DigitalUM :: Browsing by Subject "MRI"

Browsing by Subject "MRI"

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Open Access
A neuroanatomical study of the feline brain using MRI and mulligan staining: functional and pathological considerations
(Universidad de Shiraz, 2021-07-21) Díaz Martínez, Elena; Arencibia Espinosa, Alberto; Soler Laguía, Marta; Kilroy, David; Ayala Florenciano, María Dolores; Martínez Gomariz, Francisco; Ramírez Zarzosa, Gregorio José; Anatomía y Anatomía Patológica Comparadas
Despite multiple studies describing accurate diagnoses using advanced neuroimaging techniques, low and mid-field magnetic resonance imaging (MRI) are still the most frequent scanners in veterinary clinics. To date, these studies in cats do not show a clear distinction of nerve centres in MRI data. Aims: The objective of this study is to determine the efficacy of Mulligan histological staining as a tool in facilitating the location and identification of the main structures of the feline brain in MRI. This study aims to facilitate the interpretation of MRI obtained with these types of scanners. Methods: A total of 10 feline brains were used. One specimen was used for MRI (T2 sequence using a 1.5T scanner). The other 9 brains were sectioned and stained with the three Mulligan staining techniques (Mulligan, Le Masurier and Robert). Results: The uptake of stain by the grey matter in these sections allowed the determination of the location and the limits of these nervous structures within the brain. The histological location of these structures was correlated with the MRI scans, leading to the successful identification of many small, indistinct nuclei. Conclusion: Mulligan staining is proposed as a tool that facilitates the location of nerve structures in comparison with data from the most frequently-used MRI scanners in veterinary clinics
Open Access
A neuroanatomical study of the feline brain using MRI and mulligan staining: functional and pathological considerations
(2021) Diaz Martínez, E.; Ayala Florenciano, María Dolores; Arencibia Espinosa, A.; Soler Laguía, Marta; Kilroy, D.; Martínez Gomariz, Francisco; Ramírez Zarzosa, Gregorio José; Anatomía y Anatomía Patológica Comparada; Facultad de Veterinaria
Background: Despite multiple studies describing accurate diagnoses using advanced neuroimaging techniques, low and mid-field magnetic resonance imaging (MRI) are still the most frequent scanners in veterinary clinics. To date, these studies in cats do not show a clear distinction of nerve centres in MRI data. Aims: The objective of this study is to determine the efficacy of Mulligan histological staining as a tool in facilitating the location and identification of the main structures of the feline brain in MRI. This study aims to facilitate the interpretation of MRI obtained with these types of scanners. Methods: A total of 10 feline brains were used. One specimen was used for MRI (T2 sequence using a 1.5T scanner). The other 9 brains were sectioned and stained with the three Mulligan staining techniques (Mulligan, Le Masurier and Robert). Results: The uptake of stain by the grey matter in these sections allowed the determination of the location and the limits of these nervous structures within the brain. The histological location of these structures was correlated with the MRI scans, leading to the successful identification of many small, indistinct nuclei. Conclusion: Mulligan staining is proposed as a tool that facilitates the location of nerve structures in comparison with data from the most frequently-used MRI scanners in veterinary clinics.
