Dose Evaluation in Fluoroscopy

Background: Medical imaging is essential for diagnosis and treatment. However, it raises long-term radiation exposure concerns for patient safety. The measurements of entrance surface air kerma (ESAK), entrance surface dose (ESD), and dose area product (DAP) have been widely used to estimate patient doses. However, these parameters cannot represent the patient’s organ-absorbed doses. Objective: To establish a relationship between ESD and organ-absorbed doses, calculated using Monte Carlo-based software to estimate organ-absorbed doses in patients undergoing chest and abdominal X-ray examinations. Materials and methods: The SHIMADZU RADspeed Pro X-ray machine with VacuDAP meter, Radcal, and AGMS-D+ solid-state detector with Accu-Gold software was used to measure ESD. Tissue-equivalent slab phantoms with 9.8, 15.0, and 20.0 cm thickness were used at 60, 80, and 120 kVp and 3.2 mAs. Surface field sizes varied from 7×7 cm2 to 28×28 cm2. Organ-absorbed doses were calculated using PCXMC 2.0 from STUK (Finland) using the same X-ray exposure techniques as the experiment. Results: The X-ray tube voltage (kVp) is proportional to the ESD (µGy/mAs). This relationship can be described using a power equation. The ESD increased as the phantom thickness increased for each beam field size. A linear function was used to estimate the relationship between ESD and organ-absorbed doses. Due to their anatomical positions, which are most adjacent to the X-ray source, the breast, uterus, and heart have the highest organ-absorbed doses undergoing examinations of the chest (anteroposterior; AP), abdomen (AP), and chest (posteroanterior; PA), respectively. Conclusion: The relationships between ESD and kVp were established as power functions, but the relationships with DAP were linear functions. The relationship between ESD and organ-absorbed doses was described using linear equations that varied with beam field size and patient thickness. This study provides a helpful method for estimating organ-absorbed and effective patient doses. This is important in assessing the risk of radiation exposure from diagnostic radiography.

Hepatic arterial infusion chemotherapy (HAIC) has been popular for treating unresectable hepatocellular carcinoma (HCC). However, there are few reports comparing the transradial approach (TRA) and transfemoral approach (TFA) in HAIC. This study aimed to compare the duration of the hepatic artery catheterization, fluoroscopy time (FT), radiation exposure, safety, and quality of life associated with the procedure in patients undergoing HAIC via TRA and TFA. This prospective, single-center, randomized, controlled study included 120 patients with unresectable HCC undergoing HAIC procedures. Patients were randomly assigned to group A (n = 60, TRA-HAIC) or group B (n = 60, TFA-HAIC). The hepatic artery catheterization time, FT, entrance surface dose (ESD), dose area product (DAP), procedure-related complications, and quality of life associated with the procedure were assessed between the two groups. Independent-sample t-test and analysis of variance (ANOVA) were used to assess differences. Statistical significance was set at P < 0.05. HAIC procedures were successfully performed in both groups. The hepatic artery catheterization time (19.35 ± 5.84 vs. 18.93 ± 5.62 minutes, P = 0.837), FT (2.35 ± 2.23 vs. 2.25 ± 2.16 minutes, P = 0.901), ESD (259.32 ± 167.46 vs. 250.56 ± 170.58 mGy, P = 0.449), and DAP (125.37 ± 60.65 vs. 120.56 ± 64.33 Gy.cm3, P = 0.566) were comparable between the two groups. The incidence of artery occlusion (10.0% vs. 0%, P < 0.001) in the TRA group was significantly higher than that in the TFA group. TRA was associated with a statistically significant (P < 0.05) improvement in the quality of life. TRA to HAIC was associated with greater improvement in the quality of life associated with the procedure compared with TFA. Both approaches to HAIC had similar efficiency, safety, radiation exposure, and procedure duration.

