Evaluation of equipment performance, patient dose, imaging quality, and diagnostic coincidence in five Mexico City mammography services

Clinical image quality assessment and mean glandular dose for full field digital mammography

This study aims to assess the image quality (IQ) of 12 mammographic units and to identify units with potential optimisation needs. Data for 350 mammography examinations meeting inclusion criteria were collected retrospectively from April 2021 to April 2022. They were categorised based on the medical reports into 10 normal cases, 10 cases displaying calcifications and 10 cases presenting lesions. Two radiologists assessed the IQ of 1400 mammograms, evaluating system performance per Boitaet al's study and positioning performance following European guidelines. To measure agreement between the two radiologists, the Cohen's Kappa coefficient (κ) was computed, quantifying the excess of agreement beyond chance. The visual grading analysis score (VGAS) was computed to compare system and positioning performance assessments across different categories and facilities. Median average glandular dose (AGD) values for cranio caudal and medio lateral oblique views were calculated for each category and facility and compared to the national diagnostic reference levels. The health facilities were categorised by considering both IQ VGAS and AGD levels. Inter-rater agreement between radiologists ranged from poor (κ< 0.20) to moderate (0.41 <κ< 0.60), likely influenced by inherent biases and distinct IQ expectations. 50% of the facilities were classified as needing corrective actions for their system performance as they had IQ or high AGD that could increase recall rate and radiation risk and 50% of the health facilities exhibited insufficient positioning performance that could mask tumour masses and microcalcifications. The study's findings emphasise the importance of implementing quality assurance programs to ensure optimal IQ for accurate diagnoses while adhering to radiation exposure guidelines. Additionally, comprehensive training for technologists is essential to address positioning challenges. These initiatives collectively aim to enhance the overall quality of breast imaging services, contributing to improved patient care.

Mammographic image reject rate analysis and cause - A National Maltese Study

Mammography is used as a first-line investigation in the detection of breast cancer and imaging is required to be of optimal quality and achieved without adverse effects on the health of individuals. Repeated images come at a cost in terms of radiation dose, discomfort to clients and unnecessary financial burdens. No studies investigating mammography quality in Malta had been previously undertaken. Hence, this research aimed to investigate whether mammography is being performed at an acceptable level, through the investigation of reject rates. Quantitative methodology was used to collect data from eight participating mammography units, which were utilising screen film (SFM), computed radiography (CR) and direct digital mammography (DDM). Data relating to the total number of images performed, rejects and causes was prospectively collected over two weeks, resulting in a sample of 2291 images. All units were also asked to answer a questionnaire which provided other data that could be used for analysis. The national mammography reject rate was found to be 2.62%; within the 3% acceptable range. Individual rates' analysis revealed unacceptably high or low reject rates in some units. Positioning was the main reject cause. No significant difference in rejection was found between different types of mammography units or radiographers' experience. Alternatively, radiographers' qualifications, employment conditions and use of rejection criteria were proven to affect reject rates. Whilst on a national level, images are being rejected at an acceptable rate, individual units revealed suboptimal rates; at the cost of extra radiation, added discomfort and financial burden.

Relationship between the use of new or used computed tomography scanners and image retake rates in South Korea

BACKGROUND

The use of high-cost imaging has increased worldwide, contributing to increased healthcare expenditures. Without proper quality verification, the installation of used imaging equipment may lead to wasteful increases in cost due to ineffective and poor-quality imaging that requires repeat scans.

PURPOSE

To examine the relationship between the use of new or used computed tomography (CT) scanners and image retake rates to evaluate the comparative quality of used and new CT scanners.

MATERIAL AND METHODS

This was a retrospective cohort study of patients who first underwent CT from January 1 to June 30, 2008 (n = 258,572). Data were obtained by linking the Health Care Institution Registration Data with the Korean National Health Insurance Claims Database. Image retake rates within 30, 60, 90, and 180 days after the first CT scan were calculated, and differences in the image retake rate by new versus used CT scanners were assessed.

RESULTS

After adjusting for confounders, use of a used CT scanner for the first scan increased the odds of retake within 30 days (odds ratio [OR]: 1.34, 95% confidence interval [CI]: 1.22-1.48), 60 days (OR: 1.59, 95% CI: 1.47-1.72), 90 days (OR: 1.48, 95% CI: 1.38-1.59), and 180 days (OR: 1.38, 95% CI: 1.30-1.46) compared with use of a new CT scanner. Such results were evident in scans of the spine, abdomen, chest, and face or skull base.

CONCLUSION

The quality control associated with import of used CT scanners should be improved. Moreover, regular and detailed quality inspections of used CT scanners currently operating in healthcare institutions are necessary.

