Multiclass semantic segmentation and quantification of traumatic brain injury lesions on head CT using deep learning: an algorithm development and multicentre validation study

Background: Computed tomography (CT) is the most common imaging modality in traumatic brain injury (TBI). However, its conventional use requires expert clinical interpretation and does not provide detailed quantitative outputs, which may have prognostic importance. Deep learning could reliably and efficiently detect, distinguish, and quantify different lesion types, providing opportunities for personalised treatment strategies and clinical research. Methods: An initial convolutional neural network (CNN) was trained and validated on expert manual segmentations (97 scans). This CNN was then used to automatically segment a new set of 839 scans, which were then manually corrected by experts. From these, a subset of 184 scans was used to train a final CNN for multi-class, voxel-wise segmentation of lesion types. The performance of this CNN was evaluated on a held-out test set with 655 scans. External validation was performed on a large, independent set of 500 patients from a different continent. Findings: When compared to manual reference, CNN-derived lesion volumes showed a mean error of 0·86mL (95% CI -5·23 to 6·94) for intraparenchymal haemorrhage (IPH), 1·83mL (-12·01 to 15·66) for extra-axial haemorrhage (EAH), 2·09mL (-9·38 to 13·56) for perilesional oedema and 0·07mL (-1·00 to 1·13) for intraventricular haemorrhage (IVH). Further, the CNN detected lesions with AUCs of 0·90 (0·86-0·94) for IPH, 0·80 (0·75-0·85) for EAH, 0·95 (0·89-1·00) for IVH on the external, independent patient dataset. Interpretation: We demonstrate the ability of a CNN to separately segment, detect and quantify multi-class haemorrhagic lesions and importantly, perilesional oedema. These volumetric lesion estimates allow clinically relevant quantification of lesion burden and progression, with potential applications in clinical care and research in TBI. Funding: European Union 7th Framework Programme, Hannelore Kohl Stiftung; OneMind; Integra Neurosciences; European Research Council Horizon 2020; Engineering and Physical Sciences Research Council (UK); Academy of Medical Sciences/Health Foundation (UK); National Institute for Health Research (UK).CENTER-TBI study was supported by the European Union 7th Framework program (EC grant 602150). Additional funding sources: Hannelore Kohl Stiftung; NeuroTrauma Sciences; Integra Neurosciences; European Research Council (ERC) Horizon 2020 (EC grant 757173); Engineering and Physical Sciences Research Council (EPSRC) (EP/R511547/1); Academy of Medical Sciences/The Health Foundation (UK); National Institute for Health Research (UK)

Need for speed:Achieving fast image processing in acute stroke care

This thesis aims to investigate the use of high-performance computing (HPC) techniques in developing imaging biomarkers to support the clinical workflow of acute stroke patients. In the first part of this thesis, we evaluate different HPC technologies and how such technologies can be leveraged by different image analysis applications used in the context of acute stroke care. More specifically, we evaluated how computers with multiple computing devices can be used to accelerate medical imaging applications in Chapter 2. Chapter 3 proposes a novel data compression technique that efficiently processes CT perfusion (CTP) images in GPUs. Unfortunately, the size of CTP datasets makes data transfers to computing devices time-consuming and, therefore, unsuitable in acute situations. Chapter 4 further evaluates the algorithm's usefulness proposed in Chapter 3 with two different applications: a double threshold segmentation and a time-intensity profile similarity (TIPS) bilateral filter to reduce noise in CTP scans. Finally, Chapter 5 presents a cloud platform for deploying high-performance medical applications for acute stroke patients. In Part 2 of this thesis, Chapter 6 presents a convolutional neural network (CNN) for detecting and volumetric segmentation of subarachnoid hemorrhages (SAH) in non-contrast CT scans. Chapter 7 proposed another method based on CNNs to quantify the final infarct volumes in follow-up non-contrast CT scans from ischemic stroke patients