66 research outputs found

    Prevalence of hyperdense paraspinal vein sign in patients with spontaneous intracranial hypotension without dural CSF leak on standard CT myelography

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    PURPOSE:A recently identified and treatable cause of spontaneous intracranial hypotension (SIH) is cerebrospinal fluid (CSF)-venous fistula, and a recently described computed tomography myelogram (CTM) finding highly compatible with but not diagnostic of this entity is the hyperdense paraspinal vein sign. We aimed to retrospectively measure the prevalence of the hyperdense paraspinal vein sign on CTMs in SIH patients without dural CSF leak, in comparison with control groups.METHODS:Three CTM groups were identified: 1) SIH study group, which included dural CSF leak-negative standard CTMs performed for SIH, with early and delayed imaging; 2) Early control CTMs, which were performed for indications other than SIH, with imaging shortly after intrathecal contrast administration; 3) Delayed control CTMs, which included delayed imaging. CTMs were retrospectively reviewed for the hyperdense paraspinal vein sign by experienced neuroradiologists, blinded to the group assignment. All CTMs deemed by a single reader to be positive for the hyperdense paraspinal vein sign were independently reviewed by two additional neuroradiologists; findings were considered positive only if consensus was present among all three readers. For positive cases, noncontrast CTs and prior CTMs, if available, were reviewed for the presence of the sign.RESULTS:Seven of 101 (7%) SIH patients had contrast in a spinal/paraspinal vein consistent with the hyperdense paraspinal vein sign; no patient in either control group (total n=54) demonstrated the hyperdense paraspinal vein sign (P = 0.0463). The finding occurred only at thoracic levels. Each patient had a single level of involvement. Six (86%) occurred on the right. Four occurred in female patients (57%). The sign was seen on early images in 3 of 7 cases (43%) and on both early and delayed images in 4 of 7 cases (57%). In 2 of 7 patients (29%), a noncontrast CT covering the relevant location was available and negative for the sign. A prior CTM was available in 2 of 7 patients (29%), and in both cases the hyperdense paraspinal vein sign was also evident.CONCLUSION:The prevalence of the hyperdense paraspinal vein sign in SIH patients with dural CSF leak-negative standard CTM was 7%. As the sign was not seen in control groups, this sign is highly compatible with the presence of CSF-venous fistula. Since the CTMs were not specifically dedicated to identifying hyperdense paraspinal veins (i.e., they were not dynamic and were not preceded by digital subtraction myelography), the true prevalence of the sign may be higher. Radiologists should scrutinize conventional CTMs for this sign, especially in patients in whom a traditional dural CSF leak is not identified

    Livelihood activities in the Lawra Municipality of Ghana: A blessing or a curse to the riparian vegetation of the Black Volta Basin

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    The study underscores the socio-economic, ecological, chemical, and physical significance of the riparian vegetation of the Black Volta Basin in the Lawra Municipality. However, livelihood activities namely, crop farming, fishing, dry season gardening, shea and dawadawa processing, extensive livestock rearing, forest harvesting, mining, and tobacco farming adversely affect the riparian vegetation of the Black Volta Basin in the Lawra Municipality. The study sought to examine the repercussions of livelihood activities on the riparian vegetation of the Black Volta Basin in the Lawra Municipality. Estimates of Shannon Diversity Index (0.686) and Simpson's Index (1.5328) of the vegetation of the Black Volta Basin in the Lawra Municiplaity demonstrate a diminished riparian vegetation due to livelihood activities as compared to Shannon Diversity Index (1.6406) and Simpson's Index (3.5511) of the riparian vegetation of the Burkina Faso site across the Black Volta Basin. This is supported by satellite images which justifies a reduction in riparian vegetation of the Black Volta Basin in the year 2020 and 2021 as compared to the year 2000 and 2001. It is recommended that local stakeholders of the riparian vegetation of the study area should enact by-laws in order regulate the exploitation of riparian vegetation species

    Left Atrial Myxoma: A Rare Cause of Dyspnea

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    Visual object tracking challenges revisited: VOT vs. OTB.

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    Numerous benchmark datasets and evaluation toolkits have been designed to facilitate visual object tracking evaluation. However, it is not clear which evaluation protocols are preferred for different tracking objectives. Even worse, different evaluation protocols sometimes yield contradictory conclusions, further hampering reliable evaluation. Therefore, we 1) introduce the new concept of mirror tracking to measure the robustness of a tracker and identify its over-fitting scenarios; 2) measure the robustness of the evaluation ranks produced by different evaluation protocols; and 3) report a detailed analysis of milestone tracking challenges, indicating their application scenarios. Our experiments are based on two state-of-the-art challenges, namely, OTB and VOT, using the same trackers and datasets. Based on the experiments, we conclude that 1) the proposed mirror tracking metrics can identify the over-fitting scenarios of a tracker, 2) the ranks produced by OTB are more robust than those produced by VOT, and 3) the joint ranks produced by OTB and VOT can be used to measure failure recovery

    A Critical Review of Legal Issues in Artificial Intelligence

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    The legal field is steeped in history, with legal precedents deciding the outcome of each case. Even when new issues arise, traditional standards and principles are usually applie

    Long-term effectiveness of the combined minute ventilation and patient activity sensors as predictor of heart failure events in patients treated with cardiac resynchronization therapy: Results of the Clinical Evaluation of the Physiological Diagnosis Function in the PARADYM CRT device Trial (CLEPSYDRA) study

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    AIMS Monitoring early signs of clinical deterioration could allow physicians to adjust medical treatment for patients at risk of acute heart failure decompensation. To date, several strategies using different surrogate measures of clinical status emerged, but none has yet been proven to predict clinical events. We hypothesized that the Physiological Diagnostic feature, which combines data from minute ventilation and physical activity sensors, predicts heart failure events in patients implanted with cardiac resynchronization therapy with defibrillation (CRT-D) devices. METHODS AND RESULTS The Clinical Evaluation of the Physiological Diagnostic feature in the PARADYM CRT device (CLEPSYDRA) trial is a multicentre, prospective, non-randomized, double-blind study comprising 521 CRT-D patients with heart failure [67.4 ± 10.1 years (mean ± SD), 82% male, New York Heart Association class III/IV 85.0%/6.7%, QRS 155.3 ± 26.6 ms, left ventricular ejection fraction 25.7 ± 7.7%]. The objective of the study was the sensitivity and false positive rate of the Physiological Diagnostic algorithm to predict heart failure events within the following month. After a mean follow-up of 17.0 ± 8.7 months, 130 (25.6%) patients experienced a heart failure event. The sensitivity of the algorithm to predict an event was 34% and the false positive rate was 2.4 per patient-year. CONCLUSION Thirty-four per cent of heart failure events occurring within a month were predicted by the Physiological Diagnostic algorithm, and 2.4 alerts per patient per year were not followed by an heart failure event within the subsequent month
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