Radiographical evaluation of ulcerative colitis

Radiographical modalities have become important diagnostic tools in cases of ulcerative colitis(UC).Imaging can be used non-invasively to determine the extent of involvement,severity of disease and to detect disease-related complications and extra-intestinal inflammatory bowel disease(IBD)manifestations.While abdominal X-rays and barium enemas still retain their relevance in specific clinical settings,the use of computed tomography enterography(CTE)or magnetic resonance enterography(MRE)are now used as first-line investigations to exclude active small bowel disease in IBD patients and can be utilized to detect active colonic inflammation.Additionally,CT colonography and MR colonography are emerging techniques with potential applications in UC.Ultrasonography,leukocyte scintigraphy and positron emission tomography are novel abdominal imaging modalities currently being explored for IBD interrogations.This plethora of radiological imaging options has become a vital component of UC assessments.

Non-invasive optical characterization and estimation of Zn porosity in gas tungsten arc welding of Fe–Al joints using CR model and OES measurements

In this study,we employed a non-invasive approach based on the collisional radiative(CR)model and optical emission spectroscopy(OES)measurements for the characterization of gas tungsten arc welding(GTAW)discharge and quantification of Zn-induced porosity during the GTAW process of Fe–Al joints.The OES measurements were recorded as a function of weld current,welding speed,and input waveform.The OES measurements revealed significant line emissions from Zn-I in 460–640 nm and Ar-I in 680–800 nm wavelength ranges in all experimental settings.The OES coupled CR model approach for Zn-I line emission enabled the simultaneous determination of both essential discharge parameters i.e.electron temperature and electron density.Further,these predictions were used to estimate the Zn-induced porosity using OES-actinometry on Zn-I emission lines using Ar as actinometer gas.The OES-actinometry results were in good agreement with porosity data derived from an independent approach,i.e.x-ray radiography images.The current study shows that OES-based techniques can provide an efficient route for real-time monitoring of weld quality and estimate porosity during the GTAW process of dissimilar metal joints.

Intra-Articular Distal Radius Fracture with Lunate Fossa Rotated and Associated Lesions: Radiologic Analysis

Introduction: Intra-articular distal radial fractures in young patients occur in high energy trauma which can lead to a combination of bone and ligaments lesions. An articular step superior to 2 mm is pejorative, for that an adequate radiologic analysis is necessary accessing to the best surgical treatment. The purpose of our study was to investigate this type of fracture and expose radiologic analysis (radiograph and CT-scan) of bone and ligamentous associated lesions of this specific twisted lunate facet fracture for recognizing it and accessing to the best surgical treatment. Patients and Methods: Seven patients with severely displaced type 4 articular fractures of the distal radius whose wrists had been exposed to violent compression are reported in our series, they are required open treatment for the reduction and fixation of disrupted articular surfaces by using an antero-medial approach which allows direct access to the fragment of the lunate facet and easier visualization of the distal radio-ulnar joint. Results: All the patients were clinically examined with antero-posterior and lateral X ray, completed by a CT scan, all the fractures were type IV according to Melone classification. In all of our seven cases there was a lesion of the distal radioulnar joint (DRUJ) identified in the CT scan. The CT scan allowed us to individualize well the void of the lunate fossa and calculate his exact degree of rotation, which is very important for planning therapeutic management. Discussion: In all of our cases the CT scan was to expose all of the osseous and ligamentous injuries;in the sagittal reconstruction we were able to objectify and calculate the exact degree of the rotation of the lunate fossa fragment;in the frontal reconstruction the void of the lunate fossa is visible and in the axial reconstruction we can determine the incongruence of the distal radio-ulnar joint (DRUJ). Intra-articular involvement has long been recognized as a poor prognostic factor in fractures of the distal radius. However, despite early studies reporting poor results with non operative treatment for these injuries, most authors opposed operative intervention, due to lack of a good radiological analysis and the CT scan;knowledge that a number of studies have shown that inadequate reduction of intra-articular distal radius fractures leads to the development of arthritis.

