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1.
Space Sci Rev ; 220(1): 1, 2024.
Article in English | MEDLINE | ID: mdl-38130909

ABSTRACT

The Lucy Thermal Emission Spectrometer (L'TES) will provide remote measurements of the thermophysical properties of the Trojan asteroids studied by the Lucy mission. L'TES is build-to-print hardware copy of the OTES instrument flown on OSIRIS-REx. It is a Fourier Transform spectrometer covering the spectral range 5.71-100 µm (1750-100 cm-1) with spectral sampling intervals of 8.64, 17.3, and 34.6 cm-1 and a 7.3-mrad field of view. The L'TES telescope is a 15.2-cm diameter Cassegrain telescope that feeds a flat-plate Michelson moving mirror mounted on a linear voice-coil motor assembly to a single uncooled deuterated l-alanine doped triglycine sulfate (DLATGS) pyroelectric detector. A significant firmware change from OTES is the ability to acquire interferograms of different length and spectral resolution with acquisition times of 0.5, 1, and 2 seconds. A single ∼0.851 µm laser diode is used in a metrology interferometer to provide precise moving mirror control and IR sampling at 772 Hz. The beamsplitter is a 38-mm diameter, 1-mm thick chemical vapor deposited diamond with an antireflection microstructure to minimize surface reflection. An internal calibration cone blackbody target, together with observations of space, provides radiometric calibration. The radiometric precision in a single spectrum is ≤2.2 × 10-8 W cm-2 sr-1 /cm-1 between 300 and 1350 cm-1. The absolute temperature error is <2 K for scene temperatures >75 K. The overall L'TES envelope size is 37.6 × 29.0 × 30.4 cm, and the mass is 6.47 kg. The power consumption is 12.6 W average. L'TES was developed by Arizona State University with AZ Space Technologies developing the electronics. L'TES was integrated, tested, and radiometrically calibrated on the Arizona State University campus in Tempe, AZ. Initial data from space have verified the instrument's radiometric and spatial performance.

2.
Climacteric ; 23(4): 325-329, 2020 08.
Article in English | MEDLINE | ID: mdl-32648828

ABSTRACT

Introduction: Most endometrial polyps represent focal hyperplasia of the endometrium. Endometrial polyps can be diagnosed by ultrasound, hysterocontrast sonography, hysterosalpingography, endometrial biopsy, and uterine curettage, but diagnostic hysteroscopy is considered the gold-standard method, with the greatest sensitivity and specificity and also with the opportunity for treatment at the same time.Study design: A retrospective study was conducted on 424 patients between 2006 and 2018. The polyps were verified during diagnostic hysteroscopy and were removed by resectoscopy or curettage. All samples underwent histological examination. The effectivity of the type of resection and the recurrence rate were evaluated.Results: The average age of the patients was 60.2 ± 9.3 years. Polyps were excised in 62.97% by resectoscopic polypectomy and in 37.03% by curettage. Malignancy was confirmed in 4.24% of cases. Histological verification of polyps was 79.4% in the resectoscopy group and 69.04% in the curettage group; the difference was significant (p < 0.01). The recurrence rate was 20.47% after resectoscopy and 27.12% following curettage.Conclusion: Hysteroscopy remains the best option and the gold-standard method among diagnostic procedures of endometrial pathology. In this study, there was a significant difference in matching hysteroscopic and histological findings in the two methods of polypectomy. The recurrence rate is also lower following resectoscopy.


Subject(s)
Curettage/methods , Endometrial Neoplasms/surgery , Hysteroscopy/methods , Neoplasm Recurrence, Local/epidemiology , Polyps/surgery , Adult , Aged , Aged, 80 and over , Endometrial Neoplasms/pathology , Endometrium/pathology , Endometrium/surgery , Female , Humans , Middle Aged , Neoplasm Recurrence, Local/etiology , Polyps/pathology , Postmenopause , Postoperative Period , Retrospective Studies , Statistics, Nonparametric , Treatment Outcome
3.
AJNR Am J Neuroradiol ; 39(2): 385-391, 2018 Feb.
Article in English | MEDLINE | ID: mdl-29269403

