Diagnostic X-ray Research Articles

Ex-vivo atherosclerotic plaque characterization using spectral photon-counting CT: Comparing material quantification to histology

Background and aimsAtherosclerotic plaques are characterized as being vulnerable to rupture based on a series of histologically defined features, including a lipid-rich necrotic core, spotty calcification and ulceration. Existing imaging modalities have limitations in their ability to distinguish between different materials and structural features. We examined whether X-ray spectral photon-counting computer tomography (SPCCT) images were able to distinguish key plaque features in a surgically excised specimen from the carotid artery with comparison to histological images. MethodsAn excised carotid plaque was imaged in the diagnostic X-ray energy range of 30–120 keV using a small-bore SPCCT scanner equipped with a Medipix3RX photon-counting spectral X-ray detector with a cadmium telluride (CdTe) sensor. Material identification and quantification (MIQ) images of the carotid plaque were generated using proprietary MIQ software at 0.09 mm volumetric pixels (voxels). The plaque was sectioned, stained and photographed at high resolution for comparison. ResultsA lipid-rich core with spotty calcification was identified in the MIQ images and confirmed by histology. MIQ showed a core region containing lipid, with a mean concentration of 260 mg lipid/ml corresponding to a mean value of −22HU. MIQ showed calcified regions with mean concentration of 41 mg Ca/ml corresponded to a mean value of 123HU. An ulceration of the carotid wall at the bifurcation was identified to be lipid-lined, with a small calcification identified near the breach of the artery wall. ConclusionsSPCCT derived material identification and quantification images showed hallmarks of vulnerable plaque including a lipid-rich necrotic core, spotty calcifications and ulcerations.

Evaluation of Changes in the Requirements of the State Standard for Radiation Protection in Diagnostic X-Ray Machines

Evaluation of Changes in the Requirements of the State Standard for Radiation Protection in Diagnostic X-Ray Machines

Development of a z-axis tilting technique using a chest phantom to reduce radiation exposure during computed tomography coronary angiography.

Japan has the highest estimated exposure frequency of diagnostic X-rays in the world. Furthermore, the volumetric computed tomography dose index (CTDIvol) and dose length product (DLP) of computed tomography coronary angiography are relatively high in Japanese diagnostic reference levels, and it is important to reduce both dose indices. This study proposed a new exposure reduction technique, the vanishing liver position (VLP), where the body is tilted to the right in the z-axis. The VLP advantages include reduction in the scanning range and overlap between the heart and the liver. Three different electrocardiogram protocols were employed, and changes in the tube current in the z-axis were measured during each protocol. Additionally, changes in the radiation exposure caused by z-axis tilting were evaluated. Our results indicate that this technique reduced CTDIvol and DLP by 6.2 and 8.9%, respectively, at most, indicating that this technique can reduce radiation exposure.

Investigation on Physico Chemical and X-ray Shielding Performance of Zinc Doped Nano-WO3 Epoxy Composite for Light Weight Lead Free Aprons.

This report addresses a way to reduce the usage of highly toxic lead in diagnostic X-ray shielding by developing a cost-effective, eco-friendly nano-tungsten trioxide (WO3) epoxy composite for low-weight aprons. Zinc (Zn)-doped WO3 nanoparticles of 20 to 400 nm were synthesized by an inexpensive and scalable chemical acid-precipitation method. The prepared nanoparticles were subjected to X-ray diffraction, Raman spectroscopy, UV-visible spectroscopy, photoluminescence, high-resolution-transmission electron microscope, scanning electron microscope, and the results showed that doping plays a critical role in influencing the physico-chemical properties. The prepared nanoparticles were used as shielding material in this study, which were dispersed in a non-water soluble durable epoxy resin polymer matrix and the dispersed materials were coated over a rexine cloth using the drop-casting method. The X-ray shielding performance was evaluated by estimating the linear attenuation coefficient (μ), mass attenuation coefficient (μm), half value layer (HVL), and X-ray percentage of attenuation. Overall, an improvement in X-ray attenuation in the range of 40-100 kVp was observed for the undoped WO3 nanoparticles and Zn-doped WO3 nanoparticles, which was nearly equal to lead oxide-based aprons (reference material). At 40 kVp, the percentage of attenuation of 2% Zn doped WO3 was 97% which was better than that of other prepared aprons. This study proves that 2% Zn doped WO3 epoxy composite yields a better particle size distribution, μm, and lower HVL value and hence it can be a convenient lead free X-ray shielding apron.

