Objective To explore the safety and efficacy of frameless stereotactic brain biopsy.Methods Diagnostic accuracy was calculated by comparing biopsy diagnosis with definitive pathology in 62 patients who underwent frame...Objective To explore the safety and efficacy of frameless stereotactic brain biopsy.Methods Diagnostic accuracy was calculated by comparing biopsy diagnosis with definitive pathology in 62 patients who underwent frameless stereotactic brain biopsy between January 2008 and December 2010 in Xiamen University Southeast Hospital.Preoperative characteristics and histological diagnosis were reviewed and then information was analysed to identify factors associated with the biopsy not yielding a diagnosis and complications.Results Diagnostic yield was 93.5%.No differences were found between pathological diagnosis and frozen pathological diagnosis.The most common lesions were astrocytic lesions,included 16 cases of low-grade glioma and 12 cases of malignant glioma.Remote hemorrhage,metastasis,and lymphoma were following in incidence.Multiple brain lesions were found in 17 cases (27.4%).Eleven cases were frontal lesions (17.7%),8 were frontotemporal (12.9%),6 were frontoparietal (9.7%),and 5 each were temporal,parietal,and parietotemporal lesions (8.1%).Postoperative complications occurred in 21.0% of the patients after biopsies,including 10 haemorrhages (16.1%) and 3 temporary neurological deficits (1 epilepsy,1 headache,and 1 partial hemiparesis).No patient required operation for hematoma evacuation.Conclusion Frameless stereotactic biopsy is an effective and safe technique for histologic diagnosis of brain lesions,particularly for multifocal and frontal lesions.展开更多
A quantitative assessment method is proposed to sense the specific effects of atmospheric icing conditions on flight safety. A six degree-of-freedom computational flight dynamics model is used to study the effects of ...A quantitative assessment method is proposed to sense the specific effects of atmospheric icing conditions on flight safety. A six degree-of-freedom computational flight dynamics model is used to study the effects of ice accretion on aircraft dynamics, and a pilot model is also involved. In order to investigate icing severity under different icing conditions, support vector regression is applied in establishing relationship between aircraft icing parameter and weather conditions. Considering the characteristics of aircraft icing accidents, a risk probability assessment model optimized by the particle swarm method is developed to measure the safety level. In particular, angle of attack is chosen as a critical parameter in this method. Results presented in the paper for a series of simulation show that this method captures the basic effects of atmospheric icing conditions on flight safety, which may provide an important theoretical reference for icing accidents avoidance.展开更多
文摘Objective To explore the safety and efficacy of frameless stereotactic brain biopsy.Methods Diagnostic accuracy was calculated by comparing biopsy diagnosis with definitive pathology in 62 patients who underwent frameless stereotactic brain biopsy between January 2008 and December 2010 in Xiamen University Southeast Hospital.Preoperative characteristics and histological diagnosis were reviewed and then information was analysed to identify factors associated with the biopsy not yielding a diagnosis and complications.Results Diagnostic yield was 93.5%.No differences were found between pathological diagnosis and frozen pathological diagnosis.The most common lesions were astrocytic lesions,included 16 cases of low-grade glioma and 12 cases of malignant glioma.Remote hemorrhage,metastasis,and lymphoma were following in incidence.Multiple brain lesions were found in 17 cases (27.4%).Eleven cases were frontal lesions (17.7%),8 were frontotemporal (12.9%),6 were frontoparietal (9.7%),and 5 each were temporal,parietal,and parietotemporal lesions (8.1%).Postoperative complications occurred in 21.0% of the patients after biopsies,including 10 haemorrhages (16.1%) and 3 temporary neurological deficits (1 epilepsy,1 headache,and 1 partial hemiparesis).No patient required operation for hematoma evacuation.Conclusion Frameless stereotactic biopsy is an effective and safe technique for histologic diagnosis of brain lesions,particularly for multifocal and frontal lesions.
文摘A quantitative assessment method is proposed to sense the specific effects of atmospheric icing conditions on flight safety. A six degree-of-freedom computational flight dynamics model is used to study the effects of ice accretion on aircraft dynamics, and a pilot model is also involved. In order to investigate icing severity under different icing conditions, support vector regression is applied in establishing relationship between aircraft icing parameter and weather conditions. Considering the characteristics of aircraft icing accidents, a risk probability assessment model optimized by the particle swarm method is developed to measure the safety level. In particular, angle of attack is chosen as a critical parameter in this method. Results presented in the paper for a series of simulation show that this method captures the basic effects of atmospheric icing conditions on flight safety, which may provide an important theoretical reference for icing accidents avoidance.