Open Access
A study of the head during prenatal and perinatal development of two fetuses and one newborn striped dolphin (Stenella coeruleoalba, Meyen 1833) using dissections, sectional anatomy, CT, and MRI: anatomical and functional implications in cetaceans and terrestrial mammals
(MDPI, 2019-12-13) Ríos y Loshuertos, Álvaro García de los; Arencibia Espinosa, Alberto; Soler Laguía, Marta; Gil Cano, Francisco; Martínez Gomariz, Francisco; López Fernández, Alfredo; Ramírez Zarzosa, Gregorio José; Anatomía y Anatomía Patológica Comparada; Facultad de Veterinaria
Our objective was to analyze the main anatomical structures of the dolphin head during its developmental stages. Most dolphin studies use only one fetal specimen due to the difficulty in obtaining these materials. Magnetic resonance imaging (MRI) and computed tomography (CT) of two fetuses (younger and older) and a perinatal specimen cadaver of striped dolphins were scanned. Only the older fetus was frozen and then was transversely cross-sectioned. In addition, gross dissections of the head were made on a perinatal and an adult specimen. In the oral cavity, only the mandible and maxilla teeth have started to erupt, while the most rostral teeth have not yet erupted. No salivary glands and masseter muscle were observed. The melon was well identified in CT/MRI images at early stages of development. CT and MRI images allowed observation of the maxillary sinus. The orbit and eyeball were analyzed and the absence of infraorbital rim together with the temporal process of the zygomatic bone holding periorbit were described. An enlarged auditory tube was identified using anatomical sections, CT, and MRI. We also compare the dolphin head anatomy with some mammals, trying to underline the anatomical and physiological changes and explain them from an ontogenic point of view.
Open Access
Adult-onset Alexander disease with a heterozygous D128N GFAP mutation: a pathological study
(Universidad de Murcia. Departamento de Biología Celular e Histología, 2019) Cabrera Galván, Juan José; Martínez Martin, María Soledad; Déniz García, Daniel; Araujo Ruano, Eduardo; Travieso Aja, María del Mar
The various forms of Alexander disease (AD) have been linked to heterozygous point mutations in the coding region of the Human glial fibrillary acidic protein (GFAP) gene. The aim of this study was to confirm and characterise an adult variant of AD based on the presence of Rosenthal fibres, which were identified at brain autopsy. We performed histological and immunohistochemical studies and mutation screening by cycle sequencing of exons 1, 4, 6, and 8. A heterozygous D128N GFAP mutation, previously described in three other cases of adult-onset AD (AOAD), was genetically confirmed. The mutation was seemingly sporadic. Symptoms of the female, 65-year-old patient started with occasionally asymmetric motor impairment and concluded, 23 months later, with a lack of spontaneous movement in all four limbs, reduced consciousness, an acute respiratory problem, and eventually lethal exitus. The most striking characteristics were a cerebellar syndrome with subsequent clinical signs due to brainstem and spinal cord involvement. The final diagnosis was based on a complete autopsy, detection of Rosenthal fibres, GFAP, vimentin, alpha B-crystallin, ubiquitin, hsp27, neurofilament, and synaptophysin, and the identification of the corresponding GFAP gene mutation. Blood analyses were positive for ANA and rheumatoid factor. In conclusion, this work describes sporadic, rapidly advancing AOAD in a female patient and links it with other published cases with the same mutation. Reflections are provided on the influence of vasculitis and ANA in AD as well as the presence of Rosenthal fibres in the neurohypophysis.
Open Access
An anatomical study using computed tomography, magnetic resonance imaging, and rhinoscopy of the nasal cavity of domestic cat (Felis silvestris catus L.) and big cats: lion (Panthera leo leo L.), leopard (Panthera pardus kotiya L.), and cheetah (Acinonyx jubatus jubatus S.)
(MDPI, 2024-04-13) Díaz Martínez, Elena; Arencibia Espinosa, Alberto; Kilroy, David; Soler Laguía, Marta; Kilroy, David; Martínez Gomariz, Francisco; Casas García, Diego Luis; Sánchez Collado, Cayetano; Gil Cano, Francisco; Raduán Jaber, José; Ramírez Zarzosa, Gregorio José; Anatomía Humana y Psicobiología; Facultad de Veterinaria
The objective of this work was to study the normal anatomy of the nasal cavity of the three species of big cats (leopard, lion, and cheetah) compared to the domestic cat through the use of computed tomography, magnetic resonance imaging, and rhinoscopy. Computed tomography allowed us to clearly visualize the entire bony and cartilaginous framework that supports the nasal cavity. Magnetic resonance imaging permitted better visualization of the soft tissues of this cavity. On the other hand, rhinoscopy enabled the direct visualization of the mucosa of the vestibule and nasal cavity, which is very useful in the diagnosis of masses or foreign bodies. Furthermore, with this technique, it has been possible to observe several small orifices from the nasolacrimal duct, the pharyngeal auditory tube, and the lateral nasal gland. Computed tomography, magnetic resonance imaging, and rhinoscopy are useful tools in analysis of the anatomical characteristics of the nasal cavity in these species.
