Patient's effective dose and performance assessment of computed radiography systems.

Computed tomography is widely used for planar imaging. Previous studies showed that CR systems involve higher patient radiation doses compared to digital systems. Therefore, assessing the patient's dose and CR system performance is necessary to ensure that patients received minimal dose with the highest possible image quality. The study was performed at three medical diagnostic centers in Sudan: Medical Corps Hospital (MCH), Advance Diagnostic Center (ADC), and Advance Medical Center (AMC). The following tools were used in this study: Tape measure, Adhesive tape, 1.5 mm copper filtration (>10 × 10 cm), TO 20 threshold contrast test object, Resolution test object (e.g., Huttner 18), MI geometry test object or lead ruler, Contact mish, Piranha (semiconductor detector), Small lead or copper block (∼5 × 5 cm), and Steel ruler, to do a different type of tests (Dark Noise, Erasure cycle efficiency, Sensitivity Index calibration, Sensitivity Index consistency, Uniformity, Scaling errors, Blurring, Limiting spatial Resolution, Threshold, and Laser beam Function. Entrance surface air kerma (ESAK (mGy) was calculated from patient exposure parameters using DosCal software for three imaging modalities. A total of 199 patients were examined (112 chest X rays, 77 lumbar spine). The mean and standard deviation (sd) for patients ESAK (mGy) were 2.56 ± 0.1 mGy and 1.6 mGy for the Anteroposterior (AP) and lateral projections for the lumbar spine, respectively. The mean and sd for the patient's chest doses were 0.1 ± 0.01 for the chest X-ray procedures. The three medical diagnostic centers' CR system performance was evaluated and found that all of the three centers have good CR system functions. All the centers satisfy all the criteria of acceptable visual tests. CR's image quality and sensitivity were evaluated, and the CR image is good because it has good contrast and resolution. All the CR system available in the medical centers and upgraded from old X-ray systems to new systems, has been found to work well. The patient's doses were comparable for the chest X-ray procedures, while patients' doses from the lumbar spine showed variation up to 2 folds due to the variation in patients' weight and X-ray machine setting. Patients dose optimization is recommended to ensure the patients received a minimal dose while obtaining the diagnostic findings.

Paediatric effective radiation doses during brain computed tomography angiography procedure.

In comparison to adults and paediatric are more sensitive to ionizing radiation exposure. Computed tomography (CT) is now the dominant source of medical radiologic tests for patients, accounting for more than 70% of total doses to the general public. Paediatric CT brain scans (with and without contrast) are routinely performed for a variety of clinical reasons. As a result, this parameter must be calculated in order to determine relative radiation risk. The goal of this study is to assess the radiation risk to children during CT brain diagnostic procedures. Three hundred fifty three child patients' radiation risk doses were assessed over the course of a year. The mean and ranged of the children's radiation doses were 40.6 ± 8.8 (27.8-45.8) CTDIvol (mGy) and 850 ± 230 (568.1-1126.4) DLP (mGy.cm) for the brain with contrast medium. For CT brain without contrast, the patients' doses were 40.9 ± 9.4 (14.27-64.07) CTDIvol (mGy), and 866.1 ± 289.3 (203.6-2484.9) DLP (mGy.cm). The characteristics related to the radiation dose were retrieved from the scan protocol generated by the CT system by the participating physicians after each procedure. Furthermore, optimizing the CT acquisition parameter is critical for increasing the benefit while lowering the procedure's radiogenic risk. The patients' radiation dose is comparable with the most previously published studies and international diagnostic reference levels (DRLs). Radiation dose optimization is recommended due to high sensitivity of the paediatric patients to ionizing radiation.

Early Outcomes of Pelvic Trauma Patients - Complications, ICU Stay and Treatment Concepts in Two ATLS Compliant Trauma Centers: Germany and Qatar.

