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

    Energy Technology Data Exchange (ETDEWEB)

    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)

  3. Duplex/doppler ultrasound test (image)

    Science.gov (United States)

    The duplex/doppler ultrasound test examines the blood flow in the major arteries and veins in the arms and legs. The ... duplex ultrasonagraphy to visualize the blood flow and doppler ultrasonagraphy provides an audio means to hear the ...

  4. 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

  5. Duplex ultrasound for identifying renal artery stenosis

    DEFF Research Database (Denmark)

    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. Grading of proximal internal carotid artery (ICA) stenosis by Doppler/duplex ultrasound (DUS) and computed tomographic angiography (CTA): correlation and interrater reliability in real-life practice.

    Science.gov (United States)

    Matz, Oliver; Nikoubashman, Omid; Rajkumar, Parajuli; Keuler, Andreas; Wiesmann, Martin; Schulz, Jörg B; Reich, Arno

    2017-03-01

    Doppler/duplex ultrasound (DUS) and computed tomographic angiography (CTA) are frequently applied methods to assess the degree of proximal internal carotid artery (ICA) stenoses in patients with acute ischemic stroke. This study evaluated the agreement and interrater reliability (IR) of both methods using a revised DUS grading system as well as different criteria (ECST/NASCET) under real-life conditions. CTA and DUS data of 281 proximal ICA stenoses [143 patients; 65.7 % male; age (mean (years) ± SD, range) 72.2 ± 11.1, 40-99] were retrospectively analyzed. For both methods, two independent raters estimated the degree of stenosis according to NASCET and ECST criteria. DUS raters applied revised German DUS criteria. For agreement and IR assessment, the linear weighted Kappa statistic was used. Correlation between DUS and CTA was substantial irrespective of the applied classification [weighted Kappa: 0.77 (NASCET)/0.79 (ECST)]. IR for DUS was almost perfect (weighted Kappa: 0.94) and better than for CTA [weighted Kappa: 0.78 (NASCET)/0.78 (ECST)]. In a real-life setting, CTA and DUS assessments of the degree of proximal ICA stenoses agreed substantially irrespective of the criteria applied (ECST/NASCET). For DUS, IR was better than for CTA.

  7. Duplex Ultrasound Surveillance After Uncomplicated Endovascular Abdominal Aortic Aneurysm Repair.

    Science.gov (United States)

    Schaeffer, Jacob S; Shakhnovich, Irina; Sieck, Kyle N; Kallies, Kara J; Davis, Clark A; Cogbill, Thomas H

    2017-07-01

    Health-care costs and risks of radiation and intravenous contrast exposure challenge computed tomography angiography (CTA) as the standard surveillance method after endovascular abdominal aortic aneurysm repair (EVAR). We reviewed our experience using Duplex ultrasound scan (DUS) as an initial and subsequent surveillance technique after uncomplicated EVAR. The medical records of patients who underwent EVAR from 2004 to 2014 with at least 1 postoperative imaging study were retrospectively reviewed. Duplex ultrasound scan was the primary modality, with CTA reserved for patients with suspicious findings. Mean follow-up was 3.2 years for 266 patients. Fifty-seven endoleaks (7 type I, 50 type II) were detected in 51 patients (19%). Nineteen (33%) endoleaks were identified and monitored by DUS alone. Nine (16%) endoleaks were identified on CTA without prior DUS. Twenty-two (39%) endoleaks were identified on DUS and confirmed by CTA; 6 of these patients had a secondary intervention. When compared to subsequent CTA, there were 7 discordant results: 4 false-negative and 3 false-positive endoleaks on DUS. Two of these patients with discordant results required intervention. Follow-up CTA was not obtained for the other 2 patients due to severe comorbidities including renal disease. One of these patients eventually developed abdominal aortic aneurysm rupture and death. Among 88 patients with both DUS and CTA, positive predictive value and negative predictive value for DUS were 0.88 and 0.94, respectively. Sac size on DUS compared to CTA resulted in an interclass correlation coefficient of r = .84. In our experience, DUS was safe and effective for initial and follow-up surveillance after uncomplicated EVAR.

  8. Duplex ultrasound: Indications and findings in a newly created ...

    African Journals Online (AJOL)

    Conclusion: Duplex ultrasound has been shown to diagnose varied vascular pathologies even in a locale where it is a relatively new technique. It is recommended that timely referrals be made, and mobile Doppler units be acquired to save more lives and limbs in the developing world. Keywords: Calabar, deep venous ...

  9. Duplex ultrasound: Indications and findings in a newly created ...

    African Journals Online (AJOL)

    2015-09-21

    Sep 21, 2015 ... Background: Peripheral limb vascular diseases form one of the most common diseases that affect the middle-aged and the elderly. Duplex ultrasound has revolutionized medicare and is an important modality for investigating them. Unfortunately, this modality is still not popular in our environment and in ...

  10. Duplex ultrasound in the assessment of peripheral arterial disease

    Science.gov (United States)

    Aly, Sayed A. A. F.

    Arteriography plays a central role in the assessment of peripheral arterial disease. Arteriography is associated with the risk of damage to the artery, peripheral embolisation, hazards of intra-arterial injection and exposure to ionising radiation. Arteriography provides an anatomical assessment of arterial stenosis but does not measure the functional results of the stenosis. Modern high resolution ultrasound imaging technology enables non-invasive assessment of vascular diseases and allows functional assessment of blood flow. This investigation is of proven value in studying carotid disease. The aim of the study was to determine the accuracy of duplex ultrasonography (DUS) in assessment of lower limb arterial disease in comparison with arteriography (IA DSA). A technical comparison has been made between the description of arterial lesion as indicated by DUS and IA DSA. In addition, the sensitivity of DUS in assessing multisegmental arterial disease has been determined. The clinical decision has been investigated in a further study in which five surgeons were asked to determine patient management based on IA DSA and DUS data in the same patient group. Concordance between management strategies was assessed. DUS was used as the primary method of investigation in further series of patients. Criteria were established to determine which patients would require angiography. The computer-assisted image analysis was used to study the ultrasound images of arterial stenosis and a method of analysing such images objectively was established. Two studies have been included in this section. These assess the technical accuracy of ultrasound image analysis compared with histological examination of plaque. The reproducibility of the image analysis has also been tested. I have developed a classification for peripheral arterial disease to be used to facilitate the communication between vascular laboratory staff who perform the duplex ultrasonography and surgeons who use this

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

    DEFF Research Database (Denmark)

    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)....

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

    DEFF Research Database (Denmark)

    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....

  13. Can duplex Doppler ultrasound replace computerized tomography in staging patients with renal cell carcinoma?

    NARCIS (Netherlands)

    Bos, SD; Mensink, HJA

    The purpose of this study was to evaluate the accuracy and reliability of duplex Doppler ultrasound (US) and computerized tomography (CT) in staging patients with renal cell carcinoma (RCC). Sixty-six patients were evaluated pre-operatively with duplex Doppler ultrasound and CT. The results were

  14. Significance of CT scan and color Doppler duplex ultrasound in the assessment of Abernethy malformation

    National Research Council Canada - National Science Library

    Nacif, Lucas Souto; Paranaguá-Vezozzo, Denise Cerqueira; Galvão, Flávio Henrique Ferreira; Rocha, Manoel S; Andraus, Wellington; Carrilho, Flair Jose; D'Albuquerque, Luiz Carneiro

    2015-01-01

    .... In this study we highlight the significance of the use of CT scans and Color Doppler Duplex Ultrasound for the diagnosis, treatment and evolution assessment in two adults with Abernethy malformation...

  15. 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.

    Science.gov (United States)

    Colleran, Gabrielle C; Cronin, Kevin C; Browne, Ann M; Hynes, Niamh; Sultan, Sherif

    2009-11-30

    Anterior triangle masses pose an important clinical dilemma. It is very difficult to distinguish the potential pathologies pre operatively by clinical and radiological assessment. 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. 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.

  16. 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.

  17. Significance of CT scan and color Doppler duplex ultrasound in the assessment of Abernethy malformation.

    Science.gov (United States)

    Nacif, Lucas Souto; Paranaguá-Vezozzo, Denise Cerqueira; Galvão, Flávio Henrique Ferreira; Rocha, Manoel S; Andraus, Wellington; Carrilho, Flair Jose; D'Albuquerque, Luiz Carneiro

    2015-09-18

    Abernethy malformation is a rare congenital vascular abnormality in which the portal vein bypasses the liver and drains directly into the inferior vena cava. Diagnosis is complex and requires good quality imaging methods to identify details in systemic and portal circulation in order to establish diagnostic confirmation and treatment strategy. In this study we highlight the significance of the use of CT scans and Color Doppler Duplex Ultrasound for the diagnosis, treatment and evolution assessment in two adults with Abernethy malformation. The diagnosis and the treatment of two patients with Abernethy malformation by CT scan and Color Doppler Duplex Ultrasound is described. One patient was submitted to liver transplantation due to chronic liver disease and multiple nodules diagnosed as adenoma. The other patient had normal liver function and a mild neurological and psychomotor dysfunction, therefore we adopted clinical treatment and close liver parenchyma evaluation and nodule surveillance, using an imaging approach involving intercalating CT scan and Color Doppler Duplex Ultrasound every 6 months. We highlight some important direct and indirect findings of non-invasive imaging methods. Abernethy malformation requires meticulous image diagnosis to improve treatment and avoid iatrogenic procedures. CT scans and Color Doppler Duplex Ultrasound are both efficient methods for diagnosis, treatment planning and evolution assessment of patients with Abernethy malformation.

  18. 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

    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...

  19. Hepatic venous pressure gradients measured by duplex ultrasound

    Energy Technology Data Exchange (ETDEWEB)

    Tasu, J.-P.; Rocher, L.; Peletier, G.; Kuoch, V.; Kulh, E.; Miquel, A.; Buffet, C.; Biery, M

    2002-08-01

    AIMS: The hepatic venous pressure gradient is a major prognostic factor in portal hypertension but its measurement is complex and requires invasive angiography. This study investigated the relationship between the hepatic venous pressure gradient and a number of Doppler measurements, including the arterial acceleration index. METHOD: We measured the hepatic venous pressure gradient in 50 fasting patients at hepatic venography. Immediately afterwards, a duplex sonographic examination of the liver was performed at which multiple measurements and indices of the venous and arterial hepatic vasculature were made. RESULTS: Hepatic arterial acceleration was correlated directly with the hepatic venous pressure gradient (r = 0.83, P < 0.0001) and with the Child-Pugh score (r = 0.63, P < 0.0001). An acceleration index cut-off value of 1 m.s{sup -2} provided a positive predictive value of 95%, a sensitivity of 65% and a specificity of 95% for detecting patients with severe portal hypertension (hepatic venous pressure gradient > 12 mmHg). A correlation between the hepatic venous pressure gradient and the congestion index of the portal vein velocity (r = 0.45,P = 0.01) and portal vein velocity (r = 0.40,P = 0.044), was also noted. CONCLUSION: Measuring the hepatic arterial acceleration index may help in the non-invasive evaluation of portal hypertension. Tasu, J.-P. et al. (2002)

  20. 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

    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......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...... administration. RESULTS: Portal venous flow measured by EUS flowmetry and TTU flowmetry correlated significantly (R = 0.92, P flow after terlipressin measured by EUS and TTU...

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

    Energy Technology Data Exchange (ETDEWEB)

    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

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

    Directory of Open Access Journals (Sweden)

    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. 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 ...

  4. Functional assessment of high-grade ICA stenosis with duplex ultrasound and transcranial Doppler.

    Science.gov (United States)

    Zachrisson, Helene; Fouladiun, Marita; Blomstrand, Christian; Holm, Jan; Volkmann, Reinhard

    2012-05-01

    Duplex ultrasound (DUS) has shown a >90% accuracy compared to angiography, concerning the degree of internal carotid artery (ICA) stenosis. However, uncertainty may occur in a severe stenosis, in which peak systolic velocity (PSV) may decrease owing to high flow resistance or high backward pressure. We investigated intracranial collateral flows using transcranial Doppler (TCD) to further evaluate the hemodynamic significance of high-grade ICA stenosis. In this retrospective study, 320 consecutive symptomatic patients were examined. The degree of ICA stenosis and collateral capacity in the circle of Willis was investigated by DUS and TCD. In addition, magnetic resonance angiography (MRA) was added in a subgroup of 204 patients. The criterion for hemodynamic significant ICA stenosis was established collateral flow. In 91% of all symptomatic vessels (291 vessels), an ICA stenosis of ≥70% was found. Established collateral flow always indicated precerebral carotid artery disease of ≥70%. Furthermore, in 11% of the whole study material, collateral reserve capacity was found despite high-grade (≥70%) ICA stenosis. PSV in ICA ICA stenosis is of hemodynamic significance and to assess collateral patterns. Established collateral blood flow will help to identify patients with ≥70% (ECST) carotid artery disease. TCD might be of value when flow velocity criteria combined with plaque assessment by DUS are inclusive. Other diagnostic methods may also be considered. © 2012 The Authors. Clinical Physiology and Functional Imaging © 2012 Scandinavian Society of Clinical Physiology and Nuclear Medicine.

  5. Carotid duplex ultrasound and transcranial Doppler findings in commercial divers and pilots.

    Science.gov (United States)

    Dormanesh, Banafshe; Vosoughi, Kia; Akhoundi, Fahimeh H; Mehrpour, Masoud; Fereshtehnejad, Seyed-Mohammad; Esmaeili, Setareh; Sabet, Azin Shafiee

    2016-12-01

    The risky working environments of divers and pilots, and the possible role of extreme ambient pressure in carotid stenosis, make ischemic stroke an important occupational concern among these professionals. In this study, we aimed to evaluate the association of being exposed to hyperbaric or hypobaric conditions with carotid artery stenosis by comparing common carotid intima-media thickness (CCIMT) and blood flow velocities of cerebral arteries in divers and pilots using carotid duplex ultrasound (CDUS) and transcranial Doppler (TCD). CDUS and transtemporal TCD were performed in 29 divers, 36 pilots and 30 control participants. Medical history, blood pressure, lipid profile and blood sugar were recorded to control the previously well-known risk factors of atherosclerosis. Findings of the CDUS and TCD [including: CCIMT and blood flow velocities of internal carotid artery (ICA), common carotid artery (CCA), and middle cerebral artery (MCA)] of divers and pilots were compared with those of the control group using regression analysis models. Both right and left side CCIMT were significantly higher in divers (P < 0.05) and pilots (P < 0.05) in comparison with the control group. Carotid index [peak systolic velocity (PSV) of ICA/PSV of CCA) of divers and pilots were also higher than the control group. TCD findings were not significantly different between divers, pilots, and the control group. Increased CCIMT and carotid index in diver and pilot groups appear to be suggestive of accelerated atherosclerosis of carotid artery in these occupational groups.

  6. 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

    DEFF Research Database (Denmark)

    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...

  7. Selective use of duplex ultrasound to replace preoperative arteriography for failing arterial vein grafts.

    Science.gov (United States)

    Calligaro, K D; Syrek, J R; Dougherty, M J; Rua, I; McAffee-Bennett, S; Doerr, K J; Raviola, C A; DeLaurentis, D A

    1998-01-01

    In an effort to minimize costs and patient discomfort, we determined whether duplex ultrasound (DU) could selectively replace preoperative arteriography performed in the radiology suite to diagnose failing arterial bypass grafts (FABs) constructed of autogenous vein. Between January 1, 1994, and December 31, 1996, we treated 106 FABs. Graft revision solely on the basis of DU was performed only if a focal stenosis was clearly identified in the graft (peak systolic velocity [PSV] > 300 cm/sec, ratio of adjacent PSVs > 3.0) or in inflow or outflow arteries (resulting in uniform graft PSVs < 45 cm/sec). Intraoperative arteriograms were frequently obtained to confirm DU findings. Preoperative arteriograms were obtained if DU revealed multiple or ill-defined stenoses, diffuse inflow or outflow arterial disease, uniformly low PSVs without an identifiable lesion, or equivocal stenosis despite clinical evidence of an FAB. Seventy-three (69%) FABs with 81 lesions were revised on the basis of DU only. Of 76 stenotic lesions, an intraoperative arteriogram or surgical findings confirmed a diameter stenosis of 75% to 99% in 69 grafts (91%) and stenosis of 50% to 74% in three grafts (4%). DU incorrectly identified the site of stenosis or underdiagnosed the extent of disease in four grafts (5%). DU correctly identified the site of missed arteriovenous fistulas in five grafts. The 73 FABs were treated with intraoperative balloon angioplasty (30 grafts), patch angioplasty (20), interposition or jump grafts (12), ligation of arteriovenous fistula (3), a new bypass graft (1), or a combination of these interventions (7). A significant change in intraoperative strategy potentially could have been avoided if a preoperative arteriogram had been obtained in three of the 73 FABs (4.1%). DU can reliably be used to revise FABs and avoid the morbidity, discomfort, and cost of confirmatory arteriography in two thirds of cases.

  8. Early Detection of Subclinical Atherosclerosis in Asymptomatic Patients Assessed by Carotid Duplex and Coronary Computed Tomography

    Directory of Open Access Journals (Sweden)

    Cheng-Hsi Chen

    2013-03-01

    Conclusion: Carotid duplex may detect subclinical vascular atherosclerosis in more than half of asymptomatic patients without coronary artery calcification detected by coronary computed tomography. These findings have important implications for early-stage atherosclerosis screening and implementation of primary preventive intervention.

  9. Quantification of iliac artery stenoses: a methodological comparative study between intravascular ultrasound, arteriography and duplex scanning

    DEFF Research Database (Denmark)

    Vogt, K C; Rasmussen, John Bøje Grønvall; Skovgaard, Lene T

    1998-01-01

    66 y, admitted for either PTA (n=18) or femoro-femoral crossover bypass surgery (n=20), were examined by IVUS, single plane arteriography and duplex scanning. The predictive value, sensitivity, specificity and kappa value of IVUS were higher than the corresponding values for arteriography. Logistic...... regression analysis found that IVUS had a predictive value (p=0.0003) for diagnosing significant stenosis as defined by duplex scanning, but arteriography did not (p=0.1). However, this difference in usefulness as predictors did not reach significance. The agreement between arteriography and IVUS...... was relatively good. The conclusion is that IVUS seems to be superior to single-plane arteriography in predicting hemodynamically significant stenoses as defined by duplex scanning....

  10. Quantification of iliac artery stenoses: a methodological comparative study between intravascular ultrasound, arteriography and duplex scanning

    DEFF Research Database (Denmark)

    Vogt, K C; Rasmussen, John Bøje Grønvall; Skovgaard, Lene T

    1998-01-01

    66 y, admitted for either PTA (n=18) or femoro-femoral crossover bypass surgery (n=20), were examined by IVUS, single plane arteriography and duplex scanning. The predictive value, sensitivity, specificity and kappa value of IVUS were higher than the corresponding values for arteriography. Logistic...

  11. Duplex Doppler ultrasound assessment of clitoral hemodynamics after topical administration of alprostadil in women with arousal and orgasmic disorders.

    Science.gov (United States)

    Bechara, A; Bertolino, M V; Casabé, A; Munarriz, R; Goldstein, I; Morin, A; Secin, F; Literat, B; Pesaresi, M; Fredotovich, N

    2003-01-01

    There are limited hemodynamic data in women with arousal or orgasmic disorders and even fewer normative control hemodynamic data in women without sexual dysfunction. In addition, there is limited experience with topical vasoactive agents (used to maximize genital smooth muscle relaxation) applied to the external genitalia during hemodynamic evaluations. The aim of this study was to report duplex Doppler ultrasound clitoral cavernosal arterial changes before and after topical PGE-1 (Alprostadil) administration in control women and in patients with arousal and orgasmic sexual disorders. We found that women with sexual arousal and orgasmic disorders had significantly (p < 0.05) diminished clitoral peak systolic and end diastolic velocity responses compared to controls. Further research is needed to establish the diagnostic role of topical vasoactive agents in the hemodynamic evaluation of women with sexual dysfunction.

  12. A Prospective Evaluation of Duplex Ultrasound for Thoracic Outlet Syndrome in High-Performance Musicians Playing Bowed String Musicians

    Directory of Open Access Journals (Sweden)

    Garret Adam

    2018-01-01

    Full Text Available Thoracic outlet syndrome (TOS is a neurovascular condition involving the upper extremity, which is known to occur in individuals who perform chronic repetitive upper extremity activities. We prospectively evaluate the incidence of TOS in high-performance musicians who played bowed string musicians. Sixty-four high-performance string instrument musicians from orchestras and professional musical bands were included in the study. Fifty-two healthy volunteers formed an age-matched control group. Bilateral upper extremity duplex scanning for subclavian vessel compression was performed in all subjects. Provocative maneuvers including Elevated Arm Stress Test (EAST and Upper Limb Tension Test (ULTT were performed. Abnormal ultrasound finding is defined by greater than 50% subclavian vessel compression with arm abduction, diminished venous waveforms, or arterial photoplethysmography (PPG tracing with arm abduction. Bowed string instruments performed by musicians in our study included violin (41%, viola (33%, and cello (27%. Positive EAST or ULTT test in the musician group and control group were 44%, and 3%, respectively (p = 0.03. Abnormal ultrasound scan with vascular compression was detected in 69% of musicians, in contrast to 15% of control subjects (p = 0.03. TOS is a common phenomenon among high-performance bowed string instrumentalists. Musicians who perform bowed string instruments should be aware of this condition and its associated musculoskeletal symptoms.

  13. [Ultrasound duplex scanning of head and neck vessels with the aim of preoperational preparation of the patients with inherent microtia of the III degree].

    Science.gov (United States)

    Chkadua, T Z; Kuz'mina, I V; Ramazanova, Iu I

    2010-01-01

    For surgical treatment of patients with inherent microtia of the III degree we use one stage method of otoplasty with silicone implant and parietotemporal fascial flap. In order to receive most full picture of the status of superficial temporal artery and its branches the additional diagnostic study is necessary. Method of ultrasound duplex scanning let to study any vessel in real time regimen under monitor screen control. Received by us results of ultrasound duplex scanning of superficial temporal artery branches in patients with inherent microtia of the III degree let us to conclude about the status of the vessel wall, to determine diameter and vessel occlusion, to evaluate and measure blood flow parameters. It is diagnostically necessary criteria for answering the question about flap vitality and in such a way let to avoid possible complications.

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

    Science.gov (United States)

    Pezzoni, Fabio; Scroppo, Fabrizio Ildefonso

    2016-10-05

    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). 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 (PII)of 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). 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 deficit of maintenance; at the "crus"and at "mid penis" the hemodynamic

  15. 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

  16. 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.

  17. Preoperative imaging for DIEA perforator flaps: a comparative study of computed tomographic angiography and Doppler ultrasound.

    Science.gov (United States)

    Rozen, Warren M; Phillips, Timothy J; Ashton, Mark W; Stella, Damien L; Gibson, Robert N; Taylor, G Ian

    2008-01-01

    Abdominal donor-site flaps, including the transverse rectus abdominis musculocutaneous (TRAM) and deep inferior epigastric artery (DIEA) perforator flaps, are standard in autologous breast reconstruction. With significant variation in the vascular anatomy of the abdominal wall, preoperative imaging is essential for preoperative planning and reducing intraoperative error. Doppler and color duplex sonography have been used with varying results, and the quest continues for optimal preoperative assessment. Computed tomographic angiography has recently been proposed as a noninvasive modality for this purpose. This is the first study to formally compare preoperative Doppler ultrasound with computed tomographic angiography for imaging the DIEA. Eight consecutive patients undergoing DIEA perforator flap surgery for breast reconstruction underwent both computed tomographic angiography and Doppler ultrasound preoperatively. All investigations and procedures were performed at the same institution with the same primary and assisting surgeons and the same radiology team. Computed tomographic angiography was superior to Doppler ultrasound at identifying the course of the DIEA and its branching pattern, and in visualizing its perforators. Preoperative computed tomographic angiography was highly specific (100 percent) and more sensitive in mapping and visualizing perforators (p = 0.0078). It was also proficient at identifying the superficial epigastric arterial system and for effectively displaying the results intraoperatively. It was substantially quicker and removed the interobserver error associated with Doppler ultrasonography. The study was ceased after eight patients because of the overwhelming benefit of computed tomographic angiography over Doppler ultrasonography. Computed tomographic angiography is a valuable imaging modality for the preoperative assessment of the donor-site vascular supply for TRAM and DIEA perforator flaps.

  18. [Ultrasound duplex scanning in the assessment of the effectiveness of gravitation therapy and conservative treatment of patients with atherosclerosis obliterans of the lower extremities].

    Science.gov (United States)

    Galkin, R A; Makarov, I V; Preobrazhenskaia, N M

    2004-01-01

    Ultrasound duplex scanning was used to compare the results of the treatment of 162 patients suffering from atherosclerosis obliterans of the lower extremities. It is to be noted that 50 patients were administered only gravitation therapy, 72 patients underwent a complex of treatment measures including, in addition to gravitation therapy, physiotherapy and drug treatment, and 40 patients received conservative treatment alone. The assessment criteria were the maximal systolic velocity of blood flow (V(max)), end diastolic mean, velocity (V(min)), mean maximal velocity (V(mean)), volume velocity of blood flow (V(vol)), ankle/brachial index (ABI), and index of regional perfusion (IRP), proposed by us and representing the percent ratio of the volume velocity of blood flow to the minute heart volume (MHV). It has been revealed in the course of the treatment that the best clinical outcome was recorded in patients who received a complex of treatment measures. The use of gravitation therapy alone provided better treatment results as compared to those obtained in patients administered standard conservative therapy. Of all the indicators used, only V(mean), V(vol), ABI and IRP are of the clinical significance. However, the most significant information on the segmental blood flow was obtained on the assessment of the IRP whose values did not depend on the changes in central hemodynamics. In contrast to the ABI, the advantage of the IRP lies in the possibility of blood flow assessment in different segments and arteries of the extremities. So, the use of the quantitative indicators of ultrasound duplex scanning and, first of all, of the IRP, allows an objective evaluation of the segmental blood flow and may serve one of the significant criteria of the treatment effectiveness.

  19. 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

    Energy Technology Data Exchange (ETDEWEB)

    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)

  20. Ultrasound

    Science.gov (United States)

    ... reflect off body structures. A computer receives the waves and uses them to create a picture. Unlike with an x-ray or CT scan, this test does not use ionizing radiation. The test is done in the ultrasound ...

  1. 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....

  2. Reproducibility of abdominal fat assessment by ultrasound and computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Mauad, Fernando Marum; Chagas-Neto, Francisco Abaete; Benedeti, Augusto Cesar Garcia Saab; Nogueira-Barbosa, Marcello Henrique; Muglia, Valdair Francisco; Carneiro, Antonio Adilton Oliveira; Muller, Enrico Mattana; Elias Junior, Jorge, E-mail: fernando@fatesa.edu.br [Faculdade de Tecnologia em Saude (FATESA), Ribeirao Preto, SP (Brazil); Universidade de Fortaleza (UNIFOR), Fortaleza, CE (Brazil). Departmento de Radiologia; Universidade de Sao Paulo (FMRP/USP), Ribeirao Preto, SP (Brazil). Faculdade de Medicina. Departmento de Medicina Clinica; Universidade de Sao Paulo (FFCLRP/USP), Ribeirao Preto, SP (Brazil). Faculdade de Filosofia, Ciencias e Letras; Hospital Mae de Deus, Porto Alegre, RS (Brazil)

    2017-05-15

    Objective: To test the accuracy and reproducibility of ultrasound and computed tomography (CT) for the quantification of abdominal fat in correlation with the anthropometric, clinical, and biochemical assessments. Materials and Methods: Using ultrasound and CT, we determined the thickness of subcutaneous and intra-abdominal fat in 101 subjects-of whom 39 (38.6%) were men and 62 (61.4%) were women-with a mean age of 66.3 years (60-80 years). The ultrasound data were correlated with the anthropometric, clinical, and biochemical parameters, as well as with the areas measured by abdominal CT. Results: Intra-abdominal thickness was the variable for which the correlation with the areas of abdominal fat was strongest (i.e., the correlation coefficient was highest). We also tested the reproducibility of ultrasound and CT for the assessment of abdominal fat and found that CT measurements of abdominal fat showed greater reproducibility, having higher intraobserver and interobserver reliability than had the ultrasound measurements. There was a significant correlation between ultrasound and CT, with a correlation coefficient of 0.71. Conclusion: In the assessment of abdominal fat, the intraobserver and interobserver reliability were greater for CT than for ultrasound, although both methods showed high accuracy and good reproducibility. (author)

  3. 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.

  4. A fully programmable computing architecture for medical ultrasound machines.

    Science.gov (United States)

    Schneider, Fabio Kurt; Agarwal, Anup; Yoo, Yang Mo; Fukuoka, Tetsuya; Kim, Yongmin

    2010-03-01

    Application-specific ICs have been traditionally used to support the high computational and data rate requirements in medical ultrasound systems, particularly in receive beamforming. Utilizing the previously developed efficient front-end algorithms, in this paper, we present a simple programmable computing architecture, consisting of a field-programmable gate array (FPGA) and a digital signal processor (DSP), to support core ultrasound signal processing. It was found that 97.3% and 51.8% of the FPGA and DSP resources are, respectively, needed to support all the front-end and back-end processing for B-mode imaging with 64 channels and 120 scanlines per frame at 30 frames/s. These results indicate that this programmable architecture can meet the requirements of low- and medium-level ultrasound machines while providing a flexible platform for supporting the development and deployment of new algorithms and emerging clinical applications.

  5. Computational fluid dynamics using in vivo ultrasound blood flow measurements

    DEFF Research Database (Denmark)

    Traberg, Marie Sand; Pedersen, Mads Møller; Hemmsen, Martin Christian

    2012-01-01

    This paper presents a model environment for construction of patient-specific computational fluid dynamic (CFD) models for the abdominal aorta (AA). Realistic pulsatile velocity waveforms are employed by using in vivo ultrasound blood flow measurements. Ultrasound is suitable for acquisition....... The estimated and smoothed velocity profiles were quantitatively compared. The energy contained in the velocity profile after smoothing is 65% larger relative to the noise contaminated estimated profiles. In conclusion, a model environment that produces realistic patient-specific CFD simulation models without...

  6. Gray-scale and color duplex Doppler ultrasound of hand joints in the evaluation of disease activity and treatment in rheumatoid arthritis.

    Science.gov (United States)

    Ivanac, Gordana; Morović-Vergles, Jadranka; Brkljačić, Boris

    2015-06-01

    To evaluate the role of gray-scale and color duplex-Doppler ultrasound (CDUS) in diagnosis of changes of hand joints and assessment of treatment efficacy in patients with rheumatoid arthritis (RA) by comparing qualitative and quantitative US parameters with clinical and laboratory indicators of disease activity. Ulnocarpal (UC), metacarpophalangeal (MCP), and proximal interphalangeal (PIP) joints in 30 patients with RA were examined by gray-scale and CDUS before and after six months of treatment. Morphologic and quantitative Doppler findings (synovial thickness, effusion quantity, vascularization degree, resistance index, velocities) were compared with clinical indicators of disease progression: disease activity score (DAS 28), Health Assessment Questionnaire (HAQ), rheumatoid factor (RF), erythrocyte sedimentation rate (ESR), and C reactive protein (CRP). Clinical indicators changed significantly after treatment: ESR from 38.1±22.4 mm/h to 27.8±20.9 mm/h (P=0.013), DAS 28 from 5.47±1.56 to 3.87±1.65 (Pjoints we observed a significant change in at least one US parameter, in 6 out of 12 joints we observed a significant change in ≥2 parameters, and in 2 UC joints we observed significant changes in ≥3 parameters. The new finding was that the cut-off values of resistance index of 0.40 at baseline and of 0.55 after the treatment indicated the presence of active disease and the efficacy of treatment, respectively; also it was noticed that PIP joints can be omitted from examination protocol. Gray scale and CDUS are useful in diagnosis of changes in UC and MCP joints of patients with RA and in monitoring the treatment efficacy.

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

    Directory of Open Access Journals (Sweden)

    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

  8. Glasses for 3D ultrasound computer tomography: phase compensation

    Science.gov (United States)

    Zapf, M.; Hopp, T.; Ruiter, N. V.

    2016-03-01

    Ultrasound Computer Tomography (USCT), developed at KIT, is a promising new imaging system for breast cancer diagnosis, and was successfully tested in a pilot study. The 3D USCT II prototype consists of several hundreds of ultrasound (US) transducers on a semi-ellipsoidal aperture. Spherical waves are sequentially emitted by individual transducers and received in parallel by many transducers. Reflectivity volumes are reconstructed by synthetic aperture focusing (SAFT). However, straight forward SAFT imaging leads to blurred images due to system imperfections. We present an extension of a previously proposed approach to enhance the images. This approach includes additional a priori information and system characteristics. Now spatial phase compensation was included. The approach was evaluated with a simulation and clinical data sets. An increase in the image quality was observed and quantitatively measured by SNR and other metrics.

  9. Knee cartilage segmentation and thickness computation from ultrasound images.

    Science.gov (United States)

    Faisal, Amir; Ng, Siew-Cheok; Goh, Siew-Li; Lai, Khin Wee

    2017-08-29

    Quantitative thickness computation of knee cartilage in ultrasound images requires segmentation of a monotonous hypoechoic band between the soft tissue-cartilage interface and the cartilage-bone interface. Speckle noise and intensity bias captured in the ultrasound images often complicates the segmentation task. This paper presents knee cartilage segmentation using locally statistical level set method (LSLSM) and thickness computation using normal distance. Comparison on several level set methods in the attempt of segmenting the knee cartilage shows that LSLSM yields a more satisfactory result. When LSLSM was applied to 80 datasets, the qualitative segmentation assessment indicates a substantial agreement with Cohen's κ coefficient of 0.73. The quantitative validation metrics of Dice similarity coefficient and Hausdorff distance have average values of 0.91 ± 0.01 and 6.21 ± 0.59 pixels, respectively. These satisfactory segmentation results are making the true thickness between two interfaces of the cartilage possible to be computed based on the segmented images. The measured cartilage thickness ranged from 1.35 to 2.42 mm with an average value of 1.97 ± 0.11 mm, reflecting the robustness of the segmentation algorithm to various cartilage thickness. These results indicate a potential application of the methods described for assessment of cartilage degeneration where changes in the cartilage thickness can be quantified over time by comparing the true thickness at a certain time interval.

  10. 3D ultrasound computer tomography for medical imaging

    Energy Technology Data Exchange (ETDEWEB)

    Gemmeke, H. [Forschungszentrum Karlsruhe, Institute for Data Processing and Electronics, P.O. Box 3640, 76021 Karlsruhe (Germany)], E-mail: hartmut.gemmeke@ipe.fzk.de; Ruiter, N.V. [Forschungszentrum Karlsruhe, Institute for Data Processing and Electronics, P.O. Box 3640, 76021 Karlsruhe (Germany)

    2007-10-01

    Our 3D ultrasound computer tomograph (USCT) is an device method aimed at early breast cancer diagnosis. It is capable of producing images with sub-millimeter resolution and high signal-to-noise ratio. This method is universally useable for the 3D analysis of sufficient small bodies similar to the size of a breast, which may be immersed in a liquid coupling medium. In this paper, an overview of the developed method and the first results for static test examples (phantoms) and the perspective of our 3D-USCT at Forschungszentrum Karlsruhe are presented.

  11. 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 ...

  12. [Diagnosis. Radiological study. Ultrasound, computed tomography and magnetic resonance imaging].

    Science.gov (United States)

    Gallo Vallejo, Francisco Javier; Giner Ruiz, Vicente

    2014-01-01

    Because of its low cost, availability in primary care and ease of interpretation, simple X-ray should be the first-line imaging technique used by family physicians for the diagnosis and/or follow-up of patients with osteoarthritis. Nevertheless, this technique should only be used if there are sound indications and if the results will influence decision-making. Despite the increase of indications in patients with rheumatological disease, the role of ultrasound in patients with osteoarthritis continues to be limited. Computed tomography (CT) is of some -although limited- use in osteoarthritis, especially in the study of complex joints (such as the sacroiliac joint and facet joints). Magnetic resonance imaging (MRI) has represented a major advance in the evaluation of joint cartilage and subchondral bone in patients with osteoarthritis but, because of its high cost and diagnostic-prognostic yield, this technique should only be used in highly selected patients. The indications for ultrasound, CT and MRI in patients with osteoarthritis continue to be limited in primary care and often coincide with situations in which the patient may require hospital referral. Patient safety should be bourne in mind. Patients should be protected from excessive ionizing radiation due to unnecessary repeat X-rays or inadequate views or to requests for tests such as CT, when not indicated. Copyright © 2014 Elsevier España, S.L. All rights reserved.

  13. 3D ultrasound computer tomography: update from a clinical study

    Science.gov (United States)

    Hopp, T.; Zapf, M.; Kretzek, E.; Henrich, J.; Tukalo, A.; Gemmeke, H.; Kaiser, C.; Knaudt, J.; Ruiter, N. V.

    2016-04-01

    Ultrasound Computer Tomography (USCT) is a promising new imaging method for breast cancer diagnosis. We developed a 3D USCT system and tested it in a pilot study with encouraging results: 3D USCT was able to depict two carcinomas, which were present in contrast enhanced MRI volumes serving as ground truth. To overcome severe differences in the breast shape, an image registration was applied. We analyzed the correlation between average sound speed in the breast and the breast density estimated from segmented MRIs and found a positive correlation with R=0.70. Based on the results of the pilot study we now carry out a successive clinical study with 200 patients. For this we integrated our reconstruction methods and image post-processing into a comprehensive workflow. It includes a dedicated DICOM viewer for interactive assessment of fused USCT images. A new preview mode now allows intuitive and faster patient positioning. We updated the USCT system to decrease the data acquisition time by approximately factor two and to increase the penetration depth of the breast into the USCT aperture by 1 cm. Furthermore the compute-intensive reflectivity reconstruction was considerably accelerated, now allowing a sub-millimeter volume reconstruction in approximately 16 minutes. The updates made it possible to successfully image first patients in our ongoing clinical study.

  14. Automated breast segmentation in ultrasound computer tomography SAFT images

    Science.gov (United States)

    Hopp, T.; You, W.; Zapf, M.; Tan, W. Y.; Gemmeke, H.; Ruiter, N. V.

    2017-03-01

    Ultrasound Computer Tomography (USCT) is a promising new imaging system for breast cancer diagnosis. An essential step before further processing is to remove the water background from the reconstructed images. In this paper we present a fully-automated image segmentation method based on three-dimensional active contours. The active contour method is extended by applying gradient vector flow and encoding the USCT aperture characteristics as additional weighting terms. A surface detection algorithm based on a ray model is developed to initialize the active contour, which is iteratively deformed to capture the breast outline in USCT reflection images. The evaluation with synthetic data showed that the method is able to cope with noisy images, and is not influenced by the position of the breast and the presence of scattering objects within the breast. The proposed method was applied to 14 in-vivo images resulting in an average surface deviation from a manual segmentation of 2.7 mm. We conclude that automated segmentation of USCT reflection images is feasible and produces results comparable to a manual segmentation. By applying the proposed method, reproducible segmentation results can be obtained without manual interaction by an expert.

