Dose-area Product Values Research Articles

Pengaruh Teknik kV Tinggi pada Pemeriksaan Radiografi Thorak Terhadap Entrance Surface Air Kerma dan Dose Area Product yang Diterima oleh Pasien di RSUP Dr. Kariadi Semarang

This study aims to determine the effect of using the high kV technique on chest radiographic examination on Entrance Surface Air Kerma (ESAK), and Dose Area Product (DAP) received by patients. This is one of the optimization efforts in radiation protection and safety in ionizing radiation. This study used retrospective data from chest radiographic images generated by the Siemens Ysio Max radiograph at the Radiology Installation of RSUP Dr. Kariadi Semarang in 2021. Two voltages were used, 59.8 kV and 108.8 kV, with a total sample of 225 patients. The use of the high kV technique produces a smaller ESAK value, namely with a difference of 60.75%, and a smaller DAP value, namely with a difference of up to 74.92%, compared to using the standard kV technique. These results show a significant difference in the radiation dose produced using the high kV technique with image quality that can still use to diagnose a disease/disorder. Keywords: chest radiography, high kV technique, Entrance Surface Air Kerma, Dose Area Product

The impact of body mass index on patient radiation dose in general radiography

The aim of the present study was to determine the influence of the body mass index (BMI) on the dose area product (DAP) and effective dose (ED) in overweight and obese patients. We also wanted to determine the typical dose values as well as suggest adjustments to clinical practice for overweight and obese patients. In this study we considered 597 patients referred for imaging of the chest in posteroanterior and lateral projection, the lumbar spine in anteroposterior (AP) and lateral projection, the pelvis, the knee in AP and lateral projection, and the shoulder in AP projection. For each examination, the image field size, tube voltage, mAs product, source-to-image receptor distance and values of DAP were collected. Based on their BMI, the patients were divided into three groups (normal weight, overweight and obese). At the end, PCXMC 2.0 software was used to calculate the ED. The study showed a statistically significant DAP and ED increase in overweight and obese patients by 28.9% up to 275.4% in the case of DAP and an increase in ED from 11.0% to 241.9% in all mentioned examinations except knee and shoulder imaging. Typical DAP values ranged from 2.2 to 54.8 µGym2 for normal-weight patients, from 2.2 to 87.6 µGym2 for overweight patients, and from 2.2 to 172.5 µGym2 for obese patients. Spearman’s correlation coefficient revealed very weak to very strong correlations when comparing BMI and DAP, as well as when comparing BMI and ED. A strong and very strong correlation was found in the case of examinations of the torso (except for the comparison of BMI and ED in the case of lateral lumbar spine projection).

Retrospective Analysis of Doses Delivered during Embolization Procedures over the Last 10 Years.

Background: This study aimed to retrospectively analyze dosimetric indicators recorded since 2012 for thoracic, abdominal or pelvic embolizations to evaluate the contribution of new tools and technologies in dose reduction. Methods: Dosimetric indicators (dose area product (DAP) and air kerma (AK)) from 1449 embolizations were retrospectively reviewed from August 2012 to March 2022. A total of 1089 embolizations were performed in an older fixed C-Arm system (A1), 222 in a newer fixed C-Arm system (A2) and 138 in a 4DCT system (A3). The embolization procedures were gathered to compare A1, A2 and A3. Results: DAP were significantly lower with A2 compared to A1 for all procedures (median −50% ± 5%, p < 0.05), except for uterine elective embolizations and gonadal vein embolization. The DAP values were significantly lower with A3 than with A1 (p < 0.001). CT scan was used for guidance in 90% of embolization procedures. Conclusions: The last C-Arm technology allowed a median reduction of 50% of the X-ray dose. The implementation of a CT scan inside the IR room allowed for more precise 3D-guidance with no increase of the dose delivered.

Radiation induced cataracts in interventionalists occupationally exposed to ionising radiation.

