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In this article, we propose a slice-based interactive segmentation of spectral CT datasets using a bag of features method. The data are acquired from a MARS scanner that divides up the X-ray spectrum into multiple energy bins for imaging. In literature, most existing segmentation methods are limited to performing a specific task or tied to a particular imaging modality. Therefore, when applying generalized methods to MARS datasets, the additional energy information acquired from the scanner cannot be sufficiently utilized. We describe a new approach that circumvents this problem by effectively aggregating the data from multiple channels. Our method solves a classification problem to get the solution for segmentation. Starting with a set of labeled pixels, we partition the data using superpixels. Then, a set of local descriptors, extracted from each superpixel, are encoded into a codebook and pooled together to create a global superpixel-level descriptor (bag of features representation). We propose to use the vector of locally aggregated descriptors as our encoding/pooling strategy, as it is efficient to compute and leads to good results with simple linear classifiers. A linear support vector machine is then used to classify the superpixels into different labels. The proposed method was evaluated on multiple MARS datasets. Experimental results show that our method achieved an average of more than 10% increase in the accuracy over other state-of-the-art methods.

Purpose To describe interventionalist and workflow characteristics of an acute stroke endovascular thrombectomy (EVT) center without a dedicated interventional neuroradiology service and report clinical and radiologic outcomes. Materials and Methods Retrospective review was performed of all patients receiving EVT at Christchurch Hospital, New Zealand, from June 2014 to the end of December 2019 from a prospective reperfusion registry. During the study period, 5 peripheral vascular interventional radiologists, 2 of whom had experience in other neuroendovascular procedures, performed 210 EVT procedures. Median age of patients was 76 years (interquartile range: 64–83 y), and 107 (51%) were men. Results The most commonly occluded vessel was the M1 middle cerebral artery (n = 114; 54%). Successful reperfusion (Modified Treatment In Cerebral Ischemia score 2b–3) was achieved in 180 (86%) procedures. Favorable 90-day outcome (modified Rankin Scale score 0–2) was achieved in 102 (54%) patients with no disability before stroke. Symptomatic intracranial hemorrhage occurred in 3 (1.4%) patients. Treatment rates in the local catchment area increased from 6 per 100,000 population in 2017 to 15 per 100,000 in 2019. Conclusions The results of this study suggest peripheral vascular interventional radiologists with specific training can successfully perform EVT resulting in a significant increase in EVT provision.

Assessment of disease burden and drug efficacy is achieved preclinically using high resolution micro computed tomography (CT). However, micro-CT is not applicable to clinical human imaging due to operating at high dose. In addition, the technology differences between micro-CT and standard clinical CT prevent direct translation of preclinical applications. The current proof-of-concept study presents spectral photon-counting CT as a clinically translatable, molecular imaging tool by assessing contrast uptake in an ex-vivo mouse model of pulmonary tuberculosis (TB). Iodine, a common contrast used in clinical CT imaging, was introduced into a murine model of TB. The excised mouse lungs were imaged using a standard micro-CT subsystem (SuperArgus) and the contrast enhanced TB lesions quantified. The same lungs were imaged using a spectral photoncounting CT system (MARS small-bore scanner). Iodine and soft tissues (water and lipid) were materially separated, and iodine uptake quantified. The volume of the TB infection quantified by spectral CT and micro-CT was found to be 2.96 mm3 and 2.83 mm3, respectively. This proof-of-concept study showed that spectral photon-counting CT could be used as a predictive preclinical imaging tool for the purpose of facilitating drug discovery and development. Also, as this imaging modality is available for human trials, all applications are translatable to human imaging. In conclusion, spectral photon-counting CT could accelerate a deeper understanding of infectious lung diseases using targeted pharmaceuticals and intrinsic markers, and ultimately improve the efficacy of therapies by measuring drug delivery and response to treatment in animal models and later in humans.

Endovascular thrombectomy is an effective intervention for symptomatic intracranial large-vessel occlusion. This treatment has proven benefit up to 24 hours following onset in selected patients with prestroke functional independence. Limited case reports suggest that thrombectomy beyond 24 hours may also be effective. We describe a young woman managed with endovascular thrombectomy beyond 24 hours.

Policy measures, including legislation, are one method of promoting health. Participation in many voluntary health promoting behaviours is strongly socioeconomically patterned,1 and this may also apply to behaviours governed by legislation. Rear passenger seat belt use is one legally prescribed behaviour—having been made compulsory in the UK in 1991. Previous research on the socioeconomic distribution of seat belt use has relied on self reported behaviours and is therefore subject to response bias, has focused on driver seat belt use, or has been undertaken in the USA where legislation is different from the UK.2,3 We conducted the first UK based observational study to investigate the association between rear passenger seat belt use and socioeconomic status (SES), using car value as a proxy measure of SES. We observed 1032 rear seat passengers (RSPs) in 773 cars at six locations with slow car flow (for example, roundabouts and junctions) in Newcastle upon Tyne, UK over …