ABSTRACT

BACKGROUND AND PURPOSE: While the use of cervical spine CT in trauma settings has increased, the balance between image quality and dose reduction remains a concern. The purpose of our study was to compare the image quality of CT of the cervical spine of cadaveric specimens at different radiation dose levels. MATERIALS AND METHODS: The cervical spine of 4 human cadavers (mean body mass index; 30.5 ± 5.2 kg/m2; range, 24-36 kg/m2) was examined using different reference tube current-time products (45, 75, 105, 135, 150, 165, 195, 275, 355 mAs) and a tube voltage of 120 kV(peak). Data were reconstructed with filtered back-projection and iterative reconstruction. Qualitative image noise and morphologic characteristics of bony structures were quantified on a Likert scale. Quantitative image noise was measured. Statistics included analysis of variance and the Tukey test. RESULTS: Compared with filtered back-projection, iterative reconstruction provided significantly lower qualitative (mean noise score: iterative reconstruction = 2.10/filtered back-projection = 2.18; P = .003) and quantitative (mean SD of Hounsfield units in air: iterative reconstruction = 30.2/filtered back-projection = 51.8; P < .001) image noise. Image noise increased as the radiation dose decreased. Qualitative image noise at levels C1-4 was rated as either "no noise" or as "acceptable noise." Any shoulder position was at level C5 and caused more artifacts at lower levels. When we analyzed all spinal levels, scores for morphologic characteristics revealed no significant differences between 105 and 355 mAs (P = .555), but they were worse in scans at 75 mAs (P = .025). CONCLUSIONS: Clinically acceptable image quality of cervical spine CTs for evaluation of bony structures of cadaveric specimens with different body habitus can be achieved with a reference mAs of 105 at 120 kVp with iterative reconstruction. Pull-down of shoulders during acquisition could improve image quality but may not be feasible in trauma patients with unknown injuries.


Subject(s)
Cervical Vertebrae/diagnostic imaging , Radiation Dosage , Tomography, X-Ray Computed/methods , Adult , Algorithms , Artifacts , Cadaver , Female , Humans , Male , Middle Aged , Radiographic Image Interpretation, Computer-Assisted/methods
4.
Clin Radiol ; 71(6): 615.e1-6, 2016 Jun.
Article in English | MEDLINE | ID: mdl-27005016

ABSTRACT

AIM: To assess image quality and radiation dose in patients with body weights ≤75 kg undergoing abdominal computed tomography (CT) with a tube voltage of either 120 or 100 kVp. MATERIALS AND METHODS: Eighty patients weighing ≤75 kg were prospectively assigned to receive either 120 or 100 kVp abdominal CT in the portal-venous phase. Attenuation values of abdominal organs and image noise were measured, and the contrast-to-noise ratios (CNRs) were calculated. Subjective image quality was assessed by three independent radiologists. Radiation exposure was assessed by size-specific dose estimate (SSDE). RESULTS: The mean attenuation of the kidney increased by 20% at 100 kVp (p<0.0001), and the mean image noise was 27% higher in the 100 kVp (p=0.003). The CNR did not significantly differ between the groups (120 kVp, 6.6±2.8; 100 kVp, 7.4±3.6; p=0.26). Except for subjective image noise (p<0.001), no other subjective quality parameters (e.g., contrast, artefacts) were significantly different between the two groups (p between 0.094 and 0.761). The mean SSDE in the 100-kVp group (9.8±1.8 mGy) was reduced by 19% compared to the 120-kVp group (12.1±1.8 mGy; p<0.0001). CONCLUSION: Manual reduction of tube voltage from the standard 120 to 100 kVp for portal-venous phase CT in patients with body weights ≤75 kg resulted in a 19% dose reduction while maintaining objective and subjective image quality.


Subject(s)
Body Weight , Multidetector Computed Tomography/methods , Radiation Dosage , Radiation Protection/methods , Radiographic Image Interpretation, Computer-Assisted/methods , Radiography, Abdominal/methods , Female , Humans , Male , Middle Aged , Prospective Studies , Radiometry/methods , Reproducibility of Results , Sensitivity and Specificity
5.
Clin Radiol ; 70(4): 366-72, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25554541

ABSTRACT

AIM: To compare low-contrast detectability, and qualitative and quantitative image parameters on standard and reduced radiation dose abdominal CT reconstructed with filtered back projection (FBP) and model-based iterative reconstruction (MBIR). MATERIALS AND METHODS: A custom built liver phantom containing 43 lesions was imaged at 120 kVp and four radiation dose levels (100% = 188 mAs, 50%, 25%, and 10%). Image noise and contrast-to-noise ratios (CNR) were assessed. Lesion detection and qualitative image analysis (five-point Likert scale with 1 = worst, 5 = best for confidence) was performed by three independent radiologists. RESULTS: CNR on MBIR images was significantly higher (mean 246%, range 151-383%) and image noise was significantly lower (69%, 59-78%) than on FBP images at the same radiation dose (both p < 0.05). On MBIR 10% images, CNR (3.3 ± 0.3) was significantly higher and noise (15 ± 1HU) significantly lower than on FBP 100% images (2.5 ± 0.1; 21 ± 1 HU). On 100% images, lesion attenuation was significantly lower with MBIR than with FBP (mean difference -2 HU). Low-contrast detectability and qualitative results were similar with MBIR 50% and FBP 100%. CONCLUSION: Low-contrast detectability with MBIR 50% and FBP 100% were equal. Quantitative parameters on even lower dose MBIR images are superior to 100%-dose FBP images. Some attenuation values differ significantly with MBIR compared with FBP.


