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Sample records for preoperative duplex ultrasound

  1. Duplex ultrasound

    Science.gov (United States)

    Vascular ultrasound; Peripheral vascular ultrasound ... A duplex ultrasound combines: Traditional ultrasound: This uses sound waves that bounce off blood vessels to create pictures. Doppler ultrasound: This ...

  2. Role of routine pre-operative screening venous duplex ultrasound in morbidly obese patients undergoing bariatric surgery

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    P Praveen Raj

    2017-01-01

    Full Text Available Background/Aims: It is well established that obesity is a strongly associated risk factor for post-operative deep vein thrombosis (DVT. Physical effects and pro-thrombotic, pro-inflammatory and hypofibrinolytic effects of severe obesity may predispose to idiopathic DVT (pre-operatively because of which bariatric patients are routinely screened before surgery. The aim of this study was to audit the use of routine screening venous duplex ultrasound in morbidly obese patients before undergoing bariatric surgery. Methods: We retrospectively reviewed 180 patients who underwent bariatric surgery from August 2013 to August 2014 who had undergone pre-operative screening bilateral lower-extremity venous duplex ultrasound for DVT. Data were collected on patient's demographics, history of venous thromboembolism, prior surgeries and duplex ultrasound details of the status of the deep veins and superficial veins of the lower limbs. Results: No patients had symptoms or signs of DVT pre-operatively. No patient gave history of DVT. No patient was found to have iliac, femoral or popliteal vein thrombosis. Superficial venous disease was found in 17 (8%. One patient had a right lower limb venous ulcer. Conclusion: Thromboembolic problems in the morbidly obese before bariatric surgery are infrequent, and screening venous duplex ultrasound can be done in high-risk patients only.

  3. Primary chronic venous insufficiency of the lower extremities: preoperative color duplex Doppler ultrasound study; Insuficiencia venosa cronica primaria de los miembros inferiores. Valoracion prequirurgica con ecografia Doppler duplex color

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    Selfa, S.; Diago, T.; Ricart, M.; Chulia, R.; Martin, F. [Hospital Lluis Xativa. Valencia (Spain)

    2000-07-01

    To asses the role of color duplex Doppler ultrasound (CDU) in the preoperative study of patients with varicose veins in lower extremities. We employed CDU to examine varicose veins in 342 lower limbs, assessing reflux in saphenous veins (SV), deep venous system (DVS) and perforating veins (PV). We analyzed the relationship between the anatomical extent of the reflux and the clinical findings. Insufficiency of the superficial venous system alone was uncommon, occurring in only 10.8% of the limbs examined. Reflux was observed in SV and PV in 48.2% of the legs. It was detected in all three systems in 29.2% of cases. The presence of reflux in more than one system and more than one value was associated with increased clinical severity. The site of venous reflux in lower extremities with varicose veins varies. Greater clinical severity is observed in the presence of more marked reflux in the DVS and PV. CDU provides anatomic and functional data on the three venous systems of the lower limbs, allowing an individualized therapeutic surgery. Preoperative localization of incompetent PV by means of CDU facilities their ligation. CDU is the technique of choice for the preoperative examination of the venous systems of patients with varicose veins. (Author)

  4. Terminal valve of sapheno-femoral junction: a comparative assessment between pre-operative color-duplex ultrasound and intra-operative evaluation

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    Attilio Cavezzi

    2013-01-01

    Full Text Available According to literature data, up to 59% of incompetent great saphenous veins (GSV have no reflux at the terminal valve (TV of the saphenofemoral junction (SFJ. The aim was to compare color duplex ultrasound (CDU investigation and direct intra-operative assessment of competence of the TV at SFJ. A prospective comparative study was performed on 28 patients, who consecutively presented for surgical intervention for their primary varicose veins of the lower limbs with GSV incompetence. CDU assessment was performed pre-operatively to define GSV and SFJ terminal valve morphology and hemodynamics. Under local anesthesia these patients underwent SFJ disconnection (crossectomy and segmental inverted saphenous stripping of the incompetent GSV tract + phlebectomy of the varicose tributaries. SFJ disconnection was performed in four stages in an ascending fashion: I division of GSV below the lower SFJ tributaries, II disconnection of lower SFJ tributaries, III disconnection of upper tributaries, IV flush to CFV ligature of GSV stump. After the completion of stage I, the SFJ stump was opened and kept open when needed throughout the subsequent stages, in order to highlight any possible blood leak through the SFJ stump. To highlight intraoperative blood leak from SFJ stump visual observation was carried out both during respiration and when performing Valsalva maneuver and manual compression of homolateral iliac fossa. As to pre-operative CDU all limbs showed GSV reflux and they were divided in two groups according to TV competence (group A or incompetence (group B. Group A comprised 18 patients (6 M and 12 F, mean age 50.6 years. Group B included 10 patients (4 M and 6 F, mean age 54.8 years. Mean calibre of GSV at proximal/mid thigh was 6.4 mm in group A and 7.8 in group B. Concerning the intra-operative findings: in the group A, 5 patients had blood leak in the SFJ stump after stage I, 4 patients showed blood leak after stage II. After completion of stage III

  5. Duplex ultrasound for identifying renal artery stenosis

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    Zachrisson, Karin; Herlitz, Hans; Lönn, Lars

    2017-01-01

    Background Renal artery duplex ultrasound (RADUS) is an established method for diagnosis of renal artery stenosis (RAS), but there is no consensus regarding optimal RADUS criteria. Purpose To define optimal cutoff values for RADUS parameters when screening for RAS using intra-arterial trans...

  6. Renal duplex Doppler ultrasound findings in diabetics

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    Shim, Hyang Yee; Kim, Young Geun; Kook, Cheol Keu; Yoon, Chong Hyun; Lee, Shin Hyung; Lee, Chang Joon [National Medical Center, Seoul (Korea, Republic of)

    1993-12-15

    The correlation between clinical-laboratory findings and renal duplex Doppler ultrasound findings was studied in 45 patients with diabetes mellitus to see the role of duplex Doppler ultrasound in the detection of diabetic nephropathy. The resistive indices in patients with elevated serum creatinine, BUN, proteinuria, and systolic blood pressure levels were statistically significantly higher than those in patients with normal levels (p<0.05). Also resistive indics in patients with retinopathy were higher than that in patients without retinopathy (p<0.05). But the ultrasound morphologic changes of kidney such as renal length, cortical eye-catching, and corticomedullarycontrast were not well correlated with clinical-laboratory data and resistive index. The resistive index of the kidney in conjunction with clinical-laboratory data in diabetics may be helpful in the evaluation of diabetic nephropathy

  7. Duplex ultrasound scanning of peripheral arterial disease of the lower limb

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    Eiberg, Jonas Peter; Rasmussen, John Bøje Grønvall; Hansen, Marc Allan

    2010-01-01

    To assess the reliability and applicability of duplex ultrasound scanning (DUS) of lower limb arteries, compared with digital subtraction angiography (DSA), in patients with peripheral arterial disease (PAD).......To assess the reliability and applicability of duplex ultrasound scanning (DUS) of lower limb arteries, compared with digital subtraction angiography (DSA), in patients with peripheral arterial disease (PAD)....

  8. Importance of diastolic velocities in the detection of celiac and mesenteric artery disease by duplex ultrasound

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    Perko, M J; Just, S; Schroeder, T V

    1997-01-01

    To assess the predictive value of ultrasound duplex scanning in the detection of superior mesenteric artery (SMA) and celiac artery (CA) occlusive disease.......To assess the predictive value of ultrasound duplex scanning in the detection of superior mesenteric artery (SMA) and celiac artery (CA) occlusive disease....

  9. Management of multiple type Ⅱ endoleaks detected by duplex ultrasound after endovascular abdominal aneurysm repair

    Institute of Scientific and Technical Information of China (English)

    GUO Da-qiao; LI Wei-miao; JIANG Jun-hao; SHI Zhen-yu; WANG Yu-qi; FU Wei-guo

    2012-01-01

    We reported a case of multiple type Ⅱ endoleaks detected by duplex ultrasound after endovascular abdominal aneurysm repair.The patient was undergoing warfarin therapy.Duplex ultrasound was applied as the sole surveillance method during follow-up and provided the concerned information for reintervention.The endoleaks were successfully repaired by coil embolization of the collaterals from the internal iliac artery feeding the fourth lumbar artery.

  10. Endoscopic ultrasound duplex scanning for measurement of portal venous flow. Validation against transit time ultrasound flowmetry in pigs

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    Hansen, E F; Strandberg, C; Bendtsen, F;

    1999-01-01

    with that of transit time ultrasound (TTU) in healthy pigs. The ability of EUS to detect changes in the portal venous flow after pharmacologic intervention was also investigated. METHODS: Six anaesthetized pigs were studied. Portal venous flow was measured simultaneously by EUS duplex scanning, using a Pentax FG-32UA...

  11. Vertebral artery dissection with compelling evidence on duplex ultrasound presenting only with neck pain

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    Siepmann T

    2016-11-01

    Full Text Available Timo Siepmann, Monique Borchert, Kristian Barlinn Department of Neurology, Carl Gustav Carus University Hospital, Technische Universität Dresden, Dresden, Germany Abstract: Vertebral artery dissection (VAD is among the most common identifiable etiologies of stroke in young adults and poses a diagnostic challenge due to nonspecific symptoms and substantial variability of imaging results. Here, we present a case of unspecific neck pain as isolated symptom of VAD with unusually compelling evidence on duplex ultrasound. This observation has clinical relevance as the absence of any neurological symptoms in our patient highlights the necessity of considering cervical artery dissection in patients presenting with unspecific symptoms such as neck pain, even if isolated. Furthermore, our image of intramural hematoma on duplex ultrasound has been captured in an unusual, clear and distinct fashion and might therefore be a useful reference image in the clinical assessment of patients with a suspicion of cervical artery dissection. Keywords: vertebrobasilar, cervical, duplex sonography, magnetic resonance imaging

  12. Partial nephroureterectomy in duplex renal system: preoperative 3D virtual rendering and retroperitoneal laparoscopic approach in children

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    Molinaro F.

    2013-10-01

    Full Text Available Introduction: the aim of this study is to presents the results of our preliminary series of 8 partial nephroureterectomy performed by retroperitoneoscopy using harmonic scalpel with a preoperative 3D virtual reconstruction of bidimensional magnetic resonance images in children affected by duplication of the renal system. Materials and methods: We perform a retrospective study in our Pediatric Surgery Unit from January 2007 to January 2012 of all children affected by duplication of the renal system treated by retroperitoneal laparoscopic approach. Images collected were reconstructed using IRCAD VR render software. Data include: sex, age at surgery, clinical and radiological features, surgical procedure, follow-up and complications. Results: retroperitoneal laparoscopic partial nephroureterectomy was performed in 8 children (6 males and 2 females. All patients had a non-functioning moiety of a duplex kidney and in addition recurrent urinary tract infections. Two cases were associated with ureterocele; of them in one case we performed a previous endoscopic incision of the obstructing ureterocele. All patients underwent radiological evaluation prior to surgery, by ultrasound, voididng cystourethrography, renal scintigraphy and contrast-enhanced MRI evaluations. Images collected were reconstructed using IRCAD VR render software. Patients were treated by a 3-4 trocars technique and parenchymal section was performed using harmonic scalpel. The mean operative time was 180 minutes; no cases required open conversion. The mean hospital stay was 5 days. The mean follow-up was 38 months. No cases of secondary atrophy of the lower pole were observed. Discussion: Volume rendering gives high anatomical resolution and it can be useful to guide the surgical procedure. Laparoscopic retroperitoneal partial nephrectomy is a safe and feasible procedure in children for experienced pediatric laparoscopic surgeons.

  13. Vertebral artery dissection with compelling evidence on duplex ultrasound presenting only with neck pain

    Science.gov (United States)

    Siepmann, Timo; Borchert, Monique; Barlinn, Kristian

    2016-01-01

    Vertebral artery dissection (VAD) is among the most common identifiable etiologies of stroke in young adults and poses a diagnostic challenge due to nonspecific symptoms and substantial variability of imaging results. Here, we present a case of unspecific neck pain as isolated symptom of VAD with unusually compelling evidence on duplex ultrasound. This observation has clinical relevance as the absence of any neurological symptoms in our patient highlights the necessity of considering cervical artery dissection in patients presenting with unspecific symptoms such as neck pain, even if isolated. Furthermore, our image of intramural hematoma on duplex ultrasound has been captured in an unusual, clear and distinct fashion and might therefore be a useful reference image in the clinical assessment of patients with a suspicion of cervical artery dissection. PMID:27843318

  14. Duplex Doppler ultrasound study of the temporomandibular joint.

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    Stagnitti, A; Marini, A; Impara, L; Drudi, F M; Lo Mele, L; Lillo Odoardi, G

    2012-06-01

    Sommario INTRODUZIONE: La fisiologia articolare dell’articolazione temporo-mandibolare (ATM) può essere esaminata sia dal punto di vista clinico che strumentale. La diagnostica per immagini ha da tempo contribuito con la risonanza magnetica (RM) e anche con la radiografia (Rx) e la tomografia computerizzata (TC) all’analisi della morfologia dei capi articolari e della cinetica condilare. L’esame duplex-ecodoppler è una metodica di largo impiego nello studio delle strutture in movimento in particolar modo a livello delle strutture del sistema vascolare. MATERIALI E METODI: È stata utilizzata un’apparecchiatura Toshiba APLIO SSA-770A, con l’uso di tecnica duplex-ecodoppler multi display, che consente la visualizzazione contemporanea dell’immagine ecografica e dei segnali Doppler utilizzando una sonda lineare del tipo phased array con cristalli trasduttori funzionanti ad una frequenza fondamentale di 6 MHz per gli spettri Doppler pulsati e 7.5 MHz per l’imaging ecografico. Sono stati esaminati nel Dipartimento di Scienze Radiologiche, Oncologiche e Anatomo-patologiche dell’Università “Sapienza” di Roma, 30 pazienti del reparto di Ortognatodonzia dell’Istituto di Odontoiatria della stessa Università. RISULTATI: Nei pazienti normali si è ottenuta un’alternanza regolare degli spettri Doppler, mentre nei soggetti con disfunzioni del complesso condilo-meniscale, si è persa la regolarità della sommatoria degli spettri di Fourier, con altezze incostanti in relazione a spostamenti irregolari del complesso condilo-meniscale. CONCLUSIONI: L’esame ecodoppler si è dimostrato, in tutti i pazienti, capace di discriminare quelli normali dai patologici e tra questi ultimi ha permesso di identificare gli aspetti più significativi delle patologie disfunzionali.

  15. Endoscopic ultrasound duplex scanning for measurement of portal venous flow. Validation against transit time ultrasound flowmetry in pigs

    DEFF Research Database (Denmark)

    Hansen, E F; Strandberg, C; Bendtsen, F

    1999-01-01

    BACKGROUND: Endoscopic ultrasound (EUS) is a new technique that makes it possible to measure portal venous flow when transabdominal ultrasound fails. As the technique has not been evaluated previously, we compared simultaneous measurements of portal venous flow using EUS Doppler with that of tran......BACKGROUND: Endoscopic ultrasound (EUS) is a new technique that makes it possible to measure portal venous flow when transabdominal ultrasound fails. As the technique has not been evaluated previously, we compared simultaneous measurements of portal venous flow using EUS Doppler...... with that of transit time ultrasound (TTU) in healthy pigs. The ability of EUS to detect changes in the portal venous flow after pharmacologic intervention was also investigated. METHODS: Six anaesthetized pigs were studied. Portal venous flow was measured simultaneously by EUS duplex scanning, using a Pentax FG-32UA...... echoendoscope connected to a Hitachi EUB 515-A ultrasound scanner, and by TTU with a Cardiomed CM 4000 flowmeter probe placed on the portal vein. Terlipressin, 1 mg, and placebo were administered in a blind, randomized, crossover design. Measurements were taken at base line and 30 min after each drug...

  16. Duplex ultrasound and computed tomography angiography in the follow-up of endovascular abdominal aortic aneurysm repair: a comparative study*

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    Cantador, Alex Aparecido; Siqueira, Daniel Emílio Dalledone; Jacobsen, Octavio Barcellos; Baracat, Jamal; Pereira, Ines Minniti Rodrigues; Menezes, Fábio Hüsemann; Guillaumon, Ana Terezinha

    2016-01-01

    Objective To compare duplex ultrasound and computed tomography (CT) angiography in terms of their performance in detecting endoleaks, as well as in determining the diameter of the aneurysm sac, in the postoperative follow-up of endovascular abdominal aortic aneurysm repair. Materials and Methods This was a prospective study involving 30 patients who had undergone endovascular repair of infrarenal aortoiliac aneurysms. Duplex ultrasound and CT angiography were performed simultaneously by independent radiologists. Measurements of the aneurysm sac diameter were assessed, and the presence or absence of endoleaks was determined. Results The average diameter of the aneurysm sac, as determined by duplex ultrasound and CT angiography was 6.09 ± 1.95 and 6.27 ± 2.16 cm, respectively. Pearson's correlation coefficient showing a statistically significant correlation (R = 0.88; p < 0.01). Comparing the duplex ultrasound and CT angiography results regarding the detection of endoleaks, we found that the former had a negative predictive value of 92.59% and a specificity of 96.15%. Conclusion Our results show that there is little variation between the two methods evaluated, and that the choice between the two would have no significant effect on clinical management. Duplex ultrasound could replace CT angiography in the postoperative follow-up of endovascular aneurysm repair of the infrarenal aorta, because it is a low-cost procedure without the potential clinical complications related to the use of iodinated contrast and exposure to radiation. PMID:27777476

  17. Duplex ultrasound and computed tomography angiography in the follow-up of endovascular abdominal aortic aneurysm repair: a comparative study

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    Cantador, Alex Aparecido; Siqueira, Daniel Emilio Dalledone; Jacobsen, Octavio Barcellos; Baracat, Jamal; Pereira, Ines Minniti Rodrigues; Menezes, Fabio Hüsemann; Guillaumon, Ana Terezinha, E-mail: alex_cantador@yahoo.com.br [Universidade Estadual de Campinas (FCM/UNICAMP), Campinas, SP (Brazil). Faculdade de Ciencias Medicas

    2016-07-15

    Objective: To compare duplex ultrasound and computed tomography (CT) angiography in terms of their performance in detecting endoleaks, as well as in determining the diameter of the aneurysm sac, in the postoperative follow-up of endovascular abdominal aortic aneurysm repair. Materials and Methods: This was a prospective study involving 30 patients who had undergone endovascular repair of infrarenal aortoiliac aneurysms. Duplex ultrasound and CT angiography were performed simultaneously by independent radiologists. Measurements of the aneurysm sac diameter were assessed, and the presence or absence of endoleaks was determined. Results: The average diameter of the aneurysm sac, as determined by duplex ultrasound and CT angiography was 6.09 ± 1.95 and 6.27 ± 2.16 cm, respectively. Pearson's correlation coefficient showing a statistically significant correlation (R = 0.88; p < 0.01). Comparing the duplex ultrasound and CT angiography results regarding the detection of endoleaks, we found that the former had a negative predictive value of 92.59% and a specificity of 96.15%. Conclusion: Our results show that there is little variation between the two methods evaluated, and that the choice between the two would have no significant effect on clinical management. Duplex ultrasound could replace CT angiography in the postoperative follow-up of endovascular aneurysm repair of the infrarenal aorta, because it is a low-cost procedure without the potential clinical complications related to the use of iodinated contrast and exposure to radiation. (author)

  18. Duplex ultrasound and computed tomography angiography in the follow-up of endovascular abdominal aortic aneurysm repair: a comparative study

    Directory of Open Access Journals (Sweden)

    Alex Aparecido Cantador

    Full Text Available Abstract Objective: To compare duplex ultrasound and computed tomography (CT angiography in terms of their performance in detecting endoleaks, as well as in determining the diameter of the aneurysm sac, in the postoperative follow-up of endovascular abdominal aortic aneurysm repair. Materials and Methods: This was a prospective study involving 30 patients who had undergone endovascular repair of infrarenal aortoiliac aneurysms. Duplex ultrasound and CT angiography were performed simultaneously by independent radiologists. Measurements of the aneurysm sac diameter were assessed, and the presence or absence of endoleaks was determined. Results: The average diameter of the aneurysm sac, as determined by duplex ultrasound and CT angiography was 6.09 ± 1.95 and 6.27 ± 2.16 cm, respectively. Pearson's correlation coefficient showing a statistically significant correlation (R = 0.88; p < 0.01. Comparing the duplex ultrasound and CT angiography results regarding the detection of endoleaks, we found that the former had a negative predictive value of 92.59% and a specificity of 96.15%. Conclusion: Our results show that there is little variation between the two methods evaluated, and that the choice between the two would have no significant effect on clinical management. Duplex ultrasound could replace CT angiography in the postoperative follow-up of endovascular aneurysm repair of the infrarenal aorta, because it is a low-cost procedure without the potential clinical complications related to the use of iodinated contrast and exposure to radiation.

  19. Role of Duplex Power Doppler Ultrasound in Differentiation between Malignant and Benign Thyroid Nodules

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    Algin, Oktay [Ataturk Training and Research Hospital Bilkent, Ankara (Turkmenistan); Algin, Efnan [Gazi University Medical Faculty, Ankara (Turkmenistan); Gokalp, Gokhan; Ocakog, Gokhan; Erdog an, Cuneyt; Saraydaroglu, Ozlem; Ercan Tuncel, Prof [Uludag University Medical Faculty, Bursa (Turkmenistan)

    2010-12-15

    To evaluate the usage of duplex power Doppler ultrasound (PDUS) for the differentiation of benign and malignant thyroid nodules. We prospectively examined 77 thyroid nodules in 60 patients undergoing ultrasound-guided fine needle aspiration biopsy (FNAB). Each nodule was described according to size, inner structure, borders, parenchymal echogenicity, peripheral halo formation, and the presence of calcification (Bmode ultrasound findings). Vascularity as determined by PDUS imaging was defined as non-vascular, peripheral, central, or of mixed type. For each nodule, the pulsatility index (PI) and resistive index (RI) values were obtained. Results of FNAB and surgical pathological examination (if available) were used as a proof of final diagnosis to categorize all nodules as benign or malignant. A receiver operating characteristic (ROC) curve analysis was performed to establish cut-off, sensitivity, and specificity values associated with RI-PI values. A significant relationship was observed between malignancy and irregular margins, microcalcifications, and hypoechogenicity on ultrasound examination (p < 0.05). The pattern of vascularity as determined by PDUS analysis was not a statistically significant criterion to suggest benign or malignant disease in this study (p > 0.05). The central, peripheral, and mean RI-PI values were higher in malignant nodules when compared to the other cytologies (p < 0.05). Vascularity is not a useful parameter for distinguishing malignant from benign thyroid nodules. However, RI and PI values are useful in distinguishing malignant from benign thyroid nodules

  20. Value of Duplex Ultrasound Assistance for Thromboaspiration and Dilation of Thrombosed Native Arterio-Venous Fistulae

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    Garcia-Medina, J., E-mail: josegmedina57@gmail.com [Reina Sophia University Hospital, Vascular and Interventional Radiology Unit, Department of Radiology (Spain)

    2013-12-15

    Purpose: To evaluate the value of duplex ultrasound assistance during thromboaspiration of thrombosed arteriovenous fistulae for haemodialysis. Materials and Methods: We prospectively studied 54 thrombosed native fistulae (23 with total thrombosis and 31 with partial thrombosis), in which we performed manual thromboaspiration guided by ultrasonography associated with fluoroscopy. Results: The fistulae were located in the forearm (n = 39) or in the upper arm (n = 15) of 46 patients. Mean patient age was 65 years, and hypertension was the most common risk factor (74 %). Mean access age was 928 days (range 69-2,290), and most fistulae were on the left side (41 cases, 75.92 %). The success rate was 83 % in the total thrombosis group and 100 % in the partial thrombosis group. Including initial failures, the respective primary patency rates in the total thrombosis group and the partial thrombosis group were, respectively, 83 {+-} 8 % (n = 20) and 87 {+-} 6 % (n = 28) at 1 month, 39 {+-} 10 % (n = 10) and 61 {+-} 8 % (n = 20) at 6 months, and 17 {+-} 8 % (n = 5) and 26 {+-} 8 % (n = 9) at 1 year. The mean decrease of fluoroscopy time with ultrasound was 3 min (range 1-5). The mean decrease of radiation dose was 2.6 Gy cm Superscript-Two (range 0.9-4.3]. Conclusion: Ultrasound is a feasible and useful tool in the management of thrombosed native fistulae, thus decreasing radiation exposure, and has no detrimental effect on success rates.

  1. [Pulsatile flow model with elastic blood vessels for duplex ultrasound studies].

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    Petrick, J; Schlief, R; Zomack, M; Langholz, J; Urbank, A

    1992-12-01

    Using ultrasound duplex technique flow phenomena in patients' circulation can be examined. For the interpretation of these examinations it is necessary to have extensive knowledge on flow influencing parameters. This can be easily obtained from simplified flow models. This article describes the components of a flow model that allows examination of ultrasonic contrast media flowing through an artificial heart and vessel mimicking tubes. The artificial heart is the drive which pumps a water glycerol cellulose mixture through the circulation in a pulsatile manner. The shape of the ventricle, the compliance of the aorta, the viscosity of the flow medium and the wall elasticity of the examination vessel were taken into account. The attenuation caused by the surrounding tissue is simulated by a variable layer of castor oil. The flow model is suitable to produce flow profiles that are very similar to physiological profiles.

  2. The role of penile color-duplex ultrasound for the evaluation of erectile dysfunction.

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    Aversa, Antonio; Sarteschi, Lelio Mario

    2007-09-01

    In the era of orally active agents, dynamic penile color-duplex ultrasound (D-PCDU) is not considered a necessary first screening for all patients with erectile dysfunction (ED). Various parameters, such as peak systolic flow velocity, end diastolic velocity, resistance index, acceleration time, and degree of arterial dilatation, have been suggested for the diagnosis of vascular ED by D-PCDU. To highlight the clinical utility and evidence-based interpretation of D-PCDU criteria. Extensive, unsystematic PubMed literature search reviewing relevant data on D-PCDU in the evaluation of male ED. The advantage of ultrasound is the minimally invasive nature of the procedure and the ability to screen patients to identify a normal arterial response of cavernous arteries. Men with sexual dysfunctions above 55 years of age and comorbidities are more likely to have multi-organ vascular dysfunction and may necessitate further testing because erectile failure may be the first presenting symptom requiring investigation and treatment even in the absence of cardiovascular risk factors. All patients affected with Peyronie's disease and younger men with persistent ED, a history of pelvic traumas, or fractures of the penile shaft should be offered ultrasonographic penile blood flow studies before referral to surgery or more invasive vascular investigations. In the near future, D-PCDU may be used in preference to patients presenting with or without vascular risk factors, particularly those not responding to first-line orally active drugs and seeking an explanation as to why these agents failed.

  3. Duplex ultrasound: A diagnostic tool for carotid stenosis management in type 2 diabetes mellitus

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    Yogan Kisten

    2013-01-01

    Full Text Available Background: Diabetic patients are at increased risk of developing cardiac events and stroke, and prevention of diabetes mellitus is therefore desirable. Marked geographical and ethnic variation in the prevalence of diabetes caused by urbanisation, demographic and epidemiological transitions has rendered this one of the major non-communicable diseases in South Africa. Duplex ultrasound (DUS plays an important role in primary health care in early detection of carotid atherosclerotic disease and the degree of carotid stenosis present. It is a reliable, cost-effective and non-invasive diagnostic tool. The purpose of this study was to determine the role of ultrasound in carotid stenosis management in type 2 diabetes mellitus (T2DM.Objectives: To determine the prevalence of carotid stenosis in a selected T2DM population using DUS and to correlate these findings with other predisposing atherosclerotic risk factors.Methods: The study setting was at an academic hospital in the Western Cape using carotid DUS reports of 103 diabetic subjects ≥ 35 years old. Predisposing risk factors were correlated with degree of carotid stenosis present. Data were analysed using the Fischer exact test, Chisquare and Student t-test.Results: Carotid DUS reports of 63 out of 103 T2DM patients revealed no evidence of a carotid stenosis, thereby lowering the risk profile. Forty patients were identified as having carotidstenosis; 22 symptomatic patients had a > 70% carotid stenosis which warranted surgicalintervention. A greater prevalence of stenosis in the Caucasian group, in both the male (p =0.0411 and female (p = 0.0458 cohorts, was noted. The overall trend suggested a relationship between T2DM and lifestyle, and a statistically significant relationship (p = 0.0063 between smoking and carotid stenosis was observed.Conclusion: T2DM and predisposing atherosclerotic risk factors significantly increased thepossibility of carotid stenosis development.

  4. Comparison of Colour Duplex Ultrasound with Computed Tomography to Measure the Maximum Abdominal Aortic Aneurysmal Diameter

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    C. Gray

    2014-01-01

    Full Text Available Introduction. Maximum diameter of an abdominal aortic aneurysm (AAA is the main indication for surgery. This study compared colour duplex ultrasound (CDU and computed tomography (CT in assessing AAA diameter. Patients and Methods. Patients were included if they had both scans performed within 90 days. Pearson’s correlation coefficient, paired t-test, and limits of agreement (LOA were calculated for the whole group. Subgroup analysis of small (6.5 cm aneurysms was performed. A P value of <0.05 was considered statistically significant. Results. 389 patients were included, giving 130 pairs of tests for comparison. Excellent correlation was in the whole group (r = 0.95 and in the subgroups (r = 0.94; 0.69; 0.96, resp.. Small LOA between the two imaging modalities was found in all subgroups. Conclusion. Small aneurysms can be accurately measured using CDU. CDU is preferable for small AAAs, but cannot supplant CT for planning aortic intervention.

  5. Observer agreement of lower limb venous reflux assessed by duplex ultrasound scanning using manual and pneumatic cuff compression in patients with chronic venous disease and controls

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    Broholm, R; Kreiner, S; Bækgaard, Niels;

    2011-01-01

    The study aimed to evaluate observer agreement between two experienced ultrasound operators examining deep venous reflux assessed by duplex ultrasound (DU) using either manual or pneumatic cuff compression. In addition, the two methods were compared with each other with regard to immediate...

  6. Preoperative Thyroid Ultrasound Is Indicated in Patients Undergoing Parathyroidectomy for Primary Hyperparathyroidism

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    Cletus A. Arciero, Zita S. Shiue, Jeremy D. Gates, George E. Peoples, Alan P. B. Dackiw, Ralph P. Tufano, Steven K. Libutti, Martha A. Zeiger, Alexander Stojadinovic

    2012-01-01

    Full Text Available Background: Primary hyperaparathyroidism (pHPT is often accompanied by underlying thyroid pathology that can confound preoperative parathyroid localization studies and complicate intra-operative decision making. The aim of this study was to examine the utility of preoperative thyroid ultrasonography (US in patients prior to undergoing parathyroidectomy for pHPT.Methods: An Institutional Review Board approved prospective study was undertaken from January 2005 through July 2008. All patients with pHPT meeting inclusion criteria (n=94 underwent preoperative thyroid ultrasound in addition to standard 99mTc-sestamibi scintigraphy for parathyroid localization. Demographics, operative management and final pathology were examined in all cases.Results: Fifty-four of the 94 patients (57% were noted to have a thyroid nodule on preoperative US, of which 30 (56% underwent further examination with fine needle aspiration biopsy. Alteration of the operative plan attributable to underlying thyroid pathology occurred in 16 patients (17%, with patients undergoing either total thyroidectomy (n=9 or thyroid lobectomy (n=7. Thyroid cancer was noted in 33% of patients undergoing thyroid resection, and 6% of all patients with HPT.Conclusions: The routine utilization of preoperative thyroid ultrasound in patients prior to undergoing parathyroid surgery for pHPT is indicated. The added information from this non-invasive modality facilitates timely management of co-incidental, and sometimes malignant, thyroid pathology.

  7. Correlation of preoperative MRI and intraoperative 3D ultrasound to measure brain tissue shift

    Science.gov (United States)

    Gobbi, David G.; Lee, Belinda K. H.; Peters, Terence M.

    2001-05-01

    B-Mode ultrasound is often used during neurosurgery to provide intra-operative images of the brain though a craniotomy, but the use of 3D ultrasound during surgery is still in its infancy. We have developed a system that provides real-time freehand 3D ultrasound reconstruction at a reduced resolution. The reconstruction proceeds incrementally and the 3D image is overlayed, via a computer, on a pre-operative 3D MRI scan. This provides the operator with the necessary feedback to maintain a constant freehand sweep-rate, and also ensures that the sweep covers the desired anatomical volume. All of the ultrasound video frames are buffered, and a full-resolution, compounded reconstruction proceeds once the manual sweep is complete. We have also developed tools for manual tagging of homologous landmarks in the 3D MRI and 3D ultrasound volumes that use a piecewise cubic approximation of thin-plate spline interpolation to achieve interactive nonlinear registration and warping of the MRI volume to the ultrasound volume: Each time a homologous point-pair is identified by the use, the image of the warped MRI is updated on the computer screen after less than 0.5 s.

  8. A prospective feasibility study of duplex ultrasound arterial mapping, digital-subtraction angiography, and magnetic resonance angiography in management of critical lower limb ischemia by endovascular revascularization.

    Science.gov (United States)

    Lowery, A J; Hynes, N; Manning, B J; Mahendran, M; Tawfik, S; Sultan, S

    2007-07-01

    Duplex ultrasound arterial mapping (DUAM) allows precise evaluation of peripheral vascular disease (PVD). However, magnetic resonance angiography (MRA) and digital-subtraction angiography (DSA) are the diagnostic tools used most frequently prior to intervention. Our aim was to compare clinical pragmatism, hemodynamic outcomes, and cost-effectiveness when using DUAM alone compared to DSA or MRA as preoperative assessment tools for endovascular revascularization (EvR) in critical lower limb ischemia (CLI). From 2002 through 2005, 465 patients were referred with PVD. Of these, 199 had CLI and 137 required EvR. Preoperative diagnostic evaluation included DUAM (n = 41), DSA (n = 50), or MRA (n = 46). EvR was aortoiliac in 27% of cases and infrainguinal in 73%. Patients were assessed at day 1, 6 weeks, 3 months, and 6 months. Composite end points were relief of rest pain, ulcer/gangrene healing, and increase in perfusion pressure, as measured by ankle-brachial index (ABI) and digital pressures. Patency by DUAM, limb salvage, morbidity, mortality, length of stay, and cost-effectiveness were compared between groups using nonparametric t-test, analysis of variance, and Kaplan-Meier analysis. The three groups were comparable in terms of age, sex, comorbidity, and Society for Vascular Surgery/International Society of Cardiovascular Surgery clinical classification. Six-month mean improvement in ABI in the DUAM group was comparable to that in the DSA group (P = 0.25) and significantly better than that in the MRA group (P < 0.05). Six-month patency rates for the DUAM group were comparable to those in the DSA group (P = 0.68, relative risk [RR] = 0.74, 95% confidence interval [CI] 0.18-2.99) and superior to that in the MRA group (P = 0.022, RR = 0.255, 95% CI 0.09-0.71). Length of hospital stay was lower in the DUAM group compared with the DSA group (P < 0.0001) and the MRA group (P = 0.0003). The cost of DUAM is lower than that of both DSA and MRA. DUAM accurately identified the

  9. A High-Frequency High Frame Rate Duplex Ultrasound Linear Array Imaging System for Small Animal Imaging

    Science.gov (United States)

    Zhang, Lequan; Xu, Xiaochen; Hu, Changhong; Sun, Lei; Yen, Jesse T.; Cannata, Jonathan M.; Shung, K. Kirk

    2010-01-01

    High-frequency (HF) ultrasound imaging has been shown to be useful for non-invasively imaging anatomical structures of the eye and small animals in biological and pharmaceutical research, achieving superior spatial resolution. Cardiovascular research utilizing mice requires not only real-time B-scan imaging, but also ultrasound Doppler to evaluate both anatomy and blood flow of the mouse heart. This paper reports the development of a high frequency ultrasound duplex imaging system capable of both B-mode imaging and Doppler flow measurements, using a 64-element linear array. The system included a HF pulsed-wave Doppler module, a 32-channel HF B-mode imaging module, a PC with a 200 MS/s 14-bit A/D card, and real-time LabView software. A 50dB signal-to-noise ratio (SNR) and a depth of penetration of larger than 12 mm were achieved using a 35 MHz linear array with 50 μm pitch. The two-way beam widths were determined to be 165 μm to 260 μm and the clutter energy to total energy ratio (CTR) were 9.1 dB to 12 dB, when the array was electronically focused at different focal points at depths from 4.8 mm to 9.6 mm. The system is capable of acquiring real-time B-mode images at a rate greater than 400 frames per second (fps) for a 4.8 × 13 mm field of view, using a 30 MHz 64-element linear array with 100 μm pitch. Sample in vivo cardiac high frame rate images and duplex images of mouse hearts are shown to assess its current imaging capability and performance for small animals. PMID:20639149

  10. The role of ultrasound and nuclear medicine methods in the preoperative diagnostics of primary hyperparathyroidism

    Science.gov (United States)

    Cacko, Marek; Królicki, Leszek

    2015-01-01

    Primary hyperparathyroidism (PH) represents one of the most common endocrine diseases. In most cases, the disorder is caused by parathyroid adenomas. Bilateral neck exploration has been a widely used treatment method for adenomas since the 20's of the twentieth century. In the last decade, however, it has been increasingly replaced by a minimally invasive surgical treatment. Smaller extent, shorter duration and lower complication rate of such a procedure are emphasized. Its efficacy depends on a precise location of parathyroid tissue during the preoperative imaging. Scintigraphy and ultrasound play a major role in the diagnostic algorithms. The efficacy of both methods has been repeatedly verified and compared. The still-current guidelines of the European Association of Nuclear Medicine (2009) emphasize the complementary role of scintigraphy and ultrasonography in the preoperative diagnostics in patients with primary hyperparathyroidism. At the same time, attempts are made to improve both these techniques by implementing new study protocols or innovative technologies. Publications have emerged in the recent years in the field of ultrasonography, whose authors pointed out the usefulness of elastography and contrast media. Nuclear medicine studies, on the other hand, focus mainly on the assessment of new radiotracers used in the positron emission tomography (PET). The aim of this article is to present, based on literature data, the possibilities of ultrasound and scintigraphy in the preoperative diagnostics in patients with primary hyperparathyroidism. Furthermore, the main directions in the development of imaging techniques in PH patients were evaluated. PMID:26807297

  11. New prototype neuronavigation system based on preoperative imaging and intraoperative freehand ultrasound: system description and validation.

    Science.gov (United States)

    Mercier, Laurence; Del Maestro, Rolando F; Petrecca, Kevin; Kochanowska, Anna; Drouin, Simon; Yan, Charles X B; Janke, Andrew L; Chen, Sean Jy-Shyang; Collins, D Louis

    2011-07-01

    The aim of this report is to present IBIS (Interactive Brain Imaging System) NeuroNav, a new prototype neuronavigation system that has been developed in our research laboratory over the past decade that uses tracked intraoperative ultrasound to address surgical navigation issues related to brain shift. The unique feature of the system is its ability, when needed, to improve the initial patient-to-preoperative image alignment based on the intraoperative ultrasound data. Parts of IBIS Neuronav source code are now publicly available on-line. Four aspects of the system are characterized in this paper: the ultrasound probe calibration, the temporal calibration, the patient-to-image registration and the MRI-ultrasound registration. In order to characterize its real clinical precision and accuracy, the system was tested in a series of adult brain tumor cases. Three metrics were computed to evaluate the precision and accuracy of the ultrasound calibration. 1) Reproducibility: 1.77 mm and 1.65 mm for the bottom corners of the ultrasound image, 2) point reconstruction precision 0.62-0.90 mm: and 3) point reconstruction accuracy: 0.49-0.74 mm. The temporal calibration error was estimated to be 0.82 ms. The mean fiducial registration error (FRE) of the homologous-point-based patient-to-MRI registration for our clinical data is 4.9 ± 1.1 mm. After the skin landmark-based registration, the mean misalignment between the ultrasound and MR images in the tumor region is 6.1 ± 3.4 mm. The components and functionality of a new prototype system are described and its precision and accuracy evaluated. It was found to have an accuracy similar to other comparable systems in the literature.

  12. Real-time MRI navigated ultrasound for preoperative tumor evaluation in breast cancer patients: Technique and clinical implementation

    Energy Technology Data Exchange (ETDEWEB)

    Park, Ah Young; Seo, Bo Kyoung [Dept. of Radiology, Korea University Ansan Hospital, Korea University College of Medicine, Ansan (Korea, Republic of)

    2016-09-15

    Real-time magnetic resonance imaging (MRI) navigated ultrasound is an image fusion technique to display the results of both MRI and ultrasonography on the same monitor. This system is a promising technique to improve lesion detection and analysis, to maximize advantages of each imaging modality, and to compensate the disadvantages of both MRI and ultrasound. In evaluating breast cancer stage preoperatively, MRI and ultrasound are the most representative imaging modalities. However, sometimes difficulties arise in interpreting and correlating the radiological features between these two different modalities. This pictorial essay demonstrates the technical principles of the real-time MRI navigated ultrasound, and clinical implementation of the system in preoperative evaluation of tumor extent, multiplicity, and nodal status in breast cancer patients.

  13. Real-Time MRI Navigated Ultrasound for Preoperative Tumor Evaluation in Breast Cancer Patients: Technique and Clinical Implementation

    Energy Technology Data Exchange (ETDEWEB)

    Park, Ah Young; Seo, Bo Kyoung [Department of Radiology, Korea University Ansan Hospital, Korea University College of Medicine, Ansan 15355 (Korea, Republic of)

    2016-11-01

    Real-time magnetic resonance imaging (MRI) navigated ultrasound is an image fusion technique to display the results of both MRI and ultrasonography on the same monitor. This system is a promising technique to improve lesion detection and analysis, to maximize advantages of each imaging modality, and to compensate the disadvantages of both MRI and ultrasound. In evaluating breast cancer stage preoperatively, MRI and ultrasound are the most representative imaging modalities. However, sometimes difficulties arise in interpreting and correlating the radiological features between these two different modalities. This pictorial essay demonstrates the technical principles of the real-time MRI navigated ultrasound, and clinical implementation of the system in preoperative evaluation of tumor extent, multiplicity, and nodal status in breast cancer patients.

  14. Endoscopic ultrasound duplex scanning for measurement of portal venous flow. Validation against transit time ultrasound flowmetry in pigs

    DEFF Research Database (Denmark)

    Hansen, Erik Feldager; Strandberg, C; Bendtsen, F;

    1999-01-01

    echoendoscope connected to a Hitachi EUB 515-A ultrasound scanner, and by TTU with a Cardiomed CM 4000 flowmeter probe placed on the portal vein. Terlipressin, 1 mg, and placebo were administered in a blind, randomized, crossover design. Measurements were taken at base line and 30 min after each drug...

  15. Preoperative evaluation of peripheral nerve injuries: What is the place for ultrasound?

    Science.gov (United States)

    Toia, Francesca; Gagliardo, Andrea; D'Arpa, Salvatore; Gagliardo, Cesare; Gagliardo, Giuseppe; Cordova, Adriana

    2016-09-01

    OBJECTIVE The purpose of this study was to evaluate the usefulness of ultrasound in the preoperative workup of peripheral nerve lesions and illustrate how nerve ultrasonography can be integrated in routine clinical and neurophysiological evaluation and in the management of focal peripheral nerve injuries. The diagnostic role and therapeutic implications of ultrasonography for different neuropathies are described. METHODS The authors analyzed the use of ultrasound in 119 entrapment, tumoral, posttraumatic, or postsurgical nerve injuries of limbs evaluated in 108 patients during 2013 and 2014. All patients were candidates for surgery, and in all cases the evaluation included clinical examination, electrodiagnostic studies (nerve conduction study and electromyography), and ultrasound nerve study. Ultrasound was used to explore the nerve fascicular echotexture, continuity, and surrounding tissues. The maximum cross-sectional area (CSA) and the presence of epineurial hyperechogenicity or intraneural hyper- or hypoechogenicity, of anatomical anomalies, dynamic nerve dislocations, or compressions were recorded. The concordance rate of neurophysiological and ultrasonographic data was analyzed, classifying ultrasound findings as confirming, contributive, or nonconfirming with respect to electrodiagnostic data. The correlation between maximum nerve CSA and neurophysiological severity degree in entrapment syndromes was statistically analyzed. RESULTS Ultrasonography confirmed electrodiagnostic findings in 36.1% of cases and showed a contributive role in the diagnosis and surgical planning in 53.8% of all cases; the findings were negative ("nonconfirming") in only 10.1% of the patients. In 16% of cases, ultrasound was not only contributive, but had a key diagnostic role in the presence of doubtful electrodiagnostic findings. The contributive role differed according to etiology, being higher for tumors (100%) and for posttraumatic or postsurgical neuropathies (72.2%) than for

  16. Predictive factors for recurrence of cryptoglandular fistulae characterized by preoperative three-dimensional endoanal ultrasound.

    Science.gov (United States)

    Visscher, A P; Schuur, D; Slooff, R A E; Meijerink, W J H J; Deen-Molenaar, C B H; Felt-Bersma, R J F

    2016-05-01

    Precise information regarding the location of an anal fistula and its relationship to adjacent structures is necessary for selecting the best surgical strategy. Retrospective and cross-sectional studies were performed to determine predictive factors for recurrence of anal fistula from preoperative examination by three-dimensional endoanal ultrasound (3D-EAUS). Patients in our tertiary centre and in a private centre specialized in proctology undergoing preoperative 3D-EAUS for cryptoglandular anal fistulae between 2002 and 2012 were included. A questionnaire was sent in September 2013 to assess the patient's condition with regard to recurrence. Variables checked for association with recurrence were gender, type of centre, previous fistula surgery, secondary track formation and classification of the fistula. There were 143 patients of whom 96 had a low fistula treated by fistulotomy, 28 a high fistula treated by fistulectomy and 19 a high fistula treated by fistulectomy combined with a mucosal advancement flap. The median duration of follow-up was 26 (2-118) months. The fistula recurred in 40 (27%) patients. Independent risk factors included the presence of secondary track formation [hazard ratio 2.4 (95% CI 1.2-51), P = 0.016] and previous fistula surgery [hazard ratio 1.2 (95% CI 1.0-4.6), P = 0.041]. Agreement between the 3D-EAUS examination and the evaluation under anaesthesia regarding the site of the internal opening, classification of the fistula and the presence of secondary tracks was 97%, 98% and 78%. The identification of secondary tracks by preoperative 3D-EAUS examination was the strongest independent risk factor for recurrence. This stresses the importance of preoperative 3D-EAUS in mapping the pathological anatomy of the fistula and a thorough search for secondary track formation during surgery. Colorectal Disease © 2015 The Association of Coloproctology of Great Britain and Ireland.

  17. Preoperative RFA simulation for liver cancer using a CT virtual ultrasound system

    Energy Technology Data Exchange (ETDEWEB)

    Kudo, Kosei [Fourth Department of Gastroenterology and Hepatology, Tokyo Medical University, 6-7-1 Nishishinjuku, Shinjukuku-ku, Tokyo 160-0023 (Japan); Moriyasu, Fuminori [Fourth Department of Gastroenterology and Hepatology, Tokyo Medical University, 6-7-1 Nishishinjuku, Shinjukuku-ku, Tokyo 160-0023 (Japan)]. E-mail: moriyasu@tokyo-med.ac.jp; Mine, Yoshitaka [R and D, Toshiba Medical Systems Co., Tokyo (Japan); Miyata, Yuki [Fourth Department of Gastroenterology and Hepatology, Tokyo Medical University, 6-7-1 Nishishinjuku, Shinjukuku-ku, Tokyo 160-0023 (Japan); Sugimoto, Katsutoshi [Fourth Department of Gastroenterology and Hepatology, Tokyo Medical University, 6-7-1 Nishishinjuku, Shinjukuku-ku, Tokyo 160-0023 (Japan); Metoki, Ryou [Fourth Department of Gastroenterology and Hepatology, Tokyo Medical University, 6-7-1 Nishishinjuku, Shinjukuku-ku, Tokyo 160-0023 (Japan); Kamamoto, Hiroyuki [Fourth Department of Gastroenterology and Hepatology, Tokyo Medical University, 6-7-1 Nishishinjuku, Shinjukuku-ku, Tokyo 160-0023 (Japan); Suzuki, Shirou [Fourth Department of Gastroenterology and Hepatology, Tokyo Medical University, 6-7-1 Nishishinjuku, Shinjukuku-ku, Tokyo 160-0023 (Japan); Shimizu, Masafumi [Fourth Department of Gastroenterology and Hepatology, Tokyo Medical University, 6-7-1 Nishishinjuku, Shinjukuku-ku, Tokyo 160-0023 (Japan); Miyahara, Takeo [Fourth Department of Gastroenterology and Hepatology, Tokyo Medical University, 6-7-1 Nishishinjuku, Shinjukuku-ku, Tokyo 160-0023 (Japan); Yokoi, Masato [Fourth Department of Gastroenterology and Hepatology, Tokyo Medical University, 6-7-1 Nishishinjuku, Shinjukuku-ku, Tokyo 160-0023 (Japan); Horibe, Toshiya [Fourth Department of Gastroenterology and Hepatology, Tokyo Medical University, 6-7-1 Nishishinjuku, Shinjukuku-ku, Tokyo 160-0023 (Japan); Yamagata, Hitoshi [R and D, Toshiba Medical Systems Co., Tokyo (Japan)

    2007-02-15

    We developed a computed tomography (CT) virtual ultrasound system (CVUS) as an imaging system to support treatment under percutaneous ultrasound (US) guidance. This prototype clinical system, produced in collaboration with Tokyo Medical University, uses display software developed by Toshiba Medical Systems. We examined the utility of this system by scheduling treatment plans preoperatively and simulating puncture and radiofrequency ablation (RFA) for liver cancer. The study enrolled 51 liver cancer patients with 66 nodules 0.8-8 cm in diameter in which RFA was performed between June 2004 and December 2004. Virtual US and multiplanar reconstruction (MPR) images were constructed on the basis of DICOM CT data and puncture and ablation of liver cancer were simulated. The following were evaluated: (1) how to avoid complications and determine an appropriate puncture route by simulating puncture with C-mode MPR images; (2) determination of the three-dimensional location of the tumor for ablation, as well as the adjacent organs and vessels, by MPR rotation 360{sup o} around the center of the tumor (center lock); and (3) how to determine the center and volume of ablation and avoid injuries to nearby organs and vessels by simulating ablation procedures. C -mode MPR images were effective for (1) determining and modifying the puncture route in 35 of 51 cases (69.6%) and (2) determining the spatial location of vessels and nearby organs in 50 of 51 cases (98.0%) by the center lock; and (3) simulating the ablation helped determine the center and volume of ablation by avoiding injuries to vessels and nearby organs in 45 or 51 cases (88.2%). Taken together, the CVUS allowed easy simulation of local treatment of liver cancer under US guidance using CT data alone and the preoperative simulation predicted an improvement in the safety of local therapy of liver cancer.

