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1.
NMR Biomed ; 36(3): e4846, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36259628

RESUMEN

Magnetic resonance imaging (MRI) technology has profoundly transformed current healthcare systems globally, owing to advances in hardware and software research innovations. Despite these advances, MRI remains largely inaccessible to clinicians, patients, and researchers in low-resource areas, such as Africa. The rapidly growing burden of noncommunicable diseases in Africa underscores the importance of improving access to MRI equipment as well as training and research opportunities on the continent. The Consortium for Advancement of MRI Education and Research in Africa (CAMERA) is a network of African biomedical imaging experts and global partners, implementing novel strategies to advance MRI access and research in Africa. Upon its inception in 2019, CAMERA sets out to identify challenges to MRI usage and provide a framework for addressing MRI needs in the region. To this end, CAMERA conducted a needs assessment survey (NAS) and a series of symposia at international MRI society meetings over a 2-year period. The 68-question NAS was distributed to MRI users in Africa and was completed by 157 clinicians and scientists from across Sub-Saharan Africa (SSA). On average, the number of MRI scanners per million people remained at less than one, of which 39% were obsolete low-field systems but still in use to meet daily clinical needs. The feasibility of coupling stable energy supplies from various sources has contributed to the growing number of higher-field (1.5 T) MRI scanners in the region. However, these systems are underutilized, with only 8% of facilities reporting clinical scans of 15 or more patients per day, per scanner. The most frequently reported MRI scans were neurological and musculoskeletal. The CAMERA NAS combined with the World Health Organization and International Atomic Energy Agency data provides the most up-to-date data on MRI density in Africa and offers a unique insight into Africa's MRI needs. Reported gaps in training, maintenance, and research capacity indicate ongoing challenges in providing sustainable high-value MRI access in SSA. Findings from the NAS and focused discussions at international MRI society meetings provided the basis for the framework presented here for advancing MRI capacity in SSA. While these findings pertain to SSA, the framework provides a model for advancing imaging needs in other low-resource settings.


Asunto(s)
Imagen por Resonancia Magnética , Humanos , África del Sur del Sahara , Encuestas y Cuestionarios
2.
Epilepsy Behav ; 46: 91-8, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-25940105

RESUMEN

Automatic recognition of words from letter strings is a critical processing step in reading that is lateralized to the left-hemisphere middle fusiform gyrus in the so-called Visual Word Form Area (VWFA). Surgical lesions in this location can lead to irreversible alexia. Very early left hemispheric lesions can lead to transfer of the VWFA to the nondominant hemisphere, but it is currently unknown if this capability is preserved in epilepsies developing after reading acquisition. In this study, we aimed to determine the lateralization of the VWFA in late-onset left inferior occipital lobe epilepsies and also the effect of surgical disconnection from the adjacent secondary visual areas. Two patients with focal epilepsies with onset near the VWFA underwent to surgery for epilepsy, with sparing of this area. Neuropsychology evaluations were performed before and after surgery, as well as quantitative evaluation of the speed of word reading. Comparison of the surgical localization of the lesion, with the BOLD activation associated with the contrast of words-strings, was performed, as well as a study of the associated main white fiber pathways using diffusion-weighted imaging. Neither of the patients developed alexia after surgery (similar word reading speed before and after surgery) despite the fact that the inferior occipital surgical lesions reached the neighborhood (less than 1cm) of the VWFA. Surgeries partly disconnected the VWFA from left secondary visual areas, suggesting that pathways connecting to the posterior visual ventral stream were severely affected but did not induce alexia. The anterior and superior limits of the resection suggest that the critical connection between the VWFA and the Wernicke's Angular Gyrus cortex was not affected, which is supported by the detection of this tract with probabilistic tractography. Left occipital lobe epilepsies developing after reading acquisition did not produce atypical localizations of the VWFA, even with foci in the close neighborhood. Surgery for occipital lobe epilepsy should take this into consideration, as well as the fact that disconnection from the left secondary visual areas may not produce alexia.


