Temporal archetypal analysis for action segmentation

Unsupervised learning of invariant representations that efficiently describe high-dimensional time series has several applications in dynamic visual data analysis. Clearly, the problem becomes more challenging when dealing with multiple time series arising from different modalities. A prominent example of this multimodal setting is the human motion which can be represented by multimodal time series of pixel intensities, depth maps, and motion capture data. Here, we study, for the first time, the problem of unsupervised learning of temporally and modality invariant informative representations, referred to as archetypes, from multiple time series originating from different modalities. To this end a novel method, coined as temporal archetypal analysis, is proposed. The performance of the proposed method is assessed by conducting experiments in unsupervised action segmentation. Experimental results on three different real world datasets using single modal and multimodal visual representations indicate the robustness and effectiveness of the proposed methods, outperforming compared state-of-the-art methods by a large, in most of the cases, margin

Magnetic Resonance Imaging of the Hips of Runners Before and After Their First Marathon Run: Effect of Training for and Completing a Marathon

Background: No studies have focused on magnetic resonance imaging (MRI) of the hips of marathoners, despite the popularity and injury risks of marathon running. / Purpose: To understand the effect of preparing for and completing a marathon run (42 km) on runners’ hip joints by comparing MRI findings before and after their first marathon. / Study Design: Case-control study; Level of evidence, 3. / Methods: A total of 28 healthy adults (14 males, 14 females; mean age, 32.4 years) were recruited after registering for their first marathon. They underwent 3-T MRI of both hips at 16 weeks before (time point 1) and 2 weeks after the marathon (time point 2). After the first MRI, 21 runners completed the standardized, 4 month--long training program and the marathon; 7 runners did not complete the training or the marathon. Specialist musculoskeletal radiologists reported and graded the hip joint structures using validated scoring systems. Participants completed the Hip disability and Osteoarthritis Outcome Score (HOOS) at both imaging time points. / Results: At time point 1, MRI abnormalities of the hip joint were seen in 90% of participants and were located in at least 1 of these areas: labrum (29%), articular cartilage (7%), subchondral bone marrow (14%), tendons (17%), ligaments (14%), and muscles (31% had moderate muscle atrophy). At time point 2, only 2 of the 42 hips showed new findings: a small area of mild bone marrow edema appearance (nonweightbearing area of the hip and not attributable to running). There was no significant difference in HOOS between the 2 time points. Only 1 participant did not finish the training because of hip symptoms and thus did not run the marathon; however, symptoms resolved before the MRI at time point 2. Six other participants discontinued their training because of non–hip related issues: a knee injury, skin disease, a family bereavement, Achilles tendon injury, illness unrelated to training, and a foot injury unrelated to training. / Conclusion: Runners who completed a 4-month beginner training program before their first marathon run, plus the race itself, showed no hip damage on 3-T MRI scans

Quantitative 3D analysis of bone in hip osteoarthritis using clinical computed tomography.

OBJECTIVE: To assess the relationship between proximal femoral cortical bone thickness and radiological hip osteoarthritis using quantitative 3D analysis of clinical computed tomography (CT) data. METHODS: Image analysis was performed on clinical CT imaging data from 203 female volunteers with a technique called cortical bone mapping (CBM). Colour thickness maps were created for each proximal femur. Statistical parametric mapping was performed to identify statistically significant differences in cortical bone thickness that corresponded with the severity of radiological hip osteoarthritis. Kellgren and Lawrence (K&L) grade, minimum joint space width (JSW) and a novel CT-based osteophyte score were also blindly assessed from the CT data. RESULTS: For each increase in K&L grade, cortical thickness increased by up to 25 % in distinct areas of the superolateral femoral head-neck junction and superior subchondral bone plate. For increasing severity of CT osteophytes, the increase in cortical thickness was more circumferential, involving a wider portion of the head-neck junction, with up to a 7 % increase in cortical thickness per increment in score. Results were not significant for minimum JSW. CONCLUSIONS: These findings indicate that quantitative 3D analysis of the proximal femur can identify changes in cortical bone thickness relevant to structural hip osteoarthritis. KEY POINTS: • CT is being increasingly used to assess bony involvement in osteoarthritis • CBM provides accurate and reliable quantitative analysis of cortical bone thickness • Cortical bone is thicker at the superior femoral head-neck with worse osteoarthritis • Regions of increased thickness co-locate with impingement and osteophyte formation • Quantitative 3D bone analysis could enable clinical disease prediction and therapy development.TT acknowledges the support of an Evelyn Trust Clinical Training Fellowship award (RG65411). KP acknowledges support of an Arthritis Research UK Research Progression award (RG66087), and the Cambridge NIHR Biomedical Research Centre (RG64245). None of the funding sources had a role in study design, data handling, writing of the report, or decision to submit the paper for publication.This is the final version of the article. It first appeared from Springer via http://dx.doi.org/10.1007/s00330-015-4048-

Massive hematuria due to a congenital renal arteriovenous malformation mimicking a renal pelvis tumor: a case report