Analysis of the potential reasons for repeated radiography: a study in a major hospital in south eastern Iran

Introduction
 Rejecting, removing and repeating the process of taking diagnostic X-ray images could lead to professional and moral challenges in the case of radiologic imaging. The aim of this study was to investigate the reason for repetitive imaging and the types of images mostly repeated. 
 Methods
 Radiographic images taken in this center in the first half of 1400 were evaluated. At the end of each week, repetitive images were referred to the researcher to analyze the frequency of repetitive radiographies and the causes.
 Results
 In this study, a total of 4916 radiographies taken in Ali Ibn-e-Abitibi Hospital during the first 6 months of the year 1400 were evaluated. Among 398 repetitive radiographies, 94 repetitions (23.62%) were due to inappropriate positioning, 92 repetitions (23.12%) were due to patient's movements, 56 repetitions (14.07%) were due to inadequate radiation, 51 repetitions (12.81%) were due to inadequate processing, 46 repetitions (11.56%) were due to inadequate preparation of the patient, and 59 repetitions(14.82 %) were due to other reasons
 Conclusion
 In this study, the rate of repetitive radiographies taken in Ali Ibn-e-Abi Talib Hospital was estimated as 8.10%, with the most common reason for repetitions being estimated inappropriate positioning. Considering the fact that repetitive radiography mostly depends on operator-related factors, it is recommended to repeat the study after educating staff in order to compare the rate and reason of repetition.

Correlation of Entrance Skin Dose with Body Mass Index of Patients Undergoing Routing X-Ray Examination at Federal Teaching Hospital Gombe, North-Eastern Nigeria

This study was conducted to assess the amount of dose received by patients undergoing routine x-ray examinations at Federal Teaching Hospital, Gombe in Gombe State, Nigeria. Entrance skin doses (ESDs) for different kinds of x-ray procedures, include Posterior Anterior (PA) and Lateral (Lat) chest, Anterior Posterior (AP) Abdomen, AP pelvis, AP and Lat lumber spine and PA and Lat skull were assessed using standard exposure parameters. Data were obtained from eighty (80) patients who were exposed to diagnostic X-ray during their regular X-ray examinations. The patients’ age ranged from 1 to 80 years, while the weight was between 20kg and 100kg and height of these patients was between 95.0cm and 171cm. The skin dose of each patient was evaluated using a formula, based on the radiographic exposure parameters of kVp, mAS, SSD, the X-ray tube and the total filtration of the beams. The mean entrance skin dose ranged from 0.016 mGy to 3.168 mGy. Eventually, the ESDs measured for these x-ray procedures were found to be below the maximum permissible limits set by Nigeria Basic Ionizing Radiation Regulation and all the examinations conducted showed that there is a good correlation between the entrance skin doses and body mass index for the studied subjects. This implies that patients with higher body mass index will received more dose than the patients with low body mass index.

Improving X-ray Scintillating Merits of Zero-Dimensional Organic-Manganese(II) Halide Hybrids via Enhancing the Ligand Polarizability for High-Resolution Imaging.