Subject(s)
Liver/diagnostic imaging , Radiation Dosage , Radiographic Image Enhancement/methods , Radiographic Image Interpretation, Computer-Assisted/methods , Tomography, X-Ray Computed/methods , Humans , Phantoms, Imaging , Reproducibility of Results
6.
Clin Radiol ; 70(1): 54-61, 2015 Jan.
Article in English | MEDLINE | ID: mdl-25459197

ABSTRACT

AIM: To compare image quality and diagnostic confidence of 100 kVp CT pulmonary angiography (CTPA) in patients with body weights (BWs) below and above 100kg. MATERIALS AND METHODS: The present retrospective study comprised 216 patients (BWs of 75-99kg, 114 patients; 100-125kg, 88 patients; >125kg, 14 patients), who received 100 kVp CTPA to exclude pulmonary embolism. The attenuation was measured and the contrast-to-noise ratio (CNR) was calculated in the pulmonary trunk. Size-specific dose estimates (SSDEs) were evaluated. Three blinded radiologists rated subjective image quality and diagnostic confidence. Results between the BW groups and between three body mass index (BMI) groups (BMI <25kg/m(2), BMI = 25-29.9kg/m(2), and BMI ≥30kg/m(2), i.e., normal weight, overweight, and obese patients) were compared using the Kruskal-Wallis test. RESULTS: Vessel attenuation was higher and SDDE was lower in the 75-99kg group than at higher BWs (p-values between <0.001 and 0.03), with no difference between the 100-125 and >125kg groups (p = 0.892 and 1). Subjective image quality and diagnostic confidence were not different among the BW groups (p = 0.225 and 1). CNR was lower (p < 0.006) in obese patients than in normal weight or overweight subjects. Diagnostic confidence was not different in the BMI groups (p = 0.105). CONCLUSION: CTPA at 100 kVp tube voltage can be used in patients weighing up to 125kg with no significant deterioration of subjective image quality and confidence. The applicability of 100 kVp in the 125-150kg BW range needs further testing in larger collectives.


Subject(s)
Angiography/standards , Overweight/diagnostic imaging , Pulmonary Artery/diagnostic imaging , Tomography, X-Ray Computed/standards , Adult , Aged , Angiography/methods , Body Mass Index , Female , Humans , Male , Middle Aged , Obesity/diagnostic imaging , Pulmonary Embolism/diagnostic imaging , Retrospective Studies , Tomography, X-Ray Computed/methods
7.
Eur Radiol ; 25(3): 687-93, 2015 Mar.
Article in English | MEDLINE | ID: mdl-25316058

ABSTRACT

OBJECTIVES: To compare image quality and low-contrast detectability of an integrated circuit (IC) detector in abdominal CT of obese patients with conventional detector technology at low tube voltages. METHODS: A liver phantom with 45 lesions was placed in a water container to mimic an obese patient and examined on two different CT systems at 80, 100 and 120 kVp. The systems were equipped with either the IC or conventional detector. Image noise was measured, and the contrast-to-noise-ratio (CNR) was calculated. Low-contrast detectability was assessed independently by three radiologists. Radiation dose was estimated by the volume CT dose index (CTDIvol). RESULTS: The image noise was significantly lower, and the CNR was significantly higher with the IC detector at 80, 100 and 120 kVp, respectively (P = 0.023). The IC detector resulted in an increased lesion detection rate at 80 kVp (38.1 % vs. 17.2 %) and 100 kVp (57.0 % vs. 41.0 %). There was no difference in the detection rate between the IC detector at 100 kVp and the conventional detector at 120 kVp (57.0 % vs. 62.2 %). The CTDIvol at 80, 100 and 120 kVp measured 4.5-5.2, 7.3-7.9 and 9.8-10.2 mGy, respectively. CONCLUSIONS: The IC detector at 100 kVp resulted in similar low-contrast detectability compared to the conventional detector with a 120-kVp protocol at a radiation dose reduction of 37 %.