BackgroundOccupational exposure to ionising radiation may have detrimental health effects. Longer and more complex fluoroscopic procedures have placed interventionalists at increased occupational health risks especially for developing cataracts in the radiosensitive lenses of the eyes.ObjectivesThis study aimed to determine the prevalence of occupational related cataracts and describe the risk factors for cataracts in occupationally exposed interventionalists compared with unexposed doctors.MethodA cross-sectional study using multiple methods. A survey was conducted. The radiation workload was determined based on a self-administered questionnaire and dose area product values determined in previous studies. Both groups had slit lamp examinations. The data were analysed analytically using R software version 9.3.ResultsThe study included 98 interventionalists. The combined prevalence of posterior sub-capsular (PSC) and cortical cataracts was 18.8% in the exposed and 13.9% in the unexposed group. The prevalence of PSC cataracts in the exposed group was 5.9% and 2.8% in the unexposed group, with an odds ratio (OR) of 2.2 (95% confidence interval [CI]: 0.58; 8.61). Posterior sub-capsular cataracts were more common in the left eye. The increase in cataracts was not statistically significant in the exposed group but is of clinical significance.ConclusionThe findings are important as they highlight the need for greater vigilance for protecting the radiation healthcare workforce in a developing country setting.ContributionThe research is the first of its kind in South Africa and Africa and contributes to determining the prevalence in this highly skilled and occupationally vulnerable group.

Overview of cone beam CT patient radiation dose levels in a dental institution regarding patient age, clinical indications, and CBCT scanners

<h3>Objective</h3> To present an overview of typical cone beam CT patient radiation dose levels in a dental institution for different age groups, clinical indications, and CBCT scanners. <h3>Study Design</h3> The patient dose database for CBCT exams performed in 2019, using the 3D Accuitomo 170 (Morita, Kyoto, Japan) and NewTom VGi evo (QR, Verona, Italy) CBCT systems in a dental education institution was assessed and extracted through an automated dose quality management system DOSE (Qaelum NV, Leuven, Belgium). Data regarding age, gender, and clinical indications related to patients, and the type of CBCT scanner, FOV size (small, medium, and large), and dose-area product (DAP) value related to imaging were recorded for each CBCT imaging procedure. A descriptive data analysis was performed, and the average DAP, an average of effective dose, and frequency of examinations were calculated. <h3>Results</h3> A total of 5,166 CBCT examinations were screened. Surgical planning and follow-up were the most frequent clinical indication being the majority indication in medium (35.7%) and large (27.6%) FOVs. In general, DAP and effective dose increased with FOV size. The effective dose ranged from 42.9 to 188.1 µSv for Accuitomo 170 to 46.7 to 140.1 µSv for NewTom VGi evo. <h3>Conclusion</h3> DAP values and effective doses were heterogeneously distributed amongst age groups and mostly influenced by clinical indications of the related FOV size selection. While patient-specific imaging remains advocated, the fact that two-thirds of the indications are surgically oriented makes the medium and large field of views predominant. Developers of CBCT systems could be advised to move towards patient-specific collimation and dynamic field-of-view selection, preferably via an automated algorithm to facilitate clinical implementation of the optimal patient-specific and indication-oriented dose (ALADAIP). <b>Statement of Ethical Review</b> Ethical review was sought and study was exempted from ethical review

Evaluation of DAP Values Obtained from Chest X-rays in Children under 12 Years of Age Referred to Educational Hospitals of Birjand University of Medical Sciences in 2020

