National survey to update the diagnostic reference levels in interventional radiology procedures in Italy: working methodology

Interventional Radiology (IR) deals with the diagnosis and treatment of various diseases through medically guided imaging. It provides unquestionable benefits to patients, but requires, in many cases, the use of high doses of ionizing radiation with a high impact on radiation risks to patients and to overall dose to the population. The International Commission on Radiological Protection introduced Diagnostic reference levels (DRLs) as an effective tool to facilitate dose verification and optimize protection for patients undergoing radiological procedures. In addition, EURATOM Council Directive 2013/59 and its Italian transposition (Legislative Decree 101/2020) have reiterated that DRLs must be established for many common radiological diagnostic procedures to compare the radiation dose delivered for the same diagnostic examination. Within this framework, Istituto Superiore di Sanità-Italian National Institute of Health (ISS)-, in collaboration with relevant Italian Scientific Societies, has provided documents on DRLs in radiological practices such as diagnostic and IR and diagnostic nuclear medicine. These reference documents enable National Hospitals to comply national regulation. The implementation of DRLs in IR is a difficult task because of the wide distribution of doses to patients even within the same procedure. Some studies have revealed that the amount of radiation in IR procedures is influenced more by the complexity of the procedure than by the weight of the patient, so complexity should be included in the definition of DRLs. For this reason, ISS promoted a survey among a sample of Italian Centers update national DRL in IR procedures with related complexity factors than can be useful for other radiological centers and to standardize the DRLs values. In the present paper the procedural methodology developed by ISS and used for the survey will be illustrated.

Psychological health of mothers and siblings of children with autism spectrum disorders during COVID-19 pandemic: new evidence in Italian families

BACKGROUND AND AIM

Psychological challenges are well recognized in families with a child with Autism Spectrum Disorders (ASD). Instead, less is known about the effects of traumatic scenarios, such as COVID-19, on the psychological health of these families. The main aim of this research was to study the psychological health of both mothers and typically developing (TD) siblings of children with ASD during the COVID-19 pandemic. Second, we investigated the relationship between the mothers' psychological resources and their children psychological well-being.

METHODS

The sample included 52 mothers and their children: 15 with one child with ASD and at least one TD child (aged 4-14) (ASD-siblings group) and 37 with one or more TD child (aged 4-14) (TD control group). The data were collected through an online platform; four standardized questionnaires (GAD-7, BDI-II, CD-RISC 25 and CBCL) were administered.

RESULTS

The analyses revealed more internalizing and total behavioral symptoms in the siblings of children with ASD, compared to TD control group. Regarding the mothers, we did not find differences in depression and anxious symptoms between the two groups. However, the results reported a lower level of resilience in the mothers of children with ASD relative to mothers of TD children. Finally, the psychological well-being of the TD children was associated with the level of mothers' anxiety only in the ASD-siblings group.

CONCLUSIONS

Overall, our data show that the COVID-19 outbreak may had been particularly challenging for families of children with ASD, and highlight the importance of intensifying psychological support to families.

The Moderator Effect of Subthreshold Autistic Traits on the Relationship between Quality of Life and Internet Addiction

People with sub-threshold autistic traits (SATs) are more prone to develop addictive behaviors such the ones linked to Internet abuse. The restrictions for anti-COVID-19 distancing measures encourage social isolation and, consequently, increase screen time, which may lead to Internet addiction (IA). However, a better quality of life (QoL) may have function as a protective factor against the development of IA. This study wanted to investigate the relation between SATs, QoL, and the overuse of the Internet in a group of 141 university students in the North of Italy. Participants completed a battery of tests. Results suggest that QoL is a predictive factor of IA and that the relationship between QoL and IA is significantly moderated by SATs. This could mean that SATs might represent a risk factor for IA, even when people have a better quality of life. Differences between female and male students are discussed, as well as possible implications for practice.

