<p>The purpose of this thesis was to evaluate the diagnostic potential of a new ultrasound contrast agent,Sonazoid^TM, intended for use in patients with suspicion of prostate cancer.</p><p>The sonographic appearance of normal prostatic vascularity in dogs was evaluated before and after injection of Sonazoid,using different Doppler flow detection modes.The use of Sonazoid significantly improved the visibility of the vascular pattern in normal dog prostate,both with colour and power Doppler imaging.There was a significant difference in the depiction of blood flow in the prostate between the two imaging modalities,showing the power Doppler superior to colour Doppler imaging.The contrast revealed a radial,spoke-like intraprostatic pattern,not seen prior to contrast injection.</p><p>Different ultrasound imaging modalities were tested in a small group of young healthy male volunteers to evaluate the visibility of the normal prostate blood flow with and without Sonazoid.</p><p>The ultrasound contrast agent improved the visibility of the normal human prostate vascular anatomy for both colour and power Doppler imaging.Again,the improvement was significantly better for power Doppler than for colour Doppler imaging.Using fundamental B-mode,there was no major difference in the ultrasound appearance of the prost ate vascular it y before and after i njection of Sonazoid.Cont rast dynamic st udies of blood flow wit hi n t he normal gland showed a filling from the periphery towards the centre in all subjects,demonstrating a symmetric, radial vascular pattern.</p><p>A canine prostate model was used to investigate if Sonazoid,could improve the visualisation of prostatic vessels to better delineate areas on normal and decreased blood flow.Both 2D and 3D power Doppler imaging was performed in this study.The visibility of the prostate blood flow improved significantly following injection of Sonazoid for both 2D and 3D power Doppler imaging.There was,however,no major difference in depicting the vascularity using 2D and 3D imaging.After injection of Sonazoid,a disturbance of the radial vascular pattern and a lack of blood flow symmetry between the two prostate lobes were possible to identify.The added information gained by injection of Sonazoid made it possible to identify areas of decreased blood flow not seen prior to contrast injection.</p><p>The vascular pattern of lesions,identified with B-mode imaging in patients with suspicion of prostate cancer,was studied,using Sonazoid.Contrast dynamic inflow in the lesions,compared to the adjacent tissue was investigated in the same study.Prostate cancer lesions appeared hypervasuclar prior to ultrasound contrast agent.Three of six cancer lesions changed from hypervascular to marked hypervascular following injection of Sonazoid,a finding that might be interpreted as a higher level of confidence.None of the non-cancer lesions were assessed as hypervascular after Sonazoid injection,a possible increased value of a negative finding.Four of the cancer lesions enhanced earlier compared to the surrounding prostate tissue,following ultrasound contrast injection.The results indicate that changes in vascular architecture,e.g.induction of angiogenesis by tumour cells,can be observed by ultrasonographically determining the inflow pattern of an intravenously injected ultrasound contrast agent.</p>

The purpose of this thesis was to evaluate the diagnostic potential of a new ultrasound contrast agent,SonazoidTM, intended for use in patients with suspicion of prostate cancer. The sonographic appearance of normal prostatic vascularity in dogs was evaluated before and after injection of Sonazoid,using different Doppler flow detection modes.The use of Sonazoid significantly improved the visibility of the vascular pattern in normal dog prostate,both with colour and power Doppler imaging.There was a significant difference in the depiction of blood flow in the prostate between the two imaging modalities,showing the power Doppler superior to colour Doppler imaging.The contrast revealed a radial,spoke-like intraprostatic pattern,not seen prior to contrast injection. Different ultrasound imaging modalities were tested in a small group of young healthy male volunteers to evaluate the visibility of the normal prostate blood flow with and without Sonazoid. The ultrasound contrast agent improved the visibility of the normal human prostate vascular anatomy for both colour and power Doppler imaging.Again,the improvement was significantly better for power Doppler than for colour Doppler imaging.Using fundamental B-mode,there was no major difference in the ultrasound appearance of the prost ate vascular it y before and after i njection of Sonazoid.Cont rast dynamic st udies of blood flow wit hi n t he normal gland showed a filling from the periphery towards the centre in all subjects,demonstrating a symmetric, radial vascular pattern. A canine prostate model was used to investigate if Sonazoid,could improve the visualisation of prostatic vessels to better delineate areas on normal and decreased blood flow.Both 2D and 3D power Doppler imaging was performed in this study.The visibility of the prostate blood flow improved significantly following injection of Sonazoid for both 2D and 3D power Doppler imaging.There was,however,no major difference in depicting the vascularity using 2D and 3D imaging.After injection of Sonazoid,a disturbance of the radial vascular pattern and a lack of blood flow symmetry between the two prostate