Purpose: Dose Area Product (DAP) is a quantity for radiation risk assessment in diagnostic X-ray tests. Children's tissues are up to 10 times more sensitive to radiation than adults, and life expectancy is higher in children than adults, as well as a higher risk of hematopoietic and mass malignancies in them. Therefore, this study aimed to measure DAP values for X-ray fields adjusted by Birjand radio-technologists in chest X-rays of children under 12 years of age.&#x0D; Materials and Methods: 233 children from Birjand University hospitals who performed chest X-rays were included in the study. To collect data related to DAP, the DAP meter model KermaX® plus SDP was used. It should be noted that no intervention was performed in the patient's imaging method and at the time of radiation and measurement of the DAP values, there was no need for the patient's presence. In the end, the measured DAP values were compared with DAP values of other studies. Data were analyzed using SPSS software version 22 at 5% error level using Analysis of Variance (Anova), t-test, and Pearson correlation tests.&#x0D; Results: Out of 233 patients who were included in the study, 134 males (57.5%) and 99 females (42.5%) participated in the study, it should be noted that there was no significant difference between the mean of DAP in male and female (p = 0.52). In our study, the average DAP was 5.78 ± 3.54 μGy.m2 and DAP values in the range of 0.55 μGy.m2 to 15.54 μGy.m2 that were higher than the average of other studies and there was a significant difference. There was a direct relationship between radiation field dimensions and DAP values so that as the dimensions of the radiation field increase, the DAP value increases. There was a significant difference between the mean DAP of the lowest and the highest age groups, lowest and the highest age groups, and lowest and the highest height groups of patients.&#x0D; Conclusion: In our study, it was observed that there is a significant relationship between patients' weight, age, and height, radiation field dimensions with DAP values. The amount of DAP in the present study was significantly higher than in other studies. The most important effective parameter in DAP is the radiation field size and if sufficient optimization is done in imaging parameters (kVp, mAS, field size), the DAP values will be greatly reduced.

Occupational radiation dose and protection to the eye lens for interventional cardiology operators

ObjectivesInterventional professionals tend to receive extended radiation exposure given the complexity and machine settings of procedures in interventional cardiology departments, resulting in a high eye lens dose. This study developed a method for estimating the occupational radiation dose to the eye lens based on the personal dose equivalent to the skin at 0.07-mm depth [Hp(0.07)] obtained using an over-apron dose badge, investigated whether glasses with lateral shielding but a thin Pb-equivalent material could adequately protect the eye lens from radiation in clinical situations, and identified factors affecting the occupational radiation dose to the eye lens. MethodsThe occupational radiation dose was prospectively measured using dosimeters near the eye and over the lead apron at the collar level in 26 interventional professionals performing 444 procedures in interventional cardiology departments. Type A (0.07-mm front and lateral Pb equivalence) and type B (0.5-mm front Pb equivalence and 0.25-mm lateral Pb equivalence) glasses were worn by the operators during operation to protect the eye lens. ResultsThe median personal dose equivalent to the eye lens at 3-mm depth [Hp(3)/dose area product (DAP)] of the primary operator was the highest (7.6 μSv/Gycm2) for upper limb percutaneous transluminal angioplasty among all examined procedures. The secondary operator's median Hp(3)/DAP values ranged from 17% to 41% of that of the primary operator. The median Hp(3)/DAP values did not significantly differ between the primary operators wearing type A glasses and those wearing type B glasses for percutaneous coronary intervention or diagnostic cardiology studies (all p > 0.05). The Pearson correlation test results revealed significant positive correlations between the Hp(3) and Hp(0.07). The estimated annual Hp(3) values ranged from 3.3 ± 0.6 to 62.4 ± 8.3 mSv and from 6.0 to 8.0 ± 4.6 mSv for the cardiologists and radiographers, respectively. ConclusionsThe Hp(3) value can be estimated from the Hp(0.07) value obtained using an over-apron dose badge at the collar level. Glasses with 0.07-mm front and lateral Pb equivalence provide satisfactory radiation protection to the eye lens. Regularly using appropriate radiation-protective lead glasses, adopting small angles for left anterior oblique projections, and undertaking moderate workloads are highly recommended to prevent cardiologists from receiving excessive radiation doses to the eye lens.

An analysis of patient dose received during cone-beam computed tomography in relation to scan settings and imaging indications as seen in a dental institution in order to establish institutional diagnostic reference levels.

