífora, pois está presente em animais com e sem afecção; os dados do presente estudo confirmam que o exame DCG por si pode dar importantes informações, de forma semelhante à TC, devendo-se recorrer à ela apenas quando houver dúvidas sobre lesões ósseas, fraturas e corpos estranhos não detectados pelo primeiro...

Epiphora evaluation can be done through clinical exams, lachrymal excretion tests, contrasted exams, like radiologic evaluation and tomography studies; those last two allow a detailed analysis of the structures. The present study had as the objective to evaluate the lacrimal drainage system through radiography and contrasted computed tomography, which were made with animals presenting epiphora, comparing them to healthy animals, without the mentioned condition. Twenty dogs were used for tests, from a variety of breeds and coatings, males and females, weight varying from 1kg to 20kg, ages varying from 0.7 to 8 years old, presenting epiphora (epiphora group - GE*). As a control group (GC*) 15 dogs were used, with no clinical alterations of naso-lachrymal drainage system, from different breeds and coatings, males and females, weighing from 1kg to 20kg and ages varying from 0.7 to 8 years old. It was propoused the division of the lacrimal drainage system in four regions. On region 1, the GE had 29 (76.3%) animals with dilation visualized by the RX and 32 (84.2%) by CT, the GC, 4 (12.5%) in the RX and 1 (3.1% ) CT showed dilation. In region 3, 13 (34.2%) dogs showed dilatation of the DLN in RX and 14 (36.8%) on CT, and 21 (55.3%) nasolacrimal duct communication with the sinus and the X-ray 28 (73.7%) by CT. For the CG, 15 (46.9%) the X-ray and 22 (68.7%) by CT had nasolacrimal duct communication with the nasal sinus. It has been concluded that dilations can also be observed in some dogs with no clinical signs of disease; nasolacrimal duct communication to sinus does not indicate epiphora causing alteration, as it is present in animals with and without affection; the present study data confirm that DCG itself can provide important informations, in a similar manner to CT, and should resort to it just in case of doubts about bone lesions, fractures and foreign bodies undetected at first...

Equine imaging: the framework for applying therapeutic farriery.

Radiographic evaluation of a horse's foot gives tremendous insight into the relationship between the structures within the foot and between the foot and distal limb. The information gained from a radiographic study is highly dependent on the quality of the radiographs. A systematic approach should be taken when planning a radiographic study of the foot. Taking the time to examine the foot and prepare it properly will avoid the need, risk, and expense of repeating images and will improve the quality and therefore the interpretation of your radiographic images. When evaluating the foot for podiatry reasons, it is crucial that the positioning of the patient, foot, and x-ray beam be flawless.

Thermoluminescent dosimetry in veterinary diagnostic radiology.

This paper presents the results of Environmental and Personnel Dosimetry made in a radiology area of a veterinary hospital. Dosimetry was realized using thermoluminescent (TL) materials. Environmental Dosimetry results show that areas closer to the X-ray equipment are safe. Personnel Dosimetry shows important measurements of daily workday in some persons near to the limit established by ICRP. TL results of radiation measurement suggest TLDs are good candidates as a dosimeter to radiation dosimetry in veterinary radiology.

Radiographic landmarks for measurement of cranial tibial subluxation in the canine cruciate ligament deficient stifle.

OBJECTIVES: The primary objective was to develop a repeatable radiographic technique for assessment of cranial tibial subluxation (CTS) and test the intra-observer and inter-observer repeatability of the chosen landmarks. A secondary objective was to determine the effects of digital radiographic magnification on CTS measurement repeatability. METHODS: Twenty-three normal canine pelvic limbs were used to determine the magnitude of CTS before and after transection of the cranial cruciate ligament. Mediolateral radiographs were taken with and without fiduciary markers in place. Three investigators measured the CTS using radiographically visible anatomic landmarks at two different magnifications. The total observed variabilities were assessed by inter-observer and intra-observer differences. Paired t-tests were used to determine the effect of magnification and marker presence on CTS measures. RESULTS: Measurement of the CTS from the caudal margin of the intercondylar fossa on the femur to the intercondylar eminence was the most repeatable. Poor correlation between the anatomic landmarks and the fiduciary bone markers was observed. We found no effect of magnification or presence or absence of bone markers on measurement of CTS. CLINICAL SIGNIFICANCE: Cranial tibial subluxation can be detected with the most repeatability by measuring between the caudal margin of the intercondylar fossa and the intercondylar eminence. Magnification of the digitized radiographic image had minimal effect on repeatability. This technique can be used for in vivo analysis of the canine cruciate ligament deficient stifle joint.

[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.

A reliable positioning device for dorsoventral cephalometric radiography of the rat.

