Compression irréversible par ondelettes en radiologie thoracique numérique : Evaluation qualitative sur des structures anatomiques et pathologiques

La compression d'images représente une alternative de faible coût à l'augmentation systématique de la capacité de stockage des systèmes d'archivage et des lignes de transmission (PACS). Afin d'étudier les effets de la compression irréversible par ondelettes (base de la norme JPEG2000) sur des radiographies thoraciques d'emblée numériques (Thoravision®), nous avons défini un protocole complet d'évaluation. Les taux de compression de 20:1, 40:1, 60:1 ont été évalués en double aveugle par 3 radiologues dans des conditions standardisées sur des structures anatomiques (suivant 11 critères portant sur les détails, les contours et les artéfacts sur une population de 30 sujets sains) et pathologiques (pneumothorax et syndromes interstitiels). Des courbes ROC ont été réalisées à partir de deux populations de 20 patients. Notre étude détermine un taux de compression acceptable à 20:1 pour les radiographies normales et 60:1 pour les images pathologiques. L'interprétation rigoureuse d'une radiographie thoracique nécessitant la conservation des structures anatomiques, le taux de 20:1 apparaît être la limite acceptable en pratique clinique. Notre protocole d'évaluation suggère par ailleurs qu'une évaluation qualitative d'une compression par ondelettes de radiographie thoracique peut être réalisée uniquement sur des critères anatomiques portant sur la vascularisation fine du poumon où la dégradation est prédominante

Subjektive Bildqualität digitaler Panoramaschichtaufnahmen in Relation zur Exposition

Die Zielsetzung dieser Studie war es, für digitale Panoramaschichtaufnahmen die Relation der subjektiven Bildqualität zur Exposition zu bestimmen. An Hand von Humanpräparataufnahmen konnten bei Standardwerten sowie experimentellen Variationen der Expositionsdaten weiterhin Effekte der intentionellen Unterexposition sowie der Strahlenaufhärtung auf die subjektive Bildqualität quantifiziert werden. Die Herstellung der Aufnahmen erfolgte auf einem Sirona Orthophos DS. Dabei wurden 37 Aufnahmen mit Expositionswerten von 60 kV/9 mA - 84 kV/13 mA aus dem Herstellerprogramm erzeugt und mit Hilfe einer modifizierten Steuerungssoftware zusätzliche PSA mit experimentellen Einstellungen von 60 kV/3 mA - 90 kV/11 mA hergestellt. Für die Beurteilung und Auswertung der subjektiven Bildqualität wurde eine individuelle Software (Eldoredo V2.2) entwickelt. 39 Zahnärzte und 5 MTRA beurteilten die Aufnahmen damit an einem Monitor unter standardisierten Bedingungen. Ein iterativer Beurteilungsprozess erlaubte, eine Serie von 1369 (37 x 37) PSA-Abbildungspaaren darzustellen. Für jedes Paar entschieden die Untersucher an Hand definierter Kriterien, ob eine PSA hinsichtlich der subjektiv beurteilten Bildqualität vorzuziehen oder Äquivalenz gegeben sei. Nach statistischer Aufarbeitung der Einzelentscheidungen ließ sich damit für jede Expositionsstufe ein Index der Bildqualität berechnen. Bei Expositionswerten in einem Bereich von 60 kV/9 mA - 69 kV/15 mA der Herstellersoftware und 60 kV/5 - 15 mA sowie 70 kV/5 - 15mA der experimentellen Software fanden sich dabei keine signifikanten Verteilungsunterschiede der Bildqualität. Eine intentionelle Unterexposition bei digitalen PSA-Geräten, etwa bei Kindern oder häufigen Wiederholungsaufnahmen, kann nach den vorliegenden Ergebnissen vertreten werden, ohne dass es dabei zu einer signifikanten Verschlechterung der Bildqualität kommt. Damit ist im Gegensatz dazu bei einer Strahlenaufhärtung in dem untersuchten digitalen System stets zu rechnen. Insgesamt zeigen die Ergebnisse, dass auch digitale PSA-Systeme beachtliche Reserven hinsichtlich der Dosisminimierung aufweisen können.The aim of this study was to describe the relation of the subjective image quality of digital panoramic radiographs in relation to exposure. In addition, variations of exposure were compared to standard settings, thus evaluating the effects of intentional underexposure on the achievable image quality. A Sirona Orthophos DS unit was used to produce 37 digital panoramic images of a human skull. Exposure values ranged from 60 kV/9 mA to 84 kV/13 mA in the conventional and 60 kV/3 mA to 90 kV/11 mA in the experimental setting. Assessment and evaluation of the subjective image quality were performed with an HTML-based protocol. 39 dentists and 5 radiographic assistants had to assign their preference of an image or equality in 1,369 (37x37) image pairs. The decisions were computed to a quality index for each exposure setting. Statistical analysis demonstrated no significant differences of image quality between 60 kV/9 mA - 69 kV/15 mA in the conventional and 60 kV/5 to15 mA as well as 70 kV/5 to 15 mA in the experimental setting. Following these results, a considerable dose reduction by the means of intentional underexposure can be achieved without any loss of image quality. By reducing the absorbed doses, an increase of kV values up to 80 kV and more is also correlated with dose reduction. However, those images showed high significant loss of quality. In summary, the results demonstrate an equivalent image quality of digital panoramic images over a very wide range of exposure values. The feasible dose reduction might be of interest not only in individuals (minors, repeated images), but also in defining general principles of panoramic imaging