  18. Role of preoperative endoscopic ultrasound-guided fine-needle tattooing of a pancreatic head insulinoma

    Institute of Scientific and Technical Information of China (English)

    Pornchai; Leelasinjaroen; Wuttiporn; Manatsathit; Richard; Berri; Mohammed; Barawi; Frank; G; Gress

    2014-01-01

    Although insulinomas are rare, they are the most com-mon pancreatic neuroendocrine tumor, with an inci-dence of four cases per million population. Insulinomas are generally benign indolent intrapancreatic tumors. Surgical resection remains the main option for treat-ment. However, up to 67% of a pancreatic head insu-linomas are nonpalpable, thus surgical resection of the nonplapable insulinoma in this area could become prob-lematic resulting in prolonged surgical time, increased risk of pancreatic duct injury and need for pancreati-coduodenectomy. Endoscopic ultrasound-guided fine- needle tattooing(EUS-FNT), has been shown to have a crucial role for localization of pancreatic body and tail lesions, facilitating laparoscopic distal pancreatectomyand helping surgeons identify the location of the tumor. EUS-FNT might have a role for preoperative localiza-tion of pancreatic head insulinomas which are likely to be nonpalpable. We report a case of preoperative EUS-FNT for localization of a nonplapable pancreatic head insulinoma. This report demonstrates that EUS-FNT of pancreatic head insulinomas may facilitate surgical resection, reduce operative time and decrease surgical complications.

  19. Duplex ultrasound in aneurysm surveillance following endovascular aneurysm repair: a comparison with computed tomography aortography.

    LENUS (Irish Health Repository)

    Manning, Brian J

    2012-02-01

    OBJECTIVES: Cumulative radiation dose, cost, and increased demand for computed tomography aortography (CTA) suggest that duplex ultrasonography (DU) may be an alternative to CTA-based surveillance. We compared CTA with DU during endovascular aneurysm repair (EVAR) follow-up. METHODS: Patients undergoing EVAR had clinical and radiological follow-up data entered in a prospectively maintained database. For the purpose of this study, the gold standard test for endoleak detection was CTA, and an endoleak detected on DU alone was assumed to be a false positive result. DU interpretation was performed independently of CTA and vice versa. RESULTS: One hundred thirty-two patients underwent EVAR, of whom 117 attended for follow-up ranging from six months to nine years (mean, 32 months). Adequate aneurysm sac visualisation on DU was not possible in 1.7% of patients, predominantly due to obesity. Twenty-eight endoleaks were detected in 28 patients during follow-up. Of these, 24 were initially identified on DU (four false negative DU examinations), and eight had at least one negative CTA with a positive DU prior to diagnosis. Twenty-three endoleaks were type II in nature and three of these patients had increased sac size. There was one type I and four type III endoleaks. Two of these (both type III) had an increased sac size. Of 12 patients with increased aneurysm size of 5 mm or more at follow-up, five had an endoleak visible on DU, yet negative CTA and a further five had endoleak visualisation on both DU and CTA. Of six endoleaks which underwent re-intervention, all were initially picked up on DU. One of these endoleaks was never demonstrated on CTA and a further two had at least one negative CTA prior to endoleak confirmation. Positive predictive value for DU was 45% and negative predictive value 94%. Specificity of DU for endoleak detection was 67% when compared with CTA, because of the large number of false positive DU results. Sensitivity for DU was 86%, with all

  20. The value of preoperative ultrasound guided fine-needle aspiration cytology of radiologically suspicious axillary lymph nodes in breast cancer

    Directory of Open Access Journals (Sweden)

    Torill Sauer

    2014-01-01

    Full Text Available Background: Preoperative ultrasound (US and eventually US-guided fine-needle aspiration cytology (FNAC of suspicious axillary lymph nodes (ALN is a standard procedure in the work-up of suspicious breast lesions. Preoperative US FNAC may prevent sentinel node biopsy (SNB procedure in 24-30% of patients with early stage breast carcinoma. The aim of this study was to evaluate the institutional results of this preoperative diagnostic procedure. Materials and Methods: A total of 182 cases of preoperative FNAC of suspicious ALN where retrieved from the pathology files. The results were compared with the final histology and staging. False negative (FN FNAC cases were reviewed and possibly missed metastatic cases (2 were immunostained with the epithelial marker AE1/AE3. Results: There were no false positives, whereas 16 cases were FN. In all but one case the FN′s represented sampling error. Half of the 16 FN cases in this series were macrometastases. Discussion: About 83% of the preoperatively aspirated cases were N+, indicating that a radiologically suspicious ALN has a very high risk of being metastatic. Preoperative US guided FNAC from radiologically suspicious ALN is highly efficient in detecting metastases. Depending on national guidelines, a preoperative, positive ALN FNAC might help to stratify the patients as to SNB and/or ALN dissection.

  1. Pre-operative detection of thyroid pyramidal lobes by ultrasound and computed tomography.

    Science.gov (United States)

    Ryu, Ji Hwa; Kim, Dong Wook; Kang, Taewoo

    2014-07-01

    This study aimed to assess the diagnostic accuracy of pre-operative ultrasound (US) and computed tomography (CT) for detecting thyroid pyramidal lobe (TPL). A single radiologist prospectively performed thyroid US and retrospectively reviewed neck CT to detect TPLs in 135 consecutive patients scheduled for thyroid surgery. The location, size and superior extent of each TPL and its separation or continuity with the main thyroid gland were assessed by thyroid US, neck CT and surgery. The prevalence of TPLs as diagnosed by thyroid US, neck CT and surgery was 58.5% (79/135), 56.3% (76/135) and 60% (81/135), respectively. We compared US and CT detection of TPLs with surgical data to determine their sensitivity (85.2% and 91.4%), specificity (81.5% and 94.4%), positive (87.3% and 96.1%) and negative (78.6% and 87.9%) predictive values and accuracy (83.7% and 92.6%). For detecting TPLs, both neck CT and thyroid US have good diagnostic value, although neck CT is more accurate than thyroid US.

  2. [The value of transendoscopy thermometry of gastric mucosa in the evaluation of blood flow in patients with osteoarthrosis and atherosclerosis by duplex ultrasound of extracranial brachiocephalic arteries].

    Science.gov (United States)

    Chopeĭ, I V; Bratasiuk, A M; Chopeĭ, O I; Myhovych, I I; Hanynets', P P; Kanchiĭ, V M; Bychko, M M; Madi, Iu Iu

    2014-01-01

    The pathogenesis of gastric mucosa lesions in elderly and senile people has many factors. It's based on contradiction between protective factors (mucus secretion, prostaglandins, bicarbonate, microcirculation, regeneration, etc.) and aggression factors (hydrochloric acid, pepsin, bile acids, pancreatic enzymes, bacteria). In addition, such important factors as neurohumoral disorders, nutrition and vascularization of the gastric mucosa have attached. The aim of the study was to evaluate the possible relations between microcirculation and data of gastric mucosa transendoscopy thermometry in elderly and senile patients with atherosclerosis confirmed by duplex ultrasound of extracranial brachiocephalic arteries.

  3. Ductal carcinoma in situ diagnosed using an ultrasound-guided 14-gauge core needle biopsy of breast masses: can underestimation be predicted preoperatively?

    Directory of Open Access Journals (Sweden)

    Sung Hee Park

    2014-04-01

    Conclusion: We found a 30.4% rate of DCIS underestimation in breast masses based on a US-14G-CNB. The presence of abnormal lymph nodes as detected on axillary ultrasound may be useful to preoperatively predict underestimation.

  4. Endovascular aneurysm repair: state-of-art imaging techniques for preoperative planning and surveillance

    DEFF Research Database (Denmark)

    Truijers, M; Resch, T; Van Den Berg, J C

    2009-01-01

    Endovascular aneurysm repair (EVAR) represents one of the greatest advances in vascular surgery over the past 50 years. In contrast to conventional aneurysm repair, EVAR requires accurate preoperative imaging and stringent postoperative surveillance. Duplex ultrasound (DUS), transesophageal...... echocardiography, intravascular ultrasound, computed tomography (CT) and magnetic resonance (MR), each provide useful information for patient selection, choice of endograft type and surveillance. Today most interventionists and surgeons will rely on CT or MR to assess aortic morphology, evaluate access artery...

  5. Penile vascular diagnostic categorization using penile duplex Doppler ultrasound: Differences in vascular hemodynamics parameters by differences in anatomic sampling location

    Directory of Open Access Journals (Sweden)

    Fabio Pezzoni

    2016-10-01

    Full Text Available Objectives. In 2013 the International Society for Sexual Medicine(ISSM published the guidelines regarding the standard operating procedure (SOP for penile duplex Doppler ultrasound (PDDU. Although ISSM-SOP have given important strides in reducing interobserver variability in PDDU by procedural protocol and parameters these guidelines do not address the anatomic location along the penis at which hemodynamic measurements have to be done. In our opinion a “double sampling” may be interesting to detect the arteriogenic or venogenic nature of the erectile dysfunction (ED. In particular sampling measurements at the “crus” (at the level of the peno-scrotal junction may be significative for detection of veno-occlusive dysfunction (VOD,whereas an evaluation at “mid penis” (1/2 distance between peno-scrotal junction and coronal sulcus, may be useful to diagnose an arterial insufficiency (AI. Material and Methods. We evalued 90 men, mean age 56.3, affected with ED of medium degree, responder to PDE5-I that urdergone to PDDU and also responder after pharmacologic intracavernosal injection (PIIof prostaglandin E1 20 mcg, with rigid erection and normal maintenance. We moreover evalued 90 men in youthful age (mean 35.2, in absence of vascular risk factors, no responder to PDE5-I that undergone to PDDU by PII at high dosage (bimix: prostaglandin E1 20 mcg, papaverine 20 mg. Results. In the first pool the sampling at “mid penis” resulted significative for arterial insuffciency (AI in 81% (73, in presence of normal or borderline end diastolic velocity (EDV. Sampling at the “crus” resulted negative for VOD in 90% (81. In the second pool, 66.6% (60 resulted responder with rigid erection and normal maintenance in presence of normal hemodynamic parameters: peak systolic velocity (PSV and end diastolic velocity (EDV both at the “crus” and at “mid penis” sampling. 33.4% (30 responded with a semirigid erection and manifested a constant

  6. Preoperative High-Resolution Ultrasound for the Assessment of Malignant Central Compartment Lymph Nodes in Papillary Thyroid Cancer.

    Science.gov (United States)

    Khokhar, Mamoona T; Day, Kristopher M; Sangal, Rohit B; Ahmedli, Nigar N; Pisharodi, Latha R; Beland, Michael D; Monchik, Jack M

    2015-12-01

    The identification and removal of malignant central compartment lymph nodes (MCLN) is important to minimize the risk of persistent or recurrent local disease in patients with papillary thyroid cancer (PTC). While the diagnostic accuracy of preoperative ultrasound for the assessment of lateral compartment node metastases is well recognized, its role in the identification of central compartment node metastases in patients with PTC is less established. This study delineates the utility of high-resolution ultrasound (HUS) for the assessment of MCLN in patients with PTC. A retrospective chart review was performed of 227 consecutive patients who underwent total thyroidectomy for biopsy-proven PTC by a single endocrine surgeon in an academic tertiary care center between 2004 and 2014. Preoperative sonographic results were compared to postoperative pathology reports to determine the accuracy of HUS for the assessment of MCLN. Statistical analysis also included sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). HUS identified abnormal central compartment nodes in 51 (22.5%) patients. All 227 patients underwent a careful central compartment node exploration. One hundred and four (45.8%) patients had MCLN identified by surgery, of whom 65 (62.5%) had a negative preoperative central compartment HUS. The sensitivity and specificity of preoperative HUS for the assessment of MCLN were 0.38 and 0.90, respectively. The PPV and NPV were 0.76 and 0.63, with an accuracy of 0.66. Preoperative HUS is quite specific for the identification of MCLN in patients with PTC. The present findings emphasize, however, that a negative HUS does not obviate the need for careful exploration of the central compartment to minimize the risk of persistent or recurrent local disease.

  7. Ten-year technical and clinical outcomes in TransAtlantic Inter-Society Consensus II infrainguinal C/D lesions using duplex ultrasound arterial mapping as the sole imaging modality for critical lower limb ischemia.

    LENUS (Irish Health Repository)

    Sultan, Sherif

    2013-04-01

    The aim of this study was to evaluate duplex ultrasound arterial mapping (DUAM) as the sole imaging modality when planning for bypass surgery (BS) and endovascular revascularization (EvR) in patients with critical limb ischemia for TransAtlantic Inter-Society Consensus (TASC) II C\\/D infrainguinal lesions.

  8. MRI, PET/CT and ultrasound in the preoperative staging of endometrial cancer - a multicenter prospective comparative study

    DEFF Research Database (Denmark)

    Antonsen, Sofie Leisby; Jensen, Lisa Neerup; Loft, Annika;

    2013-01-01

    OBJECTIVES: The aim of this prospective multicenter study was to evaluate and compare the diagnostic performance of PET/CT, MRI and transvaginal two-dimensional ultrasound (2DUS) in the preoperative assessment of endometrial cancer (EC). METHODS: 318 consecutive women with EC were included when...... referred to three Danish tertiary gynecological centers for surgical treatment. Preoperatively they were PET/CT-, MRI-, and 2DUS scanned. The imaging results were compared to the final pathological findings. This study was approved by the National Committee on Health Research Ethics. RESULTS......: For predicting myometrial invasion, we found sensitivity, specificity, PPV, NPV, and accuracy for PET/CT to be 93%, 49%, 41%, 95% and 61%, for MRI to be 87%, 57%, 44%, 92%, and 66% and for 2DUS to be 71%, 72%, 51%, 86% and 72%. For predicting cervical invasion, the values were 43%, 94%, 69%, 85% and 83...

  9. Management of anterior triangle swellings in a tertiary vascular centre with emphasis on the roles of duplex ultrasound, computed tomography angiogram and magnetic resonance angiogram: a case series.

    LENUS (Irish Health Repository)

    Colleran, Gabrielle C

    2009-01-01

    BACKGROUND: Anterior triangle masses pose an important clinical dilemma. It is very difficult to distinguish the potential pathologies pre operatively by clinical and radiological assessment. CASE REPORT: The first case highlights the management of a bilateral chemodectoma, the second case is a presentation of castleman\\'s disease and the third is that of metastatic tonsillar adenocarcinoma. All three cases had a similar presentation and radiological appearance pre-operatively. CONCLUSION: Anterior triangle masses span the clinical spectrum of pathologies from chemodectoma to castleman\\'s disease to carcinoma. Expert vascular and radiological management is required for optimum patient care and should take place in a tertiary referral centre. Duplex US, CTA and MRA are important pre operative assessment tools to ensure that adequate information regarding the relationship of the lesion to the carotid artery is available to the operating surgeon who should have vascular expertise as deliberate practice volume has been repeatedly shown to result in improved patient outcome.

  10. Clinical utility of ultrasound and {sup 99m}Tc sestamibi SPECT/CT for preoperative localization of parathyroid adenoma in patients with primary hyperparathyroidism

    Energy Technology Data Exchange (ETDEWEB)

    Patel, C.N., E-mail: chirag_patel@totalise.co.u [Department of Radiology and Nuclear Medicine, Leeds Teaching Hospitals NHS Trust, Leeds (United Kingdom); Salahudeen, H.M. [Department of Radiology and Nuclear Medicine, Leeds Teaching Hospitals NHS Trust, Leeds (United Kingdom); Lansdown, M. [Department of Endocrine Surgery, Leeds Teaching Hospitals NHS Trust, Leeds (United Kingdom); Scarsbrook, A.F. [Department of Radiology and Nuclear Medicine, Leeds Teaching Hospitals NHS Trust, Leeds (United Kingdom)

    2010-04-15

    Aim: To evaluate the accuracy of ultrasound and parathyroid scintigraphy using single photon-emission computed tomography/computed tomography (SPECT/CT) for the preoperative localization of solitary parathyroid adenomas in patients with primary hyperparathyroidism who would be suitable for minimally invasive parathyroid surgery. Materials and methods: Retrospective study of 63 consecutive patients with biochemical evidence of primary hyperparathyroidism referred for preoperative localization of parathyroid adenoma that proceeded to surgery in the same institution. All patients underwent high-resolution ultrasound and Technetium-99m sestamibi scintigraphy with planar and SPECT/CT imaging. The accuracy of preoperative imaging was compared to surgical and histological findings as the reference standard. Results: Fifty-nine patients had solitary parathyroid adenomas, three patients had multiglandular hyperplasia, and one patient had multiple parathyroid adenomas confirmed at surgery and histology. Thirty-five solitary parathyroid adenomas were identified preoperatively with ultrasound (64%) and 53 with SPECT-CT (90%). Concordant ultrasound and SPECT/CT findings were found in 35 cases (59%). An additional three adenomas were found with ultrasound alone and 18 adenomas with SPECT/CT alone. Fifty-one of the 56 adenomas localized using combined ultrasound and SPECT/CT were found at the expected sites during surgery. Combined ultrasound and SPECT/CT has an overall sensitivity of 95% and accuracy of 91% for the preoperative localization of solitary parathyroid adenomas. Conclusions: The combination of ultrasound and SPECT/CT has incremental value in accurately localizing solitary parathyroid adenomas over either technique alone, and allows selection of patients with primary hyperparathyroidism who would be suitable for minimally invasive surgery.

  11. Surgeon-Performed Ultrasound as Preoperative Localization Study in Patients with Primary Hyperparathyroidism

    NARCIS (Netherlands)

    T.M. van Ginhoven (Tessa); A.N. Morks; T. Schepers (Tim); P.W. de Graaf; P.C. Smits (Pieter)

    2011-01-01

    textabstractBackground: Minimally invasive parathyroidectomy is the treatment of choice for single-gland primary hyperparathyroidism. However, the exact location of the abnormal gland has to be established. Sestamibi scintigraphy, computed tomography and ultrasound (US) are commonly used modalities.

  12. Surgeon-Performed Ultrasound as Preoperative Localization Study in Patients with Primary Hyperparathyroidism

    NARCIS (Netherlands)

    van Ginhoven, T. M.; Morks, A. N.; Schepers, T.; de Graaf, P. W.; Smit, P. C.

    2011-01-01

    Background: Minimally invasive parathyroidectomy is the treatment of choice for single-gland primary hyperparathyroidism. However, the exact location of the abnormal gland has to be established. Sestamibi scintigraphy, computed tomography and ultrasound (US) are commonly used modalities. We describe

  13. [Quality standards for ultrasound assessment (CW-Doppler, Duplex US) of the lower limb arteries in vascular medicine. Report of the French Society for Vascular Medicine].

    Science.gov (United States)

    Becker, F; Luizy, F; Baud, J-M; Pichot, O

    2011-12-01

    The quality standards of the French Society of Vascular Medicine for the ultrasound assessment of lower limb arteries in vascular medicine practice are based on the principle that these examinations have to meet two requirements: technical know-how (knowledge of devices and methodologies); medical know-how (level of examination matching the indication and purpose of the examination, interpretation and critical analysis of results). OBJECTIVES OF THE QUALITY STANDARDS: To describe an optimal level of examination adjusted to the indication or clinical hypothesis; to homogenize practices, methodologies, terminologies, results description and report; to provide good practice reference points and to promote a high quality process. THEMES OF THE QUALITY STANDARDS: The three levels of examination, indications and objectives for each level; the reference standard examination (level 2) and its variants according to indications; the minimal content of the exam report, the medical conclusion letter to the corresponding physician (synthesis, conclusion and management suggestions); commented glossary (anatomy, hemodynamics, signs and symptoms); technical basis. Device settings. Here, we discuss CW-Doppler and Duplex ultrasound in various indications for lower limbs arteries assessment.

  14. Repeat duplex ultrasound scanning in suspected Deep Vein Thrombosis (DVT): putting the onus back on the referring clinician.

    Science.gov (United States)

    Renton, Bryan; Thiru, S; Griffin, C P

    2016-01-01

    Duplex scanning is utilised by many departments in the investigation of suspected DVT. NICE Guideline CG144 recommended repeat scanning for patients in whom the initial Wells score was 'likely' in the presence of a raised D-Dimer, following a normal first scan. Following implementation of this recommendation in our department there was a dramatic rise in the number of repeat scans being undertaken, all of which were negative for DVT. Introduction of an electronic message to the report, placing the onus back on the referring clinician to arrange repeat scan if deemed appropriate resulted in a fall in the number of scans being undertaken without impacting on patient outcome.

  15. Does Dopplersignal enhancement with Levovist improve the diagnostic confidence of duplex scanning of the iliac arteries?--(A pilot study with correlation to intravascular ultrasound)

    DEFF Research Database (Denmark)

    Vogt, K C; Jensen, F; Schroeder, T V

    1998-01-01

    To evaluate whether echo-enhancement with Levovist improves the diagnostic confidence of duplex scanning of the iliac arteries.......To evaluate whether echo-enhancement with Levovist improves the diagnostic confidence of duplex scanning of the iliac arteries....

  16. Optimal cut-off criteria for duplex ultrasound for the diagnosis of restenosis in stented carotid arteries: Review and protocol for a diagnostic study

    Directory of Open Access Journals (Sweden)

    Brown Martin M

    2009-07-01

    Full Text Available Abstract Background Carotid angioplasty with stenting is a relatively new, increasingly used, less-invasive treatment for the treatment of symptomatic carotid artery stenosis. It is being evaluated in ongoing and nearly finished randomized trials. An important factor in the evaluation of stents is the occurrence of in-stent restenosis. An un-stented carotid artery is likely to have a more elastic vessel wall than a stented one, even if stenosis is present. Therefore, duplex ultrasound cut-off criteria for the degrees of an in-stent stenosis, based on blood velocity parameters, are probably different from the established cut-offs used for un-stented arteries. Routine criteria can not be applied to stented arteries but new criteria need to be established for this particular purpose. Methods/Design Current literature was systematically reviewed. From the selected studies, the following data were extracted: publication year, population size, whether the study was prospective, duplex ultrasound cut-off criteria reported, which reference test was used, and if there was an indication for selection bias and for verification bias in particular. Previous studies often were retrospective, or the reference test (DSA or CTA was carried out only when a patient was suspected of having restenosis at DUS, which may result in verification bias. Results In general, the velocity cut-off values for stenosis measurements in stented arteries were higher than those reported for unstented arteries. Previous studies often were retrospective, or the reference test (DSA or CTA was carried out only when a patient was suspected of having restenosis at DUS, which may result in verification bias. Discussion To address the deficiencies of the existing studies, we propose a prospective cohort study nested within the International Carotid Stenting Study (ICSS, an international multi-centre trial in which over 1,700 patients have been randomised between stenting and CEA. In this

  17. Duplex Ultrasound versus Computed Tomography for the Postoperative Follow-Up of Endovascular Abdominal Aortic Aneurysm Repair. Where Do We Stand Now?

    Science.gov (United States)

    Karanikola, Evridiki; Dalainas, Ilias; Karaolanis, Georgios; Zografos, Georgios; Filis, Konstantinos

    2014-01-01

    In the last decade, endovascular aneurysm repair (EVAR) has rapidly developed to be the preferred method for infrarenal abdominal aortic aneurysm repair in patients with suitable anatomy. EVAR offers the advantage of lower perioperative mortality and morbidity but carries the cost of device-related complications such as endoleak, graft migration, graft thrombosis, and structural graft failure. These complications mandate a lifelong surveillance of EVAR patients and their endografts. The purpose of this study is to review and evaluate the safety of color-duplex ultrasound (CDU) as compared with computed tomography (CT), based on the current literature, for post-EVAR surveillance. The post-EVAR follow-up modalities, CDU versus CT, are evaluated questioning three parameters: (1) accuracy of aneurysm size, (2) detection and classification of endoleaks, and (3) detection of stent-graft deformation. Studies comparing CDU with CT scan for investigation of post-EVAR complications have produced mixed results. Further and long-term research is needed to evaluate the efficacy of CDU versus CT, before CDU can be recommended as the primary imaging modality for EVAR surveillance, in place of CT for stable aneurysms. PMID:25317026

  18. Duplex Ultrasound versus Computed Tomography for the Postoperative Follow-Up of Endovascular Abdominal Aortic Aneurysm Repair. Where Do We Stand Now?

    Science.gov (United States)

    Karanikola, Evridiki; Dalainas, Ilias; Karaolanis, Georgios; Zografos, Georgios; Filis, Konstantinos

    2014-09-01

    In the last decade, endovascular aneurysm repair (EVAR) has rapidly developed to be the preferred method for infrarenal abdominal aortic aneurysm repair in patients with suitable anatomy. EVAR offers the advantage of lower perioperative mortality and morbidity but carries the cost of device-related complications such as endoleak, graft migration, graft thrombosis, and structural graft failure. These complications mandate a lifelong surveillance of EVAR patients and their endografts. The purpose of this study is to review and evaluate the safety of color-duplex ultrasound (CDU) as compared with computed tomography (CT), based on the current literature, for post-EVAR surveillance. The post-EVAR follow-up modalities, CDU versus CT, are evaluated questioning three parameters: (1) accuracy of aneurysm size, (2) detection and classification of endoleaks, and (3) detection of stent-graft deformation. Studies comparing CDU with CT scan for investigation of post-EVAR complications have produced mixed results. Further and long-term research is needed to evaluate the efficacy of CDU versus CT, before CDU can be recommended as the primary imaging modality for EVAR surveillance, in place of CT for stable aneurysms.

  19. Renal artery stenting with noninvasive duplex ultrasound follow-up: 3-year results from the RENAISSANCE renal stent trial.

    Science.gov (United States)

    Rocha-Singh, Krishna; Jaff, Michael R; Lynne Kelley, E

    2008-11-15

    The multicenter, single-arm RENAISSANCE trial evaluated outcomes in patients with progressive atherosclerotic renal artery stenosis (ARAS) treated with the Express Renal Premounted Stent System (Boston Scientific, Natick, MA). Renal artery stenting may prevent the morbidity and mortality of surgical revascularization and high restenosis rates of percutaneous renal angioplasty (PTRA). Renal artery duplex ultrasonography (DUS) offers an alternative to traditional invasive poststenting angiographic surveillance, though concordance with angiography for in-stent restenosis has yet to be validated independently. RENAISSANCE enrolled 100 patients (117 lesions) with de novo or restenotic ostial atherosclerotic lesions or=4.0 and or=70%. The primary endpoint, 9-month binary restenosis, was compared to an objective performance criterion (OPC) of 40% for published PTRA results. Follow-up was conducted through 3 years. Technical and procedural success was both 99%. Follow-up angiography, triggered clinically or by ultrasonography, revealed 21.3% binary restenosis at 9 months, which was superior to the OPC (P RENAISSANCE demonstrates that renal artery stenting is superior to the prespecified OPC at 9 months, and also shows that DUS can accurately identify in-stent restenosis. (c) 2008 Wiley-Liss, Inc.

  20. Carotid Ultrasound

    Science.gov (United States)

    ... this page from the NHLBI on Twitter. Carotid Ultrasound Also known as carotid duplex. Carotid ultrasound is a painless imaging test that uses high- ... of your carotid arteries. This test uses an ultrasound machine, which includes a computer, a screen, and ...

  1. Use of preoperative ultrasound in designing the true pectoralis major myocutaneous island flap

    Institute of Scientific and Technical Information of China (English)

    CHEN Xiao-hong; ZHAO Han-xue; FANG Ju-gao; YU Zhen-kun; HUANG Zhi-gang

    2012-01-01

    Background Traditional techniques used for harvesting the pectoralis major myocutaneous (PMMC) flap have accompanying disadvantages,such as the necessity for an upper chest skin incision,the bulkiness of myocutaneous tissue at the pedicle of the flap,and the risk of total or partial necrosis of flap tissue.The aim of this study was to develop a safe and fast method for preparing PMMC island flaps using preoperative ultrasonography for vessel detection.Methods Forty-one PMMC island flaps were used for one-stage reconstruction of head and neck defects,including 21 cases in the treatment group and 20 cases in the control group.In the treatment group,ultrasonography was used to mark out the course of the thoracic branches of the thoracoacromial artery and the lower end of this artery perforating from the fascia into the muscles,as well as the largest perforating branch of the fourth or fifth internal mammary artery entering the PMMC flap.A line,from the lower end of the thoracic branch to the largest perforating branch of the fourth or fifth internal mammary artery,was drawn to determine the axis of the PMMC flap.In the control group,PMMC island flaps were designed according to conventional methods without using ultrasonography.Results According to the ultrasonic marks,the distance from lower end of thoracic branch to the midpoint of the margin of the inferior clavicular was (5.1±1.2) cm.The time from designing to transferring the island flap was significantly shorter in the treatment group ((51.0±10.5) minutes) compared with the control group ((78.0±13.9) minutes,P <0.01).The rate of partial necrosis was 4.7% (1/21) in the treatment group and 35.0% (7/20) in the control group.There was one case of flap failure in the control group due to vascular injury during vascular pedicle dissection.Conclusion Preoperative vessel detection by ultrasonography facilitates easy and safe harvesting of the true PMMC island flap.

  2. Staging the axilla in women with breast cancer:the utility of preoperative ultrasound-guided needle biopsy

    Institute of Scientific and Technical Information of China (English)

    Nehmat Houssami; Robin M.Turner

    2014-01-01

    Preoperative staging of the axilla in women with invasive breast cancer using ultrasound-guided needle biopsy (UNB) identiifes approximately 50% of patients with axillary nodal metastases prior to surgical intervention. Although moderately sensitive, it is a highly speciifc staging strategy that is rarely falsely-positive, hence a positive UNB allows patients to be triaged to axillary lymph-node dissection (ALND) avoiding potentially unnecessary sentinel node biopsy (SNB). In this review, we extend our previous work through an updated literature search, focusing on studies that report data on UNB utility. Based on data for 10,934 breast cancer patients, sourced from 35 studies, a positive UNB allowed triage of 1,745 cases (simple proportion 16%) to axillary surgical treatment: the utility of UNB was a median 19.8% [interquartile range (IQR) 11.6%-26.7%] across these studies. We also modelled data from a subgroup of studies, and estimated that amongst patients with metastases to axillary nodes, the odds ratio (OR) for high nodal disease burden for a positive UNB versus a negative UNB was 4.38 [95% confidence interval (95% CI): 3.13, 6.13],P<0.001. From this model, the estimated proportion with high nodal disease burden was 58.9% (95% CI: 50.2%, 67.0%) for a positive UNB, whereas the estimated proportion with high nodal disease burden was 24.6% (95% CI: 17.7%, 33.2%) if UNB was negative. Overall, axillary UNB has good clinical utility and a positive UNB can effectively triage to ALND. However, the evolving landscape of axillary surgical treatment means that UNB will have relatively less utility where surgeons have modiifed their practice to omission of ALND for minimal nodal metastatic disease.

  3. Ultrasound elastography as an adjuvant to conventional ultrasound in the preoperative assessment of axillary lymph nodes in suspected breast cancer: A pilot study

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, K., E-mail: kathryn.taylor@addenbrookes.nhs.uk [Department of Radiology, Cambridge Breast Unit, Cambridge University Hospitals NHS Foundation Trust, Cambridge (United Kingdom); O' Keeffe, S.; Britton, P.D.; Wallis, M.G. [Department of Radiology, Cambridge Breast Unit, Cambridge University Hospitals NHS Foundation Trust, Cambridge (United Kingdom); Treece, G.M.; Housden, J. [Department of Engineering, University of Cambridge, Cambridge (United Kingdom); Parashar, D.; Bond, S. [Cambridge Cancer Trials Centre, Department of Oncology, University of Cambridge, Addenbrookes Hospital, Cambridge (United Kingdom); Cambridge Hub in Trials Methodology Research, MRC Biostatics Unit, University Forvie Site, Cambridge (United Kingdom); Sinnatamby, R. [Department of Radiology, Cambridge Breast Unit, Cambridge University Hospitals NHS Foundation Trust, Cambridge (United Kingdom)

    2011-11-15

    Aims: To compare the performance of ultrasound elastography with conventional ultrasound in the assessment of axillary lymph nodes in suspected breast cancer and whether ultrasound elastography as an adjunct to conventional ultrasound can increase the sensitivity of conventional ultrasound used alone. Materials and methods: Fifty symptomatic women with a sonographic suspicion for breast cancer underwent ultrasound elastography of the ipsilateral axilla concurrent with conventional ultrasound being performed as part of triple assessment. Elastograms were visually scored, strain measurements calculated and node area and perimeter measurements taken. Theoretical biopsy cut points were selected. The sensitivity, specificity, positive predictive value (PPV), and negative predictive values (NPV) were calculated and receiver operating characteristic (ROC) analysis was performed and compared for elastograms and conventional ultrasound images with surgical histology as the reference standard. Results: The mean age of the women was 57 years. Twenty-nine out of 50 of the nodes were histologically negative on surgical histology and 21 were positive. The sensitivity, specificity, PPV, and NPV for conventional ultrasound were 76, 78, 70, and 81%, respectively; 90, 86, 83, and 93%, respectively, for visual ultrasound elastography; and for strain scoring, 100, 48, 58 and 100%, respectively. There was no significant difference between any of the node measurements Conclusions: Initial experience with ultrasound elastography of axillary lymph nodes, showed that it is more sensitive than conventional ultrasound in detecting abnormal nodes in the axilla in cases of suspected breast cancer. The specificity remained acceptable and ultrasound elastography used as an adjunct to conventional ultrasound has the potential to improve the performance of conventional ultrasound alone.

  4. Preoperative ultrasound-guided needle biopsy of 63 uterine tumors having high signal intensity upon T2-weighted magnetic resonance imaging.

    Science.gov (United States)

    Tamura, Ryo; Kashima, Katsunori; Asatani, Mina; Nishino, Koji; Nishikawa, Nobumichi; Sekine, Masayuki; Serikawa, Takehiro; Enomoto, Takayuki

    2014-07-01

    The differential diagnosis between uterine sarcoma and benign leiomyoma is difficult when made only by magnetic resonance imaging (MRI); it usually requires an additional preoperative diagnostic procedure. We report our results using ultrasound-guided needle biopsy for these types of uterine tumors. Ultrasound-guided needle biopsy was performed on 63 patients with uterine smooth muscle tumors suspected of malignancy by MRI. We compared the results of presurgical biopsy against the postsurgical pathology of the tumor. Among 63 patients with a high signal intensity of the uterine tumor on T2-weighted MRI (1 case was undetermined), 12 cases (19.3%) were diagnosed by the needle biopsy as malignant, and 51 cases (80.6%) were benign. Among the 12 diagnosed as malignant tumors, 11 had surgery performed, and one was treated with chemotherapy. Among the 51 patients diagnosed with a benign tumor, 27 had surgery performed, and 24 were put on a wait-and-see clinical follow-up schedule. One of the 27 surgical patients with a benign tumor had a postsurgical diagnosis of a low-grade endometrial stromal sarcoma. In the 38 cases where surgery was performed, we found the sensitivity, specificity, and the positive and negative predictive values of the needle biopsy were 91.7%, 100%, 100%, and 96.2%, respectively. Ultrasound-guided needle biopsy may be a reliable preoperative diagnostic procedure for uterine tumors with suspected malignancy.

  5. Effect of Background Parenchymal Enhancement on Pre-Operative Breast Magnetic Resonance Imaging: How It Affects Interpretation and the Role of Second-Look Ultrasound in Patient Management.

    Science.gov (United States)

    Kim, Soo-Yeon; Lee, Hye Sun; Kim, Eun-Kyung; Kim, Min Jung; Moon, Hee Jung; Yoon, Jung Hyun

    2016-12-01

    Background parenchymal enhancement (BPE) on breast magnetic resonance imaging (MRI) may either obscure or mimic malignancy. We evaluated the impact of BPE on the diagnostic performance of pre-operative MRI in breast cancer patients, and how second-look ultrasound (US) can help in guiding patient management. Two hundred fifty-three breast cancer patients with pre-operative MRI were included. In moderate or marked BPE, abnormal interpretation rate (38.9% vs. 12.2%) and biopsy rate (27.8% vs. 8.3%) were higher, and specificity (64.7% vs. 89.8%) was lower, compared with minimal or mild BPE (all p abnormal interpretation rate, additional biopsy rate and decreased specificity. Second-look US was useful in visualization of MRI-detected additional suspicious lesions, regardless of BPE.

  6. Ultrasound

    Science.gov (United States)

    Ultrasound is a type of imaging. It uses high-frequency sound waves to look at organs and ... liver, and other organs. During pregnancy, doctors use ultrasound to view the fetus. Unlike x-rays, ultrasound ...

  7. MR mammography in the pre-operative staging of breast cancer in patients with dense breast tissue: comparison with mammography and ultrasound

    Energy Technology Data Exchange (ETDEWEB)

    Van Goethem, M.; Schelfout, K.; Verslegers, I.; Biltjes, I.; De Schepper, A. [Department of Radiology, University Hospital Antwerp, Antwerp (Belgium); Dijckmans, L. [Department of Gynecology, University Hospital Antwerp, Antwerp (Belgium); Van Der Auwera, J.C.; Weyler, J. [Department of Epidemiology and Social Medicine, University Hospital Antwerp, Antwerp (Belgium)

    2004-05-01

    The aim of this study was to determine whether pre-operative MR mammography could predict the extent of breast cancer in patients with dense breasts or whether dense parenchyma will lead to false-positive or inconclusive examinations. Sixty-seven patients with dense breasts with a malignant breast tumor planned for conservative surgery were reviewed. Detection rates of mammography, ultrasound, and MR mammography were studied, and the diameters of the lesions were measured and compared with pathological examination. Pathology revealed breast cancer in 65 patients. Sensitivity for detection of index lesions was 83% for mammography, 70.8% for ultrasound, and 98% for MR mammography. Mammography underestimated tumor extent in 37%, ultrasound in 40%, and MR in 12.5%. Of the 20 patients (31%) with multifocal or multicentric carcinoma, mammography detected the lesions in 35%, ultrasound in 30%, and MR in 100%, with a false-positive rate of 12.5, 14, and 23%. The MR mammography is more accurate in assessing tumor extent and multifocality in patients with dense breasts, but benign changes may lead to false-positive examinations. (orig.)

  8. 利尿B超在诊断重复肾双输尿管合并输尿管开口异位中的应用%Diuresis Ultrasound Diagnosis of Duplex Kidney with Double Ureters and Ectopic Ureteral Orifice

    Institute of Scientific and Technical Information of China (English)

    陈敏; 鲁功成; 邵明忠; 张齐钧; 张润清; 陈晓春; 曾甫清; 张秋艳; 吴玉珍

    1996-01-01

    Diuresis ultrasound was used to diagnose duplex kidney with double ureters and ectopic ureteral orifice in 8 cases.The result was satisfactory.In most cases the conventional ultrasound examination cann't show the normal ureter.Diuresis caused the ureter to be dilated(both upper and lower ureter).The duplex kidney and double ureters could be shown at same plane simultaneously.The ectopic dilated ureter did not enter into the bladder but extended along with the urethra behind the bladder.While the normal ureter showed as a slender and fine echo band,emerged into the trigone of bladder.The diagnosis of this abnormality in children sometimes may be very difficult.Diuresis ultrasound provides a reliable metod to detect this disease.The method is simple,easy to perform and also throws new light on ultrasound diagnosis.%采用利尿B超诊断重复肾双输尿管合并输尿管开口异位8例,结果令人满意.普通B超多不能显示正常输尿管.利尿可以使输尿管扩张(上、下半肾输尿管均扩张),操作者可以在同一切面上同时见到重复肾及双输尿管,而且可以在膀胱后方发现扩张的输尿管不进入膀胱而向尿道方向延伸.正常输尿管呈纤细狭长的回声带,开口于膀胱三角区.小儿重复肾双输尿管合并输尿管开口异位的诊断有时很困难.利尿B超为该病的诊断提供了确切的依据,并且简便易行,为超声诊断提供了新的方法与手段.

  9. [Effect of preoperative administration of Lugol's solution on thyroid blood flow in hyperthyroidism].

    Science.gov (United States)

    Rodier, J F; Janser, J C; Petit, H; Schneegans, O; Ott, G; Kaissling, A; Grob, J C; Velten, M

    1998-01-01

    A study of 50 patients with hyperthyroidism was conducted to evaluate the effect of preoperative administration of Lugol's iodine solution on thyroid blood flow. Highly significant reductions in diameter, time-averaged velocity, and volume flow of the superior thyroid artery were demonstrated after administration of Lugol's solution. The Duplex ultrasound scanning used in this study is a noninvasive, inexpensive, accurate, and reproducible technique suitable for analysis of thyroid blood flow in hyperthyroidism. On the basis of current ultrasonographic results and low postoperative morbidity in patients, Lugol's solution is well tolerated and may be recommended for use before thyroidectomy, especially for diffuse toxic goiters and Graves disease.

  10. Role of pre-operative imaging using {sup 99m}Tc-MIBI and neck ultrasound in patients with secondary hyperparathyroidism who are candidates for subtotal parathyroidectomy

    Energy Technology Data Exchange (ETDEWEB)

    Fuster, David; Ortin, Jaime; Setoain, Xavier; Paredes, Pilar; Duch, Joan; Pons, Francesca [Hospital Clinic, Nuclear Medicine Department, Barcelona (Spain); Ybarra, Juan; Torregrosa, Jose-Vicente [Hospital Clinic, Renal Transplant Unit, Barcelona (Spain); Gilabert, Rosa [Hospital Clinic, Radiology Department, Barcelona (Spain)

    2006-04-15

    The purpose of this study was to assess whether pre-operative {sup 99m}Tc-methoxyisobutylisonitrile (MIBI) scintigraphy and neck ultrasound (US) are of value in improving the outcome of subtotal parathyroidectomy in patients with secondary hyperparathyroidism. Forty-eight consecutive haemodialysis patients with severe secondary hyperparathyroidism prospectively underwent ''blinded'' subtotal parathyroid surgery, with 1-year follow-up to establish cure or relapse of their secondary hyperparathyroidism. Double-phase {sup 99m}Tc-MIBI scintigraphy and neck US were performed pre-operatively in all patients. When the preserved gland showed {sup 99m}Tc-MIBI uptake or an abnormal size on US, it was considered that ''{sup 99m}Tc-MIBI advice'' and ''US advice'', respectively, had not been followed. Pre-operative and follow-up parathyroid hormone (PTH) levels were obtained in all patients. All data were evaluated on a patient by patient basis. Four parathyroid glands were identified in each patient at primary surgery, resulting in an operative success rate of 100%. Their weight ranged from 15 to 7,300 mg (mean 1,120{+-}900 mg). Nine of the 48 patients (19%) showed a recurrence of their secondary hyperparathyroidism. The recurrence rate was 2% (1/48) and 10% (5/48), respectively, when {sup 99m}Tc-MIBI and US advice was followed. The sensitivity, specificity, NPV and PPV for pre-operative imaging were 72%, 95%, 97% and 80% respectively for {sup 99m}Tc-MIBI, and 55%, 67%, 87% and 28% for US. {sup 99m}Tc-MIBI scintigraphy is a reliable non-invasive exploratory tool and its preoperative use results in a significant reduction in the number of recurrences in haemodialysis patients with secondary hyperparathyroidism who are candidates for subtotal parathyroidectomy. The use of neck US did not significantly improve the results obtained with {sup 99m}Tc-MIBI alone. (orig.)

  11. Axillary ultrasound and fine-needle aspiration in preoperative staging of axillary lymph nodes in patients with invasive breast cancer*

    Science.gov (United States)

    Rocha, Rafael Dahmer; Girardi, André Ricardo; Pinto, Renata Reis; de Freitas, Viviane Aguilera Rolim

    2015-01-01

    Objective To propose an algorithm to determine the necessity for ultrasonography-guided fine-needle aspiration (US-FNA) in preoperative axillary lymph node staging of patients with invasive breast cancer. Materials and Methods Prospective study developed at National Cancer Institute. The study sample included 100 female patients with breast cancer referred for axillary staging by US-FNA. Results The overall US-FNA sensitivity was set at 79.4%. The positive predictive value was calculated to be 100%, and the negative predictive value, 69.5%. The US-FNA sensitivity for lymph nodes with normal sonographic features was 0%, while for indeterminate lymph nodes it was 80% and, for suspicious lymph nodes, 90.5%. In the assessment of invasive breast tumors stages T1, T2 and T3, the sensitivity was respectively 69.6%, 83.7% and 100%. US-FNA could avoid sentinel node biopsy in 54% of cases. Conclusion Axillary ultrasonography should be included in the preoperative staging of all patients with invasive breast cancer. The addition of US-FNA in cases of lymph nodes suspicious for malignancy may prevent more than 50% of sentinel lymphadenectomies, significantly shortening the time interval to definitive therapy. PMID:26811550

  12. Ultrasound contrast-agent improves imaging of lower limb occlusive disease

    DEFF Research Database (Denmark)

    Eiberg, J P; Hansen, M A; Jensen, F

    2003-01-01

    to evaluate if ultrasound contrast-agent infusion could improve duplex-ultrasound imaging of peripheral arterial disease (PAD) and increase the agreement with digital subtraction arteriography (DSA)....

  13. Ultrasound

    Science.gov (United States)

    ... Saunders; 2014:chap 66. Cosgrove DO, Eckersley RJ, Harvey CJ, Lim A. Ultrasound. In: Adam A, Dixon AK, Gillard ... Northside Radiology Associates, Atlanta, GA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the ...

  14. Automatic registration between 3D intra-operative ultrasound and pre-operative CT images of the liver based on robust edge matching

    Science.gov (United States)

    Nam, Woo Hyun; Kang, Dong-Goo; Lee, Duhgoon; Lee, Jae Young; Ra, Jong Beom

    2012-01-01

    The registration of a three-dimensional (3D) ultrasound (US) image with a computed tomography (CT) or magnetic resonance image is beneficial in various clinical applications such as diagnosis and image-guided intervention of the liver. However, conventional methods usually require a time-consuming and inconvenient manual process for pre-alignment, and the success of this process strongly depends on the proper selection of initial transformation parameters. In this paper, we present an automatic feature-based affine registration procedure of 3D intra-operative US and pre-operative CT images of the liver. In the registration procedure, we first segment vessel lumens and the liver surface from a 3D B-mode US image. We then automatically estimate an initial registration transformation by using the proposed edge matching algorithm. The algorithm finds the most likely correspondences between the vessel centerlines of both images in a non-iterative manner based on a modified Viterbi algorithm. Finally, the registration is iteratively refined on the basis of the global affine transformation by jointly using the vessel and liver surface information. The proposed registration algorithm is validated on synthesized datasets and 20 clinical datasets, through both qualitative and quantitative evaluations. Experimental results show that automatic registration can be successfully achieved between 3D B-mode US and CT images even with a large initial misalignment.

  15. Mechanically assisted 3D ultrasound for pre-operative assessment and guiding percutaneous treatment of focal liver tumors

    Science.gov (United States)

    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.

  16. Ultrasound contrast-agent improves imaging of lower limb occlusive disease

    DEFF Research Database (Denmark)

    Eiberg, J P; Hansen, M A; Jensen, F

    2003-01-01

    to evaluate if ultrasound contrast-agent infusion could improve duplex-ultrasound imaging of peripheral arterial disease (PAD) and increase the agreement with digital subtraction arteriography (DSA).......to evaluate if ultrasound contrast-agent infusion could improve duplex-ultrasound imaging of peripheral arterial disease (PAD) and increase the agreement with digital subtraction arteriography (DSA)....

  17. Accurate perioperative flow measurement of the portal vein and hepatic and renal artery: A role for preoperative MRI?