To investigate the dose-area product (DAP) of cone-beam computed tomography (CBCT) examinations for different scan settings and imaging indications, and to establish institutional diagnostic reference levels (DRLs) for dose optimisation. A retrospective analysis of the DAP values of 3568 CBCT examinations taken from two different devices at the Prince Philip Dental Hospital, Hong Kong between 2016 and 2021 was performed. Patient- (age, gender, and imaging indication) and imaging-related (CBCT device, field-of-view (FOV), and voxel size) were correlated with the DAPs. The indication-oriented third-quartile DAP values were compared with DRLs from the UK, Finland, and Switzerland. The obtained third-quartile DAPs lower than the national DRLs and those for which no national DRLs have been proposed were used to establish institutional DRLs. In the investigated CBCTs, the DAP value for large FOV scans was significantly lower than medium/small FOVs. CBCTs with a small voxel size exhibited a significantly higher DAP than those with a medium/large voxel size. CBCTs for endodontic, periodontal, orthodontic, or orthognathic evaluation exhibited a significantly higher DAP than other indications. Twelve indication-oriented institutional DRLs were established and five of them were lower than the national DRLs: third molars (229 mGy×cm2), jaw cysts/tumours (410 mGy×cm2), maxillary sinus pathology (520 mGy×cm2), developing dentition (164 mGy×cm2), and periapical lesions (564 mGy×cm2). CBCT examinations for endodontic, periodontal, orthodontic, or orthognathic evaluation may deliver a higher radiation dose to the patient than other imaging tasks. A periodic review of the patient dose from CBCT imaging and establishment of institutional DRLs for specific clinical settings are needed for monitoring patient dose and to optimise indication-oriented scanning protocols.

Correlation analysis between radiation exposure and the image quality of cone-beam computed tomography in the dental clinical environment.

PurposeThis study was conducted to measure the radiation exposure and image quality of various cone-beam computed tomography (CBCT) machines under common clinical conditions and to analyze the correlation between them.Materials and MethodsSeven CBCT machines used frequently in clinical practice were selected. Because each machine has various sizes of fields of view (FOVs), 1 large FOV and 1 small FOV were selected for each machine. Radiation exposure was measured using a dose-area product (DAP) meter. The quality of the CBCT images was analyzed using 8 image quality parameters obtained using a dental volume tomography phantom. For statistical analysis, regression analysis using a generalized linear model was used.ResultsPolymethyl-methacrylate (PMMA) noise and modulation transfer function (MTF) 10% showed statistically significant correlations with DAP values, presenting positive and negative correlations, respectively (P<0.05). Image quality parameters other than PMMA noise and MTF 10% did not demonstrate statistically significant correlations with DAP values.ConclusionAs radiation exposure and image quality are not proportionally related in clinically used equipment, it is necessary to evaluate and monitor radiation exposure and image quality separately.

Evaluation of Radiation Dose Reduction and its Effect on Image Quality for Different Flat-Panel Detectors.

Purpose:To evaluate the image quality of semi-anatomical chest radiographs acquired using low radiation doses from seven different flat-panel detector (FPD) systems.Materials and Methods:Radiographs of a semi-anatomical chest phantom were acquired at 70 and 110 kVp using 7 different FPDs from 5 vendors. Radiation doses were measured using a dose-area-product (DAP) meter. To standardize measurements across all FPDs, DAP value of 51.05 μGym2 obtained at 70 kVp and 9.43 μGym2 at 110 kVp was used as reference in this study. Radiation doses were reduced by manually adjusting mAs for both tube potentials in all FPD systems to achieve acceptable image quality. Contrast-to-noise ratio, signal-to-noise ratio and figure of merit (FOM) in lung, heart, and diaphragm for all images were analyzed.Results:In comparison with set standard protocol, radiation dose reduction of 20%, 21%, 21.6%, 59.5%, 60.7%, 62.2%, and 67.6% with optimal image quality was observed in Prognosys Prorad, GE Definium 8000, Siemens Fusion, Fujifilm FGX, Fujifilm FGXR, Philips Digital Diagnost and Siemens Aristos at 70 kVp. At 110 kVp, dose reduction of 15.7% and 34.8% was possible only for Philips Digital Diagnost and Siemens Aristos. FOM was high at 110 kVp even when radiation doses were reduced by a factor 2 when compared to 70 kVp in all digital radiography systems.Conclusion:This study demonstrates the feasibility of using a semi-anatomical chest phantom in the optimization of radiation dose and image quality. The FOM was a good indicator in assessing image quality between different detectors.