Are British urban foxes (Vulpes vulpes) "bold"? The importance of understanding human-wildlife interactions in urban areas

Human-wildlife interactions are believed to be increasing in urban areas. In Britain, numerous media reports have stated that urban foxes (Vulpes vulpes) are becoming "bolder," thereby posing a risk to public safety. However, such claims overlook how an individual's personality might influence urban fox behavior. Personality determines multiple aspects of an animal's interactions with both conspecifics and its environment, and can have a significant impact on how people perceive wildlife. Furthermore, describing urban foxes as "bold" confounds two different but inter-related behaviors, both of which influence an animal's propensity to take risks. Neophobia affects an animal's reaction to novelty, wariness its reaction to potential threats. Since urban wildlife frequently encounters both novel and threatening stimuli, a highly adaptable species such as the red fox might be predicted to exhibit reduced neophobia and wariness. We investigated how social status influenced both behaviors in Bristol's fox population. Dominant foxes were significantly more neophobic and warier than subordinates, which adopt a more exploratory and risk-taking lifestyle to meet their energetic and other needs. We found no seasonal effect on neophobia and wariness, although this may be due to sample size. The presence of conspecifics decreased neophobia for dominants, and wariness for both dominants and subordinates. We highlight the importance of considering animal social status and personality when planning management protocols, since interventions that destabilize fox social groups are likely to increase the number of subordinate foxes in the population, thereby increasing rather than decreasing the number of interactions between humans and urban foxes.

ICRP Publication 135: Diagnostic Reference Levels in Medical Imaging

Abstract –

The International Commission on Radiological Protection (ICRP) first introduced the term ‘diagnostic reference level’ (DRL) in 1996 in Publication 73. The concept was subsequently developed further, and practical guidance was provided in 2001. The DRL has been proven to be an effective tool that aids in optimisation of protection in the medical exposure of patients for diagnostic and interventional procedures. However, with time, it has become evident that additional advice is needed. There are issues related to definitions of the terms used in previous guidance, determination of the values for DRLs, the appropriate interval for re-evaluating and updating these values, appropriate use of DRLs in clinical practice, methods for practical application of DRLs, and application of the DRL concept to newer imaging technologies. This publication is intended as a further source of information and guidance on these issues. Some terminology has been clarified. In addition, this publication recommends quantities for use as DRLs for various imaging modalities, and provides information on the use of DRLs for interventional procedures and in paediatric imaging. It suggests modifications in the conduct of DRL surveys that take advantage of automated reporting of radiation-dose-related quantities, and highlights the importance of including information on DRLs in training programmes for healthcare workers. The target audience for this publication is national, regional, and local authorities; professional societies; and facilities that use ionising radiation for medical purposes, and responsible staff within these facilities. A full set of the Commission’s recommendations is provided.

EUTEMPE-RX, an EC supported FP7 project for the training and education of medical physics experts in radiology

The core activity of the medical physics expert (MPE) is to ensure optimal use of ionising radiation in healthcare. It is essential that these healthcare professionals are trained to the highest level, defined as European Qualifications Framework for Lifelong Learning (EQF) level 8 by the European Commission's Radiation Protection Report 174 'Guidelines on the MPE'. The main objective of the EUTEMPE-RX project is to provide a model training scheme that allows the medical physicist in diagnostic and interventional radiology (D&IR) to reach this high level. A European network of partners was brought together in this FP7 EC project to ensure sufficient expertise in all aspects of the subject and to create a harmonised course programme. Targeted participants are medical physicists in D&IR in hospitals, engineers and scientists in medical device industries and officers working in regulatory authorities. Twelve course modules will be developed at EQF level 8, with radiation safety and diagnostic effectiveness being prevalent subjects. The modules will combine online with face-to-face teaching using a blended learning approach.

