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Sample records for doppler embolic signal

  1. Operator auditory perception and spectral quantification of umbilical artery Doppler ultrasound signals.

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    Ann Thuring

    Full Text Available OBJECTIVE: An experienced sonographer can by listening to the Doppler audio signals perceive various timbres that distinguish different types of umbilical artery flow despite an unchanged pulsatility index (PI. Our aim was to develop an objective measure of the Doppler audio signals recorded from fetoplacental circulation in a sheep model. METHODS: Various degrees of pathological flow velocity waveforms in the umbilical artery, similar to those in human complicated pregnancies, were induced by microsphere embolization of the placental bed (embolization model, 7 lamb fetuses, 370 Doppler recordings or by fetal hemodilution (anemia model, 4 lamb fetuses, 184 recordings. A subjective 11-step operator auditory scale (OAS was related to conventional Doppler parameters, PI and time average mean velocity (TAM, and to sound frequency analysis of Doppler signals (sound frequency with the maximum energy content [MAXpeak] and frequency band at maximum level minus 15 dB [MAXpeak-15 dB] over several heart cycles. RESULTS: WE FOUND A NEGATIVE CORRELATION BETWEEN THE OAS AND PI: median Rho -0.73 (range -0.35- -0.94 and -0.68 (range -0.57- -0.78 in the two lamb models, respectively. There was a positive correlation between OAS and TAM in both models: median Rho 0.80 (range 0.58-0.95 and 0.90 (range 0.78-0.95, respectively. A strong correlation was found between TAM and the results of sound spectrum analysis; in the embolization model the median r was 0.91 (range 0.88-0.97 for MAXpeak and 0.91 (range 0.82-0.98 for MAXpeak-15 dB. In the anemia model, the corresponding values were 0.92 (range 0.78-0.96 and 0.96 (range 0.89-0.98, respectively. CONCLUSION: Audio-spectrum analysis reflects the subjective perception of Doppler sound signals in the umbilical artery and has a strong correlation to TAM-velocity. This information might be of importance for clinical management of complicated pregnancies as an addition to conventional Doppler parameters.

  2. Clinical study of color Doppler sonography in Graves' disease blood flow changes after thyroid arteries embolization

    International Nuclear Information System (INIS)

    Zhuang Wenquan; Li Weiduo; Yang Jianyong; Chen Wei; Huang Yonghui; Guo Wenbo; Li Jiaping

    2003-01-01

    Objective: To study the color doppler image characteristics of thyroid arteries pre- and post-interventional procedure and to assess the clinical efficacy in Gnaves' disease. Methods: 11 from 31 patients diagnosed as Graves' disease undertaken thyroid arteries embolization, were analyzed. Color Doppler sonography was applied to monitor the pre-and post- procedure thyroid size and diameters of thyroid arteries. Power Doppler was used to detect the Vmax, Vmin, RI and blood flow. Results: After thyroid arteries embolization, the size and vascularity of thyroids were reduced. The thyroid arteries showed shrinkage and stoppage blood flow at the embolized site. The changes of RI, blood parameters of Vmax, Vmin and diameters of the thyroid arteries pre- and post-procedure turned out to be statistically significant for clinical restriction. Conclusion: The color Doppler sonography plays an important role for preoperative diagnosis and predicting the prognosis

  3. Intraparenchymal Doppler ultrasound after proximal embolization of the splenic artery in trauma patients

    International Nuclear Information System (INIS)

    Dormagen, Johann B.; Gaarder, Christine; Sandvik, Leiv; Naess, Paal A.; Kloew, Nils E.

    2008-01-01

    We studied the changes in proximal embolization of the splenic artery to the intraparenchymal blood flow with Doppler ultrasound. Seventeen trauma patients with spleen injury OIS grade 2-5 underwent embolization of the splenic artery. Peak-systolic velocity (PSV) and end-diastolic velocity (EDV) were measured in intrasplenic arteries initially 1 day after embolization, at early follow-up after 7 days, at intermediate follow-up after 10 weeks, and at late follow-up after 10 months. Resistance index (RI), systolic/diastolic ratio (S/D ratio), acceleration (AC), and acceleration time (AT) were calculated. The results were compared to values from 17 volunteers. RI increased from 0.39 initially to 0.49 (P = 0.002) at intermediate and to 0.52 (P 2 initially to 1.89 m/s 2 at late follow-up (P = 0.01). AC at late follow-up was not different from reference group (2.33 m/s 2 ). In conclusion, Doppler ultrasound is a useful tool in the evaluation of improvable intraparenchymal blood flow over time after central splenic artery embolization. (orig.)

  4. Transcranial Doppler monitoring during stenting of the carotid bifurcation: evaluation of two different distal protection devices in preventing embolization.

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    Rubartelli, Paolo; Brusa, Giulia; Arrigo, Alessandro; Abbadessa, Francesco; Giachero, Corinna; Vischi, Massimo; Ricca, Maria Maddalena; Ottonello, Gian Andrea

    2006-08-01

    To compare the efficacy of 2 emboli protection devices in preventing embolization during carotid artery stenting (CAS). The GuardWire distal occlusion system (n=19) and the distal FilterWire EX (n=12) were compared in 31 consecutive patients (24 men; mean age 71+/-10 years) monitored with transcranial Doppler for microembolic signals before, during, and after CAS. The choice of the protection device was based on availability and on the patency of the contralateral carotid artery. The baseline characteristics were similar in the patients treated under protection from either device. Placement and retrieval of the protection device, stenting, and postdilation were technically successful in all patients. Two patients suffered a transient ischemic attack shortly after the procedure; no other adverse cardiovascular events occurred at 30 days. Compared to the GuardWire, the use of the FilterWire was associated with more microembolic signals during stent deployment (77.4+/-33.5 versus 1.07+/-1.94, pprotection device (21.4+/-15.4 versus 10.9+/-8.3, p=0.051). Consequently, the total amount of microembolic signals during the procedure was higher when the filter device was employed (183.0+/-42.1 versus 31.7+/-12.0, p<0.0001). The distal occlusion device appears to be more effective than the filter in reducing distal embolization detected by transcranial Doppler monitoring.

  5. Color doppler flow imaging in evaluation of uterine arterial embolization of leiomyoma with KMG

    International Nuclear Information System (INIS)

    Li Furong; Guo Yunhuai; Liu Lifang; Liu Jianhua; Guo Yunhuai

    2006-01-01

    Objective: To explore the effectiveness of a new kind of embolization agent-sodium alginate(KMG), and to evaluate the clinical value of 2D color Doppler ultrasound in assessing the therapeutic effect of uterine arterial embolization (UAE) in leiomyomas. Methods: Forty nine patients with symptomatic leiomyomas were undertaken UAE with KMG for the treatment. Sonography was performed at 3-7 days before and, 1, 3, 6 months after UAE with 2D color Doppler for evaluating the 2D echograms and hemodynamics. Results: Forty nine leiomyomas were studied after UAE, showing a marked reduction in the size (35%-90%). No blood flow was demonstrated in the leiomyomas either 3-7 days or 1 month or 3 months after the procedure. The reappearance of blood flow could be seen in only one case. Conclusion: KMG is an efficient embolization agent for the treatment of symptomatic leiomyomas with UAE, and ultrasonography is a useful tool to assess the effectiveness. (authors)

  6. Intraparenchymal Doppler ultrasound after proximal embolization of the splenic artery in trauma patients

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    Dormagen, Johann B. [Ullevaal University Hospital, Department of Radiology, Oslo (Norway); Gaarder, Christine [Ullevaal University Hospital, Department of Gastrointestinal Surgery, Oslo (Norway); Sandvik, Leiv [Ullevaal University Hospital, Center for Clinical Research, Oslo (Norway); Naess, Paal A. [Ullevaal University Hospital, Department of Pediatric Surgery, Oslo (Norway); Kloew, Nils E. [Ullevaal University Hospital, Department of Cardiovascular Radiology, Oslo (Norway)

    2008-06-15

    We studied the changes in proximal embolization of the splenic artery to the intraparenchymal blood flow with Doppler ultrasound. Seventeen trauma patients with spleen injury OIS grade 2-5 underwent embolization of the splenic artery. Peak-systolic velocity (PSV) and end-diastolic velocity (EDV) were measured in intrasplenic arteries initially 1 day after embolization, at early follow-up after 7 days, at intermediate follow-up after 10 weeks, and at late follow-up after 10 months. Resistance index (RI), systolic/diastolic ratio (S/D ratio), acceleration (AC), and acceleration time (AT) were calculated. The results were compared to values from 17 volunteers. RI increased from 0.39 initially to 0.49 (P = 0.002) at intermediate and to 0.52 (P < 0.001) at late follow-up. S/D ratio increased from 1.68 initially to 1.99 (P = 0.002) and to 2.10 (P < 0.001) at intermediate and late follow-up, respectively. Follow-up results of RI and S/D ratio differed significantly from the reference group. AC increased from 1.06 m/s{sup 2} initially to 1.89 m/s{sup 2} at late follow-up (P = 0.01). AC at late follow-up was not different from reference group (2.33 m/s{sup 2}). In conclusion, Doppler ultrasound is a useful tool in the evaluation of improvable intraparenchymal blood flow over time after central splenic artery embolization. (orig.)

  7. Abnormal uterine bleeding due to vascular abnormality caused by D and E : doppler sonography for diagnosis and transcatheter arterial embolization for treatment

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    Kim, Yong Jo; Heo, Chan; Jung, Tae Gun; Kim, Gi Sung; Kwon, Hyeok Po; Lee, Sang Kwon; Kwon, Jung Hyeok [Dongkang Hospital, Ulsan (Korea, Republic of); Lee, Yeong Hwan [Taegu Catholic Univ. School of Medicine, Taegu (Korea, Republic of)

    1996-06-01

    We attempted to evaluate the usefulness of Doppler sonography in the diagnosis of uterine vascular abnormality caused by previous D and E, and to report that transarterial embolization is an excellent treatment modality. We analyzed gray-scale US, color/duplex Doppler US and angiographic findings in seven patients with radiologically proven uterine vascular abnormality. Two of the seven cases were pseudoaneurysms and five of the seven cases were AVMs. n one of the AVMS, two small pseudoaneurysms were combined. In all cases, transarterial embolizations using 3 mm coil or/and gelfoam particles were performed. Follow-up US studies, including color Doppler US, were performed. on color/duplex Doppler sonography, two cases of pseudoaneurysm showed blood pools with turbulent arterial flow, and five cases of AVM showed asymmetrically increased cascularity, with vailable high velocities composed of the pulsatile arterial flow, with a high diastolic component. on angiography, the former showed pseudoaneruysmal sacs, and the latter densely opacified vascular tangles. No more abnormal uterine bleeding was shown following transarterial embolization in all cases. Color/duplex Doppler sonography was valuable in the diagnosis or treatment of abnormal uterine bleeding caused by uterine vascular abnormality such as acquired AVM or pseudoaneruysm.

  8. Abnormal uterine bleeding due to vascular abnormality caused by D and E : doppler sonography for diagnosis and transcatheter arterial embolization for treatment

    International Nuclear Information System (INIS)

    Kim, Yong Jo; Heo, Chan; Jung, Tae Gun; Kim, Gi Sung; Kwon, Hyeok Po; Lee, Sang Kwon; Kwon, Jung Hyeok; Lee, Yeong Hwan

    1996-01-01

    We attempted to evaluate the usefulness of Doppler sonography in the diagnosis of uterine vascular abnormality caused by previous D and E, and to report that transarterial embolization is an excellent treatment modality. We analyzed gray-scale US, color/duplex Doppler US and angiographic findings in seven patients with radiologically proven uterine vascular abnormality. Two of the seven cases were pseudoaneurysms and five of the seven cases were AVMs. n one of the AVMS, two small pseudoaneurysms were combined. In all cases, transarterial embolizations using 3 mm coil or/and gelfoam particles were performed. Follow-up US studies, including color Doppler US, were performed. on color/duplex Doppler sonography, two cases of pseudoaneurysm showed blood pools with turbulent arterial flow, and five cases of AVM showed asymmetrically increased cascularity, with vailable high velocities composed of the pulsatile arterial flow, with a high diastolic component. on angiography, the former showed pseudoaneruysmal sacs, and the latter densely opacified vascular tangles. No more abnormal uterine bleeding was shown following transarterial embolization in all cases. Color/duplex Doppler sonography was valuable in the diagnosis or treatment of abnormal uterine bleeding caused by uterine vascular abnormality such as acquired AVM or pseudoaneruysm

  9. MP3 compression of Doppler ultrasound signals.

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    Poepping, Tamie L; Gill, Jeremy; Fenster, Aaron; Holdsworth, David W

    2003-01-01

    The effect of lossy, MP3 compression on spectral parameters derived from Doppler ultrasound (US) signals was investigated. Compression was tested on signals acquired from two sources: 1. phase quadrature and 2. stereo audio directional output. A total of 11, 10-s acquisitions of Doppler US signal were collected from each source at three sites in a flow phantom. Doppler signals were digitized at 44.1 kHz and compressed using four grades of MP3 compression (in kilobits per second, kbps; compression ratios in brackets): 1400 kbps (uncompressed), 128 kbps (11:1), 64 kbps (22:1) and 32 kbps (44:1). Doppler spectra were characterized by peak velocity, mean velocity, spectral width, integrated power and ratio of spectral power between negative and positive velocities. The results suggest that MP3 compression on digital Doppler US signals is feasible at 128 kbps, with a resulting 11:1 compression ratio, without compromising clinically relevant information. Higher compression ratios led to significant differences for both signal sources when compared with the uncompressed signals. Copyright 2003 World Federation for Ultrasound in Medicine & Biology

  10. Cerebral Embolic Activity in a Patient during Acute Crisis of Takayasu's Arteritis

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    Nogueira, Ricardo de Carvalho; Bor-Seng-Shu, Edson; Marchiori, Paulo Eurípedes; Teixeira, Manoel Jacobsen

    2012-01-01

    Takayasu's arteritis is a disease that affects large vessels and may cause neurological symptoms either by stenoses/occlusions or embolisms from vessels with an inflammatory process. Transcranial Doppler (TCD) ultrasound can provide useful information for diagnosis and monitoring during the active phase of the disease. Cerebral embolic signals can be detected by TCD and have been considered a risk factor for vascular events. We report a patient in whom TCD ultrasound was used to monitor cerebral embolic signals during the active phase of the disease. This case report suggests that embolic activity in Takayasu's arteritis may represent disease activity, and its monitoring may be useful for evaluating the response to therapy. PMID:22379479

  11. Re-Normalization Method of Doppler Lidar Signal for Error Reduction

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    Park, Nakgyu; Baik, Sunghoon; Park, Seungkyu; Kim, Donglyul [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Kim, Dukhyeon [Hanbat National Univ., Daejeon (Korea, Republic of)

    2014-05-15

    In this paper, we presented a re-normalization method for the fluctuations of Doppler signals from the various noises mainly due to the frequency locking error for a Doppler lidar system. For the Doppler lidar system, we used an injection-seeded pulsed Nd:YAG laser as the transmitter and an iodine filter as the Doppler frequency discriminator. For the Doppler frequency shift measurement, the transmission ratio using the injection-seeded laser is locked to stabilize the frequency. If the frequency locking system is not perfect, the Doppler signal has some error due to the frequency locking error. The re-normalization process of the Doppler signals was performed to reduce this error using an additional laser beam to an Iodine cell. We confirmed that the renormalized Doppler signal shows the stable experimental data much more than that of the averaged Doppler signal using our calibration method, the reduced standard deviation was 4.838 Χ 10{sup -3}.

  12. Evaluation of arterial embolization in treating hyperthyroidism by colour ultrasonography

    International Nuclear Information System (INIS)

    Sun Xiuying; Yang Jijin; Chen Ningning; Gu Limin; Wang Ying; Chen Jianquan

    2003-01-01

    Objective: To assess the effect of arterial embolization in treating hyperthyroidism by colour ultrasonography. Methods: Forty two cases of hyperthyroidism were treated with thyroid-arteries embolization. A few days before and 1, 3, 6 months after embolization, the echograms of thyroids were observed including the volumes of thyroids and the internal diameters of thyroid-arteries were measured with colour ultrasonography respectively. The Vs, Vd, Vm, PI, RI were measured with the Doppler and the quantities of blood flow were calculated. The relationships of changes for all these parameters and T 3 , T 4 and TSH were analysed. Results: Before artery embolization all thyroids were enlarged with diffusely homogenous or heterogenous low-echoes and nodules in some patients accompanied by widening of the thyroid arteries and their branches full of blood supply. The volume of thyroids decreased after artery embolization. 1-3 months later the echo of thyroids enhanced and got coarse with decrease of the thyroid vasculature and narrowing of vessel calibers except a few star- or stop-like blood streams were sometimes seen within the thyroids and no blood flow signals found in some cases. 3-6 months after embolization, the echo of thyroids decreased gradually or unevenly distributed. All the parameters of blood flow before and after the treatment showed statistically significant differences (P < 0.05). Conclusions: Embolization of thyroid arteries is a relatively new and effective technique in treating hyperthyroidism. Colour Doppler ultrasonography plays an important role for correct diagnosis and prognostication

  13. Embolic Signals during Routine Transcranial Doppler Ultrasonography in Aneurysmal Subarachnoid Hemorrhage

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    Paschoal, Fernando Mendes; de Almeida Lins Ronconi, Karla; de Lima Oliveira, Marcelo; Nogueira, Ricardo de Carvalho; Paschoal, Eric Homero Albuquerque; Teixeira, Manoel Jacobsen; Figueiredo, Eberval Gadelha; Bor-Seng-Shu, Edson

    2015-01-01

    Introduction. Cerebral emboli may occur in subarachnoid hemorrhage (SAH) and intracranial aneurysm surgery. Although embolic signs (ES) have been reported in SAH, their origin remains unclear. The aim of this study was to report the detection of ES during routine TCD monitoring in patients with aneurysmal SAH. Methods. A total of 105 patients with aneurysmal SAH were submitted to TCD evaluation. Patients were monitored almost daily (5 times per week). In each monitoring session, one experienced operator performed TCD to detect or assess vasospasm and ES in arteries of the Willis polygon. Results. Four patients out of a total of 105 patients with aneurysmal SAH were found to present spontaneous cerebral embolization during routine TCD monitoring. The average age of the 4 patients (mean ± standard deviation) was 59.5 ± 8.34 years (range 49–68 ys); female patients predominated representing 75% (3/4) of subjects. Conclusion. Although detection of ES was relatively rare in this study, rates of emboli occurrence may be higher under systematic monitoring. The detection of ES after SAH surgery reinforces the need to study the role of embolus in this condition and may be an indicator for prophylactic antithrombotic treatment. PMID:25893190

  14. Automated embolic signal detection using Deep Convolutional Neural Network.

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    Sombune, Praotasna; Phienphanich, Phongphan; Phuechpanpaisal, Sutanya; Muengtaweepongsa, Sombat; Ruamthanthong, Anuchit; Tantibundhit, Charturong

    2017-07-01

    This work investigated the potential of Deep Neural Network in detection of cerebral embolic signal (ES) from transcranial Doppler ultrasound (TCD). The resulting system is aimed to couple with TCD devices in diagnosing a risk of stroke in real-time with high accuracy. The Adaptive Gain Control (AGC) approach developed in our previous study is employed to capture suspected ESs in real-time. By using spectrograms of the same TCD signal dataset as that of our previous work as inputs and the same experimental setup, Deep Convolutional Neural Network (CNN), which can learn features while training, was investigated for its ability to bypass the traditional handcrafted feature extraction and selection process. Extracted feature vectors from the suspected ESs are later determined whether they are of an ES, artifact (AF) or normal (NR) interval. The effectiveness of the developed system was evaluated over 19 subjects going under procedures generating emboli. The CNN-based system could achieve in average of 83.0% sensitivity, 80.1% specificity, and 81.4% accuracy, with considerably much less time consumption in development. The certainly growing set of training samples and computational resources will contribute to high performance. Besides having potential use in various clinical ES monitoring settings, continuation of this promising study will benefit developments of wearable applications by leveraging learnable features to serve demographic differentials.

  15. Fetal Cardiac Doppler Signal Processing Techniques: Challenges and Future Research Directions

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    Saeed Abdulrahman Alnuaimi

    2017-12-01

    Full Text Available The fetal Doppler Ultrasound (DUS is commonly used for monitoring fetal heart rate and can also be used for identifying the event timings of fetal cardiac valve motions. In early-stage fetuses, the detected Doppler signal suffers from noise and signal loss due to the fetal movements and changing fetal location during the measurement procedure. The fetal cardiac intervals, which can be estimated by measuring the fetal cardiac event timings, are the most important markers of fetal development and well-being. To advance DUS-based fetal monitoring methods, several powerful and well-advanced signal processing and machine learning methods have recently been developed. This review provides an overview of the existing techniques used in fetal cardiac activity monitoring and a comprehensive survey on fetal cardiac Doppler signal processing frameworks. The review is structured with a focus on their shortcomings and advantages, which helps in understanding fetal Doppler cardiogram signal processing methods and the related Doppler signal analysis procedures by providing valuable clinical information. Finally, a set of recommendations are suggested for future research directions and the use of fetal cardiac Doppler signal analysis, processing, and modeling to address the underlying challenges.

  16. Detection and volume estimation of embolic air in the middle cerebral artery using transcranial Doppler sonography.

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    Bunegin, L; Wahl, D; Albin, M S

    1994-03-01

    Cerebral embolism has been implicated in the development of cognitive and neurological deficits following bypass surgery. This study proposes methodology for estimating cerebral air embolus volume using transcranial Doppler sonography. Transcranial Doppler audio signals of air bubbles in the middle cerebral artery obtained from in vivo experiments were subjected to a fast-Fourier transform analysis. Audio segments when no air was present as well as artifact resulting from electrocautery and sensor movement were also subjected to fast-Fourier transform analysis. Spectra were compared, and frequency and power differences were noted and used for development of audio band-pass filters for isolation of frequencies associated with air emboli. In a bench model of the middle cerebral artery circulation, repetitive injections of various air volumes between 0.5 and 500 microL were made. Transcranial Doppler audio output was band-pass filtered, acquired digitally, then subjected to a fast-Fourier transform power spectrum analysis and power spectrum integration. A linear least-squares correlation was performed on the data. Fast-Fourier transform analysis of audio segments indicated that frequencies between 250 and 500 Hz are consistently dominant in the spectrum when air emboli are present. Background frequencies appear to be below 240 Hz, and artifact resulting from sensor movement and electrocautery appears to be below 300 Hz. Data from the middle cerebral artery model filtered through a 307- to 450-Hz band-pass filter yielded a linear relation between emboli volume and the integrated value of the power spectrum near 40 microL. Detection of emboli less than 0.5 microL was inconsistent, and embolus volumes greater than 40 microL were indistinguishable from one another. The preliminary technique described in this study may represent a starting point from which automated detection and volume estimation of cerebral emboli might be approached.

  17. Detection of Doppler Microembolic Signals Using High Order Statistics

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    Maroun Geryes

    2016-01-01

    Full Text Available Robust detection of the smallest circulating cerebral microemboli is an efficient way of preventing strokes, which is second cause of mortality worldwide. Transcranial Doppler ultrasound is widely considered the most convenient system for the detection of microemboli. The most common standard detection is achieved through the Doppler energy signal and depends on an empirically set constant threshold. On the other hand, in the past few years, higher order statistics have been an extensive field of research as they represent descriptive statistics that can be used to detect signal outliers. In this study, we propose new types of microembolic detectors based on the windowed calculation of the third moment skewness and fourth moment kurtosis of the energy signal. During energy embolus-free periods the distribution of the energy is not altered and the skewness and kurtosis signals do not exhibit any peak values. In the presence of emboli, the energy distribution is distorted and the skewness and kurtosis signals exhibit peaks, corresponding to the latter emboli. Applied on real signals, the detection of microemboli through the skewness and kurtosis signals outperformed the detection through standard methods. The sensitivities and specificities reached 78% and 91% and 80% and 90% for the skewness and kurtosis detectors, respectively.

  18. Clinical evaluation of arterial embolization for the treatment of benign prostatic hyperplasia

    International Nuclear Information System (INIS)

    Gao Yuanan; Zhang Rui; Zeng Yan; Huang Yan

    2010-01-01

    Objective: To assess the clinical efficacy of arterial embolization in treating benign prostatic hyperplasia (BPH). Methods: Embolization of prostate-feeding artery was performed in 47 patients with BPH. All the patients were followed up for seven days to two years. The preoperative and postoperative IPSS, quality of life (QOL), Qmax and residual urine (RU) were determined and were compared with each other. Signal of bloodstreams and the maximal velocity of bloodstreams were assessed by transrectal color Doppler sonography. The changes of prostatic volume were assessed by B ultrasound and CT scan. Results: The preoperative average values of IPSS, QOL, Qmax and RU were 24.2 minutes, 4.8 minutes, 9.6 ml / s and 184 ml respectively, while the postoperative ones were 4.8 minutes, 1.3 minutes, 18.9 ml / s and 3 ml respectively. After the surgery, the signal of bloodstreams was markedly decreased. The maximal velocity of bloodstreams was decreased from (21.52 ± 8.83) cm / s preoperatively to (7.4 ± 3.27) cm / s postoperatively. On ultrasonography or CT scan, the average prostatic volume was significantly decreased from 117 cm 3 to 68 cm 3 . The effective rate of arterial embolization for the treatment of BPH was 89%. Conclusion: Arterial embolization is very effective for the treatment of BPH, which can be regarded as a new therapy for BPH. (authors)

  19. Model of multicomponent micro-Doppler signal in environment MatLab

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    Kucheryavenko Alexander

    2017-01-01

    Full Text Available The article illustrates the problem of measuring the speed glider component targets in the presence of a turboprop effect of the reflected signal in a pulse-Doppler radar, proposed a model turboprop signal component and an algorithm for its suppression

  20. [Practical Use of Doppler Ultrasonography of the Cardiovascular System and Clinical Laboratory Tests for the Management of Pulmonary Embolism].

    Science.gov (United States)

    Mizukami, Naoko

    2015-08-01

    Acute or chronic pulmonary embolism (PE) is a serious disease, and the risk of mortality is increased if untreated. In 90% of cases the embolus source is deep vein thrombosis (DVT) of the lower limbs or pelvic cavity. Therefore, it is necessary to recognize these as venous thromboembolism (VTE) which includes both DVT and PE. I suggest that Doppler ultrasonography of cardiovascular and clinical laboratory tests provide very valuable medical support for the management of VTE. Specifically, in the early diagnosis of VTE and the prevention of fatal PE, Doppler ultrasonography (cardiac and vascular) can provide very useful information. On the other hand, blood coagulation and thrombophilia tests are important to determine the risk of VTE and evaluate the effect of anticoagulant therapy on VTE. In this paper, I explain the main points of each examination of VTE by describing representative cases. I also show the results on investigating cases in our hospital involving diseases related to VTE and the onset site of DVT. In addition, I introduce how we convey the results of analysis to the clinical side.

  1. Pulmonary embolism and cor pulmonale in a cat

    International Nuclear Information System (INIS)

    Sottiaux, J.; Franck, M.

    1999-01-01

    A 14-year-old male neutered cat experienced pulmonary embolism 15 days following surgical debridement of a recurrent dorsolumbar abscess. Clinical signs were dominated by respiratory distress. Pulmonary embolism was suggested from the lateral thoracic radiograph by the presence of an abruptly attenuated lobar artery and a contiguous oligaemic area in the caudal lung lobe. Pulmonary hypertension was demonstrated on Doppler echocardiography by right pulmonary artery dilation and tricuspid regurgitation raising the pulmonary arterial pressure to 56 mmHg. Chronic pulmonary hypertension, assumed from right ventricular wall hypertrophy, and hypokinesia, indicating chronic cor pulmonale, was suggestive of chronic rather than acute pulmonary embolism. Postmortem histological evidence of pulmonary arteriolar occlusion confirmed the diagnosis of pulmonary embolism

  2. Chaos weak signal detecting algorithm and its application in the ultrasonic Doppler bloodstream speed measuring

    International Nuclear Information System (INIS)

    Chen, H Y; Lv, J T; Zhang, S Q; Zhang, L G; Li, J

    2005-01-01

    At the present time, the ultrasonic Doppler measuring means has been extensively used in the human body's bloodstream speed measuring. The ultrasonic Doppler measuring means can achieve the measuring of liquid flux by detecting Doppler frequency shift of ultrasonic in the process of liquid spread. However, the detected sound wave is a weak signal that is flooded in the strong noise signal. The traditional measuring method depends on signal-to-noise ratio. Under the very low signal-to-noise ratio or the strong noise signal background, the signal frequency is not measured. This article studied on chaotic movement of Duffing oscillator and intermittent chaotic characteristic on chaotic oscillator of Duffing equation. In the light of the range of the bloodstream speed of human body and the principle of Doppler shift, the paper determines the frequency shift range. An oscillator array including many oscillators is designed according to it. The reflected ultrasonic frequency information can be ascertained accurately by the intermittent chaos quality of the oscillator. The signal-to-noise ratio of -26.5 dB is obtained by the result of the experiment. Compared with the tradition the frequency method compare, the dependence to signal-to-noise ratio is lowered consumedly. The measuring precision of the bloodstream speed is heightened

  3. Performance bounds on micro-Doppler estimation and adaptive waveform design using OFDM signals

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    Sen, Satyabrata; Barhen, Jacob; Glover, Charles W.