  15. Quantitative analysis of ultrasound images for computer-aided diagnosis.

    Science.gov (United States)

    Wu, Jie Ying; Tuomi, Adam; Beland, Michael D; Konrad, Joseph; Glidden, David; Grand, David; Merck, Derek

    2016-01-01

    We propose an adaptable framework for analyzing ultrasound (US) images quantitatively to provide computer-aided diagnosis using machine learning. Our preliminary clinical targets are hepatic steatosis, adenomyosis, and craniosynostosis. For steatosis and adenomyosis, we collected US studies from 288 and 88 patients, respectively, as well as their biopsy or magnetic resonanceconfirmed diagnosis. Radiologists identified a region of interest (ROI) on each image. We filtered the US images for various texture responses and use the pixel intensity distribution within each ROI as feature parameterizations. Our craniosynostosis dataset consisted of 22 CT-confirmed cases and 22 age-matched controls. One physician manually measured the vectors from the center of the skull to the outer cortex at every 10 deg for each image and we used the principal directions as shape features for parameterization. These parameters and the known diagnosis were used to train classifiers. Testing with cross-validation, we obtained 72.74% accuracy and 0.71 area under receiver operating characteristics curve for steatosis ([Formula: see text]), 77.27% and 0.77 for adenomyosis ([Formula: see text]), and 88.63% and 0.89 for craniosynostosis ([Formula: see text]). Our framework is able to detect a variety of diseases with high accuracy. We hope to include it as a routinely available support system in the clinic.

  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)....

  17. Prolonged CT urography in duplex kidney.

    Science.gov (United States)

    Gong, Honghan; Gao, Lei; Dai, Xi-Jian; Zhou, Fuqing; Zhang, Ning; Zeng, Xianjun; Jiang, Jian; He, Laichang

    2016-05-13

    Duplex kidney is a common anomaly that is frequently associated with multiple complications. Typical computed tomography urography (CTU) includes four phases (unenhanced, arterial, parenchymal and excretory) and has been suggested to considerably aid in the duplex kidney diagnosi. Unfortunately, regarding duplex kidney with prolonged dilatation, the affected parenchyma and tortuous ureters demonstrate a lack of or delayed excretory opacification. We used prolonged-delay CTU, which consists of another prolonged-delay phase (1- to 72-h delay; mean delay: 24 h) to opacify the duplicated ureters and affected parenchyma. Seventeen patients (9 males and 8 females; age range: 2.5-56 y; mean age: 40.4 y) with duplex kidney were included in this study. Unenhanced scans did not find typical characteristics of duplex kidney, except for irregular perirenal morphology. Duplex kidney could not be confirmed on typical four-phase CTU, whereas it could be easily diagnosed in axial and CT-3D reconstruction using prolonged CTU (prolonged-delay phase). Between January 2005 and October 2010, in this review board-approved study (with waived informed consent), 17 patients (9 males and 8 females; age range: 2.5 ~ 56 y; mean age: 40.4 y) with suspicious duplex kidney underwent prolonged CTU to opacify the duplicated ureters and confirm the diagnosis. Our results suggest the validity of prolonged CTU to aid in the evaluation of the function of the affected parenchyma and in the demonstration of urinary tract malformations.

  18. Registration of human skull computed tomography data to an ultrasound treatment space using a sparse high frequency ultrasound hemispherical array.

    Science.gov (United States)

    O'Reilly, Meaghan A; Jones, Ryan M; Birman, Gabriel; Hynynen, Kullervo

    2016-09-01

    Transcranial focused ultrasound (FUS) shows great promise for a range of therapeutic applications in the brain. Current clinical investigations rely on the use of magnetic resonance imaging (MRI) to monitor treatments and for the registration of preoperative computed tomography (CT)-data to the MR images at the time of treatment to correct the sound aberrations caused by the skull. For some applications, MRI is not an appropriate choice for therapy monitoring and its cost may limit the accessibility of these treatments. An alternative approach, using high frequency ultrasound measurements to localize the skull surface and register CT data to the ultrasound treatment space, for the purposes of skull-related phase aberration correction and treatment targeting, has been developed. A prototype high frequency, hemispherical sparse array was fabricated. Pulse-echo measurements of the surface of five ex vivo human skulls were made, and the CT datasets of each skull were obtained. The acoustic data were used to rigidly register the CT-derived skull surface to the treatment space. The ultrasound-based registrations of the CT datasets were compared to the gold-standard landmark-based registrations. The results show on an average sub-millimeter (0.9 ± 0.2 mm) displacement and subdegree (0.8° ± 0.4°) rotation registration errors. Numerical simulations predict that registration errors on this scale will result in a mean targeting error of 1.0 ± 0.2 mm and reduction in focal pressure of 1.0% ± 0.6% when targeting a midbrain structure (e.g., hippocampus) using a commercially available low-frequency brain prototype device (InSightec, 230 kHz brain system). If combined with ultrasound-based treatment monitoring techniques, this registration method could allow for the development of a low-cost transcranial FUS treatment platform to make this technology more widely available.

  19. [Measurements of blood velocities using duplex sonography in carotid artery stents: analysis of reliability in an in-vitro model and computational fluid dynamics (CFD)].

    Science.gov (United States)

    Schönwald, U G; Jorczyk, U; Kipfmüller, B

    2011-01-01

    Stents are commonly used for the treatment of occlusive artery diseases in carotid arteries. Today, there is a controversial discussion as to whether duplex sonography (DS) displays blood velocities (BV) that are too high in stented areas. The goal of this study was to evaluate the effect of stenting on DS with respect to BV in artificial carotid arteries. The results of computational fluid dynamics (CFD) were also used for the comparison. To analyze BV using DS, a phantom with a constant flow (70 cm/s) was created. Three different types of stents for carotid arteries were selected. The phantom fluid consisted of 67 % water and 33 % glycerol. All BV measurements were carried out on the last third of the stents. Furthermore, all test runs were simulated using CFD. All measurements were statistically analyzed. DS-derived BV values increased significantly after the placement of the Palmaz Genesis stent (77.6 ± 4.92 cm/sec, p = 0.03). A higher increase in BV values was registered when using the Precise RX stent (80.1 ± 2.01 cm/sec, p CFD simulations showed similar results. Stents have a significant impact on BV, but no effect on DS. The main factor of the blood flow acceleration is the material thickness of the stents. Therefore, different stents need different velocity criteria. Furthermore, the results of computational fluid dynamics prove that CFD can be used to simulate BV in stented silicone tubes. © Georg Thieme Verlag KG Stuttgart · New York.

  20. 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)....

  1. COMPLEX DIAGNOSTICS AND MONITORING OF PRIMARY GLAUCOMA SIMPLEX WITH USE OF COMPUTER COLORIMETRIC ANALYSIS AND DUPLEX DOPPLEROGRAPHY

    Directory of Open Access Journals (Sweden)

    I.O. Kolbenev

    2009-09-01

    Full Text Available Glaucoma simplex is one of the basic causes of blindness. The main problem of glaucoma is its early recognition. It's well known that changes of anatomic structure of each organ are preceded by functional disorders, including disturbances of hemodynamics. Method of computer colorimetric analysis of disk of optic nerve (DON was worked out for the purpose of objective evaluation of its chroma as one of hemodynamics detection criteria. Computer program for analysis of DON chroma with calculation of integrated index (color index was developed. DON chroma was analyzed in the group of persons suspected of glaucoma, in the group of patients with glaucoma simplex and in healthy people. This method along with confocal scanning tomography of DON allows to evaluate objectively in dynamics its state in the presence of glaucoma simplex. These methods are necessary to be used in complex for diagnostics of early stages of glaucoma simplex.

  2. Computer-aided Detection of Cancer in Automated 3D Breast Ultrasound

    NARCIS (Netherlands)

    Tan, T.; Platel, B.; Mus, R.; Tabar, L.; Mann, R.; Karssemeijer, N.

    2013-01-01

    Automated 3D breast ultrasound (ABUS) has gained a lot of interest and may become widely used in screening of dense breasts, where sensitivity of mammography is poor. However, reading ABUS images is time consuming, and subtle abnormalities may be missed. Therefore, we are developing a computer aided

  3. Dominant and recessive polycystic kidney disease in children: Classification by intravenous pyelography, ultrasound, and computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Kaeaeriaeinen, H.; Jaeaeskelaeinen, J.; Kivisaari, L.; Koskimies, O.; Norio, R.

    1988-01-01

    Both dominant and recessive polycystic kidney disease appear in childhood. We have analyzed findings of intravenous pyelography, ultrasound and computed tomography in genetically classified cases of dominant (13 children) and recessive polycystic kidney disease (5 children) and thus defined criteria by which sporadic cases of childhood polycystic kidney disease can be classified to dominant or recessive polycystic kidney disease.

  4. [Comparison of conventional radiology, ultrasound and computer tomography in the preoperative localization of intraocular foreign bodies].

    Science.gov (United States)

    Markl, A; Hasenfratz, G; Mayr, B; Fink, U; Ingrisch, H; Lissner, J

    1983-12-01

    Three methods complementing each other are available for the preoperative intraocular localisation of foreign bodies. Basing on the results obtained, it is recommended, first of all, to localise the site of the foreign body by means of conventional x-ray film, followed by fine diagnosis via ultrasound and, finally, in problematic or doubtful cases, by means of computed tomography.

  5. The resolution integral: visual and computational approaches to characterizing ultrasound images

    Energy Technology Data Exchange (ETDEWEB)

    MacGillivray, T J [Wellcome Trust Clinical Research Facility, University of Edinburgh, Western General Hospital, Edinburgh, EH4 2XU (United Kingdom); Ellis, W; Pye, S D, E-mail: t.j.macgillivray@ed.ac.u [Medical Physics Department, NHS Lothian University Hospitals Division, Royal Infirmary, Edinburgh, EH16 4SA (United Kingdom)

    2010-09-07

    The resolution integral is a figure of merit that characterizes ultrasound images in terms of the ratio of the penetration of an ultrasound beam in soft tissue to the ultrasound beam width. This concept has been implemented using a novel tissue mimicking test object (the Edinburgh pipe phantom) that comprises a series of anechoic cylinders of different diameters embedded in a block of tissue-mimicking material. The resolution integral is calculated by imaging each cylinder in turn and measuring the depth range over which it can be detected. We have carried out these measurements using two complementary approaches: by visual assessment and using a computational approach. Data were collected from 12 transducers used on 12 different models of ultrasound scanner of various makes, ages and clinical performance. Transducer centre frequencies were in the range of 3 to 7.5 MHz. The computational approach makes use of standard image processing techniques to detect and segment anechoic structures in images of the test object. This was optimized against visual assessment results for one of the transducers, and subsequently used to evaluate the resolution integral for the others. The values of the resolution integral ranged from 40 to 69 and computed values were within {+-}11% of the corresponding visual assessments. The repeatability of both approaches was {+-}2-3%. The computational approach functions well compared to visual assessment and adds to the overall robustness of resolution integral measurements by providing an objective assessment algorithm.

  6. General Ultrasound Imaging

    Medline Plus

    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 ...

  7. Computer-Aided Characterization and Diagnosis of Diffuse Liver Diseases Based on Ultrasound Imaging: A Review.

    Science.gov (United States)

    Bharti, Puja; Mittal, Deepti; Ananthasivan, Rupa

    2016-04-19

    Diffuse liver diseases, such as hepatitis, fatty liver, and cirrhosis, are becoming a leading cause of fatality and disability all over the world. Early detection and diagnosis of these diseases is extremely important to save lives and improve effectiveness of treatment. Ultrasound imaging, a noninvasive diagnostic technique, is the most commonly used modality for examining liver abnormalities. However, the accuracy of ultrasound-based diagnosis depends highly on expertise of radiologists. Computer-aided diagnosis systems based on ultrasound imaging assist in fast diagnosis, provide a reliable "second opinion" for experts, and act as an effective tool to measure response of treatment on patients undergoing clinical trials. In this review, we first describe appearance of liver abnormalities in ultrasound images and state the practical issues encountered in characterization of diffuse liver diseases that can be addressed by software algorithms. We then discuss computer-aided diagnosis in general with features and classifiers relevant to diffuse liver diseases. In later sections of this paper, we review the published studies and describe the key findings of those studies. A concise tabular summary comparing image database, features extraction, feature selection, and classification algorithms presented in the published studies is also exhibited. Finally, we conclude with a summary of key findings and directions for further improvements in the areas of accuracy and objectiveness of computer-aided diagnosis. © The Author(s) 2016.

  8. Comparison of computed tomography, ultrasound and scintigraphy in the diagnosis of alcoholic liver disease

    Energy Technology Data Exchange (ETDEWEB)

    Meek, D.R.; Mills, P.R.; Gray, H.W.; Duncan, J.G.; Russell, R.I.; McKillop, J.H. (Royal Infirmary, Glasgow (UK))

    1984-01-01

    In 35 alcoholics with histologically proven liver disease, computed tomography (CT), grey scale ultrasonography and liver scintigraphy were evaluated for their abilities to detect an abnormal liver and to identify the patients with cirrhosis. Abnormal studies were present on CT in 83% of patients, in 64% on ultrasound and in 94% on scintigraphy. In 10 control patients specificity was 90% by CT, 100% by ultrasound and 70% by scintigraphy. CT and ultrasound were poor in identifying the alcoholics with cirrhosis. Scintigraphy suggested cirrhosis in all but one of the patients with this diagnosis. Similar images were obtained in half of the patients with fatty change without cirrhosis but, with the exception of one patient, this appeared to be due to co-existent hepatitis. The results suggest that scintigraphy is the best of the imaging tests for screening alcoholics for cirrhosis.

  9. Breast ultrasound lesions classification: a performance evaluation between manual delineation and computer segmentation

    Science.gov (United States)

    Yap, Moi Hoon; Yap, Chuin Hong

    2016-03-01

    Breast cancer is a threat to women worldwide. Manual delineation on breast ultrasound lesions is time-consuming and operator dependent. Computer segmentation of ultrasound breast lesions can be a challenging task due to the ill-defined lesions boundaries and issues related to the speckle noise in ultrasound images. The main contribution of this paper is to compare the performance of the computer classifier on the manual delineation and computer segmentation in malignant and benign lesions classification. This paper we implement computer segmentation using multifractal approach on a database consists of 120 images (50 malignant lesions and 70 benign lesions). The computer segmentation result is compared with the manual delineation using Jaccard Similarity Index (JSI). The result shows that the average JSI of 0.5010 (+/-0.2088) for malignant lesions and the average JSI of 0.6787 (+/-0.1290) for benign lesions. These results indicate lower agreement in malignant lesions due to the irregular shape while the higher agreement in benign lesions with regular shape. Further, we extract the shape descriptors for the lesions. By using logistic regression with 10 fold cross validation, the classification rates of manual delineation and computer segmentation are computed. The computer segmentation produced results with sensitivity 0.780 and specificity 0.871. However, the manual delineation produced sensitivity of 0.520 and specificity of 0.800. The results show that there are no clear differences between the delineation in MD and CS in benign lesions but the computer segmentation on malignant lesions shows better accuracy for computer classifier.

  10. Automated breast tumor detection and segmentation with a novel computational framework of whole ultrasound images.

    Science.gov (United States)

    Liu, Lei; Li, Kai; Qin, Wenjian; Wen, Tiexiang; Li, Ling; Wu, Jia; Gu, Jia

    2018-02-01

    Due to the low contrast and ambiguous boundaries of the tumors in breast ultrasound (BUS) images, it is still a challenging task to automatically segment the breast tumors from the ultrasound. In this paper, we proposed a novel computational framework that can detect and segment breast lesions fully automatic in the whole ultrasound images. This framework includes several key components: pre-processing, contour initialization, and tumor segmentation. In the pre-processing step, we applied non-local low-rank (NLLR) filter to reduce the speckle noise. In contour initialization step, we cascaded a two-step Otsu-based adaptive thresholding (OBAT) algorithm with morphologic operations to effectively locate the tumor regions and initialize the tumor contours. Finally, given the initial tumor contours, the improved Chan-Vese model based on the ratio of exponentially weighted averages (CV-ROEWA) method was utilized. This pipeline was tested on a set of 61 breast ultrasound (BUS) images with diagnosed tumors. The experimental results in clinical ultrasound images prove the high accuracy and robustness of the proposed framework, indicating its potential applications in clinical practice. Graphical abstract ᅟ.

  11. Distributed network, wireless and cloud computing enabled 3-D ultrasound; a new medical technology paradigm.

    Directory of Open Access Journals (Sweden)

    Arie Meir

    Full Text Available Medical technologies are indispensable to modern medicine. However, they have become exceedingly expensive and complex and are not available to the economically disadvantaged majority of the world population in underdeveloped as well as developed parts of the world. For example, according to the World Health Organization about two thirds of the world population does not have access to medical imaging. In this paper we introduce a new medical technology paradigm centered on wireless technology and cloud computing that was designed to overcome the problems of increasing health technology costs. We demonstrate the value of the concept with an example; the design of a wireless, distributed network and central (cloud computing enabled three-dimensional (3-D ultrasound system. Specifically, we demonstrate the feasibility of producing a 3-D high end ultrasound scan at a central computing facility using the raw data acquired at the remote patient site with an inexpensive low end ultrasound transducer designed for 2-D, through a mobile device and wireless connection link between them. Producing high-end 3D ultrasound images with simple low-end transducers reduces the cost of imaging by orders of magnitude. It also removes the requirement of having a highly trained imaging expert at the patient site, since the need for hand-eye coordination and the ability to reconstruct a 3-D mental image from 2-D scans, which is a necessity for high quality ultrasound imaging, is eliminated. This could enable relatively untrained medical workers in developing nations to administer imaging and a more accurate diagnosis, effectively saving the lives of people.

  12. Distributed network, wireless and cloud computing enabled 3-D ultrasound; a new medical technology paradigm.

    Science.gov (United States)

    Meir, Arie; Rubinsky, Boris

    2009-11-19

    Medical technologies are indispensable to modern medicine. However, they have become exceedingly expensive and complex and are not available to the economically disadvantaged majority of the world population in underdeveloped as well as developed parts of the world. For example, according to the World Health Organization about two thirds of the world population does not have access to medical imaging. In this paper we introduce a new medical technology paradigm centered on wireless technology and cloud computing that was designed to overcome the problems of increasing health technology costs. We demonstrate the value of the concept with an example; the design of a wireless, distributed network and central (cloud) computing enabled three-dimensional (3-D) ultrasound system. Specifically, we demonstrate the feasibility of producing a 3-D high end ultrasound scan at a central computing facility using the raw data acquired at the remote patient site with an inexpensive low end ultrasound transducer designed for 2-D, through a mobile device and wireless connection link between them. Producing high-end 3D ultrasound images with simple low-end transducers reduces the cost of imaging by orders of magnitude. It also removes the requirement of having a highly trained imaging expert at the patient site, since the need for hand-eye coordination and the ability to reconstruct a 3-D mental image from 2-D scans, which is a necessity for high quality ultrasound imaging, is eliminated. This could enable relatively untrained medical workers in developing nations to administer imaging and a more accurate diagnosis, effectively saving the lives of people.

  13. A computational model for estimating tumor margins in complementary tactile and 3D ultrasound images

    Science.gov (United States)

    Shamsil, Arefin; Escoto, Abelardo; Naish, Michael D.; Patel, Rajni V.

    2016-03-01

    Conventional surgical methods are effective for treating lung tumors; however, they impose high trauma and pain to patients. Minimally invasive surgery is a safer alternative as smaller incisions are required to reach the lung; however, it is challenging due to inadequate intraoperative tumor localization. To address this issue, a mechatronic palpation device was developed that incorporates tactile and ultrasound sensors capable of acquiring surface and cross-sectional images of palpated tissue. Initial work focused on tactile image segmentation and fusion of position-tracked tactile images, resulting in a reconstruction of the palpated surface to compute the spatial locations of underlying tumors. This paper presents a computational model capable of analyzing orthogonally-paired tactile and ultrasound images to compute the surface circumference and depth margins of a tumor. The framework also integrates an error compensation technique and an algebraic model to align all of the image pairs and to estimate the tumor depths within the tracked thickness of a palpated tissue. For validation, an ex vivo experimental study was conducted involving the complete palpation of 11 porcine liver tissues injected with iodine-agar tumors of varying sizes and shapes. The resulting tactile and ultrasound images were then processed using the proposed model to compute the tumor margins and compare them to fluoroscopy based physical measurements. The results show a good negative correlation (r = -0.783, p = 0.004) between the tumor surface margins and a good positive correlation (r = 0.743, p = 0.009) between the tumor depth margins.

  14. Vesicoureteral Reflux and Duplex Systems

    Directory of Open Access Journals (Sweden)

    John C. Thomas

    2008-01-01

    Full Text Available Vesicoureteral reflux (VUR is the most common anomaly associated with duplex systems. In addition to an uncomplicated duplex system, reflux can also be secondary in the presence of an ectopic ureterocele with duplex systems. Controversy exists in regard to the initial and most definitive management of these anomalies when they coexist. This paper will highlight what is currently known about duplex systems and VUR, and will attempt to provide evidence supporting the various surgical approaches to an ectopic ureterocele and duplex system and the implications of concomitant VUR.

  15. Ultrasound-guided transversus abdominis plane injection with computed tomography correlation: a cadaveric study

    Directory of Open Access Journals (Sweden)

    Moeschler SM

    2013-07-01

    Full Text Available Susan M Moeschler,1 Naveen S Murthy,2 Bryan C Hoelzer,1 Halena M Gazelka,1 Richard H Rho,1 Matthew J Pingree1,31Department of Anesthesiology, 2Department of Radiology, 3Department of Physical Medicine and Rehabilitation, Mayo Clinic, Rochester, Minnesota, USABackground: Ultrasound-guided transversus abdominis plane (TAP injections are increasingly being used as an alternative to traditional perioperative analgesia in the abdominal region. With the use of a "blind" TAP block technique, these procedures have had variable success in cadaver and in vivo studies. For more accurate injection with the intended medication, ultrasound guidance allows visualization of the correct layer of the abdominal wall planes in which the thoracolumbar nerves reside.Objective: To assess the spread of various volumes of contrast placed under live ultrasound guidance into the TAP using computed tomography (CT.Methods: Four TAP blocks were performed on 2 fresh frozen cadaver torsos with predetermined contrast volumes of 5, 10, 15, or 20 mL. A CT scan of the cadaver was then performed and interpreted by a musculoskeletal radiologist. This cadaver study was carried out at a tertiary care academic medical center.Results: Cranial–caudal spread of injected contrast correlated with increasing injectate volume and was roughly 1 vertebral level (end plate to end plate for the 5 mL injection and 2 vertebral levels for the 10, 15, and 20 mL injections. However, the degree of injectate spread may be different for live patients than for cadavers.Conclusion: This study helps further the understanding of injectate spread following ultrasound-guided TAP injections. Specifically, it suggests that 15 mL provides additional cranial–caudal spread and may be an optimal volume of anesthesia.Keywords: abdominal cadaver study, abdominal computed tomography scan, abdominal wall pain, TAP block, ultrasound-guided injection

  16. In vivo coronary lesion differentiation with computed tomography angiography and intravascular ultrasound as compared to optical coherence tomography

    NARCIS (Netherlands)

    Wieringa, Wouter G.; Lexis, Chris P. H.; Lipsic, Erik; van der Werf, Hindrik W.; Burgerhof, Johannes G. M.; Hagens, Vincent E.; Bartels, G. Louis; Broersen, Alexander; Schurer, Remco A. J.; Tan, Eng-Shiong; van der Harst, Pim; van den Heuvel, Ad F. M.; Willems, Tineke P.; Pundziute, Gabija

    Background: In vitro studies have shown the feasibility of coronary lesion grading with computed tomography angiography (CTA), intravascular ultrasound (IVUS) and optical coherence tomography (OCT) as compared to histology, whereas OCT had the highest discriminatory capacity. Objective: We

  17. Computer-Aided Diagnosis of Different Rotator Cuff Lesions Using Shoulder Musculoskeletal Ultrasound.

    Science.gov (United States)

    Chang, Ruey-Feng; Lee, Chung-Chien; Lo, Chung-Ming

    2016-09-01

    The lifetime prevalence of shoulder pain approaches 70%, which is mostly attributable to rotator cuff lesions such as inflammation, calcific tendinitis and tears. On clinical examination, shoulder ultrasound is recommended for the detection of lesions. However, there exists inter-operator variability in diagnostic accuracy because of differences in the experience and expertise of operators. In this study, a computer-aided diagnosis (CAD) system was developed to assist ultrasound operators in diagnosing rotator cuff lesions and to improve the practicality of ultrasound examination. The collected cases included 43 cases of inflammation, 30 cases of calcific tendinitis and 26 tears. For each case, the lesion area and texture features were extracted from the entire lesions and combined in a multinomial logistic regression classifier for lesion classification. The proposed CAD achieved an accuracy of 87.9%. The individual accuracy of this CAD system was 88.4% for inflammation, 83.3% for calcific tendinitis and 92.3% for tears. Cohen's k was 0.798. On the basis of its diagnostic performance, clinical use of this CAD technique has promise. Copyright © 2016 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  18. Computer-aided detection system for nerve identification using ultrasound images: A comparative study

    Directory of Open Access Journals (Sweden)

    Oussama Hadjerci

    Full Text Available Ultrasound-Guided Regional Anesthesia (UGRA has been gaining importance in the last few years, offering numerous advantages over alternative methods of nerve localization (neurostimulation or paraesthesia. However, nerve detection is one of the most difficult tasks that anesthetists can encounter in the UGRA procedure. The context of the present work is to provide practitioners with a computer-aided system to facilitate the practice of UGRA. However, automatic detection and segmentation in US images is still a challenging problem in many medical applications. This paper addresses two main issues, first proposing an efficient framework for nerve detection and segmentation, and second, reviewing literature methods and evaluating their performance for this new application. The proposed system consists of four main stages: (1 despeckling filter, (2 feature extraction, (3 feature selection, (4 classification and segmentation. A comparative study was performed in each of these stages to measure their influence over the whole system. Sonographic videos were acquired with the same ultrasound machine in real conditions from 19 volunteer patients. Evaluation was designed to cover two important aspects: measure the effect of training set size, and evaluate consistency using a cross-validation technique. The results obtained were significant and indicated which method was better for a nerve detection system. The proposed scheme achieved high scores (i.e. 80% on average of 1900 tested images, demonstrating its validity. Keywords: Regional anesthesia, Computer-aided detection, Ultrasound image processing, Machine learning, Despeckling, Feature extraction, Feature selection, Classification

  19. Ultrasound pregnancy

    Science.gov (United States)

    ... sonogram; Ultrasound - pregnancy; IUGR - ultrasound; Intrauterine growth - ultrasound; Polyhydramnios - ultrasound; Oligohydramnios - ultrasound; Placenta previa - ultrasound; Multiple pregnancy - ...

  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. The comparison of measurement between ultrasound and computed tomography for abnormal degenerative facet joints: A STROBE-compliant article.

    Science.gov (United States)

    Shi, Wen; Tian, Dan; Liu, Da; Yin, Jing; Huang, Ying

    2017-08-01

    Besides the study on examining facet joints of lumbar spine by ultrasound in normal population, there has not been any related report about examining normal facet joints of lumbar spine by ultrasound so far. This study was aimed to explore the feasibility of ultrasound assessment of lumber spine facet joints by comparing ultrasound measure values of normal and degenerative lumber spine facet joints, and by comparing measure values of ultrasound and computed tomography (CT) of degenerative lumber spine facet joints.This study included 15 patients who had chronic low back pain because of degenerative change in lumbar vertebrae, and 19 volunteers who did not have low back pain or pain in the lower limb. The ultrasound measure values (height [H] and width [W]) of normal and degenerative lumber spine facet joints were compared. And the differentiation between measure values (H and W) of ultrasound and CT of degenerative lumber spine facet joints was also analyzed.The ultrasound clearly showed abnormal facet joints lesion, which was characterized by hyperostosis on the edge of joints, bone destruction under joints, and thinner or thicker articular cartilage. There were significant differences between the ultrasound measure values of the normal (H: 1.26 ± 0.03 cm, W: 0.18 ± 0.01 cm) and abnormal facet joints (H: 1.43 ± 0.05 cm, W: 0.15 ± 0.02 cm) (all P joints (all P > .05).Ultrasound can clearly show the structure of facet joints of lumbar spine. It is precise and feasible to assess facet joints of lumbar spine by ultrasound. This study has important significance for the diagnosis of lumbar facet joint degeneration.

  2. Image reconstruction for ultrasound computed tomography by use of the regularized dual averaging method

    Science.gov (United States)

    Matthews, Thomas P.; Wang, Kun; Li, Cuiping; Duric, Neb; Anastasio, Mark A.

    2017-03-01

    Waveform inversion methods can produce high-resolution reconstructed sound speed images for ultrasound computed tomography; however, they are very computational expensive. Source encoding methods can reduce this computational cost by formulating the image reconstruction problem as a stochastic optimization problem. Here, we solve this optimization problem by the regularized dual averaging method instead of the more commonly used stochastic gradient descent. This new optimization method allows use of non-smooth regularization functions and treats the stochastic data fidelity term in the objective function separately from the deterministic regularization function. This allows noise to be mitigated more effectively. The method further exhibits lower variance in the estimated sound speed distributions across iterations when line search methods are employed.

  3. Computer tomography urography assisted real-time ultrasound-guided percutaneous nephrolithotomy on renal calculus.

    Science.gov (United States)

    Fang, You-Qiang; Wu, Jie-Ying; Li, Teng-Cheng; Zheng, Hao-Feng; Liang, Guan-Can; Chen, Yan-Xiong; Hong, Xiao-Bin; Cai, Wei-Zhong; Zang, Zhi-Jun; Di, Jin-Ming

    2017-06-01

    This study aimed to assess the role of pre-designed route on computer tomography urography (CTU) in the ultrasound-guided percutaneous nephrolithotomy (PCNL) for renal calculus.From August 2013 to May 2016, a total of 100 patients diagnosed with complex renal calculus in our hospital were randomly divided into CTU group and control group (without CTU assistance). CTU was used to design a rational route for puncturing in CTU group. Ultrasound was used in both groups to establish a working trace in the operation areas. Patients' perioperative parameters and postoperative complications were recorded.All operations were successfully performed, without transferring to open surgery. Time of channel establishment in CTU group (6.5 ± 4.3 minutes) was shorter than the control group (10.0 ± 6.7 minutes) (P = .002). In addition, there was shorter operation time, lower rates of blood transfusion, secondary operation, and less establishing channels. The incidence of postoperative complications including residual stones, sepsis, severe hemorrhage, and perirenal hematoma was lower in CTU group than in control group.Pre-designing puncture route on CTU images would improve the puncturing accuracy, lessen establishing channels as well as improve the security in the ultrasound-guided PCNL for complex renal calculus, but at the cost of increased radiation exposure.

  4. Diagnostic sensitivity of ultrasound, radiography and computed tomography for gender determination in four species of lizards.

    Science.gov (United States)

    Di Ianni, Francesco; Volta, Antonella; Pelizzone, Igor; Manfredi, Sabrina; Gnudi, Giacomo; Parmigiani, Enrico

    2015-01-01

    Gender determination is frequently requested by reptile breeders, especially for species with poor or absent sexual dimorphism. The aims of the current study were to describe techniques and diagnostic sensitivities of ultrasound, radiography, and computed tomography for gender determination (identification of hemipenes) in four species of lizards. Nineteen lizards of known sex, belonging to four different species (Pogona vitticeps, Uromastyx aegyptia, Tiliqua scincoides, Gerrhosaurus major) were prospectively enrolled. With informed owner consent, ultrasound, noncontrast CT, contrast radiography, and contrast CT (with contrast medium administered into the cloaca) were performed in conscious animals. Imaging studies were reviewed by three different operators, each unaware of the gender of the animals and of the results of the other techniques. The lizard was classified as a male when hemipenes were identified. Nineteen lizards were included in the study, 10 females and nine males. The hemipenes were seen on ultrasound in only two male lizards, and appeared as oval hypoechoic structures. Radiographically, hemipenes filled with contrast medium appeared as spindle-shaped opacities. Noncontrast CT identified hemipenes in only two lizards, and these appeared as spindle-shaped kinked structures with hyperattenuating content consistent with smegma. Hemipenes were correctly identified in all nine males using contrast CT (accuracy of 100%). Accuracy of contrast radiography was excellent (94.7%). Accuracy of ultrasound and of noncontrast CT was poor (64.3% and 63.1%, respectively). Findings from the current study supported the use of contrast CT or contrast radiography for gender determination in lizards. © 2014 American College of Veterinary Radiology.

  5. The radiological manifestations of intramuscular haemangiomas in adults: magnetic resonance imaging, computed tomography and ultrasound appearances

    Energy Technology Data Exchange (ETDEWEB)

    Griffin, N.; Khan, N.; Moskovic, E.C. [Royal Marsden Hospital, Department of Diagnostic Imaging, London (United Kingdom); Meirion Thomas, J. [Royal Marsden Hospital, Sarcoma Unit, London (United Kingdom); Fisher, C. [Royal Marsden Hospital, Department of Histopathology, London (United Kingdom)

    2007-11-15

    Intramuscular haemangiomas in adults may appear similar to soft tissue sarcomas on imaging. This study evaluates the imaging characteristics of intramuscular haemangiomas on magnetic resonance imaging (MRI), computed tomography (CT) and ultrasound. Retrospective review of medical records, imaging and pathology details of 34 patients presenting with intramuscular haemangiomas was performed. Age of patient, size, site of lesion and type of imaging was recorded. Lesions were evaluated for calcification, presence of fat, outline, texture, vascularity, enhancement and involvement of local structures. There were 12 male and 22 female patients aged between 9 years and 90 years (mean 39 years). Twenty-two lesions involved muscles of the extremities and 12 involved muscles of the trunk. Mean duration of the lesions was long: 59.3 months (range 3-240 months), with an average size of 7.5 cm (1.5-15 cm). Imaging comprised 27 MR studies, seven CT scans, 19 ultrasounds, and eight plain films. All lesions were well defined, lobulated and heterogeneous. None showed local invasion. On MRI and CT, 93-100% showed the presence of fat and 100% showed vascular channels and enhancement on MRI, CT and ultrasound. Phleboliths were seen on four plain films (50%) and on the corresponding MR images. On MRI, 70% of lesions had mildly hyperintense signal on T1-weighted sequences and 96% had hyperintense signal on T2-weighted sequences (relative to skeletal muscle). Histopathology confirmed diagnosis in all cases, showing the presence of fat, medium/large vessels and skeletal muscle. Intramuscular haemangiomas have characteristic appearances on MRI, CT and ultrasound. Long history, presence of fat, calcification and internal vessels should alert the radiologist to this diagnosis prior to biopsy. (orig.)

  6. Podiatry Ankle Duplex Scan: Readily Learned and Accurate in Diabetes.

    Science.gov (United States)

    Normahani, Pasha; Powezka, Katarzyna; Aslam, Mohammed; Standfield, Nigel J; Jaffer, Usman

    2018-03-01

    We aimed to train podiatrists to perform a focused duplex ultrasound scan (DUS) of the tibial vessels at the ankle in diabetic patients; podiatry ankle (PodAnk) duplex scan. Thirteen podiatrists underwent an intensive 3-hour long simulation training session. Participants were then assessed performing bilateral PodAnk duplex scans of 3 diabetic patients with peripheral arterial disease. Participants were assessed using the duplex ultrasound objective structured assessment of technical skills (DUOSATS) tool and an "Imaging Score". A total of 156 vessel assessments were performed. All patients had abnormal waveforms with a loss of triphasic flow. Loss of triphasic flow was accurately detected in 145 (92.9%) vessels; the correct waveform was identified in 139 (89.1%) cases. Participants achieved excellent DUOSATS scores (median 24 [interquartile range: 23-25], max attainable score of 26) as well as "Imaging Scores" (8 [8-8], max attainable score of 8) indicating proficiency in technical skills. The mean time taken for each bilateral ankle assessment was 20.4 minutes (standard deviation ±6.7). We have demonstrated that a focused DUS for the purpose of vascular assessment of the diabetic foot is readily learned using intensive simulation training.

  7. Preoperative ultrasound mapping of the saphenous vein

    DEFF Research Database (Denmark)

    Levi, Niels; Schroeder, T

    1997-01-01

    A prospective series of 92 patients had their greater saphenous vein assessed with duplex ultrasound scanning prior to planned infrainguinal bypass procedures. Sixteen (17%) bypass procedures thrombosed within the first week postoperatively. A naturally occurring optimal vein diameter was discove......A prospective series of 92 patients had their greater saphenous vein assessed with duplex ultrasound scanning prior to planned infrainguinal bypass procedures. Sixteen (17%) bypass procedures thrombosed within the first week postoperatively. A naturally occurring optimal vein diameter...

  8. Computer-aided analysis of ultrasound elasticity images for classification of benign and malignant breast masses.

    Science.gov (United States)

    Moon, Woo Kyung; Choi, Ji Won; Cho, Nariya; Park, Sang Hee; Chang, Jung Min; Jang, Mijung; Kim, Kwang Gi

    2010-12-01

    The purpose of this study was to evaluate computer-aided analysis of ultrasound elasticity images for the classification of benign and malignant breast tumors. Real-time ultrasound elastography of 140 women (mean age, 46 years; age range, 35-67 years) with nonpalpable breast masses (101 benign and 39 malignant lesions) was performed before needle biopsy. A region of interest (ROI) was drawn around the margin of the mass, and a score for each pixel was assigned; scores ranged from 0 for the greatest strain to 255 for no strain. The diagnostic performances of a neural network based on the values of the six elasticity features were compared with visual assessment of elasticity images and BI-RADS assessment using B-mode images. The values for the area under the receiver operating characteristic curve (A(z)) of the six elasticity features--mean hue histogram value, skewness, kurtosis, difference histogram variation, edge density, and run length--were 0.84, 0.69, 0.63, 0.75, 0.68, and 0.71, respectively. The sensitivity, specificity, positive predictive value, and negative predictive value of the neural network based on all six features were 92% (36/39), 74% (75/101), 58% (36/62), and 96% (75/78), respectively, with an A(z) value of 0.89, which is significantly higher than the A(z) of 0.81 for visual assessment by radiologists (p = 0.01) and 0.76 for BI-RADS assessment using B-mode images (p = 0.002). Computer-aided analysis of ultrasound elasticity images has the potential to aid in the classification of benign and malignant breast tumors.

