948 resultados para Speckle tracking liver motion correction contrast-enhanced ultrasound
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PURPOSE: To evaluate gadocoletic acid (B-22956), a gadolinium-based paramagnetic blood pool agent, for contrast-enhanced coronary magnetic resonance angiography (MRA) in a Phase I clinical trial, and to compare the findings with those obtained using a standard noncontrast T2 preparation sequence. MATERIALS AND METHODS: The left coronary system was imaged in 12 healthy volunteers before B-22956 application and 5 (N = 11) and 45 (N = 7) minutes after application of 0.075 mmol/kg of body weight (BW) of B-22956. Additionally, imaging of the right coronary system was performed 23 minutes after B-22956 application (N = 6). A three-dimensional gradient echo sequence with T2 preparation (precontrast) or inversion recovery (IR) pulse (postcontrast) with real-time navigator correction was used. Assessment of the left and right coronary systems was performed qualitatively (a 4-point visual score for image quality) and quantitatively in terms of signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), vessel sharpness, visible vessel length, maximal luminal diameter, and the number of visible side branches. RESULTS: Significant (P < 0.01) increases in SNR (+42%) and CNR (+86%) were noted five minutes after B-22956 application, compared to precontrast T2 preparation values. A significant increase in CNR (+40%, P < 0.05) was also noted 45 minutes postcontrast. Vessels (left anterior descending artery (LAD), left coronary circumflex (LCx), and right coronary artery (RCA)) were also significantly (P < 0.05) sharper on postcontrast images. Significant increases in vessel length were noted for the LAD (P < 0.05) and LCx and RCA (both P < 0.01), while significantly more side branches were noted for the LAD and RCA (both P < 0.05) when compared to precontrast T2 preparation values. CONCLUSION: The use of the intravascular contrast agent B-22956 substantially improves both objective and subjective parameters of image quality on high-resolution three-dimensional coronary MRA. The increase in SNR, CNR, and vessel sharpness minimizes current limitations of coronary artery visualization with high-resolution coronary MRA.
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Magnetic resonance angiography (MRA) provides a noninvasive means to detect the presence, location and severity of atherosclerosis throughout the vascular system. In such studies, and especially those in the coronary arteries, the vessel luminal area is typically measured at multiple cross-sectional locations along the course of the artery. The advent of fast volumetric imaging techniques covering proximal to mid segments of coronary arteries necessitates automatic analysis tools requiring minimal manual interactions to robustly measure cross-sectional area along the three-dimensional track of the arteries in under-sampled and non-isotropic datasets. In this work, we present a modular approach based on level set methods to track the vessel centerline, segment the vessel boundaries, and measure transversal area using two user-selected endpoints in each coronary of interest. Arterial area and vessel length are measured using our method and compared to the standard Soap-Bubble reformatting and analysis tool in in-vivo non-contrast enhanced coronary MRA images.