    Energy Technology Data Exchange (ETDEWEB)

    Vermeulen, Mechteld A.R., E-mail: mar.vermeulen@vumc.nl [Department of Surgery, VU University Medical Center, P.O. Box 7057, 1007 MB Amsterdam (Netherlands); Ligthart-Melis, Gerdien C., E-mail: g.ligthart-melis@vumc.nl [Department of Internal Medicine, Dietetics and Nutritional Sciences, VU University Medical Center, P.O. Box 7057, 1007 MB Amsterdam (Netherlands); Buijsman, René, E-mail: renebuysman@gmail.com [Department of Surgery, VU University Medical Center, P.O. Box 7057, 1007 MB Amsterdam (Netherlands); Siroen, Michiel P.C., E-mail: m.siroen6@upcmail.nl [Department of Surgery, VU University Medical Center, P.O. Box 7057, 1007 MB Amsterdam (Netherlands); Poll, Marcel C.G. van de, E-mail: mcg.vandepoll@ah.unimaas.nl [Department of Surgery, Maastricht University Medical Center, P.O. Box 5800, 6202 AZ Maastricht (Netherlands); Boelens, Petra G., E-mail: p.boelens@mumc.nl [Department of Surgery, Maastricht University Medical Center, P.O. Box 5800, 6202 AZ Maastricht (Netherlands); Dejong, Cornelis H.C., E-mail: chc.dejong@mumc.nl [Department of Surgery, Maastricht University Medical Center, P.O. Box 5800, 6202 AZ Maastricht (Netherlands); Schaik, Cors van, E-mail: c.vanschaik@vumc.nl [Department of Radiology, VU University Medical Center, P.O. Box 7057, 1007 MB Amsterdam (Netherlands); Hofman, Mark B.M., E-mail: mbm.hofman@vumc.nl [Department of Physics and Medical Technology, VU University Medical Center, P.O. Box 7057, 1007 MB Amsterdam (Netherlands); Leeuwen, Paul A.M. van, E-mail: pam.vleeuwen@vumc.nl [Department of Surgery, VU University Medical Center, P.O. Box 7057, 1007 MB Amsterdam (Netherlands)

    2012-09-15

    Background: Quantification of abdominal blood flow is essential for a variety of gastrointestinal and hepatic topics such as liver transplantation or metabolic flux measurement, but those need to be performed during surgery. It is not clear whether Duplex Doppler Ultrasound during surgery or MRI before surgery is the tool to choose. Objective: To examine whether preoperative evaluation of abdominal blood flow using MRI could prove to be a useful and reliable alternative for the perioperative sonographic approach. Methods: In this study portal and renal venous flow and hepatic arterial flow were sequentially quantified by preoperative MRI, preoperative and perioperative Duplex Doppler Ultrasound (DDUS). 55 Patients scheduled for major abdominal surgery were studied and methods and settings were compared. Additionally, average patient population values were compared. Results: Mean (±SD) plasmaflow measured by perioperative DDUS, preoperative DDUS and MRI, respectively was 433 ± 200/423 ± 162/507 ± 96 ml/min (portal vein); 96 ± 70/74 ± 41/108 ± 91 ml/min (hepatic artery); 248 ± 139/201 ± 118/219 ± 69 ml/min (renal vein). No differences between the different settings of DDUS measurement were detected. Equality of mean was observed for all measurements. Bland Altman Plots showed widespread margins. Hepatic arterial flow measurements correlated with each other, but portal and renal venous flow correlations were absent. Conclusions: Surgery and method (DDUS vs. MRI) do not affect mean flow values. Individual comparison is restricted due to wide range in measurements. Since MRI proves to be more reliable with respect to inter-observer variability, we recommend using mean MRI results in experimental setups.

  18. Impact of preoperative screening for rectal colonization with fluoroquinolone-resistant enteric bacteria on the incidence of sepsis following transrectal ultrasound guided prostate biopsy

    Science.gov (United States)

    Farrell, John J; Hicks, Jennifer L; Wallace, Stephanie E; Seftel, Allen D

    2017-01-01

    With the universal adoption of antibiotic prophylaxis prior to prostate biopsy, the current risk of post-biopsy infection (including sepsis) is study of preoperative rectal cultures to screen for rectal colonization with fluoroquinolone-resistant bacteria using ciprofloxacin-supplemented MacConkey agar culture media. To evaluate the feasibility and practicality of this test, one provider used the results of rectal swab cultures collected during the preoperative outpatient evaluation to adjust each patient’s preoperative antibiotic prophylaxis when fluoroquinolone-resistant enteric bacteria were detected, whereas two other providers continued usual preoperative care and empiric antimicrobial prophylaxis. Rectal colonization with fluoroquinolone-resistant bacteria was detected in 19/152 (12.5%) of patients. In our intention-to-treat analysis (N=268), the rate of post-biopsy sepsis was 3.6% lower in the group that was screened for rectal colonization with fluoroquinolone-resistant bacteria prior to transrectal prostate biopsy. The observed risk reduction in the rectal screening group trended toward, but did not achieve, statistical significance. We suggest that preoperative screening for rectal colonization with fluoroquinolone-resistant enteric bacteria may be a useful step toward mitigating post-prostate biopsy sepsis. PMID:28280717

  19. Heterogeneous echogenicity of the thyroid parenchyma does not influence the detection of multi-focality in papillary thyroid carcinoma on preoperative ultrasound staging.

    Science.gov (United States)

    Herh, Sun Jin; Kim, Eun-Kyung; Sung, Ji Min; Yoon, Jung Hyun; Moon, Hee Jung; Kwak, Jin Young

    2014-05-01

    Heterogeneous echogenicity and micro-nodulations of diffuse thyroid disease on ultrasonography (US) might influence the diagnostic performance of pre-operative US staging, especially the detection of multi-focality. This study was designed to determine whether heterogeneous echogenicity of the thyroid parenchyma influences the diagnostic performance of US in the detection of multi-focality in papillary thyroid carcinoma. Between December 2010 and April 2011, 811 patients underwent pre-operative staging US for papillary thyroid carcinoma and surgery. Twelve radiologists performed the pre-operative US for T and N staging. Underlying parenchymal echogenicity and unilateral and bilateral multi-focality of the thyroid nodules were also evaluated. Patients were divided into two groups on the basis of the underlying echogenicity of the thyroid gland. To evaluate the diagnostic accuracy of US with respect to underlying echogenicity, the sensitivity, specificity, positive predictive value, negative predictive value and accuracy were calculated and compared between the two groups. Among the 811 patients included, US revealed underlying heterogeneous echogenicity of the thyroid parenchyma in 204 (25.2%) and underlying homogeneous echogenicity of the thyroid parenchyma in 607 (74.8%). There were no significant differences between the two groups in the diagnostic performance of pre-operative staging US in predicting unilateral multi-focality and bilaterality. Underlying heterogeneous echogenicity in a thyroid gland with Hashimoto's thyroiditis does not significantly influence the detection of multi-focality in papillary thyroid cancer on pre-operative US staging.

  20. Medical Imaging with Ultrasound: Some Basic Physics.

    Science.gov (United States)

    Gosling, R.

    1989-01-01

    Discussed are medical applications of ultrasound. The physics of the wave nature of ultrasound including its propagation and production, return by the body, spatial and contrast resolution, attenuation, image formation using pulsed echo ultrasound techniques, measurement of velocity and duplex scanning are described. (YP)

  1. Impact of preoperative screening for rectal colonization with fluoroquinolone-resistant enteric bacteria on the incidence of sepsis following transrectal ultrasound guided prostate biopsy

    Directory of Open Access Journals (Sweden)

    Farrell JJ

    2017-02-01

    Full Text Available John J Farrell,1,2 Jennifer L Hicks,3 Stephanie E Wallace,2 Allen D Seftel4,5 1Department of Medicine, Division of Infectious Diseases, University of Illinois College of Medicine, 2Department of Laboratory Medicine, Division of Clinical Microbiology & Serology, OSF/Saint Francis Medical Center, 3Department of Urology, OSF /Saint Francis Medical Center, Peoria, IL, 4Department of Urology, Cooper University Hospital, 5Department of Surgery, Cooper University School of Medicine, Camden, NJ, USA Abstract: With the universal adoption of antibiotic prophylaxis prior to prostate biopsy, the current risk of post-biopsy infection (including sepsis is <2%. Preoperative prophylactic antibiotic regimens can vary, and although fluoroquinolones have emerged as the standard of care, there is no universally agreed upon preoperative antibiotic regimen. Recently, an increase in the proportion of postoperative infections caused by fluoroquinolone-resistant Escherichia coli (as well as other Enterobacteriaceae has led to the exploration of simple, practical, and cost-effective methods to minimize this postoperative infection risk. We performed a prospective, nonrandomized, controlled study of preoperative rectal cultures to screen for rectal colonization with fluoroquinolone-resistant bacteria using ciprofloxacin-supplemented MacConkey agar culture media. To evaluate the feasibility and practicality of this test, one provider used the results of rectal swab cultures collected during the preoperative outpatient evaluation to adjust each patient’s preoperative antibiotic prophylaxis when fluoroquinolone-resistant enteric bacteria were detected, whereas two other providers continued usual preoperative care and empiric antimicrobial prophylaxis. Rectal colonization with fluoroquinolone-resistant bacteria was detected in 19/152 (12.5% of patients. In our intention-to-treat analysis (N=268, the rate of post-biopsy sepsis was 3.6% lower in the group that was screened

  2. Ultrasound pregnancy

    Science.gov (United States)

    Pregnancy sonogram; Obstetric ultrasonography; Obstetric sonogram; Ultrasound - pregnancy; IUGR - ultrasound; Intrauterine growth - ultrasound; Polyhydramnios - ultrasound; Oligohydramnios - ultrasound; ...

  3. Clinical Diagnostic Value of Endoluminal Ultrasound on the Preoperative Staging of Rectal Cancer%腔内超声对直肠癌术前分期的诊断价值

    Institute of Scientific and Technical Information of China (English)

    乔晓玲; 张新源

    2012-01-01

    目的 探讨腔内超声(Endoluminal ultrasound,ELUS)对术前直肠癌分期评价的临床应用价值.方法 对69例直肠癌患者术前进行ELUS检查进行术前分期诊断,并且与术后病理诊断进行对照.结果 术前ELUS检查T1期诊断正确率为93.33%(14/15),T2期为83.33%(15/18),T3期为74.07% (20/27),T4期为66.67% (6/9).ELUS诊断正确率为79.71%(55/69).ELUS对转移淋巴结诊断总正确率为65.22% (45/69),灵敏度为76.19%,特异度为61.71%.结论 ELUS对于直肠癌癌组织的浸润程度以及周围转移淋巴结诊断与术后病理诊断的正确率较高,有希望成为直肠癌术前分期的有效方法.%Objective To study the clinical value of endoluminal ultrasound (ELUS) in the preoperative staging of rectal cancer. Methods 69 cases of rectal cancer were examined with ELUS before surgery for preoperative staging and compared with the postoperative pathological diagnosis. Results The accuracy of T1, T2, T3, T4 stage of ELUS were 93. 33% (14/15), 83. 33% (15/18), 74. 07% (20/27) ,66. 67% (6/ 9), the overall accuracy of T stage of ELUS was 79. 71%(55/69). The accuracy, sensitivity and specificity of ELUS in lymph node metastasis were 79. 71%, 76.19% and 61. 71%. Conclusion ELUS should become effective method in the preoperative assessment of depth of tumor invasion and lymph node metastasis compared with pathological diagnosis.

  4. Comparative Study of Contrast-enhanced Ultrasound vs.Conventional Ultrasound in Preoperative Diagnosis and Clinical Stage of Cervical Cancer%超声造影与普通超声对宫颈癌术前诊断和分期的比较研究

    Institute of Scientific and Technical Information of China (English)

    杨碧云; 李虎宜; 尹惠

    2014-01-01

    [Obj ective]To compare the value of contrast-enhanced ultrasound vs.conventional ultrasound in preoperative diagnosis and clinical stage of cervical cancer.[Methods]Totally 50 patients with cervical cancer con-firmed by pathology were analyzed retrospectively.The diagnostic results of contrast-enhanced ultrasound and con-ventional ultrasound were analyzed and compared.[Results]The detection rate of contrast-enhanced ultrasound was 84.0% which was markedly higher than that of conventional ultrasound(50.0%),and there was significant difference(P0.05).The le-sion size and invasive range of cervical cancer measured by contrast-enhanced ultrasound was obviously larger than those measured by conventional ultrasound,and there was significant difference(P <0.05).[Conclusion]Con-trast-enhanced ultrasound can improve clinical diagnostic rate of cervical cancer,and is superior to conventional ul-trasound in preoperative diagnosis and clinical stage of cervical cancer,so it is worthy of clinical promotion.%【目的】比较超声造影与普通超声在宫颈癌术前诊断和分期中的诊断价值。【方法】回顾性分析经病理检查确诊的宫颈癌患者50例,比较超声造影与普通超声的诊断结果。【结果】超声造影检出率84.0%(42/50)显著高于普通超声检出率为50.0%(25/25),其有统计学意义(P <0.05),其中Ⅰ、Ⅱ期检出率比较有统计学意义(P<0.05),而Ⅲ期、Ⅳ期比较无统计学差异(P>0.05);超声造影检测宫颈癌病灶大小及浸润范围明显大于普通超声检测,其差异有统计学意义(P<0.05)。【结论】超声造影可提高宫颈癌临床诊断率,在宫颈癌诊断及临床分期中比普通超声更具有优势,值得临床推广应用。

  5. Implementation of real-time duplex synthetic aperture ultrasonography

    DEFF Research Database (Denmark)

    Hemmsen, Martin Christian; Larsen, Lee; Kjeldsen, Thomas;

    2015-01-01

    This paper presents a real-time duplex synthetic aperture imaging system, implemented on a commercially available tablet. This includes real-time wireless reception of ultrasound signals and GPU processing for B-mode and Color Flow Imaging (CFM). The objective of the work is to investigate the im...... and that the required bandwidth between the probe and processing unit is within the current Wi-Fi standards....

  6. Preoperative and intraoperative ultrasound aids removal of migrating plant material causing iliopsoas myositis via ventral midline laparotomy: a study of 22 dogs.

    Science.gov (United States)

    Birettoni, Francesco; Caivano, Domenico; Rishniw, Mark; Moretti, Giulia; Porciello, Francesco; Giorgi, Maria Elena; Crovace, Alberto; Bianchini, Erika; Bufalari, Antonello

    2017-02-14

    Migrating plant material is often suspected clinically to be the underlying cause of iliopsoas myositis in the dog, but cannot always be found pre- or intraoperatively. In most cases, recurrence of clinical signs is related to failure to remove the plant material. Preoperative ultrasonography can be useful to visualize migrating plant material and to determine anatomical landmarks that can assist in planning a surgical approach. The purpose of the present study was to report the role of intraoperative (intra-abdominal) ultrasonography for visualizing and removing the plant material from iliopsoas abscesses using a ventral midline laparotomy approach. A retrospective case series of 22 dogs with iliopsoas muscle abnormalities and suspected plant material was reported. Preoperative visualization and subsequent retrieval of the plant material was performed during a single hospitalization. In all 22 dogs, the plant material (including complete grass awns, grass awn fragments and a bramble twig) was successfully removed via ventral midline laparotomy in which intraoperative ultrasonography was used to direct the grasping forceps tips to the foreign body and guide its removal. In 11 of these 22 dogs, the plant material was not completely removed during prior surgery performed by the referring veterinarians without pre- or intraoperative ultrasonography. Clinical signs resolved in all dogs and all dogs resumed normal activity after successful surgical removal of the plant material. Intraoperative ultrasonography is a safe and readily available tool that improves success of surgical removal of plant material within the iliopsoas abscesses via ventral midline laparotomy. Moreover, ultrasonographic findings of unusual plant material can be useful in planning and guiding surgical removal, by providing information about the size and shape of the foreign body.

  7. Duplex scanning using sparse data sequences

    DEFF Research Database (Denmark)

    Møllenbach, S. K.; Jensen, Jørgen Arendt

    2008-01-01

    The velocity distribution in vessels can be displayed using duplex scanning where B-mode acquisitions are interspaced with the velocity data. This gives an image for orientation, but lowers the maximum detectable velocity by a factor of two. Other pulse sequences either omits the B-mode image...... or leaves gaps in the velocity data, which makes it difficult to output audio data. The near full velocity range can be maintained and B-mode images shown by using a sparse data sequence with velocity and B-mode samples intermixed. The B-mode samples are placed in a (sparse) periodical pattern, which makes...... is scaled by the factor A/T. The approach has been investigated using in vivo RF data from the Hepatic vein, Carotid artery and Aorta from a 33 year old healthy male. A B-K Medical 3535 ultrasound scanner has been used in Duplex mode with a BK 8556, 3.2 MHz linear array probe. The sampling frequency...

  8. [Carotid duplex ultrasonography for neurosurgeons].

    Science.gov (United States)

    Sadahiro, Hirokazu; Ishihara, Hideyuki; Oka, Fumiaki; Suzuki, Michiyasu

    2011-12-01

    Carotid duplex ultrasonography (CDU) is one of the most well-known imaging methods for arteriosclerosis and ischemic stroke. For neurosurgeons, it is very important for the details of carotid plaque to be thoroughly investigated by CDU. Symptomatic carotid plaque is very fragile and easily changes morphologically, and so requires frequent CDU examination. Furthermore, after carotid endarterectomy (CEA) and carotid artery stenting (CAS), restenosis is evaluated with CDU. CDU facilitates not only morphological imaging in the B mode, but also allows a flow study with color Doppler and duplex imaging. So, CDU can help assess the presence of proximal and intracranial artery lesions in spite of only having a cervical view, and the patency of the extracranial artery to intracranial artery bypass is revealed with CDU, which shows a rich velocity and low pulsatility index (PI) in duplex imaging. For the examiner, it is necessary to ponder on what duplex imaging means in examinations, and to summarize all imaging finding.

  9. Preplanning Vascularized Lymph Node Transfer with Duplex Ultrasonography: An Evaluation of 3 Donor Sites

    Directory of Open Access Journals (Sweden)

    Ketan M. Patel, MD

    2014-08-01

    Conclusions: Preoperative imaging with duplex ultrasonography before VLN transfer may allow for accurate identification of specific VLN donor-site characteristics. When considering lymph node–specific characteristics, higher quantity of lymph nodes were found on the groin and submental flap axis compared with the transverse cervical artery axis.

  10. A case report of duplex gallbladder and review of the literature

    Directory of Open Access Journals (Sweden)

    Y.M. Goh

    2015-01-01

    Full Text Available Gallbladder duplication is a rare congenital abnormality first described by Boyden in 1926. Pre-operative diagnosis is essential in identifying anatomical abnormalities in order to avoid biliary injuries at the time of surgery or performance of an incomplete operation. We present a case of a duplex gallbladder and review of the literature.

  11. Preoperative evaluation of oesophageal adenocarcinoma.

    Science.gov (United States)

    Khanna, Lauren G; Gress, Frank G

    2015-02-01

    The preoperative evaluation of oesophageal adenocarcinoma involves endoscopic ultrasound (EUS), computed tomography (CT), and positron emission tomography (PET). With routine Barrett's oesophagus surveillance, superficial cancers are often identified. EUS, CT and PET have a limited role in the staging of superficial tumours. Standard EUS has limited accuracy, but high frequency ultrasound miniprobes are valuable for assessing tumour stage in superficial tumours. However, the best method for determining depth of invasion, and thereby stage of disease, is endoscopic mucosal resection. In contrast, in advanced oesophageal cancers, a multi-modality approach is crucial. Accurate tumour staging is very important since the treatment of advanced cancers involves a combination of chemotherapy, radiation, and surgery. EUS is very useful for staging of the tumour and nodes. High frequency ultrasound miniprobes provide the ability to perform staging when the lesion is obstructing the oesophageal lumen. CT and PET provide valuable information regarding node and metastasis staging.

  12. 超声、钼靶X线联合MRI在乳腺癌术前评价中的应用%Application of Combined Ultrasound, Mammography and MRI in Preoperative Assessment of Breast Cancer

    Institute of Scientific and Technical Information of China (English)

    陈谦谦; 薛恩生

    2012-01-01

    Purpose To investigate combined application of ultrasound, mammography, MRI in preoperative assessment of breast cancer. Materials and Methods Fifty-eight patients were examined by the ultrasound (US), mammography (MG) and MRI before operation. All the cases were confirmed by percutaneous needle puncture or pathological examination. The detection rate, determining tumor size, lymph node metastasis and change in management of the three modalities and joint application were evaluated. Results In all of the examination methods, mammography showed the lowest sensitivity in detecting IDC and LDC lesions (P < 0.05). Combined use of ultrasound, mammography and MRI were more sensitive than US for detecting invasive and DCIS lesions (P < 0.05), and more accurate than mammography in diagnosing metastatic lymph nodes (P < 0.05). MRI was the most accurate in measuring tumor size with US better than mammography (P = 0.000). In 25 patients planned for breast conserving surgery, the management was changed by ultrasound in 2 patients (8.0%), by mammography in 1 patient (4.0%), by MRI in 5 patients (20.0%) and by intraoperative pathology in 1 patient (4.0%). Conclusion Application of ultrasound, mammography combined with MRI can improve breast cancer diagnosis and provide more detailed and accurate evidence for better management.%目的 探讨超声、钼靶X线联合MRI在乳腺癌术前评价中的作用.资料与方法 经超声、钼靶X线和MRI检查后拟诊为乳腺癌的58例患者,均经手术或穿刺病理证实,比较三种检查方法对癌灶检出率、癌灶大小符合率、淋巴结转移情况及手术方式的影响.结果 钼靶X线对癌灶的检出率及对浸润性导管癌(IDC)和浸润性小叶癌(LDC)的检出率最低(P<0.05);超声、钼靶X线和MRI联合对癌灶的检出率和对导管内原位癌(DCIS)的检出率均高于超声(P< 0.05),对转移淋巴结的检出率高于钼靶X线、MRI(P<0.05);癌灶影像学测值与病理测值的符

  13. 术前超声预测腹腔镜胆囊切除术手术难度的分析%Analysis of preoperative ultrasound in predicting difficulty of laparoscopic cholecystectomy

    Institute of Scientific and Technical Information of China (English)

    李琴; 韩晓东; 张弘玮; 张频

    2013-01-01

    ,the number and the max diameter of stone,and the adhesions in umbilicus, Calot triangle or fundus of gallbladder were collected, postoperative variables including operating time, blood loss, conversion to open cholecystectomy,placement of drainage-tubes,postoperative complications,length of hospital stay,incision pain,gastrointestinal reaction and anal exhaust were also collected. According to the virtual difficulty of 960 training samples,they were divided into easy group and difficult group, Chi-square test and t-test were applied to choose statistically significant ultrasonic preoperative variables which formed a scoring system for ultrasonic predicting difficulty of LC. Receiver operating characteristic curve (ROC) was then applied to analyze the scoring system. Results: The variables of preoperative ultrasonic parameters with statistically significant effect were the size of gallbladder, thickness of gallbladder wall, max diameter of single stone, incarcerated stone in neck of gallbladder and the adhesions in Calot triangle and fundus of gallbladder. A scoring system for predicting the difficulty level of LC in patients was then established. The ROC curve analysis revealed that area under the curve was 0.948,which was statistically higher than that from randomizing scheme(0. 5) (P <0. 05) . The appraisal of prospective misjudge possibility was applied to the scoring system for ultrasound predicting difficulty of LC in 118 testing samples,the misjudge rate was about 4. 2% . Conclusions:The scoring system for preoperative ultrasound is a good predictor of difficulty in patients undergoing LC, and has an important significance for selection of laparoscopic operation.

  14. Achieving single channel, full duplex wireless communication

    KAUST Repository

    Choi, Jung Il

    2010-01-01

    This paper discusses the design of a single channel full-duplex wireless transceiver. The design uses a combination of RF and baseband techniques to achieve full-duplexing with minimal effect on link reliability. Experiments on real nodes show the full-duplex prototype achieves median performance that is within 8% of an ideal full-duplexing system. This paper presents Antenna Cancellation, a novel technique for self-interference cancellation. In conjunction with existing RF interference cancellation and digital baseband interference cancellation, antenna cancellation achieves the amount of self-interference cancellation required for full-duplex operation. The paper also discusses potential MAC and network gains with full-duplexing. It suggests ways in which a full-duplex system can solve some important problems with existing wireless systems including hidden terminals, loss of throughput due to congestion, and large end-to-end delays. Copyright 2010 ACM.

  15. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... specific content. Related Articles and Media Sonohysterography Ultrasound - Abdomen Children's (Pediatric) Ultrasound - Abdomen Obstetric Ultrasound Ultrasound - Prostate Kidney and ...

  16. Corrosion behavior of duplex coatings

    Directory of Open Access Journals (Sweden)

    K. Raghu Ram Mohan Reddy

    2016-07-01

    Full Text Available The titanium alloys are used in defense, aerospace, automobile, chemical plants and biomedical applications due to their very high strength and lightweight properties. However, corrosion is a life-limiting factor when Ti alloys are exposed to different chemical environments at high temperatures. In the present paper, duplex NiCrAlY/WC–Co coating is coated onto Ti6Al4V substrate to investigate the corrosion behavior of both coated samples and the substrate. The duplex coating was performed with NiCrAlY as the intermediate coat of 200 μm thickness deposited by HVOF process and WC–Co ceramic top coat with varying thicknesses of 250 μm, 350 μm and 450 μm deposited by DS process. Potentiodynamic polarization tests were employed to investigate the corrosion performance of duplex coated samples and substrate in Ringer’s solution at 37 °C and pH value was set to 5.7. Finally the results reveal that 350 μm thick coated samples showed highest corrosion resistance compared to 250 μm thick samples as well as bare substrate. However, the 450 μm thick coated sample showed poor corrosion resistance compared to the substrate. The scale formed on the samples upon corrosion was characterized by using SEM analysis to understand the degree of corrosion behavior.

  17. Role of magnetic resonance urography in diagnosis of duplex renal system: Our initial experience at a tertiary care institute

    Directory of Open Access Journals (Sweden)

    Milind P Joshi

    2009-01-01

    Full Text Available Aim: To determine diagnostic value of magnetic resonance urography in cases of duplex renal system. Method: Twenty cases between five month to nine years with suspected or known duplex renal system were evaluated by ultrasound (USG, micturating cystourethrography (MCU, intravenous urography (IVU and magnetic resonance urography (MRU. The findings of these diagnostic imaging studies were then compared with each other and against the results of final diagnosis established at surgery. Results: Duplex renal system could be identified in two of these cases on USG, was diagnosed in four in IVU and could be diagnosed in all cases with MRU. Conclusion: MRU is superior and far accurate than IVU, MCU and USG in diagnosing duplex renal system.

  18. Role of magnetic resonance urography in diagnosis of duplex renal system: Our initial experience at a tertiary care institute

    Science.gov (United States)

    Joshi, Milind P.; Shah, Heemanshi S.; Parelkar, Sandesh V.; Agrawal, Amit A.; Sanghvi, Beejal

    2009-01-01

    Aim: To determine diagnostic value of magnetic resonance urography in cases of duplex renal system. Method: Twenty cases between five month to nine years with suspected or known duplex renal system were evaluated by ultrasound (USG), micturating cystourethrography (MCU), intravenous urography (IVU) and magnetic resonance urography (MRU). The findings of these diagnostic imaging studies were then compared with each other and against the results of final diagnosis established at surgery. Results: Duplex renal system could be identified in two of these cases on USG, was diagnosed in four in IVU and could be diagnosed in all cases with MRU. Conclusion: MRU is superior and far accurate than IVU, MCU and USG in diagnosing duplex renal system. PMID:19468429

  19. Obstetrical Ultrasound

    Science.gov (United States)

    ... Physician Resources Professions Site Index A-Z Obstetric Ultrasound Obstetric ultrasound uses sound waves to produce pictures ... limitations of Obstetrical Ultrasound Imaging? What is Obstetrical Ultrasound Imaging? Ultrasound is safe and painless, and produces ...

  20. Prostate Ultrasound

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z Ultrasound - Prostate Ultrasound of the prostate uses sound waves ... the limitations of Prostate Ultrasound Imaging? What is Ultrasound Imaging of the Prostate? Ultrasound is safe and ...

  1. Musculoskeletal Ultrasound

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z Ultrasound - Musculoskeletal Ultrasound imaging uses sound waves to produce ... Ultrasound Imaging of the Musculoskeletal System? What is Ultrasound Imaging of the Musculoskeletal System? Ultrasound is safe ...

  2. Ultrasound - Scrotum

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z Ultrasound - Scrotum Ultrasound imaging of the scrotum uses sound ... of Ultrasound Imaging of the Scrotum? What is Ultrasound Imaging of the Scrotum? Ultrasound imaging of the ...

  3. Ultrasound -- Vascular

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z Ultrasound - Vascular Vascular ultrasound uses sound waves to evaluate ... the limitations of Vascular Ultrasound? What is Vascular Ultrasound? Ultrasound is safe and painless, and produces pictures ...

  4. Hip Ultrasound

    Science.gov (United States)

    ... Physician Resources Professions Site Index A-Z Hip Ultrasound Hip ultrasound uses sound waves to produce pictures ... of Ultrasound Imaging of the Hip? What is Ultrasound Imaging of the Hip? Ultrasound images of the ...

  5. Ultrasound -- Vascular

    Science.gov (United States)

    ... Physician Resources Professions Site Index A-Z Ultrasound - Vascular Vascular ultrasound uses sound waves to evaluate the ... are the limitations of Vascular Ultrasound? What is Vascular Ultrasound? Ultrasound is safe and painless, and produces ...

  6. The effect of preoperative Lugol's iodine on thyroid blood flow in patients with Graves' hyperthyroidism.

    Science.gov (United States)

    Chang, D C; Wheeler, M H; Woodcock, J P; Curley, I; Lazarus, J R; Fung, H; John, R; Hall, R; McGregor, A M

    1987-12-01

    A study was conducted to investigate the effect of Lugol's iodine on the superior thyroid artery (STA) blood flow with use of a Duplex ultrasound scanner for 12 patients with Graves' disease. All patients were treated with antithyroid drugs until they were euthyroid and then, with randomization, the patients received either Lugol's iodine, 0.3 ml thrice daily, or placebo for 9 days in a double-blind fashion. Antithyroid drugs were continued throughout the study. Reduction in the diameter, time-averaged velocity (TAV), and volume flow (VF) of the STAs was demonstrated in all patients in the treatment group, whereas there were no consistent trends in the placebo group. The changes in TAV and VF were significantly different between the placebo and treatment groups (p less than 0.01 for TAV and p less than 0.005 for VF). These changes were more marked in patients with high initial VF and minimal in patients with low initial VF. On the basis of these results, we recommend that patients with high thyroid blood flow before thyroidectomy should receive Lugol's iodine preoperatively.

  7. Prostate Ultrasound

    Medline Plus

    Full Text Available ... through blood vessels. Ultrasound imaging is a noninvasive medical test that helps physicians diagnose and treat medical conditions. Prostate ultrasound, also called transrectal ultrasound, provides ...

  8. Assessment of preoperative ultrasonography of the neck and elective neck dissection in patients with oral squamous cell carcinoma.

    NARCIS (Netherlands)

    Wensing, B.M.; Merkx, M.A.W.; Wilde, P.C.M. de; Marres, H.A.M.; Hoogen, F.J.A. van den

    2010-01-01

    Estimating the value of our preoperative workup in the treatment of patients with clinically N0 (cN0) squamous cell carcinoma of the oral cavity. Retrospective analysis. Results of preoperative palpation, ultrasound (US) and ultrasound-guided fine needle aspiration cytology (FNAC) were compared to t

  9. Prostate Ultrasound

    Medline Plus

    Full Text Available ... Prostate Ultrasound Imaging? What is Ultrasound Imaging of the Prostate? Ultrasound is safe and painless, and produces ... of page What are some common uses of the procedure? A transrectal ultrasound of the prostate gland ...

  10. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... are the limitations of Pelvic Ultrasound Imaging? What is Pelvic Ultrasound Imaging? Ultrasound is safe and painless, ... through the blood vessels. top of page How is the procedure performed? Transabdominal: For most ultrasound exams, ...

  11. Prostate Ultrasound

    Medline Plus

    Full Text Available ... Ultrasound - Prostate Ultrasound of the prostate uses sound waves to produce pictures of a man’s prostate gland ... of the inside of the body using sound waves. Ultrasound imaging, also called ultrasound scanning or sonography , ...

  12. Ultrasound - Breast

    Science.gov (United States)

    ... Physician Resources Professions Site Index A-Z Ultrasound - Breast Ultrasound imaging of the breast uses sound waves ... the Breast? What is Ultrasound Imaging of the Breast? Ultrasound is safe and painless, and produces pictures ...

  13. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... Ultrasound - Pelvis Ultrasound imaging of the pelvis uses sound waves to produce pictures of the structures and ... pictures of the inside of the body using sound waves. Ultrasound imaging, also called ultrasound scanning or ...

  14. Prostate Ultrasound

    Medline Plus

    Full Text Available ... Z Ultrasound - Prostate Ultrasound of the prostate uses sound waves to produce pictures of a man’s prostate ... pictures of the inside of the body using sound waves. Ultrasound imaging, also called ultrasound scanning or ...

  15. Prostate Ultrasound

    Medline Plus

    Full Text Available ... Prostate Ultrasound Imaging? What is Ultrasound Imaging of the Prostate? Ultrasound is safe and painless, and produces ... of page What are some common uses of the procedure? A transrectal ultrasound of the prostate gland ...

  16. Screening of Modified RNA duplexes

    DEFF Research Database (Denmark)

    Schyth, Brian Dall; Bramsen, Jesper Bertram; Kjems, Jørgen

    Because of sequence specific gene targeting activity siRNAs are regarded as promising active compounds in gene medicine. But one serious problem with delivering siRNAs as treatment is the now well-established non-specific activities of some RNA duplexes. Cellular reactions towards double stranded...... RNAs include the 2´-5´ oligoadenylate synthetase system, the protein kinase R, RIG-I and Toll-like receptor activated pathways all resulting in antiviral defence mechanism. We have previously shown that antiviral innate immune reactions against double stranded RNAs could be detected in vivo as partial...... protection against a fish pathogenic virus. This protection corresponded with an interferon response in the fish. Here we use this fish model to screen siRNAs containing various chemical modifications of the RNA backbone for their antiviral activity, the overall aim being identification of an siRNA form...

  17. Comparative Study of LAVA-EnhancedMRI and High Frequency Cavity B Ultrasound in High Complex anal Fistula Preoperative Examination%LAVA增强磁共振检查与高频腔内B超在高位复杂性肛瘘术前检查中的对比研究

    Institute of Scientific and Technical Information of China (English)

    王庭红; 顾建平; 王丽萍

    2015-01-01

    Objective To investigate the value of LAVA-enhanced magnetic resonance imaging and high frequency cavity B ultrasound of high complex anal fistula preoperative diagnosis. Methods a retrospective analysis of 50 cases verified by operation of high complex anal fistula B ultrasound image and MRI image, the operation results as the standard, comparison of LAVA-Enhanced magnetic resonance imaging and high frequency cavity B ultrasound results. Results the operation result as the standard, high frequency cavity B ultrasound and LAVA-Enhanced magnetic resonance imaging results compared, accuracy rate of export orientation in the anal fistula were 91.1% and 82.2%(X2=1.53, P>0.05), branch display rate was 62.2%and 88.8%(X2=8.66, P0.05), other complications display rate (50% and 100%) (X2=8.6, P<0.01). export orientation in the anal fistula and perianal abscess localization accuracy without significant difference. Branch and other complications showed highly significant difference. Conclusion high frequency cavity B ultrasound diagnosis for simple anal fistula preoperative diagnosis, whereas LAVA-enhanced MRI is more suitable for high complex anal fistula preoperative.%目的:探讨LAVA增强磁共振检查与高频腔内B超对高位复杂性肛瘘的术前诊断价值。方法回顾分析经手术证实的50例高位复杂性肛瘘的MRI图像及B超图像,以手术结果为标准,比较术前LAVA增强磁共振检查与高频腔内B超的结果。结果以手术结果为标准,高频腔内B超与LAVA增强磁共振检查的结果相比较,肛瘘内口定位准确率分别为91.1%和82.2%(X2=1.53,P>0.05),支管显示率为62.2%和88.8%(X2=8.66,P<0.01),肛周脓肿显示率为(95%和100%) X2=1.07,P>0.05),其它并发症显示率(50%和100%)(X2=8.6,P<0.01),肛瘘内口及肛周脓肿定位准确率差别无统计学意义,支管及其它并发症显示率差别具有高度统计学意义。结论高频腔内B超适用于单纯

  18. 探讨实时超声造影技术评价肝移植术前门静脉通畅性的研究%Study of Real-time Contrast-enhanced Ultrasound Technology Evaluation of Portal Vein Flow Resistance Preoperative Liver Transplantation

    Institute of Scientific and Technical Information of China (English)

    许宇光

    2015-01-01

    目的:比较目前的两种超声技术,普通超声和实时超声造影技术对肝脏移植手术前门静脉的畅通性评价特点。方法:对经普通超声技术检查后被怀疑门静脉一级分支或主干中有栓塞的34例患者进行实时超声造影检查。结果:经螺旋CT的门静脉成像、三维动态磁共振的血管成像和肝移植手术等方法的证实,34例患者中有27例门静脉栓塞患者,7例门静脉畅通患者。普通超声技术和实时超声造影技术的诊断信心评分分别为(8.32±1.89)分和(9.29±1.01)分;普通超声技术和实时超声造影技术的敏感性分别为87.9%和81.9%,特异性分别为32.8%和100%,准确性分别为68.7%和89.1%;鉴别栓子程度和栓子性质时,实时超声造影技术明显优于普通超声技术。其中,对于在实时超声造影技术中显示的16例门静脉栓塞患者,实时超声造影技术是可以百分百全部鉴别的,但在普通超声技术可以显示的17例门静脉栓塞患者中,只能鉴别出9例患者。结论:在肝移植手术前诊断门静脉的畅通性时,实时超声造影技术的诊断水平明显高于普通超声技术,能够提供更准确、丰富的术前诊断信息,实时超声造影技术可以很好地补充普通超声技术,值得临床推广应用。%Objective:To compare the two kinds of ultrasonic imaging technology,common ultrasonic and real-time contrast-enhanced ultrasound technology to the smooth general characteristic evaluation characteristic of portal vein flow preoperative liver transplantation.Method:For suspected portal vein after normal ultrasound examination level branches or trunk of 34 patients with embolization were given real-time contrast-enhanced ultrasound examination.Result:The spiral CT portal imaging,3D dynamic magnetic resonance angiography and the proof of the method such as a liver transplant confirmed,in 34 patients,there were 27 cases of portal vein

  19. ULTRASOUND AND COMPUTED TOMOGRAPHIC DIAGNOSIS OF OPTIC NERVE TUMORS

    Directory of Open Access Journals (Sweden)

    S. V. Saakyan

    2012-01-01

    Full Text Available A comprehensive examination was made in 93 patients, including 18 children, with tumors of the optic nerve (ON. Duplex ultrasound scanning was performed in 39 patients, of them there were 11 patients with ON gliomas and 28 with ON meningiomas. The specific computed tomographic and echographic signs of ON glioma and meningiomas were detected. The studies have shown that duplex ultrasound scanning and structural computed tomography of orbital sockets are highly informative complementary imaging procedures for ON tumors, which permits one to make their correct diagnosis, to specify surgical volume, and to plan adequate treatment.

  20. Contemporary Applications of Ultrasound in Abdominal Aortic Aneurysm Management

    Science.gov (United States)

    Scaife, Mark; Giannakopoulos, Triantafillos; Al-Khoury, Georges E.; Chaer, Rabih A.; Avgerinos, Efthymios D.

    2016-01-01

    Ultrasound (US) is a well-established screening tool for detection of abdominal aortic aneurysms (AAAs) and is currently recommended not only for those with a relevant family history but also for all men and high-risk women older than 65 years of age. The advent of minimally invasive endovascular techniques in the treatment of AAAs [endovascular aneurysm repair (EVAR)] has increased the need for repeat imaging, especially in the postoperative period. Nevertheless, preoperative planning, intraoperative execution, and postoperative surveillance all mandate accurate imaging. While computed tomographic angiography and angiography have dominated the field, repeatedly exposing patients to the deleterious effects of cumulative radiation and intravenous nephrotoxic contrast, US technology has significantly evolved over the past decade. In addition to standard color duplex US, 2D, 3D, or 4D contrast-enhanced US modalities are revolutionizing AAA management and postoperative surveillance. This technology can accurately measure AAA diameter and volume, and most importantly, it can detect endoleaks post-EVAR with high sensitivity and specificity. 4D contrast-enhanced US can even provide hemodynamic information about the branch vessels following fenestrated EVARs. The need for experienced US operators and accredited vascular labs is mandatory to guarantee the reliability of the results. This review article presents a comprehensive overview of the literature on the state-of-art US imaging in AAA management, including post-EVAR follow-up, techniques, and diagnostic accuracy. PMID:27303669

  1. Practical, real-time, full duplex wireless

    KAUST Repository

    Jain, Mayank

    2011-01-01

    This paper presents a full duplex radio design using signal inversion and adaptive cancellation. Signal inversion uses a simple design based on a balanced/unbalanced (Balun) transformer. This new design, unlike prior work, supports wideband and high power systems. In theory, this new design has no limitation on bandwidth or power. In practice, we find that the signal inversion technique alone can cancel at least 45dB across a 40MHz bandwidth. Further, combining signal inversion cancellation with cancellation in the digital domain can reduce self-interference by up to 73dB for a 10MHz OFDM signal. This paper also presents a full duplex medium access control (MAC) design and evaluates it using a testbed of 5 prototype full duplex nodes. Full duplex reduces packet losses due to hidden terminals by up to 88%. Full duplex also mitigates unfair channel allocation in AP-based networks, increasing fairness from 0.85 to 0.98 while improving downlink throughput by 110% and uplink throughput by 15%. These experimental results show that a re- design of the wireless network stack to exploit full duplex capability can result in significant improvements in network performance. © 2011 ACM.

  2. Preoperative imaging diagnosis of carotid body tumors.

    Science.gov (United States)

    Pacheco-Ojeda, Luis A; Martínez-Viteri, Miguel A

    2010-01-01

    Carotid body tumors (CBTs) are relatively frequent lesions encountered at high altitudes, such in as the Andean Mountains. A correct preoperative diagnosis is essential for surgical planning and performance. For this reason, we have reviewed the evolution of our experience in the imaging diagnosis of these tumors. Between 1980 and June 2008, 160 CBTs were diagnosed. A total of 138 tumors were operated on, 4 are waiting for surgery, and 18 were not operated on because of age, medical conditions, or patient refusal. We have reviewed retrospectively the modalities of imaging diagnosis in our patients who underwent operation. Among the 138 tumors operated on, a correct preoperative diagnosis was done in 127 cases (92%). The preoperative diagnosis of the remaining 11 patients was unspecified benign tumor for 6 patients and neck lymph node for 5 patients. The imaging methods performed by different radiologists were conventional ultrasound, color Doppler ultrasound, carotid conventional angiography (CA), axial tomography, magnetic resonance and magnetic resonance angiography, and computed tomographic angiography (CTA). Most patients had more than one image study. Review of radiologist reports revealed a correct diagnosis in all carotid CA, magnetic resonance studies, and CTA. Additionally, CTA appeared to be a valuable method to predict the Shamblin group. Clinical suspicion and current image techniques permit a correct diagnosis in practically all cases of CBT.

  3. Validation of Doppler ultrasound and magnetic resonance imaging velocity measurements by means of a test object

    NARCIS (Netherlands)

    Oostayen, J.A. van; Bezemer, R.A.; Wasser, M.N.J.M.; Teirlinck, C.J.P.M.

    1996-01-01

    Objective: To validate Doppler ultrasound and MRI mean velocity measurements in a test object in which mean velocities are known and can be chosen within a range of 10-100 cm/s in tubes of 4 and 8 mm. This validation was carried out to check the performance of a duplex Doppler ultrasound system that

  4. Preoperatively diagnosed mucocele of the appendix.

    Science.gov (United States)

    Rojnoveanu, Gh; Ghidirim, Gh; Mishin, I; Vozian, M; Mishina, A

    2014-01-01

    Mucocele of the appendix is an infrequent entity, characterized by distension of the lumen due to accumulation of mucoid substance and is rarely diagnosed preoperatively. If untreated, mucocele may rupture producing a potentially fatal entity known as pseudomyxoma peritonei. The type of surgical treatment is related to the dimensions and the histology of the mucocele. Appendectomy is used for simple mucocele or for cystadenoma. Right hemi-colectomy is recommended for cystadeno carcinoma. In this paper, we report a case of an asymptomatic 37-year-old woman in whom mucocele was found on a routine ultrasound examination and preoperative computed tomography scan. Surgery revealed a big appendix measuring 84 mm in length and 40 mm in diameter. The final pathologic diagnosis was simple mucocele. Celsius.

  5. Prostate Ultrasound

    Medline Plus

    Full Text Available ... are the limitations of Prostate Ultrasound Imaging? What is Ultrasound Imaging of the Prostate? Ultrasound is safe ... transducer into the body. top of page How is the procedure performed? In men, the prostate gland ...

  6. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... Pelvis Ultrasound imaging of the pelvis uses sound waves to produce pictures of the structures and organs ... of the inside of the body using sound waves. Ultrasound imaging, also called ultrasound scanning or sonography , ...

  7. Prostate Ultrasound

    Medline Plus

    Full Text Available ... gel. top of page How does the procedure work? Ultrasound imaging is based on the same principles ... to-use and less expensive than other imaging methods. Ultrasound imaging uses no ionizing radiation. Ultrasound scanning ...

  8. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... a pelvic ultrasound examination. Doppler ultrasound , also called color Doppler ultrasonography, is a special ultrasound technique that ... and processes the sounds and creates graphs or color pictures that represent the flow of blood through ...

  9. Intravascular ultrasound

    Science.gov (United States)

    IVUS; Ultrasound - coronary artery; Endovascular ultrasound; Intravascular echocardiography ... A tiny ultrasound wand is attached to the top of a thin tube. This tube is called a catheter. The catheter ...

  10. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... three types of pelvic ultrasound: abdominal, vaginal (for women), and rectal (for men). These exams are frequently ... pelvic ultrasound: abdominal ( transabdominal ) vaginal ( transvaginal / endovaginal ) for women rectal ( transrectal ) for men A Doppler ultrasound exam ...

  11. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... ultrasound images are captured in real-time, they can show the structure and movement of the body's ... Obstetrical Ultrasound page for more information . Ultrasound examinations can help diagnose symptoms experienced by women such as: ...

  12. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... through blood vessels. Ultrasound imaging is a noninvasive medical test that helps physicians diagnose and treat medical conditions. There are three types of pelvic ultrasound: ...

  13. Full Duplex Communications in 5G Small Cells

    DEFF Research Database (Denmark)

    Mahmood, Nurul Huda; Gatnau, Marta; Berardinelli, Gilberto

    2017-01-01

    Full duplex communication promises system performance improvement over conventional half duplex communication by allowing simultaneous transmission and reception. However, such concurrent communication results in strong self interference and an increase in the overall network interference, and ca...

  14. Research interface on a programmable ultrasound scanner.

    Science.gov (United States)

    Shamdasani, Vijay; Bae, Unmin; Sikdar, Siddhartha; Yoo, Yang Mo; Karadayi, Kerem; Managuli, Ravi; Kim, Yongmin

    2008-07-01

    Commercial ultrasound machines in the past did not provide the ultrasound researchers access to raw ultrasound data. Lack of this ability has impeded evaluation and clinical testing of novel ultrasound algorithms and applications. Recently, we developed a flexible ultrasound back-end where all the processing for the conventional ultrasound modes, such as B, M, color flow and spectral Doppler, was performed in software. The back-end has been incorporated into a commercial ultrasound machine, the Hitachi HiVision 5500. The goal of this work is to develop an ultrasound research interface on the back-end for acquiring raw ultrasound data from the machine. The research interface has been designed as a software module on the ultrasound back-end. To increase the amount of raw ultrasound data that can be spooled in the limited memory available on the back-end, we have developed a method that can losslessly compress the ultrasound data in real time. The raw ultrasound data could be obtained in any conventional ultrasound mode, including duplex and triplex modes. Furthermore, use of the research interface does not decrease the frame rate or otherwise affect the clinical usability of the machine. The lossless compression of the ultrasound data in real time can increase the amount of data spooled by approximately 2.3 times, thus allowing more than 6s of raw ultrasound data to be acquired in all the modes. The interface has been used not only for early testing of new ideas with in vitro data from phantoms, but also for acquiring in vivo data for fine-tuning ultrasound applications and conducting clinical studies. We present several examples of how newer ultrasound applications, such as elastography, vibration imaging and 3D imaging, have benefited from this research interface. Since the research interface is entirely implemented in software, it can be deployed on existing HiVision 5500 ultrasound machines and may be easily upgraded in the future. The developed research

  15. Transcranial duplex doppler ultrasonography in dogs with hydrocephalus Ultrassonografia duplex Doppler transcraniana em cães com hidrocefalia

    Directory of Open Access Journals (Sweden)

    C.F. Carvalho

    2010-02-01

    Full Text Available Transcranial duplex Doppler ultrasound was performed in 32 conscious dogs presenting ventriculomegaly detected in B-mode, obtaining measures of lateral ventricles and resistance parameters of main cerebral arteries before and after 30 days of clinical treatment. The animals were distributed divided in two groups: group 1, dogs that presented remission or decrease of the neurological signs of the disease after clinical therapy; and group 2, dogs that displayed worsening of the neurological signs or clinical stability. The data were all presented in tables and were submitted to paired t test and to logistic regression models to evaluate the influence of the RI reduction on both groups. There was no significant influence of the variables in the B-mode. After the treatment, the mean resistive index (RI was significantly lower for the group that presented clinical improvement. There was no significant difference of the mean RI reduction for the same artery when the right and left sides were compared. It could be concluded that transcranial duplex Doppler ultrasound is a method of cerebral hemodynamic assessment able to monitor more precisely the treatment of hydrocephalus in dogs and verify the responses.Foi realizada a ultrassonografia duplex Doppler transcraniana em 32 cães, conscientes, que apresentavam ventriculomegalia previamente detectada ao exame modo-B, para obter as medidas dos ventrículos laterais e os parâmetros de resistência das artérias cerebrais antes e depois de 30 dias de tratamento clínico. Os animais foram distribuídos em dois grupos: 1 - formado por cães que apresentaram remissão ou diminuição dos sinais clínicos após tratamento; 2 - por cães que apresentaram piora dos sinais neurológicos ou estabilidade do quadro clínico. Todos os dados foram dispostos em tabelas e submetidos ao teste t pareado e a modelos de regressão logística para avaliar a influência da redução do índice de resistividade (IR. Não foi

  16. Solid breast neoplasms: Differential diagnosis with pulsed Doppler ultrasound

    NARCIS (Netherlands)

    T.J.A. Kuijpers (T. J A); A.I.M. Obdeijn (Inge-Marie); Ph.M. Kruyt (Philip); M. Oudkerk (Matthijs)

    1994-01-01

    textabstractIn this prospective study, duplex Doppler ultrasound was used in 95 consecutive patients with solid breast masses to evaluate the presence of neovascular flow. A positive Doppler signal, i.e., a Doppler shift frequency of more than 1 kHz using a 5 MHz insonating frequency, was found in 3

  17. Accuracy of diagnostic imaging in nephroblastoma before preoperative chemotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Rieden, K. [Radiologische Klinik, Abt. Klinische Radiologie, Heidelberg (Germany); Weirich, A. [Kinderklinik, Univ. of Heidelberg (Germany); Troeger, J. [Radiologische Klinik, Abt. Paediatrische Radiologie, Univ. of Heidelberg (Germany); Gamroth, A.H. [Deutsches Krebsforschungszentrum, Heidelberg (Germany); Raschke, K. [Radiologische Klinik, Abt. Paediatrische Radiologie, Univ. of Heidelberg (Germany); Ludwig, R. [Kinderklinik, Univ. of Heidelberg (Germany)

    1993-04-01

    From July 1988 to February 1991, 130 children with the tentative diagnosis of nephroblastoma were treated preoperatively. The initial diagnostic images (excretory urography, ultrasound, CT, MRI) have been analysed both prospectively and retrospectively and the findings correlated with the intraoperative and histological results. Of the preoperatively treated patients 93.8% had a Wilms` tumour or one of its variants. Five patients had a different malignant tumour and 3 patients, i.e. 2.3% of those preoperatively treated or 1.6% of all registered patients, had benign tumours of the kidney. Wilms` tumour generally presented as a well-defined mass with an inhomogeneous morphology on CT. On ultrasound only 24% of the tumours were homogeneous. Intratumoral haemorrhage and cystic areas occurred frequently; calcifications were rare (8%). With regard to caval involvement only ultrasound and MRI enabled the correct diagnosis, while CT could not differentiate compressions from invasion. The pretherapeutic diagnostic imaging was of sufficient accuracy to start preoperative chemotherapy without diagnostic biopsy. (orig.)