The impact of obesity on perioperative and postoperative outcomes after elective endovascular abdominal aortic aneurysm repair.

Obesity is a common and growing health problem in vascular surgery patients, as it is in all patient groups. Evidence regarding body mass index (BMI) on endovascular aneurysm repair (EVAR) outcomes is not clear in the literature. We aimed to determine the impact of obesity on perioperative and midterm outcomes of elective EVAR between obese and non-obese patients. Under a retrospective study design, a total of 120 patients (109 males, 11 females, mean age: 74.45 ± 8.59 (53-92 years)) undergoing elective EVAR between June 2012 and May 2020 were reviewed. Patients were stratified into two groups: obese (defined as a body mass index (BMI) ≥ 30kg/m2) and non-obese (mean BMI < 30kg/m2 (32.25 ± 1.07kg/m2 vs 25.85 ± 2.69kg/m2)). Of the 120 patients included in the study, 81 (67.5%) were defined as "nonobese," while 39 (32.5%) were obese. The mean BMI of the study group was 27.93 ± 3.78kg/m2. In obese patients, the procedure time, fluoroscopy time, and dose area product (DAP) values were longer than those of non-obese patients: 89.74 ± 20.54 vs 79.69 ± 28.77 min (p = 0.035), 33.23 ± 10.14 vs 38.17 ± 8.61 min (p = 0.01) and 133.69 ± 58.17 vs 232.56 ± 51.87Gy.cm2 (p < 0.001). Although there was no difference in sac shrinkage at 12-month follow-up, there was a significant decrease at 6-month follow-up in both groups (p = 0.017). Endoleak occurred in 17.9% (n = 7) of the obese group versus 11.1% (n = 9) of the non-obese group (p = 0.302). Iliac branch occlusion developed in four patients, 3 (3.7%) in the non-obese group and 1 (2.6%) in the obese group (p = 0.608). The all-cause mortality rate was slightly higher in the obese group; however, it did not differ between the groups (p = 0.463). In addition to the longer procedure times, fluoroscopy times, and DAP values in obese patients, regardless of obesity, significant sac shrinkage in the first 6months of follow-up was observed in both groups. No difference was documented with regards to mortality or morbidity following EVAR.

Monitoring Radiation Doses during Diagnostic and Therapeutic Neurointerventional Procedures: Multicenter Study for Establishment of Reference Levels.

PurposeTo assess patient radiation doses during diagnostic and therapeutic neurointerventional procedures from multiple centers and propose dose reference level (RL).Materials and MethodsConsecutive neurointerventional procedures, performed in 22 hospitals from December 2020 to June 2021, were retrospectively studied. We collected data from a sample of 429 diagnostic and 731 therapeutic procedures. Parameters including dose-area product (DAP), cumulative air kerma (CAK), fluoroscopic time (FT), and total number of image frames (NI) were obtained. RL were calculated as the 3rd quartiles of the distribution.ResultsAnalysis of 1160 procedures from 22 hospitals confirmed the large variability in patient dose for similar procedures. RLs in terms of DAP, CAK, FT, and NI were 101.6 Gy·cm2, 711.3 mGy, 13.3 minutes, and 637 frames for cerebral angiography, 199.9 Gy·cm2, 3,458.7 mGy, 57.3 minutes, and 1,000 frames for aneurysm coiling, 225.1 Gy·cm2, 1,590 mGy, 44.7 minutes, and 800 frames for stroke thrombolysis, 412.3 Gy·cm2, 4,447.8 mGy, 99.3 minutes, and 1,621.3 frames for arteriovenous malformation (AVM) embolization, respectively. For all procedures, the results were comparable to most of those already published. Statistical analysis showed male and presence of procedural complications were significant factors in aneurysmal coiling. Male, number of passages, and procedural combined technique were significant factors in stroke thrombolysis. In AVM embolization, a significantly higher radiation dose was found in the definitive endovascular cure group.ConclusionVarious RLs introduced in this study promote the optimization of patient doses in diagnostic and therapeutic interventional neuroradiology procedures. Proposed 3rd quartile DAP (Gy·cm2) values were 101.6 for diagnostic cerebral angiography, 199.9 for aneurysm coiling, 225.1 for stroke thrombolysis, and 412.3 for AVM embolization. Continual evolution of practices and technologies requires regular updates of RLs.

