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Freehand three dimensional ultrasound for imaging components of the musculoskeletal systemRoss, Erin January 2010 (has links)
There have been reports on the use of Ultrasound (US) for monitoring fracture repair and for measuring muscle volume. Change in muscle mass is a useful bio-marker for monitoring the use and disuse of muscle, and the affects of age, disease and injury. The main modality for imaging bone is X-ray and for muscle volume Magnetic Resonance (MR). Previous studies have shown US to have advantages over X-ray and MR. US can image all stages of the fracture repair process and can detect signs of healing 4-6 weeks before X-ray allowing earlier detection of possible complications. Compared to MR, US is less resource intensive, easier to access and also has fewer exclusion criteria for patients. Despite these advantages, the limited field of view that US can provide results in high operator dependency for scan interpretation and also for length and volume measurements. Three-dimensional Ultrasound (3D US) has been developed to overcome these limitations and has been used to provide extended field of view images of the foetus and the heart and to obtain accurate volume measurements for organs. In this thesis it is hypothesized that 3D US can provide a more comprehensive method of imaging fracture repair than X-ray and is also a viable alternative to MR for determining muscle volumes in vivo. Initially, an electromagnetically (EM) tracked 3D US system was evaluated for clinical use using phantom-based experiments. It was found that the presence of metal objects in or near the EM field caused distortion and resulted in errors in the volume measurements of phantoms of up to ±20%. An optically tracked system was also evaluated and it was found that length measurements of a phantom could be made to within ±1.3%. Fracture repair was monitored in five patients with lower limb fractures. Signs of healing were visible earlier on 3D US with a notable, although variable, lag between callus development on X-ray compared to 3D US. 3D US provided a clearer view of callus formation and the changes in density of the callus as it matured. Additional information gained by applying image processing methods to the 3D US data was used to develop a measure of callus density and to identify the frequency dependent appearance of the callus. Volume measurements of the rectus femoris quadricep muscle were obtained using 3DUS from eleven healthy volunteers and were validated against volume measurements derived using MR. The mean difference between muscle volume measurements obtained using 3D US and MR was 0.53 cm3 with a standard deviation of 1.09 cm3 and 95% confidence intervals of 0.20 - 1.27 cm3 In conclusion, 3D US demonstrates great potential as a tool for imaging components of the musculoskeletal system and as means of measuring callus density.
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Avaliação do volume endometrial pela ultra-sonografia tridimensional em procedimentos de reprodução assistida / Assessment of endometrial volume by three-dimensional ultrasound in assisted reproduction proceduresMartins, Wellington de Paula 07 November 2007 (has links)
A ultra-sonografia é essencial para a condução de casos que irão ser submetidos aos tratamentos de reprodução assistida. Apesar de inúmeras pesquisas, não se mostrou capaz de predizer o sucesso do procedimento e apenas a medida da espessura endometrial tem algum valor prognóstico. Com a introdução da ultra-sonografia tridimensional, cresceu o interesse no assunto, na esperança que a possibilidade de uma avaliação espacial mais exata dos tecidos e da vascularização pudesse melhorar nossa habilidade de predizer a resposta à estimulação ovariana ou determinar a receptividade do meio endometrial. Objetivamos nesta revisão apresentar os resultados dos trabalhos envolvendo a ultra-sonografia tridimensional e a reprodução assistida, e suas possíveis aplicações nestes procedimentos. / Ultrasonography is essential to guide the cases that will be submitted to assisted reproduction. In spite of the great amount of researchs, it is not able to predict the sucess of the treatment and only the endometrial thicknesshas some prognostic value. With the introduction of three-dimensional ultrasound, therewas a new curiosity incoming, in the expectancy that the possibility of volume assessment of tissues and its vascularization could improve our ability to determine endometrial receptivity or to predict the patient response to ovarian stimulation. In this review we intend to present the results of researchs about three-dimensional ultrasound and assisted reproduction as well as its possible clinical aplications.
