Pulsed radiofrequency on radial nerve under ultrasound guidance for treatment of intractable lateral epicondylitis.

PubMed

Oh, Dae Seok; Kang, Tae Hyung; Kim, Hyae Jin

2016-06-01

Lateral epicondylitis is a painful and functionally limiting disorder. Although lateral elbow pain is generally self-limiting, in a minority of people symptoms persist for a long time. When various conservative treatments fail, surgical approach is recommended. Surgical denervation of several nerves that innervate the lateral humeral epicondyle could be considered in patients with refractory pain because it denervates the region of pain. Pulsed radiofrequency is a minimally invasive procedure that improves chronic pain when applied to various neural tissues without causing any significant destruction and painful complication. This procedure is safe, minimally invasive, and has less risk of complications relatively compared to the surgical approach. The radial nerve can be identified as a target for pulsed radiofrequency lesioning in lateral epicondylitis. This innovative method of pulsed radiofrequency applied to the radial nerve has not been reported before. We reported on two patients with intractable lateral epicondylitis suffering from elbow pain who did not respond to nonoperative treatments, but in whom the ultrasound-guided pulsed radiofrequency neuromodulation of the radial nerve induced symptom improvement. After a successful diagnostic nerve block, radiofrequency probe adjustment around the radial nerve was performed on the lateral aspect of the distal upper arm under ultrasound guidance and multiple pulsed treatments were applied. A significant reduction in pain was reported over the follow-up period of 12 weeks.

Temperature measurement by thermal strain imaging with diagnostic power ultrasound, with potential for thermal index determination.

PubMed

Liang, Hai-Dong; Zhou, Li-Xia; Wells, Peter N T; Halliwell, Michael

2009-05-01

Over the years, there has been a substantial increase in acoustic exposure in diagnostic ultrasound as new imaging modalities with higher intensities and frame rates have been introduced; and more electronic components have been packed into the probe head, so that there is a tendency for it to become hotter. With respect to potential thermal effects, including those which may be hazardous occurring during ultrasound scanning, there is a correspondingly growing need for in vivo techniques to guide the operator as to the actual temperature rise occurring in the examined tissues. Therefore, an in vivo temperature estimator would be of considerable practical value. The commonly-used method of tissue thermal index (TI) measurement with a hydrophone in water could underestimate the actual value of TI (in one report by as much as 2.9 times). To obtain meaningful results, it is necessary to map the temperature elevation in 2-D (or 3-D) space. We present methodology, results and validation of a 2-D spatial and temporal thermal strain ultrasound temperature estimation technique in phantoms, and its apparently novel application in tracking the evolution of heat deposition at diagnostic exposure levels. The same ultrasound probe is used for both transmission and reception. The displacement and thermal strain estimation methods are similar to those used in high-intensity focused ultrasound thermal monitoring. The use of radiofrequency signals permits the application of cross correlation as a similarity measurement for tracking feature displacement. The displacement is used to calculate the thermal strain directly related to the temperature rise. Good agreement was observed between the temperature rise and the ultrasound power and scan duration. Thermal strain up to 1.4% was observed during 4000-s scan. Based on the results obtained for the temperature range studied in this work, the technique demonstrates potential for applicability in phantom (and possibly in vivo tissue

Histopathology of breast cancer after magnetic resonance-guided high-intensity focused ultrasound and radiofrequency ablation.

PubMed

Knuttel, Floortje M; Waaijer, Laurien; Merckel, Laura G; van den Bosch, Maurice A A J; Witkamp, Arjen J; Deckers, Roel; van Diest, Paul J

2016-08-01

Magnetic resonance-guided high-intensity focused ultrasound (MR-HIFU) ablation and radiofrequency ablation (RFA) are being researched as possible substitutes for surgery in breast cancer patients. The histopathological appearance of ablated tissue has not been studied in great detail. This study aimed to compare histopathological features of breast cancer after MR-HIFU ablation and RFA. MR-HIFU ablation and RFA were performed in- and ex-vivo. Tumours in six mastectomy specimens were partially ablated with RFA or MR-HIFU. In-vivo MR-HIFU ablation was performed 3-6 days before excision; RFA was performed in the operation room. Tissue was fixed in formalin and processed to haematoxylin and eosin (H&E) and cytokeratin-8 (CK-8)-stained slides. Morphology and cell viability were assessed. Ex-vivo ablation resulted in clear morphological changes after RFA versus subtle differences after MR-HIFU. CK-8 staining was decreased or absent. H&E tended to underestimate the size of thermal damage. In-vivo MR-HIFU resulted in necrotic-like changes. Surprisingly, some ablated lesions were CK-8-positive. Histopathology after in-vivo RFA resembled ex-vivo RFA, with hyper-eosinophilic stroma and elongated nuclei. Lesion borders were sharp after MR-HIFU and indistinct after RFA. Histopathological differences between MR-HIFU-ablated tissue and RF-ablated tissue were demonstrated. CK-8 was more reliable for cell viability assessment than H&E when used directly after ablation, while H&E was more reliable in ablated tissue left in situ for a few days. Our results contribute to improved understanding of histopathological features in breast cancer lesions treated with minimally invasive ablative techniques. © 2016 John Wiley & Sons Ltd.

Thermal fixation of swine liver tissue after magnetic resonance-guided high-intensity focused ultrasound ablation.

PubMed

Courivaud, Frédéric; Kazaryan, Airazat M; Lund, Alice; Orszagh, Vivian C; Svindland, Aud; Marangos, Irina Pavlik; Halvorsen, Per Steinar; Jebsen, Peter; Fosse, Erik; Hol, Per Kristian; Edwin, Bjørn

2014-07-01

The aim of this study was to investigate experimental conditions for efficient and controlled in vivo liver tissue ablation by magnetic resonance (MR)-guided high-intensity focused ultrasound (HIFU) in a swine model, with the ultimate goal of improving clinical treatment outcome. Histological changes were examined both acutely (four animals) and 1 wk after treatment (five animals). Effects of acoustic power and multiple sonication cycles were investigated. There was good correlation between target size and observed ablation size by thermal dose calculation, post-procedural MR imaging and histopathology, when temperature at the focal point was kept below 90°C. Structural histopathology investigations revealed tissue thermal fixation in ablated regions. In the presence of cavitation, mechanical tissue destruction occurred, resulting in an ablation larger than the target. Complete extra-corporeal MR-guided HIFU ablation in the liver is feasible using high acoustic power. Nearby large vessels were preserved, which makes MR-guided HIFU promising for the ablation of liver tumors adjacent to large veins. Copyright © 2014 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Comparison between ultrasound-guided interfascial pulsed radiofrequency and ultrasound-guided interfascial block with local anesthetic in myofascial pain syndrome of trapezius muscle

PubMed Central

Cho, Ik Tae; Cho, Yun Woo; Kwak, Sang Gyu; Chang, Min Cheol

2017-01-01

Abstract Myofascial pain syndrome (MPS) of the trapezius muscle (TM) is a frequently occurring musculoskeletal disorder. However, the treatment of MPS of the TM remains a challenge. We investigated the effects of ultrasound (US)-guided pulsed radiofrequency (PRF) stimulation on the interfascial area of the TM. In addition, we compared its effect with that of interfascial block (IFB) with 10 mL of 0.6% lidocaine on the interfascial area of the TM. Thirty-six patients with MPS of the TM were included and randomly assigned into 2 groups. Eighteen patients underwent PRF stimulation on the interfascial area of the TM (PRF group) and 18 patients underwent IFB with lidocaine on the same area (IFB group). Pain intensity was evaluated using a numerical rating scale (NRS) at pretreatment, 2, 4, and 8 weeks after treatment. At pretreatment and 8 weeks after treatment, quality of life was assessed using the Short Form-36 Health Survey (SF-36), which includes the physical component score (PCS) and the mental component score (MCS). One patient in the PRF group was lost to follow-up. Patients in both groups showed a significant decrease in NRS scores at 2, 4, and 8 weeks after treatments and a significant increase in PCS and MCS of the SF-36 at 8 weeks after treatments. Two weeks after each treatment, the decrements of NRS scores were not significantly different between the 2 groups. However, 4 and 8 weeks after the procedures, we found that the NRS score was significantly lower in the PRF group than in the IFB group. At 8 weeks after the treatments, PCS and MCS of the SF-36 in the PRF group were significantly higher than those in the IFB group. For the management of MPS of the TM, US-guided interfascial PRF had a better long-term effect on reducing the pain and the quality of life compared to US-guided IFB. Therefore, we think US-guided PRF stimulation on the interfascial area of the TM can be a beneficial alternative to manage the pain following MPS of the TM. PMID:28151904

Comparison between ultrasound-guided interfascial pulsed radiofrequency and ultrasound-guided interfascial block with local anesthetic in myofascial pain syndrome of trapezius muscle.

PubMed

Cho, Ik Tae; Cho, Yun Woo; Kwak, Sang Gyu; Chang, Min Cheol

2017-02-01

Myofascial pain syndrome (MPS) of the trapezius muscle (TM) is a frequently occurring musculoskeletal disorder. However, the treatment of MPS of the TM remains a challenge. We investigated the effects of ultrasound (US)-guided pulsed radiofrequency (PRF) stimulation on the interfascial area of the TM. In addition, we compared its effect with that of interfascial block (IFB) with 10 mL of 0.6% lidocaine on the interfascial area of the TM. Thirty-six patients with MPS of the TM were included and randomly assigned into 2 groups. Eighteen patients underwent PRF stimulation on the interfascial area of the TM (PRF group) and 18 patients underwent IFB with lidocaine on the same area (IFB group). Pain intensity was evaluated using a numerical rating scale (NRS) at pretreatment, 2, 4, and 8 weeks after treatment. At pretreatment and 8 weeks after treatment, quality of life was assessed using the Short Form-36 Health Survey (SF-36), which includes the physical component score (PCS) and the mental component score (MCS). One patient in the PRF group was lost to follow-up. Patients in both groups showed a significant decrease in NRS scores at 2, 4, and 8 weeks after treatments and a significant increase in PCS and MCS of the SF-36 at 8 weeks after treatments. Two weeks after each treatment, the decrements of NRS scores were not significantly different between the 2 groups. However, 4 and 8 weeks after the procedures, we found that the NRS score was significantly lower in the PRF group than in the IFB group. At 8 weeks after the treatments, PCS and MCS of the SF-36 in the PRF group were significantly higher than those in the IFB group. For the management of MPS of the TM, US-guided interfascial PRF had a better long-term effect on reducing the pain and the quality of life compared to US-guided IFB. Therefore, we think US-guided PRF stimulation on the interfascial area of the TM can be a beneficial alternative to manage the pain following MPS of the TM.

First noninvasive thermal ablation of a brain tumor with MR-guided focused ultrasound

PubMed Central

2014-01-01

Magnetic resonance-guided focused ultrasound surgery (MRgFUS) allows for precise thermal ablation of target tissues. While this emerging modality is increasingly used for the treatment of various types of extracranial soft tissue tumors, it has only recently been acknowledged as a modality for noninvasive neurosurgery. MRgFUS has been particularly successful for functional neurosurgery, whereas its clinical application for tumor neurosurgery has been delayed for various technical and procedural reasons. Here, we report the case of a 63-year-old patient presenting with a centrally located recurrent glioblastoma who was included in our ongoing clinical phase I study aimed at evaluating the feasibility and safety of transcranial MRgFUS for brain tumor ablation. Applying 25 high-power sonications under MR imaging guidance, partial tumor ablation could be achieved without provoking neurological deficits or other adverse effects in the patient. This proves, for the first time, the feasibility of using transcranial MR-guided focused ultrasound to safely ablate substantial volumes of brain tumor tissue. PMID:25671132

Endovascular ultrasound for renal sympathetic denervation in patients with therapy-resistant hypertension not responding to radiofrequency renal sympathetic denervation.

PubMed

Stiermaier, Thomas; Okon, Thomas; Fengler, Karl; Mueller, Ulrike; Hoellriegel, Robert; Schuler, Gerhard; Desch, Steffen; Lurz, Philipp

2016-06-12

Recent studies have reported a considerable number of non-responders after renal sympathetic de-nervation (RSD) with radiofrequency technology. Here we report our results of repeat RSD using ultrasound in these patients. A cohort study was performed in patients who underwent ultrasound RSD after non-response to RSD with radiofrequency. Non-response was defined as mean daytime systolic blood pressure ≥140 mmHg and/or a reduction of ≤10 mmHg in ambulatory blood pressure measurement (ABPM) ≥6 months after radiofrequency denervation. ABPM was recorded at baseline, post radiofrequency RSD as well as at three and six months post ultrasound RSD. A total of 24 non-responders underwent retreatment with the ultrasound device at a mean 15.3±8.2 months after radiofrequency RSD. Ultrasound RSD was performed successfully in all patients without severe adverse events. Mean daytime systolic blood pressure changed from 161.7±14.6 mmHg at baseline to 158.5±9.5 mmHg post radiofrequency RSD and to 150.5±10.4 mmHg and 151.6±11.0 mmHg at three and six months, respectively, post ultrasound RSD (p<0.01 with repeated measures analysis of variance). The main results of post hoc testing were as follows: baseline versus post radiofrequency RSD, p=0.83; baseline versus three months post ultrasound RSD, p=0.01; and baseline versus six months post ultrasound RSD, p=0.04. Ultrasound RSD appears to be safe and an effective therapeutic approach in patients not responding to previous RSD with radiofrequency technology.

Cost-utility analysis of great saphenous vein ablation with radiofrequency, foam and surgery in the emerging health-care setting of Thailand.

PubMed

Siribumrungwong, Boonying; Noorit, Pinit; Wilasrusmee, Chumpon; Leelahavarong, Pattara; Thakkinstian, Ammarin; Teerawattananon, Yot

2016-09-01

To conduct economic evaluations of radiofrequency ablation, ultrasound-guided foam sclerotherapy and surgery for great saphenous vein ablation. A cost-utility and cohort analysis from societal perspective was performed to estimate incremental cost-effectiveness ratio. Transitional probabilities were from meta-analysis. Direct medical, direct non-medical, indirect costs, and utility were from standard Thai costings and cohort. Probabilistic sensitivity analysis was performed to assess parameter uncertainties. Seventy-seven patients (31 radiofrequency ablation, 19 ultrasound-guided foam sclerotherapy, and 27 surgeries) were enrolled from October 2011 to February 2013. Compared with surgery, radiofrequency ablation costed 12,935 and 20,872 Baht higher, whereas ultrasound-guided foam sclerotherapy costed 6159 lower and 1558 Bath higher for outpatient and inpatient, respectively. At one year, radiofrequency ablation had slightly lower quality-adjusted life-year, whereas ultrasound-guided foam sclerotherapy yielded additional 0.025 quality-adjusted life-year gained. Because of costing lower and greater quality-adjusted life-year than other compared alternatives, outpatient ultrasound-guided foam sclerotherapy was an option being dominant. Probabilistic sensitivity analysis resulted that at the Thai ceiling threshold of 160,000 Baht/quality-adjusted life-year gained, ultrasound-guided foam sclerotherapy had chances of 0.71 to be cost-effective. Ultrasound-guided foam sclerotherapy seems to be cost-effective for treating great saphenous vein reflux compared to surgery in Thailand at one-year results. © The Author(s) 2015.

[Monitoring radiofrequency ablation by ultrasound temperature imaging and elastography under different power intensities].

PubMed

Geng, Xiaonan; Li, Qiang; Tsui, Pohsiang; Wang, Chiaoyin; Liu, Haoli

2013-09-01

To evaluate the reliability of diagnostic ultrasound-based temperature and elasticity imaging during radiofrequency ablation (RFA) through ex vivo experiments. Procine liver samples (n=7) were employed for RFA experiments with exposures of different power intensities (10 and 50w). The RFA process was monitored by a diagnostic ultrasound imager and the information were postoperatively captured for further temperature and elasticity image analysis. Infrared thermometry was concurrently applied to provide temperature change calibration during the RFA process. Results from this study demonstrated that temperature imaging was valid under 10 W RF exposure (r=0.95), but the ablation zone was no longer consistent with the reference infrared temperature distribution under high RF exposures. The elasticity change could well reflect the ablation zone under a 50 W exposure, whereas under low exposures, the thermal lesion could not be well detected due to the limited range of temperature elevation and incomplete tissue necrosis. Diagnostic ultrasound-based temperature and elastography is valid for monitoring thr RFA process. Temperature estimation can well reflect mild-power RF ablation dynamics, whereas the elastic-change estimation can can well predict the tissue necrosis. This study provide advances toward using diagnostic ultrasound to monitor RFA or other thermal-based interventions.

Comparison of microbubble presence in the right heart during mechanochemical and radiofrequency ablation for varicose veins.

PubMed

Moon, K H; Dharmarajah, B; Bootun, R; Lim, C S; Lane, Tra; Moore, H M; Sritharan, K; Davies, A H

2017-07-01

Objective Mechanochemical ablation is a novel technique for ablation of varicose veins utilising a rotating catheter and liquid sclerosant. Mechanochemical ablation and radiofrequency ablation have no reported neurological side-effect but the rotating mechanism of mechanochemical ablation may produce microbubbles. Air emboli have been implicated as a cause of cerebrovascular events during ultrasound-guided foam sclerotherapy and microbubbles in the heart during ultrasound-guided foam sclerotherapy have been demonstrated. This study investigated the presence of microbubbles in the right heart during varicose vein ablation by mechanochemical abaltion and radiofrequency abaltion. Methods Patients undergoing great saphenous vein ablation by mechanochemical abaltion or radiofrequency ablation were recruited. During the ablative procedure, the presence of microbubbles was assessed using transthoracic echocardiogram. Offline blinded image quantification was performed using International Consensus Criteria grading guidelines. Results From 32 recruited patients, 28 data sets were analysed. Eleven underwent mechanochemical abaltion and 17 underwent radiofrequency abaltion. There were no neurological complications. In total, 39% (11/28) of patients had grade 1 or 2 microbubbles detected. Thirty-six percent (4/11) of mechanochemical abaltion patients and 29% (5/17) of radiofrequency ablation patients had microbubbles with no significant difference between the groups ( p=0.8065). Conclusion A comparable prevalence of microbubbles between mechanochemical abaltion and radiofrequency ablation both of which are lower than that previously reported for ultrasound-guided foam sclerotherapy suggests that mechanochemical abaltion may not confer the same risk of neurological events as ultrasound-guided foam sclerotherapy for treatment of varicose veins.

Multi-Channel RF System for MRI-Guided Transurethral Ultrasound Thermal Therapy

NASA Astrophysics Data System (ADS)

Yak, Nicolas; Asselin, Matthew; Chopra, Rajiv; Bronskill, Michael

2009-04-01

MRI-guided transurethral ultrasound thermal therapy is an approach to treating localized prostate cancer which targets precise deposition of thermal energy within a confined region of the gland. This treatment requires a system incorporating a heating applicator with multiple planar ultrasound transducers and associated RF electronics to control individual elements independently in order to achieve accurate 3D treatment. We report the design, construction, and characterization of a prototype multi-channel system capable of controlling 16 independent RF signals for a 16-element heating applicator. The main components are a control computer, microcontroller, and a 16-channel signal generator with 16 amplifiers, each incorporating a low-pass filter and transmitted/reflected power detection circuit. Each channel can deliver from 0.5 to 10 W of electrical power and good linearity from 3 to 12 MHz. Harmonic RF signals near the Larmor frequency of a 1.5 T MRI were measured to be below -30 dBm and heating experiments within the 1.5 T MR system showed no significant decrease in SNR of the temperature images. The frequency and power for all 16 channels could be changed in less than 250 ms, which was sufficiently rapid for proper performance of the control algorithms. A common backplane design was chosen which enabled an inexpensive, modular approach for each channel resulting in an overall system with minimal footprint.

Monitoring radiofrequency ablation with ultrasound Nakagami imaging.

PubMed

Wang, Chiao-Yin; Geng, Xiaonan; Yeh, Ta-Sen; Liu, Hao-Li; Tsui, Po-Hsiang

2013-07-01

Radiofrequency ablation (RFA) is a widely used alternative modality in the treatment of liver tumors. Ultrasound B-mode imaging is an important tool to guide the insertion of the RFA electrode into the tissue. However, it is difficult to visualize the ablation zone because RFA induces the shadow effect in a B-scan. Based on the randomness of ultrasonic backscattering, this study proposes ultrasound Nakagami imaging, which is a well-established method for backscattered statistics analysis, as an approach to complement the conventional B-scan for evaluating the ablation region. Porcine liver samples (n = 6) were ablated using a RFA system and monitored by employing an ultrasound scanner equipped with a 7.5 MHz linear array transducer. During the stages of ablation (0-12 min) and postablation (12-24 min), the raw backscattered data were acquired at a sampling rate of 30 MHz for B-mode, Nakagami imaging, and polynomial approximation of Nakagami imaging. The contrast-to-noise ratio (CNR) was also calculated to compare the image contrasts of the B-mode and Nakagami images. The results demonstrated that the Nakagami image has the ability to visualize changes in the backscattered statistics in the ablation zone, including the shadow region during RFA. The average Nakagami parameter increased from 0.2 to 0.6 in the ablation stage, and then decreased to approximately 0.3 at the end of the postablation stage. Moreover, the CNR of the Nakagami image was threefold that of the B-mode image, showing that the Nakagami image has a better image contrast for monitoring RFA. Specifically, the use of the polynomial approximation equips the Nakagami image with an enhanced ability to estimate the range of the ablation region. This study demonstrated that ultrasound Nakagami imaging based on the analysis of backscattered statistics has the ability to visualize the RFA-induced ablation zone, even if the shadow effect exists in the B-scan.

Early Stage Hepatocellular Carcinomas Not Feasible for Ultrasound-Guided Radiofrequency Ablation: Comparison of Transarterial Chemoembolization Alone and Combined Therapy with Transarterial Chemoembolization and Radiofrequency Ablation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hyun, Dongho; Cho, Sung Ki, E-mail: chosk@skku.edu; Shin, Sung Wook

2016-03-15

PurposeTo report the results of combined therapy with transarterial chemoembolization (TACE) and radiofrequency ablation (RFA) for early stage hepatocellular carcinoma (HCC) considered infeasible for ultrasound (US)-guided RFA in comparison with those of TACE monotherapy.MethodsFrom January 2007 through December 2010, 91 patients with early or very early stage HCC infeasible for US-guided RFA received either TACE alone (TACE group; n = 54) or TACE immediately followed by RFA (TACE–RFA group; n = 37) as a first-line treatment. 1-month tumor response, time to progression (TTP), and overall survival (OS) rates were calculated. Univariate and multivariate analyses were performed to identify prognostic factors.ResultsTACE–RFA group showed a bettermore » 1-month tumor response than TACE group (P < .001). The mean TTP was 29.7 ± 3.4 months (95 % confidence intervals [CIs] 23.0–36.5) in TACE group and 34.9 ± 2.8 months (95 % CIs 29.4–40.4) in TACE–RFA group. TACE–RFA group had a significantly longer TTP (P = .014). Cumulative 1-, 2-, and 3-year OS rates in the TACE and TACE–RFA groups were 91, 79, and 71 % and 100, 97, and 93 %, respectively (P = .008). Initial treatment of TACE was found to be the only significant risk factor for tumor progression and OS in multivariate analysis.ConclusionTACE–RFA combination therapy appears superior to TACE monotherapy in terms of 1-month tumor response, TTP, and OS when performed for early stage HCC infeasible for US-guided RFA.« less

JAG Tearing Technique with Radiofrequency Guide Wire for Aortic Fenestration in Thoracic Endovascular Aneurysm Repair

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ricci, Carmelo; Ceccherini, Claudio, E-mail: claudiocec@hotmail.it; Leonini, Sara

An innovative approach, the JAG tearing technique, was performed during thoracic endovascular aneurysm repair in a patient with previous surgical replacement of the ascending aorta with a residual uncomplicated type B aortic dissection who developed an aneurysm of the descending thoracic aorta with its lumen divided in two parts by an intimal flap. The proximal landing zone was suitable to place a thoracic stent graft. The distal landing zone was created by cutting the intimal flap in the distal third of the descending thoracic aorta with a radiofrequency guide wire and intravascular ultrasound catheter.

Sacroiliac joint pain: Prospective, randomised, experimental and comparative study of thermal radiofrequency with sacroiliac joint block.

PubMed

Cánovas Martínez, L; Orduña Valls, J; Paramés Mosquera, E; Lamelas Rodríguez, L; Rojas Gil, S; Domínguez García, M

2016-05-01

To compare the analgesic effects between the blockade and bipolar thermal radiofrequency in the treatment of sacroiliac joint pain. Prospective, randomised and experimental study conducted on 60 patients selected in the two hospitals over a period of nine months, who had intense sacroiliac joint pain (Visual Analogue Scale [VAS]>6) that lasted more than 3 months. Patients were randomised into three groups (n=20): Group A (two intra-articular sacroiliac injections of local anaesthetic/corticosteroid guided by ultrasound in 7 days). Group B: conventional bipolar radiofrequency "palisade". Target points were the lateral branch nerves of S1, S2, and S3, distance needles 1cm. Group C: modified bipolar radiofrequency "palisade" (needle distance >1cm). Patients were evaluated at one month, three months, and one year. Demographic data, VAS reduction, and side effects of the techniques were assessed. One month after the treatment, pain reduction was >50% in the three groups P<.001. Three and 12 months after the technique, the patients of the group A did not have a significant reduction in pain. At 3 months, almost 50% patients of the group B referred to improvement of the pain (P=.03), and <25% at 12 months, and those results were statistically significant (P=.01) compared to the baseline. Group C showed an improvement of 50% at 3 and 12 months (P<.001). All patients completed the study. Bipolar radiofrequency "palisade", especially when the distance between the needles was increased, was more effective and lasted longer, compared to join block and steroids, in relieving pain sacroiliac joint. Copyright © 2015 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.

Ultrasound-guided synovial biopsy

PubMed Central

Sitt, Jacqueline C M; Wong, Priscilla

2016-01-01

Ultrasound-guided needle biopsy of synovium is an increasingly performed procedure with a high diagnostic yield. In this review, we discuss the normal synovium, as well as the indications, technique, tissue handling and clinical applications of ultrasound-guided synovial biopsy. PMID:26581578

MR-guided Focused Ultrasound for Uterine Fibroids

MedlinePlus

... Professions Site Index A-Z MR-guided Focused Ultrasound for Uterine Fibroids Magnetic Resonance-guided Focused Ultrasound ( ... are the limitations of MRgFUS? What is Focused Ultrasound of Uterine Fibroids? Magnetic Resonance-guided Focused Ultrasound ( ...

CT and Ultrasound Guided Stereotactic High Intensity Focused Ultrasound (HIFU)

NASA Astrophysics Data System (ADS)

Wood, Bradford J.; Yanof, J.; Frenkel, V.; Viswanathan, A.; Dromi, S.; Oh, K.; Kruecker, J.; Bauer, C.; Seip, R.; Kam, A.; Li, K. C. P.

2006-05-01

To demonstrate the feasibility of CT and B-mode Ultrasound (US) targeted HIFU, a prototype coaxial focused ultrasound transducer was registered and integrated to a CT scanner. CT and diagnostic ultrasound were used for HIFU targeting and monitoring, with the goals of both thermal ablation and non-thermal enhanced drug delivery. A 1 megahertz coaxial ultrasound transducer was custom fabricated and attached to a passive position-sensing arm and an active six degree-of-freedom robotic arm via a CT stereotactic frame. The outer therapeutic transducer with a 10 cm fixed focal zone was coaxially mounted to an inner diagnostic US transducer (2-4 megahertz, Philips Medical Systems). This coaxial US transducer was connected to a modified commercial focused ultrasound generator (Focus Surgery, Indianapolis, IN) with a maximum total acoustic power of 100 watts. This pre-clinical paradigm was tested for ability to heat tissue in phantoms with monitoring and navigation from CT and live US. The feasibility of navigation via image fusion of CT with other modalities such as PET and MRI was demonstrated. Heated water phantoms were tested for correlation between CT numbers and temperature (for ablation monitoring). The prototype transducer and integrated CT/US imaging system enabled simultaneous multimodality imaging and therapy. Pre-clinical phantom models validated the treatment paradigm and demonstrated integrated multimodality guidance and treatment monitoring. Temperature changes during phantom cooling corresponded to CT number changes. Contrast enhanced or non-enhanced CT numbers may potentially be used to monitor thermal ablation with HIFU. Integrated CT, diagnostic US, and therapeutic focused ultrasound bridges a gap between diagnosis and therapy. Preliminary results show that the multimodality system may represent a relatively inexpensive, accessible, and simple method of both targeting and monitoring HIFU effects. Small animal pre-clinical models may be translated to large

A unique complication of radiofrequency therapy to the tongue base

PubMed Central

Tornari, Chrysostomos; Wong, Gentle; Arora, Asit; Kotecha, Bhik

2015-01-01

Introduction Radiofrequency ablation treatment of the tongue base can be used either alone or as part of a multilevel approach in the treatment of snoring. This involves the generation of thermal energy around the circumvallate papillae of the tongue. Potential complications include ulceration, dysphagia, haematoma and abscess formation. Presentation of case We present the case of a 50-year-old patient who developed an anterior neck swelling following a second application of radiofrequency ablation therapy to the tongue base for snoring. This was secondary to an infection of a previously undiagnosed thyroglossal cyst. The patient made a full recovery following intravenous antibiotic therapy and ultrasound-guided needle aspiration. Discussion Thyroglossal tract remnants are thought to be present in seven percent of the adult population. An infection in a thyroglossal tract cyst has not previously been reported following radiofrequency ablation of the tongue base. Given the relatively high complication rate of tongue base radiofrequency ablation in some series, this complication may be under-recognised. Conclusion An infected thyroglossal tract cyst should be suspected in patients with anterior neck swellings following radiofrequency ablation therapy to the tongue base. We advise caution when performing this procedure on patients with known thyroglossal tract remnants though there is insufficient evidence to suggest that this procedure is contraindicated. PMID:25603484

Thermal ablation of pancreatic cyst with a prototype endoscopic ultrasound capable radiofrequency needle device: A pilot feasibility study

PubMed Central

Moris, Maria; Atar, Mustafa; Kadayifci, Abdurrahman; Krishna, Murli; Librero, Ariston; Richie, Eugene; Brugge, William; Wallace, Michael B.

2017-01-01

Background and Objectives: Pancreatic cysts are evaluated by endoscopic ultrasound and fine needle aspiration (EUS). The only accepted treatment is pancreatectomy, which is associated with morbidity and mortality. This study evaluated the optimal thermal dosimetry of a novel radiofrequency ablation device using a standard electrosurgical unit in ex vivo cyst models. Methods: A modified EUS 22-gauge monopolar needle prototype with a tip electrode connected to a standard electrosurgical unit (Erbe USA, Marietta, GA, USA) was used to induce a subboiling point temperature. A cyst model was created using 2-cm sections of porcine small intestine ligated and filled with saline. After ablation, the cyst models were prepared for pathological evaluation. The epithelial layers were measured in at least two different sites with a micrometer and compared with the corresponding control sample. Results: Thirty-two cyst models were ablated with maximum temperatures of 50°C, 60°C, 90°C, and 97°C in 8, 11, 11, and 2 cysts, respectively. Longer ablation times were required to induce higher temperatures. A trend in the reduction in thickness of the measured layers was observed after exposure to higher temperatures. A temperature over 50°C was required for the ablation of the muscularis, submucosa, and villi, and over 60°C was required to ablate the mucosal crypts. Conclusions: In a preclinical model, a novel radiofrequency EUS-capable needle connected to a standard electrosurgical unit using standard low-voltage coagulation provided ablation in a temperature-dependent fashion with a threshold of at least 60°C and a safe cyst margin below 97°C. This potentially will allow low-cost, convenient cyst ablation. PMID:28440238

77 FR 74668 - Compliance Policy Guide; Radiofrequency Identification Feasibility Studies and Pilot Programs for...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-17

...; Formerly Docket No. 2004D-0499] Compliance Policy Guide; Radiofrequency Identification Feasibility Studies... extending the expiration date of compliance policy guide (CPG) Sec. 400.210 entitled ``Radiofrequency... 74669

Monitoring radio-frequency thermal ablation with ultrasound by low frequency acoustic emissions--in vitro and in vivo study.

PubMed

Winkler, Itai; Adam, Dan

2011-05-01

The object of this study was to evaluate the monitoring of thermal ablation therapy by measuring the nonlinear response to ultrasound insonation at the region being treated. Previous reports have shown that during tissue heating, microbubbles are formed. Under the application of ultrasound, these microbubbles may be driven into nonlinear motion that produces acoustic emissions at sub-harmonic frequencies and a general increase of emissions at low frequencies. These low frequency emissions may be used to monitor ablation surgery. In this study, a modified commercial ultrasound system was used for transmitting ultrasound pulses and for recording raw RF-lines from a scan plane in porcine (in vitro) and rabbit (in vivo) livers during radio-frequency ablation (RFA). The transmission pulse was 15 cycles in length at 4 MHz (in vitro) and 3.6 MHz (in vivo). Thermocouples were used for monitoring temperatures during the RFA treatment.In the in vitro experiments, recorded RF signals (A-lines) were segmented, and the total energy was measured at two different frequency bands: at a low frequency band (LFB) of 1-2.5 MHz and at the transmission frequency band (TFB) of 3.5-4.5 MHz. The mean energy at the LFB and at the TFB increased substantially in areas adjacent to the RF needle. These energies also changed abruptly at higher temperatures, thus, producing great variance in the received energy. Mean energies in areas distant from RF needle showed little change and variation during treatment. It was also shown that a 3 dB increase of energy at the low frequency band was typically obtained in regions in which temperature was above 53.3 ± 5° C. Thus, this may help in evaluating regions undergoing hyperthermia. In the in vivo experiments, an imaging algorithm based on measuring the LFB energy was used. The algorithm performs a moving average of the LFB energies measured at segments within the scan plane.Results show that a colored region is formed on the image and that it is

TU-B-210-00: MR-Guided Focused Ultrasound Therapy in Oncology

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

MR guided focused ultrasound (MRgFUS), or alternatively high-intensity focused ultrasound (MRgHIFU), is approved for thermal ablative treatment of uterine fibroids and pain palliation in bone metastases. Ablation of malignant tumors is under active investigation in sites such as breast, prostate, brain, liver, kidney, pancreas, and soft tissue. Hyperthermia therapy with MRgFUS is also feasible, and may be used in conjunction with radiotherapy and for local targeted drug delivery. MRI allows in situ target definition and provides continuous temperature monitoring and subsequent thermal dose mapping during HIFU. Although MRgHIFU can be very precise, treatment of mobile organs is challenging and advancedmore » techniques are required because of artifacts in MR temperature mapping, the need for intercostal firing, and need for gated HIFU or tracking of the lesion in real time. The first invited talk, “MR guided Focused Ultrasound Treatment of Tumors in Bone and Soft Tissue”, will summarize the treatment protocol and review results from treatment of bone tumors. In addition, efforts to extend this technology to treat both benign and malignant soft tissue tumors of the extremities will be presented. The second invited talk, “MRI guided High Intensity Focused Ultrasound – Advanced Approaches for Ablation and Hyperthermia”, will provide an overview of techniques that are in or near clinical trials for thermal ablation and hyperthermia, with an emphasis of applications in abdominal organs and breast, including methods for MRTI and tracking targets in moving organs. Learning Objectives: Learn background on devices and techniques for MR guided HIFU for cancer therapy Understand issues and current status of clinical MRg HIFU Understand strategies for compensating for organ movement during MRgHIFU Understand strategies for strategies for delivering hyperthermia with MRgHIFU CM - research collaboration with Philips.« less

Ultrasound-guided Radiofrequency Lesioning of the Articular Branches of the Femoral Nerve for the Treatment of Chronic Post-arthroplasty Hip Pain.

PubMed

Kim, David J; Shen, Shiqian; Hanna, George M

2017-02-01

Total hip arthroplasty (THA) is a common surgical treatment for several conditions of the hip. While the majority of patients obtain satisfactory results, many develop chronic post-arthroplasty hip pain that can be difficult to treat. We evaluate the effectiveness of cooled (60°C) radiofrequency lesioning of the articular branches of the femoral nerve (ABFN) as a minimally invasive treatment for patients suffering from chronic post-arthroplasty hip pain. This treatment has never been described previously in this population. Case report. Center for Pain Medicine, Massachusetts General Hospital, Harvard Medical School. A 59-year-old woman with long-standing osteoarthritis of the right hip who underwent primary total hip arthroplasty and presented with chronic post-arthroplasty hip pain Intervention: Cooled (60°C) radiofrequency lesioning of the ABFN under ultrasound guidance Outcome Measure: Functional ability and numeric rating scale (NRS) scores at rest and with activity. Prior to intervention, the patient reported severe disruption in daily activities, sleep, and relationships; NRS scores at rest and with activity were 4/10 and 10/10, respectively. At 4 weeks following intervention, the patient reported significant improvement in functional ability and NRS scores decreased to 1/10 and 2/10, respectively. At 6 months, the patient's NRS scores at rest and with activity were 0/10 and 1/10, respectively. At 24-month follow-up, the patient continued to endorse significant pain relief with NRS scores at rest and with activity of 0 - 1/10 and 1 - 2/10, respectively. There were no side effects or complications including motor weakness, sensory loss, and neuralgias. Although the patient obtained good results from the intervention, the description of the study is from a single case report. Further study is necessary to investigate the widespread use of this technique and its outcomes. Cooled (60°C) radiofrequency lesioning of the ABFN under ultrasound guidance is both an

Magnetic resonance guided high-intensity focused ultrasound ablation of musculoskeletal tumors

PubMed Central

Avedian, Raffi S.; Gold, Garry; Ghanouni, Pejman; Pauly, Kim Butts

2015-01-01

This article reviews the fundamental principles and clinical experimental uses of magnetic resonance guided high-intensity focused ultrasound (MRgHIFU) ablation of musculoskeletal tumors. MRgHIFU is a noninvasive treatment modality that takes advantage of the ability of magnetic resonance to measure tissue temperature and uses this technology to guide high-intensity focused ultrasound waves to a specific focus within the human body that results in heat generation and complete thermal necrosis of the targeted tissue. Adjacent normal tissues are spared because of the accurate delivery of thermal energy, as well as, local blood perfusion that provides a cooling effect. MRgHIFU is approved by the Food and Drug Administration for the treatment of uterine fibroids and is used on an experimental basis to treat breast, prostate, liver, bone, and brain tumors. PMID:26120376

Transcranial MR-Guided Focused Ultrasound: A Review of the Technology and Neuro Applications

PubMed Central

Ghanouni, Pejman; Pauly, Kim Butts; Elias, W. Jeff; Henderson, Jaimie; Sheehan, Jason; Monteith, Stephen; Wintermark, Max

2015-01-01

MR guided focused ultrasound is a new, minimally invasive method of targeted tissue thermal ablation that may be of use to treat central neuropathic pain, essential tremor, Parkinson tremor, and brain tumors. The system has also been used to temporarily disrupt the blood-brain barrier to allow targeted drug delivery to brain tumors. This article reviews the physical principles of MR guided focused ultrasound and discusses current and potential applications of this exciting technology. PMID:26102394

Focused ultrasound guided relocation of kidney stones.

PubMed

Abrol, Nitin; Kekre, Nitin S

2015-01-01

Complete removal of all fragments is the goal of any intervention for urinary stones. This is more important in lower pole stones where gravity and spatial orientation of lower pole infundibulum may hinder spontaneous passage of fragments. Various adjuvant therapies (inversion, diuresis, percussion, oral citrate, etc.) are described to enhance stone-free rate but are not widely accepted. Focused ultrasound-guided relocation of fragments is a recently described technique aimed at improving results of intervention for stone disease. Purpose of this review is to discuss development of this technology and its potential clinical applications. Pubmed search was made using key words "Focused ultrasound" and "kidney stone". All English language articles were reviewed by title. Relevant studies describing development and application of focused ultrasound in renal stones were selected for review. Focused ultrasound has proven its efficacy in successfully relocating up to 8 mm stone fragments in vitro and in pigs. Relocation is independent of stone composition. The latest model allows imaging and therapy with a single handheld probe facilitating its use by single operator. The acoustic energy delivered by the new prototype is even less than that used for extracorporeal shock wave lithotripsy. Therapeutic exposure has not caused thermal injury in pig kidneys. Focused ultrasound-guided relocation of stones is feasible. Though it is safe in application in pigs, technology is awaiting approval for clinical testing in human beings. This technology has many potential clinical applications in the management of stone disease.

Fusion imaging of contrast-enhanced ultrasound and contrast-enhanced CT or MRI before radiofrequency ablation for liver cancers.

PubMed

Bo, Xiao-Wan; Xu, Hui-Xiong; Wang, Dan; Guo, Le-Hang; Sun, Li-Ping; Li, Xiao-Long; Zhao, Chong-Ke; He, Ya-Ping; Liu, Bo-Ji; Li, Dan-Dan; Zhang, Kun

2016-11-01

To investigate the usefulness of fusion imaging of contrast-enhanced ultrasound (CEUS) and CECT/CEMRI before percutaneous ultrasound-guided radiofrequency ablation (RFA) for liver cancers. 45 consecutive patients with 70 liver lesions were included between March 2013 and October 2015, and all the lesions were identified on CEMRI/CECT prior to inclusion in the study. Planning ultrasound for percutaneous RFA was performed using conventional ultrasound, ultrasound-CECT/CEMRI and CEUS and CECT/CEMRI fusion imaging during the same session. The numbers of the conspicuous lesions on ultrasound and fusion imaging were recorded. RFA was performed according to the results of fusion imaging. Complete response (CR) rate was calculated and the complications were recorded. On conventional ultrasound, 25 (35.7%) of the 70 lesions were conspicuous, whereas 45 (64.3%) were inconspicuous. Ultrasound-CECT/CEMRI fusion imaging detected additional 24 lesions thus increased the number of the conspicuous lesions to 49 (70.0%) (70.0% vs 35.7%; p < 0.001 in comparison with conventional ultrasound). With the use of CEUS and CECT/CEMRI fusion imaging, the number of the conspicuous lesions further increased to 67 (95.7%, 67/70) (95.7% vs 70.0%, 95.7% vs 35.7%; both p < 0.001 in comparison with ultrasound and ultrasound-CECT/CEMRI fusion imaging, respectively). With the assistance of CEUS and CECT/CEMRI fusion imaging, the confidence level of the operator for performing RFA improved significantly with regard to visualization of the target lesions (p = 0.001). The CR rate for RFA was 97.0% (64/66) in accordance to the CECT/CEMRI results 1 month later. No procedure-related deaths and major complications occurred during and after RFA. Fusion of CEUS and CECT/CEMRI improves the visualization of those inconspicuous lesions on conventional ultrasound. It also facilitates improvement in the RFA operators' confidence and CR of RFA. Advances in knowledge: CEUS and CECT/CEMRI fusion imaging

Fusion imaging of contrast-enhanced ultrasound and contrast-enhanced CT or MRI before radiofrequency ablation for liver cancers

PubMed Central

Bo, Xiao-Wan; Wang, Dan; Guo, Le-Hang; Sun, Li-Ping; Li, Xiao-Long; Zhao, Chong-Ke; He, Ya-Ping; Liu, Bo-Ji; Li, Dan-Dan; Zhang, Kun

2016-01-01

Objective: To investigate the usefulness of fusion imaging of contrast-enhanced ultrasound (CEUS) and CECT/CEMRI before percutaneous ultrasound-guided radiofrequency ablation (RFA) for liver cancers. Methods: 45 consecutive patients with 70 liver lesions were included between March 2013 and October 2015, and all the lesions were identified on CEMRI/CECT prior to inclusion in the study. Planning ultrasound for percutaneous RFA was performed using conventional ultrasound, ultrasound-CECT/CEMRI and CEUS and CECT/CEMRI fusion imaging during the same session. The numbers of the conspicuous lesions on ultrasound and fusion imaging were recorded. RFA was performed according to the results of fusion imaging. Complete response (CR) rate was calculated and the complications were recorded. Results: On conventional ultrasound, 25 (35.7%) of the 70 lesions were conspicuous, whereas 45 (64.3%) were inconspicuous. Ultrasound-CECT/CEMRI fusion imaging detected additional 24 lesions thus increased the number of the conspicuous lesions to 49 (70.0%) (70.0% vs 35.7%; p < 0.001 in comparison with conventional ultrasound). With the use of CEUS and CECT/CEMRI fusion imaging, the number of the conspicuous lesions further increased to 67 (95.7%, 67/70) (95.7% vs 70.0%, 95.7% vs 35.7%; both p < 0.001 in comparison with ultrasound and ultrasound-CECT/CEMRI fusion imaging, respectively). With the assistance of CEUS and CECT/CEMRI fusion imaging, the confidence level of the operator for performing RFA improved significantly with regard to visualization of the target lesions (p = 0.001). The CR rate for RFA was 97.0% (64/66) in accordance to the CECT/CEMRI results 1 month later. No procedure-related deaths and major complications occurred during and after RFA. Conclusion: Fusion of CEUS and CECT/CEMRI improves the visualization of those inconspicuous lesions on conventional ultrasound. It also facilitates improvement in the RFA operators' confidence and CR of RFA. Advances in

In-vivo ultrasound and photoacoustic image- guided photothermal cancer therapy using silica-coated gold nanorods.

PubMed

Kim, Seungsoo; Chen, Yun-Sheng; Luke, Geoffrey P; Emelianov, Stanislav Y

2014-05-01

In nanoparticle-augmented photothermal therapy, evaluating the delivery and spatial distribution of nanoparticles, followed by remote temperature mapping and monitoring, is essential to ensure the optimal therapeutic outcome. The utility of ultrasound and photoacoustic imaging to assist photothermal therapy has been previously demonstrated. Here, using a mouse xenograft tumor model, it is demonstrated in vivo that ultrasound-guided photoacoustic imaging can be used to plan the treatment and to guide the therapy. To evaluate nanoparticle delivery and spatial distribution, three-dimensional ultrasound and spectroscopic photoacoustic imaging of a mouse with a tumor was performed before and after intravenous injection of silica-coated gold nanorods. After injection and sufficient circulation of nanoparticles, photothermal therapy was performed for 5 min using an 808-nm continuous-wave laser. During the photothermal therapy, photoacoustic images were acquired continuously and used to measure the temperature changes within tissue. A heterogeneous distribution of temperature, which was spatially correlated with the measured distribution of nanoparticles, indicated that peak temperatures of 53°C were achieved in the tumor. An Arrhenius thermal damage model determined that this thermal deposition would result in significant cell death. The results of this study suggest that ultrasound and photoacoustic imaging can effectively guide photothermal therapy to achieve the desired thermal treatment.

Ultrasound-guided peripheral nerve blockade.

PubMed

Chin, Ki Jinn; Chan, Vincent

2008-10-01

The use of ultrasound for peripheral nerve blockade is becoming popular. Although the feasibility of ultrasound-guided nerve blockade is now clear, it is uncertain at this time whether it represents the new standard for regional anesthesia in terms of efficacy and safety. The ability to visualize nerve location, needle advancement, needle-nerve interaction, and local anesthetic spread makes ultrasound-guided nerve block an attractive option. Study results indicate that these advantages can improve the ease of block performance, block success rates, and complications. At the same time there is evidence that ultrasound-guided regional anesthesia is a unique skill in its own right, and that proficiency in it requires training and experience. Ultrasound is a valuable tool that is now available to the regional anesthesiologist, and it is fast becoming a standard part of practice. It promises to be of especial value to the less experienced practitioner. Ultrasound does not in itself, however, guarantee the efficacy and safety of peripheral nerve blockade. Proper training in its use is required and we can expect to see the development of formal standards and guidelines in this regard.

[Ultrasound-guided peripheral catheterization].

PubMed

Salleras-Duran, Laia; Fuentes-Pumarola, Concepció

2016-01-01

Peripheral catheterization is a technique that can be difficult in some patients. Some studies have recently described the use of ultrasound to guide the venous catheterization. To describe the success rate, time required, complications of ultrasound-guided peripheral venous catheterization. and patients and professionals satisfaction The search was performed in databases (Medline-PubMed, Cochrane Library, CINAHL and Cuiden Plus) for studies published about ultrasound-guided peripheral venous catheterization performed on patients that provided results on the success of the technique, complications, time used, patient satisfaction and the type of professional who performed the technique. A total of 21 studies were included. Most of them get a higher success rate 80% in the catheterization ecoguide and time it is not higher than the traditional technique. The Technical complications analyzed were arterial puncture rates and lower nerve 10%. In all studies measuring and comparing patient satisfaction in the art ecoguide is greater. Various professional groups perform the technique. The use of ultrasound for peripheral pipes has a high success rate, complications are rare and the time used is similar to that of the traditional technique. The technique of inserting catheters through ultrasound may be learned by any professional group performing venipuncture. Finally, it gets underscores the high patient satisfaction with the use of this technique. Copyright © 2015 Elsevier España, S.L.U. All rights reserved.

CEM43°C thermal dose thresholds: a potential guide for magnetic resonance radiofrequency exposure levels?

PubMed

van Rhoon, Gerard C; Samaras, Theodoros; Yarmolenko, Pavel S; Dewhirst, Mark W; Neufeld, Esra; Kuster, Niels

2013-08-01

To define thresholds of safe local temperature increases for MR equipment that exposes patients to radiofrequency fields of high intensities for long duration. These MR systems induce heterogeneous energy absorption patterns inside the body and can create localised hotspots with a risk of overheating. The MRI + EUREKA research consortium organised a "Thermal Workshop on RF Hotspots". The available literature on thresholds for thermal damage and the validity of the thermal dose (TD) model were discussed. The following global TD threshold guidelines for safe use of MR are proposed: 1. All persons: maximum local temperature of any tissue limited to 39 °C 2. Persons with compromised thermoregulation AND (a) Uncontrolled conditions: maximum local temperature limited to 39 °C (b) Controlled conditions: TD < 2 CEM43°C 3. Persons with uncompromised thermoregulation AND (a) Uncontrolled conditions: TD < 2 CEM43°C (b) Controlled conditions: TD < 9 CEM43°C The following definitions are applied: Controlled conditions A medical doctor or a dedicated trained person can respond instantly to heat-induced physiological stress Compromised thermoregulation All persons with impaired systemic or reduced local thermoregulation • Standard MRI can cause local heating by radiofrequency absorption. • Monitoring thermal dose (in units of CEM43°C) can control risk during MRI. • 9 CEM43°C seems an acceptable thermal dose threshold for most patients. • For skin, muscle, fat and bone,16 CEM43°C is likely acceptable.

High-Intensity Focused Ultrasound: Current Status for Image-Guided Therapy

PubMed Central

Copelan, Alexander; Hartman, Jason; Chehab, Monzer; Venkatesan, Aradhana M.

2015-01-01

Image-guided high-intensity focused ultrasound (HIFU) is an innovative therapeutic technology, permitting extracorporeal or endocavitary delivery of targeted thermal ablation while minimizing injury to the surrounding structures. While ultrasound-guided HIFU was the original image-guided system, MR-guided HIFU has many inherent advantages, including superior depiction of anatomic detail and superb real-time thermometry during thermoablation sessions, and it has recently demonstrated promising results in the treatment of both benign and malignant tumors. HIFU has been employed in the management of prostate cancer, hepatocellular carcinoma, uterine leiomyomas, and breast tumors, and has been associated with success in limited studies for palliative pain management in pancreatic cancer and bone tumors. Nonthermal HIFU bioeffects, including immune system modulation and targeted drug/gene therapy, are currently being explored in the preclinical realm, with an emphasis on leveraging these therapeutic effects in the care of the oncology patient. Although still in its early stages, the wide spectrum of therapeutic capabilities of HIFU offers great potential in the field of image-guided oncologic therapy. PMID:26622104

Biothermal modeling of transurethral ultrasound applicators for MR-guided prostate thermal therapy (Invited Paper)

NASA Astrophysics Data System (ADS)

Ross, Anthony B.; Diederich, Chris J.; Nau, William H.; Tyreus, Per D.; Gill, Harcharan; Bouley, Donna; Butts, R. K.; Rieke, Viola; Daniel, Bruce; Sommer, Graham

2005-04-01

Thermal ablation is a minimally-invasive treatment option for benign prostatic hyperplasia (BPH) and localized prostate cancer. Accurate spatial control of thermal dose delivery is paramount to improving thermal therapy efficacy and avoiding post-treatment complications. We have recently developed three types of transurethral ultrasound applicators, each with different degrees of heating selectivity. These applicators have been evaluated in vivo in coordination with magnetic resonance temperature imaging, and demonstrated to accurately ablate specific regions of the canine prostate. A finite difference biothermal model of the three types of transurethral ultrasound applicators (sectored tubular, planar, and curvilinear transducer sections) was developed and used to further study the performance and heating capabilities of each these devices. The biothermal model is based on the Pennes bioheat equation. The acoustic power deposition pattern corresponding to each applicator type was calculated using the rectangular radiator approximation to the Raleigh Sommerfield diffraction integral. In this study, temperature and thermal dose profiles were calculated for different treatment schemes and target volumes, including single shot and angular scanning procedures. This study also demonstrated the ability of the applicators to conform the cytotoxic thermal dose distribution to a predefined target area. Simulated thermal profiles corresponded well with MR temperature images from previous in vivo experiments. Biothermal simulations presented in this study reinforce the potential of improved efficacy of transurethral ultrasound thermal therapy of prostatic disease.

Technique for CT Fluoroscopy-Guided Lumbar Medial Branch Blocks and Radiofrequency Ablation.

PubMed

Amrhein, Timothy J; Joshi, Anand B; Kranz, Peter G

2016-09-01

The purpose of this study is to describe the procedure for CT fluoroscopy-guided lumbar medial branch blocks and facet radiofrequency ablation. CT fluoroscopic guidance allows more-precise needle tip positioning and is an alternative method for performing medial branch blocks and facet radiofrequency ablation.

Ultrasound-Guided Renal Access for Percutaneous Nephrolithotomy: A Description of Three Novel Ultrasound-Guided Needle Techniques

PubMed Central

Chu, Carissa; Masic, Selma; Usawachintachit, Manint; Hu, Weiguo; Yang, Wenzeng; Stoller, Marshall; Li, Jianxing

2016-01-01

Abstract Ultrasound-guided renal access for percutaneous nephrolithotomy (PCNL) is a safe, effective, and low-cost procedure commonly performed worldwide, but a technique underutilized by urologists in the United States. The purpose of this article is to familiarize the practicing urologist with methods for ultrasound guidance for percutaneous renal access. We discuss two alternative techniques for gaining renal access for PCNL under ultrasound guidance. We also describe a novel technique of using the puncture needle to reposition residual stone fragments to avoid additional tract dilation. With appropriate training, ultrasound-guided renal access for PCNL can lead to reduced radiation exposure, accurate renal access, and excellent stone-free success rates and clinical outcomes. PMID:26414304

Update on Clinical MR-guided Focused Ultrasound Applications

PubMed Central

McDannold, Nathan

2015-01-01

SYNOPSIS Focused ultrasound (FUS) can be used to thermally ablate tissue. The performance of FUS under magnetic resonance (MR) guidance enables aiming the focus at the target, accurate treatment planning, real-time temperature mapping, and evaluation of the treatment. This review updates several clinical applications of MR-guided FUS. MR-guided FUS has a CE mark and FDA approval for thermal ablation for uterine fibroids and bone metastases related pain management. Thousands of uterine fibroid patients have successfully been treated with minor side effects. Technical improvements, increased experience, and the use of a screening MRI examination should further improve treatment outcome. When used for bone metastases and other bone diseases, thermal ablation leads to pain relief due to denervation, and debulking of the tumor. The use of a hemi-spherical multi-element transducer and phase corrections have enabled application of FUS through the skull. Transcranial MR-guided FUS has received CE certification for ablation of deep, central locations in the brain such as the thalamus. Thermal ablation of specific parts of the thalamus can result in relief of the symptoms in neurological disorders such as essential tremor, Parkinson’s, and neuropathic pain. No CE mark or FDA approval has been obtained as yet for treatment of prostate cancer or breast cancer, but several approaches have been proposed and clinical trials should show the potential of MR-guided FUS for these and other applications. PMID:26499282

The advent of ultrasound-guided ablation techniques in nodular thyroid disease: towards a patient-tailored approach.

PubMed

Papini, Enrico; Pacella, Claudio M; Misischi, Irene; Guglielmi, Rinaldo; Bizzarri, Giancarlo; Døssing, Helle; Hegedus, Laszlo

2014-08-01

Surgery is the long-established therapeutic option for benign thyroid nodules, which steadily grow and become symptomatic. The cost of thyroid surgery, the risk of temporary or permanent complications, and the effect on quality of life, however, remain relevant concerns. Therefore, various minimally invasive treatments, directed towards office-based management of symptomatic nodules, without requiring general anaesthesia, and with negligible damage to the skin and cervical tissues, have been proposed during the past two decades. Today, ultrasound-guided percutaneous ethanol injection and thermal ablation with laser or radiofrequency have been thoroughly evaluated, and are accessible procedures in specialized centres. In clinical practice, relapsing thyroid cysts are effectively managed with percutaneous ethanol injection treatment, which should be considered therapy of choice. In solid non-functioning thyroid nodules that grow or become symptomatic, trained operators may safely induce, with a single session of laser ablation treatment or radiofrequency ablation, a 50% volume decrease and, in parallel, improve local symptoms. In contrast, hyperfunctioning nodules remain best treated with radioactive iodine, which results in a better control of hyperthyroidism, also in the long-term, and fewer side-effects. Currently, minimally invasive treatment is also investigated for achieving local control of small size neck recurrences of papillary thyroid carcinoma in patients who are poor candidates for repeat cervical lymph node dissection. This particular use should still be considered experimental. Copyright © 2014 Elsevier Ltd. All rights reserved.

Image-guided radiofrequency ablation of spinal tumors: preliminary experience with an expandable array electrode.

PubMed

Grönemeyer, Dietrich H W; Schirp, Sven; Gevargez, Athour

2002-01-01

Metastases to the spine are a challenging problem. Percutaneous, image-guided tumor ablation with a thermal energy source, such as radiofrequency, has received increasing attention as a promising technique for the treatment of focal malignant disease. We used radiofrequency ablation for patients with unresectable, osteolytic spine metastases under computed tomographic and fluoroscopic guidance. The purpose of this study was to determine the feasibility, effectiveness, and safety of radiofrequency ablation as a palliative procedure to reduce pain and back pain-related disability in patients with vertebral and paravertebral spine tumors who were not able to benefit from radiotherapy, chemotherapy, or surgery. Between November 1999 and January 2001, 10 patients with unresectable spine metastases were treated with radiofrequency ablation. For the ablation we used a 50-W radiofrequency generator that is connected to an expandable electrode catheter (RITA Medical System Inc., Mountain View, CA). The mean patient age was 64.4 years. Metastases were ablated in the thoracic spine, the lumbar spine, and/or the sacral bone. Tumor diameter ranged from 1.5 to 9 cm. Combined computed tomographic and fluoroscopic guidance was used to guide the procedure. Operations were carried out without heavy sedation with the patient under local anesthesia only. The thermal lesion was produced by applying temperatures of 50 degrees to 120 degrees C for 8-12 minutes. Vertebroplasty was performed in four patients by use of 3 to 5.5 mL of polymethyl methacrylate. Therapy outcome was documented by magnet resonance imaging. Before the therapy and on follow-up of an average of 5.8 months, pain was assessed with the help of the Visual Analogue Scale. Back pain-related disability was measured with the Hannover Functional Ability Questionnaire. Neurologic and health status were documented on the Frankel score and the Karnofsky index. At follow-up, 9 of 10 patients reported reduced pain (Visual

Are ultrasound-guided ophthalmic blocks injurious to the eye? A comparative rabbit model study of two ultrasound devices evaluating intraorbital thermal and structural changes.

PubMed

Palte, Howard D; Gayer, Steven; Arrieta, Esdras; Scot Shaw, Eric; Nose, Izuru; Lee, Elizabete; Arheart, Kristopher L; Dubovy, Sander; Birnbach, David J; Parel, Jean-Marie

2012-07-01

Since Atkinson's original description of retrobulbar block in 1936, needle-based anesthetic techniques have become integral to ophthalmic anesthesia. These techniques are unfortunately associated with rare, grave complications such as globe perforation. Ultrasound has gained widespread acceptance for peripheral nerve blockade, but its translation to ocular anesthesia has been hampered because sonic energy, in the guise of thermal or biomechanical insult, is potentially injurious to vulnerable eye tissue. The US Food and Drug Administration (FDA) has defined guidelines for safe use of ultrasound for ophthalmic examination, but most ultrasound devices used by anesthesiologists are not FDA-approved for ocular application because they generate excessive energy. Regulating agencies state that ultrasound examinations can be safely undertaken as long as tissue temperatures do not increase >1.5°C above physiological levels. Using a rabbit model, we investigated the thermal and mechanical ocular effects after prolonged ultrasonic exposure to single orbital- and nonorbital-rated devices. In a dual-phase study, aimed at detecting ocular injury, the eyes of 8 rabbits were exposed to continuous 10-minute ultrasound examinations from 2 devices: (1) the Sonosite Micromaxx (nonorbital rated) and (2) the Sonomed VuMax (orbital rated) machines. In phase I, temperatures were continuously monitored via thermocouples implanted within specific eye structures (n = 4). In phase II the eyes were subjected to ultrasonic exposure without surgical intervention (n = 4). All eyes underwent light microscopy examinations, followed at different intervals by histology evaluations conducted by an ophthalmic pathologist. Temperature changes were monitored in the eyes of 4 rabbits. The nonorbital-rated transducer produced increases in ocular tissue temperature that surpassed the safe limit (increases >1.5°C) in the lens of 3 rabbits (at 5.0, 5.5, and 1.5 minutes) and cornea of 2 rabbits (both at 1

Acoustic radiation force impulse imaging for real-time observation of lesion development during radiofrequency ablation procedures

NASA Astrophysics Data System (ADS)

Fahey, Brian J.; Trahey, Gregg E.

2005-04-01

When performing radiofrequency ablation (RFA) procedures, physicians currently have little or no feedback concerning the success of the treatment until follow-up assessments are made days to weeks later. To be successful, RFA must induce a thermal lesion of sufficient volume to completely destroy a target tumor or completely isolate an aberrant cardiac pathway. Although ultrasound, computed tomography (CT), and CT-based fluoroscopy have found use in guiding RFA treatments, they are deficient in giving accurate assessments of lesion size or boundaries during procedures. As induced thermal lesion size can vary considerably from patient to patient, the current lack of real-time feedback during RFA procedures is troublesome. We have developed a technique for real-time monitoring of thermal lesion size during RFA procedures utilizing acoustic radiation force impulse (ARFI) imaging. In both ex vivo and in vivo tissues, ARFI imaging provided better thermal lesion contrast and better overall appreciation for lesion size and boundaries relative to conventional sonography. The thermal safety of ARFI imaging for use at clinically realistic depths was also verified through the use of finite element method models. As ARFI imaging is implemented entirely on a diagnostic ultrasound scanner, it is a convenient, inexpensive, and promising modality for monitoring RFA procedures in vivo.

Assistive technology for ultrasound-guided central venous catheter placement.

PubMed

Ikhsan, Mohammad; Tan, Kok Kiong; Putra, Andi Sudjana

2018-01-01

This study evaluated the existing technology used to improve the safety and ease of ultrasound-guided central venous catheterization. Electronic database searches were conducted in Scopus, IEEE, Google Patents, and relevant conference databases (SPIE, MICCAI, and IEEE conferences) for related articles on assistive technology for ultrasound-guided central venous catheterization. A total of 89 articles were examined and pointed to several fields that are currently the focus of improvements to ultrasound-guided procedures. These include improving needle visualization, needle guides and localization technology, image processing algorithms to enhance and segment important features within the ultrasound image, robotic assistance using probe-mounted manipulators, and improving procedure ergonomics through in situ projections of important information. Probe-mounted robotic manipulators provide a promising avenue for assistive technology developed for freehand ultrasound-guided percutaneous procedures. However, there is currently a lack of clinical trials to validate the effectiveness of these devices.

Ultrasound-guided high-intensity focused ultrasound ablation for treating uterine arteriovenous malformation.

PubMed

Yan, X; Zhao, C; Tian, C; Wen, S; He, X; Zhou, Y

2017-08-01

To explore HIFU treatment for uterine arteriovenous malformation. A case report. Gynaecological department in a university teaching hospital of China. A patient with uterine arteriovenous malformation. The diagnosis of uterine arteriovenous malformation was made through MRI. Ultrasound-guided high-intensity focused ultrasound (USgHIFU) ablation was performed. HIFU is effective in treating uterine arteriovenous malformation. The patient had reduction of the lesion volume and obvious symptom relief, without significant adverse effects. HIFU can be used as a new treatment option for uterine arteriovenous malformation. Ultrasound-guided high-intensity focused ultrasound ablation is effective in treating uterine arteriovenous malformation. © 2017 Royal College of Obstetricians and Gynaecologists.

Highly directional transurethral ultrasound applicators with rotational control for MRI-guided prostatic thermal therapy

NASA Astrophysics Data System (ADS)

Ross, Anthony B.; Diederich, Chris J.; Nau, William H.; Gill, Harcharan; Bouley, Donna M.; Daniel, Bruce; Rieke, Viola; Butts, R. Kim; Sommer, Graham

2004-01-01

Transurethral ultrasound applicators with highly directional energy deposition and rotational control were investigated for precise treatment of benign prostatic hyperplasia (BPH) and adenocarcinoma of the prostate (CaP). Two types of catheter-based applicators were fabricated, using either 90° sectored tubular (3.5 mm OD × 10 mm) or planar transducers (3.5 mm × 10 mm). They were constructed to be MRI compatible, minimally invasive and allow for manual rotation of the transducer array within a 10 mm cooling balloon. In vivo evaluations of the applicators were performed in canine prostates (n = 3) using MRI guidance (0.5 T interventional magnet). MR temperature imaging (MRTI) utilizing the proton resonance frequency shift method was used to acquire multiple-slice temperature overlays in real time for monitoring and guiding the thermal treatments. Post-treatment T1-weighted contrast-enhanced imaging and triphenyl tetrazolium chloride stained tissue sections were used to define regions of tissue coagulation. Single sonications with the 90° tubular applicator (9-15 W, 12 min, 8 MHz) produced coagulated zones covering an 80° wedge of the prostate extending from 1-2 mm outside the urethra to the outer boundary of the gland (16 mm radial coagulation). Single sonications with the planar applicator (15-20 W, 10 min, ~8 MHz) generated thermal lesions of ~30° extending to the prostate boundary. Multiple sequential sonications (sweeping) of a planar applicator (12 W with eight rotations of 30° each) demonstrated controllable coagulation of a 270° contiguous section of the prostate extending to the capsule boundary. The feasibility of using highly directional transurethral ultrasound applicators with rotational capabilities to selectively coagulate regions of the prostate while monitoring and controlling the treatments with MRTI was demonstrated in this study.

Standard B-Mode Ultrasound Measures Local Carotid Artery Characteristics as Reliably as Radiofrequency Phase Tracking in Symptomatic Carotid Artery Patients.

PubMed

Steinbuch, Jeire; Hoeks, Arnold P G; Hermeling, Evelien; Truijman, Martine T B; Schreuder, Floris H B M; Mess, Werner H

2016-02-01

Local arterial stiffness can be assessed with high accuracy and precision by measuring arterial distension on the basis of phase tracking of radiofrequency ultrasound signals acquired at a high frame rate. However, in clinical practice, B-mode ultrasound registrations are made at a low frame rate (20-50 Hz). We compared the accuracy and intra-subject precision of edge tracking and phase tracking distension in symptomatic carotid artery patients. B-mode ultrasound recordings (40 mm, 37 fps) and radiofrequency recordings (31 lines covering 29 mm, 300 fps) were acquired from the left common carotid artery of 30 patients (aged 45-88 y) with recent cerebrovascular events. To extract the distension, semi-automatic echo edge and phase tracking algorithms were applied to B-mode and radiofrequency recordings, respectively. Both methods exhibited a similar intra-subject precision for distension (standard deviation = 44 μm and 47 μm, p = 0.66) and mean distension (difference: -6 ± 69 μm, p = 0.67). Intra-subject distension inhomogeneity tends to be larger for edge tracking (difference: 15 ± 35 μm, p = 0.04). Standard B-mode scanners are suitable for measuring local artery characteristics in symptomatic carotid artery patients with good precision and accuracy. Copyright © 2016 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Endoscopic ultrasound-guided biliary drainage

PubMed Central

Chavalitdhamrong, Disaya; Draganov, Peter V

2012-01-01

Endoscopic ultrasound (EUS)-guided biliary drainage has emerged as a minimally invasive alternative to percutaneous and surgical interventions for patients with biliary obstruction who had failed endoscopic retrograde cholangiopancreatography (ERCP). EUS-guided biliary drainage has become feasible due to the development of large channel curvilinear therapeutic echo-endoscopes and the use of real-time ultrasound and fluoroscopy imaging in addition to standard ERCP devices and techniques. EUS-guided biliary drainage is an attractive option because of its minimally invasive, single step procedure which provides internal biliary decompression. Multiple investigators have reported high success and low complication rates. Unfortunately, high quality prospective data are still lacking. We provide detailed review of the use of EUS for biliary drainage from the perspective of practicing endoscopists with specific focus on the technical aspects of the procedure. PMID:22363114

Determination of lesion size by ultrasound during radiofrequency catheter ablation.

PubMed

Awad, S; Eick, O

2003-01-01

The catheter tip temperature that is used to control the radiofrequency generator output poorly correlates to lesion size. We, therefore, evaluated lesions created in vitro using a B-mode ultrasound imaging device as a potential means to assess lesion generation during RF applications non-invasively. Porcine ventricular tissue was immersed in saline solution at 37 degrees C. The catheter was fixed in a holder and positioned in a parallel orientation to the tissue with an array transducer (7.5 MHz) app. 3 cm above the tissue. Lesions were produced either in a temperature controlled mode with a 4-mm tip catheter with different target temperatures (50, 60, 70 and 80 degrees C, 80 W maximum output) or in a power controlled mode (25, 50 and 75 W, 20 ml/min irrigation flow) using an irrigated tip catheter. Different contact forces (0.5 N, 1.0 N) were tested, and RF was delivered for 60 s. A total of 138 lesions was produced. Out of these, 128 could be identified on the ultrasound image. The lesion depth and volume was on average 4.1 +/- 1.6 mm and 52 +/- 53 mm3 as determined by ultrasound and 3.9 +/- 1.7 mm and 52 +/- 55 mm3 as measured thereafter, respectively. A linear correlation between the lesion size determined by ultrasound and that measured thereafter was demonstrated with a correlation coefficient of r = 0.87 for lesion depth and r = 0.93 for lesion volume. We conclude that lesions can be assessed by B-mode ultrasound imaging.

MRI-Guided Focused Ultrasound Surgery

PubMed Central

Jolesz, Ferenc A.

2014-01-01

MRI-guided focused ultrasound (MRgFUS) surgery is a noninvasive thermal ablation method that uses magnetic resonance imaging (MRI) for target definition, treatment planning, and closed-loop control of energy deposition. Integrating FUS and MRI as a therapy delivery system allows us to localize, target, and monitor in real time, and thus to ablate targeted tissue without damaging normal structures. This precision makes MRgFUS an attractive alternative to surgical resection or radiation therapy of benign and malignant tumors. Already approved for the treatment of uterine fibroids, MRgFUS is in ongoing clinical trials for the treatment of breast, liver, prostate, and brain cancer and for the palliation of pain in bone metastasis. In addition to thermal ablation, FUS, with or without the use of microbubbles, can temporarily change vascular or cell membrane permeability and release or activate various compounds for targeted drug delivery or gene therapy. A disruptive technology, MRgFUS provides new therapeutic approaches and may cause major changes in patient management and several medical disciplines. PMID:19630579

Theoretical Analysis of the Accuracy and Safety of MRI-Guided Transurethral 3-D Conformal Ultrasound Prostate Therapy

NASA Astrophysics Data System (ADS)

Burtnyk, Mathieu; Chopra, Rajiv; Bronskill, Michael

2009-04-01

MRI-guided transurethral ultrasound therapy is a promising new approach for the treatment of localized prostate cancer. Several studies have demonstrated the feasibility of producing large regions of thermal coagulation adequate for prostate therapy; however, the quantitative assessment of shaping these regions to complex 3-D human prostate geometries has not been fully explored. This study used numerical simulations and twenty manually-segmented pelvic anatomical models derived from high-quality MR images of prostate cancer patients to evaluate the treatment accuracy and safety of 3-D conformal MRI-guided transurethral ultrasound therapy. The simulations incorporated a rotating multi-element planar dual-frequency ultrasound transducer (seventeen 4×3 mm elements) operating at 4.7/9.7 MHz and 10 W/cm2 maximum acoustic power. Results using a novel feedback control algorithm which modulated the ultrasound frequency, power and device rate of rotation showed that regions of thermal coagulation could be shaped to predefined prostate volumes within 1.0 mm across the vast majority of these glands. Treatment times were typically 30 min and remained below 60 min for large 60 cc prostates. With a rectal cooling temperature of 15° C, the rectal wall did not exceed 30EM43 in half of the twenty patient models with only a few 1 mm3 voxels above this threshold in the other cases. At 4.7 MHz, heating of the pelvic bone can become significant when it is located less than 10 mm from the prostate. Numerical simulations show that MRI-guided transurethral ultrasound therapy can thermally coagulate whole prostate glands accurately and safely in 3-D.