PURPOSE OF THE STUDY Pelvic trauma causes severe threats especially to polytraumatized patients. Not only it is in itself a possible cause for significant bleeding, but it also indicates a high risk for intra-abdominal injuries. The initial treatment of patients with pelvic trauma follows the ATLS principles of priority-oriented treatment. To examine the value of this highly standardized concept and to evaluate the effect of different patient collectives on early outcome parameters, two large collectives from Germany and Qatar were analyzed regarding injury parameters and early outcomes. MATERIAL AND METHODS Patients were recruited in Hamad General Hospital, Doha, Qatar (HGH) and BG Trauma Center Ludwigshafen, Germany (BG). All patients that were treated with a pelvic fracture between 2013 and 2016 were included in this retrospective analysis. Demographic parameters were collected as well as type of injury and the frequency of complication parameters as pneumonia, acute kidney failure, ARDS, sepsis and amount of blood transfusion. 1436 patients with pelvic fracture (645 from BG and 791 from HGH) were recruited. The mean age was 57.4 years in the BG and 33.6 years in the HGH group (p<0.000). The mean ISS was 17.81 in the BG and 15.88 in the HGH group (p=0.009). The mean pelvic AIS was 2.65 in the BG and 2.25 in the HGH group (p<0.000). RESULTS The mean frequency of complications was 9.3% in the BG and 9.9% in the HGH group (p=0.128). The mean frequency of ARDS was significantly higher in the BG group than in the HGH group (5.6% vs. 1.8%, p<0.000). The mean frequency of blood transfusion was significantly lower in the BG group than in the HGH group (28.8% vs. 39.2%, p<0.000). CONCLUSIONS Despite significant differences in the two collectives, this analysis shows comparable results regarding early outcome parameters in patients with pelvic injuries. In total, pelvic injuries are accompanied by a relatively high complication risk and need to be evaluated and treated according to priority-based algorithms. Key words: ATLS®, pelvic injury, complications, polytrauma.

Patient Exposure during Fluoroscopy-guided Pacemaker Implantation Procedures.

A pacemaker, which is used for heart resynchronization with electrical impulses, is used to manage many clinical conditions. Recently, the frequency of pacemaker implantation procedures has increased to more than 50% worldwide. During this procedure, patients can be exposed to excessive radiation exposure. Wide range of doses has been reported in previous studies, suggesting that optimization of this procedure has not been fulfilled yet. The current study evaluated patient radiation exposure during cardiac pacemaker procedures and quantified the patient effective dose. A total of 145 procedures were performed for five pacemaker procedures (VVI, VVIR, VVD, VVDR, and DDDR) at two hospitals. Patient doses were measured using the kerma-area product meter. Effective doses were estimated using software based on Monte Carlo simulation from the National Radiological Protection Board (NRPB, now The Health Protection Agency). The effective dose values were used to estimate cancer risk from the pacemaker procedure. Patient demographic data and exposure parameters for fluoroscopy and radiography were quantified. The mean patient doses ± SD per procedure (Gycm2) for VVI, VVIR, VVD, VVDR, and DDDR were 1.52 ± 0.13 (1.43-1.61), 3.28 ± 2.34 (0.29-8.73), 3.04 ± 1.67 (1.57-4.86), 6.04 ± 2.326 3.29-8.58), and 8.8 ± 3.6 (4.5-26.20), respectively. The overall patient effective dose was 1.1mSv per procedure. It is obvious that the DDDR procedure exposed patients to the highest radiation dose. Patient dose variation can be attributed to procedure type, exposure parameter settings, and fluoroscopy time. The results of this study showed that patient doses during different pacemaker procedures are lower compared to previous reported values. Patient risk from pacemaker procedure is low, compared to other cardiac interventional procedures. Patients' exposures were mainly influenced by the type of procedures and the clinical indication.

Estimation of effective dose and radiation risk in pediatric barium studies procedures.

