TIME SAVING SPATIAL RESOLUTION AND LINEARITY TEST PATTERN FOR ROUTINE GAMMA CAMERA QUALITY CONTROL TESTING

1998 ◽  
Vol 23 (1) ◽  
pp. 62
Author(s):  
Joseph W. Vilani
Keyword(s):  
Quality Control ◽  
Spatial Resolution ◽  
Gamma Camera ◽  
Test Pattern ◽  
Time Saving ◽  
Quality Control Testing ◽  
Linearity Test

F-18-FDG Positron Imaging in Oncological Patients: Gamma Camera Coincidence Detection versus Dedicated PET

1999 ◽  
Vol 38 (04) ◽  
pp. 108-114 ◽  
Author(s):  
H.-J. Kaiser ◽  
U. Cremerius ◽  
O. Sabri ◽  
M. Schreckenberger ◽  
P. Reinartz ◽  
...  
Keyword(s):  
Attenuation Correction ◽  
Spatial Resolution ◽  
Gamma Camera ◽  
Lesion Detection ◽  
Coincidence Detection ◽  
System Sensitivity ◽  
Oncological Patients ◽  
Phantom Studies ◽  
Pet System ◽  
Dedicated Pet

Summary Aim of the present study was to investigate the feasibility of 2-[fluorine-18]-fluoro-2-deoxy-D-glucose (FDG) imaging in oncological patients with a dual head gamma camera modified for coincidence detection (MCD). Methods: Phantom studies were done to determine lesion detection at various lesion-to-background ratios, system sensitivity and spatial resolution. Thirty-two patients with suspected or known malignant disease were first studied with a dedicated full-ring PET system (DPET) applying measured attenuation correction and subsequently with an MCD system without attenuation correction. MCD images were first interpreted without knowledge of the DPET findings. In a second reading, MCD and DPET were evaluated simultaneously. Results: The phantom studies revealed a comparable spatial resolution for DPET and MCD (5.9 × 6.3 × 4.2 mm vs. 5.9 × 6.5 × 6.0 mm). System sensitivity of MCD was less compared to DPET (91 cps/Bq/ml/cmF0V vs. 231 cps/ Bq/ml/cmFOv). At a lesion-to-background ratio of 4:1, DPET depicted a minimal phantom lesion of 1.0 cm in diameter, MCD a minimal lesion of 1.6 cm. With DPET, a total of 91 lesions in 27 patients were classified as malignant. MCD without knowledge of DPET results revealed increased FDG uptake in all patients with positive DPET findings. MCD detected 72 out of 91 DPET lesions (79.1 %). With knowledge of the DPET findings, 11 additional lesions were detected (+12%). MCD missed lesions in six patients with relevance for staging in two patients. All lesions with a diameter above 18 mm were detected. Conclusion: MCD FDG imaging yielded results comparable to dedicated PET in most patients. However, a considerable number of small lesions clearly detectable with DPET were not detected by MCD alone. Therefore, MCD cannot yet replace dedicated PET in all oncological FDG studies. Further technical refinement of this new method is needed to improve image quality (e.g. attenuation correction).

A revised FMEA application to the quality control management

2014 ◽  
Vol 31 (7) ◽  
pp. 788-810 ◽  
Author(s):  
Claudia Paciarotti ◽  
Giovanni Mazzuto ◽  
Davide D’Ettorre
Keyword(s):  
Quality Control ◽  
Failure Modes ◽  
Cost Effective ◽  
Weight Functions ◽  
Time Saving ◽  
Content Type ◽  
Complete Procedure ◽  
Medium Enterprise ◽  
Control Management ◽  
Critical Situations

