Analysis of dose distribution around a computed tomography scanner in terms of exposure to scattered ionizing radiation of caregivers of pediatric patients.

OBJECTIVES: During computed tomography (CT), a large amount of ionizing radiation is emitted to ensure high quality of the obtained radiological image. This study measured the dose distribution around the CT scanner and the exposure of people staying near the CT scanner during the examination. MATERIAL AND METHODS: The measurements used an anthropomorphic phantom to assess human exposure to ionizing radiation. The probability of inducing leukemia and other cancers as a result of absorbing doses recorded around the CT device was also calculated. RESULTS: The highest exposure to scattered radiation in the proximity of the CT scanner is recorded at the gantry of the tomograph, i.e., 55.7 µGy, and the lowest, below lower detection limit of 6 µGy at the end of the diagnostic table. The whole-body detector placed on the anthropomorphic phantom located at the diagnostic table right next to the CT gantry recorded 59.5 µSv and at the end of the table 1.5 µSv. The average doses to the lenses in these locations were: 32.1 µSv and 2.9 µSv, respectively. CONCLUSIONS: The probability of induction of leukemia or other types of cancer is low, but the need for people to stay in the examination room during a CT examination should be limited to the necessary minimum. Int J Occup Med Environ Health. 2024;37(3).

Analysis of the threshold image contrast obtained with the CDMAM 3.4 and CDMAM 4.0 phantoms.

Quality control in mammography is a very important element. One of the parameters indicating the appropriate image quality is the threshold image contrast. The CDMAM phantom is used to measure this parameter. It is currently available in two versions 3.4 and 4.0. The aim of this work is to compare the threshold image contrast readings obtained with the CDMAM 3.4 and CDMAM 4.0 phantoms. In the measurements, 9 CDMAM 4.0 phantoms were used to check the difference in indications of individual copies. The phantom whose readings were closest to the average of all readings was used for comparative measurements with the CDMAM 3.4 phantom. Measurements were made on 40 mammography devices. The obtained images were read with the software provided by the phantom manufacturer and the CDMAM Analysis v2.3.0 (NCCPM) software. The average percentage difference between the minimum and maximum values indicated by the CDMAM 4.0 phantoms was 10.09%. Using the CDMAM Analysis v2.3.0 (NCCPM) software, the average difference in readings between the CDMAM 3.4 and CDMAM 4.0 phantoms is 7.93%, and when using the software provided by the phantom manufacturer, it is as much as 60.15%. The obtained results of the threshold image contrast are affected by the type of software used for reading and the accuracy of the execution of individual elements of the phantom. It is recommended to use CDMAM Analysis v2.3.0 (NCCPM) software or the latest software provided by the phantom manufacturer to read the phantom images.

Comparison of Radionuclide Impurities Activated during Irradiation of 18O-Enriched Water in Tantalum and Silver Targets during the Production of 18F in a Cyclotron.

During the production of 18F, as a result of the interaction of the beam of protons and secondary neutrons with the structural elements of the target body, many radionuclide impurities are created in the cyclotron. As part of this work, we theoretically predicted which isotopes would be activated in the target tantalum or silver bodies. Subsequently, we used gamma spectrometry analysis to verify these predictions. The results were compared with the work of other authors who studied titanium and niobium as materials for making the target body. Tantalum has been evaluated as the most favorable in terms of generating radionuclide impurities during the production of 18F by irradiation of 18O-enriched water in accelerated proton cyclotrons. Only three radionuclides were identified in the tested samples: 181W, 181Hf, and 182Ta with a half-life of fewer than 120 days. The remaining reactions led to the formation of stable isotopes.

Exposure to ionizing radiation by service personnel working with cyclotrons used to produce radiopharmaceuticals in PET diagnostics.

