Optimising whole body computed tomography doses for paediatric trauma patients: a Swiss retrospective analysis

We aimed to evaluate the impact of a low-dose whole-body computed tomography (WBCT) protocol on radiation doses in paediatric major trauma patients. Retrospective cohort study of paediatric trauma patients (<16 years) at a national level 1 paediatric trauma centre (PTC) over a 6 year period prior and post introduction of a low-dose WBCT protocol (2014-2019). Demographic data, patient characteristics, CT device, and exposure information including scan range, dose-length product, and volume CT dose index were collected. Effective dose (ED) and exposure parameters were compared before and after protocol introduction. Forty-eight patients underwent WBCT during the study period. Prior to introduction of the low-dose protocol (n= 18), the ED was 20.6 mSv (median 20.1 ± 5.3 mSv [range 12.5-30.7]). After introduction of the low-dose WBCT protocol (n= 30), mean ED was 4.8 mSv (median 2.6 ± 5.0 [range: 0.8-19.1]). This resulted in a reduction of 77% in mean ED (pvalue <0.001). Significant radiation dose reduction of 77% can be achieved with low-dose WBCT protocols in PTCs

Anatomic Fat Depots and Coronary Plaque Among Human Immunodeficiency Virus-Infected and Uninfected Men in the Multicenter AIDS Cohort Study.

Methods.  In a cross-sectional substudy of the Multicenter AIDS Cohort Study, noncontrast cardiac computed tomography (CT) scanning for coronary artery calcium (CAC) scoring was performed on all men, and, for men with normal renal function, coronary CT angiography (CTA) was performed. Associations between fat depots (visceral adipose tissue [VAT], abdominal subcutaneous adipose tissue [aSAT], and thigh subcutaneous adipose tissue [tSAT]) with coronary plaque presence and extent were assessed with logistic and linear regression adjusted for age, race, cardiovascular disease (CVD) risk factors, body mass index (BMI), and human immunodeficiency virus (HIV) parameters. Results.  Among HIV-infected men (n = 597) but not HIV-uninfected men (n = 343), having greater VAT was positively associated with noncalcified plaque presence (odds ratio [OR] = 1.04, P &lt; .05), with a significant interaction (P &lt; .05) by HIV serostatus. Human immunodeficiency virus-infected men had lower median aSAT and tSAT and greater median VAT among men with BMI &lt;25 and 25-29.9 kg/m(2). Among HIV-infected men, VAT was positively associated with presence of coronary plaque on CTA after adjustment for CVD risk factors (OR = 1.04, P &lt; .05), but not after additional adjustment for BMI. There was an inverse association between aSAT and extent of total plaque among HIV-infected men, but not among HIV-uninfected men. Lower tSAT was associated with greater CAC and total plaque score extent regardless of HIV serostatus. Conclusions.  The presence of greater amounts of VAT and lower SAT may contribute to increased risk for coronary artery disease among HIV-infected persons

CBCTs in a Swiss university dental clinic: a retrospective evaluation over 5 years with emphasis on radiation protection criteria.

OBJECTIVES To retrospectively evaluate all cone-beam computed tomography (CBCT) scans acquired from 2017 to 2022 in a Swiss university dental clinic with particular emphasis on radiation protection aspects. MATERIAL AND METHODS Radiological databases at the dental clinic of the University of Bern, Switzerland, were explored using a self-developed search algorithm. Data of all acquired CBCT from 01.01.2017 to 27.06.2022 were screened. Exposure parameters (exposure time, exposure angle, milliampere (mA), kilovoltage (kV), field of view (FOV) size), dose area product (DAP), age, and sex of the patient were recorded anonymously. The collected data were analyzed mainly descriptively. Correlations measured the statistical relationships between the variables. RESULTS A total of 10,348 CBCT datasets were analyzed. Patient age ranged from 5 to 96 years (mean: 49.4 years, SD: 21.6 years). The number of CBCTs in patients under 25 years was around 20% each year. In total, 10,313 (99.7%) CBCTs were acquired in small to medium FOV (FOV up to 10 cm of height), and 35 (0.3%) in large FOV (height > 10 cm). DAPs of small FOVs were 518.3 ± 233.2 mGycm2 (mean ± SD), of medium FOV 1233 ± 502.2 mGycm2, and of large FOV 2189 ± 368.7 mGycm2. DAP (ρ = 0.4048, p < 0.0001) and kV (ρ = 0.0210, p = 0.0327) correlated positively with age. Reduced scan angle correlated with young age (rpb 0.2729, p < 0.001). mA did not correlate with age (p = 0.3685). CONCLUSIONS This study demonstrates that certain well-known radiation protection aspects as the reduction of FOV, mA, kV, and scan angle were only partly considered. CLINICAL RELEVANCE Known radiation protection aspects, especially in young patients, should be fully applied in regular clinical practice

