CT anatomy and normal radiography of the skull of the Rhesus monkey (Macaca mulatta).

BACKGROUND: Considering the relationship between human morphology and physiology with the Rhesus monkey, this animal is the most prominent species of laboratory primate for human and animal health research. Moreover, sending Macaca mulatta monkey into space and simulating a living environment for humans shows the similarity of this animal's physiology with humans. OBJECTIVE: So far, no comprehensive study has been done on computed tomography (CT) scan and radiography of skulls in Rhesus monkeys. Therefore, providing accurate documents from the CT anatomy of the skull in these animals can help us to better understand normal conditions and diseases, and we can use a functional atlas of diagnostic imaging from the skull of this animal. METHODS: Ten mature monkeys weighing 6.5 kg were used for this project (five males and five females). A radiographic examination with standard views was performed during general anaesthesia. Then the monkeys were placed in a spherical CT scan during general anaesthesia with standard sternal recumbency. RESULTS: The frontal bone was seen as two parallel radiopaque lines coming forward and downward. The frontal sinus in the Rhesus monkey was not visible in both lateral and dorsoventral radiographs, which could indicate the degeneration of this sinus in this species. The number of teeth in an adult monkey was 32. Molar teeth had a bilophodont arrangement. CONCLUSIONS: The comparison between the size of the eye ball in human and Rhesus monkey, unlike other measured parameters, did not differ much, and this indicates that the volume ratio of the eye ball to the whole skull in Rhesus monkey is higher than that of humans.

CT anatomy of the lungs, bronchi and trachea in the Mature Guinea pig (cavia porcellus).

BACKGROUND: Since there is no complete study of topographic features of thorax structures in guinea pigs, this study strives to define the exact topographic features of thorax structures. OBJECTIVES: The aim of this study is to provide comprehensive topographic information about the location of the trachea, bronchi, lungs and heart inside the thoracic cavity in guinea pig, as well as to study the features of these structures, their proximity to other organs and comparative anatomical studies with CT scan images in living samples. METHODS: Ten adult male and healthy guinea pigs were selected. CT scan transverse images were taken. The morphometric parameters of the lungs, bronchi, trachea, heart, thoracic cavity and abdominal cavity were measured. RESULTS: In these studies, the position of organs such as the trachea, lungs and heart were monitored, and specified descriptions of CT scan images and anatomical observations were obtained. We realised that the heart in this animal was not inclined to the left, and due to the equal size of the lungs, the heart was almost on the midline. According to the measurements, 20.05% of the ventral cavity volume was thoracic cavity and 79.95% was abdominal cavity. CONCLUSIONS: According to studies on guinea pigs, the right and left have the volume, and the heart is located between them on the midline without a tendency to the left. It seems that one of the reasons for the reluctance of the heart to the left and its placement on the midline in the guinea pig is that the volume of the two lungs is equal. In the case of guinea pigs, both numerical parameters are smaller than rabbits', but close to it. One of the most important factors in this study is that none of the animals were euthanised, and all of samples were alive after our study.

Ultrasonographic sex determination of the flathead grey mullet (Mugil cephalus).

BACKGROUND: Determination of sex in fish without external sexual dimorphism is important. Sex determination of the flathead grey mullet (Mugil cephalus) in the culture system and spawn-producing and fish reproduction system is very important. Currently, there are several methods to determine the sex of fish; however, they are time-consuming, expensive and sometimes dangerous for the fish. OBJECTIVE: The purpose of this study was the sex determination of flathead grey mullet by ultrasonography as a safe and accurate method. METHODS: In this regard, 30 flathead grey mullets (early in their maturation) from a farm in Gomishan-Golestan province, Iran were examined using a portable ultrasound machine with a 6-12 MHz waterproof linear transducer. Scanning was performed on the ventral body surface in the sagittal and transverse planes, between ventral and anal fins. RESULTS: Differences in shape, qualitative size, echogenicity and the wall layers of the ovary and testis were evaluated for sex determination. Results of ultrasonography were confirmed immediately at necropsy. Ultrasonographic accuracy for sex determination was 100%. The speed of the procedure was around 30 s per fish. CONCLUSIONS: Overall, the sex determination of flathead grey mullet by ultrasonography was high in accuracy and speed, non-invasive and safe for fish and consumers, and may be considered a priority. Place of the organs in the M. cephalus coelomic cavity and the obtained experience showed that for rapid and easy sex identification, the best place to put the transducer is on the ventral surface of the fish in the caudal part of the coelomic cavity for taking transverse and sagittal ultrasonograms.

