1,721,020 research outputs found
Imaging cardiovascolare TC e RM: Dalla tecnica all'interpretazione clinica
No full textLa disponibilità e la diffusione di tecnologie performanti ha determinato l'affermarsi degli studi angio-TC ed angio-RM come tecniche semplici ed affidabili per la caratterizzazione ed il planning terapeutico delle principali patologie del sistema cardiocircolatorio, la cui conoscenza è divenuta ormai obbligatoria per tutti i radiologi. Lo scopo di questo testo è di fornire indicazioni tecniche in forma sintetica, ma quanto più possibile completa, relativamente ai principi tecnici ed alla metodologia d'esame per studi angio-TC ed angio-RM di alta qualità negli scenari clinici più vari, presentando allo stesso tempo un'ampia casistica di supporto, ricca di spunti interpretativi e di suggerimenti pratici per la valutazione e la refertazione degli esami. Lo scopo del testo sarà anche di dimostrare i vantaggi ed i limiti delle due metodiche a confronto nelle diverse patologie e nei diversi distretti vascolari, in modo da fornire indicazioni al radiologo esperto ed a quello in formazione
Online needle-tissue interaction model identification for force feedback enhancement in robot-assisted interventional procedures
Full text linkMany interventional procedures, e.g., biopsies and tumor ablation, imply the insertion of a needle into soft tissues. The interaction force at the needle tip can convey information important for the accuracy of needle placement and the patient’s safety. This information is essential when feedback from an imaging system is missing or only available at a low rate. To isolate the force exchanged at the needle tip during the insertion, it is necessary to remove other components from the needle-tissue interaction force. In particular, the friction along the needle shaft becomes more and more relevant as the needle penetrates deeper into the tissues. In this paper, we propose a method for the identification of the friction component during needle penetration into a multi-layered target. The proposed online identification procedure allows, at the transition from one tissue layer to the next, to subtract the friction contribution from the previous layers and isolate the force relative to the layer where the needle tip is currently located. We call this an enhanced force signal because it improves the ratio of the useful information about the force at the needle tip to the total force rendered. This result can be used in teleoperated needle insertion schemes, or other robot-assisted architectures, with the aim of facilitating the user perception of variations in tissue properties. In the proposed implementation, the force at the base of the needle can either be measured or estimated by using a model-based approach. An originally developed simulation framework provides a tool for procedure planning and online monitoring
Dysphagia lusoria in combination with multiple congenital anomalies of the aortic arch
No full text[No abstract available
Residual-based interaction force estimation for haptic feedback in teleoperated needle insertion
No full textImpact of 3D Rotational Angiography on Liver Embolization Procedures: Review of Technique and Applications
No full textIn the last years, the interest into interventional applications of C-arm
cone-beam CT (CBCT) progressively raised, widening its clinical application from
the original field of interventional neuroradiology to the field of peripheral
procedures. Liver embolization procedures, due to their complexity and potential
treatment-related life-threatening complications, represent one of the main
clinical applications of this novel angiographic technique. CBCT has been
demonstrated to render procedures safer and technically easier, and to predict
outcome as well as to avoid major complications in different treatment scenarios
(trans-arterial embolization, trans-arterial chemoembolization, selective
internal radiation therapy, percutaneous portal vein embolization). This review
summarizes all technical, dosimetric and procedural aspects of CBCT techniques,
underlying all its potential clinical advantages in the field of liver
embolization procedures. Moreover, the paper provides all the instructions to
obtain the best diagnostic performance out of this novel angiographic technique
Intradural Extramedullary Primary Ependymoma Of The Cranio-Cervical Junction Combined With C1 Partial Agenesis: Case Report And Review Of The Literature
No full textIntramedullary ependymomas represent the 40-60% of spinal cord tumors in adults and can be located along the entire spinal cord. Intradural extramedullary (IDEM) ependymomas are on the other hand a very rare entity with the exception of those located at the filum terminale or conus medullaris, with histological features of myxopapillary ependimomas (WHO I)
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