  9. 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....

  10. Computationally Efficient Adaptive Beamformer for Ultrasound Imaging Based on QR Decomposition.

    Science.gov (United States)

    Park, Jongin; Wi, Seok-Min; Lee, Jin S

    2016-02-01

    Adaptive beamforming methods for ultrasound imaging have been studied to improve image resolution and contrast. The most common approach is the minimum variance (MV) beamformer which minimizes the power of the beamformed output while maintaining the response from the direction of interest constant. The method achieves higher resolution and better contrast than the delay-and-sum (DAS) beamformer, but it suffers from high computational cost. This cost is mainly due to the computation of the spatial covariance matrix and its inverse, which requires O(L(3)) computations, where L denotes the subarray size. In this study, we propose a computationally efficient MV beamformer based on QR decomposition. The idea behind our approach is to transform the spatial covariance matrix to be a scalar matrix σI and we subsequently obtain the apodization weights and the beamformed output without computing the matrix inverse. To do that, QR decomposition algorithm is used and also can be executed at low cost, and therefore, the computational complexity is reduced to O(L(2)). In addition, our approach is mathematically equivalent to the conventional MV beamformer, thereby showing the equivalent performances. The simulation and experimental results support the validity of our approach.

  11. 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 ...

  12. 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 ...

  13. Prostate Ultrasound

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    Full Text Available ... console containing a computer and electronics, a video display screen and a transducer that is used to ... ultrasound image is immediately visible on a video display screen that looks like a computer or television ...

  14. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... console containing a computer and electronics, a video display screen and a transducer that is used to ... ultrasound image is immediately visible on a video display screen that looks like a computer or television ...

  15. Investigation of mass transfer intensification under power ultrasound irradiation using 3D computational simulation: A comparative analysis.

    Science.gov (United States)

    Sajjadi, Baharak; Asgharzadehahmadi, Seyedali; Asaithambi, Perumal; Raman, Abdul Aziz Abdul; Parthasarathy, Rajarathinam

    2017-01-01

    This paper aims at investigating the influence of acoustic streaming induced by low-frequency (24kHz) ultrasound irradiation on mass transfer in a two-phase system. The main objective is to discuss the possible mass transfer improvements under ultrasound irradiation. Three analyses were conducted: i) experimental analysis of mass transfer under ultrasound irradiation; ii) comparative analysis between the results of the ultrasound assisted mass transfer with that obtained from mechanically stirring; and iii) computational analysis of the systems using 3D CFD simulation. In the experimental part, the interactive effects of liquid rheological properties, ultrasound power and superficial gas velocity on mass transfer were investigated in two different sonicators. The results were then compared with that of mechanical stirring. In the computational part, the results were illustrated as a function of acoustic streaming behaviour, fluid flow pattern, gas/liquid volume fraction and turbulence in the two-phase system and finally the mass transfer coefficient was specified. It was found that additional turbulence created by ultrasound played the most important role on intensifying the mass transfer phenomena compared to that in stirred vessel. Furthermore, long residence time which depends on geometrical parameters is another key for mass transfer. The results obtained in the present study would help researchers understand the role of ultrasound as an energy source and acoustic streaming as one of the most important of ultrasound waves on intensifying gas-liquid mass transfer in a two-phase system and can be a breakthrough in the design procedure as no similar studies were found in the existing literature. Copyright © 2016. Published by Elsevier B.V.

  16. Acute Calculous Cholecystitis Missed on Computed Tomography and Ultrasound but Diagnosed with Fluorodeoxyglucose-Positron Emission Tomography/Computed Tomography.

    Science.gov (United States)

    Aparici, Carina Mari; Win, Aung Zaw

    2016-01-01

    We present a case of a 69-year-old patient who underwent ascending aortic aneurysm repair with aortic valve replacement. On postsurgical day 12, he developed leukocytosis and low-grade fevers. The chest computed tomography (CT) showed a periaortic hematoma which represents a postsurgical change from aortic aneurysm repair, and a small pericardial effusion. The abdominal ultrasound showed cholelithiasis without any sign of cholecystitis. Finally, a fluorodeoxyglucose (FDG)-positron emission tomography (PET)/CT examination was ordered to find the cause of fever of unknown origin, and it showed increased FDG uptake in the gallbladder wall, with no uptake in the lumen. FDG-PET/CT can diagnose acute cholecystitis in patients with nonspecific clinical symptoms and laboratory results.

  17. Acute Calculous Cholecystitis Missed on Computed Tomography and Ultrasound but Diagnosed with Fluorodeoxyglucose-Positron Emission Tomography/Computed Tomography

    Directory of Open Access Journals (Sweden)

    Carina Mari Aparici

    2016-01-01

    Full Text Available We present a case of a 69-year-old patient who underwent ascending aortic aneurysm repair with aortic valve replacement. On postsurgical day 12, he developed leukocytosis and low-grade fevers. The chest computed tomography (CT showed a periaortic hematoma which represents a postsurgical change from aortic aneurysm repair, and a small pericardial effusion. The abdominal ultrasound showed cholelithiasis without any sign of cholecystitis. Finally, a fluorodeoxyglucose (FDG-positron emission tomography (PET/CT examination was ordered to find the cause of fever of unknown origin, and it showed increased FDG uptake in the gallbladder wall, with no uptake in the lumen. FDG-PET/CT can diagnose acute cholecystitis in patients with nonspecific clinical symptoms and laboratory results.

  18. Contrast-enhanced ultrasound vs multidetector-computed tomography for detecting liver metastases in colorectal cancer: a prospective, blinded, patient-by-patient analysis

    DEFF Research Database (Denmark)

    Rafaelsen, S R; Jakobsen, A

    2011-01-01

    This study compared the sensitivity and specificity of contrast-enhanced ultrasound (CEUS) and multidetector-computed tomography (MDCT) in the detection of liver metastases in patients with colorectal cancer.......This study compared the sensitivity and specificity of contrast-enhanced ultrasound (CEUS) and multidetector-computed tomography (MDCT) in the detection of liver metastases in patients with colorectal cancer....

  19. Characterization of focal liver lesions: comparative study of contrast-enhanced ultrasound versus spiral computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Catala, V.; Nicolau, C.; Vilana, R.; Pages, M.; Bianchi, L.; Sanchez, M.; Bru, C. [Clinic Hospital, Imaging Diagnosis Center, Barcelona (Spain)

    2007-04-15

    The purpose of this study was to compare the diagnostic accuracy of contrast-enhanced ultrasound (CEUS) with spiral computed tomography (SCT) for the characterization of focal liver lesions (FLL) and to determine the degree of correlation between the two techniques. Seventy-seven FLL (45 hepatocellular carcinomas; 12 metastases; ten hemangiomas; two regenerating/dysplastic nodules; eight focal nodular hyperplasias) detected with ultrasound (US) were prospectively evaluated by CEUS using a second-generation contrast agent and SCT (with an interval of no more than one month between the two techniques). Independent observers made the most probable diagnosis and the results were compared with the final diagnoses (histology n = 59; MRI n = 18). Statistical analysis was performed by the Chi-square and Kappa tests. CEUS provided a correct, specific diagnosis in 69/77 (90%) of the FLL, while SCT did so in 67/77 (87%). The sensitivity, specificity, and diagnostic accuracy for malignancy were 91%, 90%, and 91%, respectively, for CEUS and 88%, 89%, and 88%, respectively, for SCT. No statistically significant difference was found between CEUS and SCT in the characterization of FLL (p > 0.05). In addition, agreement between the two imaging techniques was good (k = 0.75). We conclude that CEUS and SCT provide a similar diagnostic accuracy in the characterization of FLL, with a good degree of correlation between the two techniques. (orig.)

  20. Computational evaluation of the compositional factors in fracture healing affecting ultrasound axial transmission measurements.

    Science.gov (United States)

    Machado, Christiano Bittencourt; de Albuquerque Pereira, Wagner Coelho; Talmant, Maryline; Padilla, Frédéric; Laugier, Pascal

    2010-08-01

    This work aimed at computationally evaluating the compositional factors in fracture healing affecting ultrasound axial transmission (UAT), using four numerical daily-changing healing models, representing more realistic clinical conditions. Using two-dimensional (2-D) simulations, a 1-MHz source and a receiver were positioned parallel to the bone surface to detect the first arriving signal (FAS). The time-of-flight of the FAS (TOF(FAS)) was found to be sensitive only to superficial modifications in the propagation path. It was also shown that callus mature bone better explained alone the variation in TOF(FAS) (R(2) >or= 0.70, p < 0.001). Better TOF(FAS) predictions are obtained when using the callus composition inside cortical fracture gap (R(2) = 0.98, p < 0.01). Callus composition could not well explain the changes in energy attenuation. These results suggest that UAT may be an important clinical tool for fracture healing assessment, identifying callus degree of mineralization and possible consolidation delays and nonunions. Copyright 2010 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  1. Comparative study of ultrasound and computed tomography for incidentally detecting diffuse thyroid disease.

    Science.gov (United States)

    Kim, Dong Wook; Jung, Soo Jin; Ha, Tae Kwun; Park, Ha Kyoung; Kang, Taewoo

    2014-08-01

    The aim of this study was to compare the diagnostic values of thyroid ultrasound (US) and neck computed tomography (CT) in incidentally detecting diffuse thyroid disease (DTD). A single radiologist made US and CT diagnoses of incidentally detected DTD in 130 consecutive patients before thyroidectomy for various malignancies. Histopathologic examinations confirmed normal thyroid (n = 80), Hashimoto thyroiditis (n = 20), non-Hashimoto lymphocytic thyroiditis (n = 28) and diffuse hyperplasia (n = 2). Receiver operating characteristic curves revealed that the best diagnostic indices of both imaging methods were achieved on the basis of two or more abnormal imaging findings. The sensitivity, specificity and accuracy of US and CT in incidentally detecting DTD by this classification were 72% and 72%, 87.5% and 91.3% and 81.5% and 83.8%, respectively. Thyroid US and neck CT have similar diagnostic values for differentiating incidental DTD from normal thyroid. Copyright © 2014 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  2. Comparison Between Dual-Energy Computed Tomography and Ultrasound in the Diagnosis of Gout of Various Joints.

    Science.gov (United States)

    Zhu, Liang; Wu, Huaxiang; Wu, Xinyu; Sun, Wenjia; Zhang, Ting; Ye, Lv; Wang, Wenwen; Wang, Jianqing

    2015-12-01

    Dual-energy computed tomography (DECT) and ultrasound are both used to assess gouty arthritis. The present study was designed to compare the diagnostic accuracy of DECT and ultrasound in detecting monosodium urate (MSU) crystal deposition in various joints. This study enrolled 40 patients diagnosed with acute gouty arthritis. All affected and contralateral joints were scanned (128 in total) using both DECT and ultrasound to determine the MSU deposition in upper limbs (wrist and elbow) and lower limbs (the first metatarsophalangeal joints, ankles, and knee). The MSU crystal accumulation detected by each method was compared for various joints. The 128 scanned joints included 52 of the upper limbs and 76 of the lower limbs. For the upper limbs, the percentage of MSU crystal accumulation detected by DECT (22/52, 42.3%) was significantly higher than that by ultrasound (10/52, 19.2%; P = .0027). The detection rates of the two methods for the lower limbs were similar (P = .3173). For detection of MSU crystal deposition in the upper limb joints, DECT was superior to ultrasound, whereas there was no difference between the two methods for the lower limbs. Therefore, ultrasound can be used for primary screening, and DECT afterward. Although the modalities are similar in making the initial diagnosis, DECT is far superior at displaying the anatomic extent of the disease. Copyright © 2015 AUR. Published by Elsevier Inc. All rights reserved.

  3. The influence of respiration on criteria for transabdominal duplex examination of the splanchnic arteries in patients with suspected chronic splanchnic ischemia

    NARCIS (Netherlands)

    van Petersen, Andre S.; Meerwaldt, Robbert; Kolkman, Jeroen; Huisman, Ad B.; van der Palen, Jacobus Adrianus Maria; Bockel, J. Hajo; Zeebregts, Clark J.; Geelkerken, Robert H.

    2013-01-01

    Background Duplex ultrasound imaging of the mesenteric vessels is often used as a first diagnostic tool to evaluate the mesenteric circulation in patients with unexplained chronic abdominal symptoms. Several studies on duplex criteria have been published; however, most studies are small and included

  4. The influence of respiration on criteria for transabdominal duplex examination of the splanchnic arteries in patients with suspected chronic splanchnic ischemia

    NARCIS (Netherlands)

    van Petersen, Andre S.; Meerwaldt, Robbert; Kolkman, Jeroen J.; Huisman, Ad B.; van der Palen, Job; van Bockel, J. Hajo; Zeebregts, Clark J.; Geelkerken, Robert H.

    Background: Duplex ultrasound imaging of the mesenteric vessels is often used as a first diagnostic tool to evaluate the mesenteric circulation in patients with unexplained chronic abdominal symptoms. Several studies on duplex criteria have been published; however, most studies are small and

  5. Optimization of a Breast Mass Classifier for Computer-Aided Ultrasound Analysis

    Science.gov (United States)

    Andrè, M. P.; Galperin, M.; Contro, G.; Omid, N.; Olson, L.

    The goal of this research was to optimize performance of a Computer-Aided Diagnostic system to identify, analyze and compare breast masses based on parameters measured in the ultrasound image. We compared case-based reasoning using Relative Similarity to an Artificial Neural Network in order to implement an objective form of the ACR BIRADS scheme to describe and score breast masses. The image feature set was reduced to nine including margins, shape, echogenicity, echo texture, orientation and posterior acoustic attenuation. Both classifiers performed well with a high ROC AZ although RS performed significantly better than the ANN in Specificity, PPV and achieved the goal of very high Specificity without a reduction in Sensitivity. Compared to a preliminary version of the RS classifier this optimized version of RS has significantly higher AZ (0.96 vs. 0.93)

  6. Computational modeling of radiofrequency ablation: evaluation on ex vivo data using ultrasound monitoring

    Science.gov (United States)

    Audigier, Chloé; Kim, Younsu; Dillow, Austin; Boctor, Emad M.

    2017-03-01

    Radiofrequency ablation (RFA) is the most widely used minimally invasive ablative therapy for liver cancer, but it is challenged by a lack of patient-specific monitoring. Inter-patient tissue variability and the presence of blood vessels make the prediction of the RFA difficult. A monitoring tool which can be personalized for a given patient during the intervention would be helpful to achieve a complete tumor ablation. However, the clinicians do not have access to such a tool, which results in incomplete treatment and a large number of recurrences. Computational models can simulate the phenomena and mechanisms governing this therapy. The temperature evolution as well as the resulted ablation can be modeled. When combined together with intraoperative measurements, computational modeling becomes an accurate and powerful tool to gain quantitative understanding and to enable improvements in the ongoing clinical settings. This paper shows how computational models of RFA can be evaluated using intra-operative measurements. First, simulations are used to demonstrate the feasibility of the method, which is then evaluated on two ex vivo datasets. RFA is simulated on a simplified geometry to generate realistic longitudinal temperature maps and the resulted necrosis. Computed temperatures are compared with the temperature evolution recorded using thermometers, and with temperatures monitored by ultrasound (US) in a 2D plane containing the ablation tip. Two ablations are performed on two cadaveric bovine livers, and we achieve error of 2.2 °C on average between the computed and the thermistors temperature and 1.4 °C and 2.7 °C on average between the temperature computed and monitored by US during the ablation at two different time points (t = 240 s and t = 900 s).

  7. Incorporating texture features in a computer-aided breast lesion diagnosis system for automated three-dimensional breast ultrasound

    NARCIS (Netherlands)

    Liu, H.; Tan, T.; Zelst, J. van; Mann, R.; Karssemeijer, N.; Platel, B.

    2014-01-01

    We investigated the benefits of incorporating texture features into an existing computer-aided diagnosis (CAD) system for classifying benign and malignant lesions in automated three-dimensional breast ultrasound images. The existing system takes into account 11 different features, describing

  8. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... body. Doppler ultrasound, a special application of ultrasound, measures the direction and speed of blood cells as they move through vessels. The movement of blood cells causes a change in pitch of the reflected sound waves (called the Doppler effect). A computer collects ...

  9. Enhancement pattern of hilar cholangiocarcinoma: Contrast-enhanced ultrasound versus contrast-enhanced computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Xu Huixiong, E-mail: xuhuixiong@hotmail.co [Department of Medical Ultrasonics, The First Affiliated Hospital, Institute of Diagnostic and Interventional Ultrasound, Sun Yat-Sen University, 58 Zhongshan Road 2, Guangzhou 510080 (China); Chen Lida; Xie Xiaoyan; Xie Xiaohua; Xu Zuofeng; Liu Guangjian; Lin Manxia; Wang Zhu [Department of Medical Ultrasonics, The First Affiliated Hospital, Institute of Diagnostic and Interventional Ultrasound, Sun Yat-Sen University, 58 Zhongshan Road 2, Guangzhou 510080 (China); Lu Mingde, E-mail: lumd@21cn.co [Department of Hepatobiliary Surgery, First Affiliated Hospital, Sun Yat-Sen University, 58 Zhongshan Road 2, Guangzhou 510080 (China)

    2010-08-15

    Objective: To compare the enhancement pattern of hilar cholangiocarcinoma on contrast-enhanced ultrasound (CEUS) with that on contrast-enhanced computed tomography (CECT). Methods: Thirty-two consecutive patients with pathologically proven hilar cholangiocarcinomas were evaluated by both low mechanical index CEUS and CECT. The enhancement feature of the tumor, portal vein infiltration, and lesion conspicuity on them was investigated. Results: In the arterial phase, the numbers of the lesions showing hyperenhancement, isoenhancement, and hypoenhancement, were 14 (43.8%), 14 (43.8%), and 4 (12.6%), on CEUS, and 12 (37.5%), 9 (28.1%), and 11 (34.4%), on CECT (P = 0.162). In portal phase, the numbers of the lesions showing hypoenhancement, isoenhancement, and hyperenhancement were 30 (93.8%), 1 (3.1%), and 1 (3.1%), on CEUS, and 23 (71.9%), 8 (25.0%), and 1 (3.1%), on CECT (P = 0.046). The detection rates for portal vein infiltration were 84.2% (16/19) for baseline ultrasound, 89.5% (17/19) for CEUS, and 78.9% (15/19) for CECT (all P > 0.05 between every two groups). CEUS significantly improved the lesion conspicuity in comparison with CECT. CEUS and CECT made correct diagnoses in 30 (93.8%) and 25 (78.1%) lesions prior to pathological examination (P = 0.125). Conclusion: The enhancement pattern of hilar cholangiocarcinoma on CEUS was similar with that on CECT in arterial phase, whereas in portal phase hilar cholangiocarcinoma shows hypoenhancement more likely on CEUS. CEUS and CECT lead to similar results in evaluating portal vein infiltration and diagnosis of this entity.

  10. Computer-assisted assessment of ultrasound real-time elastography: Initial experience in 145 breast lesions

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xue; Xiao, Yang [Shenzhen Key Lab for Molecular Imaging, Paul C. Lauterbur Research Center for Biomedical Imaging, Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen (China); Zeng, Jie [Department of Medical Ultrasonics, Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou (China); Qiu, Weibao; Qian, Ming; Wang, Congzhi [Shenzhen Key Lab for Molecular Imaging, Paul C. Lauterbur Research Center for Biomedical Imaging, Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen (China); Zheng, Rongqin, E-mail: zhengronggin@hotmail.com [Department of Medical Ultrasonics, Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou (China); Zheng, Hairong, E-mail: hr.zheng@siat.ac.cn [Shenzhen Key Lab for Molecular Imaging, Paul C. Lauterbur Research Center for Biomedical Imaging, Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen (China)

    2014-01-15

    Purpose: To develop and evaluate a computer-assisted method of quantifying five-point elasticity scoring system based on ultrasound real-time elastography (RTE), for classifying benign and malignant breast lesions, with pathologic results as the reference standard. Materials and methods: Conventional ultrasonography (US) and RTE images of 145 breast lesions (67 malignant, 78 benign) were performed in this study. Each lesion was automatically contoured on the B-mode image by the level set method and mapped on the RTE image. The relative elasticity value of each pixel was reconstructed and classified into hard or soft by the fuzzy c-means clustering method. According to the hardness degree inside lesion and its surrounding tissue, the elasticity score of the RTE image was computed in an automatic way. Visual assessments of the radiologists were used for comparing the diagnostic performance. Histopathologic examination was used as the reference standard. The Student's t test and receiver operating characteristic (ROC) curve analysis were performed for statistical analysis. Results: Considering score 4 or higher as test positive for malignancy, the diagnostic accuracy, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were 93.8% (136/145), 92.5% (62/67), 94.9% (74/78), 93.9% (62/66), and 93.7% (74/79) for the computer-assisted scheme, and 89.7% (130/145), 85.1% (57/67), 93.6% (73/78), 92.0% (57/62), and 88.0% (73/83) for manual assessment. Area under ROC curve (A{sub z} value) for the proposed method was higher than the A{sub z} value for visual assessment (0.96 vs. 0.93). Conclusion: Computer-assisted quantification of classical five-point scoring system can significantly eliminate the interobserver variability and thereby improve the diagnostic confidence of classifying the breast lesions to avoid unnecessary biopsy.

  11. Ultrasound and computed tomography: spin-offs of the world wars.

    Science.gov (United States)

    Van Tiggelen, R; Pouders, E

    2003-01-01

    Important losses to the ships of the allied troops by the attacks of the German submarines during World War I led researchers to find specific detecting devices as a means of defence. In 1880 Pierre Curie and his brother, discovered the production of ultrasound waves. Langevin, their student, applied this invention to the localisation of boats. At the end of WWI, research and results ended up being forgotten, but gained attention again with the sonar when WWII loomed on the horizon. At the end of the war, a former military medical doctor, G. Ludwig (US Navy), tried to localize gallstones with a left-over sonar apparatus. This definitely led to firm conclusions. Other researchers in several countries contributed to refining this new imaging technique which is nowadays widely applied. During WWII, the American and British army developed considerable research in the field of the calculator (computer) to speed up deciphering the secret codes. Coupling the principles of tomography discovered during WWI with the computing capability of the calculators developed during WWII, computerized axial tomography could be obtained. This new technology, which is used daily, probably is one of the greatest acquisitions of the 20th century in the field of medical imaging.

  12. Ultrasound -- Pelvis

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    Full Text Available ... quickly. The ultrasound exam room may have a television. Feel free to ask for your child's favorite ... display screen that looks like a computer or television monitor. The image is created based on the ...

  13. Ultrasound -- Pelvis

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    Full Text Available ... of the reflected sound waves (called the Doppler effect). A computer collects and processes the sounds and ... standard diagnostic ultrasound , there are no known harmful effects on humans. top of page What are the ...

  14. 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 ... of the reflected sound waves (called the Doppler effect). A computer collects and processes the sounds and ...

  15. Ultrasound -- Pelvis

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    Full Text Available ... bladder Pelvic ultrasound exams are also used to monitor the health and development of an embryo or ... screen that looks like a computer or television monitor. The image is created based on the amplitude ( ...

  16. Dual-Modality Imaging of the Human Finger Joint Systems by Using Combined Multispectral Photoacoustic Computed Tomography and Ultrasound Computed Tomography

    Directory of Open Access Journals (Sweden)

    Yubin Liu

    2016-01-01

    Full Text Available We developed a homemade dual-modality imaging system that combines multispectral photoacoustic computed tomography and ultrasound computed tomography for reconstructing the structural and functional information of human finger joint systems. The fused multispectral photoacoustic-ultrasound computed tomography (MPAUCT system was examined by the phantom and in vivo experimental tests. The imaging results indicate that the hard tissues such as the bones and the soft tissues including the blood vessels, the tendon, the skins, and the subcutaneous tissues in the finger joints systems can be effectively recovered by using our multimodality MPAUCT system. The developed MPAUCT system is able to provide us with more comprehensive information of the human finger joints, which shows its potential for characterization and diagnosis of bone or joint diseases.

  17. Contrast-enhanced duplex scanning of crural arteries by means of continuous infusion of Levovist

    NARCIS (Netherlands)

    Coffi, Stephen B.; Ubbink, Dirk Th; Zwiers, Ineke; van Gurp, Johan A. M.; Hanson, Dianne; Legemate, Dink A.

    2004-01-01

    Objectives: To estimate the dosage needed for continuous infusion and to investigate whether continuous infusion of the ultrasound contrast-enhancing agent Levovist (SH U 508A) can improve duplex scanning of crural arteries in patients with peripheral arterial obstructive disease (PAOD) eligible for

  18. 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

    OpenAIRE

    Colleran, Gabrielle C; Cronin, Kevin C; Browne, Ann M; Hynes, Niamh; Sultan, Sherif

    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 Anteri...

  19. Full-Duplex Underwater Networking Using CDMA

    National Research Council Canada - National Science Library

    Bektas, Kurtulus

    2004-01-01

    Establishing a full-duplex underwater network, researching and applying a CDMA protocol to the network, providing a recommendation for a full-duplex underwater network and providing recommendations...

  20. Comparison of excretory urography, angiography, ultrasound and computed tomography for T category staging of renal cell carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Tammela, T.L.J.; Leinonen, A.S.S.; Kontturi, M.J. (Dept. of Surgery and Dept. of Diagnostic Radiology, Oulu Univ. Hospital (Finland))

    1991-01-01

    The diagnostic significance of excretory urography, renal angiography, ultrasound and computed tomography for predicting the stage of tumours was evaluated by comparing their results with preoperative and histopathological findings. Thirty-nine out of 178 patients operated on for renal cell carcinoma from 1981 to 1988 were subjected to all four diagnostic procedures. The T-stage was determined correctly by computed tomography in 80% of the cases, by ultrasound in 74.5%, by renal angiography in 64% and by excretory urography in 56.5%. Excretory urography did not give any significant additional information on the T category compared with the other imaging methods. Angiography is still of value in that it gives preoperative information on the collateral circulation and the number of renal arteries and their location. (au).

  1. Improved misfit function for attenuation and speed reconstruction in ultrasound computed tomography

    Science.gov (United States)

    Pérez-Liva, M.; Udías, J. M.; Herraiz, J. L.

    2017-03-01

    The reconstruction of acoustic attenuation maps for transmission Ultrasound Computed Tomography (USCT) based on the standard least-squares full wave inversion method requires the accurate knowledge of the sound speed map in the region under study. Any deviation in the reconstructed speed maps creates a very significant bias in the attenuation map, as the standard least-squares misfit function is more sensitive to time misalignments than to amplitude differences of the signals. In this work, we propose a generalized misfit function which includes an additional term that accounts for the amplitude differences between the measured and the estimated signals. The functional gradients used to minimize the proposed misfit function were obtained using an adjoint field formulation and the fractional Laplacian wave equation. The forward and backward wave propagation was obtained with the parallelized GPU version of the software k-Wave and the optimization was performed with a line search method. A numerical phantom simulating breast tissue and synthetic noisy data were used to test the performance of the proposed misfit function. The attenuation was reconstructed based on a converged speed map. An edge-preserving regularization method based on total variation was also implemented. To quantify the quality of the results, the mean values and their standard deviations in several regions of interest were analyzed and compared to the reference values. The proposed generalized misfit function decreases considerably the bias in the attenuation map caused by the deviations in the speed map in all the regions of interest analyzed.

  2. Toward Optimal Computation of Ultrasound Image Reconstruction Using CPU and GPU.

    Science.gov (United States)

    Techavipoo, Udomchai; Worasawate, Denchai; Boonleelakul, Wittawat; Keinprasit, Rachaporn; Sunpetchniyom, Treepop; Sugino, Nobuhiko; Thajchayapong, Pairash

    2016-11-24

    An ultrasound image is reconstructed from echo signals received by array elements of a transducer. The time of flight of the echo depends on the distance between the focus to the array elements. The received echo signals have to be delayed to make their wave fronts and phase coherent before summing the signals. In digital beamforming, the delays are not always located at the sampled points. Generally, the values of the delayed signals are estimated by the values of the nearest samples. This method is fast and easy, however inaccurate. There are other methods available for increasing the accuracy of the delayed signals and, consequently, the quality of the beamformed signals; for example, the in-phase (I)/quadrature (Q) interpolation, which is more time consuming but provides more accurate values than the nearest samples. This paper compares the signals after dynamic receive beamforming, in which the echo signals are delayed using two methods, the nearest sample method and the I/Q interpolation method. The comparisons of the visual qualities of the reconstructed images and the qualities of the beamformed signals are reported. Moreover, the computational speeds of these methods are also optimized by reorganizing the data processing flow and by applying the graphics processing unit (GPU). The use of single and double precision floating-point formats of the intermediate data is also considered. The speeds with and without these optimizations are also compared.

  3. Three-dimensional computer-controlled acoustic pressure scanning and quantification of focused ultrasound.

    Science.gov (United States)

    Seo, Joonho; Koizumi, Norihiro; Yoshinaka, Kiyoshi; Sugita, Naohikoa; Nomiya, Akira; Homma, Yukio; Matsumoto, Yoichiro; Mitsuishi, Mamoru

    2010-04-01

    We propose an automated needle hydrophone-based scanning system to measure high-resolution 3-D acoustic pressure distributions generated by high-intensity focused ultrasound (HIFU). The hardware consists of a host computer, subsystems for HIFU generation, and an oscilloscope to sample the pressure response from a sensor in a water tank. Software was developed to control the hardware subsystems, to search for the initial scan position, and to design the scanning path and volume. A preoperative scanning plan with three perpendicular planes is used to manipulate the position of the HIFU transducer and to automate the acquisition of the spatial acoustic pressure distribution. The post-processing process displays the scanning results, compensates time delays caused by continuous linear scans, and quantifies the focal region. A method to minimize the displacement error induced by the time delay improves the scanning speed of a conventional needle hydrophone-based scanning system. Moreover, a noise-robust, automatic-focus searching algorithm using Gaussian function fitting reduces the total number of iterations and prevents the initial scanning position search from diverging. Finally, the minimum-volume enclosing ellipsoid approximation is used to quantify the size and orientation of the 3-D focal region thresholded by the minimum pressure of interest for various input conditions and to test the reproducibility of the scanning system.

  4. Abdominal ultrasound-scanning versus non-contrast computed tomography as screening method for abdominal aortic aneurysm

    DEFF Research Database (Denmark)

    Liisberg, Mads; Diederichsen, Axel C.; Lindholt, Jes S.

    2017-01-01

    Background: Validating non-contrast-enhanced computed tomography (nCT) compared to ultrasound sonography (US) as screening method for abdominal aortic aneurysm (AAA) screening. Methods: Consecutively attending men (n = 566) from the pilot study of the randomized Danish CardioVascular Screening......CT seems superior to US concerning sensitivity, and is able to detect aneurysmal lesions not detectable with US. Finally, the prevalence of AAA in Denmark seems to remain relatively high, in this small pilot study group....

  5. Computational Complexity Reduction of Synthetic-aperture Focus in Ultrasound Imaging Using Frequency-domain Reconstruction.

    Science.gov (United States)

    Moghimirad, Elahe; Mahloojifar, Ali; Mohammadzadeh Asl, Babak

    2016-05-01

    A new frequency-domain implementation of a synthetic aperture focusing technique is presented in the paper. The concept is based on synthetic aperture radar (SAR) and sonar that is a developed version of the convolution model in the frequency domain. Compared with conventional line-by-line imaging, synthetic aperture imaging has a better resolution and contrast at the cost of more computational load. To overcome this problem, point-by-point reconstruction methods have been replaced by block-processing algorithms in radar and sonar; however, these techniques are relatively unknown in medical imaging. In this paper, we extended one of these methods called wavenumber to medical ultrasound imaging using a simple model of synthetic aperture focus. The model, derived here for monostatic mode, can be generalized to multistatic as well. The method consists of 4 steps: a 2D fast Fourier transform of the data, frequency shift of the data to baseband, interpolation to convert polar coordinates to rectangular ones, and returning the data to the spatial-domain using a 2D inverse Fourier transform. We have also used chirp pulse excitation followed by matched filtering and spotlighting algorithm to compensate the effect of differences in parameters between radar and medical imaging. Computational complexities of the two methods, wavenumber and delay-and-sum (DAS), have been calculated. Field II simulated point data have been used to evaluate the results in terms of resolution and contrast. Evaluations with simulated data show that for typical phantoms, reconstruction by the wavenumber algorithm is almost 20 times faster than classical DAS while retaining the resolution. © The Author(s) 2015.

  6. Simulation for competency assessment in vascular and cardiac ultrasound.

    Science.gov (United States)

    Sheehan, Florence H; Zierler, R Eugene

    2018-02-01

    Healthcare providers who use peripheral vascular and cardiac ultrasound require specialized training to develop the technical and interpretive skills necessary to perform accurate diagnostic tests. Assessment of competence is a critical component of training that documents a learner's progress and is a requirement for competency-based medical education (CBME) as well as specialty certification or credentialing. The use of simulation for CBME in diagnostic ultrasound is particularly appealing since it incorporates both the psychomotor and cognitive domains while eliminating dependency on the availability of live patients with a range of pathology. However, successful application of simulation in this setting requires realistic, full-featured simulators and appropriate standardized metrics for competency testing. The principal diagnostic parameter in peripheral vascular ultrasound is measurement of peak systolic velocity (PSV) on Doppler spectral waveforms, and simulation of Doppler flow detection presents unique challenges. The computer-based duplex ultrasound simulator developed at the University of Washington uses computational fluid dynamics modeling and presents real-time color-flow Doppler images and Doppler spectral waveforms along with the corresponding B-mode images. This simulator provides a realistic scanning experience that includes measuring PSV in various arterial segments and applying actual diagnostic criteria. Simulators for echocardiography have been available since the 1990s and are currently more advanced than those for peripheral vascular ultrasound. Echocardiography simulators are now offered for both transesophageal echo and transthoracic echo. These computer-based simulators have 3D graphic displays that provide feedback to the learner and metrics for assessment of technical skill that are based on transducer tracking data. Such metrics provide a motion-based or kinematic analysis of skill in performing cardiac ultrasound. The use of

  7. Ultrasound computed tomography by frequency-shift low-pass filtering and least mean square adaptive filtering

    Science.gov (United States)

    Wang, Shanshan; Song, Junjie; Peng, Yang; Zhou, Liang; Ding, Mingyue; Yuchi, Ming

    2017-03-01

    In recent years, many research studies have been carried out on ultrasound computed tomography (USCT) for improving the detection and management of breast cancer. This paper investigates a signal pre-processing method based on frequency-shift low-pass filtering (FSLF) and least mean square adaptive filtering (LMSAF) for USCT image quality enhancement (proposed in our previous work). FSLF is designed base on Zoom Fast Fourier Transform algorithm (ZFFT) for processing the ultrasound signals in the frequency domain, while LMSAPF is based on the least mean square (LMS) algorithm in the time domain. Through the combination of the two filters, the ultrasound image is expected to have less noises and artifacts, and higher resolution and contrast. The proposed method was verified with the radio-frequency (RF) data of the nylon threads and the breast phantom captured by the USCT system developed in the Medical Ultrasound Laboratory. Experimental results show that the reconstructed images of nylon threads by the proposed method had narrower main lobe width and lower side lobe level comparing to the delay-and-sum (DAS). The background noises and artifacts could also be efficiently restrained. The reconstructed image of breast phantom by the proposed method had a higher resolution and the contrast ratio (CR) could be enhanced for about 12dB to 18dB at different region of interest (ROI).

  8. Ultrasound and computed tomography description of the liver the Boa constrictor; Descricao ultrassonografica e tomografica do figado de Boa constrictor

    Energy Technology Data Exchange (ETDEWEB)

    Zulim, Rosalia Marina Infiesta; Geller, Felipe Foletto; Souza, Priscila Macedo de; Mamprim, Maria Jaqueline, E-mail: rosaliamarina@hotmail.com [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Botucatu, SP (Brazil). Faculdade de Medicina Veterinaria e Zootecnia . Dept. de Reproducao Animal e Radiologia Veterinaria; Cardoso, Guilherme Schiess; Teixeira, Carlos Roberto [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Botucatu, SP (Brazil). Faculdade de Medicina Veterinaria e Zootecnia . Dept. de Cirurgia e Anestesiologia Veterinaria; Andrade, Rafael Souza [Universidade Federal Rural da Amazonia (UFRA), Belem, PA (Brazil); Rossetti, Diogo Pascoal; Comerlato, Alexandra Tiso [Universidade Estadual Paulista Julio de Mesquita Filho (CEMPAS/UNESP), Botucatu, SP (Brazil). Faculdade de Medicina Veterinaria e Zootecnia. Centro de Medicina e Pesquisa de Animais Silvestres

    2012-07-01

    Ultrasound is a method for noninvasive diagnosis, their effectiveness in the diagnosis of liver disease has been described in snakes. The liver is the largest organ of the coelomic cavity of reptiles. Elongated and flattened. The caudal vena cava and portal vein divides the body into two lobes. The hepatic parenchyma is homogeneous hypoechoic echogenicity. The objective is to describe and to obtain reference images in the study of liver four snakes of Boa constrictor amarali, through an ultrasound and tomography. Physical restraint made for the ultrasound examination held in prone position, to compare the texture and mark the structures for the slices on CT. A linear multifrequency probe of 6-10 mHz was used. The anesthetic protocol for computed tomography consisted of isoflurane. In helical CT scanner, the animal was positioned in the prone position, and used continuous cross sections of 2 mm by 2. The ultrasound and CT examinations allowed the identification of liver contours as well as the definition and extension of the caudal vena cava and portal vein. Normal pattern recognition of CT aspect of the present study will be of help in the diagnosis of liver diseases in snakes (Boa constrictor amarali). (author)

  9. 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.

  10. Computation of nonlinear ultrasound fields using a linearized contrast source method

    NARCIS (Netherlands)

    Verweij, M.D.; Demi, L.; Van Dongen, K.W.A.

    2013-01-01

    Nonlinear ultrasound is important in medical diagnostics because imaging of the higher harmonics improves resolution and reduces scattering artifacts. Second harmonic imaging is currently standard, and higher harmonic imaging is under investigation. The efficient development of novel imaging

  11. A hybrid fuzzy-neural system for computer-aided diagnosis of ultrasound kidney images using prominent features.

    Science.gov (United States)

    Bommanna Raja, K; Madheswaran, M; Thyagarajah, K

    2008-02-01

    The objective of this work is to develop and implement a computer-aided decision support system for an automated diagnosis and classification of ultrasound kidney images. The proposed method distinguishes three kidney categories namely normal, medical renal diseases and cortical cyst. For the each pre-processed ultrasound kidney image, 36 features are extracted. Two types of decision support systems, optimized multi-layer back propagation network and hybrid fuzzy-neural system have been developed with these features for classifying the kidney categories. The performance of the hybrid fuzzy-neural system is compared with the optimized multi-layer back propagation network in terms of classification efficiency, training and testing time. The results obtained show that fuzzy-neural system provides higher classification efficiency with minimum training and testing time. It has also been found that instead of using all 36 features, ranking the features enhance classification efficiency. The outputs of the decision support systems are validated with medical expert to measure the actual efficiency. The overall discriminating capability of the systems is accessed with performance evaluation measure, f-score. It has been observed that the performance of fuzzy-neural system is superior compared to optimized multi-layer back propagation network. Such hybrid fuzzy-neural system with feature extraction algorithms and pre-processing scheme helps in developing computer-aided diagnosis system for ultrasound kidney images and can be used as a secondary observer in clinical decision making.