Evaluation of thoracic vertebrae in healthy White New Zealand rabbit (Oryctolagus Cuniculus): Computed tomographic and morphometric study.

BACKGROUND: Computed tomography currently has a prominent role in diagnosis and evaluation of vertebral column. On the other hand, a thorough knowledge about vertebral column property in normal state is prerequisite an accurate diagnosis of different abnormalities in this region. OBJECTIVE: The purpose of this study was to present a complete and exact descriptive and morphometric evaluation of thoracic vertebrae in rabbits with computed tomography. In images which were constructed by CT, several structures and different parts of the thoracic vertebrae have been named. METHODS: Ten healthy, mature, White New Zealand rabbits were evaluated. The morphologic and morphometric parameters of the thoracic vertebrae were studied. In this study, several parameters of thoracic vertebrae, such as vertebral body height, spinous process height, transverse process length, transverse process width, etc., were measured by computed tomography. RESULTS: Some parameters, such as spinal canal height, spinal canal width, pedicle length, pedicle width, end plate width, and endplate height, had no significant difference through thoracic vertebrae but other parameters, such as vertebral body height, transverse process length, transverse process width, spinous process angle, transverse process angle, and vertebral body length, had a significant difference. CONCLUSIONS: In this study, a comprehensive anatomic atlas of CT anatomy of the thoracic vertebrae was produced for use by veterinary radiologists, clinicians, and surgeons. Finally, we must mention these two important points: (1) Many of the differences observed between rabbits and humans are based on the way the trunks of these two creatures are located on the ground and the differences in the way their bodies move. (2) In studies that are done by modelling humans on animals, it should be noted that the terms used in animal anatomy are different and the names are used using the principles of veterinary anatomy.

CT anatomy of the head in the Ile de France sheep.

BACKGROUND: CT scan images provide accurate anatomical data from different areas of the body that can be used to diagnose diseases. OBJECTIVES: The present work aimed to describe the normal anatomical structures of the Ile de France sheep head and its morphometric and volumetric properties using computed tomography (CT) and stereological methods. METHODS: Five adult Ile de France sheep heads, which were of mature age (above 10 months), were included in this study. The different cavities of the head, including the nasal cavity, paranasal sinuses, oral cavity, orbital cavity and vestibulocochlear system, were evaluated using CT scans, cross, sagittal and coronal sections. RESULTS: The mean length, height and width of the skull were 25.3 ± 1.02, 9.8 ± 0.93 and 12.3 ± 0.91 cm, respectively. The results showed that the nasal cavity is divided into three regions. Vestibular, respiratory and olfactory regions. The paranasal sinuses are composed of maxillary, frontal, palatine, sphenoid, lacrimal and ethmoidal that were identified and named in the CT scan images and their corresponding anatomical cross-sections. The total volume of the head, nasal cavity and oral cavity was estimated to be 2998 ± 202.00, 303 ± 31.33 and 229.3 ± 10.61 cm3 , respectively. CONCLUSIONS: The frontal sinus in the Ile de France sheep was limited to the frontal bone without extending into the parietal, temporal, or occipital bones, similar to Saanen goat. This study provided a comprehensive atlas of Ile de France sheep anatomy to internal medicine veterinarians and surgeons.

Anatomical study of the scleral ring and eyeball of the long-eared owl (Asio otus) with anatomical methods and diagnostic imaging techniques.

BACKGROUND: The scleral ring in birds consists of ossicles that are fixed as small plates by cartilage joints and have no articulation to other parts of the skeleton. OBJECTIVE: Due to inadequate examination of the scleral ring anatomy and its specific form in owls, this study aimed to investigate the exact structure of the scleral ring and some morphometric characteristics of the eyeball in a long-eared owl (Asio otus). METHODS: The eyes of 20 alive and 10 dead male and female owls were examined. In addition to common anatomical methods, computed tomography scans and radiographic and ultrasonographic imaging techniques were used in this study. RESULTS: The structure consisted of 15 ossicles. In the ventral part of the ring, these tubercles were observed in the scleral rings of all owls; in each ring, there were four bones with these tubercles. Additionally, there was no significant difference between the left and right eye parameters. Most ocular parameters in female owls were larger than those in males, but in the case of some parameters, such as optic nerve length and optic nerve sheath diameter, this difference was not observed. CONCLUSIONS: According to this study, the scleral ring in the Asio otus has anterior and posterior parts, and the lens is in the immediate vicinity of the anterior part. The right and left scleral rings and eyeballs are bilaterally symmetrical in terms of the shape, size, and number of ossicles that form the ring.