lobes were possible to identify.The added information gained by injection of Sonazoid made it possible to identify areas of decreased blood flow not seen prior to contrast injection. The vascular pattern of lesions,identified with B-mode imaging in patients with suspicion of prostate cancer,was studied,using Sonazoid.Contrast dynamic inflow in the lesions,compared to the adjacent tissue was investigated in the same study.Prostate cancer lesions appeared hypervasuclar prior to ultrasound contrast agent.Three of six cancer lesions changed from hypervascular to marked hypervascular following injection of Sonazoid,a finding that might be interpreted as a higher level of confidence.None of the non-cancer lesions were assessed as hypervascular after Sonazoid injection,a possible increased value of a negative finding.Four of the cancer lesions enhanced earlier compared to the surrounding prostate tissue,following ultrasound contrast injection.The results indicate that changes in vascular architecture,e.g.induction of angiogenesis by tumour cells,can be observed by ultrasonographically determining the inflow pattern of an intravenously injected ultrasound contrast agent.

The early detection of prostate cancer plays a significant role in the success of treatment and outcome. To detect prostate cancer, imaging modalities such as TransRectal UltraSound (TRUS) and Magnetic Resonance Imaging (MRI) are relied on. MRI images are more comprehensible than TRUS images which are corrupted by noise such as speckles and shadowing. However, MRI screening is costly, often unavailable in many community hospitals, time consuming, and requires more patient preparation time. Therefore, TRUS is more popular for screening and biopsy guidance for prostate cancer. For these reasons, TRUS images are chosen in this research. Radiologists first segment the prostate image from ultrasound image and then identify the hypoechoic regions which are more likely to exhibit cancer and should be considered for biopsy. In this thesis, the focus is on prostate segmentation and on Regions of Interest (ROI)segmentation. First, the extraneous tissues surrounding the prostate gland are eliminated. Consequently, the process of detecting the cancerous regions is focused on the prostate gland only. Thus, the diagnosing process is significantly shortened. Also, segmentation techniques such as thresholding, region growing, classification, clustering, Markov random field models, artificial neural networks (ANNs), atlas-guided, and deformable models are investigated. In this dissertation, the deformable model technique is selected because it is capable of segmenting difficult images such as ultrasound images. Deformable models are classified as either parametric or geometric deformable models. For the prostate segmentation, one of the parametric deformable models, Gradient Vector Flow (GVF) deformable contour, is adopted because it is capable of segmenting the prostate gland, even if the initial contour is not close to the prostate boundary. The manual segmentation of ultrasound images not only consumes much time and effort, but also leads to operator-dependent results. Therefore, a fully automatic prostate segmentation algorithm is proposed based on knowledge-based rules. The new algorithm results are evaluated with respect to their manual outlining by using distance-based and area-based metrics. Also, the novel technique is compared with two well-known semi-automatic algorithms to illustrate its superiority. With hypothesis testing, the proposed algorithm is statistically superior to the other two algorithms. The newly developed algorithm is operator-independent and capable of accurately segmenting a prostate gland with any shape and orientation from the ultrasound image. The focus of the second part of the research is to locate the regions which are more prone to cancer. Although the parametric dynamic contour technique can readily segment a single region, it is not conducive for segmenting multiple regions, as required in the regions of interest (ROI) segmentation part. Since the number of regions is not known beforehand, the problem is stated as 3D one by using level set approach to handle the topology changes such as splitting and merging the contours. For the proposed ROI segmentation algorithm, one of the geometric deformable models, active contours without edges, is used. This technique is capable of segmenting the regions with either weak edges, or even, no edges at all. The results of the proposed ROI segmentation algorithm are compared with those of the two experts' manual marking. The results are also compared with the common regions manually marked by both experts and with the total regions marked by either expert. The proposed ROI segmentation algorithm is also evaluated by using region-based and pixel-based strategies. The evaluation results indicate that the proposed algorithm produces similar results to those of the experts' manual markings, but with the added advantages of being fast and reliable. This novel algorithm also detects some regions that have been missed by one expert but confirmed by the other. In conclusion, the two newly devised algorithms can assist experts in segmenting the prostate image and detecting the suspicious abnormal regions that should be considered for biopsy. This leads to the reduction the number of biopsies, early detection of the diseased regions, proper management, and possible reduction of death related to prostate cancer.

