Dissertations / Theses on the topic 'Radiographic measurement'

Musculoskeletal injuries are the most common injuries sustained by athletes and military recruits and can result in decreased performance and lifelong disability. So common and costly are these injuries that the American Academy of Orthopedic Surgeons has provided guidelines for future research, including recommendations for the development of a large animal model of bone injury (USDA 2001). In human and veterinary medicine, digital radiography represents the primary diagnostic tool the physician uses to diagnose skeletal injury. Advances in digital radiography have provided the veterinarian with opportunities to make both simple and complex radiographic assessments. We investigated a simple quantitative measurement of the solar, concave aspect of the distal phalanx in the horse, termed the Palmar-Metric (PM). The PM was a significant predictor of solar cup volume (p < 0.001) and negatively correlated with age (r2 = 0.28, p < 0.05) as determined from 544 radiographs of the distal phalanx from the left and right front feet. Therefore, veterinarians should be aware of the age related change in the solar, concave aspect of the distal phalanx in the horse. We hypothesized that the decrease in the degree of concavity with age may be due to demineralization and subsequent loss of bone density along the solar margin of the distal phalanx. Therefore, we investigated the quantification of optical bone density (bone OD) via complex radiographic calibration. By developing a brightness/darkness index (BDI), the greyscale of radiographs, calibrated with an aluminum marker of varying known thickness, can be compared to the average density of a cross-section of bone. At varying radiographic exposure intensity (kV) and exposure time (mAs), Al BDI was a significant predictor of bone BDI (r2 = 0.960, p < 0.001) and bone OD (r2 = 0.971, p < 0.001). This method of calibration can be utilized by the radiologist to accurately assess bone OD regardless of technique, and allow direct comparison of radiographs taken under different exposure settings. This method successfully quantifies bone OD via measurement of BDI from standardized digital radiographs, allowing for the opacity of radiographs to be truly comparable when taken under different circumstances.

Includes abstract.
Includes bibliographical references (leaves 112-117).
This study describes dose measurements made for linear slit scanning radiography (LSSR) and a dose prediction model that was developed for LSSR. The measurement and calculation methods used for determining entrance dose and effective dose (E) in conventional X-ray imaging systems were verified for use with LSSR. Entrance dose and E were obtained for LSSR and compared to dose measurements on conventional radiography units. Entrance dose measurements were made using an ionisation chamber and dosemeter; E was calculated from these entrance dose measurements using a Monte Carlo simulator. Comparisons with data from around the world showed that for most examinations the doses obtained for LSSR were considerably lower than those of conventional radiography units for the same image quality. Reasons for the low dose obtained with LSSR include scatter reduction and the beam geometry of LSSR. These results have been published as two papers in international peer reviewed journals. A new method to calculate entrance dose and effective dose for LSSR is described in the second part of this report. This method generates the energy spectrum for a particular set of technique factors, simulates a filter through which the beam is attenuated and then calculates entrance dose directly from this energy spectrum. The energy spectrum is then combined with previously generated organ energy absorption data for a standard sized patient to calculate effective dose to a standard sized patient.Energy imparted for different patient thicknesses can then be used to adjust the effective dose to a patient of any size. This method is performed for a large number of slit beams moving across the body in order to more effectively simulate LSSR. This also allows examinations with technique factors that vary for different parts of the anatomy to be simulated. This method was tested against measured data and Monte Carlo simulations. This model was shown to be accurate, while being specifically suited to LSSR and being considerably faster than Monte Carlo simulations.

Thesis (M.S.)--University of Florida, 2002.
Title from title page of source document. Document formatted into pages; contains xii, 91 p.; also contains graphics. Includes vita. Includes bibliographical references.

Dynamic flow of material has been studied using fast neutron radiography (FNR) and positron emission particle tracking (PEPT). A new fast neutron imaging system was commissioned at The South African Nuclear Energy Corporation, Pretoria, as part of this study, although FNR measurements were ultimately performed at PhysikalischTechnische Bundesanstalt (PTB), Braunschweig. The PEPT studies were undertaken at the PEPT Cape Town facility located at iThemba LABS, Cape Town. The steady state motion of media, within a laboratory-scale tumbling mill, was studied for a range of speed and media mixes, using both FNR and PEPT. Several operational parameters were derived from the data, which could be related to potential improvements to the milling efficiency. The blending of FNR and PEPT data for the study of steady state flow, was explored for the first time. In addition, the flow of water through porous media was studied using FNR, which enabled the determination of the hydraulic conductivity, and hence intrinsic permeability, of the media within the column. The potential of using FNR, without or without PEPT, for the study of material in motion is discussed.

The aim of this project was to develop robust interactive computer methods for measuring the shape and movement of the lumbar spine vertebrae from lateral radiographs of the spine. In order to achieve this aim, two software packages were written - the Aberdeen Vertebral Morphometry System (AVMS) and the Aberdeen Spinal Videofluoroscopy System (ASVS). AVMS was designed to analyse static images from dual energy x-ray absorptiometry (DXA) imaging densitometers. Comparative precision tests of the ability of AVMS software and Lunar EXPERT-XL software to measure vertebral height were undertaken using four vertebrae from the same lateral spine image (male, 67 years). Two of the vertebrae in this image were abnormal and two were normal. It was concluded that AVMS had higher precision when measuring abnormal and normal vertebrae. The effects of axial rotation and lateral bending, which lead to movement out of the sagittal plane, were investigated by generating a three-dimensional computer model of two adjacent vertebrae and projecting it on to the sagittal plane. The projected model was measured as if it were a radiograph, allowing the effects of out-of-plane movement and errors in reference point placement to be calculated. ASVS was used to acquire and analyse a sequence of images of the spine in motion obtained using videofluoroscopy and incorporated the findings of the computer modelling work. A clinical study for the measurement of intervertebral motion using ASVS during flexion-extension was organised and seven subjects suffering from severe lower back pain were recruited. Analysis of the image sequences using the computerised measurement system in ASVS revealed the apparent effect of analgesia/sedative on the shape and size of centroidal trajectories of vertebrae, and the differences in trajectory shape between subjects. It was concluded that ASVS was able to quantify spinal motion at a minimal radiation dose to the subject.

The thesis looks at various aspects of the modulation transfer function (MTF) and Wiener spectrum (WS) measurements for screen-film systems aiming at robust and simple methods for their routine measurement in a hospital setting. To measure the MTF of the film-screen systems, the square wave response function method was used. To normalise the MTF at a lower spatial frequency, a lead step and an object were incorporated into the measurement. Work on fitting the MTF data was carried out by considering two MTF models. To check if the current MTF calculation makes a low estimate, calculation using more terms in the Coltmann equation was performed. The value of the edge spread function method to measure the MTF was examined. The MTF of the microdensitometer was measured, and the correction factor for the screen-film. MTF based on this was calculated. MTF measurements of several screen-film combinations in use at the Aberdeen Royal Infirmary were made. The method used for the measurement of the WS of the screen-film was the fast Fourier transform digital method. A proper normalisation was chosen and implemented in the calculation. Low pass filtering, low frequency filtering, and windowing of the density fluctuation data were examined using sinusoidal and real noise data. The square shape of the scanning aperture of the microdensitomer was taken into account in the determination of WS. Slit length was synthesised and incorporated into the WS calculation. WS measurements of several screen-film combinations were made. A short receiver operating characteristic (ROC) study of two screen-film systems, recently introduced into Aberdeen Royal Infirmary, was undertaken to study the relationship between the physical measures of image quality that had been developed and the subjective measure based on the area under the ROC curve.