OBJECTIVES: While working with cyclotrons used for the production of radiopharmaceuticals, workers can experience significant exposure to the adverse effects of ionizing radiation. The aim of this paper was to determine the typical level of such exposure received by such personnel while servicing cyclotrons. MATERIAL AND METHODS: Exposure was assessed using TLD detectors placed in an anthropomorphic phantom, as well as dose meter to determine whole body and eye lens exposure. The phantom was placed in locations receiving the greatest exposure to ionizing radiation during service activities. The time spent by employees during servicing was assessed based on routine visits by service technicians. The obtained results were compared with readings of detectors worn by employees during service activities. RESULTS: The highest equivalent doses in the thoracic area were found to be received by the lungs (211.16 µSv/year). In the head and neck area, the highest dose was measured in the eye lens (3410 µSv/year). The effective dose for the whole body was found to be 1154.4 µSv/year, based on the phantom, and 149 µSv per service visit (1192 µSv/year), based on the dose meters carried by the workers. CONCLUSIONS: Service workers are exposed to significant doses of ionizing radiation, representing a clear radiological protection issue. To reduce exposure to eye lenses, it is recommended to use protective goggles when working with highly-radioactive elements. Int J Occup Med Environ Health. 2022;35(6):753-60.

LEVELS OF EXPOSURE TO IONIZING RADIATION AMONG THE PERSONNEL ENGAGED IN CYCLOTRON OPERATION AND THE PERSONNEL ENGAGED IN THE PRODUCTION OF RADIOPHARMACEUTICALS, BASED ON RADIATION MONITORING SYSTEM.

This paper aims to determine the levels of exposure to neutron and photon radiation among the personnel engaged in cyclotron operation and the personnel engaged in the production of radiopharmaceuticals, with the use of the environmental radiation monitoring system (RMS) installed in the positron emission tomography laboratory. The annual exposures of employees operating the cyclotron measured with the use of the RMS system are: 1.39 ± 0.16 mSv in case of photon radiation and 2.61 ± 0.14 mSv in case of neutron radiation. In the case of employees in the radiopharmaceuticals' production zone, the annual exposures measured by means of the RMS system are 0.15 ± 0.03 mSv in case of photon radiation and 0.11 ± 0.01 mSv in case of neutron radiation. The exposure levels among the personnel engaged in cyclotron operation and the personnel engaged in the production of radiopharmaceuticals are below the permissible radiation dose limits.

Formation of 107Cd radionuclide impurities during 18F production.

Cd isotopes (107Cd and 109Cd) are generated from the silver target body during the bombardment of [18O]water in the routine production of 2-[18F]fluoro-2-deoxy-d-glucose ([18F]FDG) for PET (Positron Emission Tomography) diagnosis. Cadmium isotopes contribute significantly to the total activity of generated impurities and, due to being potentially radiotoxic to living organisms, they should be effectively reduced from FDG to prevent accidental injection of even small concentrations into patients. Purification of the final [18F]FDG can be based on a set of columns, fulfilling various functions in the cleaning process. To assess cadmium impurities and the efficiency of the purification process, a low background gamma spectrometry system with high resolution has been applied. Even activity of 3.5 kBq and 290 kBq has been measured on QMA (Sep-Pak Light Accell Plus QMA) columns for 109Cd and 107Cd isotopes, respectively. 107Cd activity in the five column set was higher than that of 109Cd. The rate of 18F production process was about 1 GBq/min, while that of 107Cd and 109Cd radionuclides was about 4.2 kBq/min and 50 Bq/min respectively. The same purification efficiency of both isotopes has been obtained at each step of the process. The production rate of 107Cd and 109Cd radionuclides was insignificant compared to the 18F production rate. Therefore [18F]FDG final product for use in injections before PET diagnostics was efficiently purified from cadmium radionuclide impurities.

Effect of anode/filter combination on average glandular dose in mammography.