  18. Fornix Rupture in Duplex Kidney due to Internal Iliac Artery Aneurysm

    Directory of Open Access Journals (Sweden)

    Phitsanu Mahawong

    2016-01-01

    Full Text Available A 70-year-old man presented with severe pain on the right side of the abdomen for 7 days. An abdominal CT angiographic scan showed an impending rupture of a large right internal iliac artery aneurysm which compressed to a right ureter causing hydroureteronephrosis. Fornix rupture of a right duplex kidney was also detected. Selective embolization of right gluteal arteries and then ligation of the right internal iliac artery and right ureterotomy with double J stenting were performed. At the 4-month follow-up appointment, an abdominal ultrasound demonstrated a decrease in the size of the aneurysm and no hydroureteronephrosis after the removal of double J stent.

  19. Preoperative preparation of children

    Directory of Open Access Journals (Sweden)

    Priya Reshma Aranha

    2017-01-01

    Full Text Available Surgery is a stressful and anxiety provoking experience for children. Millions of children undergo surgery every year. The majority of children experience significant preoperative anxiety which intern can affect their recovery. Preoperative anxiety may bring about physical and physiological changes in children, which can be particularly evident in terms of increased heart rate and blood pressure. To identify various strategies used to minimize the preoperative anxiety of children and update their clinical effectiveness among children undergoing surgery, the authors searched PubMed, MEDLINE, CINAHL, ScienceDirect, Google Scholar, Scopus, and Cochrane Library for identifying the relevant studies and retrieved available literature. It is concluded that utilization of the strategies available to reduce the preoperative anxiety of children will be a promising intervention to reduce anxiety, to promote relaxation, satisfaction, and speedy recovery. Many of these techniques are simple, cost-effective and can be easily carried out by nurses. It is essential to use the age appropriate and individualized methods in preparing children for surgery. Further research is required to strengthen the evidence.

  20. Full Duplex Emulation via Spatial Separation of Half Duplex Nodes in a Planar Cellular Network

    DEFF Research Database (Denmark)

    Thomsen, Henning; Kim, Dong Min; Popovski, Petar;

    2016-01-01

    A Full Duplex Base Station (FD-BS) can be used to serve simultaneously two Half-Duplex (HD) Mobile Stations (MSs), one working in the uplink and one in the downlink, respectively. The same functionality can be realized by having two interconnected and spatially separated Half Duplex Base Stations...... (HD-BSs), which is a scheme termed CoMPflex (CoMP for In-Band Wireless Full Duplex). A FD-BS can be seen as a special case of CoMPflex with separation distance zero. In this paper we study the performance of CoMPflex in a two-dimensional cellular scenario using stochastic geometry and compare...... of communication reliability. Following the trend of wireless network densification, CoMPflex can be regarded as a method with a great potential to effectively use the dense HD deployments....

  1. Ultra-short silicon MMI duplexer

    Science.gov (United States)

    Yi, Huaxiang; Huang, Yawen; Wang, Xingjun; Zhou, Zhiping

    2012-11-01

    The fiber-to-the-home (FTTH) systems are growing fast these days, where two different wavelengths are used for upstream and downstream traffic, typically 1310nm and 1490nm. The duplexers are the key elements to separate these wavelengths into different path in central offices (CO) and optical network unit (ONU) in passive optical network (PON). Multimode interference (MMI) has some benefits to be a duplexer including large fabrication tolerance, low-temperature dependence, and low-polarization dependence, but its size is too large to integrate in conventional case. Based on the silicon photonics platform, ultra-short silicon MMI duplexer was demonstrated to separate the 1310nm and 1490nm lights. By studying the theory of self-image phenomena in MMI, the first order images are adopted in order to keep the device short. A cascaded MMI structure was investigated to implement the wavelength splitting, where both the light of 1310nm and 1490nm was input from the same port, and the 1490nm light was coupling cross the first MMI and output at the cross-port in the device while the 1310nm light was coupling through the first and second MMI and output at the bar-port in the device. The experiment was carried on with the SOI wafer of 340nm top silicon. The cascaded MMI was investigated to fold the length of the duplexer as short as 117μm with the extinct ratio over 10dB.

  2. On the Secrecy Degrees of Freedom with Full Duplex Communication

    DEFF Research Database (Denmark)

    Mahmood, Nurul Huda; Mogensen, Preben Elgaard

    2017-01-01

    and the delay reduction of full duplex communication are somewhat limited in realistic network settings, leading researchers to study other possible applications of full duplex communication which can provide significantly higher gains over half duplex communication. Physical layer security is an example...... of such an application. The potential of full duplex nodes in improving the physical layer security of a communication link is investigated in this contribution. We specifically derive the information theoretic secrecy degrees of freedom measure for a pair of nodes communicating in full duplex mode. Moreover, closed...

  3. On the Ergodic Secrecy Capacity with Full Duplex Communication

    DEFF Research Database (Denmark)

    Mahmood, Nurul Huda; Shafique Ansari, Imran; Mogensen, Preben Elgaard

    2017-01-01

    Full duplex communication promises performance gains in terms of the throughput and the delay. Generally, it has been shown that the throughput and delay gains of full duplex communication are somewhat limited in realistic network settings, leading researchers to study other possible applications...... capacity for a pair of nodes with full duplex communication. The ergodic secrecy rate with full duplex communication is found to grow linearly with the log of the direct channel SNR as opposed to the flattened out secrecy rate with conventional half duplex communication, irrespective of the eavesdropper...

  4. Transperitoneal laparoscopic heminephrectomy in duplex kidneys: a one centre experience

    Directory of Open Access Journals (Sweden)

    Mehdi Abedinzadeh

    2012-02-01

    Full Text Available Purpose: The standard treatment for a duplex kidney with poorly functioning upper pole moiety is ipsilateral upper pole heminephrectomy. This procedure is usually performed by open surgery, but with recent developments in techniques of uro-laparoscopy, it can be done with it, safely. In this study we evaluated the results and safety of laparoscopic heminephrectomy in our consecutive cases.Materials and Methods: From February 2001 to May 2007 fourteen unilateral laparoscopic heminephrectomy were performed in our center. Patients' characteristics, presenting symptoms, operative time, and blood loss, early and late complications were all collected retrospectively. Using pre-operative ultrasonography, intravenous pyelography (IVP and CT scanning, unilateral upper pole hydronephrosis was detected in all cases. By DMSA isotope scan hypofunctioning of ipsilateral moieties was detected in all cases.Results: Mean operative time was 203±80 minutes. No major intra-operative or early complications were identified. Mean hospital stay was 4.1 days. On mean follow-up of 32 months no disturbing symptoms or episodes of urinary tract infections (UTIs were detected. Atrophic kidney was detected in one case in post-operative IVP.Conclusion: Laparoscopic heminephrectomy is a valuable minimal invasive procedure that can be performed safely in experienced hands without any important complication. Perfect renal pedicles vascular system manipulation is important for the preservation of renal function post-operatively.

  5. Interventions for preoperative smoking cessation

    DEFF Research Database (Denmark)

    Møller, A; Villebro, N

    2005-01-01

    Smokers have a substantially increased risk of intra- and postoperative complications. Preoperative smoking intervention may be effective in decreasing this incidence. The preoperative period may be a well chosen time to offer smoking cessation interventions due to increased patient motivation....

  6. Prostate Ultrasound

    Medline Plus

    Full Text Available ... as detailed as with the transrectal probe. An MRI of the pelvis may be obtained as an ... Benign Prostatic Hyperplasia (BPH) Prostate Cancer Ultrasound- and MRI-Guided Prostate Biopsy Images related to Ultrasound - Prostate ...

  7. Prostate Ultrasound

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    Full Text Available ... is done because a potential abnormality needs further evaluation with additional views or a special imaging technique. ... other imaging methods. Ultrasound imaging uses no ionizing radiation. Ultrasound scanning may be able to give a ...

  8. Ultrasound -- Pelvis

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    Full Text Available ... needles are used to extract a sample of cells from organs for laboratory testing. Doppler ultrasound images ... ultrasound, measures the direction and speed of blood cells as they move through vessels. The movement of ...

  9. Ultrasound -- Pelvis

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    Full Text Available ... the procedure? In women, a pelvic ultrasound is most often performed to evaluate the: uterus cervix ovaries ... page How is the procedure performed? Transabdominal: For most ultrasound exams, you will be positioned lying face- ...

  10. Ultrasound -- Pelvis

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    Full Text Available ... transducer into the body. Doppler ultrasound, a special application of ultrasound, measures the direction and speed of ... understanding of the possible charges you will incur. Web page review process: This Web page is reviewed ...

  11. Ultrasound -- Pelvis

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    Full Text Available ... menstrual problems Ultrasound exams also help identify: palpable masses such as ovarian cysts and uterine fibroids ovarian ... In children, pelvic ultrasound can help evaluate: pelvic masses pelvic pain ambiguous genitalia and anomalies of pelvic ...

  12. Ultrasound -- Pelvis

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    Full Text Available ... bladder seminal vesicles prostate Transrectal ultrasound, a special study usually done to provide detailed evaluation of the ... time to the procedure. If a Doppler ultrasound study is performed, you may actually hear pulse-like ...

  13. Ultrasound -- Pelvis

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    Full Text Available ... of page What are some common uses of the procedure? In women, a pelvic ultrasound is most ... child's favorite channel. top of page What does the equipment look like? Ultrasound scanners consist of a ...

  14. Ultrasound -- Pelvis

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    Full Text Available ... ultrasound: abdominal, vaginal (for women), and rectal (for men). These exams are frequently used to evaluate the ... vaginal ( transvaginal , endovaginal ) for women rectal ( transrectal ) for men A Doppler ultrasound exam may be part of ...

  15. Ultrasound -- Pelvis

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    Full Text Available ... ultrasound: abdominal, vaginal (for women), and rectal (for men). These exams are frequently used to evaluate the ... vaginal ( transvaginal / endovaginal ) for women rectal ( transrectal ) for men A Doppler ultrasound exam may be part of ...

  16. Ultrasound -- Pelvis

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    Full Text Available ... 3-D ultrasound or sonohysterography for patients with infertility. In this setting, three-dimensional ultrasound provides information ... the transducer is pressed against the skin, it directs small pulses of inaudible, high-frequency sound waves ...

  17. Prostate Ultrasound

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    Full Text Available ... 20 minutes. top of page What will I experience during and after the procedure? Ultrasound exams in ... ultrasound , there are no known harmful effects on humans. top of page What are the limitations of ...

  18. Ultrasound -- Pelvis

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    Full Text Available ... insertion. top of page How does the procedure work? Ultrasound imaging is based on the same principles ... to-use and less expensive than other imaging methods. Ultrasound imaging is extremely safe and does not ...

  19. Prostate Ultrasound

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    Full Text Available ... top of page What are the benefits vs. risks? Benefits Ultrasound is widely available, easy-to-use ... procedures such as needle biopsies and fluid aspiration. Risks For standard diagnostic ultrasound , there are no known ...

  20. Ultrasound -- Pelvis

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    Full Text Available ... diagnose symptoms experienced by women such as: pelvic pain abnormal vaginal bleeding other menstrual problems Ultrasound exams ... pelvic ultrasound can help evaluate: pelvic masses pelvic pain ambiguous genitalia and anomalies of pelvic organs early ...

  1. Ultrasound -- Pelvis

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    Full Text Available ... Most ultrasound scanning is noninvasive (no needles or injections). Occasionally, an ultrasound exam may be temporarily uncomfortable, ... the following text box: Comment: E-mail: Area code: Phone no: Thank you! Images × Image Gallery Radiologist ...

  2. Ultrasound -- Pelvis

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    Full Text Available ... investigation of the uterine cavity . Three-dimensional (3-D) ultrasound permits evaluation of the uterus and ovaries ... abnormal uterine bleeding Some physicians also use 3-D ultrasound or sonohysterography for patients with infertility. Three- ...

  3. Ultrasound -- Pelvis

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    Full Text Available ... For most ultrasound exams, you will be positioned lying face-up on an examination table that can ... ovaries. Transvaginal ultrasound is usually performed with you lying on your back, possibly with your feet in ...

  4. Ultrasound -- Pelvis

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    Full Text Available ... investigation of the uterine cavity . Three-dimensional (3-D) ultrasound permits evaluation of the uterus and ovaries ... abnormal uterine bleeding Some physicians also use 3-D ultrasound or sonohysterography for patients with infertility. In ...

  5. Endoscopic ultrasound

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/007646.htm Endoscopic ultrasound To use the sharing features on this page, please enable JavaScript. Endoscopic ultrasound is a type of imaging test. It is ...

  6. Prostate Ultrasound

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    Full Text Available ... evaluation with additional views or a special imaging technique. A follow-up examination may also be necessary ... to-use and less expensive than other imaging methods. Ultrasound imaging uses no ionizing radiation. Ultrasound scanning ...

  7. Prostate Ultrasound

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    Full Text Available ... chest. To obtain high-quality images, an ultrasound transducer – a plastic cylinder about the size of a ... or sonography , involves the use of a small transducer (probe) and ultrasound gel placed directly on the ...

  8. Ultrasound -- Pelvis

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    Full Text Available ... by women such as: pelvic pain abnormal vaginal bleeding other menstrual problems Ultrasound exams also help identify: ... fibroids cancer, especially in patients with abnormal uterine bleeding Some physicians also use 3-D ultrasound or ...

  9. Ultrasound -- Pelvis

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    Full Text Available ... insertion. top of page How does the procedure work? Ultrasound imaging is based on the same principles ... time to the procedure. If a Doppler ultrasound study is performed, you may actually hear pulse-like ...

  10. Ultrasound -- Pelvis

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    Full Text Available ... in x-rays ), thus there is no radiation exposure to the patient. Because ultrasound images are captured ... system disorders in both sexes without x-ray exposure. Risks For standard diagnostic ultrasound , there are no ...

  11. Ultrasound -- Pelvis

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    Full Text Available ... needles are used to extract a sample of cells from organs for laboratory testing. Doppler ultrasound images ... ultrasound, measures the direction and speed of blood cells as they move through vessels. The movement of ...

  12. Prostate Ultrasound

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    Full Text Available ... ultrasound images are captured in real-time, they can show the structure and movement of the body's ... Because ultrasound provides real-time images, it also can be used to guide procedures such as needle ...

  13. Ultrasound -- Pelvis

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    Full Text Available ... ultrasound: abdominal, vaginal (for women), and rectal (for men). These exams are frequently used to evaluate the ... vaginal ( transvaginal / endovaginal ) for women rectal ( transrectal ) for men A Doppler ultrasound exam may be part of ...

  14. Ultrasound -- Pelvis

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    Full Text Available ... Ultrasound is safe, noninvasive and does not use ionizing radiation. This procedure requires little to no special preparation. ... create an image. Ultrasound examinations do not use ionizing radiation (as used in x-rays ), thus there is ...

  15. Ultrasound -- Pelvis

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    Full Text Available ... and fluid aspiration. Pelvic ultrasound can help to identify and evaluate a variety of urinary and reproductive system disorders in both sexes without x-ray exposure. Risks For standard diagnostic ultrasound , there are no known ...

  16. Ultrasound -- Pelvis

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    Full Text Available ... of page What are some common uses of the procedure? In women, a pelvic ultrasound is most ... child's favorite channel. top of page What does the equipment look like? Ultrasound scanners consist of a ...

  17. Prostate Ultrasound

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    Full Text Available ... of page What will I experience during and after the procedure? Ultrasound exams in which the transducer ... a regular ultrasound imaging probe on the perineal skin of the patient, between the legs and behind ...

  18. Artificial neural network aided non-invasive grading evaluation of hepatic fibrosis by duplex ultrasonography

    Directory of Open Access Journals (Sweden)

    Zhang Li

    2012-06-01

    Full Text Available Abstract Background Artificial neural networks (ANNs are widely studied for evaluating diseases. This paper discusses the intelligence mode of an ANN in grading the diagnosis of liver fibrosis by duplex ultrasonogaphy. Methods 239 patients who were confirmed as having liver fibrosis or cirrhosis by ultrasound guided liver biopsy were investigated in this study. We quantified ultrasonographic parameters as significant parameters using a data optimization procedure applied to an ANN. 179 patients were typed at random as the training group; 60 additional patients were consequently enrolled as the validating group. Performance of the ANN was evaluated according to accuracy, sensitivity, specificity, Youden’s index and receiver operating characteristic (ROC analysis. Results 5 ultrasonographic parameters; i.e., the liver parenchyma, thickness of spleen, hepatic vein (HV waveform, hepatic artery pulsatile index (HAPI and HV damping index (HVDI, were enrolled as the input neurons in the ANN model. The sensitivity, specificity and accuracy of the ANN model for quantitative diagnosis of liver fibrosis were 95.0%, 85.0% and 88.3%, respectively. The Youden’s index (YI was 0.80. Conclusions The established ANN model had good sensitivity and specificity in quantitative diagnosis of hepatic fibrosis or liver cirrhosis. Our study suggests that the ANN model based on duplex ultrasound may help non-invasive grading diagnosis of liver fibrosis in clinical practice.

  19. Artificial neural network aided non-invasive grading evaluation of hepatic fibrosis by duplex ultrasonography.

    Science.gov (United States)

    Zhang, Li; Li, Qiao-Ying; Duan, Yun-You; Yan, Guo-Zhen; Yang, Yi-Lin; Yang, Rui-Jing

    2012-06-20

    Artificial neural networks (ANNs) are widely studied for evaluating diseases. This paper discusses the intelligence mode of an ANN in grading the diagnosis of liver fibrosis by duplex ultrasonogaphy. 239 patients who were confirmed as having liver fibrosis or cirrhosis by ultrasound guided liver biopsy were investigated in this study. We quantified ultrasonographic parameters as significant parameters using a data optimization procedure applied to an ANN. 179 patients were typed at random as the training group; 60 additional patients were consequently enrolled as the validating group. Performance of the ANN was evaluated according to accuracy, sensitivity, specificity, Youden's index and receiver operating characteristic (ROC) analysis. 5 ultrasonographic parameters; i.e., the liver parenchyma, thickness of spleen, hepatic vein (HV) waveform, hepatic artery pulsatile index (HAPI) and HV damping index (HVDI), were enrolled as the input neurons in the ANN model. The sensitivity, specificity and accuracy of the ANN model for quantitative diagnosis of liver fibrosis were 95.0%, 85.0% and 88.3%, respectively. The Youden's index (YI) was 0.80. The established ANN model had good sensitivity and specificity in quantitative diagnosis of hepatic fibrosis or liver cirrhosis. Our study suggests that the ANN model based on duplex ultrasound may help non-invasive grading diagnosis of liver fibrosis in clinical practice.

  20. Protection of aluminium by duplex coatings

    Energy Technology Data Exchange (ETDEWEB)

    Musil, J. [Ceska Akademie Ved, Prague (Czech Republic). Fyzikalni Ustav; Vlcek, J. [West Bohemia Univ., Plzen (Czech Republic). Dept. of Phys.; Jezek, V. [West Bohemia Univ., Plzen (Czech Republic). Dept. of Phys.; Benda, M. [West Bohemia Univ., Plzen (Czech Republic). Dept. of Phys.

    1995-11-01

    The paper reports on a new way of producing duplex coatings consisting of two steps. First, the substrate is coated by a physically vapour-deposited coating. Then, this precoated substrate is plasma nitrided or vacuum heat treated. This method was tested in the protection of substrates made of aluminium with a sputtered Ti coating about 5 {mu}m thick. The as-deposited and then plasma-nitrided or vacuum-heat-treated (Ti coating)/(Al substrate) couple was characterized by elemental depth profiles measured by glow discharge optical spectroscopy. It was shown that both the plasma nitriding and vacuum heat treatment process can stimulate a strong interdiffusion between Ti and the substrate elements. It results not only in the formation of a very broad interfacial region with a dramatic redistribution of the substrate elements in the Ti film but also in a formation of intermetallic Ti-Al compounds. This new duplex coating technique is described in detail. (orig.)

  1. Duplex Stainless Steels-An overview

    Directory of Open Access Journals (Sweden)

    Dr. Sunil D.Kahar

    2017-04-01

    Full Text Available Stainless steel is one of the most important materials in the engineering world. The material‟s wide applications in chemical, petrochemical, off-shore, and power generation plants prove that it is one of the most reliable materials. The Newest fast growing family of stainless steels is duplex alloys. The ferritic-austenitic grades have a ferrite matrix intermix with austenite and in other words island of austenite in a continuous matrix of highly alloyed ferrite commonly called „Duplex‟ stainless steel. Duplex stainless steel covers ferritic/austenitic Fe-Cr-Ni alloy with between 30% to 70 % Ferrite .Due to high level of Cr, Mo, and N steels shows high pitting & stress corrosion cracking resistance in chloride-containing environments. Hence it is frequently used in oilrefinery heat exchangers & typical applications where there is a risk for SCC and localized corrosion as a result of chloride-containing process streams, cooling waters or deposits. Modern duplex stainless steels have generally good Weldability. Due to a balanced composition, where nitrogen plays an important role, austenite formation in the heat affected zone (HAZ and weld metal is rapid. Under normal welding conditions a sufficient amount of austenite is formed to maintain good resistance to localized corrosion where as too rapid cooling may result in excessive amounts of ferrite, reducing the toughness. Therefore, welding with low heat input in thick walled materials should be avoided. Welding methods, such as resistance welding, laser welding and electron beam welding, which cause extremely rapid cooling should also be avoided or used with extreme caution. Too slow cooling can in the higher alloyed duplex grades cause formation of inter-metallic phases detrimental to corrosion resistance and toughness.

  2. Full duplex communication using visible light

    CERN Document Server

    Yang, Yongchao; Li, Yuanhang; Gao, Xumin; Yuan, Jialei; Zhu, Hongbo; Wang, Yongjin

    2016-01-01

    In this work, we propose, fabricate and characterize a full duplex communication system using visible light on a single chip. Both the suspended p-n junction InGaN/GaN multiple quantum well (MQW) devices and the suspended waveguides are obtained on a GaN-on-silicon platform by wafer-level processing. Two suspended p-n junction InGaN/GaN MQW devices that can both emit and detect light simultaneously are connected using suspended waveguides to form an in-plane visible light communication (VLC) system. The light that is emitted from one suspended p-n junction InGaN/GaN MQW device can induce a current in the device located at the other end of the waveguide via in-plane light coupling, thus leading to full duplex communication using visible light. This proof-of-concept in-plane VLC system paves the way towards the implementation of a full duplex communications system operating at the same frequency using visible light on a single chip.

  3. Pre-operative anaemia.

    Science.gov (United States)

    Clevenger, B; Richards, T

    2015-01-01

    Pre-operative anaemia is a relatively common finding, affecting a third of patients undergoing elective surgery. Traditionally associated with chronic disease, management has historically focused on the use of blood transfusion as a solution for anaemia in the peri-operative period. Data from large series now suggest that anaemia is an independent risk associated with poor outcome in both cardiac and non-cardiac surgery. Furthermore, blood transfusion does not appear to ameliorate this risk, and in fact may increase the risk of postoperative complications and hospital length of stay. Consequently, there is a need to identify, diagnose and manage pre-operative anaemia to reduce surgical risk. Discoveries in the pathways of iron metabolism have found that chronic disease can cause a state of functional iron deficiency leading to anaemia. The key iron regulatory protein hepcidin, activated in response to inflammation, inhibits absorption of iron from the gastrointestinal tract and further reduces bioavailability of iron stores for red cell production. Consequently, although iron stores (predominantly ferritin) may be normal, the transport of iron either from the gastrointestinal tract or iron stores to the bone marrow is inhibited, leading to a state of 'functional' iron deficiency and subsequent anaemia. Since absorption from the gastrointestinal tract is blocked, increasing oral iron intake is ineffective, and studies are now looking at the role of intravenous iron to treat anaemia in the surgical setting. In this article, we review the incidence and impact of anaemia on the pre-operative patient. We explain how anaemia may be caused by functional iron deficiency, and how iron deficiency anaemia may be diagnosed and treated.

  4. Joint duplex mode selection, channel allocation, and power control for full-duplex cognitive femtocell networks

    Directory of Open Access Journals (Sweden)

    Mingjie Feng

    2015-02-01

    Full Text Available In this paper, we aim to maximize the sum rate of a full-duplex cognitive femtocell network (FDCFN as well as guaranteeing the quality of service (QoS of users in the form of a required signal to interference plus noise ratios (SINR. We first consider the case of a pair of channels, and develop optimum-achieving power control solutions. Then, for the case of multiple channels, we formulate joint duplex model selection, power control, and channel allocation as a mixed integer nonlinear problem (MINLP, and propose an iterative framework to solve it. The proposed iterative framework consists of a duplex mode selection scheme, a near-optimal distributed power control algorithm, and a greedy channel allocation algorithm. We prove the convergence of the proposed iterative framework as well as a lower bound for the greedy channel allocation algorithm. Numerical results show that the proposed schemes effectively improve the sum rate of FDCFNs.

  5. Upper airway imaging and its role in preoperative airway evaluation

    Directory of Open Access Journals (Sweden)

    Jagadish G Sutagatti

    2016-01-01

    Full Text Available Ultrasonography (USG is well-known as a fast, safe, and noninvasive technique. Its application for imaging of the airway is now gaining momentum. The upper airway has a complex anatomy, and its assessment forms a vital part of every preanesthetic evaluation. Ultrasound (US imaging can help in upper airway assessment in the preoperative period. There are various approaches to upper airway USG. The technique has its own advantages, disadvantages, and limitations. This simple yet challenging imaging technique is all set to become an important part of routine preoperative airway evaluation. This article reviews the various approaches to upper airway US imaging, interpretation of the images, limitations, and disadvantages of the technique and its varied clinical applications in the preoperative period. The scientific material presented here was hand searched from textbooks and journals, electronically from PubMed, and Google scholar using text words.

  6. Pancreatic Somatostatinoma Diagnosed Preoperatively: Report of a Case

    Directory of Open Access Journals (Sweden)

    Yasuhisa Mori

    2014-01-01

    Full Text Available Context Somatostatinoma is a rare neoplasm of the pancreas. Preoperative diagnosis is often difficult. Case report We report a 72-year-old woman with a pancreatic head tumor measuring 37 mm in diameter, and enlargement of the lymphnodes on the anterior surface of the pancreatic head and the posterior surface of the horizontal part of the duodenum.Laboratory data showed an elevated plasma somatostatin concentration. Examination of a biopsy specimen of thepancreatic head mass obtained by endoscopic ultrasound-guided fine needle aspiration (EUS-FNA showedhistopathological features of a neuroendocrine tumor. Immunohistochemical staining showed that the tumor cells werepositive for somatostatin, leading to a preoperative diagnosis of pancreatic somatostatinoma. The patient underwentpylorus-preserving pancreaticoduodenectomy. The plasma somatostatin concentration decreased progressively aftersurgery. Conclusions A rare case of pancreatic somatostatinoma with lymph node metastases was presented.Immunohistochemical analysis of a biopsy specimen obtained by EUS-FNA was useful for preoperative diagnosis.

  7. The diagnostic value of electronic staining endoscopy combined with endoscopic ultrasound in the preopera-tive early gastric cancer%电子染色内镜联合超声内镜在早期胃癌术前诊断中的价值

    Institute of Scientific and Technical Information of China (English)

    王利兵; 张春雨

    2015-01-01

    Objective To evaluate the diagnostic value of electronic staining endoscopy combined with endo -scopic ultrasound(EUS) in the preoperative early gastric cancer .Methods A total of 17 patients diagnosed with intramucosal carcinoma by ordinary gastric endoscopy combined with pathological findings were selected ,who under-went the T staging by EUS and electronic staining endoscopic examination before ESD .The findings were compared with pathological findings.Results 17 cases were diagnosed with gastric cancer in T1 stage by EUS(12 cases limited mucous layer or mucosal muscular layer ,5 cases involving the submucossa ) .14 cases were diagnosed with gastric cancer in T1 stage by pathological examination (11 cases limited mucous layer or mucosal muscular layer ,3 cases involving the submucossa ) ,3 cases in T2 stage had received surgery .The accuracy of EUS in determining the depth of intramucosal carcinoma invasion was 88.2%;The total accuracy of T staging was 82.4%.The lesions border was more clear in electronic staining mode ,and easier marked.Conclusion The diagnostic value of electronic staining endoscopy combined with endoscopic ultrasound in the preoperative early gastric cancer is high .%目的:探讨电子染色内镜联合超声内镜( EUS)在早期胃癌术前诊断中的应用价值。方法选取经普通胃镜检查结合镜下病理考虑为黏膜内癌的患者17例,在行内镜下黏膜剥离术( ESD )前行EUS检查并进行T分期,并在电子染色内镜模式下标记病灶切除范围后行ESD治疗,将EUS诊断结果与术后病理检查结果进行比较。结果 EUS诊断T1期17例(累及黏膜及黏膜肌层12例,黏膜下层5例);术后病理T1期14例(累及黏膜层及黏膜肌层11例,黏膜下层3例),T2期3例(已追加手术治疗);EUS对黏膜内癌浸润深度判断准确率为88.2%(15/17),T分期准确率为82.4%(14/17);电子染色模式下病变范围更加清晰,易于

  8. A comparison of colour duplex ultrasonography after transurethral alprostadil and intracavernous alprostadil in the assessment of erectile dysfunction.

    Science.gov (United States)

    Ahn, H S; Lee, S W; Yoon, S J; Hann, H J; Hong, J M

    2004-01-01

    This study aimed to investigate whether transurethral alprostadil could be used for the diagnosis of erectile dysfunction using colour duplex ultrasound. The ultrasonography results were compared after transurethral and intracavernous alprostadil administration in 20 patients with erectile dysfunction. There were no significant differences in the mean peak systolic velocities (PSVs) between the two routes of administration, but the mean end diastolic velocities (EDVs) showed significant differences, with patients treated with transurethral alprostadil having higher EDVs. Linear regression analysis of the PSVs reached following the two routes of administration showed a moderate relationship, but linear regression analysis of the EDVs showed no relationship. We concluded that transurethral alprostadil was an inappropriate vasoactive drug to use with colour duplex ultrasonography for the evaluation of patients with erectile dysfunction because it required a longer scan time and it was less effective and less reliable than intracavernous alprostadil at stimulating complete corporeal smooth muscle relaxation.

  9. q-Ising model on a duplex and a partially duplex clique

    CERN Document Server

    Chmiel, Anna; Sznajd-Weron, Katarzyna

    2016-01-01

    We analyze a modified kinetic Ising model, so called $q$- neighbor Ising model, with Metropolis dynamics,[Phys. Rev. E {\\bf92} 052105] on a duplex clique and a partially duplex clique. In the $q$-Ising model each spin interacts only with $q$ spins randomly chosen from the whole neighborhood. In the case of a duplex clique the change of a spin is allowed only if both levels simultaneously induce this change. Due to the mean-field like nature of the model we are able to derive the analytic form of transition probabilities and solve the corresponding master equation. The existence of the second level changes dramatically the character of the phase transition. In the case of the monoplex clique, the $q$-neighbor Ising model exhibits continuous phase transition for $q=3$, discontinuous phase transition for $q \\ge 4$ and for $q=1$ and $q=2$ the phase transition is not observed. On the other hand, in the case of the duplex clique continuous phase transitions are observed for all values of $q$, even for $q=1$ and $q=...

  10. 纽曼系统护理模式对 B 超引导下肾穿刺活检术患者术前焦虑及术后并发症的影响%Influence of the Neuman nursing model on preoperative anxiety and postoperative complications in patients undergoing ;ultrasound guided renal biopsy puncture

    Institute of Scientific and Technical Information of China (English)

    尹华; 欧阳涵; 王赟

    2016-01-01

    目的:探讨纽曼系统护理模式对B超引导下肾穿刺活检术(PRB)患者术前焦虑及术后并发症的影响。方法将100例B超引导下PRB患者采用随机数字表法分为干预组(49例)及对照组(51例),对照组患者采用常规护理模式,干预组患者护理方法采用纽曼系统护理模式,观察两组患者Zung焦虑自评量表(SAS)和抑郁自评量表(SDS)评分的变化及并发症发生情况。结果干预组SAS、SDS评分较治疗前明显降低,且明显低于对照组;干预组血尿、发热、肾周血肿、腰背疼痛、24 h内排尿困难及穿刺失败的发生例数均明显少于对照组。结论纽曼系统护理模式可较好地缓解肾穿刺患者术前焦虑情况,并有效降低术后并发症发生率。%Objective To investigate the influence of the Neuman nursing model on the preoperative anxiety and the postoperative complications in the patients with ultrasound guided renal biopsy puncture .Methods Totals of 100 cases of patients with renal biopsy puncture by ultrasound guided were randolIlly divided into intervention group and control group ,there are 49 patients in intervention group and 51 patients in control group .ontrol group received the usual care measulres ,while intervention group received Neuman systems model for care .After the intervention , we observe the variation of the Self‐Rating Anxiety Scale (SAS) and Self‐ratingdepressionscale (SDS) .Results The SAS and SDS score of intervention group was lower than the before ,and it was also significantly lower than the sanle time of control group ,the difference was statistically significant .The incidence of complications in intervention group such as the hematuria ,fever ,kidney hematoma ,lower back pain ,24 h of difficulty urinating and puncture failure were significantly less than that in control group .Conclusion The Newman system care model can effectively control anxi‐ety efect and the

  11. Preoperative urinary tract obstruction in scoliosis patients.

    Science.gov (United States)

    Suzuki, Shigeru; Kotani, Toshiaki; Mori, Kazuetsu; Kawamura, Ken; Ohtake, Akira

    2017-01-01

    While the association between scoliosis and cardiac and respiratory function impairments has been well characterized in clinical practice and research, the potential effect of scoliosis on urinary tract structure and renal function has received little attention. Therefore, the purpose of this study was to evaluate the preoperative clinical characteristics of urinary tract structure and renal function in pediatric patients with idiopathic scoliosis, using a combination of blood tests, urinalysis, and imaging. Preoperative measures of urinary tract structure and renal function were obtained for 16 patients, 13-17 years old, scheduled for corrective surgery for idiopathic scoliosis. Preoperative assessment included blood test and urinalysis, combined with structural imaging on ultrasound (US), magnetic resonance imaging (MRI), magnetic resonance urography (MRU), and radioisotope tracing (RI), using technetium-99 m mercaptoacetyltriglycine ((99m) Tc-MAG3). Differences in blood and urine tests between patients with and without urinary tract obstruction (UTO) were evaluated for significance using Mann-Whitney U test. For all 16 patients, blood tests and MRU were within normal limits. Dilatation of the renal pelvis was identified on US in eight patients (50.0%). UTO was identified on RI in six patients (37.5%). UTO was associated with elevated β2-microglobulin concentration. Urinary β2-microglobulin concentration >0.7 μg/mg Cr differentiated patients with UTO from those without UTO, with a sensitivity of 100% and specificity of 70%. β2-Microglobulin concentration may be a useful marker to screen for asymptomatic UTO in patients with idiopathic scoliosis. © 2016 Japan Pediatric Society.

  12. Duplex tube steam reformer development program

    Energy Technology Data Exchange (ETDEWEB)

    Lewe, C K; Nieto, J M; Papadopoulos, A

    1978-09-01

    Work done in partial fulfillment of Task 7 of the Duplex Steam Reformer Development Program is described. The DSR concept acts as a double barrier between a process heat high temperature reactor plant (PNP) and a closed loop chemical heat pipe (CHP) for the long distance transport of chemical energy to a remote industrial user. The current state of the DSR design is described as well as related systems and equipment. The PNP concept presented is based upon work currently underway in the Federal Republic of Germany.

  13. Thyroid ultrasound

    OpenAIRE

    Vikas Chaudhary; Shahina Bano

    2013-01-01

    Thyroid ultrasonography has established itself as a popular and useful tool in the evaluation and management of thyroid disorders. Advanced ultrasound techniques in thyroid imaging have not only fascinated the radiologists but also attracted the surgeons and endocrinologists who are using these techniques in their daily clinical and operative practice. This review provides an overview of indications for ultrasound in various thyroid diseases, describes characteristic ultrasound findings in th...

  14. Ultrasound physics.

    Science.gov (United States)

    Shriki, Jesse

    2014-01-01

    Bedside ultrasound has become an important modality for obtaining critical information in the acute care of patients. It is important to understand the physics of ultrasound in order to perform and interpret images at the bedside. The physics of both continuous wave and pulsed wave sound underlies diagnostic ultrasound. The instrumentation, including transducers and image processing, is important in the acquisition of appropriate sonographic images. Understanding how these concepts interplay with each other enables practitioners to obtain the best possible images.

  15. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... medical test that helps physicians diagnose and treat medical conditions. There are three types of pelvic ultrasound: abdominal ( transabdominal ) vaginal ( transvaginal / endovaginal ) ...

  16. RF Self-Interference cancellation for Full-Duplex

    NARCIS (Netherlands)

    van Liempd, B.; Debaillie, B.; Craninckx, J.; Lavin, C.; Palacios, C.; Malotaux, S.; Long, J.R.; van den Broek, Dirk-Jan; Klumperink, Eric A.M.

    2014-01-01

    This paper proposes two RF self-interference cancellation techniques. Their small form-factor enables full-duplex communication links for small-to-medium size portable devices and hence promotes the adoption of full-duplex in mass-market applications and next-generation standards, e.g. IEEE802.11 an

  17. Scintigraphic features of duplex kidneys on DMSA renal cortical scans.

    Science.gov (United States)

    Kwatra, Neha; Shalaby-Rana, Eglal; Majd, Massoud

    2013-09-01

    The spectrum of manifestations of duplex kidneys on (99m)Tc-dimercaptosuccinic acid (DMSA) renal cortical scans and correlating findings on other imaging modalities are presented. Relevant embryology of the duplex systems and technical aspects of DMSA scintigraphy are reviewed.

  18. On the Ergodic Secrecy Capacity with Full Duplex Communication

    DEFF Research Database (Denmark)

    Mahmood, Nurul Huda; Shafique Ansari, Imran; Mogensen, Preben Elgaard;

    2017-01-01

    Full duplex communication promises performance gains in terms of the throughput and the delay. Generally, it has been shown that the throughput and delay gains of full duplex communication are somewhat limited in realistic network settings, leading researchers to study other possible applications...

  19. Structural Properties of G,T-Parallel Duplexes

    Directory of Open Access Journals (Sweden)

    Anna Aviñó

    2010-01-01

    Full Text Available The structure of G,T-parallel-stranded duplexes of DNA carrying similar amounts of adenine and guanine residues is studied by means of molecular dynamics (MD simulations and UV- and CD spectroscopies. In addition the impact of the substitution of adenine by 8-aminoadenine and guanine by 8-aminoguanine is analyzed. The presence of 8-aminoadenine and 8-aminoguanine stabilizes the parallel duplex structure. Binding of these oligonucleotides to their target polypyrimidine sequences to form the corresponding G,T-parallel triplex was not observed. Instead, when unmodified parallel-stranded duplexes were mixed with their polypyrimidine target, an interstrand Watson-Crick duplex was formed. As predicted by theoretical calculations parallel-stranded duplexes carrying 8-aminopurines did not bind to their target. The preference for the parallel-duplex over the Watson-Crick antiparallel duplex is attributed to the strong stabilization of the parallel duplex produced by the 8-aminopurines. Theoretical studies show that the isomorphism of the triads is crucial for the stability of the parallel triplex.

  20. Preoperative anxiety in neurosurgical patients.

    Science.gov (United States)

    Perks, Anna; Chakravarti, Sucharita; Manninen, Pirjo

    2009-04-01

    Anxiety is common in surgical patients, with an incidence of 60% to 92%. There is little information on the incidence and severity of preoperative anxiety in patients scheduled for neurosurgery. The aim of this study was to measure the level of preoperative anxiety in neurosurgical patients and to assess any influencing factors. After the Institutional Review Board approval and informed written consent, 100 patients booked for neurosurgery were interviewed preoperatively. Each patient was asked to grade their preoperative anxiety level on a verbal analog scale, Amsterdam Preoperative Anxiety and Information Scale, and a set of specific anxiety-related questions. The anxiety scores and the responses to the questions were compared between the sex, age, weight, diagnosis, and history of previous surgery. The mean age (+/-SD) was 50+/-13 years. The preoperative diagnosis was tumor (n=64), aneurysm (n=14), and other (n=22). Overall verbal analog scale was 5.2+/-2.7; the score was higher for female (5.8+/-2.8) than male patients (4.6+/-2.5) (PAmsterdam Preoperative Anxiety and Information Scale anxiety and knowledge scores were greater for surgery than for anesthesia. Questionnaire results showed that the most common anxieties were waiting for surgery, physical/mental harm, and results of the operation. In conclusion, our study showed that neurosurgical patients have high levels of anxiety, with a higher incidence in females. There was a moderately high need for information, particularly in patients with a high level of preoperative anxiety.

  1. Carotid Ultrasound Imaging

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z Ultrasound - Carotid Carotid ultrasound uses sound waves to produce ... limitations of Carotid Ultrasound Imaging? What is Carotid Ultrasound Imaging? Ultrasound is safe and painless, and produces ...

  2. General Ultrasound Imaging

    Science.gov (United States)

    ... Physician Resources Professions Site Index A-Z General Ultrasound Ultrasound imaging uses sound waves to produce pictures ... limitations of General Ultrasound Imaging? What is General Ultrasound Imaging? Ultrasound is safe and painless, and produces ...

  3. Venous Ultrasound (Extremities)

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z Ultrasound - Venous (Extremities) Venous ultrasound uses sound waves to ... limitations of Venous Ultrasound Imaging? What is Venous Ultrasound Imaging? Ultrasound is safe and painless, and produces ...

  4. Spermine Condenses DNA, but Not RNA Duplexes

    Energy Technology Data Exchange (ETDEWEB)

    Katz, Andrea M.; Tolokh, Igor S.; Pabit, Suzette A.; Baker, Nathan; Onufriev, Alexey V.; Pollack, Lois

    2017-01-01

    Interactions between the polyamine spermine and nucleic acids drive important cellular processes. Spermine condenses DNA, and some RNAs such as poly(rA):poly(rU). A large fraction of the spermine present in cells is bound to RNA, but apparently does not condense it. Here, we study the effect of spermine binding to short duplex RNA and DNA and compare our findings with predictions of molecular dynamics simulations. When small numbers of spermine are introduced, RNA with a designed sequence, containing a mixture of 14 GC pairs and 11 AU pairs, resists condensation relative to DNA of an equivalent sequence or to 25 base pair poly(rA):poly(rU) RNA. Comparison of wide-angle x-ray scattering profiles with simulation suggests that spermine is sequestered deep within the major groove of mixed sequence RNA, preventing condensation by limiting opportunities to bridge to other molecules as well as stabilizing the RNA by locking it into a particular conformation. In contrast, for DNA, simulations suggest that spermine binds external to the duplex, offering opportunities for intermolecular interaction. The goal of this study is to explain how RNA can remain soluble, and available for interaction with other molecules in the cell, despite the presence of spermine at concentrations high enough to precipitate DNA.

  5. DNA Duplex Engineering for Enantioselective Fluorescent Sensor.

    Science.gov (United States)

    Hu, Yuehua; Lin, Fan; Wu, Tao; Zhou, Yufeng; Li, Qiusha; Shao, Yong; Xu, Zhiai

    2017-02-21

    The rapid identification of biomacromolecule structure that has a specific association with chiral enantiomers especially from natural sources will be helpful in developing enantioselective sensor and in speeding up drug exploitation. Herein, owing to its existence also in living cells, apurinic/apyrimidinic site (AP site) was first engineered into ds-DNA duplex to explore its competence in enantiomer selectivity. An AP site-specific fluorophore was utilized as an enantioselective discrimination probe to develop a straightforward chiral sensor using natural tetrahydropalmatine (L- and D-THP) as enantiomer representatives. We found that only L-THP can efficiently replace the prebound fluorophore to cause a significant fluorescence increase due to its specific binding with the AP site (two orders magnitude higher in affinity than binding with D-THP). The AP site binding specificity of L-THP over D-THP was assessed via intrinsic fluorescence, isothermal titration calorimetry, and DNA stability. The enantioselective performance can be easily tuned by the sequences near the AP site and the number of AP sites. A single AP site provides a perfect binding pocket to differentiate the chiral atom-induced structure discrepancy. We expect that our work will inspire interest in engineering local structures into a ds-DNA duplex for developing novel enantioselective sensors.

  6. Prostate Ultrasound

    Medline Plus

    Full Text Available ... Español More Info Images/Videos About Us News Physician Resources Professions Site Index A-Z Ultrasound - Prostate ... imaging is a noninvasive medical test that helps physicians diagnose and treat medical conditions. Prostate ultrasound, also ...

  7. Quantitative ultrasound in cancer imaging.

    Science.gov (United States)

    Feleppa, Ernest J; Mamou, Jonathan; Porter, Christopher R; Machi, Junji

    2011-02-01

    Ultrasound is a relatively inexpensive, portable, and versatile imaging modality that has a broad range of clinical uses. It incorporates many imaging modes, such as conventional gray-scale "B-mode" imaging to display echo amplitude in a scanned plane; M-mode imaging to track motion at a given fixed location over time; duplex, color, and power Doppler imaging to display motion in a scanned plane; harmonic imaging to display nonlinear responses to incident ultrasound; elastographic imaging to display relative tissue stiffness; and contrast-agent imaging with simple contrast agents to display blood-filled spaces or with targeted agents to display specific agent-binding tissue types. These imaging modes have been well described in the scientific, engineering, and clinical literature. A less well-known ultrasonic imaging technology is based on quantitative ultrasound (QUS), which analyzes the distribution of power as a function of frequency in the original received echo signals from tissue and exploits the resulting spectral parameters to characterize and distinguish among tissues. This article discusses the attributes of QUS-based methods for imaging cancers and providing improved means of detecting and assessing tumors. The discussion will include applications to imaging primary prostate cancer and metastatic cancer in lymph nodes to illustrate the methods. Copyright © 2011 Elsevier Inc. All rights reserved.

  8. A novel duplex finding of superficial epigastric vein flow reversal to diagnose iliocaval occlusion.

    Science.gov (United States)

    Kolluri, Raghu; Fowler, Brian; Ansel, Gary; Silver, Mitchell

    2017-05-01

    Although duplex ultrasound (DUS) imaging is the current gold standard in the diagnosis of femoropopliteal deep venous thrombosis, it is not an optimal diagnostic modality to diagnose iliocaval occlusion. Screening for iliocaval occlusion thus remains a challenge for clinicians because of the lack of a reliable noninvasive technique. This challenge results in most patients undergoing computed tomography venography or magnetic resonance venography or invasive venography and intravascular ultrasound imaging. This study reports a novel, yet simple, reproducible and intuitive, surface DUS finding of physiologic flow reversal within the superficial epigastric vein (SEV) as a sign of proximal iliocaval occlusion (ICO). This was a retrospective study of 15 patients who were diagnosed with ICO based on the finding of SEV flow reversal on DUS imaging. Patient demographics, presenting CEAP C scores, ICO characteristics, correlation with advanced imaging, and short-term follow-up findings are reported. Physiologic reversal of the SEV resulted in confirmation of ICO in all patients who underwent advanced imaging, including computed tomography venography or traditional venogram along with intravascular ultrasound imaging. All patients who underwent follow-up DUS scans demonstrated normalization of the SEV flow after ICO recanalization. ICO can result in deep venous thrombosis, post-thrombotic syndrome, and chronic venous insufficiency. Physiologic flow reversal in SEV is diagnostic of ICO. To the best of our knowledge, this is the first report of this novel DUS finding. Copyright © 2017 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

  9. INTRAOPERATIVE ULTRASOUND FOR HEPATIC NEOPLASM DURING SURGERY

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Objective.Th purpose of this study was to determine the impact of intraoperative ultrasound(IOUS)on the management of patients with neoplasms of the liver.Methods.Forty-nine patients operated on for liver or other pathologic processes were examined intraopertively with 5.0 MHz special ultrasound transducers during surgical exploration of the abdomen.Subjects were evaluated because of known or suspected disease of the liver.Preoperative imaging studies included percutaneous ultrasound(n=49),magnetic resonance imaging(n=11),and computed tomography(n=34).Intraoperative evaluation on all patients included inspection,bimanual palpation,and ultrasnography.Comparison between preoperative imagings and IOUS were analysed.Results.Sensitivity for detection of hepatic neoplasms showed in intraoperative ultrasound,percutaneous ultrasound,magnetic resonance imaging andcomputed tomography as 100%(23/23),74%(17/23),74%(14/19) and 75%(6/8).Specificity showed 100%(26/26),100%(26/26),93%(14/15) and 67(2/3).In seven patients(14%),the neoplasms were not found by inspection,bimanual palpation,and identified only by IOUS.Conclusions.Intraoperative ultrasound is the most sensitive and specific method for detection and surgery of liver neoplasms,especially the occult neoplasms and small size lesion(<2cm).