The early detection of prostate cancer plays a significant role in the success of treatment and outcome. To detect prostate cancer, imaging modalities such as TransRectal UltraSound (TRUS) and Magnetic Resonance Imaging (MRI) are relied on. MRI images are more comprehensible than TRUS images which are corrupted by noise such as speckles and shadowing. However, MRI screening is costly, often unavailable in many community hospitals, time consuming, and requires more patient preparation time. Therefore, TRUS is more popular for screening and biopsy guidance for prostate cancer. For these reasons, TRUS images are chosen in this research. Radiologists first segment the prostate image from ultrasound image and then identify the hypoechoic regions which are more likely to exhibit cancer and should be considered for biopsy. In this thesis, the focus is on prostate segmentation and on Regions of Interest (ROI)segmentation. First, the extraneous tissues surrounding the prostate gland are eliminated. Consequently, the process of detecting the cancerous regions is focused on the prostate gland only. Thus, the diagnosing process is significantly shortened. Also, segmentation techniques such as thresholding, region growing, classification, clustering, Markov random field models, artificial neural networks (ANNs), atlas-guided, and deformable models are investigated. In this dissertation, the deformable model technique is selected because it is capable of segmenting difficult images such as ultrasound images. Deformable models are classified as either parametric or geometric deformable models. For the prostate segmentation, one of the parametric deformable models, Gradient Vector Flow (GVF) deformable contour, is adopted because it is capable of segmenting the prostate gland, even if the initial contour is not close to the prostate boundary. The manual segmentation of ultrasound images not only consumes much time and effort, but also leads to operator-dependent results. Therefore, a fully automatic prostate segmentation algorithm is proposed based on knowledge-based rules. The new algorithm results are evaluated with respect to their manual outlining by using distance-based and area-based metrics. Also, the novel technique is compared with two well-known semi-automatic algorithms to illustrate its superiority. With hypothesis testing, the proposed algorithm is statistically superior to the other two algorithms. The newly developed algorithm is operator-independent and capable of accurately segmenting a prostate gland with any shape and orientation from the ultrasound image. The focus of the second part of the research is to locate the regions which are more prone to cancer. Although the parametric dynamic contour technique can readily segment a single region, it is not conducive for segmenting multiple regions, as required in the regions of interest (ROI) segmentation part. Since the number of regions is not known beforehand, the problem is stated as 3D one by using level set approach to handle the topology changes such as splitting and merging the contours. For the proposed ROI segmentation algorithm, one of the geometric deformable models, active contours without edges, is used. This technique is capable of segmenting the regions with either weak edges, or even, no edges at all. The results of the proposed ROI segmentation algorithm are compared with those of the two experts' manual marking. The results are also compared with the common regions manually marked by both experts and with the total regions marked by either expert. The proposed ROI segmentation algorithm is also evaluated by using region-based and pixel-based strategies. The evaluation results indicate that the proposed algorithm produces similar results to those of the experts' manual markings, but with the added advantages of being fast and reliable. This novel algorithm also detects some regions that have been missed by one expert but confirmed by the other. In conclusion, the two newly devised algorithms can assist experts in segmenting the prostate image and detecting the suspicious abnormal regions that should be considered for biopsy. This leads to the reduction the number of biopsies, early detection of the diseased regions, proper management, and possible reduction of death related to prostate cancer.