    2014-05-01

    We analyze the performance of a wideband orthogonal frequency division multiplexing (OFDM) signal in estimating the micro-Doppler frequency of a target having multiple rotating scatterers (e.g., rotor blades of a helicopter, propellers of a submarine). The presence of rotating scatterers introduces Doppler frequency modulation in the received signal by generating sidebands about the transmitted frequencies. This is called the micro-Doppler effects. The use of a frequency-diverse OFDM signal in this context enables us to independently analyze the micro-Doppler characteristics with respect to a set of orthogonal subcarrier frequencies. Therefore, to characterize the accuracy of micro-Doppler frequency estimation, we compute the Craḿer-Rao Bound (CRB) on the angular-velocity estimate of the target while considering the scatterer responses as deterministic but unknown nuisance parameters. Additionally, to improve the accuracy of the estimation procedure, we formulate and solve an optimization problem by minimizing the CRB on the angular-velocity estimate with respect to the transmitting OFDM spectral coefficients. We present several numerical examples to demonstrate the CRB variations at different values of the signal-to-noise ratio (SNR) and the number of OFDM subcarriers. The CRB values not only decrease with the increase in the SNR values, but also reduce as we increase the number of subcarriers implying the significance of frequency-diverse OFDM waveforms. The improvement in estimation accuracy due to the adaptive waveform design is also numerically analyzed. Interestingly, we find that the relative decrease in the CRBs on the angular-velocity estimate is more pronounced for larger number of OFDM subcarriers.

  4. Performance Bounds on Micro-Doppler Estimation and Adaptive Waveform Design Using OFDM Signals

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    Sen, Satyabrata [ORNL; Barhen, Jacob [ORNL; Glover, Charles Wayne [ORNL

    2014-01-01

    We analyze the performance of a wideband orthogonal frequency division multiplexing (OFDM) signal in estimating the micro-Doppler frequency of a target having multiple rotating scatterers (e.g., rotor blades of a helicopter, propellers of a submarine). The presence of rotating scatterers introduces Doppler frequency modulation in the received signal by generating sidebands about the transmitted frequencies. This is called the micro-Doppler effects. The use of a frequency-diverse OFDM signal in this context enables us to independently analyze the micro-Doppler characteristics with respect to a set of orthogonal subcarrier frequencies. Therefore, to characterize the accuracy of micro-Doppler frequency estimation, we compute the Cram er-Rao Bound (CRB) on the angular-velocity estimate of the target while considering the scatterer responses as deterministic but unknown nuisance parameters. Additionally, to improve the accuracy of the estimation procedure, we formulate and solve an optimization problem by minimizing the CRB on the angular-velocity estimate with respect to the transmitting OFDM spectral coefficients. We present several numerical examples to demonstrate the CRB variations at different values of the signal-to-noise ratio (SNR) and the number of OFDM subcarriers. The CRB values not only decrease with the increase in the SNR values, but also reduce as we increase the number of subcarriers implying the significance of frequency-diverse OFDM waveforms. The improvement in estimation accuracy due to the adaptive waveform design is also numerically analyzed. Interestingly, we find that the relative decrease in the CRBs on the angular-velocity estimate is more pronounced for larger number of OFDM subcarriers.

  5. Modeling and processing of laser Doppler reactive hyperaemia signals

    Science.gov (United States)

    Humeau, Anne; Saumet, Jean-Louis; L'Huiller, Jean-Pierre

    2003-07-01

    Laser Doppler flowmetry is a non-invasive method used in the medical domain to monitor the microvascular blood cell perfusion through tissue. Most commercial laser Doppler flowmeters use an algorithm calculating the first moment of the power spectral density to give the perfusion value. Many clinical applications measure the perfusion after a vascular provocation such as a vascular occlusion. The response obtained is then called reactive hyperaemia. Target pathologies include diabetes, hypertension and peripheral arterial occlusive diseases. In order to have a deeper knowledge on reactive hyperaemia acquired by the laser Doppler technique, the present work first proposes two models (one analytical and one numerical) of the observed phenomenon. Then, a study on the multiple scattering between photons and red blood cells occurring during reactive hyperaemia is carried out. Finally, a signal processing that improves the diagnosis of peripheral arterial occlusive diseases is presented.

  6. Analysis of the computational requirements of a pulse-doppler radar signal processor

    CSIR Research Space (South Africa)

    Broich, R

    2012-05-01

    Full Text Available In an attempt to find an optimal processing architecture for radar signal processing applications, the different algorithms that are typically used in a pulse-Doppler radar signal processor are investigated. Radar algorithms are broken down...

  7. Fourier and wavelet analysis of skin laser doppler flowmetry signals

    OpenAIRE

    Qi, Wei

    2011-01-01

    ObjectiveThis thesis examines the measurement of skin microvascular blood flows from Laser Doppler Flowmetry (LDF) signals. Both healthy subjects and those with features of the metabolic syndrome are studied using signal processing techniques such as the Fourier and Wavelet transforms. An aim of this study is to investigate whether change in blood flow at rest can be detected from the spectral content of the processed signals in the diferent subject groups. Additionally the effect of insulin ...

  8. Ovarian Artery: Angiographic Appearance, Embolization and Relevance to Uterine Fibroid Embolization

    International Nuclear Information System (INIS)

    Pelage, J.P.; Walker, W.J.; Le Dref, O.; Rymer, R.

    2003-01-01

    Purpose: To describe the angiographic appearance of the ovarian artery and its main variations that may be relevant to uterine fibroid embolization. Methods: The flush aortograms of 294 women who had been treated by uterine artery embolization for fibroids were reviewed. Significant arterial supply to the fibroid, and the origin and diameter of identified ovarian arteries were recorded. In patients with additional embolization of the ovarian artery, the follow-up evaluation also included hormonal levels and Doppler imaging of the ovaries. Results: A total of 75 ovarian arteries were identified in 59 women (bilaterally in 16 women and unilaterally in 43 women). All ovarian arteries originated from the aorta below the level of the renal arteries with a characteristic tortuous course. Fifteen women had at least one enlarged ovarian artery supplying the fibroids. Fourteen women (14/15, 93%) presented at least one of the following factors: prior pelvic surgery, tubo-ovarian pathology or large fundal fibroids. Conclusion: We advocate the use of flush aortography in women with prior tubo-ovarian pathology or surgery or in cases of large fundal fibroids. In the case of an ovarian artery supply to the fibroids, superselective catheterization and embolization of the ovarian artery should be considered

  9. Percutaneous Direct Puncture Embolization with N-butyl-cyanoacrylate for High-flow Priapism

    Energy Technology Data Exchange (ETDEWEB)

    Tokue, Hiroyuki, E-mail: tokue@s2.dion.ne.jp; Shibuya, Kei [Gunma University Hospital, Department of Diagnostic and Interventional Radiology (Japan); Ueno, Hiroyuki [Isesaki Municipal Hospital, Department of Radiology (Japan); Tokue, Azusa; Tsushima, Yoshito [Gunma University Hospital, Department of Diagnostic and Interventional Radiology (Japan)

    2016-09-15

    There are many treatment options in high-flow priapism. Those mentioned most often are watchful waiting, Doppler-guided compression, endovascular highly selective embolization, and surgery. We present a case of high-flow priapism in a 57-year-old man treated by percutaneous direct puncture embolization of a post-traumatic left cavernosal arteriovenous fistula using N-butyl-cyanoacrylate. Erectile function was preserved during a 12-month follow-up. No patients with percutaneous direct puncture embolization for high-flow priapism have been reported previously. Percutaneous direct puncture embolization is a potentially useful and safe method for management of high-flow priapism.

  10. Doppler shift simulation of scattered HF signals during the Tromsø HF pumping experiment on 16 February 1996

    Directory of Open Access Journals (Sweden)

    T. D. Borisova

    2002-09-01

    Full Text Available Comparisons between bistatic scatter measurements and simulation results during the Tromsø HF pumping experiment on 16 February 1996 are made. Doppler measurements of an HF diagnostic signal scattered from the field-aligned irregularities (FAIs in the auroral E-region were carried out on the London – Tromsø – St. Petersburg path at 9410 kHz from 21:00 to 22:00 UT. The scattered signals were observed both from natural and artificial ionospheric irregularities located in the vicinity of Tromsø. To simulate the Doppler frequency shifts, fd , of scattered signals, a radio channel model, named CONE, was developed. The model allows for ray tracing, group and phase paths, and Doppler frequency shift calculations. The calculated Doppler shifts were analyzed for dependence on the magnitude and direction of plasma velocities in the scattering volume. It was found that the velocity components in the north-south direction are crucial for explaining the Doppler frequency shifts of the scattered diagnostic signals. To simulate fd , real velocities obtained from the EISCAT UHF radar at an altitude of 278 km and from the digital all-sky imager during the experiment were employed. The simulation results of Doppler frequency shift variations with time are in reasonable agreement with the experimental Doppler shifts of scattered signals on the London – Tromsø – St. Petersburg path.Key words. Ionosphere (active experiments; ionospheric irregularities Radio science (ionospheric propagation

  11. A clutter removal method for the Doppler ultrasound signal based on a nonlinear diffusion equation

    International Nuclear Information System (INIS)

    Li Peng; Xin Pengcheng; Bian Zhengzhong; Yu Gang

    2008-01-01

    Strong clutter components produced by stationary and slow-moving tissue structures render the lower frequency part of the spectrogram useless and degrade the accuracy of clinical ultrasound indices. An adaptive method based on the nonlinear forward-and-backward diffusion equation (FAB-DE) is proposed to remove strong clutter components from the contaminated Doppler signal. The clutter signal is extracted first by the FAB-DE accurately, in which the nonlinear diffusion coefficient function of the FAB-DE locally adjusts according to signal features and the diffusion adaptively switches between forward and backward mode. The present method has been validated by simulated and realistic pulse wave Doppler signals, and compared with the conventional high pass filter and the matching pursuit method. The simulation results, including spectrogram, mean velocity error, standard deviation of mean velocity and signal-to-clutter ratio of a decontaminated signal, demonstrate that the present FAB-DE method can remove clutter sufficiently and retain more low blood components simultaneously as compared with the other two methods. Results of the realistic Doppler blood signal, including spectrogram and low-frequency part of the spectrum, support the conclusion drawn from simulation cases

  12. Pulmonary embolism and nuclear medicine

    International Nuclear Information System (INIS)

    Peltier, P.; Planchon, B.; Faucal, P. de; Touze, M.D.; Dupas, B.

    1988-01-01

    Risks related to pulmonary embolism require use of diagnostic procedures with good sensitivity, and the potential complications of effective anticoagulant therapy require procedures with good specificity. Clinical signs are not more accurate for diagnosis of pulmonary than are ECG, blood gas and chest X ray examinations. Perfusion-ventilation scintigraphy has good diagnostic accuracy approaching that of pulmonary angiography which remains the gold standard. Since pulmonary embolism is usually a complication of deep venous thrombosis, distal clot detection should be associated with lung explorations. Plethysmography, ultrasonography, doppler studies and scintigraphy of the lower limbs could provide data supplementing those of contrast venography. The value and role of these examinations are analyzed and discussed in terms of different clinical situations [fr

  13. Doppler shift simulation of scattered HF signals during the Tromsø HF pumping experiment on 16 February 1996

    Directory of Open Access Journals (Sweden)

    T. D. Borisova

    Full Text Available Comparisons between bistatic scatter measurements and simulation results during the Tromsø HF pumping experiment on 16 February 1996 are made. Doppler measurements of an HF diagnostic signal scattered from the field-aligned irregularities (FAIs in the auroral E-region were carried out on the London – Tromsø – St. Petersburg path at 9410 kHz from 21:00 to 22:00 UT. The scattered signals were observed both from natural and artificial ionospheric irregularities located in the vicinity of Tromsø. To simulate the Doppler frequency shifts, fd , of scattered signals, a radio channel model, named CONE, was developed. The model allows for ray tracing, group and phase paths, and Doppler frequency shift calculations. The calculated Doppler shifts were analyzed for dependence on the magnitude and direction of plasma velocities in the scattering volume. It was found that the velocity components in the north-south direction are crucial for explaining the Doppler frequency shifts of the scattered diagnostic signals. To simulate fd , real velocities obtained from the EISCAT UHF radar at an altitude of 278 km and from the digital all-sky imager during the experiment were employed. The simulation results of Doppler frequency shift variations with time are in reasonable agreement with the experimental Doppler shifts of scattered signals on the London – Tromsø – St. Petersburg path.

    Key words. Ionosphere (active experiments; ionospheric irregularities Radio science (ionospheric propagation

  14. Single aortic clamping in coronary artery bypass surgery reduces cerebral embolism and improves neurocognitive outcomes.

    Science.gov (United States)

    Gasparovic, Hrvoje; Borojevic, Marko; Malojcic, Branko; Gasparovic, Kristina; Biocina, Bojan

    2013-10-01

    Aortic manipulation releases embolic material, thereby enhancing the probability of adverse neurologic outcomes following coronary artery bypass grafting (CABG). We prospectively evaluated 59 patients undergoing CABG. Patients in the single (SC, n = 37) and multiple clamp (MC, n = 22) groups were comparable in relation to age and operative risk (p > 0.05). Neurocognitive evaluation consisted of the Auditory Verbal Learning Test (AVLT), Color Trails Test A, the Grooved Pegboard test and the Mini-Mental State Examination. Data acquisition was performed preoperatively, early postoperatively and at the 4-month follow-up. Intraoperative transcranial Doppler (TCD) monitoring was used to quantify the embolic load in relation to different aortic clamping strategies. Preoperative neurocognitive results were similar between the groups (p > 0.05). The incidence of postoperative delirium was greater in the MC group but this failed to reach statistical significance (23% vs 8%, p = 0.14). SC patients had fewer embolization signals (270 ± 181 vs 465 ± 160, p cognitive depression was greater in the MC group (p cognition deficits and superior late restoration of function.

  15. Uterine artery embolization angiography and fertility related aspects

    Directory of Open Access Journals (Sweden)

    Irina A. Horhoianu

    2016-05-01

    Full Text Available Purpose. Uterine artery embolization is a minimally invasive technique. It applies the principle of targeted anatomical structure devascularisation with utility in fibroid conservative therapy, including for future fertility preserving status. The objective of our paper represents a description and evaluation of angiography utility as a predictive method for fertility maintenance. Material and Methods. The angiography and ultrasound aspects obtained from a prospective study in which selected patients have undergone uterine artery embolization for fertility preservation are detailed. Results. The following angiography aspects have been detected: left- right shunt and utero-ovarian collaterals; these have been compared with the ultrasound aspects related to the fibroid evolution form a volumetric and Doppler ultrasound point of view. The angiographical description predicts the impact on post embolization fibroid evolution and upon fertility. An analysis is made in order to assess the way in which angiography can contribute to fertility alteration. Conclusions. The angiography aspects during embolization and the following ultrasound aspects can represent predictive factors as to fertility evolution after uterine artery embolization.

  16. Micro-Doppler Signal Time-Frequency Algorithm Based on STFRFT

    Directory of Open Access Journals (Sweden)

    Cunsuo Pang

    2016-09-01

    Full Text Available This paper proposes a time-frequency algorithm based on short-time fractional order Fourier transformation (STFRFT for identification of a complicated movement targets. This algorithm, consisting of a STFRFT order-changing and quick selection method, is effective in reducing the computation load. A multi-order STFRFT time-frequency algorithm is also developed that makes use of the time-frequency feature of each micro-Doppler component signal. This algorithm improves the estimation accuracy of time-frequency curve fitting through multi-order matching. Finally, experiment data were used to demonstrate STFRFT’s performance in micro-Doppler time-frequency analysis. The results validated the higher estimate accuracy of the proposed algorithm. It may be applied to an LFM (Linear frequency modulated pulse radar, SAR (Synthetic aperture radar, or ISAR (Inverse synthetic aperture radar, for improving the probability of target recognition.

  17. Micro-Doppler Signal Time-Frequency Algorithm Based on STFRFT.

    Science.gov (United States)

    Pang, Cunsuo; Han, Yan; Hou, Huiling; Liu, Shengheng; Zhang, Nan

    2016-09-24

    This paper proposes a time-frequency algorithm based on short-time fractional order Fourier transformation (STFRFT) for identification of a complicated movement targets. This algorithm, consisting of a STFRFT order-changing and quick selection method, is effective in reducing the computation load. A multi-order STFRFT time-frequency algorithm is also developed that makes use of the time-frequency feature of each micro-Doppler component signal. This algorithm improves the estimation accuracy of time-frequency curve fitting through multi-order matching. Finally, experiment data were used to demonstrate STFRFT's performance in micro-Doppler time-frequency analysis. The results validated the higher estimate accuracy of the proposed algorithm. It may be applied to an LFM (Linear frequency modulated) pulse radar, SAR (Synthetic aperture radar), or ISAR (Inverse synthetic aperture radar), for improving the probability of target recognition.

  18. Comparisons between PW Doppler system and enhanced FM Doppler system

    DEFF Research Database (Denmark)

    Wilhjelm, Jens E.; Pedersen, P. C.

    1995-01-01

    This paper presents a new implementation of an echo-ranging FM Doppler system with improved performance, relative to the FM Doppler system reported previously. The use of long sweeps provides a significant reduction in peak to average power ratio compared to pulsed wave (PW) emission. A PW Doppler...... system exploits the direct relationship between arrival time of the received signal and range from the transducer. In the FM Doppler systems, a similar relationship exists in the spectral domain of the demodulated received signals, so that range is represented by frequency. Thus, a shift in location...... of moving scatterers between consecutive emissions corresponds to a frequency shift in the spectral signature. The improvement relative to the earlier version of the FM Doppler system is attained by utilizing cross-correlation of real spectra rather than of magnitude spectra for assessing flow velocity...

  19. Theoretical and experimental signal-to-noise ratio assessment in new direction sensing continuous-wave Doppler lidar

    DEFF Research Database (Denmark)

    Pedersen, Anders Tegtmeier; Foroughi Abari, Farzad; Mann, Jakob

    2014-01-01

    A new direction sensing continuous-wave Doppler lidar based on an image-reject homodyne receiver has recently been demonstrated at DTU Wind Energy, Technical University of Denmark. In this contribution we analyse the signal-to-noise ratio resulting from two different data processing methods both...... leading to the direction sensing capability. It is found that using the auto spectrum of the complex signal to determine the wind speed leads to a signal-to-noise ratio equivalent to that of a standard self-heterodyne receiver. Using the imaginary part of the cross spectrum to estimate the Doppler shift...... has the benefit of a zero-mean background spectrum, but comes at the expense of a decrease in the signal-to noise ratio by a factor of √2....

  20. Selective Embolization of Bilateral Arterial Cavernous Fistulas for Posttraumatic Penile Arterial Priapism

    International Nuclear Information System (INIS)

    Lazinger, Maxwell; Beckmann, Carl F.; Cossi, Alda; Roth, Robert A.

    1996-01-01

    A 22-year-old man suffered a hiking accident with perineal trauma and developed a nonpainful priapism secondary to bilateral arterial-cavernosal fistulas. To minimize the risk of impotence in this young patient, successive selective embolizations with autologous blood clot were performed to close the fistulas. This led to an uncomplicated full recovery. No fistula was detectable on Doppler ultrasonography at 1-year follow-up. Review of the literature confirms the safety of embolization with autologous clot

  1. Analysis of Signal-to-Noise Ratio of the Laser Doppler Velocimeter

    DEFF Research Database (Denmark)

    Lading, Lars

    1973-01-01

    The signal-to-shot-noise ratio of the photocurrent of a laser Doppler anemometer is calculated as a function of the parameters which describe the system. It is found that the S/N is generally a growing function of receiver area, that few large particles are better than many small ones, and that g...

  2. Doppler ultrasound monitoring technology.

    Science.gov (United States)

    Docker, M F

    1993-03-01

    Developments in the signal processing of Doppler ultrasound used for the detection of fetal heart rate (FHR) have improved the operation of cardiotocographs. These developments are reviewed and the advantages and disadvantages of the various Doppler and signal processing methods are compared.

  3. A Case of Turner Syndrome with Multiple Embolic Infarcts

    Directory of Open Access Journals (Sweden)

    Cindy W. Yoon

    2016-09-01

    Full Text Available Only a few cases of Turner syndrome (TS with ischemic stroke have been reported. Various arteriopathies of the cerebral arteries, including fibromuscular dysplasia, congenital hypoplasia, moyamoya syndrome, and premature atherosclerosis have been assumed to be the cause of ischemic stroke in TS. There has been no case report of a TS patient presenting with an embolic stroke pattern without any cerebral arteriopathy. A 28-year-old woman with TS was referred to our hospital because of abnormal brain magnetic resonance imaging (MRI findings. She underwent brain MRI at the referring hospital because she experienced sudden-onset diffuse headache. Diffusion-weighted imaging revealed multiple acute embolic infarcts in different vascular territories. Intracranial and extracranial arterial disease was not detected on cerebral magnetic resonance angiography and carotid sonography. Embolic source workups, including transthoracic and transesophageal echocardiography, Holter monitoring, and transcranial Doppler shunt study, were all negative. Hypercoagulability and vasculitis panels were also negative. Our patient was diagnosed with cryptogenic embolic stroke. This is the first report of a TS patient with an embolic stroke pattern. Our case shows that ischemic stroke in TS could be due to embolism as well as the various cerebral arteriopathies documented in previous reports.

  4. Identification of patients at risk for ischaemic cerebral complications after carotid endarterectomy with TCD monitoring

    DEFF Research Database (Denmark)

    Horn, J; Naylor, A R; Laman, D M

    2005-01-01

    Transcranial Doppler (TCD) monitoring for micro embolic signals (MES), directly after carotid endarterectomy (CEA) may identify patients at risk of developing ischaemic complications. In this retrospective multicentre study, this hypothesis was investigated.......Transcranial Doppler (TCD) monitoring for micro embolic signals (MES), directly after carotid endarterectomy (CEA) may identify patients at risk of developing ischaemic complications. In this retrospective multicentre study, this hypothesis was investigated....

  5. Detection of geodesic acoustic mode oscillations, using multiple signal classification analysis of Doppler backscattering signal on Tore Supra

    International Nuclear Information System (INIS)

    Vermare, L.; Hennequin, P.; Gürcan, Ö.D.

    2012-01-01

    This paper presents the first observation of geodesic acoustic modes (GAMs) on Tore Supra plasmas. Using the Doppler backscattering system, the oscillations of the plasma flow velocity, localized between r/a = 0.85 and r/a = 0.95, and with a frequency, typically around 10 kHz, have been observed at the plasma edge in numerous discharges. When the additional heating power is varied, the frequency is found to scale with C s /R. The MUltiple SIgnal Classification (MUSIC) algorithm is employed to access the temporal evolution of the perpendicular velocity of density fluctuations. The method is presented in some detail, and is validated and compared against standard methods, such as the conventional fast Fourier transform method, using a synthetic signal. It stands out as a powerful data analysis method to follow the Doppler frequency with a high temporal resolution, which is important in order to extract the dynamics of GAMs. (paper)

  6. Color doppler sonography in thickened gallbladder wall

    International Nuclear Information System (INIS)

    Han, Sang Suk; Choi, Seok Jin; Seo, Chang Hae; Eun, Choong Ki

    1996-01-01

    The thickening of the gallbladder wall is a valuable finding for the diagnosis of cholecystitis, but may be seen in non-cholecystic disease as well as in acute or chronic cholecystitis. The purpose of this study is to determine the value of color Doppler sonography in differentiating the causes of thickened gallbladder wall. Ninety eight patients with thickened gallbladder wall(more than 3mm) which was not due to gallbladder cancer were prospectively evaluated with color Doppler sonography. Sixty-six cases, confirmed by pathologic reports and clinical records, were analyzed for correlation between thickened gallbladder wall and color flow signal according to the underlying causes. Of the 66 patients, 28 cases were cholecystitis and 38 cases had non-cholecystic causes such as liver cirrhosis, ascites, hepatitis, pancreatitis, renal failure, and hypoalbuminemia. Of the 28 patients with cholecystitis(12 acute, 16 chronic), 23(82%) had color Doppler flow signals in the thickened gallbladder wall. Of the 38 patients with non-cholecystic causes, eight(21%) had color Doppler flow signals. There was a statistically significant difference of color Doppler flow signals between the cholecystitis and non-cholecystic groups(p=0.0001). No significant difference of color Doppler flow signals was found between cases of acute and chronic cholecystitis. Of the 23 patients with color Doppler flow signals in 28 cases of cholecystitis, 18(78.3%) showed a linear pattern and five(21.7%) showed a spotty pattern. Of the eight patients with color Doppler flow signals in the 38 non-cholecystic cases, four(50%) showed a linear pattern and four(50%) showed a spotty pattern. In cholecystitis, a linear color Doppler flow signal pattern is a much more frequent finding than a spotty pattern. Color Doppler sonography is a useful and adequate method for determining whether a thickened gallbladder wall is the result of cholecystitis or has non-cholecystic causes

  7. Steerable Doppler transducer probes

    International Nuclear Information System (INIS)

    Fidel, H.F.; Greenwood, D.L.

    1986-01-01

    An ultrasonic diagnostic probe is described which is capable of performing ultrasonic imaging and Doppler measurement consisting of: a hollow case having an acoustic window which passes ultrasonic energy and including chamber means for containing fluid located within the hollow case and adjacent to a portion of the acoustic window; imaging transducer means, located in the hollow case and outside the fluid chamber means, and oriented to direct ultrasonic energy through the acoustic window toward an area which is to be imaged; Doppler transducer means, located in the hollow case within the fluid chamber means, and movably oriented to direct Doppler signals through the acoustic window toward the imaged area; means located within the fluid chamber means and externally controlled for controllably moving the Doppler transducer means to select one of a plurality of axes in the imaged area along which the Doppler signals are to be directed; and means, located external to the fluid chamber means and responsive to the means for moving, for providing an indication signal for identifying the selected axis

  8. Brain fat embolism

    International Nuclear Information System (INIS)

    Sugiura, Yoshihiro; Kawamura, Yasutaka; Suzuki, Hisato; Yanagimoto, Masahiro; Goto, Yukio

    1994-01-01

    Recently CT and MR imaging have demonstrated that cerebral edema is present in cases of fat embolism syndrome. To simulate this we have made a model of brain-fat embolism in rats under MR imaging. In 20 rats, we did intravenous injection of heparinized blood, 1.5 ml·kg -1 taken from femoral bone marrow cavity. Twenty four hours after the injection, we examined the MR images (1.5 tesla, spin-echo method) of brains and histologic findings of brains and lungs were obtained. In 5 of 20 rats, high signal intensity on T2-weighted images and low signal intensity on T1-weighted images were observed in the area of the unilateral cerebral cortex or hippocampus. These findings showed edema of the brains. They disappeared, however, one week later. Histologic examinations showed massive micro-fat emboli in capillaries of the deep cerebral cortex and substantia nigra, but no edematous findings of the brain were revealed in HE staining. In pulmonary arteries, we also found large fat emboli. We conclude that our model is a useful one for the study of brain fat embolism. (author)

  9. Multiple small hemorrhagic infarcts in cerebral air embolism: a case report.

    Science.gov (United States)

    Togo, Masaya; Hoshi, Taku; Matsuoka, Ryosuke; Imai, Yukihiro; Kohara, Nobuo

    2017-11-16

    Cerebral air embolism is a rare cause of cerebral infarction. In cerebral air embolism, T2 star-weighted imaging shows numerous spotty hypointense signals. Previous reports have suggested that these signals represent air in the brain and are gradually diminished and absorbed. We experienced two cases of cerebral air embolism, and in one of them, we conducted an autopsy. Case 1 was a 76-year-old Japanese man with lung cancer and emphysema. A spasmodic cough induced massive cerebral and cardiac air embolisms and the patient died because of cerebral herniation. T2 star-weighted imaging of brain magnetic resonance imaging showed multiple spotty low signals. Brain autopsy showed numerous spotty hemorrhagic infarcts in the area of T2 star-weighted imaging signals. Case 2 was an 85-year-old Japanese man with emphysema who suffered from acute stroke. Similar spotty T2 star-weighted imaging signals were observed and remained unchanged 2 months after the onset. These findings indicate that T2 star-weighted imaging in cerebral air embolism partially represents micro-hemorrhagic infarction caused by air bubbles that have migrated into the brain.