Transfer learning-based super-resolution in panoramic models for predicting mandibular third molar extraction difficulty: a multi-center study

Background:This study aims to predict the extraction difficulty of mandibular third molars based on panoramic images using transfer learning while employing super-resolution(SR)technology to enhance the feasibility and validity of the prediction.Methods:We reviewed a total of 608 preoperative mandibular third molar panoramic radiographs from two medical facilities:the First Affiliated Hospital of Zhengzhou University(n=509;456 in the training set and 53 in the test set)and the Henan Provincial Dental Hospital(n=99 in the validation set).We conducted a deep-transfer learning network on high-resolution(HR)panoramic radiographs to improve the longitudinal resolution of the images and obtained the SR images.Subsequently,we constructed models named Model-HR and Model-SR using high-dimensional quantitative features extracted through the Least Absolute Shrinkage and Selection Operator method.The models’performances were evaluated using the receiver operating characteristic curve(ROC).To assess the reliability of the model,we compared the results from the test set with those of three dentists.Results:Model-SR outperformed Model-HR(area under the curve(AUC):0.779,sensitivity:85.5%,specificity:60.9%,and accuracy:79.8%vs.AUC:0.753,sensitivity:73.7%,specificity:73.9%,and accuracy:73.7%)in predicting the difficulty of extracting mandibular third molars.Both Model-HR(AUC=0.821,95%CI 0.687–0.956)and Model-SR(AUC=0.963,95%CI 0.921–0.999)demonstrated superior performance compared to expert dentists(highest AUC=0.799,95%CI 0.671–0.927).Conclusions:Model-SR yielded superior predictive performance in determining the difficulty of extracting mandibular third molars when compared with Model-HR and expert dentists’visual assessments.

GE飞天6000型DR安装调试研究

介绍了DR的工作原理,以及在GE飞天6000型DR的安装和调试过程中的一些体会。

在过敏 bronchopulmonary 麴菌病的胸 X 光线照相术、计算的 tomographic 表明

AIM:To investigate the chest radiographic and high resolution computed tomography(HRCT)chest manifestations in glucocorticoid-naive allergic bronchopulmonary aspergillosis(ABPA)patients.METHODS:This is a prospective observational study and includes 60 consecutive glucocorticoid-naive patients with ABPA who underwent chest radiography and HRCT of the chest(1.25 mm every 10 mm)in the routine diagnostic workup for ABPA.RESULTS:Chest radiographs were normal in 50%of cases.Of the remainder,most patients demonstrated permanent findings in the form of parallel line and ring shadows suggesting bronchiectasis.Consolidation was detected in 17 cases but in the majority,the corresponding HRCT chest scan showed mucus-filled bronchiectatic cavities.Chest HRCT was normal in 22 patients,while central bronchiectasis(CB)was demonstrated in the remaining 38 patients.Bronchiectasis extended to the periphery in 33%-43%depending on the criteria used for defining CB.The other findings observed on HRCT were mucoid impaction,centrilobular nodules and high-attenuation mucus in decreasing order of frequency.CONCLUSION:Patients with ABPA can present with normal HRCT chest scans.Central bronchiectasis cannot be considered a characteristic feature of ABPA as peripheral bronchiectasis is commonly observed.Consolidation is an uncommon finding in ABPA.

The fragmentation of D-shaped casing filled with explosive under eccentric initiation

With the technical development of new warhead designs and improvised explosive device protection,irregular casing filled with explosive has been paid more attention recently. In this paper, we studied the fragmentation of a type of D-shaped casing, which is a common asymmetric casing in the field of warhead design. Based on the radiograph technique, static explosive experiments were conducted with D-shaped casings under four different eccentric initiation ratios to explore their fragmentation. A numerical model was then established to simulate the dynamic response of D-shaped casing filled with explosive. The results of numerical simulation were found to agree well with the experimental data.According to the results of numerical simulation and experimental data, the dynamic responses of Dshaped casing were analyzed. The results of the current work pave way for the innovative design of new warhead and for further studying the dynamic response of asymmetric casing.

Recent advances in imaging technologies in dentistry

Dentistry has witnessed tremendous advances in all its branches over the past three decades. With these advances, the need for more precise diagnostic tools,specially imaging methods, have become mandatory.From the simple intra-oral periapical X-rays, advanced imaging techniques like computed tomography, cone beam computed tomography, magnetic resonance imaging and ultrasound have also found place in modern dentistry. Changing from analogue to digital radiography has not only made the process simpler and faster but also made image storage, manipulation(brightness/contrast, image cropping, etc.) and retrieval easier. The three-dimensional imaging has made the complex cranio-facial structures more accessible for examination and early and accurate diagnosis of deep seated lesions. This paper is to review current advances in imaging technology and their uses in different disciplines of dentistry.

