Pediatric brain tumor classification using deep learning on MR images with age fusion.

Purpose: To implement and evaluate deep learning-based methods for the classification of pediatric brain tumors (PBT) in magnetic resonance (MR) data.

Methods: A subset of the "Children's Brain Tumor Network" dataset was retrospectively used ( = 178 subjects, female = 72, male = 102, NA = 4, age range [0.01, 36.

Early Detection of Oral Potentially Malignant Disorders: A Review on Prospective Screening Methods with Regard to Global Challenges.

Oral cancer is a cancer type that is widely prevalent in low-and middle-income countries with a high mortality rate, and poor quality of life for patients after treatment. Early treatment of cancer increases patient survival, improves quality of life and results in less morbidity and a better prognosis. To reach this goal, early detection of malignancies using technologies that can be used in remote and low resource areas is desirable.

5-ALA fluorescence in randomly selected pediatric brain tumors assessed by spectroscopy and surgical microscope.

Purpose: Fluorescence-guided surgery applying 5-aminolevulinic acid (5-ALA) in high-grade gliomas is an established method in adults. In children, results have so far been ambiguous. The aim of this study was to investigate 5-ALA-induced fluorescence in pediatric brain tumors by using the surgical microscope and a spectroscopic hand-held probe.

Diseased thyroid tissue classification in OCT images using deep learning: Towards surgical decision support.

Intraoperative guidance tools for thyroid surgery based on optical coherence tomography (OCT) could aid distinguish between normal and diseased tissue. However, OCT images are difficult to interpret, thus, real-time automatic analysis could support the clinical decision-making. In this study, several deep learning models were investigated for thyroid disease classification on 2D and 3D OCT data obtained from ex vivo specimens of 22 patients undergoing surgery and diagnosed with several thyroid pathologies.

Inflation of test accuracy due to data leakage in deep learning-based classification of OCT images.

In the application of deep learning on optical coherence tomography (OCT) data, it is common to train classification networks using 2D images originating from volumetric data. Given the micrometer resolution of OCT systems, consecutive images are often very similar in both visible structures and noise. Thus, an inappropriate data split can result in overlap between the training and testing sets, with a large portion of the literature overlooking this aspect.

Does Anatomical Contextual Information Improve 3D U-Net-Based Brain Tumor Segmentation?

Effective, robust, and automatic tools for brain tumor segmentation are needed for the extraction of information useful in treatment planning. Recently, convolutional neural networks have shown remarkable performance in the identification of tumor regions in magnetic resonance (MR) images. Context-aware artificial intelligence is an emerging concept for the development of deep learning applications for computer-aided medical image analysis.

Optical Brain Biopsy with a Fluorescence and Vessel Tracing Probe.

Background: Accurate stereotactic biopsies of brain tumors are imperative for diagnosis and tailoring of the therapy. Repetitive needle insertions enhance risks of brain lesioning, hemorrhage, and complications due to prolonged procedure.

Objective: To investigate clinical benefits of a combined 5-aminolaevulinic acid (5-ALA) fluorescence and laser Doppler flowmetry system for the detection of malignant brain tumor and blood vessels in stereotactic biopsies.

Optical coherence tomography for thyroid pathology: 3D analysis of tissue microstructure.

To investigate the potential of optical coherence tomography (OCT) to distinguish between normal and pathologic thyroid tissue, 3D OCT images were acquired on thyroid samples from adult subjects (n=22) diagnosed with a variety of pathologies. The follicular structure was analyzed in terms of count, size, density and sphericity. Results showed that OCT images highly agreed with the corresponding histopatology and the calculated parameters were representative of the follicular structure variation.

Auditory and Visual User Interface for Optical Guidance During Stereotactic Brain Tumor Biopsies.

During stereotactic brain tumor biopsies, the detection of protoporphyrin IX (PpIX) fluorescence and microvascular perfusion using laser Doppler flowmetry (LDF) with a handheld fiber optic probe allows the identification of tumor tissue while decreasing the risk of intracranial hemorrhage. Neurosurgeons performing this procedure usually view the measurement values on a screen. When their visual focus is directed at the surgical site, they require an assistant to verbally relay the values.

5-ALA fluorescence and laser Doppler flowmetry for guidance in a stereotactic brain tumor biopsy.

A fiber optic probe was developed for guidance during stereotactic brain biopsy procedures to target tumor tissue and reduce the risk of hemorrhage. The probe was connected to a setup for the measurement of 5-aminolevulinic acid (5-ALA) induced fluorescence and microvascular blood flow. Along three stereotactic trajectories, fluorescence (n = 109) and laser Doppler flowmetry (LDF) (n = 144) measurements were done in millimeter increments.

Optical monitoring of cerebral microcirculation in neurointensive care.