  10. Embolization of portal-systemic shunts in cirrhotic patients with chronic recurrent hepatic encephalopathy

    International Nuclear Information System (INIS)

    Sakurabayashi, Shin; Sezai, Shuichi; Yamamoto, Yoshihiro; Hirano, Masanori; Oka, Hiroshi

    1997-01-01

    Purpose. To evaluate the efficacy of embolization of portal-systemic shunts in cirrhotic patients with chronic recurrent hepatic encephalopathy (CRHE). Methods. Seven cirrhotic patients with CRHE refractory to medical treatment (3 men and 4 women, mean age 66 years) were studied. Five patients had splenorenal shunts, 1 had a gastrorenal shunt, and 1 had an intrahepatic portal vein-hepatic vein shunt. Shunt embolization was performed using stainless steel coils, with a percutaneous transhepatic portal vein approach in 4 patients and a transrenal vein approach in 3 patients. Results. After embolization, the shunt disappeared in 4 patients on either ultrasound pulsed Doppler monitoring or portography. Complications observed in the 7 patients were fever, transient pleural effusion, ascites, and mild esophageal varices. For 3-6 months after embolization, the 4 patients whose shunts disappeared showed minimal or no reappearance of a shunt, and had no recurrence of encephalopathy. The serum ammonia levels decreased and electroencephalograms also improved. One of the 4 patients, who developed mild esophageal varices, required no treatment. Treatment was effective in 3 of the 4 patients (75%) who underwent embolization via a transhepatic portal vein. Conclusion. Transvascular embolization of shunts improved the outcome in 4 of 7 patients. The most effective embolization was achieved via the percutaneous transhepatic portal vein approach

  11. Comparison of power Doppler and color Doppler ultrasonography in the detection of intrasticular blood flow of normal infants

    International Nuclear Information System (INIS)

    Shin, Sung Ran; Lee, Ho Kyoung; Lee, Won Gyun; Youk, Dong Joon; Rho, Taek Soo; Lee, Min Jin; Lee, Sang Chun

    1999-01-01

    To compare color Doppler ultrasonography (US) and power Doppler US in the detection of intratesticular blood flow in normal infants and to asses the symmetry of blood flow. Testicular blood flow was assessed prospectively in 100 testes of 50 infants with both power and color Doppler US. We compared the power Doppler with color Doppler to detect intratesticular blood. When the flow was detected, intratesticular blood flow was graded as follows: grade 1: single intratesticular Doppler signal ; grade 2: multiple intratesticular Doppler signals. The symmetry of intratesticular flow was assessed by using the same method. Intratesticular flow was detected in 72 (72%) and 68 (68%) testes on power and color Doppler US, respectively. In 76 testes (76%), intratesticular flow was detected in either one or both techniques. On power Doppler US, grade 1 was seen in 40 tests and grade 2 in 32 testes. On color Doppler US, grade 1 was noted in 52 testes and grade 2 in 16 testes. Testicular blood flow was symmetric on both power and color Doppler US in each patient. There was no difference between power Doppler and color Doppler ultrasonography in detecting intratesticular blood flow in normal infants.

  12. Therapeutic effects of percutaneous transhepatic variceal embolization combined with partial splenic embolization for portal hypertention

    International Nuclear Information System (INIS)

    Hua Yingxue; Yan Zhiping; Cheng Yongde; Qiao Delin; Zhou Bing; Chen Shiwei; Li Yong

    2007-01-01

    Objective: To evaluate the efficiency of percutaneous transhepatic variceal embolization (PTVE) combined with patial splenic embolization (PES)for portal hypertension. Methods: 30 patients with critical portal hypertension were divided randomly into two groups, 15 patients of A group underwent PSE PTVE combined with PSE and 15 of B group underwent PES only. The changes of collateral circulation of the two groups were compared via color Doppler ultrasonography pre-and postoperatively. Results: The hypersplenism was well controlled in both groups after PTVE and PSE. The varices of A group were embolized completely, the flow rate and velocity of portal blood stream were significantly reduced (P<0.05). In addition, the flow rate and velocity together with inner diameter of the azygous vein decreased (P<0.01), but no change shown on portal vein diameter, only with decrease of blood flow and velocity postoperatively were shown in the two groups (P<0.05). During 13-16 months follow-up, gastroesophageal variceal bleeding appeared in 2 patients and formation of portal thrombi in 1 patients of B group. There was no gastroesophageal variceal bleeding in A group but 2 patients appeared portal hypertensive gastroenteropathy (PHG)under endoscopic confirmations. Conclusion: PTVE combined PSE is very efficient for gastroesophageal variceal bleeding and hypersplenism due to portal hypertension, especially for patients with poor hepatic function, possessing simple, economic, less invasive properties and deserving to be recommended. (authors)

  13. New clutter-rejection algorithm for Doppler ultrasound

    Science.gov (United States)

    Cloutier, Guy; Chen, Danmin; Durand, Louis-Gilles

    2002-04-01

    Several strategies, known as clutter or wall Doppler filtering, were proposed to remove the strong echoes produced by stationary or slow moving tissue structures from the Doppler blood flow signal. In this study, the matching pursuit (MP) method is proposed to remove clutter components. The MP method decomposes the Doppler signal into wavelet atoms that are selected in a decreasing energy order. Thus, the high-energy clutter components are extracted first. In the present study, the pulsatile Doppler signal s(n) was simulated by a sum of random-phase sinusoids. Two types of high-amplitude clutter signals were then superimposed on s(n): a time-varying low frequency component (type 1), covering systole and early diastole, and short transient clutter signals (type 2), distributed within the whole cardiac cycle. The Doppler signals were modeled with the MP method and the most dominant atoms were subtracted until the signal-to-clutter (S/C) ratio reached a maximum. For the type 1 clutter signal, the improvement in the S/C ratio was 19.0 +/- 0.6 dB, and 72.0 +/- 4.5 atoms were required to reach this performance. For the transient type 2 clutter signal, exactly 10 atoms were required and the maximum improvement in S/C ratio was 5.5 +/- 0.5 dB. These results suggest the possibility of using this signal processing approach to implement clutter rejection filters on ultrasound commercial instruments.

  14. Treatment of symptomatic pelvic varices by ovarian vein embolization

    International Nuclear Information System (INIS)

    Capasso, Patrizio; Simons, Christine; Trotteur, Genevieve; Dondelinger, Robert F.; Henroteaux, Denis; Gaspard, Ulysse

    1997-01-01

    Purpose. Pelvic congestion syndrome is a common cause of chronic pelvic pain in women and its association with venous congestion has been described in the literature. We evaluated the potential benefits of lumboovarian vein embolization in the treatment of lower abdominal pain in patients presenting with pelvic varicosities. Methods. Nineteen patients were treated. There were 13 unilateral embolizations, 6 initial bilateral treatments and 5 treated recurrences (a total of 30 procedures). All embolizations were performed with either enbucrilate and/or macrocoils, and there was an average clinical and Doppler duplex follow-up of 15.4 months. Results. The initial technical success rate was 96.7%. There were no immediate or long-term complications. Variable symptomatic relief was observed in 73.7% of cases with complete responses in 57.9%. All 8 patients who had partial or no pain relief complained of dyspareunia. The direct relationship between varices and chronic pelvic pain was difficult to ascertain in a significant number of clinical failures. Conclusion. Transcatheter embolization of lumboovarian varices is a safe technique offering symptomatic relief of pelvic pain in the majority of cases. The presence of dyspareunia seemed to be a poor prognostic factor, indicating that other causes of pelvic pain may coexist with pelvic varicosities

  15. Power doppler 'blanching' after the application of transducer pressure

    International Nuclear Information System (INIS)

    Joshua, F.; Edmonds, J.; Lassere, M.; De Carle, R.; Rayment, M.; Bryant, C.; Shnier, R.

    2005-01-01

    The aim of this study was to determine if transducer pressure modifies power Doppler assessments of rheumatoid arthritis synovium at the metacarpophalangeal joints and metatarsophalangeal joints. Five rheumatoid arthritis patients of varying degrees of 'disease activity' and damage were assessed with power Doppler ultrasound scanning of the dominant hand second to fifth metacarpophalangeal joints. Two rheumatoid arthritis patients had their dominant foot first to fifth metatarsophalangeal joints assessed with power Doppler ultrasound. Ultrasonography was performed with a high frequency transducer (14 MHz) with a colour mode frequency of 10 Mhz, and a standard colour box and gain. In the joint that showed the highest power Doppler signal, an image was made. A further image was taken after transducer pressure was applied. In all patients, there was increased flow to at least one joint. After pressure was applied, power Doppler signal intensity markedly reduced in all images and in some there was no recordable power Doppler signal. Increased transducer pressure can result in a marked reduction or obliteration in power Doppler signal. This power Doppler 'blanching' shows the need for further studies to evaluate sources of error and standardization before power Doppler ultrasound becomes a routine measure of 'disease activity' in rheumatoid arthritis. Copyright (2005) Blackwell Science Pty Ltd

  16. Comparative of signal processing techniques for micro-Doppler signature extraction with automotive radar systems

    Science.gov (United States)

    Rodriguez-Hervas, Berta; Maile, Michael; Flores, Benjamin C.

    2014-05-01

    In recent years, the automotive industry has experienced an evolution toward more powerful driver assistance systems that provide enhanced vehicle safety. These systems typically operate in the optical and microwave regions of the electromagnetic spectrum and have demonstrated high efficiency in collision and risk avoidance. Microwave radar systems are particularly relevant due to their operational robustness under adverse weather or illumination conditions. Our objective is to study different signal processing techniques suitable for extraction of accurate micro-Doppler signatures of slow moving objects in dense urban environments. Selection of the appropriate signal processing technique is crucial for the extraction of accurate micro-Doppler signatures that will lead to better results in a radar classifier system. For this purpose, we perform simulations of typical radar detection responses in common driving situations and conduct the analysis with several signal processing algorithms, including short time Fourier Transform, continuous wavelet or Kernel based analysis methods. We take into account factors such as the relative movement between the host vehicle and the target, and the non-stationary nature of the target's movement. A comparison of results reveals that short time Fourier Transform would be the best approach for detection and tracking purposes, while the continuous wavelet would be the best suited for classification purposes.

  17. Influence of the measuring condition on vibrocardiographic signals acquired on the thorax with a laser Doppler vibrometer

    Science.gov (United States)

    Mignanelli, L.; Bauer, G.; Klarmann, M.; Wang, H.; Rembe, C.

    2017-07-01

    Velocity signals acquired with a Laser Doppler Vibrometer on the thorax (Optical Vibrocardiography) contain important information, which have a relation to cardiovascular parameters and cardiovascular diseases. The acquired signal results in a superimposition of vibrations originated from different sources of the human body. Since we study the vibration generated by the heart to reliably detect a characteristic time interval corresponding to the PR interval in the ECG, these disturbance have to be removed by filtering. Moreover, the Laser Doppler Vibrometer measures only in the direction of the laser beam and, thus, the velocity signal is only a projection of the tridimensional movement of the thorax. This work presents an analysis of the influences of the filters and of the measurement direction on the characteristic time interval in Vibrocardiographic signals. Our analysis results in recommended settings for filters and we demonstrate that reliable detection of vibrocardiographic parameters is possible within an angle deviation of 30° in respect to the perpendicular irradiation on the front side of the subject.

  18. P2X7 signaling promotes microsphere embolism-triggered microglia activation by maintaining elevation of Fas ligand

    Directory of Open Access Journals (Sweden)

    Lu Ying-mei

    2012-07-01

    Full Text Available Abstract Background The cerebral microvascular occlusion elicits microvascular injury which mimics the different degrees of stroke severity observed in patients, but the mechanisms underlying these embolic injuries are far from understood. The Fas ligand (FasL-Fas system has been implicated in a number of pathogenic states. Here, we examined the contribution of microglia-derived FasL to brain inflammatory injury, with a focus on the potential to suppress the FasL increase by inhibition of the P2X7-FasL signaling with pharmacological or genetic approaches during ischemia. Methods The cerebral microvascular occlusion was induced by microsphere injection in experimental animals. Morphological changes in microglial cells were studied immunohistochemically. The biochemical analyses were used to examine the intracellular changes of P2X7/FasL signaling. The BV-2 cells and primary microglia from mice genetically deficient in P2X7 were used to further establish a linkage between microglia activation and FasL overproduction. Results The FasL expression was continuously elevated and was spatiotemporally related to microglia activation following microsphere embolism. Notably, P2X7 expression concomitantly increased in microglia and presented a distribution pattern that was similar to that of FasL in ED1-positive cells at pathological process of microsphere embolism. Interestingly, FasL generation in cultured microglia cells subjected to oxygen-glucose deprivation-treated neuron-conditioned medium was prevented by the silencing of P2X7. Furthermore, FasL induced the migration of BV-2 microglia, whereas the neutralization of FasL with a blocking antibody was highly effective in inhibiting ischemia-induced microglial mobility. Similar results were observed in primary microglia from wild-type mice or mice genetically deficient in P2X7. Finally, the degrees of FasL overproduction and neuronal death were consistently reduced in P2X7−/− mice compared with wild

  19. Time of correlation of low-frequency fluctuations in the regional laser Doppler flow signal from human skin

    Science.gov (United States)

    Folgosi-Correa, M. S.; Nogueira, G. E. C.

    2012-06-01

    The laser Doppler flowmetry allows the non-invasive assessment of the skin perfusion in real-time, being an attractive technique to study the human microcirculation in clinical settings. Low-frequency oscillations in the laser Doppler blood flow signal from the skin have been related to the endothelial, endothelial-metabolic, neurogenic and myogenic mechanisms of microvascular flow control, in the range 0.005-0.0095 Hz, 0.0095-0.021 Hz, 0.021-0.052 Hz and 0.052- 0.145 Hz respectively. The mean Amplitude (A) of the periodic fluctuations in the laser Doppler blood flow signal, in each frequency range, derived from the respective wavelet-transformed coefficients, has been used to assess the function and dysfunctions of each mechanism of flow control. Known sources of flow signal variances include spatial and temporal variability, diminishing the discriminatory capability of the technique. Here a new time domain method of analysis is proposed, based on the Time of Correlation (TC) of flow fluctuations between two adjacent sites. Registers of blood flow from two adjacent regions, for skin temperature at 32 0C (basal) and thermally stimulated (42 0C) of volar forearms from 20 healthy volunteers were collected and analyzed. The results obtained revealed high time of correlation between two adjacent regions when thermally stimulated, for signals in the endothelial, endothelial-metabolic, neurogenic and myogenic frequency ranges. Experimental data also indicate lower variability for TC when compared to A, when thermally stimulated, suggesting a new promising parameter for assessment of the microvascular flow control.

  20. The Auscultation of a Carbon Dioxide Embolization Event during Endoscopic Vein Harvest

    Directory of Open Access Journals (Sweden)

    Erik Strauss

    2016-01-01

    Full Text Available Endoscopic vein harvest in preparation for coronary artery bypass surgery has become a preferred method of procuring saphenous vein. Several case reports have documented carbon dioxide (CO2 embolization with this procedure as well as CO2 embolization during other laparoscopic surgeries (Markar et al., 2010. Although uncommon, the potential for CO2 entrainment through an open vein or through absorption by vascular structures exists and should be recognized (Lin et al., 2003. We report a case of CO2 embolization during EVH for a 77-year-old patient who underwent CABG that was identified early by the cardiac surgeon through the indirect auscultation of a mill-wheel murmur after the pericardium was opened. This may be the first reported case of a murmur related to air emboli identified without the use of a precordial Doppler probe or a stethoscope. This diagnosis was further supported by TEE before systemic hypotension or cardiovascular collapse occurred.

  1. Potential source of cerebral embolism in migraine with aura: a transcranial Doppler study.

    Science.gov (United States)

    Anzola, G P; Magoni, M; Guindani, M; Rozzini, L; Dalla Volta, G

    1999-05-12

    The recently found association between patent foramen ovale (PFO) and transient global amnesia (TGA) has suggested that paradoxical microembolization in the terminal vertebrobasilar territory might underlie at least some TGA cases. Migraine with visual aura is another paroxysmal disturbance in which a sudden dysfunction of cortical areas fed by the terminal branches of the basilar artery is believed to trigger the attack. Therefore we investigated the prevalence of PFO in a consecutive unselected cohort of migraine patients. To investigate the prevalence of PFO in a consecutive unselected cohort of migraine patients to search for a possible mechanism for the reported association of migraine with stroke. A total of 113 patients, consecutively referred by the Headache Outpatient Clinic for migraine with aura (MA+, mean age 34+/-12 years) were compared with 53 patients with migraine without aura (MA-, mean age 36+/-13 years) and with 25 age-matched nonmigraine subjects (mean age 31+/-10 years) selected from the hospital staff. PFO was assessed with transcranial Doppler sonography with IV injection of agitated saline, a technique that is 90% sensitive and 100% specific. The prevalence of PFO was 48% (54/113) in MA+ patients, 23% (12/53) in MA- patients, and 20% (5/25) in control subjects. The difference between MA+ and MA- patients was significant (odds ratio [OR] = 3.13, 95% confidence interval [CI] = 1.41 to 7.04, chi2 = 9.52,p = 0.002) as was the difference between MA+ patients and controls (OR = 3.66, 95% CI = 1.21 to 13.25, chi2 = 6.46, p = 0.01), whereas MA- patients did not differ from controls (OR = 1.17, 95% CI = 0.32 to 4.45, chi2 = 0.07). MRI was negative in 22 MA+ and 8 MA- patients. Patency of the foramen ovale is associated with migraine with aura but not with migraine without aura. The increased risk of stroke found in epidemiologic studies in patients with migraine with aura may be explained by an increased propensity to paradoxical cerebral embolism.

  2. The effect of TACE with endostatin on hemodynamics in hepatic implantation tumor using Doppler ultrasonography

    International Nuclear Information System (INIS)

    Zhou Guangli; Wu Yuanyuan; Wang Bin; Liu Yan; Zheng Chuanli; Sang Li; Liu Feng

    2009-01-01

    Objective: To investigate the hemodynamic changes in the rabbit liver and VX2 hepatic implantation tumor after treatment by transcatheter arterial chemoembolization (TACE)/endostatin using Doppler ultrasonography. Methods: Twenty rabbits with VX2 hepatic tumor were randomly distributed into the control group (n=10) and the anti- angiogenesis group (n=10). The rabbits were administered with endostatin and adriamycin-lipiodol in the anti-angiogenesis group and with 37℃ saline in the control group via hepatic artery. The hemodynamic changes of the tumors, hepatic artery, and portal vein were recorded with Doppler ultrasonography 1 week after the treatment. The results before and after the treatment were compared. Results: In the control group, the maximal hepatic artery blood flow velocity was significantly higher than that before the treatment (P<0.05). However, the resistance index and the portal vein blood flow velocities had no significantly change compared with those before the treatment (P>0.05). In the anti-angiogenesis group, the hepatic artery blood flow velocity was significantly lower than that before the treatment (P<0.05), and the resistance index was increased (P<0.05). However, the portal vein blood flow velocity had no significantly change (P>0.05). The blood flow signal in all tumors was rich before embolization. After TACE, the blood flow signal was significantly decreased, even partly disappeared in the anti-angiogenesis group. Conclusion: TACE with endostatin can effectively block the blood supplement of VX2 hepatic implantation tumor. Doppler ultrasonography can detected the blood flow changes and can be used in evaluating the therapeutic effect in hepatic implantation tumor. (authors)

  3. Analysis of Radar Doppler Signature from Human Data

    Directory of Open Access Journals (Sweden)

    M. ANDRIĆ

    2014-04-01

    Full Text Available This paper presents the results of time (autocorrelation and time-frequency (spectrogram analyses of radar signals returned from the moving human targets. When a radar signal falls on the human target which is moving toward or away from the radar, the signals reflected from different parts of his body produce a Doppler shift that is proportional to the velocity of those parts. Moving parts of the body causes the characteristic Doppler signature. The main contribution comes from the torso which causes the central Doppler frequency of target. The motion of arms and legs induces modulation on the returned radar signal and generates sidebands around the central Doppler frequency, referred to as micro-Doppler signatures. Through analyses on experimental data it was demonstrated that the human motion signature extraction is better using spectrogram. While the central Doppler frequency can be determined using the autocorrelation and the spectrogram, the extraction of the fundamental cadence frequency using the autocorrelation is unreliable when the target is in the clutter presence. It was shown that the fundamental cadence frequency increases with increasing dynamic movement of people and simultaneously the possibility of its extraction is proportional to the degree of synchronization movements of persons in the group.

  4. Assessment of right ventricular systolic function by tissue Doppler echocardiography

    DEFF Research Database (Denmark)

    Kjærgaard, Jesper

    2012-01-01

    This thesis summarizes a series of studies performed in order to assess the clinical usefulness of a novel echocardiographic technology that allows non-invasive assessment of regional right ventricular myocardial velocities and deformation: tissue Doppler echocardiography. While the technology...... is a promising tool for improving our understanding of right ventricular hemodynamics, several aspects of the technology must be evaluated. The accuracy and reproducibility of the technology is evaluated in vitro, and normal values, impact of changes in loading of the right ventricle, response to exercise...... on right ventricular hemodynamics: pulmonary embolism, Arrhythmogenic right ventricular cardiomyopathy and pulmonary regurgitation, the latter in an animal model. The conclusions of the thesis are: Color tissue Doppler echocardiography accurately measures velocities, SR and strain in vitro. No systematic...

  5. Ultrasonic colour Doppler imaging

    DEFF Research Database (Denmark)

    Evans, David H.; Jensen, Jørgen Arendt; Nielsen, Michael Bachmann

    2011-01-01

    Ultrasonic colour Doppler is an imaging technique that combines anatomical information derived using ultrasonic pulse-echo techniques with velocity information derived using ultrasonic Doppler techniques to generate colour-coded maps of tissue velocity superimposed on grey-scale images of tissue...... anatomy. The most common use of the technique is to image the movement of blood through the heart, arteries and veins, but it may also be used to image the motion of solid tissues such as the heart walls. Colour Doppler imaging is now provided on almost all commercial ultrasound machines, and has been...... vectors. This review briefly introduces the principles behind colour Doppler imaging and describes some clinical applications. It then describes the basic components of conventional colour Doppler systems and the methods used to derive velocity information from the ultrasound signal. Next, a number of new...

  6. Frequency Diverse Array Radar Signal Processing via Space-Range-Doppler Focus (SRDF Method

    Directory of Open Access Journals (Sweden)

    Chen Xiaolong

    2018-04-01

    Full Text Available To meet the urgent demand of low-observable moving target detection in complex environments, a novel method of Frequency Diverse Array (FDA radar signal processing method based on Space-Rang-Doppler Focusing (SRDF is proposed in this paper. The current development status of the FDA radar, the design of the array structure, beamforming, and joint estimation of distance and angle are systematically reviewed. The extra degrees of freedom provided by FDA radar are fully utilizsed, which include the Degrees Of Freedom (DOFs of the transmitted waveform, the location of array elements, correlation of beam azimuth and distance, and the long dwell time, which are also the DOFs in joint spatial (angle, distance, and frequency (Doppler dimensions. Simulation results show that the proposed method has the potential of improving target detection and parameter estimation for weak moving targets in complex environments and has broad application prospects in clutter and interference suppression, moving target refinement, etc..

  7. Method and system of doppler correction for mobile communications systems

    Science.gov (United States)

    Georghiades, Costas N. (Inventor); Spasojevic, Predrag (Inventor)

    1999-01-01

    Doppler correction system and method comprising receiving a Doppler effected signal comprising a preamble signal (32). A delayed preamble signal (48) may be generated based on the preamble signal (32). The preamble signal (32) may be multiplied by the delayed preamble signal (48) to generate an in-phase preamble signal (60). The in-phase preamble signal (60) may be filtered to generate a substantially constant in-phase preamble signal (62). A plurality of samples of the substantially constant in-phase preamble signal (62) may be accumulated. A phase-shifted signal (76) may also be generated based on the preamble signal (32). The phase-shifted signal (76) may be multiplied by the delayed preamble signal (48) to generate an out-of-phase preamble signal (80). The out-of-phase preamble signal (80) may be filtered to generate a substantially constant out-of-phase preamble signal (82). A plurality of samples of the substantially constant out-of-phase signal (82) may be accumulated. A sum of the in-phase preamble samples and a sum of the out-of-phase preamble samples may be normalized relative to each other to generate an in-phase Doppler estimator (92) and an out-of-phase Doppler estimator (94).

  8. On the choice of the number of samples in laser Doppler anemometry signal processing

    Science.gov (United States)

    Dios, Federico; Comeron, Adolfo; Garcia-Vizcaino, David

    2001-05-01

    The minimum number of samples that must be taken from a sinusoidal signal affected by white Gaussian noise, in order to find its frequency with a predetermined maximum error, is derived. This analysis is of interest in evaluating the performance of velocity-measurement systems based on the Doppler effect. Specifically, in laser Doppler anemometry (LDA) it is usual to receive bursts with a poor signal-to- noise ratio, yet high accuracy is required for the measurement. In recent years special attention has been paid to the problem of monitoring the temporal evolution of turbulent flows. In this kind of situation averaging or filtering the data sequences cannot be allowed: in a rapidly changing environment each one of the measurements should rather by performed within a maximum permissible error and the bursts strongly affected by noise removed. The method for velocity extraction that will be considered here is the spectral analysis through the squared discrete Fourier transform, or periodogram, of the received bursts. This paper has two parts. In the first an approximate expression for the error committed in LDA is derived and discussed. In the second a mathematical formalism for the exact calculation of the error as a function of the signal-to- noise ratio is obtained, and some universal curves for the expected error are provided. The results presented here appear to represent a fundamental limitation on the accuracy of LDA measurements, yet, to our knowledge, they have not been reported in the literature so far.

  9. Demonstration of pulmonary embolism with gadolinium-enhanced spiral CT

    Energy Technology Data Exchange (ETDEWEB)

    Coche, E.E.; Hammer, F.D.; Goffette, P.P. [Dept. of Radiology, St. Luc University Hospital, Brussels (Belgium)

    2001-11-01

    The authors report a case of successful detection of pulmonary embolism using gadolinium-enhanced spiral CT (Gadodiamide, 0.4 mmol/kg, 2 ml/s, delay 18 s) in a 77-year-old woman, with previous allergy to iodinated contrast medium, and renal failure, who presented with pulmonary arterial hypertension. Doppler ultrasound of the lower limbs was first performed and revealed a deep venous thrombosis of the right lower limb. To establish if venous thrombosis was the cause of pulmonary hypertension and to confirm that pulmonary endarterectomy was not indicated in this situation, several imaging modalities were performed. Lung scintigraphy and MRI were non-diagnostic. Gadolinium-enhanced spiral CT demonstrated a large thrombus located proximally and in a segmental artery of the right lower lobe. This case illustrates the potential usefulness of gadolinium as alternative contrast agent with spiral CT to diagnose pulmonary embolism and elucidate the cause of pulmonary arterial hypertension in a patient with some contraindications for iodinated contrast medium injection. (orig.)

  10. Demonstration of pulmonary embolism with gadolinium-enhanced spiral CT

    International Nuclear Information System (INIS)

    Coche, E.E.; Hammer, F.D.; Goffette, P.P.

    2001-01-01

    The authors report a case of successful detection of pulmonary embolism using gadolinium-enhanced spiral CT (Gadodiamide, 0.4 mmol/kg, 2 ml/s, delay 18 s) in a 77-year-old woman, with previous allergy to iodinated contrast medium, and renal failure, who presented with pulmonary arterial hypertension. Doppler ultrasound of the lower limbs was first performed and revealed a deep venous thrombosis of the right lower limb. To establish if venous thrombosis was the cause of pulmonary hypertension and to confirm that pulmonary endarterectomy was not indicated in this situation, several imaging modalities were performed. Lung scintigraphy and MRI were non-diagnostic. Gadolinium-enhanced spiral CT demonstrated a large thrombus located proximally and in a segmental artery of the right lower lobe. This case illustrates the potential usefulness of gadolinium as alternative contrast agent with spiral CT to diagnose pulmonary embolism and elucidate the cause of pulmonary arterial hypertension in a patient with some contraindications for iodinated contrast medium injection. (orig.)

  11. An improved method based on wavelet coefficient correlation to filter noise in Doppler ultrasound blood flow signals

    Science.gov (United States)

    Wan, Renzhi; Zu, Yunxiao; Shao, Lin

    2018-04-01

    The blood echo signal maintained through Medical ultrasound Doppler devices would always include vascular wall pulsation signal .The traditional method to de-noise wall signal is using high-pass filter, which will also remove the lowfrequency part of the blood flow signal. Some scholars put forward a method based on region selective reduction, which at first estimates of the wall pulsation signals and then removes the wall signal from the mixed signal. Apparently, this method uses the correlation between wavelet coefficients to distinguish blood signal from wall signal, but in fact it is a kind of wavelet threshold de-noising method, whose effect is not so much ideal. In order to maintain a better effect, this paper proposes an improved method based on wavelet coefficient correlation to separate blood signal and wall signal, and simulates the algorithm by computer to verify its validity.