Luminescent metal halides have been exploited as a new class of X-ray scintillators for security checks, nondestructive inspection, and medical imaging. However, the charge traps and hydrolysis vulnerability are always detrimental to the three-dimensional ionic structural scintillators. Here, the two zero-dimensional organic-manganese(II) halide coordination complexes 1-Cl and 2-Br were synthesized for improvements in X-ray scintillation. The introduction of a polarized phosphine oxide can help to increase the stabilities, especially the self-absorption-free merits of these Mn-based hybrids. The X-ray dosage rate detection limits reached up to 3.90 and 0.81 μGyair/s for 1-Cl and 2-Br, respectively, superior to the medical diagnostic standard of 5.50 μGyair/s. The fabricated scintillation films were applied to radioactive imaging with high spatial resolutions of 8.0 and 10.0 lp/mm, respectively, holding promise for use in diagnostic X-ray medical imaging.

AIUM Practice Parameter for the Performance and Interpretation of Diagnostic Ultrasound of the Thyroid and Extracranial Head and Neck.

AIUM Practice Parameter for the Performance and Interpretation of Diagnostic Ultrasound of the Thyroid and Extracranial Head and Neck.

Flexible, Chemically Bonded Bi-PVA–PVP Composite for Enhanced Diagnostic X-ray Shielding Applications

Flexible, Chemically Bonded Bi-PVA–PVP Composite for Enhanced Diagnostic X-ray Shielding Applications

Response of 2-Hydroxymethyl Methacrylate Polymer Gel Dosimeter with Maltose Additive for Radiation within Diagnostic X-Ray Energies

The use of polymer gel dosimeters (PGD) in x-ray radiography has not yet been confirmed. However, if it could be applied, it could help to improve patient dosimetry, dose optimization, and quality assurance through its three-dimensional (3D) image display. This research aimed to evaluate the response of a 2-hydroxymethyl methacrylate (HEMA) polymer gel dosimeter at lower energies for possible use in diagnostic x-ray radiography and to determine the effect of maltose concentrations on the sensitivity. The dosimeter was made under normoxic conditions using Gelatin, HEMA, N, N’- Methylene – bis – acrylamide (BIS), Ascorbic Acid, deionized water, and maltose of various concentrations (10 – 50 mM). The PGDs were then irradiated using a conventional x-ray machine with exposure settings ranging from 10-200 mA, 40-100 kV, and s = 1 s. Afterward, the irradiated dosimeters were scanned using UV-spectroscopy. The result showed that the dosimeters responded to low-energy x-rays, and the effect of the maltose concentration within the tested range was not linear with the sensitivity. We concluded that the HEMA polymer gel dosimeter could be used for clinical x-ray dosimetry, but further research on the effect of maltose concentrations on the sensitivity is needed.

Application of a Portable Colorimeter for Reading a Radiochromic Film for On-Site Dosimetry

Radiochromic films have widely been used for quality assurance (QA) in radiation therapy and have many advantageous features such as self-developing visible coloration, wide dose range and easiness to handle. These features have a good potential for application to other fields associated with high-dose radiation exposure, e.g., verification of various radiation sources used in industry and research, occupational radiation monitoring as a preparedness for radiological emergencies. One of the issues in such applications is the elaborate process of acquisition and analyses of the color image using a flatbed scanner and image processing software, which is desirably to be improved for achieving a practical on-site dosimetry. In the present study, a simple method for reading a radiochromic film by using a portable colorimeter (nix pro 2; abbreviated here “Nix”) was proposed and its feasibility for diagnostic X-rays was tested with a commercial radiochromic film (Gafchromic EBT-XD). It was found that the color intensities of red and green components of EBT-XD were successfully measured by Nix over a wide dose range up to 40 Gy. Though some angle dependence was observed, this error could be well averted by careful attention to the film direction in a reading process. According to these findings, it is expected that the proposed on-site dosimetry method of combining a radiochromic film and a portable colorimeter will be practically utilized in various occasions.

Local Diagnostic Reference Levels for Common Adult Computed Tomography Procedures in Addis Ababa.