The Effect of Football Shoulder Pad Removal Technique and Equipment Removal Training on Cervical Spine Motion, Time to Task Completion, and Perceived Task Difficulty

Current recommendations for management of cervical spine injury suggest leaving football equipment in place unless otherwise indicated by the NATA position statement. We investigated the effect of three shoulder pad removal techniques and the effect of reinforced training on cervical spine motion, time, and difficulty. The RipKord shoulder pads were faster than both traditional shoulder pad removal techniques (P<0.001) and easier (P<0.05) than the flat torso to remove. Less cervical spine range of motion with the flat torso technique was observed in the sagittal and frontal planes (P<0.05) during Testing Session II in the reinforced training group. Both traditional shoulder pad removal techniques were faster during Session II [flat (P=0.001); elevated (P<0.001)]. The RipKord shoulder pads provided a method for removal with superior measure of time and difficulty compared with traditional removal techniques. With reinforced training, cervical spine motion improved with the flat torso technique.Master of Art

UWOMJ Volume 78, Supplement S1, Summer 2008

Schulich School of Medicine & Dentistyhttps://ir.lib.uwo.ca/uwomj/1083/thumbnail.jp

Next generation of growth-sparing techniques: preliminary clinical results of a magnetically controlled growing rod in 14 patients

Session 3A - Early Onset Scoliosis: Paper no. 33SUMMARY: Growth-sparing techniques are commonly used for the treatment of progressive EOS. The standard growing rod (GR) technique requires multiple surgeries for lengthening. The preliminary results of MCGR has shown the comparable outcomes to standard GR without the need for repeated surgery which can be expected to reduce the overall complication rate in GR surgery. INTRODUCTION: The growing rod (GR) technique for management of progressive Early-Onset Scoliosis (EOS) is a viable alternative but with a high complication rate attributed to frequent surgical lengthenings. The safety and efficacy of a non-invasive Magnetically Controlled Growing Rod (MCGR) has been previously reported in a porcine model. We are reporting the preliminary results of this technique in EOS. METHODS: Retrospective review of prospectively collected multi-center data. Only patients who underwent MCGR surgery and at least 3 subsequent spinal distractions were included in this preliminary review. Distractions were performed in clinic without anesthesia or analgesics. T1-T12 and T1-S1 height and the distraction distance inside the actuator were analyzed in addition to conventional clinical and radiographic data. RESULTS: Patients (N=14; 7 F and 7 M) had a mean age of 8y+10m (3y+6m to 12y+7m) and underwent a total of 14 index surgeries (SR: index single rod in 5 and DR: dual rod in 9) and 91 distractions. There were 5 idiopathic, 4 neuromuscular, 2 congenital, 2 syndromic and one NF. Mean follow-up (FU) was 10 months (5.8-18.2). Mean Cobb changed from 57° pre-op to 35° post-op and correction was maintained (35°) at latest FU. T1-T12 increased by 4 mm for SR and 10 mm for DR with mean monthly gain of 0.5 and 1.39, respectively. T1-S1 gain was 4 mm for SR and 17 mm for DR with mean monthly gain of 0.5 mm for SR and 2.35 mm for DR. The mean interval between index surgery and the first distraction was 66 days and thereafter was 43 days. Complications included one superficial infection in (SR), one prominent implant (DR) and minimal loss of initial distraction in three after index MCGR (all SR). Overall, partial loss of distraction was observed following 14 of the 91 distractions (one