Subject(s)
Liver Neoplasms/diagnostic imaging , Obesity/diagnostic imaging , Phantoms, Imaging , Tomography, X-Ray Computed/methods , Aged , Cone-Beam Computed Tomography/methods , Electricity , Female , Humans , Male , Middle Aged , Models, Anatomic , Radiation Dosage , Radiographic Image Interpretation, Computer-Assisted/methods , Signal-To-Noise Ratio
8.
Eur J Radiol ; 82(12): e873-8, 2013 Dec.
Article in English | MEDLINE | ID: mdl-24074648

ABSTRACT

OBJECTIVES: To find the best pairing of first and second reader at highest sensitivity for detecting lung nodules with CT at various dose levels. MATERIALS AND METHODS: An anthropomorphic lung phantom and artificial lung nodules were used to simulate screening CT-examination at standard dose (100 mAs, 120 kVp) and 8 different low dose levels, using 120, 100 and 80 kVp combined with 100, 50 and 25 mAs. At each dose level 40 phantoms were randomly filled with 75 solid and 25 ground glass nodules (5-12 mm). Two radiologists and 3 different computer aided detection softwares (CAD) were paired to find the highest sensitivity. RESULTS: Sensitivities at standard dose were 92%, 90%, 84%, 79% and 73% for reader 1, 2, CAD1, CAD2, CAD3, respectively. Combined sensitivity for human readers 1 and 2 improved to 97%, (p1=0.063, p2=0.016). Highest sensitivities--between 97% and 99.0%--were achieved by combining any radiologist with any CAD at any dose level. Combining any two CADs, sensitivities between 85% and 88% were significantly lower than for radiologists combined with CAD (p<0.03). CONCLUSIONS: Combination of a human observer with any of the tested CAD systems provide optimal sensitivity for lung nodule detection even at reduced dose at 25 mAs/80 kVp.


Subject(s)
Early Detection of Cancer/methods , Lung Neoplasms/diagnostic imaging , Professional Competence , Radiation Dosage , Software , Solitary Pulmonary Nodule/diagnostic imaging , Tomography, X-Ray Computed/methods , Dose-Response Relationship, Radiation , Early Detection of Cancer/instrumentation , Female , Humans , Male , Observer Variation , Pattern Recognition, Automated , Phantoms, Imaging , Radiographic Image Interpretation, Computer-Assisted/methods , Reproducibility of Results , Sensitivity and Specificity , Software Validation , Tomography, X-Ray Computed/instrumentation
9.
Neurogastroenterol Motil ; 25(9): 749-e577, 2013 Sep.
Article in English | MEDLINE | ID: mdl-23741963

ABSTRACT

BACKGROUND: The objective of the study was to correlate MR-detectable motility alterations of the terminal ileum with biopsy-documented active and chronic changes in Crohn's disease. METHODS: This IRB approved retrospective analysis of 43 patients included magnetic resonance enterography (MRE) and terminal ileum biopsies (<2 weeks apart). Motility was measured at the terminal ileum using coronal 2D trueFISP pulse sequences (1.5T MRI,TR 83.8,TE1.89) and dedicated motility assessment software. Motility grading (hypermotility, normal, hypomotility, complete arrest) was agreed by two experienced readers. Motility was compared and correlated with histopathology using two-tailed Kruskal-Wallis test and paired Spearman Rank-Order Correlation tests. KEY RESULTS: Motility abnormalities were present in 27/43 patients: nine hypomotility and 18 complete arrest. Active disease was diagnosed on 15 biopsies: eight moderate and seven severe inflammatory activity. Chronic changes were diagnosed on 17 biopsies: 13 moderate and four severe cases. In four patients with normal motility alterations on histopathology were diagnosed. Histopathology correlated with presence (P = 0.0056 for hypomotility and P = 0.0119 for complete arrest) and grade (P < 0.0001; P = 0.0004) of motility alterations. A significant difference in the motility was observed in patients with active or chronic CD compared with patients without disease (P < 0.001; P = 0.0024). CONCLUSIONS & INFERENCES: MR-detectable motility changes of the terminal ileum correlate with histopathological findings both in active and chronic CD. Motility changes may indicate the presence pathology, but do not allow differentiation of active and chronic disease.