Open Access
Comparative anatomy of the nasal cavity in the common dolphin Delphinus delphis L., striped dolphin Stenella coeruleoalba M. and pilot whale Globicephala melas T.: a developmental study
(MDPI, 2021-02-08) Ríos y Loshuertos, Alvaro García de los; Soler Laguía, Marta; Arencibia Espinosa, Alberto; López Fernández, Alfredo; Covelo Figueiredo, Pablo; Martínez Gomariz, Francisco; Sánchez Collado, Cayetano; García Carrillo, Nuria; Ramírez Zarzosa, Gregorio José; Anatomía y Anatomía Patológica Comparada; Facultad de Veterinaria
Our goal was to analyze the main anatomical structures of the dolphin external nose and nasal cavity from fetal developmental stages to adult. Endoscopy was used to study the common development of the external nose and the melon, and nasal mucosa. Magnetic resonance imaging (MRI) and anatomical sections were correlated with anatomical sections. Computed tomography (CT) was used to generate 3D reconstructions of the nasal bones and nasal cavities to study its development. Dissections, histological and pathological studies were carried out on the nasal mucosa to understand its function. These results were compared with the horse. Endoscopy showed an external nose with two lips and the upper lip is divided by a groove due to the nasal septum and an obstruction of right nasal cavity was diagnosed in a newborn. Two diverticula (air sacs) were found in the nasal vestibule and an incisive recess (premaxillary sac) in the nasal cavity. These findings were corroborated by 3D reconstructions of the nasal cavities, MRI, anatomical sections and dissections. The presphenoid and ethmoid bones were fused at early stages of fetal development. The ethmoid is the last bone to ossify in the nasal cavity.
Open Access
Endoscopic study of the oral and pharyngeal cavities in the Common dolphin, Striped dolphin, Risso’s dolphin, Harbour porpoise and Pilot whale: reinforced with other diagnostic and anatomic techniques
(MDPI, 2021-05-22) García de los Ríos y Loshuertos, Álvaro; Soler Laguía, Marta; Arencibia Espinosa, Alberto; Martínez Gomariz, Francisco; Sánchez Collado, Cayetano; López Fernández, Alfredo; Gil Cano, Francisco; Seva Alcaraz, Juan; Ramírez Zarzosa, Gregorio José; Anatomía y Anatomía Patológica Comparadas
In this work, the fetal and newborn anatomical structures of the dolphin oropharyngeal cavities were studied. The main technique used was endoscopy, as these cavities are narrow tubular spaces and the oral cavity is difficult to photograph without moving the specimen. The endoscope was used to study the mucosal features of the oral and pharyngeal cavities. Two pharyngeal diverticula of the auditory tubes were discovered on either side of the choanae and larynx. These spaces begin close to the musculotubaric channel of the middle ear, are linked to the pterygopalatine recesses (pterygoid sinus) and they extend to the maxillopalatine fossa. Magnetic Resonance Imaging (MRI), osteological analysis, sectional anatomy, dissections, and histology were also used to better understand the function of the pharyngeal diverticula of the auditory tubes. These data were then compared with the horse’s pharyngeal diverticula of the auditory tubes. The histology revealed that a vascular plexus inside these diverticula could help to expel the air from this space to the nasopharynx. In the oral cavity, teeth remain inside the alveolus and covered by gums. The marginal papillae of the tongue differ in extension depending on the fetal specimen studied. The histology reveals that the incisive papilla is vestigial and contain abundant innervation. No ducts were observed inside lateral sublingual folds in the oral cavity proper and caruncles were not seen in the prefrenular space.