The human knee is a hinge joint, primarily facilitating locomotion. Knee joint instability, due to ligament injuries, is a result of direct or indirect trauma, non-anatomical stresses during pivoting movements about the knee, imbalanced landing during jumping and rapid deceleration during high intensity locomotion. Biomechanical indications of an unstable knee joint include decreased joint integrity, hyperlaxity, abrupt locking and catching combined with clicking noises during locomotion. Approximately, two hundred and fifty thousand ACL injuries occur in the United States of America annually. Current diagnostic procedures are subjective according to the clinician's experience. This potentially leads to misdiagnosis of the injury and improper treatment. Non-invasive diagnostic techniques make use of manual methods, MRI and laxity measurement devices (e.g. arthrometers and stress radiography devices). Laxity measurement devices (the focus of this study) determine ligament health by measuring their elasticity and stiffness. Directional tibial and fibular bone translation is induced by applying an external load to the joint. The bone translation is measured in relation to the load applied, which denotes ligament laxity. The Laxmeter is a novel, cost effective and radiolucent multi-ligament laxity measurement stress radiography device. This device facilitates the measurement of MCL and LCL laxity at multiple degrees of knee joint flexion, however, it lacks the essential means to perform the laxity measurement technique. The current study aims to redesign the Laxmeter to perform ACL, PCL, MCL and LCL laxity measurement procedures at multiple fixed degrees of knee joint flexion. The in vitro functional verification of the device was limited to (according to scope) a single cadaver trial; to validate functionality, structural integrity, usability as well as demonstrate the Laxmeter concept prior to a prospective full clinical trial. The redesigned Laxmeter Prototype consists of a load applicator capable of applying a 250N load to various aspects of the proximal lower leg, to induce bone translation for laxity measurements. The load applicator is designed to integrate with the ergonomic patient support structure, the later potentially improving reproducibility and accuracy of the laxity measurement results. The cadaver trial demonstrated the device's capability of measuring the laxity of the ACL, MCL and LCL at predetermined knee flexion angles. To measure the ligament laxity, equal loads were applied to both proximal lower limbs independently. The bilateral average displacement of the tibia with respect to the femur for each ligament was noted. In the case of the ACL, the Laxmeter measured an average laxity of 3.07mm at 30° knee flexion and a load of 150N. The average laxities for the MCL and LCL at 30° knee flexion and 150N were 1.11mm and 2.02mm. The trial yielded preclinical results that were comparable with existing clinical and healthy cadaver based studies (using similar techniques), and suggests that the Laxmeter is capable of measuring the laxity of the ACL, MCL and LCL at various degrees of knee flexion. PCL laxity measurements could not be performed due to compromised structural integrity, which was essential to make the Laxmeter portable and lightweight. Future recommendations for the device include rotational ankle fixation; improved overall limb fixation; improved structural integrity to allow for PCL laxity measurements as well as further preclinical (functional) verification procedures prior to a full clinical trial.

Psoriatic arthritis is an inflammatory arthritis affecting a fifth of patients with skin psoriasis. Inflammation of the joints and tendons causes pain, stiffness, reduced function and disability. Work disability is increasingly recognised as an important, patient centred, functional measure of disease yet little is known about work disability in psoriatic arthritis. The overall aim of my thesis is to examine patient reported work disability in psoriatic arthritis by undertaking the following; • A systematic review of the relevant literature • Classification of a cohort of patients to study • Validation of a commonly used work outcome measure used in other rheumatic diseases • Selection of a suitable measure of structural damage to inflamed joints for investigating the associations of work disability in longitudinal observational studies. The results of the systematic review identified limited data reporting high levels of work disability associated with a wide variety of disease and non-disease related factors. The review also identified the lack of a validated outcome measure for use in psoriatic arthritis. I report the classification of a large single centre longitudinal cohort of patients with psoriatic arthritis and evidence supporting the retrospective application of a psoriatic arthritis classification criterion. Subsequently I report a preliminary validation study of the work productivity and activity impairment questionnaire to measure work disability in psoriatic arthritis and a further study comparing the existing measures of structural damage in psoriatic arthritis. Finally I developed and supervised a multicentre observational study to examine the associations of work disability in psoriatic arthritis. The study identified reduced work effectiveness to be associated with measures of disease activity, whereas unemployment was associated with recent disease onset, greater age and worse physical function. The study will provide a valuable cohort for prospective study of work disability and the effect of medical treatment and will form part of my planned post-doctoral studies.

Philosophiae Doctor - PhD
Radiographic examination is an essential facet of dental implant therapy, and the success of this therapy depends on a suitable treatment based on adequate clinical and radiographic information. International organisational bodies have published guidelines on the use of radiographic imaging during implant therapy, but since the cone beam computed tomography modality became available, a need for the development of comprehensive imaging guidelines to limit the misuse of this modality became necessary. There is a lack of stringency regarding the recommendations and guidelines on radiographic imaging modalities used during implant therapy. This is due to variations in practice, experience, and socioeconomic factors. The most recent published global guidelines and recommendations and their relevance to dental implant therapy are described in this chapter.

Orientador: Sergio de Toledo
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba
Made available in DSpace on 2018-08-03T10:55:36Z (GMT). No. of bitstreams: 1 Villalpando_KarinaTeixeira_D.pdf: 2781584 bytes, checksum: 258b6c60ba7d0ffa1c34543cb90f5de2 (MD5) Previous issue date: 2003
Resumo: O objetivo do presente estudo foi comparar através de parâmetros clínicos e radiográficos o tratamento cirúrgico de defeitos periodontais intra-ósseos com ou sem a utilização de um gel composto por proteínas derivadas da matriz do esmalte (EMDOGAIN ¿MARCA REGISTRADA¿. Quinze pacientes, apresentando um total de 19 defeitos intra-ósseos interproximais compostos por 1 ou 2 paredes ósseas em dentes unirradiculares, foram divididos aleatoriamente nos grupos teste e controle. Os parâmetros clínicos foram avaliados através de guias de sondagem - stents, antes do procedimento cirúrgico (baseline), com 6 e 18 meses de pós-operatório, sendo eles: posição da margem gengival relativa (PMGR), nível de inserção clínica relativo (NICR) e profundidade de sondagem (PS). Medidas radiográficas lineares foram obtidas nos mesmos períodos de avaliação, através de radiografias padronizadas e digitais. Os dados foram analisados estatisticamente usando ANOVA e o teste de Tukey (p< 0,05). Os resultados clínicos mostraram que aos 18 meses de avaliação houve, em média, uma redução da profundidade de sondagem de 3,2 '+ ou -' 1,44mm e um ganho no nível de inserção de 1,4 '+ ou - ' 1,26mm para o grupo teste, enquanto que no grupo controle, o valor médio de redução da profundidade de sondagem foi de 2,7 :t 0,89mm e do ganho de inserção clínica foi de 1,2 '+ ou -' 0,78mm. Radiograficamente, houve um preenchimento ósseo médio de 1,64 '+ ou -' 1,69mm no grupo teste e de 0,71 '+ ou -' 1,90mm no grupo controle. Os dois tratamentos cirúrgicos melhoraram os parâmetros clínicos e radiográficos quando comparados ao baseline, mas a diferença encontrada entre os grupos não foi estatisticamente significante. Portanto, pode-se concluir que o tratamento cirúrgico convencional e regenerativo têm efeitos favoráveis na redução da profundidade de sondagem, no ganho clínico de inserção e no preenchimento ósseo radiográfico após 18 meses de avaliação. Um estudo envolvendo uma amostra de tamanho maior é necessário para confirmar essa equivalência estatística entre as duas modalidades de tratamento
Abstract: The aim of the present study was to compare the clinical and radiographical effects of the treatment of intrabony periodontal defects with or without the use of a gel composed of enamel matrix proteins derivative (EMDOGAIN 'TRADEMARK¿). Fifteen patients, exhibiting a total of 19 defects 1 and 2 wall intrabony defects on one-rooted teeth, were randomly divided into test and control groups. Prior to surgery (baseline), 6 and 18 months after it the following parameters were evaluated using oclusal stents: relative gingival recession (RGR), relative clinical attachment levei (RCAL) and probing depth (PD). Linear radiographic measurements were obtained at the same time during this period through standard digital radiographies. Data were statistically analyzed using ANOVA and Tukey's Studentized Range Test (p< 0,05). The clinical results demonstrated that after 18 months there was a reduction in probing depth of 3.2 : '+ or -' 1.44mm and a gain in the clinical attachment levei of 1.4 '+ or -' 1.26mm on average for the test group. As for the control group the reduction in the probing depth was of 2.7 '+ or -' 0.89mm and the gain in the clinical attachment levei was of 1.2 '+ or -' 0.78mm on average. Radiographically, there was an average bone filling of 1.64'+ or -' 1.69mm in the test group and 0.7 '+ or -' 1.9mm in the control group. The two treatments improved clinical parameters as compared to baseline, but the differences found between the groups were not statistically significant. Therefore, it may be concluded that both therapies have similar effects in promoting probing depth reduction, clinical attachment gain, and defect bone till in the 18th month post treatment. A study involving a larger sample size is necessary to statistically confirm the equivalence between the two treatment modalities
Doutorado
Periodontia
Doutor em Clínica Odontológica