A comparative analysis of the mean glandular doses was conducted in 100 female patients who underwent screening mammography in 2011 and 2013. Siemens Mammomat Novation with the application of the W/Rh anode/filter combination was used in 2011, whereas in 2013 anode/filter combination was Mo/Mo or Mo/Rh. The functioning of mammography was checked and the effectiveness of the automatic exposure control (AEC) system was verified by measuring compensation of changes in the phantom thickness and measuring tube voltage. On the base of exposure parameters, an average glandular dose for each of 100 female patients was estimated. The images obtained by using AEC system had the acceptable threshold contrast visibility irrespective of the applied anode/filter combination. Mean glandular doses in the females, examined with the application of the W/Rh anode/filter combination, were on average 23.6% lower than that of the Mo/Mo or Mo/Rh anode/filter combinations. It is recommended to use a combination of the W/Rh anode /filter which exhibited lower mean glandular doses.

[Spinocerebellar ataxias type 1 and 2: comparison of clinical, electrophysiological and magnetic resonance evaluation]. / Ataksja rdzeniowo-mózdzkowa typu 1 i 2 - porównanie oceny klinicznej, elektrofizjologicznej i rezonansu magnetycznego.

BACKGROUND AND PURPOSE: Spinocerebellar ataxias type 1 (SCA1) and type 2 (SCA2) belong to neurodegenerative disorders of autosomal dominant inheritance, genetically and clinically heterogeneous, caused by the expansion of CAG trinucleotides. Trunk and limb ataxia, dysarthria, dysphagia, gaze palsy, sensory and motor axonal neuropathy are the dominant features in both entities. The aim of the study was to evaluate the differences between genotype and phenotype based on clinical and electrophysiological assessment of the visual, auditory pathways, and EEG alterations in comparison with the cerebellar and brain atrophy in MRI. MATERIAL AND METHODS: 44 patients with SCA1 and 24 cases with SCA2 confirmed molecularly were examined neurologically and using the International Cooperative Ataxia Rating Scale (ICARS). A correlation of clinical symptoms and signs, and CAG repeat numbers with EEG, visual (VEP) and brainstem auditory (BAEP) evoked potentials, and MRI alterations were evaluated. RESULTS: A statistically significant negative correlation between the age of disease onset and number of CAG repeats in both types of SCA was found. Examined patients with SCA2 were younger, with longer disease duration and more pronounced cerebellar and brain atrophy in MRI. We found a significant correlation between ICARS and CAG repeats in this group. The dysphagia, pyramidal tract involvement and depressive reaction were significantly frequent in SCA1 patients. However in SCA2 patients, the peripheral nerve damage and extrapyramidal signs were more prominent. The amplitude of P100 visual evoked potentials was significantly lower in SCA1 patients and negatively correlated with CAG repeats. CONCLUSIONS: These results provide further evidence for the phenotypic differences of genetically defined SCA1 and SCA2 patients, expressed by more frequent involvement of the pyramidal tract and depression reaction in SCA1, in contrast to peripheral nerve involvement and extrapyramidal signs in the clinical feature of SCA2 phenotype. Furthermore, atrophy of the brain and cerebellum revealed in MRI was more pronounced than electrophysiological functional alterations, especially in SCA2. The decreased amplitude of P100 VEP in SCA1 patients was the only electrophysiological parameter differentiating between both groups of patients.

[Diagnostic value of thermography and endothelin concentration in serum of children with Raynaud's Syndrome]. / Wartosc diagnostyczna termowizji i oznaczania stezen endoteliny we krwi w diagnostyce Zespolu Raynaud u dzieci.