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Atherosclerosis is a chronic cardiovascular disease that involves the thicken¬ing of the artery walls as well as the formation of plaques (lesions) causing the narrowing of the lumens, in vessels such as the aorta, the coronary and the carotid arteries. Magnetic resonance imaging (MRI) is a promising modality for the assessment of atherosclerosis, as it is a non-invasive and patient-friendly procedure that does not use ionizing radiation. MRI offers high soft tissue con¬trast already without the need of intravenous contrast media; while modifica¬tion of the MR pulse sequences allows for further adjustment of the contrast for specific diagnostic needs. As such, MRI can create angiographic images of the vessel lumens to assess stenoses at the late stage of the disease, as well as blood flow-suppressed images for the early investigation of the vessel wall and the characterization of the atherosclerotic plaques. However, despite the great technical progress that occurred over the past two decades, MRI is intrinsically a low sensitive technique and some limitations still exist in terms of accuracy and performance. A major challenge for coronary artery imaging is respiratory motion. State- of-the-art diaphragmatic navigators rely on an indirect measure of motion, per¬form a ID correction, and have long and unpredictable scan time. In response, self-navigation (SM) strategies have recently been introduced that offer 100% scan efficiency and increased ease of use. SN detects respiratory motion di¬rectly from the image data obtained at the level of the heart, and retrospectively corrects the same data before final image reconstruction. Thus, SN holds po-tential for multi-dimensional motion compensation. To this regard, this thesis presents novel SN methods that estimate 2D and 3D motion parameters from aliased sub-images that are obtained from the same raw data composing the final image. Combination of all corrected sub-images produces a final image with reduced motion artifacts for the visualization of the coronaries. The first study (section 2.2, 2D Self-Navigation with Compressed Sensing) consists of a method for 2D translational motion compensation. Here, the use of com- pressed sensing (CS) reconstruction is proposed and investigated to support motion detection by reducing aliasing artifacts. In healthy human subjects, CS demonstrated an improvement in motion detection accuracy with simula¬tions on in vivo data, while improved coronary artery visualization was demon¬strated on in vivo free-breathing acquisitions. However, the motion of the heart induced by respiration has been shown to occur in three dimensions and to be more complex than a simple translation. Therefore, the second study (section 2.3,3D Self-Navigation) consists of a method for 3D affine motion correction rather than 2D only. Here, different techniques were adopted to reduce background signal contribution in respiratory motion tracking, as this can be adversely affected by the static tissue that surrounds the heart. The proposed method demonstrated to improve conspicuity and vi¬sualization of coronary arteries in healthy and cardiovascular disease patient cohorts in comparison to a conventional ID SN method. In the third study (section 2.4, 3D Self-Navigation with Compressed Sensing), the same tracking methods were used to obtain sub-images sorted according to the respiratory position. Then, instead of motion correction, a compressed sensing reconstruction was performed on all sorted sub-image data. This process ex¬ploits the consistency of the sorted data to reduce aliasing artifacts such that the sub-image corresponding to the end-expiratory phase can directly be used to visualize the coronaries. In a healthy volunteer cohort, this strategy improved conspicuity and visualization of the coronary arteries when compared to a con¬ventional ID SN method. For the visualization of the vessel wall and atherosclerotic plaques, the state- of-the-art dual inversion recovery (DIR) technique is able to suppress the signal coming from flowing blood and provide positive wall-lumen contrast. How¬ever, optimal contrast may be difficult to obtain and is subject to RR variability. Furthermore, DIR imaging is time-inefficient and multislice acquisitions may lead to prolonged scanning times. In response and as a fourth study of this thesis (chapter 3, Vessel Wall MRI of the Carotid Arteries), a phase-sensitive DIR method has been implemented and tested in the carotid arteries of a healthy volunteer cohort. By exploiting the phase information of images acquired after DIR, the proposed phase-sensitive method enhances wall-lumen contrast while widens the window of opportunity for image acquisition. As a result, a 3-fold increase in volumetric coverage