Every year, about 1 million patients worldwide and 16000 patients in Sweden undergo total hip arthroplasty (THA). This surgical intervention is considered a successful, safe and cost-effective procedure to regain pain-free mobility and restore hip joint function in patients suffering from severe hip joint disease or trauma. Besides relieving the pain, restoration of biomechanical forces around the hip with appropriate femoral offset (FO), leg length and proper component position and orientation are important goals. The radiographic preoperative planning and postoperative evaluation of these parameters require good validity, interobserver reliability and intraobserver reproducibility. It remains controversial as to how much postoperative leg length discrepancy (LLD) and FO change are acceptable. Generally, lengthening of the operated leg ≥ 10mm and FO reduction of the operated hip > 5mm should be avoided by using preoperative radiological templating and intraoperative measurement methods. There is no consensus on the association between LLD and FO and outcome after THA. The aims of this thesis were to: 1. To determine the influence of non-corrected LLD after THA on patients’ reported hip function and quality of life (QoL). 2. To study the association of global FO changes after THA with patients’ reported hip function, QoL and abductor muscle strength. 3. To evaluate the concurrent validity of the Sundsvall method of measuring postoperative global FO by comparing it to a standard method and to evaluate the interobserver reliability and intraobserver reproducibility of measurement of postoperative global FO, LLD and acetabular cup inclination and anteversion. 4. To analyse the postoperative radiographs of THA patients with leg lengthening and FO reduction to determine whether the problem is located in the stem, cup or both. Study I: A prospective cohort study of 174 patients with unilateral osteoarthritis (OA), comparing patients with lengthening ≥ 10mm, restoration (between 9 mm lengthening and 5 mm shortening) or shortening > 5 mm of the operated leg after THA. Follow up was 12–15 months. We found that a LLD of up to 20 mm did not influence the functional outcome (WOMAC) or QoL (EQ-5D). However, the lengthening group showed less improvement in WOMAC and more use of a shoe lift. Study II: A prospective cohort study of 222 patients with unilateral hip OA, comparing patients with decreased global FO (> 5 mm reduction), restored FO (within 5 mm restoration), and increased FO (> 5 mm increment) after THA. Follow up was was 12–15 months. The unadjusted results showed that the decreased FO group had a worse WOMAC index, less abductor muscle strength, and more use of walking aids. When these results were adjusted for possible confounding factors, only global FO reduction was statistically significantly associated with reduced abductor muscle strength. The incidence of residual hip pain and analgesics use was similar in the 3 groups. Study III: A prospective cohort study of 90 patients with primary unilateral OA treated with THA. Global FO using the Sundsvall method, global FO (standard method), LLD, acetabular cup inclination and anteversion were measured on postoperative radiographs. The interobserver reliability and intraobserver reproducibility were tested using three independent observers. We found that the Sundsvall method is as reliable as the standard method and the evaluated radiographic measurement methods have the required validity and reliability to be used in clinical practice. Study IV: A prospective cohort study of 174 patients with unilateral primary OA treated with THA. LLD and global FO were measured on postoperative radiographs. Patients with lengthening of the operated leg ≥ 10mm (n=41) and patients with reduction of global FO > 5mm (n=58) were further studied to investigate the amount of lengthening and global FO reduction that took place in the stem and in the cup compared with the contralateral side. The interobserver reliability and intraobserver reproducibility were tested using two independent observers. We found that post-THA lengthening of the operated leg ≥ 10mm was mainly caused by improper placement of the femoral stem, whereas a decrease of global FO > 5 was caused by improper placement of both acetabular and femoral components. The radiological measurement methods used showed substantial to excellent interobserver reliability and intraobserver reproducibility and are therefore clinically useful. The main conclusions of this thesis are: LLD up to 20 mm and reduced global FO more than 5 mm did not influence the functional outcome or quality of life at 12–15 months postoperatively. Lengthening ≥ 10mm was associated with increased use of a shoe lift. A reduction of global FO more than 5 mm compared to the contralateral hip was associated with weaker hip abductor muscles and more use of walking aids. Therefore both should be avoided. The radiographic measurement methods of LLD, global FO, cup inclination and anteversion have the required validity and reliability to be used in clinical practice. Lengthening of the operated leg is mainly caused by improper femoral stem positioning while global FO reduction results from improper positioning of both acetabular and femoral components. Surgeons should be aware of these operative pitfalls in order to minimize component malpositioning.
Varje år opereras ungefär 1 miljon patienter runt om i världen och 16000 patienter i Sverige med en total höftledsprotes (THA). Operation med höftledsprotes anses vara enav de mest framgångsrika, säkra och kostnadseffektiva kirurgiska åtgärderna med syfte att för att återställa livskvalité. Målet är att smärtlindra och återställa rörligheten i dendestruerade höftleden vid artros, reumatisk destruktion eller men efter exempelvis Perthes sjukdom. Vid operation med THA är det viktigt att återställa de biomekaniskakrafterna runt höftleden med en adekvat så kallad femoral offset (FO), postoperativ benlängdsskillnad (BLS) och ett tillfredsställande komponentläge. Den preoperativaplaneringen och den postoperativa bedömning av dessa parametrar kräver god tillförlitlighet, det vill säga validitet och reproducerbarhet både mellan olika bedömareoch vid upprepade mätningar av samma bedömare. Det är fortfarande inte klarlagt hur mycket postoperativ förändring i FO och BLS som är acceptabla. I dagsläget är detacceptabelt om den postoperativa benförlängningen understiger 1 cm och förändringen i FO är under 5 mm. Det finns ingen konsensus huruvida det föreligger ett sambandmellan BLS, FO och den patientrapporterade höftfunktionen och livskvalitén efter THA. Syftet med denna avhandling var: 1. Att studera effekten av icke-korrigerad BLS efter THA på den patientrapporterade höftfunktionen och livskvalitén. 2. Att studera effekten av förändringen i FO efter THA på den patientrapporterade höftfunktion, livskvalitén och muskelstyrka i abduktion. 3. Att utvärdera validitet och reliabilitet av en så kallad global FO genom att jämföra den med den gällande standard metoden samt studera tillförlitlighet av de radiologiskamätningar av postoperativa BLS, FO, cup inklination och anteversion efter THA. 4. Att radiologiskt undersöka i vilken av komponenterna (stam eller cup) somförändringen i FO och BLS verkar vara förlagd. Studie I: En prospektiv kohortstudie med 174 patienter som behandlats med THA för en primär unilateral koxartros. Patienterna delades in i tre grupper; de som fått en BLSförlängning över 10mm, återställning (mellan 9mm förlängning och 5mm förkortning) eller förkortning >5mm av det opererande benet efter THA. Uppföljning gjordes 12-15månader postoperativt. Vi fann att BLS upp till 20mm påverkade inte höftfunktion (WOMAC) och livskvalité (EQ-5D), men den förlängda gruppen visade en mindreförbättring i WOMAC och rapporterade en mer frekvent användning av skoinlägg. Studie II: En prospektiv kohortstudie med 222 patienter som behandlats med THA för en primär unilateral koxartros. Patienterna delades in i tre grupper; de patienter medförminskad FO (> 5mm minskning), återställd FO (inom 5mm) eller ökad FO (>5mm ökning). Uppföljning genomfördes efter 1 år med WOMAC, styrkemätning av höftensabduktorer och en frågeformulär. En minskad FO var associerade med en minskad styrka i höftens abduktorer. Det var ingen skillnad mellan grupperna gällandekvarstående höftsmärta och användning av analgetika. Studie III: En prospektiv kohortstudie med 90 patienter som behandlats med THA på grund av primär unilateral koxartros. På de postoperativa röntgenbilderna uppmättesglobala FO (Sundsvalls metodologi), globala FO (standard metod), BLS, cup inklination och anteversion. Reliabilitet och reproducerbarhet bedömdes mellan treoberoende observatörer. Vi fann att global FO (enligt Sundsvalls metodologi) är lika tillförlitlig som den nuvarande standardmetoden och de utvärderade radiologiskamätmetoderna har hög validitet och reliabilitet och kan således användas i klinisk praxis. Studie IV: En prospektiv kohortstudie med 174 patienter som behandlats med en THA för en primär unilateral koxartros. På de postoperativa röntgenbilderna uppmättes BLSoch globala FO. Patienter med förlängning ≥ 10mm (n=41) och patienter med minskning av globala FO >5mm (n=58) studerades for att mäta förlängning ochglobala FO minskning som sitter i stammen eller i cup jämfört med kontralaterala sidan. Reliabilitet och reproducerbarhet bedömdes av två oberoende observatörer. Vifann att en BLS över 10mm sitter framför allt i stamkomponenten i lårbenet medan en minskning i FO över 5 mm sitter i båda stam och cup. De radiologiska mätmetodernahar hög reliabilitet och reproducerbarhet och kan således användas i klinisk praxis. De viktigaste slutsatserna i denna avhandling är: 1. BLS med en förlängning upp till 20 mm och en minskning av globala FO mer än 5 mm påverkar inte patientrapporterad höftfunktion eller livskvalitet 1 år postoperativt. 2. BLS med en förlängning mer än 9 mm var associerad med mer användning av skoinlägg. En minskad FO med mer än 5 mm jämfört med den icke opererade höftenvar associerad med en sämre muskelstyrka i abduktion och ökat användning av gånghjälpmedel. 3. De radiologiska mätmetoderna av BLS, FO, acetabulära komponentens inklination och anteversion har hög validitet och reliabilitet, vilket kan användas i klinisk praxis. 4. En förlängning av det opererade benet orsakas främst av en positioneringen av stamkomponenten i lårbenet medan förlust av FO beror på otillfredsställande placeringav både stam och den acetabulära komponenten. Kirurger bör vara medveten om dessa operativa fallgropar för att optimera det kirurgiska resultatet.