  12. A hybrid FDTD-Rayleigh integral computational method for the simulation of the ultrasound measurement of proximal femur.

    Science.gov (United States)

    Cassereau, Didier; Nauleau, Pierre; Bendjoudi, Aniss; Minonzio, Jean-Gabriel; Laugier, Pascal; Bossy, Emmanuel; Grimal, Quentin

    2014-07-01

    The development of novel quantitative ultrasound (QUS) techniques to measure the hip is critically dependent on the possibility to simulate the ultrasound propagation. One specificity of hip QUS is that ultrasounds propagate through a large thickness of soft tissue, which can be modeled by a homogeneous fluid in a first approach. Finite difference time domain (FDTD) algorithms have been widely used to simulate QUS measurements but they are not adapted to simulate ultrasonic propagation over long distances in homogeneous media. In this paper, an hybrid numerical method is presented to simulate hip QUS measurements. A two-dimensional FDTD simulation in the vicinity of the bone is coupled to the semi-analytic calculation of the Rayleigh integral to compute the wave propagation between the probe and the bone. The method is used to simulate a setup dedicated to the measurement of circumferential guided waves in the cortical compartment of the femoral neck. The proposed approach is validated by comparison with a full FDTD simulation and with an experiment on a bone phantom. For a realistic QUS configuration, the computation time is estimated to be sixty times less with the hybrid method than with a full FDTD approach. Copyright © 2013 Elsevier B.V. All rights reserved.

  13. Computer-Aided Diagnosis for Breast Ultrasound Using Computerized BI-RADS Features and Machine Learning Methods.

    Science.gov (United States)

    Shan, Juan; Alam, S Kaisar; Garra, Brian; Zhang, Yingtao; Ahmed, Tahira

    2016-04-01

    This work identifies effective computable features from the Breast Imaging Reporting and Data System (BI-RADS), to develop a computer-aided diagnosis (CAD) system for breast ultrasound. Computerized features corresponding to ultrasound BI-RADs categories were designed and tested using a database of 283 pathology-proven benign and malignant lesions. Features were selected based on classification performance using a "bottom-up" approach for different machine learning methods, including decision tree, artificial neural network, random forest and support vector machine. Using 10-fold cross-validation on the database of 283 cases, the highest area under the receiver operating characteristic (ROC) curve (AUC) was 0.84 from a support vector machine with 77.7% overall accuracy; the highest overall accuracy, 78.5%, was from a random forest with the AUC 0.83. Lesion margin and orientation were optimum features common to all of the different machine learning methods. These features can be used in CAD systems to help distinguish benign from worrisome lesions. Copyright © 2016 World Federation for Ultrasound in Medicine & Biology. All rights reserved.

  14. Ultrasound-guided versus computed tomography-scan guided biopsy of pleural-based lung lesions

    Directory of Open Access Journals (Sweden)

    Rahul Khosla

    2016-01-01

    Full Text Available Background: Computed tomography (CT guided biopsies have long been the standard technique to obtain tissue from the thoracic cavity and is traditionally performed by interventional radiologists. Ultrasound (US guided biopsy of pleural-based lesions, performed by pulmonologists is gaining popularity and has the advantage of multi-planar imaging, real-time technique, and the absence of radiation exposure to patients. In this study, we aim to determine the diagnostic accuracy, the time to diagnosis after the initial consult placement, and the complications rates between the two different modalities. Methods: A retrospective study of electronic medical records was done of patients who underwent CT-guided biopsies and US-guided biopsies for pleural-based lesions between 2005 and 2014 and the data collected were analyzed for comparing the two groups. Results: A total of 158 patients underwent 162 procedures during the study period. 86 patients underwent 89 procedures in the US group, and 72 patients underwent 73 procedures in the CT group. The overall yield in the US group was 82/89 (92.1% versus 67/73 (91.8% in the CT group (P = 1.0. Average days to the procedure was 7.2 versus 17.5 (P = 0.00001 in the US and CT group, respectively. Complication rate was higher in CT group 17/73 (23.3% versus 1/89 (1.1% in the US group (P < 0.0001. Conclusions: For pleural-based lesions the diagnostic accuracy of US guided biopsy is similar to that of CT-guided biopsy, with a lower complication rate and a significantly reduced time to the procedure.

  15. Nephrocalcinosis in rabbits - correlation of ultrasound, computed tomography, pathology and renal function

    Energy Technology Data Exchange (ETDEWEB)

    Cramer, B.; Pushpanathan, C. [Janeway Child Health Centre, St. Johns`s (Canada). Radiology Dept.; Husa, L. [Memorial Univ. of Newfoundland, St. Johns`s (Canada)

    1998-01-01

    Objective. The purpose of this study was to induce nephrocalcinosis (NC) in rabbits with phosphate, vitamin D, oxalate and furosemide, to determine the effect of renal function and to correlate detection of ultrasound (US) and computed tomography (CT) with pathology. Materials and methods. Seventy-five immature New Zealand white rabbits were divided into five groups of 15. In each group, 5 animals were controls and 10 were given oral phosphate, furosemide, vitamin D or oxalate, furosemide, vitamin D or oxalate. Unilateral nephrectomy was performed at 3-6 weeks, and 5 rabbits of each test group were withdrawn from the substance. Weekly US was performed as well as US, CT and measurement of serum creatinine at the time of nephrectomy and prior to planned demise. Results. A todal of 140 kidneys in 75 rabbits had both pathological and US correlation, with CT correlation in 126. Forty rabbits developed nephrocalcinosis with early (post nephrectomy at 3-6 weeks) or late (post demise at 10-20 weeks) phatological correlation obtained in 53 kidneys. Forty-one of these kidneys were from test animals: 23 developed NC early, 18 late. Twelve controls developed NC; 4 early, 8 late. Comparing US and CT to phatology, the sensitivity was 96% for US, 64% for CT. Specificity was 85% for US and 96% for CT. In 109 kidneys, information on serum creatinine level was available to correlate with phatology. The mean creatinine level was 138 mmol/l for those with NC and 118 mmol/l for those without NC (P<0.001).

  16. "Silent" kidney stones in "asymptomatic" primary hyperparathyroidism-a comparison of multidetector computed tomography and ultrasound.

    Science.gov (United States)

    Selberherr, Andreas; Hörmann, Marcus; Prager, Gerhard; Riss, Philipp; Scheuba, Christian; Niederle, Bruno

    2017-03-01

    The purpose of this study was to demonstrate the high number of kidney stones in primary hyperparathyroidism (PHPT) and the low number of in fact "asymptomatic" patients. Forty patients with PHPT (28 female, 12 male; median age 58 (range 33-80) years; interquartile range 17 years [51-68]) without known symptoms of kidney stones prospectively underwent multidetector computed tomography (MDCT) and ultrasound (US) examinations of the urinary tract prior to parathyroid surgery. Images were evaluated for the presence and absence of stones, as well as for the number of stones and sizes in the long axis. The MDCT and US examinations were interpreted by two experienced radiologists who were blinded to all clinical and biochemical data. Statistical analysis was performed using the Wilcoxon signed-rank test. US revealed a total of 4 kidney stones in 4 (10 %) of 40 patients (median size 6.5 mm, interquartile range 11.5 mm). MDCT showed a total of 41 stones (median size was 3 mm, interquartile range 2.25 mm) in 15 (38 %) of 40 patients. The number of kidney stones detected with MDCT was significantly higher compared to US (p = 0.00124). MDCT is a highly sensitive method for the detection of "silent" kidney stones in patients with PHPT. By widely applying this method, the number of asymptomatic courses of PHPT may be substantially reduced. MDCT should be used primarily to detect kidney stones in PHPT and to exclude asymptomatic PHPT.

  17. Congenital Giant Hydroureteric Cistern in a Duplex System of an Infant

    Directory of Open Access Journals (Sweden)

    O. T. Awolaran

    2013-01-01

    Full Text Available Duplex collecting system is a congenital genitourinary anomaly commonly found incidentally. Our experience with a duplex system associated with giant hydroureter presenting as mobile abdominal swelling that was noticed from birth, constipation, and failure to thrive is described. Ultrasound and IVU did not assist in making the diagnosis, while a barium enema suggested a colonic duplication. Congenital giant hydroureter should be considered as a differential diagnosis in infants with cystic abdominal swelling. A preserved renal moiety attributed to a dilated ureteric cistern was a unique theory in this case.

  18. Computer-aided system for diagnosing thyroid nodules on ultrasound: A comparison with radiologist-based clinical assessments.

    Science.gov (United States)

    Gao, Luying; Liu, Ruyu; Jiang, Yuxin; Song, Wenfeng; Wang, Ying; Liu, Jia; Wang, Juanjuan; Wu, Dongqian; Li, Shuai; Hao, Aimin; Zhang, Bo

    2017-12-29

    The purpose of this study was to compare the diagnostic efficiency of a thyroid ultrasound computer-aided diagnosis (CAD) system with that of 1 radiologist. This study retrospectively reviewed 342 surgically resected thyroid nodules from July 2013 to December 2013 at our center. The nodules were assessed on typical ultrasound images using the CAD system and reviewed by 1 experienced radiologist. The radiologist stratified the risk of malignancy using the Thyroid Imaging Reporting and Data Systems (TIRADS) and the American Thyroid Association (ATA) guidelines. The radiologist, using TI-RADS and ATA guidelines, performed better than the CAD system (P system was similar to that of an experienced radiologist (P > .05; P .05). However, we found that the CAD system had lower specificity (P system in differentiating nodules was similar to that of an experienced radiologist. However, the CAD system had lower specificity. © 2017 Wiley Periodicals, Inc.

  19. Computational patient-specific models based on 3-D ultrasound data to quantify uterine arterial flow during pregnancy.

    Science.gov (United States)

    Pennati, Giancarlo; Socci, Laura; Rigano, Serena; Boito, Simona; Ferrazzi, Enrico

    2008-12-01

    Information on uterine blood flow rate during pregnancy would widely improve our knowledge on feto-placental patho-physiology. Ultrasonographic flow rate evaluation requires the knowledge of the spatial velocity profiles throughout the investigated vessel; these data may be obtained from hemodynamic simulations with accurate computational models. Recently, computational models of superficial vessels have been created using 3-D ultrasound data; unfortunately, common reconstruction methods are unsuitable for the uterine arteries due to the low quality achievable of imaged deep vessels. In this paper a simplified spline-based technique was applied to create computational models for patient-specific simulations of uterine arterial heamodynamics. Moreover, a novel method to quantify the uterine flow rates was developed based on echo-Doppler measurements and computational data. Preliminary results obtained for four patients indicated a quite narrow range for the blood flow rate through the main uterine artery with large variability in the flow split between corporal and cervical branches. Furthermore, parabolic-like velocity profiles were obtained in the branching region of the different patients, suggesting a clinical use of averaged, not patient-specific, spatial velocity distribution coefficients for the blood flow rate calculation. The developed reconstruction method based on 3-D ultrasound imaging is efficient for creating realistic custom models of the uterine arteries. The results of the fluid dynamic simulations allowed us to quantify the uterine arterial flow and its repartition in normal pregnancies.

  20. 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 ...

  1. 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.

  2. Computational fluid dynamics modeling of mass-transfer behavior in a bioreactor for hairy root culture. II. Analysis of ultrasound-intensified process.

    Science.gov (United States)

    Liu, Rui; Sun, Wei; Liu, Chun-Zhao

    2011-01-01

    Recently, cichoric acid production from hairy roots of Echinacea purpurea was significantly improved by ultrasound stimulation in an airlift bioreactor. In this article, the possible mechanism on ultrasound-intensified hairy root culture of E. purpurea in the bioreactor was elucidated with the help of computational fluid dynamics (CFD) simulation, membrane permeability detection, dissolved oxygen concentration detection, confocal laser-scanning microscopy (LSM) observation, and phenylalanine ammonium lyase (PAL) activity analysis. The CFD model developed in Part I was used to simulate the hydrodynamics and oxygen mass transfer in hairy root bioreactor culture stimulated by ultrasound. A dynamic mesh model combined with a changing Schmidt number method was used for the simulation of the ultrasound field. Simulation results and experimental data illustrated that ultrasound intensified oxygen mass transfer in the hairy root clump, which subsequently stimulated root growth and cichoric acid biosynthesis. Ultrasound increased the hairy root membrane permeability, and a high root membrane permeability of 0.359 h(-1) was observed at the bottom region in the bioreactor. LSM observation showed that the change in the membrane permeability recovered to normal in the further culture after ultrasound stimulation. PAL activity in the hairy roots was stimulated by ultrasound increase and was correlated well to cichoric acid accumulation in the hairy roots of E. purpurea. Copyright © 2011 American Institute of Chemical Engineers (AIChE).

  3. Nonlinear ultrasound propagation through layered liquid and tissue-equivalent media: computational and experimental results at high frequency.

    Science.gov (United States)

    Williams, Ross; Cherin, Emmanuel; Lam, Toby Y J; Tavakkoli, Jahangir; Zemp, Roger J; Foster, F Stuart

    2006-11-21

    Nonlinear propagation has been demonstrated to have a significant impact on ultrasound imaging. An efficient computational algorithm is presented to simulate nonlinear ultrasound propagation through layered liquid and tissue-equivalent media. Results are compared with hydrophone measurements. This study was undertaken to investigate the role of nonlinear propagation in high frequency ultrasound micro-imaging. The acoustic field of a focused transducer (20 MHz centre frequency, f-number 2.5) was simulated for layered media consisting of water and tissue-mimicking phantom, for several wide-bandwidth source pulses. The simulation model accounted for the effects of diffraction, attenuation and nonlinearity, with transmission and refraction at layer boundaries. The parameter of nonlinearity, B/A, of the water and tissue-mimicking phantom were assumed to be 5.2 and 7.4, respectively. The experimentally measured phantom B/A value found using a finite-amplitude insert-substitution method was shown to be 7.4 +/- 0.6. Relative amounts of measured second and third harmonic pressures as a function of the fundamental pressures at the focus were in good agreement with simulations. Agreement within 3% was found between measurements and simulations of the beam widths of the fundamental and second harmonic signals following propagation through the tissue phantom. The results demonstrate significant nonlinear propagation effects for high frequency imaging beams.

  4. Computed Tomography and Ultrasounds for the Follow-up of Hepatocellular Carcinoma Ablation: What You Need to Know

    Directory of Open Access Journals (Sweden)

    Alexios Kelekis

    2016-02-01

    Full Text Available Image-guided tumor ablation provides curative treatment in properly selected patients or appropriate therapeutic options whenever surgical techniques are precluded. Tumor response assessment post ablation is important in determining treatment success and future therapy. Accurate interpretation of post-ablation imaging findings is crucial for therapeutic and follow-up strategies. Computed Tomography (CT and Ultrasound (US play important roles in patients’ follow-up post liver thermal ablation therapies. Contrast-enhanced ultrasound (CEUS can provide valuable information on the ablation effects faster and at a lower cost than computed tomography or magnetic resonance imaging. However, a disadvantage is that the technique cannot examine total liver parenchyma for disease progression as CT and Magnetic Resonance (MR imaging can. Follow-up strategies for assessment of tumor response includes contrast enhanced multiphasic (non-contrast, arterial, portal, delayed phases imaging with Computed Tomography at three, six, and 12 months post ablation session and annually ever since in order to prove sustained effectiveness of the ablation or detect progression.

  5. Transoesophageal ultrasound and computer tomographic assessment of the equine cricoarytenoid dorsalis muscle: Relationship between muscle geometry and exercising laryngeal function.

    Science.gov (United States)

    Kenny, M; Cercone, M; Rawlinson, J J; Ducharme, N G; Bookbinder, L; Thompson, M; Cheetham, J

    2017-05-01

    Early detection of recurrent laryngeal neuropathy (RLN) is of considerable interest to the equine industry. To describe two imaging modalities, transoesophageal ultrasound (TEU) and computed tomography (CT) with multiplanar reconstruction to assess laryngeal muscle geometry, and determine the relationship between cricoarytenoid dorsalis (CAD) geometry and function. Two-phase study evaluating CAD geometry in experimental horses and horses with naturally occurring RLN. Equine CAD muscle volume was determined from CT scan sets using volumetric reconstruction with LiveWire. The midbody and caudal dorsal-ventral thickness of the CAD muscle was determined using a TEU in the same horses; and in horses with a range of severity of RLN (n = 112). Transoesophageal ultrasound was able to readily image the CAD muscles and lower left:right CAD thickness ratios were observed with increasing disease severity. Computed tomography based muscle volume correlated very closely with ex vivo muscle volume (R2 = 0.77). Computed tomography reconstruction can accurately determine intrinsic laryngeal muscle geometry. A relationship between TEU measurements of CAD geometry and laryngeal function was established. These imaging techniques could be used to track the response of the CAD muscle to restorative surgical treatments such as nerve muscle pedicle graft, nerve anastomosis and functional electrical stimulation. © 2016 EVJ Ltd.

  6. A computer-aided diagnosis system for breast ultrasound based on weighted BI-RADS classes.

    Science.gov (United States)

    Rodríguez-Cristerna, Arturo; Gómez-Flores, Wilfrido; de Albuquerque Pereira, Wagner Coelho

    2018-01-01

    Conventional computer-aided diagnosis (CAD) systems for breast ultrasound (BUS) are trained to classify pathological classes, that is, benign and malignant. However, from a clinical perspective, this kind of classification does not agree totally with radiologists' diagnoses. Usually, the tumors are assessed by using a BI-RADS (Breast Imaging-Reporting and Data System) category and, accordingly, a recommendation is emitted: annual study for category 2 (benign), six-month follow-up study for category 3 (probably benign), and biopsy for categories 4 and 5 (suspicious of malignancy). Hence, in this paper, a CAD system based on BI-RADS categories weighted by pathological information is presented. The goal is to increase the classification performance by reducing the common class imbalance found in pathological classes as well as to provide outcomes quite similar to radiologists' recommendations. The BUS dataset considers 781 benign lesions and 347 malignant tumors proven by biopsy. Moreover, every lesion is associated to one BI-RADS category in the set {2, 3, 4, 5}. Thus, the dataset is split into three weighted classes: benign, BI-RADS 2 in benign lesions; probably benign, BI-RADS 3 and 4 in benign lesions; and malignant, BI-RADS 4 and 5 in malignant lesions. Thereafter, a random forest (RF) classifier, denoted by RF w , is trained to predict the weighted BI-RADS classes. In addition, for comparison purposes, a RF classifier is trained to predict pathological classes, denoted as RF p . The ability of the classifiers to predict the pathological classes is measured by the area under the ROC curve (AUC), sensitivity (SEN), and specificity (SPE). The RF w classifier obtained AUC=0.872,SEN=0.826, and SPE=0.919, whereas the RF p classifier reached AUC=0.868,SEN=0.808, and SPE=0.929. According to a one-way analysis of variance test, the RF w classifier statistically outperforms (p < 0.001) the RF p classifier in terms of the AUC and SEN. Moreover, the

  7. Selective application of angiography for diagnosis of abdominal complaints (liver, pancreas and kidney) with reference to computed tomography and ultrasound

    Energy Technology Data Exchange (ETDEWEB)

    Uchida, Hideo; Oishi, Hajime (Nara Medical Univ., Kashihara (Japan)); Kuroda, Chikazumi; Nakamura, Hitonobu

    1982-11-01

    Computed tomography (CT) and ultrasound (US) being used as the initial screening procedure for patients with abdominal complaints are contributory to discrimination of cystic lesions between solid and complex. Angiography should no longer be used for screening purpose and, furthermore, is not to be applied to most cases of not only the cystic lesions but also advanced hepatoma with portal tumor thrombosis as well as pancreatic cancer with liver metastasis diagnosed by CT or US. The angiography, on the other hand, should be restricted to such purposes as detection of small solid lesion, differentiation of inflammatory mass from neoplasma and determination of surgical indication, which CT and US are considered incapable of achieving.

  8. 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

  9. 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.

  10. Computer-aided diagnostic system for detection of Hashimoto thyroiditis on ultrasound images from a Polish population.

    Science.gov (United States)

    Acharya, U Rajendra; Sree, S Vinitha; Krishnan, M Muthu Rama; Molinari, Filippo; Zieleźnik, Witold; Bardales, Ricardo H; Witkowska, Agnieszka; Suri, Jasjit S

    2014-02-01

    Computer-aided diagnostic (CAD) techniques aid physicians in better diagnosis of diseases by extracting objective and accurate diagnostic information from medical data. Hashimoto thyroiditis is the most common type of inflammation of the thyroid gland. The inflammation changes the structure of the thyroid tissue, and these changes are reflected as echogenic changes on ultrasound images. In this work, we propose a novel CAD system (a class of systems called ThyroScan) that extracts textural features from a thyroid sonogram and uses them to aid in the detection of Hashimoto thyroiditis. In this paradigm, we extracted grayscale features based on stationary wavelet transform from 232 normal and 294 Hashimoto thyroiditis-affected thyroid ultrasound images obtained from a Polish population. Significant features were selected using a Student t test. The resulting feature vectors were used to build and evaluate the following 4 classifiers using a 10-fold stratified cross-validation technique: support vector machine, decision tree, fuzzy classifier, and K-nearest neighbor. Using 7 significant features that characterized the textural changes in the images, the fuzzy classifier had the highest classification accuracy of 84.6%, sensitivity of 82.8%, specificity of 87.0%, and a positive predictive value of 88.9%. The proposed ThyroScan CAD system uses novel features to noninvasively detect the presence of Hashimoto thyroiditis on ultrasound images. Compared to manual interpretations of ultrasound images, the CAD system offers a more objective interpretation of the nature of the thyroid. The preliminary results presented in this work indicate the possibility of using such a CAD system in a clinical setting after evaluating it with larger databases in multicenter clinical trials.

  11. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... Ultrasound - Abdomen Children's (Pediatric) Ultrasound - Abdomen Obstetric Ultrasound Ultrasound - Prostate Kidney and Bladder Stones Abnormal Vaginal Bleeding Ovarian Cancer ...

  12. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... Children's (Pediatric) Ultrasound - Abdomen Obstetric Ultrasound Ultrasound - Prostate Kidney and Bladder Stones Abnormal Vaginal Bleeding Ovarian Cancer Images related to Ultrasound - Pelvis Sponsored by Please ...

  13. A Computer Simulation of Ultrasound Thermal Bio-Effect in Embryonic Model

    Directory of Open Access Journals (Sweden)

    J. Rozman

    2003-12-01

    Full Text Available At the present time, the usage of ultrasound diagnostic equipmenthas become an inseparable part of diagnosis for a number of medicalinvestigations. Several scientific studies published in the last yearsshowed that when applying a diagnostic ultrasound system on animals itis possible to create negative changes in tissues. New ultrasoundtechnologies and higher output acoustic powers have brought a possiblerisk connected to the usage of ultrasound in diagnostics. The knowledgeof risk level and exploration of limiting factors is an important pointfor the assessment of marginal ultrasound exposure values of medicalinvestigation during pregnancy, especially in the first trimester. Thecontribution presents a MATLABZ application for modeling of tissueheating in human embryos at the developmental age of seven and eightweeks. Recent calculations of US fields, which are generated by severaltypes of various unfocused single transducers (rectangular, circular,and annular, represent maximum temperature elevation of 0.4 °C inembryonic model tissues for the exposure of 1 min. The models ofembryonic tissue heating provide comparative studies of possiblebio-effect with the purpose to explore limiting factors of ultrasoundexposure.

  14. Bypassing absorbing objects in focused ultrasound using computer generated holographic technique.

    Science.gov (United States)

    Hertzberg, Y; Navon, G

    2011-12-01

    Focused ultrasound (FUS) technology is based on heating a small volume of tissue, while keeping the temperature outside the focus region with minimal heating only. Several FUS applications, such as brain and liver, suffer from the existence of ultrasound absorbers in the acoustic path between the transducer and the focus. These absorbers are a potential risk for the FUS therapy since they might cause to unwanted heating outside the focus region. An acoustic simulation based solution for reducing absorbers' heating is proposed, demonstrated, and compared to the standard geometrical solution. The proposed solution uses 3D continuous acoustic holograms, generated by the Gerchberg-Saxton (GS) algorithm, which are described and demonstrated for the first time using ultrasound planar phased-array transducer. Holograms were generated using the iterative GS algorithm and fast Fourier transform (FFT) acoustic simulation. The performances of the holograms are demonstrated by temperature elevation images of the absorber, acquired by GE 1.5T MRI scanner equipped with InSightec FUS planar phased-array transducer built out of 986 transmitting elements. The acoustic holographic technology is demonstrated numerically and experimentally using the three letters patterns, "T," "A," and "U," which were manually built into 1 × 1 cm masks to represent the requested target fields. 3D holograms of a focused ultrasound field with a hole in intensity at the absorber region were generated and compared to the standard geometrical solution. The proposed holographic solution results in 76% reduction of heating on absorber, while keeping similar heating at the focus. In the present work we show for the first time the generation of efficient and uniform continuous ultrasound holograms in 3D. We use the holographic technology to generate a FUS beams that bypasses an absorber in the acoustic path to reduce unnecessary heating and potential clinical risk. The developed technique is superior

  15. Computer aided diagnosis of Coronary Artery Disease, Myocardial Infarction and carotid atherosclerosis using ultrasound images: A review.

    Science.gov (United States)

    Faust, Oliver; Acharya, U Rajendra; Sudarshan, Vidya K; Tan, Ru San; Yeong, Chai Hong; Molinari, Filippo; Ng, Kwan Hoong

    2017-01-01

    The diagnosis of Coronary Artery Disease (CAD), Myocardial Infarction (MI) and carotid atherosclerosis is of paramount importance, as these cardiovascular diseases may cause medical complications and large number of death. Ultrasound (US) is a widely used imaging modality, as it captures moving images and image features correlate well with results obtained from other imaging methods. Furthermore, US does not use ionizing radiation and it is economical when compared to other imaging modalities. However, reading US images takes time and the relationship between image and tissue composition is complex. Therefore, the diagnostic accuracy depends on both time taken to read the images and experience of the screening practitioner. Computer support tools can reduce the inter-operator variability with lower subject specific expertise, when appropriate processing methods are used. In the current review, we analysed automatic detection methods for the diagnosis of CAD, MI and carotid atherosclerosis based on thoracic and Intravascular Ultrasound (IVUS). We found that IVUS is more often used than thoracic US for CAD. But for MI and carotid atherosclerosis IVUS is still in the experimental stage. Furthermore, thoracic US is more often used than IVUS for computer aided diagnosis systems. Copyright © 2016 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  16. Speed-accuracy trade-offs in computing spatial impulse responses for simulating medical ultrasound imaging

    DEFF Research Database (Denmark)

    Jensen, Jørgen Arendt

    2001-01-01

    Medical ultrasound imaging can be simulated realistically using linear acoustics. One of the most powerful approaches is to employ spatial impulse responses. Hereby both emitted fields and pulse-echo responses from point scatterers can be determined. Also any kind of dynamic focusing and apodizat......Medical ultrasound imaging can be simulated realistically using linear acoustics. One of the most powerful approaches is to employ spatial impulse responses. Hereby both emitted fields and pulse-echo responses from point scatterers can be determined. Also any kind of dynamic focusing...... the individual elements. One of the problems in using spatial impulse responses is the abrupt changes in the responses due to the sharp transducer boundaries. Sampling the responses directly therefore have to be done at very high sampling frequencies to keep the shape and energy of the response. The high...... sampling frequency is unnecessary in the final signals, since the transducers used in medical ultrasound are band limited. Approaches to reduce the sampling frequency are, thus, needed to make efficient simulation programs. Field II uses time integration of the spatial impulse responses using a continuous...

  17. 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...

  18. Prostate Ultrasound

    Medline Plus

    Full Text Available ... 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 ...

  19. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... News Physician Resources Professions Site Index A-Z Ultrasound - Pelvis Ultrasound imaging of the pelvis uses sound ... limitations of Pelvic Ultrasound Imaging? What is Pelvic Ultrasound Imaging? Ultrasound is safe and painless, and produces ...

  20. Prostate Ultrasound

    Medline Plus

    Full Text Available ... Physician Resources Professions Site Index A-Z Ultrasound - Prostate Ultrasound of the prostate uses sound waves to ... Ultrasound Imaging? What is Ultrasound Imaging of the Prostate? Ultrasound is safe and painless, and produces pictures ...

  1. A Computer-Aided Diagnosis Scheme For Detection Of Fatty Liver In Vivo Based On Ultrasound Kurtosis Imaging.

    Science.gov (United States)

    Ma, Hsiang-Yang; Zhou, Zhuhuang; Wu, Shuicai; Wan, Yung-Liang; Tsui, Po-Hsiang

    2016-01-01

    Fatty liver disease is a common disease caused by alcoholism, obesity, and diabetes, resulting in triglyceride accumulation in hepatocytes. Kurtosis coefficient, a measure of the peakedness of the probability distribution, has been applied to the analysis of backscattered statistics for characterizing fatty liver. This study proposed ultrasound kurtosis imaging as a computer-aided diagnosis (CAD) method to visually and quantitatively stage the fatty liver. A total of 107 patients were recruited to participate in the experiments. The livers were scanned using a clinical ultrasound scanner with a 3.5-MHz curved transducer to acquire the raw ultrasound backscattered signals for kurtosis imaging. The kurtosis image was constructed using the sliding window technique. Experimental results showed that kurtosis imaging has the ability to visualize and quantify the variation of backscattered statistics caused by fatty infiltration. The kurtosis coefficient corresponding to liver parenchyma decreased from 5.41 ± 0.89 to 3.68 ± 0.12 with increasing the score of fatty liver from 0 (normal) to 3 (severe), indicating that fatty liver reduces the degree of peakedness of backscattered statistics. The best performance of kurtosis imaging was found when discriminating between normal and fatty livers with scores ≥1: the area under the curve (AUC) is 0.92 at a cutoff value of 4.36 (diagnostic accuracy =86.9 %, sensitivity =86.7 %, specificity =87.0 %). The current findings suggest that kurtosis imaging may be useful in designing CAD tools to assist in physicians in early detection of fatty liver.

  2. A computer-aided tracking and motion analysis with ultrasound (CAT & MAUS) system for the description of hip joint kinematics.

    Science.gov (United States)

    Jia, Rui; Mellon, Stephen; Monk, Paul; Murray, David; Noble, J Alison

    2016-11-01

    Investigation of joint kinematics contributes to developing a better understanding of musculoskeletal conditions. However, the most commonly used optoelectronic motion analysis systems cannot determine the movements of underlying bone landmarks with high accuracy because of soft tissue artefacts. The aim of this paper was to present a computer-aided measurement system to track the underlying bone anatomy in a 3D global coordinate frame and describe hip joint kinematics of ten healthy volunteers during gait. We have developed a measurement tool with an image-based computer-aided post-processing pipeline for automatic bone segmentation in ultrasound (US) images and a globally optimal 3D surface-to-surface registration method to quantify hip joint movements. The segmentation algorithm exploits US intensity profiles, including information about the integrated backscattering, acoustic shadows, and local phase features. A global optimization method is applied based on the traditional iterative closest point registration algorithm, which is robust to initialization. The International Society of Biomechanics recommended joint kinematics descriptor has been adapted to calculate the joint kinematics. The developed system prototype has been validated with a ball-joint femoral phantom and tested in vivo with 10 volunteers. The maximum Euclidean distance error of the automatic bone segmentation is less than 2 pixels (approximately 0.2 mm). The maximum absolute rotation angle error is less than [Formula: see text]. This computer-aided tracking and motion analysis with ultrasound (CAT & MAUS) system shows the feasibility of describing hip joint kinematics for clinical investigation and diagnosis using an image-based solution.

  3. Probing of miniPEGγ-PNA-DNA Hybrid Duplex Stability with AFM Force Spectroscopy.

    Science.gov (United States)

    Dutta, Samrat; Armitage, Bruce A; Lyubchenko, Yuri L

    2016-03-15

    Peptide nucleic acids (PNA) are synthetic polymers, the neutral peptide backbone of which provides elevated stability to PNA-PNA and PNA-DNA hybrid duplexes. It was demonstrated that incorporation of diethylene glycol (miniPEG) at the γ position of the peptide backbone increased the thermal stability of the hybrid duplexes (Sahu, B. et al. J. Org. Chem. 2011, 76, 5614-5627). Here, we applied atomic force microscopy (AFM) based single molecule force spectroscopy and dynamic force spectroscopy (DFS) to test the strength and stability of the hybrid 10 bp duplex. This hybrid duplex consisted of miniPEGγ-PNA and DNA of the same length (γ(MP)PNA-DNA), which we compared to a DNA duplex with a homologous sequence. AFM force spectroscopy data obtained at the same conditions showed that the γ(MP)PNA-DNA hybrid is more stable than the DNA counterpart, 65 ± 15 pN vs 47 ± 15 pN, respectively. The DFS measurements performed in a range of pulling speeds analyzed in the framework of the Bell-Evans approach yielded a dissociation constant, koff ≈ 0.030 ± 0.01 s⁻¹ for γ(MP)PNA-DNA hybrid duplex vs 0.375 ± 0.18 s⁻¹ for the DNA-DNA duplex suggesting that the hybrid duplex is much more stable. Correlating the high affinity of γ(MP)PNA-DNA to slow dissociation kinetics is consistent with prior bulk characterization by surface plasmon resonance. Given the growing interest in γ(MP)PNA as well as other synthetic DNA analogues, the use of single molecule experiments along with computational analysis of force spectroscopy data will provide direct characterization of various modifications as well as higher order structures such as triplexes and quadruplexes.

  4. Ultrasound and computed tomography features of primary acinic cell carcinoma in the parotid gland: A retrospective study

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jia, E-mail: xpyxpy2011@163.com [Department of Ultrasound, Shanghai Ninth People' s Hospital, School of Medicine, Shanghai Jiao tong University, Shanghai (China); Gong, Xia, E-mail: gongxiafeng@163.com [Department of Ultrasound, Shanghai Ninth People' s Hospital, School of Medicine, Shanghai Jiao tong University, Shanghai (China); Xiong, Ping, E-mail: xiongpxp@163.com [Department of Ultrasound, Shanghai Ninth People' s Hospital, School of Medicine, Shanghai Jiao tong University, Shanghai (China); Xu, Qiuhua, E-mail: xu_qiu_hua@msn.com [Department of Ultrasound, Shanghai Ninth People' s Hospital, School of Medicine, Shanghai Jiao tong University, Shanghai (China); Liu, Yu, E-mail: 13917266194@126.com [Department of Radiology, Shanghai Ninth People' s Hospital, School of Medicine, Shanghai Jiao tong University, Shanghai (China); Chen, Yazhu, E-mail: yazhuchen@sjtu.edu.cn [Department of Biomedical Engineering, Shanghai Ninth People' s Hospital, School of Medicine, Shanghai Jiao tong University, Shanghai (China); Tian, Zhen, E-mail: tian0304_cn@163.com [Department of Pathology, Shanghai Ninth People' s Hospital, School of Medicine, Shanghai Jiao tong University, Shanghai (China)

    2014-07-15

    Objective: The aim of this study was to characterize the ultrasound (US) and computed tomography (CT) findings of primary acinic cell carcinoma (AciCC) of the parotid gland. Subjects and methods: Seventy patients (70 lesions) with histopathologically proven AciCC underwent US or CT examination. The following characteristics were assessed on US images: size, shape, border, echogenicity, echotexture, internal structure, distal acoustic enhancement, and vascularity. The following characteristics were evaluated on CT images: size, shape, border, density, CT values on plain and contrast-enhanced scans, enhancement pattern, enhancement degree, and surrounding bone destruction. Results: On US images, lesions were irregular, well-defined, hypoechoic, heterogeneous, and poorly vascularized. On CT images, lesions were regular and well-defined, and showed slight heterogeneous enhancement. Conclusion: These findings suggest that most primary AciCCs show benign features on US and CT.

  5. Costs and role of ultrasound follow-up of polytrauma patients after initial computed tomography; Kosten und Stellenwert von Ultraschallverlaufskontrollen bei polytraumatisierten Patienten nach initialer Computertomografie

    Energy Technology Data Exchange (ETDEWEB)

    Maurer, M.H.; Winkler, A.; Powerski, M.J.; Elgeti, F.; Huppertz, A.; Roettgen, R.; Marnitz, T. [Charite - Universitaetsmedizin Berlin (Germany). Klinik fuer Diagnostische und Interventionelle Radiologie; Wichlas, F. [Charite - Universitaetsmedizin Berlin (Germany). Centrum fuer Muskuloskeletale Chirurgie

    2012-01-15

    Purpose: To assess the costs and diagnostic gain of abdominal ultrasound follow-up of polytrauma patients initially examined by whole-body computed tomography (CT). Materials and Methods: A total of 176 patients with suspected multiple trauma (126 men, 50 women; age 43.5 {+-} 17.4 years) were retrospectively analyzed with regard to supplementary and new findings obtained by ultrasound follow-up compared with the results of exploratory FAST (focused assessment with sonography for trauma) at admission and the findings of whole-body CT. A process model was used to document the staff, materials, and total costs of the ultrasound follow-up examinations. Results: FAST yielded 26 abdominal findings (organ injury and/or free intra-abdominal fluid) in 19 patients, while the abdominal scan of whole-body CT revealed 32 findings in 25 patients. FAST had 81 % sensitivity and 100 % specificity. Follow-up ultrasound examinations revealed new findings in 2 of the 25 patients with abdominal injuries detected with initial CT. In the 151 patients without abdominal injuries in the initial CT scan, ultrasound follow-up did not yield any supplementary or new findings. The total costs of an ultrasound follow-up examination were EUR 28.93. The total costs of all follow-up ultrasound examinations performed in the study population were EUR 5658.23. Conclusion: Follow-up abdominal ultrasound yields only a low overall diagnostic gain in polytrauma patients in whom initial CT fails to detect any abdominal injuries but incurs high personnel expenses for radiological departments. (orig.)

  6. 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...

  7. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... collects the sounds that bounce back and a computer then uses those sound waves to create an ... types of Doppler ultrasound: Color Doppler uses a computer to convert Doppler measurements into an array of ...

  8. Comprehensive and rapid assessment of carotid plaques in acute stroke using a new single sweep method for three-dimensional carotid ultrasound.