Subject(s)
Crohn Disease/pathology , Crohn Disease/physiopathology , Gastrointestinal Motility/physiology , Ileum/pathology , Ileum/physiopathology , Adult , Aged , Aged, 80 and over , Female , Humans , Image Interpretation, Computer-Assisted , Magnetic Resonance Imaging , Male , Middle Aged , Retrospective Studies , Young Adult
10.
Traffic Inj Prev ; 14(1): 1-6, 2013.
Article in English | MEDLINE | ID: mdl-23259512

ABSTRACT

OBJECTIVE: To compare offenders with high versus low perceptions of risk for being stopped by police for drinking and driving using measures of beliefs, behaviors, social context of drinking, and perceived influence from a significant other in their social network. METHOD: Telephone interviews were conducted with 161 individuals who received a first-time driving under the influence (DUI) citation in Maryland. They were divided into 2 groups: those who felt that it was almost certain or very likely that they would be stopped by the police if they drove after having too much to drink (n = 56) and those who felt that it was only somewhat likely or unlikely (n = 105). RESULTS: The 2 groups did not differ in terms of age, gender, race/ethnicity, education, employment, or marital status. Offenders with a low perceived risk of being stopped were less likely to believe that they would be convicted if they were stopped and arrested. They were more likely to report having an encounter with an aggressive driver, running through a stop sign or traffic light, drinking in a context of social facilitation, knowing someone in their social network who had received a DUI citation, and having a member of their social network suggest that they had had too much to drink and could not drive safely. CONCLUSIONS: The social context of drinking and the relationship they have to their social network have important implications for influencing first DUI offenders and preventing them from recidivating.


Subject(s)
Alcohol Drinking/legislation & jurisprudence , Attitude , Automobile Driving/legislation & jurisprudence , Risk-Taking , Adolescent , Adult , Aged , Alcohol Drinking/psychology , Automobile Driving/psychology , Female , Humans , Interpersonal Relations , Male , Maryland , Middle Aged , Qualitative Research , Risk Assessment , Social Environment , Social Support , Young Adult
11.
Clin Radiol ; 68(2): e79-86, 2013 Feb.
Article in English | MEDLINE | ID: mdl-23219454

ABSTRACT

AIM: To assess the effect of an automatic tube voltage selection technique on image quality and radiation dose in abdominal computed tomography (CT) angiography of various body sizes. MATERIALS AND METHODS: An abdominal aortic phantom was filled with iodinated contrast medium and placed into three different cylindrical water containers, which simulated a small, intermediate-sized, and large patient. The phantom was scanned with a standard 120 kVp abdominal CT angiography protocol and with an optimized tube voltage protocol that was modulated by an automatic tube voltage technique. The attenuation of the aorta, background, and image noise was measured, and the contrast-to-noise ratio (CNR) was calculated. Three independent readers assessed the overall image quality. RESULTS: The automatic tube voltage technique selected 70 kVp as the optimal tube voltage for the small phantom, 80 kVp for the intermediate phantom, and 100 kVp for the large phantom. Compared to the standard 120 kVp protocol, the automatic tube voltage selection yielded significantly increased CNR values in the small phantom (15.8 versus 19.4, p < 0.001), intermediate phantom (8.4 versus 8.7, p < 0.05), and large phantom (4.3 versus 4.6, p < 0.01). The automatic tube voltage selection resulted in a 55%, 49%, and 39% reduction in the volume CT dose index (CTDI(vol)) in the small, intermediate, and large phantoms, respectively. The subjective overall image quality of the three phantom sizes at different tube voltages ranged between poor and good. CONCLUSION: Compared to a standard 120 kVp abdominal CT angiography protocol, the automatic tube voltage selection substantially reduced the radiation dose without compromising image quality in various simulated patient sizes.


Subject(s)
Angiography/methods , Aorta, Abdominal/diagnostic imaging , Phantoms, Imaging , Radiation Dosage , Radiographic Image Interpretation, Computer-Assisted/methods , Tomography, X-Ray Computed/instrumentation , Tomography, X-Ray Computed/methods , Automation , Body Size , Humans , Radiation Injuries/prevention & control , Radiographic Image Enhancement , Radiographic Image Interpretation, Computer-Assisted/instrumentation , Sensitivity and Specificity
12.
Anaesthesia ; 67(12): 1321-6, 2012 Dec.
Article in English | MEDLINE | ID: mdl-23130724

ABSTRACT

The aim of this prospective clinical study was to evaluate the location of paravertebral catheters that were placed using the classical landmark puncture technique and to correlate the distribution of contrast dye injected through the catheters with the extent of somatic block. Paravertebral catheter placement was attempted in 31 patients after video-assisted thoracic surgery. In one patient, an ultrasound-guided approach was chosen after failed catheter placement using the landmark method. A fluoroscopic examination in two planes using contrast dye was followed by injection of local anaesthetic and subsequent clinical testing of the extent of the anaesthetised area. In nine patients (29%), spread of contrast dye was not seen within the paravertebral space as intended. Misplaced catheters were in the epidural space (three patients), in the erector spinae musculature (five patients), and in the pleural space (one patient). There was also a discrepancy between the radiological findings and the observed distribution of loss of sensation. We have demonstrated an unacceptably high misplacement rate of paravertebral catheters using the landmark method. Additional research is required to compare the efficacy and safety of continuous paravertebral block using ultrasound-guided techniques or surgical inserted catheters.