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Three-dimensional ultrasound in the management of abdominal aortic aneurysmLowe, Christopher January 2016 (has links)
Objectives: Clinical implementation of 3D ultrasound (3D-US) in vascular surgery is in its infancy. The aim of this thesis was to develop novel clinical applications for 3D-US in the diagnosis and management of abdominal aortic aneurysm (AAA). Methods: Four principle clinical applications were investigated. 1) Intraoperative imaging – The ability of 3D-US to detect and classify endoleaks was compared with digital subtraction angiography in patients undergoing EVAR. 2) Detection and classification of endoleaks following endovascular aneurysm repair (EVAR) – The abilityof 3D-US to accurately detect and classify endoleaks following EVAR was compared to CTA and the final multi-disciplinary team decision. 3) AAA volume measurement – measurements using magnetic and optically-tracked 3D-US were compared to CTA. 4) Biomechanical analysis – the challenges of using 3D-US to generate surface models for biomechanical simulation was explored by development of an interactive segmentation technique and comparison of paired CT and 3D-US datasets. Optimal results were used in finite element analysis (FEA) and computational fluid dynamic(CFD) simulations. Results: 3D-US out-performed uniplanar angiography for the detection of endoleaks during EVAR. This approach allowed contrast-free EVAR to be performed in patients with poor renal function. 3D contrast-enhanced ultrasound was superior to CTA for endoleak detection and classification when compared with the final decision of the multi-disciplinary team. Optimal results for AAA volume measurements were gained using an optically tracked 3D-US system in EVAR surveillance. However, there remained a significant mean difference of 13.6ml between CT and 3D-US. Complete technical success of generating geometries for use in biomechanical analysis using 3D-US was only 5%. When the optimal results were used, a comparable CFD analysis under the conditions of steady, laminar and Newtonian flow was achieved. Using basic modelling assumptions in FEA, peak von Mises and principle wall stress was found to be at the same anatomical location on both the CT and 3D-US models but the 3D-US model overestimated the wall stress values by 41% and 51% respectively. Conclusions: 3D-US could be clinically implemented for intra-operative imaging and EVAR surveillance in specific cases. 3D-US volume measurement is feasible but future work should aim to improve accuracy and inter-observer reliability. Although the results of biomechanical analysis using the optimal results was encouraging and provided a proof-of-principal, there are a number of technical developments required to make this approach feasible in a larger number of patients.
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AvaliaÃÃo ClÃnica, Funcional e MorfolÃgica dos Pacientes Submetidos à Esfincterotomia Lateral Interna por Fissura Anal CrÃnica / Clinical, functional and morphological evaluation of womens who underwent lateral internal sphincterotomy for chronic anal fissureGraziela OlÃvia da Silva Fernandes 05 January 2012 (has links)
CoordenaÃÃo de AperfeiÃoamento de NÃvel Superior / A fissura anal à uma das principais afecÃÃes encontradas nos consultÃrios dos coloproctologistas. O tratamento ideal para fissura anal crÃnica permanece incerto, mas, a esfincterotomia lateral interna continua sendo o tratamento mais efetivo disponÃvel. O objetivo deste trabalho foi avaliar a anatomia e a funÃÃo anorretal dos pacientes submetidos à esfincterotomia lateral interna devido à fissura anal crÃnica. AlÃm disso, determinar a correlaÃÃo dos sintomas de incontinÃncia fecal com os achados anatÃmicos utilizando ultrasonografia anorretal