    Science.gov (United States)

    Kalashyan, Harapet; Saqqur, Maher; Shuaib, Ashfaq; Romanchuk, Helen; Nanda, Navin C; Becher, Harald

    2013-04-01

    We describe a 68-year-old man with acute stroke in whom the newly developed single sweep method for three-dimensional (3D) carotid ultrasound provided a rapid and comprehensive assessment of atherosclerotic plaque burden in the internal carotid artery. The two-dimensional duplex carotid scan diagnosed 50-69% stenosis, and with the three-dimensional method, the markedly hypoechogenic plaque (total volume 1.42 mL) was shown to occupy 77% of the total arterial volume (1.84 mL), consistent with severe lesion. The ultrasound findings were confirmed by computed tomographic angiography and subsequent carotid endarterectomy. The new single sweep 3D carotid ultrasound has the potential to become a valuable clinical tool in the assessment of stroke patients. © 2013, Wiley Periodicals, Inc.

  9. A brain-computer interface based on bilateral transcranial Doppler ultrasound.

    Directory of Open Access Journals (Sweden)

    Andrew J B Myrden

    Full Text Available In this study, we investigate the feasibility of a BCI based on transcranial Doppler ultrasound (TCD, a medical imaging technique used to monitor cerebral blood flow velocity. We classified the cerebral blood flow velocity changes associated with two mental tasks--a word generation task, and a mental rotation task. Cerebral blood flow velocity was measured simultaneously within the left and right middle cerebral arteries while nine able-bodied adults alternated between mental activity (i.e. word generation or mental rotation and relaxation. Using linear discriminant analysis and a set of time-domain features, word generation and mental rotation were classified with respective average accuracies of 82.9%±10.5 and 85.7%±10.0 across all participants. Accuracies for all participants significantly exceeded chance. These results indicate that TCD is a promising measurement modality for BCI research.

  10. 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 ...

  11. 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

  12. 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.

  13. Computer-aided diagnosis of Myocardial Infarction using ultrasound images with DWT, GLCM and HOS methods: A comparative study.

    Science.gov (United States)

    Vidya, K Sudarshan; Ng, E Y K; Acharya, U Rajendra; Chou, Siaw Meng; Tan, Ru San; Ghista, Dhanjoo N

    2015-07-01

    Myocardial Infarction (MI) or acute MI (AMI) is one of the leading causes of death worldwide. Precise and timely identification of MI and extent of muscle damage helps in early treatment and reduction in the time taken for further tests. MI diagnosis using 2D echocardiography is prone to inter-/intra-observer variability in the assessment. Therefore, a computerised scheme based on image processing and artificial intelligent techniques can reduce the workload of clinicians and improve the diagnosis accuracy. A Computer-Aided Diagnosis (CAD) of infarcted and normal ultrasound images will be useful for clinicians. In this study, the performance of CAD approach using Discrete Wavelet Transform (DWT), second order statistics calculated from Gray-Level Co-Occurrence Matrix (GLCM) and Higher-Order Spectra (HOS) texture descriptors are compared. The proposed system is validated using 400 MI and 400 normal ultrasound images, obtained from 80 patients with MI and 80 normal subjects. The extracted features are ranked based on t-value and fed to the Support Vector Machine (SVM) classifier to obtain the best performance using minimum number of features. The features extracted from DWT coefficients obtained an accuracy of 99.5%, sensitivity of 99.75% and specificity of 99.25%; GLCM have achieved an accuracy of 85.75%, sensitivity of 90.25% and specificity of 81.25%; and HOS obtained an accuracy of 93.0%, sensitivity of 94.75% and specificity of 91.25%. Among the three techniques presented DWT yielded the highest classification accuracy. Thus, the proposed CAD approach may be used as a complementary tool to assist cardiologists in making a more accurate diagnosis for the presence of MI. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. A new computer aided diagnosis system for evaluation of chronic liver disease with ultrasound shear wave elastography imaging.

    Science.gov (United States)

    Gatos, Ilias; Tsantis, Stavros; Spiliopoulos, Stavros; Karnabatidis, Dimitris; Theotokas, Ioannis; Zoumpoulis, Pavlos; Loupas, Thanasis; Hazle, John D; Kagadis, George C

    2016-03-01

    Classify chronic liver disease (CLD) from ultrasound shear-wave elastography (SWE) imaging by means of a computer aided diagnosis (CAD) system. The proposed algorithm employs an inverse mapping technique (red-green-blue to stiffness) to quantify 85 SWE images (54 healthy and 31 with CLD). Texture analysis is then applied involving the automatic calculation of 330 first and second order textural features from every transformed stiffness value map to determine functional features that characterize liver elasticity and describe liver condition for all available stages. Consequently, a stepwise regression analysis feature selection procedure is utilized toward a reduced feature subset that is fed into the support vector machines (SVMs) classification algorithm in the design of the CAD system. With regard to the mapping procedure accuracy, the stiffness map values had an average difference of 0.01 ± 0.001 kPa compared to the quantification results derived from the color-box provided by the built-in software of the ultrasound system. Highest classification accuracy from the SVM model was 87.0% with sensitivity and specificity values of 83.3% and 89.1%, respectively. Receiver operating characteristic curves analysis gave an area under the curve value of 0.85 with [0.77-0.89] confidence interval. The proposed CAD system employing color to stiffness mapping and classification algorithms offered superior results, comparing the already published clinical studies. It could prove to be of value to physicians improving the diagnostic accuracy of CLD and can be employed as a second opinion tool for avoiding unnecessary invasive procedures.

  15. Early Detection of Breast Cancer on Mammograms Using: Perceptual Feedback, Computer Processed Images and Ultrasound

    National Research Council Canada - National Science Library

    Bloch, Peter

    1996-01-01

    ... (as predicted by the gaze duration), enhanced the detectability or masses. (2) Computer processing of screening mammograms for detection of clusters of microcalcifications and parenchyma patterns associated with developing lesions...

  16. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... are the limitations of Pelvic Ultrasound Imaging? What is Pelvic Ultrasound Imaging? Ultrasound is safe and painless, ... top of page What are some common uses of the procedure? In women, a pelvic ultrasound is ...

  17. 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 ...

  18. 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 ...

  19. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... Radiation Therapy for Gynecologic Cancers Radiation Therapy for Prostate Cancer top of page This page was reviewed on ... Abdomen Children's (Pediatric) Ultrasound - Abdomen Obstetric Ultrasound Ultrasound - Prostate Kidney and Bladder Stones ... to Ultrasound - Pelvis Videos related to ...

  20. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... 3-D ultrasound or sonohysterography for patients with infertility. In this setting, three-dimensional ultrasound provides information ... Ultrasound page for more information. In men and women, a pelvic ultrasound exam can help identify: kidney ...

  1. 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 , ...

  2. 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 ...

  3. Incorporating texture features in a computer-aided breast lesion diagnosis system for automated three-dimensional breast ultrasound.

    Science.gov (United States)

    Liu, Haixia; Tan, Tao; van Zelst, Jan; Mann, Ritse; Karssemeijer, Nico; Platel, Bram

    2014-07-01

    We investigated the benefits of incorporating texture features into an existing computer-aided diagnosis (CAD) system for classifying benign and malignant lesions in automated three-dimensional breast ultrasound images. The existing system takes into account 11 different features, describing different lesion properties; however, it does not include texture features. In this work, we expand the system by including texture features based on local binary patterns, gray level co-occurrence matrices, and Gabor filters computed from each lesion to be diagnosed. To deal with the resulting large number of features, we proposed a combination of feature-oriented classifiers combining each group of texture features into a single likelihood, resulting in three additional features used for the final classification. The classification was performed using support vector machine classifiers, and the evaluation was done with 10-fold cross validation on a dataset containing 424 lesions (239 benign and 185 malignant lesions). We compared the classification performance of the CAD system with and without texture features. The area under the receiver operating characteristic curve increased from 0.90 to 0.91 after adding texture features ([Formula: see text]).

  4. Computationally-efficient optical coherence elastography to assess degenerative osteoarthritis based on ultrasound-induced fringe washout (Conference Presentation)

    Science.gov (United States)

    Tong, Minh Q.; Hasan, M. Monirul; Gregory, Patrick D.; Shah, Jasmine; Park, B. Hyle; Hirota, Koji; Liu, Junze; Choi, Andy; Low, Karen; Nam, Jin

    2017-02-01

    We demonstrate a computationally-efficient optical coherence elastography (OCE) method based on fringe washout. By introducing ultrasound in alternating depth profile, we can obtain information on the mechanical properties of a sample within acquisition of a single image. This can be achieved by simply comparing the intensity in adjacent depth profiles in order to quantify the degree of fringe washout. Phantom agar samples with various densities were measured and quantified by our OCE technique, the correlation to Young's modulus measurement by atomic force micrscopy (AFM) were observed. Knee cartilage samples of monoiodo acetate-induced arthiritis (MIA) rat models were utilized to replicate cartilage damages where our proposed OCE technique along with intensity and birefringence analyses and AFM measurements were applied. The results indicate that our OCE technique shows a correlation to the techniques as polarization-sensitive OCT, AFM Young's modulus measurements and histology were promising. Our OCE is applicable to any of existing OCT systems and demonstrated to be computationally-efficient.

  5. Use of 3D ultrasound and image matching in computer-assisted neuronavigation

    Science.gov (United States)

    Maier, Michael W.; Kriete, Andres

    1997-06-01

    In most operation theaters today planning is done using pre- operatively gathered data, such as CT, MRI, or ultrasound (US). This data can become useless in cases such as lesion removal in brain, where dura opening and other preparations cause tissue shifting. A possibility to greatly increase accuracy in an ongoing operation is the use of 3D ultrasonography. The sequences of intra-operatively obtained 2D US-slices can be transformed into 3D, matched to previously acquired data, and be used to adapt the surgical planning to the current situation. The matching is done after standard image processing procedures have been applied to the 2D US data, this data has been injected into a 3D data cube, segmentation, and topological differentiation have taken place. This requires the usage of highly sophisticated graphics workstations. The objective is to create a framework in which surgeons and/or robotic neuronavigators can be informed and guided with the newest and most precise information possible during an operation.

  6. Classification of Induced Magnetic Field Signals for the Microstructural Characterization of Sigma Phase in Duplex Stainless Steels

    OpenAIRE

    Edgard M. Silva; Leandro B. Marinho; Pedro P. Rebouças Filho; Leite, João P.; Josinaldo P. Leite; Walter M. L. Fialho; Victor Hugo C. de Albuquerque; Tavares, João Manuel R. S.

    2016-01-01

    Duplex stainless steels present excellent mechanical and corrosion resistance properties. However, when heat treated at temperatures above 600 ∘ C, the undesirable tertiary sigma phase is formed. This phase presents high hardness, around 900 HV, and it is rich in chromium, the material toughness being compromised when the amount of this phase is not less than 4%. This work aimed to develop a solution for the detection of this phase in duplex stainless steels through the computational ...

  7. Interactive content-based image retrieval (CBIR) computer-aided diagnosis (CADx) system for ultrasound breast masses using relevance feedback

    Science.gov (United States)

    Cho, Hyun-chong; Hadjiiski, Lubomir; Sahiner, Berkman; Chan, Heang-Ping; Paramagul, Chintana; Helvie, Mark; Nees, Alexis V.

    2012-03-01

    We designed a Content-Based Image Retrieval (CBIR) Computer-Aided Diagnosis (CADx) system to assist radiologists in characterizing masses on ultrasound images. The CADx system retrieves masses that are similar to a query mass from a reference library based on computer-extracted features that describe texture, width-to-height ratio, and posterior shadowing of a mass. Retrieval is performed with k nearest neighbor (k-NN) method using Euclidean distance similarity measure and Rocchio relevance feedback algorithm (RRF). In this study, we evaluated the similarity between the query and the retrieved masses with relevance feedback using our interactive CBIR CADx system. The similarity assessment and feedback were provided by experienced radiologists' visual judgment. For training the RRF parameters, similarities of 1891 image pairs obtained from 62 masses were rated by 3 MQSA radiologists using a 9-point scale (9=most similar). A leave-one-out method was used in training. For each query mass, 5 most similar masses were retrieved from the reference library using radiologists' similarity ratings, which were then used by RRF to retrieve another 5 masses for the same query. The best RRF parameters were chosen based on three simulated observer experiments, each of which used one of the radiologists' ratings for retrieval and relevance feedback. For testing, 100 independent query masses on 100 images and 121 reference masses on 230 images were collected. Three radiologists rated the similarity between the query and the computer-retrieved masses. Average similarity ratings without and with RRF were 5.39 and 5.64 on the training set and 5.78 and 6.02 on the test set, respectively. The average Az values without and with RRF were 0.86+/-0.03 and 0.87+/-0.03 on the training set and 0.91+/-0.03 and 0.90+/-0.03 on the test set, respectively. This study demonstrated that RRF improved the similarity of the retrieved masses.

  8. A comparison of the accuracy of ultrasound and computed tomography in common diagnoses causing acute abdominal pain

    Energy Technology Data Exchange (ETDEWEB)

    Randen, Adrienne van; Stoker, Jaap [Academic Medical Centre, Department of Radiology (suite G1-227), Amsterdam (Netherlands); Lameris, Wytze; Boermeester, Marja A. [Academic Medical Center, Department of Surgery, Amsterdam (Netherlands); Es, H.W. van; Heesewijk, Hans P.M. van [St Antonius Hospital, Department of Radiology, Nieuwegein (Netherlands); Ramshorst, Bert van [St Antonius Hospital, Department of Surgery, Nieuwegein (Netherlands); Hove, Wim ten [Gelre Hospitals, Department of Radiology, Apeldoorn (Netherlands); Bouma, Willem H. [Gelre Hospitals, Department of Surgery, Apeldoorn (Netherlands); Leeuwen, Maarten S. van [University Medical Centre, Department of Radiology, Utrecht (Netherlands); Keulen, Esteban M. van [Tergooi Hospitals, Department of Radiology, Hilversum (Netherlands); Bossuyt, Patrick M. [Academic Medical Center, Department of Clinical Epidemiology, Biostatistics, and Bioinformatics, Amsterdam (Netherlands)

    2011-07-15

    Head-to-head comparison of ultrasound and CT accuracy in common diagnoses causing acute abdominal pain. Consecutive patients with abdominal pain for >2 h and <5 days referred for imaging underwent both US and CT by different radiologists/radiological residents. An expert panel assigned a final diagnosis. Ultrasound and CT sensitivity and predictive values were calculated for frequent final diagnoses. Effect of patient characteristics and observer experience on ultrasound sensitivity was studied. Frequent final diagnoses in the 1,021 patients (mean age 47; 55% female) were appendicitis (284; 28%), diverticulitis (118; 12%) and cholecystitis (52; 5%). The sensitivity of CT in detecting appendicitis and diverticulitis was significantly higher than that of ultrasound: 94% versus 76% (p < 0.01) and 81% versus 61% (p = 0.048), respectively. For cholecystitis, the sensitivity of both was 73% (p = 1.00). Positive predictive values did not differ significantly between ultrasound and CT for these conditions. Ultrasound sensitivity in detecting appendicitis and diverticulitis was not significantly negatively affected by patient characteristics or reader experience. CT misses fewer cases than ultrasound, but both ultrasound and CT can reliably detect common diagnoses causing acute abdominal pain. Ultrasound sensitivity was largely not influenced by patient characteristics and reader experience. (orig.)

  9. Validation of subclavian duplex velocity criteria to grade severity of subclavian artery stenosis.

    Science.gov (United States)

    Mousa, Albeir Y; Morkous, Ramez; Broce, Mike; Yacoub, Michael; Sticco, Andrew; Viradia, Ravi; Bates, Mark C; AbuRahma, Ali F

    2017-06-01

    Validation of subclavian duplex ultrasound velocity criteria (SDUS VC) to grade the severity of subclavian artery stenosis has not been established or systematically studied. Currently, there is a paucity of published literature and lack of practitioner consensus for how subclavian duplex velocity findings should be interpreted in patients with subclavian artery stenosis. The objective of the present study was to validate SDUS measurements using subclavian conventional or computed tomography angiogram (subclavian angiogram [SA])-derived measurements. Secondary objectives included measuring the correlation between SDUS peak systolic velocities and SA measurements, and to determine the optimal cutoff value for predicting significant stenosis (>70%). This is a retrospective review of all patients with suspected subclavian artery stenosis and a convenience sample of carotid artery patients who underwent SDUS and SA from May 1999 to July 2013. SA reference vessel and intralesion minimal lumen diameters were measured and compared with SDUS velocities obtained within 3 months of the imaging study. Percent stenosis was calculated using the North American Symptomatic Carotid Endarterectomy Trial method for detecting stenosis in a sufficiently large cohort. Receiver operating characteristic curves was generated for SDUS VC to predict >70% stenosis. Velocity cutoff points were determined with equal weighting of sensitivity and specificity. We examined 268 arteries for 177 patients. The majority of the arteries were for female patients (52.5%) with a mean age of 66.7 ± 11.1 years. Twenty-three arteries had retrograde vertebral artery flow and excluded from further analysis. For the remaining 245 arteries, the average peak systolic velocity was 212.6 ± 110.7 cm/s, with a range of 45-626 cm/s. Average stenosis was 25.8% ± 28.2%, with a range of 0% to 100%. Following receiver operating characteristic analysis, we found a cutoff value of >240 cm/s to be most predictive

  10. Diagnostic value of ultrasound, computed tomography, and angiography in ruptured aortic aneurysms

    Energy Technology Data Exchange (ETDEWEB)

    Landtman, M.; Kivisaari, L.; Bondestam, S.; Taavitsainen, M.; Standertskjoeld-Nordenstam, C.G.; Somer, K.

    1984-11-01

    Some ruptural aneurysms cause nonspecific symptoms and the patients are referred for radiological examination because of the problems of differential diagnosis from conditions such as renal colic, diverticulitis, herniated disc, aortic dissection etc. Seven such patients have been examined either with ultrasonography, computed tomography or angiography. The diagnostic methods are compared. The more recent US and CT imaging methods are sufficiently rapid and reliable for diagnostic purposes, which should improve the prognosis for patients requiring immediate surgery for ruptured aortic aneurysms.

  11. Fast computation of far-field pulse-echo PSF of arbitrary arrays for large sparse 2-D ultrasound array design.

    Science.gov (United States)

    Li, Zhaohui; Chi, Cheng

    2017-10-10

    Large wideband two-dimensional (2-D) arrays are essential for high-resolution three-dimensional (3-D) ultrasound imaging. Since the tremendous element number of a full sampled large 2-D array is not affordable in any practical 3-D ultrasound imaging system, it is necessary to reduce the element number through sparse 2-D array design. Sparse array design requires that both the positions and weights of the array elements should be arbitrarily alterable. Hence a proper evaluation tool that can deal with arbitrary array is integral to optimizing the array structure and apodization function. It is known that pulse-echo point spread function (PSF) has been a common tool used to evaluate the performance of wideband arrays in ultrasound imaging all along, which also plays an important role in wideband ultrasound simulations. However, so far the conventional ultrasound simulation tools can only calculate pulse-echo PSF of arbitrary wideband arrays in the time domain because of the existence of nonuniform nodes in the spatial impulse response expressions, which obstructs their application of FFT to do fast computation of the time-domain convolutions. As a result, ultra-high time consumption of pulse-echo PSF computation of a large arbitrary wideband array hampers it to be taken as the evaluation tool by any stochastic optimization methods which need massive iterations in designing large sparse 2-D arrays. This paper aims to make available the pulse-echo PSF tool in designing large sparse 2-D arrays by proposing a fast computation method of far-field pulse-echo PSFs of arbitrary wideband arrays. In the paper, fast computation of wideband spatial impulse responses of a 2-D array is first realized in frequency domain by employing the nonuniform fast Fourier transform (NUFFT), under the point source assumption in far-field. On the basis of that, fast computation of time-domain convolutions is made possible by using FFT. In addition, a short inverse FFT (IFFT) is applied in

  12. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... saved. Doppler ultrasound, a special application of ultrasound, measures the direction and speed of blood cells as they move through vessels. The movement of blood cells causes a change in pitch of the reflected sound waves (called the Doppler effect). A computer collects ...

  13. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... various body organs such as the liver or kidneys. There are three types of Doppler ultrasound: Color Doppler uses a computer to convert Doppler ... and its major ... infants hips in infants spine in infants Ultrasound is also used to: guide procedures such as ...

  14. Computer-aided tumor detection based on multi-scale blob detection algorithm in automated breast ultrasound images.

    Science.gov (United States)

    Moon, Woo Kyung; Shen, Yi-Wei; Bae, Min Sun; Huang, Chiun-Sheng; Chen, Jeon-Hor; Chang, Ruey-Feng

    2013-07-01

    Automated whole breast ultrasound (ABUS) is an emerging screening tool for detecting breast abnormalities. In this study, a computer-aided detection (CADe) system based on multi-scale blob detection was developed for analyzing ABUS images. The performance of the proposed CADe system was tested using a database composed of 136 breast lesions (58 benign lesions and 78 malignant lesions) and 37 normal cases. After speckle noise reduction, Hessian analysis with multi-scale blob detection was applied for the detection of tumors. This method detected every tumor, but some nontumors were also detected. The tumor like lihoods for the remaining candidates were estimated using a logistic regression model based on blobness, internal echo, and morphology features. The tumor candidates with tumor likelihoods higher than a specific threshold (0.4) were considered tumors. By using the combination of blobness, internal echo, and morphology features with 10-fold cross-validation, the proposed CAD system showed sensitivities of 100%, 90%, and 70% with false positives per pass of 17.4, 8.8, and 2.7, respectively. Our results suggest that CADe systems based on multi-scale blob detection can be used to detect breast tumors in ABUS images.

  15. A comparison of endoscopic ultrasound guided biopsy and positron emission tomography with integrated computed tomography in lung cancer staging

    DEFF Research Database (Denmark)

    Larsen, S S; Vilmann, P; Krasnik, K

    2009-01-01

    -stage ≥ IIIA(N2), corresponding to T4- and/or N2-N3- and/or M1 disease. Diagnostic values of PET/CT and EUS-FNA, with regard to the diagnosis of advanced lung cancer, were assessed and compared. RESULTS: The sensitivity of PET/CT and EUS-FNA were respectively 60% and 60% for T4 disease, 56% versus 100% for N2......BACKGROUND AND STUDY AIMS: Exact staging of patients with non-small-cell lung cancer (NSCLC) is important to improve selection of resectable and curable patients for surgery. Positron emission tomography with integrated computed tomography (PET/CT) and endoscopic ultrasound guided fine needle...... aspiration biopsy (EUS-FNA) are new and promising methods, but indications in lung cancer staging are controversial. Only few studies have compared the 2 methods. The aim of this study was to assess and compare the diagnostic values of PET/CT and EUS-FNA for diagnosing advanced lung cancer in patients, who...

  16. A Comparison of Endoscopic Ultrasound Guided Biopsy and Positron Emission Tomography with Integrated Computed Tomography in Lung Cancer Staging

    DEFF Research Database (Denmark)

    Larsen, Stine Schmidt; Vilmann, P; Krasnik, K

    2009-01-01

    -stage ≥ IIIA(N2), corresponding to T4- and/or N2-N3- and/or M1 disease. Diagnostic values of PET/CT and EUS-FNA, with regard to the diagnosis of advanced lung cancer, were assessed and compared. RESULTS: The sensitivity of PET/CT and EUS-FNA were respectively 60% and 60% for T4 disease, 56% versus 100% for N2......BACKGROUND AND STUDY AIMS: Exact staging of patients with non-small-cell lung cancer (NSCLC) is important to improve selection of resectable and curable patients for surgery. Positron emission tomography with integrated computed tomography (PET/CT) and endoscopic ultrasound guided fine needle...... aspiration biopsy (EUS-FNA) are new and promising methods, but indications in lung cancer staging are controversial. Only few studies have compared the 2 methods. The aim of this study was to assess and compare the diagnostic values of PET/CT and EUS-FNA for diagnosing advanced lung cancer in patients, who...

  17. Clinical feasibility of 3D automated coronary atherosclerotic plaque quantification algorithm on coronary computed tomography angiography: Comparison with intravascular ultrasound

    Energy Technology Data Exchange (ETDEWEB)

    Park, Hyung-Bok [Yonsei University Health System, Yonsei-Cedar Sinai Integrative Cardiovascular Imaging Research Center, Seoul (Korea, Republic of); Myongji Hospital, Division of Cardiology, Cardiovascular Center, Goyang (Korea, Republic of); Lee, Byoung Kwon [Yonsei University College of Medicine, Division of Cardiology, Gangnam Severance Hospital, Seoul (Korea, Republic of); Shin, Sanghoon [Yonsei University Health System, Yonsei-Cedar Sinai Integrative Cardiovascular Imaging Research Center, Seoul (Korea, Republic of); National Health Insurance Corporation Ilsan Hospital, Division of Cardiology, Goyang (Korea, Republic of); Heo, Ran; Chang, Hyuk-Jae; Chung, Namsik [Yonsei University Health System, Yonsei-Cedar Sinai Integrative Cardiovascular Imaging Research Center, Seoul (Korea, Republic of); Yonsei University Health System, Division of Cardiology, Severance Cardiovascular Hospital, Seoul (Korea, Republic of); Arsanjani, Reza [Cedars-Sinai Medical Center, Departments of Imaging and Medicine, Cedars-Sinai Heart Institute, Los Angeles, CA (United States); Kitslaar, Pieter H. [Leiden University Medical Center, Department of Radiology, Division of Image Processing, Leiden (Netherlands); Medis medical Imaging Systems B.V., Leiden (Netherlands); Broersen, Alexander; Dijkstra, Jouke [Leiden University Medical Center, Department of Radiology, Division of Image Processing, Leiden (Netherlands); Ahn, Sung Gyun [Yonsei University Wonju Severance Christian Hospital, Division of Cardiology, Wonju (Korea, Republic of); Min, James K. [New York-Presbyterian Hospital, Institute for Cardiovascular Imaging, Weill-Cornell Medical College, New York, NY (United States); Hong, Myeong-Ki; Jang, Yangsoo [Yonsei University Health System, Division of Cardiology, Severance Cardiovascular Hospital, Seoul (Korea, Republic of)

    2015-10-15

    To evaluate the diagnostic performance of automated coronary atherosclerotic plaque quantification (QCT) by different users (expert/non-expert/automatic). One hundred fifty coronary artery segments from 142 patients who underwent coronary computed tomography angiography (CCTA) and intravascular ultrasound (IVUS) were analyzed. Minimal lumen area (MLA), maximal lumen area stenosis percentage (%AS), mean plaque burden percentage (%PB), and plaque volume were measured semi-automatically by expert, non-expert, and fully automatic QCT analyses, and then compared to IVUS. Between IVUS and expert QCT analysis, the correlation coefficients (r) for the MLA, %AS, %PB, and plaque volume were excellent: 0.89 (p < 0.001), 0.84 (p < 0.001), 0.91 (p < 0.001), and 0.94 (p < 0.001), respectively. There were no significant differences in the mean parameters (all p values >0.05) except %AS (p = 0.01). The automatic QCT analysis showed comparable performance to non-expert QCT analysis, showing correlation coefficients (r) of the MLA (0.80 vs. 0.82), %AS (0.82 vs. 0.80), %PB (0.84 vs. 0.73), and plaque volume (0.84 vs. 0.79) when they were compared to IVUS, respectively. Fully automatic QCT analysis showed clinical utility compared with IVUS, as well as a compelling performance when compared with semiautomatic analyses. (orig.)

  18. Comparison between ultrasound and noncontrast helical computed tomography for identification of acute ureterolithiasis in a teaching hospital setting

    Directory of Open Access Journals (Sweden)

    Luís Ronan Marquez Ferreira de Souza

    2007-03-01

    Full Text Available CONTEXT AND OBJECTIVE: Recent studies have shown noncontrast computed tomography (NCT to be more effective than ultrasound (US for imaging acute ureterolithiasis. However, to our knowledge, there are few studies directly comparing these techniques in an emergency teaching hospital setting. The objectives of this study were to compare the diagnostic accuracy of US and NCT performed by senior radiology residents for diagnosing acute ureterolithiasis; and to assess interobserver agreement on tomography interpretations by residents and experienced abdominal radiologists. DESIGN AND SETTING: Prospective study of 52 consecutive patients, who underwent both US and NCT within an interval of eight hours, at Hospital São Paulo. METHODS: US scans were performed by senior residents and read by experienced radiologists. NCT scan images were read by senior residents, and subsequently by three abdominal radiologists. The interobserver variability was assessed using the kappa statistic. RESULTS: Ureteral calculi were found in 40 out of 52 patients (77%. US presented sensitivity of 22% and specificity of 100%. When collecting system dilatation was associated, US demonstrated 73% sensitivity, 82% specificity. The interobserver agreement in NCT analysis was very high with regard to identification of calculi, collecting system dilatation and stranding of perinephric fat. CONCLUSIONS: US has limited value for identifying ureteral calculi in comparison with NCT, even when collecting system dilatation is present. Residents and abdominal radiologists demonstrated excellent agreement rates for ureteral calculi, identification of collecting system dilatation and stranding of perinephric fat on NCT.

  19. Multidimensional ultrasound and computed tomography imaging support in bleeding plexiform neurofibromatosis of the scalp: A case report and literature review

    Directory of Open Access Journals (Sweden)

    Ximena Wortsman

    2015-01-01

    Full Text Available Active bleeding in plexiform neurofibromatosis can be a life-threatening complication in neurofibromatosis type 1 (NF1. The prompt imaging support of 2D-3D ultrasound (US and computed tomography (CT during the active hemorrhage phase of cutaneous neurofibromas has not been previously reported. We report a case with NF1 who experienced a sudden swelling in the parieto-temporal region that corresponded to a massive and active hemorrhage within a plexiform neurofibroma. The US and CT imaging characteristics of this bleeding tumor are shown. Active hemorrhage in a plexiform neurofibroma of the scalp appeared in US as a heterogeneous hypodermal mass. CT demonstrated a fully hyperdense soft tissue mass. These characteristics differ from the non-complicated or old hemorrhagic imaging appearances of scalp plexiform neurofibromas and encourage prompt surgical treatment. This case report demonstrates the usefulness of imaging support in the early diagnosis of this hemorrhagic complication of NF1 in the scalp and also stimulates multispecialty management.

  20. Borderline gastric stromal tumor: diagnosis by ultrasound and computed tomography; Tumor estromal borderline del estomago diagnostico por imagen en ecografia y TC

    Energy Technology Data Exchange (ETDEWEB)

    Feijoo, R.; Rubio, P. J.; Lopez, J. I.; Borderias, A.; Placeres, A. [Hospita San Jorge. Huesca (Spain)

    2000-07-01

    Gastrointestinal stromal tumors (GIST) are a type of undifferentiated stromal tumor that is recently being diagnosed more frequently owing to the introduction of new immunohistochemical techniques. Their main feature, indispensable for the definitive diagnosis, is immunohistochemical evidence of the presence of CD34-positive cells. We present a case of GIST of borderline malignancy involving the outer wall of the stomach, describing the ultrasound and computed tomography images and their correlation with the pathological features. (Author) 8 refs.

  1. Contrast Enhanced Ultrasound can Replace Computed Tomography Angiography for Surveillance After Endovascular Aortic Aneurysm Repair

    DEFF Research Database (Denmark)

    Bredahl, K; Taudorf, M; Lönn, L

    2016-01-01

    OBJECTIVE/BACKGROUND: Surveillance after endovascular aortic aneurysm repair (EVAR) is mandatory and computed tomography angiography (CTA) is considered the standard imaging modality, although patients are exposed to ionizing radiation and nephrotoxic contrast medium. The primary aim of this study...... August 2011 and 31 October 2014 were prospectively and consecutively enrolled. CEUS was added to the existing surveillance protocol, which included DUS, plain abdominal X-ray, and CTA at 3 and 12 months after stent implantation. RESULTS: In 278 patients, endoleaks were detected in 68, 69, and 46 cases...

  2. 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

  3. 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...

  4. 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...

  5. Development of a computer tool to detect and classify nodules in ultrasound breast images

    Science.gov (United States)

    Marcomini, Karem D.; Carneiro, Antonio O.; Schiabel, Homero

    2014-03-01

    Due to the high incidence rate of breast cancer in women, many procedures have been developed to assist the diagnosis and early detection. Currently, ultrasonography has proved as a useful tool in distinguishing benign and malignant masses. In this context, the computer-aided diagnosis schemes have provided to the specialist a second opinion more accurately and reliably, minimizing the visual subjectivity between observers. Thus, we propose the application of an automatic detection method based on the use of the technique of active contour in order to show precisely the contour of the lesion and provide a better understanding of their morphology. For this, a total of 144 images of phantoms were segmented and submitted to morphological operations of opening and closing for smoothing the edges. Then morphological features were extracted and selected to work as input parameters for the neural classifier Multilayer Perceptron which obtained 95.34% correct classification of data and Az of 0.96.

  6. Computer phantoms for simulating ultrasound B-mode and CFM images

    DEFF Research Database (Denmark)

    Jensen, Jørgen Arendt; Munk, Peter

    1997-01-01

    in a file that defines their position and amplitude. Adjusting the number of scatterers and their relative amplitude yields the proper image.Five different computer phantoms are described. The first one consists of a number of point targets. It is used for studying the point spread function as a function...... of spatial position, and can give an indication of sidelobe levels and focusing abilities. The second phantom contains a number of cysts and point tagets along with a homogeneous speckle pattern. This is used for investigating image contrast, and the system's ability to detect low-contrast objects. The third...... phantom is for realistic clinical imaging. It contains the image of a 12 week old fetus, where the placenta and the upper body of the fetus is visible. This phantom gives an indication of the whole system's capability for real imaging. The current fetus phantom is only two-dimensional, as it is constant...

  7. Ultrasound -- Pelvis

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    Full Text Available ... kidney stones bladder tumors other disorders of the urinary bladder In children, pelvic ultrasound can help evaluate: pelvic ... Ultrasound - Abdomen Obstetric Ultrasound Ultrasound - Prostate Kidney and Bladder Stones Abnormal Vaginal Bleeding ... Images related to Ultrasound - Pelvis Sponsored by Please ...

  8. 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

  9. General Ultrasound Imaging

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    Full Text Available ... computer or television monitor. The image is created based on the amplitude (loudness), frequency (pitch) and time ... How does the procedure work? Ultrasound imaging is based on the same principles involved in the sonar ...

  10. General Ultrasound Imaging

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    Full Text Available ... the patient. Because ultrasound images are captured in real-time, they can show the structure and movement ... by a computer, which in turn creates a real-time picture on the monitor. One or more ...

  11. General Ultrasound Imaging

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    Full Text Available ... of the reflected sound waves (called the Doppler effect). A computer collects and processes the sounds and ... standard diagnostic ultrasound , there are no known harmful effects on humans. top of page What are the ...

  12. General Ultrasound Imaging

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    Full Text Available ... in x-rays ), thus there is no radiation exposure to the patient. Because ultrasound images are captured ... of the reflected sound waves (called the Doppler effect). A computer collects and processes the sounds and ...

  13. Age-based computer-aided diagnosis approach for pancreatic cancer on endoscopic ultrasound images

    Science.gov (United States)

    Ozkan, Murat; Cakiroglu, Murat; Kocaman, Orhan; Kurt, Mevlut; Yilmaz, Bulent; Can, Guray; Korkmaz, Ugur; Dandil, Emre; Eksi, Ziya

    2016-01-01

    Aim: The aim was to develop a high-performance computer-aided diagnosis (CAD) system with image processing and pattern recognition in diagnosing pancreatic cancer by using endosonography images. Materials and Methods: On the images, regions of interest (ROI) of three groups of patients (60) were extracted by experts; features were obtained from images using three different techniques and were trained separately for each age group with an Artificial Neural Network (ANN) to diagnose cancer. The study was conducted on endosonography images of 202 patients with pancreatic cancer and 130 noncancer patients. Results: 122 features were identified from the 332 endosonography images obtained in the study, and the 20 most appropriate features were selected by using the relief method. Images classified under three age groups (in years; 60) were tested via 200 random tests and the following ratios were obtained in the classification: accuracy: 92%, 88.5%, and 91.7%, respectively; sensitivity: 87.5%, 85.7%, and 93.3%, respectively; and specificity: 94.1%, 91.7%, and 88.9%, respectively. When all the age groups were assessed together, the following values were obtained: accuracy: 87.5%, sensitivity: 83.3%, and specificity: 93.3%. Conclusions: It was observed that the CAD system developed in the study performed better in diagnosing pancreatic cancer images based on classification by patient age compared to diagnosis without classification. Therefore, it is imperative to take patient age into consideration to ensure higher performance. PMID:27080608

  14. 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

    (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......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...

  15. 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: ...

  16. Ultrasound -- Pelvis

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    Full Text Available ... endovaginal ) for women rectal ( transrectal ) for men A Doppler ultrasound exam may be part of a pelvic ultrasound examination. Doppler ultrasound , also called color Doppler ultrasonography, is a ...

  17. Prostate Ultrasound

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    Full Text Available ... What are the limitations of Prostate Ultrasound Imaging? What is Ultrasound Imaging of the Prostate? Ultrasound is safe and painless, and produces pictures of the inside of the body using ...

  18. Ultrasound -- Pelvis

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    Full Text Available ... What are the limitations of Pelvic Ultrasound Imaging? What is Pelvic Ultrasound Imaging? Ultrasound is safe and painless, and produces pictures of the inside of the body using ...

  19. 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 pregnancy. See the Obstetrical Ultrasound page for more information . Ultrasound examinations can help diagnose symptoms experienced by ...

  20. 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 ...

  1. Obstetrical Ultrasound

    Science.gov (United States)

    ... are similar to sonar used by boats and submarines. The ultrasound image is immediately visible on a ... has been described by patients as a whooshing noise. Doppler ultrasound, a special application of ultrasound, measures ...

  2. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... What are the limitations of Pelvic Ultrasound Imaging? What is Pelvic Ultrasound Imaging? Ultrasound is safe and ... as the liver or kidneys. top of page What are some common uses of the procedure? In ...

  3. Prostate Ultrasound

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    Full Text Available ... What are the limitations of Prostate Ultrasound Imaging? What is Ultrasound Imaging of the Prostate? Ultrasound is ... in front of the rectum. top of page What are some common uses of the procedure? A ...

  4. 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 ...

  5. Ultrasound -- Pelvis

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    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 , ...

  6. Prostate Ultrasound

    Medline Plus

    Full Text Available ... object is solid or filled with fluid). In medicine, ultrasound is used to detect changes in appearance, ... other imaging methods. Ultrasound imaging uses no ionizing radiation. Ultrasound scanning may be able to give a ...