DR and 13 SR). This loss was regained in subsequent distractions. There was no neurologic deficit or implant failure. CONCLUSION: MCGR appears to be safe and provided adequate distraction similar to the standard GR technique without the need for repeated surgeries. DR patients had better initial curve correction and greater spinal height. No major complications were observed during the short follow-up period. The FDA has not cleared the drug and/or medical device for the use described in this presentation (i.e., the drug or medical device is being discussed for an ‘off label’ use).postprin

Shoulder morphofunctional adaptations on overhead-throwing athletes : implications for physiotherapy throwing-shoulder examination.

Doutoramento em Motricidade Humana, especialidade de Ciências da Fisioterapia.The overhead throwing motion is a highly skilled movement, particularly demanding to the shoulder due to high strength levels and/or acceleration applied to the hand and by the elevated degree of control and precision required to position the arm in space. The shoulders of those involved in repeated forceful overhead throwing, the overhead-throwing athletes, undergo a range of neural, soft tissues and skeletal adaptations that could be described as, the “overhead-throwing shoulder adaptive pattern” (OTSAP). The main goal of overall studies in this thesis was to characterize the dominant overhead-throwing shoulder adaptive pattern of non-symptomatic overhead throwing athletes, comparing with a non-athletic population. Additionally, while comparing volleyball and team-handball players, we looked for specific sport-related components of the OTSAP. Knowledge on OTSAP is important for those involved on training, but also for sport physiotherapist during shoulder functional assessment. Some components of the OTSAP could be mistaken by injury signs or risk factors. Structural (osseous) and functional changes were identified on the dominant shoulder of volleyball and team-handball players. Some were similar of those described in baseball players, and others were sport-related. Thus, the OTSAP should be considered by the physiotherapist during overhead-throwing shoulder assessment. RESUMO:O movimento de lançamento é altamente especializado e particularmente exigente para o ombro devido aos excessivos níveis de carga/aceleração aplicados. Atletas cujos ombros estão envolvidos em movimentos repetidos de lançamento, consideram-se, na literatura anglo-saxónica, atletas “overhead”. Estes são sujeitos a um conjunto de adaptações neurais, tecidulares e ósseas que podem ser descritas como, o “padrão de adaptação do ombro do atleta overhead” (PAOAO). O principal objetivo da tese foi caracterizar o padrão de adaptação do ombro dominante, não sintomático, dos atletas “overhead”, comparando-os com não atletas. Adicionalmente, comparando voleibolistas e andebolistas, procurou-se encontrar componentes específicos da modalidade praticada inerentes ao PAOAO. O conhecimento detalhado deste PAOAO é crucial para os intervenientes em processos de treino, e para o fisioterapeuta responsável por uma avaliação detalhada do ombro, sob pena de alguns dos componentes do PAOAO serem erroneamente considerados como sinais de lesão ou fatores de risco. Foram identificadas alterações estruturais e funcionais no ombro dominante de voleibolistas e andebolistas. Algumas são similares às encontradas em jogadores de beisebol, enquanto outras estão diretamente relacionadas com a prática desportiva específica. Assim, este PAOAO deverá ser tido em consideração pelo fisioterapeuta aquando da avaliação do ombro do atleta “overhead”.FCT - Fundação para a Ciência e a Tecnologi