In Nigeria, a large number of radiographic examinations are conducted yearly for various diagnostic purposes. However, most examinations carried out do not have records of doses received by the patients, and the employed exposure parameters used are not documented; therefore, adequate radiation dose management is hindered. The aim of the present study was to estimate the dose‐area product (DAP) of patients examined in Nigeria, and to propose regional reference dose levels for nine common examinations (chest PA, abdomen AP, pelvis AP, lumbar AP, skull AP, leg AP, knee AP, hand AP, and thigh AP) undertaken in Nigeria. Measurement of entrance surface dose (ESD) was carried out using thermoluminescent dosimeter (TLD). Measured ESDS were converted into DAP using the beam area of patients in 12 purposely selected hospitals. Results of the study show that the maximum/minimum ratio ranged from 3 for thigh AP to 57 in abdomen AP. The range of determined mean and 75th percentile DAPs were 0.18–17.16, and 0.25–28.59 Gy cm2, respectively. Data available for comparison show that 75th percentile DAPs in this study (in chest PA, abdomen AP, pelvis AP, lumbar AP) are higher than NRPB‐HPE reference values. The DAP in this study is higher by factor of 31.4 (chest PA), 9.9 (abdomen AP), 2.2 (pelvis AP), and 2.1 (lumbar AP) than NRPB‐HPE values. The relative higher dose found in this study shows nonoptimization of practice in Nigeria. It is expected that regular dose auditing and dose optimization implementation in Nigeria would lead to lower DAP value, especially in abdomen AP. The 75th percentile DAP distribution reported in this study could be taken as regional diagnostic reference level in the Southwestern Nigeria; however, a more extensive nationwide dose survey is required to establish national reference dose.PACS number(s): 87.53.Bn, 87.59.B

Gridless adult cervical spine radiography and its' effect on image quality and radiation dose: A phantom study

The objective of the study was to derive a mathematical method for calculating the entrance surface dose (ESD) from exposure factors for all tube potentials used in clinical practice and to compare the calculated ESDs (ESD(C)) with those measured (ESD(TLD)) using thermoluminescent dosemeters (TLDs). The exposure parameters of 43 patients who underwent (a) posteroanterior (PA) and lateral (LAT) chest examination (13 patients), (b) supine abdomen (10 patients), (c) erectus abdomen (10 patients), or (d) urinary tract examination (10 patients) were recorded. Patient ESD was directly measured by TLDs and calculated from exposure factors. The differences between ESD(C) and ESD(TLD) were quite small and could be explained by the uncertainties involved in both methods, in all but the PA chest examination where the ESD(C) was about 50% larger than ESD(TLD). However, in PA chest the ESD(TLD) was close to the minimum detectable dose of TLDs, questioning the accuracy of ESD(TLD). Further investigation showed that using the high tube potential technique (130 kV) in the PA chest examination resulted in very short exposure times, in the region of 4 ms. In such short exposure times, the X-ray generator operation presented stability problems that led to loss of output linearity and consequently to false calculation of ESD. The calculation method offers a reliable and cheap alternative to the measurement of ESD by TLD, provided that the exposure times are not as short as in the PA chest examinations recorded in this study, so that the output linearity with tube current-time product (mAs) is maintained.

Objective To investigated the correlation between the focus-to-flat panel detector distance and entrance surface doses in digital radiography of lumbar spine. Methods The spine phantom used for bone mineral density(BMD)calibration was radiographed at different value of FFD (100~240 cm with the interval 10 cm, totally 15 times) using 70 kV and 90 kV with the automatic exposure control (AEC) mode without anti-scatter grid. The parameters measured by QUART dido 2100K type X-ray dose meter. So record the value parameters of the tube current (mAs) and entrance surface dose (ESD). The relation curve were counted between FFD, ESD, mAs and Exposure index (EI) use excle. Pearson correlation analysis and related coefficient difference analysis were performed using the SPSS 19.0 software (P<0.05 for the statistically significant level). The FFD and ESD values of regression equation were obtained with regression analysis. Results (1) When the tube voltage was 70 kV: FFD and ESD were negative correlation (r=-0.922, P 0.05). (3) Different position correlation coefficient analysis of the difference was not statistically significant difference. (4) The regression analysis results: The regression equation of the lumbar anterior-posterior position FFD and the ESD at 70 kV: y=0.805 x + 319.731 (F=74.175, P <0.001). The regression equation of the lumbar lateral position FFD and the ESD at 90 kV: y=3.152 x + 457.613 (F=133.524, P <0.001). Conclusions The FFD and ESD in the lumbar spine X-ray radiography were relevant and highly negative correlation. It can effectively reduce the radiographic ESD of lumbar spine with the increasing of the FFD. Key words: Radiography; Lumbar spine; Focus-to-flat panel detector distance; Entrance surface dose; Exposure index