  7. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... ultrasound exams are also used to monitor the health and development of an embryo or fetus during pregnancy. See the Obstetrical Ultrasound page for more information . Ultrasound examinations can help diagnose symptoms experienced by women such ...

  8. Transvaginal ultrasound

    Science.gov (United States)

    ... ultrasound; Menstrual bleeding - transvaginal ultrasound; Infertility - transvaginal ultrasound; Ovarian - transvaginal ... benign and malignant epithelial and germ cell neoplasms, sex-cord stromal tumors. In: Lentz GM, Lobo RA, Gershenson DM, ...

  9. Ultrasound -- Pelvis

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    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 ...

  10. The diagnostic accuracy of neck ultrasound, 4D-Computed tomographyand sestamibi imaging in parathyroid carcinoma.

    Science.gov (United States)

    Christakis, Ioannis; Vu, Thinh; Chuang, Hubert H; Fellman, Bryan; Figueroa, Angelica M Silva; Williams, Michelle D; Busaidy, Naifa L; Perrier, Nancy D

    2017-10-01

    Our aim was to investigate the accuracy of available imaging modalities for parathyroid carcinoma (PC) in our institution and to identify which imaging modality, or combination thereof, is optimal in preoperative determination of precise tumor location. All operated PC patients in our institution between 2000 and 2015 that had at least one of the following in-house preoperative scans: neck ultrasonography (US), neck 4D-Computed Tomography (4DCT) and 99mTc Sestamibi SPECT/CT (MIBI). Sensitivity, specificity and accuracy of PC tumor localization were assessed individually and in combination. 20 patients fulfilled the inclusion criteria and were analysed. There were 18 US, 18 CT and 9 MIBI scans. The sensitivity and accuracy for tumor localisation of US was 80% (CI 56-94%) and 73% respectively, of 4DCT was 79% (CI 58-93%) and 82%, and of MIBI was 81% (CI 54-96%) and 78%. The sensitivity and accuracy of the combination of CT and MIBI was 94% (CI 73-100%) and 95% and for the combination of US, CT and MIBI was 100% (CI 72-100%) and 100% respectively. The wash-out of the PC lesions, expressed as a percentage change in Hounsfield Units from the arterial phase to early delayed phase was -9.29% and to the late delayed phase was -16.88% (n=11). The sensitivity of solitary preoperative imaging of PC patients, whether by US, CT or MIBI, is approximately 80%. Combinations of CT with MIBI and US increase the sensitivity to 95% or better. Combined preoperative imaging of patients with clinical possibility of PC is therefore recommended. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Diagnostic accuracy of magnetic resonance, computed tomography and contrast enhanced ultrasound in radiological multimodality assessment of peribiliary liver metastases.

    Directory of Open Access Journals (Sweden)

    Vincenza Granata

    Full Text Available We compared diagnostic performance of Magnetic Resonance (MR, Computed Tomography (CT and Ultrasound (US with (CEUS and without contrast medium to identify peribiliary metastasis.We identified 35 subjects with histological proven peribiliary metastases who underwent CEUS, CT and MR study. Four radiologists evaluated the presence of peribiliary lesions, using a 4-point confidence scale. Echogenicity, density and T1-Weigthed (T1-W, T2-W and Diffusion Weighted Imaging (DWI signal intensity as well as the enhancement pattern during contrast studies on CEUS, CT and MR so as hepatobiliary-phase on MRI was assessed.All lesions were detected by MR. CT detected 8 lesions, while US/CEUS detected one lesion. According to the site of the lesion, respect to the bile duct and hepatic parenchyma: 19 (54.3% were periductal, 15 (42.8% were intra-periductal and 1 (2.8% was periductal-intrahepatic. According to the confidence scale MRI had the best diagnostic performance to assess the lesion. CT obtained lower diagnostic performance. There was no significant difference in MR signal intensity and contrast enhancement among all metastases (p>0.05. There was no significant difference in CT density and contrast enhancement among all metastases (p>0.05.MRI is the method of choice for biliary tract tumors but it does not allow a correct differential diagnosis among different histological types of metastasis. The presence of biliary tree dilatation without hepatic lesions on CT and US/CEUS study may be an indirect sign of peribiliary metastases and for this reason the patient should be evaluated by MRI.

  12. Fluid mechanics of human fetal right ventricles from image-based computational fluid dynamics using 4D clinical ultrasound scans.

    Science.gov (United States)

    Wiputra, Hadi; Lai, Chang Quan; Lim, Guat Ling; Heng, Joel Jia Wei; Guo, Lan; Soomar, Sanah Merchant; Leo, Hwa Liang; Biwas, Arijit; Mattar, Citra Nurfarah Zaini; Yap, Choon Hwai

    2016-12-01

    There are 0.6-1.9% of US children who were born with congenital heart malformations. Clinical and animal studies suggest that abnormal blood flow forces might play a role in causing these malformation, highlighting the importance of understanding the fetal cardiovascular fluid mechanics. We performed computational fluid dynamics simulations of the right ventricles, based on four-dimensional ultrasound scans of three 20-wk-old normal human fetuses, to characterize their flow and energy dynamics. Peak intraventricular pressure gradients were found to be 0.2-0.9 mmHg during systole, and 0.1-0.2 mmHg during diastole. Diastolic wall shear stresses were found to be around 1 Pa, which could elevate to 2-4 Pa during systole in the outflow tract. Fetal right ventricles have complex flow patterns featuring two interacting diastolic vortex rings, formed during diastolic E wave and A wave. These rings persisted through the end of systole and elevated wall shear stresses in their proximity. They were observed to conserve ∼25.0% of peak diastolic kinetic energy to be carried over into the subsequent systole. However, this carried-over kinetic energy did not significantly alter the work done by the heart for ejection. Thus, while diastolic vortexes played a significant role in determining spatial patterns and magnitudes of diastolic wall shear stresses, they did not have significant influence on systolic ejection. Our results can serve as a baseline for future comparison with diseased hearts. Copyright © 2016 the American Physiological Society.

  13. 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: ...

  14. Structural, Dynamical, and Electronic Transport Properties of Modified DNA Duplexes Containing Size-Expanded Nucleobases

    Energy Technology Data Exchange (ETDEWEB)

    Fuentes-Cabrera, Miguel A [ORNL; Orozco, Modesto [Institut de Recerca Biomedica, Parc Cientific de Barcelona, Barcelona, Spain; Luque, Javier [Universitat de Barcelona; Sumpter, Bobby G [ORNL; Blas, Jose [Universidad de Castilla-La Mancha; Ordejon, Pablo J [ORNL; Huertas, Oscar [Universitat de Barcelona; Tabares, Carolina [Universitat de Barcelona

    2011-01-01

    Among the distinct strategies proposed to expand the genetic alphabet, sizeexpanded nucleobases are promising for the development of modified DNA duplexes with improved biotechnological properties. In particular, duplexes built up by replacing canonical bases with the corresponding benzo-fused counterparts could be valuable as molecular nanowires. In this context, this study reports the results of classical molecular dynamics simulations carried out to examine the structural and dynamical features of size-expanded DNAs, including both hybrid duplexes containing mixed pairs of natural and benzo-fused bases (xDNA) and pure size-expanded (xxDNA) duplexes. Furthermore, the electronic structure of both natural and size-expanded duplexes is examined by means of density functional computations. The results confirm that the structural and flexibility properties of the canonical DNA are globally little affected by the presence of benzo-fused bases. Themost relevant differences are found in the enhanced size of the grooves, and the reduction in the twist. However, the analysis also reveals subtle structural effects related to the nature and sequence of benzo-fused bases in the duplex. On the other hand, electronic structure calculations performed for xxDNAs confirm the reduction in the HOMOLUMO gap predicted from the analysis of the natural bases and their size-expanded counterparts, which suggests that pure size-expanded DNAs can be good conductors. A more complex situation is found for xDNAs, where fluctuations in the electrostatic interaction between base pairs exerts a decisive influence on the modulation of the energy gap.

  15. A highly sensitive and selective sensor based on a graphene-coated carbon paste electrode modified with a computationally designed boron-embedded duplex molecularly imprinted hybrid membrane for the sensing of lamotrigine.

    Science.gov (United States)

    Wang, Hongjuan; Qian, Duo; Xiao, Xilin; Gao, Shuqin; Cheng, Jianlin; He, Bo; Liao, Lifu; Deng, Jian

    2017-08-15

    An innovative electrochemical sensor, based on a carbon paste electrode (CPE) modified with graphene (GR) and a boron-embedded duplex molecularly imprinted hybrid membrane (B-DMIHM), was fabricated for the highly sensitive and selective determination of lamotrigine (LMT). Density functional theory (DFT) was employed to study the interactions between the template and monomers to screen appropriate functional monomers for rational design of the B-DMIHM. The distinct synergic effect of GR and B-DMIHM was evidenced by the positive shift of the reduction peak potential of LMT at B-DMIHM/GR modified CPE (B-DMIHM/GR/CPE) by about 300mV, and the 13-fold amplification of the peak current, compared to a bare carbon paste electrode (CPE). The electrochemical reduction mechanism of lamotrigine was investigated by different voltammetric techniques. It was illustrated that square wave voltammetry (SWV) was more sensitive than different pulse voltammetry (DPV) for the quantitative analysis of LMT. Thereafter, a highly sensitive electroanalytical method for LMT was established by SWV at B-DMIHM/GR/CPE with a good linear relationship from 5.0×10-8 to 5.0×10-5 and 5.0×10-5 to 3.0×10-4molL-1 with a lower detection limit (1.52×10-9molL-1) based on the lower linear range(S/N=3). The practical application of the sensor was demonstrated by determining the concentration of LMT in pharmaceutical and biological samples with good precision (RSD 1.04-4.41%) and acceptable recoveries (92.40-107.0%). Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Ultrasound -- Pelvis

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    Full Text Available ... Radiation Therapy for Gynecologic Cancers Radiation Therapy for Prostate Cancer top of page This page was reviewed on ... Abdomen Children's (Pediatric) Ultrasound - Abdomen Obstetric Ultrasound Ultrasound - Prostate Kidney and Bladder ... Images related to Ultrasound - Pelvis Sponsored by Please ...

  17. Prostate Ultrasound

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

  18. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... both sexes without x-ray exposure. Risks For standard diagnostic ultrasound , there are no known harmful effects on humans. top of page What are the limitations of Pelvic Ultrasound Imaging? Ultrasound waves are disrupted by air or gas; therefore ultrasound is not an ideal ...

  19. Children's (Pediatric) Abdominal Ultrasound Imaging

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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 ...

  20. Children's (Pediatric) Abdominal Ultrasound Imaging

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    Full Text Available ... console containing a computer and electronics, a video display screen and a transducer that is used to ... ultrasound image is immediately visible on a video display screen that looks like a computer or television ...

  1. Discrepant findings of computed tomography quantification of minimal lumen area of coronary artery stenosis: Correlation with intravascular ultrasound

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yuehua, E-mail: andrewradiologist@hotmail.com [Department of Radiology, Shanghai No. 6 People' s Hospital, School of Medicine, Shanghai Jiaotong University, No. 600, Yishan Rd, Shanghai 200233 (China); Zhang, Jiayin, E-mail: andrewssmu@msn.com [Department of Radiology, Shanghai No. 6 People' s Hospital, School of Medicine, Shanghai Jiaotong University, No. 600, Yishan Rd, Shanghai 200233 (China); Lu, Zhigang, E-mail: andrewradiologist@gmail.com [Department of Cardiology, Shanghai No. 6 People' s Hospital, School of Medicine, Shanghai Jiaotong University (China); Pan, Jingwei, E-mail: andrewssmu@gmail.com [Department of Cardiology, Shanghai No. 6 People' s Hospital, School of Medicine, Shanghai Jiaotong University (China)

    2012-11-15

    Objectives: To study the diagnostic performance of computed tomography (CT) quantification of minimal lumen area (MLA) based on multiple factors (image quality, calcification and lesion locations), with reference to intravascular ultrasound (IVUS). Methods: Consecutive clinically ordered patients were prospectively enrolled in our study. CT quantification of MLA was manually measured on cross-sectional view and further compared with IVUS findings. A significant lesion was defined as {<=}6 mm{sup 2} MLA for the left main (LM) coronary artery and a {<=}4 mm{sup 2} MLA for other epicardial vessels. Results: Non-calcified lesions had good correlation between CT and IVUS (r = 0.96) and the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were 85% (51/60), 93.94% (31/33), 96.23% (51/53) and 77.5% (31/40) respectively. Decreased correlation (r = 0.814) lower specificity (23.81% (5/21)) and positive predictive value (60.98% (25/41)) were observed in calcified subgroup. Artifact-absent lesions demonstrated excellent correlation (r = 0.967) and the sensitivity, specificity, PPV and NPV were 96% (48/50), 93.94% (31/33), 96% (48/50) and 93.94% (31/33) respectively. Impaired correlation (r = 0.584) was noted in artifact-present lesions and the sensitivity, specificity, PPV and NPV were 80% (28/35), 23.81% (5/21), 63.64% (28/44) and 41.67% (5/12) respectively. Excellent correlation between CT and IVUS was noted in proximal epicardial vessels (r = 0.908) and the sensitivity, specificity, PPV and NPV were 92.31% (36/39), 78.13% (25/32), 83.72% (36/43) and 89.29% (25/28) respectively. Middle right coronary artery lesions showed non-significant correlation (r = 0.54, p = 0.055). Conclusions: CT quantification of MLA can only be accurately achieved in non-calcified lesions with absence of artifact. Diagnostic performance is impaired in calcified lesions.

  2. A computational study for investigating acoustic streaming and tissue heating during high intensity focused ultrasound through blood vessel with an obstacle

    Science.gov (United States)

    Parvin, Salma; Sultana, Aysha

    2017-06-01

    The influence of High Intensity Focused Ultrasound (HIFU) on the obstacle through blood vessel is studied numerically. A three-dimensional acoustics-thermal-fluid coupling model is employed to compute the temperature field around the obstacle through blood vessel. The model construction is based on the linear Westervelt and conjugate heat transfer equations for the obstacle through blood vessel. The system of equations is solved using Finite Element Method (FEM). We found from this three-dimensional numerical study that the rate of heat transfer is increasing from the obstacle and both the convective cooling and acoustic streaming can considerably change the temperature field.

  3. Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration for Staging of Patients with Non-Small Cell Lung Cancer without Mediastinal Involvement at Positron Emission Tomography-Computed Tomography

    DEFF Research Database (Denmark)

    Naur, Therese Maria Henriette; Konge, Lars; Clementsen, Paul Frost

    2017-01-01

    BACKGROUND: Staging of lung cancer is essential to the treatment, which is curative only in cases of localized disease. Previous studies have suggested that endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is unnecessary when positron emission tomography-computed...... value as 89.6%. CONCLUSIONS: The overall probability of a clinically relevant upstaging by EBUS-TBNA in patients judged as N0/N1 at PET-CT was 6.0%, compared to 0.9% in patients classified as N0 and 17.3% in patients classified as N1. The risk of overlooking N2/N3 disease after both PET-CT and EBUS...

  4. A Computer-Aided Diagnosis System Using Artificial Intelligence for the Diagnosis and Characterization of Thyroid Nodules on Ultrasound: Initial Clinical Assessment.

    Science.gov (United States)

    Choi, Young Jun; Baek, Jung Hwan; Park, Hye Sun; Shim, Woo Hyun; Kim, Tae Yong; Shong, Young Kee; Lee, Jeong Hyun

    2017-04-01

    An initial clinical assessment is described of a new, commercially available, computer-aided diagnosis (CAD) system using artificial intelligence (AI) for thyroid ultrasound, and its performance is evaluated in the diagnosis of malignant thyroid nodules and categorization of nodule characteristics. Patients with thyroid nodules with decisive diagnosis, whether benign or malignant, were consecutively enrolled from November 2015 to February 2016. An experienced radiologist reviewed the ultrasound image characteristics of the thyroid nodules, while another radiologist assessed the same thyroid nodules using the CAD system, providing ultrasound characteristics and a diagnosis of whether nodules were benign or malignant. The diagnostic performance and agreement of US characteristics between the experienced radiologist and the CAD system were compared. In total, 102 thyroid nodules from 89 patients were included; 59 (57.8%) were benign and 43 (42.2%) were malignant. The CAD system showed a similar sensitivity as the experienced radiologist (90.7% vs. 88.4%, p > 0.99), but a lower specificity and a lower area under the receiver operating characteristic (AUROC) curve (specificity: 74.6% vs. 94.9%, p = 0.002; AUROC: 0.83 vs. 0.92, p = 0.021). Classifications of the ultrasound characteristics (composition, orientation, echogenicity, and spongiform) between radiologist and CAD system were in substantial agreement (κ = 0.659, 0.740, 0.733, and 0.658, respectively), while the margin showed a fair agreement (κ = 0.239). The sensitivity of the CAD system using AI for malignant thyroid nodules was as good as that of the experienced radiologist, while specificity and accuracy were lower than those of the experienced radiologist. The CAD system showed an acceptable agreement with the experienced radiologist for characterization of thyroid nodules.

  5. Dúplex telefónico - Duplex telephonic

    Directory of Open Access Journals (Sweden)

    Santos López, Pascual

    2006-12-01

    Full Text Available Only 19 years after a timid introduction of telephony in Spain and seven years before the founding of the National Telephonic Company of Spain, Pascual Salmerón Gómez records his two patents: "Duplex telephonic" and "Simultaneous duplex telephonic with telegraph machines". Two high technical complexity patents, registered in 1917 in the town of Arucas, province of Gran Canaria analyzed to our readers.Nephew of the inventor of the "Float Salmerón," José Salmerón Rojas and brother of Gerónimo Gómez Salmerón, inventor of "Cerealémetro" and owner of the theater Borras and with which we ended the saga Salmerón.

  6. Virtual Full-Duplex Wireless Communication via Rapid On-Off-Division Duplex

    CERN Document Server

    Guo, Dongning

    2010-01-01

    This paper introduces a novel paradigm for design- ing the physical and medium access control (MAC) layers of mobile ad hoc or peer-to-peer networks formed by half-duplex radios. A node equipped with such a radio cannot simultaneously transmit and receive useful signals at the same frequency. Unlike in conventional designs, where a node's transmission frames are scheduled away from its reception, each node transmits its signal through a randomly generated on-off duplex mask (or signature) over every frame interval, and receive a signal through each of its own off-slots. This is called rapid on-off- division duplex (RODD). Over the period of a single frame, every node can transmit a message to some or all of its peers, and may simultaneously receive a message from each peer. Thus RODD achieves virtual full-duplex communication using half-duplex radios and can simplify the design of higher layers of a network protocol stack significantly. The throughput of RODD is evaluated under some general settings, which is...

  7. Duplex 2209 Weld Overlay by ESSC Process

    OpenAIRE

    Er. Manoj Kumar; Dr. Abhishek Kamboj

    2017-01-01

    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 over...

  8. Shadow effects in simulated ultrasound images derived from computed tomography images using a focused beam tracing model

    DEFF Research Database (Denmark)

    Pham, An Hoai; Lundgren, Bo; Stage, Bjarne

    2012-01-01

    Focus ultrasound scanner (BK Medical, Herlev, Denmark) equipped with a dedicated research interface giving access to beamformed radio frequency data. CT images were obtained with an Aquilion ONE Toshiba CT scanner (Toshiba Medical Systems Corp., Tochigi, Japan). CT data were mapped from Hounsfield units...

  9. 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.

  10. Fast and Accurate Data Extraction for Near Real-Time Registration of 3-D Ultrasound and Computed Tomography in Orthopedic Surgery.

    Science.gov (United States)

    Brounstein, Anna; Hacihaliloglu, Ilker; Guy, Pierre; Hodgson, Antony; Abugharbieh, Rafeef

    2015-12-01

    Automatic, accurate and real-time registration is an important step in providing effective guidance and successful anatomic restoration in ultrasound (US)-based computer assisted orthopedic surgery. We propose a method in which local phase-based bone surfaces, extracted from intra-operative US data, are registered to pre-operatively segmented computed tomography data. Extracted bone surfaces are downsampled and reinforced with high curvature features. A novel hierarchical simplification algorithm is used to further optimize the point clouds. The final point clouds are represented as Gaussian mixture models and iteratively matched by minimizing the dissimilarity between them using an L2 metric. For 44 clinical data sets from 25 pelvic fracture patients and 49 phantom data sets, we report mean surface registration accuracies of 0.31 and 0.77 mm, respectively, with an average registration time of 1.41 s. Our results suggest the viability and potential of the chosen method for real-time intra-operative registration in orthopedic surgery. Copyright © 2015 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  11. Prostate Ultrasound

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    Full Text Available ... abnormal growth within the prostate. help diagnose the cause of a man's infertility. A transrectal ultrasound of ... show up well on x-ray images. Ultrasound causes no health problems and may be repeated as ...

  12. 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 ...

  13. Ultrasound -- Pelvis

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    Full Text Available ... kidneys. top of page What are some common uses of the procedure? In women, a pelvic ultrasound ... patients with abnormal uterine bleeding Some physicians also use 3-D ultrasound or sonohysterography for patients with ...

  14. 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 ...

  15. Prostate Ultrasound

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

  16. Ultrasound -- Pelvis

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    Full Text Available ... and produces pictures of the inside of the body using sound waves. Ultrasound imaging, also called ultrasound ... from the probe through the gel into the body. The transducer collects the sounds that bounce back ...

  17. Prostate Ultrasound

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    Full Text Available ... and produces pictures of the inside of the body using sound waves. Ultrasound imaging, also called ultrasound ... from the probe through the gel into the body. The transducer collects the sounds that bounce back ...

  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 ... is at high risk for cancer. In this case, a biopsy is performed and an ultrasound probe ...

  19. Ultrasound -- Pelvis

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    Full Text Available ... safe, noninvasive and does not use ionizing radiation. This procedure requires little to no special preparation. You ... ultrasound or sonohysterography for patients with infertility. In this setting, three-dimensional ultrasound provides information about the ...

  20. 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 ... have special pediatric considerations. The teddy bear denotes child-specific content. Related Articles and Media Sonohysterography Ultrasound - ...

  1. Ultrasound -- Pelvis

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

  2. Ultrasound -- Pelvis

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    Full Text Available ... is used to evaluate the: bladder seminal vesicles prostate Transrectal ultrasound, a special study usually done to provide detailed evaluation of the prostate gland, involves inserting a specialized ultrasound transducer into ...

  3. 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 ... modality for the diagnosis and monitoring of pregnant women and their unborn babies. Ultrasound provides real-time ...

  4. 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 ... object is solid or filled with fluid). In medicine, ultrasound is used to detect changes in appearance, ...

  5. 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 ...

  6. Prostate Ultrasound

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    Full Text Available ... safe and painless, and produces pictures of the inside of the body using sound waves. Ultrasound imaging, ... to four hours before the ultrasound to clean out the bowel. top of page What does the ...

  7. Ultrasound -- Pelvis

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    Full Text Available ... tumors other disorders of the urinary bladder In children, pelvic ultrasound can help evaluate: pelvic masses pelvic pain ambiguous genitalia and anomalies of pelvic organs early or delayed puberty in girls Pelvic ultrasound is ...

  8. Ultrasound -- Pelvis

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    Full Text Available ... for more information . Ultrasound examinations can help diagnose symptoms experienced by women such as: pelvic pain abnormal ... Ultrasound is the preferred imaging modality for the diagnosis and monitoring of pregnant women and their unborn ...

  9. Prostate Ultrasound

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    Full Text Available ... patient. Because ultrasound images are captured in real-time, they can show the structure and movement of ... test result. difficulty urinating. Because ultrasound provides real-time images, it also can be used to guide ...

  10. Ultrasound -- Pelvis

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    Full Text Available ... patient. Because ultrasound images are captured in real-time, they can show the structure and movement of ... help to distract the child and make the time pass quickly. The ultrasound exam room may have ...

  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. Ultrasound -- Pelvis

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    Full Text Available ... as: pelvic pain abnormal vaginal bleeding other menstrual problems Ultrasound exams also help identify: palpable masses such ... object is solid or filled with fluid). In medicine, ultrasound is used to detect changes in appearance, ...

  13. Ultrasound -- Pelvis

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

  14. 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 the Obstetrical Ultrasound page for more information . Ultrasound examinations can help diagnose symptoms experienced by ...

  15. Prostate Ultrasound

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    Full Text Available ... with your knees toward your chest. To obtain high-quality images, an ultrasound transducer – a plastic cylinder ... and ultrasound gel placed directly on the skin. High-frequency sound waves are transmitted from the probe ...

  16. Ultrasound -- Pelvis

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    Full Text Available ... vaginal (for women), and rectal (for men). These exams are frequently used to evaluate the reproductive and ... women rectal ( transrectal ) for men A Doppler ultrasound exam may be part of a pelvic ultrasound examination. ...

  17. Prostate Ultrasound

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    Full Text Available ... in x-rays ), thus there is no radiation exposure to the patient. Because ultrasound images are captured ... standard diagnostic ultrasound , there are no known harmful effects on humans. top of page What are the ...

  18. 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 ...

  19. Ultrasound -- Pelvis

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    Full Text Available ... procedure work? Ultrasound imaging is based on the same principles involved in the sonar used by bats, ... of the images may also be saved. The same principles apply to ultrasound procedures such as transrectal ...

  20. Prostate Ultrasound

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    Full Text Available ... procedure work? Ultrasound imaging is based on the same principles involved in the sonar used by bats, ... of the images may also be saved. The same principles apply to ultrasound procedures such as transrectal ...

  1. 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 ...

  2. 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 ...

  3. Ultrasound -- Pelvis

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    Full Text Available ... your child's favorite channel. top of page What does the equipment look like? Ultrasound scanners consist of ... and lubricated before insertion. top of page How does the procedure work? Ultrasound imaging is based on ...

  4. Prostate Ultrasound

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    Full Text Available ... clean out the bowel. top of page What does the equipment look like? Ultrasound scanners consist of ... lubricated with a gel. top of page How does the procedure work? Ultrasound imaging is based on ...

  5. 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 ... are sometimes the best way to see if treatment is working or if a finding is stable ...

  6. Prostate Ultrasound

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    Full Text Available ... may be instructed to use an enema to clean out your bowel. What is Ultrasound Imaging of ... two to four hours before the ultrasound to clean out the bowel. top of page What does ...

  7. 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 ...

  8. Ultrasound -- Pelvis

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    Full Text Available ... records tiny changes in the sound's pitch and direction. These signature waves are instantly measured and displayed ... ultrasound, a special application of ultrasound, measures the direction and speed of blood cells as they move ...

  9. Prostate Ultrasound

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    Full Text Available ... prostate gland while the radiologist watches the needle placement with ultrasound. A small amount of tissue is ... on x-ray images. Ultrasound causes no health problems and may be repeated as often as is ...

  10. 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 ...

  11. Ultrasound -- Pelvis

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    Full Text Available ... object is solid or filled with fluid). In medicine, ultrasound is used to detect changes in appearance, ... extremely safe and does not use any ionizing radiation. Ultrasound scanning gives a clear picture of soft ...

  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 ... 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 ...

  14. 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 ...

  15. 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 the endometrium (the lining of the uterus) and the ovaries. Transvaginal ultrasound also evaluates the myometrium (muscular walls ...

  16. 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 ...

  17. 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 ... move through vessels. The movement of blood cells causes a change in pitch of the reflected sound ...

  18. Prostate Ultrasound

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    Full Text Available ... obtain high-quality images, an ultrasound transducer – a plastic cylinder about the size of a finger – is ... end of their bowel (rectum) removed during prior surgery are not good candidates for ultrasound of the ...

  19. 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 ... following text box: Comment: E-mail: Area code: Phone no: Thank you! Do you have a personal ...

  20. 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 ... care physician, or to the physician or other healthcare provider who requested the exam. Usually, the referring ...

  1. Prostate Ultrasound

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    Full Text Available ... Ultrasound provides real-time imaging, making it a good tool for guiding minimally invasive procedures such as ... bowel (rectum) removed during prior surgery are not good candidates for ultrasound of the prostate gland because ...

  2. Ultrasound -- Pelvis

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    Full Text Available ... transducer 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 Pelvic Ultrasound Imaging? Ultrasound waves are ...

  3. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... Physician Resources Professions Site Index A-Z Ultrasound - Pelvis Ultrasound imaging of the pelvis uses sound waves to produce pictures of the structures and organs in the lower abdomen and pelvis. There are three types of pelvic ultrasound: abdominal, ...

  4. Prostate Ultrasound

    Medline Plus

    Full Text Available ... other imaging methods. Ultrasound imaging uses no ionizing radiation. Ultrasound scanning may be able to give a clearer picture of soft tissues that do not show up well on x-ray images. Ultrasound causes no health problems and may be repeated as often as ...

  5. 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.

  6. In vitro assessment of the relationship between acoustic properties and bone mass density of the calcaneus by comparison of ultrasound parametric imaging and quantitative computed tomography.

    Science.gov (United States)

    Laugier, P; Droin, P; Laval-Jeantet, A M; Berger, G

    1997-02-01

    This in vitro study aimed to add new experimental evidence to clarify the relation between acoustic properties of bone and bone mineral density (BMD) of the human calcaneus. Parametric images of normalized broadband ultrasonic attenuation (nBUA) and ultrasound bone velocity (UBV) were compared with quantitative computed tomography (QCT) images of the calcaneus. The experimental protocol was designed to control the different potential sources of error in acoustic measurements, including the shape and thickness of the samples, intervening soft tissues and cortical bone, boundary effects, and variation in location of the regions of interest (ROIs) analyzed by ultrasound and X-ray. The present study was based on bone specimens from calcaneus removed from 15 cadavers (six male and nine female donors ranging from 69 to 89 years of age). Immersion ultrasonic measurements were performed in the through-thickness direction at normal incidence using a pair of focused broad-band 0.5-MHz transducers. QCT of the specimens was performed using standard 10-mm-thick slices with the Cann-Genant calibration standard. Identical, site-matched ROIs were selected for quantitative analysis on the three images. The pattern of acoustic parameters was similar to that of BMD with QCT. The relationships between nBUA and BMD (r2 = 0.75), between UBV and BMD (r2 = 0.88) and between nBUA and UBV (r2 = 0.84) were highly significant (p < 10(-4). From this study, it appears that ultrasound parameters as measured with current transmission techniques reflect mainly bone quantity and only reflect microarchitecture to a small extent and that BUA and UBV reflect the same bone property.

  7. 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...

  8. Thermal stability of DNA quadruplex-duplex hybrids.

    Science.gov (United States)

    Lim, Kah Wai; Khong, Zi Jian; Phan, Anh Tuân

    2014-01-14

    DNA has the capacity to adopt several distinct structural forms, such as duplex and quadruplex helices, which have been implicated in cellular processes and shown to exhibit important functional properties. Quadruplex-duplex hybrids, generated from the juxtaposition of these two structural elements, could find applications in therapeutics and nanotechnology. Here we used NMR and CD spectroscopy to investigate the thermal stability of two classes of quadruplex-duplex hybrids comprising fundamentally distinct modes of duplex and quadruplex connectivity: Construct I involves the coaxial orientation of the duplex and quadruplex helices with continual base stacking across the two components; Construct II involves the orthogonal orientation of the duplex and quadruplex helices with no base stacking between the two components. We have found that for both constructs, the stability of the quadruplex generally increases with the length of the stem-loop incorporated, with respect to quadruplexes comprising nonstructured loops of the same length, which showed a continuous drop in stability with increasing loop length. The stability of these complexes, particularly Construct I, can be substantially influenced by the base-pair steps proximal to the quadruplex-duplex junction. Bulges at the junction are largely detrimental to the adoption of the desired G-quadruplex topology for Construct I but not for Construct II. These findings should facilitate future design and prediction of quadruplex-duplex hybrids.

  9. 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.

  10. Analysing Self Interference Cancellation in Full Duplex Radios

    DEFF Research Database (Denmark)

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

    2016-01-01

    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...

  11. Children's (Pediatric) Abdominal Ultrasound Imaging

    Medline Plus

    Full Text Available ... saved. Doppler ultrasound, a special application of ultrasound, measures the direction and speed of blood cells as they move through vessels. The movement of blood cells causes a change in pitch of the reflected sound waves (called the Doppler effect). A computer collects ...

  12. Optimization of duplex stability and terminal asymmetry for shRNA design.

    Directory of Open Access Journals (Sweden)

    Olga V Matveeva

    Full Text Available Prediction of efficient oligonucleotides for RNA interference presents a serious challenge, especially for the development of genome-wide RNAi libraries which encounter difficulties and limitations due to ambiguities in the results and the requirement for significant computational resources. Here we present a fast and practical algorithm for shRNA design based on the thermodynamic parameters. In order to identify shRNA and siRNA features universally associated with high silencing efficiency, we analyzed structure-activity relationships in thousands of individual RNAi experiments from publicly available databases (ftp://ftp.ncbi.nlm.nih.gov/pub/shabalin/siRNA/si_shRNA_selector/. Using this statistical analysis, we found free energy ranges for the terminal duplex asymmetry and for fully paired duplex stability, such that shRNAs or siRNAs falling in both ranges have a high probability of being efficient. When combined, these two parameters yield a approximately 72% success rate on shRNAs from the siRecords database, with the target RNA levels reduced to below 20% of the control. Two other parameters correlate well with silencing efficiency: the stability of target RNA and the antisense strand secondary structure. Both parameters also correlate with the short RNA duplex stability; as a consequence, adding these parameters to our prediction scheme did not substantially improve classification accuracy. To test the validity of our predictions, we designed 83 shRNAs with optimal terminal asymmetry, and experimentally verified that small shifts in duplex stability strongly affected silencing efficiency. We showed that shRNAs with short fully paired stems could be successfully selected by optimizing only two parameters: terminal duplex asymmetry and duplex stability of the hypothetical cleavage product, which also relates to the specificity of mRNA target recognition. Our approach performs at the level of the best currently utilized algorithms that take

  13. Head and Neck Veins of the Mouse. A Magnetic Resonance, Micro Computed Tomography and High Frequency Color Doppler Ultrasound Study.

    Directory of Open Access Journals (Sweden)

    Marcello Mancini

    Full Text Available To characterize the anatomy of the venous outflow of the mouse brain using different imaging techniques. Ten C57/black male mice (age range: 7-8 weeks were imaged with high-frequency Ultrasound, Magnetic Resonance Angiography and ex-vivo Microcomputed tomography of the head and neck. Under general anesthesia, Ultrasound of neck veins was performed with a 20 MHz transducer; head and neck Magnetic Resonance Angiography data were collected on 9.4 T or 7 T scanners, and ex-vivo Microcomputed tomography angiography was obtained by filling the vessels with a radiopaque inert silicone rubber compound. All procedures were approved by the local ethical committee. The dorsal intracranial venous system is quite similar in mice and humans. Instead, the mouse Internal Jugular Veins are tiny vessels receiving the sigmoid sinuses and tributaries from cerebellum, occipital lobe and midbrain, while the majority of the cerebral blood, i.e. from the olfactory bulbs and fronto-parietal lobes, is apparently drained through skull base connections into the External Jugular Vein. Three main intra-extracranial anastomoses, absent in humans, are: 1 the petrosquamous sinus, draining into the posterior facial vein, 2 the veins of the olfactory bulb, draining into the superficial temporal vein through a foramen of the frontal bone 3 the cavernous sinus, draining in the External Jugular Vein through a foramen of the sphenoid bone. The anatomical structure of the mouse cranial venous outflow as depicted by Ultrasound, Microcomputed tomography and Magnetic Resonance Angiography is different from humans, with multiple connections between intra- and extra-cranial veins.

  14. Sensitivity of endoscopic ultrasound, multidetector computed tomography, and magnetic resonance cholangiopancreatography in the diagnosis of pancreas divisum: a tertiary center experience.

    Science.gov (United States)

    Kushnir, Vladimir M; Wani, Sachin B; Fowler, Kathryn; Menias, Christine; Varma, Rakesh; Narra, Vamsi; Hovis, Christine; Murad, Faris M; Mullady, Daniel K; Jonnalagadda, Sreenivasa S; Early, Dayna S; Edmundowicz, Steven A; Azar, Riad R

    2013-04-01

    There are limited data comparing imaging modalities in the diagnosis of pancreas divisum. We aimed to: (1) evaluate the sensitivity of endoscopic ultrasound (EUS), magnetic resonance cholangiopancreatography (MRCP), and multidetector computed tomography (MDCT) for pancreas divisum; and (2) assess interobserver agreement (IOA) among expert radiologists for detecting pancreas divisum on MDCT and MRCP. For this retrospective cohort study, we identified 45 consecutive patients with pancreaticobiliary symptoms and pancreas divisum established by endoscopic retrograde pancreatography who underwent EUS and cross-sectional imaging. The control group was composed of patients without pancreas divisum who underwent endoscopic retrograde pancreatography and cross-sectional imaging. The sensitivity of EUS for pancreas divisum was 86.7%, significantly higher than the sensitivity reported in the medical records for MDCT (15.5%) or MRCP (60%) (P pancreas divisum; IOA was moderate (κ = 0.43). Endoscopic ultrasound is a sensitive test for diagnosing pancreas divisum and is superior to MDCT and MRCP. Review of MDCT studies by expert radiologists substantially raises its sensitivity for pancreas divisum.

  15. Is hemifacial spasm accompanied by hemodynamic changes detectable by ultrasound?

    Science.gov (United States)

    Perren, Fabienne; Magistris, Michel R

    2014-08-01

    Arterial tortuosity of the posterior circulation compressing the facial nerve induces the ephaptic axono-axonal cross-talk that sparks hemifacial spasm. We sought if a noninvasive method such as color duplex of these arteries might detect hemodynamical changes in this condition. Nine patients with hemifacial spasm, successfully treated with botulinum toxin, were examined with color-coded duplex ultrasound. Mean blood flow velocities of the vertebral, basilar, posterior inferior cerebellar, and anterior inferior cerebellar arteries were measured and side-to-side comparison performed. In all nine patients, the mean blood flow velocity, averaging across the two arteries, was higher on the side of the hemifacial spasm (Fisher's exact p hemifacial spasm. There was no significant association between the mean flow velocity of the vertebral artery and the side of spasm (p = 0.523). Hemifacial spasm also seems to relate to hemodynamic changes, which may be detectable by color duplex imaging.

  16. 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.