  12. Uterine arterial methotrexate infusion and embolization in the treatment of uterine adenomyosis

    International Nuclear Information System (INIS)

    Xie Jingyan; Wang Suzheng; Chen Jingfang; Xuan Yinghua; Lou Wensheng; Gu Jianping

    2008-01-01

    Objective: To study the efficacy of treating different types of uterine adenomyosis with transcatheter local infusion of methotrexate (MTX) combined with uterine arterial embolization under guidance of digital subtraction angiography (DSA). Methods: 33 cases were primarily screened out according to clinical symptoms and color Doppler and then further diagnosis as diffuse or local adenomyosis were undertaken with super selective uterine arterial angiography. The patients were then treated with uterine arterial local infusion (50 mg MTX)and embolization with PVA microsphere (diameter 450-650 μm), individually. Finally, the comparison between the preoperative and postoperative menstruation volumes, the degrees of dysmenorrheal, uterine sizes and the levels of sexual hormones of diffuse and local adenomyosis was carried out. Results: The uterine arterial local infusion of MTX combined with embolization showed no chemotherapeutic side effects. In all cases, there were decrease of menstruation amount, alleviated dysmenorrhea, reduction of uterine size, and the efficacy was more evident in diffuse adenomyosis (P<0.05). Conclusions: Micro-invasive interventional technique combined with drug therapy is promising for diffuse and local adenomyosis especially for the former. (authors)

  13. Renal Arteriovenous Shunts: Clinical Features, Imaging Appearance, and Transcatheter Embolization Based on Angioarchitecture.

    Science.gov (United States)

    Maruno, Miyuki; Kiyosue, Hiro; Tanoue, Shuichi; Hongo, Norio; Matsumoto, Shunro; Mori, Hiromu; Sagara, Yoshiko; Kashiwagi, Junji

    2016-01-01

    Renal arteriovenous (AV) shunt, a rare pathologic condition, is divided into two categories, traumatic and nontraumatic, and can cause massive hematuria, retroperitoneal hemorrhage, pain, and high-output heart failure. Although transcatheter embolization is a less-invasive and effective treatment option, it has a potential risk of complications, including renal infarction and pulmonary embolism, and a potential risk of recanalization. The successful embolization of renal AV shunt requires a complete occlusion of the shunted vessel while preventing the migration of embolic materials and preserving normal renal arterial branches, which depends on the selection of adequate techniques and embolic materials for individual cases, based on the etiology and imaging angioarchitecture of the renal AV shunts. A classification of AV malformations in the extremities and body trunk could precisely correspond with the angioarchitecture of the nontraumatic renal AV shunts. The selection of techniques and choice of adequate embolic materials such as coils, vascular plugs, and liquid materials are determined on the basis of cause (eg, traumatic vs nontraumatic), the classification, and some other aspects of the angioarchitecture of renal AV shunts, including the flow and size of the fistulas, multiplicity of the feeders, and endovascular accessibility to the target lesions. Computed tomographic angiography and selective digital subtraction angiography can provide precise information about the angioarchitecture of renal AV shunts before treatment. Color Doppler ultrasonography and time-resolved three-dimensional contrast-enhanced magnetic resonance angiography represent useful tools for screening and follow-up examinations of renal AV shunts after embolization. In this article, the classifications, imaging features, and an endovascular treatment strategy based on the angioarchitecture of renal AV shunts are described. (©)RSNA, 2016.

  14. Absence of Doppler signal in transcranial color-coded ultrasonography may be confirmatory for brain death: A case report

    Directory of Open Access Journals (Sweden)

    Mehmet Akif Topçuoğlu

    2015-08-01

    Full Text Available Transcranial Doppler ultrasonography (TCD is a valuable tool for demonstrating cerebral circulatory arrest (CCA in the setting of brain death. Complete reversal of diastolic flow (to-and-fro flow and systolic spikes in bilateral terminal internal carotid arteries and vertebrobasilar circulation are considered as specific sonogram configurations supporting the diagnosis of CCA. Because of the possibility of sonic bone window impermeability, absence of any waveform in TCD is not confirmatory for CCA unless there is documentation of disappearance of a previously well detected signal by the same recording settings. Transcranial color-coded sonography (TCCS with B-mode imaging can reliably detect adequacy of bone windows with clarity contralateral skull and ipsilateral planum temporale visualization. Therefore, absence of detectable intracranial Doppler signal along with available ultrasound window in TCCS can confirm clinical diagnosis of brain death. We herein discuss this entity from the frame of a representative case.

  15. First multimodal embolization particles visible on x-ray/computed tomography and magnetic resonance imaging.

    Science.gov (United States)

    Bartling, Soenke H; Budjan, Johannes; Aviv, Hagit; Haneder, Stefan; Kraenzlin, Bettina; Michaely, Henrik; Margel, Shlomo; Diehl, Steffen; Semmler, Wolfhard; Gretz, Norbert; Schönberg, Stefan O; Sadick, Maliha

    2011-03-01

    Embolization therapy is gaining importance in the treatment of malignant lesions, and even more in benign lesions. Current embolization materials are not visible in imaging modalities. However, it is assumed that directly visible embolization material may provide several advantages over current embolization agents, ranging from particle shunt and reflux prevention to improved therapy control and follow-up assessment. X-ray- as well as magnetic resonance imaging (MRI)-visible embolization materials have been demonstrated in experiments. In this study, we present an embolization material with the property of being visible in more than one imaging modality, namely MRI and x-ray/computed tomography (CT). Characterization and testing of the substance in animal models was performed. To reduce the chance of adverse reactions and to facilitate clinical approval, materials have been applied that are similar to those that are approved and being used on a routine basis in diagnostic imaging. Therefore, x-ray-visible Iodine was combined with MRI-visible Iron (Fe3O4) in a macroparticle (diameter, 40-200 μm). Its core, consisting of a copolymerized monomer MAOETIB (2-methacryloyloxyethyl [2,3,5-triiodobenzoate]), was coated with ultra-small paramagnetic iron oxide nanoparticles (150 nm). After in vitro testing, including signal to noise measurements in CT and MRI (n = 5), its ability to embolize tissue was tested in an established tumor embolization model in rabbits (n = 6). Digital subtraction angiography (DSA) (Integris, Philips), CT (Definition, Siemens Healthcare Section, Forchheim, Germany), and MRI (3 Tesla Magnetom Tim Trio MRI, Siemens Healthcare Section, Forchheim, Germany) were performed before, during, and after embolization. Imaging signal changes that could be attributed to embolization particles were assessed by visual inspection and rated on an ordinal scale by 3 radiologists, from 1 to 3. Histologic analysis of organs was performed. Particles provided a

  16. Superimposed noninterfering probes to extend the capabilities of phase Doppler anemometry.

    Science.gov (United States)

    Onofri, Fabrice; Lenoble, Anne; Radev, Stefan

    2002-06-20

    We propose using multiple superimposed noninterfering probes (SNIPs) of the same wavelength but different beam angles to extend the capabilities of phase Doppler anemometry. When a particle is moving in a SNIP the Doppler signals that are produced exhibit multiple Doppler frequencies and phase shifts. The resolution of the measurements of particle size (i.e., by fringe spacing and Doppler frequency) increases with beam angle. Then, with the solution proposed, even with only two detectors several measurements of size can be obtained for the same particle with increasing resolution if we consider higher frequencies in the signal. Several optical solutions to produce SNIPs as well as a signal-processing algorithm to treat the multiple-frequency Doppler signals are proposed. Experimental validations of the sizing of spherical and cylindrical particles demonstrate the applicability of this technique for particle measurement. We believe that this new technique can be of great interest when high resolution of size, velocity, and even refractive index is required.

  17. Pulse Doppler radar

    CERN Document Server

    Alabaster, Clive

    2012-01-01

    This book is a practitioner's guide to all aspects of pulse Doppler radar. It concentrates on airborne military radar systems since they are the most used, most complex, and most interesting of the pulse Doppler radars; however, ground-based and non-military systems are also included. It covers the fundamental science, signal processing, hardware issues, systems design and case studies of typical systems. It will be a useful resource for engineers of all types (hardware, software and systems), academics, post-graduate students, scientists in radar and radar electronic warfare sectors and milit

  18. Transcatheter Arterial Embolization of Cystic Artery Pseudoaneurysm in Acalculous Cholecystitis: A Case Report

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hyung Ook; Lee, Young Hwan [Dept. of Radiology, Daegu Catholic University College of Medicine, Daegu (Korea, Republic of); Kim, Young Hwan [Dept. of Diagnostic Radiology, Dongsan Medical Center, Keimyung University College of Medicine, Daegu (Korea, Republic of)

    2011-04-15

    A pseudoaneurysm of the cystic artery is a rare complication of cholecystitis, and is manifested by hemobilia or hematemesis. An early diagnosis is required for the successful treatment by cholecystectomy and ligation of the cystic artery. Herein, we report a case of a pseudoaneurysm of the cystic artery diagnosed by color Doppler ultrasonography and CT, and successfully treated by transcatheter arterial embolization with N-butyl cyanoacrylate in a high-risk surgical patient.

  19. Venous and arterial thrombo-embolic complications of hormonal treatment in a male-to-female transgender patient.

    LENUS (Irish Health Repository)

    Mullins, G M

    2012-02-03

    We present a male-to-female (MTF) transgender patient admitted with a pulmonary embolism. The patient had been treated with high-dose oestrogens since the age of 16. Following a prolonged period of hypotension, our patient sustained cerebral border zone infarcts. There was evidence of bilateral carotid stenosis on Doppler ultrasound. We discuss the treatment and vascular complications of gender dysphoria.

  20. Micro-Doppler Ambiguity Resolution Based on Short-Time Compressed Sensing

    Directory of Open Access Journals (Sweden)

    Jing-bo Zhuang

    2015-01-01

    Full Text Available When using a long range radar (LRR to track a target with micromotion, the micro-Doppler embodied in the radar echoes may suffer from ambiguity problem. In this paper, we propose a novel method based on compressed sensing (CS to solve micro-Doppler ambiguity. According to the RIP requirement, a sparse probing pulse train with its transmitting time random is designed. After matched filtering, the slow-time echo signals of the micromotion target can be viewed as randomly sparse sampling of Doppler spectrum. Select several successive pulses to form a short-time window and the CS sensing matrix can be built according to the time stamps of these pulses. Then performing Orthogonal Matching Pursuit (OMP, the unambiguous micro-Doppler spectrum can be obtained. The proposed algorithm is verified using the echo signals generated according to the theoretical model and the signals with micro-Doppler signature produced using the commercial electromagnetic simulation software FEKO.

  1. Burst Format Design for Optimum Joint Estimation of Doppler-Shift and Doppler-Rate in Packet Satellite Communications

    Directory of Open Access Journals (Sweden)

    Luca Giugno

    2007-05-01

    Full Text Available This paper considers the problem of optimizing the burst format of packet transmission to perform enhanced-accuracy estimation of Doppler-shift and Doppler-rate of the carrier of the received signal, due to relative motion between the transmitter and the receiver. Two novel burst formats that minimize the Doppler-shift and the Doppler-rate Cramér-Rao bounds (CRBs for the joint estimation of carrier phase/Doppler-shift and of the Doppler-rate are derived, and a data-aided (DA estimation algorithm suitable for each optimal burst format is presented. Performance of the newly derived estimators is evaluated by analysis and by simulation, showing that such algorithms attain their relevant CRBs with very low complexity, so that they can be directly embedded into new-generation digital modems for satellite communications at low SNR.

  2. De-Dopplerization of Acoustic Measurements

    Science.gov (United States)

    2017-08-10

    accurate measurement of aircraft location to resample the time signal to account for the compression and expansion of acoustic wavefronts. Correcting...AFRL-RH-WP-TR-2017-0043 DE-DOPPLERIZATION OF ACOUSTIC MEASUREMENTS Frank Mobley, PhD 711 HPW/RHCB Wright-Patterson AFB OH...TITLE AND SUBTITLE DE-DOPPLERIZATION OF ACOUSTIC MEASUREMENTS 5a. CONTRACT NUMBER In-House 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER

  3. Physiological effects of indomethacin and celecobix: an S-transform laser Doppler flowmetry signal analysis

    International Nuclear Information System (INIS)

    Assous, S; Humeau, A; Tartas, M; Abraham, P; L'Huillier, J P

    2005-01-01

    Conventional signal processing typically involves frequency selective techniques which are highly inadequate for nonstationary signals. In this paper, we present an approach to perform time-frequency selective processing of laser Doppler flowmetry (LDF) signals using the S-transform. The approach is motivated by the excellent localization, in both time and frequency, afforded by the wavelet basis functions. Suitably chosen Gaussian wavelet functions are used to characterize the subspace of signals that have a given localized time-frequency support, thus enabling a time-frequency partitioning of signals. In this paper, the goal is to study the influence of various pharmacological substances taken by the oral way (celecobix (Celebrex (registered) ), indomethacin (Indocid (registered) ) and placebo) on the physiological activity behaviour. The results show that no statistical differences are observed in the energy computed from the time-frequency representation of LDF signals, for the myogenic, neurogenic and endothelial related metabolic activities between Celebrex and placebo, and Indocid and placebo. The work therefore proves that these drugs do not affect these physiological activities. For future physiological studies, there will therefore be no need to exclude patients having taken cyclo-oxygenase 1 inhibitions

  4. Physiological effects of indomethacin and celecobix: an S-transform laser Doppler flowmetry signal analysis

    Science.gov (United States)

    Assous, S.; Humeau, A.; Tartas, M.; Abraham, P.; L'Huillier, J. P.

    2005-05-01

    Conventional signal processing typically involves frequency selective techniques which are highly inadequate for nonstationary signals. In this paper, we present an approach to perform time-frequency selective processing of laser Doppler flowmetry (LDF) signals using the S-transform. The approach is motivated by the excellent localization, in both time and frequency, afforded by the wavelet basis functions. Suitably chosen Gaussian wavelet functions are used to characterize the subspace of signals that have a given localized time-frequency support, thus enabling a time-frequency partitioning of signals. In this paper, the goal is to study the influence of various pharmacological substances taken by the oral way (celecobix (Celebrex®), indomethacin (Indocid®) and placebo) on the physiological activity behaviour. The results show that no statistical differences are observed in the energy computed from the time-frequency representation of LDF signals, for the myogenic, neurogenic and endothelial related metabolic activities between Celebrex and placebo, and Indocid and placebo. The work therefore proves that these drugs do not affect these physiological activities. For future physiological studies, there will therefore be no need to exclude patients having taken cyclo-oxygenase 1 inhibitions.

  5. Color Doppler Ultrasonographic Findings of Vascular Leiomyoma: Pathologic Correlation

    Energy Technology Data Exchange (ETDEWEB)

    Ko, Ji Young; Koh, Sung Hye; Min, Soo Kee; Choi, A Lam; Jang, Kyung Mi; Lee, Yul; Lee, Kwan Seop; Lee, Hyun; Sohn, Jeong Hee [Hallym University Sacred Heart Hospital, Anyang (Korea, Republic of); Kim, Sam Soo [Kangwon National University College of Medicine, Chuncheon (Korea, Republic of)

    2009-12-15

    To evaluate the distribution of color flow signals on color Doppler ultrasonography of vascular leiomyomas and to correlate them with pathologic findings. We retrospectively analyzed color Doppler ultrasonographic images and pathologic slides of six vascular leiomyomas. We classified the patterns of distribution of color flow signals into localized compact cluster types and non-cluster types, and the pathologic findings into three subtypes: solid, venous and cavernous. All cases showed well-defined homogenous hypoechoic subcutaneous masses on gray-scale ultrasonography. Three cases showed localized compact cluster types on color Doppler ultrasonography, one in each subtype (solid, venous and cavernous). For the three non-cluster types, again there was on in each subtype. In addition, on pathologic analysis the zone of the localized compact cluster of color flow signals coincided with a cluster of larger, vascular caliber masses. Localized compact clusters of color flow signals on color Doppler ultrasonography were seen in 50% of our cases and correlated with a cluster of larger vascular caliber in the mass. But the pattern of distribution of color flows didn't show a correlation with pathologic type

  6. Color Doppler Ultrasonographic Findings of Vascular Leiomyoma: Pathologic Correlation

    International Nuclear Information System (INIS)

    Ko, Ji Young; Koh, Sung Hye; Min, Soo Kee; Choi, A Lam; Jang, Kyung Mi; Lee, Yul; Lee, Kwan Seop; Lee, Hyun; Sohn, Jeong Hee; Kim, Sam Soo

    2009-01-01

    To evaluate the distribution of color flow signals on color Doppler ultrasonography of vascular leiomyomas and to correlate them with pathologic findings. We retrospectively analyzed color Doppler ultrasonographic images and pathologic slides of six vascular leiomyomas. We classified the patterns of distribution of color flow signals into localized compact cluster types and non-cluster types, and the pathologic findings into three subtypes: solid, venous and cavernous. All cases showed well-defined homogenous hypoechoic subcutaneous masses on gray-scale ultrasonography. Three cases showed localized compact cluster types on color Doppler ultrasonography, one in each subtype (solid, venous and cavernous). For the three non-cluster types, again there was on in each subtype. In addition, on pathologic analysis the zone of the localized compact cluster of color flow signals coincided with a cluster of larger, vascular caliber masses. Localized compact clusters of color flow signals on color Doppler ultrasonography were seen in 50% of our cases and correlated with a cluster of larger vascular caliber in the mass. But the pattern of distribution of color flows didn't show a correlation with pathologic type

  7. Radar Doppler Processing with Nonuniform Sampling.

    Energy Technology Data Exchange (ETDEWEB)

    Doerry, Armin W. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-07-01

    Conventional signal processing to estimate radar Doppler frequency often assumes uniform pulse/sample spacing. This is for the convenience of t he processing. More recent performance enhancements in processor capability allow optimally processing nonuniform pulse/sample spacing, thereby overcoming some of the baggage that attends uniform sampling, such as Doppler ambiguity and SNR losses due to sidelobe control measures.

  8. Low-Frequency Gravitational Wave Searches Using Spacecraft Doppler Tracking

    Directory of Open Access Journals (Sweden)

    Armstrong J. W.

    2006-01-01

    Full Text Available This paper discusses spacecraft Doppler tracking, the current-generation detector technology used in the low-frequency (~millihertz gravitational wave band. In the Doppler method the earth and a distant spacecraft act as free test masses with a ground-based precision Doppler tracking system continuously monitoring the earth-spacecraft relative dimensionless velocity $2 Delta v/c = Delta u/ u_0$, where $Delta u$ is the Doppler shift and $ u_0$ is the radio link carrier frequency. A gravitational wave having strain amplitude $h$ incident on the earth-spacecraft system causes perturbations of order $h$ in the time series of $Delta u/ u_0$. Unlike other detectors, the ~1-10 AU earth-spacecraft separation makes the detector large compared with millihertz-band gravitational wavelengths, and thus times-of-flight of signals and radio waves through the apparatus are important. A burst signal, for example, is time-resolved into a characteristic signature: three discrete events in the Doppler time series. I discuss here the principles of operation of this detector (emphasizing transfer functions of gravitational wave signals and the principal noises to the Doppler time series, some data analysis techniques, experiments to date, and illustrations of sensitivity and current detector performance. I conclude with a discussion of how gravitational wave sensitivity can be improved in the low-frequency band.

  9. Experimentally induced cerebral fat embolism with linoleic acid; MR imaging and pathologic correlation

    International Nuclear Information System (INIS)

    Kim, Jong Bae; Kim, Hak Jin; Kim, Yong; Lee, Suck Hong; Park, Byeong Rae

    2000-01-01

    To investigate the correlation between the MRI findings of cerebral fat embolism induced by injecting linoleic acid into ten cats, and pathologic diagnosis. Using a microcatheter, 30μ1 of linoleic acid was injeted into the internal carotid artery of ten cats. MR T2-weighted (T2WI), diffusion-weighted (DWI), and Gd-enhanced T1-weighted images(Gd-enhanced T1WI) were obtained after 30 minutes and after 2 hours of embolization. We pathlogically examined endothelial cell damage, cellular change, perivascular abnormality and fat vacuoles, and then determined the correlation between MRI and the pathologic findings. After 30 minutes of embolization, lesions of very high signal intensity were detected by T2WI in six cats, and of slightly high signal intensity in two:in the remaining two, signal intensity was normal. DWI showed lesions of very high intensity in nine animals and of slightly high intensity in one, while Gd-enhanced T1WI showed well-enhanced lesions in nine and a minimally enhanced lesion in one. After 2 hours of embolization, T2WI revealed lesions of very high signal intensity in nine cats, and of slightly high signal intensity in one, while DWI detected lesions of very high signal intensity in all cats. On Gd-enhanced T1WI, lesions in all cats were well enhanced. According to the findings of light microscopic examination, infarcted lesions mainly involved the gray matter, but also some white matter. In the lesions, neurophil matrix edema, neuronal degeneration, perivascular swelling, the widening of extracellular space, extravascular hemorrhage, and fat vacuoles were evident. During the initial two hours following injuction, MR imaging of cerebral fat embolism induced by linoleic acid through the internal carotid artery in cats showed high signal intensity on T2WI and DWI, and clear enhancement on Gd-enhanced T1WI. In cases involving cellular edema, cerebrovascular injury and extracellular space widening, the pathologic evidence suggested the coexistence of

  10. Enhanced magnetic resonance pulmonary perfusion imaging in diagnosing pulmonary embolism: preliminary investigation

    International Nuclear Information System (INIS)

    Huang Xiaoyong; Du Jing; Zhang Zhaoqi; Guo Xi; Yan Zixu; Jiang Hong; Wang Wei

    2005-01-01

    Objective: This study was designed to investigate the sensitivity and specificity of magnetic resonance pulmonary perfusion imaging (MRPP) in diagnosing pulmonary embolism (PE) compared with enhanced magnetic resonance pulmonary angiography (MRPA) and pulmonary radionuclide perfusion imaging. Methods: Fourteen patients were definitely diagnosed as PE, whose ages were from 19 to 71 years old and mean 45.5 ± 19.8 years old. All patients under went MRPA and MRPP and 3 patients were examined again after thrombolytic treatment. Five patients underwent pulmonary radionuclide perfusion imaging. Setting ROI in top, middle, bottom of lung area and abnormal area respectively, we detected signal intensity and time-signal curve to obtain the transformation rate of signal (TROS) during perfusion peak value. Results: In 14 pulmonary embolism patients, MRPA found 62 branches of pulmonary artery obstruction. Fifty-five abnormal pulmonary perfusion zones were found by MRPP, and the above results were very alike. The coincidence was 88.71%. In 14 cases, MRPP could show 25 subsegments lesion below segments. In 5 patients who had both results Of MRPP and ECT at the same time. MRPP shows 33 perfusion defect zones and 37 segments were found by ECT, the sensitivity was 89.19%. After thrombolytic treatment, both the status of the affected pulmonary artery improved markedly and perfusion defect zones reduced obviously in 3 cases by MRPP and MRPA. TROS in normal perfusion zones perfusion defect zones and low perfusion zones had significant difference (t=22.882, P<0.01). Conclusion: Contrast enhanced MR pulmonary perfusion can show both perfusion defect zones and low perfusion zones in pulmonary embolism. Time-signal curve can show the period of maximum no perfusion zones in pulmonary artery embolism zones. And the amplitude of fluctuation is small with miminum TROS. MRPP has significant values especially in showing pulmonary artery embolism in segments and subsegments. Using both MRPP and

  11. The use of contrast-enhanced color doppler ultrasound in the differentiation of retinal detachment from vitreous membrane

    International Nuclear Information System (INIS)

    Han, Sang Suk; Chang, Seung Kook; Yoon, Jung Hee; Lee, Young Joon

    2001-01-01

    To compare the clinical utility of contrast-enhanced color Doppler US in the differentiation of retinal detachment (RD) from vitreous membrane (VM) with that of various conventional US modalities, and to analyze the enhancement patterns in cases showing an enhancement effect. In 32 eyes examined over a recent two-year period, RD (n=14) and VM (n=18) were confirmed by surgery (n=28) or clinical follow-up (n=4). In all cases, gray-scale, color Doppler, and power Doppler US were performed prior to contrast injection, and after the intravenous injection of Levovist (Schering, Berlin) by hand for 30 seconds at a dose of 2.5 g and a concentration of 300 mg/mL via an antecubital vein, contrast-enhanced color Doppler US was performed. At Doppler US, the diagnostic criterion for RD and VM was whether or not color signals were visualized in membranous structures. Diagnostic accuracy was 78% at gray-scale US, 81% at color Doppler US, 59% at power Doppler US, and 97% at contrast-enhanced color Doppler US. The sensitivity of color Doppler US to color signals in RD increased from 57% to 93% after contrast enhancement. The enhancement patterns observed were signal accentuation (n=3), signal extension (n=2), signal addition (n=3), and new signal visualization (n=5). Contrast-enhanced color Doppler US was the most accurate US modality for differentiating RD from VM, showing a significantly increased signal detection rate in RD

  12. Clinical quantitative study of therapeutic effect of partial splenic embolization (PSE) on portal vein hemodynamics

    International Nuclear Information System (INIS)

    Li Zhengran; Shan Hong; Zhu Kangshun; Jiang Zaibo; Guan Shouhai; Huang Mingsheng

    2002-01-01

    Objective: To research the changes of blood flow and pressure of the portal vein at both pre-and post-PSE. Methods: The blood flows of the portal vein (PV), splenic vein (SV), and superior mesentery vein (SMV) were measured by using color Doppler in 31 cases with clinically proved hepatic cirrhosis and hypersplenism at both pre- and post-PSE. The pressure of the portal vein and its branches was measured by percutaneous and trans-spleen portal venous catheterization, respectively both pre- and post-embolization in 11 cases of them. Results: The blood flow of PV, SV and SMV decreased significantly in all 31 cases after PSE (P < 0.05). The decreased degrees of blood flow of both PV and SV after PSE were positively related to the embolization degree (r = 0.589, P = 0.002 for PV; r= 0.862, P < 0.001 for SV). In 11 cases whose embolization degrees were more than 60%, the pressure of PV, SV and SMV decreased significantly after embolization (P<0.001). The decrease degree was (22.2 +- 5.8)%, (28.5 +- 1.7)% and (19.5 +- 8.1)%, respectively. The decreased degrees of pressure of both PV and SV after PSE were also positively related to the embolization degree (r = 0.645, P = 0.032 for PV; r = 0.687, P = 0.020 for SV). Conclusion: The embolization degree ranged from 60% to 80% may ameliorate peripheral blood WBC and PLT count, significantly decrease the blood flow and depress the pressure of portal vein, and relieve esophageal and gastric varices

  13. Gold nanorods as a contrast agent for Doppler optical coherence tomography.

    Directory of Open Access Journals (Sweden)

    Bo Wang

    Full Text Available To investigate gold nanorods (GNRs as a contrast agent to enhance Doppler optical coherence tomography (OCT imaging of the intrascleral aqueous humor outflow.A serial dilution of GNRs was scanned with a spectral-domain OCT device (Bioptigen, Durham, NC to visualize Doppler signal. Doppler measurements using GNRs were validated using a controlled flow system. To demonstrate an application of GNR enhanced Doppler, porcine eyes were perfused at constant pressure with mock aqueous alone or 1.0×10(12 GNR/mL mixed with mock aqueous. Twelve Doppler and volumetric SD-OCT scans were obtained from the limbus in a radial fashion incremented by 30°, forming a circular scan pattern. Volumetric flow was computed by integrating flow inside non-connected vessels throughout all 12 scans around the limbus.At the GNR concentration of 0.7×10(12 GNRs/mL, Doppler signal was present through the entire depth of the testing tube without substantial attenuation. A well-defined laminar flow profile was observed for Doppler images of GNRs flowing through the glass capillary tube. The Doppler OCT measured flow profile was not statistically different from the expected flow profile based upon an autoregressive moving average model, with an error of -0.025 to 0.037 mm/s (p = 0.6435. Cross-sectional slices demonstrated the ability to view anterior chamber outflow ex-vivo using GNR-enhanced Doppler OCT. Doppler volumetric flow measurements were comparable to flow recorded by the perfusion system.GNRs created a measureable Doppler signal within otherwise silent flow fields in OCT Doppler scans. Practical application of this technique was confirmed in a constant pressure ex-vivo aqueous humor outflow model in porcine eyes.