Prostate cancer is one of the leading causes of death by cancer for men. Focal therapy is being tested to target only the dominant cancer lesion in the prostate. However, due to the need to ensure that the laser is targeting only the cancer, a real-time treatment monitoring system is required. A combined optical-ultrasound monitoring system is in development at Princess Margaret Hospital based on different optical properties for coagulated versus normal tissue. In this project, we developed a light delivery and collection device that is compatible for use with an existing trans-rectal ultrasound-imaging probe. Computer-aided design software was used to visualize the prototype in relation to the trans-rectal ultrasound probe. This thesis describes the critical tasks necessary to assemble the final prototype, including listing of specifications, selection of device material based on safety and mechanical properties, method of prototype fabrication, positioning and fixation of optical fibers and testing.

Prostate cancer is one of the leading causes of death by cancer for men. Focal therapy is being tested to target only the dominant cancer lesion in the prostate. However, due to the need to ensure that the laser is targeting only the cancer, a real-time treatment monitoring system is required. A combined optical-ultrasound monitoring system is in development at Princess Margaret Hospital based on different optical properties for coagulated versus normal tissue. In this project, we developed a light delivery and collection device that is compatible for use with an existing trans-rectal ultrasound-imaging probe. Computer-aided design software was used to visualize the prototype in relation to the trans-rectal ultrasound probe. This thesis describes the critical tasks necessary to assemble the final prototype, including listing of specifications, selection of device material based on safety and mechanical properties, method of prototype fabrication, positioning and fixation of optical fibers and testing.

Prostate cancer continues to be the most commonly diagnosed cancer among men. Brachytherapy has emerged as one of the definitive treatment options for early stage prostate cancer which entails permanent implantation of radioactive seeds into the prostate to eradicate the cancer with ionizing radiation. Successful brachytherapy requires the ability to perform dosimetry -which requires seed localization- during the procedure but such function is not available today. If dosimetry could be performed intraoperatively, physicians could implant additional seeds into the under-dosed portions of the prostate while the patient is still on the operating table. This thesis addresses the brachytherapy seed localization problem with introducing intensity based registration between transrectal ultrasound (TRUS) that shows only the prostate and a 3D seed model drawn from fluoroscopy that shows only the implanted seeds. The TRUS images are first filtered and compounded, and then registered to the seed model by using mutual information. A training phantom was implanted with 48 seeds and imaged. Various ultrasound filtering techniques were analyzed. The effect of false positives and false negatives in ultrasound was investigated by randomly masking seeds from the fluoroscopy volume or adding seeds to that in random locations. Furthermore, the effect of sparse and dense ultrasound data was analyzed by running the registration for ultrasound data with different spacing. The registration error remained consistently below clinical threshold and capture range was significantly larger than the initial guess guaranteed by the clinical workflow. This fully automated method provided excellent registration accuracy and robustness in phantom studies and promises to demonstrate clinically adequate performance on human data. / Thesis (Master, Electrical & Computer Engineering) -- Queen's University, 2008-09-27 12:35:16.691