Purpose – The purpose of this paper is to propose a cost-effective, time-saving and easy-to-use failure modes and effects analysis (FMEA) system applied on the quality control of supplied products. The traditional FMEA has been modified and adapted to fit the quality control features and requirements. The paper introduces a new and revised FMEA approach, where the “failure concept” has been modified with “defect concept.” Design/methodology/approach – The typical FMEA parameters have been modified, and a non-linear scale has been introduced to better evaluate the FMEA parameters. In addition, two weight functions have been introduced in the risk priority number (RPN) calculus in order to consider different critical situations previously ignored and the RPN is assigned to several similar products in order to reduce the problem of complexity. Findings – A complete procedure is provided in order to assist managers in deciding on the critical suppliers, the creation of homogeneous families overcome the complexity of single product code approach, in RPN definition the relative importance of factors is evaluated. Originality/value – This different approach facilitates the quality control managers acting as a structured and “friendly” decision support system: the quality control manager can easily evaluate the critical situations and simulate different scenarios of corrective actions in order to choose the best one. This FMEA technique is a dynamic tool and the performed process is an iterative one. The method has been applied in a small medium enterprise producing hydro massage bathtub, shower, spas and that commercializes bathroom furniture. The firm application has been carried out involving a cross-functional and multidisciplinary team.

Development of a simultaneous imaging system to measure the optical and gamma ray images of Ir-192 source for high-dose-rate brachytherapy

2021 ◽  
Vol 16 (12) ◽  
pp. T12005
Author(s):  
J. Nagata ◽  
S. Yamamoto ◽  
Y. Noguchi ◽  
T. Nakaya ◽  
K. Okudaira ◽  
...  
Keyword(s):  
Dose Rate ◽  
Spatial Resolution ◽  
Gamma Camera ◽  
Gamma Ray ◽  
Imaging System ◽  
High Dose Rate ◽  
High Dose ◽  
Cmos Camera ◽  
Absolute Position ◽  
The Absolute

Abstract In high-dose-rate (HDR) brachytherapy, verification of the Ir-192 source's position during treatment is needed because such a source is extremely radioactive. One of the methods used to measure the source position is based on imaging the gamma rays from the source, but the absolute position in a patient cannot be confirmed. To confirm the absolute position, it is necessary to acquire an optical image in addition to the gamma ray image at the same time as well as the same position. To simultaneously image the gamma ray and optical images, we developed an imaging system composed of a low-sensitivity, high-resolution gamma camera integrated with a CMOS camera. The gamma camera has a 1-mm-thick cerium-doped yttrium aluminum perovskite (YAIO3: YAP(Ce)) scintillator plate optically coupled to a position-sensitive photomultiplier (PSPMT), and a 0.1-mm-diameter pinhole collimator was mounted in front of the camera to improve spatial resolution and reduce sensitivity. We employed the concept of a periscope by placing two mirrors tilted at 45 degrees facing each other in front of the gamma camera to image the same field of view (FOV) for the gamma camera and the CMOS camera. The spatial resolution of the imaging system without the mirrors at 100 mm from the Ir-192 source was 3.2 mm FWHM, and the sensitivity was 0.283 cps/MBq. There was almost no performance degradation observed when the mirrors were positioned in front of the gamma camera. The developed system could measure the Ir-192 source positions in optical and gamma ray images. We conclude that the developed imaging system has the potential to measure the absolute position of an Ir-192 source in real-time clinical measurements.

Implementation of modulus-based quality control testing for pavement construction in Thailand

2017 ◽  
pp. 807-811
Author(s):  
A. Sawangsuriya ◽  
P. Jitareekul ◽  
Y. Taesiri ◽  
S. Sirisak ◽  
W. Lawanwisut
Keyword(s):  
Quality Control ◽  
Quality Control Testing ◽  
Pavement Construction

scholarly journals Quality of selected anti-retroviral medicines: Tanzania Mainland market as a case study