Reference Person Dose-Area Product and Organ Dose-Area Product Estimates During Pelvis Radiography in Some Selected Centres in Lagos Conurbation, Nigeria

Background: In diagnostic radiology, focus on patient’s dose measurement has been on the estimation of entrance skin surface dose and its equivalent risk assessor (effective and organ doses). So, this study identified DAP’s as capable of performing same function as ESD in patient dose monitoring. Thus, reported estimates on dose area product (DAP) and the equivalent risk to organ’s exposed in adult patients during pelvis examination in Lagos State, Nigeria. Patients and Methods: Gender percentage ratio of 39.4 and 60.4 for male and female respectively, from six selected centres, exposed for both pelvis AP and LAT of the procedures were monitored using mathematical approach and dose Cal version 2.31 software, designed to monitor organ’s dose and DAP. Results: The average DAP and it equivalent organ dose area product (ODAP) values recorded from a population of 278 adult patients studied were found to be within expected limits for a reference adult person. Though, DAP for pelvis AP was found almost twice that recorded for the pelvis LAT. High and low organ DAP recorded for both gender from urinary bladder and lungs respectively for pelvis AP whilst these were pelvis bone and lungs for male and ovaries and lungs for female from pelvis LAT respectively. High values were equally recorded for the reproductive organs (Testicles and Ovaries) during pelvis AP. Conclusion: This study therefore suggest that better understanding of organ anatomical position in relation to specific examination will better promote as low as reasonable practicable.

Evaluation of Correlation between DAP (Dose-Area Product) Values and Cardiologist Dose during Coronary Angiography Using Monte Carlo Simulation

Introduction: The present study investigated the correlations between the patient’s dose-area product (DAP) values and cardiologist’s dose using Monte Carlo simulation. During angiography procedures, patients are exposed to the primary beam; however, the cardiologist is irradiated by the scattered radiation arising from the table and the surrounding equipment. Accordingly, the cardiologist’s dose is directly related to the patient’s dose. Material and Methods: This study investigated 25 cardiac angiography procedures. In each procedure, the DAP readings and the cardiologist dose as measured using an electronic personal dosimeter placed over the apron were recorded. Moreover, the DAP values and dose received by the cardiologist in the chest region were calculated using the Monte Carlo N-Particle extended code. For the validation of the simulated spectrum, dosimetric measurements were made using a Farmer ionization chamber and a phantom. Results: The data obtained from 18 simulations showed that there was a strong linear relationship (R2=0.71) between the two variables of cardiologist’s dose and patient’s DAP. Likewise, the obtained results of dosimetry conducted on the patients in 25 cardiac angiography procedures revealed that there was a strong relationship (R2=0.78) between the two variables. Conclusion: The reported correlation rates show the appropriateness of the physician radiation exposure to total patient’s DAP. With respect to the strong correlation coefficient obtained from the simulation method, it is recommended that this method should be verified by dosimetry. The findings of this study showed a linear relationship between the cardiologist’s dose and the total dose of the patient.

Dosimetry on first clinical dark-field chest radiography.

The purpose of this study was to evaluate the dose characteristic for patient examinations at the first clinical X-ray dark-field chest radiography system and to determine whether the effective patient dose is within a clinically acceptable dose range. A clinical setup for grating-based dark-field chest radiography was constructed and commissioned, operating at a tube voltage of 70kVp. Thermoluminescent dosimeter (TLD) measurements were conducted using an anthropomorphic phantom modeling the reference person to obtain a conversion coefficient relating dose area product (DAP) to effective patient dose at the dark-field system. For 92 patients, the DAP values for posterior-anterior measurements were collected at the dark-field system. Using the previously determined conversion coefficient, the effective dose was calculated. A reference person, modeled by an anthropomorphic phantom, receives an effective dose of 35µSv. For the examined patients, a mean effective dose of 39µSv was found. The effective dose at the clinical dark-field radiography system, generating both attenuation and dark-field images, is within the range of reported standard dose values for chest radiography.

