Muhogora W.E.,Tanzania Atomic Energy Commission |
Msaki P.,University of Dar es Salaam |
Padovani R.,Ospedale Universitario
Journal of Applied Clinical Medical Physics | Year: 2015
The objective of this study was to improve the visibility of anatomical details by applying off-line postimage processing in chest computed radiography (CR). Four spatial domain-based external image processing techniques were developed by using MATLAB software version 22.214.171.12420 (R14) and image processing tools. The developed techniques were implemented to sample images and their visual appearances confirmed by two consultant radiologists to be clinically adequate. The techniques were then applied to 200 chest clinical images and randomized with other 100 images previously processed online. These 300 images were presented to three experienced radiologists for image quality assessment using standard quality criteria. The mean and ranges of the average scores for three radiologists were characterized for each of the developed technique and imaging system. The Mann-Whitney U-test was used to test the difference of details visibility between the images processed using each of the developed techniques and the corresponding images processed using default algorithms. The results show that the visibility of anatomical features improved significantly (0.005 ≤ p ≤ 0.02) with combinations of intensity values adjustment and/or spatial linear filtering techniques for images acquired using 60 ≤ kVp ≤ 70. However, there was no improvement for images acquired using 102 ≤ kVp ≤ 107 (0.127 ≤ p ≤ 0.48). In conclusion, the use of external image processing for optimization can be effective in chest CR, but should be implemented in consultations with the radiologists.
Muhogora W.,University of Dar es Salaam |
Padovani R.,Ospedale Universitario |
Msaki P.,University of Dar es Salaam
Journal of Medical Physics | Year: 2011
The aim of this study was to develop a homemade phantom for quantitative quality control in chest computed radiography (CR). The phantom was constructed from copper, aluminium, and polymenthylmethacrylate (PMMA) plates as well as Styrofoam materials. Depending on combinations, the literature suggests that these materials can simulate the attenuation and scattering characteristics of lung, heart, and mediastinum. The lung, heart, and mediastinum regions were simulated by 10 mm × 10 mm × 0.5 mm, 10 mm × 10 mm × 0.5 mm and 10 mm × 10 mm × 1 mm copper plates, respectively. A test object of 100 mm × 100 mm and 0.2 mm thick copper was positioned to each region for CNR measurements. The phantom was exposed to x-rays generated by different tube potentials that covered settings in clinical use: 110-120 kVp (HVL=4.26-4.66 mm Al) at a source image distance (SID) of 180 cm. An approach similar to the recommended method in digital mammography was applied to determine the CNR values of phantom images produced by a Kodak CR 850A system with post-processing turned off. Subjective contrast-detail studies were also carried out by using images of Leeds TOR CDR test object acquired under similar exposure conditions as during CNR measurements. For clinical kVp conditions relevant to chest radiography, the CNR was highest over 90-100 kVp range. The CNR data correlated with the results of contrast detail observations. The values of clinical tube potentials at which CNR is the highest are regarded to be optimal kVp settings. The simplicity in phantom construction can offer easy implementation of related quality control program.
Does a different choice of clones and fluorochromes affect diagnostic sensitivity? An analysis of EQA data from UKNEQAS [La scelta di differenti cloni e fluorocromi influenza la sensibilità diagnostica? Analisi di dati VEQ di UKNEQAS]
Feruglio C.,Ospedale Universitario |
Bulian P.,Onco Ematologia Clinico Sperimentale
Rivista Italiana della Medicina di Laboratorio | Year: 2010
Pathologists utilizing FACS for diagnostic pourposes in hematooncology find a wide selection of reagents which make sometimes difficult to choose between different clones and fluorochromes. In the last few years complex multiparameter analyses were made possible due to technological advancements such as the production of cheaper solid state laser sources and a wider panel of fluorochromes. Modern cytometers are able to detect at the same time many different wavelengths of fluorescent emission, and a monoclonal antibody of a given clone could be conjugated with several diverse flourochromes. Moreover, for a given CD manufacturers usually produce distinct clones that may behave in different way in vitro. This broad offer of clones and fluorochromes make possible to test with great precision several antigens at the same time, giving the chance to perform complex analysis such as the characterization of tiny cellular population in the peripheral blood and in the bone marrow. On the other hand diverse results for the same antigen analyzed in different laboratories or in the same laboratory at different times may be conditioned by the choice of the reagent. This pitfall is usually underestimated in everyday practice. With the precious collaboration of Liam Whitby from UKNEQAS we have been able to analyze data concerning 12 EQA exercises from the Leukemia Immunophenotipic Programme. In particular we examined 22 antigens, 14 diverse and 8 replicated in different EQA exercises. We calculated the percentage of laboratories reporting a positive result for a given antigen according to the British Committee for Standards in Haematology (BCSH) guidelines which set a threshold of positivity at 20 % of the cells for acute leukemias and at 30 % of the cells for chronic leukemias. With regard to fluorochromes we found a better performance of the PE conjugate for eight antigens (CD1a, CD4, CD7, CD10, CD22, CD23, CD23, CD34 and CD79B) and of the FITC conjugate for the TdT, while no differences between FITC and PE reagents were noticed for CD13, CD20, CD33 and MPO. Concerning the clones we found out that for a given CD diverse reagents show a different behaviour. In particular TdT Dako, CD20 Becton Dickinson (BD), CD1a Dako, CD4 BD, CD22 BD and CD79b Beckman Coulter (BC) showed a better performance compared to the same products from other manufacturers. These data show that reagents do not behave in the same way despite a common CD clusterization and that their use without taking into account these differences may bring to misleading diagnosis.