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Sophia Mziray ◽  
Betty A. Maganda ◽  
Kissa Mwamwitwa ◽  
Adam M. Fimbo ◽  
Seth Kisenge ◽  
...  
Keyword(s):  
Quality Control ◽  
Screening Test ◽  
Product Information ◽  
Healthcare Delivery ◽  
Antiretroviral Drugs ◽  
World Health ◽  
Fixed Dose ◽  
People Living With Hiv ◽  
Quality Control Testing

Abstract Background Antiretroviral drugs (ARVs) have significantly reduced morbidity, mortality and improved the quality of life of people living with HIV infection. Poor quality ARVs may result in harmful consequences such as adverse drug reactions, treatment failure and development of drug resistant strains and sometimes death, which in turn may undermine the healthcare delivery system. To ensure optimal treatment outcomes, medicines quality control must be undertaken regularly. This study was aimed at evaluating the quality of ARVs circulating on the Tanzania Mainland market. Methods This was a survey study. ARVs samples were collected in 20 regions of Tanzania Mainland, between 2012 and 2018. All sampled ARVs were subjected to screening testing using the Global Pharma Health Fund® Mini-Lab kits. Sampled ARV’s that failed screening test or yielded doubtful results and 10 % (10 %) of all that complied with the screening test requirements were selected for full quality control testing. Quality control testing was conducted at the Tanzania Medicines and Medical Devices Authority (TMDA) laboratory a World Health Organisation prequalified. Samples collected from the medicine distribution outlets were also, subjected to product information review. Results A total of 2,630 samples were collected, of which 83.7 % (2200/2630) were from port of entry (POEs). All sampled ARVs were screened and conformed to the specifications, except of the fixed dose combination (FDC) lopinavir/ritonavir 0.27 % (7/2630) and lamivudine/zidovudine/nevirapine 0.27 % (7/2630) that failed the disintegration test. Out of the 100 samples selected for full quality control testing, 3 % of them failed to comply with the specifications, of which FDC stavudine/lamivudine/nevirapine failed disintegration and assay tests 2 % (2/100) and 1 % (1/100), respectively. Samples failing the assay test had low content of stavudine (86.6 %) versus specification limits (90 -110 %). Out of the 430 samples which were subjected to product information review, 25.6 % (110/430) failed to comply with the TMDA packaging and labelling requirements. Conclusions The quality of majority of ARVs circulating on the Tanzania Mainland market was good, even so, significant deficiencies on labelling and packaging were observed. These results call for continuous monitoring of quality of medicines circulating on the Tanzania Mainland market.

scholarly journals STEAD: A high-resolution daily gridded temperature dataset for Spain

2019 ◽  
Author(s):  
Roberto Serrano-Notivoli ◽  
Santiago Beguería ◽  
Martín De Luis
Keyword(s):  
Quality Control ◽  
Spatial Resolution ◽  
Minimum Temperature ◽  
Grid Point ◽  
Temporal Distribution ◽  
Original Data ◽  
Accurate Estimate ◽  
Absolute Temperature ◽  
Data Series ◽  
Absolute Maximum

Abstract. Using the full total of available 5520 observatories covering the whole territory of Spain, a daily gridded maximum and minimum temperature was built covering a period from 1901 to 2014 in peninsular Spain and 1971–2014 in Balearic and Canary Islands. A comprehensive quality control was applied to the original data and the gaps were filled on each day and location independently. Using the filled data series, a grid of 5 × 5 km spatial resolution was created by estimating daily temperatures and their corresponding uncertainties at each grid point. Four daily temperature indices were calculated to describe the spatial distribution of absolute maximum and minimum temperature, number of frost days and number of summer days in Spain. The southern plateau showed the maximum values of maximum absolute temperature and summer days, while the minimum absolute temperature and frost days reached their maximums at northern plateau. The use of all the available information, the complete quality control and the high spatial resolution of the grid allowed for an accurate estimate of temperature that represents a precise spatial and temporal distribution of daily temperatures in Spain. STEAD dataset is publicly available at http://dx.doi.org/10.20350/digitalCSIC/8622.

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