Use of the effective dose in diagnostic radiology permits the radiation exposure of diverse diagnostic procedures to be quantified. Fundamental knowledge of patient doses enhances the implementation of the "as low as reasonably achievable" (ALARA) principle. To provide comparative information on pediatric examination protocols and patient doses in skull, sinus, chest, abdominal, and pelvic radiography examinations. 24 Finnish hospitals were asked to register pediatric examination data, including patient information and examination parameters and specifications. The total number of examinations in the study was 1916 (1426 chest, 228 sinus, 96 abdominal, 94 skull, and 72 pelvic examinations). Entrance surface dose (ESD) and dose-area products (DAP) were calculated retrospectively or DAP meters were used. Organ doses and effective doses were determined using a Monte Carlo program (PCXMC). There was considerable variation in examination protocols between different hospitals, indicating large variations in patient doses. Mean effective doses of different age groups ranged from 5 microSv to 14 microSv in skull and sinus examinations, from 25 microSv to 483 microSv in abdominal examinations, and from 6 microSv to 48 microSv in chest examinations. In chest and sinus examinations, the amount of data was extensive, allowing national pediatric diagnostic reference levels to be defined. Parameter selection in pediatric examination protocols should be harmonized in order to reduce patient doses and improve optimization.

Backgound: Digital radiography is an easy method of radiological examination, so many radiology technicians often use high exposure factors because they are considered to speed up when processing images, this can increase the risk of excessive radiation doses in patients, currently the exposure index (IE) is feedback to radiology technicians for optimal images and low doses for patients. Objective: evaluating Fujifilm (S-Value) exposure index and entrance surface dose (ESD) thorax posterior-anterior as an effort to increase patient radiation protection using the ALARA principle, Method: Data taken from samples with parameters 64 kVp 16 mAs to 94 kVp 2 mAs, ESD is measured using the thermoluminescent dosimeter (TLD) chip and exposure index (S-Value) from Fujifilm's direct radiography device. Result: The relationship between S-Value and ESD has an exponential trend graph. The rise of S-Value will be followed by the ESD sequence. With the BAPETEN reference value of surface radiation dose 0.40 mGy, the minimum S-value must be achieved so that the patient's ESD does not exceed S-532 at ESD 0.39. Conclusion: The results of this study indicate that Fujifilm's S-Value allows it to be used as an evaluation of the ESD values received by patients as an effort to increase patient radiation protection. Keywords: Exposure index (S-Value), ESD, chest radiography, radiation protection

Background Patient radiation exposure in diagnostic radiology is an important concern for radiation protection and patient safety. Monitoring radiation dose levels during radiographic examinations is essential to ensure compliance with diagnostic reference levels (DRLs) and to optimize radiological practices. Objective The aim of this study was to evaluate patient radiation dose during conventional lumbar spine radiography and compare the obtained values with diagnostic reference levels. Methods A descriptive cross-sectional multicenter study was conducted in four hospitals in the Sous Massa region, Morocco, between April and June 2017. Data were collected from 142 patients undergoing lumbar spine radiography examinations and from 20 radiology technicians. Exposure parameters including tube voltage, tube current, exposure time, focus-to-film distance, and field size were recorded. Entrance surface dose (ESD) was estimated using MICADO software, and dose area product (DAP) values were subsequently calculated. The 75 th percentile values were determined and compared with diagnostic reference levels. Results The regional 75 th percentile ESD values were 5.33 mGy for the anteroposterior projection and 7.38 mGy for the lateral projection. Corresponding DAP values were 1840.9 mGy.cm 2 and 2783.65 mGy.cm 2 , respectively. All obtained values were below the diagnostic reference levels used for comparison. However, variations between hospitals were observed, likely due to differences in imaging protocols and equipment. Conclusion Radiation doses associated with lumbar spine radiography in the evaluated hospitals were within acceptable limits according to diagnostic reference levels. Continuous monitoring of patient radiation exposure and optimization of radiographic techniques remain essential to ensure effective radiation protection.