Subject(s)
Catheterization/instrumentation , Catheters, Indwelling , Foreign Bodies/diagnostic imaging , Nerve Block/instrumentation , Thoracic Vertebrae/diagnostic imaging , Adult , Aged , Anesthetics, Local/administration & dosage , Bupivacaine/administration & dosage , Catheterization/methods , Contrast Media/administration & dosage , Female , Fluoroscopy , Humans , Iopamidol/administration & dosage , Male , Middle Aged , Nerve Block/methods , Prospective Studies , Thoracic Surgery, Video-Assisted , Young Adult
13.
Acta Biol Hung ; 63(2): 277-87, 2012 Jun.
Article in English | MEDLINE | ID: mdl-22695525

ABSTRACT

Wickerhamomyces anomalus VKM Y-159 strain produces two types of toxin designated as WAKT a and WAKT b, encoded by chromosomal genes. The WAKT a toxin is heat-labile, pronase sensitive acting in pH range 3-4 affecting on several yeasts including pathogenic Candida species while the WAKT b toxin is protease- and thermo-resistant, acting in pH range 3-7 on two species, Candida alai and Candida norvegica. The rapid decrease of the number of viable cells after toxin treatment demonstrates that both toxins have cytocidic effect.


Subject(s)
Killer Factors, Yeast/toxicity , Pichia/chemistry , Candida/drug effects , Cell Wall/chemistry , Killer Factors, Yeast/chemistry , Microbial Sensitivity Tests , Polysaccharides/chemistry
14.
Traffic Inj Prev ; 12(4): 306-11, 2011 Aug.
Article in English | MEDLINE | ID: mdl-21823937

ABSTRACT

OBJECTIVE: To understand the role of social context in contributing to the incidence of alcohol-impaired driving. METHODS: Telephone interviews were conducted with 161 individuals who received a first-time DUI citation. They were predominantly white (70%), male (62%) and 21 to 45 years of age (62%). They were paid $25 for their participation. Questions were asked about their social network, the social context in which they typically drink, the specific location and circumstances where they were drinking at the time of their citation, risky driving behaviors, in the last month as well as the number of traffic tickets they received and crashes they have been involved in since they started to drive. RESULTS: Two reliable social contexts of drinking were identified through principle components factors analysis: emotional pain and social facilitation. Analyses of variance showed that drinking in a context of emotional pain (eg, to deal with depression, stress) was related to drinking alone at this location and driving when they know they have had too much to drink. Drinking in a context of social facilitation (eg, with friends, to be sociable) was related to drinking more frequently and with others (versus alone) at this location. Social facilitation was also positively related to driving over the speed limit and running a red light/stop sign. CONCLUSIONS: The social context of drinking is important for understanding the social network of drinking drivers, because most (86%) said that someone from their social network was with them at this drinking location. The need to understand how significant others influence the context of drinking as well as the likelihood of impaired driving is critical for program development. These results suggest that different types of interventions are needed for offenders depending on their social context of drinking.


Subject(s)
Adaptation, Psychological , Alcohol Drinking/psychology , Automobile Driving/psychology , Social Facilitation , Social Isolation/psychology , Adolescent , Adult , Aged , Alcohol Drinking/epidemiology , Automobile Driving/legislation & jurisprudence , Female , Humans , Male , Maryland/epidemiology , Middle Aged , Qualitative Research , Risk-Taking , Social Support , Young Adult
15.
Vasa ; 39(4): 319-24, 2010 Nov.
Article in English | MEDLINE | ID: mdl-21104621