is obtained at no extra cost in scanning time, while image quality is improved. In conclusion, this thesis presented novel methods to address some of the main challenges for MRI of atherosclerosis: the suppression of motion and flow artifacts for improved visualization of vessel lumens, walls and plaques. Such methods showed to significantly improve image quality in human healthy sub¬jects, as well as scan efficiency and ease-of-use of MRI. Extensive validation is now warranted in patient populations to ascertain their diagnostic perfor¬mance. Eventually, these methods may bring the use of atherosclerosis MRI closer to the clinical practice. Résumé L'athérosclérose est une maladie cardiovasculaire chronique qui implique le épaississement de la paroi des artères, ainsi que la formation de plaques (lé¬sions) provoquant le rétrécissement des lumières, dans des vaisseaux tels que l'aorte, les coronaires et les artères carotides. L'imagerie par résonance magné¬tique (IRM) est une modalité prometteuse pour l'évaluation de l'athérosclérose, car il s'agit d'une procédure non-invasive et conviviale pour les patients, qui n'utilise pas des rayonnements ionisants. L'IRM offre un contraste des tissus mous très élevé sans avoir besoin de médias de contraste intraveineux, tan¬dis que la modification des séquences d'impulsions de RM permet en outre le réglage du contraste pour des besoins diagnostiques spécifiques. À ce titre, l'IRM peut créer des images angiographiques des lumières des vaisseaux pour évaluer les sténoses à la fin du stade de la maladie, ainsi que des images avec suppression du flux sanguin pour une première enquête des parois des vais¬seaux et une caractérisation des plaques d'athérosclérose. Cependant, malgré les grands progrès techniques qui ont eu lieu au cours des deux dernières dé¬cennies, l'IRM est une technique peu sensible et certaines limitations existent encore en termes de précision et de performance. Un des principaux défis pour l'imagerie de l'artère coronaire est le mou¬vement respiratoire. Les navigateurs diaphragmatiques de pointe comptent sur une mesure indirecte de mouvement, effectuent une correction 1D, et ont un temps d'acquisition long et imprévisible. En réponse, les stratégies d'auto- navigation (self-navigation: SN) ont été introduites récemment et offrent 100% d'efficacité d'acquisition et une meilleure facilité d'utilisation. Les SN détectent le mouvement respiratoire directement à partir des données brutes de l'image obtenue au niveau du coeur, et rétrospectivement corrigent ces mêmes données avant la reconstruction finale de l'image. Ainsi, les SN détiennent un poten¬tiel pour une compensation multidimensionnelle du mouvement. A cet égard, cette thèse présente de nouvelles méthodes SN qui estiment les paramètres de mouvement 2D et 3D à partir de sous-images qui sont obtenues à partir des mêmes données brutes qui composent l'image finale. La combinaison de toutes les sous-images corrigées produit une image finale pour la visualisation des coronaires ou les artefacts du mouvement sont réduits. La première étude (section 2.2,2D Self-Navigation with Compressed Sensing) traite d'une méthode pour une compensation 2D de mouvement de translation. Ici, on étudie l'utilisation de la reconstruction d'acquisition comprimée (compressed sensing: CS) pour soutenir la détection de mouvement en réduisant les artefacts de sous-échantillonnage. Chez des sujets humains sains, CS a démontré une amélioration de la précision de la détection de mouvement avec des simula¬tions sur des données in vivo, tandis que la visualisation de l'artère coronaire sur des acquisitions de respiration libre in vivo a aussi été améliorée. Pourtant, le mouvement du coeur induite par la respiration se produit en trois dimensions et il est plus complexe qu'un simple déplacement. Par conséquent, la deuxième étude (section 2.3, 3D Self-Navigation) traite d'une méthode de cor¬rection du mouvement 3D plutôt que 2D uniquement. Ici, différentes tech¬niques ont été adoptées pour réduire la contribution du signal du fond dans le suivi de mouvement respiratoire, qui peut être influencé négativement par le tissu statique qui entoure le coeur. La méthode proposée a démontré une amélioration, par rapport à la procédure classique SN de correction 1D, de la visualisation des artères coronaires dans le groupe de sujets sains et des pa¬tients avec maladies cardio-vasculaires. Dans la troisième étude (section 2.4,3D Self-Navigation with Compressed Sensing), les mêmes méthodes de suivi ont été utilisées pour obtenir des sous-images triées selon la position respiratoire. Au lieu de la correction du mouvement, une reconstruction de CS a été réalisée sur toutes les sous-images triées. Cette procédure exploite la cohérence des données pour réduire les artefacts de