Navarese E.P.,Azienda Ospedaliera Ospedale Civile di Legnano |
Servi S.D.,Azienda Ospedaliera Ospedale Civile di Legnano |
Politi A.,Ospedale Meriggia Pelaschi |
Martinoni A.,Azienda Ospedaliera Ospedale Civile di Legnano |
And 7 more authors.
Journal of Thrombosis and Thrombolysis | Year: 2011
The exact relationship between primary percutaneous coronary intervention (PCI) volume and mortality remains unclear. No data are available on how this relationship could be affected by time-to-presentation. The primary aim of this study was to evaluate the impact of hospital primary PCI volume on in-hospital mortality in ST-elevation myocardial infarction (STEMI) patients depending on time-to-presentation. The impact of primary PCI volume on in-hospital mortality was investigated in a prospective registry of the Lombardy region in Northern Italy, deriving data on mortality rates and number of primary PCIs from a cohort of 2,558 patients. We also explored this relationship at different times-to-presentation (≤90 min,>90 min-180 min,>180 min) and risk profiles assessed with the TIMI Risk Index. A strong inverse relationship was found between primary PCI hospital volume and risk-adjusted mortality (r = -0.9; P<0.001). High primary PCI volumes best predicted the improvement of survival when the time-to-presentation was ≤90 min (area under the curve = 0.73, P<0.0001). At this time, the best primary PCI threshold to provide benefit was>66 primary PCIs/year (OR = 0.21 [95% CI 0.10-0.47], P<0.001) and those with high TIMI Risk Index achieved the greatest benefit (P<0.001). At>90 min-180 min, the model was less significant (P = 0.02) with a higher threshold of procedures (>145 primary PCIs/year) required to provide benefits. The model was not predictive of survival for time-to- presentation>180 min (P = 0.30). The reduction of mortality of STEMI patients treated at high-volume primary PCI centers is time-dependent and affected by risk profile. The greatest benefit was observed in high-risk patients presenting within 90 min from symptoms onset. © Springer Science+Business Media, LLC 2011.
Martinoni A.,Ospedale Fornaroli |
De Servi S.,Azienda Ospedaliera Ospedale Civile di Legnano |
Boschetti E.,Ospedale Universitario |
Zanini R.,Ospedale Carlo Poma |
And 18 more authors.
European Journal of Cardiovascular Prevention and Rehabilitation | Year: 2011
Background: The purpose of this study is to present data on the effects of pre-hospital electrocardiogram (PH-ECG) on the outcome of ST elevation myocardial infarction (STEMI) patients treated with percutaneous coronary angioplasty (PCI) included in a registry undertaken in the Italian region of Lombardy. Pre-hospital 12-lead electrocardiogram is recommended by current guidelines in order to achieve faster times to reperfusion in patients with STEMI. Methods: The registry includes 3901 STEMI patients who underwent primary PCI over an 18-month period. Results: Mean age was 63 ± 12 years. Admission through the emergency medical system (EMS) occurred in 1603 patients (40%): they were older, more frequently had previous MI, TIMI flow = 0 at entry and were more frequently in Killip class >1 than patients who were not admitted through the EMS. Among the patients admitted through the EMS, PH-ECG was obtained in 475 patients (12%). These patients had less frequently an anterior MI, but more frequently had absence of TIMI flow at entry than patients whose ECG was not teletransmitted. Moreover, they had a significantly shorter first medical contact-to-balloon time and a trend toward a lower 30-day death rate (5.3% vs 7.9 %, p = 0.06). However, only patients in Killip class 2-3 had a significantly lower mortality when the diagnostic ECG was transmitted, whereas no difference was found in Killip class 1 or Killip class 4 patients. Conclusions: In this registry, PH-ECG significantly decreased first medical contact-to-balloon time. Attempts to achieve faster reperfusion times should be undertaken, as this may result in improved outcome, particularly in patients with mild to moderate symptoms of heart failure. © The European Society of Cardiology 2011.