ABSTRACT

BACKGROUND: Endovascular treatment is an increasingly used therapeutic option in patients with chronic atherosclerotic occlusive mesenteric disease. Purpose of this study was evaluation of patency and mortality in patients treated with visceral artery percutaneous transluminal angioplasty (PTA) or stenting including follow-up. PATIENTS AND METHODS: A retrospective review of 17 consecutive patients (4 women, 13 men) with endovascular treatment for symptomatic chronic mesenteric ischemia from 1998 to 2004 was performed. Mean follow-up period was 42 months. Patient demographics, interventional details, primary and/or secondary patency and mortality were recorded. Cumulative mortality and patency rates were determined using Kaplan-Meier life table analysis. RESULTS: Twenty-six interventions (PTA alone n=13, PTA and stenting n=13) were performed in 17 patients. Interventions were performed in the superior mesenteric artery (n=13) and celiac artery (n=13). The re-intervention rate was 30% (6/26). Re-interventions were performed for the superior mesenteric artery (n=4) and celiac artery (n=2). Cumulative overall 1-year results were primary patency rate 81%, secondary patency rate 94%, and survival rate 82%. Cumulative 10-year results were primary patency rate 73%, secondary patency rate 94%, and survival rate 65%. The 10-year secondary patency rate was 100% in patients post initial stenting and 86% in patients post initial PTA. CONCLUSIONS: Long-term follow-up post endovascular treatment for chronic mesenteric ischemia demonstrated a considerable overall secondary patency rate of 94%. However, the long-term secondary patency rate was higher in patients post initial stenting compared to PTA alone.


Subject(s)
Angioplasty, Balloon/instrumentation , Atherosclerosis/therapy , Endovascular Procedures/instrumentation , Mesenteric Vascular Occlusion/therapy , Stents , Adult , Aged , Aged, 80 and over , Angioplasty, Balloon/adverse effects , Angioplasty, Balloon/mortality , Atherosclerosis/complications , Atherosclerosis/diagnostic imaging , Atherosclerosis/mortality , Constriction, Pathologic , Endovascular Procedures/adverse effects , Endovascular Procedures/mortality , Female , Humans , Kaplan-Meier Estimate , Life Tables , Male , Mesenteric Vascular Occlusion/diagnostic imaging , Mesenteric Vascular Occlusion/etiology , Mesenteric Vascular Occlusion/mortality , Middle Aged , Radiography , Recurrence , Retrospective Studies , Severity of Illness Index , Switzerland , Time Factors , Treatment Outcome , Vascular Patency
16.
Radiologe ; 50(12): 1120, 1122-7, 2010 Dec.
Article in German | MEDLINE | ID: mdl-20844858

ABSTRACT

The rapid technical advances in computed tomography have led to an increased number of clinical indications. Unfortunately, at the same time the radiation exposure to the population has also increased due to the increased total number of CT examinations. In the last few years various publications have demonstrated the feasibility of radiation dose reduction for CT examinations with no compromise in image quality and loss in interpretation accuracy. The majority of the proposed methods for dose optimization are easy to apply and are independent of the detector array configuration. This article reviews indication-dependent principles (e.g. application of reduced tube voltage for CT angiography, selection of the collimation and the pitch, reducing the total number of imaging series, lowering the tube voltage and tube current for non-contrast CT scans), manufacturer-dependent principles (e.g. accurate application of automatic modulation of tube current, use of adaptive image noise filter and use of iterative image reconstruction) and general principles (e.g. appropriate patient-centering in the gantry, avoiding over-ranging of the CT scan, lowering the tube voltage and tube current for survey CT scans) which lead to radiation dose reduction.


Subject(s)
Angiography/adverse effects , Angiography/methods , Image Processing, Computer-Assisted/methods , Radiation Dosage , Tomography, X-Ray Computed/adverse effects , Tomography, X-Ray Computed/methods , Humans , Radiometry/methods , Technology, Radiologic/methods
17.
Br J Anaesth ; 102(4): 534-9, 2009 Apr.
Article in English | MEDLINE | ID: mdl-19244265

ABSTRACT

BACKGROUND: During paravertebral block, the anterolateral limit of the paravertebral space, which consists of the pleura, should preferably not be perforated. Also it is possible that, during the block, the constant superior costotransverse ligament can be missed in the loss-of-resistance technique. We therefore aimed to develop a new technique for an ultrasound-guided puncture of the paravertebral space. METHODS: We performed 20 punctures and catheter placements in 10 human cadavers. A sonographic view showing the pleura and the superior costotransverse ligament was obtained with a slightly oblique scan using a curved array transducer. After inline approach, injection of 10 ml normal saline confirmed the correct position of the needle tip, distended the space, and enabled catheter insertion. The spread of contrast dye injected through the catheters was assessed by CT scans. RESULTS: The superior costotransverse ligament and the paravertebral space were easy to identify. The needle tip reached the paravertebral space without problems under visualization. In contrast, the introduction of the catheter was difficult. The CT scan revealed a correct paravertebral spread of contrast in 11 cases. Out of the remaining, one catheter was found in the pleural space, in six cases there was an epidural, and in two cases there was a prevertebral spread of contrast dye. CONCLUSIONS: We successfully developed a technique for an accurate ultrasound-guided puncture of the paravertebral space. We also showed that when a catheter is introduced through the needle with the tip lying in the paravertebral space, there is a high probability of catheter misplacement into the epidural, mediastinal, or pleural spaces.