Radiation doses in cerebral perfusion computed tomography: patient and phantom study

The purpose of this study was to investigate radiation doses in cerebral perfusion computed tomography (CT) examination. As a part of routine patient monitoring, data were collected on patients in terms of the skin dose and CT dose index (CTDIvol) and dose-length product (DLP) values. For the estimation of the dose to the lens a phantom study was performed. Dose values for skin and lens were below the threshold for deterministic effects. The results were also compared with already published data. For better comparison, the effective dose was also estimated. The values collected on patients were in the ranges 230-680 mGy for CTDI and 2120-2740 mGy cm for DLP, while the skin dose and estimated effective dose were 340-800 mGy and 4.9-6.3 mSv, respectively. These values measured in the phantom study were similar, while the doses estimated to the lens were 53 and 51 mGy for the right and left lens, respectively.

[The neuropsychology of prodromal schizophrenia. Brief review and proposal of a tests battery for clinical use]

The study of the neuropsychological profile of schizophrenic patients has provided systematic results in linking specific deficit (working memory, verbal learning, attentive and executive functioning, social cognition) to the functional outcome of subjects. More recently this approach has been applied to younger subjects, from the age of 14, that show prodromal signs of a possible psychotic conversion (ultra-risk subjects). The review is at first intended to describe the clinical and experimental studies that investigated the cognitive and neuropsychological profile of subjects at ultra-risk for psychosis. These studies show the presence of minor cognitive difficulties in several specific areas (working memory, verbal learning, attentive and executive functioning) that can be indicative of both a possible conversion to psychosis and a need for cognitive remediation programs. Secondarily, the article describes several neuropsychological tools, standardized for the Italian population, that can be used to approach the clinical assessment of ultra-risk subjects considering some critical aspects such as their typical age range (adolescents and young adults).

ICRP PUBLICATION 120: Radiological protection in cardiology

Cardiac nuclear medicine, cardiac computed tomography (CT), interventional cardiology procedures, and electrophysiology procedures are increasing in number and account for an important share of patient radiation exposure in medicine. Complex percutaneous coronary interventions and cardiac electrophysiology procedures are associated with high radiation doses. These procedures can result in patient skin doses that are high enough to cause radiation injury and an increased risk of cancer. Treatment of congenital heart disease in children is of particular concern. Additionally, staff(1) in cardiac catheterisation laboratories may receive high doses of radiation if radiological protection tools are not used properly. The Commission provided recommendations for radiological protection during fluoroscopically guided interventions in Publication 85, for radiological protection in CT in Publications 87 and 102, and for training in radiological protection in Publication 113 (ICRP, 2000b,c, 2007a, 2009). This report is focused specifically on cardiology, and brings together information relevant to cardiology from the Commission's published documents. There is emphasis on those imaging procedures and interventions specific to cardiology. The material and recommendations in the current document have been updated to reflect the most recent recommendations of the Commission. This report provides guidance to assist the cardiologist with justification procedures and optimisation of protection in cardiac CT studies, cardiac nuclear medicine studies, and fluoroscopically guided cardiac interventions. It includes discussions of the biological effects of radiation, principles of radiological protection, protection of staff during fluoroscopically guided interventions, radiological protection training, and establishment of a quality assurance programme for cardiac imaging and intervention. As tissue injury, principally skin injury, is a risk for fluoroscopically guided interventions, particular attention is devoted to clinical examples of radiation-related skin injuries from cardiac interventions, methods to reduce patient radiation dose, training recommendations, and quality assurance programmes for interventional fluoroscopy.

SU-E-J-130: Study of the Image Quality Degradation in Phase-Based 4DCT Imaging for Radiation Oncology

PURPOSE

Four-dimensional computed tomography (4DCT) integrated into radiation imaging system is a useful tool for accurate targeting. 4DCT has the ability to minimize breathing related artefacts compared to conventional CT but irregular breathing and large tumour motion may cause inappropriate reconstruction. Our aim is to estimate the image quality degradation of 4DCT and to assess the clinical consequences.