sous- échantillonnage de telle sorte que la sous-image correspondant à la phase de fin d'expiration peut directement être utilisée pour visualiser les coronaires. Dans un échantillon de volontaires en bonne santé, cette stratégie a amélioré la netteté et la visualisation des artères coronaires par rapport à une méthode classique SN ID. Pour la visualisation des parois des vaisseaux et de plaques d'athérosclérose, la technique de pointe avec double récupération d'inversion (DIR) est capa¬ble de supprimer le signal provenant du sang et de fournir un contraste posi¬tif entre la paroi et la lumière. Pourtant, il est difficile d'obtenir un contraste optimal car cela est soumis à la variabilité du rythme cardiaque. Par ailleurs, l'imagerie DIR est inefficace du point de vue du temps et les acquisitions "mul- tislice" peuvent conduire à des temps de scan prolongés. En réponse à ce prob¬lème et comme quatrième étude de cette thèse (chapitre 3, Vessel Wall MRI of the Carotid Arteries), une méthode de DIR phase-sensitive a été implémenté et testé
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Meprin-α is a metalloprotease overexpressed in cancer cells, leading to the accumulation of this protease in a subset of colorectal tumors. The impact of increased meprin-α levels on tumor progression is not known. We investigated the effect of this protease on cell migration and angiogenesis in vitro and studied the expression of meprin-α mRNA, protein and proteolytic activity in primary tumors at progressive stages and in liver metastases of patients with colorectal cancer, as well as inhibitory activity towards meprin-α in sera of cancer patient as compared to healthy controls. We found that the hepatocyte growth factor (HGF)-induced migratory response of meprin-transfected epithelial cells was increased compared to wild-type cells in the presence of plasminogen, and that the angiogenic response in organ-cultured rat aortic explants was enhanced in the presence of exogenous human meprin-α. In patients, meprin-α mRNA was expressed in colonic adenomas, primary tumors UICC (International Union Against Cancer) stage I, II, III and IV, as well as in liver metastases. In contrast, the corresponding protein accumulated only in primary tumors and liver metastases, but not in adenomas. However, liver metastases lacked meprin-α activity despite increased expression of the corresponding protein, which correlated with inefficient zymogen activation. Sera from cancer patients exhibited reduced meprin-α inhibition compared to healthy controls. In conclusion, meprin-α activity is regulated differently in primary tumors and metastases, leading to high proteolytic activity in primary tumors and low activity in liver metastases. By virtue of its pro-migratory and pro-angiogenic activity, meprin-α may promote tumor progression in colorectal cancer.
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Intravenously administered radiolabeled peptides targeting somatostatin receptors are used for the treatment of unresectable gastroenteropancreatic neuroendocrine tumors (GEP-NETs). Recently, we demonstrated a high first-pass effect during intra-arterial (i.a.) administration of positron emission tomography (PET) labeled (68)Ga-DOTA(0)-d-Phe(1)-Tyr(3)-octreotide (DOTATOC). In this pilot study, we investigated the therapeutic effectiveness of arterial administered DOTATOC, labeled with the therapeutic β emitters (90)Y and (177)Lu. (90)Y- and/or (177)Lu-DOTATOC were infused into the hepatic artery of 15 patients with liver metastases arising from GEP-NETs. Response was assessed using DOTATOC-PET, multiphase contrast enhanced computed tomography, magnetic resonance imaging, and the serum tumor marker chromogranin A. Pharmacokinetic data of the arterial approach were assessed using (111)In-DOTATOC scans. With the treatment regime of this pilot study, complete remission was achieved in one (7%) patient and partial remission was observed in eight (53%) patients, six patients were classified as stable (40%; response evaluation criteria in solid tumors criteria). The concomitant decrease of elevated serum tumor marker confirmed the radiologic response. Median time to progression was not reached within a mean follow-up period of 20 months. Receptor saturation and redistribution effects were identified as limiting factors for i.a. DOTATOC therapy. The high rate of objective radiologic response in NET patients treated with arterial infusion of (90)Y-/(177)Lu-DOTATOC compares favorably with systemic chemotherapy and intravenous radiopeptide therapy. While i.a. DOTATOC therapy is only applicable to patients with tumors of limited anatomic distribution, the results of this pilot study are a promising development in the treatment of GEP-NET and warrants further investigation of this novel approach.