Patient doses in CT examinations in Switzerland: implementation of national diagnostic reference levels

Diagnostic reference levels (DRLs) were established for 21 indication-based CT examinations for adults in Switzerland. One hundred and seventy-nine of 225 computed tomography (CT) scanners operated in hospitals and private radiology institutes were audited on-site and patient doses were collected. For each CT scanner, a correction factor was calculated expressing the deviation of the measured weighted computed tomography dose index (CTDI) to the nominal weighted CTDI as displayed on the workstation. Patient doses were corrected by this factor providing a realistic basis for establishing national DRLs. Results showed large variations in doses between different radiology departments in Switzerland, especially for examinations of the petrous bone, pelvis, lower limbs and heart. This indicates that the concept of DRLs has not yet been correctly applied for CT examinations in clinical routine. A close collaboration of all stakeholders is mandatory to assure an effective radiation protection of patients. On-site audits will be intensified to further establish the concept of DRLs in Switzerlan

Number of X-ray examinations performed on paediatric and geriatric patients compared with adult patients

The age of the patient is of prime importance when assessing the radiological risk to patients due to medical X-ray exposures and the total detriment to the population due to radiodiagnostics. In order to take into account the age-specific radiosensitivity, three age groups are considered: children, adults and the elderly. In this work, the relative number of examinations carried out on paediatric and geriatric patients is established, compared with adult patients, for radiodiagnostics as a whole, for dental and medical radiology, for 8 radiological modalities as well as for 40 types of X-ray examinations. The relative numbers of X-ray examinations are determined based on the corresponding age distributions of patients and that of the general population. Two broad groups of X-ray examinations may be defined. Group A comprises conventional radiography, fluoroscopy and computed tomography; for this group a paediatric patient undergoes half the number of examinations as that of an adult, and a geriatric patient undergoes 2.5 times more. Group B comprises angiography and interventional procedures; for this group a paediatric patient undergoes a one-fourth of the number of examinations carried out on an adult, and a geriatric patient undergoes five times mor

Short- and long-term effects of a multi-component physical activity intervention in primary school

There is compelling evidence that physical activity has numerous health benefits during childhood and adolescence. Insufficient levels of physical activity on the other hand can consequently affect cardiovascular and bone health, which may result in severe chronic diseases later in life. Cardiovascular disease and osteoporosis are two of the major chronic diseases affecting a large proportion of the adult population. Both diseases have their origins in childhood and it has been shown that for both, physical activity plays an important role in their prevention. The number of children not being sufficiently active has reached an alarming level and threatens to impose major health burdens worldwide. Thus, developing effective strategies to enhance children’s physical activity levels is of paramount interest for public health. School provides an optimal setting for physical activity promotion, since all children spend a large portion of their time there. This dissertation discusses a school-based randomized controlled trial aimed at increasing children’s physical activity levels and consequently their cardiovascular and bone health. The „Kinder- und Jugendsportstudie“ (KISS) is a school-based physical activity intervention lasting one school year. Of all primary school classes in the cantons of Aargau and Baselland comprising about 10% of the Swiss population, 28 first and fifth grade classes were randomly selected and allocated into an intervention (16 classes; n=297 children) and a control (12 classes, n=205 children) group. The mandatory and stringent multi-component intervention program consisted of daily physical education lessons, daily short activity breaks during academic lessons, and physical activity homework. Children in the control group had the compulsory three physical educations per week. The aim of this dissertation was to assess the effectiveness of KISS on cardiovascular risk and bone health and to explore whether the program was sufficiently effective in order to maintain health benefits over the following three years. In addition, this dissertation will provide a systematic update of existing school-based intervention studies aiming at increasing children’s physical activity and a quantification of physical education-related physical activity. There is strong evidence that school provides a promising setting for physical activity promotion. All school-based intervention studies done in recent years showed positive effects in at least one domain of physical activity. The most successful interventions had the design of a randomized controlled trial, were done over one school year using a multi-component approach integrated into the school curriculum, taught by physical education experts and involving family members. A common intervention strategy was to increase quantity and/or quality of physical education lessons. The particular role of physical education and its contribution to overall physical activity was the center of attention in the second publication of this dissertation. Even if children’s physical activity levels during physical education are relatively low, physical education contributes substantially to overall physical activity. Due to its nature of being a randomized controlled trial in children with a stringent physical activity program in and outside physical education over one school year and with the inclusion of physical education experts, KISS had excellent pre-conditions for being an effective program. Indeed, the results after nine month of intervention are promising. Compared to controls, children of the intervention group showed 14% reduced cardiovascular risk score, 5% reduced body mass index and skinfold thickness, 6% improved aerobic fitness, 18% higher physical activity levels, and 5-8% higher bone mineral content and bone mineral density. Three years after cessation of the program, intervention children still showed higher aerobic fitness and bone mineral content levels at weight-bearing sites of the skeleton compared to the control group. All other beneficial effects have disappeared. Even if short-term effects of the intervention are promising, the major key from a public health perspective is whether the effects of the prevention done during childhood will persist into late adolescence and adulthood. Although the maintained effects on aerobic fitness and bone health have considerable impact on public health, most of the beneficial health effects were not maintained three years after the intervention. This indicates that an intervention over one year is too short for maintained overall health effects. Thus, physical activity programs throughout the school years are needed. Our findings contribute to the growing body of evidence that school-based interventions can increase children’s health; however the major challenge now, is to find effective implementation strategies to transfer such programs into the real-world setting