Background: Transrectal ultrasound is commonly performed in the clinical evaluation of the prostate. Ultrasound-guided randomized sextant biopsy became the standard procedure for the diagnosis of carcinoma of the prostate (CaP). A guided biopsy of sonographically irregular lesions of the prostate is not performed in randomized biopsies. An almost generally accepted opinion is that hypoechoic lesions are suspicious for the presence of CaP. However, the role of prostatic lesions with an echogenicity other than iso- or hypoechoic, e.g. hyperechoic or irregular lesions in relation to CaP is not clear. The intention of the present prospective study was to clarify the role of different prostatic ultrasound findings with a new-generation ultrasound probe in regard to their relevance concerning the presence of cancer. Material and Methods: 265 patients who were referred for prostatic evaluation because of an elevated PSA serum level or a positive digital rectal examination were enrolled in a prospective study. All patients had a systematic ultrasound-guided sextant biopsy of the prostate and a 4-core biopsy of the transition zone. All biopsy cores taken were guided by transrectal ultrasound. In case of a sonographically suspicious lesion, biopsy was always directed into this area. The predominant ultrasound appearance was separately recorded for each core. Results: Carcinoma of the prostate was detected in 87 (32.8%) of the 265 patients. Biopsy cores with isoechoic ultrasound findings revealed CaP in 7.6%. The data for hypoechoic, hyperechoic, mixed-echoic and anechoic lesions were 34.5, 26.9, 21.1 and 0%, respectively. Hypoechoic ultrasound findings were less frequently found in the transition zone of the prostate, but the rate of CaP detection was the same as in the peripheral zone of the prostate. Conclusions:The transrectal ultrasound pattern of the prostate yields important information about the presence of carcinoma of the prostate. Especially hypoechoic lesions indicate the presence of CaP in a significant proportion of cases. However, hyperechoic lesions and lesions of mixed or irregular echogenicity were found to contain cancer in significant numbers as well, and should therefore be considered to be suspicious for cancer when performing transrectal ultrasound of the prostate. Directed biopsy of irregular ultrasound patterns in the prostate seems therefore to be recommendable. / Hintergrund: Der transrektale Ultraschall ist die häufigste bildgebende Untersuchung zur klinischen Beurteilung der Prostata. Zur Diagnostik des Prostatakarzinoms (PCa) hat sich die ultraschallgesteuerte Sextanten-Biopsie als Standardverfahren etabliert. Eine gezielte Biopsie irregulärer Ultraschallbezirke ist hier nicht vorgesehen. Es ist jedoch bekannt, daß sonographisch echoarm erscheinende Areale suspekt für die Präsenz eines PCa sind. Die Wertigkeit nicht einheitlicher oder echoreicher Ultraschallmuster ist jedoch bisher nicht zweifelsfrei geklärt. Ziel der vorliegenden Arbeit war es, mit einem Ultraschallgerät der neuesten Generation die Bedeutung der verschiedenen Ultraschallmuster bezüglich des Vorhandenseins von Prostatakarzinomen zu klären. Material und Methoden: 265 Patienten mit erhöhten PSA-Serumwerten oder suspekten Tastbefunden der Prostata wurden in die prospektive Untersuchung eingeschlossen. Bei allen Patienten wurden systematische, ultraschallgesteuerte Prostatabiopsien, wie in der Sextantenbiopsie vorgesehen, und 4 Zylinder aus der Transitionalzone entnommen. Bei der Biopsie wurde jedoch gezielt die Punktion in Bereichen von – falls vorhanden – irregulärem Ultraschallmuster vorgenommen und das entsprechende Ultraschallbild dokumentiert. Ergebnisse: Bei 87 der 265 Patienten (32,8%) wurden Prostatakarzinome nachgewiesen. Biopsiezylinder aus isodensen Bereichen wiesen in 7,6% ein Prostatakarzinom auf. Die Karzinomhäufigkeit bei Biopsie von echoarmen und echoreichen Arealen sowie von Arealen mit unterschiedlichen Echomustern und von zystischen Arealen wurde mit 34,5, 26,9, 21,1 bzw. 0% ermittelt. Echoarme Befunde wurden seltener in der Transitionalzone nachgewiesen, waren jedoch dort in etwa gleicher Häufigkeit mit einem Karzinom verbunden wie in der peripheren Zone. Schlußfolgerungen: Das transrektale Ultraschallmuster in der Prostata liefert wichtige Hinweise auf das Vorhandensein eines Prostatakarzinoms. Insbesondere echoarme Läsionen deuten auf ein PCa hin. Echoreiche Läsionen und solche mit unterschiedlichen Echomustern enthielten jedoch Karzinome in so bedeutender Anzahl, daß diese Läsionen ebenfalls als karzinomverdächtig eingestuft werden müssen und auch eine gezielte Biopsie dieser Areale im Rahmen der Sextantenbiopsie empfehlenswert erscheint. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

Diss. (sammanfattning) Göteborg : Göteborgs universitet, 2007. / Härtill 5 uppsatser.

