Miniaturized electromagnetic tracking enables efficient ultrasound-navigated needle insertions.

Ultrasound (US) has gained popularity as a guidance modality for percutaneous needle insertions because it is widely available and non-ionizing. However, coordinating scanning and needle insertion still requires significant experience. Current assistance solutions utilize optical or electromagnetic tracking (EMT) technology directly integrated into the US device or probe. This results in specialized devices or introduces additional hardware, limiting the ergonomics of both the scanning and insertion process. We developed the first ultrasound (US) navigation solution designed to be used as a non-permanent accessory for existing US devices while maintaining the ergonomics during the scanning process. A miniaturized EMT source is reversibly attached to the US probe, temporarily creating a combined modality that provides real-time anatomical imaging and instrument tracking at the same time. Studies performed with 11 clinical operators show that the proposed navigation solution can guide needle insertions with a targeting accuracy of about 5 mm, which is comparable to existing approaches and unaffected by repeated attachment and detachment of the miniaturized tracking solution. The assistance proved particularly helpful for non-expert users and needle insertions performed outside of the US plane. The small size and reversible attachability of the proposed navigation solution promises streamlined integration into the clinical workflow and widespread access to US navigated punctures.

Author Correction: Why rankings of biomedical image analysis competitions should be interpreted with care.

In the original version of this Article the values in the rightmost column of Table 1 were inadvertently shifted relative to the other columns. This has now been corrected in the PDF and HTML versions of the Article.

Toward a standard ontology of surgical process models.

PURPOSE: The development of common ontologies has recently been identified as one of the key challenges in the emerging field of surgical data science (SDS). However, past and existing initiatives in the domain of surgery have mainly been focussing on individual groups and failed to achieve widespread international acceptance by the research community. To address this challenge, the authors of this paper launched a European initiative-OntoSPM Collaborative Action-with the goal of establishing a framework for joint development of ontologies in the field of SDS. This manuscript summarizes the goals and the current status of the international initiative. METHODS: A workshop was organized in 2016, gathering the main European research groups having experience in developing and using ontologies in this domain. It led to the conclusion that a common ontology for surgical process models (SPM) was absolutely needed, and that the existing OntoSPM ontology could provide a good starting point toward the collaborative design and promotion of common, standard ontologies on SPM. RESULTS: The workshop led to the OntoSPM Collaborative Action-launched in mid-2016-with the objective to develop, maintain and promote the use of common ontologies of SPM relevant to the whole domain of SDS. The fundamental concept, the architecture, the management and curation of the common ontology have been established, making it ready for wider public use. CONCLUSION: The OntoSPM Collaborative Action has been in operation for 24 months, with a growing dedicated membership. Its main result is a modular ontology, undergoing constant updates and extensions, based on the experts' suggestions. It remains an open collaborative action, which always welcomes new contributors and applications.

Why rankings of biomedical image analysis competitions should be interpreted with care.

International challenges have become the standard for validation of biomedical image analysis methods. Given their scientific impact, it is surprising that a critical analysis of common practices related to the organization of challenges has not yet been performed. In this paper, we present a comprehensive analysis of biomedical image analysis challenges conducted up to now. We demonstrate the importance of challenges and show that the lack of quality control has critical consequences. First, reproducibility and interpretation of the results is often hampered as only a fraction of relevant information is typically provided. Second, the rank of an algorithm is generally not robust to a number of variables such as the test data used for validation, the ranking scheme applied and the observers that make the reference annotations. To overcome these problems, we recommend best practice guidelines and define open research questions to be addressed in the future.

Prognostic potential of midregional pro-adrenomedullin following decompensation for systolic heart failure: comparison with cardiac natriuretic peptides.

AIMS: Whereas guidelines recommend the routine use of natriuretic peptides (NPs) in heart failure (HF) care, the clinical relevance and prognostic potential of midregional pro-adrenomedullin (MR-proADM) is less well established. We aimed to compare the prognostic potential of MR-proADM after acute decompensation for systolic HF with that of N-terminal pro-B-type natriuretic peptide (NT-proBNP) and midregional pro-atrial NP (MR-proANP), to investigate the significance of high/rising MR-proADM, and to evaluate the incremental prognostic yield of repeat measurements. METHODS AND RESULTS: The Interdisciplinary Network Heart Failure (INH) programme enrolled patients hospitalized for acute systolic HF and followed them for 18 months (100% complete). Of 1022 INH participants, 917 (68 ± 12 years, 28% female) who had biomaterials available were enrolled. High MR-proADM was associated with more impaired left ventricular function, higher comorbidity burden, lower doses of HF medications, and lower likelihood of left ventricular reverse remodelling. Compared with NPs, MR-proADM had superior prognostic significance (concordance index 0.72 for all-cause mortality), improved Cox regression models including NPs (P < 0.001), and was the only biomarker also predicting non-cardiac death (hazard ratio 1.8 vs. 1.0). In the setting of low NPs, patients with high MR-proADM experienced non-cardiac death more often. Six month MR-proADM enhanced models including baseline MR-proADM (P < 0.001) for prediction of all-cause death (net reclassification index: 0.48, 95% confidence interval 0.19-0.78). CONCLUSION: MR-proADM was found to correlate with the global disease burden in HF and proved a potent prognostic indicator, capturing the risk for both cardiac and non-cardiac death. Serial MR-proADM measurements further enhanced risk assessment, thus facilitating substantial reclassification.