Computed Tomography has become the major source of population exposure in diagnostic x-rays. This concerned issue will be resolved by stetting Local Diagnostic Reference Levels. The main objective of this study is to assess dose indicators for the establishment of Local Diagnostic Reference Levels. A prospective cross-sectional study design was conducted on 8 public and private hospitals performing CT examinations. A total of 725 adult patients who underwent abdominopelvic, chest, and head CT examinations were evaluated from October 2021 to March 2022. Patients' demography, exposure parameters, and dose descriptors were collected. The minimum, maximum, mean, median, and third quartile values were analyzed using SPSS software version 26. Finally, the third quartile values of collected data were compared with national and international values. The third quartile values obtained from median of volumetric computed tomography dose index (mGy) and dose length product (mGy.cm) which are considered as local DRLs for head, chest, and abdominopelvic CT examination, respectively, were 53mGy, 14mGy and 13mGy; 1307mGy.cm, 575mGy.cm, and 932mGy.cm. The results of this study showed that practices of CT imaging in both public and private hospitals in Addis Ababa were comparable to other national and international values.

Assessment of entrance skin dose for adult patients undergoing diagnostic X-ray examinations in the Souss-Massa region of Morocco

The objective of this study is to evaluate the Entrance Skin Dose (ESD), and to establish the Diagnostic Reference Levels (DRLs) for the most common X-ray examinations in adult patients in the Souss-Massa region of Morocco. Data from 720 adult patients in four radiology departments in the Souss-Massa region were collected. The data concerned the following examinations: thorax posterior anterior (PA), unprepared abdominal X-ray, pelvis, hip, cervical spine anterior-posterior (AP) and lateral (Lat), lumbar spine anterior-posterior (AP) and lateral (Lat). The following parameters were reported for each examination: age, weight, patient thickness, voltage (kV), electrical charge (mAs), and the skin source distance. The Entrance Skin Dose and the Diagnostic Reference Levels are calculated for each X-ray examination. DRLs in terms of ESD for the same X-ray examination differ widely from one hospital to another. They ranged from 3 to 14 mGy for the unprepared abdominal X-ray, from 2.6 to 9.4 mGy for the pelvis, from 3.1 to 17 mGy for the hip, from 1 to 49.2 mGy for the cervical spine Lat, from 2 to 32.6 mGy for the lumbar spine AP, and from 18.1 to 50 mGy for the lumbar spine Lat. The variation of doses received by patients in the four hospitals calls into question radiological procedures and practices and calls for a standardization of guidelines for each radiological examination.

Influence of radiation dose from repeated chest X-ray on cell morphology and proliferation in peripheral blood mononuclear cells an in vitro study

The chest X-ray is a simple technique for routine medical examinations. Patients under investigation (PUI) might be exposed to radiation over the recommended dose due to the necessity of repeated X-rays. The aim of this research was to study the effects of repeated chest X-rays on peripheral blood mononuclear cells (PBMCs). The study determined characteristics of PBMCs by inverted microscope and flow cytometry after single and repeated X-ray exposure doses. The morphology of PBMCs showed cell differentiation to mesenchymal stromal cells throughout the plate and the trend of cells to differentiate in control groups more than single exposure and repeated irradiation. The cell growth of PBMCs was decreased after 10 days following repeated X-ray exposure as compared to controls. The overall results indicated that low-dose radiation from diagnostic X-rays affected PBMCs possibly indicating harmful radiation exposure. Future clinical studies will necessitate a larger sample size to more clearly assess cellular changes.

Validation and study of different parameters in the simulation of diagnostic X-ray spectra using the MCNPX code

In radiology, knowing the X-ray spectrum characteristics makes it possible to estimate the absorbed dose in the patient and to improve image quality. In this study, an X-ray generator was proposed using the MCNPX code and to validate it, the simulated spectrum was compared to the data provided from AAPM Task Group 195, which resulted in a percentage difference of 8.7%. Furthermore, several X-ray spectra were generated and compared to the spectra obtained from commercially available softwares as xpecgen and SpekCalc. The percentage differences were of the order of 13% in comparison with SpekCalc and 8% with xpecgen. The major differences obtained between those spectra were concentrated in the region of characteristic peaks, independently if variations in electron beam energy, target angle or filtration thickness were performed.