Considering Angle Selection When Using Ultrasound Electrode Displacement Elastography to Evaluate Radiofrequency Ablation of Tissues

PubMed Central

Li, Qiang; Chen, Pin-Yu; Wang, Chiao-Yin; Liu, Hao-Li; Teng, Jianfu

2014-01-01

Percutaneous radiofrequency ablation (RFA) is a minimally invasive treatment to thermally destroy tumors. Ultrasound-based electrode-displacement elastography is an emerging technique for evaluating the region of RFA-induced lesions. The angle between the imaging probe and the RFA electrode can influence electrode-displacement elastography when visualizing the ablation zone. We explored the angle effect on electrode-displacement elastography to measure the ablation zone. Phantoms embedded with meatballs were fabricated and then ablated using an RFA system to simulate RFA-induced lesions. For each phantom, a commercial ultrasound scanner with a 7.5 MHz linear probe was used to acquire raw image data at different angles, ranging from 30° to 90° at increments of 10°, to construct electrode-displacement images and facilitate comparisons with tissue section images. The results revealed that the ablation regions detected using electrode-displacement elastography were highly correlated with those from tissue section images when the angle was between 30° and 60°. However, the boundaries of lesions were difficult to distinguish, when the angle was larger than 60°. The experimental findings suggest that angle selection should be considered to achieve reliable electrode-displacement elastography to describe ablation zones. PMID:24971347

Transcervical, intrauterine ultrasound-guided radiofrequency ablation of uterine fibroids with the VizAblate® System: three- and six-month endpoint results from the FAST-EU study.

PubMed

Bongers, Marlies; Brölmann, Hans; Gupta, Janesh; Garza-Leal, José Gerardo; Toub, David

This was a prospective, longitudinal, multicenter, single-arm controlled trial, using independent core laboratory validation of MRI results, to establish the effectiveness and confirm the safety of the VizAblate® System in the treatment of symptomatic uterine fibroids. The VizAblate System is a transcervical device that ablates fibroids with radiofrequency energy, guided by a built-in intrauterine ultrasound probe. Fifty consecutive women with symptomatic uterine fibroids received treatment with the VizAblate System. Patients had a minimum Menstrual Pictogram score of 120, no desire for fertility, and met additional inclusion and exclusion criteria. The VizAblate System was inserted transcervically and individual fibroids were ablated with radiofrequency energy. An integrated intrauterine ultrasound probe was used for fibroid imaging and targeting. Anesthesia was at the discretion of each investigator. The primary study endpoint was the percentage change in perfused fibroid volume, as assessed by contrast-enhanced MRI at 3 months. Secondary endpoints, reached at 6 months, included safety, percentage reductions in the Menstrual Pictogram (MP) score and the Symptom Severity Score (SSS) subscale of the Uterine Fibroid Symptom-Quality of Life questionnaire (UFS-QOL), along with the rate of surgical reintervention for abnormal uterine bleeding and the mean number of days to return to normal activity. Additional assessments included the Health-Related Quality of Life (HRQOL) subscale of the UFS-QOL, medical reintervention for abnormal uterine bleeding, and procedure times. Fifty patients were treated, representing 92 fibroids. Perfused fibroid volumes were reduced at 3 months by an average of 68.8 ± 27.8 % ( P  < 0.0001; Wilcoxon signed-rank test). At 6 months, mean MP and SSS scores decreased by 60.8 ± 38.2 and 59.7 ± 30.4 %, respectively; the mean HRQOL score increased by 263 ± 468 %. There were two serious adverse events (overnight

Outcomes of ultrasound guided renal mass biopsies.

PubMed

Sutherland, Edward L; Choromanska, Agnieszka; Al-Katib, Sayf; Coffey, Mary

2018-06-01

The purpose of this study was to evaluate the rate of nondiagnostic ultrasound-guided renal mass biopsies (RMBs) at our institution and to determine what patient, procedural, and focal renal mass (FRM) factors were associated with nondiagnostic ultrasound-guided RMBs. Eighty-two ultrasound-guided renal mass biopsies performed between January 2014 and October 2016 were included in our study. Biopsy outcomes (diagnostic vs. nondiagnostic) and patient, procedural, and FRM characteristics were retrospectively reviewed and recorded. Univariate statistical analyses were performed to identify biopsy characteristics that were indicative of nondiagnostic biopsy. Ultrasound-guided RMBs were diagnostic in 70 out of 82 cases (85%) and non-diagnostic in 12 cases (15%). Among the diagnostic biopsies, 54 (77%) were malignant cases, 94% of which were renal cell carcinoma (RCC). Of the 12 nondiagnostic cases, the final diagnosis was RCC in 4 cases and angiomyolipoma in one case; seven of the nondiagnostic cases were lost to follow-up. A weak association (p = 0.04) was found between the number of needle passes and the biopsy outcome. None of the remaining collected RMB characteristics showed a significant correlation with a diagnostic or nondiagnostic RMB. Six patients (7%) experienced complications. Ultrasound-guided renal mass biopsy is a safe and effective method for the diagnosis of renal masses with a low rate of nondiagnostic outcomes. A nondiagnostic biopsy should not be treated as a surrogate for a diagnosis since a significant number of patients with nondiagnostic biopsies have subsequently been shown to have renal malignancies. Repeat biopsy should be considered in such cases.

Ultrasound-Guided Fine Needle Aspiration Biopsy of the Thyroid

MedlinePlus

... News Physician Resources Professions Site Index A-Z Ultrasound-Guided Fine Needle Aspiration Biopsy of the Thyroid ... Needle Aspiration Biopsy of the Thyroid? What is Ultrasound-Guided Fine Needle Aspiration Biopsy of the Thyroid? ...

Hybrid laparoscopic and robotic ultrasound-guided radiofrequency ablation-assisted clampless partial nephrectomy.

PubMed

Nadler, Robert B; Perry, Kent T; Smith, Norm D

2009-07-01

To describe a clampless approach made possible by creating an avascular plane of tissue with radiofrequency ablation. Laparoscopic partial nephrectomy is slowly gaining acceptance as a method to treat small (<4 cm) and select moderate (<7 cm) renal masses. The intricacies of laparoscopic suturing, which result in prolonged warm ischemia times, have delayed the widespread acceptance of this technique among urologists. Laparoscopic suturing to close the collecting system was done using the da Vinci robot. An avascular plane of tissue from coagulation necrosis was achieved with the Habib 4X radiofrequency ablation device and the Rita 1500X generator. Typically, we used a power setting of 50 W but have found settings as low as 25 W necessary to provide hemostasis for larger vessels. The tumor was then sharply excised with a negative margin using robotic scissors and electrocautery to facilitate tissue cutting. Retrograde injection of methylthioninium chloride and saline through an externalized ureteral catheter allowed for precise sutured closure of the collecting system. FloSeal and BioGlue were then applied, making surgical bolsters or parenchymal sutures unnecessary. Intraoperative histologic evaluation of the surgical margin and repeat resection of the tumor bed was possible because the renal hilum was not clamped, and no warm ischemia was used. This technique, which combines the improving technologies of robotic surgery, intraoperative laparoscopic ultrasonography, and radiofrequency ablation, might make more surgeons comfortable with the intricacies of laparoscopic suturing and eliminate prolonged warm ischemia times. Overall, this method should result in more patients being able to undergo minimally invasive laparoscopic partial nephrectomy.

Feasibility of MRI-guided Focused Ultrasound as Organ-Sparing Treatment for Testicular Cancer

NASA Astrophysics Data System (ADS)

Staruch, Robert; Curiel, Laura; Chopra, Rajiv; Hynynen, Kullervo

2009-04-01

High cure rates for testicular cancer have prompted interest in organ-sparing surgery for patients with bilateral disease or single testis. Focused ultrasound (FUS) ablation could offer a noninvasive approach to organ-sparing surgery. The objective of this study was to determine the feasibility of using MR thermometry to guide organ-sparing focused ultrasound surgery in the testis. The testes of anesthetized rabbits were sonicated in several discrete locations using a single-element focused transducer operating at 2.787MHz. Focal heating was visualized with MR thermometry, using a measured PRF thermal coefficient of -0.0089±0.0003 ppm/° C. Sonications at 3.5-14 acoustic watts applied for 30 seconds produced maximum temperature elevations of 10-80° C, with coagulation verified by histology. Coagulation of precise volumes in the testicle is feasible with MRI-guided focused ultrasound. Variability in peak temperature for given sonication parameters suggests the need for online temperature feedback control.

Experimental investigations of an endoluminal ultrasound applicator for MR-guided thermal therapy of pancreatic cancer

NASA Astrophysics Data System (ADS)

Adams, Matthew; Salgaonkar, Vasant; Jones, Peter; Plata, Juan; Chen, Henry; Pauly, Kim Butts; Sommer, Graham; Diederich, Chris

2017-03-01

An MR-guided endoluminal ultrasound applicator has been proposed for palliative and potential curative thermal therapy of pancreatic tumors. Minimally invasive ablation or hyperthermia treatment of pancreatic tumor tissue would be performed with the applicator positioned in the gastrointestinal (GI) lumen, and sparing of the luminal tissue would be achieved with a water-cooled balloon surrounding the ultrasound transducers. This approach offers the capability of conformal volumetric therapy for fast treatment times, with control over the 3D spatial deposition of energy. Prototype endoluminal ultrasound applicators have been fabricated using 3D printed fixtures that seat two 3.2 or 5.6 MHz planar or curvilinear transducers and contain channels for wiring and water flow. Spiral surface coils have been integrated onto the applicator body to allow for device localization and tracking for therapies performed under MR guidance. Heating experiments with a tissue-mimicking phantom in a 3T MR scanner were performed and demonstrated capability of the prototype to perform volumetric heating through duodenal luminal tissue under real-time PRF-based MR temperature imaging (MRTI). Additional experiments were performed in ex vivo pig carcasses with the applicator inserted into the esophagus and aimed towards liver or soft tissue surrounding the spine under MR guidance. These experiments verified the capacity of heating targets up to 20-25 mm from the GI tract. Active device tracking and automated prescription of imaging and temperature monitoring planes through the applicator were made possible by using Hadamard encoded tracking sequences to obtain the coordinates of the applicator tracking coils. The prototype applicators have been integrated with an MR software suite that performs real-time device tracking and temperature monitoring.

Radiofrequency Thermal Ablation Heat Energy Transfer in an Ex-Vivo Model.

PubMed

Thakur, Shivani; Lavito, Sandi; Grobner, Elizabeth; Grobner, Mark

2017-12-01

Little work has been done to consider the temperature changes and energy transfer that occur in the tissue outside the vein with ultrasound-guided vein ablation therapy. In this experiment, a Ex-Vivo model of the human calf was used to analyze heat transfer and energy degradation in tissue surrounding the vein during endovascular radiofrequency ablation (RFA). A clinical vein ablation protocol was used to determine the tissue temperature distribution in 10 per cent agar gel. Heat energy from the radiofrequency catheter was measured for 140 seconds at fixed points by four thermometer probes placed equidistant radially at 0.0025, 0.005, and 0.01 m away from the RFA catheter. The temperature rose 1.5°C at 0.0025 m, 0.6°C at 0.005 m, and 0.0°C at 0.01 m from the RFA catheter. There was a clinically insignificant heat transfer at the distances evaluated, 1.4 ± 0.2 J/s at 0.0025 m, 0.7 ± 0.3 J/s at 0.0050 m, and 0.3 ± 0.0 J/s at 0.01 m. Heat degradation occurred rapidly: 4.5 ± 0.5 J (at 0.0025 m), 4.0 ± 1.6 J (at 0.0050 m), and 3.9 ± 3.6 J (at 0.01 m). Tumescent anesthesia injected one centimeter around the vein would act as a heat sink to absorb the energy transferred outside the vein to minimize tissue and nerve damage and will help phlebologists strategize options for minimizing damage.

Ultrasound-guided chest biopsies.

PubMed

Middleton, William D; Teefey, Sharlene A; Dahiya, Nirvikar

2006-12-01

Pulmonary nodules that are surrounded by aerated lung cannot be visualized with sonography. Therefore, percutaneous biopsy must be guided with computed tomography or fluoroscopy. Although this restriction only applies to central lung nodules, it has permeated referral patterns for other thoracic lesions and has retarded the growth of ultrasound-guided interventions. Nevertheless, sonography is an extremely flexible modality that can expeditiously guide many biopsy procedures in the thorax. Peripheral pulmonary nodules can be successfully biopsied with success rates exceeding 90% and complications rates of less than 5%. Orienting the probe parallel to the intercostal space facilitates biopsies of peripheral pulmonary nodules. Anterior mediastinal masses that extend to the parasternal region are often easily approachable provided the internal mammary vessels, costal cartilage, and deep great vessels are identified and avoided. Superior mediastinal masses can be sampled from a suprasternal or supraclavicular approach. Phased array probes or tightly curved arrays may provide improved access for biopsies in this location. Posterior mediastinal masses are more difficult to biopsy with ultrasound guidance because of the overlying paraspinal muscles. However, when posterior mediastinal masses extend into the posterior medial pleural region, they can be biopsied with ultrasound guidance. Because many lung cancers metastasize to the supraclavicular nodes, it is important to evaluate the supraclavicular region when determining the best approach to obtain a tissue diagnosis. When abnormal supraclavicular nodes are present, they often are the easiest and safest lesions to biopsy.

Ultrasound-Guided Single-Injection Infraclavicular Block Versus Ultrasound-Guided Double-Injection Axillary Block: A Noninferiority Randomized Controlled Trial.

PubMed

Boivin, Ariane; Nadeau, Marie-Josée; Dion, Nicolas; Lévesque, Simon; Nicole, Pierre C; Turgeon, Alexis F

2016-01-01

Single-injection ultrasound-guided infraclavicular block is a simple, reliable, and effective technique. A simplified double-injection ultrasound-guided axillary block technique with a high success rate recently has been described. It has the advantage of being performed in a superficial and compressible location, with a potentially improved safety profile. However, its effectiveness in comparison with single-injection infraclavicular block has not been established. We hypothesized that the double-injection ultrasound-guided axillary block would show rates of complete sensory block at 30 minutes noninferior to the single-injection ultrasound-guided infraclavicular block. After approval by our research ethics committee and written informed consent, adults undergoing distal upper arm surgery were randomized to either group I, ultrasound-guided single-injection infraclavicular block, or group A, ultrasound-guided double-injection axillary block. In group I, 30 mL of 1.5% mepivacaine was injected posterior to the axillary artery. In group A, 25 mL of 1.5% mepivacaine was injected posteromedial to the axillary artery, after which 5 mL was injected around the musculocutaneous nerve. Primary outcome was the rate of complete sensory block at 30 minutes. Secondary outcomes were the onset of sensory and motor blocks, surgical success rates, performance times, and incidence of complications. All outcomes were assessed by a blinded investigator. The noninferiority of the double-injection ultrasound-guided axillary block was considered if the limits of the 90% confidence intervals (CIs) were within a 10% margin of the rate of complete sensory block of the infraclavicular block. At 30 minutes, the rate of complete sensory block was 79% in group A (90% CI, 71%-85%) compared with 91% in group I (90% CI, 85%-95%); the upper limit of CI of group A is thus included in the established noninferiority margin of 10%. The rate of complete sensory block was lower in group A (proportion

PLUS: open-source toolkit for ultrasound-guided intervention systems.

PubMed

Lasso, Andras; Heffter, Tamas; Rankin, Adam; Pinter, Csaba; Ungi, Tamas; Fichtinger, Gabor

2014-10-01

A variety of advanced image analysis methods have been under the development for ultrasound-guided interventions. Unfortunately, the transition from an image analysis algorithm to clinical feasibility trials as part of an intervention system requires integration of many components, such as imaging and tracking devices, data processing algorithms, and visualization software. The objective of our paper is to provide a freely available open-source software platform-PLUS: Public software Library for Ultrasound-to facilitate rapid prototyping of ultrasound-guided intervention systems for translational clinical research. PLUS provides a variety of methods for interventional tool pose and ultrasound image acquisition from a wide range of tracking and imaging devices, spatial and temporal calibration, volume reconstruction, simulated image generation, and recording and live streaming of the acquired data. This paper introduces PLUS, explains its functionality and architecture, and presents typical uses and performance in ultrasound-guided intervention systems. PLUS fulfills the essential requirements for the development of ultrasound-guided intervention systems and it aspires to become a widely used translational research prototyping platform. PLUS is freely available as open source software under BSD license and can be downloaded from http://www.plustoolkit.org.

[Ultrasound guided percutaneous nephrolithotripsy].

PubMed

Guliev, B G

2014-01-01

The study was aimed to the evaluation of the effectiveness and results of ultrasound guided percutaneous nephrolithotripsy (PNL) for the treatment of patients with large stones in renal pelvis. The results of PNL in 138 patients who underwent surgery for kidney stones from 2011 to 2013 were analyzed. Seventy patients (Group 1) underwent surgery with combined ultrasound and radiological guidance, and 68 patients (Group 2)--only with ultrasound guidance. The study included patients with large renal pelvic stones larger than 2.2 cm, requiring the formation of a single laparoscopic approach. Using the comparative analysis, the timing of surgery, the number of intra- and postoperative complications, blood loss and length of stay were evaluated. Percutaneous access was successfully performed in all patients. Postoperative complications (exacerbation of chronic pyelonephritis, gross hematuria) were observed in 14.3% of patients in Group 1 and in 14.7% of patients in Group 2. Bleeding requiring blood transfusion, and injuries of adjacent organs were not registered. Efficacy of PNL in the Group 1 was 95.7%; 3 (4.3%) patients required additional interventions. In Group 2, the effectiveness of PNL was 94.1%, 4 (5.9%) patients additionally underwent extracorporeal lithotripsy. There were no significant differences in the effectiveness of PNL, the volume of blood loss and duration of hospitalization. Ultrasound guided PNL can be performed in large pelvic stones and sufficient expansion of renal cavities, thus reducing radiation exposure of patients and medical staff.

Ultrasound-Guided Transesophageal High-Intensity Focused Ultrasound Cardiac Ablation in a Beating Heart: A Pilot Feasibility Study in Pigs.

PubMed

Bessiere, Francis; N'djin, W Apoutou; Colas, Elodie Constanciel; Chavrier, Françoise; Greillier, Paul; Chapelon, Jean Yves; Chevalier, Philippe; Lafon, Cyril

2016-08-01

Catheter ablation for the treatment of arrhythmia is associated with significant complications and often-repeated procedures. Consequently, a less invasive and more efficient technique is required. Because high-intensity focused ultrasound (HIFU) enables the generation of precise thermal ablations in deep-seated tissues without harming the tissues in the propagation path, it has the potential to be used as a new ablation technique. A system capable of delivering HIFU into the heart by a transesophageal route using ultrasound (US) imaging guidance was developed and tested in vivo in six male pigs. HIFU exposures were performed on atria and ventricles. At the time of autopsy, visual inspection identified thermal lesions in the targeted areas in three of the animals. These lesions were confirmed by histologic analysis (mean size: 5.5 mm(2) × 11 mm(2)). No esophageal thermal injury was observed. One animal presented with bradycardia due to an atrio-ventricular block, which provides real-time confirmation of an interaction between HIFU and the electrical circuits of the heart. Thus, US-guided HIFU has the potential to minimally invasively create myocardial lesions without an intra-cardiac device. Copyright © 2016 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Experimental application of thermosensitive paramagnetic liposomes for monitoring magnetic resonance imaging guided thermal ablation.

PubMed

Frich, Lars; Bjørnerud, Atle; Fossheim, Sigrid; Tillung, Terje; Gladhaug, Ivar

2004-12-01

The use of a liposomal paramagnetic agent with a T(1)-relaxivity that increases markedly at temperatures above the phase transition temperature (T(m)) of the liposomal membrane was evaluated during magnetic resonance imaging (MRI) guided hyperthermia ablation. A neodymium-yttrium aluminum garnet (Nd-YAG) laser unit and a radiofrequency ablation system were used for tissue ablation in eight rabbit livers in vivo. One ablation was made in each animal prior to administration of the liposomal agent. Liposomes with a T(m) of 57 degrees C containing gadodiamide (GdDTPA-BMA) were injected iv, and two additional ablations were performed. T(1)-weighted scans were performed in heated tissue, after tissue temperature had normalized, and 15-20 min after normalization of tissue temperature. Increase in signal intensity (DeltaSI) for ablations prior to injection of the agent was 13.0% (SD = 5.7) for the laser group and 9.1% (SD = 7.9) for the radiofrequency group. Signal intensity after administration of the agent unrelated to heating was not statistically significant (DeltaSI = 1.4%, P = 0.35). For ablations made after injection of the agent, a significant increase was found in the laser (DeltaSI = 34.5%, SD = 11.9) and radiofrequency group (DeltaSI = 21.6%, SD = 22.7). The persistent signal enhancement found in areas exposed to a temperature above the threshold temperature above T(m) allows thermal monitoring of MRI guided thermal ablation. (c) 2004 Wiley-Liss, Inc.

Robotic active positioning for magnetic resonance-guided high-intensity focused ultrasound

NASA Astrophysics Data System (ADS)

Xiao, Xu; Huang, Zhihong; Volovick, Alexander; Melzer, Andreas

2012-11-01

Magnetic resonance (MR) guided High-intensity focused ultrasound (HIFU) is a noninvasive method producing thermal necrosis and cavitation at the position of tumors with high accuracy. Because the typical size of the high-intensity focused ultrasound focus are much smaller than the targeted tumor or other tissues, multiple sonications and focus repositioning become necessary for HIFU treatment. In order to reach a much wider range, manual repositioning or using MR compatible mechanical actuators could be used. The repositioning technique is a time consuming procedure because it needs a series of MR imaging to detect the transducer and markers preplaced on the mechanical devices. We combined an active tracking technique into the MR guided HIFU system. In this work, the robotic system used is the MR-compatible robotics from InnoMotion{trade mark, serif} (IBSMM, Engineering spol. s r.o. / Ltd, Czech) which is originally designed for MR-guided needle biopsy. The precision and positioning speed of the combined robotic HIFU system are evaluated in this study. Compared to the existing MR guided HIFU systems, the combined robotic system with active tracking techniques provides a potential that allows the HIFU treatment to operate in a larger spatial range and with a faster speed.

Enhanced Radiofrequency Ablation With Magnetically Directed Metallic Nanoparticles.

PubMed

Nguyen, Duy T; Tzou, Wendy S; Zheng, Lijun; Barham, Waseem; Schuller, Joseph L; Shillinglaw, Benjamin; Quaife, Robert A; Sauer, William H

2016-05-01

Remote heating of metal located near a radiofrequency ablation source has been previously demonstrated. Therefore, ablation of cardiac tissue treated with metallic nanoparticles may improve local radiofrequency heating and lead to larger ablation lesions. We sought to evaluate the effect of magnetic nanoparticles on tissue sensitivity to radiofrequency energy. Ablation was performed using an ablation catheter positioned with 10 g of force over prepared ex vivo specimens. Tissue temperatures were measured and lesion volumes were acquired. An in vivo porcine thigh model was used to study systemically delivered magnetically guided iron oxide (FeO) nanoparticles during radiofrequency application. Magnetic resonance imaging and histological staining of ablated tissue were subsequently performed as a part of ablation lesion analysis. Ablation of ex vivo myocardial tissue treated with metallic nanoparticles resulted in significantly larger lesions with greater impedance changes and evidence of increased thermal conductivity within the tissue. Magnet-guided localization of FeO nanoparticles within porcine thigh preps was demonstrated by magnetic resonance imaging and iron staining. Irrigated ablation in the regions with greater FeO, after FeO infusion and magnetic guidance, created larger lesions without a greater incidence of steam pops. Metal nanoparticle infiltration resulted in significantly larger ablation lesions with altered electric and thermal conductivity. In vivo magnetic guidance of FeO nanoparticles allowed for facilitated radiofrequency ablation without direct infiltration into the targeted tissue. Further research is needed to assess the clinical applicability of this ablation strategy using metallic nanoparticles for the treatment of cardiac arrhythmias. © 2016 American Heart Association, Inc.

MRI-guided Focused Ultrasound Ablation of Lumbar Medial Branch Nerve: Feasibility and Safety Study in a Swine Model

PubMed Central

Kaye, Elena A; Monette, Sebastien; Srimathveeravalli, Govindarajan; Maybody, Majid; Solomon, Stephen B; Gulati, Amitabh

2016-01-01

Purpose About 10–40% of chronic low back pain cases involve facet joints, which are commonly treated with lumbar medial branch (MB) radiofrequency neurotomy. Magnetic Resonance Imaging-guided Focused Ultrasound (MRgFUS), a non-invasive, non-ionizing ablation modality used to treat tumors, neuropathic pain and painful bone metastasis, can also be used to disrupt nerve conduction. This work’s purpose was to study the feasibility and safety of direct MRgFUS ablation of the lumbar MB nerve in acute and subacute swine models. Materials and Methods In vivo MRgFUS ablation was performed in six swine (3 acute and 3 subacute) using a clinical MRgFUS system (ExAblate 2000®; InSightec Ltd., Haifa, Israel) and 3 T MRI scanner (SIGNA; GE Healthcare, Waukesha, WI, USA) combination. Behavioral assessment was performed, and imaging and histology were used to assess the treatment. Results and Conclusions Histological analysis of the in vivo studies confirmed thermal necrosis of the MB nerve could be achieved without damaging the spinal cord or adjacent nerve roots. MRgFUS did not cause changes in the animals’ behavior and ambulation. PMID:27443328

Comparison of Noninvasive High-Intensity Focused Ultrasound with Radiofrequency Ablation of Osteoid Osteoma.

PubMed

Sharma, Karun V; Yarmolenko, Pavel S; Celik, Haydar; Eranki, Avinash; Partanen, Ari; Smitthimedhin, Anilawan; Kim, Aerang; Oetgen, Matthew; Santos, Domiciano; Patel, Janish; Kim, Peter

2017-11-01

To evaluate clinical feasibility and safety of magnetic resonance imaging-guided high-intensity focused ultrasound (MR-HIFU) treatment of symptomatic osteoid osteoma and to compare clinical response with standard of care treatment. Nine subjects with radiologically confirmed, symptomatic osteoid osteoma were treated with MR-HIFU in an institutional review board-approved clinical trial. Treatment feasibility and safety were assessed. Clinical response was evaluated in terms of analgesic requirement, visual analog scale pain score, and sleep quality. Anesthesia, procedure, and recovery times were recorded. This MR-HIFU group was compared with a historical control group of 9 consecutive patients treated with radiofrequency ablation. Nine subjects (7 male, 2 female; 16 ± 6 years) were treated with MR-HIFU without technical difficulties or any serious adverse events. There was significant decrease in their median pain scores 4 weeks within treatment (6 vs 0, P < .01). Total pain resolution and cessation of analgesics were achieved in 8 of 9 patients after 4 weeks. In the radiofrequency ablation group, 9 patients (8 male, 1 female; 10 ± 6 years) were treated in routine clinical practice. All 9 demonstrated complete pain resolution and cessation of medications by 4 weeks with a significant decrease in median pain scores (9 vs 0, P < .001). One developed a second-degree skin burn, but there were no other adverse events. Procedure times and treatment charges were comparable between the 2 groups. This pilot study shows that MR-HIFU treatment of osteoid osteoma refractory to medical therapy is feasible and can be performed safely in pediatric patients. Clinical response is comparable with standard of care treatment but without any incisions or exposure to ionizing radiation. ClinicalTrials.govNCT02349971. Copyright © 2017 Elsevier Inc. All rights reserved.

Percutaneous Ultrasound-Guided TOPAZ Radiofrequency Coblation: A Novel Coaxial Technique for the Treatment of Recalcitrant Plantar Fasciitis-Our Experience.

PubMed

Shah, Amit; Best, Alistair J; Rennie, Winston J

2016-06-01

Various therapeutic options are available for treatment of recalcitrant plantar fasciitis. Studies using TOPAZ coblation (ArthroCare, Sunnyvale, CA) have had good early results. The current coblation technique involves a surgical incision or breach of the highly specialized plantar fat pad, which can be associated with risks. We describe a novel technique of ultrasound-guided percutaneous coblation with a lateral heel approach. Advantages include precise targeting of the plantar fascia by direct dynamic visualization of the coblation tip, a true percutaneous approach with a needle skin puncture (<5 mm), and preservation of the plantar fat pad by using a lateral heel approach. © 2016 by the American Institute of Ultrasound in Medicine.

Prostate tissue ablation with MRI guided transurethral therapeutic ultrasound and intraoperative assessment of the integrity of the neurovascular bundle

NASA Astrophysics Data System (ADS)

Sammet, Steffen; Partanen, Ari; Yousuf, Ambereen; Wardrip, Craig; Niekrasz, Marek; Antic, Tatjana; Razmaria, Aria; Sokka, Sham; Karczmar, Gregory; Oto, Aytekin

2017-03-01

OBJECTIVES: Evaluation of the precision of prostate tissue ablation with MRI guided therapeuticultrasound by intraoperative objective assessment of the neurovascular bundle in canines in-vivo. METHODS: In this ongoing IACUC approved study, eight male canines were scanned in a clinical 3T Achieva MRI scanner (Philips) before, during, and after ultrasound therapy with a prototype MR-guided ultrasound therapy system (Philips). The system includes a therapy console to plan treatment, to calculate real-time temperature maps, and to control ultrasound exposures with temperature feedback. Atransurethral ultrasound applicator with eight transducer elements was used to ablate canine prostate tissue in-vivo. Ablated prostate tissue volumes were compared to the prescribed target volumes to evaluate technical effectiveness. The ablated volumes determined by MRI (T1, T2, diffusion, dynamic contrast enhanced and 240 CEM43 thermal dose maps) were compared to H&E stained histological slides afterprostatectomy. Potential nerve damage of the neurovascular bundle was objectively assessed intraoperativelyduring prostatectomy with a CaverMap Surgical Aid nerve stimulator (Blue Torch Medical Technologies). RESULTS: Transurethral MRI -guided ultrasound therapy can effectively ablate canine prostate tissue invivo. Coronal MR-imaging confirmed the correct placement of the HIFU transducer. MRI temperature maps were acquired during HIFU treatment, and subsequently used for calculating thermal dose. Prescribed target volumes corresponded to the 240 CEM43 thermal dose maps during HIFU treatment in all canines. Ablated volumes on high resolution anatomical, diffusion weighted, and contrast enhanced MR images matched corresponding histological slides after prostatectomy. MRI guidance with realtime temperature monitoring showed no damage to surrounding tissues, especially to the neurovascular bundle (assessed intra-operatively with a nerve stimulator) or to the rectum wall. CONCLUSIONS: Our study

Analysis of "dry" mesothelioma with ultrasound guided biopsies.

PubMed

Stigt, Jos A; Boers, James E; Groen, Harry J M

2012-12-01

Image-guided sampling of the thickened pleura is a sensitive approach in patients with malignant pleural mesothelioma with pleural effusion. Malignant pleural mesothelioma presenting without effusion however is more of a diagnostic challenge. In this study we report the diagnostic yield and complications of ultrasound-guided cutting needle biopsies in this particular category of patients. A retrospective database analysis from September 2007 until January 2012 was performed in 56 patients with malignant pleural mesothelioma. Clinical characteristics and results of diagnostic evaluations were analysed. Of the 56 patients with malignant pleural mesothelioma, 20 patients presented without pleural effusion of with locular effusion. Ultrasound-guided cutting needle biopsy was performed in 14/20 patients with a diagnostic accuracy of 80%. Only 1 patient had mild haemoptysis immediately following biopsies. Diagnosing patients with pleural thickenings suspect for malignant mesothelioma without pleural effusion or with loculated pleural effusion is effective and safe with ultrasound-guided cutting needle biopsies. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Combined Ultrasound and MR Imaging to Guide Focused Ultrasound Therapies in the Brain

PubMed Central

Arvanitis, Costas D.; Livingstone, Margaret S.; McDannold, Nathan

2013-01-01

Purpose Several emerging therapies with potential for use in the brain harness effects produced by acoustic cavitation – the interaction between ultrasound and microbubbles either generated during sonication or introduced into the vasculature. Systems developed for transcranial MRI-guided focused ultrasound (MRgFUS) thermal ablation can enable their clinical translation, but methods for real-time monitoring and control are currently lacking. Acoustic emissions produced during sonication can provide information about the location, strength, and type of the microbubble oscillations within the ultrasound field, and they can be mapped in real-time using passive imaging approaches. Here, we tested whether such mapping can be achieved transcranially within a clinical brain MRgFUS system. Materials and Methods We integrated an ultrasound imaging array into the hemisphere transducer of the MRgFUS device. Passive cavitation maps were obtained during sonications combined with a circulating microbubble agent at 20 targets in the cingulate cortex in three macaques. The maps were compared with MRI-evident tissue effects. Results The system successfully mapped microbubble activity during both stable and inertial cavitation, which was correlated with MRI-evident transient blood-brain barrier disruption and vascular damage, respectively. The location of this activity was coincident with the resulting tissue changes within the expected resolution limits of the system. Conclusion While preliminary, these data clearly demonstrate, for the first time, that is possible to construct maps of stable and inertial cavitation transcranially, in a large animal model, and under clinically relevant conditions. Further, these results suggest that this hybrid ultrasound/MRI approach can provide comprehensive guidance for targeted drug delivery via blood-brain barrier disruption and other emerging ultrasound treatments, facilitating their clinical translation. We anticipate it will also prove to

Combined ultrasound and MR imaging to guide focused ultrasound therapies in the brain

NASA Astrophysics Data System (ADS)

Arvanitis, Costas D.; Livingstone, Margaret S.; McDannold, Nathan

2013-07-01

Several emerging therapies with potential for use in the brain, harness effects produced by acoustic cavitation—the interaction between ultrasound and microbubbles either generated during sonication or introduced into the vasculature. Systems developed for transcranial MRI-guided focused ultrasound (MRgFUS) thermal ablation can enable their clinical translation, but methods for real-time monitoring and control are currently lacking. Acoustic emissions produced during sonication can provide information about the location, strength and type of the microbubble oscillations within the ultrasound field, and they can be mapped in real-time using passive imaging approaches. Here, we tested whether such mapping can be achieved transcranially within a clinical brain MRgFUS system. We integrated an ultrasound imaging array into the hemisphere transducer of the MRgFUS device. Passive cavitation maps were obtained during sonications combined with a circulating microbubble agent at 20 targets in the cingulate cortex in three macaques. The maps were compared with MRI-evident tissue effects. The system successfully mapped microbubble activity during both stable and inertial cavitation, which was correlated with MRI-evident transient blood-brain barrier disruption and vascular damage, respectively. The location of this activity was coincident with the resulting tissue changes within the expected resolution limits of the system. While preliminary, these data clearly demonstrate, for the first time, that it is possible to construct maps of stable and inertial cavitation transcranially, in a large animal model, and under clinically relevant conditions. Further, these results suggest that this hybrid ultrasound/MRI approach can provide comprehensive guidance for targeted drug delivery via blood-brain barrier disruption and other emerging ultrasound treatments, facilitating their clinical translation. We anticipate that it will also prove to be an important research tool that will

Ultrasound-guided percutaneous treatment of hepatocellular carcinoma by radiofrequency hyperthermia with a 'cooled-tip needle'. A preliminary clinical experience.

PubMed

Francica, G; Marone, G

1999-05-01

Radiofrequency hyperthermia using the newly-developed 'cooled-tip' needle has recently been proposed as a therapeutic modality for hepatocellular carcinoma (HCC). Herein we report our preliminary results on feasibility and effectiveness of the thermal ablation of mono- or pauci-focal hepatocellular carcinoma with the cooled-tip needle. We treated 15 cirrhotic patients (mean age 68.8 years; 12 males; 14 HCV-positive; 13 in Child's Class A and 2 in Class B) with 20 hepatocellular carcinoma nodules (mean diameter 28.1 mm; range 10-43 mm; nine lesions with diameter greater than 3 cm). None of the patients had portal thrombosis and/or extrahepatic spread. We used a radiofrequency generator (100 W of power) connected to a 18 g perfusion electrode needle with an exposed tip of 2-3 cm. The circuit was closed through a dispersive electrode positioned under the patient's thighs. A peristaltic pump infused a chilled (2-5 degrees C) saline solution to guarantee the continuous cooling of the needle tip. The needle was placed into target lesions under US guidance. The interventional procedure was carried out in general anesthesia without intubation. Dynamic helical CT was carried out 15-20 days after thermal ablation to assess therapeutic efficacy. In all, 38 areas of coagulation necrosis (at 1000-1200 mA for 10-15 min) were generated in 24 sessions in the 20 hepatocellular carcinoma nodules (mean 1.9 lesions per nodule and 1.2 sessions per nodule). Complete necrosis as assessed at dynamic CT (lack of enhancement during the arteriographic phase) was achieved in 75% of cases in a single session; after a second RF session success rate was 90% (18 out of 20 nodules). A self-limited pleurisy along with a 5-fold increase in transaminases occurred in one patient; a 3-fold elevation of transaminases was encountered in three other patients. During the follow-up (median 15 months) five patients had recurrent hepatocellular carcinoma with a 1-year disease free interval of 64%. Of the

Ultrasound-Guided Treatment of Peripheral Nerve Pathology.

PubMed

Dettori, Nathan; Choudur, Hema; Chhabra, Avneesh

2018-07-01

High-resolution ultrasound serves as a fast, accessible, reliable, and radiation-free tool for anatomical and dynamic evaluation of various peripheral nerves. It can be used not only to identify and diagnose peripheral nerve and perineural pathology accurately but also to guide various nerve and perineural interventions. We describe the normal and pathologic appearances of peripheral nerves, the pathologies commonly affecting the individual peripheral nerves, and the current ultrasound-guided peripheral nerve interventions and techniques. Future directions are also highlighted. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Spatio-temporal control of gene expression and cancer treatment using magnetic resonance imaging-guided focused ultrasound.

PubMed

Moonen, Chrit T W

2007-06-15

Local temperature elevation may be used for tumor ablation, gene expression, drug activation, and gene and/or drug delivery. High-intensity focused ultrasound (HIFU) is the only clinically viable technology that can be used to achieve a local temperature increase deep inside the human body in a noninvasive way. Magnetic resonance imaging (MRI) guidance of the procedure allows in situ target definition and identification of nearby healthy tissue to be spared. In addition, MRI can be used to provide continuous temperature mapping during HIFU for spatial and temporal control of the heating procedure and prediction of the final lesion based on the received thermal dose. The primary purpose of the development of MRI-guided HIFU was to achieve safe noninvasive tissue ablation. The technique has been tested extensively in preclinical studies and is now accepted in the clinic for ablation of uterine fibroids. MRI-guided HIFU for ablation shows conceptual similarities with radiation therapy. However, thermal damage generally shows threshold-like behavior, with necrosis above the critical thermal dose and full recovery below. MRI-guided HIFU is being clinically evaluated in the cancer field. The technology also shows great promise for a variety of advanced therapeutic methods, such as gene therapy. MR-guided HIFU, together with the use of a temperature-sensitive promoter, provides local, physical, and spatio-temporal control of transgene expression. Specially designed contrast agents, together with the combined use of MRI and ultrasound, may be used for local gene and drug delivery.

The effectiveness of anticellulite treatment using tripolar radiofrequency monitored by classic and high-frequency ultrasound.

PubMed

Mlosek, R K; Woźniak, W; Malinowska, S; Lewandowski, M; Nowicki, A

2012-06-01

  Cellulite affects nearly 85% of the female population. Given the size of the phenomenon, we are continuously looking for effective ways to reduce cellulite. Reliable monitoring of anticellulite treatment remains a problem.   The main aim of the study was to evaluate the effectiveness of anticellulite treatment carried out using radiofrequency (RF), which was monitored by classical and high-frequency ultrasound.   Twenty-eight women underwent anticellulite treatment using RF, 17 women were in the placebo group. The therapy was monitored by classical and high-frequency ultrasound. The examinations evaluated the thickness of the epidermal echo, dermis thickness, dermis echogenicity, the length of the subcutaneous tissue bands growing into the dermis, the presence or absence of oedema, the thickness of subcutaneous tissue as well as thigh circumference and the stage of cellulite (according to the Nürnberger-Müller scale).   Cellulite was reduced in 89.286% of the women who underwent RF treatment. After the therapy, the following observations were made: a decrease in the thickness of the dermis and subcutaneous tissue, an increase in echogenicity reflecting on the increase in the number of collagen fibres, decreased subcutaneous tissue growing into bands in the dermis, and the reduction of oedema. In the placebo group, no statistically significant changes of the above parameters were observed.   Radiofrequency enables cellulite reduction. A crucial aspect is proper monitoring of the progress of such therapy, which ultrasound allows. © 2011 The Authors. Journal of the European Academy of Dermatology and Venereology © 2011 European Academy of Dermatology and Venereology.

Ultrasound-guided venous access for pacemakers and defibrillators.

PubMed

Seto, Arnold H; Jolly, Aaron; Salcedo, Jonathan

2013-03-01

Ultrasound guidance is widely recommended to reduce the risk of complications during central venous catheter placement. However, ultrasound guidance is not commonly utilized for implanting leads for cardiac rhythm management devices. We describe our technique of ultrasound-guided pacemaker implantation, including a novel pull-through technique that allows percutaneous guidewire insertion prior to the first incision. We review the literature and recent advances in ultrasound imaging technology that may facilitate the adoption of ultrasound guidance. Ultrasound guidance provides a safe and rapid technique for extrathoracic subclavian or axillary venous lead placement. © 2012 Wiley Periodicals, Inc.

Efficacy of ultrasound-guided thoracentesis catheter drainage for pleural effusion

PubMed Central

Cao, Weitian; Wang, Yi; Zhou, Ningming; Xu, Bing

2016-01-01

The factors influencing the efficacy of ultrasound-guided thoracentesis catheter drainage were investigated in the present study. A retrospective analysis of clinical data from 435 patients who presented with a pleural effusion was performed. Patients were divided into a control group and an intervention group. Thirty-seven patients in the control group were given standard care using pleural puncture to draw the excess fluid. The 398 patients in the intervention group were treated using ultrasound-guided thoracentesis catheter drainage. The rate of successful drainage of a pleural effusion was significantly higher (P<0.05), while the rate of complication was lower, in the ultrasound-guided thoracentesis cases compared to standard care treatment. In conclusion, ultrasound-guided thoracentesis catheter drainage is an efficient, safe and minimally invasive procedure to alleviate pleural effusion. The efficacy of the procedure is related to the separation of pleural effusion, drainage tube type and tube diameter. PMID:28105155

Ultrasound-guided interventional procedures around the shoulder.

PubMed

Messina, Carmelo; Banfi, Giuseppe; Orlandi, Davide; Lacelli, Francesca; Serafini, Giovanni; Mauri, Giovanni; Secchi, Francesco; Silvestri, Enzo; Sconfienza, Luca Maria

2016-01-01

Ultrasound is an established modality for shoulder evaluation, being accurate, low cost and radiation free. Different pathological conditions can be diagnosed using ultrasound and can be treated using ultrasound guidance, such as degenerative, traumatic or inflammatory diseases. Subacromial-subdeltoid bursitis is the most common finding on ultrasound evaluation for painful shoulder. Therapeutic injections of corticosteroids are helpful to reduce inflammation and pain. Calcific tendinopathy of rotator cuff affects up to 20% of painful shoulders. Ultrasound-guided treatment may be performed with both single- and double-needle approach. Calcific enthesopathy, a peculiar form of degenerative tendinopathy, is a common and mostly asymptomatic ultrasound finding; dry needling has been proposed in symptomatic patients. An alternative is represented by autologous platelet-rich plasma injections. Intra-articular injections of the shoulder can be performed in the treatment of a variety of inflammatory and degenerative diseases with corticosteroids or hyaluronic acid respectively. Steroid injections around the long head of the biceps brachii tendon are indicated in patients with biceps tendinopathy, reducing pain and humeral tenderness. The most common indication for acromion-clavicular joint injection is degenerative osteoarthritis, with ultrasound representing a useful tool in localizing the joint space and properly injecting various types of drugs (steroids, lidocaine or hyaluronic acid). Suprascapular nerve block is an approved treatment for chronic shoulder pain non-responsive to conventional treatments as well as candidate patients for shoulder arthroscopy. This review provides an overview of these different ultrasonography-guided procedures that can be performed around the shoulder.

Ultrasound guided therapeutic injections of the cervical spine and brachial plexus.

PubMed

Cormick, Wes

2014-02-01

Introduction : Recent applications in ultrasound imaging include ultrasound assessment and ultrasound guided therapeutic injections of the spine and brachial plexus. Discussion : Ultrasound is an ideal modality for these regions as it allows accurate safe and quick injection of single or multiple sites. It has the added advantages of lack of ionising radiation, and can be done without requiring large expensive radiology equipment. Conclusion : Brachial plexus pathology may be present in patients presenting for shoulder symptoms where very little is found at imaging the shoulder. It is important to understand the anatomy and normal variants that may exist to be able to recognise when pathology is present. When pathology is demonstrated it is easy to do a trial of therapy with ultrasound guided injection of steroid around the nerve lesion. This review will outline the normal anatomy and variants and common pathology, which can be amenable to ultrasound guided injection of steroid.

Magnetic resonance image guided transurethral ultrasound prostate ablation: a preclinical safety and feasibility study with 28-day followup.

PubMed

Burtnyk, Mathieu; Hill, Tracy; Cadieux-Pitre, Heather; Welch, Ian

2015-05-01

We determine the safety and feasibility of magnetic resonance image guided transurethral ultrasound prostate ablation using active temperature feedback control in a preclinical canine model with 28-day followup. After a long acclimatization period we performed ultrasound treatment in 8 subjects using the magnetic resonance image guided TULSA-PRO™ transurethral ultrasound prostate ablation system. Comprehensive examinations and observations were done before and throughout the 28-day followup, including assessment of clinically significant treatment related adverse events. In addition to gross pathology evaluation, extensive histopathological analysis was done to assess cell kill inside and outside the prostate. We evaluated prostate conformal heating by comparing the spatial difference between the treatment plan and the 55C isotherm measured on magnetic resonance imaging thermometry acquired during treatment. These findings were confirmed on contrast enhanced magnetic resonance imaging immediately after treatment and at 28 days. Clinically there were no adverse events in any of the 8 subjects throughout the 28-day followup. All subjects had normal urinary and bowel function. Gross necropsy and histology confirmed that the intended thermal cell kill was confined to the prostate. No surrounding tissue was damaged, including the rectum and the external urinary sphincter. Conformal heating was achieved with an average -0.9 mm accuracy and 0.9 mm precision. Contrast enhanced magnetic resonance imaging and histological analysis confirmed tissue ablation in targeted areas of the prostate. Urethral tissue was spared from thermal damage. Magnetic resonance image guided transurethral ultrasound is a safe, feasible procedure for accurate and precise conformal thermal ablation of prostate tissue, as demonstrated in a preclinical model with 28-day followup. Copyright © 2015 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights

Three-year outcome of the Halt trial: a prospective analysis of radiofrequency volumetric thermal ablation of myomas.

PubMed

Berman, Jay M; Guido, Richard S; Garza Leal, José Gerardo; Pemueller, Rodolfo Robles; Whaley, Fredrick S; Chudnoff, Scott G

2014-01-01

To analyze the clinical success of radiofrequency volumetric thermal ablation (RFVTA) at 3-year follow-up in terms of subject responses to validated questionnaires and surgical repeat intervention to treat myomas. Prospective follow-up of patients for 36 months after treatment in a multicenter international trial of outpatient, laparoscopic ultrasound-guided RFVTA of symptomatic uterine myomas (Canadian Task Force classification II-1). University hospitals and private surgical centers. One hundred thirty-five premenopausal women (mean [SD] age, 42.5 [4.6] years; body mass index, 30.5 [6.1]) with symptomatic uterine myomas and objectively confirmed heavy menstrual bleeding (≥ 160 to ≤ 500 mL). Laparoscopic ultrasound-guided RFVTA. One hundred four participants were followed prospectively for 36 months after treatment of myomas via RFVTA. For 104 evaluable participants with 36-month data, change in mean (SD) symptom severity from baseline (60.2 [18.8]) to 36 months was -32.6 (95% confidence interval, -37.5 to -27.8; p < .001). Health-related quality of life also was improved, from the baseline value of 39.2 (19.2) to 38.6 (95% confidence interval, 33.3 to 43.9; p < .001) at 36 months. Patient-reported Uterine Fibroid Symptom and Health-Related Quality of Life questionnaire subscores demonstrated statistically significant improvement from baseline to 36 months in all categories (Concern, Activities, Energy/Mood, Control, Self-consciousness, and Sexual Function) (p < .001). For the 104 participants with 36-month data, mean state of health scores (EuroQOL-5D Health State Index) improved from a baseline value of 71.0 (19.3) to 86.2 (11.7) at 36 months. The cumulative repeat intervention rate of 11% (14 of 135 participants) at 36 months was well below the possible 25% maximum expected at the beginning of the trial. RFVTA of uterine myomas resulted in sustained relief from myoma symptoms and continued improvement in health-related quality of life through 36 months

A New Technique of Radiofrequency-assisted Ultrasound-guided Needle-localized Laparoscopic Resection of Disappearing Colorectal Liver Metastases.

PubMed

Yigitbas, Hakan; Yazici, Pinar; Taskin, Halit E; Okoh, Alexis K; Dural, Cem; Aydin, Nail; Berber, Eren

2017-02-01

The management of disappearing colorectal liver metastases in the postadjuvant chemotherapy setting is challenging. We describe a novel technique that facilitates laparoscopic resection of disappearing metastatic liver lesions with great precision. Details of this new technique are described in 2 patients with colorectal cancer synchronously metastatic to the liver. Both patients had small indistinct intraparenchymal liver lesions after adjuvant chemotherapy. A video displays the steps of the procedure. Both patients presented with colorectal cancer with synchronous liver metastasis. They received FOLFOX regimen after resection of their primary. They both responded to adjuvant chemotherapy. On repeat posttreatment imaging, the liver lesions became smaller and indistinct. With laparoscopic ultrasound, subtle parenchymal heterogeneities were identified. The lesions were initially ablated with a wide radiofrequency ablation zone. Then, without removing the needle, the prongs were deployed to the borders of the parenchymal heterogeneity. Using an ultrasonic vessel sealer, the lesions were resected. Final pathology identified 1 viable focus of cancer in each patient. Both patients were discharged home uneventfully on their second postoperative day. There were no complications. We have described a novel technique that could facilitate precise resection of intraparenchymal small indistinct or disappearing liver metastases of colorectal origin. This option should be kept within the armamentarium of the laparoscopic liver surgeon managing patients with malignant liver tumors.

Noninvasive thermal ablation of hepatocellular carcinoma by using magnetic resonance imaging-guided focused ultrasound.

PubMed

Jolesz, Ferenc A; Hynynen, Kullervo; McDannold, Nathan; Freundlich, David; Kopelman, Doron

2004-11-01

A number of minimally invasive methods have been tested for the thermal ablation of liver tumors as an alternative to surgical resection. The use of focused ultrasound transducers to ablate deep tumors offers the first completely noninvasive alternative to these techniques. By increasing the flexibility of this technology with modern phased-array transducer design and by combining it with magnetic resonance imaging for targeting and online guidance, a powerful tool results with the potential to offer treatment to a larger population of patients, to reduce trauma to the patient, and to reduce the cost of treatment. In this article, we review previous work with focused ultrasound in the liver and recent experimental results with magnetic resonance imaging guidance.

Guiding Intramuscular Diaphragm Injections Using Real-time Ultrasound & Electromyography

PubMed Central

Sarwal, Aarti; Cartwright, Michael S.; Mitchell, Erin; Williams, Koudy; Walker, Francis O.; Childers, Martin K.

2014-01-01

Introduction We describe a unique method that combines ultrasound and electromyography to guide intramuscular diaphragm injections in anesthetized large animals. Methods Ultrasound was used to visualize the diaphragm on each side of spontaneously breathing, anesthetized beagle dogs and cynomolgus macaques. An electromyography needle was introduced and directed by ultrasound to confirm that the needle entered the muscular portion of the diaphragm, and methylene blue was injected. Injection accuracy was confirmed upon necropsy by tracking the spread of methylene blue. Results All methylene blue injections were confirmed to have been placed appropriately into the diaphragm. Conclusions This study demonstrates the feasibility and accuracy of using ultrasound and EMG to guide injections and to reduce complications associated with conventional blind techniques. Ultrasound guidance can be used for clinical electromyography of the diaphragm. Future applications may include targeted diaphragm injections with gene replacement therapy in neuromuscular diseases. PMID:25354257

Radiofrequency thermal ablation in canine femur: evaluation of coagulation necrosis reproducibility and MRI-histopathologic correlation.

PubMed

Lee, Jeong Min; Choi, Seong Hong; Park, Hee Seon; Lee, Min Woo; Han, Chang Jin; Choi, Joon-il; Choi, Ja-Young; Hong, Sung Hwan; Han, Joon Koo; Choi, Byung Ihn

2005-09-01

Our purposes were to determine whether a single application of radiofrequency energy to normal bone can create coagulation necrosis reproducibly and to assess the accuracy of MRI at revealing the extent of radiofrequency-induced thermal bone injury. Using a 200-W generator and a 17-gauge cooled-tip electrode, a total of 11 radiofrequency ablations were performed under fluoroscopic guidance in the distal femurs of seven dogs. Radiofrequency was applied in standard monopolar mode at 100 W for 10 min. During radiofrequency ablation, the changes in impedance and currents were recorded. MRI, including unenhanced T1- and T2-weighted images and contrast-enhanced fat-suppressed T1-weighted images, was performed to evaluate ablation regions. Six dogs were killed on day 4 after MRI and one dog on day 7. In all animals, radiofrequency ablation created a well-defined coagulation necrosis and no significant complications were noted. The mean long-axis diameter and the mean short-axis diameter of the coagulation zones produced were 45.9 +/- 5.5 mm and 17.7 +/- 2.7 mm, respectively. At gross examination, thermal ablation regions appeared as a central, light-brown area with a dark-brown peripheral hemorrhagic zone, which was surrounded by a pale-yellow rim. On MRI, the ablated areas showed multilayered zones with signal intensities that differed from normal marrow on unenhanced images and a perfusion defect on contrast-enhanced T1-weighted images. The maximum difference between lesion sizes on MR images, established by measuring macroscopic coagulation necrosis, was 3 mm. The correlation between the diameter of coagulation necrosis and lesion size at MRI was strong, with correlation coefficients ranging from 0.89 for unenhanced T1-weighted images and 0.97 for unenhanced T2-weighted images to 0.98 for contrast-enhanced T1-weighted images (p < 0.05). Radiofrequency ablation created well-defined coagulation necrosis in a reproducible manner, and MRI accurately determined the extent

Focused ultrasound thermal therapy system with ultrasound image guidance and temperature measurement feedback.

PubMed

Lin, Kao-Han; Young, Sun-Yi; Hsu, Ming-Chuan; Chan, Hsu; Chen, Yung-Yaw; Lin, Win-Li

2008-01-01

In this study, we developed a focused ultrasound (FUS) thermal therapy system with ultrasound image guidance and thermocouple temperature measurement feedback. Hydraulic position devices and computer-controlled servo motors were used to move the FUS transducer to the desired location with the measurement of actual movement by linear scale. The entire system integrated automatic position devices, FUS transducer, power amplifier, ultrasound image system, and thermocouple temperature measurement into a graphical user interface. For the treatment procedure, a thermocouple was implanted into a targeted treatment region in a tissue-mimicking phantom under ultrasound image guidance, and then the acoustic interference pattern formed by image ultrasound beam and low-power FUS beam was employed as image guidance to move the FUS transducer to have its focal zone coincident with the thermocouple tip. The thermocouple temperature rise was used to determine the sonication duration for a suitable thermal lesion as a high power was turned on and ultrasound image was used to capture the thermal lesion formation. For a multiple lesion formation, the FUS transducer was moved under the acoustic interference guidance to a new location and then it sonicated with the same power level and duration. This system was evaluated and the results showed that it could perform two-dimensional motion control to do a two-dimensional thermal therapy with a small localization error 0.5 mm. Through the user interface, the FUS transducer could be moved to heat the target region with the guidance of ultrasound image and acoustic interference pattern. The preliminary phantom experimental results demonstrated that the system could achieve the desired treatment plan satisfactorily.

Development of an endoluminal high-intensity ultrasound applicator for image-guided thermal therapy of pancreatic tumors

NASA Astrophysics Data System (ADS)

Adams, Matthew S.; Scott, Serena J.; Salgaonkar, Vasant A.; Jones, Peter D.; Plata-Camargo, Juan C.; Sommer, Graham; Diederich, Chris J.

2015-03-01

An ultrasound applicator for endoluminal thermal therapy of pancreatic tumors has been introduced and evaluated through acoustic/biothermal simulations and ex vivo experimental investigations. Endoluminal therapeutic ultrasound constitutes a minimally invasive conformal therapy and is compatible with ultrasound or MR-based image guidance. The applicator would be placed in the stomach or duodenal lumen, and sonication would be performed through the luminal wall into the tumor, with concurrent water cooling of the wall tissue to prevent its thermal injury. A finite-element (FEM) 3D acoustic and biothermal model was implemented for theoretical analysis of the approach. Parametric studies over transducer geometries and frequencies revealed that operating frequencies within 1-3 MHz maximize penetration depth and lesion volume while sparing damage to the luminal wall. Patient-specific FEM models of pancreatic head tumors were generated and used to assess the feasibility of performing endoluminal ultrasound thermal ablation and hyperthermia of pancreatic tumors. Results indicated over 80% of the volume of small tumors (~2 cm diameter) within 35 mm of the duodenum could be safely ablated in under 30 minutes or elevated to hyperthermic temperatures at steady-state. Approximately 60% of a large tumor (~5 cm diameter) model could be safely ablated by considering multiple positions of the applicator along the length of the duodenum to increase coverage. Prototype applicators containing two 3.2 MHz planar transducers were fabricated and evaluated in ex vivo porcine carcass heating experiments under MR temperature imaging (MRTI) guidance. The applicator was positioned in the stomach adjacent to the pancreas, and sonications were performed for 10 min at 5 W/cm2 applied intensity. MRTI indicated over 400C temperature rise in pancreatic tissue with heating penetration extending 3 cm from the luminal wall.

Laser, radiofrequency, and ethanol ablation for the management of thyroid nodules.

PubMed

Papini, Enrico; Gugliemi, Rinaldo; Pacella, Claudio Maurizio

2016-10-01

The majority of benign thyroid nodules are nearly asymptomatic, remain stable in size, and do not require treatment. However, a minority of patients with growing nodules may complain of local symptoms or have cosmetic concerns, and thus seek surgical consultation. The timely use of ultrasound-guided minimally invasive procedures can change the natural history of benign enlarging thyroid nodules. The procedures produce persistent shrinkage of thyroid nodules and are associated with improvement of local symptoms. Among the various procedures, percutaneous ethanol injection represents the first-line treatment for relapsing thyroid cysts. In solid nonfunctioning nodules, laser and radiofrequency ablation produces a more than 50% reduction in nodular volume that remains persistent over several years. For hyperfunctioning nodules, thermal ablation techniques are not appropriate unless radioactive iodine is contraindicated or not accessible. MITs are best suited for the management of medium or large-sized nodules that are sonographically well visualized. Conversely, large nodules or nodular goiters that extend into the chest are difficult to treat. MITs are performed in outpatient clinics, are less expensive, and have a lower risk of complications, compared to surgery, and usually do not induce thyroid dysfunction. However, malignancy should be ruled out with a dedicated ultrasound neck assessment and repeat fine needle aspiration of the lesion before treatment.

A new catheter design for combined radiofrequency ablation and optoacoustic treatment monitoring using copper-coated light-guides

NASA Astrophysics Data System (ADS)

Rebling, Johannes; Oyaga Landa, Francisco Javier; Deán-Ben, Xosé Luis; Razansky, Daniel

2018-02-01

Electrosurgery, i.e. the application of radiofrequency current for tissue ablation, is a frequently used treatment for many cardiac arrhythmias. Electrophysiological and anatomic mapping, as well as careful radiofrequency power control typically guide the radiofrequency ablation procedure. Despite its widespread application, accurate monitoring of the lesion formation with sufficient spatio-temporal resolution remains challenging with the existing imaging techniques. We present a novel integrated catheter for simultaneous radiofrequency ablation and optoacoustic monitoring of the lesion formation in real time and 3D. The design combines the delivery of both electric current and optoacoustic excitation beam in a single catheter consisting of copper-coated multimode light-guides and its manufacturing is described in detail. The electrical current causes coagulation and desiccation while the excitation light is locally absorbed, generating OA responses from the entire treated volume. The combined ablation-monitoring capabilities were verified using ex-vivo bovine tissue. The formed ablation lesions showed a homogenous coagulation while the ablation was monitored in realtime with a volumetric frame rate of 10 Hz over 150 seconds.

Comparative histometric analysis of the effects of high-intensity focused ultrasound and radiofrequency on skin.

PubMed

Suh, Dong Hye; Choi, Jeong Hwee; Lee, Sang Jun; Jeong, Ki-Heon; Song, Kye Yong; Shin, Min Kyung

2015-01-01

High-intensity focused ultrasound (HIFU) and radiofrequency (RF) are used for non-invasive skin tightening. Neocollagenesis and neoelastogenesis have been reported to have a mechanism of controlled thermal injury. To compare neocollagenesis and neoelastogenesis in each layer of the dermis after each session of HIFU and monopolar RF. We analyzed the area fraction of collagen and elastic fibers using the Masson's Trichrome and Victoria blue special stains, respectively, before and after 2 months of treatments. Histometric analyses were performed in each layer of the dermis, including the papillary dermis, and upper, mid, and deep reticular dermis. Monopolar RF led to neocollagenesis in the papillary dermis, and upper, mid, and deep reticular dermis, and neoelastogenesis in the papillary dermis, and upper and mid reticular dermis. HIFU led to neocollagenesis in the mid and deep reticular dermis and neoelastogenesis in the deep reticular dermis. Among these treatment methods, HIFU showed the highest level of neocollagenesis and neoelastogenesis in the deep reticular dermis. HIFU affects deep tissues and impacts focal regions. Monopolar RF also affects deep tissues, but impacts diffuse regions. We believe these data provide further insight into effective skin tightening.

Accuracy of ultrasound-guided nerve blocks of the cervical zygapophysial joints.

PubMed

Siegenthaler, Andreas; Mlekusch, Sabine; Trelle, Sven; Schliessbach, Juerg; Curatolo, Michele; Eichenberger, Urs

2012-08-01

Cervical zygapophysial joint nerve blocks typically are performed with fluoroscopic needle guidance. Descriptions of ultrasound-guided block of these nerves are available, but only one small study compared ultrasound with fluoroscopy, and only for the third occipital nerve. To evaluate the potential usefulness of ultrasound-guidance in clinical practice, studies that determine the accuracy of this technique using a validated control are essential. The aim of this study was to determine the accuracy of ultrasound-guided nerve blocks of the cervical zygapophysial joints using fluoroscopy as control. Sixty volunteers were studied. Ultrasound-imaging was used to place the needle to the bony target of cervical zygapophysial joint nerve blocks. The levels of needle placement were determined randomly (three levels per volunteer). After ultrasound-guided needle placement and application of 0.2 ml contrast dye, fluoroscopic imaging was performed for later evaluation by a blinded pain physician and considered as gold standard. Raw agreement, chance-corrected agreement κ, and chance-independent agreement Φ between the ultrasound-guided placement and the assessment using fluoroscopy were calculated to quantify accuracy. One hundred eighty needles were placed in 60 volunteers. Raw agreement was 87% (95% CI 81-91%), κ was 0.74 (0.64-0.83), and Φ 0.99 (0.99-0.99). Accuracy varied significantly between the different cervical nerves: it was low for the C7 medial branch, whereas all other levels showed very good accuracy. Ultrasound-imaging is an accurate technique for performing cervical zygapophysial joint nerve blocks in volunteers, except for the medial branch blocks of C7.

Ultrasound-guided supraclavicular block: outcome of 510 consecutive cases.

PubMed

Perlas, Anahi; Lobo, Giovanni; Lo, Nick; Brull, Richard; Chan, Vincent W S; Karkhanis, Reena

2009-01-01

Supraclavicular brachial plexus block provides consistently effective anesthesia to the upper extremity. However, traditional nerve localization techniques may be associated with a high risk of pneumothorax. In the present study, we report block success and clinical outcome data from 510 consecutive patients who received an ultrasound-guided supraclavicular block for upper extremity surgery. After institutional review board approval, the outcome of 510 consecutive patients who received an ultrasound-guided supraclavicular block for upper extremity surgery was reviewed. Real-time ultrasound guidance was used with a high-frequency linear probe. The neurovascular structures were imaged on short axis, and the needle was inserted using an in-plane technique with either a medial-to-lateral or lateral-to-medial orientation. Five hundred ten ultrasound-guided supraclavicular blocks were performed (50 inpatients, 460 outpatients) by 47 different operators at different levels of training over a 24-month period. Successful surgical anesthesia was achieved in 94.6% of patients after a single attempt; 2.8% required local anesthetic supplementation of a single peripheral nerve territory; and 2.6% received an unplanned general anesthetic. No cases of clinically symptomatic pneumothorax developed. Complications included symptomatic hemidiaphragmatic paresis (1%), Horner syndrome (1%), unintended vascular punctures (0.4%), and transient sensory deficits (0.4%). Ultrasound-guided supraclavicular block is associated with a high rate of successful surgical anesthesia and a low rate of complications and thus may be a safe alternative for both inpatients and outpatients. Severe underlying respiratory disease and coagulopathy should remain a contraindication for this brachial plexus approach.

Disinfection of a probe used in ultrasound-guided prostate biopsy.

PubMed

Rutala, William A; Gergen, Maria F; Weber, David J

2007-08-01

Transrectal ultrasound (TRUS)-guided prostate biopsies are among the most common outpatient diagnostic procedures in urology clinics and carry the risk of introducing pathogens that may lead to infection. To investigate the effectiveness of procedures for disinfecting a probe used in ultrasound-guided prostate biopsy. The effectiveness of disinfection was determined by inoculating 10(7) colony forming units (cfu) of Pseudomonas aeruginosa at the following 3 sites on the probe: the interior lumen of the biopsy needle guide, the outside surface of the biopsy needle guide, and the interior lumen of the ultrasound probe where the needle guide passes through the transducer. Each site was investigated separately. After inoculation, the probe was immersed in 2% glutaraldehyde for 20 minutes and then assessed for the level of microbial contamination. The results demonstrated that disinfection (ie, a reduction in bacterial load of greater than 7 log(10) cfu) could be achieved if the needle guide was removed from the probe. However, if the needle guide was left in the probe channel during immersion in 2% glutaraldehyde, disinfection was not achieved (ie, the reduction was approximately 1 log(10) cfu). Recommendations for probe disinfection are provided and include disassembling the device and immersing the probe and the needle guide separately in a high-level disinfectant.

Radiofrequency Ablation of Uterine Fibroids: a Review.

PubMed

Lee, Bruce B; Yu, Steve P

2016-01-01

Laparoscopic, ultrasound-guided radiofrequency ablation (RFA) is a new, FDA-cleared uterine sparing, outpatient procedure for uterine fibroids. The procedure utilizes recent technological advancements in instrumentation and imaging, allowing surgeons to treat numerous fibroids of varying size and location in a minimally invasive fashion. Early and mid-term data from multi-center clinical trials have demonstrated safety and efficacy, with resolution or improvement of symptoms and significant volume reduction. Re-intervention rates for fibroid symptoms have been low. The procedure is well tolerated with a typically uneventful and rapid recovery requiring NSAIDs only for postoperative pain. While post RFA pregnancy data are limited, the results are promising.

Intracranial inertial cavitation threshold and thermal ablation lesion creation using MRI-guided 220-kHz focused ultrasound surgery: preclinical investigation.

PubMed

Xu, Zhiyuan; Carlson, Carissa; Snell, John; Eames, Matt; Hananel, Arik; Lopes, M Beatriz; Raghavan, Prashant; Lee, Cheng-Chia; Yen, Chun-Po; Schlesinger, David; Kassell, Neal F; Aubry, Jean-Francois; Sheehan, Jason

2015-01-01

In biological tissues, it is known that the creation of gas bubbles (cavitation) during ultrasound exposure is more likely to occur at lower rather than higher frequencies. Upon collapsing, such bubbles can induce hemorrhage. Thus, acoustic inertial cavitation secondary to a 220-kHz MRI-guided focused ultrasound (MRgFUS) surgery is a serious safety issue, and animal studies are mandatory for laying the groundwork for the use of low-frequency systems in future clinical trials. The authors investigate here the in vivo potential thresholds of MRgFUS-induced inertial cavitation and MRgFUS-induced thermal coagulation using MRI, acoustic spectroscopy, and histology. Ten female piglets that had undergone a craniectomy were sonicated using a 220-kHz transcranial MRgFUS system over an acoustic energy range of 5600-14,000 J. For each piglet, a long-duration sonication (40-second duration) was performed on the right thalamus, and a short sonication (20-second duration) was performed on the left thalamus. An acoustic power range of 140-300 W was used for long-duration sonications and 300-700 W for short-duration sonications. Signals collected by 2 passive cavitation detectors were stored in memory during each sonication, and any subsequent cavitation activity was integrated within the bandwidth of the detectors. Real-time 2D MR thermometry was performed during the sonications. T1-weighted, T2-weighted, gradient-recalled echo, and diffusion-weighted imaging MRI was performed after treatment to assess the lesions. The piglets were killed immediately after the last series of posttreatment MR images were obtained. Their brains were harvested, and histological examinations were then performed to further evaluate the lesions. Two types of lesions were induced: thermal ablation lesions, as evidenced by an acute ischemic infarction on MRI and histology, and hemorrhagic lesions, associated with inertial cavitation. Passive cavitation signals exhibited 3 main patterns identified as

Ultrasound-guided fine needle aspiration versus core needle biopsy: comparison of post-biopsy hematoma rates and risk factors.

PubMed

Chae, In Hye; Kim, Eun-Kyung; Moon, Hee Jung; Yoon, Jung Hyun; Park, Vivian Y; Kwak, Jin Young

2017-07-01

To compare post-biopsy hematoma rates between ultrasound guided-fine needle aspiration and ultrasound guided-core needle biopsy, and to investigate risk factors for post-biopsy hematoma. A total of 5304 thyroid nodules which underwent ultrasound guided biopsy were included in this retrospective study. We compared clinical and US features between patients with and without post-biopsy hematoma. Associations between these features and post-biopsy hematoma were analyzed. Post-biopsy hematoma rate was 0.8% (43/5121) for ultrasound guided-fine needle aspiration and 4.9% (9/183) for ultrasound guided-core needle biopsy (P < 0.001). For ultrasound guided-fine needle aspiration, gender, age, size, presence of vascularity, and suspicious US features were not associated with post-biopsy hematoma according to experience level. Post-biopsy hematoma occurred significantly more with ultrasound guided-core needle biopsy (9/179, 5.0%) than with ultrasound guided-fine needle aspiration (9/1138, 0.8%) (P < 0.001) in experienced performers and ultrasound guided-core needle biopsy was the only significant risk factor for post-biopsy hematoma (adjusted Odds Ratio, 6.458, P < 0.001). Post-biopsy hematoma occurred significantly more in ultrasound guided-core needle biopsy than in ultrasound guided-fine needle aspiration and ultrasound guided-core needle biopsy was the only independent factor of post-biopsy hematoma in thyroid nodules.

Ultrasound image-guided therapy enhances antitumor effect of cisplatin.

PubMed

Sasaki, Noboru; Kudo, Nobuki; Nakamura, Kensuke; Lim, Sue Yee; Murakami, Masahiro; Kumara, W R Bandula; Tamura, Yu; Ohta, Hiroshi; Yamasaki, Masahiro; Takiguchi, Mitsuyoshi

2014-01-01

The aim of this study was to clarify whether ultrasound image-guided cisplatin delivery with an intratumor microbubble injection enhances the antitumor effect in a xenograft mouse model. Canine thyroid adenocarcinoma cells were used for all experiments. Before in vivo experiments, the cisplatin and microbubble concentration and ultrasound exposure time were optimized in vitro. For in vivo experiments, cells were implanted into the back of nude mice. Observed by a diagnostic ultrasound machine, a mixture of cisplatin and ultrasound contrast agent, Sonazoid, microbubbles was injected directly into tumors. The amount of injected cisplatin and microbubbles was 1 μg/tumor and 1.2 × 10(7) microbubbles/tumor, respectively, with a total injected volume of 20 μl. Using the same diagnostic machine, tumors were exposed to ultrasound for 15 s. The treatment was repeated four times. The combination of cisplatin, microbubbles, and ultrasound significantly delayed tumor growth as compared with no treatment (after 18 days, 157 ± 55 vs. 398 ± 49 mm(3), P = 0.049). Neither cisplatin alone nor the combination of cisplatin and ultrasound delayed tumor growth. The treatment did not decrease the body weight of mice. Ultrasound image-guided anticancer drug delivery may enhance the antitumor effects of drugs without obvious side effects.

Pregnancies following ultrasound-guided drainage of tubo-ovarian abscess.

