Focus-film Distance Research Articles

ANALYSIS OF THE INFLUENCE OF AGE ON THE ABSORBED DOSE OF X-RAY RADIATION IN THORAX EXAMINATION

Analysis of the Effect of Age on the Absorption Dose of X-ray Radiation in Thorax Examination. This research aimed at finding out the effect of the patient's age on the absorbed dose obtained during the thorax examination. The observation data used is the exposure factor in the form of the tube voltage (kV), tube current (mA), irradiation time (s), and focus film distance (cm). The age range used is grouped based on the elderly age category established by the Ministry of Health of the Republic of Indonesia which ranges from 46 years until 85 years of age. From the data on the exposure factor and age of elderly patients, the oneway ANOVA statistical test was conducted. From the results of these statistical tests, the results obtained FCalculate value is 0.201 and sig 0.821 for AP thorax examination and the results obtained FCalculate value is 0.790 and sig 0.476 for PA thorax examination with the FTable value is 3.81 and the sig is 0.05. Therefore, based on the testing criteria in statistics of the initial hypothesis (H0) is accepted or it can be concluded that age does not affect the amount of X-ray radiation absorbed dose received by elderly patients in thorax examinations from the age range of 46 years until 85 years.

Analysis of the Effect of Age on the Absorption Dose of X-ray Radiation in Thorax Examination

This research aimed at finding out the effect of the patient's age on the absorbed dose obtained during the thorax examination. The observation data used is the exposure factor in the form of the tube voltage (kV), tube current (mA), irradiation time (s), and focus film distance (cm). The age range used is grouped based on the elderly age category established by the Ministry of Health of the Republic of Indonesia which ranges from 46 years until 85 years of age. From the data on the exposure factor and age of elderly patients, the oneway ANOVA statistical test was conducted. From the results of these statistical tests, the results obtained FCalculate value is 0,201 and sig 0,821 for Thorax AP examination and the results obtained FCalculate value is 0,790 and sig 0,476 for Thorax PA examination with the FTable value is 3,81 and the sig is 0,05. Therefore, based on the testing criteria in statistics of the initial hypothesis (H0) is accepted or it can be concluded that age does not affect the amount of X-ray radiation absorbed dose received by elderly patients in thorax examinations from the age range of 46 years until 85 years.

Presence and magnitude of anterior physeal separation in slipped upper femoral epiphysis helps identifying those at high risk for avascular necrosis

AimsWe sought to determine if the magnitude of anterior physeal separation (APS) in slipped upper femoral epiphysis was a predictor for the subsequent development of avascular necrosis (AVN). Anterior Physeal Separation (APS) is defined as the distance between the anterior lip of the bony capital epiphysis and the lateral corresponding point of the adjacent bony metaphysis on the Lauenstein radiographic view. It represents hinging of the posterior aspect of the metaphysis with the anterior epiphysis lifting away from its adjacent metaphysis, indicating instability and potential vulnerability of the vessels. Patients and MethodsA retrospective review of all patients treated regionally for slipped upper femoral epiphysis over a 9 year period (2010–2018 inclusive) were identified. Data regarding demographics, radiological parameters and outcomes was recorded. APS was measured on a Launestein radiograph view, with the patient supine, the hip and knee are flexed to 40°, and the hip externally rotated 45°, with film-focus distance of 100 cm. Analysis of the APS was performed to validate a threshold above which AVN occurs. ResultsWe identified 147 hips in 142 patients, of which 5 had bilateral slips at the time of presentation. Average anterior physeal separation was 3.8 ± 1.8 mm, with higher grade slips having significantly greater APS values. Increased APS values were seen with Loder “unstable” slips. Seven hips (4.8%) developed AVN, and in these cases the APS was significantly larger than those who did not (8.5 ± 1.4 Vs 3.9 ± 1.7; p < 0.001). Receiver operator curve analysis demonstrated a critical value of 7.5 mm was associated with a 100% sensitivity and 98.6% specificity for AVN. We identified some grade II/moderate slips with high APS values had similar outcomes to grade III/severe slips, and therefore suggest that APS may serve to alert the surgeon on counselling patients on the risk of developing AVN and to consider strategies to minimise the risk of AVN. ConclusionsAPS is sensitive, specific, accurate and reliable for the association with AVN in SUFE. Its values closely reflect the high AVN rates seen in acute and unstable SUFE. This risk is greatest if the magnitude of APS exceeds the critical value of 7.5 mm.