Continuous optical monitoring of local cerebral microcirculation could benefit neurointensive care patients treated for subarachnoid hemorrhage (SAH). The aim of the study was to evaluate laser Doppler flowmetry (LDF) and diffuse reflectance spectroscopy (DRS) for long-term monitoring of brain microcirculation and oxygen saturation (SO) in the neurointensive care unit (NICU). A fiber optic probe was designed for intraparenchymal use and connected to LDF and DRS for assessment of the local blood flow (perfusion and tissue reflectance (TLI)) and SO in the brain.

Auditory display for fluorescence-guided open brain tumor surgery.

Purpose: Protoporphyrin (PpIX) fluorescence allows discrimination of tumor and normal brain tissue during neurosurgery. A handheld fluorescence (HHF) probe can be used for spectroscopic measurement of 5-ALA-induced PpIX to enable objective detection compared to visual evaluation of fluorescence. However, current technology requires that the surgeon either views the measured values on a screen or employs an assistant to verbally relay the values.

Combination of hand-held probe and microscopy for fluorescence guided surgery in the brain tumor marginal zone.

Background: Visualization of the tumor is crucial for differentiating malignant tissue from healthy brain during surgery, especially in the tumor marginal zone. The aim of the study was to introduce a fluorescence spectroscopy-based hand-held probe (HHF-probe) for tumor identification in combination with the fluorescence guided resection surgical microscope (FGR-microscope), and evaluate them in terms of diagnostic performance and practical aspects of fluorescence detection.

Material And Methods: Eighteen operations were performed on 16 patients with suspected high-grade glioma.

A method for monitoring of oxygen saturation changes in brain tissue using diffuse reflectance spectroscopy.

Continuous measurement of local brain oxygen saturation (SO ) can be used to monitor the status of brain trauma patients in the neurocritical care unit. Currently, micro-oxygen-electrodes are considered as the "gold standard" in measuring cerebral oxygen pressure (pO ), which is closely related to SO through the oxygen dissociation curve (ODC) of hemoglobin, but with the drawback of slow in response time. The present study suggests estimation of SO in brain tissue using diffuse reflectance spectroscopy (DRS) for finding an analytical relation between measured spectra and the SO for different blood concentrations.

405 nm versus 633 nm for protoporphyrin IX excitation in fluorescence-guided stereotactic biopsy of brain tumors.

Fluorescence diagnosis may be used to improve the safety and reliability of stereotactic brain tumor biopsies using biopsy needles with integrated fiber optics. Based on 5-aminolevulinic-acid-induced protoporphyrin IX (PpIX) fluorescence, vital tumor tissue can be localized in vivo during the excision procedure to reduce the number of necessary samples for a reliable diagnosis. In this study, the practical suitability of two different PpIX excitation wavelengths (405 nm, 633 nm) was investigated on optical phantoms.

Low dose 5-aminolevulinic acid: Implications in spectroscopic measurements during brain tumor surgery.

Background: Using 5-aminolevulinic acid (ALA) as an intraoperative fluorescence contrast has been proven to improve the resection of glioblastoma and contribute to prolonged patient survival. ALA accumulates as protoporphyrin IX (PpIX) in the tumor cells and is administered in an advised dose of 20 mg/kg body weight (b.w.

Fluorescence spectroscopy measurements in ultrasonic navigated resection of malignant brain tumors.

Background And Objective: Glioblastoma multiforme is a highly malignant primary brain tumor. It has no border but at best a marginal zone, however, invisible to the surgeon. An optical touch pointer (OTP) enabling differentiation of healthy and tumor tissue by means of fiber-optic fluorescence spectroscopy has been developed.

Optical touch pointer for fluorescence guided glioblastoma resection using 5-aminolevulinic acid.

Background And Objective: Total tumor resection in patients with glioblastoma multiforme (GBM) is difficult to achieve due to the tumor's infiltrative way of growing and morphological similarity to the surrounding functioning brain tissue. The diagnosis is usually subjectively performed using a surgical microscope. The objective of this study was to develop and evaluate a hand-held optical touch pointer using a fluorescence spectroscopy system to quantitatively distinguish healthy from malignant brain tissue intraoperatively.

Combined diffuse light reflectance and electrical impedance measurements as a navigation aid in deep brain surgery.

Aim: The aim of this study is to assess reflected light intensity combined with impedance as a navigation aid during stereotactic neurosurgery.

Methods: During creation of 21 trajectories for stereotactic implantation of deep brain stimulation electrodes in the globus pallidus internus or subthalamus (zona incerta or subthalamic nucleus), impedance at 512 kHz and reflected light intensity at 780 nm were measured continuously and simultaneously with a radio frequency electrode containing optical fibres. The signals were compared with the anatomy, determined from pre- and post-operative MRI and CT.

Comparative study on the insertion behavior of cerebral microprobes.

A series of experiments has been conducted with probes made from silicon, glass, tungsten and polyimide within a developed brain phantom, and the insertion behavior, forces and dimpling are compared to in vitro and in vivo models. This allows the choice of proper insertion parameters and probe structure to reach a compromise between needle stability and tissue trauma as a result of insertion. According to the performed experiments, the reduced interfacial area between the needle tip and the brain will result in reduced insertion force.