PubMed

Gjelland, Knut; Granberg, Seth; Kiserud, Torvid; Wentzel-Larsen, Tore; Ekerhovd, Erling

2012-07-01

To study fertility among women treated by means of ultrasound-guided drainage and antibiotics for tubo-ovarian abscess (TOA). Retrospective cohort study. A tertiary referral center. One hundred women of reproductive age treated for TOA between June 1986 and July 2003. Transvaginal ultrasound-guided drainage of TOA was performed in all patients. The procedure was repeated if a substantial amount of pus was seen using ultrasonography 2-5 days after the initial aspiration, and repeated later if necessary. Frequency of naturally conceived pregnancies. Twenty of 38 (52.6%; 95% CI 36.5-68.9%) women who intended to have a child achieved pregnancy naturally and became mothers. In addition, 7 (50%) of 14 women who were not on birth control on a regular basis became pregnant. No ectopic pregnancies were registered. Ultrasound-guided drainage of TOA in combination with antibiotics seems to preserve fertility in approximately half of the patients. Copyright © 2012 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Transurethral ultrasound-guided laser-induced prostatectomy

NASA Astrophysics Data System (ADS)

Babayan, Richard K.; Roth, Robert A.

1991-07-01

A transurethral ultrasound-guided Nd:YAG laser delivery system has been developed for use as an alternative approach to the treatment of benign prostatic hyperplasia. The TULIP system has been extensively tested in canine models and is currently undergoing FDA trials in humans.

One-year results of the use of endovenous radiofrequency ablation utilising an optimised radiofrequency-induced thermotherapy protocol for the treatment of truncal superficial venous reflux.

PubMed

Badham, George E; Dos Santos, Scott J; Lloyd, Lucinda Ba; Holdstock, Judy M; Whiteley, Mark S

2018-06-01

Background In previous in vitro and ex vivo studies, we have shown increased thermal spread can be achieved with radiofrequency-induced thermotherapy when using a low power and slower, discontinuous pullback. We aimed to determine the clinical success rate of radiofrequency-induced thermotherapy using this optimised protocol for the treatment of superficial venous reflux in truncal veins. Methods Sixty-three patients were treated with radiofrequency-induced thermotherapy using the optimised protocol and were followed up after one year (mean 16.3 months). Thirty-five patients returned for audit, giving a response rate of 56%. Duplex ultrasonography was employed to check for truncal reflux and compared to initial scans. Results In the 35 patients studied, there were 48 legs, with 64 truncal veins treated by radiofrequency-induced thermotherapy (34 great saphenous, 15 small saphenous and 15 anterior accessory saphenous veins). One year post-treatment, complete closure of all previously refluxing truncal veins was demonstrated on ultrasound, giving a success rate of 100%. Conclusions Using a previously reported optimised, low power/slow pullback radiofrequency-induced thermotherapy protocol, we have shown it is possible to achieve a 100% ablation at one year. This compares favourably with results reported at one year post-procedure using the high power/fast pullback protocols that are currently recommended for this device.

Ultrasound- versus Palpation-Guided Injection of Corticosteroid for Plantar Fasciitis: A Meta-Analysis

PubMed Central

Yu, Aixi; Qi, Baiwen

2014-01-01

Background It is controversial whether ultrasound-guided injection of corticosteroid is superior to palpation-guided injection for plantar fasciitis. This meta-analysis was performed to compare the effectiveness of ultrasound-guided and palpation-guided injection of corticosteroid for the treatment of plantar fasciitis. Methods Databases (MEDLINE, Cochrane library and EMBASE) and reference lists were searched from their establishment to August 30, 2013 for randomized controlled trials (RCTs) comparing ultrasound-guided with palpation-guided injection for plantar fasciitis. The Cochrane risk of bias (ROB) tool was used to assess the methodological quality. Outcome measurements were visual analogue scale (VAS), tenderness threshold (TT), heel tenderness index (HTI), response rate, plantar fascia thickness (PFT), hypoechogenicity and heel pad thickness (HPT). The statistical analysis was performed with software RevMan 5.2 and Stata 12.0. When I2<50%, the fixed-effects model was adopted. Otherwise the randomized-effects model was adopted. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) system was used to assess the quality of evidence. Results Five RCTs with 149 patients were identified and analyzed. Compared with palpation-guided injection, ultrasound-guided injection was superior with regard to VAS, TT, response rate, PFT and hypoechogenicity. However, there was no statistical significance between the two groups for HPT and HTI. Conclusion Ultrasound-guided injection of corticosteroid tends to be more effective than palpation-guided injection. However, it needs to be confirmed by further research. PMID:24658102

Guiding intramuscular diaphragm injections using real-time ultrasound and electromyography.

PubMed

Sarwal, Aarti; Cartwright, Michael S; Mitchell, Erin; Williams, Koudy; Walker, Francis O; Childers, Martin K

2015-02-01

We describe a unique method that combines ultrasound and electromyography to guide intramuscular diaphragm injections in anesthetized large animals. Ultrasound was used to visualize the diaphragm on each side of spontaneously breathing, anesthetized beagle dogs and cynomolgus macaques. An electromyography (EMG) needle was introduced and directed by ultrasound to confirm that the needle entered the muscular portion of the diaphragm, and methylene blue was injected. Injection accuracy was confirmed upon necropsy by tracking the spread of methylene blue. All methylene blue injections were confirmed to have been placed appropriately into the diaphragm. This study demonstrates the feasibility and accuracy of using ultrasound and EMG to guide injections and to reduce complications associated with conventional blind techniques. Ultrasound guidance can be used for clinical EMG of the diaphragm. Future applications may include targeted diaphragm injections with gene replacement therapy in neuromuscular diseases. © 2014 Wiley Periodicals, Inc.

Treatment of Refractory Idiopathic Supraorbital Neuralgia Using Percutaneous Pulsed Radiofrequency.

PubMed

Luo, Fang; Lu, Jingjing; Ji, Nan

2018-02-26

No ideal therapeutic method currently exists for refractory idiopathic supraorbital neuralgia patients who do not respond to conservative therapy, including medications and nerve blocks. Pulsed radiofrequency is a neuromodulation technique that does not produce sequelae of nerve damage after treatment. However, the efficacy of percutaneous pulsed radiofrequency for the treatment of refractory idiopathic supraorbital neuralgia is still not clear. The purpose of our study was to evaluate the efficacy and safety of pulsed radiofrequency treatment of the supraorbital nerve for refractory supraorbital neuralgia patients. We prospectively investigated the long-term effects of ultrasound-guided percutaneous pulsed radiofrequency in the treatment of 22 refractory idiopathic supraorbital neuralgia patients. A reduction in the verbal pain numeric rating scale score of more than 50% was used as the standard of effectiveness. The effectiveness rates at different time points within 2 years were calculated. After a single pulsed radiofrequency treatment, the effectiveness rate at 1 and 3 months was 77%, and the rates at 6 months, 1 year, and 2 years were 73%, 64%, and 50%, respectively. Except for a small portion of patients (23%) who experienced mild upper eyelid ecchymosis that gradually disappeared after approximately 2 weeks, no obvious complications were observed. In conclusion, the results of our study demonstrate that for patients with refractory idiopathic supraorbital neuralgia, percutaneous pulsed radiofrequency may be an effective and safe treatment choice. © 2018 World Institute of Pain.

Clinical Utility and Pitfalls of Ultrasound Guided Foreign Body Removal in War Fighters

DTIC Science & Technology

2015-12-01

1 AD_________________ AWARD NUMBER: W81XWH-08-2-0162 TITLE: Clinical Utility and Pitfalls of Ultrasound Guided Foreign Body Removal in War...Clinical Utility and Pitfalls of Ultrasound Guided Foreign Body Removal in War Fighters 5a. CONTRACT NUMBER 5b. GRANT NUMBER: W81XWH-08-2-0162 5c...Purpose: To demonstrate that 1) ultrasound guided foreign body removal (USFBR) is superior to conventional surgery in the cadaver model, 2) USFBR can be

Ultrasound-guided, percutaneous peripheral nerve stimulation: technical note.

PubMed

Chan, Isaac; Brown, Anthony R; Park, Kenneth; Winfree, Christopher J

2010-09-01

Peripheral nerve stimulation is a form of neuromodulation that applies electric current to peripheral nerves to induce stimulation paresthesias within the painful areas. To report a method of ultrasound-guided, percutaneous peripheral nerve stimulation. This technique utilizes real-time imaging to avoid injury to adjacent vascular structures during minimally invasive placement of peripheral nerve stimulator electrodes. We describe a patient that presented with chronic, bilateral foot pain following multiple foot surgeries, for whom a comprehensive, pain management treatment strategy had failed. We utilized ultrasound-guided, percutaneous tibial nerve stimulation at a thigh level to provide durable pain relief on the right side, and open peripheral nerve stimulation on the left. The patient experienced appropriate stimulation paresthesias and excellent pain relief on the plantar aspect of the right foot with the percutaneous electrode. On the left side, we were unable to direct the stimulation paresthesias to the sole of the foot, despite multiple electrode repositionings. A subsequent, open placement of a left tibial nerve stimulator was performed. This revealed that the correct electrode position against the tibial nerve was immediately adjacent to the popliteal artery, and was thus not appropriate for percutaneous placement. We describe a method of ultrasound-guided peripheral nerve stimulation that avoids the invasiveness of electrode placement via an open procedure while providing excellent pain relief. We further describe limitations of the percutaneous approach when navigating close to large blood vessels, a situation more appropriately managed with open peripheral nerve stimulator placement. Ultrasound-guided placement may be considered for patients receiving peripheral nerve stimulators placed within the deep tissues, and not easily placed in a blind fashion.

Ultrasound-guided suprascapular nerve block: a correlation with fluoroscopic and cadaveric findings.

PubMed

Peng, Philip W H; Wiley, Michael J; Liang, James; Bellingham, Geoff A

2010-02-01

Previous work on the ultrasound-guided injection technique and the sonoanatomy of the suprascapular region relevant to the suprascapular nerve (SSN) block suggested that the ultrasound scan showed the presence of the suprascapular notch and transverse ligament. The intended target of the ultrasound-guided injection was the notch. The objective of this case report and the subsequent cadaver dissection findings is to reassess the interpretation of the ultrasound images when locating structures for SSN block. A 45-yr-old man with chronic shoulder pain received an ultrasound-guided SSN block using the suprascapular notch as the intended target. The position of the needle was verified by fluoroscopy, which showed the tip of the needle well outside the suprascapular notch. Similar ultrasound-guided SSN blocks were performed in two cadavers. Dissections were performed which showed that the needle tips were not at the suprascapular notch but, more accurately, were close to the SSN but at the floor of the suprascapular fossa between the suprascapular and spinoglenoid notch. Our fluoroscopic and cadaver dissection findings both suggest that the ultrasound image of the SSN block shown by the well-described technique is actually targeting the nerve on the floor of the suprascapular spine between the suprascapular and spinoglenoid notches rather than the suprascapular notch itself. The structure previously identified as the transverse ligament is actually the fascia layer of the supraspinatus muscle.

Echo decorrelation imaging of ex vivo HIFU and bulk ultrasound ablation using image-treat arrays

NASA Astrophysics Data System (ADS)

Fosnight, Tyler R.; Hooi, Fong Ming; Colbert, Sadie B.; Keil, Ryan D.; Barthe, Peter G.; Mast, T. Douglas

2017-03-01

In this study, the ability of ultrasound echo decorrelation imaging to map and predict heat-induced cell death was tested using bulk ultrasound thermal ablation, high intensity focused ultrasound (HIFU) thermal ablation, and pulse-echo imaging of ex vivo liver tissue by a custom image-treat array. Tissue was sonicated at 5.0 MHz using either pulses of unfocused ultrasound (N=12) (7.5 s, 50.9-101.8 W/cm2 in situ spatial-peak, temporal-peak intensity) for bulk ablation or focused ultrasound (N=21) (1 s, 284-769 W/cm2 in situ spatial-peak, temporal-peak intensity and focus depth of 10 mm) for HIFU ablation. Echo decorrelation and integrated backscatter (IBS) maps were formed from radiofrequency pulse-echo images captured at 118 frames per second during 5.0 s rest periods, beginning 1.1 s after each sonication pulse. Tissue samples were frozen at -80˚C, sectioned, vitally stained, imaged, and semi-automatically segmented for receiver operating characteristic (ROC) analysis. ROC curves were constructed to assess prediction performance for echo decorrelation and IBS. Logarithmically scaled mean echo decorrelation in non-ablated and ablated tissue regions before and after electronic noise and motion correction were compared. Ablation prediction by echo decorrelation and IBS was significant for both focused and bulk ultrasound ablation. The log10-scaled mean echo decorrelation was significantly greater in regions of ablation for both HIFU and bulk ultrasound ablation. Echo decorrelation due to electronic noise and motion was significantly reduced by correction. These results suggest that ultrasound echo decorrelation imaging is a promising approach for real-time prediction of heat-induced cell death for guidance and monitoring of clinical thermal ablation, including radiofrequency ablation and HIFU.

Ultrasound Thermal Field Imaging of Opaque Fluids

NASA Technical Reports Server (NTRS)

Andereck, C. David

1999-01-01

We have initiated an experimental program to develop an ultrasound system for non-intrusively imaging the thermal field in opaque fluids under an externally imposed temperature gradient. Many industrial processes involve opaque fluids, such as molten metals, semiconductors, and polymers, often in situations in which thermal gradients are important. For example, one may wish to understand semiconductor crystal growth dynamics in a Bridgman apparatus. Destructive testing of the crystal after the process is completed gives only indirect information about the fluid dynamics of the formation process. Knowledge of the coupled thermal and velocity fields during the growth process is then essential. Most techniques for non-intrusive velocity and temperature measurement in fluids are optical in nature, and hence the fluids studied must be transparent. In some cases (for example, LDV (laser Doppler velocimetry) and PIV (particle imaging velocimetry)) the velocities of small neutrally buoyant seed particles suspended in the fluid, are measured. Without particle seeding one can use the variation of the index of refraction of the fluid with temperature to visualize, through interferometric, Schlieren or shadowgraph techniques, the thermal field. The thermal field in turn gives a picture of the pattern existing in the fluid. If the object of study is opaque, non-optical techniques must be used. In this project we focus on the use of ultrasound, which propagates easily through opaque liquids and solids. To date ultrasound measurements have almost exclusively relied on the detection of sound scattered from density discontinuities inside the opaque material of interest. In most cases it has been used to visualize structural properties, but more recently the ultrasound Doppler velocimeter has become available. As in the optical case, it relies on seed particles that scatter Doppler shifted sound back to the detector. Doppler ultrasound techniques are, however, not useful for

Forward-viewing endoscopic ultrasound-guided NOTES interventions: A study on peritoneoscopic potential

PubMed Central

Jeong, Seung Uk; Aizan, Hassanuddin; Song, Tae Jun; Seo, Dong Wan; Kim, Su-Hui; Park, Do Hyun; Lee, Sang Soo; Lee, Sung Koo; Kim, Myung-Hwan

2013-01-01

AIM: To evaluate the feasibility of diagnostic and therapeutic transgastric (TG) peritoneoscopic interventions with a forward-viewing endoscopic ultrasound (FV-EUS). METHODS: This prospective endoscopic experimental study used an animal model. Combined TG peritoneoscopic interventions and EUS examination of the intra-abdominal organs were performed using an FV-EUS on 10 animal models (1 porcine and 9 canine). The procedures carried out include EUS evaluation and endoscopic biopsy of intraperitoneal organs, EUS-guided fine needle aspiration (EUS-FNA), EUS-guided radiofrequency ablation (EUS-RFA), and argon plasma coagulation (APC) for hemostatic control. The animals were kept alive for 7 d, and then necropsy was performed to evaluate results and complications. RESULTS: In all 10 animals, TG peritoneoscopy, followed by endoscopic biopsy for the liver, spleen, abdominal wall, and omentum, was performed successfully. APC helped control minor bleeding. Visualization of intra-abdominal solid organs with real-time EUS was accomplished with ease. Intraperitoneal EUS-FNA was successfully performed on the liver, spleen, and kidney. Similarly, a successful outcome was achieved with EUS-RFA of the hepatic parenchyma. No adverse events were recorded during the study. CONCLUSION: Peritoneoscopic natural orifice transluminal endoscopic surgery (NOTES) interventions through FV-EUS were feasible in providing evaluation and performing endoscopic procedures. It promises potential as a platform for future EUS-based NOTES. PMID:24222961

Minimally invasive ultrasound thermal therapy with MR thermal monitoring and guidance

NASA Astrophysics Data System (ADS)

Diederich, Chris J.; Stafford, R. Jason; Price, Roger E.; Nau, William H.; Tyreus, Per Daniel; Rivera, Belinda; Schomer, Donald; Olsson, Lars; Hazle, John D.

2001-06-01

In this study both transurethral and interstitial ultrasound thermal therapy were applied to thermally coagulate targeted portions of the canine prostate or brain and implanted TVT tumors while using MRI-based thermal mapping techniques to monitor the therapy. MRI was also used for target definition, positioning of the applicator, and evaluation of target viability post-therapy. The complex phase-difference mapping technique using an iGE-EPI sequence with lipid suppression was used for determining temperature elevations within the in vivo prostate or brain and surrounding structures. Calculated temperature distributions, thermal dose exposures, T2-wieghted & T1-contrast enhanced images, gross inspection, and histology of sectioned prostates and brains were in good agreement with each other in defining destroyed tissue zones. Interstitial and transurethral ultrasound applicators produce directed zones of thermal coagulation within targeted tissue and implanted tumor, which can be accurately monitored and evaluated by MRI.

Transvaginal Ultrasound-Guided Biopsy of Deep Pelvic Masses: How We Do It.

PubMed

Plett, Sara K; Poder, Liina; Brooks, Rebecca A; Morgan, Tara A

2016-06-01

The purpose of this review is to discuss the rationale and indications for transvaginal ultrasound-guided biopsy. Transvaginal ultrasound-guided biopsy can be a helpful tool for diagnosis and treatment planning in the evaluation of pelvic masses, particularly when the anatomy precludes a transabdominal or posterior transgluteal percutaneous biopsy approach. A step-by-step summary of the technique with preprocedure and postprocedure considerations is included. © 2016 by the American Institute of Ultrasound in Medicine.

Photoacoustic-guided ultrasound therapy with a dual-mode ultrasound array

NASA Astrophysics Data System (ADS)

Prost, Amaury; Funke, Arik; Tanter, Mickaël; Aubry, Jean-François; Bossy, Emmanuel

2012-06-01

Photoacoustics has recently been proposed as a potential method to guide and/or monitor therapy based on high-intensity focused ultrasound (HIFU). We experimentally demonstrate the creation of a HIFU lesion at the location of an optical absorber, by use of photoacoustic signals emitted by the absorber detected on a dual mode transducer array. To do so, a dedicated ultrasound array intended to both detect photoacoustic waves and emit HIFU with the same elements was used. Such a dual-mode array provides automatically coregistered reference frames for photoacoustic detection and HIFU emission, a highly desired feature for methods involving guidance or monitoring of HIFU by use of photoacoustics. The prototype is first characterized in terms of both photoacoustic and HIFU performances. The probe is then used to perform an idealized scenario of photoacoustic-guided therapy, where photoacoustic signals generated by an absorbing thread embedded in a piece of chicken breast are used to automatically refocus a HIFU beam with a time-reversal mirror and necrose the tissue at the location of the absorber.

3D ultrasound imaging in image-guided intervention.

PubMed

Fenster, Aaron; Bax, Jeff; Neshat, Hamid; Cool, Derek; Kakani, Nirmal; Romagnoli, Cesare

2014-01-01

Ultrasound imaging is used extensively in diagnosis and image-guidance for interventions of human diseases. However, conventional 2D ultrasound suffers from limitations since it can only provide 2D images of 3-dimensional structures in the body. Thus, measurement of organ size is variable, and guidance of interventions is limited, as the physician is required to mentally reconstruct the 3-dimensional anatomy using 2D views. Over the past 20 years, a number of 3-dimensional ultrasound imaging approaches have been developed. We have developed an approach that is based on a mechanical mechanism to move any conventional ultrasound transducer while 2D images are collected rapidly and reconstructed into a 3D image. In this presentation, 3D ultrasound imaging approaches will be described for use in image-guided interventions.

Laparoscopic vs computerized tomography-guided radiofrequency ablation for large hepatic hemangiomas abutting the diaphragm

PubMed Central

Gao, Jun; Kong, Jian; Ding, Xue-Mei; Ke, Shan; Niu, Hai-Gang; Xin, Zong-Hai; Ning, Chun-Min; Guo, Shi-Gang; Li, Xiao-Long; Zhang, Long; Dong, Yong-Hong; Sun, Wen-Bing

2015-01-01

AIM: To compare safety and therapeutic efficacy of laparoscopic radiofrequency (RF) ablation vs computed tomography (CT)-guided RF ablation for large hepatic hemangiomas abutting the diaphragm. METHODS: We retrospectively reviewed our sequential experience of treating 51 large hepatic hemangiomas abutting the diaphragm in 51 patients by CT-guided or laparoscopic RF ablation due to either the presence of symptoms and/or the enlargement of hemangioma. Altogether, 24 hemangiomas were ablated via a CT-guided percutaneous approach (CT-guided ablation group), and 27 hemangiomas were treated via a laparoscopic approach (laparoscopic ablation group). RESULTS: The mean diameter of the 51 hemangiomas was 9.6 ± 1.8 cm (range, 6.0-12.0 cm). There was no difference in the diameter of hemangiomas between the two groups (P > 0.05). RF ablation was performed successfully in all patients. There was no difference in ablation times between groups (P > 0.05). There were 23 thoracic complications in 17 patients: 15 (62.5%, 15/24) in the CT-guided ablation group and 2 (7.4%, 2/27) in the laparoscopic ablation group (P < 0.05). According to the Dindo-Clavien classification, two complications (pleural effusion and diaphragmatic rupture grade III) were major in two patients. All others were minor (grade I). Both major complications occurred in the CT-guided ablation group. The minor complications were treated successfully with conservative measures, and the two major complications underwent treatment by chest tube drainage and thoracoscopic surgery, respectively. Complete ablation was achieved in 91.7% (22/24) and 96.3% (26/27) in the CT-guided and the laparoscopic ablation groups, respectively (P > 0.05). CONCLUSION: Laparoscopic RF ablation therapy should be used as the first-line treatment option for large hepatic hemangiomas abutting the diaphragm. It avoids thermal injury to the diaphragm and reduces thoracic complications. PMID:26019459

Comparison of Ultrasound-Guided and Fluoroscopy-Assisted Antegrade Common Femoral Artery Puncture Techniques

DOE Office of Scientific and Technical Information (OSTI.GOV)

Slattery, Michael M.; Goh, Gerard S.; Power, Sarah

PurposeTo prospectively compare the procedural time and complication rates of ultrasound-guided and fluoroscopy-assisted antegrade common femoral artery (CFA) puncture techniques.Materials and MethodsHundred consecutive patients, undergoing a vascular procedure for which an antegrade approach was deemed necessary/desirable, were randomly assigned to undergo either ultrasound-guided or fluoroscopy-assisted CFA puncture. Time taken from administration of local anaesthetic to vascular sheath insertion in the superficial femoral artery (SFA), patients’ age, body mass index (BMI), fluoroscopy radiation dose, haemostasis method and immediate complications were recorded. Mean and median values were calculated and statistically analysed with unpaired t tests.ResultsSixty-nine male and 31 female patients underwent antegrademore » puncture (mean age 66.7 years). The mean BMI was 25.7 for the ultrasound-guided (n = 53) and 25.3 for the fluoroscopy-assisted (n = 47) groups. The mean time taken for the ultrasound-guided puncture was 7 min 46 s and for the fluoroscopy-assisted technique was 9 min 41 s (p = 0.021). Mean fluoroscopy dose area product in the fluoroscopy group was 199 cGy cm{sup 2}. Complications included two groin haematomas in the ultrasound-guided group and two retroperitoneal haematomas and one direct SFA puncture in the fluoroscopy-assisted group.ConclusionUltrasound-guided technique is faster and safer for antegrade CFA puncture when compared to the fluoroscopic-assisted technique alone.« less

Ultrasound-guided central venous access using Google Glass.

PubMed

Wu, Teresa S; Dameff, Christian J; Tully, Jeffrey L

2014-12-01

The use of ultrasound during invasive bedside procedures is quickly becoming the standard of care. Ultrasound machine placement during procedures often requires the practitioner to turn their head during the procedure to view the screen. Such turning has been implicated in unintentional hand movements in novices. Google Glass is a head-mounted computer with a specialized screen capable of projecting images and video into the view of the wearer. Such technology may help decrease unintentional hand movements. Our aim was to evaluate whether or not medical practitioners at various levels of training could use Google Glass to perform an ultrasound-guided procedure, and to explore potential advantages of this technology. Forty participants of varying training levels were randomized into two groups. One group used Google Glass to perform an ultrasound-guided central line. The other group used traditional ultrasound during the procedure. Video recordings of eye and hand movements were analyzed. All participants from both groups were able to complete the procedure without difficulty. Google Glass wearers took longer to perform the procedure at all training levels (medical student year 1 [MS1]: 193 s vs. 77 s, p > 0.5; MS4: 197s vs. 91s, p ≤ 0.05; postgraduate year 1 [PGY1]: 288s vs. 125 s, p > 0.5; PGY3: 151 s vs. 52 s, p ≤ 0.05), and required more needle redirections (MS1: 4.4 vs. 2.0, p > 0.5; MS4: 4.8 vs. 2.8, p > 0.5; PGY1: 4.4 vs. 2.8, p > 0.5; PGY3: 2.0 vs. 1.0, p > 0.5). In this study, it was possible to perform ultrasound-guided procedures with Google Glass. Google Glass wearers, on average, took longer to gain access, and had more needle redirections, but less head movements were noted. Copyright © 2014 Elsevier Inc. All rights reserved.

WE-H-209-00: Carson/Zagzebski Distinguished Lectureship: Image Guided Ultrasound Therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

Focused ultrasound has been shown to be the only method that allows noninvasive thermal coagulation of tissues and recently this potential has been explored for image-guided drug delivery. In this presentation, the advances in ultrasound phased array technology for energy delivery, exposure monitoring and control will be discussed. Experimental results from novel multi-frequency transmit/receive arrays will be presented. In addition, the feasibility of fully electronically focused and steered high power arrays with many thousands of transducer elements will be discussed. Finally, some of the recent clinical and preclinical results for the treatment of brain disease will be reviewed. Learning Objectives:more » Introduce FUS therapy principles and modern techniques Discuss use of FUS for drug delivery Cover the technology required to deliver FUS and monitor therapy Present clinical examples of the uses of these techniques This research was supported by funding from The Canada Research Chair Program, Grants from CIHR and NIH (no. EB003268).; K. Hynynen, Canada Foundation for Innovation; Canadian Institutes of Health Research; Focused Ultrasound Surgery Foundation; Canada Research Chair Program; Natural Sciences and Engineering Research Council of Canada; Ontario Research Fund; National Institutes of Health; Canadian Cancer Society Research Institute; The Weston Brain Institute; Harmonic Medical; Focused Ultrasound Instruments.« less

Image-guided endobronchial ultrasound

NASA Astrophysics Data System (ADS)

Higgins, William E.; Zang, Xiaonan; Cheirsilp, Ronnarit; Byrnes, Patrick; Kuhlengel, Trevor; Bascom, Rebecca; Toth, Jennifer

2016-03-01

Endobronchial ultrasound (EBUS) is now recommended as a standard procedure for in vivo verification of extraluminal diagnostic sites during cancer-staging bronchoscopy. Yet, physicians vary considerably in their skills at using EBUS effectively. Regarding existing bronchoscopy guidance systems, studies have shown their effectiveness in the lung-cancer management process. With such a system, a patient's X-ray computed tomography (CT) scan is used to plan a procedure to regions of interest (ROIs). This plan is then used during follow-on guided bronchoscopy. Recent clinical guidelines for lung cancer, however, also dictate using positron emission tomography (PET) imaging for identifying suspicious ROIs and aiding in the cancer-staging process. While researchers have attempted to use guided bronchoscopy systems in tandem with PET imaging and EBUS, no true EBUS-centric guidance system exists. We now propose a full multimodal image-based methodology for guiding EBUS. The complete methodology involves two components: 1) a procedure planning protocol that gives bronchoscope movements appropriate for live EBUS positioning; and 2) a guidance strategy and associated system graphical user interface (GUI) designed for image-guided EBUS. We present results demonstrating the operation of the system.

Noninvasive body sculpting technologies with an emphasis on high-intensity focused ultrasound.

PubMed

Jewell, Mark L; Solish, Nowell J; Desilets, Charles S

2011-10-01

Body-sculpting procedures are becoming increasingly popular in the United States. Although surgical lipoplasty remains the most common body sculpting procedure, a demand exists for noninvasive alternatives capable of reducing focal adiposity without the risks of adverse events (AEs) associated with invasive excisional body-sculpting procedures. This report describes the mechanism of action, efficacy, safety, and tolerability of cryolipolysis, radiofrequency ablation, low-level external laser therapy, injection lipolysis, low-intensity nonthermal ultrasound, and high-intensity focused ultrasound (HIFU), with an emphasis on thermal HIFU. The articles cited were identified via a PubMed search, with additional article citations identified by manual searching of the reference lists of articles identified through the literature search. Each of the noninvasive treatments reviewed can be administered on an outpatient basis. These treatments generally have fewer complications than lipoplasty and require little or no anesthesia or analgesia. However, HIFU is the only treatment that can produce significant results in a single treatment, and only radiofrequency, low-level laser therapy, and cryolipolysis have been approved for use in the United States. Early clinical data on HIFU support its efficacy and safety for body sculpting. In contrast, radiofrequency, laser therapy, and injection lipolysis have been associated with significant AEs. The published literature suggests that noninvasive body-sculpting techniques such as radiofrequency ablation, cryolipolysis, external low-level lasers, laser ablation, nonthermal ultrasound, and HIFU may be appropriate options for nonobese patients requiring modest reduction of adipose tissue.

Ultrasound-guided percutaneous injection of methylene blue to identify nerve pathology and guide surgery.

PubMed

Osorio, Joseph A; Breshears, Jonathan D; Arnaout, Omar; Simon, Neil G; Hastings-Robinson, Ashley M; Aleshi, Pedram; Kliot, Michel

2015-09-01

OBJECT The objective of this study was to provide a technique that could be used in the preoperative period to facilitate the surgical exploration of peripheral nerve pathology. METHODS The authors describe a technique in which 1) ultrasonography is used in the immediate preoperative period to identify target peripheral nerves, 2) an ultrasound-guided needle electrode is used to stimulate peripheral nerves to confirm their position, and then 3) a methylene blue (MB) injection is performed to mark the peripheral nerve pathology to facilitate surgical exploration. RESULTS A cohort of 13 patients with varying indications for peripheral nerve surgery is presented in which ultrasound guidance, stimulation, and MB were used to localize and create a road map for surgeries. CONCLUSIONS Preoperative ultrasound-guided MB administration is a promising technique that peripheral nerve surgeons could use to plan and execute surgery.

[Ultrasound-guided microwave ablation with artificial pleural effusion for liver tumor adjacent to 
diaphragmatic dome].

PubMed

Tang, Tian; Gu, Shanzhi; Li, Guowen; Huang, Manping; Huang, Bin; Xiong, Zhengping

2017-02-28

To explore the value of ultrasound-guided microwave ablation with artificial pleural effusion for liver tumor adjacent to diaphragmatic dome.
 Methods: A total of 34 patients with liver tumors located at diaphragmatic dome in Hunan Provincial Tumor Hospital were recruited from January 2014 to October 2015. The number of lesions ≤3 or lesion diameter ≤5 cm was in line with the microwave ablation indications. B ultrasound-guided microwave ablation for the liver tumors was undertaken after the artificial pleural effusion being established. 3-4 weeks later after the microwave ablation, all patients were imaged with enhance CT or MRI. The effect of ablation and the complications were evaluated.
 Results: There were 49 lesions in 34 patients, including 30 cases (88.2%) of complete ablation (CA), 3 cases (8.8%) of partial ablation (PA) and one case with new lesions after ablation (2.9%). Thirty-four patients had (1 580±230.7) mL of pleural effusion volume, while one case had bloody pleural effusion. One case had a diaphragmatic thermal injury, and one case had a biliary tumor infection. All of them showed remission after symptomatic treatment. 
 Conclusion: Combination of ultrasound-guided microwave ablation with artificial pleural effusion is a safe and effective therapy for liver tumor adjacent to diaphragmatic dome.

Initial experience of EUS-guided radiofrequency ablation of unresectable pancreatic cancer.

PubMed

Song, Tae Jun; Seo, Dong Wan; Lakhtakia, Sundeep; Reddy, Nageshwar; Oh, Dong Wook; Park, Do Hyun; Lee, Sang Soo; Lee, Sung Koo; Kim, Myung-Hwan

2016-02-01

Radiofrequency ablation (RFA) has been used as a valuable treatment modality for various unresectable malignancies. EUS-guided radiofrequency ablation (EUS-RFA) of the porcine pancreas was reported to be feasible and safe in our previous study, suggesting that EUS-RFA may be applicable as an adjunct and effective alternative treatment method for unresectable pancreatic cancer. This study aimed to assess the technical feasibility and safety of EUS-RFA for unresectable pancreatic cancer. An 18-gauge endoscopic RFA electrode and a radiofrequency generator were used for the procedure. The length of the exposed tip of the RFA electrode was 10 mm. After insertion of the RFA electrode into the mass, the radiofrequency generator was activated to deliver 20 to 50 W ablation power for 10 seconds. Depending on tumor size, the procedure was repeated to sufficiently cover the tumor. EUS-RFA was performed successfully in all 6 patients (median age 62 years, range 43-73 years). Pancreatic cancer was located in the head (n = 4) or body (n = 2) of the pancreas. The median diameter of masses was 3.8 cm (range 3cm-9cm). Four patients had stage 3 disease, and 2 patients had stage 4 disease. After the procedure, 2 patients experienced mild abdominal pain, but there were no other adverse events such as pancreatitis or bleeding. EUS-RFA could be a technically feasible and safe option for patients with unresectable pancreatic cancer. Copyright © 2016 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.

An experimental model to investigate the targeting accuracy of MR-guided focused ultrasound ablation in liver.

PubMed

Petrusca, Lorena; Viallon, Magalie; Breguet, Romain; Terraz, Sylvain; Manasseh, Gibran; Auboiroux, Vincent; Goget, Thomas; Baboi, Loredana; Gross, Patrick; Sekins, K Michael; Becker, Christoph D; Salomir, Rares

2014-01-16

Magnetic Resonance-guided High Intensity Focused Ultrasound (MRgHIFU) is a hybrid technology that aims to offer non-invasive thermal ablation of targeted tumors or other pathological tissues. Acoustic aberrations and non-linear wave propagating effects may shift the focal point significantly away from the prescribed (or, theoretical) position. It is therefore mandatory to evaluate the spatial accuracy of ablation for a given HIFU protocol and/or device. We describe here a method for producing a user-defined ballistic target as an absolute reference marker for MRgHIFU ablations. The investigated method is based on trapping a mixture of MR contrast agent and histology stain using radiofrequency (RF) ablation causing cell death and coagulation. A dedicated RF-electrode was used for the marker fixation as follows: a RF coagulation (4 W, 15 seconds) and injection of the mixture followed by a second RF coagulation. As a result, the contrast agent/stain is encapsulated in the intercellular space. Ultrasonography imaging was performed during the procedure, while high resolution T1w 3D VIBE MR acquisition was used right after to identify the position of the ballistic marker and hence the target tissue. For some cases, after the marker fixation procedure, HIFU volumetric ablations were produced by a phased-array HIFU platform. First ex vivo experiments were followed by in vivo investigation on four rabbits in thigh muscle and six pigs in liver, with follow-up at Day 7. At the end of the procedure, no ultrasound indication of the marker's presence could be observed, while it was clearly visible under MR and could be conveniently used to prescribe the HIFU ablation, centered on the so-created target. The marker was identified at Day 7 after treatment, immediately after animal sacrifice, after 3 weeks of post-mortem formalin fixation and during histology analysis. Its size ranged between 2.5 and 4 mm. Experimental validation of this new ballistic marker method was performed for

Guided Interventions for Prostate Cancer Using 3D-Transurethral Ultrasound and MRI Fusion

DTIC Science & Technology

2015-10-01

AWARD NUMBER: W81XWH-14-1-0461 TITLE: Guided Interventions for Prostate Cancer Using 3D-Transurethral Ultrasound and MRI Fusion PRINCIPAL...Sep 2014 - 28 Sep 2015 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Guided Interventions for Prostate Cancer Using 3D- Transurethral Ultrasound and...Magnetic Resonance- Ultrasound (MR-US) fusion allows for specific targeting of the tumors in real-time during clinical interventions, outside of an MR

Improved accuracy of ultrasound-guided therapies using electromagnetic tracking: in-vivo speed of sound measurements

NASA Astrophysics Data System (ADS)

Samboju, Vishal; Adams, Matthew; Salgaonkar, Vasant; Diederich, Chris J.; Cunha, J. Adam M.

2017-02-01

The speed of sound (SOS) for ultrasound devices used for imaging soft tissue is often calibrated to water, 1540 m/s1 , despite in-vivo soft tissue SOS varying from 1450 to 1613 m/s2 . Images acquired with 1540 m/s and used in conjunction with stereotactic external coordinate systems can thus result in displacement errors of several millimeters. Ultrasound imaging systems are routinely used to guide interventional thermal ablation and cryoablation devices, or radiation sources for brachytherapy3 . Brachytherapy uses small radioactive pellets, inserted interstitially with needles under ultrasound guidance, to eradicate cancerous tissue4 . Since the radiation dose diminishes with distance from the pellet as 1/r2 , imaging uncertainty of a few millimeters can result in significant erroneous dose delivery5,6. Likewise, modeling of power deposition and thermal dose accumulations from ablative sources are also prone to errors due to placement offsets from SOS errors7 . This work presents a method of mitigating needle placement error due to SOS variances without the need of ionizing radiation2,8. We demonstrate the effects of changes in dosimetry in a prostate brachytherapy environment due to patientspecific SOS variances and the ability to mitigate dose delivery uncertainty. Electromagnetic (EM) sensors embedded in the brachytherapy ultrasound system provide information regarding 3D position and orientation of the ultrasound array. Algorithms using data from these two modalities are used to correct bmode images to account for SOS errors. While ultrasound localization resulted in >3 mm displacements, EM resolution was verified to <1 mm precision using custom-built phantoms with various SOS, showing 1% accuracy in SOS measurement.

Ultrasound guided double injection of blood into cisterna magna: a rabbit model for treatment of cerebral vasospasm.

PubMed

Chen, Yongchao; Zhu, Youzhi; Zhang, Yu; Zhang, Zixuan; Lian, Juan; Luo, Fucheng; Deng, Xuefei; Wong, Kelvin K L

2016-02-06

Double injection of blood into cisterna magna using a rabbit model results in cerebral vasospasm. An unacceptably high mortality rate tends to limit the application of model. Ultrasound guided puncture can provide real-time imaging guidance for operation. The aim of this paper is to establish a safe and effective rabbit model of cerebral vasospasm after subarachnoid hemorrhage with the assistance of ultrasound medical imaging. A total of 160 New Zealand white rabbits were randomly divided into four groups of 40 each: (1) manual control group, (2) manual model group, (3) ultrasound guided control group, and (4) ultrasound guided model group. The subarachnoid hemorrhage was intentionally caused by double injection of blood into their cisterna magna. Then, basilar artery diameters were measured using magnetic resonance angiography before modeling and 5 days after modeling. The depth of needle entering into cisterna magna was determined during the process of ultrasound guided puncture. The mortality rates in manual control group and model group were 15 and 23 %, respectively. No rabbits were sacrificed in those two ultrasound guided groups. We found that the mortality rate in ultrasound guided groups decreased significantly compared to manual groups. Compared with diameters before modeling, the basilar artery diameters after modeling were significantly lower in manual and ultrasound guided model groups. The vasospasm aggravated and the proportion of severe vasospasms was greater in ultrasound guided model group than that of manual group. In manual model group, no vasospasm was found in 8 % of rabbits. The ultrasound guided double injection of blood into cisterna magna is a safe and effective rabbit model for treatment of cerebral vasospasm.

Musculoskeletal ultrasound: how to treat calcific tendinitis of the rotator cuff by ultrasound-guided single-needle lavage technique.

PubMed

Lee, Kenneth S; Rosas, Humberto G

2010-09-01

The purpose of this video article is to illustrate the ultrasound appearance of calcium deposition in the rotator cuff and provide a detailed step-by-step protocol for performing the ultrasound-guided single-needle lavage technique for the treatment of calcific tendinitis with emphasis on patient positioning, necessary supplies, real-time lavage technique, and steroid injection into the subacromial subdeltoid bursa. Musculoskeletal ultrasound is well established as a safe, cost-effective imaging tool in diagnosing and treating common musculoskeletal disorders. Calcific tendinitis of the rotator cuff is a common disabling cause of shoulder pain. Although most cases are self-limiting, a subset of patients is refractory to conservative therapy and requires treatment intervention. Ultrasound-guided lavage is an effective and safe minimally-invasive treatment not readily offered in the United States as an alternative to surgery, perhaps because of the limited prevalence of musculoskeletal ultrasound programs and limited training. On completion of this video article, the participant should be able to develop an appropriate diagnostic and therapeutic algorithm for the treatment of calcific tendinitis of the rotator cuff using ultrasound.

The Effectiveness and Risks of Fluoroscopically-Guided Cervical Medial Branch Thermal Radiofrequency Neurotomy: A Systematic Review with Comprehensive Analysis of the Published Data.

PubMed

Engel, Andrew; Rappard, George; King, Wade; Kennedy, David J

2016-04-01

To determine the effectiveness and risks of fluoroscopically-guided cervical medial branch thermal radiofrequency neurotomy (CMBTRFN) for treating chronic neck pain of zygapophysial joint origin. Systematic review of the literature with comprehensive analysis of the published data. Four reviewers formally trained in evidence-based medicine searched the literature on CMBTRFN. Each assessed the methodologies of studies found and appraised the quality of evidence presented. The primary outcomes assessed were 100% relief of pain 6 and 12 months after treatment. Other outcomes were noted if reported. The evidence was evaluated in accordance with the Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) system. The searches yielded eight primary publications on the effectiveness of the procedure. The evidence shows a majority of patients were pain free at 6 months and over a third were pain free at 1 year. The number needed to treat for complete pain relief at 6 months is 2. The evidence of effectiveness is of high quality according to the GRADE system. Twelve papers were found reporting unwanted effects, most of which are minor and temporary. No serious complications have ever been reported from procedures performed according to the published guidelines. The evidence of risks is of low quality according to the GRADE system. If performed as described in the International Spine Intervention Society Guidelines, fluoroscopically-guided CMBTRFN is effective for abolishing zygapophysial joint pain and carries only minor risks. © 2015 American Academy of Pain Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Multifrequency ultrasound transducers for conformal interstitial thermal therapy.

PubMed

Chopra, Rajiv; Luginbuhl, Chris; Foster, F Stuart; Bronskill, Michael J

2003-07-01

Control over the pattern of thermal damage generated by interstitial ultrasound heating applicators can be enhanced by changing the ultrasound frequency during heating. The ability to change transmission frequency from a single transducer through the use of high impedance front layers was investigated in this study. The transmission spectrum of multifrequency transducers was calculated using the KLM equivalent circuit model and verified with experimental measurements on prototype transducers. The addition of a quarter-wavelength thick PZT (unpoled) front layer enabled the transmission of ultrasound at two discrete frequencies, 4.7 and 9.7 MHz, from a transducer with an original resonant frequency of 8.4 MHz. Three frequency transmission at 3.3, 8.4, and 10.8 MHz was possible for a transducer with a half-wavelength thick front layer. Calculations of the predicted thermal lesion size at each transmission frequency indicated that the depth of thermal lesion could be varied by a factor of 1.6 for the quarter-wavelength front layer. Heating experiments performed in excised liver tissue with a dual-frequency applicator confirmed this ability to control the shape of thermal lesions during heating to generate a desired geometry. Practical interstitial designs that enable the generation of shaped thermal lesions are feasible.

Efficacy of ultrasound-guided percutaneous needle treatment of calcific tendinitis.

PubMed

Vignesh, K Nithin; McDowall, Adam; Simunovic, Nicole; Bhandari, Mohit; Choudur, Hema N

2015-01-01

The purpose of this study was to conduct a systematic review of the efficacy of ultrasound-guided needle lavage in treating calcific tendinitis. Two independent assessors searched medical databases and screened studies for eligibility. Eleven articles were included. Heterogeneity among included studies precluded meta-analysis. Results of randomized controlled trials suggested no difference in pain relief between needle lavage and other interventions, but the studies were of low quality. Additional high-quality evidence is required to determine the relative efficacy of ultrasound-guided needle lavage in the management of calcific tendinitis of the rotator cuff.

Analgesic Effect and Functional Improvement Caused by Radiofrequency Treatment of Genicular Nerves in Patients With Advanced Osteoarthritis of the Knee Until 1 Year Following Treatment.

PubMed

Santana Pineda, María M; Vanlinthout, Luc E; Moreno Martín, Ana; van Zundert, Jan; Rodriguez Huertas, Fernando; Novalbos Ruiz, José P

Radiofrequency ablation of genicular nerves has proved to be successful in relieving pain and incapacity caused by osteoarthritis of the knee. However, long-term efficacy of such a treatment remains to be assessed. The current study aimed to reproduce radiofrequency neurotomy of genicular nerves to manage gonarthrosis pain and disability and establish therapeutic response until 1 year after intervention. This single-center, prospective, observational, noncontrolled, longitudinal study included patients with grade 3 to 4 gonarthrosis suffering from intractable knee pain, scoring 5 or more on the visual analog scale (VAS) during >6 months. Therapy was based on ultrasound guided radiofrequency neurotomy of the superior medial, superior lateral and inferior medial genicular nerves. Visual analog scale and Western Ontario and McMaster Universities Osteoarthritis scores were assessed before therapy and at 1, 6, and 12 months following treatment. Radiofrequency neurotomy of genicular nerves significantly reduced perceived pain (VAS) and disability (Western Ontario and McMaster Universities Osteoarthritis) in the majority of participants, without untoward events. The proportion of participants with improvement of 50% or greater in pretreatment VAS scores at 1, 6, and 12 months following intervention were 22/25 (88%), 16/25 (64%) and 8/25 (32%), respectively. Ultrasound-guided radiofrequency neurotomy of genicular nerves alleviates intractable pain and disability in the majority of patients with advanced osteoarthritis of the knee. Such a treatment is safe and minimally invasive and can be performed in an outpatient setting. The beneficial effect of treatment started to decline after 6 months, but even 1 year after the intervention, 32% of patients reported 50% improvement or greater in pretreatment VAS scores.

Comparison of Thermal Safety Practice Guidelines for Diagnostic Ultrasound Exposures.

PubMed

Harris, Gerald R; Church, Charles C; Dalecki, Diane; Ziskin, Marvin C; Bagley, Jennifer E

2016-02-01

This article examines the historical evolution of various practice guidelines designed to minimize the possibility of thermal injury during a diagnostic ultrasound examination, including those published by the American Institute of Ultrasound in Medicine, British Medical Ultrasound Society and Health Canada. The guidelines for prenatal/neonatal examinations are in general agreement, but significant differences were found for postnatal exposures. We propose sets of thermal index versus exposure time for these examination categories below which there is reasonable assurance that an examination can be conducted without risk of producing an adverse thermal effect under any scanning conditions. If it is necessary to exceed these guidelines, the occurrence of an adverse thermal event is still unlikely in most situations because of mitigating factors such as transducer movement and perfusion, but the general principle of "as low as reasonably achievable" should be followed. Some limitations of the biological effects studies underpinning the guidelines also are discussed briefly. Copyright © 2016 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Endoscopic ultrasound-guided transmural drainage of postoperative pancreatic collections.

PubMed

Tilara, Amy; Gerdes, Hans; Allen, Peter; Jarnagin, William; Kingham, Peter; Fong, Yuman; DeMatteo, Ronald; D'Angelica, Michael; Schattner, Mark

2014-01-01

Pancreatic leak is a major cause of morbidity after pancreatectomy. Traditionally, peripancreatic fluid collections have been managed by percutaneous or operative drainage. Data for endoscopic ultrasound (EUS)-guided drainage of postoperative fluid collections are limited. Here we report on the safety, efficacy, and timing of EUS-guided drainage of postoperative peripancreatic collections. This is a retrospective review of 31 patients who underwent EUS-guided drainage of fluid collections after pancreatic resection. Technical success was defined as successful transgastric deployment of at least one double pigtail plastic stent. Clinical success was defined as resolution of the fluid collection on follow-up CT scan and resolution of symptoms. Early drainage was defined as initial transmural stent placement within 30 days after surgery. Endoscopic ultrasound-guided drainage was performed effectively with a technical success rate of 100%. Clinical success was achieved in 29 of 31 patients (93%). Nineteen of the 29 patients (65%) had complete resolution of their symptoms and collection with the first endoscopic procedure. Repeat drainage procedures, including some with necrosectomy, were required in the remaining 10 patients, with eventual resolution of collection and symptoms. Two patients who did not achieve durable clinical success required percutaneous drainage by interventional radiology. Seventeen (55%) of 31 patients had successful early drainage completed within 30 days of their operation. Endoscopic ultrasound-guided drainage of fluid collections after pancreatic resection is safe and effective. Early drainage (<30 days) of postoperative pancreatic fluid collections was not associated with increased complications in this series. Copyright © 2014 American College of Surgeons. Published by Elsevier Inc. All rights reserved.

Minimally Invasive Ultrasound-Guided Carpal Tunnel Release: Preliminary Clinical Results.

PubMed

Henning, P Troy; Yang, Lynda; Awan, Tariq; Lueders, Daniel; Pourcho, Adam M

2018-04-02

Ultrasound-guided carpal tunnel release was performed on 14 patients (18 wrists) using dynamic expansion of the transverse safe zone. Our patient population included able-bodied patients and those with impairments. The first 8 cases (12 wrists) underwent the procedure in an operating room, the remainder in an outpatient setting. No complications occurred, and all patients were able to immediately resume use of their hands without therapy. Improvements in the Quick Form of the Disabilities of the Arm, Shoulder, and Hand Index and Boston Carpal Tunnel Questionnaire at 3 months were comparable to results reported with mini-open and endoscopic release. Our results show that ultrasound-guided carpal tunnel release can be safely and effectively performed in an outpatient setting. © 2018 by the American Institute of Ultrasound in Medicine.

In vivo characterization of tissue thermal properties of the kidney during local hyperthermia induced by MR-guided high-intensity focused ultrasound.

PubMed

Cornelis, François; Grenier, Nicolas; Moonen, Chrit T; Quesson, Bruno

2011-08-01

The purpose of this study was to evaluate quantitatively in vivo the tissue thermal properties during high-intensity focused ultrasound (HIFU) heating. For this purpose, a total of 52 localized sonications were performed in the kidneys of six pigs with HIFU monitored in real time by volumetric MR thermometry. The kidney perfusion was modified by modulation of the flow in the aorta by insertion of an inflatable angioplasty balloon. The resulting temperature data were analyzed using the bio-heat transfer model in order to validate the model under in vivo conditions and to estimate quantitatively the absorption (α), thermal diffusivity (D) and perfusion (w(b)) of renal tissue. An excellent correspondence was observed between the bio-heat transfer model and the experimental data. The absorption and thermal diffusivity were independent of the flow, with mean values (± standard deviation) of 20.7 ± 5.1 mm(3) K J(-1) and 0.23 ± 0.11 mm(2) s(-1), respectively, whereas the perfusion decreased significantly by 84% (p < 0.01) with arterial flow (mean values of w(b) of 0.06 ± 0.02 and 0.008 ± 0.007 mL(-1) mL s(-1)), as predicted by the model. The quantitative analysis of the volumetric temperature distribution during nondestructive HIFU sonication allows the determination of the thermal parameters, and may therefore improve the quality of the planning of noninvasive therapy with MR-guided HIFU. Copyright © 2010 John Wiley & Sons, Ltd.

Are Ultrasound-Guided Ophthalmic Blocks Injurious to the Eye? A Comparative Rabbit Model Study of Two Ultrasound Devices Evaluating Intraorbital Thermal and Structural Changes

PubMed Central

Palte, Howard D.; Gayer, Steven; Arrieta, Esdras; Shaw, Eric Scot; Nose, Izuru; Lee, Elizabete; Arheart, Kristopher L.; Dubovy, Sander; Birnbach, David J.; Parel, Jean-Marie

2012-01-01

Background Since Atkinson’s original description of retrobulbar block in 1936, needle-based anesthetic techniques have become integral to ophthalmic anesthesia. These techniques are unfortunately associated with rare, grave complications such as globe perforation. Ultrasound has gained widespread acceptance for peripheral nerve blockade but its translation to ocular anesthesia has been hampered because sonic energy, in the guise of thermal or biomechanical insult, is potentially injurious to vulnerable eye tissue. The United States Food and Drug Administration have defined guidelines for safe use of ultrasound for ophthalmic examination but most ultrasound devices used by anesthesiologists are not Food and Drug Administration-approved for ocular application because they generate excessive energy. Regulating agencies state that ultrasound examination can be safely undertaken as long as tissue temperatures do not increase >1.5°C above physiological levels. Methods Using a rabbit model, we investigated the thermal and mechanical ocular effects after prolonged ultrasonic exposure to single orbital and non-orbital-rated devices. In a dual-phase study, aimed at detecting ocular injury, the eyes of 8 rabbits were exposed to continuous 10-minute ultrasound examinations from two devices: 1) the Sonosite Micromaxx (non-orbital-rated) and 2) the Sonomed VuMax (orbital-rated) machines. In Phase I temperatures were continuously monitored via thermocouples implanted within specific eye structures (n=4). In Phase II the eyes were subjected to ultrasonic exposure without surgical intervention (n=4). All eyes underwent light microscopy examinations followed, at different intervals, by histology evaluations conducted by an ophthalmic pathologist. Results Temperature changes were monitored in the eyes of four rabbits. The non-orbital-rated transducer produced increases in ocular tissue temperature that surpassed the safe limit (increases> 1.50C ) in the lens of three rabbits (at 5

Radiofrequency-induced thermal therapy: results of a European multicentre study of resistive ablation of incompetent truncal varicose veins.

PubMed

Braithwaite, B; Hnatek, L; Zierau, U; Camci, M; Akkersdijk, Gjm; Nio, D; Sarlija, M; Ajduk, M; Santoro, P; Roche, E

2013-02-01

To investigate the effectiveness of bipolar radiofrequency-induced thermal therapy (RFITT) in a multicentre non-randomized study. Some 672 incompetent saphenous veins (85% great saphenous varicose vein, 15% short saphenous vein) in 462 patients (56.5% CEAP [clinical, aetiological, anatomical and pathological elements] class 3 or worse) were treated in eight European centres. Patients were assessed between 180 and 360 days postoperatively. Occlusion rates were determined by duplex ultrasound and compared with the power used for treatment, pull back rate and experience of the operating surgeon. Complete occlusion rates of 98.4% were achieved when treatments were performed by an experienced operator (more than 20 cases), when the maximum power setting on the RFITT generator was between 18 and 20 W and the applicator was withdrawn at a rate slower than 1.5 second/cm RFITT is efficacious, well tolerated by patients and has a low incidence of procedure-related post-operative complications.

Two-year clinical follow-up after pulmonary vein isolation using high-intensity focused ultrasound (HIFU) and an esophageal temperature-guided safety algorithm.

PubMed

Neven, Kars; Metzner, Andreas; Schmidt, Boris; Ouyang, Feifan; Kuck, Karl-Heinz

2012-03-01

High-intensity frequency ultrasound (HIFU) can achieve pulmonary vein isolation (PVI), but severe complications have happened. An esophageal temperature (ET)-guided safety algorithm was implemented. We investigated medium-term outcome. After left atrial access, HIFU was applied until complete PVI. The safety algorithm was as follows: ≤3 complete ablations per pulmonary vein, early abortion when ET ≥40.0°C, use of Power Modulation at ET >39.0°C or when after 20 to 30 seconds no change in PV electrograms: to reduce the ablation temperature in the surrounding tissue, acoustic power is switched on and off with a frequency of 1 Hz; in all first ablations, use of Power Modulation after 50% of programmed time. Touch-up radiofrequency ablation when PVI failed. Follow-up included interviews and Holter electrocardiograms. Recurrence was defined as atrial fibrillation (AF) >30 seconds without a blanking period. A total of 28 symptomatic patients (18 males, age 63 years), with paroxysmal AF (n = 19) and persistent AF (n = 9) were included. After a median follow-up of 738 days, 22 of the 28 patients (79%) were free of AF without antiarrhythmic drugs. After 1 repeat procedure with radiofrequency ablation, 5 patients remained free of AF. The complications were as follows: 1 lethal atrial-to-esophageal fistula at day 31, 1 pericardial effusion at day 48, 1 unexplained death at day 49, and 2 persistent phrenic nerve palsies with full recovery within 12 months. Two-year follow-up after PVI using HIFU and an ET-guided safety algorithm shows success rates similar to those of radiofrequency-based procedures but with higher complication rates. Importantly, the ET-guided safety algorithm failed to prevent severe complications. HIFU does not meet safety standards required for the treatment of AF, and this led to a halt of its clinical use. Copyright © 2012 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

X-ray–free Ultrasound-guided Percutaneous Nephrolithotomy: How to Select the Right Patient?

PubMed Central

Usawachintachit, Manint; Tzou, David T.; Hu, Weiguo; Li, Jianxing; Chi, Thomas

2017-01-01

OBJECTIVE To identify factors associated with successful ultrasound guidance for each surgical step of ultrasound-guided percutaneous nephrolithotomy (PCNL). PATIENTS AND METHODS Consecutive patients undergoing PCNL between March 2015 and June 2016 were prospectively enrolled. An attempt was made to use ultrasound guidance in renal access, tract dilation, and nephrostomy tube placement for each patient. For steps during which ultrasound guidance was unsuccessful, fluoroscopic screening was applied. Regression analysis identified patient characteristics associated with successful use of ultrasound guidance. RESULTS A total of 96 patients composed this cohort, with a mean body mass index of 28.7 kg/m2. Mean stone size was 33.1 ± 18.9 mm, and no hydronephrosis was found in 63.5% of cases. Fluoroscopic screening was required for renal access in 27 cases (28.1%), tract dilation in 38 (39.6%), and nephrostomy tube placement in 80 (83.3%). Multivariate analysis demonstrated that successful ultrasound guidance was significantly associated with the presence of hydronephrosis for renal access and the absence of staghorn calculi for tract dilation. Ultrasound-guided nephrostomy tube placement appeared linked to surgeon experience. CONCLUSION To achieve completely x-ray–free ultrasound-guided PCNL, the ideal patient should have a hydronephrotic collecting system with no staghorn stone present. For practitioners looking to adopt ultrasound guidance into their PCNL practice, these represent the most appropriate patients to safely initiate a surgical experience. PMID:27720776

An 11-Channel Radio Frequency Phased Array Coil for Magnetic Resonance Guided High Intensity Focused Ultrasound of the Breast

PubMed Central

Minalga, E.; Payne, A.; Merrill, R.; Todd, N.; Vijayakumar, S.; Kholmovski, E.; Parker, D. L.; Hadley, J. R.

2012-01-01

In this study, a radio-frequency (RF) phased array coil was built to image the breast in conjunction with a Magnetic Resonance guided High Intensity Focused Ultrasound (MRgHIFU) device designed specifically to treat the breast in a treatment cylinder with reduced water volume. The MRgHIFU breast coil was comprised of a 10-channel phased array coil placed around an MRgHIFU treatment cylinder where nearest-neighbor decoupling was achieved with capacitive decoupling in a shared leg. In addition a single loop coil was placed at the chest wall making a total of 11-channels. The RF coil array design presented in this work was chosen based on ease of implementation, increased visualization into the treatment cylinder, image reconstruction speed, temporal resolution, and resulting signal-to-noise-ratio (SNR) profiles. This work presents a dedicated 11-channel coil for imaging of the breast tissue in the MRgHIFU setup without obstruction of the ultrasound beam and, specifically, compares its performance in SNR, overall imaging time, and temperature measurement accuracy to that of the standard single chest-loop coil typically used in breast MRgHIFU. PMID:22431301

TU-H-BRA-01: The Physics of High Power Radiofrequency Isolation in a Novel Compact Linear Accelerator Based MRI Guided Radiation Therapy System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lamb, J; Low, D; Mutic, S

Purpose: To develop a method for isolating the radiofrequency waves emanating from linear accelerator components from the magnetic resonance imaging (MRI) system of an integrated MRI-linac. Methods: An MRI-guided radiation therapy system has been designed that integrates a linear accelerator with simultaneous MR imaging. The radiofrequency waves created by the accelerating process would degrade MR image quality, so a method for containing the radiofrequency waves and isolating the MR imager from them was developed. The linear accelerator radiofrequency modulator was placed outside the room, so a filter was designed to eliminate the radiofrequency corresponding to the proton Larmour frequency ofmore » 14.7 MHz. Placing the radiofrequency emitting components in a typical Faraday cage would have reduced the radiofrequency emissions, but the design would be susceptible to small gaps in the shield due to the efficiency of the Faraday cage reflecting internal radiofrequency emissions. To reduce internal radiofrequency reflections, the Faraday cage was lined with carbon fiber sheets. Carbon fiber has the property of attenuating the radiofrequency energy so that the overall radiofrequency field inside the Faraday cage is reduced, decreasing any radiofrequency energy emitted from small gaps in the cage walls. Results: Within a 1.2 MHz band centered on the Larmor frequency, the radiofrequency (RF) leakage from the Faraday cage was measured to be −90 dB with no RF on, −40 dB with the RF on and no shield, returning to −90 dB with the RF on and shields in place. The radiofrequency filter attenuated the linear accelerator modulator emissions in the 14.7 MHz band by 70 dB. Conclusions: One of the major challenges in designing a compact linear accelerator based MRI-guided radiation therapy system, that of isolating the high power RF system from the MRI, has been solved. The measured radiofrequency emissions are sufficiently small to enable system integration. This research

Thermal Imaging of Convecting Opaque Fluids using Ultrasound

NASA Technical Reports Server (NTRS)

Xu, Hongzhou; Fife, Sean; Andereck, C. David

2002-01-01

An ultrasound technique has been developed to non-intrusively image temperature fields in small-scale systems of opaque fluids undergoing convection. Fluids such as molten metals, semiconductors, and polymers are central to many industrial processes, and are often found in situations where natural convection occurs, or where thermal gradients are otherwise important. However, typical thermal and velocimetric diagnostic techniques rely upon transparency of the fluid and container, or require the addition of seed particles, or require mounting probes inside the fluid, all of which either fail altogether in opaque fluids, or necessitate significant invasion of the flow and/or modification of the walls of the container to allow access to the fluid. The idea behind our work is to use the temperature dependence of sound velocity, and the ease of propagation of ultrasound through fluids and solids, to probe the thermal fields of convecting opaque fluids non-intrusively and without the use of seed particles. The technique involves the timing of the return echoes from ultrasound pulses, a variation on an approach used previously in large-scale systems.

Improved Image-Guided Laparoscopic Prostatectomy

DTIC Science & Technology

2012-08-01

prevalent technique used in widening the field of view (FOV) of medical ultrasound images. Also referred to as stitching or panorama , the ultra- sound mosaic...tissue which can add valu- able features to the B-mode panorama . Many clinical applications deal with large cancerous lesions which expand beyond the...1999) 203–233 2. Varghese, T., Zagzebski, J., Lee Jr., F.: Elastographic imaging of thermal lesions in the liver in vivo following radiofrequency

Ultrasound-Guided Intervention for Treatment of Trigeminal Neuralgia: An Updated Review of Anatomy and Techniques

PubMed Central

Allam, Abdallah El-Sayed; Khalil, Adham Aboul Fotouh; Eltawab, Basma Aly; Wu, Wei-Ting

2018-01-01

Orofacial myofascial pain is prevalent and most often results from entrapment of branches of the trigeminal nerves. It is challenging to inject branches of the trigeminal nerve, a large portion of which are shielded by the facial bones. Bony landmarks of the cranium serve as important guides for palpation-guided injections and can be delineated using ultrasound. Ultrasound also provides real-time images of the adjacent muscles and accompanying arteries and can be used to guide the needle to the target region. Most importantly, ultrasound guidance significantly reduces the risk of collateral injury to vital neurovascular structures. In this review, we aimed to summarize the regional anatomy and ultrasound-guided injection techniques for the trigeminal nerve and its branches, including the supraorbital, infraorbital, mental, auriculotemporal, maxillary, and mandibular nerves. PMID:29808105

Ultrasound-Guided Percutaneous Tenotomy of Biceps Tendon: Technical Feasibility on Cadavers.

PubMed

Sconfienza, Luca Maria; Mauri, Giovanni; Messina, Carmelo; Aliprandi, Alberto; Secchi, Francesco; Sardanelli, Francesco; Randelli, Pietro Simone

2016-10-01

We tested the technical feasibility of ultrasound-guided percutaneous tenotomy of the long head of the biceps tendon (LHBT) in cadavers. Both shoulders of two fresh cadavers were scanned anteriorly to evaluate the extra-articular portion of the LHBT. Under ultrasound monitoring, a scalpel was advanced obliquely up to touch the superficial medial side of the LHBT, cutting it until the tendon was not visible anymore. Ultrasound evaluation was repeated after the procedure, and anatomic dissection was performed. The procedure was 100% feasible: four cuts were made to completely sever the tendon; the duration was less than 1 min. Skin incision measured 5 mm in two cases and 6 mm in two cases. Anatomic dissection confirmed complete tendon cut in all cases with proximal and distal tendon stumps very close to each other. Ultrasound-guided percutaneous LHBT tenotomy was 100% technically feasible in cadavers with a quick procedure and minimal cutaneous incision. Copyright © 2016 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Cranial nerve threshold for thermal injury induced by MRI-guided high-intensity focused ultrasound (MRgHIFU): preliminary results on an optic nerve model.

PubMed

Harnof, Sagi; Zibly, Zion; Cohen, Zvi; Shaw, Andrew; Schlaff, Cody; Kassel, Neal F

2013-04-01

Future clinical applications of magnetic resonance imaging-guided high-intensity focused ultrasound (MRgHIFU) are moving toward the management of different intracranial pathologies. We sought to validate the production, safety, and efficacy of thermal injury to cranial nerves generated by MRgHIFU. In this study, five female domestic pigs underwent a standard bifrontal craniectomy under general anesthesia. Treatment was then given using an MRgHIFU system to induce hyperthermic ablative sonication (6 to 10 s; 50 to 2000 J.) Histological analyses were done to confirm nerve damage; temperature measured on the optic nerve was approximately 53.4°C (range: 39°C to 70°C.) Histology demonstrated a clear definition between a necrotic, transitional zone, and normal tissue. MRgHIFU induces targeted thermal injury to nervous tissue within a specific threshold of 50°C to 60°C with the tissue near the sonication center yielding the greatest effect; adjacent tissue showed minimal changes. Additional studies utilizing this technology are required to further establish accurate threshold parameters for optic nerve thermo-ablation.

Point-of-Care Ultrasonography Findings and Care Use Among Patients Undergoing Ultrasound-Guided Shoulder Injections.

PubMed

Lee, Se Won; Tiu, Timothy; Roberts, Jeremy; Lee, Brian; Bartels, Matthew N; Oh-Park, Mooyeon

2018-01-01

The aims of the study were to assess the overall reduction of pain in patients undergoing ultrasound-guided shoulder injections and to characterize the preinjection point-of-care ultrasound findings and use of clinical services postinjection including the use of magnetic resonance imaging and surgeries. Data of 172 patients who underwent ultrasound-guided subacromial subdeltoid injection or glenohumeral joint injection were reviewed for preinjection point-of-care ultrasound findings, change in pain intensity at 2 mos from baseline, and use of care at 6 mos' postinjection. Pain intensity was measured by the numeric rating scale and a dichotomous report of global impression of significant improvement in pain. Responders were defined as those with 50% or more reduction in numeric rating scale or those with global impression of 50% or more improvement. There were 141 responders among the 172 patients analyzed. Full-thickness rotator cuff tears were higher in the ultrasound-guided subacromial subdeltoid injection group when compared with the glenohumeral joint injection group (P = 0.038) and abnormal bicipital tendon findings higher in the glenohumeral joint injection group (P = 0.016). There were no significant differences in specific abnormal U findings between responders versus nonresponders. Twelve patients had a shoulder magnetic resonance imaging and four patients underwent operative interventions after the injection. Overall pain reduction after ultrasound-guided shoulder injections was favorable in the short term. There was no specific preinjection point-of-care ultrasound findings associated with clinical pain reduction after injection. Additional imaging and operative intervention after ultrasound-guided shoulder injections seemed to be relatively low.

MRI-guided focused ultrasound surgery in musculoskeletal diseases: the hot topics

PubMed Central

Napoli, Alessandro; Sacconi, Beatrice; Battista, Giuseppe; Guglielmi, Giuseppe; Catalano, Carlo; Albisinni, Ugo

2016-01-01

MRI-guided focused ultrasound surgery (MRgFUS) is a minimally invasive treatment guided by the most sophisticated imaging tool available in today's clinical practice. Both the imaging and therapeutic sides of the equipment are based on non-ionizing energy. This technique is a very promising option as potential treatment for several pathologies, including musculoskeletal (MSK) disorders. Apart from clinical applications, MRgFUS technology is the result of long, heavy and cumulative efforts exploring the effects of ultrasound on biological tissues and function, the generation of focused ultrasound and treatment monitoring by MRI. The aim of this article is to give an updated overview on a “new” interventional technique and on its applications for MSK and allied sciences. PMID:26607640

Patient specific optimization-based treatment planning for catheter-based ultrasound hyperthermia and thermal ablation

NASA Astrophysics Data System (ADS)

Prakash, Punit; Chen, Xin; Wootton, Jeffery; Pouliot, Jean; Hsu, I.-Chow; Diederich, Chris J.

2009-02-01

to model thermal ablation, including the addition of temperature dependent attenuation, perfusion, and tissue damage. Pilot point control at the target boundaries was implemented to control power delivery to each transducer section, simulating an approach feasible for MR guided procedures. The computer model of thermal ablation was evaluated on representative patient anatomies to demonstrate the feasibility of using catheter-based ultrasound thermal ablation for treatment of benign prostate hyperplasia (BPH) and prostate cancer, and to assist in designing applicators and treatment delivery strategies.

A successful model to learn and implement ultrasound-guided venous catheterization in apheresis.

PubMed

Gopalasingam, Nigopan; Thomsen, Anna-Marie Eller; Folkersen, Lars; Juhl-Olsen, Peter; Sloth, Erik

2017-12-01

Apheresis treatments can be performed with peripheral venous catheters (PVC), although central venous catheters (CVC) are inserted when PVCs fail or patient with history of difficult vascular access prior to the apheresis. Ultrasound guidance for PVC has shown promising results in other settings. To investigate if ultrasound guidance for PVC could be implemented among apheresis nurses. Second, how implementation of ultrasound guidance affected the number of CVCs used for apheresis per patient. Apheresis nurses completed a systematic training program for ultrasound-guided vascular access. All independent catheterizations were registered during the implementation stage. The number of CVCs in the pre- and postimplementation stages of the ultrasound guidance was compared. Six nurses completed the training program within a median of 48 days (range 38-83 days). In 77 patients, 485 independent ultrasound-guided PVC placements were performed during the implementation stage. All apheresis treatments (485/485) were accomplished using PVCs without requiring CVC as rescue. During the preimplementation stage, 125 of 273 (45.8%) procedures required a CVC for completion of apheresis procedures; during the postimplementation stage only 30 of 227 (13.2%) procedures required a CVC (p < 0.001). In the postimplementation stage, no CVCs were placed as rescue caused by failed PVCs but were only placed for patients where the ultrasound machine was unavailable. It indicates an effective success rate of 100% for ultrasound-guided PVC use. This study showed that ultrasound guidance could be implemented among apheresis nurses as a routine tool eliminating the need of CVC as a rescue. © 2017 Wiley Periodicals, Inc.

Predicting variation in subject thermal response during transcranial magnetic resonance guided focused ultrasound surgery: Comparison in seventeen subject datasets.