Correlation between serum dosage of Calcium, Phosphorus, Alkaline Phosphatase and epifisary closing age in foals of low genetic grouping / Correlação entre as dosagens séricas de Cálcio, Fósforo, fosfatase Alcalina e idade de fechamento epifisário em potros do grupamento genético baixadeiro

The subsided region of Maranhão is characterized by its peculiar ecosystem, flooded fields in rainy seasons and an arid environment in the dry season. In this region, there is a remarkable record of the presence of a genetic group called by the local population, of horse "baixadeiro". The study aimed to determine, through radiographic evaluation, the age of closure of the radio growth plate of these animals, correlating radiographic findings with gender and serum dosages of calcium, phosphorus and alkaline phosphatase. In the study, 60 horses were used, with ages ranging from 18 to 30 months, divided into two equal groups according to gender. A portable X-ray device was used to obtain the images. The radiographic technique used was 53 kVp and 5 mAs, with a film focus distance of 70 cm in craniocaudal projection. Blood samples were performed by puncture of the external jugular vein and stored in Ependorff tubes, frozen until processing. Biochemical analyses were performed using specific kits to measure calcium, phosphorus, and alkaline phosphatase. According to the results obtained, the average age of closure of the growth plate was 26.7 months for the male and 24.5 in females. As for serum dosages, we observed that the average values found in calcium were higher in males, while the average values found for both phosphorus and alkaline phosphatase were higher in females.

Determination of radiation doses received during knee joint x-ray procedures in Kebbi State, Nigeria

Diagnostic X-ray procedures play a significant role in the health sectors of the nations. The study was performed to determine the entrance skin dose received during knee joint radiographic examination, covering two x-ray units and a sample of 121 patients. The exposure factors such as kilovolt (kV), exposure time product (mAs), Film Focus Distance (FFD), Focus to Skin Distance (FSD) and patient’s age were recorded in the data collection form designed and entered into excel spreadsheet. Entrance Skin Dose was calculated using Mathematical expression incorporated into excels spreadsheet. The mean, minimum, maximum and standard deviation of exposure parameters and ESD were estimated using Minitab software. The results of mean ESD values calculated for AP and Lateral view of Knee showed that patient exposures are remarkably high compare to the result obtained in Nigeria and international countries. The mean AP and lateral view of ESD were: 0.91 mGy and 0.90 mGy for SMH, while FMC has the values of 0.16 mGy and 0.33 mGy for AP and Lateral knee view. Therefore, for both AP &amp; lateral view of SMH results are significantly higher than FMC values as a result of variation in exposure factors.

QUALITY ASSURANCE OF PERSONAL PROTECTIVE APPAREL AT TERTIARY HOSPITALS IN YOLA, ADAMAWA STATE

Background: Exposure to ionizing radiation is hazardous to radiological workers, patient's relatives, and patients. The effect may be stochastic or deterministic. Protective apparel keeps the radiation dose received by hospital workers, patients and patient relatives as low as reasonably achievable (ALARA) under normal working conditions. Protective apparel is frequently mishandled in the diagnostic room after use leading to damage. Objective: This study aimed at assessing the integrity of the protective apparel used at the radiology department of a tertiary health institution in Adamawa State of Nigeria. Methods: From three different hospitals in Yola, 26 pieces of protective apparel were identified, inspected and classified by the hospital, type, manufacturer's name, years it had been used, and the thickness of the lead. With a 17 x 14-inch cassette two exposures were made on each garment with 70 kVp and 10 mAs with a focal film distance (FFD) of 100cm with a conventional x-ray unit. Results: The result showed 12 (46.0 %) of the protective apparel studied were defective with split 5 (42.0%), crack 4(33.0%) and hole 3(25.0%) as the most common defect. The correlation between the apparels age and the number of defective protective apparel were statistically not significant (p = 0.166). Conclusion: In order to ensure protective garments provide the best protection possible; there is a need for proper storage and regular quality assurance on the apparel in the radiology departments to ensure radiation protection.

