Search results for " mining"
showing 10 items of 1548 documents
Quantifying Net Synergy/Redundancy of Spontaneous Variability Regulation via Predictability and Transfer Entropy Decomposition Frameworks.
2017
Objective: Indexes assessing the balance between redundancy and synergy were hypothesized to be helpful in characterizing cardiovascular control from spontaneous beat-to-beat variations of heart period (HP), systolic arterial pressure (SAP), and respiration (R). Methods: Net redundancy/synergy indexes were derived according to predictability and transfer entropy decomposition strategies via a multivariate linear regression approach. Indexes were tested in two protocols inducing modifications of the cardiovascular regulation via baroreflex loading/unloading (i.e., head-down tilt at −25° and graded head-up tilt at 15°, 30°, 45°, 60°, 75°, and 90°, respectively). The net redundancy/synergy of …
The clinical value of tumor burden at diagnosis in Hodgkin lymphoma
2004
BACKGROUND The authors investigated the clinical role of tumor burden (TB) in patients with Hodgkin lymphoma, relating this parameter to most of the current clinical and prognostic factors and to the best predictive multifactorial models. METHODS The volume of TB at diagnosis was measured directly from the initial staging computed tomography scans in 351 patients who were treated on standard protocols. The mean patient age was 34.0 years ± 16.4 years. Forty-six patients had clinical Stage I disease, 201 patients had Stage II disease, 64 patients had Stage III disease, and 40 patients had Stage IV disease. There were 146 symptomatic patients. Overall survival (OS), disease-free survival (DFS…
DNA measurements for monitoring chemotherapy in advanced head and neck carcinomas
1994
Background. Quantitative DNA measurements have demonstrated prognostic relevance in various malignancies, including head and neck cancer. The application of DNA measurements in monitoring and predicting the outcome of chemotherapy in treating patients with head and neck cancer was investigated. Methods. Twenty-five patients with advanced squamous cell carcinomas of the head and neck who underwent primary chemotherapy with three courses of cisplatin and 5-fluorouracil (5-FU) were examined in this study. Cytologic smears from the tumor site, as well as from normal mucosa, were taken before and 1 week after each course of chemotherapy. Quantitative DNA measurements were performed using an auto…
MRI pattern recognition in multiple sclerosis normal-appearing brain areas
2011
ObjectiveHere, we use pattern-classification to investigate diagnostic information for multiple sclerosis (MS; relapsing-remitting type) in lesioned areas, areas of normal-appearing grey matter (NAGM), and normal-appearing white matter (NAWM) as measured by standard MR techniques.MethodsA lesion mapping was carried out by an experienced neurologist for Turbo Inversion Recovery Magnitude (TIRM) images of individual subjects. Combining this mapping with templates from a neuroanatomic atlas, the TIRM images were segmented into three areas of homogenous tissue types (Lesions, NAGM, and NAWM) after spatial standardization. For each area, a linear Support Vector Machine algorithm was used in mult…
Long-term Evolution of Hepatocellular Adenomas at MRI Follow-up.
2020
Background Hepatocellular adenomas (HCAs) are rare benign liver tumors. Guidelines recommend continued surveillance of patients diagnosed with HCAs, but these guidelines are mainly based on small studies or expert opinion. Purpose To analyze the long-term evolution of HCAs, including solitary and multiple lesions, and to identify predictive features of progression with MRI. Materials and Methods In a retrospective study, patients diagnosed with pathologically proven solitary or multiple HCAs between January 2004 and December 2015 were included; β-catenin-mutated HCAs and HCAs with foci of malignancy were considered to be at risk for progression. MRI examinations were analyzed, and tumor evo…
Diesel motor emissions and lung cancer mortality--results of the second follow-up of a cohort study in potash miners.
2009
International health authorities have graded diesel motor emissions (DME) as probably cancerogenic in human beings. There are gaps in epidemiological evidence regarding exact exposure quantification, confounder control and the investigation of highly exposed populations. We investigated the association of DME ana lung cancer mortality in a historical cohort study of 5,862 German potash miners who were followed from 1970 to 2001. Cumulative exposure (CE) was measured by representative concentrations of total carbon multiplied with exposure years from the mines' medical records. Exposure and smoking behavior were validated by interviews of 3,087 participants. We computed standardized mortalit…
Statistical analysis of life history calendar data
2016
The life history calendar is a data-collection tool for obtaining reliable retrospective data about life events. To illustrate the analysis of such data, we compare the model-based probabilistic event history analysis and the model-free data mining method, sequence analysis. In event history analysis, we estimate instead of transition hazards the cumulative prediction probabilities of life events in the entire trajectory. In sequence analysis, we compare several dissimilarity metrics and contrast data-driven and user-defined substitution costs. As an example, we study young adults' transition to adulthood as a sequence of events in three life domains. The events define the multistate event…
Serial Measurement of Static and Dynamic Cerebrovascular Autoregulation After Brain Injury
2011
In patients with neuronal injury, the knowledge of the status of cerebrovascular autoregulation can help to optimize the management of the cerebral perfusion pressure. This study characterizes dynamic and static cerebrovascular autoregulation during the first 7 days after severe traumatic brain injury or intracranial hemorrhage.After approval from the IRB, 16 patients were studied. Cerebral blood flow velocity (CBFV) was measured daily for the assessment of dynamic (10 patients) and static (16 patients) cerebrovascular autoregulation in both the middle cerebral arteries using the transcranial Doppler sonography. Dynamic cerebrovascular autoregulation (dAR) was measured using the cuff-deflat…
Diagnostic performance of qualitative and radiomics approach to parotid gland tumors: which is the added benefit of texture analysis?
2021
Objective: To investigate whether MRI-based texture analysis improves diagnostic performance for the diagnosis of parotid gland tumors compared to conventional radiological approach. Methods: Patients with parotid gland tumors who underwent salivary glands MRI between 2008 and 2019 were retrospectively selected. MRI analysis included a qualitative assessment by two radiologists (one of which subspecialized on head and neck imaging), and texture analysis on various sequences. Diagnostic performances including sensitivity, specificity, and area under the receiver operating characteristic curve (AUROC) of qualitative features, radiologists’ diagnosis, and radiomic models were evaluated. Result…
Ischemic-type biliary lesions after liver transplantation: a retrospective analysis of risk factors and outcome.
2013
BACKGROUND Ischemic-type biliary lesions (ITBL) are the most troublesome complications after liver transplantation. Their cause remains unknown and, although some risk factors have been identified, results from different research groups are often conflicting. The goal of this study was to investigate potential risk factors for ITBL. METHODS 565 transplantations performed between September 1997 and August 2010 were identified and divided into two cohorts: 77 in which the patient developed ITBL and 488 in which no ITBL occurred. The following factors were analyzed: donor age, patient Child-Pugh score, cold ischemia time, total ischemia time, type of perfusion solution, shipped versus non-ship…