Nonnegative rank-preserving operators

AbstractAnalogues of characterizations of rank-preserving operators on field-valued matrices are determined for matrices witheentries in certain structures S contained in the nonnegative reals. For example, if S is the set of nonnegative members of a real unique factorization domain (e.g. the nonnegative reals or the nonnegative integers), M is the set of m×n matrices with entries in S, and min(m,n)⩾4, then a “linear” operator on M preserves the “rank” of each matrix in M if and only if it preserves the ranks of those matrices in M of ranks 1, 2, and 4. Notions of rank and linearity are defined analogously to the field-valued concepts. Other characterizations of rank-preserving operators for matrices over these and other structures S are also given

Left Adrenal Gland Analysis in Lung Cancer Patients Using the Endobronchial Ultrasound Scope: A Feasibility Trial

In lung cancer patients, the adrenal glands are predilection sites for distant metastases. Esophageal endoscopic ultrasound - fine-needle aspiration (EUS-FNA) is a minimally invasive and accurate method for left adrenal gland (LAG) analysis but requires a conventional gastrointestinal echoendoscope. Complete endobronchial and esophageal mediastinal nodal staging can be achieved by just a single endobronchial ultrasound (EBUS) scope, introducing it into the esophagus (EUS-B) following the endobronchial procedure. Whether the LAG can also be assessed with the EBUS scope is unknown. The aim of the study was to investigate the feasibility of identifying the LAG with the EBUS scope. We conducted a retrospective analysis of lung cancer patients who underwent EBUS and EUS-B for mediastinal staging and LAG assessment between January 2013 and May 2015. A total of 143 patients with (suspected) lung cancer were investigated by the combination of EBUS and EUS-B. In 68 of the 80 patients (85%) in whom an attempt was made to identify the LAG, it was feasible to transgastrically detect the LAG with the EBUS scope. In 9 patients with endosonographic signs of malignant involvement, diagnostic transgastric FNAs were obtained in all. In the 12 patients (15%) in whom the LAG was not detected, the contact between the ultrasound transducer and the gastric wall was suboptimal - the length of the scope was not a limiting factor. The EBUS scope allows identification of the LAG in the vast majority of lung cancer patients. In patients with (suspected) lung cancer, in addition to complete hilar and mediastinal staging, LAG assessment using just a single EBUS scope also seems feasible. Prospective studies are indicate

Added value of combined endobronchial and oesophageal endosonography for mediastinal nodal staging in lung cancer: a systematic review and meta-analysis

Guidelines recommend endosonography with fine-needle aspiration for mediastinal nodal staging in non-small-cell lung cancer, but most do not specify whether this should be through endobronchial endoscopy (EBUS), oesophageal endoscopy (EUS), or both. We assessed the added value and diagnostic accuracy of the combined use of EBUS and EUS. For this systematic review and random effects meta-analysis, we searched MEDLINE, Embase, BIOSIS Previews, and Web of Science, without language restrictions, for studies published between Jan 1, 2000, and Feb 25, 2016. We included studies that assessed the accuracy of the combined use of EBUS and EUS in detecting mediastinal nodal metastases (N2/N3 disease) in patients with lung cancer. For each included study, we extracted data on the age and sex of participants, inclusion criteria regarding tumour stage on imaging, details of the endoscopic testing protocol, duration of each endoscopic procedure, number of lymph nodes sampled, serious adverse events occurring during the endoscopic procedures, the reference standard, and 2 × 2 tables for EBUS, EUS, and the combined approach. We evaluated the added value (absolute increase in sensitivity and in detection rate) of the combined use of EBUS and EUS in detecting mediastinal nodal metastases over either test alone, and the diagnostic accuracy (sensitivity and negative predictive value) of the combined approach. This study is registered with PROSPERO, number CRD42015019249. We identified 2567 unique manuscripts by database search, of which 13 studies (including 2395 patients) were included in the analysis. Median prevalence of N2/N3 disease was 34% (range 23-71). On average, addition of EUS to EBUS increased sensitivity by 0·12 (95% CI 0·08-0·18) and addition of EBUS to EUS increased sensitivity by 0·22 (0·16-0·29). Mean sensitivity of the combined approach was 0·86 (0·81-0·90), and the mean negative predictive value was 0·92 (0·89-0·93). The mean negative predictive value was significantly higher in studies with a prevalence of 34% or less (0·93 [95% CI 0·91-0·95]) compared with studies with a prevalence of more than 34% (0·89 [0·85-0·91]; p=0·013). We found no significant differences in mean sensitivity and negative predictive value between studies that did EBUS first or EUS first, or between studies that used an EBUS-scope or a regular echoendoscope to do EUS. The combined use of EBUS and EUS significantly improves sensitivity in detecting mediastinal nodal metastases, reducing the need for surgical staging procedures. No external fundin