COMPARAÇÃO ENTRE DOIS MÉTODOS DE MEDIDA DE OBLIQUIDADE PÉLVICA EM PARALISIA CEREBRAL E MIELOMENINGOCELE

ABSTRACT Objective: To evaluate the intra- and inter-observer reproducibility of the evaluation of the pelvic obliquity (PO) in patients with neuro-muscular deformities via the method that uses the iliac crests and the method that uses the upper endplate of S1 and to determine whe ther there is a relationship between the methods. Methods: The digitized panoramic radiographies of thirty patients with cerebral paralysis or myelomeningocelein outpatient monitoring were evaluated by four examiners: two experienced spinal surgeons and two fellows. Two radiographs were excluded because analysis was impossible. All exams were obtained in accordance with the periodic monitoring protocol in the sitting position, using digitized film and a film-focus distance of 110 cm Results: High intra- and inter-observer agreement was observed both for method that uses the iliac crests and the method that evaluates the S1 endplate. However, no significant relationship between the two methods was observed. Conclusions: The methods evaluated had good reproducibility and agreement among the observers. It was confirmed that, on account of the existent linear relation, it is possible to estimate the value of the iliac crest method knowing the value obtained by the S1 plateau multiplied by 0.76. There was no agreement between the iliac crest and S1 plateau PO evaluation methods. Level of evidence IV; Retrospective cross-sectional study.

Estimation of dose and cancer risk to newborn from chest X-ray in South-South Nigeria: a call for protocol optimization

BackgroundThe use of X-ray as a diagnostic tool for complication and anomaly in the neonatal patient has been helpful, but the effect of radiation on newborn stands to increase their cancer risk. This study aims to determine the mean, 50th percentile (quartile 2 (Q2)), and 75th percentile (quartile 3 (Q3)) entrance surface dose (ESD) from anteroposterior (AP) chest X-ray and to compare our findings with other relevant studies. The study used calibrated thermoluminescent dosimeters (TLDs), which was positioned on the central axis of the patient. The encapsulated TLD chips were held to the patients’ body using paper tape. The mean kilovoltage peak (kVp) and milliampere seconds (mAs) used was 56.63(52–60) and 5.7 (5–6.3). The mean background TLD counts were subtracted from the exposed TLD counts and a calibration factor was applied to determine ESD.ResultsThe mean ESDs of the newborn between 1 and 7, 8 and 14, 15 and 21, and 22 and 28 days were 1.09 ± 0.43, 1.15 ± 0.50, 1.19 ± 0.45, and 1.32 ± 0.47 mGy respectively. A one-way ANOVA test shows that there were no differences in the mean doses for the 4 age groups (P = 0.597). The 50th percentile for the 4 age groups was 1.07, 1.26, 1.09, and 1.29 mGy respectively, and 75th percentile were 1.41, 1.55, 1.55, and 1.69 mGy respectively. The mean effective dose (ED) in this study was 0.74 mSv, and the estimated cancer risk was 20.7 × 10−6.ConclusionESD was primarily affected by the film-focus distance (FFD) and the patient field size. The ESD at 75th percentile and ED in this study was higher compared to other national and international studies. The estimated cancer risk to a newborn was below the International Commission on Radiological Protection (ICRP) limit for fatal childhood cancer (2.8 × 10−2Sv−1).