METHODS

The performance of the respiratory gating system of the multi-slice CT-simulator Brilliance Big Bore was evaluated employing one-dimensional moving phantom. The binning algorithm was phased-based. 4DCT scans of the test-phantom were acquired applying periodic motion patterns characterized by amplitude and frequency spanning a clinically range and also irregular waveforms simulating realistic breathing cycles. The internal spherical objects of the moving phantom were contoured using semiautomatic segmentation for evaluating uncertainties in volume delineation and motion amplitude calculation. Motion amplitude was determined by a specially written MATLAB program. Afterwards we investigated the influence of the image distortions on the targeting and the consequences of the related uncertainties on the calculated dose distribution of the tumour and the lungs in a group of five lung-cancer patients.

RESULTS

The results obtained with the phantom show that 4DCT imaging is still affected by distortions due to residual motion. The inaccuracies are mainly related to the amplitude (R2=0.99, R2=0.97 for 20 mm-dia sphere and 10 mm-dia sphere, respectively) and to the oscillation frequency (R2=0.87 for 20 mm-dia sphere, R2=0.96 for 10 mm-dia sphere) of simulated respiratory cycle and can cause both underestimation and overestimation of the real tumour motion amplitude with an average difference between real and calculated amplitude of about 10%.

CONCLUSIONS

The resulting inaccuracies on the internal tumour volume delineated do not have significant clinical consequences on lung doses but they could be important on tumour dose distribution if they imply underestimation of the real tumour motion.

Insight into illness, neurocognition and quality of life in schizophrenia

OBJECTIVE

The aim of this study was to assess the impact of insight into illness on self-reported quality of life (QoL) for patients with schizophrenia.

METHODS

This cross-sectional study was conducted in the psychiatric department of a French public university teaching hospital. The data collected included socio-demographic information, clinical characteristics, medications, cognitive performance assessments, insight into illness, and the S-QoL 18. A multivariate analysis using multiple linear regressions was performed to determine variables potentially associated with QoL levels.

RESULTS

One hundred and thirteen outpatients with stable schizophrenia were enrolled in our study. Significant associations were found between QoL and socio-demographic characteristics: a higher QoL was associated with marital status (in couple) and employment. Concerning insight into illness, lower QoL levels were associated with better awareness of the mental disorder, whereas higher QoL levels were associated with better awareness of positive and negative symptoms. Elementary neuropsychological measures were not statistically associated with QoL.

CONCLUSION

Insight into illness, marital status and employment were the most important features associated with QoL, whereas there was no evidence that elementary neurocognition directly influenced QoL. The different facets of insight into illness should be considered to guide the development of specific interventions intended to improve QoL. Moreover, this study highlights the need for clinicians to pay more attention to the personal impact of schizophrenia, especially upon family life and work.

International project on individual monitoring and radiation exposure levels in interventional cardiology

Within the Information System on Occupational Exposure in Medicine, Industry and Research (ISEMIR), a new International Atomic Energy Agency initiative, a Working Group on interventional cardiology, aims to assess staff radiation protection (RP) levels and to propose an international database of occupational exposures. A survey of regulatory bodies (RBs) has provided information at the country level on RP practice in interventional cardiology (IC). Concerning requirements for wearing personal dosemeters, only 57 % of the RB specifies the number and position of dosemeters for staff monitoring. Less than 40 % of the RBs could provide occupational doses. Reported annual median effective dose values (often <0.5 mSv) were lower than expected considering validated data from facility-specific studies, indicating that compliance with continuous individual monitoring is often not achieved in IC. A true assessment of annual personnel doses in IC will never be realised unless a knowledge of monitoring compliance is incorporated into the analysis.

Prevalence of non-alcoholic fatty liver disease and its association with cardiovascular disease in patients with type 1 diabetes

BACKGROUND & AIMS

To estimate the prevalence of non-alcoholic fatty liver disease (NAFLD) in type 1 diabetic individuals, and to evaluate whether NAFLD is associated with increased prevalence of cardiovascular disease (CVD).

