Anatomical description of the skulls of peccaries (Tayassu tajacu, Linnaeus 1758) by computed tomography / [Descrição anatômica de crânio de catetos (Tayassu tajacu, Linnaeus, 1758) por tomografia computadorizada]

The aim of this study was to evaluate the anatomical structures of the skulls of peccaries to establish the basis for their clinical study and future preclinical research. Ten skulls of adult peccaries were subjected to tomographic examination. The data obtained were processed via three-dimensional image reconstruction software (3D images). The reconstructions obtained from the neurocranium of the studied specimens allowed the identification and description of the following structures: nasal bone, frontal bone, parietal bones, incisor bone, maxillary bone, zygomatic bone, temporal bone, palatal bone, occipital bone, vomer bone, pterygoid bone, sphenoid bone, paranasal sinuses and orbit. Computed tomography proved to be an important diagnostic tool in the investigation of the skull of this species, allowing the acquisition of anatomical values not yet documented for the species in the literature.(AU)

O objetivo deste estudo foi avaliar as estruturas anatômicas dos crânios de catetos, a fim de se estabelecerem as bases para seu estudo clínico e futuras pesquisas pré-clínicas. Dez crânios de catetos adultos foram submetidos a exame tomográfico. Os dados obtidos foram introduzidos em um software de reconstrução de imagens tridimensionais (imagens em 3D). As reconstruções obtidas do neurocrânio dos espécimes estudados permitiram a identificação e a descrição das seguintes estruturas: osso nasal, osso frontal, ossos parietais, osso incisivo, osso maxilar, osso zigomático, osso temporal, osso palatino, osso occipital, osso vômer, osso pterigoide, osso esfenoide, seios paranasais e órbita. A tomografia computadorizada mostrou-se como uma ferramenta diagnóstica importante na investigação do crânio dessa espécie, permitindo a aquisição de valores anatômicos ainda não documentados para a espécie na literatura.(AU)

Comparison of radiographic and tomographic evaluations for measurement of the Canal Flare Index in dogs / [Comparação entre avaliação radiográfica e tomográfica para mensuração do Canal Flare Index em cães]

The outcome of total hip arthroplasty (THA) in dogs is directly related to surgical planning. Templating of radiographs prior to THA should help the surgeon anticipate prosthesis size and femoral shape allowing canal fill of the proximal metaphysis by the implant ensuring primary stable fixation. The canal flare index (CFI) obtained from radiograph has been used as a measure of risk of complications for the technique in human beings and dogs. However, standard radiographs only provide limited data for the selection of cementless prostheses and the assessment of their fit within the femoral canal, due to factors like radiographic magnification and femoral rotation. Therefore, three-dimensional evaluation based on computed tomography (CT) may be a better tool for CFI measurement. The aim of this study was to compare anatomical measurement with CFI values obtained from craniocaudal radiography and CT. Craniocaudal radiographs using a horizontal radiographic beam (CR), CT, and anatomical macroscopic measurements (A) were obtained from 45 femurs from 23 canine cadavers. The differences between the values of CFI obtained from radiograph (CFI-R), computed tomography on transverse (CFI- TT) and longitudinal axis (CFI-TL) compared to the CFI obtained from macroscopic measurements - gold standard - (CFI-A), and 95% limits of agreement (LOA) between the values, were evaluated by the Bland-Altman method. Dimensions obtained from CT techniques had a greatest mean difference from anatomical and CFI values were also different (P=0.032). Under the experimental conditions, the craniocaudal radiograph, provided the most accurate measurement of the CFI (mean difference: 0.087 ± 0.42).(AU)

O resultado da artroplastia total do quadril (ATQ) em cães está diretamente relacionado ao planejamento cirúrgico. O templating radiográfico pré-operatório da ATQ deve ajudar o cirurgião a prever o tamanho da prótese e o formato do fêmur, o que permitirá um preenchimento ideal da metáfise proximal pelo implante, garantindo, assim, fixação primária estável. O índice de alargamento do canal (Canal Flare Index - CFI) obtido em radiografias tem sido utilizado como fator de risco de complicações para a técnica em humanos e cães. No entanto, as radiografias podem fornecer apenas dados limitados para a seleção de próteses não cimentadas e a avaliação do seu encaixe no canal femoral, devido a fatores como ampliação radiográfica e rotação femoral. Portanto, a avaliação tridimensional baseada na tomografia computadorizada (TC) pode ser uma ferramenta vantajosa para a mensuração do CFI. O objetivo deste estudo foi comparar a medida anatômica com os valores de CFI obtidos na radiografia craniocaudal e na TC. Radiografias craniocaudais utilizando feixe radiográfico horizontal (CR), tomografia computadorizada e medidas macroscópicas anatômicas (A) foram obtidas de 45 fêmures de 23 cadáveres caninos. As diferenças entre os valores de CFI obtidos na radiografia (CFI-R), na tomografia computadorizada no eixo transversal (CFI-TT) e no eixo longitudinal (CFI-TL), em comparação com os valores de CFI obtidos nas medições macroscópicas - padrão-ouro - (CFI-A) e os limites de concordância de 95% (LOA) entre os valores, foram avaliadas pelo método de Bland-Altman. As dimensões obtidas pelas técnicas de TC apresentaram maior diferença média dos valores anatômicos, e as do CFI também foram diferentes (P=0,032). Nas condições experimentais, a radiografia craniocaudal forneceu a medida mais precisa do CFI (diferença média: 0,087 ± 0,42) para representar o padrão-ouro deste estudo.(AU)