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Purpose: To assess liver remnant volume regeneration and maintenance, and complications in the long-time follow-up of donors after living donor liver transplantation using CT and MRI. Materials and Methods: 47 donors with a mean age of 33.5 years who donated liver tissue for transplantation and who were available for follow-up imaging were included in this retrospective study. Contrast-enhanced CT and MR studies were acquired for routine follow-up. Two observers evaluated pre- and postoperative images regarding anatomy and pathological findings. Volumes were manually measured on contrast-enhanced images in the portal venous phase, and potential postoperative complications were documented. Pre- and postoperative liver volumes were compared for evaluating liver remnant regeneration. Results: 47 preoperative and 89 follow-up studies covered a period of 22.4 months (range: 1 - 84). After right liver lobe (RLL) donation, the mean liver remnant volume was 522.0 ml (± 144.0; 36.1 %; n = 18), after left lateral section (LLS) donation 1,121.7 ml (± 212.8; 79.9 %; n = 24), and after left liver lobe (LLL) donation 1,181.5 ml (± 279.5; 72.0 %; n = 5). Twelve months after donation, the liver remnant volume were 87.3 % (RLL; ± 11.8; n = 11), 95.0 % (LS; ± 11.6; n = 18), and 80.1 % (LLL; ± 2.0; n = 2 LLL) of the preoperative total liver volume. Rapid initial regeneration and maintenance at 80 % of the preoperative liver volume were observed over the total follow-up period. Minor postoperative complications were found early in 4 patients. No severe or late complications or mortality occurred. Conclusion: Rapid regeneration of liver remnant volumes in all donors and volume maintenance over the long-term follow-up period of up to 84 months without severe or late complications are important observations for assessing the safety of LDLT donors. Key Points: Liver remnant volumes of LDLT donors rapidly regenerated after donation and volumes were maintained over the long-term follow-up period of up to 84 months without severe or late complications.
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The PROPELLER (Periodically Rotated Overlapping Parallel Lines with Enhanced Reconstruction) magnetic resonance imaging (MRI) technique has inherent advantages over other fast imaging methods, including robust motion correction, reduced image distortion, and resistance to off-resonance effects. These features make PROPELLER highly desirable for T2*-sensitive imaging, high-resolution diffusion imaging, and many other applications. However, PROPELLER has been predominantly implemented as a fast spin-echo (FSE) technique, which is insensitive to T2* contrast, and requires time-inefficient signal averaging to achieve adequate signal-to-noise ratio (SNR) for many applications. These issues presently constrain the potential clinical utility of FSE-based PROPELLER. ^ In this research, our aim was to extend and enhance the potential applications of PROPELLER MRI by developing a novel multiple gradient echo PROPELLER (MGREP) technique that can overcome the aforementioned limitations. The MGREP pulse sequence was designed to acquire multiple gradient-echo images simultaneously, without any increase in total scan time or RF energy deposition relative to FSE-based PROPELLER. A new parameter was also introduced for direct user-control over gradient echo spacing, to allow variable sensitivity to T2* contrast. In parallel to pulse sequence development, an improved algorithm for motion correction was also developed and evaluated against the established method through extensive simulations. The potential advantages of MGREP over FSE-based PROPELLER were illustrated via three specific applications: (1) quantitative T2* measurement, (2) time-efficient signal averaging, and (3) high-resolution diffusion imaging. Relative to the FSE-PROPELLER method, the MGREP sequence was found to yield quantitative T2* values, increase SNR by ∼40% without any increase in acquisition time or RF energy deposition, and noticeably improve image quality in high-resolution diffusion maps. In addition, the new motion algorithm was found to improve the performance considerably in motion-artifact reduction. ^ Overall, this work demonstrated a number of enhancements and extensions to existing PROPELLER techniques. The new technical capabilities of PROPELLER imaging, developed in this thesis research, are expected to serve as the foundation for further expanding the scope of PROPELLER applications. ^
