Interobserver variability and positive predictive value for ultrasonographic BI-RADS categories requiring pathohistological evaluation.

OBJECTIVE: The objective of this study was an analysis of interobserver variability and positive predictive value (PPV) for BI-RADS categories requiring pathohistological evaluation: 4A, 4B, 4C, and 5. MATERIAL AND METHODS: Interobserver variability for each of descriptors as well as PPV for final BI-RADS categories requiring pathohistological evaluation was measured in a retrospective study which included 30 ultrasonographic reports, with pathohistological verification, randomly selected from ultrasonographic reports from Institute for Oncology and Radiology of Serbia where about 1,100 breast cancers are verified every year. Ten observers, seven gynecologists, and three radiologists, independently rated each ultrasonographic report according to the fourth edition of BI-RADS atlas. Interobserver variability was measured with k coefficient. RESULTS: There was most conformity for a category of orientation (k = 0.79). Substantial degree of conformity was also present for both boundary (k = 0.71) and shape (k = 0.65) categories. Moderate degree of conformity was achieved for posterior features (k = 0.54) and margins (k = 0.41) descriptors, while there was poor conformity in echogenicity (k = 0.38). In case of a final score, common conformity for all BI-RADS 4A, 4B, 4C, and 5 categories was (k = 0.51); it was the greatest for category 5 (k = 0.50), and it was less for categories 4C (k = 0.37), 4B (k = 0.32), and 4A (k = 0.29). CONCLUSIONS: Interobserver conformity for ultrasonographic descriptors and final evaluation of BI-RADS 4A, 4B, 4C, and 5 categories is good. PPV implies that not only division into categories 4 and 5, but also classification into categories 4 and subcategories 4A, 4B, and 4C are justified and clinically applicable.

Abdominal aortic aneurysm volume and relative intraluminal thrombus volume might be auxiliary predictors of rupture-an observational cross-sectional study.

Objectives: The study aimed to identify differences and compare anatomical and biomechanical features between elective and ruptured abdominal aortic aneurysms (AAAs). Methods: Data (clinical, anatomical, and biomechanical) of 98 patients with AAA, 75 (76.53%) asymptomatic (Group aAAA) and 23 (23.46%) ruptured AAA (Group rAAA), were prospectively collected and analyzed. Anatomical, morphological, and biomechanical imaging markers like peak wall stress (PWS) and rupture risk equivalent diameter (RRED), comorbid conditions, and demographics were compared between the groups. Biomechanical features were assessed by analysis of Digital Imaging and Communication in Medicine images by A4clinics (Vascops), and anatomical features were assessed by 3Surgery (Trimensio). Binary and multiple logistic regression analysis were used and adjusted for confounders. Accuracy was assessed using receiving operative characteristic (ROC) curve analysis. Results: In a multivariable model, including gender and age as confounder variables, maximal aneurysm diameter [MAD, odds ratio (OR) = 1.063], relative intraluminal thrombus (rILT, OR = 1.039), and total aneurysm volume (TAV, OR = 1.006) continued to be significant predictors of AAA rupture with PWS (OR = 1.010) and RRED (OR = 1.031). Area under the ROC curve values and correct classification (cc) for the same parameters and the model that combines MAD, TAV, and rILT were measured: MAD (0.790, cc = 75%), PWS (0.713, cc = 73%), RRED (0.717, cc = 55%), TAV (0.756, cc = 79%), rILT (0.656, cc = 60%), and MAD + TAV + rILT (0.797, cc = 82%). Conclusion: Based on our results, in addition to MAD, other important predictors of rupture that might be used during aneurysm surveillance are TAV and rILT. Biomechanical parameters (PWS, RRED) as valuable predictors should be assessed in prospective clinical trials. Similar studies on AAA smaller than 55 mm in diameter, even difficult to organize, would be of even greater clinical value.

Correlation between explosive strength, aerobic power and repeated sprint ability in elite basketball players.