Ultrasound and Radiographic Imaging Diagnosis of Diaphragmatic Hernia in a Transition Cow: A Case Report

A four and half-year-old recently calved cross breed Jersey cow was presented with the clinical signs of anorexia, recurrent bloat, bruxism and not voided dung for the past one week. Clinical examination revealed congested mucous membrane, sunken eyeball, and severely distended lower abdomen; clinically, bloat was evident. On Auscultation of heart at 4th intercoastal space, low-intensity heart sounds were heard. Rectal examination revealed scanty foul-smelling dung with blood tinge. In an attempt to relieve the bloat rumen stomach was intubated, which failed to relieve the gas. The clinical suspicion pointed to the possibility of foreign body syndrome. Hence radiography was done by keeping the animal in standing position; however it revealed no clear contour of heart, reticulum, and diaphragm; another attempt was made, wherein the animal was cast on right lateral recumbency and radiography was done at 90-100 kVp, 50-60 mAs and a focus film distance of 90-100 cm using an 800 mA X-ray machine. As we would not get any diagnostic confirmation findings in radiography, an ultrasonographic assessment was planned. Ultrasonography was done with (Esoate Mylab 1) 2.5. to 5 MHz curvy linear transducer. Ultrasound examination of the heart (Venkatesan et al., 2019) and reticulum (Braun et al., 1993) was done at the left side between 4th to 5th intercostal space of thoracic cavity using the window between 6th to 8th intercoastal in the abdominal cavity. Physical examination revealed a dull and depressed animal; distended left flank, moderate dehydration, elevated rectal temperature (40°C), low-intensity heart sounds with a normal heart rate was observed. Hematology was unremarkable; smear study was negative for blood parasites.

Determination of Diagnostic Reference Level in routine Computed radiography examination in north of Iran

Introduction: Digital radiography has a major role in nowadays healthcare system so radiation protection (justification and optimization) is important in this field. Many related organizations to protection suggested to establish national and regional diagnostic reference level for medical procedures. Reference levels are typically set at the 75th percentile of the dose distribution from a survey conducted across a broad user base using a special dose measurement protocol and phantom. This study aimed to establish diagnostic reference level for computed radiography examination in north of Iran. Materials and Methods: The data were collected from 7 public hospitals for 12 computed radiographies routine examination including: skull (AP-LAT), cervical (AP-LAT), chest (PA –LAT), thoracic (AP- LAT), lumbar(AP-LAT), abdomen(AP) and pelvis (AP). For each projection, 10 patients at least 18 years olds were investigated. The study was performed by filling out the questioner which was contained the following parameters: Center name, machine manufacturer, Type of Examination, Tube Voltage (kVp), Current Time Product (mAs) and Film Focus Distance (FFD). The quantity of entrance skin dose is evaluated by measuring ESD. The third quartile of ESD related to each projection was considered as DRL of that examination. Results: Based on the data of this study, we expected that diagnostic reference level of computed radiography examination in north of Iran is in accordance with standard values that were suggested by regulatory organizations such as American College of Radiology (ACR)and European Commission (EC). Conclusion: The comparison of the results of this survey with surveys performed in other countries will indicate the protection level of patients in computed radiography examination in north of Iran.

PENGARUH FAKTOR EKSPOSI TERHADAP KUALITAS CITRA RADIOGRAFI

The research on the influence of exposure factor on radiographic image quality has been conducted. This research uses phantom, water in plastic container as human substitute with focus film distance (FFD) 100 cm and broad field of irradiation 15 cm × 15 cm. The exposure conditions are given by exposure factors including variations in tube voltages of 60 kV, 65 kV, 70 kV, 75 kV, 80 kV called standard techniques or routine voltage techniques and the time flow is as big as 20 mAs, 25 mAs and 30 mAs. The results showed that the image quality will decrease with the use of current and time high. Image quality can be seen on gray-level histogram using java Image-J Basics version 1.38 software to get optimum value from exposure factor on image quality.