Dissertação de Mestrado Integrado em Medicina Veterinária
The Degenerative Mitral Valve Disease (DMVD) has the highest prevalence of all canine heart diseases accounting for 75-80% of the cases of dogs with cardiac disease. DMVD is characterized by having an evolutive nature. As the disease progresses the microscopic and macroscopic alterations of the mitral valve’s apparatus become more severe and gradually start preventing the valve’s normal function. One of the complications that may occur is the development of pulmonary edema. Overt pulmonary edema occurs when the capacity of the pulmonary lymphatic system is exceeded, leading to an increase in the extravascular water content of the lungs. The etiology and consequently the cure for DMVD are not currently known, hence the importance of understanding and developing tools that allow the monitoring of the disease. Even though the best way to assess and confirm the diagnosis of DMVD is through echocardiography, this exam requires additional expertise to be performed and interpreted, as well as substantial financial costs to the owner. Simultaneously, radiography of the thorax is widely available and cost-effective, which justifies the interest in studying the evolution of the radiographic measures Vertebral Heart Score (VHS) and Vertebral Left Atrium Size (VLAS) in dogs with DMVD. This retrospective study aims to compare heart measurements in thoracic radiographs before and after the treatment of pulmonary edema in 18 dogs with DMVD that were submitted to consultation in a french veterinary referral center. The main conclusion of this study is that the size of the left atrium and the cardiac silhouette decreases after the resolution of cardiogenic pulmonary edema when compared to the dimensions during its occurrence. Furthermore, this decrease in the left atrium’s size is detectable using the VLAS method, which confirms its value in monitoring the progression of the disease. Consequently, it is possible for those who do not have access to an echocardiographic exam, to use the VLAS method to follow the evolution of the left atrium’s size throughout the progression of DMVD. It was also verified that VLAS measurements have a positive correlation with echocardiographic measures of the left atrium, implying that when one increases the other does so as well, and vice-versa.
RESUMO - Comparação de medições cardíacas em radiografias torácicas antes e depois do tratamento de edema pulmonar em animais com Doença Degenerativa da Válvula Mitral: um estudo retrospetivo de 18 casos clínicos - A Doença Degenerativa da Válvula Mitral (DDVM) tem a prevalência mais alta de todas as doenças cardíacas caninas, representando 75-80% dos casos destes doentes. A DDVM é caracterizada pela sua natureza evolutiva. Assim à medida que a doença progride, as alterações microscópicas e macroscópicas da válvula mitral tornam-se mais graves e começam gradualmente a impedir o seu normal funcionamento. Uma das complicações que pode ocorrer é o desenvolvimento de edema pulmonar que sucede quando a capacidade do sistema linfático do pulmão é excedida, levando, por isso, à acumulação de conteúdo aquoso no compartimento extravascular dos mesmos. A etiologia e consequentemente a cura da DDVM não são atualmente conhecidas, dai a importância em perceber e desenvolver ferramentas que permitam a monitorização da doença. Embora a melhor maneira de determinar e confirmar o diagnóstico de DDVM seja através de uma ecocardiografia, este exame de diagnóstico representa um investimento para o proprietário, necessita de material caro e exige um nível de competência mais elevado para o realizar e interpretar. Simultaneamente, a realização de radiografias do tórax é uma técnica amplamente disponível e económica, o que justifica o interesse em estudar a evolução das medidas radiográficas Vertebral Heart Score (VHS) e Vertebral Left Atrium Size (VLAS) em cães com DDVM. O objetivo deste estudo retrospetivo prende-se com a comparação de medidas cardíacas, em radiografias da cavidade torácica, antes e depois do tratamento de edema pulmonar em 18 cães com DDVM que foram apresentados em consulta num centro hospitalar veterinário de referência francês. A principal conclusão deste estudo indica que o tamanho do átrio esquerdo e da silhueta cardíaca diminui depois da resolução do edema pulmonar de origem cardíaca, quando comparado com as dimensões durante a sua ocorrência. Adicionalmente, esta diminuição de tamanho do átrio esquerdo é detetável utilizando o método VLAS, o que confirma o seu valor na monitorização da progressão da doença. Consequentemente, é possível para aqueles que não têm acesso a um exame ecocardiográfico, utilizarem o método VLAS para seguir a evolução do tamanho do átrio esquerdo durante a progressão da DDVM. Também se verificou que as medições VLAS têm uma correlação positiva com as medidas ecocardiográficas do átrio esquerdo, o que implica que quando uma medida aumenta a outra aumenta também, e vice-versa.
N/A

Objetivos: Avaliar a composição corporal através da medida das dobras cutâneas (DC) intra e inter observador em mulheres na fase reprodutiva. Estimar a confiabilidade de dois protocolos de medidas de dobras cutâneas com o método Absorciometria Radiológica de Dupla Energia (DEXA). Métodos: A amostra foi composta por 90 mulheres com faixa etária de 18 a 37 anos, com Índice de Massa Corporal entre 18 e <= 39,9 Kg/m². A reprodutibilidade dos métodos foram avaliados pelos coeficientes de correlação de concordância (CCC) e coeficiente de Saint Laurent e pelos limites de concordância e gráficos de Bland-Altman. Resultados: A comparação intra observador foi excelente (CCC = 0,99) para os valores das medidas de DC tricipital, supraíliaca, coxa, soma das dobras e percentual de gordura. O mesmo ocorreu na comparação inter observador (CCC = 0,99). As medidas das DC tricipital foram as que apresentaram maior CCC (0,98), seguido da medida da coxa (0,90), e a medida da DC da suprailíaca foi a menor (0,89). A soma das DC e o percentual de gordura tiveram valores de 0,95. Já os protocolos de medidas de DC comparados entre si e com o padrão ouro DEXA, obtiveram valores de concordância baixa (0,35). Conclusões: Nossos achados mostraram que a comparação intra e inter observador foi satisfatória, contribuindo para a reprodutibilidade das medidas de DC. Os protocolos de avaliação das DC não tiveram concordância quando comparados com a DEXA
Objectives: Assessing body composition by measuring the intra and inter observer skin folds in women in the reproductive phase and estimate the reliability of two protocols skinfold measures with radiographic absorptiometry method of dual energy absorptiometry (DEXA). Methods: The sample consisted of 170 women aged 18-37 years with body mass index between 18 and <= 39.9 kg / m². The reproducibility of methods and skinfold thickness were evaluated by the coefficient of concordance correlation (CCC) and coefficient of Saint Laurent and the limits of agreement and Bland-Altman. Results: Comparison intra observer was excellent with the same values of the CCC (0.99) for the measurements of skinfold thickness of the triceps, suprailiac, thigh and fat percentage. The same occurred in the comparison inter observer (CCC = 0.99). The measures of skinfold thickness of the triceps showed the greatest CCC (0.98), followed by thigh (0.90), and the suprailiac was the lowest (0.89). The sum of the measurements of skinfold thickness and the percentage of fat had CCC values of 0.95. Already the reliability of two protocols skinfold thickness measures compared with the gold standard DEXA method was low (CCC = 0.35). Conclusions: Our findings showed that compared intra and inter observer was satisfactory, contributing to the reproducibility of skin folds. Assessment protocols skinfold did not have agreement when compared with DEXA