[Radio diagnostic risks control: an approach of sanitary surveillance]

The X-ray diagnostic is one of the main diagnosis tools in medicine and its role, in public health, depends on the quality of the exams, the regulatory responsibility fits, mainly, in the National System of Sanitary Surveillance. With this perspective, it was developed a mathematical evaluation model of potential risks in radiodiagnostic and, through its use in the Brazilian health services of Bahia state, with the analysis of the situation found and its determinants. With that model, 94 procedures were evaluated in 38 Bahia state radiodiagnostic services. The study showed that 5.3% of the services had all of the procedures in level of acceptable potential risk. 23.7% showed, at least, one procedure with level of tolerable potential risk and 71% showed, at least, one procedure with a level of unacceptable potential risk. The analyses shows that the main determinants of the encountered situation are the deficient inspection by the sanitary surveillance system of the health services and of the industrial sector, the absence of basics of radiological protection in the curriculum of medicine courses and the fragility of practices control, by the respective professional council.

Evaluation of the entrance surface air kerma in mammographic examinations in Rio de Janeiro, Brazil

The aim of this work was to evaluate the distribution of the entrance surface air kerma (ESAK) and the average glandular dose (D(G)) in four mammography facilities located in the city of Rio de Janeiro. The ESAK values were estimated from the X-ray tube output rate (mGy/mAs) parameters. The image quality was evaluated by the radiologists in each clinic. The ESAK values obtained for a breast thickness of 45 mm were 5.58 mGy in Clinic A, 10.07 mGy in Clinic B, 13.89 mGy in Clinic C and 7.21 mGy in Clinic D. For D(G), it can be seen that, for the same compressed breast thickness (50 mm), the value varied from 0.20 to 3.60 mGy, with a mean value of 1.50 mGy for all the clinics. In image quality evaluation, Clinic D was the only one that presented a very low acceptability for quality criteria and inadequacies in relation to specks, masses and optical density.

How to implement grid technology in tissue-based diagnosis: diagnostic surgical pathology

BACKGROUND

Tissue-based diagnosis or diagnostic surgical pathology is a highly accurate, sensitive and specific medical diagnostic technique that has expanded rapidly in using both molecular biology and computer technology.

OBJECTIVE

The objective is to analyze the present stage and potential influence of distributed data acquisition, analysis and presentation in tissue-based diagnosis by using recently developed standardized network systems such as grids.

METHODS

Interpretation of medical data is often based upon specialized examination, visual information acquisition and transfer as well as upon data collected from various sources. Efficient and accurate diagnostics require standardized data and transfer modes, which can be provided by a grid environment. The medical requirements, construction of an adequate grid environment, practical experiences in various medical disciplines and potential use in tissue-based diagnosis are described.

CONCLUSIONS

Grid technology is probably a useful tool to meet the conditions of tissue-based diagnosis in the near future, and will probably play a significant role in its further development.

Grid technology in tissue-based diagnosis: fundamentals and potential developments

Tissue-based diagnosis still remains the most reliable and specific diagnostic medical procedure. It is involved in all technological developments in medicine and biology and incorporates tools of quite different applications. These range from molecular genetics to image acquisition and recognition algorithms (for image analysis), or from tissue culture to electronic communication services. Grid technology seems to possess all features to efficiently target specific constellations of an individual patient in order to obtain a detailed and accurate diagnosis in providing all relevant information and references. Grid technology can be briefly explained by so-called nodes that are linked together and share certain communication rules in using open standards. The number of nodes can vary as well as their functionality, depending on the needs of a specific user at a given point in time. In the beginning of grid technology, the nodes were used as supercomputers in combining and enhancing the computation power. At present, at least five different Grid functions can be distinguished, that comprise 1) computation services, 2) data services, 3) application services, 4) information services, and 5) knowledge services. The general structures and functions of a Grid are described, and their potential implementation into virtual tissue-based diagnosis is analyzed. As a result Grid technology offers a new dimension to access distributed information and knowledge and to improving the quality in tissue-based diagnosis and therefore improving the medical quality.

Evaluation of dual-energy subtraction of digital mammography images under conditions found in a commercial unit

Radiological contrast-to-noise ratio (CNR) is evaluated in subtracted images of microcalcifications in breast tissue. CNR is calculated for dual-kVp subtraction combining beams available in a Senographe 2000D, assuming single breast compression. Spectra were obtained from Boone et al (1997 Med. Phys. 24 1863-73), and the study was limited to lowest 25 kV Mo/Mo and highest 40 kV Rh/Rh beams, for 2.58 x 10(-4) C kg(-1) (1R) total exposure. For a standard case combining 25 kVp Mo/Mo and 40 kVp Rh/Rh beams, predicted maximum CNR for 300 microm calcification in 5 cm thick, 50% glandular, breast is about 1.2, below Rose's criterion for visualization. Total mean glandular doses are about 2.5 cGy for a standard case. The effect that input factors might have on predictions has been evaluated. Choice between alternative spectra can affect CNR by 50%. Assumed calcification composition leads to differences of 67% in calculated CNR, and assumed breast tissue composition can alter CNR by 45%; these results are weakly dependent on calcification or breast thickness, or on the assumed fraction of glandular tissue. CNR values are related to detected spectra effective energy. Calculations predict that above 37 kVp Mo/Mo beams are more energetic than Rh/Rh at the same kVp, due to beam hardening.