Advances in Clinical Molecular Imaging Instrumentation

In this article, we describe recent developments in the design of both single-photon emission computed tomography (SPECT) and positron emission tomography (PET) instrumentation that have led to the current range of superior performance instruments. The adoption of solid-state technology for either complete detectors [e.g., cadmium zinc telluride (CZT)] or read-out systems that replace photomultiplier tubes [avalanche photodiodes (APD) or silicon photomultipliers (SiPM)] provide the advantage of compact technology, enabling flexible system design. In SPECT, CZT is well suited to multi-radionuclide and kinetic studies. For PET, SiPM technology provides MR compatibility and superior time-of-flight resolution, resulting in improved signal-to-noise ratio. Similar SiPM technology has also been used in the construction of the first SPECT insert for clinical brain SPECT/MRI

Organ-Dedicated Molecular Imaging Systems

[EN] In this review, we will cover both clinical and technical aspects of the advantages and disadvantages of organ specific (dedicated) molecular imaging (MI) systems, namely positron emission tomography (PET) and single photon emission computed tomography, including gamma cameras. This review will start with the introduction to the organ-dedicated MI systems. Thereafter, we will describe the differences and their advantages/disadvantages when compared with the standard large size scanners. We will review time evolution of dedicated systems, from first attempts to current scanners, and the ones that ended in clinical use. We will review later the state of the art of these systems for different organs, namely: breast, brain, heart, and prostate. We will also present the advantages offered by these systems as a function of the special application or field, such as in surgery, therapy assistance and assessment, etc. Their technological evolution will be introduced for each organ-based imager. Some of the advantages of dedicated devices are: higher sensitivity by placing the detectors closer to the organ, improved spatial resolution, better image contrast recovery (by reducing the noise from other organs), and also lower cost. Designing a complete ring-shaped dedicated PET scanner is sometimes difficult and limited angle tomography systems are preferable as they have more flexibility in placing the detectors around the body/organ. Examples of these geometries will be presented for breast, prostate and heart imaging. Recently achievable excellent time of flight capabilities below 300-ps full width at half of the maximum reduce significantly the impact of missing angles on the reconstructed images.This work was supported in part by the European Research Council through the European Union's Horizon 2020 Research and Innovation Program under Grant 695536, in part by the EU through the FP7 Program under Grant 603002, and in part by the Spanish Ministerio de Economia, Industria y Competitividad through PROSPET (DTS15/00152) funded by the Ministerio de Economia y Competitividad under Grant TEC2016-79884-C2-1-R.González Martínez, AJ.; Sánchez, F.; Benlloch Baviera, JM. (2018). Organ-Dedicated Molecular Imaging Systems. IEEE Transactions on Radiation and Plasma Medical Sciences. 2(5):388-403. https://doi.org/10.1109/TRPMS.2018.2846745S3884032

Real-time human action and gesture recognition using skeleton joints information towards medical applications

Des efforts importants ont été faits pour améliorer la précision de la détection des actions humaines à l’aide des articulations du squelette. Déterminer les actions dans un environnement bruyant reste une tâche difficile, car les coordonnées cartésiennes des articulations du squelette fournies par la caméra de détection à profondeur dépendent de la position de la caméra et de la position du squelette. Dans certaines applications d’interaction homme-machine, la position du squelette et la position de la caméra ne cessent de changer. La méthode proposée recommande d’utiliser des valeurs de position relatives plutôt que des valeurs de coordonnées cartésiennes réelles. Les récents progrès des réseaux de neurones à convolution (RNC) nous aident à obtenir une plus grande précision de prédiction en utilisant des entrées sous forme d’images. Pour représenter les articulations du squelette sous forme d’image, nous devons représenter les informations du squelette sous forme de matrice avec une hauteur et une largeur égale. Le nombre d’articulations du squelette fournit par certaines caméras de détection à profondeur est limité, et nous devons dépendre des valeurs de position relatives pour avoir une représentation matricielle des articulations du squelette. Avec la nouvelle représentation des articulations du squelette et le jeu de données MSR, nous pouvons obtenir des performances semblables à celles de l’état de l’art. Nous avons utilisé le décalage d’image au lieu de l’interpolation entre les images, ce qui nous aide également à obtenir des performances similaires à celle de l’état de l’art.There have been significant efforts in the direction of improving accuracy in detecting human action using skeleton joints. Recognizing human activities in a noisy environment is still challenging since the cartesian coordinate of the skeleton joints provided by depth camera depends on camera position and skeleton position. In a few of the human-computer interaction applications, skeleton position, and camera position keep changing. The proposed method recommends using relative positional values instead of actual cartesian coordinate values. Recent advancements in CNN help us to achieve higher prediction accuracy using input in image format. To represent skeleton joints in image format, we need to represent skeleton information in matrix form with equal height and width. With some depth cameras, the number of skeleton joints provided is limited, and we need to depend on relative positional values to have a matrix representation of skeleton joints. We can show the state-of-the-art prediction accuracy on MSR data with the help of the new representation of skeleton joints. We have used frames shifting instead of interpolation between frames, which helps us achieve state-of-the-art performance

Advances in Therapeutic Monitoring of Lithium in the Management of Bipolar Disorder

Since the mid-20th century, lithium continues to be prescribed as a first-line mood stabilizer for the management of bipolar disorder (BD). However, lithium has a very narrow therapeutic index, and it is crucial to carefully monitor lithium plasma levels as concentrations greater than 1.2 mmol/L are potentially toxic and can be fatal. The quantification of lithium in clinical laboratories is performed by atomic absorption spectrometry, flame emission photometry, or conventional ion-selective electrodes. All these techniques are cumbersome and require frequent blood tests with consequent discomfort which results in patients evading treatment. Furthermore, the current techniques for lithium monitoring require highly qualified personnel and expensive equipment; hence, it is crucial to develop low-cost and easy-to-use devices for decentralized monitoring of lithium. The current paper seeks to review the pertinent literature rigorously and critically with a focus on different lithium-monitoring techniques which could lead towards the development of automatic and point-of-care analytical devices for lithium determination