Asunto(s)
Dominancia Cerebral/fisiología , Dislexia Adquirida/prevención & control , Epilepsias Parciales/cirugía , Lenguaje , Procedimientos Neuroquirúrgicos/normas , Complicaciones Posoperatorias/prevención & control , Lóbulo Temporal/cirugía , Adolescente , Edad de Inicio , Imagen de Difusión por Resonancia Magnética , Humanos , Masculino
3.
Epilepsia ; 50(6): 1624-31, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19183218

RESUMEN

Hypothalamic hamartomas (HHs) have been demonstrated as the cause of gelastic epilepsy, both by intracranial electrodes and functional imaging. The neocortex becomes secondarily involved, through poorly characterized propagation pathways. The detailed dynamics of seizure spread have not yet been demonstrated, owing to the limited spatial-temporal resolution of available functional mapping. We studied a patient with epilepsy associated with HH and gelastic epilepsy. Simultaneous electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) of several seizure events were obtained, with blood oxygen level dependent (BOLD) activation of the hamartoma, and left hemisphere hypothalamus, hippocampus, parietal-occipital area, cingulate gyrus, and dorsal-lateral frontal area. Integration of regional BOLD kinetics and EEG power dynamics strongly suggests propagation of the epileptic activity from the HH through the left fornix to the temporal lobe, and later through the cingulate fasciculus to the left frontal lobe. The EEG/fMRI method has the spatial-temporal resolution to study the dynamics of seizure activity, with detailed demonstration of origin and propagation pathways.


Asunto(s)
Mapeo Encefálico , Encéfalo/irrigación sanguínea , Epilepsias Parciales/patología , Hamartoma/patología , Enfermedades Hipotalámicas/patología , Encéfalo/patología , Preescolar , Electroencefalografía/métodos , Epilepsias Parciales/complicaciones , Hamartoma/complicaciones , Humanos , Enfermedades Hipotalámicas/complicaciones , Procesamiento de Imagen Asistido por Computador/métodos , Imagen por Resonancia Magnética/métodos , Masculino , Oxígeno/sangre
4.
Med Biol Eng Comput ; 56(8): 1435-1446, 2018 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-29352433

RESUMEN

The biomechanical changes in the spinal column are considered to be the main responsible for rachialgia. Although radiological techniques use ionizing radiation, they are the most applied tools to assess the biomechanics of the spine. To face this problem, non-invasive techniques must be developed. Vertebral Metrics is an ionizing radiation-free instrument designed to detect the 3D position of each vertebrae in a standing position. Using a stereo vision system combined with low intensity UV light, recognition is achieved with software capable of distinguishing fluorescent marks. The fluorescent marks are the skin projection of the vertex of the spinal processes. This paper presents a major development of Vertebral Metrics and its evaluation. It performs a scan in less than 45 s with a resolution on the order of 1 mm, in each spatial direction, therefore, allowing an accurate analysis of the spine. The instrument was applied to patients without associated pathology. Statistically significant differences between consecutive scans were not found. A positive correlation between the 3D positions of each vertebra and the homologous position of the other vertebrae was observed. Using Vertebral Metrics, innovative results can be obtained. It can be used in areas such as orthopedics, neurosurgery, and rehabilitation. Graphical abstract ᅟ.


Asunto(s)
Bioingeniería/métodos , Columna Vertebral/fisiología , Adulto , Algoritmos , Fenómenos Biomecánicos , Femenino , Humanos , Cifosis/fisiopatología , Lordosis/fisiopatología , Vértebras Lumbares/fisiopatología , Masculino , Persona de Mediana Edad , Estadística como Asunto , Adulto Joven
5.
Acta Reumatol Port ; 42(2): 168-175, 2017.
Artículo en Portugués | MEDLINE | ID: mdl-27750275