  14. Determination of intestinal viability by Doppler ultrasonography in venous infarction.

    Science.gov (United States)

    Cooperman, M; Martin, E W; Carey, L C

    1980-01-01

    The accuracy of Doppler ultrasound in predicting the viability of ischemic intestine secondary to venous obstruction was assessed. Twenty loops of ischemic intestine were created in dogs by temporarily obstructing venous return from the bowel. Doppler arterial flow signals within the intestine quickly disappeared following venous occlusion. In ten segments, arterial signals promptly returned following release of venous occlusion. Nine of these ten segments were viable at reoperation 24 hours later. In ten segments, no arterial signals could be detected following release of venous occlusion, and only one segment proved to be viable. Doppler ultrasound findings were far more accurate in distinguishing between viable and nonviable intestine thatn were clinical guides to intestinal viability. PMID:7352777

  15. The relation between the change of pathology and the metergasis of immunity after thyroid arterial embolization in treating hyperthyroidism caused by Graves' disease

    International Nuclear Information System (INIS)

    Tian Min; Zhao Wei; Shen Jin; Yu Yongzhong; Yi Genfa; Xiang Shutian; Li Liyuan; Yang Huiying; Li Hong; Lu Guijun

    2007-01-01

    Objective: To study the relation between change of thyroid tissues and thyroid auto- antibody after thyroid arterial embolization in the treatment of hyperthyroidism caused by Graves' disease with observation on changes of histopathology and thyroid auto-antibody in 3 years after thyroid arterial embolization, and to understand the foundation of the therapeutic action after arterial embolization. Methods: 1. Thirty-eight patients with Graves' disease treated by transcathter arterial embolization had been tested serum TT3, TT4, FT3, FT4, rT3, TSH, TGAb, TPOAb, TRAb and followed up with color Doppler ultrasound respectively at different periods (before arterial embolization and 7 day, 6 month, 3 year after arterial embolization). 2. 23 patients underwent needle aspiration biopsy of the thyroid gland. Results: Volume of thyroid gland instantly dwindled in size after thyroid arterial embolization or within a few days. The changes of histopathology mainly showed acute ischemic necrosis 7 days after thyroid arterial embolization and followed by fibrous hyperplasia mesenchymal proliferation and follicular atrophy occurring 6 months and 3 years afterward. TGAb, TPOAb at the 3rd year after thyroid arterial embolization were higher than those before the thyriod arterial embolization. FT3, FT4, TRAb at 6 month after thyroid arterial embolization were lower than those of the 3 years. Conclusion: Maladjustment of immunity in GD patients would be improved through the treatment of thyroid arterial embolization, synchronously with the promotion in histopathology. The outcomings of the shrinkage of thyroid tissue, decrease of thyroxin secretion and improvement of immunity provide a combination therapy for GD. (authors)

  16. Transcatheter Arterial Embolization for Upper Gastrointestinal Nonvariceal Hemorrhage: Is Empiric Embolization Warranted?

    Energy Technology Data Exchange (ETDEWEB)

    Arrayeh, Elnasif; Fidelman, Nicholas, E-mail: nicholas.fidelman@ucsf.edu; Gordon, Roy L.; LaBerge, Jeanne M.; Kerlan, Robert K. [University of California San Francisco, Department of Radiology (United States); Klimov, Alexander; Bloom, Allan I. [Hadassah Hospital, Department of Radiology (Israel)

    2012-12-15

    Purpose: To determine whether transcatheter arterial embolization performed in the setting of active gastric or duodenal nonvariceal hemorrhage is efficacious when the bleeding source cannot be identified angiographically. Methods: Records of 115 adult patients who underwent visceral angiography for endoscopically documented gastric (50 patients) or duodenal (65 patients) nonvariceal hemorrhage were retrospectively reviewed. Patients were subdivided into three groups according to whether angiographic evidence of arterial hemorrhage was present and whether embolization was performed (group 1 = no abnormality, no embolization; group 2 = no abnormality, embolization performed [empiric embolization]; and group 3 = abnormality present, embolization performed). Thirty-day rates and duration of primary hemostasis and survival were compared.ResultsFor patients with gastric sources of hemorrhage, the rate of primary hemostasis at 30 days after embolization was greater when embolization was performed in the setting of a documented angiographic abnormality than when empiric embolization was performed (67% vs. 42%). The rate of primary hemostasis at 30 days after angiography was greater for patients with duodenal bleeding who either underwent empiric embolization (60%) or embolization in the setting of angiographically documented arterial hemorrhage (58%) compared with patients who only underwent diagnostic angiogram (33%). Patients with duodenal hemorrhage who underwent embolization were less likely to require additional invasive procedures to control rebleeding (p = 0.006). Conclusion: Empiric arterial embolization may be advantageous in patients with a duodenal source of hemorrhage but not in patients with gastric hemorrhage.

  17. Laser Doppler Blood Flow Imaging Using a CMOS Imaging Sensor with On-Chip Signal Processing

    Directory of Open Access Journals (Sweden)

    Cally Gill

    2013-09-01

    Full Text Available The first fully integrated 2D CMOS imaging sensor with on-chip signal processing for applications in laser Doppler blood flow (LDBF imaging has been designed and tested. To obtain a space efficient design over 64 × 64 pixels means that standard processing electronics used off-chip cannot be implemented. Therefore the analog signal processing at each pixel is a tailored design for LDBF signals with balanced optimization for signal-to-noise ratio and silicon area. This custom made sensor offers key advantages over conventional sensors, viz. the analog signal processing at the pixel level carries out signal normalization; the AC amplification in combination with an anti-aliasing filter allows analog-to-digital conversion with a low number of bits; low resource implementation of the digital processor enables on-chip processing and the data bottleneck that exists between the detector and processing electronics has been overcome. The sensor demonstrates good agreement with simulation at each design stage. The measured optical performance of the sensor is demonstrated using modulated light signals and in vivo blood flow experiments. Images showing blood flow changes with arterial occlusion and an inflammatory response to a histamine skin-prick demonstrate that the sensor array is capable of detecting blood flow signals from tissue.

  18. Laser doppler blood flow imaging using a CMOS imaging sensor with on-chip signal processing.

    Science.gov (United States)

    He, Diwei; Nguyen, Hoang C; Hayes-Gill, Barrie R; Zhu, Yiqun; Crowe, John A; Gill, Cally; Clough, Geraldine F; Morgan, Stephen P

    2013-09-18

    The first fully integrated 2D CMOS imaging sensor with on-chip signal processing for applications in laser Doppler blood flow (LDBF) imaging has been designed and tested. To obtain a space efficient design over 64 × 64 pixels means that standard processing electronics used off-chip cannot be implemented. Therefore the analog signal processing at each pixel is a tailored design for LDBF signals with balanced optimization for signal-to-noise ratio and silicon area. This custom made sensor offers key advantages over conventional sensors, viz. the analog signal processing at the pixel level carries out signal normalization; the AC amplification in combination with an anti-aliasing filter allows analog-to-digital conversion with a low number of bits; low resource implementation of the digital processor enables on-chip processing and the data bottleneck that exists between the detector and processing electronics has been overcome. The sensor demonstrates good agreement with simulation at each design stage. The measured optical performance of the sensor is demonstrated using modulated light signals and in vivo blood flow experiments. Images showing blood flow changes with arterial occlusion and an inflammatory response to a histamine skin-prick demonstrate that the sensor array is capable of detecting blood flow signals from tissue.

  19. Direct Doppler auscultation of the carotid arteries

    International Nuclear Information System (INIS)

    Nix, L.

    1984-01-01

    The results of the carotid Doppler examinations and contrast arteriograms are presented. The overall sensitivity of the carotid Doppler examinations in detecting severe stenosis or occlusion of the carotid artery was 92%. The Doppler studies correctly differentiated these two conditions in 84% of the diseased vessels. In carotid arteries with stenosis greater than or equal to 50%, the sensitivity of the Doppler examinations was 90%, and these studies suggested stenosis in all but two of the 36 abnormal examinations. In two patent carotids with greater than 90% stenosis, a signal could not be elicited, presumably because of the low blood flow through the severely stenotic segment

  20. Comparison of four embolic materials for portal vein embolization: experimental study in pigs

    Energy Technology Data Exchange (ETDEWEB)

    Baere, Thierry de [Institut de Cancerologie Gustave Roussy, Department of Interventional Radiology, Villejuif (France); Denys, Alban [Centre Hospitalier Universitaire Vaudois, Department of Radiology and Interventional Radiology, Lausanne (Switzerland); Paradis, Valerie [Hopital Beaujon-Inserm U773, Department of Anatomie Pathologique, Clichy (France)

    2009-06-15

    Different embolic materials for portal vein embolization (PVE) were evaluated. Twenty pigs received left and median PVE. Hydrophilic phosphorylcholine, N-butyl cyanoacrylate, hydrophilic gel, and polyvinyl alcohol (PVA) particles measuring either 50-150 {mu}m or 700-900 {mu}m were used in five pigs each. Portography and portal vein pressure measurement were performed before, immediately after PVE, and before being euthanized at day 7. Tissue wedges from embolized, and non-embolized liver were obtained for pathology. After complete embolization, recanalization occurred at 7 days in one gel and one 700-900 PVA embolization. Post-PVE increase in portal pressure was found in all groups (p = 0.01). The area of the hepatic lobules in non-embolized liver was larger than in the embolized liver in all groups (p = 0.001). The ratios of the areas between non-embolized/embolized livers were 1.65, 2.19, 1.57, and 1.32 for gel, NBCA, 50-150 PVA and 700-900 PVA, respectively; the ratios of fibrosis between the embolized and non-embolized livers were 1.37, 3.01, 3.49, and 2.11 for gel, NBCA, 50-150 PVA and 700-900 PVA, respectively. Hepatic lobules in non-embolized liver were significantly larger with NBCA than in other groups (p = 0.01). Fibrosis in embolized liver was significantly higher for NBCA and 50-150 PVA (p = 0.002). The most severe changes in embolized and non-embolized liver were induced by 50-150 PVA and NCBA PVE. (orig.)

  1. Arm locking with Doppler estimation errors

    Energy Technology Data Exchange (ETDEWEB)

    Yu Yinan; Wand, Vinzenz; Mitryk, Shawn; Mueller, Guido, E-mail: yinan@phys.ufl.ed [Department of Physics, University of Florida, Gainesville, FL 32611 (United States)

    2010-05-01

    At the University of Florida we developed the University of Florida LISA Interferometer Simulator (UFLIS) in order to study LISA interferometry with hardware in the loop at a system level. One of the proposed laser frequency stabilization techniques in LISA is arm locking. Arm locking uses an adequately filtered linear combination of the LISA arm signals as a frequency reference. We will report about experiments in which we demonstrated arm locking using UFLIS. During these experiments we also discovered a problem associated with the Doppler shift of the return beam. The initial arm locking publications assumed that this Doppler shift can perfectly be subtracted inside the phasemeter or adds an insignificant offset to the sensor signal. However, the remaining Doppler knowledge error will cause a constant change in the laser frequency if unaccounted for. Several ways to circumvent this problem have been identified. We performed detailed simulations and started preliminary experiments to verify the performance of the proposed new controller designs.

  2. Application of complex discrete wavelet transform in classification of Doppler signals using complex-valued artificial neural network.

    Science.gov (United States)

    Ceylan, Murat; Ceylan, Rahime; Ozbay, Yüksel; Kara, Sadik

    2008-09-01

    In biomedical signal classification, due to the huge amount of data, to compress the biomedical waveform data is vital. This paper presents two different structures formed using feature extraction algorithms to decrease size of feature set in training and test data. The proposed structures, named as wavelet transform-complex-valued artificial neural network (WT-CVANN) and complex wavelet transform-complex-valued artificial neural network (CWT-CVANN), use real and complex discrete wavelet transform for feature extraction. The aim of using wavelet transform is to compress data and to reduce training time of network without decreasing accuracy rate. In this study, the presented structures were applied to the problem of classification in carotid arterial Doppler ultrasound signals. Carotid arterial Doppler ultrasound signals were acquired from left carotid arteries of 38 patients and 40 healthy volunteers. The patient group included 22 males and 16 females with an established diagnosis of the early phase of atherosclerosis through coronary or aortofemoropopliteal (lower extremity) angiographies (mean age, 59 years; range, 48-72 years). Healthy volunteers were young non-smokers who seem to not bear any risk of atherosclerosis, including 28 males and 12 females (mean age, 23 years; range, 19-27 years). Sensitivity, specificity and average detection rate were calculated for comparison, after training and test phases of all structures finished. These parameters have demonstrated that training times of CVANN and real-valued artificial neural network (RVANN) were reduced using feature extraction algorithms without decreasing accuracy rate in accordance to our aim.

  3. Using the global positioning satellite system to determine attitude rates using doppler effects

    Science.gov (United States)

    Campbell, Charles E. (Inventor)

    2003-01-01

    In the absence of a gyroscope, the attitude and attitude rate of a receiver can be determined using signals received by antennae on the receiver. Based on the signals received by the antennae, the Doppler difference between the signals is calculated. The Doppler difference may then be used to determine the attitude rate. With signals received from two signal sources by three antennae pairs, the three-dimensional attitude rate is determined.

  4. The Role of Color Doppler Ultrasonography in Characterization of Thyroid Tumors

    International Nuclear Information System (INIS)

    Kim, Hee Soo; Jeon, Pyong; Won, Jong Yoon; Na, Jae Beom; Lee, Hyang Mee; Yoo, Hyung Sik; Lee, Jong Tae; Park, Jeong Soo; Cho, Nam Hoon

    1995-01-01

    To assess the usefulness of color Doppler ultrasonography in the characterization of thyroid tumors, surgically proven 88 nodules in 85 patients were evaluated. Using 10 MHz linear array transducer, gray scale images were initially evaluated. Then, distribution pattern of color signals (marginal, intra-tumoral, mixed) and graded internal vascularity according to morphology of color signal (0:absence of internal signal, 1: spotty, 2: linear,3: branching) were observed on color doppler imaging. Pulsed doppler waves were analyzed with parameters including peak systolic velocity(PSV), resistive index(RI), and pulsatile index(PI). Significantly larger numbers of intra-tumoral type, 20 cases(62.5%), were observed in malignant nodules, whereas mixed forms were predominant in benign group, 37 cases (66%) In graded internal vascularity, malignant nodules tended to have grade 2 or 3 signals, whereas benign nodules tended to have grade 0 or 1 signals. Spectral wave analysis show no significant difference in the value of PSV, RI, and PI between malignancy and benignity group. In conclusion, color Doppler imaging has a potential role in the characterization of thyroid nodules as a supportive method for gray scale diagnosis

  5. Color doppler imaging of subclavian steal phenomenon

    International Nuclear Information System (INIS)

    Cho, Nari Ya; Chung, Tae Sub; Kim, Jai Keun

    1997-01-01

    To evaluate the characteristic color doppler imaging of vertebral artery flow in the subclavian steal phenomenon. The study group consisted of eight patients with reversed vertebral artery flow proved by color Doppler imaging. We classified this flow into two groups:(1) complete reversal;(2) partial reversal, as shown by Doppler velocity waveform. Vertebral angiography was performed in six of eight patients;color Doppler imaging and angiographic findings were compared. On color Doppler imaging, all eight cases with reversed vertebral artery flow showed no signal at the proximal subclavian or brachiocephalic artery. We confirmed shunting of six cases by performing angiography from the contralateral vertebral and basilar artery to the ipsilateral vertebral artery. On the Doppler spectrum, six cases showed complete reversal and two partial reversal. On angiography, one partial reversal case showed complete occlusion of the subclavian artery with abundant collateral circulation of muscular branches of the vertebral artery. On color Doppler imaging, a reversed vertebral artery suggests the subclavian steal phenomenon. In particular, partial reversal waveform may reflect collateral circulation

  6. Size distribution of air bubbles entering the brain during cardiac surgery.

    Directory of Open Access Journals (Sweden)

    Emma M L Chung

    Full Text Available Thousands of air bubbles enter the cerebral circulation during cardiac surgery, but whether high numbers of bubbles explain post-operative cognitive decline is currently controversial. This study estimates the size distribution of air bubbles and volume of air entering the cerebral arteries intra-operatively based on analysis of transcranial Doppler ultrasound data.Transcranial Doppler ultrasound recordings from ten patients undergoing heart surgery were analysed for the presence of embolic signals. The backscattered intensity of each embolic signal was modelled based on ultrasound scattering theory to provide an estimate of bubble diameter. The impact of showers of bubbles on cerebral blood-flow was then investigated using patient-specific Monte-Carlo simulations to model the accumulation and clearance of bubbles within a model vasculature.Analysis of Doppler ultrasound recordings revealed a minimum of 371 and maximum of 6476 bubbles entering the middle cerebral artery territories during surgery. This was estimated to correspond to a total volume of air ranging between 0.003 and 0.12 mL. Based on analysis of a total of 18667 embolic signals, the median diameter of bubbles entering the cerebral arteries was 33 μm (IQR: 18 to 69 μm. Although bubble diameters ranged from ~5 μm to 3.5 mm, the majority (85% were less than 100 μm. Numerous small bubbles detected during cardiopulmonary bypass were estimated by Monte-Carlo simulation to be benign. However, during weaning from bypass, showers containing large macro-bubbles were observed, which were estimated to transiently affect up to 2.2% of arterioles.Detailed analysis of Doppler ultrasound data can be used to provide an estimate of bubble diameter, total volume of air, and the likely impact of embolic showers on cerebral blood flow. Although bubbles are alarmingly numerous during surgery, our simulations suggest that the majority of bubbles are too small to be harmful.

  7. Response of a Doppler canceling system to plane gravitational waves

    International Nuclear Information System (INIS)

    Caporali, A.

    1982-01-01

    This paper discusses the interaction of long periodic gravitational waves with a three-link microwave system known as the Doppler canceling system. This system, which was developed for gravitational red-shift experiment, uses one-way and two-way Doppler information to construct the beat signal of two reference oscillators moving with respect to each other. The geometric-optics approximation is used to derive the frequency shift produced on a light signal propagating in a gravitational-wave space-time. The signature left on the Doppler-canceled beat by bursts and continuous gravitational waves is analyzed. A comparison is made between the response to gravitational waves of the Doppler canceling system and that of a (NASA) Doppler tracking system which employs two-way, round-trip radio waves. A threefold repetition of the gravitational wave form is found to be a common feature of the response functions of both systems. These two functions otherwise exhibit interesting differences

  8. Directional dual-tree rational-dilation complex wavelet transform.

    Science.gov (United States)

    Serbes, Gorkem; Gulcur, Halil Ozcan; Aydin, Nizamettin

    2014-01-01

    Dyadic discrete wavelet transform (DWT) has been used successfully in processing signals having non-oscillatory transient behaviour. However, due to the low Q-factor property of their wavelet atoms, the dyadic DWT is less effective in processing oscillatory signals such as embolic signals (ESs). ESs are extracted from quadrature Doppler signals, which are the output of Doppler ultrasound systems. In order to process ESs, firstly, a pre-processing operation known as phase filtering for obtaining directional signals from quadrature Doppler signals must be employed. Only then, wavelet based methods can be applied to these directional signals for further analysis. In this study, a directional dual-tree rational-dilation complex wavelet transform, which can be applied directly to quadrature signals and has the ability of extracting directional information during analysis, is introduced.

  9. Identification of patients at risk for ischaemic cerebral complications after carotid endarterectomy with TCD monitoring

    DEFF Research Database (Denmark)

    Horn, J; Naylor, A R; Laman, D M

    2005-01-01

    Transcranial Doppler (TCD) monitoring for micro embolic signals (MES), directly after carotid endarterectomy (CEA) may identify patients at risk of developing ischaemic complications. In this retrospective multicentre study, this hypothesis was investigated....

  10. Emborrhoid: A New Concept for the Treatment of Hemorrhoids with Arterial Embolization: The First 14 Cases

    International Nuclear Information System (INIS)

    Vidal, V.; Sapoval, M.; Sielezneff, Y.; Parades, V. De; Tradi, F.; Louis, G.; Bartoli, J. M.; Pellerin, O.

    2015-01-01

    PurposeThe ‘emborrhoid’ technique consists of the embolization of the hemorrhoidal arteries. The endovascular arterial occlusion is performed using coils placed in the terminal branches of the superior rectal arteries. The emborrhoid technique has been modeled after elective transanal Doppler-guided hemorrhoidal artery ligation which has been shown to be effective in hemorrhoidal disease. We report the first 14 cases of our experience with emborrhoid technique.Materials and MethodsFourteen patients with disabling chronic rectal bleeding were treated using the emborrhoid technique (3 women, 11 men). The stage of the hemorrhoidal disease was II (10 patients), III (3), and IV (1). This treatment was decided by a multidisciplinary team (proctologist, visceral surgeon, and radiologist). Seven patients underwent previous proctological surgery. Ten patients had coagulation disorders (anticoagulants or cirrhosis). Superior rectal arteries were embolized with pushable microcoils (0.018).ResultsTechnical success of the embolization procedure was 100 %. Clinical success at 1 month was 72 % (10/14). Of the 4 patients who experienced rebleeding, two underwent additional embolization of the posterior rectal arteries with success. No pain or ischemic complications were observed in 13 patients. One patient experienced a temporary painful and edematous, perianal reaction.ConclusionOur case studies suggest that coil embolization of the superior rectal arteries is technically feasible, safe and well tolerated. Additional studies are needed to evaluate the efficacy of this new ‘emborrhoid’ technique in the management of hemorrhoidal disease

  11. Emborrhoid: A New Concept for the Treatment of Hemorrhoids with Arterial Embolization: The First 14 Cases

    Energy Technology Data Exchange (ETDEWEB)

    Vidal, V., E-mail: vincent.vidal@ap-hm.fr [Hôpital de la Timone, Department of Radiology (France); Sapoval, M., E-mail: marc.sapoval@gmail.com [Hopital Européen Georges Pompidou, Department of Radiology (France); Sielezneff, Y., E-mail: igor.sielezneff@ap-hm.fr [Hôpital de la Timone, Department of Digestive and General Surgery (France); Parades, V. De, E-mail: v.deparades@gmail.com [Hopital Saint Joseph, Department of Proctology (France); Tradi, F., E-mail: farouk.tradi@ap-hm.fr; Louis, G., E-mail: guillaume.louis@ap-hm.fr; Bartoli, J. M., E-mail: jean-michel.bartoli@ap-hm.fr [Hôpital de la Timone, Department of Radiology (France); Pellerin, O., E-mail: olivier.pellerin@egp.aphp.fr [Hopital Européen Georges Pompidou, Department of Radiology (France)

    2015-02-15

    PurposeThe ‘emborrhoid’ technique consists of the embolization of the hemorrhoidal arteries. The endovascular arterial occlusion is performed using coils placed in the terminal branches of the superior rectal arteries. The emborrhoid technique has been modeled after elective transanal Doppler-guided hemorrhoidal artery ligation which has been shown to be effective in hemorrhoidal disease. We report the first 14 cases of our experience with emborrhoid technique.Materials and MethodsFourteen patients with disabling chronic rectal bleeding were treated using the emborrhoid technique (3 women, 11 men). The stage of the hemorrhoidal disease was II (10 patients), III (3), and IV (1). This treatment was decided by a multidisciplinary team (proctologist, visceral surgeon, and radiologist). Seven patients underwent previous proctological surgery. Ten patients had coagulation disorders (anticoagulants or cirrhosis). Superior rectal arteries were embolized with pushable microcoils (0.018).ResultsTechnical success of the embolization procedure was 100 %. Clinical success at 1 month was 72 % (10/14). Of the 4 patients who experienced rebleeding, two underwent additional embolization of the posterior rectal arteries with success. No pain or ischemic complications were observed in 13 patients. One patient experienced a temporary painful and edematous, perianal reaction.ConclusionOur case studies suggest that coil embolization of the superior rectal arteries is technically feasible, safe and well tolerated. Additional studies are needed to evaluate the efficacy of this new ‘emborrhoid’ technique in the management of hemorrhoidal disease.

  12. Preoperative trans-arterial embolization for spinal tumor: embolization techniques and results

    International Nuclear Information System (INIS)

    Shi Haibin; Xu Daizhe

    2000-01-01

    Objective: To analyze the technique and to evaluate the safety and value of preoperative trans-arterial embolization of hypervascular spinal tumors. Methods: Eighteen patients with hypervascular spinal tumors underwent trans-arterial embolization before surgery. They arose intradural in six patients and extradural in 12. Thirty-one arteries were embolized with polyvinyl alcohol (PVA) particles (150-500 μm), of which 18 with additional pieces of gelatin sponge for proximal pedicular embolization. The criteria for judging the effectiveness of embolization were the completeness of tumor removal and estimated blood loss during surgery. Results: Tumor embolization with total occlusion was obtained in eight patients, second to total in seven, subtotal in one, and partial in two. There were no symptomatic complications associated with embolization. Tumors were totally removed in 17 patients and nearly totally removed in one. The average estimated blood loss during surgery was 1100 ml (range, 200-6000 ml) for all 18 patients, and 1540 ml in patients with extradural tumors. Conclusions: Preoperative embolization of hypervascular spinal tumors is safe and effective. It can make complete resection of a tumor possible and can make an unresectable tumor resectable. Superselection or flow control is necessary to achieve effective devascularization and avoid complications

  13. Laser Doppler measurements in two-phase flows

    International Nuclear Information System (INIS)

    Durst, F.; Zare, M.

    1976-01-01

    Basic theory for laser-Doppler velocity measurements of large reflecting or refracting surfaces is provided. It is shown that the Doppler-signals contain information of the velocity and size of the large bodies, and relationships for transforming velocity and radius of curvature of moving spheres are presented. Preliminary experiments verified the analytical findings and demonstrated the applicability of the method to some two-phase flows

  14. 21 CFR 892.1550 - Ultrasonic pulsed doppler imaging system.

    Science.gov (United States)

    2010-04-01

    ... system. (a) Identification. An ultrasonic pulsed doppler imaging system is a device that combines the... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ultrasonic pulsed doppler imaging system. 892.1550... include signal analysis and display equipment, patient and equipment supports, component parts, and...

  15. Optical Doppler tomography based on a field programmable gate array

    DEFF Research Database (Denmark)

    Larsen, Henning Engelbrecht; Nilsson, Ronnie Thorup; Thrane, Lars

    2008-01-01

    We report the design of and results obtained by using a field programmable gate array (FPGA) to digitally process optical Doppler tomography signals. The processor fits into the analog signal path in an existing optical coherence tomography setup. We demonstrate both Doppler frequency and envelope...... extraction using the Hilbert transform, all in a single FPGA. An FPGA implementation has certain advantages over general purpose digital signal processor (DSP) due to the fact that the processing elements operate in parallel as opposed to the DSP. which is primarily a sequential processor....

  16. Noise Studies of Externally Dispersed Interferometry for Doppler Velocimetry

    International Nuclear Information System (INIS)

    Erskine, D J; Edelstein, J; Lloyd, J; Muirhead, P

    2006-01-01

    Externally Dispersed Interferometry (EDI) is the series combination of a fixed-delay field-widened Michelson interferometer with a dispersive spectrograph. This combination boosts the spectrograph performance for both Doppler velocimetry and high resolution spectroscopy. The interferometer creates a periodic comb that multiplies against the input spectrum to create moire fringes, which are recorded in combination with the regular spectrum. Both regular and high-frequency spectral components can be recovered from the data--the moire component carries additional information that increases the signal to noise for velocimetry and spectroscopy. Here we present simulations and theoretical studies of the photon limited Doppler velocity noise in an EDI. We used a model spectrum of a 1600K temperature star. For several rotational blurring velocities 0, 7.5, 15 and 25 km/s we calculated the dimensionless Doppler quality index (Q) versus wavenumber v. This is the normalized RMS of the derivative of the spectrum and is proportional to the photon-limited Doppler signal to noise ratio

  17. Cross-correlation Doppler global velocimetry (CC-DGV)

    Science.gov (United States)

    Cadel, Daniel R.; Lowe, K. Todd

    2015-08-01

    A flow velocimetry method, cross-correlation Doppler global velocimetry (CC-DGV), is presented as a robust, simplified, and high dynamic range implementation of the Doppler global/planar Doppler velocimetry technique. A sweep of several gigahertz of the vapor absorption spectrum is used for each velocity sample, with signals acquired from both Doppler-shifted scattered light within the flow and a non-Doppler shifted reference beam. Cross-correlation of these signals yields the Doppler shift between them, averaged over the duration of the scan. With presently available equipment, velocities from 0 ms-1 to over 3000 ms-1 can notionally be measured simultaneously, making the technique ideal for high speed flows. The processing routine is shown to be robust against large changes in the vapor pressure of the iodine cell, benefiting performance of the system in facilities where ambient conditions cannot be easily regulated. Validation of the system was performed with measurements of a model wind turbine blade boundary layer made in a 1.83 m by 1.83 m subsonic wind tunnel for which laser Doppler velocimetry (LDV) measurements were acquired alongside the CC-DGV results. CC-DGV uncertainties of ±1.30 ms-1, ±0.64 ms-1, and ±1.11 ms-1 were determined for the orthogonal stream-wise, transverse-horizontal, and transverse-vertical velocity components, and root-mean-square deviations of 2.77 ms-1 and 1.34 ms-1 from the LDV validation results were observed for Reynolds numbers of 1.5 million and 2 million, respectively. Volumetric mean velocity measurements are also presented for a supersonic jet, with velocity uncertainties of ±4.48 ms-1, ±16.93 ms-1, and ±0.50 ms-1 for the orthogonal components, and self-validation done by collapsing the data with a physical scaling.