Radiation Dose Estimation to Adult Patients Undergoing Diagnostic Chest X-Rays Examinations in Kebbi State, North-Western Nigeria

The hyperconsciousness of radiation dose delivered to the patient during chest radiological X-ray procedures are prerequisite to negate menace of exposure. The pinpoint of this research is to inquest radiation doses received by the patient for routine individual radiological chest x-ray procedures in health care system associated to Kebbi State Government, Nigeria. Entrance Surface Dose and effective dose in accordance with the exposure factors collected for the real examinations were estimated by Cal Dose_X 5.0 software. Diagnostic reference levels [75^th percentile] and other statistical parameters were calculated by the use of M. S excels spread sheet. The results obtained for ESD in this research work were 2.95mGy, 2.24mGy & 2.25mGy and 1.71mGy, 1.77mGy & 2.55mGy for Chest anteroposterior [AP], posteroanterior [PA] and lateral [LAT] respectively for Sir Yahaya Memorial Hospital (SYMH) and Federal Medical Centre (FMC), Birnin Kebbi. The effective doses were 0.68 mSv, 0.18 mSv& 0.09 mSv and 0.31 mSv, 0.13 mSv & 0.14 mSv for Chest AP, PA & LAT for SYMH and FMC respectively. Similarly, diagnostic reference level for chest AP, PA, & LAT were 2.34, 3.32 & 2.82, and 2.02, 1.88 & 3.19 respectively for SYMH and FMC. The results were compared with national and international studies. The ESD and DRLs reported in this research work for chest examinations were remarkably higher than that of the European Commission (2010), Australia (2017), NRPB (2000), UNSCEAR (2008), Iran (2008) and other research work reported elsewhere. For effective dose, the results were comparatively high except for few research work published in literatures. Therefore, the obtained results in this work revealed that the variations in the results among the two centres and other studies may likely be due to the improper selection of exposure parameters, patientbody sizes, and technical know-how of the staff. Finally, proper selection of radiological parameters and educational training to the staff can significantly reduce the risk of absorbed dose to patients.

Magnetic resonance imaging in screening women at high risk of breast cancer: A meta-analysis.

Magnetic resonance imaging (MRI) is more accurate than mammography in screening for breast cancer. Exposure to ionizing radiation from repeated diagnostic X-rays may be a cause of breast cancer. We conducted systematic searches on PubMed, Cochrane and Embase to identify studies on women who underwent mammography or MRI screening. A meta-analysis was performed to compare the detection rate of breast cancer by mammography, MRI or both. A total of 18 diagnostic publications were identified and included in the meta-analysis. Among the 1000 screened women, MRI alone increased the detection rate of breast cancer by 8 compared with mammography alone (RR 0.48, 95% CI 0.42-0.54), and MRI plus mammography increased the detection rate of breast cancer by 1 compared with MRI alone (RR 0.86, 95% CI 0.78-0.96). Subgroup analysis demonstrated that the diagnostic efficacy of MRI plus mammography in breast was obviously better than that of MRI alone or mammography alone. Screening with MRI alone might be the best choice for women at high risk of breast cancer.

Mandibular symphyseal fracture in dogs: a retrospective study on the incidence and age of cases admitted to the referral teaching hospital of faculty of veterinary medicine, Cairo University, and some private clinics