RESUMEN

OBJECTIVE: To perform the cultural adaptation of the instrument Activity Record (ACTRE) and evaluate its psychometric qualities. METHOD: Six steps were followed:1) translation of the original instrument, 2) back-translation, 3) formal equivalence assessment, 4) evaluation by an expert in Portuguese language, 5) final critique by experts in the field and 6 ) applying the questionnaire to 53 pregnant women, aged between 18 and 39 years, at two different moments with an interval time of two hours aimed to evaluate the reliability level of temporal stability (test-retest) using the the Intraclass Correlation. RESULTS: The results of the Intraclass Correlation at the level of test / retest reliability ranged between 0.88 and 1.00. The Cronbach's alpha, calculated for all the questions in the activities most often mentioned, was 0.77, we obtained a further significant correlations between the various issues together in this set of activities. CONCLUSION: The Portuguese version of the ACTRE was easily understood by all pregnant women and revealed a high reliability.


Asunto(s)
Actividades Cotidianas , Autoinforme , Adolescente , Adulto , Femenino , Humanos , Embarazo , Psicometría , Reproducibilidad de los Resultados , Traducciones , Adulto Joven
6.
Med Biol Eng Comput ; 48(11): 1161-4, 2010 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-20635224

RESUMEN

We designed and built a non-invasive instrument, called Vertebral Metrics, to measure the x, y, and z positions of each spinous process of the spine on a standing position. In the present study, we perform a comparative evaluation of Vertebral Metrics, by comparing the results obtained from this instrument with those from a validated optoelectronic system of stereophotogrammetry, with 10 infrared cameras. The sample was composed of 11 women aged between 14 and 39 years. After marking the various points on the spinal column, from the first cervical vertebra to the first sacral vertebra, they were measured first with the new instrument (Vertebral Metrics) and then by means of the optoelectronics system. Afterwards, the results were subjected to a thorough comparison. The statistical comparison of the results was performed using an ANOVA model with three factors (Instrument, Subject, and Vertebra) for the intervertebral distance.


Asunto(s)
Dolor de Espalda/patología , Modelos Anatómicos , Columna Vertebral/patología , Adolescente , Adulto , Análisis de Varianza , Fenómenos Biomecánicos , Diseño de Equipo , Femenino , Humanos , Masculino , Fotogrametría , Postura , Adulto Joven
7.
Epilepsia ; 48(6): 1179-83, 2007 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-17553119

RESUMEN

The Panayiotopoulos type of occipital lobe epilepsy has generated great interest, but the particular brain areas involved in the peculiar seizure manifestations have not been established. We studied a patient with the syndrome, using high-resolution EEG and simultaneous EEG and functional magnetic resonance imaging (fMRI). Resolution of the scalp EEG was improved using a realistic spline Laplacian algorithm, and produced a complex distribution of current sinks and sources over the occipital lobe. The spike-related blood oxygen level dependent (BOLD) effect was multifocal, with clusters in lateral and inferior occipital lobe and lateral and anterior temporal lobe. We also performed regional dipole seeding in BOLD clusters to determine their relative contribution to generation of scalp spikes. The integrated model of the neurophysiologic and vascular data strongly suggests that the epileptic activity originates in the lateral occipital area, spreading to the occipital pole and lateral temporal lobe.


Asunto(s)
Mapeo Encefálico/métodos , Corteza Cerebral/fisiopatología , Electroencefalografía/estadística & datos numéricos , Epilepsias Parciales/fisiopatología , Imagen por Resonancia Magnética/estadística & datos numéricos , Algoritmos , Niño , Interpretación Estadística de Datos , Electroencefalografía/métodos , Epilepsias Parciales/diagnóstico , Lateralidad Funcional , Humanos , Procesamiento de Imagen Asistido por Computador , Masculino , Modelos Neurológicos , Monitoreo Fisiológico/estadística & datos numéricos , Lóbulo Occipital/fisiopatología , Oxígeno/sangre , Lóbulo Temporal/fisiopatología
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