PubMed

Vyas, Urvi; Ghanouni, Pejman; Halpern, Casey H; Elias, Jeff; Pauly, Kim Butts

2016-09-01

In transcranial magnetic resonance-guided focused ultrasound (tcMRgFUS) treatments, the acoustic and spatial heterogeneity of the skull cause reflection, absorption, and scattering of the acoustic beams. These effects depend on skull-specific parameters and can lead to patient-specific thermal responses to the same transducer power. In this work, the authors develop a simulation tool to help predict these different experimental responses using 3D heterogeneous tissue models based on the subject CT images. The authors then validate and compare the predicted skull efficiencies to an experimental metric based on the subject thermal responses during tcMRgFUS treatments in a dataset of seventeen human subjects. Seventeen human head CT scans were used to create tissue acoustic models, simulating the effects of reflection, absorption, and scattering of the acoustic beam as it propagates through a heterogeneous skull. The hybrid angular spectrum technique was used to model the acoustic beam propagation of the InSightec ExAblate 4000 head transducer for each subject, yielding maps of the specific absorption rate (SAR). The simulation assumed the transducer was geometrically focused to the thalamus of each subject, and the focal SAR at the target was used as a measure of the simulated skull efficiency. Experimental skull efficiency for each subject was calculated using the thermal temperature maps from the tcMRgFUS treatments. Axial temperature images (with no artifacts) were reconstructed with a single baseline, corrected using a referenceless algorithm. The experimental skull efficiency was calculated by dividing the reconstructed temperature rise 8.8 s after sonication by the applied acoustic power. The simulated skull efficiency using individual-specific heterogeneous models predicts well (R(2) = 0.84) the experimental energy efficiency. This paper presents a simulation model to predict the variation in thermal responses measured in clinical ctMRGFYS treatments while

Predicting variation in subject thermal response during transcranial magnetic resonance guided focused ultrasound surgery: Comparison in seventeen subject datasets

PubMed Central

Vyas, Urvi; Ghanouni, Pejman; Halpern, Casey H.; Elias, Jeff; Pauly, Kim Butts

2016-01-01

Purpose: In transcranial magnetic resonance-guided focused ultrasound (tcMRgFUS) treatments, the acoustic and spatial heterogeneity of the skull cause reflection, absorption, and scattering of the acoustic beams. These effects depend on skull-specific parameters and can lead to patient-specific thermal responses to the same transducer power. In this work, the authors develop a simulation tool to help predict these different experimental responses using 3D heterogeneous tissue models based on the subject CT images. The authors then validate and compare the predicted skull efficiencies to an experimental metric based on the subject thermal responses during tcMRgFUS treatments in a dataset of seventeen human subjects. Methods: Seventeen human head CT scans were used to create tissue acoustic models, simulating the effects of reflection, absorption, and scattering of the acoustic beam as it propagates through a heterogeneous skull. The hybrid angular spectrum technique was used to model the acoustic beam propagation of the InSightec ExAblate 4000 head transducer for each subject, yielding maps of the specific absorption rate (SAR). The simulation assumed the transducer was geometrically focused to the thalamus of each subject, and the focal SAR at the target was used as a measure of the simulated skull efficiency. Experimental skull efficiency for each subject was calculated using the thermal temperature maps from the tcMRgFUS treatments. Axial temperature images (with no artifacts) were reconstructed with a single baseline, corrected using a referenceless algorithm. The experimental skull efficiency was calculated by dividing the reconstructed temperature rise 8.8 s after sonication by the applied acoustic power. Results: The simulated skull efficiency using individual-specific heterogeneous models predicts well (R2 = 0.84) the experimental energy efficiency. Conclusions: This paper presents a simulation model to predict the variation in thermal responses measured in

Technical tips to perform safe and effective ultrasound guided steroid joint injections in children.

PubMed

Parra, Dimitri A

2015-01-01

The aim of this article is to describe the technique used to perform ultrasound guided steroid joint injections in children in a group of joints that can be injected using ultrasound as the only image guidance modality. The technique is described and didactic figures are provided to illustrate key technical concepts. It is very important to be familiar with the sonographic appearance of the pediatric joints and the developing bone when performing ultrasound-guided joint injections in children.

Ultrasound-guided thrombin injection of genicular artery pseudoaneurysm.

PubMed

Rachakonda, Aditya; Qato, Khalil; Khaddash, Tamim; Carroccio, Alfio; Pamoukian, Vicken; Giangola, Gary

2015-07-01

Pseudoaneurysm is a rare complication after arthroscopic procedures involving the knee. A 38-year-old man presented 1 month after right-knee arthroscopy with a 2-cm pulsating mass on the medial side of the right knee. Duplex ultrasound evaluation revealed 2.5 × 2.1-cm pseudoaneurysm just distal to the patella with arterialized flow communicating with the inferior medial genicular artery. Ultrasound-guided thrombin injection was performed in an office setting, and the resolution of active flow within the pseudoaneurysm was confirmed with duplex ultrasonography. Copyright © 2015 Elsevier Inc. All rights reserved.

Ultrasound-Guided Regional Anesthesia Simulation Training: A Systematic Review.

PubMed

Chen, Xiao Xu; Trivedi, Vatsal; AlSaflan, AbdulHadi A; Todd, Suzanne Clare; Tricco, Andrea C; McCartney, Colin J L; Boet, Sylvain

Ultrasound-guided regional anesthesia (UGRA) has become the criterion standard of regional anesthesia practice. Ultrasound-guided regional anesthesia teaching programs often use simulation, and guidelines have been published to help guide URGA education. This systematic review aimed to examine the effectiveness of simulation-based education for the acquisition and maintenance of competence in UGRA. Studies identified in MEDLINE, EMBASE, CINAHL, Cochrane Central Register of Controlled Trials, and ERIC were included if they assessed simulation-based UGRA teaching with outcomes measured at Kirkpatrick level 2 (knowledge and skills), 3 (transfer of learning to the workplace), or 4 (patient outcomes). Two authors independently reviewed all identified references for eligibility, abstracted data, and appraised quality. After screening 176 citations and 45 full-text articles, 12 studies were included. Simulation-enhanced training improved knowledge acquisition (Kirkpatrick level 2) when compared with nonsimulation training. Seven studies measuring skill acquisition (Kirkpatrick level 2) found that simulation-enhanced UGRA training was significantly more effective than alternative teaching methods or no intervention. One study measuring transfer of learning into the clinical setting (Kirkpatrick level 3) found no difference between simulation-enhanced UGRA training and non-simulation-based training. However, this study was discontinued early because of technical challenges. Two studies examined patient outcomes (Kirkpatrick level 4), and one of these found that simulation-based UGRA training improved patient outcomes compared with didactic teaching. Ultrasound-guided regional anesthesia knowledge and skills significantly improved with simulation training. The acquired UGRA skills may be transferred to the clinical setting; however, further studies are required to confirm these changes translate to improved patient outcomes.

Endoscopic ultrasound-guided transesophageal thoracentesis for minimal pleural effusion.

PubMed

Rana, Surinder Singh; Sharma, Ravi; Gupta, Rajesh

2018-06-19

Pleural effusion is a common finding both in patients with benign and malignant diseases of pleura and lung with diagnostic thoracentesis establishing the diagnosis in the majority of cases. The diagnostic thoracentesis can be done either blindly or under the guidance of ultrasound or computed tomography. However, minimal pleural effusion is difficult to sample even under image guidance. Endoscopic ultrasound (EUS) is known to detect smaller volume of pleural effusion and, thus, can help in guiding thoracentesis. To analyze the safety and efficacy of EUS-guided diagnostic thoracentesis in patients with undiagnosed minimal pleural effusion retrospectively. Retrospective analysis of the data of patients with minimal pleural effusion, who underwent EUS-guided transesophageal diagnostic thoracentesis over last 2 years, was performed. Thirteen patients (11 male; mean age 46.7 ± 16.2 years) with undiagnosed minimal pleural effusion underwent successful EUS-guided transesophageal diagnostic thoracentesis using a 22-G needle. Seven (53%) patients had fever on presentation whereas two presented with cough and loss of appetite. Eight to 54 mL fluid was aspirated with an attempt to completely empty the pleural cavity. There were no complications of the procedure. EUS-guided diagnostic thoracentesis is a safe and effective alternative for evaluating patients with minimal pleural effusion.

Real-time ultrasound-guided spinal anesthesia using the SonixGPS ultrasound guidance system: a feasibility study.

PubMed

Niazi, A U; Chin, K J; Jin, R; Chan, V W

2014-08-01

Real-time ultrasound-guided neuraxial blockade remains a largely experimental technique. SonixGPS® is a new needle tracking system that displays needle tip position on the ultrasound screen. We investigated if this novel technology might aid performance of real-time ultrasound-guided spinal anesthesia. Twenty patients with body mass index < 35 kg/m(2) undergoing elective total joint arthroplasty under spinal anesthesia were recruited. Patients with previous back surgery and spinal abnormalities were excluded. Following a pre-procedural ultrasound scan, a 17G proprietary needle-sensor assembly was inserted in-plane to the transducer in four patients and out-of-plane in 16 patients. In both approaches, the trajectory of insertion was adjusted in real-time until the needle tip lay just superficial to the ligamentum flavum-dura mater complex. At this point, a 25G 120 mm Whitacre spinal needle was inserted through the 17G SonixGPS® needle. Successful dural puncture was confirmed by backflow of cerebrospinal fluid from the spinal needle. An overall success rate of 14/20 (70%) was seen with two failures (50%) and four failures (25%) in the in-plane and out-of-plane groups respectively. Dural puncture was successful on the first skin puncture in 71% of patients and in a single needle pass in 57% of patients. The median total procedure time was 16.4 and 11.1 min in the in-plane and out-of-plane groups respectively. The SonixGPS® system simplifies real-time ultrasound-guided spinal anesthesia to a large extent, especially the out-of-plane approach. Nevertheless, it remains a complex multi-step procedure that requires time, specialized equipment, and a working knowledge of spinal sonoanatomy. © 2014 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

'X-ray'-free balloon dilation for totally ultrasound-guided percutaneous nephrolithotomy.

PubMed

Zhou, Tie; Chen, Guanghua; Gao, Xiaofeng; Zhang, Wei; Xu, Chuanliang; Li, Lei; Sun, Yinghao

2015-04-01

The objective of the study was to evaluate the feasibility and safety of balloon dilation for 'X-ray'-free ultrasound-guided percutaneous nephrolithotomy (PCNL). From January 2012 to December 2012, patients underwent 'X-ray'-free ultrasound-guided PCNL with Amplatz dilator (Group A). From January 2013 to April 2014, patients underwent 'X-ray'-free ultrasound-guided PCNL with balloon dilator (Group B). For balloon dilation, a 10 F fascial dilator was used to dilate the tract. Subsequently, the 6 F nephrostomy balloon (8 mm in diameter) was indwelled along the guidewire with a marked length equal to the dilation depth. Under the monitoring of ultrasound, the location of balloon was secured and disappearance of balloon waist was confirmed when the balloon was inflated at a pressure of 20 atm. A total of 163 patients were involved in this study. Of 81 procedures in Group A, 45 procedures were performed by a senior urologist while 36 procedures by a resident. Of 82 patients in Group B, 47 procedures were performed by the same senior urologist while 35 procedures by another resident. For the senior urologist, there was no statistically significant difference between two groups in calyx of entry, stone-free rate, decline of hemoglobin and hematocrit, operation time and hospitalization. But for the residents, there was less decline of hemoglobin and hematocrit, tract development time and hospitalization in Group B compared to Group A (0.6 vs. 1.7 g/dl, p = 0.001; 2.3% vs. 5.5%, p = 0.003; 10.1 vs. 11.0 min, p = 0.027; 7.8 vs. 13.9 days, p < 0.001). Balloon dilation method introduced in this study is compensable for tract development when 'X-ray'-free ultrasound-guided PCNL is performed. Modified techniques make totally ultrasound guidance for PCNL feasible, easy and safe. In addition, such a procedure is preferable for initial operators because of less hemorrhage complication.

Endoluminal ultrasound applicators for MR-guided thermal ablation of pancreatic tumors: Preliminary design and evaluation in a porcine pancreas model

PubMed Central

Adams, Matthew S.; Salgaonkar, Vasant A.; Plata-Camargo, Juan; Jones, Peter D.; Pascal-Tenorio, Aurea; Chen, Hsin-Yu; Bouley, Donna M.; Sommer, Graham; Pauly, Kim Butts; Diederich, Chris J.

2016-01-01

Purpose: Endoluminal ultrasound may serve as a minimally invasive option for delivering thermal ablation to pancreatic tumors adjacent to the stomach or duodenum. The objective of this study was to explore the basic feasibility of this treatment strategy through the design, characterization, and evaluation of proof-of-concept endoluminal ultrasound applicators capable of placement in the gastrointestinal (GI) lumen for volumetric pancreas ablation under MR guidance. Methods: Two variants of the endoluminal applicator, each containing a distinct array of two independently powered transducers (10 × 10 mm 3.2 MHz planar; or 8 × 10 × 20 mm radius of curvature 3.3 MHz curvilinear geometries) at the distal end of a meter long flexible catheter assembly, were designed and fabricated. Transducers and circulatory water flow for acoustic coupling and luminal cooling were contained by a low-profile polyester balloon covering the transducer assembly fixture. Each applicator incorporated miniature spiral MR coils and mechanical features (guiding tips and hinges) to facilitate tracking and insertion through the GI tract under MRI guidance. Acoustic characterization of each device was performed using radiation force balance and hydrophone measurements. Device delivery into the upper GI tract, adjacent to the pancreas, and heating characteristics for treatment of pancreatic tissue were evaluated in MR-guided ex vivo and in vivo porcine experiments. MR guidance was utilized for anatomical target identification, tracking/positioning of the applicator, and MR temperature imaging (MRTI) for PRF-based multislice thermometry, implemented in the real-time RTHawk software environment. Results: Force balance and hydrophone measurements indicated efficiencies of 48.8% and 47.8% and −3 dB intensity beam-widths of 3.2 and 1.2 mm for the planar and curvilinear transducers, respectively. Ex vivo studies on whole-porcine carcasses revealed capabilities of producing ablative temperature rise

Endoluminal ultrasound applicators for MR-guided thermal ablation of pancreatic tumors: Preliminary design and evaluation in a porcine pancreas model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Adams, Matthew S., E-mail: matt.adams@ucsf.edu; Di

Purpose: Endoluminal ultrasound may serve as a minimally invasive option for delivering thermal ablation to pancreatic tumors adjacent to the stomach or duodenum. The objective of this study was to explore the basic feasibility of this treatment strategy through the design, characterization, and evaluation of proof-of-concept endoluminal ultrasound applicators capable of placement in the gastrointestinal (GI) lumen for volumetric pancreas ablation under MR guidance. Methods: Two variants of the endoluminal applicator, each containing a distinct array of two independently powered transducers (10 × 10 mm 3.2 MHz planar; or 8 × 10 × 20 mm radius of curvature 3.3 MHzmore » curvilinear geometries) at the distal end of a meter long flexible catheter assembly, were designed and fabricated. Transducers and circulatory water flow for acoustic coupling and luminal cooling were contained by a low-profile polyester balloon covering the transducer assembly fixture. Each applicator incorporated miniature spiral MR coils and mechanical features (guiding tips and hinges) to facilitate tracking and insertion through the GI tract under MRI guidance. Acoustic characterization of each device was performed using radiation force balance and hydrophone measurements. Device delivery into the upper GI tract, adjacent to the pancreas, and heating characteristics for treatment of pancreatic tissue were evaluated in MR-guided ex vivo and in vivo porcine experiments. MR guidance was utilized for anatomical target identification, tracking/positioning of the applicator, and MR temperature imaging (MRTI) for PRF-based multislice thermometry, implemented in the real-time RTHawk software environment. Results: Force balance and hydrophone measurements indicated efficiencies of 48.8% and 47.8% and −3 dB intensity beam-widths of 3.2 and 1.2 mm for the planar and curvilinear transducers, respectively. Ex vivo studies on whole-porcine carcasses revealed capabilities of producing ablative

Ultrasound-guided synovial Tru-cut biopsy: indications, technique, and outcome in 111 cases.

PubMed

Sitt, Jacqueline C M; Griffith, James F; Lai, Fernand M; Hui, Mamie; Chiu, K H; Lee, Ryan K L; Ng, Alex W H; Leung, Jason

2017-05-01

To investigate the diagnostic performance of ultrasound-guided synovial biopsy. Clinical notes, pathology and microbiology reports, ultrasound and other imaging studies of 100 patients who underwent 111 ultrasound-guided synovial biopsies were reviewed. Biopsies were compared with the final clinical diagnosis established after synovectomy (n = 43) or clinical/imaging follow-up (n = 57) (mean 30 months). Other than a single vasovagal episode, no complication of synovial biopsy was encountered. One hundred and seven (96 %) of the 111 biopsies yielded synovium histologically. Pathology ± microbiology findings for these 107 conclusive biopsies comprised synovial tumour (n = 30, 28 %), synovial infection (n = 18, 17 %), synovial inflammation (n = 45, 42 %), including gouty arthritis (n = 3), and no abnormality (n = 14, 13 %). The accuracy, sensitivity, and specificity of synovial biopsy was 99 %, 97 %, and 100 % for synovial tumour; 100 %, 100 %, and 100 % for native joint infection; and 78 %, 45 %, and 100 % for prosthetic joint infection. False-negative synovial biopsy did not seem to be related to antibiotic therapy. Ultrasound-guided Tru-cut synovial biopsy is a safe and reliable technique with a high diagnostic yield for diagnosing synovial tumour and also, most likely, for joint infection. Regarding joint infection, synovial biopsy of native joints seems to have a higher diagnostic yield than that for infected prosthetic joints. • Ultrasound-guided Tru-cut synovial biopsy has high accuracy (99 %) for diagnosing synovial tumour. • It has good accuracy, sensitivity, and high specificity for diagnosis of joint infection. • Synovial biopsy of native joints works better than biopsy of prosthetic joints. • A negative synovial biopsy culture from a native joint largely excludes septic arthritis. • Ultrasound-guided Tru-cut synovial biopsy is a safe and well-tolerated procedure.

Consistent evaluation of an ultrasound-guided surgical navigation system by utilizing an active validation platform

NASA Astrophysics Data System (ADS)

Kim, Younsu; Kim, Sungmin; Boctor, Emad M.

2017-03-01

An ultrasound image-guided needle tracking systems have been widely used due to their cost-effectiveness and nonionizing radiation properties. Various surgical navigation systems have been developed by utilizing state-of-the-art sensor technologies. However, ultrasound transmission beam thickness causes unfair initial evaluation conditions due to inconsistent placement of the target with respect to the ultrasound probe. This inconsistency also brings high uncertainty and results in large standard deviations for each measurement when we compare accuracy with and without the guidance. To resolve this problem, we designed a complete evaluation platform by utilizing our mid-plane detection and time of flight measurement systems. The evaluating system uses a PZT element target and an ultrasound transmitting needle. In this paper, we evaluated an optical tracker-based surgical ultrasound-guided navigation system whereby the optical tracker tracks marker frames attached on the ultrasound probe and the needle. We performed ten needle trials of guidance experiment with a mid-plane adjustment algorithm and with a B-mode segmentation method. With the midplane adjustment, the result showed a mean error of 1.62+/-0.72mm. The mean error increased to 3.58+/-2.07mm without the mid-plane adjustment. Our evaluation system can reduce the effect of the beam-thickness problem, and measure ultrasound image-guided technologies consistently with a minimal standard deviation. Using our novel evaluation system, ultrasound image-guided technologies can be compared under equal initial conditions. Therefore, the error can be evaluated more accurately, and the system provides better analysis on the error sources such as ultrasound beam thickness.

Intracavitary ultrasound phased arrays for thermal therapies

NASA Astrophysics Data System (ADS)

Hutchinson, Erin

Currently, the success of hyperthermia and thermal surgery treatments is limited by the technology used in the design and fabrication of clinical heating devices and the completeness of the thermometry systems used for guidance. For both hyperthermia and thermal surgery, electrically focused ultrasound generated by phased arrays provides a means of controlling localized energy deposition in body tissues. Intracavitary applicators can be used to bring the energy source close to a target volume, such as the prostate, thereby minimizing normal tissue damage. The work performed in this study was aimed at improving noninvasive prostate thermal therapies and utilized three research approaches: (1) Acoustic, thermal and optimization simulations, (2) Design and fabrication of multiple phased arrays, (3) Ex vivo and in vivo experimental testing of the heating capabilities of the phased arrays. As part of this study, a novel aperiodic phased array design was developed which resulted in a 30- 45% reduction in grating lobe levels when compared to conventional phased arrays. Measured acoustic fields generated by the constructed aperiodic arrays agreed closely with the fields predicted by the theoretical simulations and covered anatomically appropriate ranges. The power capabilities of these arrays were demonstrated to be sufficient for the purposes of hyperthermia and thermal surgery. The advantage of using phased arrays in place of fixed focus transducers was shown by demonstrating the ability of electronic scanning to increase the size of the necrosed tissue volume while providing a more uniform thermal dose, which can ultimately reduce patient treatment times. A theoretical study on the feasibility of MRI (magnetic resonance imaging) thermometry for noninvasive temperature feedback control was investigated as a means to improve transient and steady state temperature distributions achieved in hyperthermia treatments. MRI guided ex vivo and in vivo experiments demonstrated

Conventional Landmark-Guided Midline Versus Preprocedure Ultrasound-Guided Paramedian Techniques in Spinal Anesthesia.

PubMed

Kallidaikurichi Srinivasan, Karthikeyan; Iohom, Gabriella; Loughnane, Frank; Lee, Peter J

2015-10-01

Multiple passes and attempts while administering spinal anesthesia are associated with a greater incidence of postdural puncture headache, paraesthesia, and spinal hematoma. We hypothesized that the routine use of a preprocedural ultrasound-guided paramedian technique for spinal anesthesia would reduce the number of passes required to achieve entry into the subarachnoid space when compared with the conventional landmark-guided midline approach. One hundred consenting patients scheduled for elective total joint replacements (hip and knee) were randomized into group C (conventional) and group P (preprocedural ultrasound-guided paramedian technique) with 50 in each group. The patients were blinded to the study group. All spinal anesthetics were administered by a consultant anesthesiologist. In group C, spinal anesthetic was done via the midline approach using clinically palpated landmarks. In group P, a preprocedural ultrasound scan was used to mark the paramedian insertion site, and spinal anesthetic was performed via the paramedian approach. The average number of passes (defined as the number of forward advancements of the spinal needle in a given interspinous space, i.e., withdrawal and redirection of spinal needle without exiting the skin) in group P was approximately 0.34 times that in group C, a difference that was statistically significant (P = 0.01). Similarly, the average number of attempts (defined as the number of times the spinal needle was withdrawn from the skin and reinserted) in group P was approximately 0.25 times that of group C (P = 0.0021). In group P, on an average, it took 81.5 (99% confidence interval, 68.4-97 seconds) seconds longer to identify the landmarks than in group C (P = 0.0002). All other parameters, including grading of palpated landmarks, time taken for spinal anesthetic injection, periprocedural pain scores, periprocedural patient discomfort visual analog scale score, conversion to general anesthetic, paresthesia, and radicular pain

Ultrasonographic percutaneous anatomy of the atlanto-occipital region and indirect ultrasound-guided cisternal puncture in the dog and the cat.

PubMed

Etienne, A-L; Audigié, F; Peeters, D; Gabriel, A; Busoni, V

2015-04-01

Cisternal puncture in dogs and cats is commonly carried out. This article describes the percutaneous ultrasound anatomy of the cisternal region in the dog and the cat and an indirect technique for ultrasound-guided cisternal puncture. Ultrasound images obtained ex vivo and in vivo were compared with anatomic sections and used to identify the landmarks for ultrasound-guided cisternal puncture. The ultrasound-guided procedure was established in cadavers and then applied in vivo in seven dogs and two cats. The anatomic landmarks for the ultrasound-guided puncture are the cisterna magna, the spinal cord, the two occipital condyles on transverse images, the external occipital crest and the dorsal arch of the first cervical vertebra on longitudinal images. Using these ultrasound anatomic landmarks, an indirect ultrasound-guided technique for cisternal puncture is applicable in the dog and the cat. © 2014 Blackwell Verlag GmbH.

An experimental model to investigate the targeting accuracy of MR-guided focused ultrasound ablation in liver

PubMed Central

2014-01-01

Background Magnetic Resonance-guided High Intensity Focused Ultrasound (MRgHIFU) is a hybrid technology that aims to offer non-invasive thermal ablation of targeted tumors or other pathological tissues. Acoustic aberrations and non-linear wave propagating effects may shift the focal point significantly away from the prescribed (or, theoretical) position. It is therefore mandatory to evaluate the spatial accuracy of ablation for a given HIFU protocol and/or device. We describe here a method for producing a user-defined ballistic target as an absolute reference marker for MRgHIFU ablations. Methods The investigated method is based on trapping a mixture of MR contrast agent and histology stain using radiofrequency (RF) ablation causing cell death and coagulation. A dedicated RF-electrode was used for the marker fixation as follows: a RF coagulation (4 W, 15 seconds) and injection of the mixture followed by a second RF coagulation. As a result, the contrast agent/stain is encapsulated in the intercellular space. Ultrasonography imaging was performed during the procedure, while high resolution T1w 3D VIBE MR acquisition was used right after to identify the position of the ballistic marker and hence the target tissue. For some cases, after the marker fixation procedure, HIFU volumetric ablations were produced by a phased-array HIFU platform. First ex vivo experiments were followed by in vivo investigation on four rabbits in thigh muscle and six pigs in liver, with follow-up at Day 7. Results At the end of the procedure, no ultrasound indication of the marker’s presence could be observed, while it was clearly visible under MR and could be conveniently used to prescribe the HIFU ablation, centered on the so-created target. The marker was identified at Day 7 after treatment, immediately after animal sacrifice, after 3 weeks of post-mortem formalin fixation and during histology analysis. Its size ranged between 2.5 and 4 mm. Conclusions Experimental validation of this

Carbon dioxide dissociation in non-thermal radiofrequency and microwave plasma

NASA Astrophysics Data System (ADS)

Huang, Qiang; Zhang, Diyu; Wang, Dongping; Liu, Kezhao; Kleyn, Aart W.

2017-07-01

We have studied carbon dioxide dissociation in inductively coupled radiofrequency plasma and microwave plasma at low gas pressure. Both systems exhibit features of non-thermal plasma. The highest energy efficiency observed is 59.3% (2.13 mmol kJ-1), exceeding the maximum value of about 45% in case of thermodynamic equilibrium, and a maximum conversion of 80.6% is achieved. Different discharge conditions, such as the source frequency, discharge gas pressure and the addition of argon, will affect the plasma parameters, especially the electron energy distribution. This plays a great role in the energy transfer from non-thermal plasma to the molecular dissociation reaction channel by enabling the ladder climbing of the carbon dioxide molecular vibration. The results indicate the importance of ladder climbing.

Non-thermal High-intensity Focused Ultrasound for Breast Cancer Therapy

DTIC Science & Technology

2012-07-01

AD ________________ Award Number: W81XWH-11-1-0341 TITLE: Non-thermal high-intensity focused ultrasound for breast cancer therapy PRINCIPAL...30 Jun 2012 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Non-thermal high-intensity focused ultrasound for breast cancer therapy 5b. GRANT NUMBER W81XWH...the in vivo animal experiments. However, the tasks planned for the animal studies were not completed due to the delayed approval of the animal

Ultrasound-guided interventional therapy for recurrent ovarian chocolate cysts.

PubMed

Wang, Lu-Lu; Dong, Xiao-Qiu; Shao, Xiao-Hui; Wang, Si-Ming

2011-10-01

The aim of this study was to determine the effectiveness of ultrasound-guided interventional therapy in the treatment of postoperative recurrent chocolate cysts. The 198 patients enrolled in this study were divided into three groups. In group 1, the saline washing group, the cavity of the cyst was washed thoroughly with warm saline. In group 2, the ethanol short-time retention group, after washing with saline, the cyst was injected with 95% ethanol with a volume of half of the fluid aspirated from the cyst. Ten minutes later, the rest of the ethanol was aspirated. In group 3, the ethanol retention group, the procedures were the same as with the ethanol short-time retention group, except that 95% of the ethanol was retained in the cyst. An ultrasound examination was performed in the third, sixth and 12th months after therapy. The chocolate cyst cure rate was significantly higher in the ethanol retention group (96%, 66/69) than in the ethanol short-time retention group (82%, 56/68) and no case was cured in the first group (saline washing). We conclude that ultrasound-guided injection and 95% ethanol retention are an effective therapy for the treatment of postoperative recurrent chocolate cysts. Copyright © 2011 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

In-line positioning of ultrasound images using wireless remote display system with tablet computer facilitates ultrasound-guided radial artery catheterization.

PubMed

Tsuchiya, Masahiko; Mizutani, Koh; Funai, Yusuke; Nakamoto, Tatsuo

2016-02-01

Ultrasound-guided procedures may be easier to perform when the operator's eye axis, needle puncture site, and ultrasound image display form a straight line in the puncture direction. However, such methods have not been well tested in clinical settings because that arrangement is often impossible due to limited space in the operating room. We developed a wireless remote display system for ultrasound devices using a tablet computer (iPad Mini), which allows easy display of images at nearly any location chosen by the operator. We hypothesized that the in-line layout of ultrasound images provided by this system would allow for secure and quick catheterization of the radial artery. We enrolled first-year medical interns (n = 20) who had no prior experience with ultrasound-guided radial artery catheterization to perform that using a short-axis out-of-plane approach with two different methods. With the conventional method, only the ultrasound machine placed at the side of the head of the patient across the targeted forearm was utilized. With the tablet method, the ultrasound images were displayed on an iPad Mini positioned on the arm in alignment with the operator's eye axis and needle puncture direction. The success rate and time required for catheterization were compared between the two methods. Success rate was significantly higher (100 vs. 70 %, P = 0.02) and catheterization time significantly shorter (28.5 ± 7.5 vs. 68.2 ± 14.3 s, P < 0.001) with the tablet method as compared to the conventional method. An ergonomic straight arrangement of the image display is crucial for successful and quick completion of ultrasound-guided arterial catheterization. The present remote display system is a practical method for providing such an arrangement.

Success of ultrasound-guided versus landmark-guided arthrocentesis of hip, ankle, and wrist in a cadaver model.

PubMed

Berona, Kristin; Abdi, Amin; Menchine, Michael; Mailhot, Tom; Kang, Tarina; Seif, Dina; Chilstrom, Mikaela

2017-02-01

The objectives of this study were to evaluate emergency medicine resident-performed ultrasound for diagnosis of effusions, compare the success of a landmark-guided (LM) approach with an ultrasound-guided (US) technique for hip, ankle and wrist arthrocentesis, and compare change in provider confidence with LM and US arthrocentesis. After a brief video on LM and US arthrocentesis, residents were asked to identify artificially created effusions in the hip, ankle and wrist in a cadaver model and to perform US and LM arthrocentesis of the effusions. Outcomes included success of joint aspiration, time to aspiration, and number of attempts. Residents were surveyed regarding their confidence in identifying effusions with ultrasound and performing LM and US arthrocentesis. Eighteen residents completed the study. Sensitivity of ultrasound for detecting joint effusion was 86% and specificity was 90%. Residents were successful with ultrasound in 96% of attempts and with landmark 89% of attempts (p=0.257). Median number of attempts was 1 with ultrasound and 2 with landmarks (p=0.12). Median time to success with ultrasound was 38s and 51s with landmarks (p=0.23). After the session, confidence in both US and LM arthrocentesis improved significantly, however the post intervention confidence in US arthrocentesis was higher than LM (4.3 vs. 3.8, p<0.001). EM residents were able to successfully identify joint effusions with ultrasound, however we were unable to detect significant differences in actual procedural success between the two modalities. Further studies are needed to define the role of ultrasound for arthrocentesis in the emergency department. Copyright © 2016 Elsevier Inc. All rights reserved.

Enhanced Lesion Visualization in Image-Guided Noninvasive Surgery With Ultrasound Phased Arrays

DTIC Science & Technology

2001-10-25

81, 1995. [4] N. Sanghvi et al., “Noninvasive surgery of prostate tissue by high-intensity focused ultrasound ,” IEEE Trans. UFFC, vol. 43, no. 6, pp...ENHANCED LESION VISUALIZATION IN IMAGE-GUIDED NONINVASIVE SURGERY WITH ULTRASOUND PHASED ARRAYS Hui Yao, Pornchai Phukpattaranont and Emad S. Ebbini...Department of Electrical and Computer Engineering University of Minnesota Minneapolis, MN 55455 Abstract- We describe dual-mode ultrasound phased

Non-Invasive Targeted Peripheral Nerve Ablation Using 3D MR Neurography and MRI-Guided High-Intensity Focused Ultrasound (MR-HIFU): Pilot Study in a Swine Model.

PubMed

Huisman, Merel; Staruch, Robert M; Ladouceur-Wodzak, Michelle; van den Bosch, Maurice A; Burns, Dennis K; Chhabra, Avneesh; Chopra, Rajiv

2015-01-01

Ultrasound (US)-guided high intensity focused ultrasound (HIFU) has been proposed for noninvasive treatment of neuropathic pain and has been investigated in in-vivo studies. However, ultrasound has important limitations regarding treatment guidance and temperature monitoring. Magnetic resonance (MR)-imaging guidance may overcome these limitations and MR-guided HIFU (MR-HIFU) has been used successfully for other clinical indications. The primary purpose of this study was to evaluate the feasibility of utilizing 3D MR neurography to identify and guide ablation of peripheral nerves using a clinical MR-HIFU system. Volumetric MR-HIFU was used to induce lesions in the peripheral nerves of the lower limbs in three pigs. Diffusion-prep MR neurography and T1-weighted images were utilized to identify the target, plan treatment and immediate post-treatment evaluation. For each treatment, one 8 or 12 mm diameter treatment cell was used (sonication duration 20 s and 36 s, power 160-300 W). Peripheral nerves were extracted < 3 hours after treatment. Ablation dimensions were calculated from thermal maps, post-contrast MRI and macroscopy. Histological analysis included standard H&E staining, Masson's trichrome and toluidine blue staining. All targeted peripheral nerves were identifiable on MR neurography and T1-weighted images and could be accurately ablated with a single exposure of focused ultrasound, with peak temperatures of 60.3 to 85.7°C. The lesion dimensions as measured on MR neurography were similar to the lesion dimensions as measured on CE-T1, thermal dose maps, and macroscopy. Histology indicated major hyperacute peripheral nerve damage, mostly confined to the location targeted for ablation. Our preliminary results indicate that targeted peripheral nerve ablation is feasible with MR-HIFU. Diffusion-prep 3D MR neurography has potential for guiding therapy procedures where either nerve targeting or avoidance is desired, and may also have potential for post

Non-Invasive Targeted Peripheral Nerve Ablation Using 3D MR Neurography and MRI-Guided High-Intensity Focused Ultrasound (MR-HIFU): Pilot Study in a Swine Model

PubMed Central

Huisman, Merel; Staruch, Robert M.; Ladouceur-Wodzak, Michelle; van den Bosch, Maurice A.; Burns, Dennis K.; Chhabra, Avneesh; Chopra, Rajiv

2015-01-01

Purpose Ultrasound (US)-guided high intensity focused ultrasound (HIFU) has been proposed for noninvasive treatment of neuropathic pain and has been investigated in in-vivo studies. However, ultrasound has important limitations regarding treatment guidance and temperature monitoring. Magnetic resonance (MR)-imaging guidance may overcome these limitations and MR-guided HIFU (MR-HIFU) has been used successfully for other clinical indications. The primary purpose of this study was to evaluate the feasibility of utilizing 3D MR neurography to identify and guide ablation of peripheral nerves using a clinical MR-HIFU system. Methods Volumetric MR-HIFU was used to induce lesions in the peripheral nerves of the lower limbs in three pigs. Diffusion-prep MR neurography and T1-weighted images were utilized to identify the target, plan treatment and immediate post-treatment evaluation. For each treatment, one 8 or 12 mm diameter treatment cell was used (sonication duration 20 s and 36 s, power 160–300 W). Peripheral nerves were extracted < 3 hours after treatment. Ablation dimensions were calculated from thermal maps, post-contrast MRI and macroscopy. Histological analysis included standard H&E staining, Masson’s trichrome and toluidine blue staining. Results All targeted peripheral nerves were identifiable on MR neurography and T1-weighted images and could be accurately ablated with a single exposure of focused ultrasound, with peak temperatures of 60.3 to 85.7°C. The lesion dimensions as measured on MR neurography were similar to the lesion dimensions as measured on CE-T1, thermal dose maps, and macroscopy. Histology indicated major hyperacute peripheral nerve damage, mostly confined to the location targeted for ablation. Conclusion Our preliminary results indicate that targeted peripheral nerve ablation is feasible with MR-HIFU. Diffusion-prep 3D MR neurography has potential for guiding therapy procedures where either nerve targeting or avoidance is desired, and may

Twelve-month prostate volume reduction after MRI-guided transurethral ultrasound ablation of the prostate.

PubMed

Bonekamp, David; Wolf, M B; Roethke, M C; Pahernik, S; Hadaschik, B A; Hatiboglu, G; Kuru, T H; Popeneciu, I V; Chin, J L; Billia, M; Relle, J; Hafron, J; Nandalur, K R; Staruch, R M; Burtnyk, M; Hohenfellner, M; Schlemmer, H-P

2018-06-25

To quantitatively assess 12-month prostate volume (PV) reduction based on T2-weighted MRI and immediate post-treatment contrast-enhanced MRI non-perfused volume (NPV), and to compare measurements with predictions of acute and delayed ablation volumes based on MR-thermometry (MR-t), in a central radiology review of the Phase I clinical trial of MRI-guided transurethral ultrasound ablation (TULSA) in patients with localized prostate cancer. Treatment day MRI and 12-month follow-up MRI and biopsy were available for central radiology review in 29 of 30 patients from the published institutional review board-approved, prospective, multi-centre, single-arm Phase I clinical trial of TULSA. Viable PV at 12 months was measured as the remaining PV on T2-weighted MRI, less 12-month NPV, scaled by the fraction of fibrosis in 12-month biopsy cores. Reduction of viable PV was compared to predictions based on the fraction of the prostate covered by the MR-t derived acute thermal ablation volume (ATAV, 55°C isotherm), delayed thermal ablation volume (DTAV, 240 cumulative equivalent minutes at 43°C thermal dose isocontour) and treatment-day NPV. We also report linear and volumetric comparisons between metrics. After TULSA, the median 12-month reduction in viable PV was 88%. DTAV predicted a reduction of 90%. Treatment day NPV predicted only 53% volume reduction, and underestimated ATAV and DTAV by 36% and 51%. Quantitative volumetry of the TULSA phase I MR and biopsy data identifies DTAV (240 CEM43 thermal dose boundary) as a useful predictor of viable prostate tissue reduction at 12 months. Immediate post-treatment NPV underestimates tissue ablation. • MRI-guided transurethral ultrasound ablation (TULSA) achieved an 88% reduction of viable prostate tissue volume at 12 months, in excellent agreement with expectation from thermal dose calculations. • Non-perfused volume on immediate post-treatment contrast-enhanced MRI represents only 64% of the acute thermal ablation volume

Ultrasound-guided injection of triamcinolone and bupivacaine in the management of De Quervain's disease.

PubMed

Jeyapalan, Kanagaratnam; Choudhary, Surabhi

2009-11-01

The aim of this study was to describe the technique and usefulness of ultrasound-guided intrasynovial injection of triamcinolone and bupivacaine in treatment of de Quervain's disease. A total of 17 patients with symptomatic De Quervain's disease were included in this study. The procedure involved confirmation of diagnosis with ultrasound followed by guided injection of a mixture of 20 mg of triamcinolone (40 mg/ml) and 1 ml of 0.5% bupivacaine. Ultrasound guidance with a high resolution 15-Mhz footprint probe was used for injection into the first dorsal extensor compartment tendon sheath (E1). The response to ultrasound-guided injection was ascertained at the post procedure outpatient clinic appointment according to the follow-up clinic notes. There were 14 female and 3 male patients aged 29 to 74 years. Mean duration of symptoms was 8.9 months. One patient had an atypical septum in the first extensor compartment and the extensor pollicis brevis alone was involved. The mean post-injection follow-up was at 6.75 weeks. One patient was lost to follow-up. Fifteen out of 16 patients had significant symptomatic relief (93.75%). There were no immediate or delayed complications. Recurrence of symptoms was seen in 3 (20%) patients. Ultrasound-guided injection of triamcinolone and bupivacaine is safe and useful in controlling symptoms of De Quervain's disease. Correct needle placement with ultrasound guidance avoids intratendinous injection as well as local complications like fat atrophy and depigmentation.

[Ultrasound-guided rectus sheath block for upper abdominal surgery].

PubMed

Osaka, Yoshimune; Kashiwagi, Masanori; Nagatsuka, Yukio; Oosaku, Masayoshi; Hirose, Chikako

2010-08-01

Upper abdominal surgery leads to severe postoperative pain. Insufficient postoperative analgesia accompanies a high incidence of complications. Therefore, postoperative analgesia is very important. The epidural analgesia has many advantages. However it has a high risk of epidural hematoma in anticoagulated patients. Rectus sheath block provided safer and more reliable analgesia in recent years, by the development of ultrasound tools. We experienced two cases of the rectus sheath block in upper abdominal surgery under ultrasound guidance. Ultrasound guided rectus sheath block can reduce the risk of peritoneal puncture, bleeding, and other complications. Rectus sheath block is very effective to reduce postoperative pain in upper abdominal surgery as an alternative method to epidural anesthesia in anticoagulated patients.

Real-time computed tomography dosimetry during ultrasound-guided brachytherapy for prostate cancer.

PubMed

Kaplan, Irving D; Meskell, Paul; Oldenburg, Nicklas E; Saltzman, Brian; Kearney, Gary P; Holupka, Edward J

2006-01-01

Ultrasound-guided implantation of permanent radioactive seeds is a treatment option for localized prostate cancer. Several techniques have been described for the optimal placement of the seeds in the prostate during this procedure. Postimplantation dosimetric calculations are performed after the implant. Areas of underdosing can only be corrected with either an external beam boost or by performing a second implant. We demonstrate the feasibility of performing computed tomography (CT)-based postplanning during the ultrasound-guided implant and subsequently correcting for underdosed areas. Ultrasound-guided brachytherapy is performed on a modified CT table with general anesthesia. The postplanning CT scan is performed after the implant, while the patient is still under anesthesia. Additional seeds are implanted into "cold spots," and the resultant dosimetry confirmed with CT. Intraoperative postplanning was successfully performed. Dose-volume histograms demonstrated adequate dose coverage during the initial implant, but on detailed analysis, for some patients, areas of underdosing were observed either at the apex or the peripheral zone. Additional seeds were implanted to bring these areas to prescription dose. Intraoperative postplanning is feasible during ultrasound-guided brachytherapy for prostate cancer. Although the postimplant dose-volume histograms for all patients, before the implantation of additional seeds, were adequate according to the American Brachytherapy Society criteria, specific critical areas can be underdosed. Additional seeds can then be implanted to optimize the dosimetry and reduce the risk of underdosing areas of cancer.

Improving Thermal Dose Accuracy in Magnetic Resonance-Guided Focused Ultrasound Surgery: Long-Term Thermometry Using a Prior Baseline as a Reference

PubMed Central

Bitton, Rachel R.; Webb, Taylor D.; Pauly, Kim Butts; Ghanouni, Pejman

2015-01-01

Purpose To investigate thermal dose volume (TDV) and non-perfused volume (NPV) of magnetic resonance-guided focused ultrasound (MRgFUS) treatments in patients with soft tissue tumors, and describe a method for MR thermal dosimetry using a baseline reference. Materials and Methods Agreement between TDV and immediate post treatment NPV was evaluated from MRgFUS treatments of five patients with biopsy-proven desmoid tumors. Thermometry data (gradient echo, 3T) were analyzed over the entire course of the treatments to discern temperature errors in the standard approach. The technique searches previously acquired baseline images for a match using 2D normalized cross-correlation and a weighted mean of phase difference images. Thermal dose maps and TDVs were recalculated using the matched baseline and compared to NPV. Results TDV and NPV showed between 47%–91% disagreement, using the standard immediate baseline method for calculating TDV. Long-term thermometry showed a nonlinear local temperature accrual, where peak additional temperature varied between 4–13°C (mean = 7.8°C) across patients. The prior baseline method could be implemented by finding a previously acquired matching baseline 61% ± 8% (mean ± SD) of the time. We found 7%–42% of the disagreement between TDV and NPV was due to errors in thermometry caused by heat accrual. For all patients, the prior baseline method increased the estimated treatment volume and reduced the discrepancies between TDV and NPV (P = 0.023). Conclusion This study presents a mismatch between in-treatment and post treatment efficacy measures. The prior baseline approach accounts for local heating and improves the accuracy of thermal dose-predicted volume. PMID:26119129

Improving thermal dose accuracy in magnetic resonance-guided focused ultrasound surgery: Long-term thermometry using a prior baseline as a reference.

PubMed

Bitton, Rachel R; Webb, Taylor D; Pauly, Kim Butts; Ghanouni, Pejman

2016-01-01

To investigate thermal dose volume (TDV) and non-perfused volume (NPV) of magnetic resonance-guided focused ultrasound (MRgFUS) treatments in patients with soft tissue tumors, and describe a method for MR thermal dosimetry using a baseline reference. Agreement between TDV and immediate post treatment NPV was evaluated from MRgFUS treatments of five patients with biopsy-proven desmoid tumors. Thermometry data (gradient echo, 3T) were analyzed over the entire course of the treatments to discern temperature errors in the standard approach. The technique searches previously acquired baseline images for a match using 2D normalized cross-correlation and a weighted mean of phase difference images. Thermal dose maps and TDVs were recalculated using the matched baseline and compared to NPV. TDV and NPV showed between 47%-91% disagreement, using the standard immediate baseline method for calculating TDV. Long-term thermometry showed a nonlinear local temperature accrual, where peak additional temperature varied between 4-13°C (mean = 7.8°C) across patients. The prior baseline method could be implemented by finding a previously acquired matching baseline 61% ± 8% (mean ± SD) of the time. We found 7%-42% of the disagreement between TDV and NPV was due to errors in thermometry caused by heat accrual. For all patients, the prior baseline method increased the estimated treatment volume and reduced the discrepancies between TDV and NPV (P = 0.023). This study presents a mismatch between in-treatment and post treatment efficacy measures. The prior baseline approach accounts for local heating and improves the accuracy of thermal dose-predicted volume. © 2015 Wiley Periodicals, Inc.

Transient thermal driven bubble's surface and its potential ultrasound-induced damage

NASA Astrophysics Data System (ADS)

Movahed, Pooya; Freund, Jonathan B.

2017-11-01

Ultrasound-induced bubble activity in soft tissues is well-known to be a potential injury mechanism in therapeutic ultrasound treatments. We consider damage by transient thermal effects, including a hypothetical mechanism based on transient thermal phenomena, including viscous dissipation. A spherically symmetric compressible Navier-Stokes discretization is developed to solve the full governing equations, both inside and outside of the bubble, without the usual simplifications in the Rayleigh-Plesset bubble dynamics approach. Equations are solved in the Lagrangian framework, which provides a sharp and accurate representation of the interface as well as the viscous dissipation and thermal transport effects, which preclude reduction to the usual Rayleigh-Plesset ordinary differential equation. This method is used to study transient thermal effects at different frequencies and pressure amplitudes relevant to therapeutic ultrasound treatments. High temperatures achieved in the surrounding medium during the violent bubble collapse phase due to the viscous dissipation in the surrounding medium and thermal conduction from the bubble are expected to cause damage. This work was supported by NIH NIDDK Grant P01-DK043881.

Ultrasound-guided percutaneous fine-needle aspiration of 545 focal pancreatic lesions.

PubMed

Zamboni, Giulia A; D'Onofrio, Mirko; Idili, Antonio; Malagò, Roberto; Iozzia, Roberta; Manfrin, Erminia; Mucelli, Roberto Pozzi

2009-12-01

The purpose of this study was to assess the accuracy and short-term complication rate of ultrasound-guided fine-needle aspiration cytologic sampling of focal pancreatic lesions. We reviewed 545 consecutive ultrasound-guided fine-needle aspiration cytologic sampling procedures for focal pancreatic lesions from January 2004 through June 2008. The procedures were performed with a 20- or 21-gauge needle. The onsite cytopathologist evaluated the appropriateness of the sample and made a diagnosis. We reviewed the final diagnosis and the radiologic and medical records of all patients for onset of complications during or within 7 days of the procedure. The study sample included 262 women and 283 men (mean age, 62 years; range, 25-86 years). The head or uncinate process of the pancreas was the location of 63.0% of the lesions, and 35.2% of the lesions were located in the body or tail of the pancreas. The site of 10 lesions (1.8%) was not specified. Sampling was diagnostic in 509 of the 545 cases (93.4%). Excluding the 36 nondiagnostic samples, ultrasound-guided fine-needle aspiration cytologic sampling had 99.4% sensitivity, 100% specificity, and 99.4% accuracy. In 537 of the 545 cases (98.5%), the procedure was uneventful. In two cases, abdominal fluid was found after the procedure that was not present before the procedure. Six patients experienced postprocedural pain without abnormal findings at subsequent imaging. No major complications occurred. Ultrasound-guided cytologic sampling is safe and accurate for the diagnosis and planning of management of focal pancreatic lesions. With a cytologist on site, the rate of acquisition of samples adequate for diagnosis is high, reducing the need for patient recall.

Backscattering analysis of high frequency ultrasonic imaging for ultrasound-guided breast biopsy

NASA Astrophysics Data System (ADS)

Cummins, Thomas; Akiyama, Takahiro; Lee, Changyang; Martin, Sue E.; Shung, K. Kirk

2017-03-01

A new ultrasound-guided breast biopsy technique is proposed. The technique utilizes conventional ultrasound guidance coupled with a high frequency embedded ultrasound array located within the biopsy needle to improve the accuracy in breast cancer diagnosis.1 The array within the needle is intended to be used to detect micro- calcifications indicative of early breast cancers such as ductal carcinoma in situ (DCIS). Backscattering analysis has the potential to characterize tissues to improve localization of lesions. This paper describes initial results of the application of backscattering analysis of breast biopsy tissue specimens and shows the usefulness of high frequency ultrasound for the new biopsy related technique. Ultrasound echoes of ex-vivo breast biopsy tissue specimens were acquired by using a single-element transducer with a bandwidth from 41 MHz to 88 MHz utilizing a UBM methodology, and the backscattering coefficients were calculated. These values as well as B-mode image data were mapped in 2D and matched with each pathology image for the identification of tissue type for the comparison to the pathology images corresponding to each plane. Microcalcifications were significantly distinguished from normal tissue. Adenocarcinoma was also successfully differentiated from adipose tissue. These results indicate that backscattering analysis is able to quantitatively distinguish tissues into normal and abnormal, which should help radiologists locate abnormal areas during the proposed ultrasound-guided breast biopsy with high frequency ultrasound.

Teaching medical students ultrasound-guided vascular access - which learning method is best?

PubMed

Lian, Alwin; Rippey, James C R; Carr, Peter J

2017-05-15

Ultrasound is recommended to guide insertion of peripheral intravenous vascular cannulae (PIVC) where difficulty is experienced. Ultrasound machines are now common-place and junior doctors are often expected to be able to use them. The educational standards for this skill are highly varied, ranging from no education, to self-guided internet-based education, to formal, face-to-face traditional education. In an attempt to decide which educational technique our institution should introduce, a small pilot trial comparing educational techniques was designed. Thirty medical students were enrolled and allocated to one of three groups. PIVC placing ability was then observed, tested and graded on vascular access phantoms. The formal, face-to-face traditional education was rated best by the students, and had the highest success rate in PIVC placement, the improvement statistically significant compared to no education (p = 0.01) and trending towards significance when compared to self-directed internet-based education (p<0.06). The group receiving traditional face-to-face teaching on ultrasound-guided vascular access, performed significantly better than those not receiving education. As the number of ultrasound machines in clinical areas increases, it is important that education programs to support their safe and appropriate use are developed.

Ultrasound guided electrical impedance tomography for 2D free-interface reconstruction

NASA Astrophysics Data System (ADS)

Liang, Guanghui; Ren, Shangjie; Dong, Feng

2017-07-01

The free-interface detection problem is normally seen in industrial or biological processes. Electrical impedance tomography (EIT) is a non-invasive technique with advantages of high-speed and low cost, and is a promising solution for free-interface detection problems. However, due to the ill-posed and nonlinear characteristics, the spatial resolution of EIT is low. To deal with the issue, an ultrasound guided EIT is proposed to directly reconstruct the geometric configuration of the target free-interface. In the method, the position of the central point of the target interface is measured by a pair of ultrasound transducers mounted at the opposite side of the objective domain, and then the position measurement is used as the prior information for guiding the EIT-based free-interface reconstruction. During the process, a constrained least squares framework is used to fuse the information from different measurement modalities, and the Lagrange multiplier-based Levenberg-Marquardt method is adopted to provide the iterative solution of the constraint optimization problem. The numerical results show that the proposed ultrasound guided EIT method for the free-interface reconstruction is more accurate than the single modality method, especially when the number of valid electrodes is limited.

Preliminary study of ergonomic behavior during simulated ultrasound-guided regional anesthesia using a head-mounted display.

PubMed

Udani, Ankeet D; Harrison, T Kyle; Howard, Steven K; Kim, T Edward; Brock-Utne, John G; Gaba, David M; Mariano, Edward R

2012-08-01

A head-mounted display provides continuous real-time imaging within the practitioner's visual field. We evaluated the feasibility of using head-mounted display technology to improve ergonomics in ultrasound-guided regional anesthesia in a simulated environment. Two anesthesiologists performed an equal number of ultrasound-guided popliteal-sciatic nerve blocks using the head-mounted display on a porcine hindquarter, and an independent observer assessed each practitioner's ergonomics (eg, head turning, arching, eye movements, and needle manipulation) and the overall block quality based on the injectate spread around the target nerve for each procedure. Both practitioners performed their procedures without directly viewing the ultrasound monitor, and neither practitioner showed poor ergonomic behavior. Head-mounted display technology may offer potential advantages during ultrasound-guided regional anesthesia.

A cMUT probe for ultrasound-guided focused ultrasound targeted therapy.

PubMed

Gross, Dominique; Coutier, Caroline; Legros, Mathieu; Bouakaz, Ayache; Certon, Dominique

2015-06-01

Ultrasound-mediated targeted therapy represents a promising strategy in the arsenal of modern therapy. Capacitive micromachined ultrasonic transducer (cMUT) technology could overcome some difficulties encountered by traditional piezoelectric transducers. In this study, we report on the design, fabrication, and characterization of an ultrasound-guided focused ultrasound (USgFUS) cMUT probe dedicated to preclinical evaluation of targeted therapy (hyperthermia, thermosensitive liposomes activation, and sonoporation) at low frequency (1 MHz) with simultaneous ultrasonic imaging and guidance (15 to 20 MHz). The probe embeds two types of cMUT arrays to perform the modalities of targeted therapy and imaging respectively. The wafer-bonding process flow employed for the manufacturing of the cMUTs is reported. One of its main features is the possibility of implementing two different gap heights on the same wafer. All the design and characterization steps of the devices are described and discussed, starting from the array design up to the first in vitro measurements: optical (microscopy) and electrical (impedance) measurements, arrays' electroacoustic responses, focused pressure field mapping (maximum peak-to-peak pressure = 2.5 MPa), and the first B-scan image of a wire-target phantom.

Ultrasound-Guided Cryoanalgesia of Peripheral Nerve Lesions.

PubMed

Djebbar, Sahlya; Rossi, Ignacio M; Adler, Ronald S

2016-11-01

The real-time nature of ultrasound makes it ideally suited to provide guidance for a variety of musculoskeletal interventional procedures involving peripheral nerves. Continuous observation of the needle ensures proper placement and allows continuous monitoring when performing localized ablative therapy and therefore more accurate positioning of a cryoprobe, use of smaller needles, as well as access to small structures. We describe our experience performing cryoablative procedures. Patients undergoing cryoneurolysis have largely reported varying degrees of long-term pain relief and improvement in function; no serious complications have yet been identified. Ultrasound-guided cryoneurolysis can provide a useful, safe alternative to other ablative techniques to achieve long-term analgesia from painful peripheral nerve lesions. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Computerized tomography-guided sphenopalatine ganglion pulsed radiofrequency treatment in 16 patients with refractory cluster headaches: Twelve- to 30-month follow-up evaluations.

PubMed

Fang, Luo; Jingjing, Lu; Ying, Shen; Lan, Meng; Tao, Wang; Nan, Ji

2016-02-01

Sphenopalatine ganglion percutaneous radiofrequency thermocoagulation treatment can improve the symptoms of cluster headaches to some extent. However, as an ablation treatment, radiofrequency thermocoagulation treatment also has side effects. To preliminarily evaluate the efficacy and safety of a non-ablative computerized tomography-guided pulsed radiofrequency treatment of sphenopalatine ganglion in patients with refractory cluster headaches. We included and analysed 16 consecutive cluster headache patients who failed to respond to conservative therapy from the Pain Management Center at the Beijing Tiantan Hospital between April 2012 and September 2013 treated with pulsed radiofrequency treatment of sphenopalatine ganglion. Eleven of 13 episodic cluster headaches patients and one of three chronic cluster headaches patient were completely relieved of the headache within an average of 6.3 ± 6.0 days following the treatment. Two episodic cluster headache patients and two chronic cluster headache patients showed no pain relief following the treatment. The mean follow-up time was 17.0 ± 5.5 months. All patients enrolled in this study showed no treatment-related side effects or complications. Our data show that patients with refractory episodic cluster headaches were quickly, effectively and safely relieved from the cluster period after computerized tomography-guided pulsed radiofrequency treatment of sphenopalatine ganglion, suggesting that it may be a therapeutic option if conservative treatments fail. © International Headache Society 2015.

Ultrasound-Guided Vascular Access Simulator for Medical Training: Proposal of a Simple, Economic and Effective Model.

PubMed

Fürst, Rafael Vilhena de Carvalho; Polimanti, Afonso César; Galego, Sidnei José; Bicudo, Maria Claudia; Montagna, Erik; Corrêa, João Antônio

2017-03-01

To present a simple and affordable model able to properly simulate an ultrasound-guided venous access. The simulation was made using a latex balloon tube filled with water and dye solution implanted in a thawed chicken breast with bones. The presented model allows the simulation of all implant stages of a central catheter. The obtained echogenicity is similar to that observed in human tissue, and the ultrasound identification of the tissues, balloon, needle, wire guide and catheter is feasible and reproducible. The proposed model is simple, economical, easy to manufacture and capable of realistically and effectively simulating an ultrasound-guided venous access.

A multimodal image guiding system for Navigated Ultrasound Bronchoscopy (EBUS): A human feasibility study

PubMed Central

Hofstad, Erlend Fagertun; Amundsen, Tore; Langø, Thomas; Bakeng, Janne Beate Lervik; Leira, Håkon Olav

2017-01-01

Background Endobronchial ultrasound transbronchial needle aspiration (EBUS-TBNA) is the endoscopic method of choice for confirming lung cancer metastasis to mediastinal lymph nodes. Precision is crucial for correct staging and clinical decision-making. Navigation and multimodal imaging can potentially improve EBUS-TBNA efficiency. Aims To demonstrate the feasibility of a multimodal image guiding system using electromagnetic navigation for ultrasound bronchoschopy in humans. Methods Four patients referred for lung cancer diagnosis and staging with EBUS-TBNA were enrolled in the study. Target lymph nodes were predefined from the preoperative computed tomography (CT) images. A prototype convex probe ultrasound bronchoscope with an attached sensor for position tracking was used for EBUS-TBNA. Electromagnetic tracking of the ultrasound bronchoscope and ultrasound images allowed fusion of preoperative CT and intraoperative ultrasound in the navigation software. Navigated EBUS-TBNA was used to guide target lymph node localization and sampling. Navigation system accuracy was calculated, measured by the deviation between lymph node position in ultrasound and CT in three planes. Procedure time, diagnostic yield and adverse events were recorded. Results Preoperative CT and real-time ultrasound images were successfully fused and displayed in the navigation software during the procedures. Overall navigation accuracy (11 measurements) was 10.0 ± 3.8 mm, maximum 17.6 mm, minimum 4.5 mm. An adequate sample was obtained in 6/6 (100%) of targeted lymph nodes. No adverse events were registered. Conclusions Electromagnetic navigated EBUS-TBNA was feasible, safe and easy in this human pilot study. The clinical usefulness was clearly demonstrated. Fusion of real-time ultrasound, preoperative CT and electromagnetic navigational bronchoscopy provided a controlled guiding to level of target, intraoperative overview and procedure documentation. PMID:28182758

[Percutaneous radiofrequency ablation of hepatic metastases. Preliminary experience].

PubMed

De Baere, T; Elias, D; Ducreux, M; Dromain, C; Kuach, V; Gamal El Din, M; Sobotka, A; Lasser, P; Roche, A

1999-11-01

To evaluate the efficiency of percutaneous radiofrequency ablation in the treatment of liver metastases. Eighteen patients with 31 liver metastases, mainly from colorectal cancer, 10 - 35 mm in diameter (m = 23), underwent 26 courses of percutaneous radiofrequency ablation. Fifteen patients had previously undergone hepatectomy, and 3 patients had contra-indications to surgery. Imaging guidance was ultrasound in 21 patients, CT in 4 (tumors not seen with ultrasound), and both in 1. A generator working at 450 KHz with a maximum output power of 150 W was used to treat each lesion for 18 - 20 min. Treatment was monitored with real time ultrasound. Among the 12 patients followed more than 3 months, only one of the 24 treated lesions recurred after a mean follow up of 259 ¿ 109 days. Liver disease was controlled in 8 of the 12 patients after 90 - 509 days (m = 306). Among these 8 patients, 3 were tumor free after 559, 378 and 90 days, respectively; 2 died tumor free of non-tumoral disease (pulmonary embolism, digestive bleeding); 3 developed lung metastases treated with chemotherapy (n = 2) or surgery (n = 1). Three of the 12 patients had widespread hepatic tumor occurrence, and one patient died of these metastases. Six patients experienced mild skin burns, but no major complication was observed. Radiofrequency ablation of hepatic metastases appears safe and promising in this preliminary experience. Further investigation is needed.

Real-time visualization of ultrasound-guided retrobulbar blockade: an imaging study.

PubMed

Luyet, C; Eichenberger, U; Moriggl, B; Remonda, L; Greif, R

2008-12-01

Retrobulbar anaesthesia allows eye surgery in awake patients. Severe complications of the blind techniques are reported. Ultrasound-guided needle introduction and direct visualization of the spread of local anaesthetic may improve quality and safety of retrobulbar anaesthesia. Therefore, we developed a new ultrasound-guided technique using human cadavers. In total, 20 blocks on both sides in 10 embalmed human cadavers were performed. Using a small curved array transducer and a long-axis approach, a 22 G short bevel needle was introduced under ultrasound guidance lateral and caudal of the eyeball until the needle tip was seen 2 mm away from the optic nerve. At this point, 2 ml of contrast dye as a substitute for local anaesthetic was injected. Immediately after the injection, the spread of the contrast dye was documented by means of CT scans performed in each cadaver. The CT scans showed the distribution of the contrast dye in the muscle cone and behind the posterior sclera in all but one case. No contrast dye was found inside the optic nerve or inside the eyeball. In one case, there could be an additional trace of contrast dye behind the orbita. Our new ultrasound-guided technique has the potential to improve safety and efficacy of the procedure by direct visualization of the needle placement and the distribution of the injected fluid. Furthermore, the precise injection near the optic nerve could lead to a reduction of the amount of the local anaesthetic needed with fewer related complications.

A Randomized Double-Blinded Trial on the Effects of Ultrasound Transducer Orientation on Teaching and Learning Ultrasound-Guided Regional Anesthesia.

PubMed

Lam, Nicholas C K; Baker, Elizabeth B; Fishburn, Steven J; Hammer, Angie R; Petersen, Timothy R; Mariano, Edward R

2016-07-01

Learning ultrasound-guided regional anesthesia skills, especially needle/ beam alignment, can be especially difficulty for trainees, who can often become frustrated. We hypothesized that teaching novices to orient the transducer and needle perpendicular to their shoulders will improve performance on a standardized task, compared to holding the transducer and needle parallel to the shoulders. This study compared the effects of transducer orientation on trainees' ability to complete a standardized ultrasound-guided nerve block simulation. The time to task completion and percentage of the attempt time without adequate needle visualization were measured. Participants were right-handed healthy adults with no previous ultrasound experience and were randomly assigned to training in either transducer and needle alignment in a coronal plane, parallel to the shoulders (parallel group) or transducer and needle alignment in a sagittal plane, perpendicular to the shoulders (perpendicular group). Participants used ultrasound to direct a needle to 3 targets in a standardized gelatin phantom and repeated this task 3 times. Their efforts were timed and evaluated by an assessor, who was blinded to group assignment. Data were analyzed on 28 participants. The perpendicular group was able to complete the task more quickly (P < .001) and with a smaller proportion of time lost to inadequate needle visualization (P < .001). Ultrasound-guided regional anesthesia trainees complete a standardized task more quickly and efficiently when instructed to hold the transducer and needle in an orientation perpendicular to their shoulders.

Meta-analysis of bipolar radiofrequency endometrial ablation versus thermal balloon endometrial ablation for the treatment of heavy menstrual bleeding.

PubMed

Zhai, Yan; Zhang, Zihan; Wang, Wei; Zheng, Tingping; Zhang, Huili

2018-01-01

Heavy menstrual bleeding is a common problem that can severely affect quality of life. To compare bipolar radiofrequency endometrial ablation and thermal balloon ablation for heavy menstrual bleeding in terms of efficacy and health-related quality of life (HRQoL). Online registries were systematically searched using relevant terms without language restriction from inception to November 24, 2016. Randomized control trials or cohort studies of women with heavy menstrual bleeding comparing the efficacy of two treatments were eligible. Data were extracted. Results were expressed as risk ratios (RRs) or weighted mean differences (WMDs) with 95% confidence intervals (CIs). Six studies involving 901 patients were included. Amenorrhea rate at 12 months was significantly higher after bipolar radiofrequency endometrial ablation than after thermal balloon ablation (RR 2.73, 95% CI 2.00-3.73). However, no difference at 12 months was noted for dysmenorrhea (RR 1.04, 95% CI 0.68-1.58) or treatment failure (RR 0.78, 95% CI 0.38-1.60). The only significant difference for HRQoL outcomes was for change in SAQ pleasure score (12 months: WMD -3.51, 95% CI -5.42 to -1.60). Bipolar radiofrequency endometrial ablation and thermal balloon ablation reduce menstrual loss and improve quality of life. However, bipolar radiofrequency endometrial ablation is more effective in terms of amenorrhea rate and SAQ pleasure. © 2017 International Federation of Gynecology and Obstetrics.

Predicting variation in subject thermal response during transcranial magnetic resonance guided focused ultrasound surgery: Comparison in seventeen subject datasets

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vyas, Urvi, E-mail: urvi.vyas@gmail.com; Ghanouni,

Purpose: In transcranial magnetic resonance-guided focused ultrasound (tcMRgFUS) treatments, the acoustic and spatial heterogeneity of the skull cause reflection, absorption, and scattering of the acoustic beams. These effects depend on skull-specific parameters and can lead to patient-specific thermal responses to the same transducer power. In this work, the authors develop a simulation tool to help predict these different experimental responses using 3D heterogeneous tissue models based on the subject CT images. The authors then validate and compare the predicted skull efficiencies to an experimental metric based on the subject thermal responses during tcMRgFUS treatments in a dataset of seventeen humanmore » subjects. Methods: Seventeen human head CT scans were used to create tissue acoustic models, simulating the effects of reflection, absorption, and scattering of the acoustic beam as it propagates through a heterogeneous skull. The hybrid angular spectrum technique was used to model the acoustic beam propagation of the InSightec ExAblate 4000 head transducer for each subject, yielding maps of the specific absorption rate (SAR). The simulation assumed the transducer was geometrically focused to the thalamus of each subject, and the focal SAR at the target was used as a measure of the simulated skull efficiency. Experimental skull efficiency for each subject was calculated using the thermal temperature maps from the tcMRgFUS treatments. Axial temperature images (with no artifacts) were reconstructed with a single baseline, corrected using a referenceless algorithm. The experimental skull efficiency was calculated by dividing the reconstructed temperature rise 8.8 s after sonication by the applied acoustic power. Results: The simulated skull efficiency using individual-specific heterogeneous models predicts well (R{sup 2} = 0.84) the experimental energy efficiency. Conclusions: This paper presents a simulation model to predict the variation in thermal

Comparison of Radiofrequency Thermal Ablation and Microdebrider-Assisted Turbinoplasty in Inferior Turbinate Hypertrophy: A Prospective, Randomized, and Clinical Study

PubMed Central

Akagün, Fatih; İmamoğlu, Mehmet; Çobanoğlu, Hatice Bengü; Ural, Ahmet

2016-01-01

Objective To compare the effectiveness of radiofrequency thermal ablation with those of microdebrider-assisted turbinoplasty, we designed a prospective, randomized clinical study. Methods Forty patients suffering from nasal obstruction due to bilateral inferior turbinate hypertrophy were enrolled. Half of the patients were operated by radiofrequency thermal ablation, while the other half underwent microdebrider-assisted turbinoplasty. The outcomes of both techniques were compared in terms of symptomatology, nasal patency, and mucociliary transport. Results A statistically significant difference existed between the two groups with respect to nasal obstruction and the frequency of obstruction at the first post-operative week and first and third post-operative months (p<0.05). Rhinomanometry detected a significant decrease in nasal resistance values in both surgical groups compared to the preoperative values. The mucociliary transport time was significantly prolonged in the first postoperative week and first postoperative month in microdebrider-assisted inferior turbinoplasty group. Conclusion Both radiofrequency thermal ablation and microdebrider-assisted turbinoplasty are effective techniques for treating inferior turbinate hypertrophy. The treatment modality should be individually determined, and parameters such as tissue healing, volume reduction, and mucociliary activity must be taken into account. PMID:29392030

Open-source, small-animal magnetic resonance-guided focused ultrasound system.

PubMed

Poorman, Megan E; Chaplin, Vandiver L; Wilkens, Ken; Dockery, Mary D; Giorgio, Todd D; Grissom, William A; Caskey, Charles F

2016-01-01

MR-guided focused ultrasound or high-intensity focused ultrasound (MRgFUS/MRgHIFU) is a non-invasive therapeutic modality with many potential applications in areas such as cancer therapy, drug delivery, and blood-brain barrier opening. However, the large financial costs involved in developing preclinical MRgFUS systems represent a barrier to research groups interested in developing new techniques and applications. We aim to mitigate these challenges by detailing a validated, open-source preclinical MRgFUS system capable of delivering thermal and mechanical FUS in a quantifiable and repeatable manner under real-time MRI guidance. A hardware and software package was developed that includes closed-loop feedback controlled thermometry code and CAD drawings for a therapy table designed for a preclinical MRI scanner. For thermal treatments, the modular software uses a proportional integral derivative controller to maintain a precise focal temperature rise in the target given input from MR phase images obtained concurrently. The software computes the required voltage output and transmits it to a FUS transducer that is embedded in the delivery table within the magnet bore. The delivery table holds the FUS transducer, a small animal and its monitoring equipment, and a transmit/receive RF coil. The transducer is coupled to the animal via a water bath and is translatable in two dimensions from outside the magnet. The transducer is driven by a waveform generator and amplifier controlled by real-time software in Matlab. MR acoustic radiation force imaging is also implemented to confirm the position of the focus for mechanical and thermal treatments. The system was validated in tissue-mimicking phantoms and in vivo during murine tumor hyperthermia treatments. Sonications were successfully controlled over a range of temperatures and thermal doses for up to 20 min with minimal temperature overshoot. MR thermometry was validated with an optical temperature probe, and focus

Ultrasound-Guided 50% Ethyl Alcohol Injection for Patients With Malleolar and Olecranon Bursitis: A Prospective Pilot Study

PubMed Central

Hong, Ji Seong; Lee, Jin Hyung

2016-01-01

Objective To evaluate the feasibility and effect of ultrasound-guided ethyl alcohol injection on malleolar and olecranon synovial proliferative bursitis. Methods Twenty-four patients received ultrasound-guided 50% diluted ethyl alcohol injection at the site of synovial proliferative bursitis after aspiration of the free fluid. Results Swelling and symptoms significantly decreased in 13 of the 24 patients without any complications. Eleven patients had partial improvement in swelling and symptoms. Conclusion Ultrasound-guided alcohol injection could be an alternative therapeutic option before surgery in patients with chronic intractable malleolar and olecranon synovial proliferative bursitis. PMID:27152282

Targeted Prostate Thermal Therapy with Catheter-Based Ultrasound Devices and MR Thermal Monitoring

NASA Astrophysics Data System (ADS)

Diederich, Chris; Ross, Anthony; Kinsey, Adam; Nau, Will H.; Rieke, Viola; Butts Pauly, Kim; Sommer, Graham

2006-05-01

Catheter-based ultrasound devices have significant advantages for thermal therapy procedures, including potential for precise spatial and dynamic control of heating patterns to conform to targeted volumes. Interstitial and transurethral ultrasound applicators, with associated treatment strategies, were developed for thermal ablation of prostate combined with MR thermal monitoring. Four types of multielement transurethral applicators were devised, each with different levels of selectivity and intended therapeutic goals: sectored tubular transducer devices with fixed directional heating patterns; planar and lightly focused curvilinear devices with narrow heating patterns; and multi-sectored tubular devices capable of dynamic angular control without applicator movement. These devices are integrated with a 4 mm delivery catheter, incorporate an inflatable cooling balloon (10 mm OD) for positioning within the prostate and capable of rotation via an MR-compatible motor. Similarly, interstitial devices (2.4 mm OD) have been developed for percutaneous implantation with fixed directional heating patterns (e.g., 180 deg.). In vivo experiments in canine prostate (n=15) under MR temperature imaging were used to evaluate the heating technology and develop treatment strategies. MR thermal imaging in a 0.5 T interventional MRI was used to monitor temperature contours and thermal dose in multiple slices through the target volume. Sectored transurethral devices produce directional coagulation zones, extending 15-20 mm radial distance to the outer prostate capsule. The curvilinear applicator produces distinct 2-3 mm wide lesions, and with sequential rotation and modulated dwell time can precisely conform thermal ablation to selected areas or the entire prostate gland. Multi-sectored transurethral applicators can dynamically control the angular heating profile and target large regions of the gland in short treatment times without applicator manipulation. Interstitial implants with

Needle tip visibility in 3D ultrasound images

NASA Astrophysics Data System (ADS)

Arif, Muhammad; Moelker, Adriaan; van Walsum, Theo

2017-03-01

Needle visibility is of crucial importance for ultrasound guided interventional procedures. However, several factors, such as shadowing by bone or gas and tissue echogenic properties similar to needles, may compromise needle visibility. Additionally, small angle between the ultrasound beam and the needle, as well as small gauged needles may reduce visibility. Variety in needle tips design may also affect needle visibility. Whereas several studies have investigated needle visibility in 2D ultrasound imaging, no data is available for 3D ultrasound imaging, a modality that has great potential for image guidance interventions1. In this study, we evaluated needle visibility using a 3D ultrasound transducer. We examined different needles in a tissue mimicking liver phantom at three angles (200, 550 and 900) and quantify their visibility. The liver phantom was made by 5% polyvinyl alcohol solution containing 1% Silica gel particles to act as ultrasound scattering particles. We used four needles; two biopsy needles (Quick core 14G and 18G), one Ablation needle (Radiofrequency Ablation 17G), and Initial puncture needle (IP needle 17G). The needle visibility was quantified by calculating contrast to noise ratio. The results showed that the visibility for all needles were almost similar at large angles. However the difference in visibility at lower angles is more prominent. Furthermore, the visibility increases with the increase in angle of ultrasound beam with needles.