  10. Ultrasound determination of rotator cuff tear repairability

    Science.gov (United States)

    Tse, Andrew K; Lam, Patrick H; Walton, Judie R; Hackett, Lisa

    2015-01-01

    Background Rotator cuff repair aims to reattach the torn tendon to the greater tuberosity footprint with suture anchors. The present study aimed to assess the diagnostic accuracy of ultrasound in predicting rotator cuff tear repairability and to assess which sonographic and pre-operative features are strongest in predicting repairability. Methods The study was a retrospective analysis of measurements made prospectively in a cohort of 373 patients who had ultrasounds of their shoulder and underwent rotator cuff repair. Measurements of rotator cuff tear size and muscle atrophy were made pre-operatively by ultrasound to enable prediction of rotator cuff repairability. Tears were classified following ultrasound as repairable or irreparable, and were correlated with intra-operative repairability. Results Ultrasound assessment of rotator cuff tear repairability has a sensitivity of 86% (p rotator cuff repairability were tear size (p rotator cuff tear. Conclusions Ultrasound assessment is accurate in predicting rotator cuff tear repairability. Tear size or anteroposterior tear length and age were the best predictors of repairability. PMID:27582996

  11. Cranial Ultrasound/Head Ultrasound

    Science.gov (United States)

    ... sickle cell disease. It is also used to measure conditions affecting blood flow to and within the brain, such as: Stenosis : ... saved. Doppler ultrasound, a special application of ultrasound, measures ... represent the flow of blood through the blood vessels. top of ...

  12. Kinetics and thermodynamics of DNA, RNA, and hybrid duplex formation.

    Science.gov (United States)

    Rauzan, Brittany; McMichael, Elizabeth; Cave, Rachel; Sevcik, Lesley R; Ostrosky, Kara; Whitman, Elisabeth; Stegemann, Rachel; Sinclair, Audra L; Serra, Martin J; Deckert, Alice A

    2013-02-05

    The rates of duplex formation for two octamers of DNA (5' d-CACGGCTC/5' d-GAGCCGTG and 5' d-CACAGCAC/5' d-GTGCTGTG), the homologous RNA, and both sets of hybrids in 1 M NaCl buffer have been measured using stopped-flow spectroscopy. In addition, the thermodynamic parameters, ΔH° and ΔS°, have been determined for the same sequences under the same buffer conditions using optical melting techniques. These data reveal a linear free energy relationship between the free energy of activation for denaturation and the change in free energy for formation of the duplexes. This relationship indicates that these duplex formation reactions occur through a common unstructured transition state that is more similar to the single strands in solution than to the ensuing duplex. In addition, these data confirm that the greater stability of RNA duplexes relative to that of homologous DNA and hybrid duplexes is controlled by the denaturation rate and not the duplex formation rate.

  13. Buffer management in wireless full-duplex systems

    KAUST Repository

    Bouacida, Nader

    2015-10-19

    Wireless full-duplex radios can simultaneously transmit and receive using the same frequency. In theory, this can double the throughput. In fact, there is only little work addressing aspects other than throughput gains in full-duplex systems. Over-buffering in today\\'s networks or the so-called “bufferbloat” phenomenon creates excessive end-to-end delays resulting in network performance degradation. Our analysis shows that full-duplex systems may suffer from high latency caused by bloated buffers. In this paper, we address the problem of buffer management in full-duplex networks by using Wireless Queue Management (WQM), which is an active queue management technique for wireless networks. Our solution is based on Relay Full-Duplex MAC (RFD-MAC), an asynchronous media access control protocol designed for relay full-duplexing. We compare the performance of WQM in full-duplex environment to Drop Tail mechanism over various scenarios. Our solution reduces the end-to-end delay by two orders of magnitude while achieving similar throughput in most of the cases.

  14. Target motion predictions for pre-operative planning during needle-based interventions

    NARCIS (Netherlands)

    Buijs, op den Jorn; Abayazid, Momen; Korte, de Chris L.; Misra, Sarthak

    2011-01-01

    During biopsies, breast tissue is subjected to displacement upon needle indentation, puncture, and penetration. Thus, accurate needle placement requires pre-operative predictions of the target motions. In this paper, we used ultrasound elastography measurements to non-invasively predict elastic prop

  15. Duplex 2209 Weld Overlay by ESSC Process

    Directory of Open Access Journals (Sweden)

    Er. Manoj Kumar

    2017-03-01

    Full Text Available In the modern world of industrialization the wear is eating metal assets worth millions of dollars per year. The wear is in the form of corrosion, erosion, abrasion etc. which occur in the process industries like oil & gas, refineries, cement plants, steel plants, shipping and offshore working structures. The equipments like pressure vessels, heat exchangers, hydro processing reactors which very often work at elevated temperatures face corrosion in the internal diameter. Duplex 2209 weld overlay on ferrous material is developed for high corrosion resistance properties and having high productivity by Electroslag strip cladding process due to its less dilution ~10% as compared to SMAW , GTAW or FCAW process. Because of Low Dilution ~10% undiluted chemistry can be achieved with single layer as compared to other weld overlay processes. The facility was developed inhouse to carry out weld overlay by ESSC and Testing

  16. MICROSCOPIC CORROSION STUDIES OF DUPLEX STAINLESS STEELS

    Institute of Scientific and Technical Information of China (English)

    C.Leygraf; J.Pan; M.Femenia

    2004-01-01

    Electrochemical scanning tunneling microscopy and scanning electrochemical microscopy have been used for in situ monitoring of localized corrosion processes of different Duplex stainless steels (DSS) in acidic chloride solutions. The techniques allow imaging of local dissolution events with micrometer resolution, as opposed to conventional electrochemical techniques, which only give an overall view of the corrosion behavior. In addition, combined scanning Kelvin probe force microscopy and magnetic force microscopy were used for mapping the Volta potential variation over the surface of DSSs. A significant difference in Volta potential between the austenite and ferrite phases suggests galvanic interaction between the phases. A compositional gradient appears within 2 micrometers across the phase boundary, as seen with scanning Auger microscopy (SAM). In all, the studies suggest that higher alloyed DSS exhibit a more homogeneous dissolution behavior than lower alloyed DSS, due to higher and more similar corrosion resistance of the two phases, and enhanced resistance of the ferrite/austenite phase boundary regions.

  17. Rietveld and impedance analysis of cold and hot rolled duplex and lean duplex steels for application in paper and pulp industry

    Energy Technology Data Exchange (ETDEWEB)

    Esteves, Luiza; Lins, Vanessa de Freitas Cunha, E-mail: luizaeq@yahoo.com.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Quimica; Paiva, Paulo Renato Perdigao [Centro Federal de Educacao Tecnologica de Minas Gerais (CEFET), Belo Horizonte, MG (Brazil); Viana, Adolfo Kalergis do Nascimento [APERAM South America, Timoteo, MG (Brazil)

    2017-01-15

    In this study, X-Ray Diffraction (XRD) and Rietveld Refinement were performed to identify and quantify the ferrite and austenite phase of cold and hot rolled duplex stainless steels (UNS S31803) and lean duplex stainless steels (UNS S32304). Electrochemical impedance spectroscopy (EIS) was applied to evaluate the chemical behavior of duplex and lean duplex stainless steels in white, green, and black liquors of paper and pulp industry. Rietveld analysis results showed a higher austenite content than the standard limit for duplex steels in the hot rolled condition. The hot rolling condition plays a major role in improving corrosion resistance in white liquor mainly for the lean duplex steel. (author)

  18. Clinical neurosonography. Ultrasound of the central nervous system

    Energy Technology Data Exchange (ETDEWEB)

    Naidich, T.P.; Quencer, R.M.

    1987-01-01

    Neurosonography is the application of ultrasound technology to the diagnosis and follow-up of lesions of the brain and meninges, spinal cord and canal, carotid arteries, eye and orbit. The authors of this book have reviewed neurosonography in separate sections on fetal neurosonography, the neonate head, the neonatal spine, intraoperative neurosonography, post-operative neurosonography, carotid sonography, and orbital echography. In each section, the authors discuss basic diagnosis, present recent advances in the area. The contents discussed are: Fetal neurosonography. - The neonatal head. - The neonatal spine. - Intraopertive neurosonography. - Post-operative neurosonography. - Duplex carotid ultrasound. - Orbital echography. Subject Index.

  19. Preoperative alcoholism and postoperative morbidity

    DEFF Research Database (Denmark)

    Tonnesen, H; Kehlet, H

    1999-01-01

    BACKGROUND: Preoperative risk assessment has become part of daily clinical practice, but preoperative alcohol abuse has not received much attention. METHODS: A Medline search was carried out to identify original papers published from 1967 to 1998. Relevant articles on postoperative morbidity...... in alcohol abusers were used to evaluate the evidence. RESULTS: Prospective and retrospective studies demonstrate a twofold to threefold increase in postoperative morbidity in alcohol abusers, the most frequent complications being infections, bleeding and cardiopulmonary insufficiency. Wound complications...... to postoperative morbidity. CONCLUSION: Alcohol consumption should be included in the preoperative assessment of likely postoperative outcome. Reduction of postoperative morbidity in alcohol abusers may include preoperative alcohol abstinence to improve organ function, or perioperative alcohol administration...

  20. Duplex scanning on admission prevents unnecessary carotid endarterectomies.

    Science.gov (United States)

    Dalainas, I; Nano, G; Casana, R; Bianchi, P; Stegher, S; Malacrida, G; Tealdi, D G

    2006-06-01

    This retrospective single Institution study, aims to evaluate the performance of duplex scanning on admission of patients with carotid artery disease to avoid unnecessary carotid endarterectomies. From 1 January 1997 until 31 Decem-ber 2004, 1 504 patients were admitted to our Institution to undergo carotid endarterectomy. A duplex scan on admission was performed in all of them. A total of 1 369 from these patients (91%) underwent surgery, while 135 (9%) were dismissed because there was no indication for surgical treatment. They were put in conservative treatment and periodic duplex control appointments. In 9% of the patients, unnecessary carotid endarterectomy was avoided.

  1. Investigation of the Hot Plasticity of Duplex Stainless Steel

    Institute of Scientific and Technical Information of China (English)

    LIN Gang; ZHANG Zhi-xia; SONG Hong-wei; TONG Jun; ZHOU Can-dong

    2008-01-01

    Hot plasticity of a nitrogen alloyed 25Cr-7Ni-4 Mo duplex stainless steel was investigated.The results indicate that thc main factors affecting the hot plasticity of duplex stainless steel are listed as follows:coalescent force of phase interface,microstructure,and the phase ratio and difference between the mechanicsl propertms of ferrite and austenite.The heat treatment and sulphur contents have a notable effect on the hot plasticity.The reasonable heat treatrnents and the irlcreased interfacial coalescent force will effectively enhance the hot plasticity of duplex stainless steel.

  2. Analysing Self Interference Cancellation in Full Duplex Radios

    DEFF Research Database (Denmark)

    Mahmood, Nurul Huda; Shafique Ansari, Imran; Berardinelli, Gilberto;

    2016-01-01

    Full duplex communication promises a theoretical $100\\%$ throughput gain by doubling the number of simultaneous transmissions. Such compelling gains are conditioned on perfect cancellation of the self interference power resulting from simultaneous transmission and reception. Generally, self...... cancellation. In this study, we derive an analytical model for the residual self interference power, and demonstrate various applications of the derived model in analysing the performance of a Full Duplex radio. In general, full duplex communication is found to provide only modest throughput gains over half...

  3. Preoperative diagnosis of carcinoma within fibroadenoma on screening mammograms.

    Science.gov (United States)

    Borecky, N; Rickard, M

    2008-02-01

    Three cases of fibroadenoma associated with carcinoma are reported. These cases were diagnosed within a screening programme as a result of suspicious mammographic findings, and the diagnosis of malignancy was confirmed preoperatively by core biopsy in all cases. The mammographic findings suggestive of carcinoma within fibroadenoma were irregularity of margins in one case and associated new suspicious pleomorphic and linear calcifications in the two other cases. The preoperative diagnosis of carcinoma within fibroadenoma was provided by ultrasound-guided core biopsy in two cases and core biopsy under stereotactic guidance in one case. Whereas asymptomatic fibroadenoma with benign imaging appearances usually does not require further investigation, fibroadenoma with atypical imaging features requires a triple test investigation.

  4. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... uterine cavity . Three-dimensional (3-D) ultrasound permits evaluation of the uterus and ovaries in planes that ... a special study usually done to provide detailed evaluation of the prostate gland, involves inserting a specialized ...

  5. Prostate Ultrasound

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    Full Text Available ... sends out high-frequency sound waves (that the human ear cannot hear) into the body and then ... ultrasound , there are no known harmful effects on humans. top of page What are the limitations of ...

  6. Prostate Ultrasound

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    Full Text Available ... areas of the body while other areas, especially air-filled lungs, are poorly suited for ultrasound. For ... appearance, size or contour of organs, tissues, and vessels or to detect abnormal masses, such as tumors. ...

  7. Prostate Ultrasound

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    Full Text Available ... the prostate is enlarged, also known as benign prostatic hyperplasia (BPH) , with measurements acquired as needed for any ... size with caption Related Articles and Media Benign Prostatic Hyperplasia (BPH) Prostate Cancer Ultrasound- and MRI-Guided Prostate ...

  8. Ultrasound -- Pelvis

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    Full Text Available ... ovaries. Transvaginal ultrasound also evaluates the myometrium (muscular walls of the uterus). Sonohysterography allows for a more ... needle insertion) is usually minimal because the rectal wall is relatively insensitive to the pain in the ...

  9. Prostate Ultrasound

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    Full Text Available ... object is solid or filled with fluid). In medicine, ultrasound is used to detect changes in appearance, ... of the pelvis may be obtained as an alternative imaging test, because it may be obtained with ...

  10. Ultrasound -- Pelvis

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    Full Text Available ... is safe, noninvasive and does not use ionizing radiation. This procedure requires little to no special preparation. ... an image. Ultrasound examinations do not use ionizing radiation (as used in x-rays ), thus there is ...

  11. Prostate Ultrasound

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    Full Text Available ... is safe, noninvasive, and does not use ionizing radiation. This procedure requires little to no special preparation. ... an image. Ultrasound examinations do not use ionizing radiation (as used in x-rays ), thus there is ...

  12. Ultrasound -- Pelvis

    Science.gov (United States)

    ... help diagnose symptoms experienced by women such as: pelvic pain abnormal bleeding other menstrual problems and help identify: ... children, pelvic ultrasound can help evaluate: pelvic masses pelvic pain ambiguous genitalia and anomalies of pelvic organs early ...

  13. Prostate Ultrasound

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    Full Text Available ... the returning echoes from the tissues in the body. The principles are similar to sonar used by boats and submarines. The ultrasound image is immediately visible on a video display screen ...

  14. Ultrasound -- Pelvis

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    Full Text Available ... the returning echoes from the tissues in the body. The principles are similar to sonar used by boats and submarines. The ultrasound image is immediately visible on a video display screen ...

  15. Ultrasound -- Pelvis

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    Full Text Available ... to-use and less expensive than other imaging methods. Ultrasound imaging is extremely safe and does not ... barium exams, CT scanning , and MRI are the methods of choice in such a setting. Large patients ...

  16. Prostate Ultrasound

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    Full Text Available ... collects the sounds that bounce back and a computer then uses those sound waves to create an ... Ultrasound scanners consist of a console containing a computer and electronics, a video display screen and a ...

  17. Ultrasound -- Pelvis

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    Full Text Available ... collects the sounds that bounce back and a computer then uses those sound waves to create an ... Ultrasound scanners consist of a console containing a computer and electronics, a video display screen and a ...

  18. Prostate Ultrasound

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    Full Text Available ... patient consultation. View full size with caption Related Articles and Media Benign Prostatic Hyperplasia (BPH) (Enlargement of the Prostate) Prostate Cancer Ultrasound- and MRI-Guided Prostate Biopsy Images related ...

  19. Ultrasound -- Pelvis

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    Full Text Available ... ovarian cysts and uterine fibroids ovarian or uterine cancers A transvaginal ultrasound is usually performed to view ... detect: uterine anomalies uterine scars endometrial polyps fibroids cancer, especially in patients with abnormal uterine bleeding Some ...

  20. Prostate Ultrasound

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    Full Text Available ... use of a small transducer (probe) and ultrasound gel placed directly on the skin. High-frequency sound waves are transmitted from the probe through the gel into the body. The transducer collects the sounds ...

  1. Ultrasound -- Pelvis

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    Full Text Available ... use of a small transducer (probe) and ultrasound gel placed directly on the skin. High-frequency sound waves are transmitted from the probe through the gel into the body. The transducer collects the sounds ...

  2. Ultrasound -- Pelvis

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    Full Text Available ... ovarian cysts and uterine fibroids ovarian or uterine cancers A transvaginal ultrasound is usually performed to view ... detect: uterine anomalies uterine scars endometrial polyps fibroids cancer, especially in patients with abnormal uterine bleeding Some ...

  3. Prostate Ultrasound

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    Full Text Available ... uses sound waves to produce pictures of a man’s prostate gland and to help diagnose symptoms such ... also called transrectal ultrasound, provides images of a man's prostate gland and surrounding tissue. The exam typically ...

  4. Ultrasound -- Pelvis

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    Full Text Available ... sends out high-frequency sound waves (that the human ear cannot hear) into the body and then ... ultrasound , there are no known harmful effects on humans. top of page What are the limitations of ...

  5. Ultrasound -- Pelvis

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    Full Text Available ... legs, neck and/or brain (in infants and children) or within various body organs such as the ... tumors other disorders of the urinary bladder In children, pelvic ultrasound can help evaluate: pelvic masses pelvic ...

  6. Prostate Ultrasound

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    Full Text Available ... requested the exam. Usually, the referring physician or health care provider will share the results with you. ... well on x-ray images. Ultrasound causes no health problems and may be repeated as often as ...

  7. Ultrasound -- Pelvis

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    Full Text Available ... ultrasound exams are also used to monitor the health and development of an embryo or fetus during ... requested the exam. Usually, the referring physician or health care provider will share the results with you. ...

  8. Prostate Ultrasound

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    Full Text Available ... physician during a routine physical exam or prostate cancer screening exam. an elevated blood test result. difficulty ... vessels or to detect abnormal masses, such as tumors. In an ultrasound examination, a transducer both sends ...

  9. Prostate Ultrasound

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    Full Text Available ... of page How is the procedure performed? In men, the prostate gland is located directly in front ... What are the limitations of Prostate Ultrasound Imaging? Men who have had the tail end of their ...

  10. Prostate Ultrasound

    Science.gov (United States)

    ... prostate. help diagnose the cause of a man's infertility. A transrectal ultrasound of the prostate gland is ... the transducer is pressed against the skin, it directs small pulses of inaudible, high-frequency sound waves ...

  11. Prostate Ultrasound

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    Full Text Available ... prostate. help diagnose the cause of a man's infertility. A transrectal ultrasound of the prostate gland is ... the transducer is pressed against the skin, it directs small pulses of inaudible, high-frequency sound waves ...

  12. Ultrasound -- Pelvis

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    Full Text Available ... areas of the body while other areas, especially air-filled lungs, are poorly suited for ultrasound. For ... make secure contact with the body and eliminate air pockets between the transducer and the skin that ...

  13. Ultrasound -- Pelvis

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    Full Text Available ... the object is as well as the object's size, shape and consistency (whether the object is solid ... ultrasound is used to detect changes in appearance, size or contour of organs, tissues, and vessels or ...

  14. Prostate Ultrasound

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    Full Text Available ... an ultrasound transducer – a plastic cylinder about the size of a finger – is inserted short distance into ... the object is as well as the object's size, shape and consistency (whether the object is solid ...

  15. Ultrasound -- Pelvis

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    Full Text Available ... are reviewed. top of page What will I experience during and after the procedure? For a transabdominal ... ultrasound , there are no known harmful effects on humans. top of page What are the limitations of ...

  16. Ultrasound -- Pelvis

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    Full Text Available ... to-use and less expensive than other imaging methods. Ultrasound imaging is extremely safe and does not ... barium exams, CT scanning , and MRI are the methods of choice in such a setting. Large patients ...

  17. Ultrasound -- Pelvis

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    Full Text Available ... ultrasound exams are also used to monitor the health and development of an embryo or fetus during ... requested the exam. Usually, the referring physician or health care provider will share the results with you. ...

  18. Prostate Ultrasound

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    Full Text Available ... difficulty urinating or an elevated blood test result. It’s also used to investigate a nodule found during ... difficulty urinating. Because ultrasound provides real-time images, it also can be used to guide procedures such ...

  19. Ultrasound -- Pelvis

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    Full Text Available ... the examination process. To ensure a smooth experience, it often helps to explain the procedure to the ... on the amplitude (loudness), frequency (pitch) and time it takes for the ultrasound signal to return from ...

  20. Ultrasound -- Pelvis

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    Full Text Available ... collects the sounds that bounce back and a computer then uses those sound waves to create an ... Ultrasound scanners consist of a console containing a computer and electronics, a video display screen and a ...

  1. Prostate Ultrasound

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    Full Text Available ... collects the sounds that bounce back and a computer then uses those sound waves to create an ... Ultrasound scanners consist of a console containing a computer and electronics, a video display screen and a ...

  2. Ultrasound -- Pelvis

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    Full Text Available ... to distract the child and make the time pass quickly. The ultrasound exam room may have a ... tissue attenuate (weaken) the sound waves as they pass deeper into the body. top of page Additional ...

  3. Prostate Ultrasound

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    Full Text Available ... examinations do not use ionizing radiation (as used in x-rays ), thus there is no radiation exposure to the patient. Because ultrasound images are captured in real-time, they can show the structure and ...

  4. Ultrasound -- Pelvis

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    Full Text Available ... uterine cavity . Three-dimensional (3-D) ultrasound permits evaluation of the uterus and ovaries in planes that ... a special study usually done to provide detailed evaluation of the prostate gland, involves inserting a specialized ...

  5. Ultrasound -- Pelvis

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    Full Text Available ... are also used to monitor the health and development of an embryo or fetus during pregnancy. See ... I prepare? You should wear comfortable, loose-fitting clothing for your ultrasound exam. You may need to ...

  6. Ultrasound -- Pelvis

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    Full Text Available ... also used to guide procedures such as needle biopsies , in which needles are used to extract a ... gynecologic examination. For a transrectal exam: If no biopsy is required, transrectal ultrasound of the prostate is ...

  7. Ultrasound -- Pelvis

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    Full Text Available ... ultrasound exam room may have a television. Feel free to ask for your child's favorite channel. top ... be turned to either side to improve the quality of the images. After you are positioned on ...

  8. Ultrasound -- Pelvis

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    Full Text Available ... probe) and ultrasound gel placed directly on the skin. High-frequency sound waves are transmitted from the ... small amount of gel is put on the skin to allow the sound waves to best travel ...

  9. Prostate Ultrasound

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    Full Text Available ... probe) and ultrasound gel placed directly on the skin. High-frequency sound waves are transmitted from the ... small amount of gel is put on the skin to allow the sound waves to best travel ...

  10. Ultrasound -- Pelvis

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    Full Text Available ... extract a sample of cells from organs for laboratory testing. Doppler ultrasound images can help the physician ... the returning sound waves), as well as the type of body structure and composition of body tissue ...

  11. Hip Ultrasound

    Science.gov (United States)

    ... be used in infants to check for developmental dysplasia of the hip. Ultrasound is safe, noninvasive, and does not use ... be used to check the hips for developmental dysplasia of the hip (DDH), which in infants can range from a ...

  12. Ultrasound -- Pelvis

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    Full Text Available ... called color Doppler ultrasonography, is a special ultrasound technique that allows the physician to see and evaluate ... evaluation with additional views or a special imaging technique. A follow-up examination may also be necessary ...

  13. Ultrasound -- Pelvis

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    Full Text Available ... are obtained from different orientations to get the best views of the uterus and ovaries. Transvaginal ultrasound ... over time. Follow-up examinations are sometimes the best way to see if treatment is working or ...

  14. Ultrasound -- Pelvis

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    Full Text Available ... probe) and ultrasound gel placed directly on the skin. High-frequency sound waves are transmitted from the ... the transducer (the device placed on the patient's skin to send and receive the returning sound waves), ...

  15. Prostate Ultrasound

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    Full Text Available ... probe) and ultrasound gel placed directly on the skin. High-frequency sound waves are transmitted from the ... the transducer (the device placed on the patient's skin to send and receive the returning sound waves), ...

  16. Ultrasound -- Pelvis

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    Full Text Available ... or sonography , involves the use of a small transducer (probe) and ultrasound gel placed directly on the ... probe through the gel into the body. The transducer collects the sounds that bounce back and a ...

  17. Ultrasound -- Pelvis

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    Full Text Available ... insertion. top of page How does the procedure work? Ultrasound imaging is based on the same principles ... requested the exam. Usually, the referring physician or health care provider will share the results with you. ...

  18. Prostate Ultrasound

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    Full Text Available ... gel. top of page How does the procedure work? Ultrasound imaging is based on the same principles ... requested the exam. Usually, the referring physician or health care provider will share the results with you. ...

  19. Ultrasound -- Pelvis

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    Full Text Available ... Leave jewelry at home and wear loose, comfortable clothing. You may be asked to wear a gown. ... I prepare? You should wear comfortable, loose-fitting clothing for your ultrasound exam. You may need to ...

  20. Prostate Ultrasound

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    Full Text Available ... Leave jewelry at home and wear loose, comfortable clothing. You may be asked to wear a gown ... I prepare? You should wear comfortable, loose-fitting clothing for your ultrasound exam. You may need to ...

  1. Prostate Ultrasound

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    Full Text Available ... gel. top of page How does the procedure work? Ultrasound imaging is based on the same principles ... these links. About Us | Contact Us | FAQ | Privacy | Terms of Use | Links | Site Map Copyright © 2017 Radiological ...

  2. Ultrasound -- Pelvis

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    Full Text Available ... insertion. top of page How does the procedure work? Ultrasound imaging is based on the same principles ... these links. About Us | Contact Us | FAQ | Privacy | Terms of Use | Links | Site Map Copyright © 2017 Radiological ...

  3. Prostate Ultrasound

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    Full Text Available ... physician during a routine physical exam or prostate cancer screening exam. an elevated blood test result. difficulty urinating. Because ultrasound provides real-time images, it also can be used to guide ...

  4. Ultrasound -- Pelvis

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    Full Text Available ... in the abdomen, arms, legs, neck and/or brain (in infants and children) or within various body organs ... or uterine cancers A transvaginal ultrasound is usually performed to view ...

  5. Prostate Ultrasound

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    Full Text Available ... uses sound waves to produce pictures of a man’s prostate gland and to help diagnose symptoms such ... also called transrectal ultrasound, provides images of a man's prostate gland and surrounding tissue. The exam typically ...

  6. Prostate Ultrasound

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    Full Text Available ... a nodule found during a rectal exam, detect abnormalities, and determine whether the gland is enlarged. Ultrasound ... follow-up exam is done because a potential abnormality needs further evaluation with additional views or a ...

  7. Ultrasound -- Pelvis

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    Full Text Available ... uterine cavity . Three-dimensional (3-D) ultrasound permits evaluation of the uterus and ovaries in planes that ... is done because a potential abnormality needs further evaluation with additional views or a special imaging technique. ...

  8. Ultrasound -- Pelvis

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    Full Text Available ... internal organs, as well as blood flowing through blood vessels. Ultrasound imaging is a noninvasive medical test that ... as clots) narrowing of vessels tumors and congenital vascular malformations reduced or absent blood flow to various ...

  9. Prostate Ultrasound

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    Full Text Available ... information you were looking for? Yes No Please type your comment or suggestion into the following text box: Comment: E-mail: ... Images related to Ultrasound - Prostate Sponsored by Please ...

  10. Prostate Ultrasound

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    Full Text Available ... prostate is enlarged, also known as benign prostatic hyperplasia (BPH) , with measurements acquired as needed for any ... with caption Related Articles and Media Benign Prostatic Hyperplasia (BPH) Prostate Cancer Ultrasound- and MRI-Guided Prostate ...

  11. Ultrasound -- Pelvis

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    Full Text Available ... frequently used to evaluate the reproductive and urinary systems. Ultrasound is safe, noninvasive and does not use ... and evaluate a variety of urinary and reproductive system disorders in both sexes without x-ray exposure. ...

  12. Ultrasound -- Pelvis

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    Full Text Available ... prior to the exam. Bringing books, small toys, music or games can help to distract the child ... modality for the diagnosis and monitoring of pregnant women and their unborn babies. Ultrasound provides real-time ...

  13. Ultrasound -- Pelvis

    Science.gov (United States)

    ... prior to the exam. Bringing books, small toys, music or games can help to distract the child ... modality for the diagnosis and monitoring of pregnant women and their unborn babies. Ultrasound provides real-time ...

  14. Ultrasound -- Pelvis

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    Full Text Available ... of urinary and reproductive system disorders in both sexes without x-ray exposure. Risks For standard diagnostic ... have special pediatric considerations. The teddy bear denotes child-specific content. Related Articles and Media Sonohysterography Ultrasound - ...

  15. Ultrasound -- Pelvis

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    Full Text Available ... a sample of cells from organs for laboratory testing. Doppler ultrasound images can help the physician to ... computer or television monitor. The image is created based on the amplitude (loudness), frequency (pitch) and time ...

  16. Prostate Ultrasound

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    Full Text Available ... difficulty urinating or an elevated blood test result. It’s also used to investigate a nodule found during ... difficulty urinating. Because ultrasound provides real-time images, it also can be used to guide procedures such ...

  17. Ultrasound -- Pelvis

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    Full Text Available ... the examination process. To ensure a smooth experience, it often helps to explain the procedure to the ... on the amplitude (loudness), frequency (pitch) and time it takes for the ultrasound signal to return from ...

  18. Ultrasound -- Pelvis

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    Full Text Available ... patient consultation. View full size with caption Pediatric Content Some imaging tests and treatments have special pediatric considerations. The teddy bear denotes child-specific content. Related Articles and Media Sonohysterography Ultrasound - Abdomen Children's ( ...

  19. Ultrasound -- Pelvis

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    Full Text Available ... the procedure. Ultrasound examinations are very sensitive to motion, and an active or crying child can prolong ... computer, which in turn creates a real-time picture on the monitor. One or more frames of ...

  20. Ultrasound -- Pelvis

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    Full Text Available ... extract a sample of cells from organs for laboratory testing. Doppler ultrasound images can help the physician ... The transducer sends out inaudible, high—frequency sound waves into the body and then listens for the ...

  1. Trauma Ultrasound.

    Science.gov (United States)

    Wongwaisayawan, Sirote; Suwannanon, Ruedeekorn; Prachanukool, Thidathit; Sricharoen, Pungkava; Saksobhavivat, Nitima; Kaewlai, Rathachai

    2015-10-01

    Ultrasound plays a pivotal role in the evaluation of acute trauma patients through the use of multi-site scanning encompassing abdominal, cardiothoracic, vascular and skeletal scans. In a high-speed polytrauma setting, because exsanguinations are the primary cause of trauma morbidity and mortality, ultrasound is used for quick and accurate detection of hemorrhages in the pericardial, pleural, and peritoneal cavities during the primary Advanced Trauma Life Support (ATLS) survey. Volume status can be assessed non-invasively with ultrasound of the inferior vena cava (IVC), which is a useful tool in the initial phase and follow-up evaluations. Pneumothorax can also be quickly detected with ultrasound. During the secondary survey and in patients sustaining low-speed or localized trauma, ultrasound can be used to help detect abdominal organ injuries. This is particularly helpful in patients in whom hemoperitoneum is not identified on an initial scan because findings of organ injuries will expedite the next test, often computed tomography (CT). Moreover, ultrasound can assist in detection of fractures easily obscured on radiography, such as rib and sternal fractures.

  2. Sonography of intrathyroid parathyroid adenomas: Are there distinctive features that allow for preoperative identification?

    Energy Technology Data Exchange (ETDEWEB)

    Heller, Matthew T., E-mail: hellermt@upmc.edu [University of Pittsburgh Medical Center, Department of Radiology, 200 Lothrop St, Suite 3950 PUH S. Tower, Pittsburgh, PA 15213 (United States); Yip, Linwah, E-mail: yipl@upmc.edu [University of Pittsburgh Medical Center, Department of Endocrine Surgery, Kaufmann Building, 3471 Fifth Ave, Suite 101, Pittsburgh, PA 15213 (United States); Tublin, Mitchell E., E-mail: tublme@upmc.edu [University of Pittsburgh Medical Center, Department of Radiology, 200 Lothrop St, Suite 3950 PUH S. Tower, Pittsburgh, PA 15213 (United States)

    2013-01-15

    Objective: The purpose of our study was to determine if intra-thyroid parathyroid adenomas can be accurately identified by applying proposed criteria to preoperative ultrasound examinations in patients with primary hyperparathyroidism. Materials/methods: Fifty-three patients with pathology proven intra-thyroid parathyroid adenomas and pre-operative ultrasounds were identified from a surgical database for a blinded, retrospective review. A contemporary, age-matched cohort of 54 patients with extra-thyroid parathyroid adenomas was identified as a control. A total of 64 patients within these cohorts had co-existing thyroid nodules. Proposed ultrasound criteria for identifying a parathyroid adenoma included solid composition, profound hypoechogenicity, and presence of a feeding polar vessel. Parathyroid adenomas were classified as extra-thyroid or intra-thyroid (partial or complete) based on their relationship with the thyroid gland during ultrasound evaluation and results were compared to surgical and histopathology reports as the gold standard. The results from the blinded, retrospective review during which the proposed, specific ultrasound criteria were applied were compared to the initial, pre-operative reports during which the proposed criteria were not applied. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of the blinded, retrospective review and initial, pre-operative reports were calculated. Additionally, in patients with co-existing thyroid nodules, an attempt was made to differentiate parathyroid adenomas from the thyroid nodules. Results: Application of the proposed ultrasound criteria during blinded retrospective review yielded a sensitivity and specificity for detecting intra-thyroid parathyroid adenomas of 76% and 92%, respectively. The sensitivity and specificity of ultrasound for detecting intra-thyroid parathyroid adenomas on the initial reports was 29% and 95%, respectively. The sensitivity and

  3. Role of axillary lymph node ultra-sound and large core biopsy in the preoperative assessment of patients selected for sentinel node biopsy; Ruolo dell'ecografia e della microbiopsia istologica nella valutazione del cavo ascellare in pazienti candidate a biopsia del linfonodo sentinella

    Energy Technology Data Exchange (ETDEWEB)

    Nori, Jacopo; Boeri, Cecilia; Vanzi, Ermanno; Nori Bufalini, Filippo; Masi, Andrea [Azienda Ospedaliero-Universitaria Careggi, Firenze (Italy). Diagnostica senologica; Bazzocchi, Massimo; Londero, Viviana [Udine Univ., Udine (Italy). Istituto di radiologia universitaria; Mangialavori, Giuseppe [Ospedale di Merano, Bolzano (Italy). Servizio di radiologia; Distante, Vito; Simoncini, Roberta [Firenze Univ., Firenze (Italy). Clinica chirurgica I

    2005-04-01

    Purpose: To aim of this study was to evaluate the diagnostic accuracy of axillary lymph node sonography, if necessary in collaboration with US-guided large core biopsy, in the preoperative evaluation of breast cancer patients scheduled for quadrantectomy and sentinel lymph node excision. Materials and methods: From July 2001 to December 2002, we evaluated 117 breast cancer patients with ultrasound and, where indicated, FNAB. Breast lesions has diameters between 4 and 26 mm (mean diameter 11 mm). Fifteen (13%) of the 117 patients were excluded from the series as they did not found fulfil the criteria for preliminary sonography of the axilla: in 9 patients fewer than 4 nodes were detected and in 6 patients the breast lesions were intraoperatively found to be benign. Eleven patients (10.7%) with sonographically suspicious axillary nodes were sampled by US-guided core biopsy using a 14 or 16 Gauge Tru-Cut needle. Results: The ultrasound study aims to evaluate the dimensions and morphology of the breast lesion as well as detect and assess at least 4 axillary nodes. These were evaluated for hilar and cortical thickening and radio between the sinus diameter and the total longitudinal diameter. Lymph nodes with hilar diameters equal to or greater than 50% of the longitudinal diameter were considered normal. Of the 102 patients evaluated, 77 (75.7%) had normal axillary nodes according to the US criteria adopted. Negativity was confirmed by histology in 56 cases (72.7%, true negative); 21 (27.3%, false negative) were found to be positive, in contrast with the sonographic appearance. The false negative cases were due to lymph node micrometastasis which probably did not cause morphologic alterations perceptible at ultrasound. The remaining 25 patients (24.5%) had axillary lymph nodes classified as suspicious. In 13 cases of (52%, true positive) there was agreement with histology, whereas in 12 cases (48%, false positive) the US suspicion was not confirmed at surgery. The most

  4. Magnetic resonance urography in duplex kidney with ectopic ureteral insertion

    Science.gov (United States)

    Thambidorai, Conjeevaram Rajendrarao; Anuar, Zulfiqar

    2011-01-01

    This is a report on the use of magnetic resonance urography (MRU) in a 6-year-old girl who presented with urinary incontinence. She had a left duplex kidney with poorly functioning upper moiety and ectopic insertion of the dilated upper pole ureter. MRU has been shown to be superior to conventional imaging techniques in delineating poorly functioning moieties of duplex kidneys and ectopic ureters. PMID:21897576

  5. Magnetic resonance urography in duplex kidney with ectopic ureteral insertion

    Directory of Open Access Journals (Sweden)

    Conjeevaram Rajendrarao Thambidorai

    2011-01-01

    Full Text Available This is a report on the use of magnetic resonance urography (MRU in a 6-year-old girl who presented with urinary incontinence. She had a left duplex kidney with poorly functioning upper moiety and ectopic insertion of the dilated upper pole ureter. MRU has been shown to be superior to conventional imaging techniques in delineating poorly functioning moieties of duplex kidneys and ectopic ureters.

  6. Properties of duplex stainless steels made by powder metallurgy

    OpenAIRE

    Rosso, M.; M. Actis Grande; Z. Brytan; L.A. Dobrzański

    2007-01-01

    Purpose: of this paper was to examine the mechanical properties of duplex stainless steels.Design/methodology/approach: In presented study duplex stainless steels were obtained through powder metallurgy starting from austenitic, martensitic base powders by controlled addition of alloying elements, such as Cr, Ni, Mo and Cu. In the studies behind the preparation of mixes, Schaeffler’s diagram was taken into consideration. Prepared mixes have been sintered in a vacuu...

  7. General Ultrasound Imaging

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    Full Text Available ... are the limitations of General Ultrasound Imaging? What is General Ultrasound Imaging? Ultrasound is safe and painless, ... through the blood vessels. top of page How is the procedure performed? For most ultrasound exams, you ...

  8. General Ultrasound Imaging

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    Full Text Available ... A-Z General Ultrasound Ultrasound imaging uses sound waves to produce pictures of the inside of the ... of the inside of the body using sound waves. Ultrasound imaging, also called ultrasound scanning or sonography , ...

  9. General Ultrasound Imaging

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    Full Text Available ... of an ultrasound examination. Doppler ultrasound , also called color Doppler ultrasonography, is a special ultrasound technique that ... kidneys. There are three types of Doppler ultrasound: Color Doppler uses a computer to convert Doppler measurements ...

  10. General Ultrasound Imaging

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    Full Text Available ... Index A-Z General Ultrasound Ultrasound imaging uses sound waves to produce pictures of the inside of ... pictures of the inside of the body using sound waves. Ultrasound imaging, also called ultrasound scanning or ...

  11. Endovenous laser ablation of great saphenous vein with ultrasound-guided perivenous tumescence:early and midterm results

    Institute of Scientific and Technical Information of China (English)

    CHEN Jia-quan; XIE Hui; DENG Hao-yu; YUAN Kai; ZHANG Ji-wei; ZHANG Hao; ZHANG Lan

    2013-01-01

    Background Endovenous laser ablation (EVLA) is an improved method to treat varicose great saphenous veins (GSV)with a high satisfactory rate.This study aimed to evaluate the efficiency and safety of treatment by EVLA procedures with ultrasound-guided perivenous tumescence.Methods Thirty-one patients (31 limbs) with symptomatic varicose vein primary to chronic venous insufficiency (CVI) treated with EVLA were prospectively studied.The entire procedure was performed under ultrasound-guided tumescent local anesthesia.The patients were evaluated with a 18 month follow-up postoperation using clinical examination and venous duplex ultrasonography.Pain scores and quality of life (QOL) were recorded using visual analog scale (VAS) and the chronic venous insufficiency questionnaire (CIVIQ) at 1 week,1 month,and 12 months after operation.Results All patients tolerated EVLA procedure well.The overall success occlusion rates of GSV were 92%,94%,and 94% at 1,12,and 18 months follow-up,respectively.The score of CIVIQ one week preoperation was 69.14±11.44 while that of CIVIQ one month postoperation was 85.32±4.89.The life quality has significantly improved after the operation of EVLA (t=12.71,P <0.05).The VAS one month after treatment was lower than 1 week before therapy (t=8.048,P <0.05).Major complications such as deep vein thrombosis and skin bums were not found.Most of the complications were minor and improved quickly.Conclusions This refinement type of EVLA procedure is a safe and effective treatment with a high satisfaction rate; it displayed noteworthy features including shortening hospitalization,early ambulant activity,and preferable occlusion rates.

  12. Phase Transformations in Cast Duplex Stainless Steels

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yoon-Jun [Iowa State Univ., Ames, IA (United States)

    2004-01-01

    Duplex stainless steels (DSS) constitute both ferrite and austenite as a matrix. Such a microstructure confers a high corrosion resistance with favorable mechanical properties. However, intermetallic phases such as σ and χ can also form during casting or high-temperature processing and can degrade the properties of the DSS. This research was initiated to develop time-temperature-transformation (TTT) and continuous-cooling-transformation (CCT) diagrams of two types of cast duplex stainless steels, CD3MN (Fe-22Cr-5Ni-Mo-N) and CD3MWCuN (Fe-25Cr-7Ni-Mo-W-Cu-N), in order to understand the time and temperature ranges for intermetallic phase formation. The alloys were heat treated isothermally or under controlled cooling conditions and then characterized using conventional metallographic methods that included tint etching, and also using electron microscopy (SEM, TEM) and wavelength dispersive spectroscopy (WDS). The kinetics of intermetallic-phase (σ + χ) formation were analyzed using the Johnson-Mehl-Avrami (MA) equation in the case of isothermal transformations and a modified form of this equation in the case of continuous cooling transformations. The rate of intermetallic-phase formation was found to be much faster in CD3MWCuN than CD3MN due mainly to differences in the major alloying contents such as Cr, Ni and Mo. To examine in more detail the effects of these elements of the phase stabilities; a series of eight steel castings was designed with the Cr, Ni and Mo contents systematically varied with respect to the nominal composition of CD3MN. The effects of varying the contents of alloying additions on the formation of intermetallic phases were also studied computationally using the commercial thermodynamic software package, Thermo-Calc. In general, σ was stabilized with increasing Cr addition and χ by increasing Mo addition. However, a delicate balance among Ni and other minor elements such as N and Si also exists. Phase equilibria in DSS can be affected by

  13. Phase Transformations in Cast Duplex Stainless Steels

    Energy Technology Data Exchange (ETDEWEB)

    Yoon-Jun Kim

    2004-12-19

    Duplex stainless steels (DSS) constitute both ferrite and austenite as a matrix. Such a microstructure confers a high corrosion resistance with favorable mechanical properties. However, intermetallic phases such as {sigma} and {chi} can also form during casting or high-temperature processing and can degrade the properties of the DSS. This research was initiated to develop time-temperature-transformation (TTT) and continuous-cooling-transformation (CCT) diagrams of two types of cast duplex stainless steels, CD3MN (Fe-22Cr-5Ni-Mo-N) and CD3MWCuN (Fe-25Cr-7Ni-Mo-W-Cu-N), in order to understand the time and temperature ranges for intermetallic phase formation. The alloys were heat treated isothermally or under controlled cooling conditions and then characterized using conventional metallographic methods that included tint etching, and also using electron microscopy (SEM, TEM) and wavelength dispersive spectroscopy (WDS). The kinetics of intermetallic-phase ({sigma} + {chi}) formation were analyzed using the Johnson-Mehl-Avrami (MA) equation in the case of isothermal transformations and a modified form of this equation in the case of continuous cooling transformations. The rate of intermetallic-phase formation was found to be much faster in CD3MWCuN than CD3MN due mainly to differences in the major alloying contents such as Cr, Ni and Mo. To examine in more detail the effects of these elements of the phase stabilities; a series of eight steel castings was designed with the Cr, Ni and Mo contents systematically varied with respect to the nominal composition of CD3MN. The effects of varying the contents of alloying additions on the formation of intermetallic phases were also studied computationally using the commercial thermodynamic software package, Thermo-Calc. In general, {sigma} was stabilized with increasing Cr addition and {chi} by increasing Mo addition. However, a delicate balance among Ni and other minor elements such as N and Si also exists. Phase equilibria in

  14. Comparison of diagnostic value of duplex and color Doppler ultrasound in experimental acute renal failure in rabbits%二维超声、频谱及彩色多普勒超声在评价实验性兔急性肾衰竭中的价值比较

    Institute of Scientific and Technical Information of China (English)

    黄晓玲; 高云华

    2000-01-01

    Objective To compare the diagnostic value of two-dimentional ultrasound, spectrum and color Doppler ultrasound in experimental acute renal failure(ARF)in rabbits.Methods 50%glycerin(12~15 ml/kg)were injected into the thigh muscle of the back leg of the rabbit to induce an animal model of ARF. Ultrasonic examination was performed on the day before(T0)and days 1,3…13 after the injection(T1,T3… T13).Renal size was evaluated by two-dimensional ultrasound.The hemodynamic changes of the kidney were quantitatively analysed by spectrum Doppler, while color Doppler flow imaging(CDFI)and color Doppler power imaging(CDPI)were used to qualitatively study the blood perfusion of the kidney during ARF. The renal imaging in CDFI and CDPI were classified three grades.Grade I, the blood perfusion of the kidney was normal and the flow singles could be seen at the site near to the renal capsule.Grade II, the blood perfusion of the kidney was slightly abnormal and the flow singles could be seen in the renal cortex but not near to the capsule. Grade Ⅲ, the blood perfusion was heavily abnormal and the flow singles could not be seen in the renal cortex.Results The changes of renal hemodynamics and renal size began at T3,peaked at T5 and T7,and returned to normal at T9. The renal imaging of all rabbits were grade I in CDPI and CDFI at T0.In CDFI, all were gradeⅢat T1~T9, at T11 and T13 most of them only returned to grade Ⅱ, no one returned to grade I.In CDPI, however, all were grade Ⅱ at T1 and T3,while only a few were grade Ⅲ at T5 and T7,and most have returned to grade Ⅰ at T9. Conclusions During the period of ARF, two-dimensional ultrasound is useful in showing the echo and measuring the depth of renal cortex.Spectrum Doppler is helpful in quantitatively analysing the renal hemodynamic hanges. CDPI is more sensitive than CDFI in showing the blood perfusion of the kidney%目的 比较二维超声、频谱及彩色多普勒超声在诊断

  15. Non-invasive imaging modalities for preoperative axillary lymph node staging in patients with breast cancer; Nichtinvasive bildgebende Verfahren zum praeoperativen axillaeren Lymphknotenstaging beim Mammakarzinom

    Energy Technology Data Exchange (ETDEWEB)

    Wasser, K.; Schnitzer, A.; Schoenberg, S.O. [Universitaetsmedizin Mannheim, Institut fuer Klinische Radiologie und Nuklearmedizin, Mannheim (Germany); Brade, J. [Universitaetsmedizin Mannheim, Institut fuer Medizinische Statistik, Mannheim (Germany)

    2010-11-15

    In the last decade sentinel lymph node biopsy has become a well-established method for axillary lymph node staging in patients with breast cancer. Using preoperative imaging modalities it can be tested whether patients are suitable for sentinel node biopsy or if they should directly undergo an axillary dissection. The imaging modalities used must be mainly characterized by a high positive predictive value (PPV). For this question B-mode ultrasound is the best evaluated method and provides clear morphological signs for a high PPV (>90%) but the sensitivity barely exceeds 50%. It has not yet been proven whether other modalities such as duplex sonography, magnetic resonance imaging, computed tomography (CT) or scintigraphy might achieve a higher sensitivity while still maintaining a high PPV. There is only some evidence that positron emission tomography (PET) might achieve a higher sensitivity. This should be confirmed by further studies because PET or PET/CT will play an increasing role for an initial whole body staging in patients with breast cancer in the near future. (orig.) [German] Die Waechterlymphknotenbiopsie hat sich in den letzten 10 Jahren fuer das axillaere Lymphknotenstaging des Mammakarzinoms fest etabliert. Durch praeoperative bildgebende Verfahren kann getestet werden, ob sich Patientinnen fuer eine Waechterlymphknotenbiopsie eignen oder direkt einer axillaeren Dissektion unterzogen werden sollten. Diese bildgebenden Verfahren muessen sich in erster Linie durch einen hohen positiven Vorhersagewert (PVW) auszeichnen. Die B-Bild-Sonographie ist diesbezueglich bisher am besten evaluiert. Sie liefert eindeutige morphologische Kriterien fuer einen hohen PVW (>90%). Die Sensitivitaet liegt dabei allerdings kaum ueber 50%. Bisher ist nicht erwiesen, dass andere Verfahren wie die Duplexsonographie, die MRT, die CT oder Szintigraphie eine bessere Sensitivitaet bei hohem PVW liefern. Lediglich fuer die Positronenemissionstomographie (PET) bestehen Hinweise

  16. Interventions for preoperative smoking cessation

    DEFF Research Database (Denmark)

    Thomsen, Thordis; Villebro, Nete; Møller, Ann Merete

    2014-01-01

    : Randomized controlled trials that recruited people who smoked prior to surgery, offered a smoking cessation intervention, and measured preoperative and long-term abstinence from smoking or the incidence of postoperative complications or both outcomes. DATA COLLECTION AND ANALYSIS: The review authors......BACKGROUND: Smokers have a substantially increased risk of postoperative complications. Preoperative smoking intervention may be effective in decreasing this incidence, and surgery may constitute a unique opportunity for smoking cessation interventions. OBJECTIVES: The objectives of this review...... are to assess the effect of preoperative smoking intervention on smoking cessation at the time of surgery and 12 months postoperatively, and on the incidence of postoperative complications. SEARCH METHODS: We searched the Cochrane Tobacco Addiction Group Specialized Register in January 2014. SELECTION CRITERIA...