Objective To investigate the entrance surface dose to the examined patients in radiography using digital and screen-film system in hospitals at different levels in 15 provinces and municipalities in China, in order to provide data for developing diagnostic reference level of radiography suitable for our national physical characteristics. Methods According to the requirements of the Technical Study on Medical Radiation Hazard Assessment and Control, the examined patients aged 20-70 years were selected, with body weight ranging from 55 to 80 kg for male and 50 to 70 kg for female. TLDs were used to measure the entrance surface dose to adult patients in radiography. No less than 10 examined patients were required at each body position, with examined locations including head (PA, LAT), chest (PA, LAT), abdomen (AP), pelvis (AP), lumbar (AP, LAT), and thoracic vertebra (AP, LAT). Results A total of 19 975 individuals undergoing radiography and 1 813 radiographic equipment of different types including screen-film radiography, computed radiography (CR) and digital radiography (DR), were investigated in 342 hospitals in 15 provinces and municipalities throughout the country. For these three types of equipment, the average entrance surface dose to the examined were 1.75, 1.9, and 1.15 mGy in head (PA), 1.69, 1.46 and 1.03 mGy in head (LAT), 0.75, 0.65 and 0.36 mGy in chest (PA), 1.81, 1.26 and 0.88 mGy in chest (LAT), 4.37, 3.77 and 2.15 mGy in abdomen (AP), 3.73, 3.56 and 2.75 mGy in pelvis (AP), 5.49, 5.84 and 4.17 mGy in lumbar (AP), 12.01, 9.37 and 6.82 mGy in lumbar (LAT), 4.53, 3.65 and 2.49 mGy in thoracic vertebra (AP), and 6.91, 6.43 and 4.15 Gy in thoracic vertebra (LAT). Conclusions Entrance surface dose caused by radiography examination varies dependent on different exposure locations. Entrance surface doses caused by digital radiography are all lower than by screen-film radiography; those caused by digital radiography are lower than by computed radiography, except for thoracic vertebra (AP). In all examinations, no difference of statistical significance is found between CR and screen-film radiography in entrance surface dose. Key words: Screen-film radiography; Computed radiography(CR); Digital radiography(DR); Entrance surface dose(ESD); Diagnostic reference level

It is necessary to reduce the exposure doses from both fluoroscopy and angiocardiography. Pulsed fluoroscopy clearly reduces patients' exposure. By contrast, whether digital acquisition reduces patients' exposure is not clear. This study simulated the skin radiation doses of patients in cardiac catheterization laboratories with various radiography systems used in percutaneous transluminal coronary angioplasty to determine whether digital acquisition reduces patient exposure as compared with cine film recording. The entrance surface doses with cineangiography and fluoroscopy of acrylic phantoms were compared for 11 radiography systems at seven facilities; each performs more than 100 cardiac intervention procedures per year. The entrance surface dose for an acrylic plate (20 cm thick) was measured using a skin-dose monitor. The maximum dose exceeded the minimum dose by 6.44 times for cineangiography and by 3.42 times for fluoroscopy. The entrance surface dose with acrylic plate was lower with digital-only acquisition (mean +/- SD, 3.07 +/- 0.84 mGy/sec) than with film recording (6.00 +/- 3.04 mGy/sec). By contrast, the entrance surface frame dose, after correction for the cine frame rate, tended to be higher with digital acquisition than with film recording (0.210 +/- 0.053 vs 0.179 +/- 0.058 mGy/frame, respectively). CONCLUSION. The entrance surface dose was approximately 50% less with digital-only acquisition than with film recording. However, after correcting the dose for cine frame rate, filmless acquisition did not in itself reduce the exposure. For the surface dose to be reduced for cardiac interventional radiography, even with digital filmless radiography systems, a low recording speed is necessary for angiocardiography.