AIM: The aim of this study was to examine the relationship between explosive strength and aerobic power with basketball-specific repeated sprint ability in elite male basketball players. METHODS: Twenty-four elite basketball players (age 22.2±3.4 years, height 197.1±6.2 cm, weight 95.7±8.8 kg; training experience 11.0±3.1 years; mean±SD), participated in the study. Subjects performed countermovement jump (CMJ) test and incremental pseudo-ramp test protocol with measured CMJ height and VO2max, respectively. Specific repeated sprint ability (RSA) test was conducted, with total sprinting time (summation of 10 sprint times - RSAtot) and sprint decrement (fatigue index - RSAFI) calculated. RESULTS: Significant decrements in sprint performance from the eight 30-m sprint (P<0.05) were observed. Strong inverse correlation was found between CMJ and RSAtot (r=-0.74, P<0.01). No significant correlation was found between VO2max and RSA outcomes neither between CMJ and RSAFI. CONCLUSION: CMJ is a predictor of RSA in elite basketball players. It seems that coaches and strength and conditioning professionals should devote additional time for explosive strength development in elite basketball players during preparatory period to enhance RSA performance.

Survival of Campylobacter jejuni in chicken meat, chicken skin and chicken liver at low temperatures.

The aim of this study was to determine survival of Campylobacter jejuni (C. jejuni) in chicken meat, chicken skin medallions and chicken liver contaminated with this bacterium at +4 °C and -20 °C, after 24 hours of incubation. The survival of C. jejuni at +4 °C, -20 °C in chicken meat, chicken skin medallions and chicken liver were examined after 24 hours of incubation with C. jejuni. All samples were previously tested for the presence of Campylobacter species according to ISO 10272-1:2006. After 24 hours of incubation at +4 ° C, the number of survived C. jejuni in chicken meat slightly decreased on both non-selective and selective plates, but still in range of 10. After 24 hours of incubation at -20 ° C, the number of survived C. jejuni in chicken meat was in range of 10 cfu/ml on non-selective plate, with complete absence of growth on selective plate. After 24 hours of incubation, the number of survived C. jejuni in chicken liver increased on selective and non-selective plates (>10) at +4 ° C, while at -20 ° C there were no C. jejuni survived on both plates. 24 hours of incubation at both temperatures did not much influence the number of C. jejuni in chicken meet, while chicken skin medaillons allowed increase of the number of bacteria. Incubation of chicken liver at + 4° C allowed bacterial multiplication, while incubation at -20 ° C caused absence of survival (Tab. 1, Ref. 12).

Local control of glomus tumors of the head & neck by radiation therapy and surgery.

PURPOSE: Glomus tumors are rare tumors, highly vascular and typically radiosensitive. Therapeutic options include surgery, radiation therapy (RT), embolisation or any combination of them, but the appropriate treatment still remains a challenge. The purpose of this study was to report the results of local control of 7 patients with glomus tumors treated with surgery and external beam RT (EBRT). METHODS: All of the patients underwent primary surgery and then postoperative EBRT. Follow-up was calculated from the date of initiation of EBRT and ranged from 3 to 15 years (mean 7.14, median 6.2). The likelihood of local control was analysed using the Kaplan-Meier product limit method. We also analysed the average duration of response between two groups of patients with different doses of EBRT as well as the presence of acute and late EBRT complications. RESULTS: Local control was obtained in 6/7 (85.7%) patients. Moreover, local control was achieved in 3/4 (75%) patients with recurrent glomus tumors, while in patients with postoperative residual disease local control was obtained in 3/3 (100%) of them. Patients who received <50 Gy (n=2) had shorter average duration of response compared to patients who received >50 Gy (n=5; p=0.248). There were no severe treatment complications. CONCLUSION: Surgery and RT represent an appropriate treatment approach for advanced glomus tumors with acceptable complications.

Percutaneous nephrostomy in the management of advanced and terminal-stage gynecologic malignancies: outcome and complications.

PURPOSE: The goal of the study was to evaluate the outcome and complications after percutaneous nephrostomy (PCN) insertion in advanced and terminal-stage gynecological malignancies with ureteral obstruction (UO). MATERIALS AND METHODS: We analyzed data of 117 patients with UO due to gynecological malignancies, who had undergone PCN between 1996 and 2006. Cervical cancer was evidenced in 108 patients, uterine carcinoma in six and ovarian cancer in three patients. Eighty-nine had UO at the initial manifestation of the disease, 22 had persistent or recurrent cancer, and six were disease-free after initial therapy. Oliguria was observed in 22.2% and creatine elevation in 79.5%. Mean follow-up was 11.43 months (range 0-112). RESULTS: The median age was 51 years (range 28-85). Bilateral nephrostomy was performed in 36.7% and unilateral in 63.3%. Renal function normalization occurred in 24.8%. Overall two-year survival (OS) was 16.8%. Higher OS occurred in patients without initial azotemia versus those with azotemia (26.8% vs 13.9%). Median survival time for all the patients was seven months, eight in primary cases versus six in recurrent ones, and eight months in patients after initial therapy. Complications appeared in 53.85%. Most frequent were the loss of the nephrostomy catheter in 37.61% and urinary tract infections in 19.6%. CONCLUSION: Improvement of renal function after PCN can be of clinical benefit in patients who might be cured or for prolonged palliative care. Azotemia seems to be poor prognostic sign.