Shwachman-Diamondin oireyhtymän kliiniset, geneettiset ja radiologiset piirteet

Shwachman-Diamond syndrome (SDS) is a rare autosomal recessive disorder in which the cardinal symptoms arise from exocrine pancreatic insufficiency and bone marrow dysfunction. Previous studies have suggested increased risk of fatal complications among Finnish SDS infants. The genetic defect responsible for the disease was recently identified; the SBDS gene is located at chromosome 7q11 and encodes a protein that is involved in ribosome biosynthesis. The discovery of the SBDS gene has opened new insights into the pathogenesis of this multi-organ disease. This study aimed to assess phenotypic and genotypic features of Finnish patients with SDS. Seventeen Finnish patients with a clinical diagnosis of SDS were included in the study cohort. Extensive clinical, biochemical and imaging assessments were performed to elucidate the phenotypic features, and the findings were correlated with the SBDS genotype. Imaging studies included abdominal magnetic reso-nance imaging (MRI), brain MRI, cardiac echocardiography including tissue Doppler examination, and cardiac MRI. The skeletal phenotype was assessed by dual-energy X-ray absorptiometry and bone histomorphometry. Twelve patients had mutations in the SBDS gene. In MRI, a characteristic pattern of fat-replaced pancreas with occasional enhancement of scattered parenchymal foci and of pancreatic duct was noted in the SBDS mutation-positive patients while the mutation-negative patients did not have pancreatic fat accumulation. The patients with SBDS mutations had significantly reduced bone mineral density associated with low-energy peripheral fractures and vertebral compression fractures. Bone histomorphometry confirmed low-turnover osteoporosis. The patients with SBDS mutations had learning difficulties and smaller head size and brain volume than control subjects. Corpus callosum, cerebellar vermis, and pos-terior fossa structures were significantly smaller in SDS patients than in controls. Patients with SDS did not have evidence of clinical heart disease or myocardial fibrosis. However, subtle diastolic changes in the right ventricle and exercise-induced changes in the left ventricle contractile reserve were observed. This study expanded the phenotypic features of SDS to include primary low-turnover osteoporosis and structural alterations in the brain. Pancreatic MRI showed characteristic changes in the SBDS mutation-positive patients while these were absent in the mutation-negative patients, suggesting that MRI can be used to differentiate patients harbouring SBDS mutations from those without mutations. No evidence for clinical cardiac manifestations was found, but imaging studies revealed