Risk of neonatal hypothyroidism in newborns from mothers exposed to CTPA during pregnancy: Ancillary data from a prospective outcome study

Background: Neonatal hypothyroidism is often raised as a potential concern for the use of computed tomography pulmonary angiography (CTPA) in pregnant women with suspected pulmonary embolism (PE). Objectives: To assess the incidence of neonatal hypothyroidism among newborns from mothers exposed to CTPA. Patients/methods: Pregnant women with clinically suspected PE were included in a multicenter, multinational prospective diagnostic management outcome study, based on pretest clinical probability assessment, high-sensitivity D-dimer testing, bilateral lower limb venous compression ultrasonography, and CTPA. Results of Guthrie tests were systematically collected for newborns of all women who required CTPA as part of the diagnostic strategy. A thyroid-stimulating hormone (TSH) level above 15 U/ml was used to define hypothyroidism. Results: Out of the 166 women included in the Swiss participating centers, 149 underwent a CTPA including 14 with twin pregnancies. Eight women suffered a pregnancy loss and results of the Guthrie test could not be retrieved for four newborns. All TSH levels were reported as being below 15 U/ml. The incidence of neonatal hypothyroidism was 0/151 (0.0%, 95% confidence interval: 0.0%-2.5%). Conclusions: We did not identify any cases of neonatal hypothyroidism in our cohort of 149 pregnant women investigated for suspected PE using a CTPA. Along with previous literature data, this provides further reassuring data regarding the use of CTPA in this indication. Keywords: Guthrie test; diagnosis; hypothyroidism; pregnancy; pulmonary embolism

A Nordic survey of CT doses in hybrid PET/CT and SPECT/CT examinations

Background Computed tomography (CT) scans are routinely performed in positron emission tomography (PET) and single photon emission computed tomography (SPECT) examinations globally, yet few surveys have been conducted to gather national diagnostic reference level (NDRL) data for CT radiation doses in positron emission tomography/computed tomography (PET/CT) and single photon emission computed tomography/computed tomography (SPECT/CT). In this first Nordic-wide study of CT doses in hybrid imaging, Nordic NDRL CT doses are suggested for PET/CT and SPECT/CT examinations specific to the clinical purpose of CT, and the scope for optimisation is evaluated. Data on hybrid imaging CT exposures and clinical purpose of CT were gathered for 5 PET/CT and 8 SPECT/CT examinations via designed booklet. For each included dataset for a given facility and scanner type, the computed tomography dose index by volume (CTDIvol) and dose length product (DLP) was interpolated for a 75-kg person (referred to as CTDIvol,75kg and DLP75kg). Suggested NDRL (75th percentile) and achievable doses (50th percentile) were determined for CTDIvol,75kg and DLP75kg according to clinical purpose of CT. Differences in maximum and minimum doses (derived for a 75-kg patient) between facilities were also calculated for each examination and clinical purpose. Results Data were processed from 83 scanners from 43 facilities. Data were sufficient to suggest Nordic NDRL CT doses for the following: PET/CT oncology (localisation/characterisation, 15 systems); infection/inflammation (localisation/characterisation, 13 systems); brain (attenuation correction (AC) only, 11 systems); cardiac PET/CT and SPECT/CT (AC only, 30 systems); SPECT/CT lung (localisation/characterisation, 12 systems); bone (localisation/characterisation, 30 systems); and parathyroid (localisation/characterisation, 13 systems). Great variations in dose were seen for all aforementioned examinations. Greatest differences in DLP75kg for each examination, specific to clinical purpose, were as follows: SPECT/CT lung AC only (27.4); PET/CT and SPECT/CT cardiac AC only (19.6); infection/inflammation AC only (18.1); PET/CT brain localisation/characterisation (16.8); SPECT/CT bone localisation/characterisation (10.0); PET/CT oncology AC only (9.0); and SPECT/CT parathyroid localisation/characterisation (7.8). Conclusions Suggested Nordic NDRL CT doses are presented according to clinical purpose of CT for PET/CT oncology, infection/inflammation, brain, PET/CT and SPECT/CT cardiac, and SPECT/CT lung, bone, and parathyroid. The large variation in doses suggests great scope for optimisation in all 8 examinations.Peer reviewe