Hip joint center localisation: A biomechanical application to hip arthroplasty population

AIM: To determine hip joint center(HJC) location on hip arthroplasty population comparing predictive and functional approaches with radiographic measurements.METHODS: The distance between the HJC and the mid-pelvis was calculated and compared between the three approaches. The localisation error between the predictive and functional approach was compared using the radiographic measurements as the reference. The operated leg was compared to the non-operated leg.RESULTS: A significant difference was found for the distance between the HJC and the mid-pelvis when comparing the predictive and functional method. The functional method leads to fewer errors. A statistical difference was found for the localization error between the predictive and functional method. The functional method is twice more precise.CONCLUSION: Although being more individualized, the functional method improves HJC localization and should be used in three-dimensional gait analysis.

Effect of varying computed tomography acquisition and reconstruction parameters on semi-automated clot volume quantification

AIM To examine effects of computed tomography(CT)image acquisition/reconstruction parameters on clot volume quantification in vitro for research method validation purposes.METHODS This study was performed in conformance with HIPAA and IRB Regulations(March 2015-November 2016).A ten blood clot phantom was designed and scanned on a dual-energy CT scanner(SOMATOM Force,Siemens Healthcare Gm BH,Erlangen,Germany)with varying pitch,iterative reconstruction,energy level and slicethickness.A range of clot and tube sizes were used in an attempt to replicate in vivo emboli found within central and segmental branches of the pulmonary arteries in patients with pulmonary emboli.Clot volume was the measured parameter and was analyzed by a single image analyst using a semi-automated region growing algorithm implemented in the FDA-approved Siemens syngo.via image analysis platform.Mixed model analysis was performed on the data.RESULTS On the acquisition side,the continuous factor of energy showed no statistically significant effect on absolute clot volume quantification(P=0.9898).On the other hand,when considering the fixed factor of pitch,there were statistically significant differences in clot volume quantification(P<0.0001).On the reconstruction side,with the continuous factor of reconstruction slice thickness no statistically significant effect on absolute clot volume quantification was demonstrated(P=0.4500).Also on the reconstruction side,with the fixed factor of using iterative reconstructions there was also no statistically significant effect on absolute clot volume quantification(P=0.3011).In addition,there was excellent R^2 correlation between the scale-measured mass of the clots both with respect to the CT measured volumes and with respect to volumes measure by the water displacement method.CONCLUSION Aside from varying pitch,changing CT acquisition parameters and using iterative reconstructions had no significant impact on clot volume quantification with a semi-automated region growing algorithm.

Factors influencing the yield of mesenteric angiography in lower gastrointestinal bleed

AIM: To assess if certain triaging rules could be established to optimize the yield of mesenteric angiography. METHODS: Medical records of 101 patients were retrospectively reviewed and parameters relating to age, gender, pulse rate, blood pressure, serum hemoglobin, intensive care unit(ICU) admission, and the number of packed red blood cells(PRBC) transfused in the 12 and 24 h prior to the angiography were tabulated in two groups with positive and negative angiography results. RESULTS: We found no correlation between gender, pulse rate, blood pressure or serum hemoglobin and positivity of the mesenteric angiogram. But patients with positive angiogram were found to be on average 7 years older(73.2 years vs 65.9 years old)(P = 0.02). Angiogram was positive in 39.3 %(11/28) of patientsadmitted in ICU vs 23.2%(17/73) who were admitted elsewhere in the hospital(P = 0.03). In the 12 and 24 h prior to angiography, patients with a positive angiogram received a mean of 2.7 ± 2.3 and 3.3 ± 2.6 units of PRBC s respectively, while patients with a negative angiogram had a mean of 1.6 ± 1.9(P = 0.02) and 2.1 ± 2.6 units(P = 0.04) received respectively in the same period. CONCLUSION: Older age, ICU admission, having received at least 4 units PRBC over 12 h or 5 units over 24 h prior to angiogram are leading indicators for a positive study.

Weld extraction from real-time radiograph based on bidirectional accumulator Hough Transform

An effective approach is presented to extract welds from real-time radiographs, Firstly an algorithm based on an adaptive bidirectional threshold was proposed to segment the gradient image into ternary image, and then the bidirectional accumulator Hough Transform was developed to extract weld edges from the ternary image. Different values of the coefficient proposed in the threshold algorithm were tested, and the proposed approach was applied to extract welds from real-time radiographic images of different types of welds with defects. Results show that the proposed method is adaptive and effective to extract welds from real-time radiographs of linear welds.

