464 research outputs found

    US-guided laser treatment of parathyroid adenomas

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    Objective: To determine the clinical efficacy of laser ablation for the tredatment of primary hyperparathyroidism (pHPT). Materials and methods: Twelve patients with pHPT were treated with laser ablation. Energy was administered by means of 1.5 m optical fibers percutaneously placed into the target via 21 G needles. A laser ablation unit (EchoLaser X4, Esaote) applied 3 W power for 400\u2013600 s/fiber/insertion to a total 3600\u20139000 Joules of energy. Patient serum parathyroid hormone (PTH) and calcium levels were checked at baseline and thereafter every 6 months. Patients were followed-up for 2 years with serologic and contrast-enhanced ultrasound. Therapeutic success was defined as normal PTH and calcium levels together with disappearance of nodule-related symptoms. Results: All procedures were performed in single session. Immediately following ablation, contrast enhanced ultrasound confirmed that all but one target had become avascular (technical success rate 11/12; 92%), remaining avascular at all follow-up ultrasound examinations, thereafter. The mean volume of parathyroid nodules decreased from 0.54 cc to 0.36 cc (72.0%). Serum PTH and calcium levels were significantly lower at 1, 12 and 24 m compared to baseline (p < 0.01). By 6 m, PTH and calcium returned to normal and were stable until 24 m in all successfully treated patients. All cases of hyperparathyroid-related symptoms resolved by 6 m (ostealgia [n = 5], repeated renal colic [n = 5], vomiting [n = 3]). Only one patient (8%) reported transient dysphonia as a minor complication. Conclusion: Laser ablation of enlarged, symptomatic parathyroid glands is safe and well-tolerated and can produce long-term, sustained reduction of serum PTH and calcium levels

    Ultrasound and cone beam CT fusion for liver ablation : technical note

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    Purpose: To assess the feasibility of fusion imaging between intraprocedural ultrasound (US) and contrast-enhanced cone-beam CT (CBCT) for small (< 2 cm) hepatocellular carcinoma (HCC). Materials and methods: Six patients (five males, one female, age range 58\u201380, mean 69 years), with small (mean diameter 16.8 mm) HCC poorly visible at US underwent percutaneous microwave ablation under US/CBCT fusion guidance. During general anesthesia with apnea control, a contrast- enhanced CBCT was acquired with an active tracker. Subsequently, real time US images were fused with CBCT images, and treatment performed under fusion imaging guidance. Feasibility of fusion imaging and percutaneous ablation were assessed, correct targeting (distance from center of tumor and center of ablation area <5 mm) and one-month primary technical efficacy were evaluated. Major and minor complications as well as overall procedural time were recorded. Results: US/CBCT fusion was feasible in all cases, allowing for completion of the treatment as previously planned (technical success 100%). Correct targeting was achieved in 4/6 cases (66%), while in two cases, center of tumor and center of ablated area were respectively 7 and 8 mm distant. At 1 month CT scan, all tumors were completely ablated (primary technical efficacy 100%). No major or minor complications occurred. Mean overall procedure time was 127 min. Conclusions: US/CBCT fusion is a feasible technique for liver ablation, and might represent a useful tool to increase the correct targeting of poorly US-visible HCC nodules in the angio suite

    A virtual musical instrument exhibit for a science centre.

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    Virtual reality is a technology rapidly gaining interest from research and commercial groups around the world, but it's introduction into New Zealand has been slow. The majority of the general public have no concept of virtual reality, and only a few research institutes have begun virtual reality programmes of any sort. Partially this is due to the high cost of 'off the shelf' virtual reality systems, which is usually beyond the range of many organisations. Also the complexity of the software and the knowledge required to create and manipulate this software makes it a daunting prospect for many. This work describes the development of an economical system for the demonstration of virtual reality and some of its concepts and applications to the general public, in the form of an educational science centre exhibit. The system creates virtual musical instruments, overlayed onto the real world, and the user experiences these instruments as if they were in physical existence

    Preoperative Magnetic Resonance and Intraoperative Ultrasound Fusion Imaging for Real-Time Neuronavigation in Brain Tumor Surgery = Präoperative MRI- und intraoperative Ultraschallfusion für die Echtzeit-Neuronavigation in der Neurochirurgie von Hirntumoren