Experimental determination of the HPGe spectrometer efficiency curve.

A review of the calibration procedures of the semiconductor HPGe spectrometer is presented in this paper. Calibration standards were prepared using the standardized radioactive solution of the common monoenergetic radionuclides mixture and standardized multigamma (152)Eu solution. The matrix materials were spiked using the activated carbon, and homogenized mechanically or by suspension in C(2)H(5)OH. Experimentally determined efficiency curves were compared with those obtained by Monte Carlo simulation.

Determination of the specific alpha activity of thick sources with a large area ZnS(Ag) scintillation detector.

A method for determining the specific alpha activity of thick sources using a large area ZnS(Ag) scintillation detector is presented. In this method a quadratic relationship between the detector response and window thickness is assumed. This method provides a quick estimation of alpha activity in the sample, so it is an indicative method. The aim of this experimental work is to approve theoretical assumption and to develop a standard routine method for absolute alpha measurements of thick contaminated environmental sources. For this purpose reference material U(3)O(8) and spiked standards of soil were used. Measurements of contaminated soil samples from south Serbia showed the practical application of this method.

Retrospective estimation of the concentration of 241Pu in air sampled at a Belgrade site following the Chernobyl accident.

The surface air activity concentration of 241Pu for the period May 01-15, 1986, for a monitoring site in Vinca, Belgrade was retrospectively estimated. The results were obtained by re-measurement of plutonium fraction alpha-spectrometric sources, with 236Pu as a tracer, used almost 13 years earlier for the determination of (239,240)Pu concentration in surface air immediately after the Chernobyl accident. The estimated 241Pu concentration, based on the 241Am in-growth method for air samples, ranged from 240 to 7800 microBq/m3. The average activity ratio 241Pu/(239,240)Pu originating from the Chernobyl accident at Belgrade site was approximately 100 at the collection time.

Numerical solutions of differential equations of a cylindrical ionization chamber.

The differential equations of the cylindrical ionization chamber filled with air have been solved numerically for different ratios of the outer and inner electrode for both polarities of the voltage supply. The obtained distributions of the electric field strength inside the chamber confirm the analysis of Thomson and Thomson and the calculations made by Mie. The calculated collection efficiencies are in good agreement with the results of the calculation of Sprinkle and Tate, and with the experimental data of Moriuchi et al.

The mechanism of detection of air pollution by an ionization chamber.

The mechanism of detection of chemical vapors in air by an ionization chamber supplied by DC and AC voltage has been described. The theoretical explanation is based on numerical solutions of the differential equations of the cylindrical ionization chamber. The current of the ionization chamber operating in the AC regime has two components: a conductive component, caused by the ions drifts, and a capacitive component, caused by the distortion of the electric field. The ionization chamber operating in the DC regime has only the first component; hence the AC supplied chamber has larger response than the DC supplied chamber.

Natural radioactivity in lignite samples from open pit mines "Kolubara", Serbia--risk assessment.

Coal as fossil fuel mainly contains naturally occurring radionuclides from the uranium and thorium series and (40)K. Use of coal, primarily in industry, as a result has dispersion of radioactive material from coal in and through air and water. The aim of this study was to determine the activity concentrations of natural radionuclides in coal samples from open pit mines "Kolubara" and to evaluate its effect on population health. The results showed that all measured and calculated values were below the limits recommended in international legislation.

Disability caused by multiple sclerosis is associated with the number of extra cranial venous stenoses: possible improvement by venous angioplasty. Results of a prospective study.