Image Mosaic Algorithm-Based Analysis of Effects of Low-Dose X-Rays on Blood Immune Cells

This work aimed to explore the effects of image mosaic algorithm- (IMA-) based low-dose X-rays on deoxyribonucleic acid (DNA) damage of peripheral blood lymphocytes in cardiovascular patients. 84 patients with interventional cardiovascular surgeries were selected as the research objects and divided into coronary intervention surgery (A) group, coronary angiography (B) group, radiofrequency ablation (C) group, and permanent cardiac pacemaker implantation (D) group. They were treated with IMA-based low-dose X-rays, DNA damage indicators of lymphocytes were detected, and the relationship was analyzed between those indicators and radiation dose. Results showed that the cumulative dose (CD) and dose area product (DAP) of group A were the lowest, and those of group D were obviously higher than those of the other three groups ( P &lt; 0.01 ). Besides, the results also showed that the values of CD and DAP of patients from group A and group D were 0.38 ± 0.08 (Gy) and 0.38 ± 0.08 (Gy/cm2) and 1.37 ± 0.21 (Gy) and 1.37 ± 0.21(Gy/cm2), respectively. The comet tail DNA content (TDNA) and tail moment (TM) of each group after surgery increased dramatically compared with before surgery ( P &lt; 0.01 ), and the TDNA and TM of group D were greatly higher than those of the other three groups ( P &lt; 0.01 ). Therefore, TDNA and TM were markedly positively correlated with DAP and CD ( P &lt; 0.01 ). IMA-based X-ray radiotherapy caused reliable DNA damage to peripheral blood lymphocytes of cardiovascular patients, and the greater the radiation dose, the more serious the DNA damage.

Ultrasound-guided portal vein puncture during Transjugular Intrahepatic Portosystemic Shunt: Technique and experience of a quaternary liver transplant hospital.

Portal hypertension (PH) is associated with complications including refractory ascites and variceal haemorrhage and can be treated endovascularly with a Transjugular Intrahepatic Portosystemic Shunt (TIPS). Portal vein puncture during TIPS using real-time transabdominal ultrasound guidance is one of many portal vein puncture techniques and is seldom used compared with other methods. The purpose of this manuscript is to describe this technique and its associated procedural outcomes at a quaternary liver transplant hospital. Clinical data of all patients who underwent ultrasound-guided TIPS at our institution between 1 January 2009 and 1 January 2019 were retrospectively obtained from electronic medical records and reviewed. Patient demographics, indications, procedural outcomes and complications were recorded. Forty-four ultrasound-guided TIPS procedures were performed during the study period. The most common indication for TIPS was refractory ascites (n = 26; 57%) and variceal haemorrhage (n = 12; 26%). Technical success rate was 100%. No intraprocedural complications occurred. Periprocedural complication rate was 35% (n = 16) with encephalopathy (n = 8; 17%) and sepsis (n = 5; 11%) the most common. One patient with sepsis died. No other TIPS-related deaths occurred. Median fluoroscopy time, contrast volume, air kerma and dose area product values for all procedures were 35 minutes (IQR 24-51), 100 ml (IQR 70-160), 0.95 Gy (IQR 0.50-1.53) and 127 Gycm2 (IQR 68.75-206), respectively. Transabdominal ultrasound-guided portal vein puncture during TIPS is safe and technically feasible. When compared to fluoroscopically guided methods, it is associated with lower intraprocedural complication rates, fluoroscopy times, contrast volumes and radiation doses in our experience. Radiation doses, FTs and contrast volumes were also considerably lower than recommended limits.