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    Purpose: Brain shift and tissue deformation during surgery for intracranial lesions are the main actual limitations of neuro-navigation (NN), which currently relies mainly on preoperative imaging. Ultrasound (US), being a real-time imaging modality, is becoming progressively more widespread during neurosurgical procedures, but most neurosurgeons, trained on axial computed tomography (CT) and magnetic resonance imaging (MRI) slices, lack specific US training and have difficulties recognizing anatomic structures with the same confidence as in preoperative imaging. Therefore real-time intraoperative fusion imaging (FI) between preoperative imaging and intraoperative ultrasound (ioUS) for virtual navigation (VN) is highly desirable. We describe our procedure for real-time navigation during surgery for different cerebral lesions. Materials and Methods: We performed fusion imaging with virtual navigation for patients undergoing surgery for brain lesion removal using an ultrasound-based real-time neuro-navigation system that fuses intraoperative cerebral ultrasound with preoperative MRI and simultaneously displays an MRI slice coplanar to an ioUS image. Results: 58 patients underwent surgery at our institution for intracranial lesion removal with image guidance using a US system equipped with fusion imaging for neuro-navigation. In all cases the initial (external) registration error obtained by the corresponding anatomical landmark procedure was below 2mm and the craniotomy was correctly placed. The transdural window gave satisfactory US image quality and the lesion was always detectable and measurable on both axes. Brain shift/deformation correction has been successfully employed in 42 cases to restore the co-registration during surgery. The accuracy of ioUS/MRI fusion/overlapping was confirmed intraoperatively under direct visualization of anatomic landmarks and the error was < \u30083mm in all cases (100%). Conclusion: Neuro-navigation using intraoperative US integrated with preoperative MRI is reliable, accurate and user-friendly. Moreover, the adjustments are very helpful in correcting brain shift and tissue distortion. This integrated system allows true real-time feedback during surgery and is less expensive and time-consuming than other intraoperative imaging techniques, offering high precision and orientation.Brain Shift und Gewebeverschiebung w\ue4hrend der chirurgischen Entfernung intrakranialer Raumforderungen sind die limitierenden Faktoren bei der Neuronavigation (NN), welche aktuell haupts\ue4chlich pr\ue4operative Bilder einsetzt. Ultraschall (US) als Echtzeit-Bildgebung wird bei neurochirurgischen Prozeduren zunehmend angewandt. Vielen Neurochirurgen fehlt aber die US Expertise, da schon in der Ausbildung standarisierte (typisch axiale) CT und MRT Schnittbilder f\ufcr die Navigation bevorzugt eingesetzt werden und somit die Sicherheit bei der sonografischen Identifikation anatomischer Strukturen fehlt. Daher ist eine intraoperative Echtzeitfusion zwischen pr\ue4operativen CT bzw. MRT Bildern und intraoperativem Ultraschall (ioUS) im Rahmen der virtuellen Navigation (VN) au ferordentlich w\ufcnschenswert. Wir pr\ue4sentieren hier die bei uns angewandte Methode f\ufcr dieEchtzeitnavigation bei der Entfernung verschiedener Hirntumoren. Material und Methoden: Wir wandten die Bildfusion mit virtueller Navigation bei der chirurgischen Entfernung von Hirntumoren an. Zum Einsatz kam ein Neuronavigationssystem, welches intraoperative Ultraschallbilder mit pr\ue4operativen MRT Bildern in Echtzeit \ufcberlagert und zu jedem US Bild simultan die dazu passende ko-planare MRTSchnittebene anzeigt. Ergebnisse: Die US-basierte Neuronavigation wurde bei der Operation von 58 Patienten mit Hirntumoren eingesetzt. In allen F\ue4llen war der Fehler der initialen (externen) Registrierung, welche anhand von anatomischen Landmarken erfolgte, unterhalb von 2mm und die Kraniotomie konnte korrekt angesetzt werden. Die Bildqualit\ue4t des transduralen Ultraschalls war gut und die L\ue4sion konnte bei allen Patienten detektiert und in allen Achsen vermessen werden. Die Korrektur von Brain Shift sowie Gewebeverschiebung gelang erfolgreich in 42 F\ue4llen zur Wiederherstel lung der intraoperativen Co-Registrierung. Die Genauigkeit der cberlagerung von ioUS und MRT wurde intraoperativ anhand der Visualisierung anatomischerLandmarken \ufcberpr\ufcft und der Fehler lag in allen F\ue4llen (100 %) unterhalb von 3mm. Schlussfolgerung: Neuronavigation mit Hilfe von in pr\ue4operative MRT Bilder integrierten intraoperativen US Bildern ist eine zuverl\ue4ssige, genaue und anwenderfreundliche neue Technologie. Brain Shift und Gewebeverlagerungen k\uf6nnen anhand verschiedener Einstellungsm\uf6glichkeiten am System erfolgreich intraoperativ korrigiert werden. Das integrierte System erm\uf6glicht eine intraoperative cberpr\ufcfung der Navigation in Echtzeit und ist dabei kosteng\ufcnstiger und weniger Zeit aufw\ue4ndig als andere intraoperative Bild-gebende Verfahren, trotzdem aber hoch pr\ue4zise