In dental research, dorsoventral cephalometric radiography is often used to assess skull growth and dental movement in rat models. To ensure that images can be reproduced, radiographers must use a cephalostat to maintain the rat's head in a consistent position across imaging sessions. The authors describe a positioning device they designed that connects easily to a standard dental X-ray machine. The device enabled researchers to position rats repeatedly for radiographic imaging with very little variation.

Radiographic imaging of the equine foot.

Radiographic examination of the equine foot can provide the veterinarian and farrier with a wealth of information. Positioning and selection of exposure factors are of central importance if one is to produce radiographs of maximum diagnostic value.

Computed radiography.

CR is a useful tool for the equine veterinarian and has many advantages. Its only major disadvantage is the initial cost, in dollars and time, for setup in one's practice. CR is already in use at several universities and private practices in the United States and around the world. In the future, as is the case with any computer-based technology, this modality should become more affordable and readily available to smaller practices. The potential of CR in veterinary medicine combined with saturation of the human market is driving the development of specialized software and algorithms for veterinary medicine.

A review of portal screen-film technology and five radiologists' evaluations of some existing products.

Portal radiographs, radiographs made to document the accuracy of radiotherapy treatment fields, are typically of poor image contrast. Recently, a new portal film and screened-cassette system was marketed, the Kodak EC-L system, with the claim of greatly improved image contrast. This new EC-L system was tested on a canine cadaver exposed to Cobalt-60 teletherapy gamma radiation, and image quality was compared to earlier marketed Kodak portal film products. The EC-L system was found to provide portal images of improved contrast/quality.

Radiographic measurement of craniocaudal instability in stifle joints of clinically normal dogs and dogs with injury of a cranial cruciate ligament.

OBJECTIVE: To determine craniocaudal laxity of the stifle joint of dogs when joints were positioned in tibial compression or neutral position. SAMPLE POPULATION: 19 normal stifle joints in 10 clinically normal dogs, 29 stifle joints with varying injury to the cranial cruciate ligament (10 complete ruptures alone, 10 complete ruptures with concomitant damage to the medial meniscus, 6 partial ruptures alone, and 3 partial ruptures with concomitant meniscal tearing), and 19 unaffected contralateral stifle joints in those 29 dogs. PROCEDURE: Relative displacement of bony landmarks was measured on paired lateral radiographs (neutral and tibial compression positions). Two measuring techniques were customized for use in dogs. RESULTS: The first technique failed to distinguish results in normal stifle joints from those in stifle joints with partial deficiency of cranial cruciate ligaments. Significant differences were found for joints with complete rupture, compared with stifle joints in clinically normal dogs. The second technique detected differences between normal stifle joints and injured joints with partial or complete rupture of the cranial cruciate ligament. Significant differences were not detected between joints with partial versus complete rupture. Adjusting data to account for size of dog did not improve results. CONCLUSIONS AND CLINICAL RELEVANCE: A wide range in measurements of laxity was found for stifle joints with intact cranial cruciate ligaments. Differences in degree of damage to the ligament and medial meniscus cannot be deduced from the amount of relative displacement measured on radiographs. Pathologic changes to the cranial cruciate ligament will not necessarily induce detectable changes in laxity of stifle joints in dogs.

Artifacts and technical errors presented as part of the 1996 ACVR oral certification examination.

Cases used for the examination consisted of various imaging artifacts and technical errors. The candidate was expected to name or identify the problem and discuss its cause and prevention. For the purpose of completeness, the scope and detail given here is in excess of that needed to pass the examination. Unless the problem was obvious, the examiner pointed out the problem to be discussed.

Receiver operating characteristic curve analysis of the performance of various radiographic protocols when screening dogs for pulmonary metastases.

Five radiographic protocols for detecting pulmonary metastases in dogs were compared by analyzing receiver operating characteristic curves for the protocols. Protocols compared were a right lateral view only, a left lateral view only, right lateral and dorsoventral views, both lateral views, and all 3 views. Three radiologists used each of the protocols to evaluate 99 sets of thoracic radiographs. Fifty-two sets of radiographs were from dogs confirmed histologically to have pulmonary metastases and 47 were from dogs proven at necropsy to be free of pulmonary metastases. Results of the 5 protocols were not statistically different. We concluded that a third view is not necessary when routinely screening dogs with cancer for pulmonary metastases and that the standard 2-view thoracic examination should be adequate. However, in individual cases, a third view may be the determining factor in establishing a radiographic diagnosis and should be obtained if any suspicious areas are seen.

[Veterinary radiology in Germany, Switzerland and Austria: a comparative analysis of problems]. / Veterinärröntgenologie in Deutschland, Schweiz und Osterreich: Eine vergleichende Problemanalyse.