slightly altered myocardial function that may have clinical implications. These findings confirm the pleiotropic nature of SDS and underscore the importance of careful multidisciplinary follow-up of the affected individuals.Shwachman-Diamondin oireyhtymä on harvinainen autosomissa peittyvästi periytyvä sairaus, jonka pääpiir-teet ovat imeytymishäiriöön johtava haiman ulkoeritystoiminnan vajaatoiminta sekä verenkuvamuutoksiin, tulehdusherkkyyteen ja kohonneeseen leukemiariskiin johtava luuytimen häiriö. Oireyhtymään liittyvä geeni (SBDS geeni) kromosomissa 7q11 on hiljattain tunnistettu ja siinä on kuvattu useita mutaatioita. Tutkimuksen tavoitteena oli kartoittaa Shwachman-Diamondin oireyhtymän ilmentymistä ja geneettistä taustaa suomalaisilla potilailla. Väitöskirjatyöhön on kerätty suomalaiset oireyhtymää sairastavat potilaat, yhteensä 17 potilasta, ja he ovat osallistuneet laajoihin kliinisiin, biokemiallisiin ja kuvantamistutkimuksiin. Kuvantamismenetelminä käytettiin vatsan, aivojen ja sydämen magneettitutkimuksia. Sydäntä tutkittiin lisäksi kaikukuvauksella ja siihen liitetyllä kudos Doppler mittauksella. Selkärangan röntgenkuvauksella ja luuston mineraalitiheysmittauksella selvitettiin osteoporoosin ja osteoporoottisten nikamamuutosten esiintyvyyttä. Tutkimus osoitti, että haiman magneettikuvauksessa kaikilla SBDS-geenimutaatioita omaavilla potilailla oli tyypillisenä löydöksenä rasvoittunut haimakudos, kun taas potilailla, jolla mutaatioita ei todettu, haiman alueella ei rasvoittumista todettu. Tämän perusteella haiman vajaatoiminnasta kärsiville lapsipotilaille kannattaa tehdä haiman magneettikuvaus diagnostiikan tueksi. Kaikilla SBDS-mutaatioita kantavilla potilailla luuntiheys oli alentunut ja osalla oli lisääntynyt murtuma-alttius, mutta luukudosnäytteen perusteella osteoporoosi ei johtunut imeytymishäiriöstä. Näin ollen on mahdollista, että todetut osteoporoosimuutokset ovat yhteydessä oireyhtymään liittyvään luuytimen toimintahäiriöön. Aivojen magneettitutkimuksessa aivokurkiaisen ja aivojen takakuopan rakenteet olivat SBDS-mutaatioita kantavilla potilailla pienempiä kuin ikä- ja sukupuoli-vakioiduilla verrokkihenkilöillä. Lisäksi aivojen kokonaistilavuus oli verrokkihenkilöitä pienempi. Löydöksillä saattaa olla yhteyttä potilaiden raportoimiin oppimishäiriöihin. Kaikki potilaat olivat sydämen toiminnan osalta oireettomia. Potilailla todettiin kuvantamistutkimuksissa normaali sydämen anatomia ja sydänlihaksen rakenne, mutta sydämen toimintaa mittaavilla menetelmillä havaitiin kuitenkin lieviä oikean kammion diastolisen toiminnan muutoksia ja alentunut vasemman kammion supistuvuus rasituksessa. Nämä lievät muutokset saattavat altistaa potilaita sydänperäisiin oireisiin elimistön stressitilanteissa