    Role of image-guided fine-needle aspiration biopsy in the management of patients with splenic metastasis

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    BACKGROUND: Splenic metastases are very rare and are mostly diagnosed at the terminal phase of the disease or at the time of autopsy. The cytohistological diagnosis, when done, is made prevalently by splenectomy. Reports on splenic percutaneous biopsies in the diagnosis of splenic metastasis are fragmentary and very poor. The aims of this study are to analyse retrospectively the accuracy, safety and the clinical impact of ultrasound (US)-guided fine-needle aspiration biopsy (UG-FNAB) in patients with suspected splenic metastasis. METHODS: A retrospective analysis of 1800 percutaneous abdominal biopsies performed at our institute during the period from 1993 to 2003 was done and 160 patients that underwent splenic biopsy were found. Among these 160 patients, 12 cases with the final diagnosis of solitary splenic metastases were encountered and they form the basis of this report. The biopsies were performed under US guidance using a 22-gauge Chiba needle. All the patients underwent laboratory tests, CT examination of the abdomen and chest, US examination of abdomen and pelvis. RESULTS: There were 5 women and 7 men, median age 65 years (range 48ā€“80). Eight patients had a known primary cancer at the time of the diagnosis of splenic metastasis: 3 had breast adenocarcinoma, 2 colon adenocarcinoma, 2 melanoma and 1 lung adenocarcinoma. Four patients were undiagnosed at the time of the appearance of splenic metastasis and subsequent investigations showed adenocarcinoma of the lung in 2 patients and colon adenocarcinoma in the remaining 2. There was a complete correspondence between the US and Computed Tomography (CT) in detecting focal lesions of the spleen. The splenic biopsies allowed a cytological diagnosis of splenic metastasis in all the 12 patients and changed clinical management in all cases. Reviewing the 160 patients that underwent UG-FNAB of the spleen we found no complications related to the biopsies. CONCLUSION: These results indicate that UG-FNAB is a successful technique for diagnosis of splenic metastasis allowing an adequate treatment of the affected patients

    Benign thyroid nodules treatment using Percutaneous Laser Ablation (PLA) and Radiofrequency Ablation (RFA)

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    Purpose: To evaluate the reduction over time of benign thyroid nodules treated using percutaneous laser ablation (PLA) and radiofrequency ablation (RFA) by the same equipe. Materials and methods: Ninety patients (age 55.6\u2009\ub1\u200914.1 years) underwent ablation for benign thyroid nodule causing compression/aesthetic dissatisfaction from 2011. Fifty-nine (age 55.8\u2009\ub1\u200914.1 years) underwent RFA and 31 (age 55.2\u2009\ub1\u200914.2 years) PLA, ultrasound guided. Technical success, complications, duration of ablation and treatment, energy deployed, volumetric percentage reduction at 1, 6 and 12 months were derived. A regression model for longitudinal measurements was used with random intercept and random slope. Values are expressed as mean\u2009\ub1\u2009standard deviation or N (%). Results: Technical success was always obtained. No major complications occurred. Mean ablation time was 30.1\u2009\ub1\u200913.8 vs. 13.9\u2009\ub1\u20095.9\u2009min (p\u2009<\u2009.0001) and mean energy deployment was 5422.3\u2009\ub1\u20092484.5 J vs. 34 662.7\u2009\ub1\u200915 812.3 J in PLA vs. RFA group. Mean volume reduced from 20.3\u2009\ub1\u200916.4\u2009ml to 13.17\u2009\ub1\u200910.74\u2009ml (42%\u2009\ub1\u200917% reduction) at 1st month, 8.7\u2009\ub1\u20097.4\u2009ml (60%\u2009\ub1\u200915% reduction) at 6th month and 7.1\u2009\ub1\u20097.7\u2009ml (70%%\u2009\ub1\u200916% reduction) at 12th month, in PLA group, and from 32.7\u2009\ub1\u200919.5\u2009ml to 17.2\u2009\ub1\u200912.9\u2009ml (51%\ub115% reduction) at 1st month, 12.8\u2009\ub1\u20099.6\u2009ml (64\u2009\ub1\u200914% reduction) at 6th month and 9.9\u2009\ub1\u20099.2\u2009ml (74%\u2009\ub1\u200914% reduction) at 12th month in RFA group. No difference in time course of the relative volume reduction between the two techniques was found. Conclusions: RFA and PLA are similarly feasible, safe and effective in treating benign thyroid nodules when performed by the same equipe. RFA is faster than PLA but require significantly higher energy

    Management of primary hepatic malignancies during the COVID-19 pandemic: recommendations for risk mitigation from a multidisciplinary perspective