As dores lombares acometem a maioria dos atletas, inclusive os equinos. Somente o exame clínico não é suficiente para identificar a localização exata do foco doloroso. O diagnóstico definitivo só é atingido através da utilização dos meios diagnósticos complementares, neste caso, a ultrassonografia. Caso sejam constatadas anomalias discal lombossacras e/ou artropatias ITLS e/ou SI, o veterinário ainda não é capaz de quantificar a influência destas sobre o desempenho atlético do cavalo de esporte. Face a esta dúvida, objetivou-se estabelecer uma relação entre os achados dos exames físicos e ultrassonográficos, executados em 200 cavalos atletas, de quatro raças diferentes (Trote Francês, Quarto de Milha, Puro Sangue Inglês e Cavalos de Sela Francesa e Brasileiro de Hipismo). Todos os animais estavam em treinamento, participando de provas, e não apresentavam claudicação. Após exame físico, os animais foram avaliados ultrassonograficamente, por via transretal, para visualização do aspecto ventral do disco LS (L6-S1), das articulações intertransversas (ITLS) e sacroilíacas (SI), direitas e esquerdas. Para a avaliação transretal os animais foram colocados em tronco de contenção, não tendo sido observada necessidade de sedação ou emprego de outros métodos físicos. Ato contínuo foi introduzido um transdutor linear de 5-7,5 MHz e imagens do disco lombossacro, das articulações intertransversas lombossacras e sacroilíacas foram obtidas. A determinação do número de animais que apresentavam alterações durante os exames de inspeção, palpação, mobilização e avaliação dinâmica assim como a caracterização dos tipos de anomalias discais (T1, T2, T3 e T4) e artropatias ITLS e SI, sugere que durante a execução do exame físico, cavalos que não apresentem sinais clínicos não devem ser descartados de possuírem algum tipo de anomalia discal lombossacra e/ou atropatias ITLS e/ou SI. Observou-se também que as artropatias SI podem afetar o desempenho dos cavalos de trote atrelado, já para as artropatias ITLS e anomalias LS não houve significância quanto às suas influências aos achados no desempenho. / Back pain affects most athletes, including horses. The clinical examination alone is not sufficient to identify the exact location of the painful focus. The definitive diagnosis is only achieved by using complementary diagnostic tools, in the case of this study the ultrasonography. Lumbosacral anomalies and intertransverse lumbosacral and sacroiliac arthropathies, if detected ultrasonographicaly, do not directly input in loss of performance or locomotor impairment. In order to assess this issue, this study aimed to establish a relationship between the findings of physical and ultrasound examinations, performed on 200 horses athletes, from 4 different breeds, French Trotters, Quarter Horse, Thoroughbred Horses and Show Jumpers. After physical examination, the animals were evaluated by a transrectal approach with ultrasonography and the images collected were, ventral aspect of the disc LS (L6-S1), intertransverse joints (ITLS) and sacroiliac (SI), right and left. To perform this evaluation, the animals were placed in the containment trunk with any sedation methods. Immediately thereafter introduced a 5 - 7.5 MHz linear transducer, images of lumbosacral, intertransverse lombossacral and sacroiliac joints were obtained. The determination of number of animals showing abnormalities during clinical examination of inspection, palpation, mobilization and dynamic examination as well as the characterization of the types of disc anomalies (T1, T2, T3 and T4) and arthropathies ITLS and SI, enabled the realization of the following framework, where even the patient, during the execution of the clinical examination, will not provide a positive signals for certain tests, this does not rule out the possibility it has some kind of anomaly in LS joint and/or arthropathy ITLS and/or SI. It was also observed that the arthropathy of SI can affect the performance of French Trotters, and anomalies of ITLS and LS have no significance or influence on athletic performance.