Effective Dose Levels from Computed Tomography of the Head during Contrast Studies in Nigeria

Background: Diagnostic reference levels for a number of common diagnostic radiological examinations against which individual centres could compare their performance have been recommended by relevant international agencies. Due to variations in different populations globally, local and national diagnostic reference levels are more reliable. To the best of our knowledge, no centre-specific study has been carried out and national surveys are not available. Objective: To establish a preliminary local and national diagnostic reference level in Nigeria. Methods: A pro-spective and cross-sectional study involving 30 conscious paediatrics and adult patients referred for head computed tomography scan. They were positioned supine and scanned according to the standard protocol for head computed tomography with manual mA selection. The total dose-length products were recorded at the end of the pre-contrast and post-contrast sequences respectively. The pre-contrast dose was taken into cognizance in the determination of the post-contrast value. The effective dose was established by multiplying the dose-length product by 0.0023 mSv.mGy-1.cm-1, a conversion coefficient for brain tissue adopted from the European Commission. Statistical Package for Social Sciences version 17.0 was used to analyze the data. Results: 30 paediatrics and adult patients of mixed gender participated in the study. Their ages ranged from 1 to 74 years with a mean age of 41.47 ± 23.30 years. The pre-contrast effective dose ranged from 1.93 mSv to 3.32 mSv with mean of 2.56 ± 0.51 mSv and 75th percentile of 3.11 mSv while the post-contrast effective dose ranged from 4.06 mSv to 6.97 mSv with mean of 5.27 ± 0.97 mSv and 75th percentile of 6.13 mSv. The mean effective dose from this work and two other isolated studies was 3.0 mSv. Conclusion: Although our quantified doses are below threshold limits for occupational exposures they are higher than the recommended level for the public. A further optimization of scanning protocols by the radiographers could lower the effective dose for patients undergoing contrast head computed tomography in our centre and in the country.

Prevalence of osteoarthritis and association between smoking patterns and osteoarthritis in China:a cross-sectional study

Objective： The aims of this study were to estimate the prevalence of radiographic osteoarthritis （OA） and to assess the association between smoking patterns and OA prevalence in adults aged 50 years or older belonging to the Shanxi province of China.Methods： A cross-sectional study in the rural regions of the Shanxi province was conducted among 2638 Chinese adults （aged ≥50 years）. Demographic characteristics and behavioral information were collected through epidemiological surveys. All participants with joint pain underwent plain radiographic examination and were diagnosed by a professional orthopedist. Associations between smoking patterns and the prevalence of OA were assessed using binary logistic regression modeling.Results： Among 2638 individuals （men, 50.3% and women, 49.7%; mean age, 61.5 years） included in the analysis, 49.8% had radiographic OA and 27.5% had knee OA. The prevalence of radiographic OA was higher in women than in men （P〈0.001）. After adjusting for potential confounding factors, there was a nonsignificant correlation between smoking and OA prevalence in the muttivariate model. Odds ratios （ORs） for all types of OA and knee OA were higher in active and passive smokers than in nonsmoking individuals after adjustments （OR 1.374; 95% confidence interval [CI] 1.049-1.802; OR 1.440; 95% CI 1.059-1.958, respectively）.Conclusions： This study showed th at smoking may not be an independent risk factor for OA; however, there was a positive correlation between active and passive smoking and OA.

Lung cancer screening-don't forget the chest radiograph

Lung cancer is a major health burden and early detection only bears the possibility of curative treatment. Screening with computed tomography(CT) recently demonstrated a mortality reduction in selected patients and has been incorporated in clinical guidelines. Problems of screening with CT are the excessive number of false positive findings, costs, radiation burden and from a global point of view shortage of CT capacity. In contrast, chest radiography could be an ideal screening tool in the early detection of lung cancer. It is widely available, easy to perform, cheap, the radiation burden is negligible and there is only a low rate of false positive findings. Large randomized controlled trials could not show a mortality reduction, but different large population-based cohort studies have shown a lung cancer mortality reduction. It has been argued that community-based cohort studies are more closely reflecting the "real world" of everyday medicine. Radiologists should be aware of the found mortality reduction and realize that early detection of lung cancer is possible when reading their daily chest radiographs. Offering a chest radiograph in selected scenarios for the early detection of lung cancer is therefore still justified.