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    Around the world, recommendations for cancer treatment are being adapted in real time in response to the pandemic of COVID-19. We, as a multidisciplinary team, reviewed the standard management options, according to the Barcelona Clinic Liver Cancer classification system, for hepatocellular carcinoma. We propose treatment recommendations related to COVID-19 for the different stages of hepatocellular carcinoma (ie, 0, A, B, and C), specifically in relation to surgery, locoregional therapies, and systemic therapy. We suggest potential strategies to modify risk during the pandemic and aid multidisciplinary treatment decision making. We also review the multidisciplinary management of intrahepatic cholangiocarcinoma as a potentially curable and incurable diagnosis in the setting of COVID-19

    Identification of residual tumor with intraoperative contrast-enhanced ultrasound during glioblastoma resection

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    Objective: The purpose of this study was to assess the capability of contrast-enhanced ultrasound (CEUS) to identify residual tumor mass during glioblastoma multiforme (GBM) surgery, to increase the extent of resection. Methods: The authors prospectively evaluated 10 patients who underwent surgery for GBM removal with navigated ultrasound guidance. Navigated B-mode and CEUS were performed prior to resection, during resection, and after complete tumor resection. Areas suspected for residual tumors on B-mode and CEUS studies were localized within the surgical field with navigated ultrasound and samples were sent separately for histopathological analysis to confirm tumor presence. Results: In all cases tumor remnants were visualized as hyperechoic areas on B-mode, highlighted as CEUS-positive areas, and confirmed as tumoral areas on histopathological analysis. In 1 case only, CEUS partially failed to demonstrate residual tumor because the residual hyperechoic area was devascularized prior to ultrasound contrast agent injection. In all cases CEUS enhanced B-mode findings. Conclusions: As has already been shown in other neoplastic lesions in other organs, CEUS is extremely specific in the identification of residual tumor. The ability of CEUS to distinguish between tumor and artifacts or normal brain on B-mode is based on its capacity to show the vascularization degree and not the echogenicity of the tissues. Therefore, CEUS can play a decisive role in the process of maximizing GBM resection

    Contrast-enhanced MR Imaging versus Contrast-enhanced US: A Comparison in Glioblastoma Surgery by Using Intraoperative Fusion Imaging

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    Purpose To compare contrast material enhancement of glioblastoma multiforme (GBM) with intraoperative contrast-enhanced ultrasonography (US) versus that with preoperative gadolinium-enhanced T1-weighted magnetic resonance (MR) imaging by using real-time fusion imaging. Materials and Methods Ten patients with GBM were retrospectively identified by using routinely collected, anonymized data. Navigated contrast-enhanced US was performed after intravenous administration of contrast material before tumor resection. All patients underwent tumor excision with navigated intraoperative US guidance with use of fusion imaging between real-time intraoperative US and preoperative MR imaging. With use of fusion imaging, glioblastoma contrast enhancement at contrast-enhanced US (regarding location, morphologic features, margins, dimensions, and pattern) was compared with that at gadolinium-enhanced T1-weighted MR imaging. Results Fusion imaging for virtual navigation enabled matching of real-time contrast-enhanced US scans to corresponding coplanar preoperative gadolinium-enhanced T1-weighted MR images in all cases, with a positional discrepancy of less than 2 mm. Contrast enhancement of gadolinium-enhanced T1-weighted MR imaging and contrast-enhanced US was superimposable in all cases with regard to location, margins, dimensions, and morphologic features. The qualitative analysis of contrast enhancement pattern demonstrated a similar distribution in contrast-enhanced US and gadolinium-enhanced T1-weighted MR imaging in nine patients: Seven lesions showed peripheral inhomogeneous ring enhancement, and two lesions showed a prevalent nodular pattern. In one patient, the contrast enhancement pattern differed between the two modalities: Contrast-enhanced US showed enhancement of the entire bulk of the tumor, whereas gadolinium-enhanced T1-weighted MR imaging demonstrated peripheral contrast enhancement. Conclusion Glioblastoma contrast enhancement with contrast-enhanced US is superimposable on that provided with preoperative gadolinium-enhanced T1-weighted MR imaging regarding location, margins, morphologic features, and dimensions, with a similar enhancement pattern in most cases. Thus, contrast-enhanced US is of potential use in the surgical management of GBM

    Percutaneous laser ablation for benign and malignant thyroid diseases

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    Minimally invasive image-guided thermal ablation is becoming increasingly common as an alternative to surgery for the treatment of benign thyroid nodules. Among the various techniques for thermal ablation, laser ablation (LA) is the least invasive, using the smallest applicators available on the market and enabling extremely precise energy deposition. However, in some cases, multiple laser fibers must be used simultaneously for the treatment of large nodules. In this review, the LA technique is described, and its main clinical applications and results are discussed and illustrated
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