Anaesthetics, steroids and platelet-rich plasma (PRP) in ultrasound-guided musculoskeletal procedures.

PubMed

Barile, Antonio; La Marra, Alice; Arrigoni, Francesco; Mariani, Silvia; Zugaro, Luigi; Splendiani, Alessandra; Di Cesare, Ernesto; Reginelli, Alfonso; Zappia, Marcello; Brunese, Luca; Duka, Ejona; Carrafiello, Giampaolo; Masciocchi, Carlo

2016-09-01

This review aims to evaluate the role of anaesthetics, steroids and platelet-rich plasma (PRP) employed with ultrasound-guided injection in the management of musculoskeletal pathology of the extremities. Ultrasound-guided injection represents an interesting and minimally invasive solution for the treatment of tendon and joint inflammatory or degenerative diseases. The availability of a variety of new drugs such as hyaluronic acid and PRP provides expansion of the indications and therapeutic possibilities. The clinical results obtained in terms of pain reduction and functional recovery suggest that the use of infiltrative procedures can be a good therapeutic alternative in degenerative and inflammatory joint diseases.

Palpation- and ultrasound-guided brachial plexus blockade in Hispaniolan Amazon parrots (Amazona ventralis).

PubMed

da Cunha, Anderson F; Strain, George M; Rademacher, Nathalie; Schnellbacher, Rodney; Tully, Thomas N

2013-01-01

To compare palpation-guided with ultrasound-guided brachial plexus blockade in Hispaniolan Amazon parrots. Prospective randomized experimental trial. Eighteen adult Hispaniolan Amazon parrots (Amazona ventralis) weighing 252-295 g. After induction of anesthesia with isoflurane, parrots received an injection of lidocaine (2 mg kg(-1)) in a total volume of 0.3 mL at the axillary region. The birds were randomly assigned to equal groups using either palpation or ultrasound as a guide for the brachial plexus block. Nerve evoked muscle potentials (NEMP) were used to monitor effectiveness of brachial plexus block. The palpation-guided group received the local anesthetic at the space between the pectoral muscle, triceps, and supracoracoideus aticimus muscle, at the insertion of the tendons of the caudal coracobrachial muscle, and the caudal scapulohumeral muscle. For the ultrasound-guided group, the brachial plexus and the adjacent vessels were located with B-mode ultrasonography using a 7-15 MHz linear probe. After location, an 8-5 MHz convex transducer was used to guide injections. General anesthesia was discontinued 20 minutes after lidocaine injection and the birds recovered in a padded cage. Both techniques decreased the amplitude of NEMP. Statistically significant differences in NEMP amplitudes, were observed within the ultrasound-guided group at 5, 10, 15, and 20 minutes after injection and within the palpation-guided group at 10, 15, and 20 minutes after injection. There was no statistically significant difference between the two groups. No effect on motor function, muscle relaxation or wing droop was observed after brachial plexus block. The onset of the brachial plexus block tended to be faster when ultrasonography was used. Brachial plexus injection can be performed in Hispaniolan Amazon parrots and nerve evoked muscle potentials were useful to monitor the effects on nerve conduction in this avian species. Neither technique produced an effective block at the

Dual-frequency ultrasound focal therapy for MRI-guided transurethral treatment of the prostate: Study in gel phantom

NASA Astrophysics Data System (ADS)

N'Djin, W. Apoutou; Mougenot, Charles; Kobelevskiy, Ilya; Ramsay, Elizabeth; Bronskill, Michael; Chopra, Rajiv

2012-11-01

Ultrasound thermal therapy of localized prostate cancer offers a minimally-invasive non-ionizing alternative [1-3] to surgery and radiotherapy. MRI-controlled transurethral ultrasound prostate therapy [4-6] has previously been investigated in a pilot human feasibility study [7], by treating a small sub-volume of prostate tissue. In this study, the feasibility of transurethral dual-frequency ultrasound focal therapy has been investigated in gel phantom. A database of pelvic anatomical models of human prostate cancer patients have been created using MR clinical images. The largest prostate boundary (47 cm3) was used to fabricate an anatomical gel phantom which included various MR characteristics to mimic prostate tissues, 4 localized tumors and surrounding prostate tissues. A 9-element transurethral ultrasound applicator working in dual-frequency mode (f = 4.6/14.5 MHz) was evaluated to heat: (i) the entire prostate volume (Full prostate treatment strategy), (ii) a prostate region restricted to tumors (Focal therapy). Acoustic power of each element and rotation rate of the device were adjusted in realtime based on MR-thermometry feedback control (nine thermal slices updated every 6.2s). Experiments have been performed using dual-frequency ultrasound exposures (surface Pmax: 20W.cm-2). (i) For full prostate heating, 7 elements of the device were used to cover the entire prostate length. The heating process was completed within 35 min. Ultrasound exposures at the fundamental frequency allowed full heating of the largest prostate radii (>18 mm), while exposures at the 3rd harmonic ensured homogeneous treatment of the smallest radii. Undertreated and overtreated regions represented respectively 2% and 17% of the prostate volume. (ii) For focal therapy, the target region was optimized to maintain safe regions in the prostate and to cover all tumor-mimics. Only 5 ultrasound elements were used to treat successfully all tumor-mimics within 26 min. Undertreated and

Transmural ultrasound imaging of thermal lesion and action potential changes in perfused canine cardiac wedge preparations by high intensity focused ultrasound ablation.

PubMed

Wu, Ziqi; Gudur, Madhu S R; Deng, Cheri X

2013-01-01

Intra-procedural imaging is important for guiding cardiac arrhythmia ablation. It is difficult to obtain intra-procedural correlation of thermal lesion formation with action potential (AP) changes in the transmural plane during ablation. This study tested parametric ultrasound imaging for transmural imaging of lesion and AP changes in high intensity focused ultrasound (HIFU) ablation using coronary perfused canine ventricular wedge preparations (n = 13). The preparations were paced from epi/endocardial surfaces and subjected to HIFU application (3.5 MHz, 11 Hz pulse-repetition-frequency, 70% duty cycle, duration 4 s, 3500 W/cm(2)), during which simultaneous optical mapping (1 kframes/s) using di-4-ANEPPS and ultrasound imaging (30 MHz) of the same transmural surface of the wedge were performed. Spatiotemporally correlated AP measurements and ultrasound imaging allowed quantification of the reduction of AP amplitude (APA), shortening of AP duration at 50% repolarization, AP triangulation, decrease of optical AP rise, and change of conduction velocity along tissue depth direction within and surrounding HIFU lesions. The threshold of irreversible change in APA correlating to lesions was determined to be 43 ± 1% with a receiver operating characteristic (ROC) area under curve (AUC) of 0.96 ± 0.01 (n = 13). Ultrasound imaging parameters such as integrated backscatter, Rayleigh (α) and log-normal (σ) parameters, cumulative extrema of σ were tested, with the cumulative extrema of σ performing the best in detecting lesion (ROC AUC 0.89 ± 0.01, n = 13) and change of APA (ROC AUC 0.79 ± 0.03, n = 13). In conclusion, characteristic tissue and AP changes in HIFU ablation were identified and spatiotemporally correlated using optical mapping and ultrasound imaging. Parametric ultrasound imaging using cumulative extrema of σ can detect HIFU lesion and APA reduction.

Transmural Ultrasound Imaging of Thermal Lesion and Action Potential Changes in Perfused Canine Cardiac Wedge Preparations by High Intensity Focused Ultrasound Ablation

PubMed Central

Wu, Ziqi; Gudur, Madhu S. R.; Deng, Cheri X.

2013-01-01

Intra-procedural imaging is important for guiding cardiac arrhythmia ablation. It is difficult to obtain intra-procedural correlation of thermal lesion formation with action potential (AP) changes in the transmural plane during ablation. This study tested parametric ultrasound imaging for transmural imaging of lesion and AP changes in high intensity focused ultrasound (HIFU) ablation using coronary perfused canine ventricular wedge preparations (n = 13). The preparations were paced from epi/endocardial surfaces and subjected to HIFU application (3.5 MHz, 11 Hz pulse-repetition-frequency, 70% duty cycle, duration 4 s, 3500 W/cm2), during which simultaneous optical mapping (1 kframes/s) using di-4-ANEPPS and ultrasound imaging (30 MHz) of the same transmural surface of the wedge were performed. Spatiotemporally correlated AP measurements and ultrasound imaging allowed quantification of the reduction of AP amplitude (APA), shortening of AP duration at 50% repolarization, AP triangulation, decrease of optical AP rise, and change of conduction velocity along tissue depth direction within and surrounding HIFU lesions. The threshold of irreversible change in APA correlating to lesions was determined to be 43±1% with a receiver operating characteristic (ROC) area under curve (AUC) of 0.96±0.01 (n = 13). Ultrasound imaging parameters such as integrated backscatter, Rayleigh (α) and log-normal (σ) parameters, cumulative extrema of σ were tested, with the cumulative extrema of σ performing the best in detecting lesion (ROC AUC 0.89±0.01, n = 13) and change of APA (ROC AUC 0.79±0.03, n = 13). In conclusion, characteristic tissue and AP changes in HIFU ablation were identified and spatiotemporally correlated using optical mapping and ultrasound imaging. Parametric ultrasound imaging using cumulative extrema of σ can detect HIFU lesion and APA reduction. PMID:24349337

Endobronchial ultrasound elastography: a new method in endobronchial ultrasound-guided transbronchial needle aspiration.

PubMed

Jiang, Jun-Hong; Turner, J Francis; Huang, Jian-An

2015-12-01

TBNA through the flexible bronchoscope is a 37-year-old technology that utilizes a TBNA needle to puncture the bronchial wall and obtain specimens of peribronchial and mediastinal lesions through the flexible bronchoscope for the diagnosis of benign and malignant diseases in the mediastinum and lung. Since 2002, the Olympus Company developed the first generation ultrasound equipment for use in the airway, initially utilizing an ultrasound probe introduced through the working channel followed by incoroporation of a fixed linear ultrasound array at the distal tip of the bronchoscope. This new bronchoscope equipped with a convex type ultrasound probe on the tip was subsequently introduced into clinical practice. The convex probe (CP)-EBUS allows real-time endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) of mediastinal and hilar lymph nodes. EBUS-TBNA is a minimally invasive procedure performed under local anesthesia that has been shown to have a high sensitivity and diagnostic yield for lymph node staging of lung cancer. In 10 years of EBUS development, the Olympus Company developed the second generation EBUS bronchoscope (BF-UC260FW) with the ultrasound image processor (EU-M1), and in 2013 introduced a new ultrasound image processor (EU-M2) into clinical practice. FUJI company has also developed a curvilinear array endobronchial ultrasound bronchoscope (EB-530 US) that makes it easier for the operator to master the operation of the ultrasonic bronchoscope. Also, the new thin convex probe endobronchial ultrasound bronchoscope (TCP-EBUS) is able to visualize one to three bifurcations distal to the current CP-EBUS. The emergence of EBUS-TBNA has also been accompanied by innovation in EBUS instruments. EBUS elastography is, then, a new technique for describing the compliance of structures during EBUS, which may be of use in the determination of metastasis to the mediastinal and hilar lymph nodes. This article describes these new EBUS

Transvaginal ultrasound-guided embryo transfer in IVF.

PubMed

Larue, L; Keromnes, G; Massari, A; Roche, C; Moulin, J; Gronier, H; Bouret, D; Cassuto, N G; Ayel, J P

2017-05-01

To determine whether transvaginal ultrasound-guided embryo transfer is a technique that can be used routinely, whether it improves IVF outcomes and whether it makes difficult transfers easier and more successful. Non-randomized retrospective study conducted between 2012 and 2016 in the fertility center of the Diaconesses-Croix St-Simon hospital group. The outcomes of 3910 transfers, performed by 5 senior operators, under transabdominal ultrasound guidance are compared with those of 800 transfers, performed by 1 senior operator under transvaginal ultrasound guidance. The criteria studied are the feasibility of the technique and the percentage of pregnancies per transfer in the two populations described, as well as in the difficult and very difficult transfer populations. All the transfers were feasible under transvaginal ultrasound guidance without the use of forceps or additional instruments. The percentage of pregnancies per transfer is significantly increased, when the transfer is performed under transvaginal ultrasound guidance compared with that performed under transabdominal ultrasound guidance, in the general population (38%, n=800 vs 30%, n=3910; P 0.0004) and in the reference population characterized by age <38 years and >6 oocytes collected per puncture (45%, n=490 vs 36%, n=1968; P 0.002). The percentage of pregnancies per transfer (P/T) is not significantly different in the populations of easy transfers (n 695, 38% P/T), difficult transfers (n 58, 46% P/T; P=ns) and very difficult transfers (n 47, 34% P/T; P=ns). Embryo transfer is a key stage in IVF, in which the quality of performance determines the outcome. In this study, transvaginal ultrasound guidance of the transfer, which is the reference procedure in gynaecological imaging, significantly increases the percentage of pregnancies per transfer, both in the general population and in the reference population, compared with transfers performed under transabdominal ultrasound guidance. Transvaginal

Treatment of Partial Rotator Cuff Tear with Ultrasound-guided Platelet-rich Plasma.

PubMed

Sengodan, Vetrivel Chezian; Kurian, Sajith; Ramasamy, Raghupathy

2017-01-01

The treatment of symptomatic partial rotator cuff tear has presented substantial challenge to orthopaedic surgeons as it can vary from conservative to surgical repair. Researches have established the influence of platelet rich plasma in healing damaged tissue. Currently very few data are available regarding the evidence of clinical and radiological outcome of partial rotator cuff tear treated with ultrasound guided platelet rich plasma injection in English literature. 20 patients with symptomatic partial rotator cuff tears were treated with ultrasound guided platelet rich plasma injection. Before and after the injection of platelet rich plasma scoring was done with visual analogue score, Constant shoulder score, and UCLA shoulder score at 8 weeks and third month. A review ultrasound was performed 8 weeks after platelet rich plasma injection to assess the rotator cuff status. Our study showed statistically significant improvements in 17 patients in VAS pain score, constant shoulder score and UCLA shoulder score. No significant changes in ROM were noted when matched to the contra-lateral side ( P < 0.001) at the 3 month follow-up. The study also showed good healing on radiological evaluation with ultrasonogram 8 weeks after platelet rich plasma injection. Ultrasound guided platelet rich plasma injection for partial rotator cuff tears is an effective procedure that leads to significant decrease in pain, improvement in shoulder functions, much cost-effective and less problematic compared to a surgical treatment.

Image-guided tumor ablation: standardization of terminology and reporting criteria.

PubMed

Goldberg, S Nahum; Grassi, Clement J; Cardella, John F; Charboneau, J William; Dodd, Gerald D; Dupuy, Damian E; Gervais, Debra A; Gillams, Alice R; Kane, Robert A; Lee, Fred T; Livraghi, Tito; McGahan, John; Phillips, David A; Rhim, Hyunchul; Silverman, Stuart G; Solbiati, Luigi; Vogl, Thomas J; Wood, Bradford J; Vedantham, Suresh; Sacks, David

2009-07-01

The field of interventional oncology with use of image-guided tumor ablation requires standardization of terminology and reporting criteria to facilitate effective communication of ideas and appropriate comparison between treatments that use different technologies, such as chemical (ethanol or acetic acid) ablation, and thermal therapies, such as radiofrequency (RF), laser, microwave, ultrasound, and cryoablation. This document provides a framework that will hopefully facilitate the clearest communication between investigators and will provide the greatest flexibility in comparison between the many new, exciting, and emerging technologies. An appropriate vehicle for reporting the various aspects of image-guided ablation therapy, including classification of therapies and procedure terms, appropriate descriptors of imaging guidance, and terminology to define imaging and pathologic findings, are outlined. Methods for standardizing the reporting of follow-up findings and complications and other important aspects that require attention when reporting clinical results are addressed. It is the group's intention that adherence to the recommendations will facilitate achievement of the group's main objective: improved precision and communication in this field that lead to more accurate comparison of technologies and results and, ultimately, to improved patient outcomes. The intent of this standardization of terminology is to provide an appropriate vehicle for reporting the various aspects of image-guided ablation therapy.

Thermal build-up, decay and retention responses to local therapeutic application of 448 kHz capacitive resistive monopolar radiofrequency: A prospective randomised crossover study in healthy adults.

PubMed

Kumaran, Binoy; Watson, Tim

2015-01-01

Radiofrequency-based electrophysical agents are widely used in therapy-related clinical practice for their thermal effects, mainly relieving pain and inflammation and improving tissue extensibility. The most commonly used and researched are shortwave therapies that operate at 27.12 MHz. Although relatively new, electrophysical agents employing much lower frequencies have also emerged. Capacitive resistive monopolar radiofrequency employing 448 kHz is one such therapy. This laboratory-based study was aimed to investigate the skin thermal responses to 448 kHz radiofrequency-based therapy in healthy adults. In a two-group randomised crossover study, 15 volunteers attended two modes (capacitive and resistive) of 448 kHz radiofrequency-based therapy (using 'Indiba Activ 902') administered locally to the lower thigh region. Starting at minimum, the intensity was increased incrementally until thermal discomfort was felt. Participants reported three time points: thermal onset, definite thermal sensation, and onset of thermal discomfort. Local skin temperature was measured before, immediately post-treatment and up to 45 min post-treatment. Both capacitive and resistive modes of therapy significantly increased the skin temperature and sustained it over the 45-min follow-up. There was statistically significant difference between the thermal response patterns produced by the two modes. Peak post-treatment temperatures attained were not significantly different between the two; however, the retention rate at follow-up was significantly higher for the resistive mode. This study confirms that radiofrequency-based therapy at 448 kHz can significantly increase and sustain skin temperature. The study also provides useful baseline data for further research in the low frequency ranges of radiofrequency-based therapy that remain largely unexplored.

Value of cytopathologist-performed ultrasound-guided fine-needle aspiration as a screening test for ultrasound-guided core-needle biopsy in nonpalpable breast masses.

PubMed

Lieu, David

2009-04-01

Fine-needle aspiration (FNA) of breast masses in the United States has been on the decline for the last decade and has been largely replaced by ultrasound-guided core-needle biopsy (UG-CNB). Some studies show core-needle biopsy (CNB) is superior to FNA in terms of absolute sensitivity, specificity, and inadequate rate. However, the importance of a skilled aspirator, experienced cytopathologist, and immediate cytological evaluation (ICE) in FNA is often not considered. CNB is more expensive, invasive, risky, and painful than FNA. This prospective study examines the value of cytopathologist-performed ultrasound-guided FNA (UG-FNA) with ICE as a screening test for cytopathologist-performed UG-CNB on nonpalpable or difficult-to-palpate solid breast masses visible on ultrasound. One hundred twenty consecutive nonpalpable or difficult-to-palpate presumably solid breast masses in 109 female patients from January2, 2008 to June 30, 2008 underwent cytopathologist-performed UG-FNA with ICE. Twenty cases were converted to cytopathologist-performed UG-CNB because ICE was inadequate, hypocellular, atypical, suspicious, or malignant. Patients with clearly benign cytology did not undergo UG-CNB. UG-FNA with ICE reduced the percentage of patients undergoing UG-CNB by 87%. A new role for cytopathologist-performed UG-FNA of nonpalpable breast masses has been identified.

Real-time ultrasound-guided endoscopic surgery for putaminal hemorrhage.

PubMed

Sadahiro, Hirokazu; Nomura, Sadahiro; Goto, Hisaharu; Sugimoto, Kazutaka; Inamura, Akinori; Fujiyama, Yuichi; Yamane, Akiko; Oku, Takayuki; Shinoyama, Mizuya; Suzuki, Michiyasu

2015-11-01

Endoscopic surgery plays a significant role in the treatment of intracerebral hemorrhage. However, the residual hematoma cannot be measured intraoperatively from the endoscopic view, and it is difficult to determine the precise location of the endoscope within the hematoma cavity. The authors attempted to develop real-time ultrasound-guided endoscopic surgery using a bur-hole-type probe. From November 2012 to March 2014, patients with hypertensive putaminal hemorrhage who underwent endoscopic hematoma removal were enrolled in this study. Real-time ultrasound guidance was performed with a bur-hole-type probe that was advanced via a second bur hole, which was placed in the temporal region. Ultrasound was used to guide insertion of the endoscope sheath as well as to provide information regarding the location of the hematoma during surgical evacuation. Finally, the cavity was irrigated with artificial cerebrospinal fluid and was observed as a low-echoic space, which facilitated detection of residual hematoma. Ten patients with putaminal hemorrhage>30 cm3 were included in this study. Their mean age (±SD) was 60.9±8.6 years, and the mean preoperative hematoma volume was 65.2±37.1 cm3. The mean percentage of hematoma that was evacuated was 96%±3%. None of the patients exhibited rebleeding after surgery. This navigation method was effective in demonstrating both the real-time location of the endoscope and real-time viewing of the residual hematoma. Use of ultrasound guidance minimized the occurrence of brain injury due to hematoma evacuation.

Ultrasound-guided Subclavian Vein Cannulation Using a Micro-Convex Ultrasound Probe

PubMed Central

Fair, James; Hirshberg, Eliotte L.; Grissom, Colin K.; Brown, Samuel M.

2014-01-01

Background: The subclavian vein is the preferred site for central venous catheter placement due to infection risk and patient comfort. Ultrasound guidance is useful in cannulation of other veins, but for the subclavian vein, current ultrasound-guided techniques using high-frequency linear array probes are generally limited to axillary vein cannulation. Methods: We report a series of patients who underwent clinically indicated subclavian venous catheter placement using a micro-convex pediatric probe for real-time guidance in the vein’s longitudinal axis. We identified rates of successful placement and complications by chart review. Results: Twenty-four catheters were placed using the micro-convex pediatric probe with confirmation of placement of the needle medial to the lateral border of the first rib. Sixteen of the catheters were placed by trainee physicians. In 23 patients, the catheter was placed without complication (hematoma, pneumothorax, infection). In one patient, the vein could not be safely cannulated without risk of arterial puncture, so an alternative site was selected. Conclusions: Infraclavicular subclavian vein cannulation using real-time ultrasound with a micro-convex pediatric probe appears to be a safe and effective method of placing subclavian vascular catheters. This technique merits further study to confirm safety and efficacy. PMID:24611628

Impacts of microalgae pre-treatments for improved anaerobic digestion: thermal treatment, thermal hydrolysis, ultrasound and enzymatic hydrolysis.

PubMed

Ometto, Francesco; Quiroga, Gerardo; Pšenička, Pavel; Whitton, Rachel; Jefferson, Bruce; Villa, Raffaella

2014-11-15

Anaerobic digestion (AD) of microalgae is primarily inhibited by the chemical composition of their cell walls containing biopolymers able to resist bacterial degradation. Adoption of pre-treatments such as thermal, thermal hydrolysis, ultrasound and enzymatic hydrolysis have the potential to remove these inhibitory compounds and enhance biogas yields by degrading the cell wall, and releasing the intracellular algogenic organic matter (AOM). This work investigated the effect of four pre-treatments on three microalgae species, and their impact on the quantity of soluble biomass released in the media and thus on the digestion process yields. The analysis of the composition of the soluble COD released and of the TEM images of the cells showed two main degradation actions associated with the processes: (1) cell wall damage with the release of intracellular AOM (thermal, thermal hydrolysis and ultrasound) and (2) degradation of the cell wall constituents with the release of intracellular AOM and the solubilisation of the cell wall biopolymers (enzymatic hydrolysis). As a result of this, enzymatic hydrolysis showed the greatest biogas yield increments (>270%) followed by thermal hydrolysis (60-100%) and ultrasounds (30-60%). Copyright © 2014 Elsevier Ltd. All rights reserved.

Ultrasound-guided piriformis muscle injection. A new approach.

PubMed

Bevilacqua Alén, E; Diz Villar, A; Curt Nuño, F; Illodo Miramontes, G; Refojos Arencibia, F J; López González, J M

2016-12-01

Piriformis syndrome is an uncommon cause of buttock and leg pain. Some treatment options include the injection of piriformis muscle with local anesthetic and steroids. Various techniques for piriformis muscle injection have been described. Ultrasound allows direct visualization and real time injection of the piriformis muscle. We describe 5 consecutive patients, diagnosed of piriformis syndrome with no improvement after pharmacological treatment. Piriformis muscle injection with local anesthetics and steroids was performed using an ultrasound technique based on a standard technique. All 5 patients have improved their pain measured by numeric verbal scale. One patient had a sciatic after injection that improved in 10 days spontaneously. We describe an ultrasound-guided piriformis muscle injection that has the advantages of being effective, simple, and safe. Copyright © 2016 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.

Radiofrequency Guide Wire Recanalization of Venous Occlusions in Patients with Malignant Superior Vena Cava Syndrome

DOE Office of Scientific and Technical Information (OSTI.GOV)

Davis, Robert M.; David, Elizabeth; Pugash, Robyn A.

Fibrotic central venous occlusions in patients with thoracic malignancy and prior radiotherapy can be impassable with standard catheters and wires, including the trailing or stiff end of a hydrophilic wire. We report two patients with superior vena cava syndrome in whom we successfully utilized a radiofrequency guide wire (PowerWire, Baylis Medical, Montreal, Quebec, Canada) to perforate through the occlusion and recanalize the occluded segment to alleviate symptoms.

Design and Production of an Articulating Needle Guide for Ultrasound-Guided Needle Block Manufactured With a Three-Dimensional Printer: Technical Communication.

PubMed

Bigeleisen, Paul E

2017-05-15

Needle guides may allow the practitioner to align the needle with the probe when ultrasound-guided nerve block is performed. The author's goal was to design and fabricate an inexpensive ($1.90), disposable, needle guide that could articulate over a range from 85 degrees to 0 degrees with a three-dimension printer. Three-dimensional representations of an L50, L25, and C 60 ultrasound probe (Sono Site, Bothell, WA) were created using a laser scanner. Computer-aided design software (Solid Works, Waltham, MA) was used to design a needle bracket and needle guide to attach to these probes. A three-dimensional printer was used to fabricate the needle bracket and guide with acrylonitrile polybutadiene polystyrene. An echogenic needle was held in plane with the needle guide. The author performed a supraclavicular block in a morbidly obese patient. The needle was easily visualized. Similar guides that are commercially available cost as much as $400. A knowledge of computer-aided design is necessary for this work.

Neurologic Outcomes After Low-Volume, Ultrasound-Guided Interscalene Block and Ambulatory Shoulder Surgery.

PubMed

Rajpal, Gaurav; Winger, Daniel G; Cortazzo, Megan; Kentor, Michael L; Orebaugh, Steven L

2016-01-01

Postoperative neurologic symptoms after interscalene block and shoulder surgery have been reported to be relatively frequent. Reports of such symptoms after ultrasound-guided block have been variable. We evaluated 300 patients for neurologic symptoms after low-volume, ultrasound-guided interscalene block and arthroscopic shoulder surgery. Patients underwent ultrasound-guided interscalene block with 16 to 20 mL of 0.5% bupivacaine or a mix of 0.2% bupivacaine/1.2% mepivacaine solution, followed by propofol/ketamine sedation for ambulatory arthroscopic shoulder surgery. Patients were called at 10 days for evaluation of neurologic symptoms, and those with persistent symptoms were called again at 30 days, at which point neurologic evaluation was initiated. Details of patient demographics and block characteristics were collected to assess any association with persistent neurologic symptoms. Six of 300 patients reported symptoms at 10 days (2%), with one of these patients having persistent symptoms at 30 days (0.3%). This was significantly lower than rates of neurologic symptoms reported in preultrasound investigations with focused neurologic follow-up and similar to other studies performed in the ultrasound era. There was a modest correlation between the number of needle redirections during the block procedure and the presence of postoperative neurologic symptoms. Ultrasound guidance of interscalene block with 16- to 20-mL volumes of local anesthetic solution results in a lower frequency of postoperative neurologic symptoms at 10 and 30 days as compared with investigations in the preultrasound period.

Gestrinone combined with ultrasound-guided aspiration and ethanol injection for treatment of chocolate cyst of ovary.

PubMed

Wu, Xiaoyun; Xu, Yun

2015-05-01

The aim of this study was to determine clinical performance of gestrinone combined with ultrasound-guided aspiration and ethanol injection in treating chocolate cyst of ovary. Sixty-eight patients enrolled in this study were randomly divided into two groups: control group and combination treatment group. In the control group, 34 patients were treated with ultrasound-guided aspiration and ethanol injection. In the combination treatment group, 34 patients received gestrinone p.o. following ultrasound-guided aspiration and ethanol injection. The recurrence rate of chocolate cyst was 10-fold lower in the combination treatment group (2.94%, 1/34) than in the control group (29.4%, 10/34) at 12 months. The effective rate for reduction of chocolate cyst was significantly higher in the combination treatment group (94.12%, 32/34) than in the control group (64.71%, 22/34) (P = 0.009). Gestrinone combined with ultrasound-guided aspiration and ethanol injection therapy is an effective treatment for ovarian chocolate cyst with low recurrence rate. © 2014 The Authors. Journal of Obstetrics and Gynaecology Research © 2014 Japan Society of Obstetrics and Gynecology.

Image-guided tumor ablation: standardization of terminology and reporting criteria.

PubMed

Goldberg, S Nahum; Grassi, Clement J; Cardella, John F; Charboneau, J William; Dodd, Gerald D; Dupuy, Damian E; Gervais, Debra; Gillams, Alice R; Kane, Robert A; Lee, Fred T; Livraghi, Tito; McGahan, John; Phillips, David A; Rhim, Hyunchul; Silverman, Stuart G

2005-06-01

The field of interventional oncology with use of image-guided tumor ablation requires standardization of terminology and reporting criteria to facilitate effective communication of ideas and appropriate comparison between treatments that use different technologies, such as chemical (ethanol or acetic acid) ablation, and thermal therapies, such as radiofrequency, laser, microwave, ultrasound, and cryoablation. This document provides a framework that will hopefully facilitate the clearest communication between investigators and will provide the greatest flexibility in comparison between the many new, exciting, and emerging technologies. An appropriate vehicle for reporting the various aspects of image-guided ablation therapy, including classification of therapies and procedure terms, appropriate descriptors of imaging guidance, and terminology to define imaging and pathologic findings, are outlined. Methods for standardizing the reporting of follow-up findings and complications and other important aspects that require attention when reporting clinical results are addressed. It is the group's intention that adherence to the recommendations will facilitate achievement of the group's main objective: improved precision and communication in this field that lead to more accurate comparison of technologies and results and, ultimately, to improved patient outcomes. Copyright RSNA, 2005.

Ultrasound-guided microwave ablation in the treatment of benign thyroid nodules in 435 patients

PubMed Central

Qian, Lin-Xue; Liu, Dong; Zhao, Jun-Feng

2017-01-01

The objective of the present study was to investigate the effectiveness and safety of ultrasound-guided microwave ablation in the treatment of benign thyroid nodules. A total of 474 benign thyroid nodules in 435 patients who underwent ultrasound-guided microwave ablation from September 2012 to August 2015 were included. Nodule volume and thyroid function were measured before treatment and at 1, 3, 6, and 12 months and subsequently after every 6 months. The nodule volume reduction rate and changes of thyroid function were evaluated. The volume of all thyroid nodules significantly decreased after ultrasound-guided microwave ablation. The average volume was 13.07 ± 0.95 ml before treatment, and 1.14 ± 0.26 ml at 12-months follow-up. The mean volume reduction rate was 90% and the final volume reduction rate was 94%. The volume reduction rate of mainly cystic nodules was significantly higher than that of simple solid and mainly solid nodules (all P < 0.05). The pretreatment volume of nodules was positively correlated with the final volume reduction rate at final follow-up (P = 0.004). No serious complications were observed after treatment. In conclusion, ultrasound-guided microwave ablation is an effective and safe technique for treatment of benign thyroid nodules, and has the potential for clinical applications. Impact statement Ultrasound-guided MWA is an effective and safe technique for the treatment of benign thyroid nodules. It can significantly reduce the nodule volume, improve the patients’ clinical symptoms, has less complication, guarantees quick recovery, meets patients' aesthetic needs, and shows less interference on the physiological and psychological aspects of the body. MWA should be a good complement to traditional open surgery and has potentials in clinical applications. PMID:28847173

Ultrasound-guided microwave ablation in the treatment of benign thyroid nodules in 435 patients.

PubMed

Liu, Yu-Jiang; Qian, Lin-Xue; Liu, Dong; Zhao, Jun-Feng

2017-09-01

The objective of the present study was to investigate the effectiveness and safety of ultrasound-guided microwave ablation in the treatment of benign thyroid nodules. A total of 474 benign thyroid nodules in 435 patients who underwent ultrasound-guided microwave ablation from September 2012 to August 2015 were included. Nodule volume and thyroid function were measured before treatment and at 1, 3, 6, and 12 months and subsequently after every 6 months. The nodule volume reduction rate and changes of thyroid function were evaluated. The volume of all thyroid nodules significantly decreased after ultrasound-guided microwave ablation. The average volume was 13.07 ± 0.95 ml before treatment, and 1.14 ± 0.26 ml at 12-months follow-up. The mean volume reduction rate was 90% and the final volume reduction rate was 94%. The volume reduction rate of mainly cystic nodules was significantly higher than that of simple solid and mainly solid nodules (all P < 0.05). The pretreatment volume of nodules was positively correlated with the final volume reduction rate at final follow-up ( P = 0.004). No serious complications were observed after treatment. In conclusion, ultrasound-guided microwave ablation is an effective and safe technique for treatment of benign thyroid nodules, and has the potential for clinical applications. Impact statement Ultrasound-guided MWA is an effective and safe technique for the treatment of benign thyroid nodules. It can significantly reduce the nodule volume, improve the patients' clinical symptoms, has less complication, guarantees quick recovery, meets patients' aesthetic needs, and shows less interference on the physiological and psychological aspects of the body. MWA should be a good complement to traditional open surgery and has potentials in clinical applications.

Endoscopic ultrasound-guided choledochoduodenostomy after a failed or impossible ERCP.

PubMed

Mora Soler, Ana María; Álvarez Delgado, Alberto; Piñero Pérez, María Concepción; Velasco-Guardado, Antonio; Marcos Prieto, Héctor; Rodríguez Pérez, Antonio

2018-05-01

endoscopic ultrasound-guided biliary drainage (EUS-BD) is an alternative to percutaneous trans-hepatic biliary drainage (PTBD) in cases of failed endoscopic retrograde cholangiopancreatography (ERCP). this is a retrospective description of six cases of endoscopic ultrasound-guided biliary drainage via choledochoduodenostomy (EUCD), as well as the clinical characteristics, endoscopic procedure, complications and monitoring. all cases had malignant distal biliary obstruction. The procedure was concluded with good drainage in four out of six patients. Two late complications were recorded that were caused by stent migration and there were no deaths related with the procedure. The average monitoring period was six months. EUCD can be considered as a valid therapeutic choice in some selected cases and when performed by a team of expert endoscopists in cases of failed ERCP drainage or as an alternative to PTBD. However, the procedure has some associated complications.

Effect of tumor properties on energy absorption, temperature mapping, and thermal dose in 13.56-MHz radiofrequency hyperthermia.

PubMed

Prasad, Bibin; Kim, Subin; Cho, Woong; Kim, Suzy; Kim, Jung Kyung

2018-05-01

Computational techniques can enhance personalized hyperthermia-treatment planning by calculating tissue energy absorption and temperature distribution. This study determined the effect of tumor properties on energy absorption, temperature mapping, and thermal dose distribution in mild radiofrequency hyperthermia using a mouse xenograft model. We used a capacitive-heating radiofrequency hyperthermia system with an operating frequency of 13.56 MHz for in vivo mouse experiments and performed simulations on a computed tomography mouse model. Additionally, we measured the dielectric properties of the tumors and considered temperature dependence for thermal properties, metabolic heat generation, and perfusion. Our results showed that dielectric property variations were more dominant than thermal properties and other parameters, and that the measured dielectric properties provided improved temperature-mapping results relative to the property values taken from previous study. Furthermore, consideration of temperature dependency in the bio heat-transfer model allowed elucidation of precise thermal-dose calculations. These results suggested that this method might contribute to effective thermoradiotherapy planning in clinics. Copyright © 2018 Elsevier Ltd. All rights reserved.

Image-Guided Spinal Ablation: A Review

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tsoumakidou, Georgia, E-mail: gtsoumakidou@yahoo.com; Koch, Guillaume, E-mail: guillaume.koch@chru-strasbourg.fr; Caudrelier, Jean, E-mail: jean.caudrelier@chru-strasbourg.fr

2016-09-15

The image-guided thermal ablation procedures can be used to treat a variety of benign and malignant spinal tumours. Small size osteoid osteoma can be treated with laser or radiofrequency. Larger tumours (osteoblastoma, aneurysmal bone cyst and metastasis) can be addressed with radiofrequency or cryoablation. Results on the literature of spinal microwave ablation are scarce, and thus it should be used with caution. A distinct advantage of cryoablation is the ability to monitor the ice-ball by intermittent CT or MRI. The different thermal insulation, temperature and electrophysiological monitoring techniques should be applied. Cautious pre-procedural planning and intermittent intra-procedural monitoring of themore » ablation zone can help reduce neural complications. Tumour histology, patient clinical-functional status and life-expectancy should define the most efficient and least disabling treatment option.« less

Ultrasound-guided thoracenthesis: the V-point as a site for optimal drainage positioning.

PubMed

Zanforlin, A; Gavelli, G; Oboldi, D; Galletti, S

2013-01-01

In the latest years the use of lung ultrasound is increasing in the evaluation of pleural effusions, because it makes follow-up easier and drainage more efficient by providing guidance on the most appropriate sampling site. However, no standardized approach for ultrasound-guided thoracenthesis is actually available. To evaluate our usual ultrasonographic landmark as a possible standard site to perform thoracenthesis by assessing its value in terms of safety and efficiency (success at first attempt, drainage as complete as possible). Hospitalized patients with non organized pleural effusion underwent thoracenthesis after ultrasound evaluation. The point showing on ultrasound the maximum thickness of the effusion ("V-point") was chosen for drainage. 45 ultrasound guided thoracenthesis were performed in 12 months. In 22 cases there were no complications; 16 cases of cough, 2 cases of mild dyspnea without desaturation, 4 cases of mild pain; 2 cases of complications requiring medical intervention occurred. No case of pneumothorax related to the procedure was detected. In all cases drainage was successful on the first attempt. The collected values of maximum thickness at V-point (min 3.4 cm - max 15.3 cm) and drained fluid volume (min 70 ml - max 2000 ml) showed a significative correlation (p < 0.0001). When the thickness was greater or equal to 9.9 cm, drained volume was always more than 1000 ml. The measure of the maximum thickness at V-point provides high efficiency to ultrasound guided thoracentesis and allows to estimate the amount of fluid in the pleural cavity. It is also an easy parameter that makes the proposed method quick to learn and apply.  

Anaesthetics, steroids and platelet-rich plasma (PRP) in ultrasound-guided musculoskeletal procedures

PubMed Central

La Marra, Alice; Arrigoni, Francesco; Mariani, Silvia; Zugaro, Luigi; Splendiani, Alessandra; Di Cesare, Ernesto; Reginelli, Alfonso; Zappia, Marcello; Brunese, Luca; Duka, Ejona; Carrafiello, Giampaolo; Masciocchi, Carlo

2016-01-01

This review aims to evaluate the role of anaesthetics, steroids and platelet-rich plasma (PRP) employed with ultrasound-guided injection in the management of musculoskeletal pathology of the extremities. Ultrasound-guided injection represents an interesting and minimally invasive solution for the treatment of tendon and joint inflammatory or degenerative diseases. The availability of a variety of new drugs such as hyaluronic acid and PRP provides expansion of the indications and therapeutic possibilities. The clinical results obtained in terms of pain reduction and functional recovery suggest that the use of infiltrative procedures can be a good therapeutic alternative in degenerative and inflammatory joint diseases. PMID:27302491

Septic bursitis after ultrasound-guided percutaneous treatment of rotator cuff calcific tendinopathy.

PubMed

Sconfienza, Luca Maria; Randelli, Filippo; Sdao, Silvana; Sardanelli, Francesco; Randelli, Pietro

2014-08-01

Calcific tendinopathy of the rotator cuff is a common condition. Ultrasound-guided percutaneous aspiration is one of several options to treat this condition. The main advantages of this procedure are short duration, good outcome, and low cost. Furthermore, only minor complications have been reported in the literature, namely, vagal reactions during the procedure and mild postprocedural pain. We report the first case of septic bursitis after ultrasound-guided percutaneous treatment of calcific tendinopathy. Although this is generally considered a very safe procedure, a risk of infection should be taken into account. Copyright © 2014 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

Electro-opto-mechanical radio-frequency oscillator driven by guided acoustic waves in standard single-mode fiber

NASA Astrophysics Data System (ADS)

London, Yosef; Diamandi, Hilel Hagai; Zadok, Avi

2017-04-01

An opto-electronic radio-frequency oscillator that is based on forward scattering by the guided acoustic modes of a standard single-mode optical fiber is proposed and demonstrated. An optical pump wave is used to stimulate narrowband, resonant guided acoustic modes, which introduce phase modulation to a co-propagating optical probe wave. The phase modulation is converted to an intensity signal at the output of a Sagnac interferometer loop. The intensity waveform is detected, amplified, and driven back to modulate the optical pump. Oscillations are achieved at a frequency of 319 MHz, which matches the resonance of the acoustic mode that provides the largest phase modulation of the probe wave. Oscillations at the frequencies of competing acoustic modes are suppressed by at least 40 dB. The linewidth of the acoustic resonance is sufficiently narrow to provide oscillations at a single longitudinal mode of the hybrid cavity. Competing longitudinal modes are suppressed by at least 38 dB as well. Unlike other opto-electronic oscillators, no radio-frequency filtering is required within the hybrid cavity. The frequency of oscillations is entirely determined by the fiber opto-mechanics.

Ultrasound-Guided Drainage of Supralevator Hematoma in a Hemodynamically Stable Patient.

PubMed

Mukhopadhyay, Debjani; Jennings, Paul E; Banerjee, Mamta; Gada, Ruta

2015-12-01

Paravaginal hematomas can be life-threatening. In patients with intact vaginal walls and perineum, they may pose a diagnostic and therapeutic challenge. Supralevator hematomas are much less common than infralevator hematomas. We present a case of puerperal hemorrhagic shock after a normal vaginal delivery in a low-risk parous woman resulting from an occult supralevator hematoma. Because the woman was hemodynamically unstable initially, she underwent a vaginal surgical drainage. A week later, the supravaginal hematoma reformed. At this time the patient was hemodynamically stable, and ultrasound-guided drainage was performed, which resulted in complete resolution of the hematoma within 10 days. In a clinically stable puerperal patient, ultrasound-guided drainage of a supralevator hematoma resulted in rapid and complete resolution of symptoms.

Noninvasive Label-Free Detection of Micrometastases in the Lymphatics with Ultrasound-Guided Photoacoustic Imaging

DTIC Science & Technology

2015-10-01

imaging can be used to guide dissection. We have also successfully integrated a programmable ultrasound machine (Verasonics Vantage ) and tunable pulsed...Mobile HE) with the programmable ultrasound machine (Verasonics Vantage ). We have synchronized the signals to enable interleaved acquisition of US

Comparison of Stereotactic and Ultrasound-guided Biopsy of Solid Supratentorial Tumor: A Preliminary Report

PubMed Central

Satyarthee, Guru Dutta; Chandra, P. Sarat; Sharma, Bhawani S.; Mehta, V. S.

2017-01-01

Introduction: The computed tomography (CT) guided stereotactic biopsy (STB) is considered as method of choice for biopsy of intracranial mass lesions. However, it's disadvantages are frame fixation, time requirement for transportation between CT scan suit to the operation theater with added much higher equipment cost in the relatively resource scarred developing country. Ultrasound-guided biopsy (USGB) is relatively simpler, economical, less time consuming, and real-time procedure. Clinical Materials and Methods: Thirty-seven consecutively admitted patients with supratentorial brain tumors, who underwent biopsy of the lesion using CT compatible stereotactic and ultrasound-guided (USGB) procedure formed cohort of the study. Based on location and size of the lesions, the cases were divided into two groups, superficial and deep. Twenty-two patients underwent ultrasound-guided biopsy and 15 with STB. Results: The diagnostic yield of STB was 93% and 91% for ultrasound-guided biopsy. The mean operation time of STB group was 149.00 min and 94 min for USGB, which was statistically significant. Two cases in each group developed hematoma; however, one case in USGB group needed surgical evacuation. The real-time monitoring detected two hematoma intraoperatively, which were further also confirmed on postoperative CT scan head. Conclusions: The ultrasound-guided biopsy procedure (USGB) was simple, relatively shorter time-consuming procedure and equally efficacious and utilizing economical equipment and can act as a safer alternative to CT STB process for biopsy of the intracranial mass lesion. Furthermore, USGB also provided intra-operative real-time monitoring, which provided clue for close monitoring in the postoperative period after completion of biopsy to look for development of fresh hematoma development not only at the biopsy site but also along the biopsy track and adjoining area. Perhaps, a longer period of ultrasonic monitoring following the procedure would be of

Treatment of Partial Rotator Cuff Tear with Ultrasound-guided Platelet-rich Plasma

PubMed Central

Sengodan, Vetrivel Chezian; Kurian, Sajith; Ramasamy, Raghupathy

2017-01-01

Background: The treatment of symptomatic partial rotator cuff tear has presented substantial challenge to orthopaedic surgeons as it can vary from conservative to surgical repair. Researches have established the influence of platelet rich plasma in healing damaged tissue. Currently very few data are available regarding the evidence of clinical and radiological outcome of partial rotator cuff tear treated with ultrasound guided platelet rich plasma injection in English literature. Materials and Methods: 20 patients with symptomatic partial rotator cuff tears were treated with ultrasound guided platelet rich plasma injection. Before and after the injection of platelet rich plasma scoring was done with visual analogue score, Constant shoulder score, and UCLA shoulder score at 8 weeks and third month. A review ultrasound was performed 8 weeks after platelet rich plasma injection to assess the rotator cuff status. Results: Our study showed statistically significant improvements in 17 patients in VAS pain score, constant shoulder score and UCLA shoulder score. No significant changes in ROM were noted when matched to the contra-lateral side (P < 0.001) at the 3 month follow-up. The study also showed good healing on radiological evaluation with ultrasonogram 8 weeks after platelet rich plasma injection. Conclusion: Ultrasound guided platelet rich plasma injection for partial rotator cuff tears is an effective procedure that leads to significant decrease in pain, improvement in shoulder functions, much cost-effective and less problematic compared to a surgical treatment. PMID:28900553

Simulators for training in ultrasound guided procedures.

PubMed

Farjad Sultan, Syed; Shorten, George; Iohom, Gabrielle

2013-06-01

The four major categories of skill sets associated with proficiency in ultrasound guided regional anaesthesia are 1) understanding device operations, 2) image optimization, 3) image interpretation and 4) visualization of needle insertion and injection of the local anesthetic solution. Of these, visualization of needle insertion and injection of local anaesthetic solution can be practiced using simulators and phantoms. This survey of existing simulators summarizes advantages and disadvantages of each. Current deficits pertain to the validation process.

Radiofrequency Energy and Electrode Proximity Influences Stereoelectroencephalography-Guided Radiofrequency Thermocoagulation Lesion Size: An In Vitro Study with Clinical Correlation.

PubMed

Staudt, Michael D; Maturu, Sarita; Miller, Jonathan P

2018-02-16

Radiofrequency thermocoagulation of epileptogenic foci via stereoelectroencephalography (SEEG) electrodes has been suggested as a treatment for medically intractable epilepsy, but reported outcomes have been suboptimal, possibly because lesions generated using conventional high-energy radiofrequency parameters are relatively small. To describe a technique of delivering low energy across separate SEEG electrodes in order to create large confluent radiofrequency lesions. The size and configuration of radiofrequency lesions using different radiofrequency intensity and interelectrode distance was assessed in egg whites. Magnetic resonance images (MRI) from 3 patients who had undergone radiofrequency lesion creation were evaluated to determine the contribution of lesion intensity and electrode separation on lesion size. Electroencephalography, MRI, and clinical data were assessed before and after lesion creation. Both in Vitro and in Vivo analysis revealed that less energy paradoxically produced larger lesions, with the largest possible lesions produced when radiofrequency power was applied for long duration at less than 3 W. Linear separation of electrodes also contributed to lesion size, with largest lesions produced when electrodes were separated by a linear distance of between 5 and 12 mm. Clinical lesions produced using these parameters were large and resulted in improvement in interictal and ictal activity. Radiofrequency lesions produced using low-energy delivery between SEEG electrodes in close proximity can produce a large lesion. These findings might have advantages for treatment of focal epilepsy.

Renal Tumors: Technical Success and Early Clinical Experience with Radiofrequency Ablation of 18 Tumors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sabharwal, Rohan, E-mail: rohan50000@yahoo.com; Vladica, Philip

2006-04-15

Purpose. To evaluate the feasibility, safety, and technical efficacy of image-guided radiofrequency ablation (RFA) for the treatment of small peripheral renal tumors and to report our early results with this treatment modality. Methods. Twenty-two RFA sessions for 18 tumors were performed in 11 patients with renal tumors. Indications included coexistent morbidity, high surgical or anesthetic risk, solitary kidney, and hereditary predisposition to renal cell carcinoma. Ten patients had CT-guided percutaneous RFA performed on an outpatient basis. One patient had open intraoperative ultrasound-guided RFA. Technical success was defined as elimination of areas that enhanced at imaging within the entire tumor. Withmore » the exception of one patient with renal insufficiency who required gadolinium-enhanced MRI, the remaining patients underwent contrast-enhanced CT for post-treatment follow-up assessment. Follow-up was performed after 2-4 weeks and then at 3, 6, 12 months, and every 12 months thereafter. Results. Fourteen (78%) of 18 tumors were successfully ablated with one session. Three of the remaining four tumors required two sessions for successful ablation. One tumor will require a third session for areas of persistent enhancement. Mean patient age was 72.82 {+-} 10.43 years. Mean tumor size was 1.95 {+-} 0.79 cm. Mean follow-up time was 10.91 months. All procedures were performed without any major complications. Conclusions. Our early experience with percutaneous image-guided radiofrequency ablation demonstrates it to be a feasible, safe, noninvasive, and effective treatment of small peripheral renal tumors.« less

Magnetic Resonance-Guided High-Intensity Focused Ultrasound Ablation of Osteoid Osteoma: A Case Series Report.

PubMed

Rovella, Marcello S; Martins, Guilherme L P; Cavalcanti, Conrado F A; Bor-Seng-Shu, Edson; Camargo, Olavo P; Cerri, Giovanni G; Menezes, Marcos R

2016-04-01

Osteoid osteoma is painful benign tumor. The aim of this study was to report our initial experience using magnetic resonance-guided focused ultrasound to treat osteoid osteomas. This retrospective single-center study included four patients treated with magnetic resonance-guided focused ultrasound. They presented with severe pain with reduced quality of life and a poor response to clinical treatment. The pre- and post-treatment evaluation comprised computed tomography and magnetic resonance imaging and focused on quality of life and the impact of pain on daily activities. After treatment, three patients had complete pain resolution with no recurrence. One patient had a recurrence of symptoms after 2 wk and underwent a new successful treatment with increased energy levels. On average, 13 sonications were administered (8-18 sonications/treatment) with an average energy of 2,003 J (range: 1,063-3,522 J). Magnetic resonance-guided focused ultrasound appears to be a feasible, tolerable and effective treatment in selected patients with osteoid osteomas. Copyright © 2016 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

[Echo-guided radiofrequency percutaneous ablation of hepatocellular carcinoma in cirrhosis using a cooled needle].

PubMed

Marone, G; Francica, G; D'Angelo, V; Iodice, G; Pastore, P; Altamura, G; Cusati, B; Siani, A

1998-06-01

Radiofrequency hyperthermia using the newly-developed "cooled-tip" needle is one of the latest US-guided percutaneous treatments of hepatocellular carcinoma arising in cirrhosis. The continuous cooling of the needle tip allows tissue heating and necrosis far from the electrode without tissue charring, which was the major drawback of the old monopolar technique. Herein we report our preliminary results on feasibility and effectiveness of the thermoablation of mono- or paucifocal hepatocellular carcinoma with the cooled-tip needle. November, 1996, to January, 1998, we treated thirteen cirrhotic patients (mean age 69.5 yrs, 10 men, 12 HCV-positive; 11 in Child's Class A and 2 in Class B) with 19 hepatocellular carcinoma nodules (mean diameter: 27 mm; range: 10-41 mm; 6 with diameter > 3 cm). None of the patients had portal thrombosis and/or extrahepatic spread. We used a radiofrequency generator (100 W power) connected to an 18 G perfusion electrode needle with an exposed tip of 2-3 cm. The circuit is closed through a dispersive electrode positioned under the patient's thighs. A peristaltic pump infuses a chilled (2-5 degrees C) saline solution to guarantee the continuous cooling of the needle tip. The needle was placed into target lesions under US guidance. The interventional procedure was carried out under general anesthesia using Propofol without intubation. Dynamic CT (more recently with the helical technique) was carried out 15-20 days after thermoablation to assess treatment efficacy. In all, 31 thermal injuries (at 1000-1200 mA for 10-15 minutes) were caused in 21 sessions in the 19 hepatocellular carcinoma nodules (mean: 1.5 lesions per nodule and 1.6 sessions per patient). Complete necrosis as assessed at dynamic CT (no enhancement during the arteriographic phase) was achieved in 16 of 19 nodules (84%). No side-effects occurred. During the follow-up (median: 11 months) no death occurred and five patients had recurrent hepatocellular carcinoma appearing either

Ultrasound - Breast

MedlinePlus

... the patient. Because ultrasound images are captured in real-time, they can show the structure and movement of ... perform an ultrasound-guided biopsy . Because ultrasound provides real-time images, it is often used to guide biopsy ...

Safety of ultrasound-guided high-intensity focused ultrasound ablation for diffuse adenomyosis: A retrospective cohort study.

PubMed

Feng, Yujie; Hu, Liang; Chen, Wenzhi; Zhang, Rong; Wang, Xi; Chen, Jinyun

2017-05-01

To evaluate the safety of ultrasound-guided high-intensity focused ultrasound (HIFU) ablation for patients with diffuse adenomyosis. This was a retrospective cohort study. The data was collected from 417 symptomatic adenomyosis patients who underwent ultrasound-guided HIFU between January 2012 and December 2015 at 1st Affiliated Hospital of Chongqing Medical University, Chongqing, China. Among them were 260 patients with diffuse adenomyosis (Group D) and 157 patients with focal adenomyosis (Group F). All patients underwent contrast-enhanced magnetic resonance imaging (MRI) one week before and the day after HIFU treatment. Successful treatment with HIFU was measured by the non-perfused volume ratio (NPVR). Intraprocedural and postprocedural adverse effects and complications were recorded to assess the safety of the procedure. Patients were followed-up for three months post-treatment. Complications were given a grade A through F according to the SIR Standards. All patients successfully completed the procedure, non-perfused regions appeared in 415 (99.5%) patients. The non-perfused volume ratio (NPVR) of Group D was significantly lower than that of Group F (P<0.05). During the procedure, the odds ratio of skin-burning pain was 1.7 (OR=1.617, 95% CI: 1.103-2.532), when comparing Group D with Group F, while the odds ratio of inguinal pain was equal to 2.0 (OR=2.038, 95% CI: 1.161-3.580), when Group F was compared to Group D. 97 patients (23.3%) received nominal therapy due to complications ([Society of interventional radiology, SIR]-B grade), among them, there were 62 cases (23.8%) in Group D and 35 cases (22.3%) in Group F. No significant difference was found between the two groups (P>0.05) and neither of the reported complications of SIR-C-SIR-F occurred within the two groups. Based on our results, ultrasound-guided HIFU is safe for the treatment of diffuse adenomyosis, and controlling the ablation zone is crucial to ensure patients' safety. Copyright © 2016 Elsevier

A novel ultrasound-guided shoulder arthroscopic surgery

NASA Astrophysics Data System (ADS)

Tyryshkin, K.; Mousavi, P.; Beek, M.; Chen, T.; Pichora, D.; Abolmaesumi, P.

2006-03-01

This paper presents a novel ultrasound-guided computer system for arthroscopic surgery of the shoulder joint. Intraoperatively, the system tracks and displays the surgical instruments, such as arthroscope and arthroscopic burrs, relative to the anatomy of the patient. The purpose of this system is to improve the surgeon's perception of the three-dimensional space within the anatomy of the patient in which the instruments are manipulated and to provide guidance towards the targeted anatomy. Pre-operatively, computed tomography images of the patient are acquired to construct virtual threedimensional surface models of the shoulder bone structure. Intra-operatively, live ultrasound images of pre-selected regions of the shoulder are captured using an ultrasound probe whose three-dimensional position is tracked by an optical camera. These images are used to register the surface model to the anatomy of the patient in the operating room. An initial alignment is obtained by matching at least three points manually selected on the model to their corresponding points identified on the ultrasound images. The registration is then improved with an iterative closest point or a sequential least squares estimation technique. In the present study the registration results of these techniques are compared. After the registration, surgical instruments are displayed relative to the surface model of the patient on a graphical screen visible to the surgeon. Results of laboratory experiments on a shoulder phantom indicate acceptable registration results and sufficiently fast overall system performance to be applicable in the operating room.

Ultrasound-guided injection for plantar fasciitis: A brief review

PubMed Central

Nair, AS; Sahoo, RK

2016-01-01

Plantar fasciitis (PF) is a distressing condition experienced by many patients. Although self-limiting, it tends to become a chronic ailment if the precipitating factors are not addressed. One of the modality of treating PF is intra-lesional corticosteroid injection. This was done using palpation technique earlier but nowadays many specialists use ultrasound (US) imaging as a guide to give injection accurately instead of inadvertently damaging the plantar fascia or injecting into surrounding soft tissue, both of which can have serious implications. We did a literature search in Medline, Scopus, and Embase databases to find out articles describing US-guided corticosteroid injection for treating PF and whether guided injection was effective than injection given by palpation. PMID:27833490

Ultrasound-Guided Percutaneous Drainage of Neonatal Pyometrocolpos Under Local Anesthesia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Algin, Oktay, E-mail: droktayalgin@gmail.com; Erdogan, Cuneyt; Kilic, Nizamettin

2011-02-15

Hydrometrocolpos is an uncommon congenital disorder with cystic dilatation of the vagina and uterus that occurs as a result of accumulated secretions from the reproductive tract due to distal genital tract obstruction. Secondary infection may also occur, resulting in pyometrocolpos, a potentially lethal disease. Immediate drainage of the cystic mass in patients determined to have pyometrocolpos is required to prevent or treat uropathy and septicemia until definitive corrective surgery can be performed. We report an unusual cause of obstructive uropathy in three infants: pyometrocolpos due to lower genital tract atresia. Ultrasound-guided percutaneous drainage of the pyometrocolpos resulted in dramatically improvedmore » clinical and laboratory findings in these patients. Ultrasound-guided percutaneous drainage under local anesthesia is a simple, minimally invasive, safe, and effective procedure that facilitates later successful corrective surgery and avoids the need for more complex drainage procedures.« less

Pulse-dose radiofrequency treatment in pain management-initial experience.

PubMed

Ojango, Christine; Raguso, Mario; Fiori, Roberto; Masala, Salvatore

2018-05-01

Radiofrequency procedures have been used for treating various chronic pain conditions for decades. These minimally invasive percutaneous treatments employ an alternating electrical current with oscillating radiofrequency wavelengths to eliminate or alter pain signals from the targeted site. The aim of the continuous radiofrequency procedure is to increase the temperature sufficiently to create an irreversible thermal lesion on nerve fibres and thus permanently interrupt pain signals. The pulsed radiofrequency procedure utilises short pulses of radiofrequency current with intervals of longer pauses to avert a temperature increase to the level of permanent tissue damage. The goal of these pulses is to alter the processing of pain signals, but to avoid relevant structural damage to nerve fibres, as seen in the continuous radiofrequency procedure. The pulse-dose radiofrequency procedure is a technical improvement of the pulsed radiofrequency technique in which the delivery mode of the current is adapted. During the pulse-dose radiofrequency procedure thermal damage is avoided. In addition, the amplitude and width of the consecutive pulses are kept the same. The method ensures that each delivered pulse keeps the same characteristics and therefore the dose is similar between patients. The current review outlines the pulse-dose radiofrequency procedure and presents our institution's chronic pain management studies.

Utility of rapid on-site cytologic evaluation during endobronchial ultrasound with a guide sheath for peripheral pulmonary lesions.

PubMed

Izumo, Takehiro; Matsumoto, Yuji; Sasada, Shinji; Chavez, Christine; Nakai, Toshiyuki; Tsuchida, Takaaki

2017-03-01

The utility of rapid on-site evaluation during endobronchial ultrasound with a guide sheath for peripheral pulmonary lesions is unclear. The aim of this study was to evaluate the role of rapid on-site evaluation during endobronchial ultrasound with a guide sheath for peripheral pulmonary lesions. Consecutive patients who underwent endobronchial ultrasound with a guide sheath for the diagnosis of peripheral pulmonary lesions at our hospital between September 2012 and July 2014 were included in this retrospective study. Cytology slides were air-dried, and modified Giemsa (Diff-Quik) staining was used for rapid on-site evaluation. Additional smears were prepared for Papanicolaou staining and tissue samples were placed in formalin for histologic evaluation. The results of rapid on-site evaluation were compared with the final diagnoses of endobronchial ultrasound with a guide sheath. A total of 718 cases were included in the study population. The sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of rapid on-site evaluation during endobronchial ultrasound with a guide sheath for peripheral pulmonary lesions was 88.6%, 65.9%, 81.2%, 77.7% and 80.1%, respectively. There were no procedure-related deaths. Rapid on-site evaluation during endobronchial ultrasound with a guide sheath had high sensitivity for peripheral pulmonary lesions. When carrying out rapid on-site evaluation of transbronchial biopsy samples from peripheral pulmonary lesions, careful interpretation and clinical correlation are necessary. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com

Radiofrequency sensory ablation as a treatment for symptomatic unilateral lumbosacral junction pseudarticulation (Bertolotti's syndrome): a case report.

PubMed

Burnham, Robert

2010-06-01

Describe the clinical presentation, diagnostic evaluation, and successful treatment of a case of symptomatic unilateral lumbosacral junction pseudarticulation using a novel radiofrequency nerve ablation technique. A 56-year-old female patient who had suffered with low back and right upper buttock pain for 16 years experienced incomplete relief with L4/5 facet joint radiofrequency ablation. She was found to have an elongated right L5 transverse process that articulated with the sacral ala (Bertolotti's syndrome). Fluoroscopically guided local anesthetic/corticosteroid injection into the pseudarthrosis eliminated her residual right buttock pain for the duration of the local anesthetic only. Complete pain relief was achieved by injecting local anesthetic circumferentially around the posterior pseudarthrosis articular margin. Accordingly, bipolar radiofrequency strip thermal lesions were created at the same locations. Complete pain relief and full restoration of function was achieved for 16 months postprocedure. This case report describes a novel radiofrequency technique for treating symptomatic lumbosacral junction pseudarticulation that warrants further evaluation.

Toward a real-time system for temporal enhanced ultrasound-guided prostate biopsy.

PubMed

Azizi, Shekoofeh; Van Woudenberg, Nathan; Sojoudi, Samira; Li, Ming; Xu, Sheng; Abu Anas, Emran M; Yan, Pingkun; Tahmasebi, Amir; Kwak, Jin Tae; Turkbey, Baris; Choyke, Peter; Pinto, Peter; Wood, Bradford; Mousavi, Parvin; Abolmaesumi, Purang

2018-03-27

We have previously proposed temporal enhanced ultrasound (TeUS) as a new paradigm for tissue characterization. TeUS is based on analyzing a sequence of ultrasound data with deep learning and has been demonstrated to be successful for detection of cancer in ultrasound-guided prostate biopsy. Our aim is to enable the dissemination of this technology to the community for large-scale clinical validation. In this paper, we present a unified software framework demonstrating near-real-time analysis of ultrasound data stream using a deep learning solution. The system integrates ultrasound imaging hardware, visualization and a deep learning back-end to build an accessible, flexible and robust platform. A client-server approach is used in order to run computationally expensive algorithms in parallel. We demonstrate the efficacy of the framework using two applications as case studies. First, we show that prostate cancer detection using near-real-time analysis of RF and B-mode TeUS data and deep learning is feasible. Second, we present real-time segmentation of ultrasound prostate data using an integrated deep learning solution. The system is evaluated for cancer detection accuracy on ultrasound data obtained from a large clinical study with 255 biopsy cores from 157 subjects. It is further assessed with an independent dataset with 21 biopsy targets from six subjects. In the first study, we achieve area under the curve, sensitivity, specificity and accuracy of 0.94, 0.77, 0.94 and 0.92, respectively, for the detection of prostate cancer. In the second study, we achieve an AUC of 0.85. Our results suggest that TeUS-guided biopsy can be potentially effective for the detection of prostate cancer.

An ultrasound-guided fluorescence tomography system: design and specification

NASA Astrophysics Data System (ADS)

D'Souza, Alisha V.; Flynn, Brendan P.; Kanick, Stephen C.; Torosean, Sason; Davis, Scott C.; Maytin, Edward V.; Hasan, Tayyaba; Pogue, Brian W.

2013-03-01

An ultrasound-guided fluorescence molecular tomography system is under development for in vivo quantification of Protoporphyrin IX (PpIX) during Aminolevulinic Acid - Photodynamic Therapy (ALA-PDT) of Basal Cell Carcinoma. The system is designed to combine fiber-based spectral sampling of PPIX fluorescence emission with co-registered ultrasound images to quantify local fluorophore concentration. A single white light source is used to provide an estimate of the bulk optical properties of tissue. Optical data is obtained by sequential illumination of a 633nm laser source at 4 linear locations with parallel detection at 5 locations interspersed between the sources. Tissue regions from segmented ultrasound images, optical boundary data, white light-informed optical properties and diffusion theory are used to estimate the fluorophore concentration in these regions. Our system and methods allow interrogation of both superficial and deep tissue locations up to PpIX concentrations of 0.025ug/ml.

Ultrasound-guided breast-sparing surgery to improve cosmetic outcomes and quality of life. A prospective multicentre randomised controlled clinical trial comparing ultrasound-guided surgery to traditional palpation-guided surgery (COBALT trial)

PubMed Central

2011-01-01

Background Breast-conserving surgery for breast cancer was developed as a method to preserve healthy breast tissue, thereby improving cosmetic outcomes. Thus far, the primary aim of breast-conserving surgery has been the achievement of tumour-free resection margins and prevention of local recurrence, whereas the cosmetic outcome has been considered less important. Large studies have reported poor cosmetic outcomes in 20-40% of patients after breast-conserving surgery, with the volume of the resected breast tissue being the major determinant. There is clear evidence for the efficacy of ultrasonography in the resection of nonpalpable tumours. Surgical resection of palpable breast cancer is performed with guidance by intra-operative palpation. These palpation-guided excisions often result in an unnecessarily wide resection of adjacent healthy breast tissue, while the rate of tumour-involved resection margins is still high. It is hypothesised that the use of intra-operative ultrasonography in the excision of palpable breast cancer will improve the ability to spare healthy breast tissue while maintaining or even improving the oncological margin status. The aim of this study is to compare ultrasound-guided surgery for palpable tumours with the standard palpation-guided surgery in terms of the extent of healthy breast tissue resection, the percentage of tumour-free margins, cosmetic outcomes and quality of life. Methods/design In this prospective multicentre randomised controlled clinical trial, 120 women who have been diagnosed with palpable early-stage (T1-2N0-1) primary invasive breast cancer and deemed suitable for breast-conserving surgery will be randomised between ultrasound-guided surgery and palpation-guided surgery. With this sample size, an expected 20% reduction of resected breast tissue and an 18% difference in tumour-free margins can be detected with a power of 80%. Secondary endpoints include cosmetic outcomes and quality of life. The rationale, study

A long arm for ultrasound: a combined robotic focused ultrasound setup for magnetic resonance-guided focused ultrasound surgery.

PubMed

Krafft, Axel J; Jenne, Jürgen W; Maier, Florian; Stafford, R Jason; Huber, Peter E; Semmler, Wolfhard; Bock, Michael

2010-05-01

Focused ultrasound surgery (FUS) is a highly precise noninvasive procedure to ablate pathogenic tissue. FUS therapy is often combined with magnetic resonance (MR) imaging as MR imaging offers excellent target identification and allows for continuous monitoring of FUS induced temperature changes. As the dimensions of the ultrasound (US) focus are typically much smaller than the targeted volume, multiple sonications and focus repositioning are interleaved to scan the focus over the target volume. Focal scanning can be achieved electronically by using phased-array US transducers or mechanically by using dedicated mechanical actuators. In this study, the authors propose and evaluate the precision of a combined robotic FUS setup to overcome some of the limitations of the existing MRgFUS systems. Such systems are typically integrated into the patient table of the MR scanner and thus only provide an application of the US wave within a limited spatial range from below the patient. The fully MR-compatible robotic assistance system InnoMotion (InnoMedic GmbH, Herxheim, Germany) was originally designed for MR-guided interventions with needles. It offers five pneumatically driven degrees of freedom and can be moved over a wide range within the bore of the magnet. In this work, the robotic system was combined with a fixed-focus US transducer (frequency: 1.7 MHz; focal length: 68 mm, and numerical aperture: 0.44) that was integrated into a dedicated, in-house developed treatment unit for FUS application. A series of MR-guided focal scanning procedures was performed in a polyacrylamide-egg white gel phantom to assess the positioning accuracy of the combined FUS setup. In animal experiments with a 3-month-old domestic pig, the system's potential and suitability for MRgFUS was tested. In phantom experiments, a total targeting precision of about 3 mm was found, which is comparable to that of the existing MRgFUS systems. Focus positioning could be performed within a few seconds

Objective assessment of operator performance during ultrasound-guided procedures.

PubMed

Tabriz, David M; Street, Mandie; Pilgram, Thomas K; Duncan, James R

2011-09-01

Simulation permits objective assessment of operator performance in a controlled and safe environment. Image-guided procedures often require accurate needle placement, and we designed a system to monitor how ultrasound guidance is used to monitor needle advancement toward a target. The results were correlated with other estimates of operator skill. The simulator consisted of a tissue phantom, ultrasound unit, and electromagnetic tracking system. Operators were asked to guide a needle toward a visible point target. Performance was video-recorded and synchronized with the electromagnetic tracking data. A series of algorithms based on motor control theory and human information processing were used to convert raw tracking data into different performance indices. Scoring algorithms converted the tracking data into efficiency, quality, task difficulty, and targeting scores that were aggregated to create performance indices. After initial feasibility testing, a standardized assessment was developed. Operators (N = 12) with a broad spectrum of skill and experience were enrolled and tested. Overall scores were based on performance during ten simulated procedures. Prior clinical experience was used to independently estimate operator skill. When summed, the performance indices correlated well with estimated skill. Operators with minimal or no prior experience scored markedly lower than experienced operators. The overall score tended to increase according to operator's clinical experience. Operator experience was linked to decreased variation in multiple aspects of performance. The aggregated results of multiple trials provided the best correlation between estimated skill and performance. A metric for the operator's ability to maintain the needle aimed at the target discriminated between operators with different levels of experience. This study used a highly focused task model, standardized assessment, and objective data analysis to assess performance during simulated

Novel ultrasound-responsive chitosan/perfluorohexane nanodroplets for image-guided smart delivery of an anticancer agent: Curcumin.

PubMed

Baghbani, Fatemeh; Chegeni, Mahdieh; Moztarzadeh, Fathollah; Hadian-Ghazvini, Samaneh; Raz, Majid

2017-05-01

Ultrasound-responsive nanodroplets are a class of new emerging smart drug delivery systems which provide image-guided nano-therapy of various diseases, especially cancers. Here, we developed multifunctional smart curcumin-loaded chitosan/perfluorohexane nanodroplets for contrast-ultrasound imaging and on-demand drug delivery. The nanodroplets were synthesized via nanoemulsion process. The optimal formulation with the size of 101.2nm and 77.8% curcumin entrapment was chosen for release study and cytotoxicity evaluation. Sonication at the frequency of 1MHz, 2W/cm 2 for 4min triggered the release of 63.5% of curcumin from optimal formulation (Cur-NDs-2). Ultrasound aided release study indicated that the concentration of perfluorohexane and the degree of acoustic droplet vaporization play important role in ultrasound-active drug release. B-mode ultrasound imaging confirmed strong ultrasound contrast of chitosan nanodroplets even at low concentrations via droplet to bubble transition. Finally, cytotoxicity of the ultrasound-responsive nanodroplets in the presence of ultrasound was evaluated in-vitro on 4T1 human breast cancer cells. Cell growth inhibitory effects of curcumin-loaded nanodroplets significantly increased by ultrasound exposure. According to the obtained results, these ultrasound responsive curcumin-loaded chitosan/perfluorohexane nanodroplets have a great potential for imaged-guided cancer therapy. Copyright © 2016 Elsevier B.V. All rights reserved.