The objectives of this study are to assess pediatric radiation exposure in certain barium studies and to quantify the organ and effective doses and radiation risk resultant from patients' irradiation. A total of 69 pediatric barium studies for upper and lower gastrointestinal tract. Patients' radiation dose was quantified in terms of Entrance surface air kerma (ESAKs) using exposure parameters and DosCal software. Organ and effective doses (E) were extrapolated using national Radiological Protection Board software (NRPB-R279). The mean ± (SD) and the range of patient doses per procedure were 3.7 ± 0.4 (1.0-13.0)mGy, 7.4 ± 1.7(5.5-8.0)mGy and 1.4 ± 0.9 (0.5-3.6)mGy for barium meal, swallow and enema, respectively. The mean effective doses were 0.3 ± 0.03 (0.08-1.1)mSv, 0.2 ± 1.6 (0.44-0.7)mSv and 0.3 ± 0.9 (0.1-0.8)mSv at the same order. The radiation dose were higher compared to previous studies. Therefore, pediatrics are exposed to avoidable radiation exposure. Certain optimization measures are recommended along with establishing national diagnostic reference level (DRL) to reduce the radiation risk.

Patient radiation biological risk in computed tomography angiography procedure.

Computed tomography angiography (CTA) has become the most valuable imaging modality for the diagnosis of blood vessel diseases; however, patients are exposed to high radiation doses and the probability of cancer and other biological effects is increased. The objectives of this study were to measure the patient radiation dose during a CTA procedure and to estimate the radiation dose and biological effects. The study was conducted in two radiology departments equipped with 64-slice CT machines (Aquilion) calibrated according to international protocols. A total of 152 patients underwent brain, lower limb, chest, abdomen, and pelvis examinations. The effective radiation dose was estimated using ImPACT scan software. Cancer and biological risks were estimated using the International Commission on Radiological Protection (ICRP) conversion factors. The mean patient dose value per procedure (dose length product [DLP], mGy·cm) for all examinations was 437.8 ± 166, 568.8 ± 194, 516.0 ± 228, 581.8 ± 175, and 1082.9 ± 290 for the lower limbs, pelvis, abdomen, chest, and cerebral, respectively. The lens of the eye, uterus, and ovaries received high radiation doses compared to thyroid and testis. The overall patient risk per CTA procedure ranged between 15 and 36 cancer risks per 1 million procedures. Patient risk from CTA procedures is high during neck and abdomen procedures. Special concern should be provided to the lens of the eye and thyroid during brain CTA procedures. Patient dose reduction is an important consideration; thus, staff should optimize the radiation dose during CTA procedures.

Radiation exposure in pediatric patients during micturating cystourethrography procedures.

The objectives of this study were to measure the entrance surface air kerma (ESAK) and the effective doses in pediatric patients undergoing micturating cystourethrography (MCU) procedures. The ESAK was determined using calibrated thermoluminescent dosimeters (TLD- GR 200 A) in 167 pediatric patients. The patient population was categorized into three groups according to age (0-5 years (group 1), 6-10 years (group 2) and 11-15 years (group 3)). The mean ESAK±SD and range (mGy) resulting from a MCU procedure was estimated to be 2.2±0.5 (0.8-9.2), 2.48±0.6 (0.9-8.1) and 3.90±0.6 (1.1-10.3) for group 1, 2 and 3, respectively. The mean effective dose was between 0.03 and 0.4 mSv per procedure for the pediatric population. Pediatric patients were exposed to avoidable radiation doses because no gonad shields were used.

Assessment of patient dose and radiogenic risks during endoscopic retrograde cholangiopancreatography.

Endoscopic retrograde cholangiopancreatography (ERCP) is an invasive technique that has been used for over 30 years in the diagnosis and management of pancreaticobiliary disorders. The objectives of this study were to evaluate the patient entrance surface air kerma doses (ESAK) and estimate the organ and effective doses during ERCP in three hospitals in Khartoum. A total of 55 patients were examined in three hospitals in Khartoum state, Sudan. Calibrated thermoluinescent dosimeters (TLD) were used to measure patients' ESAK. Organ and effective doses were estimated using National Radiological Protection Board (NRPB) software. The overall mean of ESAK for all ERCP procedures was 42.4mGy. The mean patient ESAK in Fedail (A), Soba (B) and Ibn sena (C) hospitals were 26.7mGy, 26.0mGy and 72.4mGy, respectively. The effective doses in three hospitals were 1.60, 1.56 and 2.67mSv in that order and the overall mean effective dose was 1.94mSv. Patient radiation doses vary widely among the hospitals. Patient ESAK is low compared to previous studies in the light of the current practice. Patient dose was decreased significantly in the last two decades.