Measurements of patient entrance surface dose rate provide valuable data for interpreting results from dose-area product studies on fluoroscopic X-ray equipment. Methods for measurement of entrance surface dose rate with backscatter and incident dose rate without backscatter have been investigated. Entrance surface dose rate is measured with an ionization chamber in contact with a tissue-equivalent phantom. Backscattered radiation contributes 27-45% to the measurement and is affected by field size and chamber position. Incident dose rate measured using a copper phantom provides an alternative approach. Consistent relationships between thicknesses of Perspex and copper giving similar incident dose rates under automatic gain control have been established for different tube potentials with and without a grid. This allows measurements of incident dose rate made using copper to be linked to corresponding thicknesses of tissue-equivalent material. Since only a few millimetres of copper are required, contributions from backscatter can be minimized and transport of phantoms is simplified. Incident dose can be related to dose-area product and entrance surface dose derived using backscatter factors. Such measurements play a valuable role in interpreting patient dose data and recommending options to reduce patient dose.

The surface dose of radiation in conventional diagnostic radiology exams, also known as the entrance surface dose (ESD), is measured to ensure optimal radiation protection for patients. This study aimed to determine and analyze the doses received by pediatric patients who underwent a chest X-ray examination while being treated in the NICU and PICU rooms at Hermina Karawang Hospital. The research involved measuring the radiation dose in pediatric patients using the OSLD nanoDot. This susceptible device can detect low-dose X-ray radiation exposure, especially in pediatric patients. The study was conducted from September to December 2022 and included 35 patients aged 0 to 5. The results of the ESD measurements received by pediatric patients at Hermina Karawang Hospital in the 0-1 year age group were found to be in line with the DRL (Diagnostic Reference Levels) of the United Kingdom (UK) and Austria, which recommend a range of 0.05 – 0.055 mGy. The average ESD value for this age group was 0.05 mGy. Similarly, for the 1-5 year age group, an average ESD value of 0.048 mGy was obtained, below the UK and Austria DRL range of 0.05 – 0.069 mGy. These results indicate that the ESD received by pediatric patients during thoracic examination at Hermina Karawang Hospital is close to the DRL values recommended by the UK and Austria. However, it is essential to note that regardless of the dose received, it must always be justified and optimized to prevent unnecessary radiation exposure. Keywords: ESD, OSLD, unnecessary exposure, paediatric radiation protection, radiation exposure

Increasing FFD: An effective dose-reducing tool for lateral lumbar spine investigations

Introduction: Given the high radiation tissue sensitivity of pediatric patients, it is necessary to monitor their received dose to optimize radiation protection. The first aim of this study was to evaluate the entrance surface dose (ESD) in pediatric patients undergoing a chest X-ray at the main hospital of Dezful, Iran. The second aim was to compare our results with the established dose reference levels (DRLs).&#x0D; Materials and Methods: The studied population included 204 pediatric patients less than 15 years who were referred to as chest X-ray. A calibrated dose area product meter (DAP-meter) with permanent installation on the X-ray unit was used to radiation dose measurements. For each patient, the demographic data, exposure parameters and the dose read by DAP-meter were recorded and ESD was calculated using a standard mathematical formula.&#x0D; Results: The average value of ESD was 119 μGy in patients less than 15 years. This value was 51.3, 122.3, 131.5 and 171.2 μGy for the age groups for less than 1 year, 1 to 5 years, 5 to 10 years and 10 to 15 years, respectively. A statistically significant difference was seen between ESD values ​​in different age groups (P&lt;0.001), whereas no statistical difference was seen between ESD values in ​ girls and boys (P =0.993).&#x0D; Conclusion: Pediatric patients in hospital investigated (except age group less than 1 year) are subjected to unnecessary radiation exposure, especially due to the use of non-optimize X-ray protocols.