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MR and CT Arthrography of the Wrist
(Thieme Gruppe, 2012-02-01) Cerezal Pesquera, Luis; Berná Mestre, Juan de Dios; Canga, Ana; Llopis, Eva; Rolon, Alejandro; Martín Oliva, Xavier; Piñal, Francisco del; Dermatología, Estomatología, Radiología y Medicina Física
The study of the wrist represents a major diagnostic challenge because of its complex anatomy and the small size of individual structures. Recent advances in imaging techniques have increased our diagnostic capabilities. However, 3T magnets, multichannel specific wrist coils, and new MRI sequences have not restricted the indications of arthrographic imaging techniques (CT arthrography and MR arthrography). Distension of the different wrist compartments at CT arthrography and MR arthrography significantly improves the diagnostic accuracy for triangular fibrocartilage (TFC) complex injuries and carpal instability. Dedicated multichannel wrist coils are essential for an adequate study of the wrist, but the placement of these coils and the positioning of the wrist are also important for proper diagnosis. The development of dynamic multislice CT studies allows a diagnostic approach that combines dynamic information and the accurate assessment of ligaments and the TFC complex. New advances in arthroscopy have changed the anatomical description of the TFC with a functional division in the proximal and distal TFC complex, and they have allowed a better characterization of lesions of the TFC complex with subclassification of Palmer 1B and 1D lesions and description of new lesions not included in the Palmer classification, such as capsular injuries.
Open Access
pH and temperature – sensitive chitosan hydrogels: swelling and magnetic resonance imaging (MRI) studies
(Wiley, 2011-02-25) Goycoolea Valencia, Francisco Martín; Fernández Valle, María E.; Aranaz, Inmaculada; Heras, Ángeles; Biología Celular e Histología; Facultades de la UMU::Facultad de Biología
MRI and swelling experiments are used to probe the state of water and infer the microstructure of chitosan hydrogels. SEM reveals a porous open scaffold-type structure for hydrogels that were equilibrated at 2 °C before freezing as compared to those equilibrated at 37 °C. ADC MRI measurements reveal an anisotropy in the microstructure of these gels. T1 relaxation MRI values were larger as the pH increased from 7.6 to 12.0, the result of a lower rate of exchange between protons of the hydration sphere of the polymer and bulk water. The thermosensitive and pH-sensitive properties of these hydrogels can be utilized in the development of innovative materials for biotechnological and biomedical applications, including criobiocatalysis and bioremediation as well as in programmed drug delivery.
Open Access
Tracking stem cell migration and survival in brain injury: Current approaches and future prospects
(F. Hernández y Juan F. Madrid. Universidad de Murcia. Departamento de Biología Celular e Histología, 2012) Darkazalli, Ali; Levenson, Cathy W.
In recent years, stem cell-mediated therapies have gained considerable ground as potential treatments for a wide variety of brain pathologies including traumatic brain injury, stroke and neurodegenerative diseases. Despite extensive preclinical studies, many of these therapies have not been fully translated into viable clinical approaches. This is partly due to our inability to reliably track and monitor transplanted stem cells longitudinally over long periods of time in vivo. In this review, we discuss the predominant histological cell tracing methodologies, such as immunohistochemistry, and fluorescent cellular dyes and proteins, and compare them to emerging cellular imaging technologies. We show that advances in magnetic resonance imaging (MRI) have resulted in opportunities to use this technology to further our understanding of stem cell characteristics and behaviors in vivo. While MRI may not completely replace conventional cell tracking methods in pre-clinical, mechanistic work, it is clear that it has the potential to function as a powerful diagnostic tool for tracking stem cell migration and survival as well as for evaluating the efficacy of stem cell-mediated therapies.

Browsing by Subject "MRI"

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