tridimensional e estabelecer o percentual do esfÃncter anal interno (EAI) que pode ser seccionado durante a realizaÃÃo de uma esfincterotomia. Foram avaliadas, prospectivamente, 31 mulheres com mÃdia de idade de 40 anos com fissura anal crÃnica tratadas com esfincterotomia lateral interna. Foi utilizado o escore de incontinÃncia de Wexner, a manometria anorretal e a ultassonografia anorretal tridimensional (US3D). Foram incluÃdas ainda, 26 mulheres saudÃveis como grupo controle com mÃdia de idade de 38 anos. Quatro meses apÃs a cirurgia, foram medidas as pressÃes anais, os comprimentos dos mÃsculos do canal anal, sendo os grupos comparados. O comprimento longitudinal e a porcentagem do esfÃncter anal interno seccionado em relaÃÃo ao total do esfÃncter interno contra lateral foram correlacionados com o escore de incontinÃncia. Na anÃlise estatÃstica, aplicou-se o teste t Student, one-way ANOVA, o teste qui quadrado, o teste de correlaÃÃo de Spearman e o coeficiente de correlaÃÃo intraclasse(ICC). O p<0.05 foi o valor utilizado para significÃncia estatÃstica. No grupo da esfincterotomia, 11 eram nulÃparas, 11 possuÃam pelo menos um parto vaginal e 9 foram submetidas a cesariana. A distribuiÃÃo da paridade e tipo de parto entre os grupos foram similares. O escore de incontinÃncia foi semelhante quando comparado as pacientes quanto a paridade e ao tipo de parto. NÃo houve correlaÃÃo entre a idade e o escore de incontinÃncia fecal. As pressÃes anais de repouso reduziram significativamente no pÃs-operatÃrio. NÃo houve diferenÃa entre as pressÃes voluntÃrias mÃximas no prÃ- e pÃs-operatÃrio. NÃo houve diferenÃa estatisticamente significante no comprimento dos esfÃncteres Ãntegros e do GAP quando comparadas as pacientes submetidas a esfincterotomia com pacientes voluntÃrias. Houve uma correlaÃÃo positiva significante entre o comprimento de mÃsculo seccionado e o escore de incontinÃncia fecal. Dezoito pacientes incluÃdas no estudo tiveram menos de 25% do esfÃncter anal interno seccionado, sendo a mÃdia do comprimento da lesÃo 0,54cm. Treze pacientes tiveram 25% ou mais do esfÃncter anal interno seccionado e a mÃdia do tamanho do esfÃncter seccionado de 1,00cm. O escore de incontinÃncia foi significantemente menor nos pacientes que apresentaram menos de 25% do esfÃncter anal interno seccionado. NÃo houve correlaÃÃo entre o Ãngulo de lesÃo e o escore de incontinÃncia. O coeficiente de correlaÃÃo intra classe variou de 0,714-0,989 para as medidas ultrassonogrÃficas realizadas por dois examinadores. Conclui-se que houve uma correlaÃÃo entre o tamanho do esfÃncter anal interno seccionado e o escore de incontinÃncia anal e que a secÃÃo do EAI deve ser limitada a menos de 25% do comprimento total do mÃsculo. / The anal fissure is one of the main diseases found in the offices of colorectal surgeons. The ideal treatment for chronic anal fissure remains uncertain, but, until now, the lateral internal sphincterotomy is still the most effective treatment available. The aim of this study was to evaluate the anatomy and anorectal function of patients undergoing lateral internal sphincterotomy for chronic anal fissure. Also, determine the correlation between fecal incontinence symptoms and the anatomic findings using three-dimensional anorectal ultrasonography to establish the percentage of the internal anal sphincter that could be safely divided during lateral sphincterotomy. In a prospective study, 31 females, mean age 40years, with chronic anal fissure treated with lateral internal sphincterotomy were evaluated using Wexnerâs incontinence score, anal manometry and 3D anorectal ultrasonography. It was also included 26 healthy females control, mean age 38years. Anal canal pressures and the muscles length were measured 4 months after surgery and compared between both groups. The