  18. Experimental studies on canine terminal carotid arterial aneurysm models pre- and post-embolized with microcoil

    International Nuclear Information System (INIS)

    Wang Qihong; Zhou Liangfu; Gong Jianqiu; Dai Jianhua; Zhang Xiaojun; Zhang Xinyuan

    2005-01-01

    Objective: To establish canine terminal saccular aneurysm model of common carotid artery (CCA), and evaluate the images and hemodynamic changes of aneurysm cavities pre- and post-embolized with microcoil (MC). Methods: Seven CCA terminal saccular aneurysm models had been created by using improved microsurgical technique. Seven to fourteen days after surgery, models were undergone color Doppler, Magnetic resonance image (MRI), Magnetic resonance angiography (MRA), digital subtraction angiography (DSA), and then the analysis of computational fluid dynamics (CFD) on these animal models were conducted. Afterwards they were compactly packed with MC, and then aneurysms again were examed under these methods, and simulation of pathological changes. Results: Models were created successfully with good MC compactly pack aneurysm cavities. DSA combined with other imaging methods can improve the diagnosis of aneurysms completely. CFD models can show the imitation hemodynamics of canine carotid aneurysms. Conclusions: This kind of aneurysm model is an ideal one on the area for the research of aneurysm embolization. Non-DSA imaging examination can noninvasively, repeatedly, clearly evaluate aneurysms pre- and post-embolized with MC. The interference on the inflow zone of the aneurysm is an effective method for cure and preventing recurrence of aneurysms. (authors)

  19. Effectiveness of Pulse Oximetry Versus Doppler for Tourniquet Monitoring.

    Science.gov (United States)

    Wall, Piper L; Buising, Charisse M; Grulke, Lisa; Troester, Alexander; Bianchina, Nicholas; White, Shannon; Freymark, Rosemarie; Hassan, Ali; Hopkins, James W; Renner, Catherine Hackett; Sahr, Sheryl M

    Pulse oximeters are common and include arterial pulse detection as part of their methodology. The authors investigated the possible usefulness of pulse oximeters for monitoring extremity tourniquet arterial occlusion. Tactical Ratcheting Medical Tourniquets were tightened to the least Doppler-determined occluding pressure at mid-thigh or mid-arm locations on one limb at a time on all four limbs of 15 volunteers. A randomized block design was used to determine the placement locations of three pulse oximeter sensors on the relevant digits. The times and pressures of pulsatile signal absences and returns were recorded for 200 seconds, with the tourniquet being tightened only when the Doppler ultrasound and all three pulse oximeters had pulsatile signals present (pulsatile waveform traces for the pulse oximeters). From the first Doppler signal absence to tourniquet release, toe-located pulse oximeters missed Doppler signal presence 41% to 50% of the times (discrete 1-second intervals) and missed 39% to 49% of the pressure points (discrete 1mmHg intervals); fingerlocated pulse oximeters had miss rates of 11% to 15% of the times and 13% to 19% of the pressure points. On toes, the pulse oximeter ranges of sensitivity and specificity for Doppler pulse detection were 71% to 90% and 44% to 51%, and on fingers, the respective ranges were 65% to 77% and 78% to 83%. Use of a pulse oximeter to monitor limb tourniquet effectiveness will result in some instances of an undetected weak arterial pulse being present. If a pulse oximeter waveform is obtained from a location distal to a tourniquet, the tourniquet should be tightened. If a pulsatile waveform is not detected, vigilance should be maintained. 2017.

  20. Power Doppler ultrasonography and synovitis: correlating ultrasound imaging with histopathological findings and evaluating the performance of ultrasound equipments.

    Science.gov (United States)

    Koski, J M; Saarakkala, S; Helle, M; Hakulinen, U; Heikkinen, J O; Hermunen, H

    2006-12-01

    To examine the validity of power Doppler ultrasound imaging to identify synovitis, using histopathology as gold standard, and to assess the performance of ultrasound equipments. 44 synovial sites in small and large joints, bursae and tendon sheaths were depicted with ultrasound. A synovial biopsy was performed on the site depicted and a synovial sample was taken for histopathological evaluation. The performance of three ultrasound devices was tested using flow phantoms. A positive Doppler signal was detected in 29 of 35 (83%) of the patients with active histological inflammation. In eight additional samples, histological examination showed other pathological synovial findings and a Doppler signal was detected in five of them. No significant correlation was found between the amount of Doppler signal and histological synovitis score (r = 0.239, p = NS). The amount of subsynovial infiltration of polymorphonuclear leucocytes and surface fibrin correlated significantly with the amount of power Doppler signal: r = 0.397 (pultrasound devices differed in showing the smallest detectable flow. A negative Doppler signal does not exclude the possibility of synovitis. A positive Doppler signal in the synovium is an indicator of an active synovial inflammation in patients. A Doppler signal does not correlate with the extent of the inflammation and it can also be seen in other synovial reactions. It is important that the quality measurements of ultrasound devices are reported, because the results should be evaluated against the quality of the device used.

  1. Clinical study on embolization syndromes after splenic arterial embolization

    International Nuclear Information System (INIS)

    Liu Minhua; Zhou Rumin

    2004-01-01

    Objective: To analyze the reaction of splenic arterial embolization (embolization syndromes) using 3 different materials together with the therapeutic methods. Methods: Thirty nine patients of cirrhosis with hypersplenism and hypersplenotrophy, 11 of them were treated with steel coils, 15 with gelfoam, 13 with the PVA. The embolized area was approximately 60% of the whole splenic area. Results: Thirty nine cases obtained the curative effect. The blood white cell and platelet counts were normal or close to normal. The rates of splenic pain in steel coils group, gelfoam group and PVA group were 81.8%, 100% and 100% respectively. The duration of serious pain were 2-5 d, 1-7 d and 1-7 d in coil group, gelfoam group and PVA group respectively. 33 patients had moderate fever around 38.5 degree C and 8 patients had eructation after embolization. The symptoms disappeared after using antibiotics, dexamethasone and analgesic. Conclusions: The algetic grade of splenic arterial embolization was inverse proportional with the size of embolus. The correct management could effectively control the symptoms of postembolization of the spleen

  2. Wayside Bearing Fault Diagnosis Based on a Data-Driven Doppler Effect Eliminator and Transient Model Analysis

    Science.gov (United States)

    Liu, Fang; Shen, Changqing; He, Qingbo; Zhang, Ao; Liu, Yongbin; Kong, Fanrang

    2014-01-01

    A fault diagnosis strategy based on the wayside acoustic monitoring technique is investigated for locomotive bearing fault diagnosis. Inspired by the transient modeling analysis method based on correlation filtering analysis, a so-called Parametric-Mother-Doppler-Wavelet (PMDW) is constructed with six parameters, including a center characteristic frequency and five kinematic model parameters. A Doppler effect eliminator containing a PMDW generator, a correlation filtering analysis module, and a signal resampler is invented to eliminate the Doppler effect embedded in the acoustic signal of the recorded bearing. Through the Doppler effect eliminator, the five kinematic model parameters can be identified based on the signal itself. Then, the signal resampler is applied to eliminate the Doppler effect using the identified parameters. With the ability to detect early bearing faults, the transient model analysis method is employed to detect localized bearing faults after the embedded Doppler effect is eliminated. The effectiveness of the proposed fault diagnosis strategy is verified via simulation studies and applications to diagnose locomotive roller bearing defects. PMID:24803197

  3. [Feasibility and efficiency of embolization of spinal dural arteriovenous fistula].

    Science.gov (United States)

    Zhang, Hong-qi; Liu, Jiang; Wang, Jian-sheng; Zhi, Xing-long; Zhang, Peng; Bian, Li-song; He, Chuan; Ye, Ming; Wang, Zhi-chao; Li, Meng; Ling, Feng

    2013-03-01

    To evaluate the feasibility and efficiency of embolization of spinal dural arteriovenous fistula (SDAVF). From December 2010 to May 2012, there were 104 cases of SDAVF were treated, and 26 cases were selected to be treated with embolization. The inclusion criteria was as follows: (1) No anterior or posterior spinal artery originated from the fistula segment; (2) The segmental artery can be catheterized with guiding or micro catheter; (3) High flow in fistula; (4) Patient's situation was not suitable for surgery or general anesthesia. Among 26 cases, there were 22 male and 4 female patients, the average age was 55.9 years (ranged from 34 to 81 years). The locations of SDAVF were 10 cases in thoracic, 9 in lumbar and 7 in sacral segment. The main symptoms were progressive numbness and weakness in both lower extremities, most cases accompanied with difficulties in urination and defecation. The average history was 17.1 months (from 1 to 156 months). ONYX-18 liquid embolic agent or Glubran-2 surgical glue were used as embolic material. The patients not cured with embolization were treated with surgery in the following 1 - 2 weeks. Follow-up evaluation was done with MRI after 3 months and DSA after 6 months, besides physical examination. Fifteen from 26 cases achieved immediate angiographic cure results: 14 in 20 cases which embolized with ONYX-18; only 1 in 6 cases with Glubran-2. Three in 10 cases of thoracic SDAVF and 12 in 16 cases of lumbar/sacral SDAVF were cured with embolization. Partially embolized cases were treated with surgical obliteration of drainage veins within 2 weeks. Cured patients experienced immediate improvement after embolization and kept getting better in the follow-up. All the patients had MRI follow-up after 3 months and DSA follow-up after 6 months. In 6 month's follow-up, MRI showed the edema and flow void signal in the spinal cord disappeared. DSA showed no fistula recurrence or remnant. There was no deterioration case in all of the embolized

  4. Catheter Embolization

    Science.gov (United States)

    ... or treatment. top of page What are the benefits vs. risks? Benefits Embolization is a highly effective way of controlling ... risk of infection after embolization, even if an antibiotic has been given. However, the physician takes ample ...

  5. Fisher information and Shannon entropy for on-line detection of transient signal high-values in laser Doppler flowmetry signals of healthy subjects

    International Nuclear Information System (INIS)

    Humeau, Anne; Trzepizur, Wojciech; Abraham, Pierre; Rousseau, David; Chapeau-Blondeau, Francois

    2008-01-01

    Laser Doppler flowmetry (LDF) is an easy-to-use method for the assessment of microcirculatory blood flow in tissues. However, LDF recordings very often present TRAnsient Signal High-values (TRASH), generally of a few seconds. These TRASH can come from tissue motions, optical fibre movements, movements of the probe head relative to the tissue, etc. They often lead to difficulties in signal global interpretations. In order to test the possibility of detecting automatically these TRASH for their removal, we process noisy and noiseless LDF signals with two indices from information theory, namely Fisher information and Shannon entropy. For this purpose, LDF signals from 13 healthy subjects are recorded at rest, during vascular occlusion of 3 min, and during post-occlusive hyperaemia. Computation of Fisher information and Shannon entropy values shows that, when calibrated, these two indices can be complementary to detect TRASH and be insensitive to the rapid increases of blood flow induced by post-occlusive hyperaemia. Moreover, the real-time algorithm has the advantage of being easy to implement and does not require any frequency analysis. This study opens new fields of application for Fisher information and Shannon entropy: LDF 'denoising'

  6. Efficacy analysis of thyroidal arterial embolization in treating hyperthyroidism with different embolizing materials

    International Nuclear Information System (INIS)

    Yang Jijin; Ling Ling; Tian Jianming; Ye Hua; Zhang Huojun; Bi Yongmin; Zou Dajing; Chen Wei

    2003-01-01

    Objective: To study the efficacy of thyroidal arterial embolization in treating hyperthyroidism by using different embolizing materials and the relationship between recurrence rate and the numbers of embolized arteries. Methods: 56 cases with hyperthyroidism were divided into group A (25 cases) and group B (31 cases). Patients of group A had their thyroidal arteries embolized with gelfoam particles and stainless coils after arterial infusion of a total dosage of 24 mg of bleomycin. Patients of group B had their thyroidal arteries occluded with polyvinyl alcohol (PVA) particles. The effectiveness and general complications of arterial embolization for these two groups were compared and the relationship between recurrence rate of hyperthyroidism after treatment and numbers of embolized thyroidal arteries was studied. Results: It showed effectiveness in all patients within 2-3 months. The follow-up records showed, the recurrence rate of hyperthyroidism was 28% and 16.1% for group A and group B respectively but without statistical difference. The recurrence rates were 46.7% for those patients with 2 thyroid-arteries embolized and 12.2% for those with 3-4 arteries embolized, showing significant difference (χ 2 =7.751, P < 0.01). General complications for group A were much more than those for group B. Conclusions: Thyroidal arterial embolization is minimally invasive and highly effective in treating hyperthyroidism. With better results obtained by more than three thyroid-arteries be embolized, PVA particles are easy to be used and perhaps more effective in occluding thyroidal arteries

  7. Management of post-biopsy renal allograft arteriovenous fistulas with selective arterial embolization: immediate and long-term outcomes

    International Nuclear Information System (INIS)

    Loffroy, R.; Guiu, B.; Lambert, A.; Mousson, C.; Tanter, Y.; Martin, L.; Cercueil, J.-P.; Krause, D.

    2008-01-01

    Aim: To evaluate the outcomes after transcatheter embolization of percutaneous biopsy-related arteriovenous fistulas in renal allografts. Materials and methods: All post-biopsy renal-transplant vascular injuries referred for embolization between June 1999 and October 2006 were reviewed retrospectively. There were six male and six female patients with a mean age of 49.8 years (range 25-67 years); nine patients were symptomatic, three asymptomatic. Colour Doppler ultrasound (CDUS) and angiography showed one intra-renal arteriovenous fistula in 10 patients and two in two patients, combined with a pseudoaneurysm in six patients. Superselective embolization using a single catheter or coaxial microcatheter was performed with 0.035'' coils or 0.018''microcoils, respectively, in all 12 cases. 24-h creatinine clearance values before (the day of biopsy) and after (7-14 days; 3 months) the procedure were compared using the Wilcoxon signed-rank test. Physical examination and CDUS were performed after 1, 6, and 12 months, and yearly thereafter. Mean follow-up was 33.6 months. Results: Complete definitive occlusion of the fistula was achieved consistently with a single procedure. No procedure-related complications occurred. Renal infarction was minor in all patients (0-10% in nine and 10-20% in three). Symptoms resolved completely. Creatinine clearance values obtained before and after embolization were not statistically different (p = 0.168;.889 respectively). No late recurrences were reported. Conclusion: Transcatheter embolization with coaxial or single-catheter techniques was effective and safe for treating post-biopsy arteriovenous fistulas in renal transplants. The loss of renal parenchyma was minimal and no mid-term deterioration of allograft function was noted. The long-term survival of the renal allograft seemed to be not affected by embolization

  8. Deep vein thrombosis of lower extremity: What is the most important finding in duplex Doppler sonography

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yong Soo; Koh, Byung Hee; Cho, On Koo; Rhim, Hyun Chul; Seo, Heung Suk; Hahm, Chang Kok; Kwak, Jin Young [Hanyang University College of Medicine, Seoul (Korea, Republic of)

    1993-12-15

    The positive findings of deep vein thrombosis on duplex Doppler ultrasonography such as intraluminal clot,non-compressibility of the venous lumen and abnormal or absent Doppler shift signal are well known. However, relatively hypoechoic thrombus is not always seen in sonography, and the vein is frequently compressible in partial thrombosis. In order to evaluate the most common and important findings of deep vein thrombosis, we analysed the findings at duplex Doppler ultrasound in 19 patients and compared the results with those of contrast venography in 11 patients. Duplex Doppler ultrasound examination of the common femoral and popliteal veins was performed for one extremity in 14 patients, and for both extremities in 5 (total 24 extremities). Contrast venography was performed for one extremity in 7 patients, and for both sides in 4 (total 15 extremities).Thrombosis was seen in 45.8%, non-compressibility of lumen in 75%, absent or decreased Doppler signal from common femoral vein in 95.8%. Thrombosis was seen in 41.7%, non-compressibility of lumen in 70.8%, absent or decreased Doppler shift signal from popliteal vein in 95.8%. We conclude that abnormal or absent Doppler shift signal is the most sensitive and important finding of the deep vein thrombosis

  9. Endometrium evaluation with high-field (3-Tesla) magnetic resonance imaging in patients submitted to uterine leiomyoma embolization

    International Nuclear Information System (INIS)

    Jacobs, Monica Amadio Piazza; Nasser, Felipe; Zlotnik, Eduardo; Messina, Marcos de Lorenzo; Baroni, Ronaldo Hueb

    2013-01-01

    To evaluate the endometrial alterations related to embolization of uterine arteries for the treatment of symptomatic uterine leiomyomatosis (pelvic pain and/or uterine bleeding) by means of high-field (3-Tesla) magnetic resonance. This is a longitudinal and prospective study that included 94 patients with a clinical and imaging diagnosis of symptomatic uterine leiomyomatosis, all of them treated by embolization of the uterine arteries. The patients were submitted to evaluations by high-field magnetic resonance of the pelvis before and 6 months after the procedure. Specific evaluations were made of the endometrium on the T2-weighted sequences, and on the T1-weighted sequences before and after the intravenous dynamic infusion of the paramagnetic contrast. In face of these measures, statistical analyses were performed using Student's t test for comparison of the results obtained before and after the procedure. An average increase of 20.9% was noted in the endometrial signal on T2-weighted images obtained after the uterine artery embolization procedure when compared to the pre-procedure evaluation (p=0.0004). In the images obtained with the intravenous infusion of paramagnetic contrast, an average increase of 18.7% was noted in the post-embolization intensity of the endometrial signal, compared to the pre-embolization measure (p<0.035). After embolization of the uterine arteries, there was a significant increase of the endometrial signal on the T2-weighted images and on the post-contrast images, inferring possible edema and increased endometrial flow. Future studies are needed to assess the clinical impact of these findings

  10. Endometrium evaluation with high-field (3-Tesla) magnetic resonance imaging in patients submitted to uterine leiomyoma embolization

    Energy Technology Data Exchange (ETDEWEB)

    Jacobs, Monica Amadio Piazza [Post-graduation Program in Abdominal Imaging, Hospital Israelita Albert Einstein, São Paulo, SP (Brazil); Nasser, Felipe [Intervention Radiology Department, Hospital Israelita Albert Einstein, São Paulo, SP (Brazil); Zlotnik, Eduardo; Messina, Marcos de Lorenzo [Gynecology and Obstetrics Department, Hospital Israelita Albert Einstein, São Paulo, SP (Brazil); Baroni, Ronaldo Hueb [Magnetic Resonance Unit, Imaging Department, Hospital Israelita Albert Einstein, São Paulo, SP (Brazil)

    2013-07-01

    To evaluate the endometrial alterations related to embolization of uterine arteries for the treatment of symptomatic uterine leiomyomatosis (pelvic pain and/or uterine bleeding) by means of high-field (3-Tesla) magnetic resonance. This is a longitudinal and prospective study that included 94 patients with a clinical and imaging diagnosis of symptomatic uterine leiomyomatosis, all of them treated by embolization of the uterine arteries. The patients were submitted to evaluations by high-field magnetic resonance of the pelvis before and 6 months after the procedure. Specific evaluations were made of the endometrium on the T2-weighted sequences, and on the T1-weighted sequences before and after the intravenous dynamic infusion of the paramagnetic contrast. In face of these measures, statistical analyses were performed using Student's t test for comparison of the results obtained before and after the procedure. An average increase of 20.9% was noted in the endometrial signal on T2-weighted images obtained after the uterine artery embolization procedure when compared to the pre-procedure evaluation (p=0.0004). In the images obtained with the intravenous infusion of paramagnetic contrast, an average increase of 18.7% was noted in the post-embolization intensity of the endometrial signal, compared to the pre-embolization measure (p<0.035). After embolization of the uterine arteries, there was a significant increase of the endometrial signal on the T2-weighted images and on the post-contrast images, inferring possible edema and increased endometrial flow. Future studies are needed to assess the clinical impact of these findings.

  11. Power doppler ultrasound findings of renal infarct after experimental renal artery occlusion: comparison with spiral CT

    International Nuclear Information System (INIS)

    Jung, Seung Eun; Shinn, Kyung Sub; Kim, Hak Hee; Mun, Seok Hwan; Lee, Young Joon; Lee, Bae Young; Choi, Byung Gil; Lee, Jae Mun; Lee, Hee Jeong

    1999-01-01

    To evaluate the efficacy of power Doppler ultrasonography (PDUS) in depicting renal infarction in rabbits during experimental renal segmental arterial occlusion, and to compare the results with those of CT scanning. In 28 rabbits weighing 2.5 4kg, the segmental renal artery was occluded through the left main renal artery by embolization with Ivalon (Nycomed, Paris, France). Power Doppler ultrasonography and spiral CT scanning were performed before and at 2, 5, 8, 15, and 24 hours, and 3 and 7 days after occlusion of the segmental renal artery. The location of infarcted areas and collaterals, as seen on PDUS and CT scans, was evaluated by two radiologists. In all cases, as seen on power Doppler ultrasonography, infarcted areas-when compared with normal parenchyma, clearly demonstrated wedge-shaped perfusion defects in the kidney. The location of the lesion closely corresponded to the location seen during CT scanning. After renal arterial occlusion, transiently congested capsular arteries, which were named 'capsular sign', were seen in 63% of rabbits in the two and five-hour groups. No significant cortical rim sign was demonstrated on power Doppler ultrasonography, though it was noted on spiral CT at 15 and 24 hours, and 3 and 7 days after renal arterial occlusion. Power Doppler ultrasonography was useful for the diagnosis of renal infarction. Congested capsular artery seen in the early stage of renal infarction might be a characteristic finding of this condition, as seen on power Doppler ultrasonography

  12. A Doppler Radar System for Sensing Physiological Parameters in Walking and Standing Positions

    Directory of Open Access Journals (Sweden)

    Malikeh Pour Ebrahim

    2017-03-01

    Full Text Available Doppler radar can be implemented for sensing physiological parameters wirelessly at a distance. Detecting respiration rate, an important human body parameter, is essential in a range of applications like emergency and military healthcare environments, and Doppler radar records actual chest motion. One challenge in using Doppler radar is being able to monitor several patients simultaneously and in different situations like standing, walking, or lying. This paper presents a complete transmitter-receiver Doppler radar system, which uses a 4 GHz continuous wave radar signal transmission and receiving system, to extract base-band data from a phase-shifted signal. This work reports experimental evaluations of the system for one and two subjects in various standing and walking positions. It provides a detailed signal analysis of various breathing rates of these two subjects simultaneously. These results will be useful in future medical monitoring applications.

  13. Laser doppler perfusion imaging

    International Nuclear Information System (INIS)

    Waardell, K.

    1992-01-01

    Recording of tissue perfusion is important in assessing the influence of peripheral vascular diseases on the microcirculation. This thesis reports on a laser doppler perfusion imager based on dynamic light scattering in tissue. When a low power He-Ne laser beam sequentally scans the tissue, moving blood cells generate doppler components in the back-scattered light. A fraction of this light is detected by a photodetector and converted into an electrical signal. In the processor, a signal proportional to the tissue perfusion at each measurement site is calculated and stored. When the scanning procedure is completed, a color-coded perfusion image is presented on a monitor. To convert important aspects of the perfusion image into more quantitative parameters, data analysis functions are implemented in the software. A theory describing the dependence of the distance between individual measurement points and detector on the system amplification factor is proposed and correction algorithms are presented. The performance of the laser doppler perfusion imager was evaluated using a flow simulator. A linear relationship between processor output signal and flow through the simulator was demonstrated for blood cell concentrations below 0.2%. The median sampling depth of the laser beam was simulated by a Monte Carlo technique and estimated to 235 μm. The perfusion imager has been used in the clinic to study perfusion changes in port wine stains treated with argon laser and to investigate the intensity and extension of the cutaneous axon reflex response after electrical nerve stimulation. The fact that perfusion can be visualized without touching the tissue implies elimination of sterilization problems, thus simplifying clinical investigations of perfusion in association with diagnosis and treatment of peripheral vascular diseases. 22 refs

  14. Risk factors associated with the occurrence of silent pulmonary embolism in patients with deep venous thrombosis of the lower limb.

    Science.gov (United States)

    Li, Fenghe; Wang, Xuehu; Huang, Wen; Ren, Wei; Cheng, Jun; Zhang, Mao; Zhao, Yu

    2014-08-01

    The aim of our study is to investigate the prevalence of silent pulmonary embolism in patients with deep venous thrombosis in the lower limbs and to evaluate the associated risk factors. A total of 322 patients with acute deep venous thrombosis confirmed by CT venography or Doppler ultrasonography were studied. The diagnosis of silent pulmonary embolism was established by computed tomography pulmonary arteriography (CTPA). The association between covariates and the prevalence of silent pulmonary embolism in patients with deep venous thrombosis in lower limbs were assessed using chi-square test and multivariable regression. The incidence of silent pulmonary embolism was 33.5% (108 in 322 patients) in all patients with deep venous thrombosis in lower limbs. Chi-square test showed male gender, the right lower limb, proximal location of the thrombus, unprovoked venous thrombosis and coexisting heart diseases were related to a higher incidence of silent pulmonary embolism in patients with deep venous thrombosis in lower limbs. The multivariate regression analysis confirmed that the risk factors associated with silent pulmonary embolism in deep venous thrombosis patients included the right side and proximal location of the thrombus (odds ratio: 2.023, 95% CI: 1.215-3.368; odds ratio: 3.610, 95% CI: 1.772-7.354), unprovoked venous thrombosis (odds ratio: 2.037, 95% CI: 1.188-3.493), coexisting heart diseases (odds ratio: 4.507, 95% CI: 2.667-7.618). Silent pulmonary embolism occurred frequently in patients with deep venous thrombosis in lower limbs. The right side, the proximal location of the thrombus, unprovoked venous thrombosis and coexisting heart diseases increased the risk for the occurrence of silent pulmonary embolism. © The Author(s) 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  15. Doppler echography and utilization of intravenous echo enhancer in the follow-up of hepato carcinoma with percutaneous radiological techniques; Ecografia Doppler y empleo del ecopotenciador intravenoso en el seguimiento del hepatocarcinoma con tecnicas radiologicas percutaneas

    Energy Technology Data Exchange (ETDEWEB)

    Forner, J; Flored de la Torre, M.; Senis, C; Lozano de Arnilla, M C; Ferrer, S; Celma, M I [Hospital General Universitario de Valencia. Valencia (Spain)

    2002-07-01

    To evaluate the utilization of Doppler ultrasound scan in conjunction with echographic enhancer in the follow-up of hepato carcinomas treated by means of radiological intervention techniques. We treated 20 hepatic nodules diagnosed with hepato carcinoma either by means of chemo embolization or percutaneously (either injection of acetic acid or radio-frequency thermo-ablation). Doppler ultrasound scan was performed before and after the treatment by means of sectorial and convex multifrequency probes. Evaluated were the absence, presence and degree of vascularisation, as well as its distribution and characteristics. In all cases, a contrast-en-handed spiral CT was performed. Both studies served as a pattern for comparison before and after treatment. In post-treatment enhanced-echo-Doppler controls of the 18 patients treated with acetic acid, vascularisation was not demonstrated in 7 cases, peripheral vascularisation was detected in 4 cases, perforation vascularisation in another four, and central vascularisation was detected in 3 cases. Contrast-enhanced spiral CT demonstrated superimposed findings, except in one cases, in which the spiral CT detected central capitation of the nodule.With enhanced echo-Doppler, peripheral vascularisation was detected. In both nodules treated by means of radio-frequency thermo ablation, there was detected neither vascularisation in the echo-Doppler nor captation of contrast media in the CT. Doppler ultrasound scan is a good method of follow-up for treated hepato carcinomas. The utilization of echoenhancers increases its ability to detect vascularization it being comparable to that of contrast-enhanced CT. As such, Doppler ultrasound scan together with echoenhancers can help us both in the selection of treatment and evaluation of therapeutic response. (Author) 35 refs.

  16. Contrast-enhanced color Doppler ultrasound characteristics in hypervascular breast tumors: comparison with MRI

    International Nuclear Information System (INIS)

    Alamo, L.; Fischer, U.