Silizium-Elektroden werden aufgrund ihrer um eine Gröÿenordnung höheren Kapazität als mögliches Elektrodenmaterial in Lithium-Ionen-Batterien betrachtet. Diese Kapazität geht jedoch mit einer Volumenausdehnung von bis zu 310 % einher. Dies begünstigt einen schnellen Kapazitätsabfall und ein kontinuierliches Wachstum der SEI-Schicht. Ziel dieser Arbeit ist es daher, die Morphologie-Änderung der Siliziumelektrode während des Lithiierungs-Prozesses besser zu verstehen unter Nutzung von operando-Methoden Im ersten Teil wurde Neutronenreflektometrie (NR) genutzt, um die Morphologie-Änderung auf der Nanometerskala einer Siliziumelektrode zu untersuchen. Das Wachsen/Schrumpfen der lithiierten Zone im Silizium wurde beobachtet. Auf der Oberfläche der Elektrode wächst im delithiierten Zustand eine Grenzschicht, welche die Lithiierung verhindert. Nachdem diese Schicht aufgelöst ist, kann Lithium eingelagert werden. Im zweiten Teil wurde operando Röntgen- Phasenkontrast-Radiographie genutzt. Ein rechteckiges Riss-Gitter wurde dabei im delithiierten Zustand beobachtet, welches sich während der Lithiierung schließt. Dieses Gitter ist entlang der Kristallachsen des Siliziums orientiert. Im nächsten Zyklus entsteht das Gitter am selben Ort wieder, und breitet sich mit steigender Zyklenzahl über die Elektrode aus. Im dritten Teil wurde der Einfluss einer künstlichen Grenzschicht auf die Lithiierung untersucht. Erneut wurde NR genutzt. Die künstliche Schicht verringert das Wachstum der SEI-Schicht, unterdrückt es jedoch nicht komplett. Nach 2 Zyklen ist die Grenzschicht degradiert, und Seitenreaktionen können beobachtet werden.
Silicon electrodes receive great interest as potential electrode material in lithium-based batteries due to their one order of magnitude higher capacity. This is accompanied by a volume expansion of up to 310 %, leading to an accelerated capacity loss of the electrodes. The volume expansion creates mechanical stress, leading to fracturization of the electrode and the continuous growth of the solid-electrolyte-interphase (SEI) layer under the consumption of active material. The aim of this thesis is to investigate the morphological changes of silicon electrodes during lithiation/ delithiation. Especially operando-techniques are well-suited to investigate these morphological changes since they allow us to precisely link structural data and the electrochemical state. The first project uses operando neutron reflectometry (NR) and in-situ electrochemical impedance spectroscopy (EIS) to analyze the morphology change of the silicon surface on the nanometer-scale. The growth and shrinkage of the lithiated layers within the electrode as well as the lithium concentration was determined with this method. An SEI-layer forms on top of the silicon electrode in the delithiated state, which hinders the lithium uptake in the initial part of the subsequent lithiation. The second project analyzes the morphology-change of the electrode on the µm-scale. Here the fracturization of the silicon electrode is investigated by operando X-ray phase-contrast radiography. A rectangular fracturization pattern was observed during the second half of the delithiation, which vanished again during the lithiation. The third project investigates the influence of an artificial coating layer on the lithiation process. Again operando NR was chosen as analysis tool. The artificial coating decreased the formation of the SEI-layer within the first cycles, but did not suppress it completely. However, this layer degraded already in an early stage of cycling, resulting in the occurrence of side reactions afterward.

O objetivo deste trabalho foi avaliar o efeito do tratamento periodontal não cirúrgico (TPNC), na densidade e na altura óssea alveolar, em pacientes com periodontite, utilizando radiografias digitais diretas. Cento e um sítios, em dezenove pacientes (idade média 36 7.3 anos) foram acompanhados no dia 0, e 90 e 180 dias após TPNC. Os índices clínicos de profundidade de bolsa a sondagem (PBS), nível de inserção clínica, sangramento à sondagem e índice de placa foram registrados e radiografias digitais foram feitas. A densidade foi analisada através de regiões ósseas de interesse colocadas sobre a crista óssea alveolar (ROI I) e sobre o osso medular (ROI II). A altura óssea alveolar foi medida através da distância da crista óssea alveolar até a junção cemento esmalte. Os sítios profundos (PBS ≥ 5mm) apresentaram uma melhora clínica significante (p <0.01), acompanhada de um aumento na densidade da ROI I (p <0.01). A ROI II mostrou um aumento na densidade dos sítios com PBS ≤ 3mm em pacientes com periodontite agressiva (p <0.05). No entanto, houve diminuição nos sítios com PBS ≥ 5mm nesses mesmos pacientes (p <0.03). A altura óssea alveolar não sofreu alteração após TPNC. Após o tratamento periodontal não cirúrgico, observou-se que as radiografias obtidas através da técnica digital direta parecem mostrar um aumento na densidade da crista óssea, nos sítios profundos dos pacientes com periodontite. No entanto, a redução da profundidade de bolsa e do ganho no nível de inserção clínica não foi acompanhada por alterações significantes na altura óssea alveolar nestes sítios.
The aim of this study was to access the effects of non-surgical periodontal treatment (NSPT), on the bone density and alveolar bone height (ABH), in patients with periodontitis, using direct digital radiographs. One hundred one sites in nineteen patients (mean age 36 7.3 years) were accompanied on day 0, and 90 and 180 days after the TPNC. The clinical scores of probing pocket depth (PPD), clinical attachment level, bleeding on probing and plaque index were registered and digital radiographs were taken. The density was accessed considering the bone regions of interest at the alveolar bone crest (ROI I) and the medullar bone (ROI II). The ABH measured the distance between the alveolar bone crest and the cementoenamel junction. The deep sites (PPD ≥ 5mm) presented a clinical improvement (p <0.01), accompanied by an increase in bone density at ROI I (p <0.01). ROI II showed an increase in density at sites with PPD ≤ 3mm in patients with aggressive periodontitis (p <0.05). However, there was a decrease in density in sites with PPD ≥ 5mm of the same patients (p <0.03). The ABH didnt change after TPNC. After non-surgical periodontal treatment, the direct digital radiographs showed a significant increase in bone crest density of deep sites in patients with periodontitis. Moreover, the reduction in the probing pocket depth and the increase in the attachment level were not followed by changes in alveolar bone height in these sites.

