The FBK system for the CHiME-4 challenge

This paper describes the ASR system submitted by FBK to the CHiME-4 challenge for the single channel track. The proposed solution employs multiple subsystems, whose DNNs are trained with different training criteria and strategies (i.e. diverse training material, with and without batch normalization). A ``self" adaptation of acoustic models is applied to each subsystem, relying on a blind estimate of the accuracy of automatic transcriptions. This adaptation, performed in a batch fashion over the entire evaluation set, significantly improves the performance of each subsystem. The final output is obtained by combining the multiple transcriptions through ROVER, which provides a further improvement, reducing the average WER on the evaluation set from 22.3% to 16.5%

Non-lesional white matter in relapsing-remitting multiple sclerosis assessed by multicomponent T2 relaxation

Introduction: The purpose of the study is to investigate, by T2 relaxation, non-lesional white matter (WM) in relapsing-remitting (RR) multiple sclerosis (MS). Methods: Twenty stable RR MS patients underwent 1.5T Magnetic Resonance Imaging (MRI) with 3D Fluid-Attenuated Inversion-Recovery (FLAIR), 3D-T1-weighted, and T2-relaxation multi-echo sequences. The Lesion Segmentation Tool processed FLAIR images to identify focal lesions (FLs), whereas T1 images were segmented to identify WM and FL sub-volumes with T1 hypo-intensity. Non-lesional WM was obtained as the segmented WM, excluding FL volumes. The multi-echo sequence allowed decomposition into myelin water, intra-extracellular water, and free water (Fw), which were evaluated on the segmented non-lesional WM. Correlation analysis was performed between the non-lesional WM relaxation parameters and Expanded Disability Status Scale (EDSS), disease duration, patient age, and T1 hypo-intense FL volumes. Results: The T1 hypo-intense FL volumes correlated with EDSS. On the non-lesional WM, the median Fw correlated with EDSS, disease duration, age, and T1 hypo-intense FL volumes. Bivariate EDSS correlation of FL volumes and WM T2-relaxation parameters did not improve significance. Conclusion: T2 relaxation allowed identifying subtle WM alterations, which significantly correlated with EDSS, disease duration, and age but do not seem to be EDSS-predictors independent from FL sub-volumes in stable RR patients. Particularly, the increase in the Fw component is suggestive of an uninvestigated prodromal phenomenon in brain degeneration

Planning field-junction in proton cranio-spinal irradiation – the ancillary-beam technique

Planning field-junction in proton cranio-spinal irradiation – the ancillary-beam techniqu

Proton beam versus photon beam dose to the heart and left anterior descending artery for left-sided breast cancer

<p><b>Purpose.</b> The purpose of this study was to compare the dose to heart, left anterior descending (LAD) artery and lung between proton and photon beam irradiation for left-sided early stage breast cancer.</p> <p><b>Material and methods.</b> Ten women with early stage left-sided breast cancer were treated with breast conserving surgery and radiation. Whole breast radiation was delivered for actual treatment via a tangential technique with deep inspiration breath hold (DIBH) utilizing inverse planned intensity-modulated radiation therapy (IMRT). Each patient was replanned on an Institutional Review Board (IRB)-approved prospective study using en face proton beam radiation with both uniform scanning (US) and pencil beam scanning (PBS) techniques.</p> <p><b>Results.</b> Both PBS (0.011 Gy) and US (0.009 Gy) proton plans resulted in a significantly lower mean heart dose compared to IMRT (1.612 Gy) (p < 0.05 for PBS vs. IMRT and US vs. IMRT). The Dmean, Dmin, Dmax, and D0.2cm³ of the LAD with either proton technique were significantly lower (p = 0.005) compared to IMRT. Both US and PBS reduced the mean dose to the lungs compared to IMRT. The coverage of the breast planning target volume was comparable between photon and proton plans.</p> <p><b>Conclusions.</b> The dose to whole heart was relatively low in this study of patients treated under conditions of DIBH. However, proton beam radiation was associated with lower minimum, maximum, and dose to 0.2 cm³ of the LAD, which is the critical structure for late radiation therapy effects, compared to even the most optimized photon beam plan with DIBH and IMRT.</p