OBJECTIVE: The primary Raynaud's Syndrome may occur in pubescent children, the secondary is connected with connective tissue diseases. The aim of this study was to evaluate the diagnostic value of thermography and endothelin concentration in patients with Raynaud's Syndrome (RS). MATERIAL AND METHODS: 49 patients aged 11 to 18 years with clinical symptoms of RS and 12 healthy children participated in the study. 17 patients had secondary and 32 primary RS. Thermography was conducted in all children. Vasomotor disturbances were diagnosed by Doppler ultrasonography. Palm temperature measurements were taken in room temperature before, directly after the cooling test and 4 minutes later. ET-1 serum concentration was tested by ELISA. RESULTS: The mean palm temperatures after the cooling test were significantly lower than in control group. (26.28 +/- 3.13C vs 30.26 +/- 1.11C p<0.001). There was no difference between primary and secondary RS. After cooling, the palm temperatures were statistically lower than before the test in all children (primary RS -19.56 +/- 1.68; secondary RS -18.7 +/- 1.02; control group -- 18.98 +/- 0.39). The warming up speed of palm after 4 minutes from the cooling test was similar in investigated and control groups. There was no statistically significant difference in the mean concentration values of ET-1 in sera of children with RS and the control group (1.62 +/- 0.86 pg/ml vs 1.27 +/- 0.4 pg/ml). CONCLUSIONS: 1. Thermographic estimation of palm temperatures in children with RS is a good diagnostic method of vasomotor disturbances. 2. Assay of ET-1 serum levels seem not to have significant diagnostic value.

[Thermography in the early detection of breast cancer--our own experiences]. / Termografia we wczesnej diagnostyce raka piersi--wlasne doswiadczenia.

In combination with X-ray mammography and clinical examination thermography adds to the accuracy of breast cancer diagnosis. Thermographic examinations can be repeated at short intervals with no radiation hazard to the patient. However, performing and interpreting thermograms requires meticulous training. It was found that women with an abnormal thermogram are at a higher risk and have a poorer prognosis. A change in the thermal pattern is often the earliest sign of a cancer. The authors believe that the fault lies in misinterpretation of the thermogram, rather than the thermogram itself. Computer stimulations could be an adjunct tool to help the clinician in the interpretation.

[The effect of rivastigmine on cognitive functions and regional cerebral blood flow in Alzheimer's disease and vascular dementia: follow-up for 2 years]. / Wplyw riwastygminy na funkcje poznawcze i regionalny przeplyw mózgowy w chorobie Alzheimera i w otepieniu naczyniopochodnym -- dwuletnia obserwacja chorych.

BACKGROUND AND PURPOSE: The aim of the work was to investigate the effect of treatment with rivastigmine, one of the inhibitors of acetylcholinesterase (AChE-I) on the regional cerebral perfusion (rCBF) and the cognitive functions of the brain in patients with Alzheimer's Disease (AD) and Vascular Dementia (VaD). MATERIAL AND METHODS: The investigations of rCBF were carried out using SPECT (Single Photon Emission Computed Tomography). The results given concern investigations of patients carried out at the onset of the investigation, after 12 months, and 24 months of rivastigmine treatment. RESULTS: In patients with AD it was found that treatment with rivastigmine increases rCBF by 5-7% in the temporal areas during the first 12 months. In the frontal areas the increase was by 3-5%. During the next 12 months rCBF with an accuracy of 2% returned to the initial level, with the exception of the motor cortex, where it remained on the level increased by 5-6%. However, the cognitive functions remained constant during the first 12 months of treatment and decreased significantly during the next 12 months. In patients with VaD rCBF increased in all the regions of the brain except for the temporal posterior regions, and remained at an elevated level for the next 12 months. The cognitive functions deteriorated slowly, but to a much lesser degree than in the case of AD. CONCLUSIONS: From the investigations carried out it follows that treatment with rivastigmine during 24 months prevents a decrease of rCBF in patients with AD. However, the cognitive functions deteriorate after 24 months.

The effect of cholinesterase inhibitors on the regional blood flow in patients with Alzheimer's disease and vascular dementia.