Dissertação de Mestrado Integrado em Medicina Veterinária
A radiografia assume-se como o mais importante meio complementar de diagnóstico disponível na clínica de animais selvagens para a avaliação das dimensões do coração. Considerando que a grande variedade de aves existente na fauna ibérica é acompanhada por uma escassez de estudos, na área clínica, que lhe digam respeito, torna-se pertinente a abordagem à interpretação da silhueta cardíaca em águia-de-Bonelli (Aquila fasciata), espécie protegida por diversos programas de conservação a nível nacional e europeu, nomeadamente o projecto LIFE Bonelli. O principal objectivo deste estudo consiste na determinação de valores de referência para a silhueta cardíaca na imagem radiográfica de águias-de-Bonelli. Para tal, foram utilizadas radiografias, em projecção ventrodorsal, de vinte exemplares da espécie clinicamente saudáveis. Nestas radiografias foram mensuradas as larguras da silhueta cardíaca, do esterno, do tórax, do coracóide e da silhueta hepática. O rácio entre a largura da silhueta cardíaca e as restantes estruturas anatómicas foi calculado. Os resultados do presente estudo evidenciam que a largura da silhueta cardíaca deve constituir entre 81 a 93% da largura esternal, entre 48 a 57% da largura torácica e entre 506 a 673% da largura do coracóide. A largura da silhueta cardíaca correlacionou-se fortemente com as larguras esternal e torácica e moderadamente com a largura do coracóide. Não se verificou correlação com a largura da silhueta hepática. A largura do esterno e a largura do tórax apresentam-se como as variáveis que deverão ser preferencialmente utilizadas para comparação com a largura da silhueta cardíaca. Considera-se válida a utilização dos valores obtidos neste estudo, enquanto referência para o normal tamanho do coração de águias-de-Bonelli em radiografias.
ABSTRACT - RADIOGRAPHIC REFERENCE VALUES FOR THE CARDIAC SILHOUETTE IN BONELLI’S EAGLE (Aquila fasciata) - Radiographs are the most important diagnostic tools available in wildlife practice hospitals to evaluate the size of the avian heart. Despite of the great variability of birds in Iberian wildlife, there is a lack of clinical studies addressing these species. This is the reason why is so relevant the approach to the cardiac silhouette interpretation in Bonelli’s eagle (Aquila fasciata), a species that is protect by national and European conservation programs, including LIFE Bonelli. The main purpose of this study was to establish reference values for cardiac size in Bonelli’s eagle. Radiographs in ventrodorsal projection of twenty healthy birds were included in this study and width of the cardiac silhouette, sternum, thorax, coracoid and hepatic silhouette were measured. The ratio between cardiac width and other mentioned indices was calculated. The results show that cardiac silhouette width should occupy 81 to 93% of sternal width, 48 to 57% of thoracic width and 506 to 673% of coracoid width. Width of cardiac silhouette was strongly correlated with sternal and thoracic widths. There was a moderate correlation between width of the heart and width of the coracoid. There was no significant correlation between cardiac silhouette width and hepatic silhouette width. It is possible to conclude that sternal and thoracic width should be preferentially used when evaluating the width of the cardiac silhouette. The values obtained in this study can be used as a reference of normal cardiac size of Bonelli’s eagle in radiology.

A research report submitted to the Faculty of Health Sciences, University of the Witwatersrand, in partial fulfilment of the requirements for the degree of Master of Medicine, Johannesburg, 2018
Introduction: The hallux valgus interphalangeus (HVI) deformity has a common association with hallux valgus and hallux rigidus. The radiographic measurement of the hallux valgus interphalangeus is formed by the angle between the long axes of the proximal and distal phalanges. The normal value for this angular deformity in the coronal plane is less than 10 degrees. The reliability of measuring the hallux interphalangeal angle has not been verified as yet .The purpose of this study is to analyse the intra- and inter-observer reliability of measurements of the interphalangeal angle by orthopaedic surgeons. This study is going to be the first study to evaluate the reliability and reproducibility of the hallux valgus interphalangeal angle. Methods: Twenty one X-ray prints (images) of the weight bearing foot constituted a set. Three such sets were sent to each evaluator at four week intervals. Sixteen qualified orthopaedic surgeons were asked to measure the hallux interphalangeal angle of all twenty one X-ray images at three different occasions. After all three sets were measured, data was retrieved and statistically analysed to determine the incidence of inter- and intra-observer variability and reliability in the measurement of the hallux interphalangeal angle. Results: Reproducibility of the hallux interphalangeal angle measurement was assessed using three categories which included the ability to measure the same angle three times and achieve: three degrees or less, five degrees or less, more than five degrees. The intra-observer reliability was found to be 5 degrees and less in 75.2% of participants and for the inter-observer reliability was 61.2%. The researcher did not find significant correlation between the surgeons’ level of experience with respect to the reliability of measurement of the hallux interphalangeal angle. Conclusion: The reliability and reproducibility of measurement of the hallux interphalangeal angle is low. The level of experience of the surgeon does not improve this reliability.
XL2018

Function of the shoulder complex is highly dependent on the relationship between the scapula and the humerus. Etiologies for the disruption of the glenohumeral relationship include impaired or abnormal scapular function, motion, or position. The lateral scapular slide test (LSST) has been developed as a clinical tool to assess this phenomenon, also known as scapular dyskinesis. The primary purpose of this study was to determine the validity of the LSST by comparing the clinical measurements on the skin surface to the actual anatomical distance between the scapula and the spine as seen on radiographic images. The secondary purpose of this study was to determine the intra-rater and inter-rater reliability of the LSST. Nine subjects (18 shoulders) were assessed with the clinical LSST and radiographic images in three test positions (0��, 45��, and 90�� of glenohumeral abduction). Comparison of the clinical LSST measurements with the radiographs revealed the LSST to be valid (>0.80) in only the 0�� and 45�� test positions with respective Pearson correlation values of 0.91 and 0.98. Excellent (>0.75) intra-rater ICC (2,1) reliability (0.91-0.97) was found for all three test positions. Inter-rater ICC (2,1) reliability values were excellent for the 0�� (0.87) and 45�� (0.83) test positions, and fair to good for the 90�� position (0.71). This study demonstrated that the LSST is an accurate and consistent measure of scapular movement and position for the 0�� and 45�� test positions. Clinicians should exercise caution when interpreting measurements obtained at the 90�� test position because the validity and reliability values did not reach established standards.
Graduation date: 2002

Osteoarthritis (OA) of the knee affects between 5.4% and 38% of older adults and this prevalence is increasing as the population ages and becomes more obese. As health costs rise, it is important to have accurate and cost-effective methods to assess knee OA and the risk for OA. One risk factor for progression of knee OA is lower extremity (LE) frontal-plane malalignment. The first goal of this thesis was to assess the suitability of knee radiographs and LE photographs for the estimation of frontal-plane LE alignment. In the first study, several versions of the femoral shaft-tibial shaft (FS-TS) angle, assessed from knee radiographs, were compared to the hip-knee-ankle (HKA) angle, assessed from full-length radiographs. We concluded that the FS-TS angle is not a recommended substitute for the HKA angle, because the association between the two measures differs depending on alignment, OA severity and the method of determining the FS-TS angle. In the second study, the hip-knee-ankle angle determined from a pelvis-to-ankle photograph (HKA-P) was assessed for its ability to estimate the HKA angle. The HKA-P angle was reliable and highly correlated to the HKA. It therefore shows promise as an accurate and cost-effective assessment tool for the estimation of LE alignment. Commonly-used grading scales for the severity of knee OA seen on a radiograph emphasize just one feature of OA; therefore the second goal of this thesis was to assess the psychometric properties of the unicompartmental osteoarthritis grade (UCOAG), a composite scale which grades several features of OA in the tibiofemoral (TF) compartment. In the third and fourth studies, the reliability, validity and sensitivity to change of the UCOAG scale was assessed and compared to two commonly-used scales (Kellgren-Lawrence and Osteoarthritis Research Society International joint space narrowing). The UCOAG scale showed moderate to excellent reliability. All three scales demonstrated comparable validity and sensitivity to change. The UCOAG is therefore recommended for the assessment of OA severity and change over time. This research provides evidence for the use of accurate and cost-effective measures to assess LE alignment using photographs, and TF OA severity using radiographs, for clinical assessment and research purposes.
Thesis (Ph.D, Rehabilitation Science) -- Queen's University, 2013-09-26 13:21:06.097

Thesis (M.S.)--University of Louisville, 1996.
School of Dentistry, Department of Biological and Biophysical Sciences. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Yes
We read with interest the recent article by Yun et al. [1] comparing acetabular and hip measurements across pelvis, hip and lumbar spine radiographs. The authors assert that lumbar radiographs can be utilised in place of routine pelvis radiographs for these measurements. The example lumbar spine radiograph (figure 2) appears to be an abdominal image, with a contrast urogram. Indeed, standard texts [2,3] confirm that the anteroposterior lumbar spine radiograph should not include any coverage of the hips as appropriate collimation should limit the anatomy to T12 superiorly, lower sacrum inferiorly and the sacroiliac joints laterally, which would exclude the hip joints. Thus assessing any hip measurements on an appropriately collimated lumbar spine radiograph should not be possible. This is further compounded by the description of the centring point within their study (iliac crest), which varies from the internationally recognised standard of lower costal margin/L3 [2,3].