Printing 3D models of canine jaw fractures for teaching undergraduate veterinary medicine

Abstract Purpose To develop 3D anatomical models, and corresponding radiographs, of canine jaw fractures. Methods A base model was generated from a mandibular bone scan. With this model it was possible to perform fracture planning according to the anatomical location. Results The 3D base model of the canine mandible was similar in conformation to the natural bone, demonstrating structures such as canine tooth crowns, premolars and molars, mental foramina, body of the mandible, ramus of the mandible, masseteric fossa, the coronoid process, condylar process, and angular process. It was not possible to obtain detail of the crown of the incisor teeth, mandibular symphysis, and the medullary channel. Production of the 3D CJF model took 10.6 h, used 150.1 g of filament (ABS) and cost US$5.83. Conclusion The 3D canine jaw fractures models, which reproduced natural canine jaw fractures, and their respective radiographic images, are a possible source of educational material for the teaching of veterinary medicine.

Methodological approaches to planar and volumetric scintigraphic imaging of small volume targets with high spatial resolution and sensitivity

Single-photon emission computed tomography (SPECT) is a non-invasive imaging technique, which provides information reporting the functional states of tissues. SPECT imaging has been used as a diagnostic tool in several human disorders and can be used in animal models of diseases for physiopathological, genomic and drug discovery studies. However, most of the experimental models used in research involve rodents, which are at least one order of magnitude smaller in linear dimensions than man. Consequently, images of targets obtained with conventional gamma-cameras and collimators have poor spatial resolution and statistical quality. We review the methodological approaches developed in recent years in order to obtain images of small targets with good spatial resolution and sensitivity. Multipinhole, coded mask- and slit-based collimators are presented as alternative approaches to improve image quality. In combination with appropriate decoding algorithms, these collimators permit a significant reduction of the time needed to register the projections used to make 3-D representations of the volumetric distribution of target’s radiotracers. Simultaneously, they can be used to minimize artifacts and blurring arising when single pinhole collimators are used. Representation images are presented, which illustrate the use of these collimators. We also comment on the use of coded masks to attain tomographic resolution with a single projection, as discussed by some investigators since their introduction to obtain near-field images. We conclude this review by showing that the use of appropriate hardware and software tools adapted to conventional gamma-cameras can be of great help in obtaining relevant functional information in experiments using small animals.

Stereolithographic biomodeling of equine ovary based on 3D serial digitizing device

The 3D internal structure microscopy (3D-ISM) was applied to the equine ovary, which possesses peculiar structural characteristics. Stereolithography was applied to make a life-sized model by means of data obtained from 3D-ISM. Images from serially sliced surfaces contributed to a successful 3D reconstruction of the equine ovary. Photopolymerized resin models of equine ovaries produced by stereolithography can clearly show the internal structure and spatial localizations in the ovary. The understanding of the spatial relationship between the ovulation fossa and follicles and/or corpora lutea in the equine ovary was a great benefit. The peculiar structure of the equine ovary could be thoroughly observed and understood through this model.

Ultra-sonografia bidimensional convencional, de alta resolução e tridimensional no acompanhamento da gestação em cadela / Two-dimensional conventional, high resolution two-dimensional and three-dimensional ultrasonography in the evaluation of pregnant bitch

Gestational period in a bitch, after natural mating with a normal dog, was evaluated by two-dimensional conventional, high-resolution two-dimensional and three-dimensional ultrasonography. High-resolution two-dimensional ultrasonography show better image and provides early diagnosis of pregnancy (15 days) in comparison to conventional one (20 days). Three-dimensional ultrasonography was use to evaluate fetal morphology during late gestation period, however its application is still limited