Endobronchial Ultrasound for the Diagnosis of Centrally Located Lung Tumors: A Systematic Review and Meta-Analysis

Introduction: Obtaining a tissue diagnosis of centrally located lung tumors in patients presenting without endobronchial abnormalities is challenging, and therefore a considerable diagnostic problem. Objective: The objective of this study was to evaluate the performance of linear endobronchial ultrasound guided-transbronchial-needle aspiration (EBUS-TBNA) for the diagnosis of centrally located lung tumors. Methods: We performed a systematic review (PROSPERO, CRD42017080968) and searched MEDLINE, Embase, BIOSIS Previews, and Web of Science till November 18, 2018 for studies that evaluated the yield and/or sensitivity of EBUS-TBNA for diagnosing centrally located lung tumors. We assessed the study quality using QUADAS-2 and performed random-effects meta-analysis. Results: A total of 5,657 manuscripts were identified; of these 14 were considered for the study, including 1,175 patients who underwent EBUS-TBNA for diagnosing an intrapulmonary tumor. All studies had a high risk of bias or applicability concerns, predominately regarding patient selection. The average yield of EBUS-TBNA for diagnosing centrally located lung tumors was 0.89 (95% CI 0.84-0.92) and average sensitivity for diagnosing malignant tumors was 0.91 (95% CI 0.88-0.94). Among studies reporting this information, EBUS-related complications occurred in 5.4% of patients (42/721). Conclusion: EBUS-TBNA has a high yield and sensitivity for diagnosing centrally located lung tumors and is safe in selected patients. Prospective studies are recommended to evaluate the routine use of this procedure for diagnosing intrapulmonary tumors

Endobronchial Ultrasound for the Diagnosis of Centrally Located Lung Tumors: A Systematic Review and Meta-Analysis

Introduction: Obtaining a tissue diagnosis of centrally located lung tumors in patients presenting without endobronchial abnormalities is challenging, and therefore a considerable diagnostic problem. Objective: The objective of this study was to evaluate the performance of linear endobronchial ultrasound guided-transbronchial-needle aspiration (EBUS-TBNA) for the diagnosis of centrally located lung tumors. Methods: We performed a systematic review (PROSPERO, CRD42017080968) and searched MEDLINE, Embase, BIOSIS Previews, and Web of Science till November 18, 2018 for studies that evaluated the yield and/or sensitivity of EBUS-TBNA for diagnosing centrally located lung tumors. We assessed the study quality using QUADAS-2 and performed random-effects meta-analysis. Results: A total of 5,657 manuscripts were identified; of these 14 were considered for the study, including 1,175 patients who underwent EBUS-TBNA for diagnosing an intrapulmonary tumor. All studies had a high risk of bias or applicability concerns, predominately regarding patient selection. The average yield of EBUS-TBNA for diagnosing centrally located lung tumors was 0.89 (95% CI 0.84-0.92) and average sensitivity for diagnosing malignant tumors was 0.91 (95% CI 0.88-0.94). Among studies reporting this information, EBUS-related complications occurred in 5.4% of patients (42/721). Conclusion: EBUS-TBNA has a high yield and sensitivity for diagnosing centrally located lung tumors and is safe in selected patients. Prospective studies are recommended to evaluate the routine use of this procedure for diagnosing intrapulmonary tumors

The European Respiratory Society led training programme improves self-reported competency and increases the use of thoracic ultrasound

Thoracic ultrasound has become a well-implemented diagnostic tool for assessment and monitoring of patients with respiratory symptoms or disease. However, ultrasound examinations are user dependent and sufficient competencies are needed. The European Respiratory Society (ERS) hosts a structured and evidence-based training programme in thoracic ultrasound. This study aimed to explore and discuss the self-reported activity and self-reported competency of the participants during the ERS course. Online surveys were sent to the training programme participants before the second part of the course (practical part of the course), and before and 3 months after the third part of the course (final certification exam). A total of 77 participants completed the surveys. The self-reported frequency of thoracic ultrasound examinations increased during the course, and in the final survey more than 90% of the participants used thoracic ultrasound on weekly basis. The self-reported competency (on technical execution of the thoracic ultrasound examination and overall competency) also increased. The ERS thoracic ultrasound training programme forms the basis of broad theoretical knowledge and sufficient practical skills that seem to lead to behavioural changes, whereby a large proportion of the participants implemented ultrasound in their clinical practice.</p