9,108,865 research outputs found
The role of 3 Tesla diffusion-weighted imaging in the differential diagnosis of benign versus malignant cervical lymph nodes in patients with head and neck squamous cell carcinoma.
Get PDFhe aim of this study was to validate the role of diffusion-weighted imaging (DWI) at 3 Tesla in the differential diagnosis between benign and malignant laterocervical lymph nodes in patients with head and neck squamous cell carcinoma (HNSCC). Materials and Methods. Before undergoing surgery, 80 patients, with biopsy proven HNSCC, underwent a magnetic resonance exam. Sensitivity (Se) and specificity (Spe) of conventional criteria and DWI in detecting laterocervical lymph node metastases were calculated. Histological results from neck dissection were used as standard of reference. Results. In the 239 histologically proven metastatic lymphadenopathies, the mean apparent diffusion coefficient (ADC) value was 0.903 x 10-3 mm2/sec. In the 412 pathologically confirmed benign lymph nodes, an average ADC value of 1.650 x 10"3 mm2/sec was found. For differentiating between benign versus metastatic lymph nodes, DWI showed Se of 97% and Spe of 93%, whereas morphological criteria displayed Se of 61% and Spe of 98%. DWI showed an area under the ROC curve (AUC) of 0.964, while morphological criteria displayed an AUC of 0.715. Conclusions. In a DWI negative neck for malignant lymph nodes, the planned dissection could be converted to a wait-and-scan policy, whereas DWI positive neck would support the decision to perform a neck dissection
High resolution 3-T MR imaging in the evaluation of the trigeminal nerve course
No full textBACKGROUND: The evaluation of the trigeminal course and his anatomical relationships with surrounding structures, is important for the assessment of the injury that may occur in tumors and several orofacial trauma and for avoiding the damage during surgeries. AIM: The aim of this retrospective study was to assess the use of 3-T MRI in the evaluation of the course of the four segments of the trigeminal nerve: cisternal and Meckels's cave, cavernous sinus, skull base and mandibular extracranial segments. PATIENTS AND METHODS: 78 patients were studied, for a total of 156 trigeminal nerves examined. T2-weighted 3D Fast imaging employing steady-state acquisition and T1-weighted Fast spoiled gradient recalled echo sequences were used. Two radiologists (reader A and B), independently, evaluated the course of the four segments of the trigeminal nerve according to a qualitative scale. The Intraclass correlation coefficient (ICC) and Pearson correlation coefficient were used to assess the intraobserver and interobserver variability in the nerve course evaluation. RESULTS: Reader A evaluated 47 trigeminal nerves excellent, 94 good, 12 fair and 3 poor. Reader B rated 43 trigeminal nerves excellent, 92 good, 16 fair and 5 poor. The intraobserver variability was ICC = 0.937 in reader A and ICC = 0.894 in reader B. The interobserver variability was 0.734 (p = 0.01). CONCLUSIONS: High resolution 3-T MRI imaging allows an accurate study of the trigeminal nerve and especially of its mandibular branch. The knowledge of the course and of the anatomic relationships of these nerve bundles with surrounding structures, as well as of the anatomical variants, allow oral and maxillofacial surgical plannings thus reducing the risk of nerve damage
Atypical localization and atypical magnetic resonance imaging findings of a paraganglioma at the mouth mucosa.
No full textWe present a case of a paraganglioma located at the cheek. The benign nature of the lesion was certainly suggested by the patient's anamnesis, ecotomography, and needle biopsy; nevertheless, before the excision, the surgeon requested magnetic resonance imaging with contrast stain only to better evaluate the relationship between the lesion and the surrounding structures and not to have a precise diagnosis.Under magnetic resonance examination by using T1, T2, and T1 before and after contrast sequences, it showed an aspect different from the conventionally described features for this kind of lesion. After excision, the mass showed a yellowish color and a liquid content. Histologic examination described it as having the features of a glomus tumor
Comparing proton density and turbo spin echo T2 weighted static sequences with dynamic half-Fourier single-shot TSE pulse sequence at 3.0 T in diagnosis of temporomandibular joint disorders: a prospective study.