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Two-dimensional (2-D) strain (epsilon(2-D)) on the basis of speckle tracking is a new technique for strain measurement. This study sought to validate epsilon(2-D) and tissue velocity imaging (TVI)based strain (epsilon(TVI)) with tagged harmonic-phase (HARP) magnetic resonance imaging (MRI). Thirty patients (mean age. 62 +/- 11 years) with known or suspected ischemic heart disease were evaluated. Wall motion (wall motion score index 1.55 +/- 0.46) was assessed by an expert observer. Three apical images were obtained for longitudinal strain (16 segments) and 3 short-axis images for radial and circumferential strain (18 segments). Radial epsilon(TVI) was obtained in the posterior wall. HARP MRI was used to measure principal strain, expressed as maximal length change in each direction. Values for epsilon(2-D), epsilon(TVI), and HARP MRI were comparable for all 3 strain directions and were reduced in dysfunctional segments. The mean difference and correlation between longitudinal epsilon(2-D) and HARP MRI (2.1 +/- 5.5%, r = 0.51, p < 0.001) were similar to those between longitudinal epsilon(TVI), and HARP MRI (1.1 +/- 6.7%, r = 0.40, p < 0.001). The mean difference and correlation were more favorable between radial epsilon(2-D) and HARP MRI (0.4 +/- 10.2%, r = 0.60, p < 0.001) than between radial epsilon(TVI), and HARP MRI (3.4 +/- 10.5%, r = 0.47, p < 0.001). For circumferential strain, the mean difference and correlation between epsilon(2-D) and HARP MRI were 0.7 +/- 5.4% and r = 0.51 (p < 0.001), respectively. In conclusion, the modest correlations of echocardiographic and HARP MRI strain reflect the technical challenges of the 2 techniques. Nonetheless, epsilon(2-D) provides a reliable tool to quantify regional function, with radial measurements being more accurate and feasible than with TVI. Unlike epsilon(TVI), epsilon(2-D) provides circumferential measurements. (c) 2006 Elsevier Inc. All rights reserved.
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A 50-year-old woman presented with pancreatitis, fluctuant jaundice, weight loss, and abdominal pain. Contrast-enhanced computed tomography and abdominal ultrasound showed slight dilatation of the biliary tree and gallbladder without calculi. Endoscopy demonstrated a tumor protruding from the papilla of Vater. First endoscopically biopsy diagnosed no tumor, and a second biopsy diagnosed as papillary adenocarcinoma. The patient underwent duodenopancreatectomy. The specimen was fixed in formalin (10%). The tissue was processed routinely, and paraffin sections were stained with hematoxylin-eosin and periodic acid Schiff. Gross examination showed two tumors seen as prolapsed nodules growing isolated from the minor and major duodenal papillae measuring 1.5 and 1.0 cm, respectively, both covered by duodenal mucosa and the histologic study of both lesions demonstrated a moderately differentiated tubular adenocarcinoma, which invaded duodenal wall. After surgery, she is alive 24 months without evidence of recurrence.
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Osteoarthritis (OA) is a widely prevalent disease of the whole joint including cartilage, bone and soft tissues. Increasing importance of imaging including assessment of all joint structures has been recognized recently. Conventional radiography is still the first and most commonly used imaging technique for evaluation of a patient with a known or suspected diagnosis of OA. However, limitations have been revealed by recent MRI-based knee OA studies. MRI plays a crucial role in understanding the natural history of the disease and in guiding future therapies due to its ability to image the knee as a whole organ and to directly and three-dimensionally assess cartilage morphology and composition. It is crucial to use the appropriate MR pulse sequences to assess various OA features, and thus support from experienced musculoskeletal radiologists should be sought for study design, image acquisition and interpretation. The aim of this article is to describe the roles and limitations of conventional radiography and MRI in imaging of OA, and also to give insight into the use of other modalities such as ultrasound, scintigraphy, computed tomography (CT) and CT arthrography in clinical practice and research in OA, particularly focusing on the assessment of knee OA in the tibiofemoral joint.
