Machine learning assisted DSC-MRI radiomics as a tool for glioma classification by grade and mutation status.

BACKGROUND: Combining MRI techniques with machine learning methodology is rapidly gaining attention as a promising method for staging of brain gliomas. This study assesses the diagnostic value of such a framework applied to dynamic susceptibility contrast (DSC)-MRI in classifying treatment-naïve gliomas from a multi-center patients into WHO grades II-IV and across their isocitrate dehydrogenase (IDH) mutation status. METHODS: Three hundred thirty-three patients from 6 tertiary centres, diagnosed histologically and molecularly with primary gliomas (IDH-mutant = 151 or IDH-wildtype = 182) were retrospectively identified. Raw DSC-MRI data was post-processed for normalised leakage-corrected relative cerebral blood volume (rCBV) maps. Shape, intensity distribution (histogram) and rotational invariant Haralick texture features over the tumour mask were extracted. Differences in extracted features across glioma grades and mutation status were tested using the Wilcoxon two-sample test. A random-forest algorithm was employed (2-fold cross-validation, 250 repeats) to predict grades or mutation status using the extracted features. RESULTS: Shape, distribution and texture features showed significant differences across mutation status. WHO grade II-III differentiation was mostly driven by shape features while texture and intensity feature were more relevant for the III-IV separation. Increased number of features became significant when differentiating grades further apart from one another. Gliomas were correctly stratified by mutation status in 71% and by grade in 53% of the cases (87% of the gliomas grades predicted with distance less than 1). CONCLUSIONS: Despite large heterogeneity in the multi-center dataset, machine learning assisted DSC-MRI radiomics hold potential to address the inherent variability and presents a promising approach for non-invasive glioma molecular subtyping and grading.

[Lazzaro Spallanzani and his refutation of the theory of spontaneous generation]. / Lazzaro Spallanzani e la confutazione della teoria della generazione spontanea.

The development and refinement of microscopy in the 17th century revealed to science a whole new world of microorganisms, until then unknown, that appeared to arise spontaneously, and fuelled a controversy that had seemed definitively resolved by Francesco Redi's experiments, the question of the spontaneous generation and origin of life. At the half of the 18th century a young Italian abbot, Lazzaro Spallanzani, Professor of Physics and Mathematics at the University of Reggio Emilia, started repeating the experiments of John Turberville Needham. The English Catholic priest claimed to have demonstrated the validity of the theory of spontaneous generation after observing the growth of small organisms in some chicken broth placed in sealed flasks and heated for 30 minutes. Spallanzani found significant errors in the experiments conducted by Needham and, after trying several variations on them, disproved the theory of spontaneous generation.

GPU-accelerated interactive visualization and planning of neurosurgical interventions.

Advances in computational methods and hardware platforms provide efficient processing of medical-imaging datasets for surgical planning. For neurosurgical interventions employing a straight access path, planning entails selecting a path from the scalp to the target area that's of minimal risk to the patient. A proposed GPU-accelerated method enables interactive quantitative estimation of the risk for a particular path. It exploits acceleration spatial data structures and efficient implementation of algorithms on GPUs. In evaluations of its computational efficiency and scalability, it achieved interactive rates even for high-resolution meshes. A user study and feedback from neurosurgeons identified this methods' potential benefits for preoperative planning and intraoperative replanning.

Anatomía microquirúrgico del epidímo / Microsurgical antaomy of the epididymis

La microcirugía epididimaria requiere un conocimiento profundo de anatomía de este órgano, poco conocida hasta la fecha. Se basa esta descripción anatómica en la disección microquirúrgica de epididimos normales en fresco, y en el estudio de cortes histológicos sagitales, frontales y transversales luego de su fijación en formol al 10%. Se describe macroscópicamente al epidídimo considerándolo clásicamente como una lámina delgada con dos caras, dos extremos y dos bordes, siendo éstos: el in interno fijo o vascular y el externo, libre o linfático. Lo conceptual de este trabajo se refiere a la descripción original de la sistematización microscópica del tubo epididimario denominándose a este: primario o simple. A su plicatura se la llam circunvolución de primer grado, y mediante ellas se organiza en una estructura alargada llamada columna epidimaria que en la cabeza es múltiple y en el cuerpo es única, describiendo en este un desarrollo helicoidal aplanado de forma prismática en volumen y de sección triangular llamado circunvolución de segundo grado. Se considera que esta descrición anatómica tiene gran utilidad para quienes practiquen microcirugía epididimaria o deseen iniciarse en ella, enfrentándola con la información adecuada sobre el tema, permitiendo mejores resultados prácticos en su ejecución