<p>Abstract</p> <p>Introduction</p> <p>Congenital renal arteriovenous malformations (AVMs) are very rare benign lesions. They are more common in women and rarely manifest in elderly people. In some cases they present with massive hematuria. Contemporary treatment consists of transcatheter selective arterial embolization which leads to resolution of the hematuria whilst preserving renal parenchyma.</p> <p>Case presentation</p> <p>A 72-year-old man, who was heavy smoker, presented with massive hematuria and flank pain. CT scan revealed a filling defect caused by a soft tissue mass in the renal pelvis, which initially led to the suspicion of a transitional cell carcinoma (TCC) of the upper tract, in view of the patient's age and smoking habits. However a subsequent retrograde study could not depict any filling defect in the renal pelvis. Selective right renal arteriography confirmed the presence of a renal AVM by demonstrating abnormal arterial communication with a vein with early visualization of the venous system. At the same time successful selective transcatheter embolization of the lesion was performed.</p> <p>Conclusion</p> <p>This case highlights the importance of careful diagnostic work-up in the evaluation of upper tract hematuria. In the case presented, a congenital renal AVM proved to be the cause of massive upper tract hematuria and flank pain in spite of the initial evidence indicating the likely diagnosis of a renal pelvis tumor.</p

Aphasia blog talk: How does stroke and aphasia affect a person’s social relationships?

Background: Stroke and aphasia can negatively affect a person’s ability to maintain healthy social relationships, both within the family and also with friends and the wider network. To date, this has been explored predominantly through qualitative interviews and questionnaires. Blogs written by people with aphasia constitute a novel source of data, comprised of people’s own voices on issues that are of concern to them. Aims: To explore the impact of stroke and aphasia on a person’s relationships with family, friends and the wider network through analysing blogs written by people with aphasia. Methods & Procedures: Blog search engines were used to identify blogs sustained by a sole author who had aphasia following a stroke, and which reflected on their social network. The data were analysed qualitatively using framework analysis. Outcomes & Results: The systematic search resulted in 10 relevant blogs. Participants were aged between 26 and 69 years old, lived in the community, were at least 1 year post stroke and included six women and four men. Aphasia was a consistent thread running through the blogs affecting conversations with all parts of a person’s network and impacting on participants’ sense of self. They found it more difficult to take part in family activities and described higher degrees of dependence and changed family dynamics. Contact with friends was reduced, partly due to communication and physical difficulties. While some participants became motivated to become members of groups post stroke, contact with the wider network sometimes diminished, in part because of loss of work and community activities. An additional factor impacting on social relationships was other people’s positive or negative reaction towards the person with aphasia. Finally, the blogs reflected on the importance of support they had received, both from close family and also from the wider community. Conclusions: This study found that social relationships played a crucial role in people’s lives following a stroke and aphasia. Nonetheless, family relationships, friendships and social exchanges within the wider social network were all substantially affected. Exploring this area through online narratives offered a rich and highly authentic source of data. The findings suggest that clinicians should incorporate social approaches in rehabilitation and consider ways to foster the maintenance of social networks. The use of social media by people with aphasia should be further explored, both as a therapeutic outlet and also as a way for people with aphasia to feel connected to a wider community

The Italian Version of the Borderline Personality Disorder Severity Index IV:Psychometric Properties, Clinical Usefulness, and Possible Diagnostic Implications

Borderline personality disorder (BPD) has a core embodied in affective and behavioral dysregulations, impulsivity, and relational disturbance. Clinical presentation might be heterogeneous due to a combination of different symptoms listed in the DSM-5. Clinical diagnosis and assessment of the severity of manifestations might be improved through the administration of structured interviews such as the Borderline Personality Disorder Severity Index, 4th edition (BPDSI-IV). The psychometric properties of the Italian version of the BPDSI-IV were examined for the first time in 248 patients affected by BPD and 113 patients affected by bipolar disorder, proving to be a valid and accurate instrument with good internal consistency and high accuracy. The Italian version also demonstrates significant validity in the discrimination between these clinical groups (p < .001)

Joint Multimodal Segmentation of Clinical CT and MR from Hip Arthroplasty Patients

Magnetic resonance imaging (MRI) is routinely employed to assess muscular response and presence of inflammatory reactions in patients treated with metal-on-metal hip arthroplasty, driving the decision for revision surgery. However, MRI is lacking contrast for bony structures and as a result orthopaedic surgical planning is mostly performed on computed tomography images. In this paper, we combine the complementary information of both modalities into a novel framework for the joint segmentation of healthy and pathological musculoskeletal structures as well as implants on all images. Our processing pipeline is fully automated and was designed to handle the highly anisotropic resolution of clinical MR images by means of super resolution reconstruction. The accuracy of the intra-subject multimodal registration was improved by employing a non-linear registration algorithm with hard constraints on the deformation of bony structures, while a multi-atlas segmentation propagation approach provided robustness to the large shape variability in the population. The suggested framework was evaluated in a leave-one-out cross-validation study on 20 hip sides. The proposed pipeline has potential for the extraction of clinically relevant imaging biomarkers for implant failure detection