METHODS

All patients with diagnosed type 1 diabetes with available liver ultrasound data (n=250), who regularly attended our diabetes clinic, were enrolled. Main study measures were detection of NAFLD (by patient history and liver ultrasound) and asymptomatic/symptomatic CVD (by patient history, chart review, electrocardiogram, and echo-Doppler scanning of carotid and lower limb arteries).

RESULTS

The prevalence of NAFLD was 44.4%, and NAFLD was the most common cause (69.8%) of hepatic steatosis on ultrasound examination. Patients with NAFLD had a remarkably higher (p<0.001) age- and sex-adjusted prevalence of coronary (10.8% vs. 1.1%), cerebrovascular (37.3% vs. 5.5%) and peripheral (24.5% vs. 2.5%) vascular disease than their counterparts without NAFLD. In logistic regression analysis, NAFLD was associated with prevalent CVD (as composite endpoint), independently of age, sex, diabetes duration, hemoglobin A(1c), smoking history, systolic blood pressure, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglycerides, and medication use (adjusted odds ratio 7.36, 95% confidence intervals 1.60-34.3, p<0.01).

CONCLUSIONS

Our findings suggest that NAFLD is very common in type 1 diabetic subjects and is associated, independently of several confounding factors, with a higher prevalence of CVD. Future prospective studies are needed to evaluate whether NAFLD predicts incident CVD events in type 1 diabetes.

Hourglass cystic schwannoma of the trochlear nerve

Cranial nerves' schwannomas most commonly arise from the vestibular nerve. Involvement of other cranial nerves, in absence of neurofibromatosis, is extremely rare. A case of a pathology proven trochlear nerve schwannoma, with internal cystic components, in a patient with isolated right superior oblique muscle palsy, is described. Only 67 cases of such entity have been previously reported in the literature.

Count-rate analysis from clinical scans in PET with LSO detectors

The purpose of optimising the acquisition parameters in positron emission tomography is to improve the quality of the diagnostic images. Optimisation can be done by maximising the noise equivalent count rate (NECR) that in turn depends on the coincidence rate. For each bed position the scanner records coincidences and singles rates. For each patient, the true, random and scattered coincidences as functions of the single count rate(s) are determined by fitting the NEMA (National Electrical Manufacturers Association) 70 cm phantom count rate curves to measured clinical points. This enables analytical calculation of the personalised PNECR [pseudo NECR(s)] curve, linked to the NECR curve. For central bed positions, missing activity of approximately 70% is estimated to get maximum PNECR (PNECR(max)), but the improvement in terms of signal-toz-noise ratio would be approximately 15%. The correlation between patient weight and PNECR(max) is also estimated to determine the optimal scan duration of a single bed position as a function of patient weight at the same PNEC. Normalising the counts at PNECR(max) for the 70 kg patient, the bed duration for a 90 kg patient should be 230 s, which is approximately 30% longer. Although the analysis indicates that the fast scanner electronics allow using higher administered activities, this would involve poor improvement in terms of NECR. Instead, attending to higher bed duration for heavier patients may be more useful.

An international calibration of Kerma-Area Product meters for patient dose optimisation study

The results of international calibration of Kerma Area Product (KAP) meters for European SENTINEL survey on patient dose optimisation of cardiac and interventional radiology practice are presented. Twelve countries were involved in the study. An investigation was conduced on 25 KAP meters fitted to undercouch X-ray tubes; 13 KAP meters were installed on cardiac units and the remaining 12 on interventional ones. The simplified calibration method has been applied, consisting of KAP estimation by multiplying the air kerma at the centre of the X-ray field by the irradiated area. The obtained values of calibration factors range from 0.4 to 0.9 and from 0.4 to 0.8 for KAP meters installed on cardiac and interventional units, respectively. They account also for table and mattress attenuation. For air kerma assessment, measurements with thermoluminescent dosemeters have been applied and when possible compared against an additional reference dosemeter. As the result of the investigation, the importance of calibration of KAP meters in clinical conditions that include mattress and table attenuation has been recognised.