    2001-01-01

    The aim of this study was to evaluate the accuracy of contrast-enhanced color Doppler ultrasound (CE-US) in comparison with contrast-enhanced MR imaging (CE-MRI) in the discrimination of hypervascularized breast tumors. An additional CE-US of the breast was preoperatively performed in 40 patients with a hypervascular breast lesion detected on CE-MRI. The presence of blood flow signals and the morphological characteristics of the vessels in the breast lesions were evaluated pre- and post-contrast administration, as well as the dynamic aspects of the Doppler signal, including time interval to maximum signal enhancement and persistence of the signal enhancement. Twenty-three carcinomas and 17 fibroadenomas were explored. Considering initial signal enhancement > 100 % after the administration of contrast material as a criterion suggesting malignancy, CE-MRI showed a sensitivity of 100 % and a specificity of 76.5 % in the detection of malignant breast tumors. Color Doppler signals were consistently demonstrated in all carcinomas and in 68.7 % of fibroadenomas after the administration of Levovist, with CE-US showing a sensitivity of 95.6 % and a specificity of 5.9 %. Neither the mean number of vessels per tumor, nor the location of vessels, the time to maximum increase of the Doppler signal or the persistence of signal enhancement showed significant differences between benign and malignant lesions. Additional CE-US does not increase the low specificity of MRI in patients with hypervascularized breast tumors. (orig.)

  17. Evaluation of Hemodynamic Changes and Respiratory Physical Findings in Patients with Pulmonary Embolism

    Directory of Open Access Journals (Sweden)

    Masome Rabieepour

    2014-07-01

    Full Text Available Introduction: Pulmonary thromboembolism (PTE is a potentially fatal disease with nonspecific symptoms and signs. Patients with Pulmonary embolism often have dyspnea, chest pain, haemoptysis, tachycardia tachypnea and respiratory physical finding including hypoxia and decreased ETCO2. Daily patients with Pulmonary embolism are very few in hospital course and we aimed to determine clinical and paraclinical findings in hospital pulmonary embolism patients. Methods: we assessed in hospital course of 104 patients with pulmonary embolism with symptom (dyspnea, chest pain, and hemoptysis and signs (tachypnea, tachycardia, DVT signs, blood pressure and respiratory physical findings (PO2, ETCO2. Results: majority of patients had risk factor for PTE; the most common was cancer. 21.2% of patients had apparent DVT in Doppler sonography. Isolated dyspnea (38%, chest pain with and without hemoptysis (60% and syncope (2% were observed in patients. Mean duration of dyspnea resolution was 3.4 days. Mean duration of chest pain resolution was 1.76 days. Mean duration of hemoptysis resolution was 2 days. 64.4% of the patients were hypoxic and mean duration of hypoxic resolution was 2.63 days. Mean duration of tachycardia resolution was 2.37 days. No relation was observed between size of PTE and mortality or hypotension and PO2. Mean ETCO2 was 23±2 mmHg and 86.5% of patients had ETCO2 lower than 28. Mean duration of ETCO2 resolution was 3.6 days. Most common physical finding that resolved later than others was ETCO2. In 32.7% of patients, ETCO2 did not resolve.   Key words: Pulmonary thromboembolism; Tachycardia; Tachypnea; Hemoptysis; Hypoxic; ETCO2

  18. Pelvic artery embolization in gynecological bleeding

    International Nuclear Information System (INIS)

    Hausegger, K.A.; Schreyer, H.; Bodhal, H.

    2002-01-01

    The most common reasons for gynecological bleeding are pregnancy-related disorders, fibroids of the uterus, and gynecological malignances. Transarterial embolization is an effective treatment modality for gynecological bleeding regardless of its etiology. Depending on the underlying disease, a different technique of embolization is applied. In postpartal bleeding a temporary effect of embolization is desired, therefore gelatine sponge is used as embolizing agent. In fibroids and malignant tumors the effect should permanent, therefore PVA particles are used. Regardless the etiology, the technical and clinical success of transarterial embolization is at least 90%. In nearly every patient a post-embolization syndrome can be observed, represented by local pain and fever. This post-embolization syndrome usually does not last longer than 3 days. If embolization is performed with meticulous attention to angiographic technique and handling of embolic material, ischemic damage of adjacent organs is rarely observed. Transarterial embolization should be an integrative modality in the treatment of gynecological bleeding. (orig.) [de

  19. PAU/GNSS-R: Implementation, Performance and First Results of a Real-Time Delay-Doppler Map Reflectometer Using Global Navigation Satellite System Signals

    Directory of Open Access Journals (Sweden)

    Enric Valencia

    2008-05-01

    Full Text Available Signals from Global Navigation Satellite Systems (GNSS were originally conceived for position and speed determination, but they can be used as signals of opportunity as well. The reflection process over a given surface modifies the properties of the scattered signal, and therefore, by processing the reflected signal, relevant geophysical data regarding the surface under study (land, sea, ice… can be retrieved. In essence, a GNSS-R receiver is a multi-channel GNSS receiver that computes the received power from a given satellite at a number of different delay and Doppler bins of the incoming signal. The first approaches to build such a receiver consisted of sampling and storing the scattered signal for later post-processing. However, a real-time approach to the problem is desirable to obtain immediately useful geophysical variables and reduce the amount of data. The use of FPGA technology makes this possible, while at the same time the system can be easily reconfigured. The signal tracking and processing constraints made necessary to fully design several new blocks. The uniqueness of the implemented system described in this work is the capability to compute in real-time Delay-Doppler maps (DDMs either for four simultaneous satellites or just one, but with a larger number of bins. The first tests have been conducted from a cliff over the sea and demonstrate the successful performance of the instrument to compute DDMs in real-time from the measured reflected GNSS/R signals. The processing of these measurements shall yield quantitative relationships between the sea state (mainly driven by the surface wind and the swell and the overall DDM shape. The ultimate goal is to use the DDM shape to correct the sea state influence on the L-band brightness temperature to improve the retrieval of the sea surface salinity (SSS.

  20. Complex regression Doppler optical coherence tomography

    Science.gov (United States)

    Elahi, Sahar; Gu, Shi; Thrane, Lars; Rollins, Andrew M.; Jenkins, Michael W.

    2018-04-01

    We introduce a new method to measure Doppler shifts more accurately and extend the dynamic range of Doppler optical coherence tomography (OCT). The two-point estimate of the conventional Doppler method is replaced with a regression that is applied to high-density B-scans in polar coordinates. We built a high-speed OCT system using a 1.68-MHz Fourier domain mode locked laser to acquire high-density B-scans (16,000 A-lines) at high enough frame rates (˜100 fps) to accurately capture the dynamics of the beating embryonic heart. Flow phantom experiments confirm that the complex regression lowers the minimum detectable velocity from 12.25 mm / s to 374 μm / s, whereas the maximum velocity of 400 mm / s is measured without phase wrapping. Complex regression Doppler OCT also demonstrates higher accuracy and precision compared with the conventional method, particularly when signal-to-noise ratio is low. The extended dynamic range allows monitoring of blood flow over several stages of development in embryos without adjusting the imaging parameters. In addition, applying complex averaging recovers hidden features in structural images.

  1. Interventional embolization with coils for the treatment of surgical stoma bleeding caused by portal hypertension: a therapeutic analysis

    International Nuclear Information System (INIS)

    Chen Feng; Chen Shiwei; Qiao Delin; Tang Zhen

    2010-01-01

    Objective: To assess the feasibility and safety of interventional embolization with coils in treating surgical stoma bleeding caused by portal hypertension. Methods: From February 2008 to May 2010, the authors treated eight patients with surgical stoma bleeding associated with portal hypertension. The patients included 5 females and 3 males, with a mean age of 57 years. The diagnosis was confirmed preoperatively by enhanced CT scanning and vascular reconstruction, and was further verified by angiography after operation. All patients were treated with coil embolization. The percutaneous transhepatic catheterization was performed, after that the catheter was manipulated to pass portal vein into the tortuous dilated mesenteric vein. The bleeding veins were occluded with gelatin sponge, and the spleen was embolized at the same time. The patients were followed up for two months to two years. Based on CT angiographic manifestations, color-Doppler ultrasound findings and clinical conditions the therapeutic results were evaluated. Results: Technical success with single procedure was achieved in all eight patients, the hemostasis rate was 100%. No serious complications occurred. During the follow-up period no recurrent bleeding of the surgical stoma was seen. Conclusion: For the treatment of surgical stoma bleeding caused by portal hypertension interventional embolization with coils is a safe and effective technique. It is worth popularizing this method in clinical practice. (authors)

  2. MR and CT imaging of cerebral fat embolism

    International Nuclear Information System (INIS)

    Li Ying; Xu Jianmin; Wan Xiaohong; Chen Yu; Guo Yi

    2003-01-01

    Objective: To summarize the clinical characteristics and imaging features of cerebral fat embolism (CFE). Methods: The clinical features and imaging appearances of 3 cases with acute CFE were analyzed. Results: (1) 3 non-head injured cases had sudden mental status changes after leg injury. (2) The main clinical manifestation was vigil coma. (3) MRI showed lesions of the brain in all 3 cases. Cranial CT showed lesions in only 1 case. (4) MRI and CT showed spotty and patchy symmetrical lesions, which were low signal on T 1 WI and high signal on T 2 WI, and low density on CT scan. The lesions were distributed in the white matter along the boundary zones of the major vascular territories, thalamus and basal ganglia, internal capsule, corpus callosum, brain stem, and cerebellum. The margins of the lesions were obscure. (5) 1 case received MRI examination after therapy for 3 months, which showed no lesions in the brain. Conclusion: Cerebral fat embolism has its own clinical features and imaging characteristics. MRI is superior to CT in diagnosing CFE

  3. Paradoxical embolization via a patent foramen ovale following acute pulmonary embolism

    International Nuclear Information System (INIS)

    Thomas, D.V.; Bynevelt, V.; Price, R.

    2005-01-01

    The foramen ovale is usually obliterated following establishment of the adult circulation but remains patent in 25% of individuals. This potential communication between the venous and arterial circulations can allow thromboembolic material to bypass the lungs and enter the systemic circulation. We report two cases of paradoxical embolization through a patent foramen ovale following acute large pulmonary embolism (PE) and discuss the factors that predispose to paradoxical embolization following PE Copyright (2005) Blackwell Publishing Asia Pty Ltd

  4. Thrombolysis for acute lower limb arterial embolism in patients with recent cerebral embolism

    International Nuclear Information System (INIS)

    Si Tongguo; Guo Zhi

    2008-01-01

    Objective: To assess the feasibility and efficacy of catheter-directed thrombolysis with recombinant tissue plasminogen activator (rt-PA)for acute limb embolism in patients with recent cerebral embolism. Methods: Eight patients with atrial fibrillation history happened to suffer acute limb embolism after recent cerebral embolism. The affected arteries included 2 left common iliac arteries, 4 femoral arteries (3 left, 1 right), 2 right popliteal arteries. Catheter-directed thrombolysis with rt-PA was applied with bolus administration plus continuous perfusion. Percutaneous transluminal angioplasty with balloon dilatation was applied in 3 patients, and one stent placement in one patient. Results: The mean duration of continuous perfusion was 3.6 hours and the mean dose of rt-PA administered was 23.6 mg (range, 20-28 mg)with complete recanalization rate of 100%. Clinical complete relief rate was 7/8 with one patient suffering from rest pain due to distal occlusion of anterior/posterior tibial artery. The complications included hematoma at puncture site (6/8), bleeding around the vascular sheath (2/8)and hematuria (1/8). NO intracerebral hemorrhage was found on CT scans after the thrombolysis. During follow up of 3-6 months, no recurrent embolism or thrombosis occurred in the limbs except one patient with recurrent cerebral embolism and died. Conclusions: Catheter-directed thrombolysis with rt-PA is probably to be a safe and effective method for acute limb embolism in patients with recent cerebral embolism and atrial fibrillation history. (authors)

  5. Doppler-guided retrograde catheterization system

    Science.gov (United States)

    Frazin, Leon J.; Vonesh, Michael J.; Chandran, Krishnan B.; Khasho, Fouad; Lanza, George M.; Talano, James V.; McPherson, David D.

    1991-05-01

    The purpose of this study was to investigate a Doppler guided catheterization system as an adjunctive or alternative methodology to overcome the disadvantages of left heart catheterization and angiography. These disadvantages include the biological effects of radiation and the toxic and volume effects of iodine contrast. Doppler retrograde guidance uses a 20 MHz circular pulsed Doppler crystal incorporated into the tip of a triple lumen multipurpose catheter and is advanced retrogradely using the directional flow information provided by the Doppler waveform. The velocity detection limits are either 1 m/second or 4 m/second depending upon the instrumentation. In a physiologic flow model of the human aortic arch, multiple data points revealed a positive wave form when flow was traveling toward the catheter tip indicating proper alignment for retrograde advancement. There was a negative wave form when flow was traveling away from the catheter tip if the catheter was in a branch or bent upon itself indicating improper catheter tip position for retrograde advancement. In a series of six dogs, the catheter was able to be accurately advanced from the femoral artery to the left ventricular chamber under Doppler signal guidance without the use of x-ray. The potential applications of a Doppler guided retrograde catheterization system include decreasing time requirements and allowing safer catheter guidance in patients with atherosclerotic vascular disease and suspected aortic dissection. The Doppler system may allow left ventricular pressure monitoring in the intensive care unit without the need for x-ray and it may allow left sided contrast echocardiography. With pulse velocity detection limits of 4 m/second, this system may allow catheter direction and passage into the aortic root and left ventricle in patients with aortic stenosis. A modification of the Doppler catheter may include transponder technology which would allow precise catheter tip localization once the

  6. Adaptive OFDM Radar Waveform Design for Improved Micro-Doppler Estimation

    Energy Technology Data Exchange (ETDEWEB)

    Sen, Satyabrata [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Center for Engineering Science Advanced Research, Computer Science and Mathematics Division

    2014-07-01

    Here we analyze the performance of a wideband orthogonal frequency division multiplexing (OFDM) signal in estimating the micro-Doppler frequency of a rotating target having multiple scattering centers. The use of a frequency-diverse OFDM signal enables us to independently analyze the micro-Doppler characteristics with respect to a set of orthogonal subcarrier frequencies. We characterize the accuracy of micro-Doppler frequency estimation by computing the Cramer-Rao bound (CRB) on the angular-velocity estimate of the target. Additionally, to improve the accuracy of the estimation procedure, we formulate and solve an optimization problem by minimizing the CRB on the angular-velocity estimate with respect to the OFDM spectral coefficients. We present several numerical examples to demonstrate the CRB variations with respect to the signal-to-noise ratios, number of temporal samples, and number of OFDM subcarriers. We also analysed numerically the improvement in estimation accuracy due to the adaptive waveform design. A grid-based maximum likelihood estimation technique is applied to evaluate the corresponding mean-squared error performance.

  7. Paradoxical cerebral air embolism

    International Nuclear Information System (INIS)

    Lopez-Negrete, L.; Garcia-Lozano, J.; Sanchez, J. L.; Sala, J.

    2000-01-01

    We present a fatal case of intracranial air embolism produced by the passage of intravenous air to the arteries owing to the existence of a patent foremen ovale associated with pulmonary hypertension, which permitted a right-left shunt (paradoxical embolism). The pathophysiological mechanisms of pneumcephalus and paradoxical embolism are discussed and the pertinent literature is reviewed. (Author) 6 refs

  8. Evaluation of preoperative embolization of meningioma

    International Nuclear Information System (INIS)

    Park, Sung Tae; Suh, Dae Chul; Lee, Ho Kyu; Choi, Choong Gon; Lee, Myung Jun; Ji, Eun Kyung; Shin, Byung Suck; Kim, Chang Jin; Kim, Jong Uk; Whang, C. Jin

    1998-01-01

    To evaluate the efficacy and safety of preoperative embolization of intrancranial meningioma.Materials and Methods : We retrospectively reviewed intrancranial meningioma patients (n=37) who underwent preoperative embolization. They were categorized into two groups, skull base lesions (n=22) and non-skull base lesions (n=15), according to tumor location. In addition, embolization results were classified by comparison between pre- and post-embolization angiography as complete (residual tumor staining 10 or 30%). In each group, estimated blood loss (EBL) was estimated by amount of intraoperative transfusion with pre- and post-operative hemoglobin level. Tumor resectability was evaluated by follow-up computed tomography. New symptoms occurring within 24 hours of embolization were considered to be those associated with embolization ; symptoms improved by conservative treatment were regarded as mild, while those resulting in new deficits were considered severe. Results : In the group with skull base lesions (n=22), complete embolization with the criteria of residual tumor staining of less than 30% was performed in 14 patients(EBL=1770ml;complete surgical removal in nine patients and incomplete removal four). Incomplete embolization was performed in eight patients (EBL=3210ml; complete and incomplete removal each in four patients). In the group with non-skull base lesions, complete embolization with the criteria of residual tumor staining of less than 10% was performed in five patients (EBL=970ml) and incomplete embolization in ten (EBL=2260ml). Complete tumor removal was possible in this group regardless of the completeness of preoperative tumor embolization. In a case of intraventricular meningioma (3%), intratumoral hemorrhage occurred on the day following embolization. Other mild post-embolization complications occurred in three cases (8%). Conclusion : Preoperative embolization can be an effective and safe procedure for meningioma and may reduce intraoperative blood

  9. Combined Endovascular Treatment with Distal Radial Artery Coil Embolization and Angioplasty in Steal Syndrome Associated with Forearm Dialysis Fistula

    Energy Technology Data Exchange (ETDEWEB)

    Tercan, Fahri, E-mail: ftercan@yahoo.com; Koçyiğit, Ali, E-mail: alkoc@yahoo.com [Pamukkale University, Department of Radiology, School of Medicine (Turkey); Güney, Bünyamin [Muğla Sıtkı Kocman University, Department of Radiology, School of Medicine (Turkey)

    2016-09-15

    PurposeThe present study was performed to define the results of the endovascular treatment with angioplasty and distal radial artery embolization in ischemic steal syndrome associated with forearm arteriovenous accesses.MethodThe cases referred to our interventional radiology unit with symptoms and physical examination findings suggestive of ischemic steal syndrome were retrospectively evaluated first by Doppler ultrasonography, and then by angiography. Cases with proximal artery stenosis were applied angioplasty, and those with steal syndrome underwent coil embolization to distal radial artery.ResultsOf 589 patients who underwent endovascular intervention for dialysis arteriovenous fistulae (AVF)-associated problems, 6 (1.01 %) (5 female, 1 males; mean age 62 (range 41–78) with forearm fistula underwent combined endovascular treatment for steal syndrome. In addition to steal phenomenon, there were stenosis and/or occlusion in proximal radial and/or ulnar artery in 6 patients concurrently. Embolization of distal radial artery and angioplasty to proximal arterial stenoses were performed in all patients. Ischemic symptoms were eliminated in all patients and the AVF were in use at the time of study. In one patient, ischemic symptoms recurring 6 months later were alleviated by repeat angioplasty of ulnar artery.ConclusionIn palmar arch steal syndrome affecting forearm fistulae, combined distal radial embolization and angioplasty is also an effective treatment method in the presence of proximal radial and ulnar arterial stenoses and occlusions.

  10. Radiologic diagnosis of pulmonary embolism

    International Nuclear Information System (INIS)

    Fink, C.; Ley, S.; Kauczor, H.U.

    2004-01-01

    Pulmonary embolism is a frequent and potentially life-threatening complication of venous thromboembolism. Despite numerous modern diagnostic methods, the diagnosis of pulmonary embolism remains problematic, especially in view of the nonspecific clinical presentation. In this educational review, current diagnostic methods and their role in the diagnostic workup of pulmonary embolism will be discussed. In addition, practical guidelines are given for the diagnostic cascade contingent on the clinical probability for pulmonary embolism. (orig.) [de

  11. Cerebral fat embolism studied with MRI and SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Erdem, E. (Dept. of Neurology, Hacettepe Univ. School of Medicine, Ankara (Turkey)); Namer, I.J. (Inst. of Biophysics, Faculty of Medicine, Louis Pasteur Univ., Strasbourg (France)); Saribas, O. (Dept. of Neurology, Hacettepe Univ. School of Medicine, Ankara (Turkey)); Aras, T. (Dept. of Nuclear Medicine, Hacettepe Univ. School of Medicine Ankara (Turkey)); Tan, E. (Dept. of Neurology, Hacettepe Univ. School of Medicine, Ankara (Turkey)); Bekdik, C. (Dept. of Nuclear Medicine, Hacettepe Univ. School of Medicine Ankara (Turkey)); Zileli, T. (Dept. of Neurology, Hacettepe Univ. School of Medicine, Ankara (Turkey))

    1993-03-01

    In a patient with fat embolism to the brain CT showed no abnormality. MRI performed after recovery from coma, when the patient had aphasia and quadriparesis, demonstrated multiple high signal abnormalities in the white matter on both T1- and T2-weighted images. HMPAO-SPECT showed left-sided hypoperfusion which resolved in parallel with clinical improvement 1 month later. (orig.)

  12. A novel method for the angiographic estimation of the percentage of spleen volume embolized during partial splenic embolization

    International Nuclear Information System (INIS)

    Ou, Ming-Ching; Chuang, Ming-Tsung; Lin, Xi-Zhang; Tsai, Hong-Ming; Chen, Shu-Yuan; Liu, Yi-Sheng

    2013-01-01

    Purpose: To evaluate the efficacy of estimating the volume of spleen embolized in partial splenic embolization (PSE) by measuring the diameters of the splenic artery and its branches. Materials and methods: A total of 43 liver cirrhosis patients (mean age, 62.19 ± 9.65 years) with thrombocytopenia were included. Among these, 24 patients underwent a follow-up CT scan which showed a correlation between angiographic estimation and measured embolized splenic volume. Estimated splenic embolization volume was calculated by a method based on diameters of the splenic artery and its branches. The diameters of each of the splenic arteries and branches were measured via 2D angiographic images. Embolization was performed with gelatin sponges. Patients underwent follow-up with serial measurement of blood counts and liver function tests. The actual volume of embolized spleen was determined by computed tomography (CT) measuring the volumes of embolized and non-embolized spleen two months after PSE. Results: PSE was performed without immediate major complications. The mean WBC count significantly increased from 3.81 ± 1.69 × 10 3 /mm 3 before PSE to 8.56 ± 3.14 × 10 3 /mm 3 at 1 week after PSE (P < 0.001). Mean platelet count significantly increased from 62.00 ± 22.62 × 10 3 /mm 3 before PSE to 95.40 ± 46.29 × 10 3 /mm 3 1 week after PSE (P < 0.001). The measured embolization ratio was positively correlated with estimated embolization ratio (Spearman's rho [ρ] = 0.687, P < 0.001). The mean difference between the actual embolization ratio and the estimated embolization ratio was 16.16 ± 8.96%. Conclusions: The method provides a simple method to quantitatively estimate embolized splenic volume with a correlation of measured embolization ratio to estimated embolization ratio of Spearman's ρ = 0.687

  13. Blood flow in intracranial aneurysms treated with Pipeline embolization devices: computational simulation and verification with Doppler ultrasonography on phantom models

    Directory of Open Access Journals (Sweden)

    Anderson Chun On Tsang

    2015-04-01

    Full Text Available Purpose: The aim of this study was to validate a computational fluid dynamics (CFD simulation of flow-diverter treatment through Doppler ultrasonography measurements in patient-specific models of intracranial bifurcation and side-wall aneurysms. Methods: Computational and physical models of patient-specific bifurcation and sidewall aneurysms were constructed from computed tomography angiography with use of stereolithography, a three-dimensional printing technology. Flow dynamics parameters before and after flow-diverter treatment were measured with pulse-wave and color Doppler ultrasonography, and then compared with CFD simulations. Results: CFD simulations showed drastic flow reduction after flow-diverter treatment in both aneurysms. The mean volume flow rate decreased by 90% and 85% for the bifurcation aneurysm and the side-wall aneurysm, respectively. Velocity contour plots from computer simulations before and after flow diversion closely resembled the patterns obtained by color Doppler ultrasonography. Conclusion: The CFD estimation of flow reduction in aneurysms treated with a flow-diverting stent was verified by Doppler ultrasonography in patient-specific phantom models of bifurcation and side-wall aneurysms. The combination of CFD and ultrasonography may constitute a feasible and reliable technique in studying the treatment of intracranial aneurysms with flow-diverting stents.

  14. The Dynamics of Embolism Refilling in Abscisic Acid (ABA-Deficient Tomato Plants

    Directory of Open Access Journals (Sweden)

    Francesca Secchi

    2012-12-01

    Full Text Available Plants are in danger of embolism formation in xylem vessels when the balance between water transport capacity and transpirational demand is compromised. To maintain this delicate balance, plants must regulate the rate of transpiration and, if necessary, restore water transport in embolized vessels. Abscisic acid (ABA is the dominant long-distance signal responsible for plant response to stress, and it is possible that it plays a role in the embolism/refilling cycle. To test this idea, a temporal analysis of embolism and refilling dynamics, transpiration rate and starch content was performed on ABA-deficient mutant tomato plants. ABA-deficient mutants were more vulnerable to embolism formation than wild-type plants, and application of exogenous ABA had no effect on vulnerability. However, mutant plants treated with exogenous ABA had lower stomatal conductance and reduced starch content in the xylem parenchyma cells. The lower starch content could have an indirect effect on the plant’s refilling activity. The results confirm that plants with high starch content (moderately stressed mutant plants were more likely to recover from loss of water transport capacity than plants with low starch content (mutant plants with application of exogenous ABA or plants experiencing severe water stress. This study demonstrates that ABA most likely does not play any direct role in embolism refilling, but through the modulation of carbohydrate content, it could influence the plant’s capacity for refilling.

  15. Pulsed and Color Doppler Sonographic Findings of Penile Mondor' Disease

    Energy Technology Data Exchange (ETDEWEB)

    Han, Hye Yeon; Chung, Dong Jin; Kim, Kum Won; Hwang, Cheol Mog [University of Konyang School of Medicine, Daejeon (Korea, Republic of)

    2008-04-15

    Penile Mondor's disease is a rare disease that's characterized by thrombosis in the dorsal vein of the penis. Doppler ultrasonography (US) clearly visualizes dorsal vein thrombosis and the associated hemodynamic alterations. Previous studies have demonstrated the typical color Doppler US findings of superficial dorsal vein thrombosis without the flow signals in this area, yet this is insufficient to understand the hemodynamics in penile Mondor's disease. We report here for the first time a cavernosal artery flow signal pattern in a penile Mondor's disease patient, in addition to its previously reported classic US findings. In conclusion, the Doppler US findings of thrombus without blood flow in the superficial dorsal vein and the low-flow, high resistance in the cavernosal artery may be suggestive of penile Mondor's disease.

  16. Evaluation of Effectiveness of Embolization in Pelvic Congestion Syndrome with the New Vascular Occlusion Device (ArtVentive EOS™): Preliminary Results

    International Nuclear Information System (INIS)

    Pyra, Krzysztof; Woźniak, Sławomir; Drelich-Zbroja, Anna; Wolski, Andrzej; Jargiełło, Tomasz

    2016-01-01

    PurposeThis study aimed to collect confirmatory data in support of the safety and efficiency of the ArtVentive EOS™ for the treatment of the pelvic congestion syndrome (PCS). This study was based on the OCCLUDE 1 Study Protocol approved by the Local Ethics Committee.Materials and MethodsA prospective study carried out in June and July 2014 included 12 women aged 21–48 years (mean 31 years) scheduled for PCS embolization using the ArtVentive EOS™. The inclusion criteria were clinical symptoms of PCS documented by transvaginal Doppler ultrasound and pelvic MRI. The pelvic pain was assessed by VAS score from 0 to 10 (0 represents lack of pain and 10 unbearable pain). A decrease in pelvic pain intensity based on the VAS was considered a clinical success.ResultsSuccessful embolization procedures with ArtVentive EOS™ were performed in 11 out of 12 patients. Nine patients underwent unilateral embolization of the left ovarian vein, and two had bilateral embolization of the ovarian veins. Complete ovarian vein occlusion confirmed by post deployment venography was achieved in all 11 patients. Procedures lasted from 19 to 45 min (average 28 min). Pain intensity decrease was observed in all 11 patients—a decrease of 5.6 points—from 7.3 pre-procedure to 1.6 post-embolization (standard deviation: 0.67). In one case, the left ovarian vein was injured by guide wire manipulation with contrast extravasation—not clinically significant.ConclusionsThe use of ArtVentive EOS™ for occlusion of the ovarian veins in PCS patients is safe and effective.

  17. Safety and efficacy of superior rectal artery embolization with particles and metallic coils for the treatment of hemorrhoids (Emborrhoid technique).