longitudinal length and percentage of internal anal sphincter divided in relation to total contralateral sphincter length were assessed and correlated with incontinence score. Student t test, one-way ANOVA, chi square test, Spearman correlation and the intraclass correlation coefficient (ICC) were used. The p <0.05 was the value used for statistical significance. The sphincterotomy group included 11 nulliparous, 11 vaginal delivery and 9 cesarian cessation. The figures for control group were similar. The incontinence score was similar when compared the parity and mode of delivery of the patients. There was no correlation between age and scores of fecal incontinence. The anal resting pressure decreased significantly after surgery. There was no difference between the maximal voluntary pressure in pre-and postoperatively. There was no statistically significant difference in the length of the anterior external anal sphincter, external anal sphincter- puborectalis complex and GAP when compared the patients undergoing sphincterotomy with voluntary patients. There was a statistically significant positive correlation between the length of muscle divided and the score of fecal incontinence. Eighteen patients had less than 25% of the internal anal sphincter divided and the average size of 0,54cm divided sphincter.Thirteen patients had 25% or more of the internal anal sphincter divided and the average size of 1.00 cm divided sphincter. The incontinence score was significantly lower in patients with less than 25% of the internal anal sphincter divided. There was no correlation between the angle of injury and incontinence score. The intra-class correlation coefficient ranged from 0.714 to 0.989 for the ultrasound measurements performed by two examiners. It is concluded that there was a correlation between the size of the internal anal sphincter divided and anal incontinence score and the division of the IAS must be limited to less than 25% of the total length of the muscle.
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Avaliação do volume endometrial pela ultra-sonografia tridimensional em procedimentos de reprodução assistida / Assessment of endometrial volume by three-dimensional ultrasound in assisted reproduction proceduresWellington de Paula Martins 07 November 2007 (has links)
A ultra-sonografia é essencial para a condução de casos que irão ser submetidos aos tratamentos de reprodução assistida. Apesar de inúmeras pesquisas, não se mostrou capaz de predizer o sucesso do procedimento e apenas a medida da espessura endometrial tem algum valor prognóstico. Com a introdução da ultra-sonografia tridimensional, cresceu o interesse no assunto, na esperança que a possibilidade de uma avaliação espacial mais exata dos tecidos e da vascularização pudesse melhorar nossa habilidade de predizer a resposta à estimulação ovariana ou determinar a receptividade do meio endometrial. Objetivamos nesta revisão apresentar os resultados dos trabalhos envolvendo a ultra-sonografia tridimensional e a reprodução assistida, e suas possíveis aplicações nestes procedimentos. / Ultrasonography is essential to guide the cases that will be submitted to assisted reproduction. In spite of the great amount of researchs, it is not able to predict the sucess of the treatment and only the endometrial thicknesshas some prognostic value. With the introduction of three-dimensional ultrasound, therewas a new curiosity incoming, in the expectancy that the possibility of volume assessment of tissues and its vascularization could improve our ability to determine endometrial receptivity or to predict the patient response to ovarian stimulation. In this review we intend to present the results of researchs about three-dimensional ultrasound and assisted reproduction as well as its possible clinical aplications.