Skeletal dysplasias: A radiographic approach and review of common non-lethal skeletal dysplasias

Skeletal dysplasias are not uncommon entities and a radiologist is likely to encounter a suspected case of dysplasia in his practice. The correct and early diagnosis of dysplasia is important for management of complications and for future genetic counselling. While there is an exhaustive classification system on dysplasias, it is important to be familiar with the radiological features of common dysplasias. In this article, we enumerate a radiographic approach to skeletal dysplasias, describe the essential as well as differentiating features of common non-lethal skeletal dysplasias and conclude by presenting working algorithms to either definitively diagnose a particular dysplasia or suggest the most likely differential diagnoses to the referring clinician and thus direct further workup of the patient.

A Comparison between 2D and 3D Images to Study Maxillary and Mandibular Widths: A Pilot Study

The objective of this study is to compare the transverse dimensions of the jaws, obtained from traditional posteroanterior (PA) cephalometric radiographs, and with the similar respective measurements obtained by means of cone beam computed tomography (CBCT). Data of twelve subjects were selected from the clinical records of Orthodontic Department. All of the subjects had their permanent teeth in occlusion and had good quality regular (2D), and CBCT (3D) images as part of their initial records. Subjects were divided to a posterior cross-bite and non-cross bite groups. The ratio of the maxillary, to mandibular transverse widths was calculated for the sample. In subjects without dental cross-bites the average ratio of the maxillary, to mandibular jaw widths was 0.75 on the standard radiographs and 1.04 on the CBCT scans. In subjects with dental cross-bites the average ratio of these widths was 0.70 on the standard radiographs and 0.9 on the CBCT scans. The ratios of the maxillary, to mandibular widths differ when obtained from conventional cephalometric radiographs as compared to the respective ratios obtained from CBCT scans. Maxillary, to mandibular width ratio is in the order of 1:1 as determined by means of CBCT scans.

Higher-Order Statistics for Automatic Weld Defect Detection

Image processing and image analysis are the main aspects for obtaining information from digital image owing to the fact that this techniques give the desired details in most of the applications generally and Non-Destructive testing specifically. This paper presents a proposed method for the automatic detection of weld defects in radiographic images. Firstly, the radiographic images were enhanced using adaptive histogram equalization and are filtered using mean and wiener filters. Secondly, the welding area is selected from the radiography image. Thirdly, the Cepstral features are extracted from the Higher-Order Spectra (Bispectrum and Trispectrum). Finally, neural networks are used for feature matching. The proposed method is tested using 100 radiographic images in the presence of noise and image blurring. Results show that in spite of time consumption, the proposed method yields best results for the automatic detection of weld defects in radiography images when the features were extracted from the Trispectrum of the image.

5-year audit of the range and volume of diagnostic radiographic services at the University of Nairobi Dental Hospital

Background: Dental and cranio-maxillofacial diagnostic imaging constitutes an invaluable tool in the accurate diagnosis and management of a diverse range of conditions and diseases that afflict the oral and cranio-maxillofacial region. In order to improve on any existing facility, periodic audit evaluation is paramount. In this way proper and relevant service delivery can be achieved. Objective: To evaluate the range and volume of dental and cranio-maxillofacial diagnostic radiographic services offered at the University of Nairobi Dental Hospital (UNDH) in Kenya over a 5-year period (2006-2010). Methods: Retro-spective survey involving manual examination of patient records at the Division of Dental and cra-nio-maxillofacial Radiology registry of the UNDH. Results: Over the study period, the range of diagnostic radiographic services offered comprised of both intra- and extra- oral examinations. The total volume of radiographs taken was 48,874 among which 41,980 (86%) were intraoral and 6894 (14%) extraoral views. Among the intraoral views, 74% were bitewing, 25% periapical and only 1% were occlusal diagnostic views. The majority (95%) of the extraoral projections consisted of panoramic views and only 5% constituted other techniques. The volume of radiographs was high from January to September while November and December had the lowest number of examination requests. Conclusion: Intraoral radiography was the commonest examination with bitewings having been the majority while the panoramic tomography was the commonest extraoral examination performed.