The mandible and maxilla have unique structural and functional characteristics compared to the rest of the skeleton, which affect the incidence of their fractures, as well as the complications that occur as a result, which may affect other vital systems such as the central nervous, the digestive, and the respiratory systems. Mandibular symphysial fracture in dogs and cats frequently happens as a result of forced trauma like being hit by vehicles, falling down from a height,or fighting. The current study was designed as a retrospective study to record the incidence of dogs’ mandibular symphysial fractures at the hospital of the faculty of veterinary medicine, Cairo University, and some private clinics in Egypt during a three-year study period from Jan 2020 to Dec 2022. This study was conducted on a total admitted fracture case of 949 dogs including 94 skull fractures and 855 other fracture cases with an age ranging from 2 months to 14 years of both sexes. Establishing of skull fractures diagnosis was based on history, clinical signs, and further diagnostic orthopedic examination and x-ray. From the obtained data, it could be concluded that the incidence of dogs’ mandibular symphysial fractures at the hospital of the faculty of veterinary medicine, Cairo University, and some private clinics in Egypt was 5.1% of total canine fracture cases, and 51.1% of total canine skull fractures. Concerning age, mandibular symphysial fractures percentage were 60.4%, 27.1%, and 12.5% out of total mandibular symphysial fracture cases, 30.8%, 13.8%, and 6.4% out of total skull fracture cases, 7.1%, 3.5% and 3.5% out of total fracture cases related age, 3.1%, 1.4% and 0.6% out of total fracture cases, and 59.2%, 46.2% and 40.0% out of skull fracture cases related age of age less than one year, between one to three years and more than three years respectively.

Utilization of three-layers heterogeneous mammographic phantom through MCNPX code for breast and chest radiation dose levels at different diagnostic X-ray energies: A Monte Carlo simulation study.

We report the breast and chest radiation dose assessment for mammographic examinations using a three-layer heterogeneous breast phantom through the MCNPX Monte Carlo code. A three-layer heterogeneous phantom along with compression plates and X-ray source are modeled. The validation of the simulation code is obtained using the data of AAPM TG-195 report. Deposited energy amount as a function of increasing source energy is calculated over a wide energy range. The behavioral changes in X-ray absorption as well as transmission are examined using the F6 Tally Mesh extension of MCNPX code. Moreover, deposited energy amount is calculated for modeled body phantom in the same energy range. The diverse distribution of glands has a significant impact on the quantity of energy received by the various breast layers. In layers with a low glandular ratio, low-energy primary X-ray penetrability is highest. In response to an increase in energy, the absorption in layers with a low glandular ratio decreased. This results in the X-rays releasing their energy in the bottom layers. Additionally, the increase in energy increases the quantity of energy absorbed by the tissues around the breast.

Effective doses and risks from medical diagnostic x-ray examinations for male and female patients from childhood to old age

The consideration of risks from medical diagnostic x-ray examinations and their justification commonly relies on estimates of effective dose, although the quantity is actually a health-detriment-weighted summation of organ/tissue-absorbed doses rather than a measure of risk. In its 2007 Recommendations, the International Commission on Radiological Protection (ICRP) defines effective dose in relation to a nominal value of stochastic detriment following low-level exposure of 5.7 × 10−2 Sv−1, as an average over both sexes, all ages, and two fixed composite populations (Asian and Euro-American). Effective dose represents the overall (whole-body) dose received by a person from a particular exposure, which can be used for the purposes of radiological protection as set out by ICRP, but it does not provide a measure that is specific to the characteristics of the exposed individual. However, the cancer incidence risk models used by ICRP can be used to provide estimates of risk separately for males and females, as a function of age-at-exposure, and for the two composite populations. Here, these organ/tissue-specific risk models are applied to estimates of organ/tissue-specific absorbed doses from a range of diagnostic procedures to derive lifetime excess cancer incidence risk estimates; the degree of heterogeneity in the distribution of absorbed doses between organs/tissues will depend on the procedure. Depending on the organs/tissues exposed, risks are generally higher in females and notably higher for younger ages-at-exposure. Comparing lifetime cancer incidence risks per Sv effective dose from the different procedures shows that overall risks are higher by about a factor of two to three for the youngest age-at-exposure group, 0–9 yr, than for 30–39 yr adults, and lower by a similar factor for an age-at-exposure of 60–69 yr. Taking into account these differences in risk per Sv, and noting the substantial uncertainties associated with risk estimates, effective dose as currently formulated provides a reasonable basis for assessing the potential risks from medical diagnostic examinations.