碩士
中臺科技大學
醫學影像暨放射科學系暨研究所
105
X-ray examination has been playing an important role to detect early lesion for centuries, the unwanted radiation irritates to patient and relatives is much concerned. The purpose of this study focused on the detection of unwanted radiation by using TLD-100H to record the space radiation distribution. 80 TLD-100H (Harshaw, USA) were allocated in the matrix of space of 140×180 cm², 20 cm each. A LUNGMAN (Kyoto Kagaku, Japan) chest phantom were radiographed 20 times by X-ray machine (Shimadzu, Japan) with 110 kVp, 3.2 mAs, FOV set at 40×40 cm², SID at 100 cm, All data were calculated by Excel software with descriptive analysis. The results depicted the average of primary beam of X-ray to the phantom was 1545.10 μԌy, and that of surround radiation dose was 25.11 μԌy, the average of scatter radiation at cathode side was197.15 μԌy, and that of 81.07 μԌy at anode one, background radiation dose was detected of 2.98 μԌy. The study suggests that the radiation dose other than primary bean was lower and obviously directional. It shows the heel effect plays an important role of radiation distribution at exposure. The study also receives the highest average scatter radiation dose at the point of 50cm away from examination table, it gradually decreased of center of primary beam were also observed.

The purpose of this study was to assess the accuracy of digital radiographs and hence their effectiveness in templating. The methodology involved a retrospective study of post operative radiographs of patients with hemiarthroplasty of the hip. Three observers made observations blinded to each other¿s measurements. A statistical analysis of the data highlights magnification varying from 6 to 31 percent. There is a statistically significant relationship between the size of the error (size measured on radiograph minus implant size, i.e. magnification) and the implant size (p = 0.005) but the percentage error (error/implant size x 100) is independent of implant size (p = 0.505). It is our impression that digital radiographs and templating on the digital radiographs should not be considered a precise process.

Thesis (M.Sc.)--University of Alberta, 2010.
A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Master of Science in Medical Sciences - Orthodontics. Title from pdf file main screen (viewed on January 24, 2010). Includes bibliographical references.

碩士
中臺科技大學
放射科學研究所
98
Alveolar bone mineral density (BMD) and Alveolar bone thickness play a unique and critical role in dental implant. Investigators have demonstrated that high BMD may accelerate the osseointegration, but low BMD may reduce the success of implant surgery. A large implant increases the stability of the implants, but also increases the risk of alveolar collapse. Quantitative ultrasound (QUS) and dual X-ray absorptiometry (DXA) are widely used in BMD measurement. Dental computed tomography (dental CT) and cone-beam computed tomography (CBCT) are used to measure the thickness of alveolar bone. However, the cost of DXA, dental CT and CBCT system are too expensive for clinics to afford. And the sensitivity and specificity of QUS were 71% and 73%. Therefore, a BMD reference level was developed for alveolar BMD measuring, the relative BMD of reference level is in the range of human body (0.31-1.41g/cm2), and the sensitivity was over 95%; an economic and convenient diagnostic x-ray machine and image analysis system are utilized to measure the thickness of the alveolar bone, the error was less than 0.5 mm. Thus, proposed methods can be widely used to replace the instruments that clinical used.

This study assessed the accuracy and reliability of tooth length measurements through axial, coronal and sagittal serial slices of CBCT volumes; conventional panoramic radiographs; and CBCT panoramic reconstructions to that of a digital caliper gold standard. Samples consisted of maxillary premolars collected from patients requiring extractions for routine orthodontic treatment. Extracted teeth were measured directly with digital calipers and images were digitally measured in Dolphin 3D software. Analysis of CBCT serial slices resulted in highly accurate and reliable tooth length measurements for all slice orientations compared to the gold standard. Conventional panoramic radiographs were relatively inaccurate, overestimating tooth lengths by 29%, while CBCT panoramic reconstructions underestimated lengths by 4%. CBCT serial slice volume analysis provides clinicians with greater measurement confidence, while panoramic radiographs, produced either by conventional means or reconstructed from 3-D volumes should be considered less accurate and reliable for the detection of mild root resorption.
Medical Sciences - Orthodontics

博士
國立中興大學
資訊科學與工程學系
103
Periodontitis is a set of inflammatory diseases affecting the periodontium, the tissues that surround and support the teeth. It is caused by microorganisms that adhere to and grow on the tooth''s surfaces. Periodontitis involves progressive loss of the alveolar bone around the teeth and its diagnosis can be established from a) clinical examination by inspecting the soft gum tissues around the teeth with a probe, and b) radiographic examination by evaluating the patient''s X-ray films (radiographs) to determine the amount of alveolar bone loss around the teeth. For diagnosing the degree of alveolar bone-loss, periapical radiograph that is a close-up view of a few individual teeth is the best choice, as bone loss usually occur around tooth boundaries and can only be detected in close-up views. Due to large amount of images, dentists may possibly make some mistakes or misjudgment under long working hours. For automatic measuring the degree of alveolar bone-loss, alveolar bone-loss areas in the radiograph and three critical positions (CEJ, BLC, and APEX) of each infective tooth within the radiograph must firstly be identified. Since APEX is the apex of tooth contour, CEJ is at the location that divides the tooth into crown and root parts, and BLC is located at the intersection of the alveolar bone-loss area and tooth contour, automatic teeth segmentation for periapical radiographs, localization of alveolar bone-loss areas, and CEJ detection are three essential and critical tasks. In this dissertation, we propose three effective methods: TSLS, ABLIFBM, and CEJTG for each of the three aforementioned critical tasks, respectively. Our teeth segmentation method TSLS consists of four stages: image enhancement using adaptive power law transformation, local singularity analysis using Holder exponent, tooth recognition using Otsu’s thresholding and connected component analysis, and tooth delineation using snake boundary tracking and morphological operations. The experimental results showed that TSLS can achieve accuracy of approximately 99% for tooth isolation and (90%, 0.9%) for tooth segmentation in terms of (TPVF, FPVF), respectively. The proposed alveolar bone-loss area localization method ABLIFBM is a thresholded segmentation method using a hybrid feature obtained from a weighted average of both intensity and the H-value of fractional Brownian motion model FBM-H. Adopting leave-one-out cross validation (LOOCV) training and testing mechanism, we train a pair of weights for both features using Bayesian classifier and transform the radiograph image into a feature image using weighted average of both features. Finally, by Otsu’s thresholding, we segment the feature image into normal and bone-loss regions. The experimental results on 28 periodontitis radiograph images showed that ABLIFBM can achieve accuracy of approximately (92.5%, 12.8%) for bone-loss area detection in terms of (TPVF, FPVF). As for the proposed CEJ detection method (CEJTG), we first preprocessed the image based on bilateral filter to remove noise while preserving edge information and power law transformation to stretch contrast. Then, we calculate gradient image by using the Sobel operator to obtain horizontal changes. Finally, we track on gradient image to find the CEJ position. The experimental results showed that out of 30 detected CEJs, CEJTG has mean pixels distance of 4.3 when compared to the ground truth.