The effects of therapy with cholinesterase inhibitors (ChE-I) on regional cerebral blood flow (rCBF) disturbances were investigated by means of single photon emission computed tomography (SPECT). The changes in rCBF were compared with the results of the medical examination and neuropsychological tests. The sample consisted of 41 patients with the Alzheimer's dementia (AD) and vascular dementia (VaD). The effect of ChE-I (rivastigmine) treatment was studied on 33 patients, while the nontreated control group consisted of 8 patients. In the treated patients, an increase in the rCBF was observed, while the scores of the neuropsychological tests decreased slightly. In the VaD group, the increase in rCBF was more significant in the frontal regions, whereas in the group with AD in the temporal regions, respectively. In the nontreated patients, a decrease of both rCBF and scores of neuropsychological tests were observed. The scores of the neuropsychological tests correlated with the results of rCBF. Increased levels of acetylcholine in the brain after ChE-I treatment may support the cholinergic regulation of rCBF, and in result increase it. Such effects seem to be more pronounced in the more affected brain regions.

SPECT as a diagnostic test in the investigation of dementia.

Single photon emission tomography (SPECT) permits the assessment of the decrease of regional cerebral blood flow (rCBF). The aim of this study was to assess the relationship between the different types of dementia (Alzheimer's disease (AD), vascular dementia (VaD) and frontotemporal dementia (FTD)) and the rCBF in the SPECT examination. In patients with AD, the SPECT examination showed hypoperfusion in temporoparietal regions, contrary to patients with frontotemporal dementia, where hypoperfusion was limited to the frontal area, and compared to patients with VaD, where "patchy" rCBF changes were observed in different regions. In mild cases of AD, perfusion deficits were observed in the frontal regions equal to those in VaD. The study shows that the SPECT examination may be useful in distinguishing between AD, VaD, and FTD; however, for proper diagnosis in the early stages of AD, additional factors must be taken into consideration.

[Clinical and genetic study of juvenile form of Huntington's disease]. / Badania kliniczne i genetyczne w mlodzienczej postaci choroby Huntingtona.

Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder caused by high instability and extension of CAG sequences within the coding region of IT15 gene. It affects both sexes and age at onset of the disease may be different but usually occurs in midlife. The term Juvenile Huntington's disease is generally applied to 10% of the cases with onset before 20. We present clinical features and results of DNA analysis in 16 patients from 14 families aged 9 to 36. The age of onset was between 5 to 20 years; duration of the disease was from 2 to 16 years. In 10 cases the mutated gene was transmitted by the affected father; only in two cases by the mother. In all cases anticipation manifested by earlier onset of the disease in subsequent generations and expansion of CAG repeats was documented. The number of CAG repeats was between 50 and 92 (mean 67.3). Progressive mental deterioration, declining school performance, hyperactivity and emotional disturbances were the first symptoms of juvenile HD. Neuropsychological assessment showed mean IQ in Wechsler test 59.6 and Mini-Mental State Examination scores 22.8. Rigidity and bradykinesia were predominant features in the cases with juvenile onset, the remaining ones developed choreatic movements. Three persons had epileptic seizures; two (both females) revealed behaviour and psychiatric disturbances. Amplitudes of somatosensory evoked potentials, visual evoked potentials and brainstem auditory evoked potentials were markedly reduced. MRI of the brain showed atrophy of heads of the caudate nuclei, putamen and globus pallidus.

[Nicergoline in the treatment of patients after a mild ischemic stroke]. / Nicergolina w leczeniu chorych po lekkim udarze niedokrwiennym mózgu.

25 patients with neurological and neuropsychological deficits after a mild ischaemic stroke were treated with nicergoline (Adavin 60 mg/d) versus placebo in a double blind cross-over trial (3 and 3 months). The patients were examined repeatedly by a neurologist and a neuropsychologist using a battery of tests (PPL, AVLT, Benton and Bourdon tests, number-repetition test). On completion of the trial the improvement of neurological signs (mainly cerebellar deficits) and neuropsychological impairments (in particular of attention and manual manipulation difficulties) was found to be more marked after the period of nicergoline treatment than after placebo. No drug-dependent side effects--including the influence on blood pressure--were observed in the whole group treated.