OBJECTIVE: Chronic cerebrospinal venous insufficiency (CCSVI) was recently described in patients with multiple sclerosis (MS). The hypothesis of the vascular aetiology provides a new approach in the investigation and treatment of MS. METHODS: Our open-label study included 94 MS patients who fulfilled ultrasound sonographic criteria required for CCSVI. The internal jugular and/or azygous veins by a catheter venography were dilated. RESULTS: In 34.8% of the patients unilateral, in 65.2% bilateral venous abnormalities and in 2.1% no luminal obstructions were demonstrated. The patient group with the higher disability score had a significantly higher number of venous lesions (P < 0.005). Significant improvement of clinical disability in relapsing-remitting patients was (P < 0.001) achieved. In our study no stents were used. Re-stenosis occurred in 21.7% of the patients. CONCLUSION: The number of venous narrowings is higher in more disabled patients. A significant improvement in clinical disability in the relapsing-remitting group was observed.

Mechanical revascularization for acute ischemic stroke: a single-center, retrospective analysis.

BACKGROUND: Endovascular mechanical revascularization (thrombectomy) is an increasingly used method for intracranial large vessel recanalization in acute stroke. The purpose of the study was to analyze the recanalization rate, clinical outcome, and complication rate in our stroke patients treated with mechanical revascularization. METHODS: A total of 57 patients with large vessel stroke (within 3 h for anterior and 12 h for posterior circulation) were treated with mechanical revascularization at a single center during 24 months. The primary goal of endovascular treatment using different mechanical devices was recanalization of the occluded vessel. Recanalization rate (reported as thrombolysis in cerebral infarction [TICI] score), clinical outcome (reported as National Institutes of Health Stroke Scale [NIHSS] score and modified Rankin scale [mRS] score), as well as periprocedural complications were analyzed. RESULTS: The mean age of the patients was 63.1 ± 12.9 years, with baseline median NIHSS score of 14 (interquartile range, 9.5-19). Successful recanalization (TICI 2b or 3) was achieved in 41 (72 %) patients. Twenty patients (35 %) presented with favorable outcome (mRS ≤2) 30 days after stroke. Overall, significant neurological improvement (≥4 NIHSS point reduction) occurred in 36 (63 %) patients. A clinically significant procedure-related adverse events (vessel disruption, peri/postprocedural intracranial bleeding) defined with decline in NIHSS of ≥4 or death occurred in three (5 %) patients. CONCLUSIONS: The study showed a high recanalization rate with improved clinical outcome and a low rate of periprocedural complications in our stroke patients treated with mechanical revascularization. Therefore, we could conclude that endovascular revascularization (primary or in combination with a bridging thrombolysis) was an effective and safe procedure for intracranial large vessel recanalization in acute stroke.

The direct measurement of 57Co activity by the sum-peak method.

The direct measurement of the activities of (57)Co sources by application of the sum-peak method recently developed by Novkovic et al., is described in this paper. The comprehensive assessment of the uncertainty budget of the activity of the measured sources has been analyzed. The presented method is successfully tested using an HPGe spectrometer with efficiencies of 50%. The accuracy of this method is confirmed to be comparable with the commonly used methods of the activity measurement of (57)Co.

On the long-term stability of calibration standards in different matrices.

In order to assure Quality Control in accordance with ISO/IEC 17025, it was important, from metrological point of view, to examine the long-term stability of calibration standards previously prepared. Comprehensive reconsideration on efficiency curves with respect to the ageing of calibration standards is presented in this paper. The calibration standards were re-used after a period of 5 years and analysis of the results showed discrepancies in efficiency values.

Patient specific multiscale modelling for plaque formation and progression.

We present a three-dimensional model of plaque formation and progression that was tested in a set of patients who underwent coronary Computed Tomography angiography (CTA) for anginal symptoms. The 3D blood flow is described by the Navier-Stokes equations, together with the continuity equation. Mass transfer within the blood lumen and through the arterial wall is coupled with the blood flow and is modeled by a convection-diffusion equation. The Low Density Lipoprotein (LDL) transports in lumen of the vessel and through the vessel tissue (which has a mass consumption term) are coupled by Kedem-Katchalsky equations. The inflammatory process is modeled using three additional reaction-diffusion partial differential equations. A full three-dimensional model was created. Furthermore, features potentially affecting plaque growth, such as patient risk score, circulating biomarkers, localization and composition of the initial plaque, and coronary vasodilating capability were also investigated. The proof of concept of the model effectiveness was assessed 6 months after the baseline evaluation.

A simple method for determination of natural and depleted uranium in surface soil samples.

A simple and efficient method for determination of uranium content in surface soil samples contaminated with depleted uranium, by gamma ray spectrometry is presented. The content of natural uranium and depleted uranium, as well as the activity ratio (235)U/(238)U of depleted uranium, were determined in contaminated surface soil samples by application of this method.