A review of randomised controlled trials comparing ultrasound-guided foam sclerotherapy with endothermal ablation for the treatment of great saphenous varicose veins.

PubMed

Davies, Huw Ob; Popplewell, Matthew; Darvall, Katy; Bate, Gareth; Bradbury, Andrew W

2016-05-01

The last 10 years have seen the introduction into everyday clinical practice of a wide range of novel non-surgical treatments for varicose veins. In July 2013, the UK National Institute for Health and Care Excellence recommended the following treatment hierarchy for varicose veins: endothermal ablation, ultrasound-guided foam sclerotherapy, surgery and compression hosiery. The aim of this paper is to review the randomised controlled trials that have compared endothermal ablation and ultrasound-guided foam sclerotherapy to determine if the level 1 evidence base still supports an "endothermal ablation first" strategy for the treatment of varicose veins. A PubMed and OVID literature search (until 31 January 2015) was performed and randomised controlled trials comparing endothermal ablation and ultrasound-guided foam sclerotherapy were obtained. Although anatomical success appeared higher with endothermal ablation than ultrasound-guided foam sclerotherapy, clinical success and patient-reported outcomes measures were similar. Morbidity and complication rates were very low and not significantly different between endothermal ablation and ultrasound-guided foam sclerotherapy. Ultrasound-guided foam sclerotherapy was consistently less expensive that endothermal ablation. All endovenous modalities appear to be successful and have a role in modern day practice. Although further work is required to optimise ultrasound-guided foam sclerotherapy technique to maximise anatomical success and minimise retreatment, the present level 1 evidence base shows there is no significant difference in clinical important outcomes between ultrasound-guided foam sclerotherapy and endothermal ablation. As ultrasound-guided foam sclerotherapy is less expensive, it is likely to be a more cost-effective option in most patients in most healthcare settings. Strict adherence to the treatment hierarchy recommended by National Institute for Health and Care Excellence seems unjustified. © The Author

A technical report on ultrasound-guided scapulocostal syndrome injection.

PubMed

McCarthy, C; Harmon, D

2016-08-01

We describe a case report and technique for using an ultrasound scanner and a linear transducer to guide serratus posterior superior (SPS) muscle injection. A 43-year-old female presented with chronic pain centered under the right upper portion of her scapula impacting her activities of daily living. For the ultrasound-guided SPS muscle injection, the patient was placed in the prone position. The transducer was oriented in a transverse orientation at the level of the C6-T1 vertebrae. Here the SPS muscle attaches to the lower portion of the ligament nuchae and the intervening interspinous ligaments. The muscle fibers run inferiorly and laterally to attach to the 2nd-5th ribs which were identified along with the lateral portion of the serratus posterior superior muscle which is covered by the scapula. Real-time imaging was used to direct a spinal needle into the trigger points of the SPS muscle, where solution was injected under direct vision. The patient's pain symptoms improved significantly. Serratus posterior superior injection can confirm a diagnosis of scapulocostal syndrome and be therapeutically beneficial.

Study of ultrasound-assisted radio-frequency plasma discharges in n-dodecane

NASA Astrophysics Data System (ADS)

Camerotto, Elisabeth; De Schepper, Peter; Nikiforov, Anton Y.; Brems, Steven; Shamiryan, Denis; Boullart, Werner; Leys, Christophe; De Gendt, Stefan

2012-10-01

This paper investigates the generation of a stable plasma phase in a liquid hydrocarbon (n-dodecane) by means of ultrasound (US) and radio-frequency (RF) or electromagnetic radiation. It is demonstrated for the first time that ultrasonic aided RF plasma discharges can be generated in a liquid. Plasma discharges are obtained for different gas mixtures at a pressure of 12 kPa and at low ignition powers (100 W for RF and 2.4 W cm-2 for US). Direct carbon deposition from the liquid precursor on Cu, Ni, SiO2 and Si substrates has been obtained and no apparent compositional or structural difference among the substrate materials was observed. Characterization of the deposited solid phase revealed an amorphous structure. In addition, structural changes in the liquid precursor after plasma treatment have been analysed. Optical emission spectroscopy (OES) allowed the estimation of several plasma characteristic temperatures. The plasma excitation temperature was estimated to be about 2.3-2.4 eV. The rotational and vibrational temperatures of the discharge in n-dodecane with Ar as a feed gas were 1400 K and 6500 K, respectively. In Ar/O2 plasma, an increased rotational (1630 K) and vibrational temperature (7200 K) were obtained.

Effects of arthroscopy-guided suprascapular nerve block combined with ultrasound-guided interscalene brachial plexus block for arthroscopic rotator cuff repair: a randomized controlled trial.

PubMed

Lee, Jae Jun; Hwang, Jung-Taek; Kim, Do-Young; Lee, Sang-Soo; Hwang, Sung Mi; Lee, Na Rea; Kwak, Byung-Chan

2017-07-01

The aim of this study was to compare the pain relieving effect of ultrasound-guided interscalene brachial plexus block (ISB) combined with arthroscopy-guided suprascapular nerve block (SSNB) with that of ultrasound-guided ISB alone within the first 48 h after arthroscopic rotator cuff repair. Forty-eight patients with rotator cuff tears who had undergone arthroscopic rotator cuff repair were enrolled. The 24 patients in group 1 received ultrasound-guided ISB and arthroscopy-guided SSNB; the remaining 24 patients in group 2 underwent ultrasound-guided ISB alone. Visual analogue scale pain score and patient satisfaction score were checked at 1, 3, 6, 12, 18, 24, and 48 h post-operatively. Group 1 had a lower visual analogue scale pain score at 3, 6, 12, 18, 24, and 48 h post-operatively (1.7 < 2.6, 1.6 < 4.0, 3.5 < 5.8, 3.6 < 5.2, 3.2 < 4.2, 1.3 < 2.0), and a higher patient satisfaction score at 6, 12, 18, 24, and 36 h post-operatively than group 2 (7.8 > 6.0, 6.2 > 4.3, 6.4 > 5.1, 6.9 > 5.9, 7.9 > 7.1). Six patients in group 1 developed rebound pain twice, and the others in group 1 developed it once. All of the patients in group 2 had one rebound phenomenon each (p = 0.010). The mean timing of rebound pain in group 1 was later than that in group 2 (15.5 > 9.3 h, p < 0.001), and the mean size of rebound pain was smaller in group 1 than that in group 2 (2.5 > 4.0, p = 0.001). Arthroscopy-guided SSNB combined with ultrasound-guided ISB resulted in lower visual analogue scale pain scores at 3-24 and 48 h post-operatively, and higher patient satisfaction scores at 6-36 h post-operatively with the attenuated rebound pain compared to scores in patients who received ultrasound-guided ISB alone after arthroscopic rotator cuff repair. The combined blocks may relieve post-operative pain more effectively than the single block within 48 h after arthroscopic cuff repair. Randomized controlled trial, Level I. ClinicalTrials.gov Identifier

Sonoanatomy relevant for ultrasound-guided central neuraxial blocks via the paramedian approach in the lumbar region

PubMed Central

Karmakar, M K; Li, X; Kwok, W H; Ho, A M-H; Ngan Kee, W D

2012-01-01

Objectives The use of ultrasound to guide peripheral nerve blocks is now a well-established technique in regional anaesthesia. However, despite reports of ultrasound guided epidural access via the paramedian approach, there are limited data on the use of ultrasound for central neuraxial blocks, which may be due to a poor understanding of spinal sonoanatomy. The aim of this study was to define the sonoanatomy of the lumbar spine relevant for central neuraxial blocks via the paramedian approach. Methods The sonoanatomy of the lumbar spine relevant for central neuraxial blocks via the paramedian approach was defined using a “water-based spine phantom”, young volunteers and anatomical slices rendered from the Visible Human Project data set. Results The water-based spine phantom was a simple model to study the sonoanatomy of the osseous elements of the lumbar spine. Each osseous element of the lumbar spine, in the spine phantom, produced a “signature pattern” on the paramedian sagittal scans, which was comparable to its sonographic appearance in vivo. In the volunteers, despite the narrow acoustic window, the ultrasound visibility of the neuraxial structures at the L3/L4 and L4/L5 lumbar intervertebral spaces was good, and we were able to delineate the sonoanatomy relevant for ultrasound-guided central neuraxial blocks via the paramedian approach. Conclusion Using a simple water-based spine phantom, volunteer scans and anatomical slices from the Visible Human Project (cadaver) we have described the sonoanatomy relevant for ultrasound-guided central neuraxial blocks via the paramedian approach in the lumbar region. PMID:22010025

Real-time ultrasound-guided spinal anesthesia using the SonixGPS® needle tracking system: a case report.

PubMed

Wong, Simon W; Niazi, Ahtsham U; Chin, Ki J; Chan, Vincent W

2013-01-01

The SonixGPS® is an electromagnetic needle tracking system for ultrasound-guided needle intervention. Both current and predicted needle tip position are displayed on the ultrasound screen in real-time, facilitating needle-beam alignment and guidance to the target. This case report illustrates the use of the SonixGPS system for successful performance of real-time ultrasound-guided spinal anesthesia in a patient with difficult spinal anatomy. A 67-yr-old male was admitted to our hospital to undergo revision of total right hip arthroplasty. His four previous arthroplasties for hip revision were performed under general anesthesia because he had undergone L3-L5 instrumentation for spinal stenosis. The L4-L5 interspace was viewed with the patient in the left lateral decubitus position. A 19G 80-mm proprietary needle (Ultrasonix Medical Corp, Richmond, BC, Canada) was inserted and directed through the paraspinal muscles to the ligamentum flavum in plane to the ultrasound beam. A 120-mm 25G Whitacre spinal needle was then inserted through the introducer needle in a conventional fashion. Successful dural puncture was achieved on the second attempt, as indicated by a flow of clear cerebrospinal fluid. The patient tolerated the procedure well, and the spinal anesthetic was adequate for the duration of the surgery. The SonixGPS is a novel technology that can reduce the technical difficulty of real-time ultrasound-guided neuraxial blockade. It may also have applications in other advanced ultrasound-guided regional anesthesia techniques where needle-beam alignment is critical.

Sonothrombolysis of Intra-Catheter Aged Venous Thrombi Using Microbubble Enhancement and Guided Three Dimensional Ultrasound Pulses

PubMed Central

Kutty, Shelby; Xie, Feng; Gao, Shunji; Drvol, Lucas K; Lof, John; Fletcher, Scott E; Radio, Stanley J; Danford, David A; Hammel, James M; Porter, Thomas R

2010-01-01

Central venous and arterial catheters are a major source of thrombo-embolic disease in children. We hypothesized that guided high mechanical index (MI) impulses from diagnostic three-dimensional (3D) ultrasound during an intravenous microbubble infusion could dissolve these thrombi. An in vitro system simulating intra-catheter thrombi was created and then treated with guided high MI impulses from 3D ultrasound, utilizing low MI microbubble sensitive imaging pulse sequence schemes to detect the microbubbles (Perflutren Lipid Microsphere, Definity®, Lantheus). Ten aged thrombi over 24 hours old were tested using 3D ultrasound coupled with a continuous diluted microbubble infusion (Group A), and ten with 3D ultrasound alone (Group B). Mean thrombus age was 28.6 hours (range 26.6–30.3). Groups A exhibited a 55 ± 19 % reduction in venous thrombus size, compared to 31±10 % for Group B (p=0.008). Feasibility testing was performed in 4 pigs, establishing a model to further investigate the efficacy. Sonothrombolysis of aged intra-catheter venous thrombi can be achieved with commercially available microbubbles and guided high MI ultrasound from a diagnostic 3D transducer. PMID:20696549

Non-Thermal High-Intensity Focused Ultrasound for Breast Cancer Therapy

DTIC Science & Technology

2013-07-01

ultrasound for breast cancer therapy PRINCIPAL INVESTIGATOR: Chang Ming (Charlie) Ma, Ph.D...TITLE AND SUBTITLE 5a. CONTRACT NUMBER Non-thermal high-intensity focused ultrasound for breast cancer therapy 5b. GRANT NUMBER W81XWH-11-1-0341...treatment systems for small animal models. Advanced imaging systems will be required to determine the gross tumor volume, to plan the HIFU treatment, to

Temperature mapping and thermal dose calculation in combined radiation therapy and 13.56 MHz radiofrequency hyperthermia for tumor treatment

NASA Astrophysics Data System (ADS)

Kim, Jung Kyung; Prasad, Bibin; Kim, Suzy

2017-02-01

To evaluate the synergistic effect of radiotherapy and radiofrequency hyperthermia therapy in the treatment of lung and liver cancers, we studied the mechanism of heat absorption and transfer in the tumor using electro-thermal simulation and high-resolution temperature mapping techniques. A realistic tumor-induced mouse anatomy, which was reconstructed and segmented from computed tomography images, was used to determine the thermal distribution in tumors during radiofrequency (RF) heating at 13.56 MHz. An RF electrode was used as a heat source, and computations were performed with the aid of the multiphysics simulation platform Sim4Life. Experiments were carried out on a tumor-mimicking agar phantom and a mouse tumor model to obtain a spatiotemporal temperature map and thermal dose distribution. A high temperature increase was achieved in the tumor from both the computation and measurement, which elucidated that there was selective high-energy absorption in tumor tissue compared to the normal surrounding tissues. The study allows for effective treatment planning for combined radiation and hyperthermia therapy based on the high-resolution temperature mapping and high-precision thermal dose calculation.

[An easy, safe and affective method for the treatment of intussusception: ultrasound-guided hydrostatic reduction].

PubMed

Ülger, Fatma Esra Bahadır; Ülger, Aykut; Karakaya, Ali Erdal; Tüten, Fatih; Katı, Ömer; Çolak, Mustafa

2014-03-01

Intussusception is one of the important causes of intestinal obstruction in children. Hydrostatic reduction under ultrasound guidance is a popular treatment method for intussusception. In the present study, we aimed to explain the demographic characteristics of and treatment approaches in patients diagnosed with intussusception by ultrasound. Forty-one patients diagnosed with intussusception by ultrasound between August 2011 and May 2013 were retrospectively analyzed. Twenty-four of these patients who had no contraindications had been treated with ultrasound-guided hydrostatic reduction. Twenty-four of the patients were male and 17 were female, a 1.4/1 male-to-female ratio. The majority of the patients were between the ages of 6-24 months and 2-5 years. The mean age was 31.12±26.32 months (range 3-125). Patients were more frequently diagnosed in April and May. Seventeen patients who had clinical contraindications enrolled directly for surgery. In 20 of the 24 patients who underwent ultrasound-guided hydrostatic reduction, reduction was achieved. Three experienced recurrence. In two of these patients, successful reduction was achieved with the second attempt. The remaining patient was enrolled for surgery. Hydrostatic reduction was performed 26 times on these 24 patients, and in 22, success was achieved (84.6%). No procedure-related complications occurred in the patients. Ultrasound-guided hydrostatic reduction, with its high success rates and lack of radiation risk, should be the first choice therapeutic approach for children diagnosed with intussusception.

Ultrasound-guided medical thoracoscopy in the absence of pleural effusion.

PubMed

Marchetti, Giampietro; Valsecchi, Alberto; Indellicati, Davide; Arondi, Sabrina; Trigiani, Marco; Pinelli, Valentina

2015-04-01

Medical thoracoscopy (MT) is a diagnostic and therapeutic procedure that permits the study of the pleural space. The presence of pleural adhesions is the most important contraindication to performing MT. Lesions of the pleura in absence of pleural effusion are usually studied in video-assisted thoracoscopic surgery (VATS) with preoperative ultrasound evaluation. No data are available about ultrasound-guided MT in the absence of pleural effusion. From January 2007 to June 2013, 622 consecutive MTs were performed under ultrasound guidance without inducing a pneumothorax. A retrospective cohort of 29 patients affected by pleural diseases without fluid was reviewed. The fifth or sixth intercostal spaces along the midaxillary line with a good echographic "sliding sign" and normal appearance of the pleural line were chosen as the entry site. The pleural cavity was explored, and biopsies were performed. The mean age of the patient cohort was 62.8 years; there were 20 male patients and nine female patients. Pleural adherences were avoided, and adequate number of pleural biopsies were performed. No parenchymal lung injuries, bleeding, or hematoma occurred. Seventeen patients had a completely free pleural cavity, four patients had a single pleural adhesion, and eight had multiple pleural adhesions; in all cases, however, endoscopic exploration was possible and biopsy specimens were adequate. The most frequent histopathologic diagnosis was malignant pleural mesothelioma. We have shown that thoracic ultrasound accurately identifies intrathoracic adhesions and, in experienced hands, can guide MT access, replacing the VATS approach, even in the complete absence of pleural effusion.

Single-operator real-time ultrasound-guided spinal injection using SonixGPS™: a case series.

PubMed

Brinkmann, Silke; Tang, Raymond; Sawka, Andrew; Vaghadia, Himat

2013-09-01

The SonixGPS™ is a novel needle tracking system that has recently been approved in Canada for ultrasound-guided needle interventions. It allows optimization of needle-beam alignment by providing a real-time display of current and predicted needle tip position. Currently, there is limited evidence on the effectiveness of this technique for performance of real-time spinal anesthesia. This case series reports performance of the SonixGPS system for real-time ultrasound-guided spinal anesthesia in elective patients scheduled for joint arthroplasty. In this single-centre case series, 20 American Society of Anesthesiologists' class I-II patients scheduled for lower limb joint arthroplasty were recruited to undergo real-time ultrasound-guided spinal anesthesia with the SonixGPS after written informed consent. The primary outcome for this clinical cases series was the success rate of spinal anesthesia, and the main secondary outcome was time required to perform spinal anesthesia. Successful spinal anesthesia for joint arthroplasty was achieved in 18/20 patients, and 17 of these required only a single skin puncture. In 7/20 (35%) patients, dural puncture was achieved on the first needle pass, and in 11/20 (55%) patients, dural puncture was achieved with two or three needle redirections. Median (range) time taken to perform the block was 8 (5-14) min. The study procedure was aborted in two cases because our clinical protocol dictated using a standard approach if spinal anesthesia was unsuccessful after three ultrasound-guided insertion attempts. These two cases were classified as failures. No complications, including paresthesia, were observed during the procedure. All patients with successful spinal anesthesia found the technique acceptable and were willing to undergo a repeat procedure if deemed necessary. This case series shows that real-time ultrasound-guided spinal anesthesia with the SonixGPS system is possible within an acceptable time frame. It proved effective with

Ultrasound-guided injection of botulinum toxin A in the treatment of iliopsoas spasticity

PubMed Central

Sconfienza, L.M.; Perrone, N.; Lacelli, F.; Lentino, C.; Serafini, G.

2008-01-01

Purpose Intramuscular injection of botulinum toxin A (BTX-A) is a common treatment for iliopsoas muscle spasticity, but it is not easy to position the needle in this muscle without guidance. In this paper we describe an ultrasound-guided technique for the intramuscular injection of BTX-A to treat spasticity of the iliopsoas muscle. Its effectiveness was assessed in 10 patients. Method and materials The ultrasound-guided technique for BTX-A injection was used on 10 patients. The needle was inserted into the muscle belly at an angle of 45° along the longitudinal axis of the muscle when allowed by patient's condition. Results In all cases, the iliopsoas muscle was easily identified and both the iliac and psoas components were assessed. Introduction of the needle and drug injection were entirely carried out under ultrasonographic guidance. The procedure was successful in all patients, even in those with a high-grade spasticity, and general anesthesia was not required. Conclusions This ultrasound-guided technique allows accurate guidance for the injection of BTX-A, and it can be considered as an alternate supportive therapy in patients with spasticity and dystonia. PMID:23396653

Image guided radiofrequency thermo-ablation therapy of chondroblastomas: should it replace surgery?

PubMed

Lalam, Radhesh K; Cribb, Gillian L; Tins, Bernard J; Cool, Wim P; Singh, Jaspreet; Tyrrell, Prudencia N M; Cassar-Pullicino, Victor N

2014-04-01

To assess the safety and effectiveness of image-guided radiofrequency ablation (RF ablation) in the treatment of chondroblastomas as an alternative to surgery. Twelve patients with histologically proven chondroblastoma at our institution from 2003 to date. We reviewed the indications, recurrences and complications in patients who underwent RF ablation. Twelve patients were diagnosed with chondroblastoma. Out of these, 8 patients (6 male, 2 female, mean age 17 years) with chondroblastoma (mean size 2.7 cm) underwent RF ablation. Multitine expandable electrodes were used in all patients. The number of probe positions needed varied from 1 to 4 and lesions were ablated at 90 °C for 5 min at each probe position. The tumours were successfully treated and all patients became asymptomatic. There were no recurrences. There were 2 patients with knee complications, 1 with minor asymptomatic infraction of the subchondral bone and a second patient with osteonecrosis/chondrolysis. Radiofrequency ablation appears to be a safe and effective alternative to surgical treatment with a low risk of recurrence and complications for most chondroblastomas. RF ablation is probably superior to surgery when chondroblastomas are small (less than 2.5 cm) with an intact bony margin with subchondral bone and in areas of difficult surgical access.

Usage of Magnetic Resonance Guided Focused Ultrasound Surgery (mrgfus) in Oncology

NASA Astrophysics Data System (ADS)

Bauer, Yair

2011-09-01

Magnetic resonance guided focused ultrasound surgery (MRgFUS) is a non-invasive incision-less surgical approach which limits the tissue destruction to the targeted tumor. Acoustic energy penetrates through intact skin and through the tissues surrounding the tumor without causing any significant bio-effects. Energy deposition takes place mainly at the focal spot where heat induced thermal coagulation of the targeted tissue is accomplished. Real time targeting and image guidance is provided by MRI tumor margin definition and real time thermometry provides closed loop feedback control of energy deposition. The patient lies in the MRI scanner throughout the treatment planning and treatment, and the physician conducts the treatment from the MRgFUS workstation in the adjacent MR control room. The ExAblate system for MRgFUS is commercially available in many countries for treatment of uterine fibroids. The system has also received CE and KFDA approval for pain palliation of bone metastases, and research of other oncologic applications is underway.

Propogation loss with frequency of ultrasound guided waves in a composite metal-honeycomb structure

NASA Astrophysics Data System (ADS)

Saxena, Indu F.; Baid, Harsh K.; Guzman, Narciso; Kempen, Lothar U.; Mal, Ajit

2009-05-01

Non-destructive testing of critical structural components is time consuming, while necessary for maintaining safe operation. Large aerospace structures, such as the vertical stabilizers of aircraft undergo inspection at regular intervals for damage diagnostics. However, conventional techniques for damage detection and identification before repair can be scheduled are conducted off-line and therefore can take weeks. The use of guided ultrasound waves is being investigated to expedite damage detection in composites. We measure the frequency dependent loss of ultrasonic guided waves for a structure comprising a boron-nitride composite skin sandwiching an aluminum honeycomb. A wide range of ultrasound frequencies propagate as measured using PZTs, with the lowest attenuation observed about 200-250 kHz. These measurements are confirmed using optical fiber Bragg grating arrays used as ultrasound transducers.

Feasibility of ultrasound-guided epidural access at the lumbo-sacral space in dogs.

PubMed

Liotta, Annalisa; Busoni, Valeria; Carrozzo, Maria Valentina; Sandersen, Charlotte; Gabriel, Annick; Bolen, Géraldine

2015-01-01

Epidural injections are commonly performed blindly in veterinary medicine. The aims of this study were to describe the lumbosacral ultrasonographic anatomy and to assess the feasibility of an ultrasound-guided epidural injection technique in dogs. A cross sectional anatomic atlas of the lumbosacral region and ex vivo ultrasound images were obtained in two cadavers to describe the ultrasound anatomy and to identify the landmarks. Sixteen normal weight canine cadavers were used to establish two variations of the technique for direct ultrasound-guided injection, using spinal needles or epidural catheters. The technique was finally performed in two normal weight cadavers, in two overweight cadavers and in five live dogs with radiographic abnormalities resulting of the lumbosacral spine. Contrast medium was injected and CT was used to assess the success of the injection. The anatomic landmarks to carry out the procedure were the seventh lumbar vertebra, the iliac wings, and the first sacral vertebra. The target for directing the needle was the trapezoid-shaped echogenic zone between the contiguous articular facets of the lumbosacral vertebral canal visualized in a parasagittal plane. The spinal needle or epidural catheter was inserted in a 45° craniodorsal-caudoventral direction through the subcutaneous tissue and the interarcuate ligament until reaching the epidural space. CT examination confirmed the presence of contrast medium in the epidural space in 25/25 dogs, although a variable contamination of the subarachnoid space was also noted. Findings indicated that this ultrasound-guided epidural injection technique is feasible for normal weight and overweight dogs, with and without radiographic abnormalities of the spine. © 2014 American College of Veterinary Radiology.

MR-guided focused ultrasound robot for performing experiments on large animals

NASA Astrophysics Data System (ADS)

Mylonas, N.; Damianou, C.

2011-09-01

Introduction: In this paper an experimental MRI-guided focused ultrasound robot for large animals is presented. Materials and methods: A single element spherically focused transducer of 4 cm diameter, focusing at 10 cm and operating at 1 MHz was used. A positioning device was developed in order to scan the ultrasound transducer for performing MR-guided focused ultrasound experiments in large animals such as pig, sheep and dog. The positioning device incorporates only MRI compatible materials such as piezoelectric motors, Acrylonitrile Butadiene Styrene (ABS) plastic, brass screws, and brass pulleys. The system is manufactured automatically using a rapid prototyping system. Results: The system was tested successfully in a number of animals for various tasks (creation of single lesions, creation of overlapping lesions, and MR compatibility). Conclusions: A simple, cost effective, portable positioning device has been developed which can be used in virtually any clinical MRI scanner since it can be sited on the scanner's table. The propagation of HIFU can be via a lateral or superior-inferior approach. This system has the potential to be marketed as a cost effective solution for performing experiments in small and large animals.

Visualization of risk structures for interactive planning of image guided radiofrequency ablation of liver tumors

NASA Astrophysics Data System (ADS)

Rieder, Christian; Schwier, Michael; Weihusen, Andreas; Zidowitz, Stephan; Peitgen, Heinz-Otto

2009-02-01

Image guided radiofrequency ablation (RFA) is becoming a standard procedure as a minimally invasive method for tumor treatment in the clinical routine. The visualization of pathological tissue and potential risk structures like vessels or important organs gives essential support in image guided pre-interventional RFA planning. In this work our aim is to present novel visualization techniques for interactive RFA planning to support the physician with spatial information of pathological structures as well as the finding of trajectories without harming vitally important tissue. Furthermore, we illustrate three-dimensional applicator models of different manufactures combined with corresponding ablation areas in homogenous tissue, as specified by the manufacturers, to enhance the estimated amount of cell destruction caused by ablation. The visualization techniques are embedded in a workflow oriented application, designed for the use in the clinical routine. To allow a high-quality volume rendering we integrated a visualization method using the fuzzy c-means algorithm. This method automatically defines a transfer function for volume visualization of vessels without the need of a segmentation mask. However, insufficient visualization results of the displayed vessels caused by low data quality can be improved using local vessel segmentation in the vicinity of the lesion. We also provide an interactive segmentation technique of liver tumors for the volumetric measurement and for the visualization of pathological tissue combined with anatomical structures. In order to support coagulation estimation with respect to the heat-sink effect of the cooling blood flow which decreases thermal ablation, a numerical simulation of the heat distribution is provided.

Ultrasound-guided percutaneous tracheostomy in critically ill obese patients

PubMed Central

2012-01-01

Introduction The purpose of this study was to evaluate the feasibility of ultrasound (US)-guided percutaneous tracheostomy (PCT) and the incidence of complications in critically ill, obese patients. Methods Fifty consecutive patients were included in a prospective study in two surgical and critical care medicine departments. Obesity was defined as a body mass index (BMI) of at least 30 kg/m2. The feasibility of PCT and the incidence of complications were compared in obese patients (n = 26) and non-obese patients (n = 24). Results are expressed as the median (25th-75th percentile) or number (percentage). Results The median BMIs were 34 kg/m2 (32-38) in the obese patient group and 25 kg/m2 (24-28) in the non-obese group (p < 0.001). The median times for tracheostomy were 10 min (8-14) in non-obese patients and 9 min (5-10) in obese-patients (p = 0.1). The overall complication rate was similar in obese and non-obese patient groups (35% vs. 33%, p = 0.92). Most complications were minor (hypotension, desaturation, tracheal cuff puncture and minor bleeding), with no differences between obese and non-obese groups. Bronchoscopic inspection revealed two cases of granuloma (8%) in obese patients. One non-obese patient developed a peristomal skin infection, which was treated with intravenous antibiotics. Ultrasound-guided PCT was possible in all enrolled patients and there were no surgical conversions or deaths. Conclusions This study demonstrated that US-guided PCT is feasible in obese patients with a low complication rate. Obesity may not constitute a contra-indication for US-guided PCT. A US examination provides information on cervical anatomy and hence modifies and guides choice of the PCT puncture site. Trial registration ClinicalTrials.gov: NCT01502657. PMID:22390815

Ultrasound-guided percutaneous tracheostomy in critically ill obese patients.

PubMed

Guinot, Pierre-Grégoire; Zogheib, Elie; Petiot, Sandra; Marienne, Jean-Pierre; Guerin, Anne-Marie; Monet, Pauline; Zaatar, Rody; Dupont, Hervé

2012-12-12

The purpose of this study was to evaluate the feasibility of ultrasound (US)-guided percutaneous tracheostomy (PCT) and the incidence of complications in critically ill, obese patients. Fifty consecutive patients were included in a prospective study in two surgical and critical care medicine departments. Obesity was defined as a body mass index (BMI) of at least 30 kg/m². The feasibility of PCT and the incidence of complications were compared in obese patients (n = 26) and non-obese patients (n = 24). Results are expressed as the median (25th-75th percentile) or number (percentage). The median BMIs were 34 kg/m² (32-38) in the obese patient group and 25 kg/m² (24-28) in the non-obese group (p < 0.001). The median times for tracheostomy were 10 min (8-14) in non-obese patients and 9 min (5-10) in obese-patients (p = 0.1). The overall complication rate was similar in obese and non-obese patient groups (35% vs. 33%, p = 0.92). Most complications were minor (hypotension, desaturation, tracheal cuff puncture and minor bleeding), with no differences between obese and non-obese groups. Bronchoscopic inspection revealed two cases of granuloma (8%) in obese patients. One non-obese patient developed a peristomal skin infection, which was treated with intravenous antibiotics. Ultrasound-guided PCT was possible in all enrolled patients and there were no surgical conversions or deaths. This study demonstrated that US-guided PCT is feasible in obese patients with a low complication rate. Obesity may not constitute a contra-indication for US-guided PCT. A US examination provides information on cervical anatomy and hence modifies and guides choice of the PCT puncture site. ClinicalTrials.gov: NCT01502657.

New platform for evaluating ultrasound-guided interventional technologies

NASA Astrophysics Data System (ADS)

Kim, Younsu; Guo, Xiaoyu; Boctor, Emad M.

2016-04-01

Ultrasound-guided needle tracking systems are frequently used in surgical procedures. Various needle tracking technologies have been developed using ultrasound, electromagnetic sensors, and optical sensors. To evaluate these new needle tracking technologies, 3D volume information is often acquired to compute the actual distance from the needle tip to the target object. The image-guidance conditions for comparison are often inconsistent due to the ultrasound beam-thickness. Since 3D volumes are necessary, there is often some time delay between the surgical procedure and the evaluation. These evaluation methods will generally only measure the final needle location because they interrupt the surgical procedure. The main contribution of this work is a new platform for evaluating needle tracking systems in real-time, resolving the problems stated above. We developed new tools to evaluate the precise distance between the needle tip and the target object. A PZT element transmitting unit is designed as needle introducer shape so that it can be inserted in the needle. We have collected time of flight and amplitude information in real-time. We propose two systems to collect ultrasound signals. We demonstrate this platform on an ultrasound DAQ system and a cost-effective FPGA board. The results of a chicken breast experiment show the feasibility of tracking a time series of needle tip distances. We performed validation experiments with a plastisol phantom and have shown that the preliminary data fits a linear regression model with a RMSE of less than 0.6mm. Our platform can be applied to more general needle tracking methods using other forms of guidance.

MR-guided radiofrequency ablation of hepatic malignancies at 1.5 T: initial results.

PubMed

Mahnken, Andreas H; Buecker, Arno; Spuentrup, Elmar; Krombach, Gabriele A; Henzler, Dietrich; Günther, Rolf W; Tacke, Josef

2004-03-01

To assess the feasibility of magnetic resonance (MR)-guided radiofrequency ablation (RFA) of hepatic malignancies using a high-field MR scanner. A total of 10 patients with 14 primary (N = 1) or secondary (N = 13) hepatic malignancies underwent MR-guided RFA using a closed-bore 1.5 T MR scanner. Lesion diameters ranged from 2.0 cm to 4.7 cm. RFA was performed using a 200-W generator in combination with a 3.5-cm LeVeen electrode applying a standardized energy protocol. RFA was technically feasible in all patients. Necrosis diameter ranged from 2.5 cm to 6.8 cm. The mean follow-up period is 12.2 (1-18) months. In nine out of 10 patients, local tumor control was achieved. For this purpose, a second CT-guided RFA was required in two patients. In four patients, multifocal hepatic tumor progression occurred, with the treated lesion remaining tumor-free in three of these patients. Two patients showed extrahepatic tumor progression. Four patients remained tumor-free. No major complications occurred. MR-guided RFA of hepatic malignancies in a closed-bore high-field MR scanner is technically feasible and safe. It can be advantageous in locations considered unfavorable for CT-guided puncture or in patients in which iodinated contrast material is contraindicated. Copyright 2004 Wiley-Liss, Inc.

Outcomes of Ultrasound-Guided Thrombin Injection of Nongroin Arterial Pseudoaneurysms.

PubMed

Valesano, Johnathan C; Schmitz, John J; Kurup, A Nicholas; Schmit, Grant D; Moynagh, Michael R; Atwell, Thomas D; Lewis, Bradley D; Lee, Robert A; Callstrom, Matthew R

2017-08-01

To evaluate success and complication rates of percutaneous ultrasound-guided thrombin injection of nongroin pseudoaneurysms (PSAs). Retrospective review of a prospectively maintained institutional database yielded 39 cases of arterial PSAs occurring at nongroin sites that were treated with percutaneous ultrasound-guided thrombin injection between 2000 and 2016 (average patient age 69.2 y ± 14.0). Of PSAs, 74.4% (29/39) arose in the upper extremities, and 92.3% (36/39) were iatrogenic. The brachial artery was the most commonly affected vessel (51.3% [20/39]), and arterial access was the most common cause (56.4% [22/39]). Average overall PSA size was 2.4 cm (range, 0.5-7.2 cm); average amount of thrombin injected was 320 IU (range, 50-2,000 IU). Technical success was defined as absence of flow within the PSA immediately after thrombin injection. Treatment success was defined as sustained thrombosis on follow-up imaging obtained at 1-3 days after treatment. Technical and treatment success rates of thrombin injections were 100% (39/39) and 84.8% (28/33), respectively. Longer term follow-up imaging (average 71 d; range, 12-201 d) was available for 7 of the treatment successes with 100% (7/7) showing sustained thrombosis. Comparing treatment successes and failures, there was no significant difference in average PSA size (2.3 cm vs 2.0 cm, P = .51) or average amount of thrombin injected (360 IU vs 180 IU, P = .14). There were no complications. Ultrasound-guided thrombin injection is a safe, efficacious treatment option for PSAs arising in nongroin locations. Copyright © 2017 SIR. Published by Elsevier Inc. All rights reserved.

Electromagnetic Tracking Navigation to Guide Radiofrequency Ablation (RFA) of a Lung Tumor

PubMed Central

Amalou, Hayet; Wood, Bradford J.

2013-01-01

Radiofrequency ablation (RFA) may be an option for patients with lung tumors who have unresectable disease and are not suitable for available palliative modalities. RFA electrode positioning may take several attempts, necessitating multiple imaging acquisitions or continuous use of CT (Computed Tomography). Electromagnetic tracking utilizes miniature sensors integrated with RFA equipment to guide tools in real-time, while referencing to pre-procedure imaging. This technology was demonstrated successfully during a lung tumor ablation, and was more accurate at targeting the tumor, compared to traditional freehand needle insertion. It is possible, although speculative and anecdotal, that more accuracy could prevent unnecessary repositioning punctures and decrease radiation exposure. Electromagnetic tracking has theoretical potential to benefit minimally invasive interventions. PMID:23207535

Guiding tissue regeneration with ultrasound in vitro and in vivo

NASA Astrophysics Data System (ADS)

Dalecki, Diane; Comeau, Eric S.; Raeman, Carol H.; Child, Sally Z.; Hobbs, Laura; Hocking, Denise C.

2015-05-01

Developing new technologies that enable the repair or replacement of injured or diseased tissues is a major focus of regenerative medicine. This paper will discuss three ultrasound technologies under development in our laboratories to guide tissue regeneration both in vitro and in vivo. A critical obstacle in tissue engineering is the need for rapid and effective tissue vascularization strategies. To address this challenge, we are developing acoustic patterning techniques for microvascular tissue engineering. Acoustic radiation forces associated with ultrasound standing wave fields provide a rapid, non-invasive approach to spatially pattern cells in three dimensions without affecting cell viability. Acoustic patterning of endothelial cells leads to the rapid formation of microvascular networks throughout the volumes of three-dimensional hydrogels, and the morphology of the resultant microvessel networks can be controlled by design of the ultrasound field. A second technology under development uses ultrasound to noninvasively control the microstructure of collagen fibers within engineered tissues. The microstructure of extracellular matrix proteins provides signals that direct cell functions critical to tissue regeneration. Thus, controlling collagen microfiber structure with ultrasound provides a noninvasive approach to regulate the mechanical properties of biomaterials and control cellular responses. The third technology employs therapeutic ultrasound to enhance the healing of chronic wounds. Recent studies demonstrate increased granulation tissue thickness and collagen deposition in murine dermal wounds exposed to pulsed ultrasound. In summary, ultrasound technologies offer noninvasive approaches to control cell behaviors and extracellular matrix organization and thus hold great promise to advance tissue regeneration in vitro and in vivo.

Ergonomic task analysis of ultrasound-guided femoral nerve block: a pilot study.

PubMed

Ajmal, Muhammad; Power, Susan; Smith, Tim; Shorten, George D

2011-02-01

To apply ergonomic task analysis to the performance of ultrasound-guided (US-guided) femoral nerve block (FNB) in an acute hospital setting. Pilot prospective observational study. Orthopedic operating room of a regional trauma hospital. 15 anesthesiologists of various levels of experience in US-guided FNB (estimated minimum experience < 10 procedures; maximum about 50 procedures, and from basic trainees to consultants); and 15 patients (5 men and 10 women), aged 77 ± 15 (mean ± SD yrs) years. MEASUREMENTS/OBSERVATIONS: A data capture "tool", which was modified from one previously developed for ergonomic study of spinal anesthesia, was studied. Patient, operator, and heterogeneous environmental factors related to ergonomic performance of US-guided FNB were identified. The observation period started immediately before commencement of positioning the patient and ended on completion of perineural injection. Data were acquired using direct observations, photography, and application of a questionnaire. The quality of ergonomic performance was generally suboptimal and varied greatly among operators. Eight (experience < 10 procedures) of 15 operators excessively rotated their head, neck, and/or back to visualize the image on the ultrasound machine. Eight operators (experience < 10 procedures) performed the procedure with excessive thoracolumbar flexion. Performance of US-guided FNB presents ergonomic challenges and was suboptimal during most of the procedures observed. Formal training in US-guided peripheral nerve blockade should include reference to ergonomic factors. Copyright © 2011 Elsevier Inc. All rights reserved.

Safety of Ultrasound-Guided Botulinum Toxin Injections for Sialorrhea as Performed by Pediatric Otolaryngologists.

PubMed

Shariat-Madar, Bahbak; Chun, Robert H; Sulman, Cecille G; Conley, Stephen F

2016-05-01

To evaluate incidence of complications and hospital readmission as a result of ultrasound-guided botulinum toxin injections to manage sialorrhea. Case series with chart review. Children's Hospital of Wisconsin. A case series with chart review was performed of all cases of ultrasound-guided injection of botulinum toxin by pediatric otolaryngologists from March 5, 2010, to September 26, 2014,. Primary outcomes included complications such as dysphagia, aspiration pneumonia, and motor paralysis. Secondary outcomes included hospitalization, intubation, and nasogastric tube placement. There were 48 patients, 111 interventions, and 306 intraglandular injections identified. Botulinum toxin type A and type B were utilized in 4 and 107 operative interventions, respectively. Type A was injected into 4 parotid and 4 submandibular glands, utilizing doses of 20 U per parotid and 30 U per submandibular gland. Type B was injected into 98 parotid and 200 submandibular glands, with average dosing of 923 U per parotid and 1170 U per submandibular gland, respectively. There were 2 instances of subjectively worsening of baseline dysphagia that self-resolved. No cases were complicated by aspiration pneumonia or motor paralysis. No patients required hospital readmission, intubation, or nasogastric tube placement. Prior published data indicated 16% complication incidence with ultrasound-guided injection of botulinum toxin. Our study found a low complication rate (0.6%) with ultrasound-guided injections of botulinum toxin to manage sialorrhea, without cases of aspiration pneumonia or motor paralysis. Of 306 intraglandular injections, there were 2 cases of worsening baseline subjective dysphagia that self-resolved. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2016.

Ultrasound interstitial thermal therapy (USITT) for the treatment of uterine myomas

NASA Astrophysics Data System (ADS)

Nau, William H., Jr.; Diederich, Chris J.; Simko, Jeff; Juang, Titania; Jacoby, Alison; Burdette, E. C.

2007-02-01

Uterine myomas (fibroids) are the most common pelvic tumors occurring in women, and are the leading cause of hysterectomy. Symptoms can be severe, and traditional treatments involve either surgical removal of the uterus (hysterectomy), or the fibroids (myomectomy). Interstitial ultrasound technologies have demonstrated potential for hyperthermia and high temperature thermal therapy in the treatment of benign and malignant tumors. These ultrasound devices offer favorable energy penetration allowing large volumes of tissue to be treated in short periods of time, as well as axial and angular control of heating to conform thermal treatment to a targeted tissue, while protecting surrounding tissues from thermal damage. The goal of this project is to evaluate interstitial ultrasound for controlled thermal coagulation of fibroids. Multi-element applicators were fabricated using tubular transducers, some of which were sectored to produce 180° directional heating patterns, and integrated with water cooling. Human uterine fibroids were obtained after routine myomectomies, and instrumented with thermocouples spaced at 0.5, 1.0, 1.5, 2.0, 2.5 and 3.0 cm from the applicator. Power levels ranging from 8-15 W per element were applied for up to 15 minute heating periods. Results demonstrated that therapeutic temperatures >50° C and cytotoxic thermal doses (t 43) extended beyond 2 cm radially from the applicator (>4 cm diameter). It is anticipated that this system will make a significant contribution toward the treatment of uterine fibroids.

Ultrasound-directed robotic system for thermal ablation of liver tumors: a preliminary report

NASA Astrophysics Data System (ADS)

Zheng, Jian; Tian, Jie; Dai, Yakang; Zhang, Xing; Dong, Di; Xu, Min

2010-03-01

Thermal ablation has been proved safe and effective as the treatment for liver tumors that are not suitable for resection. Currently, manually performed thermal ablation is greatly dependent on the surgeon's acupuncture manipulation against hand tremor. Besides that, inaccurate or inappropriate placement of the applicator will also directly decrease the final treatment effect. In order to reduce the influence of hand tremor, and provide an accurate and appropriate guidance for a better treatment, we develop an ultrasound-directed robotic system for thermal ablation of liver tumors. In this paper, we will give a brief preliminary report of our system. Especially, three innovative techniques are proposed to solve the critical problems in our system: accurate ultrasound calibration when met with artifacts, realtime reconstruction with visualization using Graphic Processing Unit (GPU) acceleration and 2D-3D ultrasound image registration. To reduce the error of point extraction with artifacts, we propose a novel point extraction method by minimizing an error function which is defined based on the geometric property of our N-fiducial phantom. Then realtime reconstruction with visualization using GPU acceleration is provided for fast 3D ultrasound volume acquisition with dynamic display of reconstruction progress. After that, coarse 2D-3D ultrasound image registration is performed based on landmark points correspondences, followed by accurate 2D-3D ultrasound image registration based on Euclidean distance transform (EDT). The effectiveness of our proposed techniques is demonstrated in phantom experiments.

Harmonic motion imaging for focused ultrasound (HMIFU): a fully integrated technique for sonication and monitoring of thermal ablation in tissues.

PubMed

Maleke, C; Konofagou, E E

2008-03-21

FUS (focused ultrasound), or HIFU (high-intensity-focused ultrasound) therapy, a minimally or non-invasive procedure that uses ultrasound to generate thermal necrosis, has been proven successful in several clinical applications. This paper discusses a method for monitoring thermal treatment at different sonication durations (10 s, 20 s and 30 s) using the amplitude-modulated (AM) harmonic motion imaging for focused ultrasound (HMIFU) technique in bovine liver samples in vitro. The feasibility of HMI for characterizing mechanical tissue properties has previously been demonstrated. Here, a confocal transducer, combining a 4.68 MHz therapy (FUS) and a 7.5 MHz diagnostic (pulse-echo) transducer, was used. The therapy transducer was driven by a low-frequency AM continuous signal at 25 Hz, producing a stable harmonic radiation force oscillating at the modulation frequency. A pulser/receiver was used to drive the pulse-echo transducer at a pulse repetition frequency (PRF) of 5.4 kHz. Radio-frequency (RF) signals were acquired using a standard pulse-echo technique. The temperature near the ablation region was simultaneously monitored. Both RF signals and temperature measurements were obtained before, during and after sonication. The resulting axial tissue displacement was estimated using one-dimensional cross correlation. When temperature at the focal zone was above 48 degrees C during heating, the coagulation necrosis occurred and tissue damage was irreversible. The HMI displacement profiles in relation to the temperature and sonication durations were analyzed. At the beginning of heating, the temperature at the focus increased sharply, while the tissue stiffness decreased resulting in higher HMI displacements. This was confirmed by an increase of 0.8 microm degrees C(-1)(r=0.93, p<.005). After sustained heating, the tissue became irreversibly stiffer, followed by an associated decrease in the HMI displacement (-0.79 microm degrees C(-1), r=-0.92, p<0.001). Repeated

Comparison of ultrasound-guided supraclavicular block according to the various volumes of local anesthetic

PubMed Central

Kim, Seok Kon; Kang, Bong Jin; Kwon, Min A; Song, Jae Gyok; Jeon, Soo Mi

2013-01-01

Background The ultrasound guidance in regional nerve blocks has recently been introduced and gaining popularity. Ultrasound-guided supraclavicular block has many advantages including the higher success rate, faster onset time, and fewer complications. The aim of this study was to examine the clinical data according to the varied volume of local anesthetics in the ultrasound-guided supraclavicular block. Methods One hundred twenty patients were randomized into four groups, according to the local anesthetic volume used: Group 35 (n = 30), Group 30 (n = 30), Group 25 (n = 30), and Group 20 (n = 30). Supraclavicular blocks were performed with 1% mepivacaine 35 ml, 30 ml, 25 ml, and 20 ml, respectively. The success rate, onset time, and complications were checked and evaluated. Results The success rate (66.7%) was lower in Group 20 than that of Group 35 (96.7%) (P < 0.05). The average onset times of Group 35, Group 30, Group 25, and Group 20 were 14.3 ± 6.9 min, 13.6 ± 4.5 min, 16.7 ± 4.6 min, and 16.5 ± 3.7 min, respectively. There were no significant differences. Horner's syndrome was higher in Group 35 (P < 0.05). Conclusions In conclusion, we achieved 90% success rate with 30 ml of 1% mepivacaine. Therefore, we suggest 30 ml of local anesthetic volume for ultrasound-guided supraclavicular block. PMID:23814648

An in-vitro animal experiment on metal implants’ thermal effect on radiofrequency ablation

PubMed Central

2013-01-01

Background To explore metal implants’ thermal effect on radiofrequency ablation (RFA) and ascertain distance-thermal relationship between the metal implants and radiofrequency (RF) electrode. Methods Metal implants models were established in seven in-vitro porcine livers using silver clips or 125I seeds. RFA were conducted centering the RF electrode axis1 cm away from them, with one side containing a metal implants model the test group and the other side the control group. The thermometric needles were used to measure multi-point temperatures in order to compare the time-distance-temperature difference between the two groups. The gross scopes of the ablation of the two groups were measured and the tissues were analyzed for microscopic histology. Results At the ablation times of 8, 12, and 15 min, the average multi-point temperatures of the test group and the control group were 48.2±18.07°C, 51.5±19.57°C, 54.6±19.75°C, and 48.6±17.69°C, 52.2±19.73°C, 54.9±19.24°C, respectively, and the differences were not statistically significant (n=126, P>0.05). At the ablation times of 12 and 15 min, the ablation scopes of the test group and the control group were (horizontal/longitudinal diameter) 1.55/3.48 cm, 1.89/3.72 cm, and 1.56/3.48 cm, 1.89/3.72 cm, respectively, and the differences were not statistically significant (n=14, P>0.05). The two groups had the same manifestations in microscopy. Conclusions Metal implants do not cause significant thermal effect on RFA. PMID:23799942

Therapy of Pancreatic Neuroendocrine Tumors: Fine Needle Intervention including Ethanol and Radiofrequency Ablation

PubMed Central

Lakhtakia, Sundeep

2017-01-01

Pancreatic neuroendocrine tumors (PNETs) are increasingly being detected, though usually as incidental findings. Majority of the PNETs are non-functional and surgical resection is the standard of care for most of them. However, in patients with small PNETs localized within the pancreas, who are unfit or unwilling for surgery, alternate methods of treatment are needed. Direct methods of ablation of PNETs, using either ethanol injection or radiofrequency ablation (RFA), are emerging as effective methods. The limited literature available as case reports or case series on endoscopic ultrasound (EUS)-guided local ablation using either ethanol or RFA has demonstrated safety and efficacy along with short- to medium-term sustained relief. Long-term benefits with these local ablative therapies are awaited. Comparative studies are needed to show which of these two competing technologies is superior. Finally, comparative trials of EUS-guided ablation with surgical resection in terms of efficacy and safety will ensure their place in the management algorithm. PMID:29207860

Size and Ultrasound Features Affecting Results of Ultrasound-Guided Fine-Needle Aspiration of Thyroid Nodules.

PubMed

Dong, YiJie; Mao, MinJing; Zhan, WeiWei; Zhou, JianQiao; Zhou, Wei; Yao, JieJie; Hu, YunYun; Wang, Yan; Ye, TingJun

2018-06-01

Our goal was to assess the diagnostic efficacy of ultrasound (US)-guided fine-needle aspiration (FNA) of thyroid nodules according to size and US features. A retrospective correlation was made with 1745 whole thyroidectomy and hemithyroidectomy specimens with preoperative US-guided FNA results. All cases were divided into 5 groups according to nodule size (≤5, 5.1-10, 10.1-15, 15.1-20, and >20 mm). For target nodules, static images and cine clips of conventional US and color Doppler were obtained. Ultrasound images were reviewed and evaluated by two radiologists with at least 5 years US working experience without knowing the results of pathology, and then agreement was achieved. The Bethesda category I rate was higher in nodules larger than 15 mm (P < .05). The diagnostic accuracy was best in nodules of 5 to 10 mm in diameter. The sensitivity, accuracy, PPV, and LR for negative US-guided FNA results were better in nodules with a size range of 5 to 15 mm. The specificity, negative predictive value (NPV), and LR for positive results and the Youden index rose with increasing nodule size. Seventeen false-positive and 60 false-negative results were found in this study. The false-negative rate rose with increasing nodule size. However, the false-positive rate was highest in the group containing the smallest nodules. Nodules with circumscribed margins and those that were nonsolid and nonhypoechoic and had no microcalcifications correlated with Bethesda I FNA results. Nodules with circumscribed margins and those that were nonsolid, heterogeneous, and nonhypoechoic and had increased vascularity correlated with false-negative FNA results. Borders correlated with Bethesda I false-negative and false-positive FNA results. Tiny nodules (≤5 mm) with obscure borders tended to yield false-positive FNA results. Large nodules (>20 mm) with several US features tended to yield false-negative FNA results. © 2017 by the American Institute of Ultrasound in Medicine.

Ultrasound criteria and guided fine-needle aspiration diagnostic yields in small animal peritoneal, mesenteric and omental disease.

PubMed

Feeney, Daniel A; Ober, Christopher P; Snyder, Laura A; Hill, Sara A; Jessen, Carl R

2013-01-01

Peritoneal, mesenteric, and omental diseases are important causes of morbidity and mortality in humans and animals, although information in the veterinary literature is limited. The purposes of this retrospective study were to determine whether objectively applied ultrasound interpretive criteria are statistically useful in differentiating among cytologically defined normal, inflammatory, and neoplastic peritoneal conditions in dogs and cats. A second goal was to determine the cytologically interpretable yield on ultrasound-guided, fine-needle sampling of peritoneal, mesenteric, or omental structures. Sonographic criteria agreed upon by the authors were retrospectively and independently applied by two radiologists to the available ultrasound images without knowledge of the cytologic diagnosis and statistically compared to the ultrasound-guided, fine-needle aspiration cytologic interpretations. A total of 72 dogs and 49 cats with abdominal peritoneal, mesenteric, or omental (peritoneal) surface or effusive disease and 17 dogs and 3 cats with no cytologic evidence of inflammation or neoplasia were included. The optimized, ultrasound criteria-based statistical model created independently for each radiologist yielded an equation-based diagnostic category placement accuracy of 63.2-69.9% across the two involved radiologists. Regional organ-associated masses or nodules as well as aggregated bowel and peritoneal thickening were more associated with peritoneal neoplasia whereas localized, severely complex fluid collections were more associated with inflammatory peritoneal disease. The cytologically interpretable yield for ultrasound-guided fine-needle sampling was 72.3% with no difference between species, making this a worthwhile clinical procedure. © 2013 Veterinary Radiology & Ultrasound.

Treatment of Parkinson's disease in rats by Nrf2 transfection using MRI-guided focused ultrasound delivery of nanomicrobubbles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Long, Ling; Cai, Xiaodong; Guo, Ruomi

Parkinson's disease (PD) is a very common neurological disorder. However, effective therapy is lacking. Although the blood-brain-barrier (BBB) protects the brain, it prevents the delivery of about 90% of drugs and nucleotides into the brain, thereby hindering the development of gene therapy for PD. Magnetic resonance imaging (MRI)-guided focused ultrasound delivery of microbubbles enhances the delivery of gene therapy vectors across the BBB and improves transfection efficiency. In the present study, we delivered nuclear factor E2-related factor 2 (Nrf2, NFE2L2) contained in nanomicrobubbles into the substantia nigra of PD rats by MRI-guided focused ultrasound, and we examined the effect ofmore » Nrf2 over-expression in this animal model of PD. The rat model of PD was established by injecting 6-OHDA in the right substantia nigra stereotactically. Plasmids (pDC315 or pDC315/Nrf2) were loaded onto nanomicrobubbles, and then injected through the tail vein with the assistance of MRI-guided focused ultrasound. MRI-guided focused ultrasound delivery of nanomicrobubbles increased gene transfection efficiency. Furthermore, Nrf2 gene transfection reduced reactive oxygen species levels, thereby protecting neurons in the target region. - Highlights: • MRI-guided focused ultrasound enhances gene transfection into the brain of rats. • Increased Nrf2 expression protects neurons in the rat model of PD. • Nrf2 protects neurons in PD by inhibiting ROS production.« less

Transvaginal 3D Image-Guided High Intensity Focused Ultrasound Array

NASA Astrophysics Data System (ADS)

Held, Robert; Nguyen, Thuc Nghi; Vaezy, Shahram

2005-03-01

The goal of this project is to develop a transvaginal image-guided High Intensity Focused Ultrasound (HIFU) device using piezocomposite HIFU array technology, and commercially-available ultrasound imaging. Potential applications include treatment of uterine fibroids and abnormal uterine bleeding. The HIFU transducer was an annular phased array, with a focal length range of 30-60 mm, an elliptically-shaped aperture of 35×60 mm, and an operating frequency of 3 MHz. A pillow-shaped bag with water circulation will be used for coupling the HIFU energy into the tissue. An intra-cavity imaging probe (C9-5, Philips) was integrated with the HIFU array such that the focal axis of the HIFU transducer was within the image plane. The entire device will be covered by a gel-filled condom when inserted in the vaginal cavity. To control it, software packages were developed in the LabView programming environment. An imaging algorithm processed the ultrasound image to remove noise patterns due to the HIFU signal. The device will be equipped with a three-dimensional tracking system, using a six-degrees-of-freedom articulating arm. Necrotic lesions were produced in a tissue-mimicking phantom and a turkey breast sample for all focal lengths. Various HIFU doses allow various necrotic lesion shapes, including thin ellipsoidal, spherical, wide cylindrical, and teardrop-shaped. Software control of the device allows multiple foci to be activated sequentially for desired lesion patterns. Ultrasound imaging synchronization can be achieved using hardware signals obtained from the imaging system, or software signals determined empirically for various imaging probes. The image-guided HIFU device will provide a valuable tool in visualization of uterine fibroid tumors for the purposes of planning and subsequent HIFU treatment of the tumor, all in a 3D environment. The control system allows for various lesions of different shapes to be optimally positioned in the tumor to cover the entire tumor

Radiofrequency ablation of neuroendocrine liver metastases: the Middlesex experience.

PubMed

Gillams, A; Cassoni, A; Conway, G; Lees, W

2005-01-01

Current treatment options for neuroendocrine liver metastases are not widely applicable or not that effective. Image-guided thermal ablation offers the possibility of a minimally invasive, albeit palliative, treatment that decreases tumor volume, preserves most of the normal liver, and can be repeated several times. We report our experience with image-guided thermal ablation in 25 patients with unresectable liver metastases. Since 1990 we have treated 189 tumors at 66 treatment sessions in 25 patients (12 female, 13 male; median age, 56 years; age range, 26--78 years). Thirty treatments were performed with a solid-state laser, and 36 treatments were performed with radiofrequency ablation. All but one treatment was performed percutaneously under image guidance. Sixteen patients had metastases from carcinoid primaries, three from gastrinoma, two from insulinoma, and four from miscellaneous causes. Fourteen of 25 had symptoms from hormone secretion. Imaging follow-up was available in 19 patients at a median of 21 months (range, 4--75 months). There was a complete response in six patients, a partial response in seven, and stable disease in one; hence, tumor load was controlled in 14 of 19 patients (74%). Relief of hormone-related symptoms was achieved in nine of 14 patients (69%). The median survival period from the diagnosis of liver metastases was 53 months. One patient with end-stage cardiac disease died after a carcinoid crisis. There were eight (12%) complications: five local and three distant, four major and four minor. As a minimally invasive, readily repeatable procedure that can be used to ablate small tumors, preferably before patients become severely symptomatic, radiofrequency ablation can provide effective control of liver tumor volume in most patients over many years.

Monitoring high-intensity focused ultrasound (HIFU) therapy using radio frequency ultrasound backscatter to quantify heating

NASA Astrophysics Data System (ADS)

Kaczkowski, Peter J.; Anand, Ajay

2005-09-01

The spatial distribution and temporal history of tissue temperature is an essential indicator of thermal therapy progress, and treatment safety and efficacy. Magnetic resonance methods provide the gold standard noninvasive measurement of temperature but are costly and cumbersome compared to the therapy itself. We have been developing the use of ultrasound backscattering for real-time temperature estimation; ultrasonic methods have been limited to relatively low temperature rise, primarily due to lack of sensitivity at protein denaturation temperatures (50-70°C). Through validation experiments on gel phantoms and ex vivo tissue we show that temperature rise can be accurately mapped throughout the therapeutic temperature range using a new BioHeat Transfer Equation (BHTE) model-constrained inverse approach. Speckle-free temperature and thermal dose maps are generated using the ultrasound calibrated model over the imaged region throughout therapy delivery and post-treatment cooling periods. Results of turkey breast tissue experiments are presented for static HIFU exposures, in which the ultrasound calibrated BHTE temperature maps are shown to be very accurate (within a degree) using independent thermocouple measurements. This new temperature monitoring method may speed clinical adoption of ultrasound-guided HIFU therapy. [Work supported by Army MRMC.

Direct measurement of the lethal isotherm for radiofrequency ablation of myocardial tissue.

PubMed

Wood, Mark; Goldberg, Scott; Lau, Melissa; Goel, Aneesh; Alexander, Daniel; Han, Frederick; Feinstein, Shawn

2011-06-01

The lethal isotherm for radiofrequency catheter ablation of cardiac myocardium is widely accepted to be 50°C, but this has not been directly measured. The purpose of this study was to directly measure the tissue temperature at the edge of radiofrequency lesions in real time using infrared thermal imaging. Fifteen radiofrequency lesions of 6 to 240 seconds in duration were applied to the left ventricular surface of isolated perfused pig hearts. At the end of radiofrequency delivery, a thermal image of the tissue surface was acquired with an infrared camera. The lesion was then stained and an optical image of the lesion was obtained. The thermal and optical images were electronically merged to allow determination of the tissue temperature at the edge of the lesion at the end of radiofrequency delivery. By adjusting the temperature overlay display to conform with the edge of the radiofrequency lesion, the lethal isotherm was measured to be 60.6°C (interquartile ranges, 59.7° to 62.4°C; range, 58.1° to 64.2°C). The areas encompassed by the lesion border in the optical image and the lethal isotherm in the thermal image were statistically similar and highly correlated (Spearman ρ=0.99, P<0.001). The lethal isotherm temperature was not related to the duration of radiofrequency delivery or to lesion size (both P>0.64). The areas circumscribed by 50°C isotherms were significantly larger than the areas of the lesions on optical imaging (P=0.002). By direct measurement, the lethal isotherm for cardiac myocardium is near 61°C for radiofrequency energy deliveries <240 seconds in duration. A 50°C isotherm overestimates lesion size. Accurate knowledge of the lethal isotherm for radiofrequency ablation is important to clinical practice as well as mathematical modeling of radiofrequency lesions.

Ultrasound-guided platelet-rich plasma injection for distal biceps tendinopathy.

PubMed

Barker, Scott L; Bell, Simon N; Connell, David; Coghlan, Jennifer A

2015-04-01

Distal biceps tendinopathy is an uncommon cause of elbow pain. The optimum treatment for cases refractory to conservative treatment is unclear. Platelet-rich plasma has been used successfully for other tendinopathies around the elbow. Six patients with clinical and radiological evidence of distal biceps tendinopathy underwent ultrasound-guided platelet-rich plasma (PRP) injection. Clinical examination findings, visual analogue score (VAS) for pain and Mayo Elbow Performance scores were recorded. The Mayo Elbow Performance Score improved from 68.3 (range 65 to 85) (fair function) to 95 (range 85 to 100) (excellent function). The VAS at rest improved from a mean of 2.25 (range 2 to 5) pre-injection to 0. The VAS with movement improved from a mean of 7.25 (range 5 to 8) pre-injection to 1.3 (range 0 to 2). No complications were noted. Ultrasound-guided PRP injection appears to be a safe and effective treatment for recalcitrant cases of distal biceps tendinopathy. Further investigation with a randomized controlled trial is needed to fully assess its efficacy.

Ultrasound-guided platelet-rich plasma injection for distal biceps tendinopathy

PubMed Central

Bell, Simon N; Connell, David; Coghlan, Jennifer A

2015-01-01

Background Distal biceps tendinopathy is an uncommon cause of elbow pain. The optimum treatment for cases refractory to conservative treatment is unclear. Platelet-rich plasma has been used successfully for other tendinopathies around the elbow. Methods Six patients with clinical and radiological evidence of distal biceps tendinopathy underwent ultrasound-guided platelet-rich plasma (PRP) injection. Clinical examination findings, visual analogue score (VAS) for pain and Mayo Elbow Performance scores were recorded. Results The Mayo Elbow Performance Score improved from 68.3 (range 65 to 85) (fair function) to 95 (range 85 to 100) (excellent function). The VAS at rest improved from a mean of 2.25 (range 2 to 5) pre-injection to 0. The VAS with movement improved from a mean of 7.25 (range 5 to 8) pre-injection to 1.3 (range 0 to 2). No complications were noted. Discussion Ultrasound-guided PRP injection appears to be a safe and effective treatment for recalcitrant cases of distal biceps tendinopathy. Further investigation with a randomized controlled trial is needed to fully assess its efficacy. PMID:27582965

Training and certification in endobronchial ultrasound-guided transbronchial needle aspiration

PubMed Central

Konge, Lars; Nayahangan, Leizl Joy; Clementsen, Paul Frost

2017-01-01

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) plays a key role in the staging of lung cancer, which is crucial for allocation to surgical treatment. EBUS-TBNA is a complicated procedure and simulation-based training is helpful in the first part of the long learning curve prior to performing the procedure on actual patients. New trainees should follow a structured training programme consisting of training on simulators to proficiency as assessed with a validated test followed by supervised practice on patients. The simulation-based training is superior to the traditional apprenticeship model and is recommended in the newest guidelines. EBUS-TBNA and oesophageal ultrasound-guided fine needle aspiration (EUS-FNA or EUS-B-FNA) are complementary to each other and the combined techniques are superior to either technique alone. It is logical to learn and to perform the two techniques in combination, however, for lung cancer staging solely EBUS-TBNA simulators exist, but hopefully in the future simulation-based training in EUS will be possible. PMID:28840013

Image-guided Tumor Ablation: Standardization of Terminology and Reporting Criteria—A 10-Year Update

PubMed Central

Solbiati, Luigi; Brace, Christopher L.; Breen, David J.; Callstrom, Matthew R.; Charboneau, J. William; Chen, Min-Hua; Choi, Byung Ihn; de Baère, Thierry; Dodd, Gerald D.; Dupuy, Damian E.; Gervais, Debra A.; Gianfelice, David; Gillams, Alice R.; Lee, Fred T.; Leen, Edward; Lencioni, Riccardo; Littrup, Peter J.; Livraghi, Tito; Lu, David S.; McGahan, John P.; Meloni, Maria Franca; Nikolic, Boris; Pereira, Philippe L.; Liang, Ping; Rhim, Hyunchul; Rose, Steven C.; Salem, Riad; Sofocleous, Constantinos T.; Solomon, Stephen B.; Soulen, Michael C.; Tanaka, Masatoshi; Vogl, Thomas J.; Wood, Bradford J.; Goldberg, S. Nahum

2014-01-01

Image-guided tumor ablation has become a well-established hallmark of local cancer therapy. The breadth of options available in this growing field increases the need for standardization of terminology and reporting criteria to facilitate effective communication of ideas and appropriate comparison among treatments that use different technologies, such as chemical (eg, ethanol or acetic acid) ablation, thermal therapies (eg, radiofrequency, laser, microwave, focused ultrasound, and cryoablation) and newer ablative modalities such as irreversible electroporation. This updated consensus document provides a framework that will facilitate the clearest communication among investigators regarding ablative technologies. An appropriate vehicle is proposed for reporting the various aspects of image-guided ablation therapy including classification of therapies, procedure terms, descriptors of imaging guidance, and terminology for imaging and pathologic findings. Methods are addressed for standardizing reporting of technique, follow-up, complications, and clinical results. As noted in the original document from 2003, adherence to the recommendations will improve the precision of communications in this field, leading to more accurate comparison of technologies and results, and ultimately to improved patient outcomes. © RSNA, 2014 Online supplemental material is available for this article. PMID:24927329

Image-guided tumor ablation: standardization of terminology and reporting criteria--a 10-year update.

PubMed

Ahmed, Muneeb; Solbiati, Luigi; Brace, Christopher L; Breen, David J; Callstrom, Matthew R; Charboneau, J William; Chen, Min-Hua; Choi, Byung Ihn; de Baère, Thierry; Dodd, Gerald D; Dupuy, Damian E; Gervais, Debra A; Gianfelice, David; Gillams, Alice R; Lee, Fred T; Leen, Edward; Lencioni, Riccardo; Littrup, Peter J; Livraghi, Tito; Lu, David S; McGahan, John P; Meloni, Maria Franca; Nikolic, Boris; Pereira, Philippe L; Liang, Ping; Rhim, Hyunchul; Rose, Steven C; Salem, Riad; Sofocleous, Constantinos T; Solomon, Stephen B; Soulen, Michael C; Tanaka, Masatoshi; Vogl, Thomas J; Wood, Bradford J; Goldberg, S Nahum

2014-10-01

Image-guided tumor ablation has become a well-established hallmark of local cancer therapy. The breadth of options available in this growing field increases the need for standardization of terminology and reporting criteria to facilitate effective communication of ideas and appropriate comparison among treatments that use different technologies, such as chemical (eg, ethanol or acetic acid) ablation, thermal therapies (eg, radiofrequency, laser, microwave, focused ultrasound, and cryoablation) and newer ablative modalities such as irreversible electroporation. This updated consensus document provides a framework that will facilitate the clearest communication among investigators regarding ablative technologies. An appropriate vehicle is proposed for reporting the various aspects of image-guided ablation therapy including classification of therapies, procedure terms, descriptors of imaging guidance, and terminology for imaging and pathologic findings. Methods are addressed for standardizing reporting of technique, follow-up, complications, and clinical results. As noted in the original document from 2003, adherence to the recommendations will improve the precision of communications in this field, leading to more accurate comparison of technologies and results, and ultimately to improved patient outcomes. Online supplemental material is available for this article . © RSNA, 2014.

Simulating thermal effects of MR-guided focused ultrasound in cortical bone and its surrounding tissue.

PubMed

Hudson, Thomas J; Looi, Thomas; Pichardo, Samuel; Amaral, Joao; Temple, Michael; Drake, James M; Waspe, Adam C

2018-02-01

Magnetic resonance-guided focused ultrasound (MRgFUS) is emerging as a treatment alternative for osteoid osteoma and painful bone metastases. This study describes a new simulation platform that predicts the distribution of heat generated by MRgFUS when applied to bone tissue. Calculation of the temperature distribution was performed using two mathematical models. The first determined the propagation and absorption of acoustic energy through each medium, and this was performed using a multilayered approximation of the Rayleigh integral method. The ultrasound energy distribution derived from these equations could then be converted to heat energy, and the second mathematical model would then use the heat generated to determine the final temperature distribution using a finite-difference time-domain application of Pennes' bio-heat transfer equation. Anatomical surface geometry was generated using a modified version of a mesh-based semiautomatic segmentation algorithm, and both the acoustic and thermodynamic models were calculated using a parallelized algorithm running on a graphics processing unit (GPU) to greatly accelerate computation time. A series of seven porcine experiments were performed to validate the model, comparing simulated temperatures to MR thermometry and assessing spatial, temporal, and maximum temperature accuracy in the soft tissue. The parallelized algorithm performed acoustic and thermodynamic calculations on grids of over 10 8 voxels in under 30 s for a simulated 20 s of heating and 40 s of cooling, with a maximum time per calculated voxel of less than 0.3 μs. Accuracy was assessed by comparing the soft tissue thermometry to the simulation in the soft tissue adjacent to bone using four metrics. The maximum temperature difference between the simulation and thermometry in a region of interest around the bone was measured to be 5.43 ± 3.51°C average absolute difference and a percentage difference of 16.7%. The difference in heating location

Solar thermal technical information guide

NASA Astrophysics Data System (ADS)

1985-05-01

This guide is designed to help investigators search for information in the solar thermal technology field. The information ranges from history and technology basics to the latest in research and develoment. It is written to help several audiences, including engineers and scientists who may be unfamiliar with a particular aspect of solar thermal energy, university researchers who are interested in the field, manufacturers needing to learn more about specific topics, and librarians who provide information to their clientele. The guide is divided into ten chapters, with Chapters 1 to 8 providing background on solar thermal energy development (including its history and current status) by topic. Within each topic, an overview is provided with references to relevant publications or information sources. Chapters 9 and 10 contain directories listing research centers and major technical information sources, respectively.

Novel needle guide reduces time to perform ultrasound-guided femoral nerve catheter placement: A randomised controlled trial.

