Towards Whole Placenta Segmentation At Late Gestation Using Multi-View Ultrasound Images

We propose a method to extract the human placenta at late gestation using multi-view 3D US images. This is the first step towards automatic quantification of placental volume and morphology from US images along the whole pregnancy beyond early stages (where the entire placenta can be captured with a single 3D US image). Our method uses 3D US images from different views acquired with a multi-probe system. A whole placenta segmentation is obtained from these images by using a novel technique based on 3D convolutional neural networks. We demonstrate the performance of our method on 3D US images of the placenta in the last trimester. We achieve a high Dice overlap of up to 0.8 with respect to manual annotations, and the derived placental volumes are comparable to corresponding volumes extracted from MR.Wellcome Trust IEH Award; EPSRC Centre for Medical Engineering; National Institute for Health Research (NIHR); King’s College London; NHS Foundation Trus

Generalisability of deep learning models in low-resource imaging settings: A fetal ultrasound study in 5 African countries

Most artificial intelligence (AI) research have concentrated in high-income countries, where imaging data, IT infrastructures and clinical expertise are plentiful. However, slower progress has been made in limited-resource environments where medical imaging is needed. For example, in Sub-Saharan Africa the rate of perinatal mortality is very high due to limited access to antenatal screening. In these countries, AI models could be implemented to help clinicians acquire fetal ultrasound planes for diagnosis of fetal abnormalities. So far, deep learning models have been proposed to identify standard fetal planes, but there is no evidence of their ability to generalise in centres with limited access to high-end ultrasound equipment and data. This work investigates different strategies to reduce the domain-shift effect for a fetal plane classification model trained on a high-resource clinical centre and transferred to a new low-resource centre. To that end, a classifier trained with 1,792 patients from Spain is first evaluated on a new centre in Denmark in optimal conditions with 1,008 patients and is later optimised to reach the same performance in five African centres (Egypt, Algeria, Uganda, Ghana and Malawi) with 25 patients each. The results show that a transfer learning approach can be a solution to integrate small-size African samples with existing large-scale databases in developed countries. In particular, the model can be re-aligned and optimised to boost the performance on African populations by increasing the recall to $0.92 \pm 0.04$ and at the same time maintaining a high precision across centres. This framework shows promise for building new AI models generalisable across clinical centres with limited data acquired in challenging and heterogeneous conditions and calls for further research to develop new solutions for usability of AI in countries with less resources

Aprendizaje automático profundo y visión por computadora: aplicaciones en el reconocimiento de lengua de señas e imágenes astronómicas

Esta línea de investigación se centra en el estudio y desarrollo de Sistemas Inteligentes para la resolución de problemas de reconocimiento de patrones en imágenes y video, utilizando técnicas de Aprendizaje Automático clásicas, junto con Redes Neuronales Convolucionales y Aprendizaje profundo. El trabajo presentado describe diferentes casos de aplicación en visión por computadora. Una de las líneas de investigación principales que se continúa desarrollando es el reconocimiento de lengua de señas. Este es un problema complejo y multidisciplinar, que presenta diversos subproblemas a resolver como el reconocimiento del intérprete, la segmentación de manos, la clasificación de diferentes configuraciones y de un gesto dinámico, entre otros. En esta área se está estudiando la forma de reconocer formas de mano de la Lengua de Señas con conjuntos de datos de tamaño reducido, dada la falta de datos de entrenamiento para este dominio. Además, se están comenzando a utilizar Redes Generativas Adversarias (GANs) para aumentar bases de datos de formas de mano, con el objetivo de complementar desde otro enfoque el entrenamiento de modelos para su clasificación. Por otro lado, se está estudiando la forma en que las redes neuronales codifican la invarianza a las transformaciones y otras propiedades transformacionales, con el objetivo de poder analizar y comparar estos modelos, y finalmente mejorarlos. De esta forma se espera poder mejorar los modelos de clasificación de objetos transformados, en particular, de formas de mano. Siguiendo con la línea de reconocimiento de patrones en imágenes, se está llevando a cabo una colaboración con investigadores de la Facultad de Astronomía y Geofísica de la UNLP para crear modelos de clasificación de imágenes de objetos celestes. Además, se está desarrollando un sistema para recuperar la información de placas espectrográficas astronómicas antiguas, con el objetivo de recuperar los espectrogramas que contienen. Por último, se está diseñando un prototipo para crear experiencias interactivas multimedia que incorpore técnicas de aprendizaje profundo tanto para la entrada de datos por parte de los usuarios, como para la generación de una salida en forma de imágenes, videos, sonido y texto.Eje: Agentes y Sistemas Inteligentes.Red de Universidades con Carreras en Informátic

Generalisability of fetal ultrasound deep learning models to low-resource imaging settings in five African countries

Most artificial intelligence (AI) research and innovations have concentrated in high-income countries, where imaging data, IT infrastructures and clinical expertise are plentiful. However, slower progress has been made in limited-resource environments where medical imaging is needed. For example, in Sub-Saharan Africa, the rate of perinatal mortality is very high due to limited access to antenatal screening. In these countries, AI models could be implemented to help clinicians acquire fetal ultrasound planes for the diagnosis of fetal abnormalities. So far, deep learning models have been proposed to identify standard fetal planes, but there is no evidence of their ability to generalise in centres with low resources, i.e. with limited access to high-end ultrasound equipment and ultrasound data. This work investigates for the first time different strategies to reduce the domain-shift effect arising from a fetal plane classification model trained on one clinical centre with high-resource settings and transferred to a new centre with low-resource settings. To that end, a classifier trained with 1,792 patients from Spain is first evaluated on a new centre in Denmark in optimal conditions with 1,008 patients and is later optimised to reach the same performance in five African centres (Egypt, Algeria, Uganda, Ghana and Malawi) with 25 patients each. The results show that a transfer learning approach for domain adaptation can be a solution to integrate small-size African samples with existing large-scale databases in developed countries. In particular, the model can be re-aligned and optimised to boost the performance on African populations by increasing the recall to 0.92 0.04 and at the same time maintaining a high precision across centres. This framework shows promise for building new AI models generalisable across clinical centres with limited data acquired in challenging and heterogeneous conditions and calls for further research to develop new solutions for the usability of AI in countries with fewer resources and, consequently, in higher need of clinical support