  17. Therapeutic ultrasound

    Energy Technology Data Exchange (ETDEWEB)

    Crum, Lawrence A [Center for Industrial and Medical Ultrasound, 1013 NE 40th Street, University of Washington, Seattle, WA 98105 (United States)

    2004-01-01

    The use of ultrasound in medicine is now quite commonplace, especially with the recent introduction of small, portable and relatively inexpensive, hand-held diagnostic imaging devices. Moreover, ultrasound has expanded beyond the imaging realm, with methods and applications extending to novel therapeutic and surgical uses. These applications broadly include: tissue ablation, acoustocautery, lipoplasty, site-specific and ultrasound mediated drug activity, extracorporeal lithotripsy, and the enhancement of natural physiological functions such as wound healing and tissue regeneration. A particularly attractive aspect of this technology is that diagnostic and therapeutic systems can be combined to produce totally non-invasive, imageguided therapy. This general lecture will review a number of these exciting new applications of ultrasound and address some of the basic scientific questions and future challenges in developing these methods and technologies for general use in our society. We shall particularly emphasize the use of High Intensity Focused Ultrasound (HIFU) in the treatment of benign and malignant tumors as well as the introduction of acoustic hemostasis, especially in organs which are difficult to treat using conventional medical and surgical techniques. (amum lecture)

  18. INTRAOPERATIVE ULTRASOUND EXAMINATION OF HILAR CHOLANGIOCARCINOMA /TUMOR OF KLATSKIN /

    Directory of Open Access Journals (Sweden)

    Daniel V. Kostov

    2012-07-01

    Full Text Available Purpose: To compare the opportunities of the intraoperative ultrasound examination of the liver with the preoperative imaging methods – Computer tomography (CT, Ultrasound examination (US in detecting hepatic lesions in patients with tumor of Klatskin (hilar cholangiocarcinoma.Patients and methods: This is a prospective study of 7 patients, which had undergone open operative intervention for tumor of Klatskin. The affecting of the liver by the tumor process was examined preoperatively with Ultrasound examination and Computer tomography with contrast amplification, and by inspection and palpation and intra operative ultrasound during the operative intervention.Results: The maximum numbers of malignant lesions are found by IOUS - totally 21. Preoperative ultrasound found 5 lesions or 23,80% of the maximum number and preoperative CT – 9 or 33,33%. The information from IOUS changed the operative plan in 2/7 of the patients (28,57%. A biliary stent was placed under the control of IOUS in one patient with a heavy hyperbilirubinemia – 791,6 µmol/l.Conclusions: IOUS is significantly helpful in surgery of tumor of Klatskin. Besides the precise localization and staging of the tumor the information of IOUS changes the surgical strategy in some patients.

  19. Wavelength-tunable duplex integrated light source

    Science.gov (United States)

    Okamoto, Hiroshi; Yasaka, Hiroshi; Oe, Kunishige

    1996-04-01

    A monolithically integrated opto-electronic device is proposed as a fast wavelength-switching light source. This tunable duplex integrated light source comprises two wavelength-tunable distributed Bragg reflector (DBR) laser diodes (LDs), two MQW-electro-absorption optical switches, a Y-shaped waveguide coupler, a MQW-electro-absorption modulator, and two thermal drift compensators (TDCs). The wavelength-switching time of the optical switches was estimated to be 60 ps including a 50-ps rise time for the electrical-pulse generator. The wavelength of a 10-Gbit/s NRZ-modulated optical signal can be switched without bit loss. The function of the TDCs is to keep the device-chip temperature constant. Thermal-transient- induced wavelength drift with a millisecond-order time constant, which has been reported for DBR-LDs, and thermal crosstalk between the tuning regions of the integrated LDs, which causes wavelength fluctuation, are effectively suppressed by thermal-drift-compensation operation using the TDCs.

  20. Ferrite Quantification Methodologies for Duplex Stainless Steel

    Directory of Open Access Journals (Sweden)

    Arnaldo Forgas Júnior

    2016-07-01

    Full Text Available In order to quantify ferrite content, three techniques, XRD, ferritoscope and optical metallography, were applied to a duplex stainless steel UNS S31803 solution-treated for 30 min at 1,000, 1,100 and 1,200 °C, and then compared to equilibrium of phases predicted by ThermoCalc® simulation. As expected, the microstructure is composed only by austenite and ferrite phases, and ferrite content increases as the solution treatment temperature increases. The microstructure presents preferred grains orientation along the rolling directions even for a sample solution treated for 30 min at 1,200 °C. For all solution treatment temperatures, the ferrite volume fractions obtained by XRD measurements were higher than those achieved by the other two techniques and ThermoCalc® simulation, probably due to texturing effect of previous rolling process. Values obtained by quantitative metallography look more assertive as it is a direct measurement method but the ferritoscope technique should be considered mainly for in loco measurement.

  1. Corrosion behaviour of sintered duplex stainless steels

    Energy Technology Data Exchange (ETDEWEB)

    Utrilla, M. Victoria; Urena, Alejandro; Otero, Enrique; Munez, Claudio Jose [Escuela Superior de Ciencias Experimentales y Tecnologia, Universidad Rey Juan Carlos, C/ Tulipan s/n, 28933 Mostoles, Madrid (Spain)

    2004-07-01

    Duplex austenite-ferrite stainless steels were prepared by mixing austenitic (316L) and ferritic (434L) atomized powders. Although different 316L/434L ratios were prepared, present work centred its study on 50% ferrite - 50% austenite sintered steel. The powders were mixed and pressed at 700 MPa and sintered at 1250 deg. C for 30 min in vacuum. The cooling rate was 5 deg. C/min. Solution treatment was carried out to homogenize the microstructure at 1100 deg. C during 20 min. A microstructural study of the material in solution was performed, evaluating the microstructure, proportion and shape of porosity, and ferrite percentage. This last was measured by two methods, quantitative metallography and Fischer ferrito-metry. The materials were heat treated in the range of 700 to 1000 deg. C, for 10, 30 and 60 min and water quenched, to study the microstructural changes and the influence on the intergranular corrosion resistance. The method used to evaluate the sensitization to the intergranular corrosion was the electrochemical potentio-kinetic reactivation procedure (EPR). The test solution was 0.5 M H{sub 2}SO{sub 4} + 0,01 M KSCN at 30 deg. C. The criterion used to evaluate the sensitization was the ratio between the maximum reactivation density (Ir) and the maximum activation density (Ia). The results of the electrochemical tests were discussed in relation with the microstructures observed at the different heat treatments. (authors)

  2. Preoperative staging of rectal cancer.

    Science.gov (United States)

    Smith, Neil; Brown, Gina

    2008-01-01

    Detailed preoperative staging using high resolution magnetic resonance imaging (MRI) enables the selection of patients that require preoperative therapy for tumour regression. This information can be used to instigate neoadjuvant therapy in those patients with poor prognostic features prior to disturbing the tumour bed and potentially disseminating disease. The design of trials incorporating MR assessment of prognostic factors prior to therapy has been found to be of value in assessing treatment modalities and outcomes that are targeted to these preoperative prognostic subgroups and in providing a quantifiable assessment of the efficacy of particular chemoradiation treatment protocols by comparing pre-treatment MR staging with post therapy histology assessment. At present, we are focused on achieving clear surgical margins of excision (CRM) to avoid local recurrence. We recommend that all patients with rectal cancer should undergo pre-operative MRI staging. Of these, about half will have good prognosis features (T1-T3b, N0, EMVI negative, CRM clear) and may safely undergo primary total mesorectal excision. Of the remainder, those with threatened or involved margins will certainly benefit from pre-operative chemoradiotherapy with the aim of downstaging to permit safe surgical excision. In the future, our ability to recognise features predicting distant failure, such as extramural vascular invasion (EMVI) may be used to stratify patients for neo-adjuvant systemic chemotherapy in an effort to prevent distant relapse. The optimal pre-operative treatment regimes for these patients (radiotherapy alone, systemic chemotherapy alone or combination chemo-radiotherapy) is the subject of current and future trials.

  3. Significance of preoperative calculation of uterine weight as an indicator for preserving the uterus in pelvic reconstructive surgery.

    Science.gov (United States)

    Sheng, Qingsong; Ma, Ning; Huang, Huijuan; Xu, Bo; He, Chunni; Song, Yanfeng

    2015-01-01

    Recently, increasing evidence has shown that uterus preservation is beneficial for pelvic organ prolapse (POP) patients, both physiologically and psychologically. However, the preoperative indicators for uterus preservation have rarely been examined. The current study was designed to determine the relationship between the preoperative evaluated uterus weight and the operation selection (preserving the uterus or not) in pelvic reconstructive surgery (PRS) using vaginal meshes. First, in a series of 96 patients undergoing hysterectomy, the uterine weight was calculated by preoperative ultrasound measurements, and was then compared with the postoperative actual weight of the uterus. Subsequently, in a series of 65 patients undergone PRS using vaginal meshes and preserving the uterus, the uterine weight was calculated by preoperative ultrasound measurements. Lastly, in a series of 43 patients with a uterine weight > 56.12 g who had undergone PRS using vaginal meshes, the operation success rate in patients with a preserved uterus was compared to patients for whom the uterus was not preserved. The results showed that uterus weight can be evaluated by ultrasound and used as a preoperative indicator for whether the uterus should be preserved or not in PRS when using vaginal meshes. It was indicated that preoperative evaluation of uterine weight is beneficial for surgical planning and guidance.

  4. Ultrasound-guided three-dimensional needle steering in biological tissue with curved surfaces

    NARCIS (Netherlands)

    Abayazid, M.; Lopes da Frota Moreira, P.; Shahriari, N.; Patil, S.; Alterovitz, Ron; Misra, S.

    2015-01-01

    In this paper, we present a system capable of automatically steering a bevel-tipped flexible needle under ultrasound guidance toward a physical target while avoiding a physical obstacle embedded in gelatin phantoms and biological tissue with curved surfaces. An ultrasound pre-operative scan is perfo

  5. Anxiety in preoperative anesthetic procedures.

    Science.gov (United States)

    Valenzuela Millán, Jaquelyn; Barrera Serrano, José René; Ornelas Aguirre, José Manuel

    2010-01-01

    Preoperative anxiety is a common and poorly evaluated condition in patients who will undergo an anesthetic and surgical intervention. The objective of this study was to determine the prevalence of anxiety in a group of patients undergoing elective surgery, as assessed by the Amsterdam Anxiety Preoperative and Information (AAPI) scale. We studied 135 patients scheduled for elective surgery applying the AAPI scale 24 h before the surgical procedure to evaluate the presence of anxiety and patient characteristics. A descriptive analysis with mean +/- standard deviation for categorical variables was done. For intragroup differences, chi(2) test was used. Pearson correlation for the association between anxiety and postoperative complications was carried out. A value of p =0.05 was considered significant. One hundred six patients were surgically treated, 88% were female (average age 44 +/- 12 years). Some degree of preoperative anxiety was present in 72 patients (76%; p = 0.001) with a grade point average on the AAPI scale equal to 17 +/- 7 points, of which 95 (70%, OR = 5.08; p = 0.002) were females. Results of this study suggest the presence of high levels of preoperative anxiety in patients scheduled for elective surgery. The origin of the anxiety appears to be related to many factors that can be evaluated in pre-anesthetic consultation. Further study is needed to prevent the presence of this disorder.

  6. Prostate Ultrasound

    Medline Plus

    Full Text Available ... and ultrasound gel placed directly on the skin. High-frequency sound waves are transmitted from the probe through ... during a single exam. The transducer sends out high-frequency sound waves (that the human ear cannot hear) ...

  7. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... and ultrasound gel placed directly on the skin. High-frequency sound waves are transmitted from the probe through ... during a single exam. The transducer sends out high-frequency sound waves (that the human ear cannot hear) ...

  8. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... and Resources RTAnswers.org Radiation Therapy for Gynecologic Cancers Radiation Therapy for Prostate Cancer top of page This page was reviewed on ... with caption Pediatric Content Some imaging tests and treatments have special pediatric ... Images related to Ultrasound - Pelvis Sponsored by Please ...

  9. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... Español More Info Images/Videos About Us News Physician Resources Professions Site Index A-Z Ultrasound - Pelvis ... imaging is a noninvasive medical test that helps physicians diagnose and treat medical conditions. There are three ...

  10. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician ... blood vessels. Ultrasound imaging is a noninvasive medical test that helps physicians diagnose and treat medical conditions. ...

  11. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician ... blood vessels. Ultrasound imaging is a noninvasive medical test that helps physicians diagnose and treat medical conditions. ...

  12. CT and orbital ultrasound findings in a case of Castleman disease.

    Science.gov (United States)

    Brubaker, Jacob W; Harrie, Roger P; Patel, Bhupendra C; Davis, Don K; Mamalis, Nick

    2011-01-01

    A 53-year-old man with a 2-month history of left periorbital swelling was found to have a large solid intraconal mass on CT scan. Orbital ultrasound showed that the lesion had a cavernous pattern of internal reflectivity. Histopathology revealed hyaline-vascular type Castleman disease (CD). This article represents the first reported orbital ultrasound findings in CD. The findings of CT scan and ultrasound may be useful in the preoperative evaluation of orbital hyaline-vascular type CD.

  13. [Design of a preoperative predictive score for choledocholithiasis].

    Science.gov (United States)

    Bueno Lledó, Jose; Ibáñez Cirión, Jose Luis; Torregrosa Gallud, Antonio; López Andújar, Rafael

    2014-11-01

    Choledocholithiasis is the most common cause of obstructive jaundice and occurs in 5-10% of patients with cholelithiasis. To design a preoperative predictive score for choledocholithiasis. A prospective study was carried out in 556 patients admitted to our department for biliary disease. Preoperative clinical, laboratory, and ultrasound variables were compared between patients without choledocholithiasis and 65 patients with this diagnosis. A multivariate logistic analysis was performed to obtain a predictive model of choledocholithiasis, determining sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). Predictors of choledocholithiasis were the presence of a prior history of biliary disease (history of biliary colic, acute cholecystitis, choledocholithiasis or acute biliary pancreatitis) (p=0.021, OR=2.225, 95% CI: 1.130-4.381), total bilirubin values >4mg/dl (p=0.046, OR=2.403, 95% CI: 1.106-5.685), alkaline phosphatase values >150mg/dl (p=0.022 income, OR=2.631, 95%: 1.386-6.231), gamma-glutamyltransferase (GGT) values >100mg/dl (p=0.035, OR=2.10, 95% CI: 1.345-5.850), and an ultrasound finding of biliary duct >8mm (p=0.034, OR=3.063 95% CI: 1086-8649). A score superior to 5 had a specificity and PPV of 100% for detecting choledocholithiasis and a score less than 3 had a sensitivity and NPV of 100% for excluding this diagnosis. The preoperative score can exclude or confirm the presence of choledocholithiasis and allows patients to directly benefit from laparoscopic cholecystectomy (LC) or prior endoscopic retrograde cholangiopancreatography (ERCP). Copyright © 2014 Elsevier España, S.L.U. and AEEH y AEG. All rights reserved.

  14. Ultrasound treatment of centrifugally atomized 316 stainless steel powders

    Science.gov (United States)

    Rawers, James C.; McCune, Robert A.; Dunning, John S.

    1991-12-01

    The Bureau of Mines is studying the surface characteristics of rapidly solidified powders and the potential for surface modification of fine powders prior to consolidation. The surface modification and work hardening of fine powders were accomplished by applying high-energy ultrasound to centrifugally atomized austenitic 316 stainless steel powders suspended in liquid media. Cavitation implosion changed the surface morphology, hammering the surface and occasionally fretting off microchips of work-hardened metal. Ultrasound-cavitation work-hardened metal powder surfaces producing a strained, duplex austenite face-centered cubic (fcc)-martensite body-centered tetragonal (bct) phase structure. The amount of work hardening depended upon the quantity of ultrasound energy used, considering both power level and experimental time. Work hardening was relatively independent of the liquid media used.

  15. Defined presentation of carbohydrates on a duplex DNA scaffold.

    Science.gov (United States)

    Schlegel, Mark K; Hütter, Julia; Eriksson, Magdalena; Lepenies, Bernd; Seeberger, Peter H

    2011-12-16

    A new method for the spatially defined alignment of carbohydrates on a duplex DNA scaffold is presented. The use of an N-hydroxysuccinimide (NHS)-ester phosphoramidite along with carbohydrates containing an alkylamine linker allows for on-column labeling during solid-phase oligonucleotide synthesis. This modification method during solid-phase synthesis only requires the use of minimal amounts of complex carbohydrates. The covalently attached carbohydrates are presented in the major groove of the B-form duplex DNA as potential substrates for murine type II C-type lectin receptors mMGL1 and mMGL2. CD spectroscopy and thermal melting revealed only minimal disturbance of the overall helical structure. Surface plasmon resonance and cellular uptake studies with bone-marrow-derived dendritic cells were used to assess the capability of these carbohydrate-modified duplexes to bind to mMGL receptors.

  16. Sarcomatoid carcinoma of the renal pelvis in duplex kidney

    Institute of Scientific and Technical Information of China (English)

    CHEN Ge-ming; CHEN Shan-wen; XIA Dan; LI Jun; YAN Sheng; JIN Bai-ye

    2011-01-01

    Sarcomatoid transitional cell carcinoma of the renal pelvis is a rare neoplasm with only 14 well-illustrated examples reported previously. Duplex kidney is the most common congenital abnormality of the urinary tract, with an incidence of around 2%. Neoplasia of the renal pelvis in duplex kidney is rare. We reported a case whose sarcomatoid carcinoma originated from the upper portion of the duplicated renal pelvis with hydronephrosis, and total nephroureterectomy with bladder cuff excision surgery of both renal units was carried out. Because of the rare nature of renal pelvic sarcomatoid carcinoma and its apparent lack of response to adjuvant therapy, it is essential to do early diagnosis and early radical surgery to improve survival. It is important to stress the need for frequent and diligent monitoring or treating complex duplex kidney with hydronephrosis of either moiety in case of a risk of having neoplasias.

  17. [Preoperative fasting guidelines: an update].

    Science.gov (United States)

    López Muñoz, A C; Busto Aguirreurreta, N; Tomás Braulio, J

    2015-03-01

    Anesthesiology societies have issued various guidelines on preoperative fasting since 1990, not only to decrease the incidence of lung aspiration and anesthetic morbidity, but also to increase patient comfort prior to anesthesia. Some of these societies have been updating their guidelines, as such that, since 2010, we now have 2 evidence-based preoperative fasting guidelines available. In this article, an attempt is made to review these updated guidelines, as well as the current instructions for more controversial patients such as infants, the obese, and a particular type of ophthalmic surgery. Copyright © 2014 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.

  18. Interventions for preoperative smoking cessation

    DEFF Research Database (Denmark)

    Thomsen, Thordis; Villebro, Nete; Møller, Ann Merete

    2010-01-01

    and keywords (surgery) or (operation) or (anaesthesia) or (anesthesia). MEDLINE, EMBASE and CINAHL were also searched, combining tobacco- and surgery-related terms. Most recent search April 2010. Selection criteria Randomized controlled trials that recruited people who smoked prior to surgery, offered......Background Smokers have a substantially increased risk of postoperative complications. Preoperative smoking intervention may be effective in decreasing this incidence, and surgery may constitute a unique opportunity for smoking cessation interventions. Objectives The objective of this review...... was to assess the effect of preoperative smoking intervention on smoking cessation at the time of surgery and 12 months postoperatively and on the incidence of postoperative complications. Search strategy The specialized register of the Cochrane Tobacco Addiction Group was searched using the free text...

  19. Interventions for preoperative smoking cessation

    DEFF Research Database (Denmark)

    Thomsen, Thordis; Villebro, N.; Møller, Ann Merete;

    2010-01-01

    Background Smokers have a substantially increased risk of postoperative complications. Preoperative smoking intervention may be effective in decreasing this incidence, and surgery may constitute a unique opportunity for smoking cessation interventions. Objectives The objective of this review...... was to assess the effect of preoperative smoking intervention on smoking cessation at the time of surgery and 12 months postoperatively and on the incidence of postoperative complications. Search strategy The specialized register of the Cochrane Tobacco Addiction Group was searched using the free text......; pooled RR 10.76 (95% confidence interval (CI) 4.55 to 25.46, two trials) and RR 1.41 (95% CI 1.22 to 1.63, five trials) respectively. Four trials evaluating the effect on long-term smoking cessation found a significant effect; pooled RR 1.61 (95% CI 1.12 to 2.33). However, when pooling intensive...

  20. Development of duplex-PCR for identification of Aeromonas species

    Directory of Open Access Journals (Sweden)

    Carina Lucena Mendes-Marques

    2013-10-01

    Full Text Available Introduction The number of reports of intestinal infections caused by Aeromonas spp. has increased significantly in recent years. In most clinical laboratories, identification of these bacteria is carried out by general phenotypic tests that sometimes do not accurately differentiate Aeromonas and Vibrio. Methods A duplex-polymerase chain reaction (PCR was developed directed to 2 targets identifying Aeromonas spp. pathogenic to humans. Results The duplex-PCR results were reproducible and specific for Aeromonas spp. pathogenic to humans. Conclusions This method will allow differentiation between Vibrio and Aeromonas spp. in patients with in cholera-like symptoms and can also be used in water quality monitoring.

  1. Comparison of simulated and measured quantities of a duplex reactor

    Energy Technology Data Exchange (ETDEWEB)

    Koskela, M.; Kajava, M. [ABB Marine, Helsinki (Finland)

    1997-12-31

    The purpose of this article is to illustrate the use of an analog simulator as a design tool when designing new power electric equipment. The purpose of simulation is to predict the functionality of electrical equipment to be constructed. Duplex reactor is an electromagnetic device designed to reduce voltage harmonics and short circuit currents in the ship electrical network. In this report a comparison between simulated and measured electrical quantities of a duplex reactor has been made. The purpose of the measurements was to show the correct functioning of the reactor. The simulation results and the measured waveforms corresponds well to each other. (orig.) 4 refs.

  2. Development of duplex-PCR for identification of Aeromonas species

    Directory of Open Access Journals (Sweden)

    Carina Lucena Mendes-Marques

    2013-05-01

    Full Text Available Introduction The number of reports of intestinal infections caused by Aeromonas spp. has increased significantly in recent years. In most clinical laboratories, identification of these bacteria is carried out by general phenotypic tests that sometimes do not accurately differentiate Aeromonas and Vibrio. Methods A duplex-polymerase chain reaction (PCR was developed directed to 2 targets identifying Aeromonas spp. pathogenic to humans. Results The duplex-PCR results were reproducible and specific for Aeromonas spp. pathogenic to humans. Conclusions This method will allow differentiation between Vibrio and Aeromonas spp. in patients with in cholera-like symptoms and can also be used in water quality monitoring.

  3. The Role of Airway and Endobronchial Ultrasound in Perioperative Medicine

    Directory of Open Access Journals (Sweden)

    Jiri Votruba

    2015-01-01

    Full Text Available Recent years have witnessed an increased use of ultrasound in evaluation of the airway and the lower parts of the respiratory system. Ultrasound examination is fast and reliable and can be performed at the bedside and does not carry the risk of exposure to ionizing radiation. Apart from use in diagnostics it may also provide safe guidance for invasive and semi-invasive procedures. Ultrasound examination of the oral cavity structures, epiglottis, vocal cords, and subglottic space may help in the prediction of difficult intubation. Preoperative ultrasound may diagnose vocal cord palsy or deviation or stenosis of the trachea. Ultrasonography can also be used for confirmation of endotracheal tube, double-lumen tube, or laryngeal mask placement. This can be achieved by direct examination of the tube inside the trachea or by indirect methods evaluating lung movements. Postoperative airway ultrasound may reveal laryngeal pathology or subglottic oedema. Conventional ultrasound is a reliable real-time navigational tool for emergency cricothyrotomy or percutaneous dilational tracheostomy. Endobronchial ultrasound is a combination of bronchoscopy and ultrasonography and is used for preoperative examination of lung cancer and solitary pulmonary nodules. The method is also useful for real-time navigated biopsies of such pathological structures.

  4. The Role of Airway and Endobronchial Ultrasound in Perioperative Medicine.

    Science.gov (United States)

    Votruba, Jiri; Zemanová, Petra; Lambert, Lukas; Vesela, Michaela Michalkova

    2015-01-01

    Recent years have witnessed an increased use of ultrasound in evaluation of the airway and the lower parts of the respiratory system. Ultrasound examination is fast and reliable and can be performed at the bedside and does not carry the risk of exposure to ionizing radiation. Apart from use in diagnostics it may also provide safe guidance for invasive and semi-invasive procedures. Ultrasound examination of the oral cavity structures, epiglottis, vocal cords, and subglottic space may help in the prediction of difficult intubation. Preoperative ultrasound may diagnose vocal cord palsy or deviation or stenosis of the trachea. Ultrasonography can also be used for confirmation of endotracheal tube, double-lumen tube, or laryngeal mask placement. This can be achieved by direct examination of the tube inside the trachea or by indirect methods evaluating lung movements. Postoperative airway ultrasound may reveal laryngeal pathology or subglottic oedema. Conventional ultrasound is a reliable real-time navigational tool for emergency cricothyrotomy or percutaneous dilational tracheostomy. Endobronchial ultrasound is a combination of bronchoscopy and ultrasonography and is used for preoperative examination of lung cancer and solitary pulmonary nodules. The method is also useful for real-time navigated biopsies of such pathological structures.

  5. Breaking the Transmitter-Receiver Isolation Barrier in Mobile Handsets with Spatial Duplexing

    DEFF Research Database (Denmark)

    Alrabadi, Osama; Tatomirescu, Alexandru; Knudsen, Mikael;

    2013-01-01

    In full-duplex radio communication systems like eUTRAN, CDMA-2000, the radio transmitter (Tx) is active at the same time as the radio receiver (Rx). The Tx and the Rx will be using separate dedicated frequency bands and the Tx-Rx isolation is ensured by duplex filters. However, agile duplexers req...

  6. On the Potential of Full Duplex Performance in 5G Ultra-Dense Small Cell Networks

    DEFF Research Database (Denmark)

    Gatnau, Marta; Fleischer, Marko; Berardinelli, Gilberto;

    2016-01-01

    Full duplex allows a device to transmit and receive simultaneously in the same frequency band, theoretically doubling the throughput compared to traditional half duplex systems. However, several limitations restrict the promised full duplex gain: non-ideal self-interference cancellation, increase...

  7. Laparoscopy and ultrasound examination in women with acute pelvic pain

    DEFF Research Database (Denmark)

    Mikkelsen, A L; Felding, C

    1990-01-01

    The results of preoperative pelvic examination and eventual ultrasound examination were correlated with the laparoscopic findings in 316 women with acute pelvic pain. The predictive values of normal and abnormal findings at pelvic examination were 46.9 and 82.1%, respectively. 42.1% of the women...... had ultrasound examination performed. This investigation showed to be helpful especially in patients with normal findings at pelvic examination. If ultrasonic findings were abnormal the results at laparoscopy were also abnormal in 90%. On the contrary, normal findings at ultrasound examination did...... not exclude abnormal pelvic findings. The predictive value of normal results at ultrasound examination was 50.0%. This discrepancy between ultrasonic and pelvic findings can be explained by the size of the pelvic masses. Ultrasound examination is a valuable tool in the evaluation of patients with acute pelvic...

  8. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... of page How is the procedure performed? For most ultrasound exams, you will be positioned lying face- ... Ultrasound examinations are painless and easily tolerated by most patients. Ultrasound exams in which the transducer is ...

  9. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... data into 3-D images. A Doppler ultrasound study may be part of an ultrasound examination. Doppler ... usually stain or discolor clothing. In some ultrasound studies, the transducer is attached to a probe and ...

  10. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... flat sections of the body. Advancements in ultrasound technology include three-dimensional (3-D) ultrasound that formats ... object is solid or filled with fluid). In medicine, ultrasound is used to detect changes in appearance, ...

  11. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... ultrasound. top of page How does the procedure work? Ultrasound imaging is based on the same principles ... to-use and less expensive than other imaging methods. Ultrasound imaging is extremely safe and does not ...

  12. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... ultrasound. top of page How does the procedure work? Ultrasound imaging is based on the same principles ... not stain or discolor clothing. In some ultrasound studies, the transducer is attached to a probe and ...

  13. Ultrasound guided supraclavicular block.

    LENUS (Irish Health Repository)

    Hanumanthaiah, Deepak

    2013-09-01

    Ultrasound guided regional anaesthesia is becoming increasingly popular. The supraclavicular block has been transformed by ultrasound guidance into a potentially safe superficial block. We reviewed the techniques of performing supraclavicular block with special focus on ultrasound guidance.

  14. Breast ultrasound.

    Science.gov (United States)

    Ueno, E

    1996-03-01

    In ultrasound, ultrasonic images are formed by means of echoes among tissues with different acoustic impedance. Acoustic impedance is the product of sound speed and bulk modulus. The bulk modulus expresses the elasticity of an object, and in the human body, the value is increased by conditions such as fibrosis and calcification. The sound speed is usually high in elastic tissues and low in water. In the body, it is lowest in the fatty tissue. Ultrasound echoes are strong on the surface of bones which are hard and have a high sound speed. In organs filled with air such as the lungs, the bulk modulus is low and the sound speed is extremely low at 340 m/s, which produce strong echoes (the sound speed in solid tissues is 1,530 m/s). Human tissue is constructed of units smaller than the ultrasonic beam, and it is necessary to understand back-scattering in order to understand the ultrasonic images of these tissues. When ultrasound passes through tissue, it is absorbed as thermal energy and attenuated. Fiber is a tissue with a high absorption and attenuation rate. When the rate increases, the posterior echoes are attenuated. However, in masses with a high water content such as cysts, the posterior echoes are accentuated. This phenomenon is an important, basic finding for determining the properties of tumors. Breast cancer can be classified into two types: stellate carcinoma and circumscribed carcinoma. Since stellate carcinoma is rich in fiber, the posterior echoes are attenuated or lacking. However, circumscribed carcinoma has a high cellularity and the posterior echoes are accentuated. The same tendency is also seen in benign tumors. In immature fibroadenomas, posterior echoes are accentuated, while in fibroadenomas with hyalinosis, the posterior echoes are attenuated. Therefore, if the fundamentals of this tissue characterization and the histological features are understood, reading of ultrasound becomes easy. Color Doppler has also been developed and has contributed

  15. Ultrasound of the Thyroid Gland

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z Ultrasound - Thyroid Thyroid ultrasound uses sound waves to produce ... of Ultrasound of the Thyroid? What is an Ultrasound of the Thyroid? Ultrasound is safe and painless, ...

  16. Do psychological interventions reduce preoperative anxiety?

    Science.gov (United States)

    Renouf, Tessa; Leary, Alison; Wiseman, Theresa

    The systematic review investigates whether, during preoperative assessments, nurse-delivered psychological interventions reduce anxiety levels preoperatively for patients undergoing elective surgery. Seventeen studies met the inclusion criteria for data extraction and in-depth critiquing. Of these, two were discarded due to lack of validity, while the remaining studies were organised thematically in a narrative synthesis, generating two principal results: patients' preoperative anxieties were lowered by nurse-delivered general preoperative psychological interventions; and patients valued individualised preoperative interventions delivered by nurses. However, the single oncology study in the review showed an elevation in preoperative anxiety, regardless of intervention, and highlights the need for more research in this under-reviewed area. In the meantime, the authors believe that service improvements should be implemented to ensure that, where possible, psychological preoperative interventions are individualised.

  17. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... through blood vessels. Ultrasound imaging is a noninvasive medical test that helps physicians diagnose and treat medical conditions. Conventional ultrasound displays the images in thin, ...

  18. Effect of Radiofrequency Radiation on DNA Duplex Stability and Replication.

    Science.gov (United States)

    1983-08-01

    R.W., J.B. Dodgson, I.F. Nes, and R.D. Wells. Duplex regions in single-stranded OX174 DNA are cleaved by a restriction endonuclease from Haemophilus ... aegyptius . J Biol Chem 252:7300-7306 (1977). *i Brown, R.F., S.V. Marshall, and C.W. Hughes. Effect of radiofrequency radi- ation (RFR) on excision

  19. Analysis of full-duplex relay networks with opportunistic scheduling

    Directory of Open Access Journals (Sweden)

    Lei Shao

    2015-05-01

    Full Text Available This Letter addresses a two-hop decode-and-forward relay system with full-duplex relaying and opportunistic scheduling. Exact expressions for outage probability, average capacity and symbol error rate are presented in an independent identically distributed Rayleigh fading environment. Numerical and simulated results show the validity of the analytical results.

  20. Reliability Capacity of Half-Duplex Channels with Strict Deadlines

    DEFF Research Database (Denmark)

    Costa, Rui; Roetter, Daniel Enrique Lucani; Vinhoza, Tiago

    2015-01-01

    A fundamental characterization of a half-duplex wireless system with packet losses under traffic with hard deadlines is instrumental to understanding and developing efficient, coding aware policies for real-time applications. We set forth the concept of reliability capacity with a limited number...

  1. Full-duplex wireless communications systems self-interference cancellation

    CERN Document Server

    Le-Ngoc, Tho

    2017-01-01

    This book introduces the development of self-interference (SI)-cancellation techniques for full-duplex wireless communication systems. The authors rely on estimation theory and signal processing to develop SI-cancellation algorithms by generating an estimate of the received SI and subtracting it from the received signal. The authors also cover two new SI-cancellation methods using the new concept of active signal injection (ASI) for full-duplex MIMO-OFDM systems. The ASI approach adds an appropriate cancelling signal to each transmitted signal such that the combined signals from transmit antennas attenuate the SI at the receive antennas. The authors illustrate that the SI-pre-cancelling signal does not affect the data-bearing signal. This book is for researchers and professionals working in wireless communications and engineers willing to understand the challenges of deploying full-duplex and practical solutions to implement a full-duplex system. Advanced-level students in electrical engineering and computer ...

  2. Capacity of the Degraded Half-Duplex Relay Channel

    CERN Document Server

    Vijayakumaran, Saravanan; Lok, Tat M

    2007-01-01

    A discrete memoryless half-duplex relay channel is constructed from a broadcast channel from the source to the relay and destination and a multiple access channel from the source and relay to the destination. When the relay listens, the channel operates in the broadcast mode. The channel switches to the multiple access mode when the relay transmits. If the broadcast component channel is physically degraded, the half-duplex relay channel will also be referred to as physically degraded. The capacity of this degraded half-duplex relay channel is examined. It is shown that the block Markov coding suggested in the seminal paper by Cover and El Gamal can be modified to achieve capacity for the degraded half-duplex relay channel. In the code construction, the listen-transmit schedule of the relay is made to depend on the message to be sent and hence the schedule carries information itself. If the schedule is restricted to be deterministic, it is shown that the capacity can be achieved by a simple management of infor...

  3. Full-duplex MIMO system based on antenna cancellation technique

    DEFF Research Database (Denmark)

    Foroozanfard, Ehsan; Franek, Ondrej; Tatomirescu, Alexandru

    2014-01-01

    The performance of an antenna cancellation technique for a multiple-input– multiple-output (MIMO) full-duplex system that is based on null-steering beamforming and antenna polarization diversity is investigated. A practical implementation of a symmetric antenna topology comprising three dual-pola...

  4. Micromechanics of base pair unzipping in the DNA duplex.

    Science.gov (United States)

    Volkov, Sergey N; Paramonova, Ekaterina V; Yakubovich, Alexander V; Solov'yov, Andrey V

    2012-01-25

    All-atom molecular dynamics (MD) simulations of DNA duplex unzipping in a water environment were performed. The investigated DNA double helix consists of a Drew-Dickerson dodecamer sequence and a hairpin (AAG) attached to the end of the double-helix chain. The considered system is used to examine the process of DNA strand separation under the action of an external force. This process occurs in vivo and now is being intensively investigated in experiments with single molecules. The DNA dodecamer duplex is consequently unzipped pair by pair by means of the steered MD. The unzipping trajectories turn out to be similar for the duplex parts with G·C content and rather distinct for the parts with A·T content. It is shown that during the unzipping each pair experiences two types of motion: relatively quick rotation together with all the duplex and slower motion in the frame of the unzipping fork. In the course of opening, the complementary pair passes through several distinct states: (i) the closed state in the double helix, (ii) the metastable preopened state in the unzipping fork and (iii) the unbound state. The performed simulations show that water molecules participate in the stabilization of the metastable states of the preopened base pairs in the DNA unzipping fork.

  5. Increased Y-chromosome detection by SRY duplexing

    DEFF Research Database (Denmark)

    Hansen, Morten Høgh; Clausen, Frederik Banch; Dziegiel, Morten Hanefeld

    2012-01-01

    Determining fetal sex noninvasively is dependent of a robust assay. We designed a novel SRY assay and combined it with a SRY assay from literature forming a duplex assay with the same fluorescent dye to increase detection of Y-chromosome at low cell-free fetal DNA or chimeric DNA concentrations....

  6. A nomogram to predict the probability of axillary lymph node metastasis in early breast cancer patients with positive axillary ultrasound

    NARCIS (Netherlands)

    Qiu, Si-Qi; Zeng, Huan-Cheng; Zhang, Fan; Chen, Cong; Huang, Wen-He; Pleijhuis, Rick G.; Wu, Jun-Dong; van Dam, Gooitzen M.; Zhang, Guo-Jun

    2016-01-01

    Among patients with a preoperative positive axillary ultrasound, around 40% of them are pathologically proved to be free from axillary lymph node (ALN) metastasis. We aimed to develop and validate a model to predict the probability of ALN metastasis as a preoperative tool to support clinical

  7. Free energy estimation of short DNA duplex hybridizations

    Directory of Open Access Journals (Sweden)

    Leger Serge

    2010-02-01

    Full Text Available Abstract Background Estimation of DNA duplex hybridization free energy is widely used for predicting cross-hybridizations in DNA computing and microarray experiments. A number of software programs based on different methods and parametrizations are available for the theoretical estimation of duplex free energies. However, significant differences in free energy values are sometimes observed among estimations obtained with various methods, thus being difficult to decide what value is the accurate one. Results We present in this study a quantitative comparison of the similarities and differences among four published DNA/DNA duplex free energy calculation methods and an extended Nearest-Neighbour Model for perfect matches based on triplet interactions. The comparison was performed on a benchmark data set with 695 pairs of short oligos that we collected and manually curated from 29 publications. Sequence lengths range from 4 to 30 nucleotides and span a large GC-content percentage range. For perfect matches, we propose an extension of the Nearest-Neighbour Model that matches or exceeds the performance of the existing ones, both in terms of correlations and root mean squared errors. The proposed model was trained on experimental data with temperature, sodium and sequence concentration characteristics that span a wide range of values, thus conferring the model a higher power of generalization when used for free energy estimations of DNA duplexes under non-standard experimental conditions. Conclusions Based on our preliminary results, we conclude that no statistically significant differences exist among free energy approximations obtained with 4 publicly available and widely used programs, when benchmarked against a collection of 695 pairs of short oligos collected and curated by the authors of this work based on 29 publications. The extended Nearest-Neighbour Model based on triplet interactions presented in this work is capable of performing accurate

  8. Preoperative localization in primary hyperparathyroidism

    Energy Technology Data Exchange (ETDEWEB)

    Han, Sanson; Kitamura, Hiroyuki; Takagita, Shin-ichi; Maetani, Toshiki; Iwahashi, Yuka; Miyazaki, Masakazu; Yamamoto, Norio [Tenri Hospital, Nara (Japan)

    1998-04-01

    Between 1992 and 1996, 31 cases (8 men and 23 women) with primary hyperparathyroidism (PHPT) were treated in our department. In this study, we compared which of the preoperative localization methods was most useful in the detection of PHPT. The sensitivity for detection of abnormal parathyroid glands was 88.6% on ultrasonography (US), 76.9% on magnetic resonance imaging (MRI), 74.3% on Tl-Tc subtraction scintigraphy and 68.8% on computed tomography. We concluded that US should be performed first, with MRI as a supplementary method, for the detection of abnormal parathyroid glands and the evaluation of invasion within the body. (author)

  9. Preoperative Evaluation for Noncardiac Surgery.

    Science.gov (United States)

    Cohn, Steven L

    2016-12-06

    This issue provides a clinical overview of preoperative evaluation for noncardiac surgery, focusing on risk factors, elements of evaluation, medication management, and practice improvement. The content of In the Clinic is drawn from the clinical information and education resources of the American College of Physicians (ACP), including MKSAP (Medical Knowledge and Self-Assessment Program). Annals of Internal Medicine editors develop In the Clinic in collaboration with the ACP's Medical Education and Publishing divisions and with the assistance of additional science writers and physician writers.

  10. Clinical Utility of Endoscopic Ultrasound in Solid Pancreatic Mass Lesions Deemed Resectable by Computer Tomography

    Directory of Open Access Journals (Sweden)

    Mark A Virtue

    2008-03-01

    Full Text Available Context Appropriate surgical exploration and resection of pancreatic carcinoma depends on accurate preoperative evaluation. Objective Determine the accuracy of endoscopic ultrasound in predicting the need for surgical exploration in patients with solid pancreatic masses deemed by computer tomography to be resectable without venous grafting (absence of distant metastatic disease or major vascular involvement. Patients All patients between March 2000 and November 2003 with focal pancreatic mass lesions deemed to be surgically resectable by computer tomography. Fortynine patients participated (29 males, 20 females; age range: 40-86 years. Intervention Preoperative linear-array endoscopic ultrasound. Main outcome measure Surgical pathology compared to computer tomography and endoscopic ultrasound results. Results Out of the 49 patients, 33 (67.3% had pancreatic neoplasms and 16 (32.7% had chronic pancreatitis. Endoscopic ultrasound correctly diagnosed all 16 patients with chronic pancreatitis. Endoscopic ultrasound correctly identified 18 (54.5% of those with neoplasms as having unresectable disease while 6 (18.2% patients were appropriately identified as resectable by endoscopic ultrasound. The remaining 9 patients (27.3% were deemed resectable by endoscopic ultrasound, but were unresectable at the time of surgery. None of the patients were falsely designated as unresectable by endoscopic ultrasound. Conclusion Endoscopic ultrasound is an important compliment to computed tomography in predicting resectability and in avoiding nontherapeutic laparotomy of solid pancreatic neoplasms. Moreover, endoscopic ultrasound classification did not discourage surgery of resectable pancreatic masses.

  11. DMT of Multi-hop Cooperative Networks - Part II: Half-Duplex Networks with Full-Duplex Performance

    CERN Document Server

    Sreeram, K; Kumar, P Vijay

    2008-01-01

    We consider single-source single-sink (ss-ss) multi-hop relay networks, with slow-fading links and single-antenna half-duplex relay nodes. In a companion paper, we established some basic results which laid the foundation for the results presented here. In the present paper, we consider two families of networks of half-duplex networks. KPP networks may be viewed as the union of K node-disjoint parallel relaying paths. Generalizations of these networks include KPP(I) networks, which permit interference between paths and KPP(D) networks, which possess a direct link between source and sink. We characterize the DMT of these families of networks completely and show that they can achieve the cut-set bound, thus proving that full-duplex performance can be obtained even in the presence of the half-duplex constraint. We then consider layered networks, and prove that a linear DMT between maximum diversity and maximum multiplexing gain is achievable. All protocols in this paper are explicit and use only amplify-and-forwa...

  12. Preoperative fasting time in children.

    LENUS (Irish Health Repository)

    Adeel, S

    2012-02-01

    The aim of preoperative fasting is to prevent regurgitation and pulmonary aspiration while limiting potential problems of thirst, dehydration and hypoglycaemia. The American Society of Anaesthesiologists (ASA) has suggested guidelines for preoperative fasting for children undergoing elective surgery. We did a postal survey to determine the current practice regarding these guidelines amongst all specialist registrars in anaesthesia in Ireland. A questionnaire was sent to all specialist registrars in anaesthesia (90 in total), 60 (67%) were returned and analysed. The question asked was how long children should be kept fasting before elective surgery. The results of our survey suggest that most of the respondents are following the ASA guidelines for clear fluids and solids however there were differing opinion regarding the duration of fasting for formula milk and breast milk. In conclusion, we would recommend greater awareness and collaboration between anaesthetists, nurses and surgeons to ensure that fasting instructions are consistent with the ASA guidelines and that patient and their parents understand these directives as well.

  13. The increasing role of duplex scanning in the follow-up after endovascular repair of abdominal aortic aneurysms

    Directory of Open Access Journals (Sweden)

    Pulli R

    2014-04-01

    Full Text Available Raffaele Pulli, Walter Dorigo, Leonidas Azas, Stefano Matticari, Aaron Fargion, Carlo PratesiDepartment of Vascular Surgery, University of Florence, Florence, ItalyAim: To analyze the results of a follow-up program after endovascular repair of abdominal aortic aneurysm (EVAR mainly based on duplex ultrasound (DUS examinations.Materials and methods: The postoperative surveillance program changed over the time. In recent years (2007-2012 we are used to performing a DUS and an angio-CT scan within one month after EVAR, a DUS at 6 and 12 months and every 6 months thereafter (Group 2, 498 interventions. Data were compared with our historical series (2000-2006; Group 1, 345 interventions. Perioperative results were recorded. The long-term results were analysed by Kaplan-Meier curves.Results: The rates of perioperative mortality were 1.1% and 1.2% respectively (P=0.9. The cumulative rates of perioperative complications were 16% and 6.5%, respectively (P=0.001. The rate of reinterventions at 60 months was significantly higher in group 2 than in group 1 (29.1% and 20.1% respectively, P=0.03, log rank 4.6. Also the 5-year rate of endoleak was significantly greater in group 2 than group 1 (43.3% and 34.5% respectively, P<0.001, log rank 13.4; however, the rate of endoleaks requiring a redo procedure was lower in group 2 (35/163, 21.5% than in group 1 (51/108, 47%; P<0.001.Conclusion: Data from our study confirm that a DUS-based follow-up program in patients undergoing EVAR is equally sensitive in identifying endoleaks to the CT scan-based program used in past years.Keywords: duplex ultrasound, contrast-enhanced, endovascular aneurysm repair

  14. Blood velocity estimation using ultrasound and spectral iterative adaptive approaches

    DEFF Research Database (Denmark)

    Gudmundson, Erik; Jakobsson, Andreas; Jensen, Jørgen Arendt;

    2011-01-01

    This paper proposes two novel iterative data-adaptive spectral estimation techniques for blood velocity estimation using medical ultrasound scanners. The techniques make no assumption on the sampling pattern of the emissions or the depth samples, allowing for duplex mode transmissions where B......-mode images are interleaved with the Doppler emissions. Furthermore, the techniques are shown, using both simplified and more realistic Field II simulations as well as in vivo data, to outperform current state-of-the-art techniques, allowing for accurate estimation of the blood velocity spectrum using only 30...

  15. Endoanal ultrasound in perianal fistulae and abscesses.

    Science.gov (United States)

    Visscher, Arjan Paul; Felt-Bersma, Richelle J F

    2015-06-01

    Endoanal ultrasound is a technique that provides imaging of the anal sphincters and its surrounding structures as well as the pelvic floor. However, endoanal magnetic resonance imaging (MRI) is preferred by most physicians, although costs are higher and demand easily outgrows availability. Endoanal ultrasound is an accurate imaging modality delineating anatomy of both cryptoglandular as well as Crohn perianal fistula and abscess. Endoanal ultrasound is comparable with examination under anesthesia and equally sensitive as endoanal MRI in fistula detection. When fistula tracts or abscesses are located above the puborectal muscle, an additional endoanal MRI should be performed. Preoperative imaging is advocated in recurrent cryptoglandular fistula because a more complex pattern can be expected. Endoanal ultrasound can help avoid missing tracts during surgery, lowering the chance for the fistula to persist or recur. It can easily be performed in an outpatient setting and endosonographic skills are quickly incremented. Costs are low and endoanal ultrasound has the potential to improve outcome of patients with both cryptoglandular and fistulizing Crohn disease; therefore, it values more attention.

  16. Full-Duplex Communications in Large-Scale Cellular Networks

    KAUST Repository

    AlAmmouri, Ahmad

    2016-04-01

    In-band full-duplex (FD) communications have been optimistically promoted to improve the spectrum utilization and efficiency. However, the penetration of FD communications to the cellular networks domain is challenging due to the imposed uplink/downlink interference. This thesis presents a tractable framework, based on stochastic geometry, to study FD communications in multi-tier cellular networks. Particularly, we assess the FD communications effect on the network performance and quantify the associated gains. The study proves the vulnerability of the uplink to the downlink interference and shows that the improved FD rate gains harvested in the downlink (up to 97%) comes at the expense of a significant degradation in the uplink rate (up to 94%). Therefore, we propose a novel fine-grained duplexing scheme, denoted as α-duplex scheme, which allows a partial overlap between the uplink and the downlink frequency bands. We derive the required conditions to harvest rate gains from the α-duplex scheme and show its superiority to both the FD and half-duplex (HD) schemes. In particular, we show that the α-duplex scheme provides a simultaneous improvement of 28% for the downlink rate and 56% for the uplink rate. We also show that the amount of the overlap can be optimized based on the network design objective. Moreover, backward compatibility is an essential ingredient for the success of new technologies. In the context of in-band FD communication, FD base stations (BSs) should support HD users\\' equipment (UEs) without sacrificing the foreseen FD gains. The results show that FD-UEs are not necessarily required to harvest rate gains from FD-BSs. In particular, the results show that adding FD-UEs to FD-BSs offers a maximum of 5% rate gain over FD-BSs and HD-UEs case, which is a marginal gain compared to the burden required to implement FD transceivers at the UEs\\' side. To this end, we shed light on practical scenarios where HD-UEs operation with FD-BSs outperforms the

  17. Preoperative information management system using wireless PDAs.

    Science.gov (United States)

    Sawa, Tomohiro; Okahara, Masaharu; Santo, Masayuki; Schmidt, Ulrich; Nakata, Yoshinori; Morita, Shigeho; Ohno-Machado, Lucila

    2003-01-01

    Personal Digital Assistant (PDA) and wireless communication are currently available in clinical settings. We developed wireless PDA software that assists anesthesiologists in pre-operative patient assessment. The device communicates with the hospital information system through a wireless LAN and is equipped with pre-programmed data entry templates for pre-operative assessment. As a preliminary test of the device, we randomly assigned residents in preoperative assessment to an intervention and a control arm and compared the results.