Thesis (M.Tech.: Chiropractic)-Durban University of Technology, 2008
To evaluate the lumbar lordosis, lumbosacral angle, lumbosacral disc angle, lumbosacral lordosis angle, intervertebral disc angles and heights, interpedicular distances, sagittal canal diameters and the lumbar gravity line (selected radiographic parameters) in young to middle aged Indian females in Durban. To determine any association between the selected radiographic parameters and the age of the subjects, weight, height and body mass index of the subjects, occupation, smoking, previous pregnancy and leg length inequality (selected anthropometric and demographic factors). Methods: Sixty healthy, asymptomatic, young to middle aged, Indian females were recruited for this study. All subjects underwent a case history, a physical examination and radiographic evaluation (AP and lateral views) of the lumbar spine. SPSS version 15.0 (SPSS Inc., Chicago, Ill, USA) was used to analyze the data. Results: The mean (± SD) of the lumbar lordosis, lumbosacral angle, lumbosacral disc angle and lumbosacral lordosis angle was 49º (± 6º), 39º (± 8º), 12º (± 5º) and 143.2º (± 5º) respectively. For the lumbar intervertebral disc angles at L1-L2, L2-L3, L3-L4, L4-L5 and L5- S1 levels, the mean (± SD) was 6º (± 2º), 8º (± 2º), 10º (± 3º), 12º (± 4º) and 12º (± 5º) respectively. The anterior and posterior intervertebral disc heights at the respective vertebral levels were: L1-L2: anterior: 8 mm (± 2), posterior 5 mm (± 2); L2-L3: anterior: 10 mm (± 2), posterior 5 mm (± 2); L3-L4: anterior: 12 mm (± 2), posterior 5 mm (± 2); L4-L5: anterior: 14 mm (± 3), posterior 5 mm (± 2) and L5-S1: anterior: 13 mm (± 4), posterior 6 mm (± 2). The mean (± SD) of the interpedicular distance at the L1, L2, L3, L4 and L5 vertebral levels was 23 mm (± 2), 24 mm (± 2), 25 mm (± 2), 27 mm (± 2) and 31 mm (± 3) respectively. For the sagittal canal diameter at the L1, L2, L3, L4 and L5 vertebral levels, the mean (± SD) was 20 mm (± 5), 21 mm (± 3), 21 mm (± 3), 21 mm (± 3) and 19 mm (± 3) respectively. The lumbar gravity line intersected the sacrum in 67.3% of the subjects. In 29.1% of the subjects, the lumbar gravity line passed anterior to the sacrum while in 3.6% of the subjects, it passed posterior to the sacrum. iv A significant association was found between lumbar lordosis and the height of the subjects in this study (p = 0.004). A decrease in the intervertebral disc height at L5-S1 was associated with smoking (p = 0.005). A decrease in the intervertebral disc height at L4-L5 was associated with previous pregnancy (p = 0.016). Body mass index of 26–30 kg.m-2 was significantly associated with an increase in the intervertebral disc angles at L3-L4 (p = 0.028) and L4-L5 (p = 0.031). A decrease in the L5-S1 intervertebral disc angle was also significantly associated with smoking (p = 0.023). There was a significant association between previous pregnancy and an increase in the intervertebral disc angle at L3-L4 (p = 0.016). A significant association was found between the age of the subjects and the L5-S1 intervertebral disc angle (p = 0.007). Specifically it was the 23–27 year group and 33–37 year group who were significantly different from each other (p = 0.033). Conclusion: Similarities and differences were found in the mean values of the radiographic parameters measured in this study and those reported in the literature. A number of the selected anthropometric and demographic factors were associated with some of the lumbar radiographic parameters. Further studies are required to establish the clinical significance of these findings.

A dissertation submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in ful filment of the requirements for the degree of Master of Science in Engineering. Johannesburg, May 2018
This work was aimed at the advancement of the Laser Shock Peening (LSP) process for aeronautical applications. This involved developing a robust strategy for residual stress measurements to various depths in LSP treated samples with different thicknesses and then to perform a parametric analysis of the LSP process. For the residual stress measurement part of the study, aluminium alloy 7075 samples with thicknesses of 10, 6, 3 and 1.6 mm were treated with LSP and the residual stresses were measured using various complementary techniques: Incremental Hole Drilling (IHD), Neutron Diffraction (ND), Synchrotron Energy-Dispersive X-Ray Diffraction (ED-XRD), Laboratory XRD (L-XRD) and Synchrotron Angle-Dispersive XRD (AD-XRD). The results compared favourably and it was concluded that to obtain a complete depth profile in the subsequent work, the residual stresses would need to be measured using at least three methods: one for near the surface, one at intermediate depths and one at greater depths. For the parametric analysis phase of the study, aluminium alloy 7075 samples with thicknesses of 10 and 1.6 mm were treated with LSP; the following LSP parameters were varied: Power Intensity (PI), Spot Size (SS) and %Overlap. The residual stresses were measured using L-XRD, IHD and ED-XRD. In addition to this, the following were investigated: the sample deformation, the surface integrity, the microhardness, and the microstructure under a Scanning Electron Microscope (SEM). A clear trend in the residual stress depth profile as well as the additional characterisations was observed as the parameters varied. This work will form part of a database of LSP results for various alloys that can be used for engineering residual stress profiles using optimal parameter selection for specific industrial applications and as benchmark for the development of LSP Finite Element tools.
MT 2018

Pre-publication drafts are reproduced with permission and copyright © 2013 of the Journal of Orthopaedic Trauma [Mutch J, Rouleau DM, Laflamme GY, Hagemeister N. Accurate Measurement of Greater Tuberosity Displacement without Computed Tomography: Validation of a method on Plain Radiography to guide Surgical Treatment. J Orthop Trauma. 2013 Nov 21: Epub ahead of print.] and copyright © 2014 of the British Editorial Society of Bone and Joint Surgery [Mutch JAJ, Laflamme GY, Hagemeister N, Cikes A, Rouleau DM. A new morphologic classification for greater tuberosity fractures of the proximal humerus: validation and clinical Implications. Bone Joint J 2014;96-B:In press.]
Les fractures isolées de la Grosse Tubérosité (GT) de l’humerus proximal sont rares et peu étudiées. Trois problèmes importants existent: 1: Même si 5mm + de déplacement supérieur du GT est cité comme indication chirurgicale, les mesures basées sur radiographie peuvent errer de plus que 10mm. 2: Les classifications de Neer et l’AO décrivent seulement un type de fracture de GT (gros fragment, ligne de fracture verticale). Deux autres types de fracture existent: type fracture-avulsion avec petit fragment osseux et type Hill-Sachs très latéral. 3: On manque d’études de pronostic ou de traitement des fractures de GT selon la morphologie. Article 1 montre et évalue une méthode simple de mesurer le déplacement supérieur de la GT (le GT ratio) sur les radiographies standard; ceci corrèle très bien avec tomographie (CT). Article 2 introduit une méthode de classification Morphologique des fractures de GT (Avulsion, Split, Dépression) qui a une fiabilité de bonne à excellente. Les données échographiques, radiologiques, et cliniques de 54 patients porteurs de fracture de GT (suivie moyenne 2.5 années) sont aussi incluses. Les patients <50 ans ont eu plus de déchirures de la coiffe et ceux avec fractures déplacées (≥ 5mm) avaient plus d’atrophie du susépineux. Les déchirures complètes de la coiffe et l’atrophie du susépineux augmentaient l’atteinte permanente. La morphologie des fractures de GT n’a pas eu un impact significatif sur le pronostic. Cependant, l’âge, le sexe, et le taux de luxation glénohumérale étaient différents selon le type de fracture et ceci pourrait refléter la pathophysiologie. Une évaluation plus précise de l’impact de la Morphologie des fractures de GT sur le pronostic et traitement nécessitera une étude prospective multicentrique.
Isolated fractures of the Greater Tuberosity (GT) of the proximal humerus are rare and a challenge to study. Three main problems arise: 1: Though 5mm+ superior GT displacement is often a surgical indication, measurement errors on radiographs may surpass 10mm. 2: The Neer and AO classifications describe only one type of GT fracture (large fragment, vertical fracture line). Two other fracture types have been described: an avulsion-type (small fragment), and a very lateral Hill-Sachs-type. 3: There are no studies on the treatment or prognosis of GT fractures according to fracture morphology. Article 1 introduces and tests a simple method to measure superior GT displacement (the GT ratio) using standard radiographs; this correlates very well with computed tomography (CT). Article 2 presents the Morphologic classification for GT fractures. It describes three fracture types (Avulsion, Split, Depression) and has good to excellent reliability. The ultrasonographic, radiologic, and clinical results of 54 patients (average follow-up 2.5 years) with isolated GT fractures are then described. Patients <50 years had higher rates of rotator cuff tears and displaced (≥ 5mm) GT fractures were associated with supraspinatus atrophy. Both full rotator cuff tears and supraspinatus atrophy resulted in poor outcomes. The impact of fracture morphology on prognosis was not significant. However, age, sex, and associated glenohumeral dislocation differed by fracture type and this may reflect their pathophysiology. A more thorough evaluation of the prognosis and treatment of GT fractures by morphologic type would require a prospective multicenter study.