CT anatomy of cervical vertebrae of Asian elephant (Elephas maximus).

BACKGROUND: Elephants are currently the largest mammals on earth. A comprehensive examination of the anatomy of this animal to diagnose various disorders is required. In addition, due to the heavy head of these animals, adaptations have been made in the anatomical structure of the neck that is worth studying. OBJECTIVE: This study aimed to investigate a standard morphologic and morphometric description of the elephant cervical spine. Another aim of this study was to compare the changes in the cervical skeleton of elephants with horses and cattle. METHODS: For this study, the cervical vertebrae of the Asian elephant, cattle and horse were examined. CT Images were obtained using Somatom Spirit II CT Machine. Statistical analysis was done by SPSS 24 software. RESULTS: Two dorsal tubercles and a groove between them were observed on the dorsal arch of the atlas vertebra of the Asian elephant. In elephant samples, the variation of vertebral body height, spinous process height, transverse process width, vertebral body length and vertebral foramen volume indices were statistically significant. The volume of the vertebral foramen in the elephant decreases in the second vertebra compared to the first vertebra, decreases in the third vertebra, decreases in the fourth, increases in the fifth, decreases in the sixth and increases in the seventh. CONCLUSIONS: In this study, the structure of the cervical vertebrae of the Asian elephant was examined, and certain features were observed. One of the main features was the reduction of the length of the vertebrae, which leads to the decrease of the ratio of neck length to the size of the body. This condition can be due to the high weight of the head in the elephant. To maintain this weight, it is necessary to reduce the length of the neck and confer less mobility.

Applied anatomy of the skull in the Arabian horse: A computed tomographic, cross-sectional, volumetric and morphometric study.

This study was conducted to present a comprehensive and integrative computed tomography (CT) - anatomical cross sections atlas of skull, volumetric properties of the paranasal sinuses, and morphometric values for surface cranial nerves in the adult Arabian horse. Ten heads of Arabian horse breed were used. The different structures in the nasal, oral and cranial cavities were determined and labelled in the anatomical sections and their corresponding CT scan images. Three paranasal sinuses namely maxillary, conchofrontal and sphenopalatine sinuses were identified in the CT scan images. The caudal maxillary sinus was the largest paranasal sinus with 131.93 ± 7.67 cm3 volume and the sphenopalatine sinus 13.3 ± 1.2 cm3 volume was the smallest one. The infraorbital foramen was located 4.16 ± 0.18 cm and 4.70 ± 0.35 cm far away from the most rostral point of the facial crest and alveolar root, respectively. The mean distance between the mental foramen and most lateral incisive tooth was 3.12 ± 0.29 cm. These results including present CT scan-cross-sectional atlas, paranasal sinuses volume and morphometric properties would be applicable in practice for more precise diagnosis of head lesions and blocking the surface terminal branches of the cranial nerves during surgical operations in this valuable horse's breed.

Cimetidine administration decreases radiogenic damage on the thyroid gland in mice.

PURPOSE: To study if Cimetidine administration could ameliorate the thyroid damage in external radiation. MATERIALS AND METHODS: Forty healthy male adult mice were used in the present study. The animals were randomized into four groups. Untreated mice (Group 1) that received 1 mg/kg saline intraperitoneally (IP). Group 2 received a single 10 Gy gamma radiation dose with 1 mg/kg saline IP and group 3 were treated with Cimetidine IP. Group 4 was irradiated 1 hour after treatment with Cimetidine. The serum were assayed for the contents of triiodothyronine (T3), tetraiodothyronine (T4), thyroid stimulating hormone (TSH), Free T4 (FT4) and Cortisol using a radioimmunological technique 7 days following radiation. The thyroid tissue was processed and stained with hematoxylin and eosin (H&E), and periodic acid-Schiff (PAS) for histological examination. Data were statistically analyzed using Tukey's post-hoc test and were considered significant at p < 0.05. RESULTS: External radiation resulted in weight loss and reduction of serum thyroid hormone levels. However, Cimetidine administration prevented marked changes. Histological study showed that Cimetidine injection to irradiated mice minimized the thyroid damage. CONCLUSIONS: These findings suggested that Cimetidine administration 1 hour before radiation exposure was potent in ameliorating the thyroid damages.