The SENTINEL project

Health-care expenditure on radiological equipment in Europe is a growing fraction of the gross domestic product for all member states. This increase in expenditure has been driven by technical developments in equipment design, matched by the introduction of novel clinical practices, examinations and procedures. The radiation protection implications of these developments have to be assessed. The SENTINEL co-ordination action covered radiation protection, safety and related issues that arise from these technical and clinical developments. SENTINEL covered 90% of patient examinations in European Radiology, 60% of the collective dose from medical sources and approximately 50% of the collective dose to European citizens from man-made sources. The SENTINEL co-ordination actions 'main' objective was to address the safety and efficacy issues which are common to all digital diagnostic imaging systems, including nuclear medicine. High-dose procedures and sensitive groups (such as children) were covered by the project. Specifically, the co-ordination action aimed: (1) to establish both physical and clinical image quality criteria and link the two, (2) to undertake a series of dosimetry studies to establish the reference levels for new procedures and (3) to develop good practice guidelines for radiation protection in digital imaging and produce training material.

Survey on performance assessment of cardiac angiography systems

Advances in imaging technology have facilitated the development of increasingly complex interventional cardiac equipment. Consequently, there is a need for definitive equipment requirements. The aim of the study is to assess the performances of different cardiac angiographic systems. A questionnaire was sent to centres participating in SENTINEL Project to collect dosimetry data (typical entrance dose rate in fluoroscopy and imaging mode), image quality evaluations (low and high contrast resolutions) and KAP calibration factors. Results from this survey could contribute to the explanation of patient dose variability in angiographic cardiac procedures and to derive reference levels for cardiac angiographic equipment performance parameters.

Reference levels at European level for cardiac interventional procedures

In interventional cardiology, a wide variation in patient dose for the same type of procedure has been recognised by different studies. Variation is almost due to procedure complexity, equipment performance, procedure protocol and operator skill. The SENTINEL consortium has performed a survey in nine european centres collecting information on near 2000 procedures, and a new set of reference levels (RLs) for coronary angiography and angioplasty and diagnostic electrophysiology has been assessed for air kerma-area product: 45, 85 and 35 Gy cm2, effective dose: 8, 15 and 6 mSv, cumulative dose at interventional reference point: 650 and 1500 mGy, fluoroscopy time: 6.5, 15.5 and 21 min and cine frames: 700 and 1000 images, respectively. Because equipment performance and set-up are the factors contributing to patient dose variability, entrance surface air kerma for fluoroscopy, 13 mGy min(-1), and image acquisition, 0.10 mGy per frame, have also been proposed in the set of RLs.

Proposal for a patient database on cardiac interventional exposures for epidemiological studies

Relatively high organ doses absorbed by patients in interventional cardiology suggest the opportunity to define these patients as a cohort to be followed forward in time in an epidemiological study of the cancer risks associated with exposure to low-dose ionising radiation. In this paper, the UNSCEAR 2000 Report risk estimates for the most exposed organs/tissues in cardiac interventional procedures are reviewed, as well as the critical features of such an epidemiological study that is anticipated to have an intrinsically low statistical power because of the low levels of risk and possible confounding factors. To overcome these limitations, data collected in different institutions can be combined provided that a common design and conduct are used for dose assessment. A minimum dataset to be collected on a patient basis is proposed that can be implemented routinely in most facilities. This data should be linked to the local patient information system in order to retrieve all the exposures of a given patient.