  17. Ultrasound for the Anesthesiologists: Present and Future

    Directory of Open Access Journals (Sweden)

    Abdullah S. Terkawi

    2013-01-01

    Full Text Available Ultrasound is a safe, portable, relatively inexpensive, and easily accessible imaging modality, making it a useful diagnostic and monitoring tool in medicine. Anesthesiologists encounter a variety of emergent situations and may benefit from the application of such a rapid and accurate diagnostic tool in their routine practice. This paper reviews current and potential applications of ultrasound in anesthesiology in order to encourage anesthesiologists to learn and use this useful tool as an adjunct to physical examination. Ultrasound-guided peripheral nerve blockade and vascular access represent the most popular ultrasound applications in anesthesiology. Ultrasound has recently started to substitute for CT scans and fluoroscopy in many pain treatment procedures. Although the application of airway ultrasound is still limited, it has a promising future. Lung ultrasound is a well-established field in point-of-care medicine, and it could have a great impact if utilized in our ORs, as it may help in rapid and accurate diagnosis in many emergent situations. Optic nerve sheath diameter (ONSD measurement and transcranial color coded duplex (TCCD are relatively new neuroimaging modalities, which assess intracranial pressure and cerebral blood flow. Gastric ultrasound can be used for assessment of gastric content and diagnosis of full stomach. Focused transthoracic (TTE and transesophageal (TEE echocardiography facilitate the assessment of left and right ventricular function, cardiac valve abnormalities, and volume status as well as guiding cardiac resuscitation. Thus, there are multiple potential areas where ultrasound can play a significant role in guiding otherwise blind and invasive interventions, diagnosing critical conditions, and assessing for possible anatomic variations that may lead to plan modification. We suggest that ultrasound training should be part of any anesthesiology training program curriculum.

  18. [Potentialities of computed tomography and ultrasound in diagnosis of hormonally active adrenal diseases: results of comparison CT and US with operative adn histological data].

    Science.gov (United States)

    Denisova, L B; Vorontsova, S V; Emel'ianova, L N

    2000-01-01

    The data given in the paper suggest that X-ray computed tomography (CT) is highly effective in detecting all types of hormonally active adrenal abnormalities. CT used in hormonally active adrenal diseases yielded data on major quantitative and qualitative (primarily densitometric) criteria that could be used in assessing the images of the adrenal area in these patients. Ultrasound study (USS) made at the first stage of topical diagnostic searches was of informative value in detecting adrenal tumor lesions, the technique being highly sensitive in the diagnosis of adrenal pheochromocytomas and adenocarcinomas, but less informative in the detection of hormonally active adrenocortical adenomas (aldesterone-producing ones in particular) than CT. The diagnosis of various adrenocortical hyperplasies and the differentiation of hyperplastic and tumor forms of hypercorticoidism are a prerogative of CT that substantially supplements USS findings in such cases.

  19. The human Bosniak model applied to a cat with renal cystadenoma. A classification to differentiate benign and malignant cystic renal masses via computed tomography and ultrasound.

    Science.gov (United States)

    Baloi, P; Del Chicca, F; Ruetten, M; Gerber, B

    2015-01-01

    A 13-year-old domestic shorthair cat was presented with weight loss and azotemia. Abdominal ultrasound revealed a large cystic space- occupying lesion with multiple septae in the left kidney. A core needle biopsy yielded a renal cystadenoma originating from the epithelial cells. This report describes the clinical, ultrasonographic and computed tomographic features and the growth progression of a renal cystadenoma. We describe the first attempt to apply the human Bosniak classification to a cat with renal cystic neoplasia to differentiate between benign and malignant lesions. Cystadenoma should be a differential diagnosis in cases of renal cystic space-occupying lesions. Other differentials, imaging features to differentiate benign and malignant lesions and the risk of malignant transformation will be discussed.

  20. Children's (Pediatric) Abdominal Ultrasound Imaging

    Medline Plus

    Full Text Available ... More Info Images/Videos About Us News Physician Resources Professions Site Index A-Z Children's (Pediatric) Ultrasound - ... computer or television monitor. The image is created based on the amplitude (loudness), frequency (pitch) and time ...

  1. 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.

  2. Tunable microwave photonic duplexer for full-duplex radio-over-fiber access.

    Science.gov (United States)

    Li, Peixuan; Pan, Wei; Zou, Xihua; Yan, Lianshan; Luo, Bin; Lu, Bing

    2017-02-20

    A tunable microwave photonic duplexer (MPD) for full-duplex radio-over-fiber access is proposed and experimentally demonstrated. The proposed MPD is implemented by two single-bandpass microwave photonic filters (MPFs) to separate the transmit (Tx) and receive (Rx) channels. More specifically, a broadband optical source (BOS) is spectrally sliced by a differential-group-delay interferometer (DGDI) and a Mach-Zehnder interferometer (MZI) to form two tunable single-bandpass MPFs with different central frequencies. The two MPFs are used for the Tx and Rx channels, respectively. By adjusting the free spectral ranges (FSRs) of the DGDI and MZI, the central frequencies of the Tx and Rx channels can be tuned independently in a wide frequency range. In the experiments, tunable ranges from 0 to 6.1 GHz for the Tx channel and from 0 to 17 GHz for the Rx channel are achieved. Meanwhile, a high isolation up to 44 dB between the Tx and Rx channels is also obtained. Based on the proposed MPD, the duplex transmission of a 10-MBaud 16-quadrature-amplitude-modulation (QAM) signal at 2.45 GHz and 2.82 GHz is demonstrated.

  3. 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)

  4. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... in the abdomen, arms, legs, neck and/or brain (in infants and children) or within various body organs such as the liver or kidneys. There are three types of Doppler ultrasound: Color Doppler uses a computer to convert Doppler measurements into an array of ...

  5. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... so that your bladder is full when the scan begins. top of page What does the equipment look like? Ultrasound scanners consist of a console containing a computer and electronics, a video display screen and a transducer that is used ...

  6. Numerical Simulation of Duplex Steel Multipass Welding

    Directory of Open Access Journals (Sweden)

    Giętka T.

    2016-12-01

    Full Text Available Analyses based on FEM calculations have significantly changed the possibilities of determining welding strains and stresses at early stages of product design and welding technology development. Such an approach to design enables obtaining significant savings in production preparation and post-weld deformation corrections and is also important for utility properties of welded joints obtained. As a result, it is possible to make changes to a simulated process before introducing them into real production as well as to test various variants of a given solution. Numerical simulations require the combination of problems of thermal, mechanical and metallurgical analysis. The study presented involved the SYSWELD software-based analysis of GMA welded multipass butt joints made of duplex steel sheets. The analysis of the distribution of stresses and displacements were carried out for typical welding procedure as during real welding tests.

  7. Corrosion behavior of sensitized duplex stainless steel.

    Science.gov (United States)

    Torres, F J; Panyayong, W; Rogers, W; Velasquez-Plata, D; Oshida, Y; Moore, B K

    1998-01-01

    The present work investigates the corrosion behavior of 2205 duplex stainless steel in 0.9% NaCl solution after various heat-treatments, and compares it to that of 316L austenitic stainless steel. Both stainless steels were heat-treated at 500, 650, and 800 degrees C in air for 1 h, followed by furnace cooling. Each heat-treated sample was examined for their microstructures and Vickers micro-hardness, and subjected to the X-ray diffraction for the phase identification. Using potentiostatic polarization method, each heat-treated sample was corrosion-tested in 37 degrees C 0.9% NaCl solution to estimate its corrosion rate. It was found that simulated sensitization showed an adverse influence on both steels, indicating that corrosion rates increased by increasing the sensitization temperatures.

  8. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... internal organs, as well as blood flowing through blood vessels. Ultrasound imaging is a noninvasive medical test that helps physicians diagnose and treat medical conditions. ...

  9. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... 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 ...

  10. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... inserted into a man's rectum to view the prostate. Transvaginal ultrasound. The transducer is inserted into a ... Stenting Ultrasound-Guided Breast Biopsy Obstetric Ultrasound Ultrasound - Prostate Biopsies - Overview Images related to General Ultrasound Videos ...

  11. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... the body while other areas, especially air-filled lungs, are poorly suited for ultrasound. For ultrasound procedures requiring insertion of the transducer, such as transvaginal or transrectal exams, the device is covered with a sheath and lubricated before insertion. ...

  12. Prostate Ultrasound

    Medline Plus

    Full Text Available ... the body while other areas, especially air-filled lungs, are poorly suited for ultrasound. For ultrasound procedures such as transrectal exams that require insertion of an imaging probe, also called a transducer, the device is covered and lubricated with a gel. top of ...

  13. Prostate Ultrasound

    Medline Plus

    Full Text Available ... transducer 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 Prostate Ultrasound Imaging? Men who have ...

  14. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... are some common uses of the procedure? In women, a pelvic ultrasound is most often performed to evaluate the: uterus cervix ovaries fallopian tubes bladder Pelvic ultrasound exams are also used to monitor the health and development of an embryo or fetus during ...

  15. Prostate Ultrasound

    Medline Plus

    Full Text Available ... well on x-ray images. Ultrasound causes no health problems and may be repeated as often as is necessary if medically indicated. Ultrasound provides real-time imaging, making it a good tool for guiding minimally invasive procedures such as ...

  16. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... areas of the body while other areas, especially air-filled lungs, are poorly suited for ultrasound. For ultrasound procedures requiring insertion of the transducer, such as transvaginal or transrectal exams, the device is covered with a sheath and lubricated before ...

  17. Prostate Ultrasound

    Medline Plus

    Full Text Available ... areas of the body while other areas, especially air-filled lungs, are poorly suited for ultrasound. For ultrasound procedures such as transrectal exams that require insertion of an imaging probe, also called a transducer, the device is covered and lubricated with a gel. top ...

  18. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... then uses those sound waves to create an image. Ultrasound 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 ...

  19. Ultrasound - Scrotum

    Science.gov (United States)

    ... then uses those sound waves to create an image. Ultrasound 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 ...

  20. Prostate Ultrasound

    Medline Plus

    Full Text Available ... then uses those sound waves to create an image. Ultrasound 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 ...

  1. Prostate Ultrasound

    Medline Plus

    Full Text Available ... as needle biopsies and fluid aspiration. Risks For standard diagnostic ultrasound , there are no known harmful effects on humans. top of page What are the limitations of Prostate Ultrasound Imaging? Men who have had the tail end of their bowel ( ...

  2. Prostate Ultrasound

    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 Resources Professions Site Index A-Z Ultrasound - Prostate Ultrasound of ...

  3. 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 Resources Professions Site Index A-Z Ultrasound - Pelvis Ultrasound imaging ...

  4. Prostate Ultrasound

    Medline Plus

    Full Text Available ... radiation exposure to the patient. Because ultrasound images are captured in real-time, they can show the structure and movement of ... if a finding is stable or changed over time. top of page What are the benefits vs. risks? Benefits Ultrasound is widely ...

  5. Diagnostic utility of endobronchial ultrasound with a guide sheath under the computed tomography workstation (ziostation) for small peripheral pulmonary lesions.

    Science.gov (United States)

    Matsumoto, Yuji; Izumo, Takehiro; Sasada, Shinji; Tsuchida, Takaaki; Ohe, Yuichiro

    2017-03-01

    The application of radial probe endobronchial ultrasound (R-EBUS) and virtual bronchoscopic navigation has improved the diagnostic outcome of bronchoscopy for peripheral pulmonary lesions (PPLs). Nonetheless, while existing navigation systems are very useful for selecting the bronchus containing the target lesion, the associated introductory costs are high. Therefore, we focused on virtual bronchoscopy (VB) using the workstation, ziostation that was already available in many countries as an adjunct modality. Consecutive patients who underwent bronchoscopy with R-EBUS for PPLs (major diameter ≤30 mm) were enrolled. From late June 2013 to November 2013, 121 patients were examined with ziostation, and from September 2012 to early June 2013, 113 patients were examined without ziostation. We compared the diagnostic yield, EBUS detection rate and procedure time between two groups to evaluate the utility of the VB. The ziostation group had significantly higher diagnostic yield than the non-ziostation group (77.7% vs 64.6%, P = 0.030). Following the multivariate analysis, use of ziostation was a significant factor affecting the diagnostic yield. Meanwhile, EBUS detection rate was significantly higher in the ziostation group (94.2% vs 75.2%, P workstation was a valuable tool that facilitated more accurate and rapid bronchoscopy procedure for diagnosis of PPLs. © 2015 John Wiley & Sons Ltd.

  6. Improper Signaling for Virtual Full-Duplex Relay Systems

    KAUST Repository

    Gaafar, Mohamed

    2017-02-14

    Virtual full-duplex (VFD) is a powerful solution to compensate the rate loss of half-duplex relaying without the need to full-duplex capable nodes. Inter-relay interference (IRI) challenges the operation of VFD relaying systems. Recently, improper signaling is employed at both relays of the VFD to mitigate the IRI by imposing the same signal characteristics for both relays. To further boost the achievable rate performance, asymmetric time sharing VFD relaying system is adopted with different improper signals at the half-duplex relays. The joint tuning of the three design parameters improves the achievable rate performance at different ranges of IRI and different relays locations. Extensive simulation results are presented and analyzed to show the achievable rate gain of the proposed system and understand the system behavior.

  7. Sports Ultrasound

    Science.gov (United States)

    Finnoff, Jonathan T.; Ray, Jeremiah; Corrado, Gianmichael; Kerkhof, Deanna; Hill, John

    2016-01-01

    Background: Traditionally, ultrasound has been used to evaluate musculoskeletal injuries in athletes; however, ultrasound applications extend well beyond musculoskeletal conditions, many of which are pertinent to athletes. Evidence Acquisition: Articles were identified in PubMed using the search terms ultrasound, echocardiogram, preparticipation physical examination, glycogen, focused assessment with sonography of trauma, optic nerve, and vocal cord dysfunction. No date restrictions were placed on the literature search. Study Design: Clinical review. Level of Evidence: Level 4. Results: Several potential applications of nonmusculoskeletal ultrasound in sports medicine are presented, including extended Focused Assessment with Sonography for Trauma (eFAST), limited echocardiographic screening during preparticipation physical examinations, assessment of muscle glycogen stores, optic nerve sheath diameter measurements in athletes with increased intracranial pressure, and assessment of vocal cord dysfunction in athletes. Conclusion: Ultrasound can potentially be used to assist athletes with monitoring their muscle glycogen stores and the diagnosis of multiple nonmusculoskeletal conditions within sports medicine. PMID:27519599

  8. Base flipping of the thymine dimer in duplex DNA.

    Science.gov (United States)

    O'Neil, Lauren L; Grossfield, Alan; Wiest, Olaf

    2007-10-11

    Exposure of two adjacent thymines in DNA to UV light of 260-320 nm can result in the formation of the cis,syn-cyclobutane pyrimidine dimer (CPD). The structure of DNA containing an intrahelical CPD lesion has been previously studied experimentally and computationally. However, the structure of the extrahelical, flipped-out, CPD lesion, which has been shown to be the structure that binds to the CPD repair enzyme, DNA photolyase, has yet to be reported. In this work the structure of both the flipped-in and the flipped-out CPD lesions in duplex DNA is reported. These structures were calculated using 8 ns molecular dynamics (MD) simulations. These structures are then used to define the starting and ending points for the base-flipping process for the CPD lesion. Using a complex, two-dimensional pseudodihedral coordinate, the potential of mean force (PMF) for the base-flipping process was calculcated using novel methodology. The free energy of the flipped-out CPD is roughly 6.5 kcal/mol higher than that of the flipped-in state, indicating that the barrier to flipping out is much lower for CPD than for undamaged DNA. This may indicate that the flipped-out CPD lesion may be recognized by its repair enzyme, DNA photolyase, whereas previous studies of other damaged, as well as nondamaged, bases indicate that they are recognized by enzymes in the intrahelical, flipped-in state.

  9. QUANTITATIVE ANALYSIS OF FATIGUE FRACTURE SURFACE IN THE DUPLEX STEEL

    OpenAIRE

    Maria Sozańska; Francesco Iacoviello; Jan Cwajna; Michel Jerome; Jaroslav Sojka; Jacques Galland

    2011-01-01

    We present a quantitative and qualitative analysis of the fatigue surface of Z2CND2205 duplex steel. Both the ferritic and austenitic phases of this duplex steel are investigated. The observed brittleness of the steel is here due to the presence of hydrogen. The hydrogen influence is complex in that the two phases are altered by hydrogen in different ways. Quantitative parameters describing striations spacing in each phase are measured.

  10. QUANTITATIVE ANALYSIS OF FATIGUE FRACTURE SURFACE IN THE DUPLEX STEEL

    Directory of Open Access Journals (Sweden)

    Maria Sozańska

    2011-05-01

    Full Text Available We present a quantitative and qualitative analysis of the fatigue surface of Z2CND2205 duplex steel. Both the ferritic and austenitic phases of this duplex steel are investigated. The observed brittleness of the steel is here due to the presence of hydrogen. The hydrogen influence is complex in that the two phases are altered by hydrogen in different ways. Quantitative parameters describing striations spacing in each phase are measured.

  11. 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.

  12. Protein-DNA footprinting by endcapped duplex oligodeoxyribonucleotides.

    Science.gov (United States)

    Ng, Pei-Sze; Bergstrom, Donald E

    2004-07-19

    Oligodeoxyribonucleotides (5'-phosphorylated) of varying lengths were capped using a polyamide linker to form thermodynamically stable, endcapped DNA duplexes containing 8-14 bp. We have employed these endcapped DNA duplexes as tools to determine the DNA footprint of T4 DNA ligase. By high-performance liquid chromatography and PAGE analysis of the ligation mixtures of the endcapped DNA duplexes, we have found that by varying the lengths and the position of the nick, we can determine the minimal DNA-binding site as well as the mode of binding (symmetrical or asymmetrical binding) by the enzyme. The results of the study revealed that a 11 bp endcapped duplex was the shortest duplex effectively ligated. Dependence of ligation efficiency on nick position demonstrates that T4 DNA ligase bound asymmetrically to its DNA substrate. The use of a set of thermodynamically stable endcapped deoxyribonucleoside duplexes as a tool to elucidate the DNA footprint provides an efficient strategy for footprinting, which avoids ambiguities associated with chemical and biochemical footprinting methods.

  13. A brain-computer interface based on functional transcranial doppler ultrasound using wavelet transform and support vector machines.

    Science.gov (United States)

    Khalaf, Aya; Sybeldon, Matthew; Sejdic, Ervin; Akcakaya, Murat

    2018-01-01

    Functional transcranial Doppler (fTCD) is an ultrasound based neuroimaging technique used to assess neural activation that occurs during a cognitive task through measuring velocity of cerebral blood flow. The objective of this paper is to investigate the feasibility of a 2-class and 3-class real-time BCI based on blood flow velocity in left and right middle cerebral arteries in response to mental rotation and word generation tasks. Statistical features based on a five-level wavelet decomposition were extracted from the fTCD signals. The Wilcoxon test and support vector machines (SVM), with a linear kernel, were employed for feature reduction and classification. The experimental results showed that within approximately 3s of the onset of the cognitive task average accuracies of 80.29%, and 82.35% were obtained for the mental rotation versus resting state and the word generation versus resting state respectively. The mental rotation task versus word generation task achieved an average accuracy of 79.72% within 2.24s from the onset of the cognitive task. Furthermore, an average accuracy of 65.27% was obtained for the 3-class problem within 4.68s. The results presented here provide significant improvement compared to the relevant fTCD-based systems presented in literature in terms of accuracy and speed. Specifically, the reported speed in this manuscript is at least 12 and 2.5 times faster than any existing binary and 3-class fTCD-based BCIs, respectively. These results show fTCD as a promising and viable candidate to be used towards developing a real-time BCI. Published by Elsevier B.V.

  14. Cranial Ultrasound/Head Ultrasound

    Science.gov (United States)

    ... then uses those sound waves to create an image. Ultrasound 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 ...

  15. Accuracy of computer-aided ultrasound as compared with magnetic resonance imaging in the evaluation of nonalcoholic fatty liver disease in obese and eutrophic adolescents

    Energy Technology Data Exchange (ETDEWEB)

    Nascimento, Jose Hermes Ribas do, E-mail: josehermesnascimento@gmail.com [Instituto Cenecista de Ensino Superior de Santo Angelo (IESA), Santo Angelo, RS (Brazil); Soder, Ricardo Bernardi; Epifanio, Matias; Baldisserotto, Matteo [Pontificia Universidade Catolica do Rio Grande do Sul (InsCer/PUCRS), Porto Alegre, RS (Brazil). Instituto do Cerebro

    2015-07-15

    Objective: to compare the accuracy of computer-aided ultrasound (US) and magnetic resonance imaging (MRI) by means of hepatorenal gradient analysis in the evaluation of nonalcoholic fatty liver disease (NAFLD) in adolescents. Materials and methods: this prospective, cross-sectional study evaluated 50 adolescents (aged 11-17 years), including 24 obese and 26 eutrophic individuals. All adolescents underwent computer-aided US, MRI, laboratory tests, and anthropometric evaluation. Sensitivity, specificity, positive and negative predictive values and accuracy were evaluated for both imaging methods, with subsequent generation of the receiver operating characteristic (ROC) curve and calculation of the area under the ROC curve to determine the most appropriate cutoff point for the hepatorenal gradient in order to predict the degree of steatosis, utilizing MRI results as the gold-standard. Results: the obese group included 29.2% girls and 70.8% boys, and the eutrophic group, 69.2% girls and 30.8% boys. The prevalence of NAFLD corresponded to 19.2% for the eutrophic group and 83% for the obese group. The ROC curve generated for the hepatorenal gradient with a cutoff point of 13 presented 100% sensitivity and 100% specificity. As the same cutoff point was considered for the eutrophic group, false-positive results were observed in 9.5% of cases (90.5% specificity) and false-negative results in 0% (100% sensitivity). Conclusion: computer-aided US with hepatorenal gradient calculation is a simple and noninvasive technique for semiquantitative evaluation of hepatic echogenicity and could be useful in the follow-up of adolescents with NAFLD, population screening for this disease as well as for clinical studies. (author)

  16. Accuracy of computer-aided ultrasound as compared with magnetic resonance imaging in the evaluation of nonalcoholic fatty liver disease in obese and eutrophic adolescents

    Directory of Open Access Journals (Sweden)

    José Hermes Ribas do Nascimento

    2015-08-01

    Full Text Available AbstractObjective:To compare the accuracy of computer-aided ultrasound (US and magnetic resonance imaging (MRI by means of hepatorenal gradient analysis in the evaluation of nonalcoholic fatty liver disease (NAFLD in adolescents.Materials and Methods:This prospective, cross-sectional study evaluated 50 adolescents (aged 11–17 years, including 24 obese and 26 eutrophic individuals. All adolescents underwent computer-aided US, MRI, laboratory tests, and anthropometric evaluation. Sensitivity, specificity, positive and negative predictive values and accuracy were evaluated for both imaging methods, with subsequent generation of the receiver operating characteristic (ROC curve and calculation of the area under the ROC curve to determine the most appropriate cutoff point for the hepatorenal gradient in order to predict the degree of steatosis, utilizing MRI results as the gold-standard.Results:The obese group included 29.2% girls and 70.8% boys, and the eutrophic group, 69.2% girls and 30.8% boys. The prevalence of NAFLD corresponded to 19.2% for the eutrophic group and 83% for the obese group. The ROC curve generated for the hepatorenal gradient with a cutoff point of 13 presented 100% sensitivity and 100% specificity. As the same cutoff point was considered for the eutrophic group, false-positive results were observed in 9.5% of cases (90.5% specificity and false-negative results in 0% (100% sensitivity.Conclusion:Computer-aided US with hepatorenal gradient calculation is a simple and noninvasive technique for semiquantitative evaluation of hepatic echogenicity and could be useful in the follow-up of adolescents with NAFLD, population screening for this disease as well as for clinical studies.

  17. Computer-aided diagnosis for classifying benign versus malignant thyroid nodules based on ultrasound images: A comparison with radiologist-based assessments

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Yongjun [School of Electrical Engineering, Korea Advanced Institute of Science and Technology, 291, Daehak-ro, Yuseong-gu, Daejeon 34141 (Korea, Republic of); Paul, Anjan Kumar [Funzin, Inc., 148 Ankuk-dong, Jongro-gu, Seoul 03060 (Korea, Republic of); Kim, Namkug, E-mail: namkugkim@gmail.com; Baek, Jung Hwan; Choi, Young Jun [Department of Radiology, University of Ulsan College of Medicine, 388-1 Pungnap2-dong, Songpa-gu, Seoul 05505 (Korea, Republic of); Ha, Eun Ju [Department of Radiology, Ajou University School of Medicine, Wonchon-Dong, Yeongtong-Gu, Suwon 16499 (Korea, Republic of); Lee, Kang Dae; Lee, Hyoung Shin [Department of Otolaryngology Head and Neck Surgery, Kosin University College of Medicine, 34 Amnamdong, Seu-Gu, Busan 49267 (Korea, Republic of); Shin, DaeSeock; Kim, Nakyoung [MIDAS Information Technology, Pangyo-ro 228, Bundang-gu, Seongnam-si, Gyeonggi 13487 (Korea, Republic of)

    2016-01-15

    Purpose: To develop a semiautomated computer-aided diagnosis (CAD) system for thyroid cancer using two-dimensional ultrasound images that can be used to yield a second opinion in the clinic to differentiate malignant and benign lesions. Methods: A total of 118 ultrasound images that included axial and longitudinal images from patients with biopsy-confirmed malignant (n = 30) and benign (n = 29) nodules were collected. Thyroid CAD software was developed to extract quantitative features from these images based on thyroid nodule segmentation in which adaptive diffusion flow for active contours was used. Various features, including histogram, intensity differences, elliptical fit, gray-level co-occurrence matrixes, and gray-level run-length matrixes, were evaluated for each region imaged. Based on these imaging features, a support vector machine (SVM) classifier was used to differentiate benign and malignant nodules. Leave-one-out cross-validation with sequential forward feature selection was performed to evaluate the overall accuracy of this method. Additionally, analyses with contingency tables and receiver operating characteristic (ROC) curves were performed to compare the performance of CAD with visual inspection by expert radiologists based on established gold standards. Results: Most univariate features for this proposed CAD system attained accuracies that ranged from 78.0% to 83.1%. When optimal SVM parameters that were established using a grid search method with features that radiologists use for visual inspection were employed, the authors could attain rates of accuracy that ranged from 72.9% to 84.7%. Using leave-one-out cross-validation results in a multivariate analysis of various features, the highest accuracy achieved using the proposed CAD system was 98.3%, whereas visual inspection by radiologists reached 94.9% accuracy. To obtain the highest accuracies, “axial ratio” and “max probability” in axial images were most frequently included in the

  18. A failure of preoperative duplex imaging to diagnose a lower extremity venous aneurysm in a patient with severe chronic venous insufficiency

    Directory of Open Access Journals (Sweden)

    Roy Wesley Jones

    2017-02-01

    Full Text Available Objective: We present a case of recurrent bilateral lower extremity venous stasis ulcers in association with a superficial venous aneurysm at the right saphenofemoral junction that was misdiagnosed on preoperative duplex scanning. Methods: A 53-year-old female presented to our clinic with 6-year history of bilateral lower extremity venous stasis ulcers. Her past medical history was significant for refractory venous stasis ulcers of the bilateral lower extremities present for 6 years and morbid obesity. Results: Preoperative venous duplex demonstrated severe venous insufficiency of the superficial and deep systems, but a venous aneurysm was not appreciated. During the high ligation of the right saphenofemoral junction, a 3 × 4 × 5 cm aneurysm was encountered. Repair consisted of aneurysm resection, high ligation of the greater saphenous vein, dissociation of the great saphenous and anterior saphenous veins, and stab phlebectomy of large varicose veins of the thigh and lower leg. The patient recovered uneventfully and experienced complete healing of the venous stasis ulcer in several weeks. Conclusion: Superficial venous aneurysms of the lower extremity are rare and can be often missed on preoperative duplex ultrasound imaging. Large diameter measurements of the proximal greater saphenous vein and obesity increase the risk of misdiagnosing venous aneurysms with duplex imaging; therefore, clinical suspicion must remain high. These aneurysms can be associated with significant symptoms for which repair is indicated.

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

    OpenAIRE

    Prabhu Paulraj; Rajnish Garg

    2015-01-01

    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 pha...

  20. Venous duplex and pathologic differences in thrombus characteristics between de novo deep vein thrombi and endovenous heat-induced thrombi.

    Science.gov (United States)

    Santin, Brian J; Lohr, Joanne M; Panke, Thomas W; Neville, Patrick M; Felinski, Melissa M; Kuhn, Brian A; Recht, Matthew H; Muck, Patrick E

    2015-04-01

    Superficial venous reflux disease has been treated with endovenous ablation techniques for more than 15 years. Thrombi discovered in the postoperative period are referred to as endovenous heat-induced thrombi (EHIT). In spite of the few studies of the ultrasound differentiation between EHIT and deep vein thrombi (DVT), there remains a paucity of literature regarding the evaluation of ultrasound examination and pathologic differentiation. Six Yorkshire cross swine underwent femoral vein thrombosis by suture ligation or endovenous radiofrequency ablation. At 1 week after the procedure, each femoral vein was imaged by color Duplex ultrasound and sent for histologic interpretation for differentiation between EHIT and DVT. Five blinded vascular surgery faculty, two vascular surgery fellows, and three vascular surgery residents reviewed the ultrasound images. Thrombi associated with radiofrequency ablation demonstrated a greater degree of hypercellular response, fibroblastic reaction, and edema (3.42 vs 2.92; 3.75 vs 2.42; 2.83 vs 1.33). Specimens harvested from the iatrogenic-induced DVT swine demonstrated a more prolific response to trichrome staining (3.42 vs 2.67). Evidence of revascularization was found in all of the EHIT specimens but in 33% of DVT specimens. On the basis of histologic findings, the pathologist predicted correct modality 92% of the time. Subgroup analysis comparing paired specimens from each swine failed to demonstrate any marked pathologic differences. Recorded ultrasound images from EHIT and DVT samples were reviewed by fellows, residents, and vascular surgery staff to determine whether clot was stationary or free-floating (n = 111; 93%), evidence of retracted or adherent vein (n = 105; 88%), and absence of color flow (n = 102; 85%). The degree of occlusion (partial vs total) and degree of distention of a visualized vein were least likely to be agreed on by reviewers (n = 95; 79% each, respectively). In subgroup (DVT vs EHIT) analyses, the

  1. 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. Copyright © 2014 Elsevier Inc. All rights reserved.

  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...... form expressions for the instantaneous and ergodic throughput gain of full duplex communication over conventional half duplex is derived. The secrecy degrees of freedom with full duplex is shown to be two as opposed to that of zero in half duplex mode....

  3. 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.

  4. 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)

  5. Standard duplex criteria overestimate the degree of stenosis after eversion carotid endarterectomy.

    Science.gov (United States)

    Benzing, Travis; Wilhoit, Cameron; Wright, Sharee; McCann, P Aaron; Lessner, Susan; Brothers, Thomas E

    2015-06-01

    The eversion technique for carotid endarterectomy (eCEA) offers an alternative to longitudinal arteriotomy and patch closure (pCEA) for open carotid revascularization. In some reports, eCEA has been associated with a higher rate of >50% restenosis of the internal carotid when it is defined as peak systolic velocity (PSV) >125 cm/s by duplex imaging. Because the conformation of the carotid bifurcation may differ after eCEA compared with native carotid arteries, it was hypothesized that standard duplex criteria might not accurately reflect the presence of restenosis after eCEA. In a case-control study, the outcomes of all patients undergoing carotid endarterectomy by one surgeon during the last 10 years were analyzed retrospectively, with a primary end point of PSV >125 cm/s. Duplex flow velocities were compared with luminal diameter measurements for any carotid computed tomography arteriography or magnetic resonance angiography study obtained within 2 months of duplex imaging, with the degree of stenosis calculated by the methodology used in the North American Symptomatic Carotid Endarterectomy Trial (NASCET) and the European Carotid Surgery Trial (ECST) as well as cross-sectional area (CSA) reduction. Simulations were generated and analyzed by computational model simulations of the eCEA and pCEA arteries. Eversion and longitudinal arteriotomy with patch techniques were used in 118 and 177 carotid arteries, respectively. Duplex follow-up was available in 90 eCEA arteries at a median of 16 (range, 2-136) months and in 150 pCEA arteries at a median of 41 (range, 3-115) months postoperatively. PSV >125 cm/s was present at some time during follow-up in 31% of eCEA and pCEA carotid arteries, each, and in the most recent duplex examination in 7% after eCEA and 21% after pCEA (P = .003), with no eCEA and two pCEA arteries occluding completely during follow-up (P = .29). In 19 carotid arteries with PSV >125 cm/s after angle correction (median, 160 cm/s; interquartile range

  6. Differentiation of pancreatic cancer and chronic pancreatitis using computer-aided diagnosis of endoscopic ultrasound (EUS) images: a diagnostic test.

    Science.gov (United States)

    Zhu, Maoling; Xu, Can; Yu, Jianguo; Wu, Yijun; Li, Chunguang; Zhang, Minmin; Jin, Zhendong; Li, Zhaoshen

    2013-01-01

    Differentiating pancreatic cancer (PC) from normal tissue by computer-aided diagnosis of EUS images were quite useful. The current study was designed to investigate the feasibility of using computer-aided diagnostic (CAD) techniques to extract EUS image parameters for the differential diagnosis of PC and chronic pancreatitis (CP). This study recruited 262 patients with PC and 126 patients with CP. Typical EUS images were selected from the sample sets. Texture features were extracted from the region of interest using computer-based techniques. Then the distance between class algorithm and sequential forward selection (SFS) algorithm were used for a better combination of features; and, later, a support vector machine (SVM) predictive model was built, trained, and validated. Overall, 105 features of 9 categories were extracted from the EUS images for pattern classification. Of these features, the 16 were selected as a better combination of features. Then, SVM predictive model was built and trained. The total cases were randomly divided into a training set and a testing set. The training set was used to train the SVM, and the testing set was used to evaluate the performance of the SVM. After 200 trials of randomised experiments, the average accuracy, sensitivity, specificity, the positive and negative predictive values of pancreatic cancer were 94.2±0.1749%,96.25±0.4460%, 93.38±0.2076%, 92.21±0.4249% and 96.68±0.1471%, respectively. Digital image processing and computer-aided EUS image differentiation technologies are highly accurate and non-invasive. This technology provides a kind of new and valuable diagnostic tool for the clinical determination of PC.

  7. Diagnosis of an infected central venous catheter with ultrasound and computed tomography; Diagnose eines infizierten Thrombus der Vena cava inferior mit Sonographie und Computertomographie

    Energy Technology Data Exchange (ETDEWEB)

    Tacke, J. [RWTH Aachen (Germany). Klinik fuer Radiologische Diagnostik; Adam, G. [RWTH Aachen (Germany). Klinik fuer Radiologische Diagnostik; Sliwka, U. [RWTH Aachen (Germany). Neurologische Klinik; Klosterhalfen, B. [RWTH Aachen (Germany). Inst. fuer Pathologie; Schoendube, F. [RWTH Aachen (Germany). Klinik fuer Thorax- Herz- und Gefaesschirurgie

    1995-08-01

    The authors report the case of a 16-year-old male patient, who suffered from meningitis and Waterhouse-Friderichsen syndrome. After initial improvement in the intensive care unit, he developed septic temperatures, caused by an infected thrombus of a central venous catheter in the inferior vena cava, Color-coded ultrasound showed hyperechogenic signals and missing flow detection at the catheter tip. Computed tomography showed air bubbles in the thrombosed catheter tip and confirmed the diagnosis. Vasuclar surgery was done and an infected, 17-cm-long infected thrombus was removed. (orig./VHE) [Deutsch] Die Autoren berichten ueber den Fall eines 16jaehrigen Patienten, dem wegen einer Meningitis und der Zeichen eines Waterhouse-Friderichsen-Syndroms ein femoralvenoeser Zentralkatheter gelegt wurde. Nach initialer Entfieberung entwickelte sich eine Sepsis, deren Ursache in einem infizierten Thrombus des Zentralvenenkatheters lag. Die Diagnose wurde sonographisch gestellt und nachfolgend computertomographisch bestaetigt. In beiden Verfahren wiesen Lufteinschluesse im Katheterthrombus auf die Injektion hin. Der Befund wurde durch eine gefaesschirurgische Thrombektomie bestaetigt und therapiert. (orig./VHE)

  8. The adaptive computer-aided diagnosis system based on tumor sizes for the classification of breast tumors detected at screening ultrasound.

    Science.gov (United States)

    Moon, Woo Kyung; Chen, I-Ling; Chang, Jung Min; Shin, Sung Ui; Lo, Chung-Ming; Chang, Ruey-Feng

    2017-04-01

    Screening ultrasound (US) is increasingly used as a supplement to mammography in women with dense breasts, and more than 80% of cancers detected by US alone are 1cm or smaller. An adaptive computer-aided diagnosis (CAD) system based on tumor size was proposed to classify breast tumors detected at screening US images using quantitative morphological and textural features. In the present study, a database containing 156 tumors (78 benign and 78 malignant) was separated into two subsets of different tumor sizes (<1cm and ⩾1cm) to explore the improvement in the performance of the CAD system. After adaptation, the accuracies, sensitivities, specificities and Az values of the CAD for the entire database increased from 73.1% (114/156), 73.1% (57/78), 73.1% (57/78), and 0.790 to 81.4% (127/156), 83.3% (65/78), 79.5% (62/78), and 0.852, respectively. In the data subset of tumors larger than 1cm, the performance improved from 66.2% (51/77), 68.3% (28/41), 63.9% (23/36), and 0.703 to 81.8% (63/77), 85.4% (35/41), 77.8% (28/36), and 0.855, respectively. The proposed CAD system can be helpful to classify breast tumors detected at screening US. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Comparison of contrast-enhanced ultrasound and contrast-enhanced computed tomography in evaluating the treatment response to transcatheter arterial chemoembolization of hepatocellular carcinoma using modified RECIST

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Ming; Lin, Man-xia; Xu, Zuo-feng; Wang, Wei; Xie, Xiao-yan [Sun Yat-Sen University, Department of Medical Ultrasonics, Guangzhou (China); Sun Yat-Sen University, The First Affiliated Hospital, Institute of Diagnostic and Interventional Ultrasound, Guangzhou (China); Lu, Ming-de; Kuang, Ming [Sun Yat-Sen University, Department of Hepatobiliary Surgery, Guangzhou (China); Sun Yat-Sen University, The First Affiliated Hospital, Institute of Diagnostic and Interventional Ultrasound, Guangzhou (China); Zheng, Ke-guo [Sun Yat-Sen University, Department of Radiology, Guangzhou (China); Zhuang, Wen-quan [Sun Yat-Sen University, Department of Interventional Radiology, Guangzhou (China)

    2015-08-15

    We aimed to compare contrast-enhanced ultrasound (CEUS) with contrast-enhanced computed tomography (CECT) for evaluating the treatment response to transcatheter arterial chemoembolization (TACE) of hepatocellular carcinoma (HCC). Treatment responses of 130 patients who underwent TACE were evaluated by CEUS and CECT. We initially compared the abilities of CEUS and CECT to detect residual tumour, which were confirmed by histology or angiography. Then, we compared the tumour response to TACE assessed by CEUS and CECT, according to Modified Response Evaluation Criteria in Solid Tumours (mRECIST). The sensitivity and accuracy of detecting residual tumour by CEUS vs. CECT were 95.9 % vs. 76.2 % (p < 0.001) and 96.2 % vs. 77.7 % (p < 0.001), respectively. For target lesions, 13 patients were observed as complete response (CR) by CEUS, compared to 36 by CECT (p < 0.001). For nontarget lesions, 12 patients were observed as CR by CEUS, compared to 22 by CECT (p = 0.006). For overall response, eight patients were observed as CR by CEUS, compared to 31 by CECT (p < 0.001). The diagnostic performance of CEUS was superior to CECT for detecting residual tumour after TACE. In clinical, CEUS should be recommended as an optional procedure for assessing the tumour response to TACE. (orig.)