The result of an investigation in 1988/89 to grasp the problems of veterinary radiology in Austria left some uncertainties. By an enquiry of 200 vets (49% answered) additional information was received. A comparison between Austria, Germany and Switzerland revealed the same problems: neglected darkroom work. The causes are absent or not seldom false advice by medical/technical firms, the lacking willingness of vets to become advised, false parsimony and insufficient offer of meetings and seminars providing the physical know-how in producing X-ray pictures.

[The use of a test model in a stepped form (test steps) for the clarification of different problem situations in X-ray diagnosis. 2. The use of test steps for testing the POLAROID-TPX immediate X-ray picture system]. / Der Einsatz eines Testphantoms in treppenförmiger Gestalt (Testtrepe) zur Klärung verschiedener Problemstellungen in der Röntgendiagnostik. Teil 2: Der Einsatz der Testtreppe zur Prüfung des POLAROID-TPX-Röntgensofortbildsystems.

The stepwedge, described in part 1 and in other publications, was used for the examination of the POLAROID-Instant Radiographic System. The result showed, that this system is a quite acceptable method for the practitioner. POLAROID-radiographs, in comparison with the classic radiographs, show equal contrast and detail-visibility, but demand a higher radiation dose.

[The use of a test phantom in step-shaped forms (test steps) for the clarification of different problem situations in x-ray diagnosis. 1. The use of test steps for the estimation of image quality after modified darkroom technics]. / Der Einsatz eines Testphantoms in treppenförmiger Gestalt (Testtreppe) zur Klärung verschiedener Problemstellungen in der Röntgendiagnostik. Teil 1: Der Einsatz der Testtreppe zur Beurteilung der Bildgüte nach modifizierter Dunkelkammertechnik.

Properly exposed radiographs and under- or overexposed ones were processed differently with regard to temperature and time. Using a step wedge for the objective estimation, the alteration of well-exposed radiographs by neglecting time and temperature control was examined. Further information is given about the possibility to improve the quality of wrongly exposed radiographs by manipulation of the processing, and about the quantity of acceptable radiographs received in this way. Stop bath, fixation bath, wash bath and drying were performed regularly. The result showed, that the only chance to get high quality radiographs is by exact and correct working.

[A simple test phantom in the form of a staircase for running control of the image in veterinary roentgenology]. / Ein einfaches Testphantom in Gestalt einer Treppe zur laufenden Kontrolle der Bildgüte in der Veterinärröntgenologie.

Quality control in veterinary radiology seems to be neglected. For the correct estimation of the radiographic quality, there is no adequate phantom available. Although measurements have shown that the exposure to radiation is far under the admissible limits, the quantity of repeated examination has to be reduced. So it was necessary to create a phantom, which allows the objective judgement of the x-ray photograph taken immediately from the patient. The phantom shows the following characteristics: 1) It is small-sized, so that it can be represented on the radiograph together with the object, but without remarkable enlargement of the beam and additional exposure to radiation. 2) It consists of tissue-similar material, which absorbs and scatters x-rays similar to the body region. According to the fact that the indications for radiographs in veterinary medicine are mostly problems in skeleton regions, this region is represented first of all. 3) Therefore the phantom shows variable thickness, so that it can simulate different skeleton parts. 4) The represented parameters are: 4.1 the different radiographic densities; 4.2 the latitude; 4.3 the radiographic contrast; 4.4 the radiographic detail visibility (film-far, film-close) in the relevant parts of the x-ray picture 5) The phantom is universally applicable. By a way of "calibration" it is multipurpose for certain kinds and sizes of animals.

[The diagnostic value of the 'skyline' view for the radiographic study of the navicular bone in horses]. / De diagnostische betekenis van de 'skyline'-opname ten behoeve van het röntgenologisch onderzoek van het straalbeen van het paard.

The radiographic diagnostic value of Rose's palmaroproximal-dorsodistal ('skyline') projection and Oxspring's dorsopalmar projection of the equine navicular bone were compared, by examining radiographs of 102 navicular bones originating from 66 randomly selected horses with clinical evidence of lameness located in the navicular area. In 27 navicular bones essential information was obtained from the skyline view, 15 independently of Oxspring's projection and 12 in addition to this view. For 11 navicular studies the D.P. projection was the most important diagnostic view. In the other 64 navicular bones information obtained from both views was of equal diagnostic value. Based on these results it is suggested that the skyline projection be utilised as an additional view, especially if there is a significant discrepancy between the clinical and radiographic findings based on lateromedial and Oxspring projections, and if ill-defined lesions of unknown significance are visible on the Oxspring projection.

[A new version of the x-ray regulation]. / Zur Neufassung der Röntgenverordnung.

In the Federal Republic of Germany, the medical and veterinary uses of X-rays are governed by legal rules entitled "Röntgenverordnung" which have been enacted in 1973. In the meantime, these directives have undergone an amendment, coming into effect January 1st, 1988. Some new regulations with concern to veterinary medicine are outlined below.