Staff dosimetry in interventional cardiology: survey on methods and level of exposure

In interventional cardiac procedures, staff operates near the patient in a non-uniformly scattered radiation field. Consequently, workers may receive, over a period, relatively high radiation doses. The measurement of individual doses to personnel becomes critical due to the use of protective devices and, as a consequence of the large number of methods proposed to assess the effective dose, great variability in monitoring programmes is expected among European countries. SENTINEL consortium has conducted a survey on staff dosimetry methods and on the level of staff exposure in 12 European cardiac centres demonstrating the urgent need to harmonise dosimetry methods. From the dosimetry survey, constraint annual effective dose of 1.4 mSv and Hp(0.07) over the protective apron of 14 mSv are proposed for the optimisation the exposure the most-exposed operator.

Patient dose in interventional radiology: a European survey

Patient doses for a few common fluoroscopy-guided procedures in interventional radiology (IR) (excluding cardiology) were collected from a few radiological departments in 13 European countries. The major aim was to evaluate patient doses for the basis of the reference levels. In total, data for 20 procedures for about 1300 patients were collected. There were many-fold variations in the number of IR equipment and procedures per population, in the entrance dose rates, and in the patient dose data (total dose area product or DAP, fluoroscopy time and number of frames). There was no clear correlation between the total DAP and entrance dose rate, or between the total DAP and fluoroscopy time, indicating that a number of parameters affect the differences. Because of the limited number of patients, preliminary reference levels were proposed only for a few procedures. There is a need to improve the optimisation of IR procedures and their definitions and grouping, in order to account for their different complexities.

Application of European protocol in the evaluation of contrast-to-noise ratio and mean glandular dose for two digital mammography systems

The performance of two digital mammography systems, Agfa CR75 and CRMM3 computed radiography (CR) and IMS Giotto MD direct digital radiography (DR), was assessed by applying a method recommended in the European protocol for quality control in mammography screening. The contrast-to-noise ratio (CNR) and mean glandular dose (MGD) values were measured and contrast detail (CD) analysis was performed. The CNRs for system CR were 21.9, 12.9, 9.5, 8.8, 7.4, 5.5 and 4.4 for 2, 3, 4, 4.5, 5, 6 and 7-cm polymenthylmethacrylate (PMMA) thickness, respectively. The respective CNRs for system DR were 10.4, 8.8, 6.3, 7.3, 7.2, 6.4 and 6.54. For the same phantom thickness sequence, the MGDs were 0.7, 1.1, 1.3, 1.6, 1.9, 2.5 and 3.4 mGy for system CR, whereas they were 0.7, 1.2, 1.1, 1.3, 1.8, 3.5 and 3.9 mGy for system DR. The CNR and MGD results satisfactorily correlate with CD analysis results. The MGD values compare well with the values recommended in the European protocol. Despite being simple, CNR and MGD can provide an effective system for performance assessment and constancy checks for related optimisations.

Quality criteria for cardiac images: an update

The DIMOND II and III Cardiology Groups have agreed on quality criteria for cardiac images and developed a scoring system, to provide a tool to test quality of coronary angiograms, which was demonstrated to be of value in clinical practice. In the last years, digital flat panel technology has been introduced in cardiac angiographic systems and the radiological technique may have been influenced by the better performance of these new detectors. This advance in digital imaging, together with the lesson learned from previous studies, warranted the revision of the quality criteria for cardiac angiographic images as formerly defined. DIMOND criteria were reassessed to allow a simpler evaluation of angiograms. Clinical criteria were simplified and separated from technical criteria. Furthermore, the characteristics of an optimised angiographic technique have been outlined.

Commissioning and constancy protocols for digital angiographic units

During the European Concerted Action SENTINEL 'Safety and Efficacy for New Techniques and Imaging using New Equipment to Support European Legislation', protocols for commissioning and constancy tests for dynamic digital flat detectors angiography units have been developed in order to harmonise practice among the European counties. The commissioning protocol includes measurements on X-ray tube and generator, patient and detector radiation dose and image quality. The constancy protocol is based on the dose and image quality measurements. The commissioning protocol was tested by SENTINEL partners who expressed an interest in checking their dynamic digital systems using this protocol. The results of basic tests are reported.