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Möglichkeiten und Grenzen minimal-invasiver SchulterchirurgieKääb, Max Josef 19 January 2005 (has links)
Zur Diagnostik von Rupturen der Rotatorenmanschette wird häufig die im Vergleich zur Sonografie deutlich kostenintensivere Magnetresonanztomografie durchgeführt. Ein Grund hierfür ist, dass es zum Teil schwierig ist, standardisierte statische Sonografie-Bilder zu gewinnen, was die reproduzierbare, untersucherunabhängige diagnostische Information verringert. Ziel des ersten Teils der Arbeit war es einerseits, zu analysieren, ob mit der 3D-Sonografie diese Probleme verringert werden könnten und andererseits die Sensitivität mit dem 2D-Ultraschall zur Diagnostik von Komplett- und Partialrupturen zu vergleichen. Bei der Untersuchung von 114 Patienten konnten mit dem 3D-Ultraschall Rupturen der Rotatorenmanschette gut dargestellt werden. Der Vergleich zwischen 2D- und 3D-Ultraschall ergab keinen statistisch signifikanten Unterschied zwischen beiden Verfahren für die Diagnostik von Komplett- und Partialrupturen. Ein Vorteil war die Möglichkeit der untersucherunabhängigen simultanen Auswertung von drei standardisierten Schnittebenen zu einem späteren Zeitpunkt. Bei der Verwendung biodegradierbarer Anker zur Fixierung von Weichteilen können ossäre Reaktionen auftreten. Ziel war es, die frühen Reaktionen des umgebenden Gewebes auf einen Poly-(L-co-D/L-Lactid) 70/30 Anker im Vergleich zu einem Titananker im Schafsknochen zu analysieren. Innerhalb von 20 Wochen nach Implantation zeigte sich keinerlei Verlust von Knochensubstanz im Bereich des distalen Schafsfemur bei Ankern aus Titan oder aus Polylactid. Vielmehr zeigte sich eine ausgeprägte Neuformation von spongiösem Knochen in die Implantathohlräume vor allem für das biodegradierbare Material. Daher sollten neben materialbedingten Ursachen auch biomechanische Ursachen wie zyklische Belastungen für mögliche Osteolysen in Betracht gezogen werden. Die arthroskopische subacromiale Dekompression (ASD) ist ein häufig durchgeführtes Verfahren zur Therapie von Subachromialsyndromen. Es sollten die eigenen Ergebnisse seit 1993 unter Berücksichtigung von Nebendiagnosen sowie die Möglichkeit, verschiedene Scores und VAS auch telefonisch erheben zu können, analysiert werden. Die Untersuchung von 422 Schultern zwischen 1,5 und 9,5 Jahren (durchschnittlich 4,8 Jahre) nach der Operation zeigte, dass die ASD mit überwiegend guten und sehr guten subjektiven und objektiven Resultaten (ca. 75%) ein zuverlässiges operatives Verfahren ist. Im Gegensatz zu einem laufenden Rentenverfahren hatten Rupturen der Rotatorenmanschette zum Zeitpunkt der Operation keinen negativen Einfluss auf das Operationsergebnis. Bei Nichtbeachtung der Pathologie des superioren Labrums und bei Rezidivoperation kam es zu einem erhöhten Anteil an Therapieversagern. Die telefonische Erhebung verschiedener Schulter-Scores (ausgenommen Constant-Score) und der VAS lieferte valide Resultate, die eine klinische Untersuchung entbehrlich machen und insbesondere bei Langzeitstudien eine wesentlich höhere Nachuntersuchungsrate ermöglichen. Das Konzept der winkelstabilen Osteosynthese ermöglicht eine weichteilschonende, minimal-invasive Frakturstabilisierung. Um eine sichere Verankerung von winkelstabilen Schrauben zu erreichen, ist eine korrekte Positionierung der Schraube in der Platte erforderlich. In biomechanischen Testungen konnte gezeigt werden, dass bei einer geringen Abweichung des Insertionswinkels winkelstabiler Schrauben von bis zu 5° vom optimalen Winkel immer noch eine hohe Stabilität der Schrauben-/Plattenverbindung gewährleistet war. Ab einem Winkel von über 5° kam es zu einer signifikanten Abnahme der Festigkeit dieser Verbindung. Um eine optimale Festigkeit der Verbindung Schraube/Platte zu erreichen und das Risiko der Schraubenlockerung zu minimieren, ist die konsequente Benutzung eines Zielgerätes zu empfehlen. Die klinische Nachuntersuchung von 53 Patienten mit winkelstabiler Osteosynthese bei proximaler Humerusfraktur zeigte eine mit der Literatur vergleichbare Komplikationsrate bei verringertem sekundären Dislokationsrisiko. Es zeigte sich aber auch die Problematik dieser Fakturen mit langer Nachbehandlungsdauer und dem Risiko einer Humeruskopfnekrose im Verlauf. Winkelstabile Implantate ermöglichten eine sichere Stabilisierung von proximalen Humerusfrakturen, konnten jedoch eine insuffiziente Anwendung - wie eine fehlerhafte Verankerung der Kopfverriegelungsschrauben - nicht kompensieren. Erhöht war das Risiko einer Schraubenperforation durch die