  10. The value of preoperative computed tomography combined with ultrasound in the investigation of small indeterminate liver lesions in patients with colorectal cancer.

    Science.gov (United States)

    Abraham-Nordling, Mirna; Öistämö, Emma; Josephson, Thomas; Hjern, Fredrik; Blomqvist, Lennart

    2017-11-01

    Background Computed tomography (CT) is used routinely for the preoperative detection of colorectal cancer (CRC) metastases. When small indeterminate focal liver lesions are detected that are too small to characterize (TSTC) on CT, additional imaging is usually needed, resulting in a potential delay in obtaining a complete diagnostic work-up. Purpose To determine the diagnostic accuracy of ultrasound (US) of the liver performed in direct conjunction to CT in the preoperative investigation among patients with newly diagnosed CRC when indeterminate liver lesions were found on CT. Material and Methods Preoperative investigations with CT and consecutive US where CT had shown at least one focal liver lesion in 74 patients diagnosed with CRC between June 2009 and February 2012 were retrospectively reviewed. Either histopathological findings or a combination of imaging and clinical follow-up one to three years after surgery was used as the reference. Results Liver metastases were diagnosed with CT/US in 13 out of 74 patients (17.6%). In one patient, a liver cyst was preoperatively regarded as liver metastasis by a combined CT/US. The sensitivity and specificity for the CT with consecutive US procedure was 100% (13/13) and 98.4% (60/61). Conclusion US performed in conjunction with CT in patients with indeterminate focal liver lesions on CT is an accurate work-up for detection of liver metastases in patients with newly diagnosed CRC. Although our results are promising, they cannot be considered safely generalizable to all hospitals.

  11. Acute myocardial infarction due to spontaneous, localized, acute dissection of the sinus of Valsalva detected by intravascular ultrasound and electrocardiogram-gated computed tomography.

    Science.gov (United States)

    Ichihashi, Taku; Ito, Tsuyoshi; Murai, Shunsuke; Ikehara, Noriyuki; Fujita, Hiroshi; Suda, Hisao; Ohte, Nobuyuki

    2016-09-01

    A 58-year-old man was referred to our hospital because of chest pain. The 12-lead electrocardiogram (ECG) revealed ST-segment elevation in II, III, and a Vf with advanced heart block. Transthoracic echocardiography demonstrated aortic root dilatation at the sinus of Valsalva, moderate aortic regurgitation, and decreased wall motion in the inferior part of the left ventricle. Non-ECG-gated enhanced computed tomography (CT) did not reveal an aortic dissection. The patient underwent emergent coronary angiography, which revealed a severely narrowed ostium of the right coronary artery (RCA). Percutaneous coronary intervention (PCI) was performed under intravascular ultrasound (IVUS) guidance. IVUS images demonstrated an intimal flap extending from the aortic wall to the proximal RCA, suggesting that a periaortic hematoma in the false lumen compressed the ostium of the RCA, leading to acute myocardial infarction. To recover hemodynamic stability, the RCA ostium was stented. Subsequent ECG-gated enhanced CT clearly depicted the entry point and extension of the dissection localized within the sinus of Valsalva. The dissection likely involved the left main coronary artery and an emergent Bentall procedure was performed. Intraoperative findings confirmed an intimal tear and extension of the dissection. Thus, ECG-gated CT can clearly depict the entry site and extension of a dissection occurring in the localized area that cannot be detected by conventional CT.

  12. SENSITIVITY OF ENDOSCOPIC ULTRASOUND, MULTIDETECTOR COMPUTER TOMOGRAPHY AND MAGNETIC RESONANCE CHOLANGIOPANCREATOGRAPHY IN THE DIAGNOSIS OF PANCREAS DIVISUM: A TERTIARY CENTER EXPERIENCE

    Science.gov (United States)

    Kushnir, Vladimir M.; Wani, Sachin B.; Fowler, Kathryn; Menias, Christine; Varma, Rakesh; Narra, Vamsi; Hovis, Christine; Murad, Faris; Mullady, Daniel; Jonnalagadda, Sreenivasa S.; Early, Dayna S.; Edmundowicz, Steven A.; Azar, Riad R.

    2014-01-01

    OBJECTIVES There are limited data comparing imaging modalities in the diagnosis of pancreas divisum. We aimed to: 1. Evaluate the sensitivity of endoscopic ultrasound (EUS), magnetic resonance cholangiopancreatography (MRCP) and multi-detector computed tomography (MDCT) for pancreas divisum. 2. Assess interobserver agreement (IOA) among expert radiologists for detecting pancreas divisum on MDCT and MRCP. METHODS For this retrospective cohort study, we identified 45 consecutive patients with pancreaticobiliary symptoms and pancreas divisum established by endoscopic retrograde pancreatography (ERP) who underwent EUS and cross-sectional imaging. The control group was composed of patients without pancreas divisum who underwent ERP and cross-sectional imaging. RESULTS The sensitivity of EUS for pancreas divisum was 86.7%, significantly higher than sensitivity reported in the medical records for MDCT (15.5%) or MRCP (60%) [ppancreas divisum; IOA was moderate (қ=0.43). CONCLUSIONS EUS is a sensitive test for diagnosing pancreas divisum and is superior to MDCT and MRCP. Review of MDCT studies by expert radiologists substantially raises its sensitivity for pancreas divisum. PMID:23211370

  13. Ultrasound -- Pelvis

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    Full Text Available ... various body organs such as the liver or kidneys. top of page What are some common uses ... women, a pelvic ultrasound exam can help identify: kidney stones bladder tumors other disorders of the urinary ...

  14. 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 ...

  15. Ultrasound -- Pelvis

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    Full Text Available ... a more in-depth investigation of the uterine cavity . Three-dimensional (3-D) ultrasound permits evaluation of ... that the human ear cannot hear) into the body and then listens for the returning echoes from ...

  16. Ultrasound -- Pelvis

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    Full Text Available ... used when performing a Pap test . A protective cover is placed over the transducer, lubricated with a ... exam. Transrectal: For a transrectal ultrasound, a protective cover is placed over the transducer . It is lubricated ...

  17. 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 ... by Please note RadiologyInfo.org is not a medical facility. Please contact your physician with specific medical ...

  18. Ultrasound -- Pelvis

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    Full Text Available ... tip of the transducer is smaller than the standard speculum used when performing a Pap test . A ... both sexes without x-ray exposure. Risks For standard diagnostic ultrasound , there are no known harmful effects ...

  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. 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 ...

  1. Prostate Ultrasound

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    Full Text Available ... rectum. top of page What are some common uses of the procedure? A transrectal ultrasound of the ... the scanner by a cord. Some exams may use different transducers (with different capabilities) during a single ...

  2. Prostate Ultrasound

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    Full Text Available ... less than 20 minutes. top of page What will I experience during and after the procedure? Ultrasound ... in the region of the prostate. A biopsy will add time to the procedure. Rarely, a small ...

  3. Ultrasound -- Pelvis

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    Full Text Available ... ultrasound images are reviewed. top of page What will I experience during and after the procedure? For ... in the region of the prostate. A biopsy will add time to the procedure. If a Doppler ...

  4. 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 ... will share the results with you. In some cases, the radiologist may discuss results with you at ...

  5. Prostate Ultrasound

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    Full Text Available ... with measurements acquired as needed for any treatment planning. detect an abnormal growth within the prostate. help ... ultrasound , there are no known harmful effects on humans. top of ... Radiation Therapy for Prostate Cancer top ...

  6. Ultrasound -- Pelvis

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    Full Text Available ... the uterus). Sonohysterography allows for a more in-depth investigation of the uterine cavity . Three-dimensional (3- ... fluid). In medicine, ultrasound is used to detect changes in appearance, size or contour of organs, tissues, ...

  7. Prostate Ultrasound

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    Full Text Available ... later laboratory testing. top of page How should I prepare? You should wear comfortable, loose-fitting clothing ... than 20 minutes. top of page What will I experience during and after the procedure? Ultrasound exams ...

  8. Ultrasound -- Pelvis

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    Full Text Available ... needle biopsies , in which needles are used to extract a sample of cells from organs for laboratory ... Any portions that are not wiped off will dry quickly. The ultrasound gel does not usually stain ...

  9. 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 ...

  10. 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 ...

  11. Ultrasound -- Pelvis

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    Full Text Available ... fluid). In medicine, ultrasound is used to detect changes in appearance, size or contour of organs, tissues, ... the sensitive receiver in the transducer records tiny changes in the sound's pitch and direction. These signature ...

  12. Prostate Ultrasound

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    Full Text Available ... fluid). In medicine, ultrasound is used to detect changes in appearance, size or contour of organs, tissues, ... the sensitive receiver in the transducer records tiny changes in the sound's pitch and direction. These signature ...

  13. Prostate Ultrasound

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    Full Text Available ... safe, noninvasive, and does not use ionizing radiation. This procedure requires little to no special preparation. Leave ... examination, an ultrasound-guided biopsy can be performed. This procedure involves advancing a needle into the prostate ...

  14. Ultrasound -- Pelvis

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    Full Text Available ... abdomen, arms, legs, neck and/or brain (in infants and children) or within various body organs such ... and monitoring of pregnant women and their unborn babies. Ultrasound provides real-time imaging, making it a ...

  15. 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 ...

  16. 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), ...

  17. 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), ...

  18. Ultrasound -- Pelvis

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    Full Text Available ... direction and speed of blood cells as they move through vessels. The movement of blood cells causes ... ultrasound exams, you will be positioned lying face-up on an examination table that can be tilted ...

  19. 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) (Enlargement of the Prostate) Prostate Cancer Ultrasound- ...

  20. Ultrasound -- Pelvis

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    Full Text Available ... The principles are similar to sonar used by boats and submarines. The ultrasound image is immediately visible ... principles involved in the sonar used by bats, ships and fishermen. When a sound wave strikes an ...

  1. Prostate Ultrasound

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    Full Text Available ... The principles are similar to sonar used by boats and submarines. The ultrasound image is immediately visible ... principles involved in the sonar used by bats, ships and fishermen. When a sound wave strikes an ...

  2. Ultrasound -- Pelvis

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    Full Text Available ... These exams are frequently used to evaluate the reproductive and urinary systems. Ultrasound is safe, noninvasive and ... identify and evaluate a variety of urinary and reproductive system disorders in both sexes without x-ray ...

  3. 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. ...

  4. Prostate Ultrasound

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    Full Text Available ... abnormal area in the prostate gland for later laboratory testing. top of page How should I prepare? ... object is solid or filled with fluid). In medicine, ultrasound is used to detect changes in appearance, ...

  5. Ultrasound -- Pelvis

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    Full Text Available ... is sometimes seen in infections top of page How should I prepare? You should wear comfortable, loose- ... sheath and lubricated before insertion. top of page How does the procedure work? Ultrasound imaging is based ...

  6. Prostate Ultrasound

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    Full Text Available ... gland for later laboratory testing. top of page How should I prepare? You should wear comfortable, loose- ... and lubricated with a gel. top of page How does the procedure work? Ultrasound imaging is based ...

  7. 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 ...

  8. Ultrasound -- Pelvis

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    Full Text Available ... safe and painless, and produces pictures of the inside of the body using sound waves. Ultrasound imaging, ... capabilities) during a single exam. The transducer sends out high-frequency sound waves (that the human ear ...

  9. Ultrasound -- Pelvis

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    Full Text Available ... sonography , involves the 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 ...

  10. Prostate Ultrasound

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    Full Text Available ... sonography , involves the 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 ...

  11. 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 ...

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  13. 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 ...

  14. 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 ...

  15. Ultrasound -- Pelvis

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    Full Text Available ... images may also be saved. The same principles apply to ultrasound procedures such as transrectal and transvaginal ... supervise and interpret radiology examinations) or sonographer will apply a warm water-based gel to the area ...

  16. Ultrasound -- Pelvis

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    Full Text Available ... the amplitude (loudness), frequency (pitch) and time it takes for the ultrasound signal to return from the ... and/or your insurance provider to get a better understanding of the possible charges you will incur. ...

  17. 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 ...

  18. 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 ...

  19. 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 ... seen in infections top of page How should I prepare? You should wear comfortable, loose-fitting clothing ...

  20. Ultrasound -- Pelvis

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    Full Text Available ... ultrasound exams, you will be positioned lying face-up on an examination table that can be tilted ... you at the conclusion of your examination. Follow-up examinations may be necessary. Your doctor will explain ...

  1. Ultrasound -- Pelvis

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    Full Text Available ... abdomen, arms, legs, neck and/or brain (in infants and children) or within various body organs such as the liver or ... tubes bladder Pelvic ultrasound exams are also used to ...

  2. Prostate Ultrasound

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    Full Text Available ... examination is complete, you may be asked to dress and wait while the ultrasound images are reviewed. ... the following text box: Comment: E-mail: Area code: Phone no: Thank you! Do you have a ...

  3. Ultrasound -- Pelvis

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    Full Text Available ... examination is complete, you may be asked to dress and wait while the ultrasound images are reviewed. ... the following text box: Comment: E-mail: Area code: Phone no: Thank you! Do you have a ...

  4. Ultrasound -- Pelvis

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

  5. 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 ... as detailed as with the transrectal probe. An MRI of the pelvis may be obtained as an ...

  6. 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 ... In most cases, barium exams, CT scanning , and MRI are the methods of choice in such a ...

  7. Prostate Ultrasound

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    Full Text Available ... to investigate a nodule found during a rectal exam, detect abnormalities, and determine whether the gland is ... a man's prostate gland and surrounding tissue. The exam typically requires insertion of an ultrasound probe into ...

  8. Prostate Ultrasound

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    Full Text Available ... of the prostate uses sound waves to produce pictures of a man’s prostate gland and to help ... Prostate? Ultrasound is safe and painless, and produces pictures of the inside of the body using sound ...

  9. Ultrasound -- Pelvis

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    Full Text Available ... of the pelvis uses sound waves to produce pictures of the structures and organs in the lower ... Imaging? Ultrasound is safe and painless, and produces pictures of the inside of the body using sound ...

  10. Ultrasound -- Pelvis

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    Full Text Available ... or within various body organs such as the liver or kidneys. top of page What are some ... object is solid or filled with fluid). In medicine, ultrasound is used to detect changes in appearance, ...

  11. 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 - ...

  12. 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 ...

  13. 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 ...

  14. Prostate Ultrasound

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    Full Text Available ... the prostate gland which is situated right in front of the rectum. top of page What are ... men, the prostate gland is located directly in front of the rectum, so the ultrasound exam is ...

  15. Prostate Ultrasound

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    Full Text Available ... biopsy is planned, you may be told to avoid aspirin and other blood thinners for seven to ... abnormal growth within the prostate. help diagnose the cause of a man's infertility. A transrectal ultrasound of ...

  16. Prostate Ultrasound

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    Full Text Available ... Ultrasound Imaging? Men who have had the tail end of their bowel (rectum) removed during prior surgery ... or suggestion into the following text box: Comment: E-mail: Area code: Phone no: Thank you! Please ...

  17. 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 ...

  18. Prostate Ultrasound

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    Full Text Available ... elevated blood test result. It’s also used to investigate a nodule found during a rectal exam, detect ... as needle biopsies and fluid aspiration. Risks For standard diagnostic ultrasound , there are no known harmful effects ...

  19. Prostate Ultrasound

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    Full Text Available ... BPH) , with measurements acquired as needed for any treatment planning. detect an abnormal growth within the prostate. help diagnose the cause of a man's infertility. A transrectal ultrasound of the prostate gland is ...

  20. 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 ... the exam. Bringing books, small toys, music or games can help to distract the child and make ...

  1. 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: ... Images related to Ultrasound - Prostate Sponsored by Please ...

  2. 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 ...

  3. 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 ...

  4. Ultrasound -- Pelvis

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    Full Text Available ... arteries and veins in the abdomen, arms, legs, neck and/or brain (in infants and children) or ... diagnose symptoms experienced by women such as: pelvic pain abnormal vaginal bleeding other menstrual problems Ultrasound exams ...

  5. Prostate Ultrasound

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    Full Text Available ... records tiny changes in the sound's pitch and direction. These signature waves are instantly measured and displayed ... may be present in the sperm or urine following the procedure. After an ultrasound examination, you should ...

  6. 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 ...

  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 ... a special study usually done to provide detailed evaluation of the prostate gland, involves inserting a specialized ...

  8. 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. ...

  9. Ultrasound -- Pelvis

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    Full Text Available ... of the body's internal organs, as well as blood flowing through blood vessels. Ultrasound imaging is a noninvasive medical test ... that allows the physician to see and evaluate blood flow through arteries and veins in the abdomen, ...

  10. Prostate Ultrasound

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    Full Text Available ... obtain high-quality images, an ultrasound transducer – a plastic cylinder about the size of a finger – is ... side with your knees bent. A disposable protective cover is placed over the transducer, it is lubricated, ...

  11. Prostate Ultrasound

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    Full Text Available ... echoes from the tissues in the body. The principles are similar to sonar used by boats and ... work? Ultrasound imaging is based on the same principles involved in the sonar used by bats, ships ...

  12. Ultrasound -- Pelvis

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    Full Text Available ... echoes from the tissues in the body. The principles are similar to sonar used by boats and ... work? Ultrasound imaging is based on the same principles involved in the sonar used by bats, ships ...

  13. 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 ...

  14. 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 ...

  15. 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 ...

  16. 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 ...

  17. 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 ... time to the procedure. If a Doppler ultrasound study is performed, you may actually hear pulse-like ...

  18. Ultrasound -- Pelvis

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    Full Text Available ... water prior to the examination to fill your bladder. Leave jewelry at home and wear loose, comfortable ... to evaluate the: uterus cervix ovaries fallopian tubes bladder Pelvic ultrasound exams are also used to monitor ...

  19. 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 ... creates a real-time picture on the monitor. One or more frames of the moving pictures are ...

  20. 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 ... creates a real-time picture on the monitor. One or more frames of the moving pictures are ...

  1. 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 ... ovarian cysts and uterine fibroids ovarian or uterine cancers A transvaginal ultrasound is usually performed to view ...

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  3. 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 ...

  4. 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 ...

  5. 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 ... of page How is the procedure performed? In men, the prostate gland is located directly in front ...

  6. Prostate Ultrasound

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

  7. Ultrasound -- Pelvis

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

  8. 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 ...

  9. Morphologic and functional assessment of hemodialysis arteriovenous fistula with duplex doppler sonography

    Energy Technology Data Exchange (ETDEWEB)

    Cho, On Koo; Kim, Yong Soo; Rhim, Hyun Chul; Koh, Byung Hee; Kim, Bong Soo; Song, Soon Young; Park, Chan Hyun [Hanyang University College of Medicine, Seoul (Korea, Republic of)

    2001-03-15

    The pattern of morphologic and functional status of the hemodialysis AV fistula was studied using doppler ultrasound to define the useful parameter and its normal range for detecting the initial dysfunctional. Sixty patients of chronic renal failure with radial artery-cephalic vein fistula for hemodialysis (50 clinically normal and 10 clinically abnormal functioning AV fistula) were studied by duplex ultrasound. The examination followed the feeding artery to the draining vein and observed the morphology and waveform of the vessels. Peak systolic velocity (PSV), End diastolic velocity (EDV) and Systolic/Diastolic ratio (S/D ratio) were measured in the feeding artery. In the draining vein, peak velocity was measured and the presence of arterial pulsation was observed. Normal range of these measuring parameters and its significance and reliability for detecting dysfunction AV fistula were studied. In normally functioning fistula, waveforms of flow in the feeding artery were monophasic, with PSV 0.5-3.48 m/sec (average 1.75 {+-} 0.79 m/sec), EDV 0.2-1.47 m/sec (average 0.82 {+-} 0.41 m/sec) and S/D ratio 1.44-3.48 (average 2.34 {+-} 0.56). The draining vein showed components of arterial pulsations with peak velocity of 0.21-1.20 m/sec (average 0.54 {+-} 0.23 m/sec). Of the 10 clinically dysfunctional AV fistula, two cases had arteriosclerous vessel wall calcification and showed normal function on doppler sonography. Two cases of focal stenotic lesion of the draining vein showed significantly increased PSV which were more than 4.0 m/sec. Six cases of venous thrombosis showed a high resistance pattern of reversed diastolic flow with a measured S/D ratio of more than 4.0 and the absence of flow was noted within the draining S/D ratio was statically very reliable parameter (P=0.003) for defining normal and abnormal functioning AV fistula, however PSV and EDVV were unreliable (P=0.459). Duplex ultrasound is a useful diagnostic method for interpretating function of the

  10. An evaluation of the clinical diagnostic value of contrast-enhanced ultrasound combined with contrast-enhanced computed tomography in space-occupying lesions of the kidney

    Directory of Open Access Journals (Sweden)

    Tian W

    2017-07-01

    Full Text Available Wen Tian,1 Jianbo Lu,2 Dan Jiao,3 Zhibin Cong2 1Department of Blood Transfusion, The Second Hospital of Jilin University, 2Department of Ultrasound, Affiliated Hospital of Changchun University of Traditional Chinese Medicine, 3Department of Ultrasound, China-Japan Union Hospital of Jilin University, Changchun, Jilin, People’s Republic of China Background: There are a variety of space-occupying lesions of the kidney, and the benign lesions may be difficult to differentiate from the malignant ones. Therefore, an accurate judgment of the benign and malignant nature of the space-occupying lesions of the kidney is of high importance for the treatment and prognosis of these patients.Objective: To evaluate the diagnostic value of contrast-enhanced ultrasound (CEUS combined with contrast-enhanced computed tomography (CECT in space-occupying lesions of the kidney.Data and methods: Three hundred and sixty-seven patients with space-occupying lesions of the kidney (378 lesions were examined by CEUS and CECT, respectively, then, a combined diagnosis was made after the combination of CEUS and CECT by a multidisciplinary team. The diagnoses from the three methods were compared. The pathological results were taken as the gold standard. The sensitivity, specificity, positive and negative predictive values and area under the receiver operating characteristic (ROC curve were calculated for the three methods. Thus, the diagnostic value of the three methods was assessed.Results: Of the 378 lesions examined, there were 301 malignant lesions and 77 benign lesions. The combined examination revealed 303 malignant lesions, with 9 benign lesions mistakenly diagnosed as malignant ones; thus, the misdiagnosis rate was 11.7%. By using the combined examination, 75 benign lesions were diagnosed, with the missed diagnosis of 7 malignant lesions, so the missed diagnosis rate was 2.3%. The sensitivity, specificity, positive and negative predictive values and area under the ROC

  11. General Ultrasound Imaging

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    Full Text Available ... data into 3-D images. A Doppler ultrasound study may be part of an ultrasound examination. Doppler ultrasound , also called color Doppler ultrasonography, is a special ultrasound technique that ...

  12. 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, ... top of page What are some common uses of the procedure? Ultrasound examinations can help to diagnose ...

  13. 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 ...

  14. 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 , ...

  15. General Ultrasound Imaging

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    Full Text Available ... What are the limitations of General Ultrasound Imaging? What is General Ultrasound Imaging? Ultrasound is safe and ... be heard with every heartbeat. top of page What are some common uses of the procedure? Ultrasound ...

  16. Quantifying the Temperature Dependence of Glycine Betaine RNA Duplex Destabilization

    Science.gov (United States)

    Schwinefus, Jeffrey J.; Menssen, Ryan J.; Kohler, James M.; Schmidt, Elliot C.; Thomas, Alexandra L.

    2013-01-01

    Glycine betaine stabilizes folded protein structure due to its unfavorable thermodynamic interactions with amide oxygen and aliphatic carbon surface area exposed during protein unfolding. However, glycine betaine can attenuate nucleic acid secondary structure stability, although its mechanism of destabilization is not currently understood. In this work we quantify glycine betaine interactions with the surface area exposed during thermal denaturation of nine RNA dodecamer duplexes with guanine-cytosine (GC) contents of 17–100%. Hyperchromicity values indicate increasing glycine betaine molality attenuates stacking. Glycine betaine destabilizes higher GC content RNA duplexes to a greater extent than low GC content duplexes due to greater accumulation at the surface area exposed during unfolding. The accumulation is very sensitive to temperature and displays characteristic entropy-enthalpy compensation. Since the entropic contribution to the m-value (used to quantify GB interaction with the RNA solvent accessible surface area exposed during denaturation) is more dependent on temperature than the enthalpic contribution, higher GC content duplexes with their larger transition temperatures are destabilized to a greater extent than low GC content duplexes. The concentration of glycine betaine at the RNA surface area exposed during unfolding relative to bulk was quantified using the solute partitioning model. Temperature correction predicts a glycine betaine concentration at 25 °C to be nearly independent of GC content, indicating that glycine betaine destabilizes all sequences equally at this temperature. PMID:24219229

  17. Feasibility of Ultrasound-Based Computational Fluid Dynamics as a Mitral Valve Regurgitation Quantification Technique: Comparison with 2-D and 3-D Proximal Isovelocity Surface Area-Based Methods.

    Science.gov (United States)

    Jamil, Muhammad; Ahmad, Omar; Poh, Kian Keong; Yap, Choon Hwai

    2017-07-01

    Current Doppler echocardiography quantification of mitral regurgitation (MR) severity has shortcomings. Proximal isovelocity surface area (PISA)-based methods, for example, are unable to account for the fact that ultrasound Doppler can measure only one velocity component: toward or away from the transducer. In the present study, we used ultrasound-based computational fluid dynamics (Ub-CFD) to quantify mitral regurgitation and study its advantages and disadvantages compared with 2-D and 3-D PISA methods. For Ub-CFD, patient-specific mitral valve geometry and velocity data were obtained from clinical ultrasound followed by 3-D CFD simulations at an assumed flow rate. We then obtained the average ratio of the ultrasound Doppler velocities to CFD velocities in the flow convergence region, and scaled CFD flow rate with this ratio as the final measured flow rate. We evaluated Ub-CFD, 2-D PISA and 3-D PISA with an in vitro flow loop, which featured regurgitation flow through (i) a simplified flat plate with round orifice and (ii) a 3-D printed realistic mitral valve and regurgitation orifice. The Ub-CFD and 3-D PISA methods had higher precision than the 2-D PISA method. Ub-CFD had consistent accuracy under all conditions tested, whereas 2-D PISA had the lowest overall accuracy. In vitro investigations indicated that the accuracy of 2-D and 3-D PISA depended significantly on the choice of aliasing velocity. Evaluation of these techniques was also performed for two clinical cases, and the dependency of PISA on aliasing velocity was similarly observed. Ub-CFD was robustly accurate and precise and has promise for future translation to clinical practice. Copyright © 2017 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  18. Herpes Zoster Duplex Bilateralis in a Patient with Breast Cancer

    Science.gov (United States)

    Yoo, Kwang Ho; Park, Ju Hee; Kim, Myeung Nam; Song, Kye Yong

    2009-01-01

    The skin lesion of herpes zoster is classically limited to a single dermatome, and most cases of multi-dermatomal herpes zoster have contiguous skin lesions. Noncontigous multi-dermatomal herpes zoster is very rare in both immunocompetent and immunosuppressed persons. The phenomenon of zoster occurring in two non-contiguous dermatomes has been referred to as zoster duplex unilateralis or bilateralis. We report here on a case of herpes zoster duplex bilateralis in a 49-year-old woman who had previously received chemotherapy for breast cancer treatment. PMID:19688072

  19. 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.

  20. 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.

  1. Integration of intracardiac echocardiography and computed tomography during atrial fibrillation ablation: Combining ultrasound contours obtained from the right atrium and ventricular outflow tract.

    Science.gov (United States)

    Nakamura, Kohki; Naito, Shigeto; Kaseno, Kenichi; Nakatani, Yosuke; Sasaki, Takehito; Anjo, Naofumi; Yamashita, Eiji; Kumagai, Koji; Funabashi, Nobusada; Kobayashi, Yoshio; Oshima, Shigeru

    2017-02-01

    We aimed to optimize the acquisition of the left atrial (LA) and pulmonary vein (PV) ultrasound contours for more accurate integration of intracardiac echocardiography (ICE) and computed tomography (CT) using the CARTO® 3 system during atrial fibrillation (AF) ablation. Eighty-five AF patients underwent integration of ICE and CT using (1) the LA roof and posterior wall contours acquired from the right atrium (RA), (2) all LA/PV contours from the RA (Whole-RA-integration), (3) the LA roof/posterior wall contours from the RA and right ventricular outflow tract (RVOT) (Posterior-RA/RV-integration), and (4) all LA/PV contours from the RA and RVOT (Whole-RA/RV-integration). The integration accuracy was compared using the (1) surface registration error, (2) distances between the three-dimensional CT and eight specific sites on the anterior, posterior, superior, and inferior aspects of the right and left circumferential PV isolation lines, and (3) registration score: a score of 0 or 1 was assigned for whether or not each specific site was visually aligned with the CT, and summed for each method (0 best, 8 worst). Posterior-RA/RV-integration revealed a significantly lower surface registration error (1.30±0.15mm) than Whole-RA- and Whole-RA/RV-integration (pintegration (median 1.26mm and 2, respectively) were significantly smaller than those for the other integration approaches (pintegration with the LA roof and posterior wall contours acquired from the RA and RVOT may provide greater accuracy for catheter navigation with three-dimensional CT during AF ablation. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  2. Computer-aided diagnosis for estimating the malignancy grade of hepatocellular carcinoma using contrast-enhanced ultrasound: an ROC observer study.

    Science.gov (United States)

    Sugimoto, Katsutoshi; Shiraishi, Junji; Tanaka, Hironori; Tsuchiya, Kaoru; Aso, Kazunobu; Kobayashi, Yoshiyuki; Iijima, Hiroko; Moriyasu, Fuminori

    2016-07-01

    We are developing a computer-aided diagnosis (CAD) system for estimating the malignancy grade of hepatocellular carcinoma (HCC) using contrast-enhanced ultrasound (CEUS). In this study, observers estimated the malignancy grade of HCC with and without the cues provided by CAD. Institutional review board approval was obtained and informed consent was waived. A total of 232 histologically confirmed HCCs were studied: 76 well-differentiated HCC (w-HCC), 133 moderately differentiated HCC (m-HCC), and 23 poorly differentiated HCC (p-HCC). In this observer study, CEUS vascular images acquired using the maximum intensity projection technique were displayed together with static B-mode and Kupffer-phase (defined as 10 min after injection) images. Five hepatologists independently assigned confidence ratings for the malignancy grade of each HCC. Each hepatologist first read each case without CAD and then immediately afterwards with CAD. The observers' rating data were evaluated by multireader multicase receiver operating characteristic (ROC) analysis. The overall sensitivity of our CAD system for discrimination between three histological differentiation grades of HCC was 87.5% (203/232). For discrimination between w-HCC and m/p-HCC, the mean area under the ROC curve (AUC) for the five observers was significantly improved from 0.779 ± 0.074 to 0.872 ± 0.090 with CAD (P = 0.0069). For discrimination between m-HCC and p-HCC, the mean AUC was also significantly improved from 0.713 ± 0.107 to 0.863 ± 0.101 with CAD (P = 0.0321). The use of our CAD system can significantly improve the diagnostic performance of hepatologists in discriminating between three histological differentiation grades of HCC using CEUS. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  3. Clinical evaluation of spatial accuracy of a fusion imaging technique combining previously acquired computed tomography and real-time ultrasound for imaging of liver metastases.

    Science.gov (United States)

    Hakime, Antoine; Deschamps, Frederic; De Carvalho, Enio Garcia Marques; Teriitehau, Christophe; Auperin, Anne; De Baere, Thierry

    2011-04-01

    This study was designed to evaluate the spatial accuracy of matching volumetric computed tomography (CT) data of hepatic metastases with real-time ultrasound (US) using a fusion imaging system (VNav) according to different clinical settings. Twenty-four patients with one hepatic tumor identified on enhanced CT and US were prospectively enrolled. A set of three landmarks markers was chosen on CT and US for image registration. US and CT images were then superimposed using the fusion imaging display mode. The difference in spatial location between the tumor visible on the CT and the US on the overlay images (reviewer #1, comment #2) was measured in the lateral, anterior-posterior, and vertical axis. The maximum difference (Dmax) was evaluated for different predictive factors. CT performed 1-30 days before registration versus immediately before. Use of general anesthesia for CT and US versus no anesthesia. Anatomic landmarks versus landmarks that include at least one nonanatomic structure, such as a cyst or a calcification Overall, Dmax was 11.53 ± 8.38 mm. Dmax was 6.55 ± 7.31 mm with CT performed immediately before VNav versus 17.4 ± 5.18 with CT performed 1-30 days before (p < 0.0001). Dmax was 7.05 ± 6.95 under general anesthesia and 16.81 ± 6.77 without anesthesia (p < 0.0015). Landmarks including at least one nonanatomic structure increase Dmax of 5.2 mm (p < 0.0001). The lowest Dmax (1.9 ± 1.4 mm) was obtained when CT and VNav were performed under general anesthesia, one immediately after the other. VNav is accurate when adequate clinical setup is carefully selected. Only under these conditions (reviewer #2), liver tumors not identified on US can be accurately targeted for biopsy or radiofrequency ablation using fusion imaging.

  4. 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...

  5. Focused Ultrasound and Lithotripsy.

    Science.gov (United States)

    Ikeda, Teiichiro; Yoshizawa, Shin; Koizumi, Norihiro; Mitsuishi, Mamoru; Matsumoto, Yoichiro

    2016-01-01

    Shock wave lithotripsy has generally been a first choice for kidney stone removal. The shock wave lithotripter uses an order of microsecond pulse durations and up to a 100 MPa pressure spike triggered at approximately 0.5-2 Hz to fragment kidney stones through mechanical mechanisms. One important mechanism is cavitation. We proposed an alternative type of lithotripsy method that maximizes cavitation activity to disintegrate kidney stones using high-intensity focused ultrasound (HIFU). Here we outline the method according to the previously published literature (Matsumoto et al., Dynamics of bubble cloud in focused ultrasound. Proceedings of the second international symposium on therapeutic ultrasound, pp 290-299, 2002; Ikeda et al., Ultrasound Med Biol 32:1383-1397, 2006; Yoshizawa et al., Med Biol Eng Comput 47:851-860, 2009; Koizumi et al., A control framework for the non-invasive ultrasound the ragnostic system. Proceedings of 2009 IEEE/RSJ International Conference on Intelligent Robotics and Systems (IROS), pp 4511-4516, 2009; Koizumi et al., IEEE Trans Robot 25:522-538, 2009). Cavitation activity is highly unpredictable; thus, a precise control system is needed. The proposed method comprises three steps of control in kidney stone treatment. The first step is control of localized high pressure fluctuation on the stone. The second step is monitoring of cavitation activity and giving feedback on the optimized ultrasound conditions. The third step is stone tracking and precise ultrasound focusing on the stone. For the high pressure control we designed a two-frequency wave (cavitation control (C-C) waveform); a high frequency ultrasound pulse (1-4 MHz) to create a cavitation cloud, and a low frequency trailing pulse (0.5 MHz) following the high frequency pulse to force the cloud into collapse. High speed photography showed cavitation collapse on a kidney stone and shock wave emission from the cloud. We also conducted in-vitro erosion tests of model and natural

  6. Ultrasound -- Pelvis

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    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. ...

  7. Prostate Ultrasound

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    Full Text Available ... cells (tissue) from an abnormal area in the prostate gland for later laboratory testing. top of page How should I prepare? You should wear comfortable, loose-fitting clothing for your ultrasound exam. You may need to remove all clothing and jewelry in the area to be ...

  8. Ultrasound -- Pelvis

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    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos ... can help identify: kidney stones bladder tumors other disorders of the urinary bladder In children, pelvic ultrasound ...

  9. Prostate Ultrasound

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    Full Text Available ... do not use ionizing radiation (as used in x-rays ), thus there is no radiation exposure to the ... tissues that do not show up well on x-ray images. Ultrasound causes no health problems and may ...

  10. Ultrasound -- Pelvis

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    Full Text Available ... do not use ionizing radiation (as used in x-rays ), thus there is no radiation exposure to the ... tissues that do not show up well on x-ray images. Ultrasound is the preferred imaging modality for ...

  11. 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 ... areas. Outside links: For the convenience of our users, RadiologyInfo .org provides links to relevant websites. RadiologyInfo. ...

  12. Prostate Ultrasound

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    Full Text Available ... little to no special preparation. Leave jewelry at home and wear loose, comfortable clothing. You may be asked to wear a gown and to lie on your side with your knees toward your chest. To obtain high-quality images, an ultrasound transducer – a plastic cylinder about ...

  13. Prostate Ultrasound

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    Full Text Available ... blood, may be administered to determine if a patient is at high risk for cancer. In this case, a biopsy is performed and ... patient story here Images × Image Gallery ... Hyperplasia (BPH) (Enlargement of the Prostate) Prostate Cancer Ultrasound- and MRI-Guided Prostate Biopsy Images related ...

  14. Hip Ultrasound

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    ... prior to the exam. Bringing books, small toys, music or games can help to distract the child and make the time pass quickly. The ultrasound exam room may have a television. Feel free to ask for your child's favorite channel. In the case of an infant, it ...

  15. Ultrasound -- Vascular

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    ... prior to the exam. Bringing books, small toys, music or games can help to distract the child and make the time pass quickly. The ultrasound exam room may have a television. Feel free to ask for your child's favorite channel. top of page What does the equipment ...

  16. 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 and make the time pass quickly. The ultrasound exam room may have a television. Feel free to ask for your child's favorite channel. top of page What does the equipment ...

  17. Ultrasound -- Pelvis

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

  18. Ultrasound -- Pelvis

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    Full Text Available ... noninvasive medical test that helps physicians diagnose and treat medical conditions. There are three types of pelvic ... or within various body organs such as the liver or kidneys. top of page What ... or uterine cancers A transvaginal ultrasound is usually performed to view ...

  19. Ultrasound -- Pelvis

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    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos ... internal organs, as well as blood flowing through blood vessels. Ultrasound imaging is a noninvasive medical test that ...

  20. Prostate Ultrasound

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    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos ... internal organs, as well as blood flowing through blood vessels. Ultrasound imaging is a noninvasive medical test that ...