Radiation doses in chest, abdomen and pelvis CT procedures.

Computed tomography (CT) scanning is recognised as a high-radiation dose modality and estimated to be 17 % of the radiological procedure and responsible for 70 % of medical radiation exposure. Although diagnostic X rays provide great benefits, their use involves some risk for developing cancer. The objectives of this study are to estimate radiation doses during chest, abdomen and pelvis CT. A total of 51 patients were examined for the evaluation of metastasis of a diagnosed primary tumour during 4 months. A calibrated CT machine from Siemens 64 slice was used. The mean age was 48.0 ± 18.6 y. The mean patient weight was 73.8 ± 16.1 kg. The mean dose-length product was 1493.8 ± 392.1 mGy cm, Volume CT dose index (CTDI vol) was 22.94 ± 5.64 mGy and the mean effective dose was 22.4 ± 5.9 mSv per procedure. The radiation dose per procedure was higher as compared with previous studies. Therefore, the optimisation of patient's radiation doses is required in order to reduce the radiation risk.

Radiation dose levels for conventional chest and abdominal X-ray procedures in elected hospitals in Sudan.

This study aimed to assess patient entrance surface air kerma (ESAK) during chest and abdominal X-ray procedures in screen film radiography (SFR) and computed radiography (CR) to establish dose reference levels. Patients' doses were measured in five hospitals for a total of 196 patients. ESAK was calculated from exposure parameters using DosCal software. The X-ray tube output (mGy mAs(-1)), accuracy of exposure factors, linearity and reproducibility were measured using an Unfors Xi dosimeter. The overall mean and range of ESAK during chest X-ray were 0.6 ± 0.3 (0.1-1.3) mGy, while for abdominal X-rays they were 4.0 ± 3.2 (1.3-9.2) mGy. Hospital with a CR system was found to use relatively higher doses. Dose values for abdominal X-ray procedures were comparable with previous studies. The dose for chest X-ray procedure was higher by a factor of 2-3 compared with the current international reference levels.

Dose reduction in chest CT examination.

Computed tomography (CT) examinations involve relatively high doses to patients. The objectives of this study were to optimise the radiation dose for patient during CT chest scan and to estimate the lifetime cancer risk. A total of 50 patients were studied: control group (A) (38 patients) and optimisation group (B) (12 patients). The optimisation protocol was based on CT pitch increment and lowering tube current. The mean volume CT dose index (CTDI vol) was 21.17 mGy and dose length product (DLP) was 839.0 mGy cm for Group A, and CTDI vol was 8.3 mGy and DLP was 339.7 for Group B. The overall cancer risk was estimated to be 8.0 and 3.0 cancer incidence per million for Groups A and B, respectively. The patient dose optimisation during CT chest was investigated. Lowering tube current and pitch increment achieved a radiation dose reduction of up to 60 % without compromising the diagnostic findings.

Estimation of effective dose during hystrosalpingography procedures in certain hospitals in Sudan.

The aims of this study were to measure the patients' entrance surface air kerma doses (ESAK), effective doses and to compare practices between different hospitals in Sudan. ESAK were measured for patient using calibrated thermo luminance dosimeters (TLDs, GR200A). Effective doses were estimated using National radiological Protection Board (NRPB) software. This study was conducted in five radiological departments: Two Teaching Hospitals (A and D), two private hospitals (B and C) and one University Hospital (E). The mean ESAK was 20.1mGy, 28.9mGy, 13.6mGy, 17.5mGy, 35.7mGy for hospitals A, B, C, D, and E, respectively. The mean effective dose was 2.4mSv, 3.5mSv, 1.6mSv, 2.1mSv and 4.3mSv in the same order. The study showed wide variations in the ESDs with three of the hospitals having values above the internationally reported values.