Sinterung des Kopfes auf das rigide Implantat. / Goal of the study was evaluation of advantages and limitations of shoulder diagnosis and different techniques of minimal invasive shoulder surgery. MRI has become the standard for diagnosis of rotator cuff lesions, since it can be difficult to obtain standardized ultrasound images. Goal of the study was analysis of sensitivity of 3D- in comparison to 2D-ultrasound. Examination of 114 patients showed excellent visualization of rotor cuff defects with 3D-ultrasound. Comparison to 2D-ultrasound showed no statistical significant difference between both methods for diagnosis of full- and partial thickness defects of the rotator cuff. Advantage of 3D-ultrasound was the possibility of simultaneous visualization of three standardized planes. For the reattachment of ligaments and tendons biodegradable implants are increasingly used today. However, with the use of biodegradable implants early and late osteolysis has been reported. Goal of this study was to analyze the early osseous integration of a newly designed suture anchor in comparison to a titanium implant. The implants made of Poly-(L-co-D/L-lactide) 70/30 or titanium were inserted into the cancellous bone of the distal femoral condyle in four sheep. The animals were followed radiographically over a period of 20 weeks in which no final implant degradation was anticipated. After sacrifice new bone formation was quantitatively and local tissue response qualitatively analyzed from microradiographs and histological sections were examined. New bone formation was seen around both implant materials within 20 weeks. Inside the recess of the polylactide suture anchor there was significantly higher bony ingrowth (p = 0.026) as compared to the titanium implant. Histologically non of the materials did show any inflammatory reaction. These data indicate that early osteolysis around Poly-(L-co-D/L-lactide) 70/30 suture anchors in cancellous bone may not be attributable to the material properties but rather to other reasons such as the mechanical situation at the implant-bone interface. Arthroscopic subacromial decompression (ASD) has become a well established procedure to treat chronic subacromial impingement syndrome. Goal of the study was to retrospectively evaluate the outcome and to evaluate the validity of data collection by telephone interview. The examination of 422 patients average 4.8 years after peration showed in 75% goog and excellent results. The average Constant score (raw score) improved from 46 to 80 Pts. Patients who had a second ASD had good results in only 25%. Patients with running workers compensation application showed no satisfying outcome. Lesions of the rotator cuff were shown to have no significant influence on the outcome in comparison to patients with intact rotator cuff. Additionally, it was shown that the assessment of various shoulder scores (except Constant Score) by telephone interview is possible. Internal fixators with angular stability have been developed in order to provide high stability without compression of the plate on to the bone. The insertion angle of the screw must correspond precisely to the axis of the screw hole. The objective of this study was to examine the relationship between the stability of the locked screw-plate on the insertion angle of the screw. Locking screws were inserted in a isolated or combined locking hole with the use of an aiming device. The screws were inserted with an axis deviation of 0°(optimal condition), 5° and 10°. The samples were tested under shear or axial (push out) loading conditions until failure occurred. Locking screws inserted in the isolated locking hole (PC-Fix) showed a significant decrease of failure load if inserted at 5° and 10° angle. Screws inserted in the combined locking hole (LCP) also showed a significant decrease of push-out force of 77% with 10° axis deviation. A locking head screw exhibits a high stability with a moderate axis deviation in the angle of insertion of up to 5°. However there is a significant decrease in stability with increasing axis deviation (>5°). A aiming device is recommended to provide an optimal fixation with angular stability. Clinical Examination of 53 patients with angular stable osteosynthesis of proximal humeral fractures showed a rate of complications, which can be compared with literature with lower risk of secondary dislocation. Implants with angular stability allow stable fixation of proximal humeral fractures however the risk of screw perforation is higher.
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