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Mestrado em Tecnologia de Diagnóstico e Intervenção Cardiovascular. Área de especialização - Ultrassonografia Cardiovascular
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Mestrado em Tecnologia de Diagnóstico e Intervenção Cardiovascular - Área de especialização: Ultrassonografia cardiovascular
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BACKGROUND: To evaluate the safety and clinical feasibility of focal irreversible electroporation (IRE) of the prostate. METHODS: We assessed the toxicity profile and functional outcomes of consecutive patients undergoing focal IRE for localised prostate cancer in two centres. Eligibility was assessed by multi-parametric magnetic resonance imaging (mpMRI) and targeted and/or template biopsy. IRE was delivered under transrectal ultrasound guidance with two to six electrodes positioned transperineally within the cancer lesion. Complications were recorded and scored accordingly to the NCI Common Terminology Criteria for Adverse Events; the functional outcome was physician reported in all patients with at least 6 months follow-up. A contrast-enhanced MRI 1 week after the procedure was carried out to assess treatment effect with a further mpMRI at 6 months to rule out evidence of residual visible cancer. RESULTS: Overall, 34 patients with a mean age of 65 years (s.d.=±6) and a median PSA of 6.1 ng ml(-1) (interquartile range (IQR)= 4.3-7.7) were included. Nine (26%), 24 (71%) and 1 (3%) men had low, intermediate and high risk disease, respectively (D'Amico criteria). After a median follow-up of 6 months (range 1-24), 12 grade 1 and 10 grade 2 complications occurred. No patient had grade >/= 3 complication. From a functional point of view, 100% (24/24) patients were continent and potency was preserved in 95% (19/20) men potent before treatment. The volume of ablation was a median 12 ml (IQR=5.6-14.5 ml) with the median PSA after 6 months of 3.4 ng ml(-1) (IQR=1.9-4.8 ng ml(-1)). MpMRI showed suspicious residual disease in six patients, of whom four (17%) underwent another form of local treatment. CONCLUSIONS: Focal IRE has a low toxicity profile with encouraging genito-urinary functional outcomes. Further prospective development studies are needed to confirm the functional outcomes and to explore the oncological potential.
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The best way to appraise the size of abdominal organs remains undefined. Herein we compare the size of liver and spleen in hepatosplenic schistosomiasis using clinical and ultrasound (US) examination, and the size of the organs measured by US with their visualization below the costal margin ("palpable by US"). For this study, 411 individuals from an endemic area for schistosomiasis mansoni in Brazil have been selected. We found that palpable spleens and left liver lobes are larger than non palpable ones. Also, 23% of normal spleens measured by US were palpable on clinical examination, and 22% of spleens increased in size on US were non palpable. A total of 21% of normal spleens were "palpable by US". We also found 54% of normal sized right liver lobes palpable on clinical examination, whilst 54% of the increased livers, measured by US, were non palpable. About 76% of normal right liver lobes were "palpable by US". We conclude that the association of clinical, ultrasound and magnetic resonance imaging (MRI) examinations, in the near future, should give the investigators the necessary tools to perform a more accurate clinical diagnosis of hepatosplenic schistosomiasis mansoni.
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Necrotizing fasciitis is a rare, rapidly spreading, deep-seated infection causing thrombosis of the blood vessels located in the fascia. Necrotizing fasciitis is a surgical emergency. The diagnosis typically relies on clinical findings of severe sepsis and intense pain, although subacute forms may be difficult to recognize. Imaging studies can help to differentiate necrotizing fasciitis from infections located more superficially (dermohypodermitis). The presence of gas within the necrotized fasciae is characteristic but may be lacking. The main finding is thickening of the deep fasciae due to fluid accumulation and reactive hyperemia, which can be visualized using computed tomography and, above all, magnetic resonance imaging (high signal on contrast-enhanced T1 images and T2 images, best seen with fat saturation). These findings lack specificity, as they can be seen in non-necrotizing fasciitis and even in non-inflammatory conditions. Signs that support a diagnosis of necrotizing fasciitis include extensive involvement of the deep intermuscular fascias (high sensitivity but low specificity), thickening to more than 3mm, and partial or complete absence on post-gadolinium images of signal enhancement of the thickened fasciae (fairly high sensitivity and specificity). Ultrasonography is not recommended in adults, as the infiltration of the hypodermis blocks ultrasound transmission. Thus, imaging studies in patients with necrotizing fasciitis may be challenging to interpret. Although imaging may help to confirm deep tissue involvement and to evaluate lesion spread, it should never delay emergency surgical treatment in patients with established necrotizing fasciitis.