PubMed

Turan, Alparslan; Babazade, Rovnat; Elsharkawy, Hesham; Esa, Wael Ali Sakr; Maheshwari, Kamal; Farag, Ehab; Zimmerman, Nicole M; Soliman, Loran Mounir; Sessler, Daniel I

2017-03-01

Ultrasound-guided nerve blocks have become the standard when performing regional nerve blocks in anaesthesia. Infiniti Plus (CIVCO Medical Solutions, Kalona, Iowa, USA) is a needle guide that has been recently developed to help clinicians in performing ultrasound-guided nerve blocks. We tested the hypothesis that femoral nerve catheter placement carried out with the Infiniti Plus needle guide will be quicker to perform than without the Infiniti Plus. Secondary aims were to assess whether the Infiniti Plus needle guide decreased the number of block attempts and also whether it improved needle visibility. A randomised, controlled trial. Cleveland Clinic, Cleveland, Ohio, USA. We enrolled adult patients having elective total knee arthroplasty with a femoral nerve block and femoral nerve catheter. Patients, who were pregnant or those who had preexisting neuropathy involving the surgical limb, coagulopathy, infection at the block site or allergy to local anaesthetics were excluded. Patients were randomised into two groups to receive the ultrasound-guided femoral nerve catheter placement with or without the Infiniti Plus needle guide. The time taken to place the femoral nerve catheter, the number of attempts, the success rate and needle visibility were recorded. We used an overall α of 0.05 for both the primary and secondary analyses; the secondary analyses were Bonferroni corrected to control for multiple comparisons. The median (interquartile range Q1 to Q3) time to perform the femoral nerve catheter placement was 118 (100 to 150) s with Infiniti Plus and 177 (130 to 236) s without Infiniti Plus. Infiniti Plus significantly reduced the time spent performing femoral nerve catheterisation, with estimated ratio of means [(95% confidence interval), P value] of 0.67 [(0.60 to 0.75), P < 0.001] with Infiniti Plus compared with no Infiniti Plus. However, Infiniti Plus had no effect on the odds of a successful femoral nerve catheter placement, number of attempts or

Two-year results after convective radiofrequency water vapor thermal therapy of symptomatic benign prostatic hyperplasia.

PubMed

Dixon, Christopher M; Cedano, Edwin Rijo; Pacik, Dalibor; Vit, Vítězslav; Varga, Gabriel; Wagrell, Lennart; Larson, Thayne R; Mynderse, Lance A

2016-01-01

The objective of this study was to assess the effectiveness and safety of convective radiofrequency (RF) water vapor thermal therapy in men with lower urinary tract symptoms (LUTS) associated with benign prostatic hyperplasia (BPH); a pilot study design with 2-year follow-up evaluations. Men aged ≥45 years with an International Prostate Symptom Score ≥13, a maximum urinary flow rate (Q max ) ≤15 mL/s, and prostate volume 20-120 cc were enrolled in a prospective, open-label pilot study using convective RF water vapor energy with the Rezūm System. Patients were followed up for 2 years after transurethral thermal treatment at 3 international centers in the Dominican Republic, Czech Republic, and Sweden. The transurethral thermal therapy utilizes radiofrequency to generate wet thermal energy in the form of water vapor injected through a rigid endoscope into the lateral lobes and median lobe as needed. Urinary symptom relief, urinary flow, quality of life (QOL) impact, sexual function, and adverse events (AEs) were assessed at 1 week, 1, 3, 6, 12, and 24 months. LUTS, flow rate, and QOL showed significant improvements from baseline; prostate volumes were appreciably reduced. Sexual function was maintained and no de novo erectile dysfunction occurred. The responses evident as early as 1 month after treatment remained consistent and durable over the 24 months of study. Early AEs were typically transient and mild to moderate; most were related to endoscopic instrumentation. No procedure related to late AEs were seen. The Rezūm System convective RF thermal therapy is a minimally invasive treatment for BPH/LUTS which can be performed in the office or as an outpatient procedure with minimal associated perioperative AEs. It has no discernable effect on sexual function and provides significant improvement of LUTS that remain durable at 2 years.

Two-year results after convective radiofrequency water vapor thermal therapy of symptomatic benign prostatic hyperplasia

PubMed Central

Dixon, Christopher M; Cedano, Edwin Rijo; Pacik, Dalibor; Vit, Vítězslav; Varga, Gabriel; Wagrell, Lennart; Larson, Thayne R; Mynderse, Lance A

2016-01-01

Objective The objective of this study was to assess the effectiveness and safety of convective radiofrequency (RF) water vapor thermal therapy in men with lower urinary tract symptoms (LUTS) associated with benign prostatic hyperplasia (BPH); a pilot study design with 2-year follow-up evaluations. Patients and methods Men aged ≥45 years with an International Prostate Symptom Score ≥13, a maximum urinary flow rate (Qmax) ≤15 mL/s, and prostate volume 20–120 cc were enrolled in a prospective, open-label pilot study using convective RF water vapor energy with the Rezūm System. Patients were followed up for 2 years after transurethral thermal treatment at 3 international centers in the Dominican Republic, Czech Republic, and Sweden. The transurethral thermal therapy utilizes radiofrequency to generate wet thermal energy in the form of water vapor injected through a rigid endoscope into the lateral lobes and median lobe as needed. Urinary symptom relief, urinary flow, quality of life (QOL) impact, sexual function, and adverse events (AEs) were assessed at 1 week, 1, 3, 6, 12, and 24 months. Results LUTS, flow rate, and QOL showed significant improvements from baseline; prostate volumes were appreciably reduced. Sexual function was maintained and no de novo erectile dysfunction occurred. The responses evident as early as 1 month after treatment remained consistent and durable over the 24 months of study. Early AEs were typically transient and mild to moderate; most were related to endoscopic instrumentation. No procedure related to late AEs were seen. Conclusion The Rezūm System convective RF thermal therapy is a minimally invasive treatment for BPH/LUTS which can be performed in the office or as an outpatient procedure with minimal associated perioperative AEs. It has no discernable effect on sexual function and provides significant improvement of LUTS that remain durable at 2 years. PMID:27921028

Long-axis view for ultrasound-guided central venous catheter placement via the internal jugular vein.

PubMed

Mahan, Angel F; McEvoy, Matthew D; Gravenstein, Nikolaus

2016-04-01

In modern practice, real-time ultrasound guidance is commonly employed for the placement of internal jugular vein catheters. With a new tool, such as ultrasound, comes the opportunity to refine and further optimize the ultrasound view during jugular vein catheterization. We describe jugular vein access techniques and use the long-axis view as an alternative to the commonly employed short-axis cross-section view for internal jugular vein access and cannulation. The long-axis ultrasound-guided internal jugular vein approach for internal jugular vein cannulation is a useful alternative technique that can provide better needle tip and guidewire visualization than the more traditional short-axis ultrasound view.

Treatment of great auricular neuralgia with real-time ultrasound-guided great auricular nerve block

PubMed Central

Jeon, Younghoon; Kim, Saeyoung

2017-01-01

Abstract Rationale: The great auricular nerve can be damaged by the neck surgery, tumor, and long-time pressure on the neck. But, great auricular neuralgia is very rare condition. It was managed by several medication and landmark-based great auricular nerve block with poor prognosis. Patient concerns: A 25-year-old man presented with a pain in the left lateral neck and auricle. Diagnosis: He was diagnosed with great auricular neuralgia. Interventions: His pain was not reduced by medication. Therefore, the great auricular nerve block with local anesthetics and steroid was performed under ultrasound guidance. Outcomes: Ultrasound guided great auricular nerve block alleviated great auricular neuralgia. Lessons: This medication-resistant great auricular neuralgia was treated by the ultrasound guided great auricular nerve block with local anesthetic agent and steroid. Therefore, great auricular nerve block can be a good treatment option of medication resistant great auricular neuralgia. PMID:28328811

Intravascular ultrasound guided directional atherectomy versus directional atherectomy guided by angiography for the treatment of femoropopliteal in-stent restenosis.

PubMed

Krishnan, Prakash; Tarricone, Arthur; K-Raman, Purushothaman; Majeed, Farhan; Kapur, Vishal; Gujja, Karthik; Wiley, Jose; Vasquez, Miguel; Lascano, Rheoneil A; Quiles, Katherine G; Distin, Tashanne; Fontenelle, Ran; Atallah-Lajam, Farah; Kini, Annapoorna; Sharma, Samin

2018-01-01

The aim of this study was to compare 1-year outcomes for patients with femoropopliteal in-stent restenosis using directional atherectomy guided by intravascular ultrasound (IVUS) versus directional atherectomy guided by angiography. This was a retrospective analysis for patients with femoropopliteal in-stent restenosis treated with IVUS-guided directional atherectomy versus directional atherectomy guided by angiography from a single center between March 2012 and February 2016. Clinically driven target lesion revascularization was the primary endpoint and was evaluated through medical chart review as well as phone call follow up. Directional atherectomy guided by IVUS reduces clinically driven target lesion revascularization for patients with femoropopliteal in-stent restenosis.

Workflow oriented software support for image guided radiofrequency ablation of focal liver malignancies

NASA Astrophysics Data System (ADS)

Weihusen, Andreas; Ritter, Felix; Kröger, Tim; Preusser, Tobias; Zidowitz, Stephan; Peitgen, Heinz-Otto

2007-03-01

Image guided radiofrequency (RF) ablation has taken a significant part in the clinical routine as a minimally invasive method for the treatment of focal liver malignancies. Medical imaging is used in all parts of the clinical workflow of an RF ablation, incorporating treatment planning, interventional targeting and result assessment. This paper describes a software application, which has been designed to support the RF ablation workflow under consideration of the requirements of clinical routine, such as easy user interaction and a high degree of robust and fast automatic procedures, in order to keep the physician from spending too much time at the computer. The application therefore provides a collection of specialized image processing and visualization methods for treatment planning and result assessment. The algorithms are adapted to CT as well as to MR imaging. The planning support contains semi-automatic methods for the segmentation of liver tumors and the surrounding vascular system as well as an interactive virtual positioning of RF applicators and a concluding numerical estimation of the achievable heat distribution. The assessment of the ablation result is supported by the segmentation of the coagulative necrosis and an interactive registration of pre- and post-interventional image data for the comparison of tumor and necrosis segmentation masks. An automatic quantification of surface distances is performed to verify the embedding of the tumor area into the thermal lesion area. The visualization methods support representations in the commonly used orthogonal 2D view as well as in 3D scenes.

Comparison of the analgesic efficacy of ultrasound-guided rectus sheath block and local anesthetic infiltration for laparoscopic percutaneous extraperitoneal closure in children.

PubMed

Uchinami, Yuka; Sakuraya, Fumika; Tanaka, Nobuhiro; Hoshino, Koji; Mikami, Eri; Ishikawa, Taro; Fujii, Hitomi; Ishikawa, Takehiko; Morimoto, Yuji

2017-05-01

Ultrasound-guided rectus sheath block and local anesthetic infiltration are the standard options to improve postoperative pain for children undergoing surgery with a midline incision. However, there is no study comparing the effect of ultrasound-guided rectus sheath block with local anesthetic infiltration for children undergoing laparoscopic surgery. The aim of this trial was to compare the onset of ultrasound-guided rectus sheath block with that of local anesthetic infiltration for laparoscopic percutaneous extraperitoneal closure in children. We performed an observer-blinded, randomized, prospective trial. Enrolled patients were assigned to either an ultrasound-guided rectus sheath block group or a local anesthetic infiltration group. The ultrasound-guided rectus sheath block group (n = 17) received ultrasound-guided rectus sheath block with 0.2 ml·kg -1 of 0.375% ropivacaine per side in the posterior rectus sheath compartment. The local anesthetic infiltration group (n = 17) received local anesthetic infiltration with 0.2 ml·kg -1 of 0.75% ropivacaine. The Face, Legs, Activity, Cry, and Consolability (FLACC) pain scores were recorded at 0, 30, 60 min after arrival at the postanesthesia care unit. Of the 37 patients enrolled in this study, 34 completed the study protocol. A significant difference in the pain scale between the ultrasound-guided rectus sheath block group and local anesthetic infiltration group was found at 0 min (median: 0, interquartile range [IQR]: 0-1.5, vs median: 1, IQR 0-5, confidence interval of median [95% CI]: 0-3, P = 0.048), but no significant difference was found at 30 min (median: 1, IQR: 0-4 vs median: 6, IQR: 0-7, 95% CI: 0-5, P = 0.061), or 60 min (median: 0, IQR: 0-2 vs median: 1, IQR: 0-3, 95% CI: -1 to 1, P = 0.310). No significant difference was found in anesthesia time between the ultrasound-guided rectus sheath block and local anesthetic infiltration groups. No procedure-related complications were observed in either group

An ultrasound needle insertion guide in a porcine phantom model.

PubMed

Whittaker, S; Lethbridge, G; Kim, C; Keon Cohen, Z; Ng, I

2013-08-01

We compared nerve blockade with and without the Infiniti(TM) needle guide in an ultrasound in-plane porcine simulation. We recruited 30 anaesthetists with varying blockade experience. Using the guide, the needle tip was more visible (for a median (IQR [range]) of 67 (56-100]) % of the time; and invisible for 2 (1-4 [0-19]) s) than when the guide was not used (respectively 23 (13-43 [0-80]) % and 25 (9-52 [1-198]) s; both p < 0.001). The corresponding block times were 8 (6-10 [3-28]) s and 32 (15-67 [5-225]) s, respectively; p < 0.001. The needle guide reduced the block time and the time that the needle was invisible, irrespective of anaesthetist experience. Anaesthesia © 2013 The Association of Anaesthetists of Great Britain and Ireland.

Cost-Effectiveness Comparison of Imaging-Guided Prostate Biopsy Techniques: Systematic Transrectal Ultrasound, Direct In-Bore MRI, and Image Fusion.

PubMed

Venderink, Wulphert; Govers, Tim M; de Rooij, Maarten; Fütterer, Jurgen J; Sedelaar, J P Michiel

2017-05-01

Three commonly used prostate biopsy approaches are systematic transrectal ultrasound guided, direct in-bore MRI guided, and image fusion guided. The aim of this study was to calculate which strategy is most cost-effective. A decision tree and Markov model were developed to compare cost-effectiveness. Literature review and expert opinion were used as input. A strategy was deemed cost-effective if the costs of gaining one quality-adjusted life year (incremental cost-effectiveness ratio) did not exceed the willingness-to-pay threshold of €80,000 (≈$85,000 in January 2017). A base case analysis was performed to compare systematic transrectal ultrasound- and image fusion-guided biopsies. Because of a lack of appropriate literature regarding the accuracy of direct in-bore MRI-guided biopsy, a threshold analysis was performed. The incremental cost-effectiveness ratio for fusion-guided biopsy compared with systematic transrectal ultrasound-guided biopsy was €1386 ($1470) per quality-adjusted life year gained, which was below the willingness-to-pay threshold and thus assumed cost-effective. If MRI findings are normal in a patient with clinically significant prostate cancer, the sensitivity of direct in-bore MRI-guided biopsy has to be at least 88.8%. If that is the case, the incremental cost-effectiveness ratio is €80,000 per quality-adjusted life year gained and thus cost-effective. Fusion-guided biopsy seems to be cost-effective compared with systematic transrectal ultrasound-guided biopsy. Future research is needed to determine whether direct in-bore MRI-guided biopsy is the best pathway; in this study a threshold was calculated at which it would be cost-effective.

Effectiveness of ultrasound-guided injections combined with shoulder exercises in the treatment of subacromial adhesive bursitis.

PubMed

Gasparre, Giuseppe; Fusaro, Isabella; Galletti, Stefano; Volini, Silvia; Benedetti, Maria Grazia

2012-05-01

The aim of this study was to evaluate whether the association of exercises for the shoulder with ultrasound-guided injection into the bursa significantly improves the treatment outcome in adhesive bursitis. Two groups of 35 patients, one treated with ultrasound-guided injection (UGI) and the other one with ultrasound-guided injection and home exercise program (UGI-exercise) for 1 month, were assessed for pain and shoulder function before treatment, 1 and 3 months post-treatment. Fourteen patients in UGI group and 23 patients in the UGI-exercises group were completely free of pain after 1 month (p = 0.031). At 3 months' follow-up, patients in the UGI-exercise group showed a significant improvement with respect to the other group (p = 0.005). No differences were found in function assessment. The UGI combined with shoulder exercises in the treatment of subacromial adhesive bursitis is effective to ensure a more frequent complete pain relief in the medium term.

Evaluation of a simplified augmented reality device for ultrasound-guided vascular access in a vascular phantom.

PubMed

Jeon, Yunseok; Choi, Seungpyo; Kim, Heechan

2014-09-01

To investigate whether a novel ultrasound device may be used with a simplified augmented reality technique, and to compare this device with conventional techniques during vascular access using a vascular phantom. Prospective, randomized study. Anesthesiology and Pain Medicine departments of a university-affiliated hospital. 20 physicians with no experience with ultrasound-guided techniques. All participants performed the vascular access technique on the vascular phantom model using both a conventional device and the new ultrasound device. Time and the number of redirections of the needle until aspiration of dye into a vessel of the vascular phantom were measured. The median/interquartile range of time was 39.5/41.7 seconds versus 18.6/10.0 seconds (P < 0.001) and number of redirections was 3/3.5 versus 1/0 (P < 0.001) for the conventional and novel ultrasound devices, respectively. During vascular access in a vascular phantom model, the novel device decreased the time and the number of redirections significantly. The device successfully improved the efficiency of the ultrasound-guided vascular access technique. Copyright © 2014 Elsevier Inc. All rights reserved.

Stereo-electro-encephalography-Guided Radiofrequency Thermocoagulation: From In Vitro and In Vivo Data to Technical Guidelines.

PubMed

Bourdillon, Pierre; Isnard, Jean; Catenoix, Hélène; Montavont, Alexandra; Rheims, Sylvain; Ryvlin, Philippe; Ostrowsky-Coste, Karine; Mauguiere, François; Guénot, Marc

2016-10-01

Deep brain electrodes have been used for the past 10 years to produce bipolar stereo-electro-encephalography-guided radiofrequency thermocoagulation (SEEG RF-TC). However, this technique is based on empiric knowledge. The aim of this study is 3-fold: 1) provide in vivo animal data concerning the effect of bipolar RF-TC on brain and its safety; 2) assess the parameters of this procedure (current delivery and dipole selection) that produce the most efficient lesion; and 3) provide technical guidelines. First we achieved in vivo RF-TC on rabbit brains with several conditions (power delivered and lesioning duration) and analyzed their influence on the lesion produced. Only a difference in terms of volume was found, and type of histologic lesions was similar whatever the settings were. We then performed multiple RF-TC in vitro on egg albumen, first with several parameters of radiofrequency and then with different dipole spatial selections. The end point was the size of the radiofrequency thermolesion produced. Using unfixed parameters of radiofrequency current delivery and increasing it until the power delivered by the generator collapsed produced significantly larger lesions (P = 0.008) than other conditions. Concerning the dipole selection, the use of contiguous contacts on electrodes led to lesions with a higher volume (P = 7.7 × 10 -13 ) than those produced with noncontiguous ones. Besides the target selection in SEEG RF-TC, which is summarized on the basis of a literature review, we report the optimal parameters: Radiofrequency current must be increased until the power delivered collapses, and dipoles should be constituted by contiguous electrode contacts. Copyright © 2016 Elsevier Inc. All rights reserved.

Optimizing MR imaging-guided navigation for focused ultrasound interventions in the brain

NASA Astrophysics Data System (ADS)

Werner, B.; Martin, E.; Bauer, R.; O'Gorman, R.

2017-03-01

MR imaging during transcranial MR imaging-guided Focused Ultrasound surgery (tcMRIgFUS) is challenging due to the complex ultrasound transducer setup and the water bolus used for acoustic coupling. Achievable image quality in the tcMRIgFUS setup using the standard body coil is significantly inferior to current neuroradiologic standards. As a consequence, MR image guidance for precise navigation in functional neurosurgical interventions using tcMRIgFUS is basically limited to the acquisition of MR coordinates of salient landmarks such as the anterior and posterior commissure for aligning a stereotactic atlas. Here, we show how improved MR image quality provided by a custom built MR coil and optimized MR imaging sequences can support imaging-guided navigation for functional tcMRIgFUS neurosurgery by visualizing anatomical landmarks that can be integrated into the navigation process to accommodate for patient specific anatomy.

Thermal Imaging of Medical Saw Blades and Guides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dinwiddie, Ralph Barton; Steffner, Thomas E

2007-01-01

Better Than New, LLC., has developed a surface treatment to reduce the friction and wear of orthopedic saw blades and guides. The medical saw blades were thermally imaged while sawing through fresh animal bone and an IR camera was used to measure the blade temperature as it exited the bone. The thermal performance of as-manufactured saw blades was compared to surface-treated blades, and a freshly used blade was used for temperature calibration purposes in order to account for any emissivity changes due to organic transfer layers. Thermal imaging indicates that the treated saw blades cut faster and cooler than untreatedmore » blades. In orthopedic surgery, saw guides are used to perfectly size the bone to accept a prosthesis. However, binding can occur between the blade and guide because of misalignment. This condition increases the saw blade temperature and may result in tissue damage. Both treated ad untreated saw guides were also studied. The treated saw guide operated at a significantly lower temperature than untreated guide. Saw blades and guides that operate at a cooler temperature are expected to reduce the amount of tissue damage (thermal necrosis) and may reduce the number of post-operative complications.« less

Pre-procedure ultrasound-guided paramedian spinal anaesthesia at L5–S1: Is this better than landmark-guided midline approach? A randomised controlled trial

PubMed Central

Srinivasan, Karthikeyan Kallidaikurichi; Leo, Anne-Marie; Iohom, Gabriella; Loughnane, Frank; Lee, Peter J

2018-01-01

Background and Aims: Routine use of pre-procedural ultrasound guided midline approach has not shown to improve success rate in administering subarachnoid block. The study hypothesis was that the routine use of pre-procedural (not real time) ultrasound-guided paramedian spinals at L5-S1 interspace could reduce the number of passes (i.e., withdrawal and redirection of spinal needle without exiting the skin) required to enter the subarachnoid space when compared to the conventional landmark-guided midline approach. Methods: After local ethics approval, 120 consenting patients scheduled for elective total joint replacements (Hip and Knee) were randomised into either Group C where conventional midline approach with palpated landmarks was used or Group P where pre-procedural ultrasound was used to perform subarachnoid block by paramedian approach at L5-S1 interspace (real time ultrasound guidance was not used). Results: There was no difference in primary outcome (difference in number of passes) between the two groups. Similarly there was no difference in the number of attempts (i.e., the number of times the spinal needle was withdrawn from the skin and reinserted). The first pass success rates (1 attempt and 1 pass) was significantly greater in Group C compared to Group P [43% vs. 22%, P = 0.02]. Conclusion: Routine use of paramedian spinal anaesthesia at L5-S1 interspace, guided by pre-procedure ultrasound, in patients undergoing lower limb joint arthroplasties did not reduce the number of passes or attempts needed to achieve successful dural puncture. PMID:29416151

Guided Interventions for Prostate Cancer Using 3D-Transurethral Ultrasound and MRI Fusion

DTIC Science & Technology

2017-06-01

standard transrectal ultrasound (TRUS) probe, a TUUS probe, and MRI. (a) (b) Figure 2: 3D printed prostate phantom mold (a), and pelvis phantom mold...with prostate agar phantom in place (b). The TUUS phantoms were prepared using a standard recipe [ii] for the prostate and the 3D printed mold...AWARD NUMBER: W81XWH-14-1-0461 TITLE: Guided Interventions for Prostate Cancer Using 3D -Transurethral Ultrasound and MRI Fusion PRINCIPAL

Review of MRI positioning devices for guiding focused ultrasound systems.

PubMed

Yiallouras, C; Damianou, C

2015-06-01

This article contains a review of positioning devices that are currently used in the area of magnetic resonance imaging (MRI) guided focused ultrasound surgery (MRgFUS). The paper includes an extensive review of literature published since the first prototype system was invented in 1991. The technology has grown into a fast developing area with application to any organ accessible to ultrasound. The initial design operated using hydraulic principles, while the latest technology incorporates piezoelectric motors. Although, in the beginning there were fears regarding MRI safety, during recent years, the deployment of MR-safe positioning devices in FUS has become routine. Many of these positioning devices are now undergoing testing in clinical trials. Existing MRgFUS systems have been utilized mostly in oncology (fibroids, brain, liver, kidney, bone, pancreas, eye, thyroid, and prostate). It is anticipated that, in the near future, there will be a positioning device for every organ that is accessible by focused ultrasound. Copyright © 2014 John Wiley & Sons, Ltd.

Therapeutic outcome of CT-guided radiofrequency ablation in patients with osteoid osteoma.

PubMed

Lassalle, Louis; Campagna, R; Corcos, G; Babinet, A; Larousserie, F; Stephanazzi, J; Feydy, A

2017-07-01

To assess the long-term outcome of computed tomography-guided radiofrequency ablation (CT-guided RFA) in patients with suspected osteoid osteoma (OO). Single-center retrospective study. Patients with clinical suspicion and imaging diagnosis of osteoid osteoma were treated by CT-guided RFA using the same device with either a 7- or 10-mm active tip electrode. Specific precautions were applied in case of articular or spinal OO. Patients were contacted by phone to evaluate the long-term outcome in terms of pain, ability to perform daily activities (including sports), and long-term complications. Success was defined as the absence of residual pain and ability to perform daily activities normally. From 2008 to 2015, 126 patients were treated by CT-guided RFA for OO in our institution. Mean patient age was 26.1 years (SD = 11, range 1-53); mean delay to diagnosis was 16.9 months (SD = 15.2, range 1-120). Among patients who answered the follow-up call (n = 88), the overall success rate was 94.3%: 79/88 (89.8%) had primary success of the procedure, and 4/88 (4.5%) had a secondary success (repeat-RFA after pain recurrence). Mean follow-up time was 34.6 months (SD = 24.7, range 3-90). Few complications occurred: two mild reversible peripheral nerve injuries, one brachial plexus neuropathy, one broken electrode tip fragment, and one muscular hematoma. Osteoid osteoma can be effectively and safely treated by CT-guided RFA using the presented ablation protocol. Beneficial effects of the treatment persist at long-term follow-up.

Evaluation of the eZono 4000 with eZGuide for ultrasound-guided procedures.

PubMed

Gadsden, Jeff; Latmore, Malikah; Levine, Daniel M

2015-05-01

Ultrasound-guided procedures are increasingly common in a variety of acute care settings, such as the operating room, critical care unit and emergency room. However, accurate judgment of needle tip position using traditional ultrasound technology is frequently difficult, and serious injury can result from inadvertently advancing beyond or through the target. Needle navigation is a recent innovation that allows the clinician to visualize the needle position and trajectory in real time as it approaches the target. A novel ultrasound machine has recently been introduced that is portable and designed for procedural guidance. The eZono 4000™ features an innovative needle navigation technology that is simple to use and permits the use of a wide range of commercially available needles, avoiding the inconvenience and cost of proprietary equipment. This article discusses this new ultrasound machine in the context of other currently available ultrasound machines featuring needle navigation.

Ultrasound-Guided Rectus Sheath Block in Gynaecological Surgery with Pfannenstiel Incision

PubMed Central

Cüneyitoğlu, Şule; Türktan, Mediha; Biricik, Ebru; Özcengiz, Dilek

2015-01-01

Objective This study aimed to evaluate the effects of ultrasound-guided rectus sheath block in gynaecological surgery with Pfannenstiel incision. Methods After the approval of the ethics committee and the patients’ consent, 75 ASA I–II patients who were aged between 20 and 70 years and scheduled for a gynaecological surgery with Pfannenstiel incision were included in this study. After induction of general anaesthesia, patients were randomly divided into three groups. In Group UR patients (n=25), ultrasound-guided rectus sheath block with 0.25% levobupivacaine (0.2 mL kg−1) was performed. In Group SR patients (n=25), surgical rectus sheath block with 0.25% levobupivacaine (0.2 mL kg−1) was applied. In Group T (n=25) patients, tramadol (2 mg kg−1) was intravenously administered 30 min before the end of surgery. Patient-controlled analgesia device was established for postoperative pain relief in all groups. Haemodynamic data and inspired sevoflurane concentration were recorded during the operation. Pain scores, total tramadol consumption, supplemental analgesic requirement and side effects were postoperatively evaluated. Results Demographic characteristics, duration of surgery and haemodynamic parameters were similar between the groups. Inspired sevoflurane concentration (%) and VAS scores were significantly lower in Group UR than those in Groups SR and T. Total tramadol consumption was significantly lower in Groups UR and SR than that in Group T. There was no significant difference in the incidence of side effects. Conclusion This study demonstrates that ultrasound-guided rectus sheath block helps to provide the effective analgesia without any side effects compared with surgical rectus sheath block and intravenous tramadol for gynaecological surgery with Pfannenstiel incision. PMID:27366521

Ultrasound-Guided Rectus Sheath Block in Gynaecological Surgery with Pfannenstiel Incision.

PubMed

Cüneyitoğlu, Şule; Türktan, Mediha; Biricik, Ebru; Özcengiz, Dilek

2015-10-01

This study aimed to evaluate the effects of ultrasound-guided rectus sheath block in gynaecological surgery with Pfannenstiel incision. After the approval of the ethics committee and the patients' consent, 75 ASA I-II patients who were aged between 20 and 70 years and scheduled for a gynaecological surgery with Pfannenstiel incision were included in this study. After induction of general anaesthesia, patients were randomly divided into three groups. In Group UR patients (n=25), ultrasound-guided rectus sheath block with 0.25% levobupivacaine (0.2 mL kg(-1)) was performed. In Group SR patients (n=25), surgical rectus sheath block with 0.25% levobupivacaine (0.2 mL kg(-1)) was applied. In Group T (n=25) patients, tramadol (2 mg kg(-1)) was intravenously administered 30 min before the end of surgery. Patient-controlled analgesia device was established for postoperative pain relief in all groups. Haemodynamic data and inspired sevoflurane concentration were recorded during the operation. Pain scores, total tramadol consumption, supplemental analgesic requirement and side effects were postoperatively evaluated. Demographic characteristics, duration of surgery and haemodynamic parameters were similar between the groups. Inspired sevoflurane concentration (%) and VAS scores were significantly lower in Group UR than those in Groups SR and T. Total tramadol consumption was significantly lower in Groups UR and SR than that in Group T. There was no significant difference in the incidence of side effects. This study demonstrates that ultrasound-guided rectus sheath block helps to provide the effective analgesia without any side effects compared with surgical rectus sheath block and intravenous tramadol for gynaecological surgery with Pfannenstiel incision.

Thermal mechanisms of interaction of radiofrequency energy with biological systems with relevance to exposure guidelines.

PubMed

Foster, Kenneth R; Glaser, Roland

2007-06-01

This article reviews thermal mechanisms of interaction between radiofrequency (RF) fields and biological systems, focusing on theoretical frameworks that are of potential use in setting guidelines for human exposure to RF energy. Several classes of thermal mechanisms are reviewed that depend on the temperature increase or rate of temperature increase and the relevant dosimetric considerations associated with these mechanisms. In addition, attention is drawn to possible molecular and physiological reactions that could be induced by temperature elevations below 0.1 degrees, which are normal physiological responses to heat, and to the so-called microwave auditory effect, which is a physiologically trivial effect resulting from thermally-induced acoustic stimuli. It is suggested that some reported "nonthermal" effects of RF energy may be thermal in nature; also that subtle thermal effects from RF energy exist but have no consequence to health or safety. It is proposed that future revisions of exposure guidelines make more explicit use of thermal models and empirical data on thermal effects in quantifying potential hazards of RF fields.

First Experience of Ultrasound-guided Percutaneous Ablation for Recurrent Hepatoblastoma after Liver Resection in Children

PubMed Central

Liu, Baoxian; Zhou, Luyao; Huang, Guangliang; Zhong, Zhihai; Jiang, Chunlin; Shan, Quanyuan; Xu, Ming; Kuang, Ming; Xie, Xiaoyan

2015-01-01

This study aimed to summarize the first experience with ultrasound-guided percutaneous ablation treatment (PAT) for recurrent hepatoblastoma (HB) after liver resection in children. From August 2013 to October 2014, PAT was used to treat 5 children with a total of 8 recurrent HB (mean size, 1.4 ± 0.8 cm; size range, 0.7–3.1 cm), including 4 patients with 7 tumors in the liver and 1 patient with 1 tumor in the lung. Technical success was achieved in all patients (5/5, 100%). The complete ablation rate after the first ablation session was 80% (4/5) on a patient-by-patient basis and 87.5% (7/8) on a tumor-by-tumor basis. Only 1 patient developed a fever with temperature >39 °C; it lasted 4 days after radiofrequency ablation (RFA) and was resolved by conservative therapy. During the follow-up period, new intrahepatic recurrences after PAT were detected in two patients. One died due to tumor progression 4 months after ablation. The median overall survival time after PAT was 13.8 months. PAT is a safe and promising therapy for children with recurrent HB after liver resection, and further investigation in large-scale randomized clinical trials is required to determine its role in the treatment of this disease. PMID:26578035

Mechanically assisted 3D ultrasound for pre-operative assessment and guiding percutaneous treatment of focal liver tumors

NASA Astrophysics Data System (ADS)

Sadeghi Neshat, Hamid; Bax, Jeffery; Barker, Kevin; Gardi, Lori; Chedalavada, Jason; Kakani, Nirmal; Fenster, Aaron

2014-03-01

Image-guided percutaneous ablation is the standard treatment for focal liver tumors deemed inoperable and is commonly used to maintain eligibility for patients on transplant waitlists. Radiofrequency (RFA), microwave (MWA) and cryoablation technologies are all delivered via one or a number of needle-shaped probes inserted directly into the tumor. Planning is mostly based on contrast CT/MRI. While intra-procedural CT is commonly used to confirm the intended probe placement, 2D ultrasound (US) remains the main, and in some centers the only imaging modality used for needle guidance. Corresponding intraoperative 2D US with planning and other intra-procedural imaging modalities is essential for accurate needle placement. However, identification of matching features of interest among these images is often challenging given the limited field-of-view (FOV) and low quality of 2D US images. We have developed a passive tracking arm with a motorized scan-head and software tools to improve guiding capabilities of conventional US by large FOV 3D US scans that provides more anatomical landmarks that can facilitate registration of US with both planning and intra-procedural images. The tracker arm is used to scan the whole liver with a high geometrical accuracy that facilitates multi-modality landmark based image registration. Software tools are provided to assist with the segmentation of the ablation probes and tumors, find the 2D view that best shows the probe(s) from a 3D US image, and to identify the corresponding image from planning CT scans. In this paper, evaluation results from laboratory testing and a phase 1 clinical trial for planning and guiding RFA and MWA procedures using the developed system will be presented. Early clinical results show a comparable performance to intra-procedural CT that suggests 3D US as a cost-effective alternative with no side-effects in centers where CT is not available.

Ultrasound-guided approach for axillary brachial plexus, femoral nerve, and sciatic nerve blocks in dogs.

PubMed

Campoy, Luis; Bezuidenhout, Abraham J; Gleed, Robin D; Martin-Flores, Manuel; Raw, Robert M; Santare, Carrie L; Jay, Ariane R; Wang, Annie L

2010-03-01

To describe an ultrasound-guided technique and the anatomical basis for three clinically useful nerve blocks in dogs. Prospective experimental trial. Four hound-cross dogs aged 2 +/- 0 years (mean +/- SD) weighing 30 +/- 5 kg and four Beagles aged 2 +/- 0 years and weighing 8.5 +/- 0.5 kg. Axillary brachial plexus, femoral, and sciatic combined ultrasound/electrolocation-guided nerve blocks were performed sequentially and bilaterally using a lidocaine solution mixed with methylene blue. Sciatic nerve blocks were not performed in the hounds. After the blocks, the dogs were euthanatized and each relevant site dissected. Axillary brachial plexus block Landmark blood vessels and the roots of the brachial plexus were identified by ultrasound in all eight dogs. Anatomical examination confirmed the relationship between the four ventral nerve roots (C6, C7, C8, and T1) and the axillary vessels. Three roots (C7, C8, and T1) were adequately stained bilaterally in all dogs. Femoral nerve block Landmark blood vessels (femoral artery and femoral vein), the femoral and saphenous nerves and the medial portion of the rectus femoris muscle were identified by ultrasound in all dogs. Anatomical examination confirmed the relationship between the femoral vessels, femoral nerve, and the rectus femoris muscle. The femoral nerves were adequately stained bilaterally in all dogs. Sciatic nerve block. Ultrasound landmarks (semimembranosus muscle, the fascia of the biceps femoris muscle and the sciatic nerve) could be identified in all of the dogs. In the four Beagles, anatomical examination confirmed the relationship between the biceps femoris muscle, the semimembranosus muscle, and the sciatic nerve. In the Beagles, all but one of the sciatic nerves were stained adequately. Ultrasound-guided needle insertion is an accurate method for depositing local anesthetic for axillary brachial plexus, femoral, and sciatic nerve blocks.

MR-guided focused ultrasound: a potentially disruptive technology.

PubMed

Bradley, William G

2009-07-01

A disruptive technology is a technological innovation that overturns the existing dominant technologies in a market. Magnetic resonance (MR)-guided focused ultrasound (MRgFUS) is a noninvasive procedure based on the combination of real-time MR anatomic guidance, MR thermometry, and high-intensity focused ultrasound. Several hundred transducer elements become convergent at a point under MR guidance, leading to heating and coagulation necrosis. Outside the focal point, there is no significant heating. There is no need to break the skin for procedures in the body or to perform a craniotomy for procedures in the brain. This lack of invasiveness is what makes MRgFUS so disruptive compared with surgery. At present, MRgFUS has been used for the ablation of uterine fibroids, breast tumors, painful bony metastases, and liver tumors. In the brain, it has been used for the ablation of glioblastomas and for functional neurosurgery. Phantom and animal studies suggest future applications for prostate cancer and acute stroke treatment.

Intravascular ultrasound guided directional atherectomy versus directional atherectomy guided by angiography for the treatment of femoropopliteal in-stent restenosis

PubMed Central

Krishnan, Prakash; Tarricone, Arthur; K-Raman, Purushothaman; Majeed, Farhan; Kapur, Vishal; Gujja, Karthik; Wiley, Jose; Vasquez, Miguel; Lascano, Rheoneil A.; Quiles, Katherine G.; Distin, Tashanne; Fontenelle, Ran; Atallah-Lajam, Farah; Kini, Annapoorna; Sharma, Samin

2017-01-01

Background: The aim of this study was to compare 1-year outcomes for patients with femoropopliteal in-stent restenosis using directional atherectomy guided by intravascular ultrasound (IVUS) versus directional atherectomy guided by angiography. Methods and results: This was a retrospective analysis for patients with femoropopliteal in-stent restenosis treated with IVUS-guided directional atherectomy versus directional atherectomy guided by angiography from a single center between March 2012 and February 2016. Clinically driven target lesion revascularization was the primary endpoint and was evaluated through medical chart review as well as phone call follow up. Conclusions: Directional atherectomy guided by IVUS reduces clinically driven target lesion revascularization for patients with femoropopliteal in-stent restenosis. PMID:29265002

Prospective evaluation of magnetic resonance imaging guided in-bore prostate biopsy versus systematic transrectal ultrasound guided prostate biopsy in biopsy naïve men with elevated prostate specific antigen.

PubMed

Quentin, Michael; Blondin, Dirk; Arsov, Christian; Schimmöller, Lars; Hiester, Andreas; Godehardt, Erhard; Albers, Peter; Antoch, Gerald; Rabenalt, Robert

2014-11-01

Magnetic resonance imaging guided biopsy is increasingly performed to diagnose prostate cancer. However, there is a lack of well controlled, prospective trials to support this treatment method. We prospectively compared magnetic resonance imaging guided in-bore biopsy with standard systematic transrectal ultrasound guided biopsy in biopsy naïve men with increased prostate specific antigen. We performed a prospective study in 132 biopsy naïve men with increased prostate specific antigen (greater than 4 ng/ml). After 3 Tesla functional multiparametric magnetic resonance imaging patients were referred for magnetic resonance imaging guided in-bore biopsy of prostate lesions (maximum 3) followed by standard systematic transrectal ultrasound guided biopsy (12 cores). We analyzed the detection rates of prostate cancer and significant prostate cancer (greater than 5 mm total cancer length or any Gleason pattern greater than 3). A total of 128 patients with a mean ± SD age of 66.1 ± 8.1 years met all study requirements. Median prostate specific antigen was 6.7 ng/ml (IQR 5.1-9.0). Transrectal ultrasound and magnetic resonance imaging guided biopsies provided the same 53.1% detection rate, including 79.4% and 85.3%, respectively, for significant prostate cancer. Magnetic resonance imaging and transrectal ultrasound guided biopsies missed 7.8% and 9.4% of clinically significant prostate cancers, respectively. Magnetic resonance imaging biopsy required significantly fewer cores and revealed a higher percent of cancer involvement per biopsy core (each p <0.01). Combining the 2 methods provided a 60.9% detection rate with an 82.1% rate for significant prostate cancer. Magnetic resonance imaging guided in-bore and systematic transrectal ultrasound guided biopsies achieved equally high detection rates in biopsy naïve patients with increased prostate specific antigen. Magnetic resonance imaging guided in-bore biopsies required significantly fewer cores and revealed a

A high-performance wave guide cryogenic thermal break

NASA Astrophysics Data System (ADS)

Melhuish, S. J.; McCulloch, M. A.; Piccirillo, L.; Stott, C.

2016-10-01

We describe a high-performance wave guide cryogenic thermal break. This has been constructed both for Ka band, using WR28 wave guide, and Q band, using WR22 wave guide. The mechanical structure consists of a hexapod (Stewart platform) made from pultruded carbon fibre tubing. We present a tentative examination of the cryogenic Young's modulus of this material. The thermal conductivity is measured at temperatures above the range explored by Runyan and Jones, resulting in predicted conductive loads through our thermal breaks of 3.7 mW to 3 K and 17 μK to 1 K.

[Prognostic analysis of plantar fasciitis treated by pneumatic ballistic extracorporeal shock wave versus ultrasound guided intervention].

PubMed

Huo, Xiu-Lin; Wang, Ke-Tao; Zhang, Xiao-Ying; Yang, Yi-Tian; Cao, Fu-Yang; Yang, Jing; Yuan, Wei-Xiu; Mi, Wei-Dong

2018-02-20

To compare the medium- and long-term effect of pneumatic ballistic extracorporeal shock wave versus ultrasound-guided hormone injection in the treatment of plantar fasciitis. The clinical data were collected from patients with plantar fasciitis admitted to PLA General Hospital pain department from September, 2015 to February, 2017. The patients were randomly divided into ultrasound-guided drug injection group and shock wave group. The therapeutic parameters including the numerical rating scale (NRS) scores in the first step pain in the morning, American Orthopedic Foot and Ankle Society (AOFAS) Ankle Hindfoot Scale, and thickness of the plantar fascia were monitored before and at 1 week, 1 month, 3 months, and 6 months after the treatment. The recurrence rate, effectiveness, and patient satisfaction were compared between the two groups at 6 months after the treatment. Thirty-nine patients were enrolled in shock wave group and 38 patients in ultrasound group. The NRS scores in the first step pain in the morning were lowered after treatment in both groups (P<0.05), and the scores were significantly lower in ultrasound group than in shock wave group at 1 week and 1 month (P<0.01), but significantly higher in ultrasound group than in shock wave group at 3 and 6 months after treatment (P<0.05). The AOFAS functional scores were increased in both groups (P<0.05) at 6 months after treatment, was significantly lower in ultrasound group than in shock wave group than group B (90.44∓13.27 vs 75.76∓21.40; P<0.05). The effective rates in shock wave group and ultrasound group were 92.31% and 76.32%, respectively (P<0.05). Recurrence was found in 1 patient (2.56%) in shock wave group and in 8 (21.05%) in ultrasound group (P<0.05). The patient satisfaction scores were significantly higher in shock wave group than in ultrasound group (8.13∓2.67 vs 6.63∓3.75, P=0.048). Pneumatic ballistic extracorporeal shock achieves better medium- and long-term outcomes than ultrasound-guided

Ultrasound-guided peripheral nerve interventions for common pain disorders

PubMed Central

Krishna Prasad, B P; Joy, Binu; Raghavendra, Vijayakumar A; Toms, Ajith; George, Danny; Ray, Brijesh

2018-01-01

There are a number of common pain disorders that can be managed effectively by injections around or ablation of peripheral nerves. Ultrasound is a universally available imaging tool, is safe, cost-effective, and is excellent in imaging many peripheral nerves and guiding needles to the site of the nerves. This article aims to present an overview of indications and techniques of such procedures that can be effectively performed by a radiologist. PMID:29692534

In-Plane Ultrasound-Guided Knee Injection Through a Lateral Suprapatellar Approach: A Safe Technique.

PubMed

Chagas-Neto, Francisco A; Taneja, Atul K; Gregio-Junior, Everaldo; Nogueira-Barbosa, Marcello H

2017-06-01

This study aims to describe a technique for in-plane ultrasound-guided knee arthrography through a lateral suprapatellar approach, reporting its accuracy and related complications. A retrospective search was performed for computed tomography and magnetic resonance reports from June 2013 through June 2015. Imaging studies, puncture descriptions, and guided-procedure images were reviewed along with clinical and surgical history. A fellowship-trained musculoskeletal radiologist performed all procedures under sterile technique and ultrasound guidance with the probe in oblique position on the lateral suprapatellar recess after local anesthesia with the patient on dorsal decubitus, hip in neutral rotation, and 30 to 45 degrees of knee flexion. A total of 86 consecutive subjects were evaluated (mean, 55 years). All subjects underwent intra-articular injection of contrast, which was successfully reached in the first attempt in 94.2% of the procedures (81/86), and in the second attempt in 5.8% (5/86) after needle repositioning without a second puncture. There were no postprocedural reports of regional complications at the puncture site, such as significant pain, bleeding, or vascular lesions. Our study demonstrates that in-plane ultrasound-guided injection of the knee in semiflexion approaching the lateral suprapatellar recess is a safe and useful technique to administer intra-articular contrast solution, as an alternative method without radiation exposure.

Laparoscopic-guided abdominal wall nerve blocks in the pediatric population: a novel technique with comparison to ultrasound-guided blocks and local wound infiltration alone.

PubMed

Landmann, Alessandra; Visoiu, Mihaela; Malek, Marcus M

2018-03-01

Abdominal wall nerve blocks have been gaining popularity for the treatment of perioperative pain in children. Our aim was to compare a technique of surgeon-performed, laparoscopic abdominal wall nerve blocks to anesthesia-placed, ultrasound-guided abdominal wall nerve blocks and the current standard of local wound infiltration. After institutional review board approval was obtained, a retrospective chart review was performed of pediatric patients treated at a single institution during a 2-year period. Statistics were calculated using analysis of variance with post-hoc Bonferonni t tests for pair-wise comparisons. Included in this study were 380 patients who received ultrasound-guided abdominal wall nerve blocks (n = 125), laparoscopic-guided abdominal wall nerve blocks (n = 88), and local wound infiltration (n = 117). Groups were well matched for age, sex, and weight. There was no significant difference in pain scores within the first 8 hours or narcotic usage between groups. Local wound infiltration demonstrated the shortest overall time required to perform (P < .0001). Patients who received a surgeon-performed abdominal wall nerve block demonstrated a shorter duration of hospital stay when compared to the other groups (P = .02). Our study has demonstrated that laparoscopic-guided abdominal wall nerve blocks show similar efficacy to ultrasound-guided nerve blocks performed by pain management physicians without increasing time in the operating room. Copyright © 2017 Elsevier Inc. All rights reserved.

Acoustic Droplet Vaporization for the Enhancement of Ultrasound Thermal Therapy.

PubMed

Zhang, Man; Fabiilli, Mario; Carson, Paul; Padilla, Frederic; Swanson, Scott; Kripfgans, Oliver; Fowlkes, Brian

2010-10-11

Acoustic droplet vaporization (ADV) is an ultrasound method for converting biocompatible microdroplets into microbubbles. The objective is to demonstrate that ADV bubbles can enhance high intensity focused ultrasound (HIFU) therapy by controlling and increasing energy absorption at the focus. Thermal phantoms were made with or without droplets. Compound lesions were formed in the phantoms by 5-second exposures with 5-second delays. Center to center spacing of individual lesions was 5.5 mm in either a linear pattern or a spiral pattern. Prior to the HIFU, 10 cycle tone bursts with 0.25% duty cycle were used to vaporize the droplets, forming an "acoustic trench" within 30 seconds. The transducer was then focused in the middle of the back bubble wall to form thermal lesions in the trench. All lesions were imaged optically and with 2T MRI. With the use of ADV and the acoustic trench, a uniform thermal ablation volume of 15 cm(3) was achieved in 4 minutes; without ADV only less than 15% of this volume was filled. The commonly seen tadpole shape characteristic of bubble-enhanced HIFU lesions was not evident with the acoustic trench. In conclusion, ADV shows promise for the spatial control and dramatic acceleration of thermal lesion production by HIFU.

Ultrasound-guided cable-free 13-gauge vacuum-assisted biopsy of non-mass breast lesions

PubMed Central

Seo, Jiwoon; Jang, Mijung; Yun, Bo La; Lee, Soo Hyun; Kim, Eun-Kyu; Kang, Eunyoung; Park, So Yeon; Moon, Woo Kyung; Choi, Hye Young; Kim, Bohyoung

2017-01-01

Purpose To compare the outcomes of ultrasound-guided core biopsy for non-mass breast lesions by the novel 13-gauge cable-free vacuum-assisted biopsy (VAB) and by the conventional 14-gauge semi-automated core needle biopsy (CCNB). Materials and methods Our institutional review board approved this prospective study, and all patients provided written informed consent. Among 1840 ultrasound-guided percutaneous biopsies performed from August 2013 to December 2014, 145 non-mass breast lesions with suspicious microcalcifications on mammography or corresponding magnetic resonance imaging finding were subjected to 13-gauge VAB or 14-gauge CCNB. We evaluated the technical success rates, average specimen numbers, and tissue sampling time. We also compared the results of percutaneous biopsy and final surgical pathologic diagnosis to analyze the rates of diagnostic upgrade or downgrade. Results Ultrasound-guided VAB successfully targeted and sampled all lesions, whereas CCNB failed to demonstrate calcification in four (10.3%) breast lesions with microcalcification on specimen mammography. The mean sampling time were 238.6 and 170.6 seconds for VAB and CCNB, respectively. No major complications were observed with either method. Ductal carcinoma in situ (DCIS) and atypical ductal hyperplasia (ADH) lesions were more frequently upgraded after CCNB (8/23 and 3/5, respectively) than after VAB (2/26 and 0/4, respectively P = 0.028). Conclusion Non-mass breast lesions were successfully and accurately biopsied using cable-free VAB. The underestimation rate of ultrasound-detected non-mass lesion was significantly lower with VAB than with CCNB. Trial registration CRiS KCT0002267. PMID:28628656

Ultrasound Imaging and Guided Injection for the Lateral and Posterior Hip.

PubMed

Chang, Ke-Vin; Wu, Wei-Ting; Lew, Henry L; Özçakar, Levent

2018-04-01

Ultrasound has emerged as one of the most utilized tools to diagnose musculoskeletal disorders and to assist in interventions. Traditionally, sonographic examination of the hip joint has been challenging because most of the major structures are deeply situated, thus requiring the use of curvilinear transducer for better penetrance. The posterior lateral hip is a frequent area for musculoskeletal pain and nerve entrapments. Common disorders include greater trochanteric pain syndrome, gluteus medius tendinopathy, piriformis syndrome, pudendal neuralgia, and proximal hamstring tendinopathy. The present review article aims to delineate sonoanatomy of the posterior lateral hip and to exemplify several common ultrasound guided procedures at the greater trochanteric, gluteal, and ischial tuberosity regions.

High-intensity focused ultrasound (HIFU) array system for image-guided ablative therapy (IGAT)

NASA Astrophysics Data System (ADS)

Kaczkowski, Peter J.; Keilman, George W.; Cunitz, Bryan W.; Martin, Roy W.; Vaezy, Shahram; Crum, Lawrence A.

2003-06-01

Recent interest in using High Intensity Focused Ultrasound (HIFU) for surgical applications such as hemostasis and tissue necrosis has stimulated the development of image-guided systems for non-invasive HIFU therapy. Seeking an all-ultrasound therapeutic modality, we have developed a clinical HIFU system comprising an integrated applicator that permits precisely registered HIFU therapy delivery and high quality ultrasound imaging using two separate arrays, a multi-channel signal generator and RF amplifier system, and a software program that provides the clinician with a graphical overlay of the ultrasound image and therapeutic protocol controls. Electronic phasing of a 32 element 2 MHz HIFU annular array allows adjusting the focus within the range of about 4 to 12 cm from the face. A central opening in the HIFU transducer permits mounting a commercial medical imaging scanhead (ATL P7-4) that is held in place within a special housing. This mechanical fixture ensures precise coaxial registration between the HIFU transducer and the image plane of the imaging probe. Recent enhancements include development of an acoustic lens using numerical simulations for use with a 5-element array. Our image-guided therapy system is very flexible and enables exploration of a variety of new HIFU therapy delivery and monitoring approaches in the search for safe, effective, and efficient treatment protocols.

Image-guided tumor ablation: proposal for standardization of terms and reporting criteria.

PubMed

Goldberg, S Nahum; Charboneau, J William; Dodd, Gerald D; Dupuy, Damian E; Gervais, Debra A; Gillams, Alice R; Kane, Robert A; Lee, Fred T; Livraghi, Tito; McGahan, John P; Rhim, Hyunchul; Silverman, Stuart G; Solbiati, Luigi; Vogl, Thomas J; Wood, Bradford J

2003-08-01

The field of image-guided tumor ablation requires standardization of terms and reporting criteria to facilitate effective communication of ideas and appropriate comparison between treatments with different technologies, such as chemical ablation (ethanol or acetic acid) and thermal therapies, such as radiofrequency, laser, microwave, ultrasound, and cryoablation. On the basis of this premise, a working committee was established with the goal of producing a proposal on such standardization. The intent of the Working Group is to provide a framework that will facilitate the clearest communication between investigators and will provide the greatest flexibility in comparisons between the many new, exciting, and emerging technologies. The members of the Working Group now propose a vehicle for reporting the various aspects of image-guided ablation therapy, including classifications of therapies and procedures, appropriate descriptors of image guidance, and terms to define imaging and pathologic findings. Methods for standardizing the reporting of follow-up findings and complications and other important aspects that require attention when reporting clinical results are addressed. It is the group's hope and intention that adherence to the recommendations of this proposal will facilitate achievement of the group's main objective: improved precision and communication in this field that lead to more accurate comparison of technologies and results and ultimately to improved patient outcomes. Copyright RSNA, 2003.

Targeted Ultrasound-Guided Perineural Hydrodissection of the Sciatic Nerve for the Treatment of Piriformis Syndrome.

PubMed

Burke, Christopher J; Walter, William R; Adler, Ronald S

2018-05-01

Piriformis syndrome is a common cause of lumbar, gluteal, and thigh pain, frequently associated with sciatic nerve symptoms. Potential etiologies include muscle injury or chronic muscle stretching associated with gait disturbances. There is a common pathological end pathway involving hypertrophy, spasm, contracture, inflammation, and scarring of the piriformis muscle, leading to impingement of the sciatic nerve. Ultrasound-guided piriformis injections are frequently used in the treatment of these pain syndromes, with most of the published literature describing injection of the muscle. We describe a safe, effective ultrasound-guided injection technique for the treatment of piriformis syndrome using targeted sciatic perineural hydrodissection followed by therapeutic corticosteroid injection.

Endobronchial ultrasound-guided transbronchial needle injection for local control of recurrent non-small cell lung cancer.

PubMed

Khan, Farrah; Anker, Christopher J; Garrison, Garth; Kinsey, C Matthew

2015-01-01

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is an established technique for the diagnosis of thoracic malignancies. Non-ultrasound-guided transbronchial needle injection has been used previously to deliver chemotherapeutic agents. To use endobronchial ultrasound-guided transbronchial needle injection (EBUS-TBNI) to achieve local control of recurrent early-stage lung cancer. A 63-year-old man presented with recurrent early stage non-small cell lung carcinoma after chemotherapy and external beam radiation. We used EBUS-TBNI to deliver cisplatin into the tumor located outside the airway. This procedure was performed on three separate occasions without complication. EBUS-TBNI resulted in resolution of fluorodeoxyglucose avidity, measured by positron emission tomography-computed tomography, in the region at 4 weeks. However, at 5 months, there was evidence of distal recurrence. This is the first description of EBUS-TBNI to treat local recurrence of lung cancer and one of the first reports of the use of EBUS for intratumoral therapy. Additional research is warranted to determine the clinical usefulness and safety of this therapeutic approach.

Enhanced Thermal Ablation by Combining Ultrasound Contrast Agents with a Miniature Flat Transducer

NASA Astrophysics Data System (ADS)

Murillo, A.; Goldendstedt, C.; Lafon, C.; Cathignol, D.; Chapelon, J.-Y.

2007-05-01

Miniature transducers can be used for performing interstitial thermal ablation. Increasing the frequency of non-focused transducers enhances energy deposition but limits the therapeutic range. In order to treat extended tumors, new therapeutic strategies must be explored. This work aimed to combine ultrasound contrast agents (UCA) with flat transducers for increasing the treatment depth. The idea consists in increasing attenuation away from the transducer to favor remote heat deposition. Thermal ablation is induced in three steps. 1- Attenuation raises by injecting UCA; 2- Destruction of bubbles next to the transducer by pulsed high intensity bursts, results in a gradient of attenuation; 3- Continuous ultrasound are applied for generating a localized thermal lesion. In vitro tests were performed on temperature-sensitive tissue phantoms in which the UCA BR14 (Bracco) was injected during the liquid phase. The feasibility of the idea was demonstrated in three stages. 1- The coefficient of attenuation was measured with the force balance as a function of the concentration of BR14. For 0.8 and 4.8% attenuation at 10MHz was found to be 0.35 and 1.33 Np/cm respectively. 2- Pulsed ultrasound was applied on phantoms to destroy UCA. Based on the echogenicity decay evidenced on ultrasound images, a 1MPa-pressure was required at 10MHz. 3- Heating beams were applied on phantoms presenting a gradient in attenuation. Lesions were 1.5 times larger than in phantoms with constant attenuation. This study demonstrates that UCA can be selectively destroyed in order to generate a gradient of attenuation and extended thermal lesions.

Accuracy of electromyography needle placement in cadavers: non-guided vs. ultrasound guided.

PubMed

Boon, Andrea J; Oney-Marlow, Theresa M; Murthy, Naveen S; Harper, Charles M; McNamara, Terrence R; Smith, Jay

2011-07-01

Accuracy of needle electromyography is typically ensured by use of anatomical landmarks and auditory feedback related to voluntary activation of the targeted muscle; however, in certain clinical situations, landmarks may not be palpable, auditory feedback may be limited or not present, and targeting a specific muscle may be more critical. In such settings, image guidance might significantly enhance accuracy. Two electromyographers with different levels of experience examined 14 muscles in each of 4 fresh-frozen cadaver lower limbs. Each muscle was tested a total of eight times; four fine wires were inserted without ultrasound (US) guidance and four were inserted under US guidance. Overall accuracy as well as accuracy rates for the individual electromyographers were calculated. Non-guided needle placement was significantly less accurate than US-guided needle placement, particularly in the hands of less experienced electromyographers, supporting the use of real-time US guidance in certain challenging situations in the electromyography laboratory. Copyright © 2011 Wiley Periodicals, Inc.

Custom molded thermal MRg-FUS phantom

NASA Astrophysics Data System (ADS)

Eames, Matthew D. C.; Snell, John W.; Hananel, Arik; Kassell, Neal F.

2012-11-01

This article describes a method for creating custom-molded thermal phantoms for use with MR-guided focused ultrasound systems. The method is defined here for intracranial applications, though it may be modified for other anatomical targets.

A pitfall during endobronchial ultrasound-guided transbronchial forceps biopsy of the mediastinal lymph nodes.

PubMed

Krenke, Rafal; Korczynski, Piotr; Gorska, Katarzyna; Chazan, Ryszarda

2014-03-01

The high diagnostic yield and favorable safety profile of endobronchial ultrasound-guided transbronchial forceps biopsy of the mediastinal lymph nodes have been recently demonstrated. We report an unusual technical problem during endobronchial ultrasound-guided transbronchial forceps biopsy that could be a prerequisite for severe complications. A rupture of the steering band precluded closure of the forceps jaws opened in the subcarinal lymph node. A solution to the problem is presented, together with other procedure-related complications reported in the literature. The report emphasizes that a dysfunction of the forceps steering band can result in severe complications when it occurs during transbronchial sampling of mediastinal lesions. Copyright © 2014 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Polyplex-microbubble hybrids for ultrasound-guided plasmid DNA delivery to solid tumors.

PubMed

Sirsi, Shashank R; Hernandez, Sonia L; Zielinski, Lukasz; Blomback, Henning; Koubaa, Adel; Synder, Milo; Homma, Shunichi; Kandel, Jessica J; Yamashiro, Darrell J; Borden, Mark A

2012-01-30

Microbubble ultrasound contrast agents are being developed as image-guided gene carriers for targeted delivery in vivo. In this study, novel polyplex-microbubbles were synthesized, characterized and evaluated for systemic circulation and tumor transfection. Branched polyethylenimine (PEI; 25 kDa) was modified with polyethylene glycol (PEG; 5 kDa), thiolated and covalently attached to maleimide groups on lipid-coated microbubbles. The PEI-microbubbles demonstrated increasingly positive surface charge and DNA loading capacity with increasing maleimide content. The in vivo ultrasound contrast persistence of PEI-microbubbles was measured in the healthy mouse kidney, and a two-compartment pharmacokinetic model accounting for free and adherent microbubbles was developed to describe the anomalous time-intensity curves. The model suggested that PEI loading dramatically reduced free circulation and increased nonspecific adhesion to the vasculature. However, DNA loading to form polyplex-microbubbles increased circulation in the bloodstream and decreased nonspecific adhesion. PEI-microbubbles coupled to a luciferase bioluminescence reporter plasmid DNA were shown to transfect tumors implanted in the mouse kidney. Site-specific delivery was achieved using ultrasound applied over the tumor area following bolus injection of the DNA/PEI-microbubbles. In vivo imaging showed over 10-fold higher bioluminescence from the tumor region compared to untreated tissue. Ex vivo analysis of excised tumors showed greater than 40-fold higher expression in tumor tissue than non-sonicated control (heart) tissue. These results suggest that the polyplex-microbubble platform offers improved control of DNA loading and packaging suitable for ultrasound-guided tissue transfection. Copyright © 2011 Elsevier B.V. All rights reserved.

Pocket ultrasound device as a complement to physical examination for ascites evaluation and guided paracentesis.

PubMed

Keil-Ríos, Daniel; Terrazas-Solís, Hiram; González-Garay, Alejandro; Sánchez-Ávila, Juan Francisco; García-Juárez, Ignacio

2016-04-01

The pocket ultrasound device (PUD) is a new tool that may be of use in the early detection of ascites. Abdominal ultrasound-guided paracentesis has been reported to decrease the rate of complications due to the procedure, but must be performed in a healthcare setting; this new tool may be a useful on an ambulatory basis. The aim of this study was to determine the diagnostic usefulness of the PUD in the diagnosis of ascites and the safety of guided paracentesis. We conducted a retrospective study that included adult patients suspected of having ascites and in whom an evaluation was performed with the PUD to identify it. Concordance with abdominal ultrasound (AUS) was determined with the Kappa coefficient. Sensitivity (Se), specificity (Sp) and likelihood ratios (LR) were determined and compared with physical examination, AUS, computed tomography and procurement of fluid by paracentesis. Complications resulting from the guided paracentesis were analyzed. 89 participants were included and 40 underwent a paracentesis. The PUD for ascites detection had 95.8 % Se, 81.8 % Sp, 5.27 +LR and 0.05 -LR. It had a concordance with AUS of 0.781 (p < 0.001). Technical problems during the guided paracentesis were present in only two participants (5 %) and three patients (7.5 %) developed minor complications that required no further intervention. There were no severe complications or deaths. This study suggests that the PUD is a reliable tool for ascites detection as a complement to physical examination and appears to be a safe method to perform guided paracentesis.

Pulsed Dose Radiofrequency Before Ablation of Medial Branch of the Lumbar Dorsal Ramus for Zygapophyseal Joint Pain Reduces Post-procedural Pain.

PubMed

Arsanious, David; Gage, Emmanuel; Koning, Jonathon; Sarhan, Mazin; Chaiban, Gassan; Almualim, Mohammed; Atallah, Joseph

2016-01-01

One of the potential side effects with radiofrequency ablation (RFA) includes painful cutaneous dysesthesias and increased pain due to neuritis or neurogenic inflammation. This pain may require the prescription of opioids or non-opioid analgesics to control post-procedural pain and discomfort. The goal of this study is to compare post-procedural pain scores and post-procedural oral analgesic use in patients receiving continuous thermal radiofrequency ablation versus patients receiving pulsed dose radiofrequency immediately followed by continuous thermal radiofrequency ablation for zygopophaseal joint disease. This is a prospective, double-blinded, randomized, controlled trial. Patients who met all the inclusion criteria and were not subject to any of the exclusion criteria were required to have two positive diagnostic medial branch blocks prior to undergoing randomization, intervention, and analysis. University hospital. Eligible patients were randomized in a 1:1 ratio to either receive thermal radiofrequency ablation alone (standard group) or pulsed dose radiofrequency (PDRF) immediately followed by thermal radiofrequency ablation (investigational group), all of which were performed by a single Board Certified Pain Medicine physician. Post-procedural pain levels between the two groups were assessed using the numerical pain Scale (NPS), and patients were contacted by phone on post-procedural days 1 and 2 in the morning and afternoon regarding the amount of oral analgesic medications used in the first 48 hours following the procedure. Patients who received pulsed dose radiofrequency followed by continuous radiofrequency neurotomy reported statistically significantly lower post-procedural pain scores in the first 24 hours compared to patients who received thermal radiofrequency neurotomy alone. These patients also used less oral analgesic medication in the post-procedural period. These interventions were carried out by one board accredited pain physician at one

A serious game for learning ultrasound-guided needle placement skills.

PubMed

Chan, Wing-Yin; Qin, Jing; Chui, Yim-Pan; Heng, Pheng-Ann

2012-11-01

Ultrasound-guided needle placement is a key step in a lot of radiological intervention procedures such as biopsy, local anesthesia and fluid drainage. To help training future intervention radiologists, we develop a serious game to teach the skills involved. We introduce novel techniques for realistic simulation and integrate game elements for active and effective learning. This game is designed in the context of needle placement training based on the some essential characteristics of serious games. Training scenarios are interactively generated via a block-based construction scheme. A novel example-based texture synthesis technique is proposed to simulate corresponding ultrasound images. Game levels are defined based on the difficulties of the generated scenarios. Interactive recommendation of desirable insertion paths is provided during the training as an adaptation mechanism. We also develop a fast physics-based approach to reproduce the shadowing effect of needles in ultrasound images. Game elements such as time-attack tasks, hints and performance evaluation tools are also integrated in our system. Extensive experiments are performed to validate its feasibility for training.

Long-term follow-up of ultrasound-guided botulinum toxin-A injections for sialorrhea in neurological dysphagia.

PubMed

Barbero, Pierangelo; Busso, Marco; Tinivella, Marco; Artusi, Carlo Alberto; De Mercanti, Stefania; Cucci, Angele; Veltri, Andrea; Avagnina, Paolo; Calvo, Andrea; Chio', Adriano; Durelli, Luca; Clerico, Marinella

2015-12-01

Literature provides reports only of a limited follow-up single injection of botulinum toxin-A (BoNT-A) in patients with sialorrhea. The aim of our study is to evaluate the long-lasting efficacy and safety of ultrasound-guided BoNT-A injections for severe sialorrhea secondary to neurological dysphagia. We enrolled 38 severe adult sialorrhea patients referred consecutively to the neurology unit and performed bilateral parotid and submandibular gland BoNT-A injections under ultrasound guidance. The outcomes of the study were reduction of sialorrhea, duration of therapeutic effect, and subjective patient- and caregiver-reported satisfaction. A total of 113 BoNT-A administrations were given during the study period with a mean duration of follow-up of 20.2 ± 4.4 months. We observed a significant decrease from baseline in mean number of daily aspirations and a significant improvement in patient- and caregiver-reported outcomes following ultrasound-guided BoNT-A injections (p < 0.001 vs baseline for all comparisons) and the mean duration of the efficacy was 5.6 ± 1 months. No major treatment-related adverse events occurred and a low incidence of minor adverse events was reported. This study confirms the long-lasting efficacy and safety of ultrasound-guided BoNT-A injections for sialorrhea, regardless of the causative neurological disorder. These results should encourage the use of BoNT-A in the treatment of severe sialorrhea and highlight the role of ultrasound guidance to obtain optimal results in terms of safety and reproducible outcomes.

Review of temperature dependence of thermal properties, dielectric properties, and perfusion of biological tissues at hyperthermic and ablation temperatures.

PubMed

Rossmanna, Christian; Haemmerich, Dieter

2014-01-01

The application of supraphysiological temperatures (>40°C) to biological tissues causes changes at the molecular, cellular, and structural level, with corresponding changes in tissue function and in thermal, mechanical and dielectric tissue properties. This is particularly relevant for image-guided thermal treatments (e.g. hyperthermia and thermal ablation) delivering heat via focused ultrasound (FUS), radiofrequency (RF), microwave (MW), or laser energy; temperature induced changes in tissue properties are of relevance in relation to predicting tissue temperature profile, monitoring during treatment, and evaluation of treatment results. This paper presents a literature survey of temperature dependence of electrical (electrical conductivity, resistivity, permittivity) and thermal tissue properties (thermal conductivity, specific heat, diffusivity). Data of soft tissues (liver, prostate, muscle, kidney, uterus, collagen, myocardium and spleen) for temperatures between 5 to 90°C, and dielectric properties in the frequency range between 460 kHz and 3 GHz are reported. Furthermore, perfusion changes in tumors including carcinomas, sarcomas, rhabdomyosarcoma, adenocarcinoma and ependymoblastoma in response to hyperthmic temperatures up to 46°C are presented. Where appropriate, mathematical models to describe temperature dependence of properties are presented. The presented data is valuable for mathematical models that predict tissue temperature during thermal therapies (e.g. hyperthermia or thermal ablation), as well as for applications related to prediction and monitoring of temperature induced tissue changes.

Review of temperature dependence of thermal properties, dielectric properties, and perfusion of biological tissues at hyperthermic and ablation temperatures

PubMed Central

Rossmann, Christian; Haemmerich, Dieter

2016-01-01

The application of supraphysiological temperatures (>40°C) to biological tissues causes changes at the molecular, cellular, and structural level, with corresponding changes in tissue function and in thermal, mechanical and dielectric tissue properties. This is particularly relevant for image-guided thermal treatments (e.g. hyperthermia and thermal ablation) delivering heat via focused ultrasound (FUS), radiofrequency (RF), microwave (MW), or laser energy; temperature induced changes in tissue properties are of relevance in relation to predicting tissue temperature profile, monitoring during treatment, and evaluation of treatment results. This paper presents a literature survey of temperature dependence of electrical (electrical conductivity, resistivity, permittivity) and thermal tissue properties (thermal conductivity, specific heat, diffusivity). Data of soft tissues (liver, prostate, muscle, kidney, uterus, collagen, myocardium and spleen) for temperatures between 5 to 90°C, and dielectric properties in the frequency range between 460 kHz and 3 GHz are reported. Furthermore, perfusion changes in tumors including carcinomas, sarcomas, rhabdomyosarcoma, adenocarcinoma and ependymoblastoma in response to hyperthmic temperatures up to 46°C are presented. Where appropriate, mathematical models to describe temperature dependence of properties are presented. The presented data is valuable for mathematical models that predict tissue temperature during thermal therapies (e.g. hyperthermia or thermal ablation), as well as for applications related to prediction and monitoring of temperature induced tissue changes. PMID:25955712

Thermal contribution of compact bone to intervening tissue-like media exposed to planar ultrasound

NASA Astrophysics Data System (ADS)

Moros, Eduardo G.; Novak, Petr; Straube, William L.; Kolluri, Prashant; Yablonskiy, Dmitriy A.; Myerson, Robert J.

2004-03-01

The presence of bone in the ultrasound beam path raises concerns, both in diagnostic and therapeutic applications, because significant temperature elevations may be induced at nearby soft tissue-bone interfaces due the facts that ultrasound is (i) highly absorbed in bone and (ii) reflected at soft tissue-bone interfaces in various degrees depending on angle of incidence. Consequently, in ultrasonic thermal therapy, the presence of bone in the ultrasound beam path is considered a major disadvantage and it is usually avoided. However, based on clinical experience and previous theoretical studies, we hypothesized that the presence of bone in superficial unfocused ultrasound hyperthermia can actually be exploited to induce more uniform and enhanced (with respect to the no-bone situation) temperature distributions in superficial target volumes. In particular, we hypothesize that the presence of underlying bone in superficial target volume enhances temperature elevation not only by additional direct power deposition from acoustic reflection, but also from thermal diffusion from the underlying bone. Here we report laboratory results that corroborate previous computational studies and strengthen the above-stated hypothesis. Three different temperature measurement techniques, namely, thermometric (using fibre-optic temperature probes), thermographic (using an infrared camera) and magnetic resonance imaging (using proton resonance frequency shifts), were used in high-power short-exposure, and in low-power extended-exposure, experiments using a 19 mm diameter planar transducer operating at 1.0 and 3.3 MHz (frequencies of clinical relevance). The measurements were performed on three technique-specific phantoms (with and without bone inclusions) and experimental set-ups that resembled possible superficial ultrasound hyperthermia clinical situations. Results from all three techniques were in general agreement and clearly showed that significantly higher heating rates (greater

Effectiveness of imaging-guided intra-articular injection: a comparison study between fluoroscopy and ultrasound.