Comparison of digital radiography and computed tomography morphometric profiles of cervical spinal canal vertebrae

The study aim was to determine the size of the normal cervical spinal canal on plain film and to correlate it with its size on computed tomography (CT) to make a diagnostic model of spinal stenosis based on plain film radiography. The study included 51 subjects who had no spinal deformities (age range, 16–60 years). We measured the sagittal and interpedicular diameters of the cervical canal by plain film and by CT. If the CT result was normal, anteroposterior and lateral x-rays of the cervical spine were taken in the neutral position at a 100-cm focal-film distance. SPSS statistical software was used to measure and analyze the sagittal diameter of the cervical canal and interpedicular diameters. The mean sagittal diameter of the cervical canal ranged from 16 mm (C4) to 18 mm (C6). The mean interpedicular diameter ranged from 25.2 mm (C3) to 26.2 mm (C6). There were significant differences in the sagittal and interpedicular diameters between sex, height, and weight groups. There was a strong correlation between the radiographic and CT sagittal canal diameters but a weak one between the interpedicular diameters. The plain film/CT sagittal canal diameter correlation coefficients were 0.73 (C3), 0.75 (C4–C6), and 0.77 (C7).

UJI KESESUAIAN BERKAS SINAR-X DENGAN BERKAS KOLIMATOR PADA PESAWAT SINAR-X DI INSTALASI RADIOLOGI RSUD RADEN MATTAHER JAMBI

The collimator test is one of the X-ray Quality Control (QC) program, one of the central point beam testing and the area of the collimator beam using the RMI unit. The purpose of the collimator test is to find out the suitability of the broad field of collimator with the area of X-ray beam in tolerance of ≤ 2% Focus Film Distance (FFD) and the correspondence of the X-ray center point in tolerance Ɵ = 3˚ as determined by the Minister of Health Decree No . 1250 / SK / XII / 2009. The study was conducted using variations of FFD at 100 Cm, 90 Cm, 80 Cm, on three X-ray radiation radiology radiation RSUD Raden Matther Jambi. In this study using digital radiograph unit (DR) or computed radiographaphy, no longer using conventional radiographs such as previous studies. Irregularities or wide discrepancies in the area of the X-ray beam are evaluated by evaluating the firm boundary of the line formed by the X-axis and Y-axis, then determining the midpoint between the line boundary and the radiation boundary of the scatter. The deviation results concluded that there was no deviation at the central point of X-ray beam for all X-ray aircraft tested by all aircraft still within the tolerance threshold Ɵ = 3˚. But for the value of the collimator area all the X-ray macine tested has deviations exceeding the predefined 2% FFD threshold where the radiologie france plane occurs deviation on the Y axis with FFD 90 Cm and 80 Cm, hyundai medicaly X- ray on X axis with FFD 100 Cm and 80 Cm, Y axis with FFD 80 Cm, and on villa sistei medicali SpA plane on X axis with FFD 80 Cm, Y axis at FFD 80 Cm.

A Proposed Mathematical Method to Quantify y-Axis Pelvic Rotation on the Anteroposterior Radiograph

ObjectiveResearchers have identified potential errors in the Gonstead method’s analysis of pelvic alignment resulting from y-axis rotation of the pelvis on the anteroposterior (A-P) radiograph. The purpose of this article is to propose a method that can be used to determine the magnitude of y-axis rotation of the pelvis present on the A-P radiograph. MethodsIn this proposed method, measurements are obtained from the patient and from the lateral and A-P radiographs. With a mathematical method, these measurements are used with the focal film distance to calculate the degree of pelvic rotation present on an individual A-P radiograph. ResultsThis method may help with the accuracy of measurement of pelvic y-axis rotation on the A-P radiograph. ConclusionThe method proposed can be used to calculate the magnitude of pelvic y-axis rotation on an A-P radiograph.