  18. Ultrasound in Space Medicine

    Science.gov (United States)

    Dulchavsky, Scott A.; Sargsyan, A.E.

    2009-01-01

    This slide presentation reviews the use of ultrasound as a diagnostic tool in microgravity environments. The goals of research in ultrasound usage in space environments are: (1) Determine accuracy of ultrasound in novel clinical conditions. (2) Determine optimal training methodologies, (3) Determine microgravity associated changes and (4) Develop intuitive ultrasound catalog to enhance autonomous medical care. Also uses of Ultrasound technology in terrestrial applications are reviewed.

  19. A motorized ultrasound system for MRI-ultrasound fusion guided prostatectomy

    Science.gov (United States)

    Seifabadi, Reza; Xu, Sheng; Pinto, Peter; Wood, Bradford J.

    2016-03-01

    Purpose: This study presents MoTRUS, a motorized transrectal ultrasound system, to enable remote navigation of a transrectal ultrasound (TRUS) probe during da Vinci assisted prostatectomy. MoTRUS not only provides a stable platform to the ultrasound probe, but also allows the physician to navigate it remotely while sitting on the da Vinci console. This study also presents phantom feasibility study with the goal being intraoperative MRI-US image fusion capability to bring preoperative MR images to the operating room for the best visualization of the gland, boundaries, nerves, etc. Method: A two degree-of-freedom probe holder is developed to insert and rotate a bi-plane transrectal ultrasound transducer. A custom joystick is made to enable remote navigation of MoTRUS. Safety features have been considered to avoid inadvertent risks (if any) to the patient. Custom design software has been developed to fuse pre-operative MR images to intraoperative ultrasound images acquired by MoTRUS. Results: Remote TRUS probe navigation was evaluated on a patient after taking required consents during prostatectomy using MoTRUS. It took 10 min to setup the system in OR. MoTRUS provided similar capability in addition to remote navigation and stable imaging. No complications were observed. Image fusion was evaluated on a commercial prostate phantom. Electromagnetic tracking was used for the fusion. Conclusions: Motorized navigation of the TRUS probe during prostatectomy is safe and feasible. Remote navigation provides physician with a more precise and easier control of the ultrasound image while removing the burden of manual manipulation of the probe. Image fusion improved visualization of the prostate and boundaries in a phantom study.

  20. The role of contrast-enhanced ultrasound in risk assessment of carotid atheroma

    Directory of Open Access Journals (Sweden)

    Silviu Stanciu

    2016-07-01

    Full Text Available Background and objective: Contrast-enhanced ultrasound, used to assess atherosclerotic carotid plaques, improves visualization of vessel wall irregularities and depicts intraplaque neovascularization. This article illustrates the use of contrast-enhanced ultrasound in the risk assessment of carotid atherosclerotic lesions, especially in challenging plaques evaluation. Materials and methods: For 23 patients with difficult duplex ultrasound examination due to carotid tortuosity or calcifications we assessed plaque morphology (contour, echogenicity and stenosis degree using contrast substance (Sonovue, Braco with dedicated vascular low mechanical index CPC software. Conclusion: Contrast-enhanced ultrasound is a new, noninvasive, and safe procedure for imaging carotid atherosclerotic lesions. It is a valuable tool for evaluating the vulnerable plaque at risk for rupture and for the diagnostic of the development and severity of systemic atherosclerotic disease

  1. Preoperative management of children with esophageal atresia: current perspectives

    Directory of Open Access Journals (Sweden)

    Parolini F

    2017-01-01

    Full Text Available Filippo Parolini,1 Anna Lavinia Bulotta,1 Sonia Battaglia,1 Daniele Alberti1,2 1Department of Pediatric Surgery, “Spedali Civili” Children’s Hospital, 2Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy Abstract: Esophageal atresia remains one of the most challenging congenital anomalies of the newborn. In recent years, because of the advances in prenatal diagnosis, neonatal critical care, and surgical procedures, overall outcomes have improved substantially, including for premature children. Nowadays, most of the research is focused on medium- and long-term morbidity, with particular reference to respiratory and gastroesophageal problems; the high frequency of late sequelae in esophageal atresia warrants regular and multidisciplinary checkups throughout adulthood. Surprisingly, there are few studies on the impact of prenatal diagnosis and there is continuing debate over the prenatal and preoperative management of these complex patients. In this review, we analyze the literature surrounding current knowledge on the management of newborns affected by esophageal atresia, focusing on prenatal management and preoperative assessment. Keywords: prenatal diagnosis, esophageal atresia, tracheoesophageal fistula, ultrasound scan, tracheobronchoscopy

  2. Comments on process of duplex coatings on aluminum alloys

    Institute of Scientific and Technical Information of China (English)

    Samir H.A.; QIAN Han-cheng(钱翰城); XIA Bo-cai(夏伯才); WU Shi-ming(吴仕明)

    2004-01-01

    Despite the great achievements made in improvement of wear resistance properties of aluminum alloys,their applications in heavy surface load-bearing are limited. Single coating is insufficient to produce the desired combination of surface properties. These problems can be solved through the duplex coatings. The aim of the present study is to overview the research advances on processes of duplex coatings on aluminum alloys combined with micro plasma oxidation process and with other modern processes such as physical vapour deposition and plasma assisted chemical vapour deposition and also to evaluate the performance of micro plasma oxidation coatings in improving the load-bearing, friction and wear resistance properties of aluminum alloys in comparison with other coatings. Wherein, a more detailed presentation of the processes and their performances and disadvantages are given as well.

  3. Herpes Zoster Duplex Unilateralis: Two Cases and Brief Literature Review

    Science.gov (United States)

    Son, Jee Hee; Chung, Bo Young; Kim, Hye One; Cho, Hee Jin

    2016-01-01

    Cases involving dermatomal herpes zoster in two or more locations are rare, especially in immunocompetent patients. When two noncontiguous dermatomes are involved, if affected unilaterally, it is called herpes zoster duplex unilateralis; if bilaterally, bilateralis. Here, we report two cases of herpes zoster duplex unilateralis. A 66-year-old man presented with painful erythematous grouped vesicles on his left scalp, forehead, trunk, and back (left [Lt.] V1, Lt. T8). Histologic findings were consistent with herpetic infection. A 33-year-old woman presented with painful erythematous grouped vesicles and crust on her left forehead and neck (Lt. V1, Lt. C5). Both patients were treated with oral administration of famcyclovir 750 mg/day for seven days. PMID:27904277

  4. Listen and talk full-duplex cognitive radio networks

    CERN Document Server

    Liao, Yun; Han, Zhu

    2016-01-01

    This brief focuses on the use of full-duplex radio in cognitive radio networks, presenting a novel spectrum sharing protocol that allows the secondary users to simultaneously sense and access the vacant spectrum. This protocol, called “Listen-and-talk” (LAT), is evaluated by both mathematical analysis and computer simulations in comparison with other existing protocols, including the listen-before-talk protocol. In addition to LAT-based signal processing and resource allocation, the brief discusses techniques such as spectrum sensing and dynamic spectrum access. The brief proposes LAT as a suitable access scheme for cognitive radio networks, which can support the quality-of-service requirements of these high priority applications. Fundamental theories and key techniques of cognitive radio networks are also covered. Listen and Talk: Full-duplex Cognitive Radio Networks is designed for researchers, developers, and professionals involved in cognitive radio networks. Advanced-level students studying signal pr...

  5. Smectic phase in suspensions of gapped DNA duplexes

    Science.gov (United States)

    Salamonczyk, Miroslaw; Zhang, Jing; Portale, Giuseppe; Zhu, Chenhui; Kentzinger, Emmanuel; Gleeson, James T.; Jakli, Antal; de Michele, Cristiano; Dhont, Jan K. G.; Sprunt, Samuel; Stiakakis, Emmanuel

    2016-11-01

    Smectic ordering in aqueous solutions of monodisperse stiff double-stranded DNA fragments is known not to occur, despite the fact that these systems exhibit both chiral nematic and columnar mesophases. Here, we show, unambiguously, that a smectic-A type of phase is formed by increasing the DNA's flexibility through the introduction of an unpaired single-stranded DNA spacer in the middle of each duplex. This is unusual for a lyotropic system, where flexibility typically destabilizes the smectic phase. We also report on simulations suggesting that the gapped duplexes (resembling chain-sticks) attain a folded conformation in the smectic layers, and argue that this layer structure, which we designate as smectic-fA phase, is thermodynamically stabilized by both entropic and energetic contributions to the system's free energy. Our results demonstrate that DNA as a building block offers an exquisitely tunable means to engineer a potentially rich assortment of lyotropic liquid crystals.

  6. Conserved guanine-guanine stacking in tetraplex and duplex DNA.

    Science.gov (United States)

    Kypr, J; Fialová, M; Chládková, J; Tůmová, M; Vorlícková, M

    2001-12-01

    Using a series of suitably chosen oligonucleotides, we demonstrate that the DNA duplex of d(CCCCGGGG) provides an almost identical CD spectrum as the parallel-stranded tetraplex of d(GGGG). The CD spectra are very sensitive to base stacking in DNA so that the above observation indicates that guanine-guanine stacking is essentially the same within the duplex of d(CCCCGGGG) and the tetraplex of d(GGGG). A very similar CD spectrum is also provided by the A-form of d(CCCCGGGG) induced by trifluoroethanol. These results reveal that guanine-guanine stacking is a structural invariant conserved in various nucleic acid conformers. The structural invariance is likely to cohere with evolution of the genetic molecules and be important for fundamental functions, e.g. initiation of transcription.

  7. A 2-order MIMO Full-Duplex Antenna System

    DEFF Research Database (Denmark)

    Tsakalaki, Elpiniki; Foroozanfard, Ehsan; De Carvalho, Elisabeth

    2014-01-01

    The paper presents an antenna system with combined full-duplex and 2-order multiple-input-multiple-output (MIMO) functionalities, i.e., a system capable of spatially multiplexing and spatially demultiplexing 2 datastreams in the same frequency and in the same time. By exploiting symmetries....... On the other hand, the 2 MIMO ports (either at the Tx or at the Rx) are sufficiently decoupled thanks to polarization diversity. The proposed antenna system exhibits a remarkable level of fullduplex isolation over a wide bandwidth while maintaining low coupling between its MIMO ports and can serve...... as a concrete implementation of an antenna system equipped with both MIMO as well as full-duplex capabilities....

  8. Opto-acoustic breast imaging with co-registered ultrasound

    Science.gov (United States)

    Zalev, Jason; Clingman, Bryan; Herzog, Don; Miller, Tom; Stavros, A. Thomas; Oraevsky, Alexander; Kist, Kenneth; Dornbluth, N. Carol; Otto, Pamela

    2014-03-01

    We present results from a recent study involving the ImagioTM breast imaging system, which produces fused real-time two-dimensional color-coded opto-acoustic (OA) images that are co-registered and temporally inter- leaved with real-time gray scale ultrasound using a specialized duplex handheld probe. The use of dual optical wavelengths provides functional blood map images of breast tissue and tumors displayed with high contrast based on total hemoglobin and oxygen saturation of the blood. This provides functional diagnostic information pertaining to tumor metabolism. OA also shows morphologic information about tumor neo-vascularity that is complementary to the morphological information obtained with conventional gray scale ultrasound. This fusion technology conveniently enables real-time analysis of the functional opto-acoustic features of lesions detected by readers familiar with anatomical gray scale ultrasound. We demonstrate co-registered opto-acoustic and ultrasonic images of malignant and benign tumors from a recent clinical study that provide new insight into the function of tumors in-vivo. Results from the Feasibility Study show preliminary evidence that the technology may have the capability to improve characterization of benign and malignant breast masses over conventional diagnostic breast ultrasound alone and to improve overall accuracy of breast mass diagnosis. In particular, OA improved speci city over that of conventional diagnostic ultrasound, which could potentially reduce the number of negative biopsies performed without missing cancers.

  9. Effect of heat treatment on corrosion behavior of duplex coatings

    Directory of Open Access Journals (Sweden)

    K. Raghu Ram Mohan Reddy

    2017-01-01

    Full Text Available In the present paper, duplex WC-Co/NiCrAlY coating is coated onto Ti6Al4V substrate and vacuum heat treatment is employed to investigate the corrosion behavior of heat treated samples as well as Ti6Al4V substrate for comparison. In this duplex coating system, High Velocity Oxy Fuel (HVOF process is used to deposit NiCrAlY interlayer with a constant thickness of 200 μm and WC-Co ceramic top layer with varying thickness of 250 μm, 350 μm and 450 μm deposited by Detonation Spray (DS process. Different heat treatment temperatures (600–1150 °C were employed for the coated samples to study the microstructure and the effect on corrosion resistance of the duplex coatings. Potentiodynamic polarization tests were carried to investigate the corrosion performance of duplex coated heat treated samples and the substrate in Ringer’s solution at 37 °C and prepared the pH to 5.7. The microstructure upon corrosion after heat treatment was characterized by SEM analysis to understand the corrosion behavior. The results disclosed that at all heat treatment temperatures, all the coated samples exhibited better corrosion resistance than the base substrate. However, during 950 °C and 1150 °C heat treatment temperatures, it was observed highest corrosion potential than 600 °C and 800 °C. The 350 μm thickness, coated sample exhibited highest corrosion resistance compared to other two coated samples and the substrate at all heat treatment temperatures.

  10. Evolution of microstresses in plastically deformed duplex steel

    Energy Technology Data Exchange (ETDEWEB)

    Baczmanski, A.; Wierzbanowski, K. [Akademia Gorniczo-Hutnicza, Krakow (Poland). WFTJ; Braham, C. [LMMM, URA-CNRS 1219, Ecole Nationale Superieure d' Arts et Metiers, Paris (France); Lodini, A. [IFTS, Univ. de Reims Charleville-Mezieres (France)

    2000-07-01

    The X-ray diffraction method has been applied to determine the internal stresses in two phases austeno-ferritic steel during uniaxial tensile test. The elasto-plastic deformation model was used to predict internal stresses and critical resolved shear stress for the both phases. The model calculations were successfully compared with the information obtained from the shift and broadening of diffraction peak. Finally, the parameters characterising elasto-plastic deformation for duplex steel were determined. (orig.)

  11. Tensile properties of duplex UNS S32205 and lean duplex UNS S32304 steels and the influence of short duration 475 ºC aging

    Directory of Open Access Journals (Sweden)

    Sérgio Souto Maior Tavares

    2012-12-01

    Full Text Available Duplex stainless steels are high strength and corrosion resistant steels extensively used in the petrochemical and chemical industries. The aging at 475 ºC for long periods of time provokes embrittlement and deterioration of corrosion resistance. However, short duration aging at 475 ºC may be used as heat treatment to improve mechanical resistance with small decrease in the other properties. In this work the flow stress curves of lean duplex UNS S32304 and duplex UNS S32205 steels were modeled with Hollomon's equation and work hardening exponents (n were determined. The analyses were conducted in specimens annealed and heat treated at 475 ºC for short periods of time. The aging at 475 ºC for 4 hours, 8 hours and 12 hours promoted significant hardening with small decrease of ductility. The work hardening exponents of both steels were compared, being higher in the duplex steel than in the lean duplex grade.

  12. Role of ultrasound in the perioperative evaluation of percutaneous transhepatic biliary drainage

    Institute of Scientific and Technical Information of China (English)

    Chuan Fu; Si-Ze Wu; Guang-Qing Liu; Tian-Lun Fan; You-Ke Chen

    2015-01-01

    Objective:To explore the evaluation and application of the color doppler ultrasound imaging for percutaneous transhepatic biliary drainage (PTBD) in the treatment of obstructive jaundice of preoperative, intraoperative and postoperative.Methods: The related information of 133 patients prepared with PTBD in our hospital from January 2009 to January 2015 was analyzed retrospectively. Including the clinical manifestation of PTBD preoperative, intraoperative and postoperative, laboratory examination, color Doppler ultrasound imaging, CT and/or MR imaging, X-ray and ultrasound guided interventional therapy, surgical treatment, histopathologic analysis record, the evaluation analysis of the role of ultrasound in the perioperative PTBD.Result:In 133 patients prepare with PTBD, preoperative evaluation for ultrasound guided PTBD 105 cases (78.94%, 105/133), finally complete the ultrasound guided PTBD 56 cases, with smoothly and one-time 100% success rate. Postoperative patients with jaundice and skin itching rate significantly reduced, increase food intake and better mental state. At seventh day of postoperative, liver function index improved significantly, ultrasonic follow-up show bile duct with different degree of inside and outside diameters. Postoperative complications were mild with the rate of 7.14%. No biliary infection, liver abscess, bile leakage complications, biliary tumor or liver function damage.Conclusion:The ultrasound evaluation of preoperative PTBD can be helpful with certain patients. Also to formulate operation program, correct positioning and guided with ultrasound is the key to the successful PTBD. Beside to avoid or reduce the complications, ultrasound follow-up provide important information in the detection of postoperative complications.

  13. Duplex Schemes in Multiple Antenna Two-Hop Relaying

    Directory of Open Access Journals (Sweden)

    Anja Klein

    2008-04-01

    Full Text Available A novel scheme for two-hop relaying defined as space division duplex (SDD relaying is proposed. In SDD relaying, multiple antenna beamforming techniques are applied at the intermediate relay station (RS in order to separate downlink and uplink signals of a bi-directional two-hop communication between two nodes, namely, S1 and S2. For conventional amplify-and-forward two-hop relaying, there appears a loss in spectral efficiency due to the fact that the RS cannot receive and transmit simultaneously on the same channel resource. In SDD relaying, this loss in spectral efficiency is circumvented by giving up the strict separation of downlink and uplink signals by either time division duplex or frequency division duplex. Two novel concepts for the derivation of the linear beamforming filters at the RS are proposed; they can be designed either by a three-step or a one-step concept. In SDD relaying, receive signals at S1 are interfered by transmit signals of S1, and receive signals at S2 are interfered by transmit signals of S2. An efficient method in order to combat this kind of interference is proposed in this paper. Furthermore, it is shown how the overall spectral efficiency of SDD relaying can be improved if the channels from S1 and S2 to the RS have different qualities.

  14. On full duplex Gaussian relay channels with self-interference

    KAUST Repository

    Behboodi, Arash

    2016-08-15

    Self interference (SI) in full duplex (FD) systems is the interference caused by the transmission stream on the reception stream. Being one of the main restrictive factors for performance of practical full duplex systems, however, not too much is known about its effect on the fundamental limits of relaying systems. In this work, we consider the full duplex three-node relay channel with SI where SI is modeled as an additive Gaussian noise whose variance is dependent on instantaneous input power. The classical achievable rates and upper bounds for the single three-node relay channel no longer apply due to the structure of SI. Achievable rates for Decode-and-Forward (DF) and Compress-and-Forward (CF) and upper bounds on the capacity are derived assuming Gaussian inputs and SI. The deterministic model is also introduced and its capacity is characterized. The optimal joint source-relay distributions is discussed. Numerical results are provided comparing the achievable rates and upper bound. © 2016 IEEE.

  15. Ultrasound-based servoing of manipulators for telesurgery

    Science.gov (United States)

    Stoll, Jeff; Dupont, Pierre; Howe, Robert D.

    2002-02-01

    Certain minimally invasive surgical procedures involve the treatment of highly precise target locations within deformable tissues. While preoperative MRI and CT models can be used for surgical planning, they provide only coarse guidance during surgery due to their limited resolution and owing to tissue deformation. Ultrasound imaging is a promising means of obtaining real-time intraoperative data for target localization that is particularly well suited to minimally invasive surgery due to its portability, speed, and safety. This paper presents a system, in which ultrasound images are used to guide a manipulator to a surgical site. Electromagnetic tracking of the ultrasound probe is used to orient the images. These are then segmented in real time to determine target locations. Finally, target coordinates are used to produce control inputs to drive the manipulator to the target site. The potential of the approach is demonstrated experimentally using a manipulator arm, phantom target, and commercial ultrasound machine.

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

    Science.gov (United States)

    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.

  17. Preoperative Smoking Status and Postoperative Complications

    DEFF Research Database (Denmark)

    Grønkjær, Marie; Eliasen, Marie; Skov-Ettrup, Lise Skrubbeltrang;

    2014-01-01

    To systematically review and summarize the evidence of an association between preoperative smoking status and postoperative complications elaborated on complication type.......To systematically review and summarize the evidence of an association between preoperative smoking status and postoperative complications elaborated on complication type....

  18. EFFECT OF INTERMETALLIC PHASES ON CORROSION BEHAVIOR AND MECHANICAL PROPERTIES OF DUPLEX STAINLESS STEEL AND SUPER-DUPLEX STAINLESS STEEL

    Directory of Open Access Journals (Sweden)

    Prabhu Paulraj

    2015-08-01

    Full Text Available Duplex Stainless Steels (DSS and Super Duplex Stainless Steel (SDSS have excellent integration of mechanical and corrosion properties. However, the formation of intermetallic phases is a major problem in their usage. The mechanical and corrosion properties are deteriorated due to the presence of intermetallic phases. These phases are induced during welding, prolonged exposure to high temperatures, and improper heat treatments. The main emphasis of this review article is on intermetallic phases and their effects on corrosion and mechanical properties. First the effect of various alloying elements on DSS and SDSS has been discussed followed by formation of various intermetallic phases. The intermetallic phases affect impact toughness and corrosion resistance significantly. Their deleterious effect on weldments has also been reviewed.

  19. Application research of hlgh-frequency ultrasound on perianal abscess and anal fistula of pre-operative assessment%高频超声在直肠肛管周围脓肿术前评估中的应用研究

    Institute of Scientific and Technical Information of China (English)

    董愉

    2013-01-01

    Objective To explore the value of hlgh-frequency ultrasound on the perianal abscess and anal fistula of pre -operative assessment.Methods Totally 188 patients with perianal inflammatory disease were examined with hlgh-frequency.The diagnostic results were confirmed by clinical diagnosis,including operative and pathological detection.Results All cases were correctly diagnosed.Perianal abscess 120 cases,anal fistula 47 cases were confirmed by operation,other 21 cases underwend ultrasound were not fourd any abnormal and were cured by anti-inflammatory.Conclusions Application of per perineal high-frequency ultrasound examination has great practical value for ascertaining the trend and internal orifice location of anal fistula,location of perianul abscess.%目的 探讨高频超声在肛周脓肿、肛瘘术前评估中的应用价值.方法 通过对188例肛周感染性疾病患者选用高频超声进行肛管及周围超声扫查.并将检查结果与手术所见及病理结果相对照.结果 超声检查结果均与临床诊断相符合,肛周脓肿120例,及肛瘘47例,均经手术可以证实,其余21例超声未见异常,未经手术经消炎输液即治愈.结论 应用经会阴高频超声检查,对肛瘘的走行及内口的定位、肛周脓肿的定位有非常高效的临床诊断价值.

  20. Characterization of microstructure and texture across dissimilar super duplex/austenitic stainless steel weldment joint by super duplex filler metal

    Energy Technology Data Exchange (ETDEWEB)

    Eghlimi, Abbas, E-mail: a.eghlimi@ma.iut.ac.ir [Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Shamanian, Morteza [Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Eskandarian, Masoomeh [Department of Materials Engineering, Shiraz University, Shiraz 71348-51154 (Iran, Islamic Republic of); Zabolian, Azam [Department of Natural Resources, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Szpunar, Jerzy A. [Department of Mechanical Engineering, University of Saskatchewan, Saskatoon SK S7N 5A9 (Canada)

    2015-08-15

    In the present paper, microstructural changes across an as-welded dissimilar austenitic/duplex stainless steel couple welded by a super duplex stainless steel filler metal using gas tungsten arc welding process is characterized with optical microscopy and electron back-scattered diffraction techniques. Accordingly, variations of microstructure, texture, and grain boundary character distribution of base metals, heat affected zones, and weld metal were investigated. The results showed that the weld metal, which was composed of Widmanstätten austenite side-plates and allotriomorphic grain boundary austenite morphologies, had the weakest texture and was dominated by low angle boundaries. The welding process increased the ferrite content but decreased the texture intensity at the heat affected zone of the super duplex stainless steel base metal. In addition, through partial ferritization, it changed the morphology of elongated grains of the rolled microstructure to twinned partially transformed austenite plateaus scattered between ferrite textured colonies. However, the texture of the austenitic stainless steel heat affected zone was strengthened via encouraging recrystallization and formation of annealing twins. At both interfaces, an increase in the special character coincident site lattice boundaries of the primary phase as well as a strong texture with <100> orientation, mainly of Goss component, was observed. - Graphical abstract: Display Omitted - Highlights: • Weld metal showed local orientation at microscale but random texture at macroscale. • Intensification of <100> orientated grains was observed adjacent to the fusion lines. • The austenite texture was weaker than that of the ferrite in all duplex regions. • Welding caused twinned partially transformed austenites to form at SDSS HAZ. • At both interfaces, the ratio of special CSL boundaries of the primary phase increased.

  1. Residual stresses and fatigue in a duplex stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Johansson, Johan

    1999-05-01

    Duplex stainless steels, consisting of approximately equal amounts of austenite and ferrite, often combine the best features of austenitic and ferritic stainless steels. They generally have good mechanical properties, including high strength and ductility, and the corrosion resistance is often better than conventional austenitic grades. This has lead to a growing use of duplex stainless steels as a material in mechanically loaded constructions. However, detailed knowledge regarding its mechanical properties and deformation mechanisms are still lacking. In this thesis special emphasis has been placed on the residual stresses and their influence on mechanical behaviour of duplex stainless steels. Due to the difference in coefficient of thermal expansion between the two phases, tensile microstresses are found in the austenitic phase and balancing compressive microstresses in the ferritic phase. The first part of this thesis is a literature survey, which will give an introduction to duplex stainless steels and review the fatigue properties of duplex stainless steels and the influence of residual stresses in two-phase material. The second part concerns the evolution of the residual stress state during uniaxial loading. Initial residual stresses were found to be almost two times higher in the transverse direction compared to the rolling direction. During loading the absolute value of the microstresses increased in the macroscopic elastic regime but started to decrease with increasing load in the macroscopic plastic regime. A significant increase of the microstresses was also found to occur during unloading. Finite element simulations also show stress variation within one phase and a strong influence of both the elastic and plastic anisotropy of the individual phases on the simulated stress state. In the third part, the load sharing between the phases during cyclic loading is studied. X-ray diffraction stress analysis and transmission electron microscopy show that even if

  2. Children's (Pediatric) Abdominal Ultrasound Imaging

    Medline Plus

    Full Text Available ... are the limitations of Abdominal Ultrasound Imaging? What is Abdominal Ultrasound Imaging? Ultrasound is safe and painless, ... through the blood vessels. top of page How is the procedure performed? For most ultrasound exams, you ...

  3. Ultrasound of the Thyroid Gland

    Science.gov (United States)

    ... Physician Resources Professions Site Index A-Z Ultrasound - Thyroid Thyroid ultrasound uses sound waves to produce pictures ... the Thyroid? What is an Ultrasound of the Thyroid? Ultrasound is safe and painless, and produces pictures ...

  4. Ultrasound-Guided Breast Biopsy

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z Ultrasound-Guided Breast Biopsy An ultrasound-guided breast biopsy ... limitations of Ultrasound-Guided Breast Biopsy? What is Ultrasound-Guided Breast Biopsy? Lumps or abnormalities in the ...

  5. Children's (Pediatric) Abdominal Ultrasound Imaging

    Medline Plus

    Full Text Available ... of page What are some common uses of the procedure? Abdominal ultrasound imaging is performed to evaluate ... for ultrasound examinations. top of page What does the ultrasound equipment look like? Ultrasound scanners consist of ...

  6. Ultrasound in Arthritis.

    Science.gov (United States)

    Sudoł-Szopińska, Iwona; Schueller-Weidekamm, Claudia; Plagou, Athena; Teh, James

    2017-09-01

    Ultrasound is currently performed in everyday rheumatologic practice. It is used for early diagnosis, to monitor treatment results, and to diagnose remission. The spectrum of pathologies seen in arthritis with ultrasound includes early inflammatory features and associated complications. This article discusses the spectrum of ultrasound features of arthritides seen in rheumatoid arthritis and other connective tissue diseases in adults, such as Sjögren syndrome, lupus erythematosus, dermatomyositis, polymyositis, and juvenile idiopathic arthritis. Ultrasound findings in spondyloarthritis, osteoarthritis, and crystal-induced diseases are presented. Ultrasound-guided interventions in patients with arthritis are listed, and the advantages and disadvantages of ultrasound are discussed. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Biopsy needle detection in transrectal ultrasound.

    Science.gov (United States)

    Ayvaci, Alper; Yan, Pingkun; Xu, Sheng; Soatto, Stefano; Kruecker, Jochen

    2011-01-01

    Using the fusion of pre-operative MRI and real time intra-procedural transrectal ultrasound (TRUS) to guide prostate biopsy has been shown as a very promising approach to yield better clinical outcome than the routinely performed TRUS only guided biopsy. In several situations of the MRI/TRUS fusion guided biopsy, it is important to know the exact location of the deployed biopsy needle, which is imaged in the TRUS video. In this paper, we present a method to automatically detect and segment the biopsy needle in TRUS. To achieve this goal, we propose to combine information from multiple resources, including ultrasound probe stability, TRUS video background model, and the prior knowledge of needle orientation and position. The proposed algorithm was tested on TRUS video sequences which have in total more than 25,000 frames. The needle deployments were successfully detected and segmented in the sequences with high accuracy and low false-positive detection rate.

  8. Effect of ultrafine grain on tensile behaviour and corrosion resistance of the duplex stainless steel.

    Science.gov (United States)

    Jinlong, Lv; Tongxiang, Liang; Chen, Wang; Limin, Dong

    2016-05-01

    The ultrafine grained 2205 duplex stainless steel was obtained by cold rolling and annealing. The tensile properties were investigated at room temperature. Comparing with coarse grained stainless steel, ultrafine grained sample showed higher strength and plasticity. In addition, grain size changed deformation orientation. The strain induced α'-martensite was observed in coarse grained 2205 duplex stainless steel with large strain. However, the grain refinement inhibited the transformation of α'-martensite;nevertheless, more deformation twins improved the strength and plasticity of ultrafine grained 2205 duplex stainless steel. In addition, the grain refinement improved corrosion resistance of the 2205 duplex stainless steel in sodium chloride solution.

  9. Analyzing the Potential of Full Duplex in 5G Ultra-Dense Small Cell Networks

    DEFF Research Database (Denmark)

    Gatnau, Marta; Berardinelli, Gilberto; Mahmood, Nurul Huda;

    2016-01-01

    Full duplex technology has become an attractive solution for future 5th Generation (5G) systems for accommodating the exponentially growing mobile traffic demand. Full duplex allows a node to transmit and receive simultaneously in the same frequency band, thus, theoretically, doubling the system......-interference cancellation are demonstrated using our own developed test bed. Secondly, a detailed evaluation of full duplex communication in 5G ultra-dense small cell networks via system level simulations is provided. The results are presented in terms of throughput and delay. Two types of full duplex are studied: when...

  10. Laparoscopic ultrasound imaging in colorectal cancer resection may increase the detection rate of small liver metastases

    DEFF Research Database (Denmark)

    Ellebæk, Signe Bremholm; Fristrup, Claus Wilki; Mortensen, Michael Bau

    2016-01-01

    Up to 20% of the patients with colorectal cancer (CRC) will have liver metastases at the time of the diagnosis, and some of these metastases may be missed during preoperative evaluation. While intraoperative ultrasound is considered the gold standard for liver evaluation during primary open CRC...... surgery, laparoscopic ultrasound (LUS) is not performed routinely during laparoscopic CRC surgery. Based on the available literature LUS had a higher detection rate for especially small liver metastases compared to preoperative imaging modalities, but better prospective trials are needed....

  11. The comparison of color Doppler ultrasound and computed tomography angiography in the preoperative planning of lower extremity perforators%彩色多普勒超声与CT血管造影技术在下肢穿支血管定位中的比较

    Institute of Scientific and Technical Information of China (English)

    冯少清; 喜雯婧; 王珏; 李华; 李科; 章一新

    2016-01-01

    目的 比较彩色多普勒超声(CDU)及CT血管造影技术(CTA)在下肢穿支血管术前定位中的特征和效果.方法 2013年2月至2014年12月,对自下肢切取穿支皮瓣的40个病例术前均采用两种技术进行穿支血管的评估,包括位置、口径、走行路径等信息,依据评估结果选择合适的穿支血管,并将术前检测的结果与术中探查所见进行对比分析.结果 CDU和CTA在下肢穿支血管的识别率分别为95.0%和90.0%、定位准确率分别为95.0%和82.5%,CDU表现出更高的精确度.在检查及图像分析总时间上两种技术没有明显差异.设计的所有皮瓣均成活,仅1例皮瓣远端出现2.0 cm× 2.0 cm的表皮坏死,经换药后愈合.供区35例直接关闭缝合,5例通过部分植皮关闭.结论 术前影像学技术可提供准确的穿支血管解剖学信息,方便手术设计,减少供区损伤,获得最佳手术效果.对于下肢穿支血管的术前评估,建议首选CDU技术.%Objective To compare the application of CDU and CTA in preoperative planning of lower extremity perforator flaps.Methods From February, 2013 to December, 2014, 40 patients who underwent reconstruction with perforator flaps harvested from lower extremities were treated.The position, caliber and route of the perforator vessels were detected by CDU and CTA pre-operatively.The results of the pre-operative navigation with both imaging techniques assisted the selection of the perforators and the flap design and were verified during the operation.Results CDU had a higher accuracy in terms of identification (95.0% vs.90.0%) and location (95.0% vs.82.5%) of the perforators in the lower extremity.There was no significant difference between the two methods in examination and image analysis time.All the flaps survived, besides 1 flap presented with a 2.0 cm × 2.0 cm distal necrosis which healed after regular dressing change.For 35 cases, the donor sites were closed directly while partial

  12. Breast ultrasound scans – surgeons’ expectations

    Directory of Open Access Journals (Sweden)

    Piotr Bednarski

    2015-06-01

    Full Text Available Recent years have witnessed a dynamic development of mammary gland imaging techniques, particularly ultrasonography and magnetic resonance imaging. A challenge related to these studies is the increase in the precision of the anatomical assessment of breast, particularly for early detection of subclinical lesions, performance of ultrasound-guided biopsy procedures, and accurate preoperative location of pathological lesions so as to optimize the surgical treatment. Ultrasound imaging is a primary and baseline diagnostic procedure the patient with suspected pathological lesions within breast is referred to by the surgeon. Lesions visualized in ultrasound scans are classifi ed according to the BI-RADS US assessment categories. The successive categories (2 through 6 encompass individual pathological lesions, estimating the risk of malignancy and provide guidelines for further diagnostic and therapeutic management. This article described the important aspects of ultrasonographic imaging of focal lesions within the breasts as signifi cant from the standpoint of surgical treatment of patients falling within BI-RADS US categories 3, 4, 5, and 6. Attention is drawn to the importance of ultrasound scans in the assessment of axillary fossa lymph nodes before the decision regarding the surgical treatment.

  13. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... flat sections of the body. Advancements in ultrasound technology include three-dimensional (3-D) ultrasound that formats ... also used to: guide procedures such as needle biopsies , in which needles are used to sample cells ...

  14. Medical Ultrasound Imaging.

    Science.gov (United States)

    Hughes, Stephen

    2001-01-01

    Explains the basic principles of ultrasound using everyday physics. Topics include the generation of ultrasound, basic interactions with material, and the measurement of blood flow using the Doppler effect. (Author/MM)

  15. General Ultrasound Imaging

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    Full Text Available ... may also be saved. Doppler ultrasound, a special application of ultrasound, measures the direction and speed of ... understanding of the possible charges you will incur. Web page review process: This Web page is reviewed ...

  16. General Ultrasound Imaging

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    Full Text Available ... of page What are some common uses of the procedure? Ultrasound examinations can help to diagnose a ... the scan begins. top of page What does the equipment look like? Ultrasound scanners consist of a ...

  17. General Ultrasound Imaging

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    Full Text Available ... flat sections of the body. Advancements in ultrasound technology include three-dimensional (3-D) ultrasound that formats ... accredited facilities database . This website does not provide cost information. The costs for specific medical imaging tests, ...

  18. General Ultrasound Imaging

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    Full Text Available ... diagnose heart conditions, and assess damage after a heart attack. Ultrasound is safe, noninvasive, and does not use ... heart failure, and to assess damage after a heart attack. Ultrasound of the heart is commonly called an “ ...

  19. General Ultrasound Imaging

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    Full Text Available ... Us News Physician Resources Professions Site Index A-Z General Ultrasound Ultrasound imaging uses sound waves to ... type of examination you will have. For some scans your doctor may instruct you not to eat ...

  20. General Ultrasound Imaging

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    Full Text Available ... and ovaries. top of page What will I experience during and after the procedure? Ultrasound examinations are ... ultrasound , there are no known harmful effects on humans. top of page What are the limitations of ...

  1. General Ultrasound Imaging

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    Full Text Available ... top of page What are the benefits vs. risks? Benefits Most ultrasound scanning is noninvasive (no needles ... procedures such as needle biopsies and fluid aspiration. Risks For standard diagnostic ultrasound , there are no known ...

  2. General Ultrasound Imaging

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    Full Text Available ... saved. Doppler ultrasound, a special application of ultrasound, measures the direction and speed of blood cells as ... tests, treatments and procedures may vary by geographic region. Discuss the fees associated with your prescribed procedure ...

  3. General Ultrasound Imaging

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    Full Text Available ... help guide biopsies, diagnose heart conditions, and assess damage after a heart attack. Ultrasound is safe, noninvasive, ... a variety of conditions and to assess organ damage following illness. Ultrasound is used to help physicians ...

  4. General Ultrasound Imaging

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    Full Text Available ... Most ultrasound scanning is noninvasive (no needles or injections). Occasionally, an ultrasound exam may be temporarily uncomfortable, ... the following text box: Comment: E-mail: Area code: Phone no: Thank you! Images × Image Gallery General ...

  5. General Ultrasound Imaging

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    Full Text Available ... attached to a probe and inserted into a natural opening in the body. These exams include: Transesophageal ... Imaging? Ultrasound waves are disrupted by air or gas; therefore ultrasound is not an ideal imaging technique ...

  6. Abdominal ultrasound (image)

    Science.gov (United States)

    Abdominal ultrasound is a scanning technique used to image the interior of the abdomen. Like the X-ray, MRI, ... it has its place as a diagnostic tool. Ultrasound scans use high frequency sound waves to produce ...

  7. Prenatal ultrasound - slideshow

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/presentations/100197.htm Prenatal ultrasound - series—Procedure, part 1 To use the sharing ... Editorial team. Related MedlinePlus Health Topics Prenatal Testing Ultrasound A.D.A.M., Inc. is accredited by ...

  8. Transvaginal ultrasound (image)

    Science.gov (United States)

    Transvaginal ultrasound is a method of imaging the genital tract in females. A hand held probe is inserted directly ... vaginal cavity to scan the pelvic structures, while ultrasound pictures are viewed on a monitor. The test ...

  9. General Ultrasound Imaging

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    Full Text Available ... ultrasound. top of page How does the procedure work? Ultrasound imaging is based on the same principles ... requested the exam. Usually, the referring physician or health care provider will share the results with you. ...

  10. General Ultrasound Imaging

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    Full Text Available ... flat sections of the body. Advancements in ultrasound technology include three-dimensional (3-D) ultrasound that formats ... of the reflected sound waves (called the Doppler effect). A computer collects and processes the sounds and ...

  11. General Ultrasound Imaging

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    Full Text Available ... ultrasound. top of page How does the procedure work? Ultrasound imaging is based on the same principles ... these links. About Us | Contact Us | FAQ | Privacy | Terms of Use | Links | Site Map Copyright © 2017 Radiological ...

  12. General Ultrasound Imaging

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    Full Text Available ... diagnose heart conditions, and assess damage after a heart attack. Ultrasound is safe, noninvasive, and does not use ... heart failure, and to assess damage after a heart attack. Ultrasound of the heart is commonly called an “ ...

  13. General Ultrasound Imaging

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    Full Text Available ... information you were looking for? Yes No Please type your comment or suggestion into the following text box: Comment: ... Ultrasound Ultrasound - Prostate Biopsies - Overview Images related ...

  14. General Ultrasound Imaging

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    Full Text Available ... of page What are some common uses of the procedure? Ultrasound examinations can help to diagnose a ... the scan begins. top of page What does the equipment look like? Ultrasound scanners consist of a ...

  15. American Thyroid Association Statement on Preoperative Imaging for Thyroid Cancer Surgery

    Science.gov (United States)

    Bauer, Andrew J.; Bernet, Victor A.; Ferris, Robert L.; Loevner, Laurie A.; Mandel, Susan J.; Orloff, Lisa A.; Randolph, Gregory W.; Steward, David L.

    2015-01-01

    Background: The success of surgery for thyroid cancer hinges on thorough and accurate preoperative imaging, which enables complete clearance of the primary tumor and affected lymph node compartments. This working group was charged by the Surgical Affairs Committee of the American Thyroid Association to examine the available literature and to review the most appropriate imaging studies for the planning of initial and revision surgery for thyroid cancer. Summary: Ultrasound remains the most important imaging modality in the evaluation of thyroid cancer, and should be used routinely to assess both the primary tumor and all associated cervical lymph node basins preoperatively. Positive lymph nodes may be distinguished from normal nodes based upon size, shape, echogenicity, hypervascularity, loss of hilar architecture, and the presence of calcifications. Ultrasound-guided fine-needle aspiration of suspicious lymph nodes may be useful in guiding the extent of surgery. Cross-sectional imaging (computed tomography with contrast or magnetic resonance imaging) may be considered in select circumstances to better characterize tumor invasion and bulky, inferiorly located, or posteriorly located lymph nodes, or when ultrasound expertise is not available. The above recommendations are applicable to both initial and revision surgery. Functional imaging with positron emission tomography (PET) or PET-CT may be helpful in cases of recurrent cancer with positive tumor markers and negative anatomic imaging. PMID:25188202

  16. [Scar or recurrence--comparison of MRI and color-coded ultrasound with echo signal amplifiers].

    Science.gov (United States)

    Aichinger, U; Schulz-Wendtland, R; Krämer, S; Lell, M; Bautz, W

    2002-11-01

    MRI is the most reliable method to differentiate scar and recurrent carcinoma of the breast after surgical treatment. This study compares MRI and color-coded ultrasound with and without echo signal amplifier (ESA). Forty-two patients with suspected recurrent tumors were enrolled in this prospective study, with 38 patients after breast conserving therapy and 4 after mastectomy. All patients had a clinical examination, mammography (n = 38), real time ultrasound (US), color-coded ultrasound without and with ESA (Levovist(R), Schering, Berlin), and dynamic MRI. The criteria used for duplex ultrasound were tumor vascularisation and flow pattern. The results were compared with histologic findings or the results of follow-up examinations for at least 12 months. The detection of penetrating or central vessels proved to be an accurate sign of malignancy in duplex ultrasound. With the application of ESA, additional vessels were detected within the lesions, increasing the diagnostic accuracy (83 % with ESA versus 79 % without ESA). The sensitivity of color-coded ultrasound improved from 64 % to 86 % with echo signal amplifier. The specificity was 86 % without and 82 % with echo signal amplifier. MRI was found to have a sensitivity of 100 % and a specificity of 82 %. The same 5 lesions were false positive on MRI and color-coded US after Levovist(R). No lesion without signs of vascularity within or in its vicinity was malignant. Color-coded ultrasound seems to be a promising method in the differentiation between scar and recurrence. Lesions with penetrating or central vessels have a high probability of being malignant, whereas lesions without any signs of vascularity inside or nearby have a high probability of being benign. Advantage of contrast-enhanced US is its ubiquitous availability.

  17. Harmonic Intravascular Ultrasound

    NARCIS (Netherlands)

    M.E. Frijlink (Martijn)

    2006-01-01

    textabstractMedical ultrasound is a popular imaging modality in cardiology. Harmonic Imaging is a technique that has been shown to increase the image quality of diagnostic ultrasound at frequencies below 10 MHz. However, Intravascular Ultrasound, which is a technique to acoustically investigate arte

  18. Ultrasound: Abdomen (For Parents)

    Science.gov (United States)

    ... for TV, Video Games, and the Internet Ultrasound: Abdomen KidsHealth > For Parents > Ultrasound: Abdomen Print A A A What's in this article? ... Child If You Have Questions en español Ultrasonido: abdomen What It Is An abdominal ultrasound is a ...

  19. Properties of Ultrasound Probes

    OpenAIRE

    Rusina, M.

    2015-01-01

    This work deals with the measurement properties of ultrasound probes. Ultrasound probes and their parameters significantly affect the quality of the final image. In this work there are described the possibility of measuring the spatial resolution, sensitivity of the probe and measuring the length of the dead zone. Ultrasound phantom ATS Multi Purpose Phantom Type 539 was used for measurements.

  20. Ultrasound: Bladder (For Parents)

    Science.gov (United States)

    ... Old Feeding Your 1- to 2-Year-Old Ultrasound: Bladder KidsHealth > For Parents > Ultrasound: Bladder A A A What's in this article? ... español Ultrasonido: vejiga What It Is A bladder ultrasound is a safe and painless test that uses ...

  1. Harmonic Intravascular Ultrasound

    NARCIS (Netherlands)

    M.E. Frijlink (Martijn)

    2006-01-01

    textabstractMedical ultrasound is a popular imaging modality in cardiology. Harmonic Imaging is a technique that has been shown to increase the image quality of diagnostic ultrasound at frequencies below 10 MHz. However, Intravascular Ultrasound, which is a technique to acoustically investigate arte

  2. Ultrasound: Pelvis (For Parents)

    Science.gov (United States)

    ... Old Feeding Your 1- to 2-Year-Old Ultrasound: Pelvis KidsHealth > For Parents > Ultrasound: Pelvis A A A What's in this article? ... español Ultrasonido: pelvis What It Is A pelvic ultrasound is a safe and painless test that uses ...

  3. Ultrasound: Infant Hip

    Science.gov (United States)

    ... Old Feeding Your 1- to 2-Year-Old Ultrasound: Infant Hip KidsHealth > For Parents > Ultrasound: Infant Hip A A A What's in this ... en los lactantes What It Is A hip ultrasound is a safe and painless test that uses ...

  4. Ultrasound: Abdomen (For Parents)

    Science.gov (United States)

    ... Old Feeding Your 1- to 2-Year-Old Ultrasound: Abdomen KidsHealth > For Parents > Ultrasound: Abdomen A A A What's in this article? ... español Ultrasonido: abdomen What It Is An abdominal ultrasound is a safe and painless test that uses ...

  5. Force-Induced Rupture of a DNA Duplex: From Fundamentals to Force Sensors.

    Science.gov (United States)

    Mosayebi, Majid; Louis, Ard A; Doye, Jonathan P K; Ouldridge, Thomas E

    2015-12-22

    The rupture of double-stranded DNA under stress is a key process in biophysics and nanotechnology. In this article, we consider the shear-induced rupture of short DNA duplexes, a system that has been given new importance by recently designed force sensors and nanotechnological devices. We argue that rupture must be understood as an activated process, where the duplex state is metastable and the strands will separate in a finite time that depends on the duplex length and the force applied. Thus, the critical shearing force required to rupture a duplex depends strongly on the time scale of observation. We use simple models of DNA to show that this approach naturally captures the observed dependence of the force required to rupture a duplex within a given time on duplex length. In particular, this critical force is zero for the shortest duplexes, before rising sharply and then plateauing in the long length limit. The prevailing approach, based on identifying when the presence of each additional base pair within the duplex is thermodynamically unfavorable rather than allowing for metastability, does not predict a time-scale-dependent critical force and does not naturally incorporate a critical force of zero for the shortest duplexes. We demonstrate that our findings have important consequences for the behavior of a new force-sensing nanodevice, which operates in a mixed mode that interpolates between shearing and unzipping. At a fixed time scale and duplex length, the critical force exhibits a sigmoidal dependence on the fraction of the duplex that is subject to shearing.

  6. Numerical modeling and optimization of machining duplex stainless steels

    Directory of Open Access Journals (Sweden)

    Rastee D. Koyee

    2015-01-01

    Full Text Available The shortcomings of the machining analytical and empirical models in combination with the industry demands have to be fulfilled. A three-dimensional finite element modeling (FEM introduces an attractive alternative to bridge the gap between pure empirical and fundamental scientific quantities, and fulfill the industry needs. However, the challenging aspects which hinder the successful adoption of FEM in the machining sector of manufacturing industry have to be solved first. One of the greatest challenges is the identification of the correct set of machining simulation input parameters. This study presents a new methodology to inversely calculate the input parameters when simulating the machining of standard duplex EN 1.4462 and super duplex EN 1.4410 stainless steels. JMatPro software is first used to model elastic–viscoplastic and physical work material behavior. In order to effectively obtain an optimum set of inversely identified friction coefficients, thermal contact conductance, Cockcroft–Latham critical damage value, percentage reduction in flow stress, and Taylor–Quinney coefficient, Taguchi-VIKOR coupled with Firefly Algorithm Neural Network System is applied. The optimization procedure effectively minimizes the overall differences between the experimentally measured performances such as cutting forces, tool nose temperature and chip thickness, and the numerically obtained ones at any specified cutting condition. The optimum set of input parameter is verified and used for the next step of 3D-FEM application. In the next stage of the study, design of experiments, numerical simulations, and fuzzy rule modeling approaches are employed to optimize types of chip breaker, insert shapes, process conditions, cutting parameters, and tool orientation angles based on many important performances. Through this study, not only a new methodology in defining the optimal set of controllable parameters for turning simulations is introduced, but also

  7. Technology of Welding Joints Mixed with Duplex Steel

    OpenAIRE

    Słania J.; Krawczyk R.; Masłoń D.