PubMed

Furtado, Rita Nely Vilar; Pereira, Daniele Freitas; da Luz, Karine Rodrigues; dos Santos, Marla Francisca; Konai, Monique Sayuri; Mitraud, Sonia de Aguiar Vilela; Rosenfeld, Andre; Fernandes, Artur da Rocha Correa; Natour, Jamil

2013-01-01

Compare the effectiveness of ultrasound and fluoroscopy to guide intra-articular injections (IAI) in selected cases. A prospective study in our outpatient clinics at the Rheumatology Division at Universidade Federal de São Paulo (UNIFESP), Brazil, was conducted to compare the short-term (4 weeks) effectiveness of ultrasound and fluoroscopy-guided IAI in patients with rheumatic diseases. Inclusion criteria were: adults with refractory synovitis undergoing IAI with glucocorticoid. All patients had IAI performed with triamcinolone hexacetonide (20mg/ml) with varying doses according to the joint injected. A total of 71 rheumatic patients were evaluated (52 women, 44 whites). Mean age was 51.9 ± 13 years and 47 of them (66.2%) were on regular DMARD use. Analysis of the whole sample (71 patients) and hip sub-analysis (23 patients) showed that significant improvement was observed for both groups in terms of pain (P < 0.001). Global analysis also demonstrated better outcomes for patients in the FCG in terms of joint flexion (P < 0.001) and percentage change in joint flexion as compared to the USG. Likert scale score analyses demonstrated better results for the patients in the USG as compared to the FCG at the end of the study (P < 0.05). No statistically significant difference between groups was observed for any other study variable. Imaging-guided IAI improves regional pain in patients with various types of synovitis in the short term. For the vast majority of variables, no significant difference in terms of effectiveness was observed between fluoroscopy and ultrasound guided IAI.

Laser-enhanced thermal effect of moderate intensity focused ultrasound on bio-tissues

NASA Astrophysics Data System (ADS)

Zhao, JinYu; Zhang, ShuYi; Shui, XiuJi; Fan, Li

2017-09-01

For avoiding extra-damage to healthy tissues surrounding the focal point during high intensity focused ultrasound (HIFU) treatment in medical therapy, to reduce the ultrasonic intensity outside the focal point is expected. Thus, the heating processes induced by moderate intensity focused ultrasound (MIFU) and enhanced by combined irradiation of laser pulses for bio-tissues are studied in details. For fresh bio-tissues, the enhanced thermal effects by pulsed laser combined with MIFU irradiation are observed experimentally. To explore the mechanisms of these effects, several tissue-mimicking materials composed of agar mixed with graphite powders are prepared and studied for comparison, but the laser-enhanced thermal effects in these mimicking materials are much less than that in the fresh bio-tissues. Therefore, it is suggested that the laser-enhanced thermal effects may be mainly attributed to bio-activities and related photo-bio-chemical effects of fresh tissues.

Stereo electroencephalography-guided radiofrequency thermocoagulation (SEEG-guided RF-TC) in drug-resistant focal epilepsy: Results from a 10-year experience.

PubMed

Bourdillon, Pierre; Isnard, Jean; Catenoix, Hélène; Montavont, Alexandra; Rheims, Sylvain; Ryvlin, Philippe; Ostrowsky-Coste, Karine; Mauguiere, François; Guénot, Marc

2017-01-01

Stereo electroencephalography (SEEG)-guided radiofrequency thermocoagulation (SEEG-guided RF-TC) has been proposed since 2004 as a possible treatment of some focal drug-resistant epilepsy. The aim of this study is to provide extensive data about efficacy and safety of SEEG-guided RF-TC. Over a 10-year period, 162 patients with drug-resistant focal epilepsy were eligible for SEEG-guided RF-TG during phase II invasive investigation by SEEG. All follow-up and safety data were collected prospectively. The primary outcome was seizure freedom at 2 months and at 1 year after SEEG-guided RF-TC. Secondary outcomes were the responders' rate (patient with at least 50% decrease in seizure frequency) and their long-term follow-up. Twenty-five percent of patients were seizure-free at 2 months and 7% at 1 year. We reported 67% of responders at 2 months and 48% at 1 year; 58% of responders maintained their status during the long-term follow-up. The seizure outcome was significantly better when the SEEG-guided RF-TC involved the occipital region (p = 0.007). When surgery followed an SEEG-guided RF-TC, the positive predictive value of being a responder 2 months after an SEEG-guided RF-TC and to be Engel's class I or II after surgery was 93%. We reported 1.1% of permanent deficit and 2.4% of transient side effects. Our results, gathered in a large population over a 10-year period, confirm that SEEG-guided RF-TC is a safe technique, being efficient in many cases. More than two thirds of patients showed a short-term improvement, and almost half of them were responders at 1-year follow-up. The technique appears to be especially interesting for limited epileptic zone inaccessible to surgery and when epilepsy is related to a large unilateral network (network disruption by multiple RF-TC). Furthermore, SEEG-guided RF-TC effect is a predictor of outcome after conventional cortectomy in patients eligible for surgery. Wiley Periodicals, Inc. © 2016 International League Against Epilepsy.

Value of artisanal simulators to train veterinary students in performing invasive ultrasound-guided procedures.

PubMed

Hage, Maria Cristina F N S; Massaferro, Ana Beatriz; Lopes, Érika Rondon; Beraldo, Carolina Mariano; Daniel, Jéssika

2016-03-01

Pericardial effusion can lead to cardiac tamponade, which endangers an animal's life. Ultrasound-guided pericardiocentesis is used to remove abnormal liquid; however, it requires technical expertise. In veterinary medical education, the opportunity to teach this procedure to save lives during emergencies is rare; therefore, simulators are recommended for this practice. The present study aimed to create a model that can be made "at home" at low cost for ultrasound-guided pericardiocentesis training and to gather feedback about this model through questionnaires given to the participants. Eighteen professionals and thirty-six students were introduced to the simulator in pairs. After the simulation training session, participants filled out the questionnaire. Participants considered the model strong in the following areas: visualization of the pericardium, the heart, fluid in the pericardium, and fluid decrease during fictitious pericardiocentesis and its realism. They considered the model weak or moderate in the following areas: visualization of the surrounding tissues, difficulty of pericardial puncture, and visualization of the catheter. The professionals classified the realism of the experimental heart as moderate, whereas the undergraduate students classified it as strong. All participants believed that the experimental model could be useful in preparing for a future real situation. This model fulfills the need for a practical, realistic, and cost-effective model for ultrasound-guided pericardiocentesis training. Copyright © 2016 The American Physiological Society.

Adaptive model-predictive controller for magnetic resonance guided focused ultrasound therapy.

PubMed

de Bever, Joshua; Todd, Nick; Payne, Allison; Christensen, Douglas A; Roemer, Robert B

2014-11-01

Minimising treatment time and protecting healthy tissues are conflicting goals that play major roles in making magnetic resonance image-guided focused ultrasound (MRgFUS) therapies clinically practical. We have developed and tested in vivo an adaptive model-predictive controller (AMPC) that reduces treatment time, ensures safety and efficacy, and provides flexibility in treatment set-up. The controller realises time savings by modelling the heated treatment cell's future temperatures and thermal dose accumulation in order to anticipate the optimal time to switch to the next cell. Selected tissues are safeguarded by a configurable temperature constraint. Simulations quantified the time savings realised by each controller feature as well as the trade-offs between competing safety and treatment time parameters. In vivo experiments in rabbit thighs established the controller's effectiveness and reliability. In all in vivo experiments the target thermal dose of at least 240 CEM43 was delivered everywhere in the treatment volume. The controller's temperature safety limit reliably activated and constrained all protected tissues to <9 CEM43. Simulations demonstrated the path independence of the controller, and that a path which successively proceeds to the hottest untreated neighbouring cell leads to significant time savings, e.g. when compared to a concentric spiral path. Use of the AMPC produced a compounding time-saving effect; reducing the treatment cells' heating times concurrently reduced heating of normal tissues, which eliminated cooling periods. Adaptive model-predictive control can automatically deliver safe, effective MRgFUS treatments while significantly reducing treatment times.

Evaluation of a Standardized Program for Training Practicing Anesthesiologists in Ultrasound-Guided Regional Anesthesia Skills.

PubMed

Mariano, Edward R; Harrison, T Kyle; Kim, T Edward; Kan, Jack; Shum, Cynthia; Gaba, David M; Ganaway, Toni; Kou, Alex; Udani, Ankeet D; Howard, Steven K

2015-10-01

Practicing anesthesiologists have generally not received formal training in ultrasound-guided perineural catheter insertion. We designed this study to determine the efficacy of a standardized teaching program in this population. Anesthesiologists in practice for 10 years or more were recruited and enrolled to participate in a 1-day program: lectures and live-model ultrasound scanning (morning) and faculty-led iterative practice and mannequin-based simulation (afternoon). Participants were assessed and recorded while performing ultrasound-guided perineural catheter insertion at baseline, at midday (interval), and after the program (final). Videos were scored by 2 blinded reviewers using a composite tool and global rating scale. Participants were surveyed every 3 months for 1 year to report the number of procedures, efficacy of teaching methods, and implementation obstacles. Thirty-two participants were enrolled and completed the program; 31 of 32 (97%) completed the 1-year follow-up. Final scores [median (10th-90th percentiles)] were 21.5 (14.5-28.0) of 30 points compared to 14.0 (9.0-20.0) at interval (P < .001 versus final) and 12.0 (8.5-17.5) at baseline (P < .001 versus final), with no difference between interval and baseline. The global rating scale showed an identical pattern. Twelve of 26 participants without previous experience performed at least 1 perineural catheter insertion after training (P < .001). However, there were no differences in the monthly average number of procedures or complications after the course when compared to baseline. Practicing anesthesiologists without previous training in ultrasound-guided regional anesthesia can acquire perineural catheter insertion skills after a 1-day standardized course, but changing clinical practice remains a challenge. © 2015 by the American Institute of Ultrasound in Medicine.

Enhancing laser thermal-therapy using ultrasound-microbubbles and gold nanorods: In vitro investigation

NASA Astrophysics Data System (ADS)

Tarapacki, Christine; Kumaradas, Carl; Karshafian, Raffi

2012-11-01

Gold nanorods (GNR) in laser-induced thermal therapy can significantly increase light absorption, leading to a local temperature increase and causing irreversible cell damage. One of the key challenges in using GNR as a thermal therapy agent is to deliver a concentration of GNR to generate sufficient heat and cause cell death. In this study, ultrasound and microbubble induced sonoporation is used to enhance intracellular uptake of GNR and improve the therapeutic outcome of laserinduced thermal therapy. Acute myeloid leukemia (AML) cells in suspension (0.6 mL) were treated with ultrasound and microbubbles (USMB) at 1 MHz frequency, 16 microseconds pulse duration, 1 kHz pulse repetition frequency, 1 minute insonation time, varying acoustic pressures (0, 1.26 and 1.73 MPa) and 10 μL Definity microbubble agent with and without GNR (12 nm × 48 nm) at varying concentration (1.0×1010 to 2.5×1011 GNR/mL). The GNR were manufactured through wet chemical synthesis process and measured using Transmission Electron Microscopy (TEM) and Atomic Absorption Spectroscopy (AAS) for size and concentration respectively. Following ultrasound and microbubble treatment, cells were centrifuged to remove excess gold nanorods and treated in suspension with an 810 nm laser (Diomed 60 NIR) at 4 W for 5 minutes. A thermal camera (FLIR Thermovision A40) was positioned to monitor the sample temperature throughout laser treatment and cell viability was assessed using flow cytometry with propidium iodide. Cell viability of 18±2% was achieved with GNR+USMB (1.26 MPa) compared to 72±3% with GNR alone (12 hour incubation) and 99±0.2% with USMB (1.26 MPa) alone. With increasing GNR concentration during ultrasound and microbubble treatment, laser induced sample temperature increased and consequently cell viability decreased. Cell viability decreased from 92±1% at 1.0×1011 GNR/mL to 29±5% at 1.5×1011 GNR/mL concentration with corresponding maximum temperatures of 50°C and 54°C, respectively

Development of a 3D ultrasound-guided prostate biopsy system

NASA Astrophysics Data System (ADS)

Cool, Derek; Sherebrin, Shi; Izawa, Jonathan; Fenster, Aaron

2007-03-01

Biopsy of the prostate using ultrasound guidance is the clinical gold standard for diagnosis of prostate adenocarinoma. However, because early stage tumors are rarely visible under US, the procedure carries high false-negative rates and often patients require multiple biopsies before cancer is detected. To improve cancer detection, it is imperative that throughout the biopsy procedure, physicians know where they are within the prostate and where they have sampled during prior biopsies. The current biopsy procedure is limited to using only 2D ultrasound images to find and record target biopsy core sample sites. This information leaves ambiguity as the physician tries to interpret the 2D information and apply it to their 3D workspace. We have developed a 3D ultrasound-guided prostate biopsy system that provides 3D intra-biopsy information to physicians for needle guidance and biopsy location recording. The system is designed to conform to the workflow of the current prostate biopsy procedure, making it easier for clinical integration. In this paper, we describe the system design and validate its accuracy by performing an in vitro biopsy procedure on US/CT multi-modal patient-specific prostate phantoms. A clinical sextant biopsy was performed by a urologist on the phantoms and the 3D models of the prostates were generated with volume errors less than 4% and mean boundary errors of less than 1 mm. Using the 3D biopsy system, needles were guided to within 1.36 +/- 0.83 mm of 3D targets and the position of the biopsy sites were accurately localized to 1.06 +/- 0.89 mm for the two prostates.

Ultrasound-Guided Intermediate Site Greater Occipital Nerve Infiltration: A Technical Feasibility Study.

PubMed

Zipfel, Jonathan; Kastler, Adrian; Tatu, Laurent; Behr, Julien; Kechidi, Rachid; Kastler, Bruno

2016-01-01

Two studies recently reported that computed tomography (CT) guided infiltration of the greater occipital nerve at its intermediate site allows a high efficacy rate with long-lasting pain relief following procedure in occipital neuralgia and in various craniofacial pain syndromes. The purpose of our study was to evaluate the technical feasibility and safety of ultrasound-guided intermediate site greater occipital nerve infiltration. Retrospective study. This study was conducted at the imaging department of a 1,409 bed university hospital. Local institutional review board approval was obtained and written consent was waived. In this retrospective study, 12 patients suffering from refractory occipital neuralgia or craniofacial pain syndromes were included between April and October 2014. They underwent a total of 21 ultrasound-guided infiltrations. Infiltration of the greater occipital nerve was performed at the intermediate site of the greater occipital nerve, at its first bend between obliqus capitis inferior and semispinalis capitis muscles with local anestetics and cortivazol. Technical success was defined as satisfactory diffusion of added iodinated contrast media in the fatty space between these muscles depicted on control CT scan. We also reported first data of immediate block test efficacy and initial clinical efficacy at 7 days, one month, and 3 months, defined by a decrease of at least 50% of visual analog scale (VAS) scores. Technical success rate was 95.24%. Patients suffered from right unilateral occipital neuralgia in 3 cases, left unilateral occipital neuralgia in 2 cases, bilateral occipital neuralgia in 2 cases, migraine in one case, cervicogenic headache in one case, tension-type headache in 2 cases, and cluster headache in one case. Block test efficacy was found in 93.3% (14/15) cases. Clinical efficacy was found in 80% of cases at 7 days, in 66.7% of cases at one month and in 60% of cases at 3 months. No major complications were noted. Some of the

Ultrasound-guided versus computed tomography-scan guided biopsy of pleural-based lung lesions

PubMed Central

Khosla, Rahul; McLean, Anna W; Smith, Jessica A

2016-01-01

Background: Computed tomography (CT) guided biopsies have long been the standard technique to obtain tissue from the thoracic cavity and is traditionally performed by interventional radiologists. Ultrasound (US) guided biopsy of pleural-based lesions, performed by pulmonologists is gaining popularity and has the advantage of multi-planar imaging, real-time technique, and the absence of radiation exposure to patients. In this study, we aim to determine the diagnostic accuracy, the time to diagnosis after the initial consult placement, and the complications rates between the two different modalities. Methods: A retrospective study of electronic medical records was done of patients who underwent CT-guided biopsies and US-guided biopsies for pleural-based lesions between 2005 and 2014 and the data collected were analyzed for comparing the two groups. Results: A total of 158 patients underwent 162 procedures during the study period. 86 patients underwent 89 procedures in the US group, and 72 patients underwent 73 procedures in the CT group. The overall yield in the US group was 82/89 (92.1%) versus 67/73 (91.8%) in the CT group (P = 1.0). Average days to the procedure was 7.2 versus 17.5 (P = 0.00001) in the US and CT group, respectively. Complication rate was higher in CT group 17/73 (23.3%) versus 1/89 (1.1%) in the US group (P < 0.0001). Conclusions: For pleural-based lesions the diagnostic accuracy of US guided biopsy is similar to that of CT-guided biopsy, with a lower complication rate and a significantly reduced time to the procedure. PMID:27625440

Models to teach lung sonopathology and ultrasound-guided thoracentesis.

PubMed

Wojtczak, Jacek A

2014-12-01

Lung sonography allows rapid diagnosis of lung emergencies such as pulmonary edema, hemothorax or pneumothorax. The ability to timely diagnose an intraoperative pneumothorax is an important skill for the anesthesiologist. However, lung ultrasound exams require an interpretation of not only real images but also complex acoustic artifacts such as A-lines and B-lines. Therefore, appropriate training to gain proficiency is important. Simulated environment using ultrasound phantom models allows controlled, supervised learning. We have developed hybrid models that combine dry or wet polyurethane foams, porcine rib cages and human hand simulating a rib cage. These models simulate fairly accurately pulmonary sonopathology and allow supervised teaching of lung sonography with the immediate feedback. In-vitro models can also facilitate learning of procedural skills, improving transducer and needle positioning and movement, rapid recognition of thoracic anatomy and hand - eye coordination skills. We described a new model to teach an ultrasound guided thoracentesis. This model consists of the experimenter's hand placed on top of the water-filled container with a wet foam. Metacarpal bones of the human hand simulate a rib cage and a wet foam simulates a diseased lung immersed in the pleural fluid. Positive fluid flow offers users feedback when a simulated pleural effusion is accurately assessed.

Tracked 3D ultrasound in radio-frequency liver ablation

NASA Astrophysics Data System (ADS)

Boctor, Emad M.; Fichtinger, Gabor; Taylor, Russell H.; Choti, Michael A.

2003-05-01

Recent studies have shown that radio frequency (RF) ablation is a simple, safe and potentially effective treatment for selected patients with liver metastases. Despite all recent therapeutic advancements, however, intra-procedural target localization and precise and consistent placement of the tissue ablator device are still unsolved problems. Various imaging modalities, including ultrasound (US) and computed tomography (CT) have been tried as guidance modalities. Transcutaneous US imaging, due to its real-time nature, may be beneficial in many cases, but unfortunately, fails to adequately visualize the tumor in many cases. Intraoperative or laparoscopic US, on the other hand, provides improved visualization and target imaging. This paper describes a system for computer-assisted RF ablation of liver tumors, combining navigational tracking of a conventional imaging ultrasound probe to produce 3D ultrasound imaging with a tracked RF ablation device supported by a passive mechanical arm and spatially registered to the ultrasound volume.

Dual-mode transducers for ultrasound imaging and thermal therapy.

PubMed

Owen, N R; Chapelon, J Y; Bouchoux, G; Berriet, R; Fleury, G; Lafon, C

2010-02-01

Medical imaging is a vital component of high intensity focused ultrasound (HIFU) therapy, which is gaining clinical acceptance for tissue ablation and cancer therapy. Imaging is necessary to plan and guide the application of therapeutic ultrasound, and to monitor the effects it induces in tissue. Because they can transmit high intensity continuous wave ultrasound for treatment and pulsed ultrasound for imaging, dual-mode transducers aim to improve the guidance and monitoring stages. Their primary advantage is implicit registration between the imaging and treatment axes, and so they can help ensure before treatment that the therapeutic beam is correctly aligned with the planned treatment volume. During treatment, imaging signals can be processed in real-time to assess acoustic properties of the tissue that are related to thermal ablation. Piezocomposite materials are favorable for dual-mode transducers because of their improved bandwidth, which in turn improves imaging performance while maintaining high efficiency for treatment. Here we present our experiences with three dual-mode transducers for interstitial applications. The first was an 11-MHz monoelement designed for use in the bile duct. It had a 25x7.5 mm(2) aperture that was cylindrically focused to 10mm. The applicator motion was step-wise rotational for imaging and therapy over a 360 degrees, or smaller, sector. The second transducer had 5-elements, each measuring 3.0x3.8 mm(2) for a total aperture of 3.0x20 mm(2). It operated at 5.6 MHz, was cylindrically focused to 14 mm, and was integrated with a servo-controlled oscillating probe designed for sector imaging and directive therapy in the liver. The last transducer was a 5-MHz, 64-element linear array designed for beam-formed imaging and therapy. The aperture was 3.0x18 mm(2) with a pitch of 0.280 mm. Characterization results included conversion efficiencies above 50%, pulse-echo bandwidths above 50%, surface intensities up to 30 W/cm(2), and axial imaging

PERCUTANEOUS RADIOFREQUENCY ASSISTED LIVER PARTITION WITH PORTAL VEIN EMBOLIZATION FOR STAGED HEPATECTOMY (PRALPPS).

PubMed

Giménez, Mariano E; Houghton, Eduardo J; Davrieux, C Federico; Serra, Edgardo; Pessaux, Patrick; Palermo, Mariano; Acquafresca, Pablo A; Finger, Caetano; Dallemagne, Bernard; Marescaux, Jacques

2018-03-01

When a major hepatic resection is necessary, sometimes the future liver remnant is not enough to maintain sufficient liver function and patients are more likely to develop liver failure after surgery. To test the hypothesis that performing a percutaneous radiofrecuency liver partition plus percutaneous portal vein embolization (PRALPPS) for stage hepatectomy in pigs is feasible. Four pigs (Sus scrofa domesticus) both sexes with weights between 25 to 35 kg underwent percutaneous portal vein embolization with coils of the left portal vein. By contrasted CT, the difference between the liver parenchyma corresponding to the embolized zone and the normal one was identified. Immediately, using the fusion of images between ultrasound and CT as a guide, radiofrequency needles were placed percutaneouslyand then ablated until the liver partition was complete. Finally, hepatectomy was completed with a laparoscopic approach. All animals have survived the procedures, with no reported complications. The successful portal embolization process was confirmed both by portography and CT. In the macroscopic analysis of the pieces, the depth of the ablation was analyzed. The hepatic hilum was respected. On the other hand, the correct position of the embolization material on the left portal vein could be also observed. "Percutaneous radiofrequency assisted liver partition with portal vein embolization" (PRALLPS) is a feasible procedure.

Thermal Field Imaging Using Ultrasound

NASA Technical Reports Server (NTRS)

Andereck, D.; Rahal, S.; Fife, S.

2000-01-01

It is often desirable to be able to determine the temperature field in the interiors of opaque fluids forced into convection by externally imposed temperature gradients. To measure the temperature at a point in an opaque fluid in the usual fashion requires insertion of a probe, and to determine the full field therefore requires either the ability to move this probe or the introduction of multiple probes. Neither of these solutions is particularly satisfactory, although they can lead to quite accurate measurements. As an alternative we have investigated the use of ultrasound as a relatively non-intrusive probe of the temperature field in convecting opaque fluids. The temperature dependence of the sound velocity can be sufficiently great to permit a determination of the temperature from timing the traversal of an ultrasound pulse across a chamber. In this paper we will present our results on convecting flows of transparent and opaque fluids. Our experimental cells consist of relatively narrow rectangular cavities made of thermally insulating materials on the sides, and metal top and bottom plates. The ultrasound transducer is powered by a pulser/receiver, the signal output of which goes to a very high speed signal averager. The average of several hundred to several thousand signals is then sent to a computer for storage and analysis. The experimental procedure is to establish a convective flow by imposing a vertical temperature gradient on the chamber, and then to measure, at several regularly spaced locations, the transit time for an ultrasound pulse to traverse the chamber horizontally (parallel to the convecting rolls) and return to the transducer. The transit time is related to the temperature of the fluid through which the sound pulse travels. Knowing the relationship between transit time and temperature (determined in a separate experiment), we can extract the average temperature across the chamber at that location. By changing the location of the transducer it

Thermal and mechanical high-intensity focused ultrasound: perspectives on tumor ablation, immune effects and combination strategies.

PubMed

van den Bijgaart, Renske J E; Eikelenboom, Dylan C; Hoogenboom, Martijn; Fütterer, Jurgen J; den Brok, Martijn H; Adema, Gosse J

2017-02-01

Tumor ablation technologies, such as radiofrequency-, cryo- or high-intensity focused ultrasound (HIFU) ablation will destroy tumor tissue in a minimally invasive manner. Ablation generates large volumes of tumor debris in situ, releasing multiple bio-molecules like tumor antigens and damage-associated molecular patterns. To initiate an adaptive antitumor immune response, antigen-presenting cells need to take up tumor antigens and, following activation, present them to immune effector cells. The impact of the type of tumor ablation on the precise nature, availability and suitability of the tumor debris for immune response induction, however, is poorly understood. In this review, we focus on immune effects after HIFU-mediated ablation and compare these to findings using other ablation technologies. HIFU can be used both for thermal and mechanical destruction of tissue, inducing coagulative necrosis or subcellular fragmentation, respectively. Preclinical and clinical results of HIFU tumor ablation show increased infiltration and activation of CD4 + and CD8 + T cells. As previously observed for other types of tumor ablation technologies, however, this ablation-induced enhanced infiltration alone appears insufficient to generate consistent protective antitumor immunity. Therapies combining ablation with immune stimulation are therefore expected to be key to boost HIFU-induced immune effects and to achieve systemic, long-lasting, antitumor immunity.

Ultrasound-guided core needle biopsy in diagnosis of abdominal and pelvic neoplasm in pediatric patients.

PubMed

Wang, Hailing; Li, Fangxuan; Liu, Juntian; Zhang, Sheng

2014-01-01

Ultrasound-guided core needle biopsy of abdominal and pelvic masses in adults has gained tremendous popularity. However, the application of the same treatment in children is not as popular because of apprehensions regarding inadequate tissues for the biopsy and accidental puncture of vital organs. Data of the application of ultrasound-guided core needle biopsy in 105 pediatric patients with clinically or ultrasound-diagnosed abdominopelvic masses were reviewed. Diagnostic procedures were conducted in our institution from May 2011 to May 2013. The biopsies were conducted on 86 malignant lesions and 19 benign lesions. 86 malignant tumors comprised neuroblastomas (30 cases), hepatoblastomas (15 cases), nephroblastomas (11 cases), and primitive neuroectodermal tumors/malignant small round cells (6 cases). Among malignant tumor cases, only a pelvic primitive neuroectodermal tumor did not receive a pathological diagnosis. Therefore, the biopsy accuracy was 98.8 % in malignant tumor. However, the biopsies for one neuroblastomas and one malignant small round cell tumor were inadequate for cytogenetic analysis. Therefore, 96.5 % of the malignant tumor patients received complete diagnosis via biopsy. 19 benign tumors comprised mature teratoma (10 cases), hemangioendothelioma (3 cases), paraganglioma (2 cases), and infection (2 cases). The diagnostic accuracy for benign neoplasm was 100 %. Five patients experienced postoperative complications, including pain (2 patients), bleeding from the biopsy site (2 patients), and wound infection (1 patient). Ultrasound-guided core needle biopsy is an efficient, minimally invasive, accurate, and safe diagnostic method that can be applied in the management of abdominal or pelvic mass of pediatric patients.

[MR-guided focused ultrasound. Current and future applications].

PubMed

Trumm, C G; Napoli, A; Peller, M; Clevert, D-A; Stahl, R; Reiser, M; Matzko, M

2013-03-01

High-intensity focused ultrasound (synonyms FUS and HIFU) under magnetic resonance imaging (MRI) guidance (synonyms MRgFUS and MR-HIFU) is a completely non-invasive technology for accurate thermal ablation of a target tissue while neighboring tissues and organs are preserved. The combination of FUS with MRI for planning, (near) real-time monitoring and outcome assessment of treatment markedly enhances the safety of the procedure. The MRgFUS procedure is clinically established in particular for the treatment of symptomatic uterine fibroids, followed by palliative ablation of painful bone metastases. Furthermore, promising results have been shown for the treatment of adenomyosis, malignant tumors of the prostate, breast and liver and for various intracranial applications, such as thermal ablation of brain tumors, functional neurosurgery and transient disruption of the blood-brain barrier.

Dual-mode ultrasound arrays for image-guided targeting of atheromatous plaques

NASA Astrophysics Data System (ADS)

Ballard, John R.; Casper, Andrew J.; Liu, Dalong; Haritonova, Alyona; Shehata, Islam A.; Troutman, Mitchell; Ebbini, Emad S.

2012-11-01

A feasibility study was undertaken in order to investigate alternative noninvasive treatment options for atherosclerosis. In particular, the aim of this study was to investigate the potential use of Dual-Mode Ultrasound Arrays (DMUAs) for image guided treatment of atheromatous plaques. DMUAs offer a unique treatment paradigm for image-guided surgery allowing for robust image-based identification of tissue targets for localized application of HIFU. In this study we present imaging and therapeutic results form a 3.5 MHz, 64-element fenestrated prototype DMUA for targeting lesions in the femoral artery of familial hypercholesterolemic (FH) swine. Before treatment, diagnostic ultrasound was used to verify the presence of plaque in the femoral artery of the swine. Images obtained with the DMUA and a diagnostic (HST 15-8) transducer housed in the fenestration were analyzed and used for guidance in targeting of the plaque. Discrete therapeutic shots with an estimated focal intensity of 4000-5600 W/cm2 and 500-2000 msec duration were performed at several planes in the plaque. During therapy, pulsed HIFU was interleaved with single transmit focus imaging from the DMUA and M2D imaging from the diagnostic transducer for further analysis of lesion formation. After therapy, the swine's were recovered and later sacrificed after 4 and 7 days for histological analysis of lesion formation. At sacrifice, the lower half of the swine was perfused and the femoral artery with adjoining muscle was fixed and stained with H&E to characterize HIFU-induced lesions. Histology has confirmed that localized thermal lesion formation within the plaque was achieved according to the planned lesion maps. Furthermore, the damage was confined to the plaque tissue without damage to the intima. These results offer the promise of a new treatment potentially suited for vulnerable plaques. The results also provide the first real-time demonstration of DMUA technology in targeting fine tissue structures for

Radiofrequency power deposition near metallic wires during MR imaging: feasibility study using T1-weighted thermal imaging.

PubMed

Oulmane, F; Detti, V; Grenier, D; Perrin, E; Saint-Jalmes, H

2007-01-01

The presence of metallic conductors (implants, wires or catheters) is prohibited in MR imaging for safety purpose with respect to radiofrequency (RF) power deposition caused by RF excitation B1 field. This work describes the use of T1-weigthed MR imaging for estimating a thermal map around a metallic (copper) wire located in the center of a MR imaging unit during an imaging sequence. The experimental set up and the methodology used for capturing the elevation of temperature created by radiofrequency power deposition around the wire is presented. A proof of its efficiency to followup temperature elevation about 0,5 degrees C in a milimetric region of interest (pixel size: 1 x 1 mm2, slice thickness 5 mm) located around the wire is given, leading to further developments of MR imaging in presence of metallic implants, coils or catheters.

Thermal ablation for partial splenectomy hemostasis, spleen trauma, splenic metastasis and hypersplenism.

PubMed

Duan, Ya-Qi; Liang, Ping

2013-05-01

Many studies have been conducted on splenic thermal ablation for partial splenectomy hemostasis, spleen trauma, splenic metastasis and hypersplenism. In this article, we review the evolution and current status of radiofrequency and microwave ablation in the treatment of spleen diseases. All publications from 1990 to 2011 on radiofrequency and microwave ablation for partial splenectomy hemostasis, spleen trauma, splenic metastasis and hypersplenism were retrieved by searching PubMed. Thermal ablation in the spleen for partial splenectomy hemostasis, spleen trauma, splenic metastasis and hypersplenism can preserve part of the spleen and maintain splenic immunologic function. Thermal ablation for assisting hemostasis in partial splenectomy minimizes blood loss during operation. Thermal ablation for spleen trauma reduces the number of splenectomy and the amount of blood transfusion. Thermal ablation for splenic metastasis is minimally invasive and can be done under the guidance of an ultrasound, which helps shorten the recovery time. Thermal ablation for hypersplenism increases platelet (PLT) and white blood cell (WBC) counts and improves liver function. It also helps to maintain splenic immunologic function and even improves splenic immunologic function in the short-term. In conclusion, thermal ablative approaches are promising for partial splenectomy hemostasis, spleen trauma, splenic metastasis and hypersplenism. In order to improve therapeutic effects, directions for future studies may include standardized therapeutic indications, prolonged observation periods and enlarged sample sizes.

A numerical study on the oblique focus in MR-guided transcranial focused ultrasound

NASA Astrophysics Data System (ADS)

Hughes, Alec; Huang, Yuexi; Pulkkinen, Aki; Schwartz, Michael L.; Lozano, Andres M.; Hynynen, Kullervo

2016-11-01

Recent clinical data showing thermal lesions from treatments of essential tremor using MR-guided transcranial focused ultrasound shows that in many cases the focus is oblique to the main axis of the phased array. The potential for this obliquity to extend the focus into lateral regions of the brain has led to speculation as to the cause of the oblique focus, and whether it is possible to realign the focus. Numerical simulations were performed on clinical export data to analyze the causes of the oblique focus and determine methods for its correction. It was found that the focal obliquity could be replicated with the numerical simulations to within 23.2+/- {{13.6}\\circ} of the clinical cases. It was then found that a major cause of the focal obliquity was the presence of sidelobes, caused by an unequal deposition of power from the different transducer elements in the array at the focus. In addition, it was found that a 65% reduction in focal obliquity was possible using phase and amplitude corrections. Potential drawbacks include the higher levels of skull heating required when modifying the distribution of power among the transducer elements, and the difficulty at present in obtaining ideal phase corrections from CT information alone. These techniques for the reduction of focal obliquity can be applied to other applications of transcranial focused ultrasound involving lower total energy deposition, such as blood-brain barrier opening, where the issue of skull heating is minimal.

Cooled radiofrequency ablation for bilateral greater occipital neuralgia.

PubMed

Vu, Tiffany; Chhatre, Akhil

2014-01-01

This report describes a case of bilateral greater occipital neuralgia treated with cooled radiofrequency ablation. The case is considered in relation to a review of greater occipital neuralgia, continuous thermal and pulsed radiofrequency ablation, and current medical literature on cooled radiofrequency ablation. In this case, a 35-year-old female with a 2.5-year history of chronic suboccipital bilateral headaches, described as constant, burning, and pulsating pain that started at the suboccipital region and radiated into her vertex. She was diagnosed with bilateral greater occipital neuralgia. She underwent cooled radiofrequency ablation of bilateral greater occipital nerves with minimal side effects and 75% pain reduction. Cooled radiofrequency ablation of the greater occipital nerve in challenging cases is an alternative to pulsed and continuous RFA to alleviate pain with less side effects and potential for long-term efficacy.

Cooled Radiofrequency Ablation for Bilateral Greater Occipital Neuralgia

PubMed Central

Chhatre, Akhil

2014-01-01

This report describes a case of bilateral greater occipital neuralgia treated with cooled radiofrequency ablation. The case is considered in relation to a review of greater occipital neuralgia, continuous thermal and pulsed radiofrequency ablation, and current medical literature on cooled radiofrequency ablation. In this case, a 35-year-old female with a 2.5-year history of chronic suboccipital bilateral headaches, described as constant, burning, and pulsating pain that started at the suboccipital region and radiated into her vertex. She was diagnosed with bilateral greater occipital neuralgia. She underwent cooled radiofrequency ablation of bilateral greater occipital nerves with minimal side effects and 75% pain reduction. Cooled radiofrequency ablation of the greater occipital nerve in challenging cases is an alternative to pulsed and continuous RFA to alleviate pain with less side effects and potential for long-term efficacy. PMID:24716017

Thermal Modeling for the Next Generation of Radiofrequency Exposure Limits: Commentary.

PubMed

Foster, Kenneth R; Ziskin, Marvin C; Balzano, Quirino

2017-07-01

This commentary evaluates two sets of guidelines for human exposure to radiofrequency (RF) energy, focusing on the frequency range above the "transition" frequency at 3-10 GHz where the guidelines change their basic restrictions from specific absorption rate to incident power density, through the end of the RF band at 300 GHz. The analysis is based on a simple thermal model based on Pennes' bioheat equation (BHTE) (Pennes 1948) assuming purely surface heating; an Appendix provides more details about the model and its range of applicability. This analysis suggests that present limits are highly conservative relative to their stated goals of limiting temperature increase in tissue. As applied to transmitting devices used against the body, they are much more conservative than product safety standards for touch temperature for personal electronics equipment that are used in contact with the body. Provisions in the current guidelines for "averaging time" and "averaging area" are not consistent with scaling characteristics of the bioheat equation and should be refined. The authors suggest the need for additional limits on fluence for protection against brief, high intensity pulses at millimeter wave frequencies. This commentary considers only thermal hazards, which form the basis of the current guidelines, and excludes considerations of reported "non-thermal" effects of exposure that would have to be evaluated in the process of updating the guidelines.

Two-treatment protocol for skin laxity using 90-Watt dynamic monopolar radiofrequency device with real-time impedance intelligence monitoring.

PubMed

McDaniel, David; Weiss, Robert; Weiss, Margaret; Mazur, Chris; Griffen, Charmaine

2014-09-01

Multiple devices are currently on the market that employ radiofrequency to non-invasively treat skin laxity and wrinkle reduction. The study device was a unique monopolar radiofrequency device FDA cleared for the treatment of wrinkles and rhytids. The delivery system allows constant monitoring of the real-time local skin impedance changes, which allows radiofrequency energy to be more uniformly dosed over an entire treatment area. The objective was to validate effectiveness of a modified treatment protocol for a unique monopolar radiofrequency device, which has been engineered with greater power and self-monitoring circuitry. Twenty-four female subjects received bilateral monopolar radiofrequency treatments to the mid and lower face from the sub malar region to the submentum. Subjects completed 1 and 3 month follow ups with digital imaging. Skin biopsies (on 4 subjects) and ultrasound measurements (on 12 subjects) were completed. Assessments demonstrated a reduction in skin laxity of 35%, a reduction in fine lines/wrinkles of 42%, and a reduction in the appearance of global photodamage of 33%. Expert photograding demonstrated 92% of subjects showing at least a mild improvement in skin laxity at three months post treatment. 50 MHz ultrasound measurements in 12 subjects showed an increase of 19% in skin density. Histology showed a marked increase in dermal collagen and elastin fibers in two subjects who demonstrated a clinically noticeable reduction in skin laxity and minimal changes in two subjects who demonstrated minimal clinical improvements. There were no significant adverse events reported. This modified radiofrequency device and treatment protocol was well tolerated and produced improvements in the appearance of skin laxity and overall anti-aging effects in the majority of subjects. Objective measurements including ultrasound and histology help explain the clinical outcome.

Catheter-based high-intensity ultrasound for epicardial ablation of the left ventricle: device design and in vivo feasiblity

NASA Astrophysics Data System (ADS)

Salgaonkar, Vasant A.; Nazer, Babak; Jones, Peter D.; Tanaka, Yasuaki; Martin, Alastair; Ng, Bennett; Duggirala, Srikant; Diederich, Chris J.; Gerstenfeld, Edward P.

2015-03-01

The development and in vivo testing of a high-intensity ultrasound thermal ablation catheter for epicardial ablation of the left ventricle (LV) is presented. Scar tissue can occur in the mid-myocardial and epicardial space in patients with nonischemic cardiomyopathy and lead to ventricular tachycardia. Current ablation technology uses radiofrequency energy, which is limited epicardially by the presence of coronary vessels, phrenic nerves, and fat. Ultrasound energy can be precisely directed to deliver targeted deep epicardial ablation while sparing intervening epicardial nerve and vessels. The proof-of-concept ultrasound applicators were designed for sub-xyphoid access to the pericardial space through a steerable 14-Fr sheath. The catheter consists of two rectangular planar transducers, for therapy (6.4 MHz) and imaging (5 MHz), mounted at the tip of a 3.5-mm flexible nylon catheter coupled and encapsulated within a custom-shaped balloon for cooling. Thermal lesions were created in the LV in a swine (n = 10) model in vivo. The ultrasound applicator was positioned fluoroscopically. Its orientation and contact with the LV were verified using A-mode imaging and a radio-opaque marker. Ablations employed 60-s exposures at 15 - 30 W (electrical power). Histology indicated thermal coagulation and ablative lesions penetrating 8 - 12 mm into the left ventricle on lateral and anterior walls and along the left anterior descending artery. The transducer design enabled successful sparing from the epicardial surface to 2 - 4 mm of intervening ventricle tissue and epicardial fat. The feasibility of targeted epicardial ablation with catheter-based ultrasound was demonstrated.

Neurosurgical Applications of High-Intensity Focused Ultrasound with Magnetic Resonance Thermometry.

PubMed

Colen, Rivka R; Sahnoune, Iman; Weinberg, Jeffrey S

2017-10-01

Magnetic resonance guided focused ultrasound surgery (MRgFUS) has potential noninvasive effects on targeted tissue. MRgFUS integrates MRI and focused ultrasound surgery (FUS) into a single platform. MRI enables visualization of the target tissue and monitors ultrasound-induced effects in near real-time during FUS treatment. MRgFUS may serve as an adjunct or replace invasive surgery and radiotherapy for specific conditions. Its thermal effects ablate tumors in locations involved in movement disorders and essential tremors. Its nonthermal effects increase blood-brain barrier permeability to enhance delivery of therapeutics and other molecules. Copyright © 2017 Elsevier Inc. All rights reserved.

Pulsed Radiofrequency Ablation Under Ultrasound Guidance for Huge Neuroma

PubMed Central

Jung, Il; Lee, Chang Hee; Kim, Se Hun; Kim, Jin Sun; Yoo, Byoung Woo

2014-01-01

Amputation neuroma can cause very serious, intractable pain. Many treatment modalities are suggested for painful neuroma. Pharmacologic treatment shows a limited effect on eliminating the pain, and surgical treatment has a high recurrence rate. We applied pulsed radiofrequency treatment at the neuroma stalk under ultrasonography guidance. The long-term outcome was very successful, prompting us to report this case. PMID:25031817

3D conformal MRI-guided transurethral ultrasound therapy: results of gel phantom experiments

NASA Astrophysics Data System (ADS)

N'Djin, W. A.; Burtnyk, M.; McCormick, S.; Bronskill, M.; Chopra, R.

2011-09-01

MRI-guided transurethral ultrasound therapy shows promise for minimally invasive treatment of localized prostate cancer. Previous in-vivo studies demonstrated the feasibility of performing conservative treatments using real-time temperature feedback to control accurately the establishment of coagulative lesions within circumscribed prostate regions. This in-vitro study tested device configuration and control options for achieving full prostate treatments. A multi-channel MRI compatible ultrasound therapy system was evaluated in gel phantoms using 3 canine prostate models. Prostate profiles were 5 mm-step-segmented from T2-weighted MR images performed during previous in-vivo experiments. During ultrasound exposures, each ultrasound element was controlled independently by the 3D controller. Decisions on acoustic power, frequency, and device rotation rate were made in real time based on MR thermometry feedback and prostate radii. Low and high power treatment approaches using maximum acoustic powers of 10 or 20 W.cm-2 were tested as well as single and dual-frequency strategies (4.05/13.10 MHz). The dual-frequency strategy used either the fundamental frequency or the 3rd harmonic component, depending on the prostate radius. The 20 W.cm-2 dual frequency approach was the most efficient configuration in achieving full prostate treatments. Treatment times were about half the duration of those performed with 10 W.cm-2 configurations. Full prostate coagulations were performed in 16.3±6.1 min at a rate of 1.8±0.2 cm3.min-1, and resulted in very little undertreated tissue (<3%). Surrounding organs positioned beyond a safety distance of 1.4±1.0 mm from prostate boundaries were not damaged, particularly rectal wall tissues. In this study, a 3D, MR-thermometry-guided transurethral ultrasound therapy was validated in vitro in a tissue-mimicking phantom for performing full prostate treatment. A dual-frequency configuration with 20 W.cm-2 ultrasound intensity exposure showed good

Primary malignant tumours of the bony pelvis: US-guided high intensity focused ultrasound ablation.

PubMed

Wang, Yang; Wang, Wei; Tang, Jie

2013-11-01

The aim of this review is to evaluate the value of ultrasound (US)-guided high intensity focused ultrasound (HIFU) ablation in the treatment of primary malignant tumours of the bony pelvis. Eleven patients with primary malignant tumours of the bony pelvis received US-guided HIFU ablation. The maximum tumour size ranged from 5.6 to 25.0 cm (median 10.5 cm). Treatment was curative in four patients and palliative in seven patients. During follow-up, the effectiveness of HIFU ablation was assessed by contrast-enhanced magnetic resonance (MR). Significant coagulative necrosis was obtained in all patients after scheduled HIFU ablations; the volume ablation ratio was 86.7% ± 12.5% (range 65-100%). Complete tumour necrosis was achieved in all patients receiving curative HIFU ablation. No major complications were encountered. No patients died of local tumour progression during follow-up. US-guided HIFU ablation may be a safe and effective minimally invasive technique for the local treatment of primary malignant tumours of the bony pelvis.

Ultrasound-guided vs endoscopic ultrasound-guided fine-needle aspiration for pancreatic cancer diagnosis

PubMed Central

Matsuyama, Masato; Ishii, Hiroshi; Kuraoka, Kensuke; Yukisawa, Seigo; Kasuga, Akiyoshi; Ozaka, Masato; Suzuki, Sho; Takano, Kouichi; Sugiyama, Yuko; Itoi, Takao

2013-01-01

AIM: To clarify the effectiveness and safety of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) for the diagnosis of pancreatic cancer (PC). METHODS: Patients who were diagnosed with unresectable, locally advanced or metastatic PC between February 2006 and September 2011 were selected for this retrospective study. FNA biopsy for pancreatic tumors had been performed percutaneously under extracorporeal ultrasound guidance until October 2009; then, beginning in November 2009, EUS-FNA has been performed. We reviewed the complete medical records of all patients who met the selection criteria for the following data: sex, age, location and size of the targeted tumor, histological and/or cytological findings, details of puncture procedures, time from day of puncture until day of definitive diagnosis, and details of severe adverse events. RESULTS: Of the 121 patients who met the selection criteria, 46 had a percutaneous biopsy (Group A) and 75 had an EUS-FNA biopsy (Group B). Adequate cytological specimens were obtained in 42 Group A patients (91.3%) and all 75 Group B patients (P = 0.0192), and histological specimens were obtained in 41 Group A patients (89.1%) and 65 Group B patients (86.7%). Diagnosis of malignancy by cytology was positive in 33 Group A patients (78.6%) and 72 Group B patients (94.6%) (P = 0.0079). Malignancy by both cytology and pathology was found in 43 Group A (93.5%) and 73 Group B (97.3%) patients. The mean period from the puncture until the cytological diagnosis in Group B was 1.7 d, which was significantly shorter than that in Group A (4.1 d) (P < 0.0001). Severe adverse events were experienced in two Group A patients (4.3%) and in one Group B patient (1.3%). CONCLUSION: EUS-FNA, as well as percutaneous needle aspiration, is an effective modality to obtain cytopathological confirmation in patients with advanced PC. PMID:23613631

Endocavitary thermal therapy by MRI-guided phased-array contact ultrasound: experimental and numerical studies on the multi-input single-output PID temperature controller's convergence and stability.

PubMed

Salomir, Rares; Rata, Mihaela; Cadis, Daniela; Petrusca, Lorena; Auboiroux, Vincent; Cotton, François

2009-10-01

Endocavitary high intensity contact ultrasound (HICU) may offer interesting therapeutic potential for fighting localized cancer in esophageal or rectal wall. On-line MR guidance of the thermotherapy permits both excellent targeting of the pathological volume and accurate preoperatory monitoring of the temperature elevation. In this article, the authors address the issue of the automatic temperature control for endocavitary phased-array HICU and propose a tailor-made thermal model for this specific application. The convergence and stability of the feedback loop were investigated against tuning errors in the controller's parameters and against input noise, through ex vivo experimental studies and through numerical simulations in which nonlinear response of tissue was considered as expected in vivo. An MR-compatible, 64-element, cooled-tip, endorectal cylindrical phased-array applicator of contact ultrasound was integrated with fast MR thermometry to provide automatic feedback control of the temperature evolution. An appropriate phase law was applied per set of eight adjacent transducers to generate a quasiplanar wave, or a slightly convergent one (over the circular dimension). A 2D physical model, compatible with on-line numerical implementation, took into account (1) the ultrasound-mediated energy deposition, (2) the heat diffusion in tissue, and (3) the heat sink effect in the tissue adjacent to the tip-cooling balloon. This linear model was coupled to a PID compensation algorithm to obtain a multi-input single-output static-tuning temperature controller. Either the temperature at one static point in space (situated on the symmetry axis of the beam) or the maximum temperature in a user-defined ROI was tracked according to a predefined target curve. The convergence domain in the space of controller's parameters was experimentally explored ex vivo. The behavior of the static-tuning PID controller was numerically simulated based on a discrete-time iterative solution

Ultrasound guided transarterial coil placement in the internal and external carotid artery in horses.

PubMed

Muñoz, Juan; Iglesias, Manuel; Chao, Eduardo Lloret; Bussy, Christian

2015-04-01

To assess ultrasound guided transarterial coil placement (UGTACP) for occlusion of the internal carotid artery (ICA) and external carotid artery (ECA) in horses. Cadaveric and in vivo study. Cadaveric horses (n = 10), healthy horses (3), and 1 clinical case. Cadaveric and in vivo (healthy horses): UGTACP was performed in the caudal part of the ICA and ECA. Coil placement in the rostral part of the ICA was performed blindly and controlled by conventional radiography. No coils were placed in the rostral part of the ECA. UGTACP of the ICA was in a horse with guttural pouch mycosis of the left guttural pouch. Accurate ultrasound-guided catheterization of the ICA and ECA was performed in all specimens. Ultrasound-guided coil placement was successfully performed in all cases except 1. No complications occurred in the in vivo study. The clinical case fully recovered and returned to its intended use. Based on our study, UGTACP of the ICA and ECA caudal part is a feasible alternative to fluoroscopy. An advantage of this technique is the accuracy with which you can catheterize both ICA and ECA and the ability to identify unusual branching at the origin of the ICA. Regarding the rostral part of the ICA, angiographic catheter guidance in this region is probably more precise using fluoroscopy as it is performed blindly. In a clinical situation, combination of US and fluoroscopy guidance can result in reduction of radiation exposure time. © Copyright 2014 by The American College of Veterinary Surgeons.

Improving needle tip identification during ultrasound-guided procedures in anaesthetic practice.

PubMed

Scholten, H J; Pourtaherian, A; Mihajlovic, N; Korsten, H H M; A Bouwman, R

2017-07-01

Ultrasound guidance is becoming standard practice for needle-based interventions in anaesthetic practice, such as vascular access and peripheral nerve blocks. However, difficulties in aligning the needle and the transducer can lead to incorrect identification of the needle tip, possibly damaging structures not visible on the ultrasound screen. Additional techniques specifically developed to aid alignment of needle and probe or identification of the needle tip are now available. In this scoping review, advantages and limitations of the following categories of those solutions are presented: needle guides; alterations to needle or needle tip; three- and four-dimensional ultrasound; magnetism, electromagnetic or GPS systems; optical tracking; augmented (virtual) reality; robotic assistance; and automated (computerised) needle detection. Most evidence originates from phantom studies, case reports and series, with few randomised clinical trials. Improved first-pass success and reduced performance time are the most frequently cited benefits, whereas the need for additional and often expensive hardware is the greatest limitation to widespread adoption. Novice ultrasound users seem to benefit most and great potential lies in education. Future research should focus on reporting relevant clinical parameters to learn which technique will benefit patients most in terms of success and safety. © 2017 The Association of Anaesthetists of Great Britain and Ireland.

Prospective randomized trial comparing magnetic resonance imaging (MRI)-guided in-bore biopsy to MRI-ultrasound fusion and transrectal ultrasound-guided prostate biopsy in patients with prior negative biopsies.

PubMed

Arsov, Christian; Rabenalt, Robert; Blondin, Dirk; Quentin, Michael; Hiester, Andreas; Godehardt, Erhard; Gabbert, Helmut E; Becker, Nikolaus; Antoch, Gerald; Albers, Peter; Schimmöller, Lars

2015-10-01

A significant proportion of prostate cancers (PCas) are missed by conventional transrectal ultrasound-guided biopsy (TRUS-GB). It remains unclear whether the combined approach using targeted magnetic resonance imaging (MRI)-ultrasound fusion-guided biopsy (FUS-GB) and systematic TRUS-GB is superior to targeted MRI-guided in-bore biopsy (IB-GB) for PCa detection. To compare PCa detection between IB-GB alone and FUS-GB + TRUS-GB in patients with at least one negative TRUS-GB and prostate-specific antigen ≥4 ng/ml. Patients were prospectively randomized after multiparametric prostate MRI to IB-GB (arm A) or FUS-GB + TRUS-GB (arm B) from November 2011 to July 2014. The study was powered at 80% to demonstrate an overall PCa detection rate of ≥60% in arm B compared to 40% in arm A. Secondary endpoints were the distribution of highest Gleason scores, the rate of detection of significant PCa (Gleason ≥7), the number of biopsy cores to detect one (significant) PCa, the positivity rate for biopsy cores, and tumor involvement per biopsy core. The study was halted after interim analysis because the primary endpoint was not met. The trial enrolled 267 patients, of whom 210 were analyzed (106 randomized to arm A and 104 to arm B). PCa detection was 37% in arm A and 39% in arm B (95% confidence interval for difference, -16% to 11%; p=0.7). Detection rates for significant PCa (29% vs 32%; p=0.7) and the highest percentage tumor involvement per biopsy core (48% vs 42%; p=0.4) were similar between the arms. The mean number of cores was 5.6 versus 17 (p<0.001). A limitation is the limited number of patients because of early cessation of accrual. This trial failed to identify an important improvement in detection rate for the combined biopsy approach over MRI-targeted biopsy alone. A prospective comparison between MRI-targeted biopsy alone and systematic TRUS-GB is justified. Our randomized study showed similar prostate cancer detection rates between targeted prostate biopsy

Inexpensive homemade models for ultrasound-guided vein cannulation training.

PubMed

Di Domenico, Stefano; Santori, Gregorio; Porcile, Elisa; Licausi, Martina; Centanaro, Monica; Valente, Umberto

2007-11-01

To test the hypothesis that low-cost homemade models may be used to acquire the basic skills for ultrasound-guided central vein puncture. Training study. University transplantation department. Training was performed using three different homemade models (A, B, and C). Segments of a common rubber tourniquet (V1) and Silastic tube (V2) were used to simulate vessels within agar-based models. Overall cost for each model was less than 5 euro (US$7). For each test (test I, A-V1; II, A-V2; III, B-V1; IV, C-V2), the number of punctures and attempts needed to locate the needle inside the lumen were recorded. Each test was considered completed when participants punctured the vessels at the first attempt for three consecutive times. In test I, the mean number of punctures and attempts were 3.85 +/- 1.26 and 4.95 +/- 3.05; in test II, 4.60 +/- 1.14 and 6.30 +/- 2.51; in test III, 4.80 +/- 1.06 and 4.65 +/- 2.21; and in test IV, 4.45 +/- 1.23 and 6.05 +/- 2.92, respectively. For each test, no statistical difference was found by comparison of number of punctures and attempts for anesthesiologists versus nonanesthesiologists, men versus women, or previous experience versus no experience with central vein cannulation (CVC). Video game users obtained better results than did nonusers in test I (punctures, P = 0.033; attempts, P = 0.038), test II (punctures, P = 0.052; attempts, P = 0.011), and test IV (punctures, P = 0.001; attempts, P = 0.003). A posttraining questionnaire showed favorable opinions about the clarity of the instructions, aptness of the models, and adequacy of the training. In our operative unit, the use of ultrasound guidance for CVC increased from 2% to 23% in the first month after training. Low-cost homemade models are useful in acquiring basic coordination skills for ultrasound-guided CVC.

RADC thermal guide for reliability engineers

NASA Astrophysics Data System (ADS)

Morrison, G. N.; Kallis, J. M.; Strattan, L. A.; Jones, I. R.; Lena, A. L.

1982-06-01

This guide was developed to provide a reliability engineer, who is not proficient in thermal design and analysis techniques, with the tools for managing and evaluating the thermal design and production of electronic equipment. It defines the requirements and tasks that should be addressed in system equipment specifications and statements of work, and describes how to evaluate performance.

Comparison between ultrasound guided technique and digital palpation technique for radial artery cannulation in adult patients: An updated meta-analysis of randomized controlled trials.

PubMed

Bhattacharjee, Sulagna; Maitra, Souvik; Baidya, Dalim K

2018-06-01

Possible advantages and risks associated with ultrasound guided radial artery cannulation in-comparison to digital palpation guided method in adult patients are not fully known. We have compared ultrasound guided radial artery cannulation with digital palpation technique in this meta-analysis. Meta-analysis of randomized controlled trials. Trials conducted in operating room, emergency department, cardiac catheterization laboratory. PubMed and Cochrane Central Register of Controlled Trials (CENTRAL) were searched (from 1946 to 20th November 2017) to identify prospective randomized controlled trials in adult patients. Two-dimensional ultrasound guided radial artery catheterization versus digital palpation guided radial artery cannulation. Overall cannulation success rate, first attempt success rate, time to cannulation and mean number of attempts to successful cannulation. Odds ratio (OR) and standardized mean difference (SMD) or mean difference (MD) with 95% confidence interval (CI) were calculated for categorical and continuous variables respectively. Data of 1895 patients from 10 studies have been included in this meta- analysis. Overall cannulation success rate was similar between ultrasound guided technique and digital palpation [OR (95% CI) 2.01 (1.00, 4.06); p = 0.05]. Ultrasound guided radial artery cannulation is associated with higher first attempt success rate of radial artery cannulation in comparison to digital palpation [OR (95% CI) 2.76 (186, 4.10); p < 0.001]. No difference was seen in time to cannulate [SMD (95% CI) -0.31 (-0.65, 0.04); p = 0.30] and mean number of attempt [MD (95% CI) -0.65 (-1.32, 0.02); p = 0.06] between USG guided technique with palpation technique. Radial artery cannulation by ultrasound guidance may increase the first attempt success rate but not the overall cannulation success when compared to digital palpation technique. However, results of this meta-analysis should be interpreted with caution due presence of

Real-time ultrasound-guided PCNL using a novel SonixGPS needle tracking system.

PubMed

Li, Xiang; Long, Qingzhi; Chen, Xingfa; He, Dalin; Dalin, He; He, Hui

2014-08-01

SonixGPS is a successful ultrasound guidance position system. It helps to improve accuracy in performing complex puncture operations. This study firstly used SonixGPS to perform kidney calyx access in PCNL to investigate its effectiveness and safety. This was a prospectively randomized controlled study performed from September 2011 to October 2012. A total of 97 patients were prospectively randomized into two groups using random number generated from SAS software. 47 Patients were enrolled in conventional ultrasound-guided (US-guided) group and 50 patients were classified into SonixGPS-guided group. Nine patients were lost during follow-up. Hence, a total of 88 patients were qualified and analyzed. Preoperative examinations included urine analysis, urine culture, kidney function, coagulation profile and routine analysis of blood. Ultrasonography was used to evaluate the degree of hydronephrosis. The intraoperative findings, including blood loss, operating time, time to successful puncture, the number of attempts for successful puncture and hospital stay were recorded. The stone clearance rate and complications were analyzed. The present study showed no significant difference between the two groups in terms of demographic data, preoperative markers, stone clearance rate and the stone composition. However, the time to successful puncture, the number of trials for successful puncture, operating time and hospital length of stay were significantly decreased in the SonixGPS-guided group. Furthermore, the hemoglobin decrease was also obviously lower in the SonixGPS group than that in conventional US-guided group. SonixGPS needle tacking system guided PCNL is safe and effective in treating upper urinary tract stones. This novel technology makes puncturing more accuracy and can significantly decrease the incidence of relative hemorrhage and accelerate recovery.

From the RSNA refresher courses: Image-guided thermal therapy of uterine fibroids.

PubMed

Tempany, Clare M

2007-01-01

One of the most recent additions to the methods for image-guided therapy is magnetic resonance (MR)-guided focused ultrasound. This method represents a unique closed-loop therapy, with planning, guidance, control, and direct feedback (called MR thermometry), which work together to ensure an effective therapy. The focused ultrasound induces focal tissue destruction by thermocoagulation in a noninvasive manner. MR also enables real-time thermometry to be performed during each and every sonication. These characteristics make MR-guided focused ultrasound an exciting new approach for treating fibroids. Fibroids are diagnosed based on findings from the patient's physical examination supplemented by imaging results. MR imaging is preferred to other imaging modalities because it enables the fibroids and the entire pelvis to be fully examined. After individual fibroids are identified and the target area is defined by the radiologist, the target volume is analyzed in a three-dimensional assessment to ensure the patient's safety. The procedure begins with the delivery of low-power sonication, and the power is gradually increased until the therapeutic dose is reached. After the procedure, postcontrast images are acquired; these should demonstrate tissue necrosis. The results of clinical trials have shown that the treatment is safe, effective, and highly acceptable to patients. RSNA, 2007

Pulsed Compared to Thermal Radiofrequency to the Medial Calcaneal Nerve for Management of Chronic Refractory Plantar Fasciitis: A Prospective Comparative Study.

PubMed

Osman, Ayman M; El-Hammady, Dina H; Kotb, Mohamed M

2016-01-01

Radiofrequency (RF) treatment is a minimally invasive procedure that has been used for more than 3 decades in treating various chronic pain syndromes. Conventional (continuous) RF treatment occasionally results in worsening or even initiating a new type of pain. The use of pulsed radiofrequency (PRF), which has a non- or minimally neurodestructive neuromodulatory effect, serves as an alternative to conventional RF therapy in many medical situations. To evaluate the effect of applying PRF for 6 minutes vs. thermal radiofrequency (TRF) for 90 seconds to the medial calcaneal nerve for treatment of chronic refractory plantar fasciitis pain. Prospective comparative study. Pain, Orthopedic, and Rheumatology and Rehabilitation Clinics of Assiut University Hospital. Twenty patients with refractory chronic bilateral plantar fasciitis received PRF to the medial calcaneal nerve for 6 minutes for one heel and TRF to the same nerve on the other heel (as their own control) for 90 seconds. Numerical verbal rating scale (NVRS) at waking up from bed and after prolonged walking, and satisfaction score were used for assessment of studied patients at one, 3, 6, 12, and 24 weeks from the intervention. All studied patients showed significant improvement in their pain scale after the intervention that lasted for 24 weeks; however, the PRF heels had significantly better pain scale and satisfaction scores at the first and third weeks assessments when compared to the TRF heels. Effective analgesia was achieved after one week or less after PRF compared to 3 weeks for the TRF (P < 0.001). No randomization. PRF to the medial calcaneal nerve is a safe and effective method for treatment of chronic plantar fasciitis pain. The onset of effective analgesia can be achieved more rapidly with PRF compared to TRF on the same nerve. Further randomized trials are needed to confirm the therapeutic effect and optimizing the dose of RF needed.Key words: Pulsed radiofrequency, thermal radiofrequency, medial

Contrast-Enhanced Ultrasound Guided Biopsy of Undetermined Abdominal Lesions: A Multidisciplinary Decision-Making Approach.

PubMed

Mao, Feng; Dong, Yi; Ji, Zhengbiao; Cao, Jiaying; Wang, Wen-Ping

2017-01-01

Aim. To investigate the value of contrast-enhanced ultrasound (CEUS) guided biopsy of undetermined abdominal lesions in multidisciplinary treatment (MDT) decision-making approach. Methods. Between Jan 2012 and Dec 2015, 60 consecutive patients (male, 37; female, 23; mean age, 51.3 years ± 14.6) who presented with undetermined abdominal lesions were included. CEUS and core needle percutaneous biopsy was performed under real-time CEUS guidance in all lesions. Data were recorded and compared with conventional ultrasound (US) guidance group ( n = 75). All CEUS findings and clinical data were evaluated in MDT. Results. CEUS enabled the delimitation of more (88.3% versus 41.3%) and larger (14.1 ± 10.7 mm versus 32.3 ± 18.5 mm) nonenhanced necrotic areas. More inner (20.0% versus 6.7%) and surrounding (18.3% versus 2.7%) major vessels were visualized and avoided during biopsies. CEUS-guided biopsy increased the diagnostic accuracy from 93.3% to 98.3%, with correct diagnosis in 57 of 60 lesions (95.0%). The therapeutic plan was influenced by CEUS guided biopsies findings in the majority of patients (98.3%). Conclusion. The combination of CEUS guided biopsy and MDT decision-making approach is useful in the diagnostic work-up and therapeutic management.

CT-Guided Percutaneous Step-by-Step Radiofrequency Ablation for the Treatment of Carcinoma in the Caudate Lobe

PubMed Central

Dong, Jun; Li, Wang; Zeng, Qi; Li, Sheng; Gong, Xiao; Shen, Lujun; Mao, Siyue; Dong, Annan; Wu, Peihong

2015-01-01

Abstract The location of the caudate lobe and its complex anatomy make caudate lobectomy and radiofrequency ablation (RFA) under ultrasound guidance technically challenging. The objective of the exploratory study was to introduce a novel modality of treatment of lesions in caudate lobe and discuss all details with our experiences to make this novel treatment modality repeatable and educational. The study enrolled 39 patients with liver caudate lobe tumor first diagnosed by computerized tomography (CT) or magnetic resonance imaging (MRI). After consultation of multi-disciplinary team, 7 patients with hepatic caudate lobe lesions were enrolled and accepted CT-guided percutaneous step-by-step RFA treatment. A total of 8 caudate lobe lesions of the 7 patients were treated by RFA in 6 cases and RFA combined with percutaneous ethanol injection (PEI) in 1 case. Median tumor diameter was 29 mm (range, 18–69 mm). A right approach was selected for 6 patients and a dorsal approach for 1 patient. Median operative time was 64 min (range, 59–102 min). Median blood loss was 10 mL (range, 8-16 mL) and mainly due to puncture injury. Median hospitalization time was 4 days (range, 2–5 days). All lesions were completely ablated (8/8; 100%) and no recurrence at the site of previous RFA was observed during median 8 months follow-up (range 3–11 months). No major or life-threatening complications or deaths occurred. In conclusion, percutaneous step-by-step RFA under CT guidance is a novel and effective minimally invasive therapy for hepatic caudate lobe lesions with well repeatability. PMID:26426638

Pathological fracture of the patella due to an atypical located aneurysmal bone cyst: verification by means of ultrasound-guided biopsy.

PubMed

Plaikner, Michaela; Gruber, Hannes; Henninger, Benjamin; Gruber, Leonhard; Kosiol, Juana; Loizides, Alexander

2016-03-01

We report on a rare case of an atypical located aneurysmal bone cyst (ABC) in the patella presenting with pathological fracture after trauma. Using all available diagnostic modalities and by means of ultrasound-guided core-needle biopsy an unclear and suspected pathological fractured cystic bone lesion in the patella of a young man could be further clarified. The acquired images suggested the diagnosis of a pathological fractured aneurysmal bone cyst after mild trauma. However, due to the extraordinary location and clinical presentation the diagnosis was secured by means of ultrasound-guided biopsy through a small cortical gap. As shown in this rare case of an atypical aneurysmal bone cyst of the patella, the quite seldom but sometimes possible ultrasound-guided biopsy of intraosseous lesions can help to achieve the diagnostic clarification and should also be taken into account as a non-standard procedure.

Focused US system for MR imaging-guided tumor ablation.

PubMed

Cline, H E; Hynynen, K; Watkins, R D; Adams, W J; Schenck, J F; Ettinger, R H; Freund, W R; Vetro, J P; Jolesz, F A

1995-03-01

To measure the performance characteristics of a focused ultrasound (US) system for magnetic resonance (MR) imaging-guided tumor ablation. The authors constructed a focused US system for MR imaging-guided tumor ablation. The location of the heated region and thermal dose were monitored with temperature-sensitive MR images obtained in phantoms and rabbit skeletal muscle after application of each sonic pulse. The region heated by the focused ultrasound beam was within 1 mm of that observed on temperature-sensitive fast gradient-echo MR images of in vivo rabbit skeletal muscle. Analysis of heat flow and the rate of coagulation necrosis provided an estimate of the size of the ablated region that was in agreement with experimental findings. MR imaging provides target definition and control for thermal therapy in regions of variable perfusion or in tissues that are not well characterized.

Ultrasound-guided drainages and sclerotherapy.

PubMed

Lohela, P

2002-02-01

Ultrasonically guided fluid collection and abscess drainage have become routine procedures in various parts of the body. In most cases ultrasound is the only imaging and guidance modality needed; however, it is of the utmost importance to remember that CT and fluoroscopy with contrast often give invaluable information when the true extent of the process has to be determined and when assessing the safest route for the catheter in anatomically complicated areas. The importance of irrigation of the abscess cavity with fluids and the ready use of urokinase should be emphasized. Ethanol sclerotherapy is a simple and safe procedure to treat symptomatic hepatic or renal cysts. Parathyroid adenomas and cysts, as well as thyroid cysts, can also be treated with ethanol sclerotherapy in selected cases. Purified mineral talc has been used in pleurodesis and hydrocele sclerotherapy, whereas doxycycline or ethanol is used for postoperative lymphoceles. Both abscess drainages and sclerotherapy procedures are minimally invasive, simple, safe, inexpensive and reasonably efficacious treatment in many clinical instances and may be at least an alternative to surgical treatment, often offering significant advantages over surgery.

Paraffin-gel tissue-mimicking material for ultrasound-guided needle biopsy phantom.

PubMed

Vieira, Sílvio L; Pavan, Theo Z; Junior, Jorge E; Carneiro, Antonio A O

2013-12-01

Paraffin-gel waxes have been investigated as new soft tissue-mimicking materials for ultrasound-guided breast biopsy training. Breast phantoms were produced with a broad range of acoustical properties. The speed of sound for the phantoms ranged from 1425.4 ± 0.6 to 1480.3 ± 1.7 m/s at room temperature. The attenuation coefficients were easily controlled between 0.32 ± 0.27 dB/cm and 2.04 ± 0.65 dB/cm at 7.5 MHz, depending on the amount of carnauba wax added to the base material. The materials do not suffer dehydration and provide adequate needle penetration, with a Young's storage modulus varying between 14.7 ± 0.2 kPa and 34.9 ± 0.3 kPa. The phantom background material possesses long-term stability and can be employed in a supine position without changes in geometry. These results indicate that paraffin-gel waxes may be promising materials for training radiologists in ultrasound biopsy procedures. Copyright © 2013 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Acute Calcific Bursitis After Ultrasound-Guided Percutaneous Barbotage of Rotator Cuff Calcific Tendinopathy: A Case Report.

PubMed

Kang, Bo-Sung; Lee, Seung Hak; Cho, Yung; Chung, Sun Gun

2016-08-01

Ultrasound-guided percutaneous barbotage is an effective treatment for rotator cuff calcific tendinopathy, providing rapid and substantial pain relief. We present the case of a 49-year-old woman with aggravated pain early after ultrasound-guided barbotage of a large calcific deposit in the supraspinatus tendon. Subsequent examination revealed a thick calcification spreading along the subacromial-subdeltoid bursa space, suggesting acute calcific bursitis complicated by barbotage. Additional barbotage alleviated her pain completely. Therefore, a high index of suspicion for acute calcific bursitis is required in patients with unresolved or aggravated pain after barbotage. Repeated barbotage could be effective for this condition. Copyright © 2016 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

Does ultrasound-guided lidocaine injection improve local anaesthesia before femoral artery catheterization?

PubMed

Spiliopoulos, S; Katsanos, K; Diamantopoulos, A; Karnabatidis, D; Siablis, D

2011-05-01

To present the results of a prospective, randomized, single-centre study investigating local anaesthesia before percutaneous common femoral artery (CFA) puncture and catheterization with the use of ultrasound-guided injection of lidocaine versus standard infiltration by manual palpation. Patients scheduled to undergo diagnostic or therapeutic transfemoral catheter-based procedures gave informed consent and were randomized in two groups. In the first arm local anaesthesia with lidocaine hydrochloride 1% was performed under ultrasound guidance (group U/S), while in the second arm the standard method of manual artery palpation was applied (group M). In both groups, subsequent CFA catheterization was achieved under ultrasound guidance. The primary study endpoint was peri-procedural pain level evaluated with a visual-analogue scale (VAS score 0-10). Between January 2009 and 2010, 200 patients (161 men, mean age 63±12 years) were equally assigned to each group without any significant differences in baseline demographics. Patients in group U/S experienced significantly less pain during CFA catheterization in comparison with group M with a difference of three points in mean VAS score reported (1.6±1.6 versus 4.6±1.9, p<0.0001). In addition, significantly less volume of lidocaine was used in group U/S compared to group M (16±2.7 versus 19±0.8ml, p<0.001).Total vascular access time was similar in both groups (4.4±1.3 versus 4.5±1.3min). Overall complications included two small groin haematomas in each group. Ultrasound-guided local anaesthesia of the CFA prior to percutaneous transcatheter procedures is safe and achieves superior levels of analgesia with minimal patient pain and discomfort compared to the standard method of manual palpation. Copyright © 2011 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

Ultrasound-guided rectus sheath block in children with umbilical hernia: Case series.

PubMed

Alsaeed, Abdul Hamid; Thallaj, Ahmed; Khalil, Nancy; Almutaq, Nada; Aljazaeri, Ayman