Radiographic Assessment of Dental Pathology and Abnormalities in Dolphins

This study proposes a simple standardized method for the production of analog X-ray images of dolphin teeth, and to explore its potential use as a complementary technique in the evaluation of dental pathology in small cetaceans. We investigated exposure times that produced the best results, and whether radiographs helped in the diagnosis of macroscopic abnormalities. Teeth of six species of dolphins (Delphinidae: Tursiops truncatus, Steno bredanensis, Sotalia guianensis, Delphinus sp., Stenella coeruleoalba, and Stenella frontalis) were X-rayed in an analog dental X-ray machine operating at 70 kVp and 7 mA. Intraoral size 2 standard films were used, and the focus-film distance was standardised at 35 cm. Those species with smaller teeth (total length 12-20 mm) had the best results when exposed for 0.3 seconds, while species with larger teeth (30-45 mm) had to be exposed for 0.4 seconds for their best result. Three independent examiners analysed all the images taken. The average pairwise percent agreement was 73% (Fleiss' Kappa = 0.229), suggesting fair agreement between examiners. Analog X-ray images produced were useful in complementing the diagnosis of dental pathology and abnormalities in dolphins, in addition to allowing the observation of internal details and lesion depths, which would not be possible with conventional macroscopic methods. The use of analog X-ray imaging is easily applicable to the study of dolphin teeth, with low operating costs and simple logistics compared to other non-destructive analytical approaches such as Micro-CT.

Rancang Bangun Alat Pengujian Focus Film Distance (FFD)

Background : Focus film distance (FFD) settings may affect the quality of radiograph, such as: density of the film, contrast, the intensity of x-ray radiation, detail and distortion of the image of the object, so that should be done appropriately. However, in practice, focus markers are often not given, lost or covered by accessories in x-ray tubes, so the technologist difficulties in determining the location of the focal point. It will make the technologist in the measurement of FFD done by measuring the approximate location of the focal point to the receptors. And yet there is a special tool that can be used to measure the accuracy of the settings of the FFD.Methods : The research will focus on the design of FFD measurement tools using acrylic materials, copper wire and small iron balls. Research methods is experimental with trial and error design, tool architecture will be done some test functions, include: Test of acrillic material (radiograph image), copper wire alignment test, test of steady ball of iron ball, FFD measure test. Evaluation is done by comparing wire image measurement with mathematical calculation using magnification formula.Results : The results of this research is the formation of FFD testing tool that is made has dimensions of 18 cm x 10 cm x 20 cm using acrillic material wich inside the part there is wire measuring 2 cm, 10 cm, and 16 cm and two iron balls are mutually perpendicular. The function test of the device is obtained as follows: the test of acrilic material in the radiographic image has been able to distinguish the acrylic material with wire and iron ball so as not to interfere with the measurement of the length of the wire image; copper wire alignment test found that the position of each wire mounted on plate A is aligned and is 20 cm from the bottom of the tool; the steady iron ball deformity test on plate A and plate B is straight-forward

Medical Imaging Teacher: A program to simulate X-ray images of the body by considering kVp, mAs and FFD values

Introduction: Teaching styles and methods have been constantly changing in the recent years. In the 1980s and 90s, the world was introduced to various developed devices, such as smart boards and early generation smart phones that had an immediate innovative effect on education. These advancements has resulted in a considerable improvement in the current educational techniques. The innovations in medical techniques and their quality is of paramount importance. The aim of this study was to provide an innovative and useful software on radiological applications and contribute to the related literature. Materials and Methods: The Medical Imaging Teacher (MIT) program was created and the prototype application was implemented on the Android platform for free use. The programing and testing of the usability of the application were performed by the users of the Google Play Store. Results: In this program, we have developed new software to simulate the X-ray images of the body by considering the peak kilovoltage (kVp), milliamperage per second (mAs), and film focus distance (FFD) values. The application has been downloaded more than 1,000 times without paid advertising. We enrolled 131 participants, who made comments and gave 4.8 points on average. Conclusion: It can be concluded that with innovative digital programs, such as the MIT, the medical machine-based learning and medical applications have risen to new levels. The software on medical testing and examination is gaining increasing popularity among the health-related applications for smart phones.