    2016-01-01

    Results of the examinations of sample plates of mixed joints with the duplex steel were discussed. Examinations were taken on the sample plates of mixed joints of sheet plates type P355NL1 and X2CrNiMoN22-5-3 welded by the flux-cored wire DW-329A by the Kobelco company of the following category T 22 9 3 NL RC/M3 in the gas shroud M21 (Ar+18%CO2) (plate no.1), and nickel covered electrodes E Ni 6082 by the Böhler company (plate no. 2). Results of the side bend test of welded joint, transverse ...

  8. Protocols For Half-Duplex Multiple Relay Networks

    CERN Document Server

    Rost, P

    2007-01-01

    In this paper we present several strategies for multiple relay networks which are constrained by a half-duplex operation, i. e., each node either transmits or receives on a particular resource. Using the discrete memoryless multiple relay channel we present achievable rates for a multilevel partial decode-and-forward approach which generalizes previous results presented by Kramer and Khojastepour et al.. Furthermore, we derive a compress-and-forward approach using a regular encoding scheme which simplifies the encoding and decoding scheme and improves the achievable rates in general. Finally, we give achievable rates for a mixed strategy used in a four-terminal network with alternately transmitting relay nodes.

  9. Reliability Capacity of Half-Duplex Channels with Strict Deadlines

    DEFF Research Database (Denmark)

    Costa, Rui; Roetter, Daniel Enrique Lucani; Vinhoza, Tiago;

    2015-01-01

    A fundamental characterization of a half-duplex wireless system with packet losses under traffic with hard deadlines is instrumental to understanding and developing efficient, coding aware policies for real-time applications. We set forth the concept of reliability capacity with a limited number...... and in terms of its advantages towards the mean number of packets that can be transmitted reliably. Optimal schemes for leveraging feedback are presented and the results show that a judicious use of even a single feedback packet can have a significant impact on the mean performance....

  10. Corrosion resistance properties of sintered duplex stainless steel

    Directory of Open Access Journals (Sweden)

    L.A. Dobrzański

    2006-09-01

    Full Text Available Purpose: of this paper was to examine the corrosion resistance of duplex stainless steels using electrochemical methods in 1M NaCl solution. The influence of powder mixes preparation and cooling cycle after sintering on corrosion properties was evaluated.Design/methodology/approach: In presented study duplex stainless steels were obtained through powder metallurgy starting from austenitic, martensitic base powders by controlled addition of alloying elements, such as Cr, Ni, Mo and Cu. In the studies behind the preparation of mixes, Schaeffler’s diagram was taken into consideration. Prepared mixes have been compacted at 800 MPa and sintered in a vacuum furnace with argon backfilling at 1260°C for 1 h. After sintering two different cooling cycles were applied: rapid cooling with an average cooling rate of 245 °C/min and slow cooling of 5 °C/min in argon atmosphere. Produced duplex stainless steels have been studied by scanning and optical microscopy and EDS chemical analysis of microstructure components. Corrosion properties have been studied through electrochemical methods in 1M NaCl water solutionFindings: According to achieved results, it was affirmed that applied sintering method as well as powder mixes preparation allows for manufacturing the sintered duplex steels with good corrosion properties which depends on austenite/ferrite ratio in the microstructure and elements partitioning between phases. Corrosion resistance of sintered stainless steels is strictly connected with the density and the pore morphology present in the microstructure too. The highest resistance to pitting corrosion in 1M NaCl solution was achieved for composition with approximate balance of ferrite and austenite in the microstructure.Research limitations/implications: According to the powders characteristic, the applied fast cooling rate seems to be a good compromise for corrosion properties and microstructures, nevertheless further tests should be carried out in

  11. The Terahertz Controlled Duplex Isolator: Physical Grounds and Numerical Experiment

    Directory of Open Access Journals (Sweden)

    Konstantin Vytovtov

    2016-01-01

    Full Text Available Electromagnetic properties of an anisotropic stratified slab with an arbitrary orientation of the anisotropy axis under an oblique incidence of a plane harmonic wave are studied. The dependence of the eigenwave wavenumbers and the reflection coefficient on an anisotropy axis orientation and frequency is investigated. For the first time, the expression for the translation matrix is obtained in the compact analytical form. The controlled two-way dual-frequency (duplex isolator based on the above described slab is presented for the first time. It is based on the properties of the anisotropic structure described here but not on the Faraday effect.

  12. A fresh look at preoperative body washing

    Science.gov (United States)

    Tanner, Judith; Gould, Dinah; Jenkins, Philip; Hilliam, Rachel; Mistry, Neetesh; Walsh, Susannah

    2012-01-01

    National guidelines do not support preoperative body washing to reduce surgical site infections, instead recommending bathing or showering with soap. Yet preoperative body washing continues to be widely used in many hospitals across Europe. This paper suggests that existing trials of preoperative body washing, upon which guidelines are based, are dated and proposes a new investigation of preoperative body washing using modern definitions of surgical site infection with standardised patient follow up, modern surgical techniques and well designed trials. This paper provides a critique of existing guidelines and describes a randomised trial with 60 participants to compare the effect of soap and two antiseptic washing products on colony forming units (CFUs) for up to six hours. Chlorhexidine gluconate and octenidine were significantly more effective than soap in reducing CFUs in the underarm, and chlorhexidine was significantly more effective than soap in reducing CFUs in the groin. PMID:22448182

  13. Preoperative steroid in abdominal wall reconstruction

    DEFF Research Database (Denmark)

    Jensen, Kristian Kiim; Brøndum, Tina Lee; Belhage, Bo

    2016-01-01

    INTRODUCTION: Preoperative administration of high-dose glucocorticoid leads to improved recovery and decreased length of stay after abdominal surgery. Even so, studies on administration of glucocorticoids for patients undergoing abdominal wall reconstruction (AWR) for giant ventral hernia repair ...

  14. Preoperative alcohol cessation prior to elective surgery

    DEFF Research Database (Denmark)

    Oppedal, Kristian; Møller, Ann Merete; Pedersen, Bolette

    2012-01-01

    Hazardous drinking has been associated with an increased postoperative complication rate after surgery. Common complications include postoperative infections, cardiopulmonary complications, and bleeding episodes. Preoperative abstinence may to some degree reverse alcohol-induced pathophysiological...

  15. Preoperative steroid in abdominal wall reconstruction

    DEFF Research Database (Denmark)

    Jensen, Kristian Kiim; Brøndum, Tina Lee; Belhage, Bo;

    2016-01-01

    INTRODUCTION: Preoperative administration of high-dose glucocorticoid leads to improved recovery and decreased length of stay after abdominal surgery. Even so, studies on administration of glucocorticoids for patients undergoing abdominal wall reconstruction (AWR) for giant ventral hernia repair ...

  16. Skull registration for prone patient position using tracked ultrasound

    Science.gov (United States)

    Underwood, Grace; Ungi, Tamas; Baum, Zachary; Lasso, Andras; Kronreif, Gernot; Fichtinger, Gabor

    2017-03-01

    PURPOSE: Tracked navigation has become prevalent in neurosurgery. Problems with registration of a patient and a preoperative image arise when the patient is in a prone position. Surfaces accessible to optical tracking on the back of the head are unreliable for registration. We investigated the accuracy of surface-based registration using points accessible through tracked ultrasound. Using ultrasound allows access to bone surfaces that are not available through optical tracking. Tracked ultrasound could eliminate the need to work (i) under the table for registration and (ii) adjust the tracker between surgery and registration. In addition, tracked ultrasound could provide a non-invasive method in comparison to an alternative method of registration involving screw implantation. METHODS: A phantom study was performed to test the feasibility of tracked ultrasound for registration. An initial registration was performed to partially align the pre-operative computer tomography data and skull phantom. The initial registration was performed by an anatomical landmark registration. Surface points accessible by tracked ultrasound were collected and used to perform an Iterative Closest Point Algorithm. RESULTS: When the surface registration was compared to a ground truth landmark registration, the average TRE was found to be 1.6+/-0.1mm and the average distance of points off the skull surface was 0.6+/-0.1mm. CONCLUSION: The use of tracked ultrasound is feasible for registration of patients in prone position and eliminates the need to perform registration under the table. The translational component of error found was minimal. Therefore, the amount of TRE in registration is due to a rotational component of error.

  17. Ultrasound-based servoing of manipulators for telesurgery

    OpenAIRE

    Stoll, Jeff; Dupont, Pierre E.; Howe, Robert D.

    2001-01-01

    Certain minimally invasive surgical procedures involve the treatment of highly precise target locations within deformable tissues. While preoperative MRI and CT models can be used for surgical planning, they provide only coarse guidance during surgery due to their limited resolution and owing to tissue deformation. Ultrasound imaging is a promising means of obtaining real-time intraoperative data for target localization that is particularly well suited to minimally invasive surgery due to its...

  18. Preoperative education for lumbar surgery for radiculopathy

    OpenAIRE

    Louw, A; Louw, Q; L. Crous

    2009-01-01

    To date no studies have been published on preoperative education forpatients who had lumbar surgery. The aim of this study was to determine if there is a demand for preoperative education for patients who had lumbar surgery for radiculopathy. A convenience sample of 47 patients who had lumbar surgery and a random sample of 141 physiotherapists involved in treating patients who had lumbar surgery completed a newly developed spinal surgery questionnaire. The data were analyzed using descriptive...

  19. Preoperative prediction of severe postoperative pain.

    Science.gov (United States)

    Kalkman, C J; Visser, K; Moen, J; Bonsel, G J; Grobbee, D E; Moons, K G M

    2003-10-01

    We developed and validated a prediction rule for the occurrence of early postoperative severe pain in surgical inpatients, using predictors that can be easily documented in a preoperative setting. A cohort of surgical inpatients (n=1416) undergoing various procedures except cardiac surgery and intracranial neurosurgery in a University Hospital were studied. Preoperatively the following predictors were collected: age, gender, type of scheduled surgery, expected incision size, blood pressure, heart rate, Quetelet index, the presence and severity of preoperative pain, health-related quality of life the (SF-36), Spielberger's State-Trait Anxiety Inventory (STAI) and the Amsterdam Preoperative Anxiety and Information Scale (APAIS). The outcome was the presence of severe postoperative pain (defined as Numeric Rating Scale > or =8) within the first hour postoperatively. Multivariate logistic regression in combination with bootstrapping techniques (as a method for internal validation) was used to derive a stable prediction model. Independent predictors of severe postoperative pain were younger age, female gender, level of preoperative pain, incision size and type of surgery. The area under the receiver operator characteristic (ROC) curve was 0.71 (95% CI: 0.68-0.74). Adding APAIS scores (measures of preoperative anxiety and need for information), but not STAI, provided a slightly better model (ROC area 0.73). The reliability of this extended model was good (Hosmer and Lemeshow test p-value 0.78). We have demonstrated that severe postoperative pain early after awakening from general anesthesia can be predicted with a scoring rule, using a small set of variables that can be easily obtained from all patients at the preoperative visit. Before this internally validated preoperative prediction rule can be applied in clinical practice to support anticipatory pain management, external validation in other clinical settings is necessary.

  20. Counterview: Pre-operative breast MRI (magnetic resonance imaging) is not recommended for all patients with newly diagnosed breast cancer.

    Science.gov (United States)

    Solin, Lawrence J

    2010-02-01

    For the woman with a newly diagnosed early stage breast cancer, the routine use of pre-operative breast MRI (magnetic resonance imaging) is not indicated beyond conventional breast imaging (i.e., mammography with correlation ultrasound as indicated). There is no consistent evidence that a pre-operative breast MRI confers a benefit to the patient by improving clinical outcomes or surgical procedures. In a meta-analysis of studies reporting on the use of pre-operative breast MRI for the patient with an established index cancer, multifocal or multicentric disease was found on breast MRI in 16% of the patients, a rate substantially higher than the rate of local recurrence after breast conserving surgery plus definitive radiation treatment. In the largest retrospective study of patients treated with breast conserving surgery plus radiation, no gain was found for adding a breast MRI to conventional breast imaging. No randomized clinical trial has been designed to evaluate long term clinical outcomes associated with adding a pre-operative breast MRI. Adding pre-operative breast MRI can alter clinical management in ways that are potentially harmful to patients, for example, increased ipsilateral mastectomies, increased contralateral prophylactic mastectomies, increased work-ups, and delay to definitive surgery. In summary, the routine use of pre-operative breast MRI is not warranted for the typical patient with a newly diagnosed early stage breast cancer.

  1. RF Self-Interference reduction techniques for compact full duplex radios

    NARCIS (Netherlands)

    Deballie, B.; van den Broek, Dirk-Jan; Lavin, C.; van Liempd, B.; Klumperink, Eric A.M.; Palacios, C.; Craninckx, J.; Nauta, Bram

    2015-01-01

    This paper describes three RF self-interference reduction techniques for full-duplex wireless links, which specifically target integration in compact radios. Concretely, a self-interference cancelling front-end, a dual-polarized antenna, and an electrical balance duplexer are proposed. Each techniqu

  2. Accuracy of colour duplex sonography for the diagnosis of renal artery stenosis

    DEFF Research Database (Denmark)

    Saeed, Aso; Bergström, Göran; Zachrisson, Karin

    2009-01-01

    OBJECTIVE: To examine the diagnostic value of novel velocimetric colour duplex sonography indices in the screening of renal artery stenosis (RAS). METHODS: We performed a retrospective analysis of all consecutively studied patients at our centre with suspected RAS, and a colour duplex sonography ...

  3. Pushing the limits of Full-duplex: Design and Real-time Implementation

    CERN Document Server

    Sahai, Achaleshwar; Sabharwal, Ashutosh

    2011-01-01

    Recent work has shown the feasibility of single-channel full-duplex wireless physical layer, allowing nodes to send and receive in the same frequency band at the same time. In this report, we first design and implement a real-time 64-subcarrier 10 MHz full-duplex OFDM physical layer, FD-PHY. The proposed FD-PHY not only allows synchronous full-duplex transmissions but also selective asynchronous full-duplex modes. Further, we show that in over-the-air experiments using optimal antenna placement on actual devices, the self-interference can be suppressed upto 80dB, which is 10dB more than prior reported results. Then we propose a full-duplex MAC protocol, FD-MAC, which builds on IEEE 802.11 with three new mechanisms -- shared random backoff, header snooping and virtual backoffs. The new mechanisms allow FD-MAC to discover and exploit full-duplex opportunities in a distributed manner. Our over-the-air tests show over 70% throughput gains from using full-duplex over half-duplex in realistically used cases.

  4. Deformation in thrust-ramp anticlines and duplexes: implications for geometry and porosity

    Energy Technology Data Exchange (ETDEWEB)

    Groshong, R.H. Jr.; Usdansky, S.I.

    1986-05-01

    A computerized kinematic model of thrust-ramp anticline geometry allows workers to predict the zones of greatest deformation in ramp anticlines and fault duplexes. The model assumes a constant cross-section area, symmetrical fold hinges, and slip in the hanging wall parallel to the ramp and forelimb. Assuming that the collapse of original porosity or the generation of secondary fracture porosity is proportional to deformation, the model can be used to predict porosity changes. Deformation in a single ramp anticline is greatest in the forelimb and backlimb, and may be absent in the crest. A duplex structure results from comparatively closely spaced thrusts that have a common upper detachment horizon. Relatively wide spacing between the duplex faults yields a bumpy roofed duplex as in the central Appalachians. Forelimbs may be deformed twice and should show greater porosity modification. Relatively close spacing between ramp-and-flat thrusts can produce a listric-fault, snakehead anticline geometry because younger faults deform the preexisting thrust slices. The resulting geometry is here called a snakehead duplex and appears to be fairly common, as in the Jumpingpound field in the Canadian Rockies. Each thrust slice within the duplex is deformed six times or more, providing the maximum opportunity for deformation-related porosity changes. Maximum fracture porosity should occur in thrusts having listric-fan or snakehead duplex geometry. Structures involving duplexes generally should be better than isolated ramp anticlines.

  5. [Imaging techniques in the preoperative diagnosis of soft tissue tumors. A comparison of MRT, CT, sonography, angiography and conventional x-rays].

    Science.gov (United States)

    Roeren, T; Gindele, A; Grosspietsch, C; Dueck, M; Kauffmann, G W

    1992-12-01

    In a study on 51 patients with histologically confirmed soft tissue tumors (STT), we retrospectively evaluated the preoperative use of imaging procedures (MRI, CT, ultrasound, angiography, plain film) for identification of tumor size, delineation, and determination of malignancy and tissue type. The findings were correlated with intraoperative findings and histological diagnosis. The overall diagnostic method of choice for preoperative imaging of STT is MRI, followed by CT. Ultrasound, although sensitive, lacks the required specificity. Angiography and plain film can only be used for specific indications, as they generally do not make it possible to stage the tumor. Combining our results with those from the more recent literature, we propose a diagnostic algorithm according to which MRI would generally be performed for preoperative staging of STT. CT and plain film should only be used if bony infiltration is suspected; angiography is indicated for planning intraarterial chemotherapy or embolization or if vascular infiltration is probable.

  6. Pre-operative Identification and Surgical Management of the Appendiceal Mucocele: A Case Report.

    Science.gov (United States)

    Lynch, Kevin; Cho, Sung; Andres, Robert; Knight, Jennifer; Con, Jorge

    2016-01-01

    An appendiceal mucocele (AM) is an uncommon differential in the patient being evaluated for acute appendicitis. Although often asymptomatic, AMs can clinically mimic acute appendicitis, and preoperative distinction between these processes facilitates optimal management. We report the case of a 60-year-old male with an AM presenting with nausea and periumbilical pain radiating to the right lower quadrant. Literature relevant to the diagnosis and treatment of AMs is reviewed, with emphasis on diagnosis through radiographic imaging and surgical management. Abdominal CT scan or ultrasound are useful in identifying AMs preoperatively. A decision to perform a right hemicolectomy should be influenced by the criteria reported by Gonzalez-Moreno. The safety of the laparoscopic resection relative to an open appendectomy is debated.

  7. Thermal Aging Phenomena in Cast Duplex Stainless Steels

    Energy Technology Data Exchange (ETDEWEB)

    Byun, T. S.; Yang, Y.; Overman, N. R.; Busby, J. T.

    2016-02-28

    Cast stainless steels (CASSs) have been extensively used for the large components of light water reactor (LWR) power plants such as primary coolant piping and pump casing. The thermal embrittlement of CASS components is one of the most serious concerns related to the extended-term operation of nuclear power plants. Many past researches have concluded that the formation of Cr–rich α'-phase by Spinodal decomposition of δ-ferrite phase is the primary mechanism for the thermal embrittlement. Cracking mechanism in the thermally-embrittled duplex stainless steels consists of the formation of cleavage at ferrite and its propagation via separation of ferrite-austenite interphase. This article intends to provide an introductory overview on the thermal aging phenomena in LWR relevant conditions. Firstly, the thermal aging effect on toughness is discussed in terms of the cause of embrittlement and influential parameters. An approximate analysis of thermal reaction using Arrhenius equation was carried out to scope the aging temperatures for the accelerated aging experiments to simulate the 60 and 80 years of services. Further, equilibrium precipitation calculation was performed for model CASS alloys using the CALPHAD program and the results are used to describe the precipitation behaviors in duplex stainless steels. These results are also to be used to guide an on-going research aiming to provide knowledge-based conclusive prediction for the integrity of the CASS components of LWR power plants during the service life extended up to and beyond 60 years.

  8. Fabrication of Duplex Coated U-Mo-Ti Atomized Powder

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Ji Min; Kim, Woo Jeong; Lee, Kyu Hong [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Ryu, Ho Jin [Korea Advanced Institue of Science and Technology, Daejeon (Korea, Republic of)

    2013-10-15

    The results of an annealing test showed that the coating layers inhibit the formation of interaction layers. The results of duplex coating showed that nitride coating layers inhibit the formation of other coating layers. High-density U-Mo alloys are regarded as promising candidates for advanced research reactor fuel as they have shown stable irradiation performance when compared to other uranium alloys and compounds. However, interaction layer formation between the U-Mo alloys and Al matrix degrades the irradiation performance of U-Mo dispersion fuel. Therefore, the addition of Ti in U-Mo alloys, the addition of Si in a Al matrix, and silicide or nitride coating on the surface of U-Mo particles have been proposed to inhibit the interaction layer growth. In this study, U-Mo-Ti alloy powder was produced using a centrifugal atomization method. In addition, nitride and silicide duplex coating layers were fabricated on the surface of the U-Mo-Ti particles. The coated powders were characterized by using X-ray diffraction, SEM, and EDX. Silicide and nitride single coating layers were fabricated on the surface of U-7wt%Mo-1wt%Ti alloys with a thickness of about 10.20 micrometers.

  9. Sex determination in 6 bovid species by duplex PCR.

    Science.gov (United States)

    Prashant; Gour, Digpal S; Dubey, Prem P; Jain, Anubhav; Gupta, Subhash C; Joshi, Balwinder K; Kumar, Dinesh

    2008-01-01

    Sex determination in domestic animals is of potential value to livestock breeding programs. The aim of this study was to develop a simple and accurate PCR-based sex determination protocol, which can be applicable to 6 major domesticated species of the family Bovidae, viz. Bos frontalis, B. grunniens, B. indicus, Bubalus bubalis, Capra hircus, and Ovis aries. In silico analysis was done to identify conserved DNA sequence in the HMG box region of the sex-determining region of the Y-chromosome (SRY gene) across the bovids. Duplex PCR assay, including the SRY gene and the GAPDH housekeeping gene, was optimized by using genomic DNA extracted from blood samples of known sex. It was possible to identify the sex of animals by amplifying both gender-specific (SRY) and autosomal (GAPDH) genes simultaneously in the duplex reaction, with the male yielding two bands and the female one band. The protocol was subjected to a blind test that showed a 100 percent specificity and accuracy, thus it can be used in sex determination in livestock breeding programs.

  10. Physical-Layer Security of a Buffer-Aided Full-Duplex Relaying System

    KAUST Repository

    El Shafie, Ahmed

    2016-07-07

    This letter proposes a novel hybrid half-/full-duplex relaying scheme to enhance the relay channel security. A source node (Alice) communicates with her destination node (Bob) in the presence of a buffer-aided full-duplex relay node (Rooney) and a potential eavesdropper (Eve). Rooney adopts two different relaying, namely randomize-and-forward and decode-andforward relaying strategies, to improve the security of the legitimate system. In the first relaying strategy, Rooney uses a codebook different from that used at Alice. In the second relaying strategy, Rooney and Alice use the same codebooks. In addition, Rooney switches between half-duplex and full-duplex modes to further enhance the security of the legitimate system. The numerical results demonstrate that our proposed scheme achieves a significant average secrecy end-to-end throughput improvement relative to the conventional bufferless full-duplex relaying scheme.

  11. Hole Transport in A-form DNA/RNA Hybrid Duplexes

    Science.gov (United States)

    Wong, Jiun Ru; Shao, Fangwei

    2017-01-01

    DNA/RNA hybrid duplexes are prevalent in many cellular functions and are an attractive target form for electrochemical biosensing and electric nanodevice. However the electronic conductivities of DNA/RNA hybrid duplex remain relatively unexplored and limited further technological applications. Here cyclopropyl-modified deoxyribose- and ribose-adenosines were developed to explore hole transport (HT) in both DNA duplex and DNA/RNA hybrids by probing the transient hole occupancies on adenine tracts. HT yields through both B-form and A-form double helixes displayed similar shallow distance dependence, although the HT yields of DNA/RNA hybrid duplexes were lower than those of DNA duplexes. The lack of oscillatory periods and direction dependence in HT through both helixes implied efficient hole propagation can be achieved via the hole delocalization and coherent HT over adenine tracts, regardless of the structural variations.

  12. Throughput Analysis of Full Duplex Communication with Asymmetric Traffic in Small Cell Systems

    DEFF Research Database (Denmark)

    Mahmood, Nurul Huda; Berardinelli, Gilberto; Mogensen, Preben Elgaard;

    2015-01-01

    in this contribution using network analysis tools from stochastic geometry. The analytical findings are further confirmed through computer-based Monte-Carlo simulations. Asymmetric downlink/uplink traffic pattern and the increased network interference stemming from full duplex transmissions are found to limit its......Full duplex communication promises a 100% throughput gain by enabling simultaneous transmission and reception. However, such simultaneous communication leads to a corresponding increase in the network interference. In addition, full duplex communication can only be exploited when traffic...... is available in both uplink and downlink directions; while, cellular network traffic tend to be downlink heavy in practice. The potential throughput gains of full duplex communication over conventional half duplex transmission in a small cell network with asymmetric traffic conditions are investigated...

  13. Sequence-selective targeting of duplex DNA by peptide nucleic acids

    DEFF Research Database (Denmark)

    Nielsen, Peter E

    2010-01-01

    Sequence-selective gene targeting constitutes an attractive drug-discovery approach for genetic therapy, with the aim of reducing or enhancing the activity of specific genes at the transcriptional level, or as part of a methodology for targeted gene repair. The pseudopeptide DNA mimic peptide...... nucleic acid (PNA) can recognize duplex DNA with high sequence specificity and affinity in triplex, duplex and double-duplex invasive modes or non-invasive triplex modes. Novel PNA modification has improved the affinity for DNA recognition via duplex invasion, double-duplex invasion and triplex...... recognition considerably. Such modifications have also resulted in new approaches to targeted gene repair and sequence-selective double-strand cleavage of genomic DNA....

  14. Enhanced H-bonding and pi-stacking in DNA: a potent duplex-stabilizing and mismatch sensing nucleobase analogue

    DEFF Research Database (Denmark)

    Lou, Chenguang; Dallmann, Andre; Marafini, Pietro;

    2014-01-01

    X-pyrene is a new nucleic acid duplex stabilizing cytosine analogue that combines enhanced pi-stacking, hydrogen bonding and electrostatic interactions to greatly increase the stability of bulged DNA duplexes and DNA/RNA hybrids. X-pyrene is highly selective for guanine as a partner and duplex...... analogue for use in a variety of biological applications....

  15. Water-evaporation reduction by duplex films: application to the human tear film.

    Science.gov (United States)

    Cerretani, Colin F; Ho, Nghia H; Radke, C J

    2013-09-01

    Water-evaporation reduction by duplex-oil films is especially important to understand the physiology of the human tear film. Secreted lipids, called meibum, form a duplex film that coats the aqueous tear film and purportedly reduces tear evaporation. Lipid-layer deficiency is correlated with the occurrence of dry-eye disease; however, in-vitro experiments fail to show water-evaporation reduction by tear-lipid duplex films. We review the available literature on water-evaporation reduction by duplex-oil films and outline the theoretical underpinnings of spreading and evaporation kinetics that govern behavior of these systems. A dissolution-diffusion model unifies the data reported in the literature and identifies dewetting of duplex films into lenses as a key challenge to obtaining significant evaporation reduction. We develop an improved apparatus for measuring evaporation reduction by duplex-oil films including simultaneous assessment of film coverage, stability, and temperature, all under controlled external mass transfer. New data reported in this study fit into the larger body of work conducted on water-evaporation reduction by duplex-oil films. Duplex-oil films of oxidized mineral oil/mucin (MOx/BSM), human meibum (HM), and bovine meibum (BM) reduce water evaporation by a dissolution-diffusion mechanism, as confirmed by agreement between measurement and theory. The water permeability of oxidized-mineral-oil duplex films agrees with those reported in the literature, after correction for the presence of mucin. We find that duplex-oil films of bovine and human meibum at physiologic temperature reduce water evaporation only 6-8% for a 100-nm film thickness pertinent to the human tear film. Comparison to in-vivo human tear-evaporation measurements is inconclusive because evaporation from a clean-water surface is not measured and because the mass-transfer resistance is not characterized.

  16. Half-Duplex and Full-Duplex AF and DF Relaying with Energy-Harvesting in Log-Normal Fading

    KAUST Repository

    Rabie, Khaled M.

    2017-08-15

    Energy-harvesting (EH) and wireless power transfer in cooperative relaying networks have recently attracted a considerable amount of research attention. Most of the existing work on this topic however focuses on Rayleigh fading channels, which represent outdoor environments. In contrast, this paper is dedicated to analyze the performance of dual-hop relaying systems with EH over indoor channels characterized by log-normal fading. Both half-duplex (HD) and full-duplex (FD) relaying mechanisms are studied in this work with decode-and-forward (DF) and amplify-and-forward (AF) relaying protocols. In addition, three EH schemes are investigated, namely, time switching relaying, power splitting relaying and ideal relaying receiver which serves as a lower bound. The system performance is evaluated in terms of the ergodic outage probability for which we derive accurate analytical expressions. Monte Carlo simulations are provided throughout to validate the accuracy of our analysis. Results reveal that, in both HD and FD scenarios, AF relaying performs only slightly worse than DF relaying which can make the former a more efficient solution when the processing energy cost at the DF relay is taken into account. It is also shown that FD relaying systems can generally outperform HD relaying schemes as long as the loop-back interference in FD is relatively small. Furthermore, increasing the variance of the log-normal channel has shown to deteriorate the performance in all the relaying and EH protocols considered.

  17. Ultrasound guidance system for prostate biopsy

    Science.gov (United States)

    Hummel, Johann; Kerschner, Reinhard; Kaar, Marcus; Birkfellner, Wolfgang; Figl, Michael

    2017-03-01

    We designed a guidance system for prostate biopsy based on PET/MR images and 3D ultrasound (US). With our proposed method common inter-modal MR-US (or CT-US in case of PET/CTs) registration can be replaced by an intra-modal 3D/3D-US/US registration and an optical tracking system (OTS). On the pre-operative site, a PET/MR calibration allows to link both hybrid modalities with an abdominal 3D-US. On the interventional site, another abdominal 3D US is taken to merge the pre-operative images with the real-time 3D-US via 3D/3D-US/US registration. Finally, the images of a tracked trans-rectal US probe can be displayed with the pre-operative images by overlay. For PET/MR image fusion we applied a point-to-point registration between PET and OTS and MR and OTS, respectively. 3D/3D-US/US registration was evaluated for images taken in supine and lateral patient position. To enable table shifts between PET/MR and US image acquisition a table calibration procedure is presented. We found fiducial registration errors of 0.9 mm and 2.8 mm, respectively, with respect to the MR and PET calibration. A target registration error between MR and 3D US amounted to 1.4 mm. The registration error for the 3D/3D-US/US registration was found to be 3.7 mm. Furthermore, we have shown that ultrasound is applicable in an MR environment.

  18. Ultrasound in differential diagnosis of periapical radiolucencies: A radiohistopathological study

    Directory of Open Access Journals (Sweden)

    Neha Khambete

    2015-01-01

    Full Text Available Objectives: To evaluate the efficacy of ultrasound in differential diagnosis of periapical radiolucencies. Materials and Methods: Ten patients aged between 19 years and 40 years with periapical lesions associated with anterior maxillary or mandibular teeth were selected and consented for the study. Pre-operative periapical radiographs were obtained. Measurements and provisional diagnoses of the apical areas were made by two specialist observers on two separate occasions. Preoperative ultrasound examinations with Doppler flowmetry were then performed and the images assessed by two specialist observers for the size, contents, vascular supply and a provisional diagnosis made as to whether the lesion was a cyst or granuloma. Endodontic surgery was performed including curettage of the apical tissues to enable histopathological investigation, which provided the gold standard diagnosis. All measurements and findings were compared and statistically analyzed. Results: Total 10 lesions were identified in 10 patients. On periapical radiographs, lesions were readily identified but observers were unable to differentiate granuloma from cyst using either modality. Where sufficient buccal cortical bone had been resorbed, ultrasound imaging was simple but underestimated the size of the lesions compared with periapical radiographs. In all cases, the ultrasound diagnosis agreed with the histopathological gold standard. Conclusion: Ultrasonography (USG can provide accurate information about the nature of intraosseous lesions of the jaws before any surgical procedure. It is proposed that USG with Doppler flowmetry can provide an additional diagnostic tool without invasive surgery, where treatment option is nonsurgical.

  19. Preoperative education for lumbar surgery for radiculopathy

    Directory of Open Access Journals (Sweden)

    A. Louw

    2009-02-01

    Full Text Available To date no studies have been published on preoperative education forpatients who had lumbar surgery. The aim of this study was to determine if there is a demand for preoperative education for patients who had lumbar surgery for radiculopathy. A convenience sample of 47 patients who had lumbar surgery and a random sample of 141 physiotherapists involved in treating patients who had lumbar surgery completed a newly developed spinal surgery questionnaire. The data were analyzed using descriptiveand inferential statistical tests. Results showed that 100% of the patients and 99% of therapists view preoperative education to be an important component for lumbar surgery for radiculopathy. The most important factors identifiedfor inclusion in preoperative educational programs were reason for surgery, risks associated with surgery, limitations following surgery and more education regarding pain. The preferred method of education delivery was verbal one-on-one education. This study demonstrates that there is a demand for preoperative education for patients who had lumbar surgery.

  20. [Preoperative assessment of lung disease patients.].

    Science.gov (United States)

    Ramos, Gilson; Ramos Filho, José; Pereira, Edísio; Junqueira, Marcos; Assis, Carlos Henrique C

    2003-02-01

    Lung complications are the most frequent causes of postoperative morbidity-mortality, especially in lung disease patients. So, those patients should be preoperatively carefully evaluated and prepared, both clinically and laboratorially. This review aimed at determining surgical risk and at establishing preoperative procedures to minimize peri and postoperative morbidity-mortality in lung disease patients. Major anesthetic-surgical repercussions in lung function have already been described. Similarly, we tried to select higher-risk patients, submitted or not to lung resection. To that end, clinical and laboratorial propedeutics were used. Finally, a proposal of a preoperative algorithm was presented for procedures with lung resection. Lung disease patients, especially those with chronic evolution, need to be preoperatively thoroughly evaluated. ASA physical status and Goldmans cardiac index are important risk forecasting factors for lung disease patients not candidates for lung resection. Adding to these criteria, estimated postoperative max VO2, FEV1 and diffusion capacity are mandatory for some patients submitted to lung resection. beta2-agonists and steroids should be considered in the preoperative period of these patients.

  1. Color doppler ultrasound and quantitative histologic study of angiogenesis in ovarian tumors.

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Objective: To investigate whether there is any correlation between minimum resistance index (RImin) and mierovessel density (MVD) in ovarian tumors. Methods: The intratumor artery RImin of 61 patients with ovarian tumor was measured by color doppler ultra-sound (CDU) preoperatively. MVD i-

  2. Automatic Ultrasound Scanning

    DEFF Research Database (Denmark)

    Moshavegh, Ramin

    Medical ultrasound has been a widely used imaging modality in healthcare platforms for examination, diagnostic purposes, and for real-time guidance during surgery. However, despite the recent advances, medical ultrasound remains the most operator-dependent imaging modality, as it heavily relies...... on the user adjustments on the scanner interface to optimize the scan settings. This explains the huge interest in the subject of this PhD project entitled “AUTOMATIC ULTRASOUND SCANNING”. The key goals of the project have been to develop automated techniques to minimize the unnecessary settings...... on the scanners, and to improve the computer-aided diagnosis (CAD) in ultrasound by introducing new quantitative measures. Thus, four major issues concerning automation of the medical ultrasound are addressed in this PhD project. They touch upon gain adjustments in ultrasound, automatic synthetic aperture image...

  3. Ultrasound-Guided Breast Biopsy

    Science.gov (United States)

    ... Professions Site Index A-Z Ultrasound-Guided Breast Biopsy An ultrasound-guided breast biopsy uses sound waves ... Guided Breast Biopsy? What is Ultrasound-Guided Breast Biopsy? Lumps or abnormalities in the breast are often ...

  4. Children's (Pediatric) Abdominal Ultrasound Imaging

    Medline Plus

    Full Text Available ... located within a child's abdomen. A Doppler ultrasound study may be part of a child's abdominal ultrasound ... pain from the procedure. If a Doppler ultrasound study is performed, your child may actually hear pulse- ...

  5. Children's (Pediatric) Abdominal Ultrasound Imaging

    Medline Plus

    Full Text Available ... of page What are some common uses of the procedure? Abdominal ultrasound imaging is performed to evaluate ... for ultrasound examinations. top of page What does the equipment look like? Ultrasound scanners consist of a ...

  6. Children's (Pediatric) Abdominal Ultrasound Imaging

    Medline Plus

    Full Text Available ... News Physician Resources Professions Site Index A-Z Children's (Pediatric) Ultrasound - Abdomen Children’s (pediatric) ultrasound imaging of ... 30 minutes. top of page What will my child experience during and after the procedure? Ultrasound examinations ...

  7. Children's (Pediatric) Abdominal Ultrasound Imaging

    Medline Plus

    Full Text Available ... ultrasound. top of page How does the procedure work? Ultrasound imaging is based on the same principles ... to-use and less expensive than other imaging methods. Ultrasound imaging is extremely safe and does not ...

  8. Children's (Pediatric) Abdominal Ultrasound Imaging

    Medline Plus

    Full Text Available ... ultrasound. top of page How does the procedure work? Ultrasound imaging is based on the same principles ... pain from the procedure. If a Doppler ultrasound study is performed, your child may actually hear pulse- ...

  9. Children's (Pediatric) Abdominal Ultrasound Imaging

    Medline Plus

    Full Text Available ... child's abdominal ultrasound examination. Doppler ultrasound , also called color Doppler ultrasonography, is a special ultrasound technique that ... and processes the sounds and creates graphs or color pictures that represent the flow of blood through ...

  10. Preoperative and Postoperative Assessing for Chronic Occlusive Arterial Diseases in Lower Limbs Using Color Doppler Ultrasound%彩色多普勒超声在下肢慢性动脉闭塞性疾病手术前后的应用

    Institute of Scientific and Technical Information of China (English)

    查长松; 赵玉华; 黄月红; 隋向梅

    2001-01-01

    Objective:To explore the value of color Dopplerultrasound(CDU)for the examination of chronic occlusive arterial diseases in lower limbs before and after operation.Methods:Thirty patients were examined by CDU and DSA.Vascular bypass grafts in 9 patients were assessed after operation.Results:Twenty patients had occlusive lesions confirmed by DSA,and 18 patients(90%)got the same results using CDU.CDU revealed diagnostic according with DSA in 6 of 9 patients with single or multilevel segmental significant stenosis.One patient was normal both in DSA and CDU.Vascular grafts in 7 patients had normal flow.2 patients had acute thrombosis in grafts.One patient had muscular hematoma in the calf.Conclusions:(CDU) is a valuable method for preoperative assessment and postoperative followup of chronic occlusive arterial diseases in lower limbs.%目的:探讨彩色多普勒超声(CDU)在下肢慢性动脉闭塞性疾病手术前后的应用价值。方法:对30例患者下肢动脉同时进行了CDU和数字减影血管造影(DSA)检查。9例血管移植术后进行了超声随访。结果:20例DSA显示动脉闭塞,其中18例(90%)CDU检查结果相吻合。9例DSA为单个或多个动脉节段显著性狭窄,其中6例(66.7%)CDU判断正确。1例双下肢动脉DSA和CDU均未见异常。7例血管移植物血流通畅,2例PTFE移植物术后急性血栓形成。1例小腿肌层血肿。结论:CDU是下肢慢性动脉闭塞性疾病术前评价和术后随访有价值的方法。

  11. l-Proline and RNA Duplex m-Value Temperature Dependence.

    Science.gov (United States)

    Schwinefus, Jeffrey J; Baka, Nadia L; Modi, Kalpit; Billmeyer, Kaylyn N; Lu, Shutian; Haase, Lucas R; Menssen, Ryan J

    2017-08-03

    The temperature dependence of l-proline interactions with the RNA dodecamer duplex surface exposed after unfolding was quantified using thermal and isothermal titration denaturation monitored by uv-absorbance. The m-value quantifying proline interactions with the RNA duplex surface area exposed after unfolding was measured using RNA duplexes with GC content ranging between 17 and 83%. The m-values from thermal denaturation decreased with increasing GC content signifying increasingly favorable proline interactions with the exposed RNA surface area. However, m-values from isothermal titration denaturation at 25.0 °C were independent of GC content and less negative than those from thermal denaturation. The m-value from isothermal titration denaturation for a 50% GC RNA duplex decreased (became more negative) as the temperature increased and was in nearly exact agreement with the m-value from thermal denaturation. Since RNA duplex transition temperatures increased with GC content, the more favorable proline interactions with the high GC content duplex surface area observed from thermal denaturation resulted from the temperature dependence of proline interactions rather than the RNA surface chemical composition. The enthalpy contribution to the m-value was positive and small (indicating a slight increase in duplex unfolding enthalpy with proline) while the entropic contribution to the m-value was positive and increased with temperature. Our results will facilitate proline's use as a probe of solvent accessible surface area changes during biochemical reactions at different reaction temperatures.

  12. Analysis of Structural Flexibility of Damaged DNA Using Thiol-Tethered Oligonucleotide Duplexes.

    Directory of Open Access Journals (Sweden)

    Masashi Fujita

    Full Text Available Bent structures are formed in DNA by the binding of small molecules or proteins. We developed a chemical method to detect bent DNA structures. Oligonucleotide duplexes in which two mercaptoalkyl groups were attached to the positions facing each other across the major groove were prepared. When the duplex contained the cisplatin adduct, which was proved to induce static helix bending, interstrand disulfide bond formation under an oxygen atmosphere was detected by HPLC analyses, but not in the non-adducted duplex, when the two thiol-tethered nucleosides were separated by six base pairs. When the insert was five and seven base pairs, the disulfide bond was formed and was not formed, respectively, regardless of the cisplatin adduct formation. The same reaction was observed in the duplexes containing an abasic site analog and the (6–4 photoproduct. Compared with the cisplatin case, the disulfide bond formation was slower in these duplexes, but the reaction rate was nearly independent of the linker length. These results indicate that dynamic structural changes of the abasic site- and (6–4 photoproduct-containing duplexes could be detected by our method. It is strongly suggested that the UV-damaged DNA-binding protein, which specifically binds these duplexes and functions at the first step of global-genome nucleotide excision repair, recognizes the easily bendable nature of damaged DNA.

  13. Preparation and property of duplex Ni-B-TiO2/Ni nano-composite coatings

    Science.gov (United States)

    Wang, Shu-Jen; Wang, Yuxin; Shu, Xin; Tay, Seeleng; Gao, Wei; Shakoor, R. A.; Kahraman, Ramazan

    2015-03-01

    The duplex Nickel-Boron-Titania/Nickel (Ni-B-TiO2/Ni) coatings were deposited on mild steel by using two baths with Ni as the inner layer. TiO2 nanoparticles were incorporated into the Ni-B coatings as the outer layer by using solid particle mixing method. The microstructure, morphology and corrosion resistance of the duplex Ni-B-TiO2/Ni nanocomposite coatings were systemically investigated. The results show that the duplex interface was uniform and the adhesion between two layers was very good. The microhardness of duplex Ni-B-TiO2/Ni coating was much higher than the Ni coating due to the outer layer of Ni-B-TiO2 coating. The corrosion resistance of the duplex Ni-B-TiO2/Ni coating was also significantly improved comparing with single Ni-B coating. The Ni-B-10 g/L TiO2/Ni coating was found to have the best corrosion resistance among these duplex coatings. This type of duplex Ni-B-TiO2/Ni coating, with high hardness and good corrosion resistance properties, should be able to find broad applications under adverse environmental conditions.

  14. Focused ultrasound in ophthalmology

    Directory of Open Access Journals (Sweden)

    Silverman RH

    2016-09-01

    Full Text Available Ronald H Silverman1,2 1Department of Ophthalmology, Columbia University Medical Center, 2F.L. Lizzi Center for Biomedical Engineering, Riverside Research, New York, NY, USA Abstract: The use of focused ultrasound to obtain diagnostically significant information about the eye goes back to the 1950s. This review describes the historical and technological development of ophthalmic ultrasound and its clinical application and impact. Ultrasound, like light, can be focused, which is crucial for formation of high-resolution, diagnostically useful images. Focused, single-element, mechanically scanned transducers are most common in ophthalmology. Specially designed transducers have been used to generate focused, high-intensity ultrasound that through thermal effects has been used to treat glaucoma (via cilio-destruction, tumors, and other pathologies. Linear and annular transducer arrays offer synthetic focusing in which precise timing of the excitation of independently addressable array elements allows formation of a converging wavefront to create a focus at one or more programmable depths. Most recently, linear array-based plane-wave ultrasound, in which the array emits an unfocused wavefront and focusing is performed solely on received data, has been demonstrated for imaging ocular anatomy and blood flow. While the history of ophthalmic ultrasound extends back over half-a-century, new and powerful technologic advances continue to be made, offering the prospect of novel diagnostic capabilities. Keywords: ophthalmic ultrasound, ultrasound biomicroscopy (UBM, high-intensity focused ultrasound (HIFU, ultrafast imaging, Doppler imaging 

  15. Ultrasound skin tightening.

    Science.gov (United States)

    Minkis, Kira; Alam, Murad

    2014-01-01

    Ultrasound skin tightening is a noninvasive, nonablative method that allows for energy deposition into the deep dermal and subcutaneous tissue while avoiding epidermal heating. Ultrasound coagulation is confined to arrays of 1-mm(3) zones that include the superficial musculoaponeurotic system and connective tissue. This technology gained approval from the Food and Drug Administration as the first energy-based skin "lifting" device, specifically for lifting lax tissue on the neck, submentum, and eyebrows. Ultrasound has the unique advantage of direct visualization of treated structures during treatment. Ultrasound is a safe and efficacious treatment for mild skin tightening and lifting.

  16. Full Duplex Wireless Communications for Cognitive Radio Networks

    CERN Document Server

    Cheng, Wenchi; Zhang, Hailin

    2011-01-01

    As a key in cognitive radio networks (CRNs), dynamic spectrum access needs to be carefully designed to minimize the interference and delay to the \\emph{primary} (licensed) users. One of the main challenges in dynamic spectrum access is to determine when the \\emph{secondary} (unlicensed) users can use the spectrum. In particular, when the secondary user is using the spectrum, if the primary user becomes active to use the spectrum, it is usually hard for the secondary user to detect the primary user instantaneously, thus causing unexpected interference and delay to primary users. The secondary user cannot detect the presence of primary users instantaneously because the secondary user is unable to detect the spectrum at the same time while it is transmitting. To solve this problem, we propose the full duplex wireless communications scheme for CRNs. In particular, we employ the Antennas Cancellation (AC), the RF Interference Cancellation (RIC), and the Digital Interference Cancellation (DIC) techniques for second...

  17. Current status of duplex surface engineered Ti-based materials

    Institute of Scientific and Technical Information of China (English)

    T.Bell

    2004-01-01

    Industrial exploitation of the high specific strength and corrosion resistance of titanium were dominated historically by the technological advances which have been made in gas-turbine engine and aircraft components. Realization of the possible benefits in general engineering has been limited by the absence of any proven and reliable means of overcoming the poor wear resistance and galling tendency suffered by titanium alloys when in contact with other materials. This problem can only be addressed by optimizing and demonstrating industrially viable surface engineering processes for titanium in general engineering. The status of single and duplex surface engineering systems are reviewed. In addition, in order to fully realize the potential of advanced surface engineering of titanium components contact mechanics models are developed to enable the automotive engineers to design dynamically the loaded automotive engine and transmission components.

  18. Technology of Welding Joints Mixed with Duplex Steel

    Directory of Open Access Journals (Sweden)

    Słania J.

    2016-03-01

    Full Text Available Results of the examinations of sample plates of mixed joints with the duplex steel were discussed. Examinations were taken on the sample plates of mixed joints of sheet plates type P355NL1 and X2CrNiMoN22-5-3 welded by the flux-cored wire DW-329A by the Kobelco company of the following category T 22 9 3 NL RC/M3 in the gas shroud M21 (Ar+18%CO2 (plate no.1, and nickel covered electrodes E Ni 6082 by the Böhler company (plate no. 2. Results of the side bend test of welded joint, transverse tensile test, stretching of the weld metal, impact strength, micro and macroscopic metallographic examinations, and measurements of the delta ferrite content were presented.

  19. Duplex Stirling gas fired heating only heat pump

    Science.gov (United States)

    Beale, W.

    1982-03-01

    In phase I the Duplex Stirling Gas fired Heat Pump was analyzed with the aid of the Sunpower third order simulation and optimization code and found to show heating COP of 1.7 at the rating point of 8 C (17 F) with a heat delivery of 10 kW. Also it was found that a direct heat exchange between working fluid and source and sink air was consistent with high COP in the heat pump, thus eliminating the need for an intermediate heat transfer fluid and its associated pumps and controls. Further, it was demonstrated in the simulation that the heat engine power output could be matched to the heat pump load over the range of source temperatures without need of complex control systems. Cost estimates, along with COP figures from the analysis indicated a payback time of 2 to 4 years in completion with existing combustion heating systems in northern climates.

  20. The Modern Applications of Surface Duplex Treatment Technology

    Institute of Scientific and Technical Information of China (English)

    JerzySmolik; JanWalkowicz; AdamMazurkiewicz; JerzyTomaszewski

    2004-01-01

    The paper presents results of the research carried out by the authors in different fields of plasma surface technologies applications. Three groups of different surface engineering technologies are shown in the paper. The first one concerns the possibility of using the duplex treatment technology for creation of biocompatible diamond-like a-C:H films. The paper presents research results concerning influence of the process parameters of the a-C:H coatings creation by means of the RFPACVD method in the pure methane amlosphere on their phase structure and mechanical properties. In the second case authors present the concept of a new special multilayer thermal barrier coatings with the PAPVD diffusion barrier layers based on aluminium oxide. As the last one the special application of plasma techniques for creation of composite materials characterized by the muffling of mechanical vibration was presented.