UWOMJ Volume 73, No. 1, 2004

Schulich School of Medicine & Dentistryhttps://ir.lib.uwo.ca/uwomj/1082/thumbnail.jp

UWOMJ Volume 67, Number 2, Summer 1998

Schulich School of Medicine & Dentistryhttps://ir.lib.uwo.ca/uwomj/1244/thumbnail.jp

The role of functional, radiological and self-reported measures in predicting clinical outcome in spondylotic cervical radiculopathy

BackgroundCervical radiculopathy (CR) results in significant disability and pain and is commonly treated conservatively with satisfactory clinical outcomes. However, a considerable number of patients require surgery to prevent irreversible neurological damage or when pain is unremitting. Both conservative and surgical treatments are characterised by a plethora of strategies and interventions, making comparisons between treatment groups a difficult task.The ability to predict the likely outcomes of treatment is important to clinicians involved in treatment and serves as an important basis for health policy, resource management and core knowledge essential for patients to have an informed consent when being offered both conservative and surgical interventions. Generic and condition specific measures in clinical conditions may have a role in predicting clinical outcome after treatment. Common measures employed in the examination and evaluation of cervical radiculopathy patients include self reported measures of pain and disability, measures of impairment and function, neurological and radiological evidence of the disease. Unfortunately, few studies exist that provide knowledge in understanding factors associated with the presentation of cervical radiculopathy and the ensuing long-term clinical outcome.The objective of this thesis was to address the limited understanding of the impairment measures and prognostic outcomes associated with cervical radiculopathy in an Indian population for both surgical and conservative treatment strategies. In these aspects, this thesis was original.AimThe principal aim of this thesis was to evaluate the role of clinical (pain, disability), functional (posture, cervical ROM), radiological (radiographic segmental curvature and segmental movements in the sagittal plane), socio-demographic and lifestyle factors (age, gender, BMI, work characteristics, physical activity, smoking, life-style changes, duration of symptoms, co-morbidities and number of previous episodes) in predicting clinical outcome (pain and disability) at one year in a cervical radiculopathy cohort which was treated conservatively or surgically. To support and substantiate the primary aim, associations, relationships, differences between the outcome variables at different measurement times, and effects of treatment were determined. Furthermore, a series of studies were undertaken examining key assessments of cervical spine impairment to further support the primary clinical outcome study.MethodsThe main element of the thesis derived clinical data from a sample of convenience of 163 patients (109 patients in the conservative group and 54 in the surgical group). All measurements were done at baseline, that is, prior to any form of intervention, and then at pre-determined intervals until a one year follow-up period in both treatment groups. After baseline assessments, the conservative group underwent medical treatment and physiotherapy whereas the surgery group underwent surgery, and post-surgery, were given ergonomic advice and exercises. An intention to treat analysis approach was adopted for dropouts (14% at 12 months).A large series of other studies were undertaken prior to and in parallel with the main clinical trial (Agarwal et al. 2005 a,b,c; Agarwal et al. 2006). Emphasis was placed on tester reliability for each measure used in this study and consequently methodological studies establishing reliability and validity of measures were carried out and published. Cervical range of motion, a key measure of impairment and neck functions, frequently used by physiotherapists as an assessment tool, was analysed to determine the effects of age, gender and repeat measurements over time in asymptomatic individuals (n = 219) as well as differences in range of motion between asymptomatics and patients with cervical radiculopathy. During the initial course of this research, it became evident that the pain and disability questionnaire (Neck Pain and Disability scale) in the English language was not applicable to a section of the patient population. This was therefore translated into Hindi (the national language of India).The outcome variables with their respective measuring instruments were neck pain and arm pain (101 Numerical Pain Rating Scale), pain and disability (NPAD), depression (NPAD factor 3 scores), posture (head neck angle), cervical range of movement (Spin-T goniometer), radiographic sagittal segmental curvature (Posterior Tangent Method) and radiographic sagittal segmental motion (Penning’s method). Demographics and lifestyle factors consisted of either continuous or dichotomous variables.A range of parametric and non-parametric tests analysed the correlations and differences between outcome variables at different times of measurements as well as determined treatment efficacy. The Clinical Prediction Rule (CPR) analysis was used to determine the group of predictor variables which could result in a successful outcome in a CR cohort, following conservative or surgical intervention. The NPAD (English and Hindi) was the outcome criterion for the CPR analysis of this study with a score of 55°. Three of the four predictors generated a 9.8 fold increase (likelihood ratio 95% CI 3.3 to 29.8) for the individual to be a responder, with a post-test probability of success at 93%.Surgery (3 months): Age 55°. Two of the four predictors generated a 16-fold increase (likelihood ratio 95% CI 2.3 to 112) for the individual to be a responder and the post test probability of success increased to 94% from a pre-test probability of success at 50%.ConclusionIn conclusion, this study was able to provide original and long-term assessments of cervical spine movement characteristics as well as translating the primary outcome into Hindi. The clinical finding was able to identify predictor clusters that provide level IV evidence of predicting outcomes at different timelines for cervical radiculopathy for both conservative and surgically treated patients. The use of these predictors in future studies may help in decision making for the appropriate type of treatment and expected outcome in CR patients