Patient dose measurement in common medical X‐ray examinations in Iran

The main purpose of this study was to investigate patient dose in the chest (PA/AP/LAT) and skull (PA/AP/LAT) X‐ray examinations, as frequent procedures. The study was performed in eight public hospitals of Khuzestan province, Iran. Patient dosimetry was conducted on 567 standard patient X‐ray examinations (males: 61.2%, female: 38.2%). Dosimetry protocol in this study was indirect method, according to the International Atomic Energy Agency (IAEA) Technical Reports series No. 457. Patients weighing 70±10 kg were considered as standard. In the indirect dosimetry approach, exposure parameters such as kVp, mAs, focal film distance (FFD), and tube outputs recorded during data acquisition were used for calculating incident air kerma on the patient's skin, entrance surface air kerma (ESAK) that is recommended by the IAEA as the most appropriate patient dosimetry quantity in simple radiographic examinations. This survey reveals significant variations in the radiological practice. Results showed that the parameters set by radiologic technologists change in a wide range: mAs varied from 2 to 80 for skull PA, 2 to 202 for chest LAT, and FFD varied from 50 to 180 for skull LAT projection. The study showed that patient doses in three chest projections exceed the IAEA and European Commission dose reference levels (EC DRLs) — 1.0, 1.12, and 2.20 mGy for chest PA, chest AP, and chest LAT, respectively. Results also showed that mean ESAKs of patients in skull projections were generally lower than the IAEA and EC DRLs, 1.5, 1.72, and 2.25 for skull LAT, skull AP, and skull PA, respectively. This study provides evidence that dose reduction in the simple X‐ray examinations is feasible by updating clinical audits and implementation of systematic quality assurance (QA) and quality control (QC) programs. The authors recommend that DRLs obtained in this study can be used as local DRLs in Khuzestan area and dose surveys must be performed in all provinces to establish national dose reference levels (NDRLs) in Iran.PACS numbers: 87.53.Bn, 87.57.uq, 87.59.B

Analysis of the reproducibility of the gray values and noise of a direct digital radiography system

The aim of this study was to evaluate the reproducibility of the gray values and noise of a direct digital radiography system (Visualix eHD) for various exposure times and analyzed regions. To obtain radiographic images in a standardized manner, the digital sensor of the system and a stepwedge were positioned in a phantom at a focus-film distance of 30 cm in a dental device at 70 kV, 7 mA and 2.2 mm filtration. Ten consecutive repetitions of X-ray imaging were performed at each exposure time (0.05, 0.07, 0.09 and 0.13 s). Gray values were analyzed using ImageJ software in five regions of interest (ROIs): alveolar bone (AB), soft tissue (ST) and three steps of the stepwedge (S1, S2 and S3). The results showed that both the variability of the gray values and the noise were statistically greater (p < 0.05) in the most radiolucent region (ST). Only the noise was affected by the exposure time. In conclusion, the reproducibility of the gray values and the noise of the Visualix eHD system can vary in specific areas with different radiolucency.

Changes in Tip-Apex Distance by Position and Film Distance Measured by Picture Archiving and Communication System (PACS).

PurposeThe tip-apex distance (TAD) is used to predict the clinical outcome of intertrochanteric fracture fixation. We aimed to measure the changes in TAD by position and film distance using Picture Archiving and Communication System (PACS).Materials and MethodsWe used a femur replica with a 10° femoral neck anteversion and a 130° neck shaft angle. Proximal femoral nail antirotation nail and a helical blade were inserted into the replica. Radiographs were taken at the neutral position and after applying 10°, 20°, 30°, 40° internal/external rotation, 10° abduction, and 10° and 40° adduction to the mechanical axis. Radiographs were taken at the replica-film distance of 10 cm and 20 cm under the same conditions, mimicking the differences in Focus-film distance (FFD), which reflect the patient's contour in clinical settings. A radiologist and an orthopedic surgeon measured the TAD twice using PACS. The average error was 2 mm (4.5%) and the standard error was ±3.04. TADs in the neutral position constituted the standard values to measure the relative errors.ResultsTADs increased with an increase in the external rotation and abduction of the replica. TADs decreased with an increase in the internal rotation and adduction of the replica. For comparable measurements, relative errors were higher at FFDs of 20 cm compared to FFDs of 10 cm.ConclusionSince the femur is internally rotated and adducted for reduction, orthopedic surgeons would assess the lag screw to be closer to the apex of femur on intraoperative radiographs. To have a correct measurement of the TAD after fixation of intertrochanteric fractures, radiographs should be taken in neutral position and measurement errors should be considered based on the patient's size.