Subject(s)
Nerve Block/methods , Ultrasonography, Interventional/methods , Catheterization/methods , Contrast Media/pharmacokinetics , Feasibility Studies , Humans , Models, Anatomic , Pleura/diagnostic imaging , Thoracic Vertebrae , Tomography, X-Ray Computed
18.
J Nanosci Nanotechnol ; 7(4-5): 1357-69, 2007.
Article in English | MEDLINE | ID: mdl-17450899

ABSTRACT

In this work, comparative analysis of processes in carbon arc and radio frequency (RF) plasma during fullerene synthesis has been presented. The kinetic model of fullerene formation developed earlier has been verified in both types of plasma reactors. The fullerene yield depended on carbon concentration, velocity of plasma flame and rotational temperature of C2 radicals predominantly. When mean rotational temperature of C2 radicals was 3000 K, the fullerene yield was the highest regardless of the type of used reactor. The zone of fullerene formation is larger significantly in RF plasma reactor compared to arc reactor.


Subject(s)
Carbon/chemistry , Fullerenes/chemistry , Nanotechnology/methods , Crystallization , Electrochemistry/methods , Graphite/chemistry , Kinetics , Microscopy, Electron, Scanning , Models, Chemical , Models, Statistical , Nanoparticles/chemistry , Radio Waves , Spectrum Analysis, Raman , Temperature
19.
Ther Umsch ; 63(10): 639-45, 2006 Oct.
Article in German | MEDLINE | ID: mdl-17048182

ABSTRACT

From conventional radiography to cross-sectional imaging methods, modern radiology offers a wide range of diagnostic tools for investigating patients with fever. To achieve the best results and to yield a correct diagnosis, the radiologist must tailor the diagnostic protocol individually for every patient. The decision on the most suitable imaging method, and the type and timing of contrast media strongly depends on the suspected diagnosis. Based on patient history and laboratory data, some modalities may be contraindicated or the patient may need a premedication. The authors give a short overview of diagnostic strategies in evaluating the most important causes of fever and point to the need of discussion and co-operation between clinicians and radiologists.


Subject(s)
Diagnostic Imaging , Fever of Unknown Origin/etiology , Contrast Media/administration & dosage , Cooperative Behavior , Diagnosis, Differential , Humans , Medical History Taking , Patient Care Team , Sensitivity and Specificity
20.
Ophthalmologe ; 103(6): 517-22, 2006 Jun.
Article in German | MEDLINE | ID: mdl-16763869

ABSTRACT

PURPOSE: The aim of this study was to evaluate the short-term effectiveness of transpalpebral orbital lipectomy. METHOD: Using a transpalpebral approach, 2.0-6.5 ml connective tissue was removed from 50 orbits of 33 patients with mild to severe Graves' orbitopathy (25 females, 8 males) over a 5-year period. Indications for surgery comprised cosmetic correction of exophthalmos (27/33 patients), corneal damage (5/33), and rapid bilateral deterioration of visual acuity in 1 patient. RESULTS: In 27 patients undergoing correction for aesthetic purposes no change in visual acuity ensued; in 4 of 5 keratopathy patients an improvement in visual acuity was detected. Diplopia ceased in 4 of 13 patients, diminished in 3 of 13 cases, and constantly increased in 2 of 13 cases. The high intraocular pressure returned to normal in 8 of 13 patients. The proptosis was reduced at 3.2+/-1.3 mm. CONCLUSION: Transpalpebral orbital lipectomy is a low-risk, highly effective technique for orbital decompression in both acute and chronic cases of Graves' orbitopathy.


Subject(s)
Decompression, Surgical/methods , Graves Ophthalmopathy/surgery , Lipectomy/methods , Ophthalmologic Surgical Procedures/methods , Plastic Surgery Procedures/methods , Vision Disorders/prevention & control , Adolescent , Adult , Aged , Female , Graves Ophthalmopathy/complications , Humans , Male , Middle Aged , Orbit/surgery , Pilot Projects , Treatment Outcome , Vision Disorders/etiology
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