DOSE EVALUATION AND PROPOSAL OF LOCAL DIAGNOSTIC REFERENCE LEVELS FOR PAEDIATRIC CARDIAC CATHETERIZATIONS PERFORMED ON A HIGH-SENSITIVITY ANGIOGRAPHIC SYSTEM ALLOWING LOW-DOSE IMAGING.

Radiation doses from paediatric cardiac catheterizations were analysed based on procedure type and patient weight, and local diagnostic reference levels (LDRLs) were proposed. The procedures were performed on a Siemens Artis Q.zen biplane system with high-sensitivity detectors allowing low-dose imaging. Good radiological practice, e.g. adapting dose level and frame rate continuously and minimizing the x-ray field with collimators, was routine during procedures. The median total dose-area-product (DAP) value was 58 μGym2 for diagnostic catheterizations, 48 μGym2 for interventional catheterizations and 33 μGym2 for myocardial biopsies. The median DAP per body weight was 4.0 μGym2 kg-1. The median total fluoroscopy time varied from 6.0min for myocardial biopsies, to 9.7 and 10.5min, respectively, for diagnostic and interventional catheterizations. The third quartile of the DAP values in each weight group was proposed as LDRL. LDRLs for fluoroscopy time were determined solely based on procedure type, due to the absence of weight dependence.

How does a non-optimal tube potential influence radiation dose to the patient in lumbar spine radiography?

IntroductionWhen comparing the radiation dose to the patient, the lumbar spine has one of the highest dose values in general radiography, therefore the procedure needs to be optimised. The aim of this study was to investigate the effect of a non-optimal tube potential (66 kV) during anteroposterior (AP) lumbar spine radiography on the radiation dose received by the patient compared with the radiation dose when an optimal tube potential (79 kV) is used, in accordance with European guidelines. MethodsThis retrospective study involved 100 patients referred for lumbar radiography in two different diagnostic departments. Half of the patients were admitted to a department which used optimal tube potential and the other half to the department which used non-optimal tube potential for AP lumbar spine radiography protocols. The height and weight of the patients were collected to calculate the body mass index (BMI) of the patients. The image field size and dose area product (DAP) values were collected after each imaging session. The effective dose and selected organ dose were calculated using the PCXMC 2.0 program. ResultsThe results showed that a non-optimal tube potential resulted in a significant increase in the DAP value by 360% (p < 0.001) and a significant increase in the effective dose by 160% (p < 0.001). Dose to selected organs due to non-optimal tube potential increased from 107% (breasts) up to 631% (prostate) (p < 0.001). The images were not assessed using visual grading characteristics (VGC) analysis, but the radiologists evaluated all the images appropriate for diagnostic reading. ConclusionBased on our study's stated results, we can conclude that optimal tube potential use is essential to achieve the ALARA principle. Implications for practiceThe study shows the effect of a non-optimal tube potential on the radiation dose received by the patient during radiography of the lumbar spine. This could influence possible diagnostic departments to consider protocol optimisation due to the high radiation dose received by the patient.

Patient-Based Dose Audit for Common Radiographic Examinations With Digital Radiology Systems: A Retrospective Cross-Sectional Study.

This study aims to audit radiation doses of adult patients who underwent common diagnostic X-ray examinations and compare dose area product (DAP) values with the established International Diagnostic Reference Level (IDRLs). Retrospective cross-sectional records of 339-patients who underwent 699-radiographic examinations between October 2018 and March 2019 were obtained. Patient-related factors, exposure, and DAP data were recorded for the six most common examinations. The mean and 75th percentile of DAPs were recorded and compared to IDRLs values. The 75th percentiles of the locally measured DAPs were below IDRLs for all examinations except for lateral lumbar, AP, and lateral thoracic spine, in which DAP-75th-percentile exceeded all IDRLs by up to 40.7%, 2.8%, 365.5%, respectively. Considering the type of detector used, the mean of the locally measured DAPs significantly exceeded the UK DRLs for the lateral thoracic spine and lateral lumbar spine. Locally measured DAP values were below the IDRLs except for thoracic and lumbar spine projections, which significantly exceeded.