No full textObjectives: The aim of this prospective study was to compare dynamic and static sequences in the evaluation of temporomandibular joint disorders using a 3.0-T imaging unit. Methods: 194 patients were evaluated by static (double echo proton density weighted/turbo spin echo T-2 weighted sequences) and dynamic (half-Fourier single-shot turbo spin echo sequences) imaging. Two radiologists evaluated in consensus the quality of images, the disc position and morphological alterations. The Kendall rank correlation coefficient (tau-b) was used to compare the qualitative rating between static and dynamic sequences. Cohen's kappa coefficient (k) was used to assess the agreement of disc position and morphological alterations between both sequences. The intraclass correlation coefficient was used to calculate the intraobserver variability. The significance was set at p <= 0.05. Results: The correlation between both sequences in the qualitative evaluation was tau-b = 0.632. The agreement between both techniques in the evaluation of disc position was k = 0.856. The agreement between both techniques in assessing the morphological alterations was k = 0.487. In the static sequences, the intraclass correlation coefficient was 0.915 in the qualitative evaluation, 0.873 in the evaluation of disc position and 0.934 in the assessment of morphological alterations. In the dynamic sequences, the intraclass correlation coefficient was 0.785 in the qualitative evaluation, 0.935 in the evaluation of disc position and 0.826 in the assessment of morphological alterations. Conclusions: Static imaging remains the gold standard in the evaluation of the temporomandibular joint. Dynamic imaging is a valuable tool that can provide additional information about topographic changes in the disc condyle relationship
Surveillance of patients affected by Peutz-Jeghers syndrome: Diagnostic value of MR enterography in prone and supine position
No full textIntroduction: Peutz-Jeghers syndrome (PJS) is a familial polyposis syndrome characterized by multiple hamartomatous polyps throughout the gastrointestinal tract. The aim of our study was to retrospectively determine the diagnostic value of MR enterography (MRE), performed in supine and prone position, in the detection of small bowel polyps in PJ patients. Materials and methods: We retrospectively reviewed MRE examinations of 8 PJS patients who underwent MRE, pushed-double-ballon enteroscopy, laparoscopic endoscopy or surgery, within 3 months. Polietilenglicole was orally administered before the examination. True FISP and HASTE sequences were acquired in supine and prone position; 3D VIBE Gd-enhanced sequences in prone position only. Results: Concordance between MRE and endoscopy was 72.6% for polyps 15 mm. In supine and prone position concordance with endoscopy for polyps <15 mm was 63% and 66.8%, respectively. In the detection of smaller polyps the difference between supine position only and supine plus prone position was statistically significant (P < 0.027). Discussion: MRE performed by combining prone and supine position was accurate in the detection of PJS polyps, with 93% concordance with enteroscopy for larger and more risky polyps. MRE offers a promising and non invasive alternative to capsule endoscopy, suggesting the possibility of an effective yearly surveillance in PJ patients. © Springer Science+Business Media, LLC 2011
Pitfalls in Interpreting mp-MRI of the Prostate: A Pictorial Review with Pathologic Correlation
Get PDFObjectives: The purpose of this pictorial review is to present a wide spectrum of prostate multiparametric MRI (mp-MRI) pitfalls that may occur in clinical practice, with radiological and pathological correlation. Methods: All examinations were performed according to ESUR Guidelines protocols. Results and Conclusion: mp-MRI imaging of the prostate often leads to interpreting doubts and misdiagnosis due to the many interpretative pitfalls that a tissue, whether healthy or treated, may cause. These “false-positive” findings may occur in each stage of the disease history, from the primary diagnosis and staging, to the post-treatment stage, and whether they are caused by the tissue itself or are iatrogenic, their recognition is critical for proper treatment and management. Knowledge of these known pitfalls and their interpretation in the anatomical-radiological context can help radiologists avoid misdiagnosis and consequently mistreatment. Main Messages: • Some physiological changes in the peripheral and central zone may simulate prostate cancer. • Technical errors, such as mispositioned endorectal coils, can affect the mp-MRI interpretation. • Physiological changes post-treatment can simulate recurrenc
Die Familien v. Hartmann und v. Barchetti Eigentümer des Hauses Wels, Pfarrgasse 15, im 19. Jahrhundert
No full textSupply Chain Management meets Auto-ID Management: A Structured Approach
No full textNowadays, firms need to support e-business through solutions that guarantee, on the one hand, the supply chain management (SCM) and, on the other, products’ identification and traceability (ID automation). These two
aspects have been faced, up until now, in a separate manner and adhered to the definition of established standards. Thus, we propose an approach that allows the integration of SCM and ID-automation software architectures and, at the same time, guarantees the separation of concerns. In this paper, we also present an implementation that uses two systems: the data interchange system based on the ebXML standard and the traceability system based on the EPCglobal standard. According to this approach, we propose a preliminary implementation experience for the pharmaceutical sector
B2B Interoperability using Business-Driven Integration: Conceptual Framework and Case Study
No full textThe interoperability among companies and the business-to-business (B2B) message exchange are key aspects of the growth of businesses: in the next years the companies that are able to cooperate with each other will be winners. The use of B2B messages modifies a company’s method of operation and, of course, its internal business process. In this paper, we propose a conceptual framework to solve the two types of problems that arise in the B2B field: one is more methodological, aimed at choosing guidelines oriented to the integration of business processes and the definition of business messages; the other is more technological, aimed at choosing an infrastructural solution more suitable for the development of message exchanges. The paper also defines a case study in order to show the feasibility of the conceptual framework. Using a specific case study, the paper will show the methodological and technological choices and how ontologies are the glue for different standards and notations involved in business-driven integration problems. Using BPMN notation, we design in this paper a business process that involves different business messages. The paper also presents a REST implementation of the business message exchange
Including Nomadic People in Collaborative E-learning: Experiences in Research Projects
No full textThe focus of this chapter is the design of a solution for Computer-Supported Cooperative Learning (CSCL) that is able to connect both stationary and mobile users in live shared-learning sessions. The authors started from experiences that were mainly technology-driven to arrive at the development of two subsystems, OpenWebTalk and MobileWebTalk, that build, flexibly and simply, mixed reality environments in which users cooperate to perform the same learning task. From these experiences, the authors argue that heterogeneous learning environments (stationary and mobile) can only be really effective if they are designed from a unique abstract model. Therefore the challenge is to derive a conceptual model to describe a collaborative learning session that can be deployed in different devices
- …