    Science.gov (United States)

    Zakharchenko, A; Kaitoukov, Y; Vinnik, Y; Tradi, F; Sapoval, M; Sielezneff, I; Galkin, E; Vidal, V

    2016-11-01

    The purpose of this study was to comprehensively evaluate the short-term outcomes after percutaneous embolization of the superior rectal artery (SRA) with metallic coils and particles for the management of hemorrhoids. Forty patients (15 men, 25 women) with a mean age of 35±5 years (SD) (range: 25-65 years) were prospectively enrolled. All patients had symptomatic hemorrhoids. The distribution of internal hemorrhoids was as follows: grade I (n=6, 16%); grade II (n=28, 69%) and grade III (n=6; 15%). All patients had percutaneous embolization of the SRA with metallic coils and synthetic polyvinyl alcohol particles. Follow-up evaluation included clinical examination, rectoscopy, histopathological analysis of rectal mucosa, duplex Doppler blood flow quantification, electromyography, sphincterometry of the anal sphincter and analysis of patient satisfaction. No immediate complications were observed and no patients had anal pain syndrome after embolization. Hemorrhoids showed a 43% size reduction after embolization (Phemorrhoids and 32/34 patients (94%) with grades I-II hemorrhoids. One month after embolization, anal sphincter contractility normalized and no changes in anal electromyography were observed. Blood flow in the hemorrhoidal plexus dropped from 109±1.2ml/min/100g (SD) before treatment to 60.2±4.4ml/min/100g (SD) (Phemorrhoids. Short-term results with regard to symptom management for hemorrhoidal disease are very encouraging and should stimulate further prospective and multicenter studies. Copyright © 2016 Editions françaises de radiologie. Published by Elsevier Masson SAS. All rights reserved.

  18. Evaluation of Effectiveness of Embolization in Pelvic Congestion Syndrome with the New Vascular Occlusion Device (ArtVentive EOS™): Preliminary Results

    Energy Technology Data Exchange (ETDEWEB)

    Pyra, Krzysztof, E-mail: k.pyra@poczta.fm [Medical University of Lublin, Department of Interventional Radiology and Neuroradiology (Poland); Woźniak, Sławomir, E-mail: slavwo7572@gmail.com [Medical University of Lublin, III Gynecology Clinic (Poland); Drelich-Zbroja, Anna, E-mail: zbroanna@interia.pl; Wolski, Andrzej, E-mail: andrzej.s.wolski@gmail.com; Jargiełło, Tomasz, E-mail: tojarg@interia.pl [Medical University of Lublin, Department of Interventional Radiology and Neuroradiology (Poland)

    2016-08-15

    PurposeThis study aimed to collect confirmatory data in support of the safety and efficiency of the ArtVentive EOS™ for the treatment of the pelvic congestion syndrome (PCS). This study was based on the OCCLUDE 1 Study Protocol approved by the Local Ethics Committee.Materials and MethodsA prospective study carried out in June and July 2014 included 12 women aged 21–48 years (mean 31 years) scheduled for PCS embolization using the ArtVentive EOS™. The inclusion criteria were clinical symptoms of PCS documented by transvaginal Doppler ultrasound and pelvic MRI. The pelvic pain was assessed by VAS score from 0 to 10 (0 represents lack of pain and 10 unbearable pain). A decrease in pelvic pain intensity based on the VAS was considered a clinical success.ResultsSuccessful embolization procedures with ArtVentive EOS™ were performed in 11 out of 12 patients. Nine patients underwent unilateral embolization of the left ovarian vein, and two had bilateral embolization of the ovarian veins. Complete ovarian vein occlusion confirmed by post deployment venography was achieved in all 11 patients. Procedures lasted from 19 to 45 min (average 28 min). Pain intensity decrease was observed in all 11 patients—a decrease of 5.6 points—from 7.3 pre-procedure to 1.6 post-embolization (standard deviation: 0.67). In one case, the left ovarian vein was injured by guide wire manipulation with contrast extravasation—not clinically significant.ConclusionsThe use of ArtVentive EOS™ for occlusion of the ovarian veins in PCS patients is safe and effective.

  19. Revisiting the four-level inverted-Y system under both Doppler-free and Doppler-broadened conditions: an analytical approach

    International Nuclear Information System (INIS)

    Ghosh, Arindam; Islam, Khairul; Bandyopadhyay, Amitava; Bhattacharyya, Dipankar

    2016-01-01

    We report the occurrence of electromagnetically induced transparency (EIT) in the simulated probe response signal for a four-level inverted-Y type system that is being acted upon by a weak coherent probe field, a strong coherent pump field and a coherent repump field. There are two ground energy levels, one intermediate energy level and one uppermost energy level. The weak probe field couples the lowest ground level to the intermediate level whereas the repump field connects the other ground level with the intermediate level. The strong control field couples the intermediate level with the uppermost energy level, thereby forming an inverted-Y type system. The density matrix based theoretical model has been developed and solved analytically for this four-level system and the probe response signal has been simulated at different values of the control and repump Rabi frequencies, control and repump frequency detunings and under both Doppler-free and Doppler-broadened conditions using the parameters of 87 Rb D 2 transition. Extremely low line width (few tens of kHz) for the EIT signal has been noticed under thermal averaging for copropagating probe, control and repump field configuration. The EIT signal is found to be immune to the variation in the control Rabi frequency. (paper)

  20. A novel method for the angiographic estimation of the percentage of spleen volume embolized during partial splenic embolization

    Energy Technology Data Exchange (ETDEWEB)

    Ou, Ming-Ching; Chuang, Ming-Tsung [Department of Diagnostic Radiology, National Cheng-Kung University Hospital, No. 138 Sheng Li Road, Tainan 704, Taiwan, ROC (China); Lin, Xi-Zhang [Department of Internal Medicine, National Cheng-Kung University Hospital, No. 138 Sheng Li Road, Tainan 704, Taiwan, ROC (China); Tsai, Hong-Ming; Chen, Shu-Yuan [Department of Diagnostic Radiology, National Cheng-Kung University Hospital, No. 138 Sheng Li Road, Tainan 704, Taiwan, ROC (China); Liu, Yi-Sheng, E-mail: taicheng100704@yahoo.com.tw [Department of Diagnostic Radiology, National Cheng-Kung University Hospital, No. 138 Sheng Li Road, Tainan 704, Taiwan, ROC (China)

    2013-08-15

    Purpose: To evaluate the efficacy of estimating the volume of spleen embolized in partial splenic embolization (PSE) by measuring the diameters of the splenic artery and its branches. Materials and methods: A total of 43 liver cirrhosis patients (mean age, 62.19 ± 9.65 years) with thrombocytopenia were included. Among these, 24 patients underwent a follow-up CT scan which showed a correlation between angiographic estimation and measured embolized splenic volume. Estimated splenic embolization volume was calculated by a method based on diameters of the splenic artery and its branches. The diameters of each of the splenic arteries and branches were measured via 2D angiographic images. Embolization was performed with gelatin sponges. Patients underwent follow-up with serial measurement of blood counts and liver function tests. The actual volume of embolized spleen was determined by computed tomography (CT) measuring the volumes of embolized and non-embolized spleen two months after PSE. Results: PSE was performed without immediate major complications. The mean WBC count significantly increased from 3.81 ± 1.69 × 10{sup 3}/mm{sup 3} before PSE to 8.56 ± 3.14 × 10{sup 3}/mm{sup 3} at 1 week after PSE (P < 0.001). Mean platelet count significantly increased from 62.00 ± 22.62 × 10{sup 3}/mm{sup 3} before PSE to 95.40 ± 46.29 × 10{sup 3}/mm{sup 3} 1 week after PSE (P < 0.001). The measured embolization ratio was positively correlated with estimated embolization ratio (Spearman's rho [ρ] = 0.687, P < 0.001). The mean difference between the actual embolization ratio and the estimated embolization ratio was 16.16 ± 8.96%. Conclusions: The method provides a simple method to quantitatively estimate embolized splenic volume with a correlation of measured embolization ratio to estimated embolization ratio of Spearman's ρ = 0.687.

  1. Ovarian protection by selective coil embolization of a uteroovarian anastomosis before uterine fibroid embolization: a report of two cases

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Seung Boo; Im, Han Hyeok [Soonchunhyang University, Gumi (Korea, Republic of); Chang, Yun Woo; Goo, Dong Erk [Soonchunhyang University Hospital, Gumi (Korea, Republic of)

    2006-09-15

    Premature menopause can be developed as a result of undesired nontarget ovary embolization during the performance of uterine fibroid embolization. The etiology of varian failure after uterine fibroid embolization is not yet clearly defined, but one of the leading possibilities is nontarget embolization of the varies. We report here on two cases in which superselective coil embolization of distal uterine artery collateral pathways to the ovary was performed during uterine fibroid embolization.

  2. Digital setup for Doppler broadening spectroscopy

    International Nuclear Information System (INIS)

    Cizek, J; Vlcek, M; Prochazka, I

    2011-01-01

    New digital spectrometer for measurement of the Doppler shift of annihilation photons was developed and tested in this work. Digital spectrometer uses a fast 12-bit digitizer for direct sampling of signals from HPGe detectors. Analysis of sampled waveforms is performed off-line in software. Performance of the new digital setup was compared with its traditional analogue counterpart. Superior energy resolution was achieved in the digital setup. Moreover, the digital setup allows for a better control of the shape of detector signals. This enables to eliminate undesired signals damaged by pile-up effects or by ballistic deficit.

  3. Embolization of spinal arteriovenous malformations

    International Nuclear Information System (INIS)

    Son, Mi Young; Kim, Sun Yong; Park, Bok Hwan

    1990-01-01

    Recently, therapeutic embolization has been advocated as the treatment of choice for spinal AVM(arteriovenous malformations). The authors review our experience with two cases of spinal AVM treated by embolization using coaxial Tracker-18 microcatheter with Latvian. The patients included a 10 year old male with glomus type and a 14 year old female with juvenile type spinal AVM revealed recanalization 5 month later. Embolization provides curative or temporary treatment for spinal AVM. After embolic occlusion, delayed reassessment with arteriography is indicated, particularly if symptoms persist or recur

  4. Liver Regeneration After Portal Vein Embolization Using Absorbable and Permanent Embolization Materials in a Rabbit Model

    NARCIS (Netherlands)

    van den Esschert, Jacomina W.; van Lienden, Krijn P.; Alles, Lindy K.; van Wijk, Albert C.; Heger, Michal; Roelofs, Joris J.; van Gulik, Thomas M.

    2012-01-01

    Objective: To compare the safety and hypertrophy response after portal vein embolization (PVE) using 2 absorbable and 3 permanent embolization materials. Background: Portal vein embolization is used to increase future remnant liver volume preoperatively. Application of temporary, absorbable

  5. The MR imaging and DSA features and embolization therapy of spinal dural arteriovenous fistulae

    International Nuclear Information System (INIS)

    Zhang Hua; Hu Jinqing; Lin Dong; Wu Daming; Wang Dengbin; Yang Yanmin; Cheng Kemin

    2005-01-01

    Objective: To investigate the MR imaging and DSA features together with endovascular embolization of spinal dural arteriovenous fistulae (SDAVF). Methods: Twelve patients with SDAVF underwent both MR imaging and angiography of spinal cord, 4 of them received endovascular embolization. The imaging findings of MRI and angiography in all patients were analyzed. Results: Among 12 cases with SDAVF, 11 cases showed diffuse long T 2 signal, 2 cases demonstrated inhomogeneous maculate enhancement in the spinal cord and 6 cases revealed abnormal vessels in the dorsal spaces of spinal cord on MRI. Angiography of spinal cord showed orifices of all fistulae, draining veins, the extent of lesions, amount of feeding vessels and the angiographic features in all the 12 cases. 4 cases with embolization treatment showed improvement clinically. Conclusions: Angiography of spinal cord is the main method and MRI provides important assistance for diagnosing SDAVF while endovascular embolization is an effective method for the treatment. (authors)

  6. A new laser Doppler flowmeter prototype for depth dependent monitoring of skin microcirculation

    Science.gov (United States)

    Figueiras, E.; Campos, R.; Semedo, S.; Oliveira, R.; Requicha Ferreira, L. F.; Humeau-Heurtier, A.

    2012-03-01

    Laser Doppler flowmetry (LDF) is now commonly used in clinical research to monitor microvascular blood flow. However, the dependence of the LDF signal on the microvascular architecture is still unknown. That is why we propose a new laser Doppler flowmeter for depth dependent monitoring of skin microvascular perfusion. This new laser Doppler flowmeter combines for the first time, in a device, several wavelengths and different spaced detection optical fibres. The calibration of the new apparatus is herein presented together with in vivo validation. Two in vivo validation tests are performed. In the first test, signals collected in the ventral side of the forearm are analyzed; in the second test, signals collected in the ventral side of the forearm are compared with signals collected in the hand palm. There are good indicators that show that different wavelengths and fibre distances probe different skin perfusion layers. However, multiple scattering may affect the results, namely the ones obtained with the larger fibre distance. To clearly understand the wavelength effect in LDF measurements, other tests have to be performed.

  7. Assessment of 'on-treatment platelet reactivity' and relationship with cerebral micro-embolic signals in asymptomatic and symptomatic carotid stenosis.

    Science.gov (United States)

    Kinsella, Justin A; Oliver Tobin, W; Tierney, Sean; Feeley, Timothy M; Egan, Bridget; Coughlan, Tara; Ronan Collins, D; O'Neill, Desmond; Harbison, Joseph A; Doherty, Colin P; Madhavan, Prakash; Moore, Dermot J; O'Neill, Sean M; Colgan, Mary-Paula; Saqqur, Maher; Murphy, Raymond P; Moran, Niamh; Hamilton, George; McCabe, Dominick J H

    2017-05-15

    The relationship between on-treatment platelet reactivity and cerebral micro-embolic signals (MES) is unknown, and has not been previously simultaneously assessed in asymptomatic and symptomatic carotid stenosis patients. Consecutive eligible patients with ≥50% asymptomatic or recently symptomatic carotid stenosis (≤4weeks following TIA/ischaemic stroke) were recruited to this pilot study. Symptomatic patients were followed up to the 'late' phase (≥3months) following symptom onset or carotid intervention; longitudinal data were analysed from symptomatic patients with data available at both time-points. Platelet function/reactivity was assessed with the PFA-100® to measure collagen-ADP (C-ADP) and collagen-epinephrine (C-EPI) closure times in citrate-anticoagulated whole blood. Bilateral simultaneous 1-hour transcranial Doppler ultrasound (TCD) monitoring of the middle cerebral arteries was performed to classify patients as MES +ve or MES -ve. 31 patients with ≥50% asymptomatic and 46 with early symptomatic carotid stenosis or occlusion were included. 35 symptomatic patients were followed up to the late phase (23 following carotid intervention). Prevalence of 'high on-treatment platelet reactivity' (HTPR) on the C-EPI cartridge did not differ between asymptomatic and symptomatic patients overall, but was lower in 'symptomatic post-intervention' than asymptomatic patients on aspirin monotherapy (10% vs. 50%; p=0.03). The prevalence of HTPR on the C-EPI cartridge decreased between the early and late phases in symptomatic patients (63% vs. 34%; p=0.017), including those on aspirin monotherapy (p=0.016). There were no significant differences in HTPR status between asymptomatic vs. early or late symptomatic MES +ve or MES -ve patients. Carotid interventional treatment, presumably in combination with resolution of the acute phase response, may decrease the prevalence of HTPR in patients with recently symptomatic carotid stenosis over time. Preliminary subgroup

  8. Diagnostic Indication for Venous Echo-Doppler of the Lower Limbs in the Diagnosis of Thromboembolic

    International Nuclear Information System (INIS)

    Bolado, A. G.; Barcena, M. V.; Cura, J. L. del; Gorrno, O.; Grande, D.

    2003-01-01

    To study the effectiveness of Doppler echography in the deep venous system of the lower limbs for deep venous thrombosis detection in patients suspected of having pulmonary thromboembolism. There were received 341 consecutive suspected pulmonary thromboembolism patients, all of whom were emergency room attended. All were submitted to CT pulmonary angiography in order to evaluate thrombus presence in the pulmonary tree. Without knowing the results of the previous exploration, we studied 301 of the patients using Doppler echography in deep venous system of the lower limbs in order to evaluate thrombus presence. In the group of CT-detected pulmonary thromboembolism patients, the percentage of Doppler echography-detected deep venous thrombosis was 46.3%, while in the group of non-detected patients this percentage decreased to 4.7%. Additional deep venous system exploration in clinically suspected pulmonary thiolcarbamate patients is useful, since it can increase the detection rate of venous thromboembolic disease, thereby leading to early treatment and prevention of the disease's manifestation in the lungs. Realization of Doppler echography is especially beneficial in those patients who exhibit no factors which predispose them to thromboembolic disease, as well as in patients who have previously had venous thrombosis. This exploration account for 4.7% of non-detected pulmonary embolism patients being added to the ranks of those with thromboembolic disease, an important percentage when taking into consideration the high pulmonary thromboembolism morbimortality rate. (Author) 30 refs

  9. Korea-China Joint R and D on Doppler Lidar Technology

    International Nuclear Information System (INIS)

    Cha, Hyung Ki; Kim, D. H.; Kwon, S. O.; Yang, K. H.; Song, I. K.

    2009-03-01

    Doppler lidar technology is to monitor atmospheric wind velocity by measuring the light scattering signals between a laser and aerosol particles or molecules existing in the atmosphere. When the particles (or molecules) in the atmosphere are moving by wind force, the frequency of backscattering light is shifted by doppler effect, so that the wind velocity profile can be obtained by measurement of the shifted frequencies. When the laser radiation is scanned in four different direction, three dimensional wind profiles are obtained. The Anhui Institute of Optics and Fine Mechanics under the China Academy of Sciences has developed and operated the doppler lidar system for long time. In this project we want to developed a new technologies adopted to the chinese doppler system and to test the updated In the process of collaboration between China and Korea research teams, we want to learn the state-of-art technology involved in the doppler lidar system

  10. Embolization Therapy for Traumatic Splenic Lacerations

    Energy Technology Data Exchange (ETDEWEB)

    Dasgupta, Niloy; Matsumoto, Alan H., E-mail: ahm4d@virginia.edu; Arslan, Bulent; Turba, Ulku C.; Sabri, Saher; Angle, John F. [University of Virginia Health System, Division of Vascular and Interventional Radiology, Department of Radiology (United States)

    2012-08-15

    Purpose: This study was designed to evaluate the clinical success, complications, and transfusion requirements based on the location of and agents used for splenic artery embolization in patients with splenic trauma. Methods: A retrospective study was performed of patients with splenic trauma who underwent angiography and embolization from September 2000 to January 2010 at a level I trauma center. Electronic medical records were reviewed for demographics, imaging data, technical aspects of the procedure, and clinical outcomes. Results: Fifty patients were identified (34 men and 16 women), with an average age of 48 (range, 16-80) years. Extravasation was seen on initial angiography in 27 (54%) and was absent in 23 (46%). All 27 patients with extravasation were embolized, and 18 of 23 (78.2%) without extravasation were embolized empirically. Primary clinical success was similar (>75%) across all embolization locations, embolic agents, and grades of laceration treated. Of 45 patients treated, 9 patients (20%) were embolized in the main splenic artery, 34 (75.6%) in the splenic hilum, and 2 (4.4%) were embolized in both locations. Partial splenic infarctions developed in 47.3% treated in the splenic hilum compared with 12.5% treated in the main splenic artery. There were four (8.9%) mortalities: two occurred in patients with multiple critical injuries and two from nonbleeding etiologies. Conclusions: Embolization of traumatic splenic artery injuries is safe and effective, regardless of the location of treatment. Embolization in splenic hilar branches may have a higher incidence of infarction. The grade of laceration and agents used for embolotherapy did not impact the outcomes.

  11. Embolization Therapy for Traumatic Splenic Lacerations

    International Nuclear Information System (INIS)

    Dasgupta, Niloy; Matsumoto, Alan H.; Arslan, Bulent; Turba, Ulku C.; Sabri, Saher; Angle, John F.

    2012-01-01

    Purpose: This study was designed to evaluate the clinical success, complications, and transfusion requirements based on the location of and agents used for splenic artery embolization in patients with splenic trauma. Methods: A retrospective study was performed of patients with splenic trauma who underwent angiography and embolization from September 2000 to January 2010 at a level I trauma center. Electronic medical records were reviewed for demographics, imaging data, technical aspects of the procedure, and clinical outcomes. Results: Fifty patients were identified (34 men and 16 women), with an average age of 48 (range, 16–80) years. Extravasation was seen on initial angiography in 27 (54%) and was absent in 23 (46%). All 27 patients with extravasation were embolized, and 18 of 23 (78.2%) without extravasation were embolized empirically. Primary clinical success was similar (>75%) across all embolization locations, embolic agents, and grades of laceration treated. Of 45 patients treated, 9 patients (20%) were embolized in the main splenic artery, 34 (75.6%) in the splenic hilum, and 2 (4.4%) were embolized in both locations. Partial splenic infarctions developed in 47.3% treated in the splenic hilum compared with 12.5% treated in the main splenic artery. There were four (8.9%) mortalities: two occurred in patients with multiple critical injuries and two from nonbleeding etiologies. Conclusions: Embolization of traumatic splenic artery injuries is safe and effective, regardless of the location of treatment. Embolization in splenic hilar branches may have a higher incidence of infarction. The grade of laceration and agents used for embolotherapy did not impact the outcomes.

  12. Doppler electron velocimetry : notes on creating a practical tool.

    Energy Technology Data Exchange (ETDEWEB)

    Reu, Phillip L.; Milster, Tom (University of Arizona)

    2008-11-01

    The Doppler electron velocimeter (DEV) has been shown to be theoretically possible. This report attempts to answer the next logical question: Is it a practical instrument? The answer hinges upon whether enough electrons are available to create a time-varying Doppler current to be measured by a detector with enough sensitivity and bandwidth. The answer to both of these questions is a qualified yes. A target Doppler frequency of 1 MHz was set as a minimum rate of interest. At this target a theoretical beam current signal-to-noise ratio of 25-to-1 is shown for existing electron holography equipment. A detector is also demonstrated with a bandwidth of 1-MHz at a current of 10 pA. Additionally, a Linnik-type interferometer that would increase the available beam current is shown that would offer a more flexible arrangement for Doppler electron measurements over the traditional biprism.

  13. Congenital arterioportal fistulas: radiological treatment and color Doppler US follow-up

    Energy Technology Data Exchange (ETDEWEB)

    Teplisky, Dario; Tincani, Eliana Uruena; Lipsich, Jose; Sierre, Sergio [Department of Interventional Radiology, Pichincha 1890, Buenos Aires (Argentina)

    2012-11-15

    Congenital intrahepatic arterioportal fistulas (APFs) are a rare cause of portal hypertension in children. Doppler US is a useful diagnostic imaging modality. Transarterial embolization is a minimally invasive and effective therapy allowing occlusion of the fistula and restoration of liver hemodynamics. To describe the clinical and radiologic findings, percutaneous treatment and role of D-US in the postembolization follow-up of children with APF. Between 2002 and 2011, four children with APF were treated. Initial diagnosis and follow-up was performed with D-US and confirmed by arteriography, followed by endovascular embolization in all patients. D-US demonstrated abnormal arterioportal communications in all patients. Six endovascular procedures were performed in these four children. In two children, no residual fistula was seen on D-US after the first procedure and symptoms resolved. In the other two children, D-US demonstrated residual flow through the fistula, with resolution of pathological D-US findings and symptoms after the second endovascular procedure. All four children were successfully treated and asymptomatic at the end of follow-up. The mean follow-up was 24 months. Interventional radiology has a key role in the treatment of congenital APF. D-US is a noninvasive and effective tool for the diagnosis and follow-up of these patients. (orig.)

  14. Glare Spot Phase Doppler Anemometry

    Science.gov (United States)

    Hespel, Camille; Ren, Kuanfang; Gréhan, Gérard; Onofri, Fabrice

    2007-06-01

    The Phase Doppler anemometry has been developed to measure simultaneously the velocity and the size of droplets. The measurement of the refractive index would be also interesting since it depends on the temperature and the composition of the particle and its measurement permits both to increase the quality of the diameter measurement and to obtain information on the temperature and/or the composition of the droplets. In this paper, we introduce a Glare Spot Phase Doppler Anemometry which uses two large beams. In this case, the images of the particle formed by the reflected and refracted light, known as glare spots, are separated in space. When a particle passes in the probe volume, the two parts in a signal obtained by a detector in forward direction are then separated in time. If two detectors are used the phase differences between two signals, the distance and the intensity ratio of reflected and refracted parts can be obtained and they provide rich information about the particle diameter and its refractive index, as well as its velocity. This paper is devoted to the numerical study of such a configuration with two theoretical models: geometrical optics and rigorous electromagnetism solution.

  15. Doppler echography and utilization of intravenous echo enhancer in the follow-up of hepato carcinoma with percutaneous radiological techniques

    International Nuclear Information System (INIS)

    Forner, J.; Flored de la Torre, M.; Senis, C.; Lozano de Arnilla, M. C.; Ferrer, S.; Celma, M. I.

    2002-01-01

    To evaluate the utilization of Doppler ultrasound scan in conjunction with echographic enhancer in the follow-up of hepato carcinomas treated by means of radiological intervention techniques. We treated 20 hepatic nodules diagnosed with hepato carcinoma either by means of chemo embolization or percutaneously (either injection of acetic acid or radio-frequency thermo-ablation). Doppler ultrasound scan was performed before and after the treatment by means of sectorial and convex multifrequency probes. Evaluated were the absence, presence and degree of vascularisation, as well as its distribution and characteristics. In all cases, a contrast-en-handed spiral CT was performed. Both studies served as a pattern for comparison before and after treatment. In post-treatment enhanced-echo-Doppler controls of the 18 patients treated with acetic acid, vascularisation was not demonstrated in 7 cases, peripheral vascularisation was detected in 4 cases, perforation vascularisation in another four, and central vascularisation was detected in 3 cases. Contrast-enhanced spiral CT demonstrated superimposed findings, except in one cases, in which the spiral CT detected central capitation of the nodule.With enhanced echo-Doppler, peripheral vascularisation was detected. In both nodules treated by means of radio-frequency thermo ablation, there was detected neither vascularisation in the echo-Doppler nor captation of contrast media in the CT. Doppler ultrasound scan is a good method of follow-up for treated hepato carcinomas. The utilization of echoenhancers increases its ability to detect vascularization it being comparable to that of contrast-enhanced CT. As such, Doppler ultrasound scan together with echoenhancers can help us both in the selection of treatment and evaluation of therapeutic response. (Author) 35 refs

  16. Doppler ultrasound scan during normal gestation: umbilical circulation; Ecografia Doppler en la gestacion normal: circulacion umbilical

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz, T.; Sabate, J.; Martinez-Benavides, M. M.; Sanchez-Ramos, J. [Hospital Virgen Macarena. Sevilla (Spain)

    2002-07-01

    To determine normal umbilical circulation patterns by means of Doppler ultrasound scan in a healthy gestating population without risk factors and with normal perinatal results, and to evaluate any occurring modifications relative to gestational age by obtaining records kept during pregnancy. One hundred and sixteen pregnant women carrying a single fetus have been studied. These women had no risk factors, with both clinical and analytical controls, as well as ultrasound scans, all being normal. There were performed a total of 193 Doppler ultrasound scans between weeks 15 and 41 of gestation, with blood-flow analysis in the arteries and vein of the umbilical cord. The obtained information was correlated with parameters that evaluate fetal well-being (fetal monitoring and/or oxytocin test) and perinatal result (delivery type, birth weight, Apgar score). Statistical analysis was performed with the programs SPSS 6.0.1 for Windows and EPIINFO 6.0.4. With pulsed Doppler, the umbilical artery in all cases demonstrated a biphasic morphology with systolic and diastolic components and without retrograde blood flow. As the gestation period increased, there was observed a progressive decrease in resistance along with an increase in blood-flow velocity during the diastolic phase. The Doppler ultrasound scan is a non-invasive method that permits the hemodynamic study of umbilical blood circulation. A knowledge of normal blood-flow signal morphology, as well as of the normal values for Doppler indices in relation to gestational age would permit us to utilize this method in high-risk pregnancies. (Author) 30 refs.

  17. New phase method of measuring particle size with laser Doppler radar

    Science.gov (United States)

    Zemlianskii, Vladimir M.

    1996-06-01

    A vast field of non-contact metrology, vibrometry, dynamics and microdynamics problems solved on the basis of laser Doppler method resulted in the development of great variety of laser Doppler radar (LDR). In coherent LDR few beams with various polarization are generally adopted, that are directed at the zone of measurement, through which the probing air stream moves. Studies of various coherent LDR demonstrated that polarization-phase effects of scattering can in some cases considerably effect on the signal-to-noise ratio of the Doppler signal. On the other side using phase effects can simultaneous measurement of size and velocity of spherical particles. New possibilities for improving the accuracy of measuring spherical particles' sizes come to light when application is made in coherent LDR of two waves- probing and one out of the types of symmetrical reception of scattered radiation, during which phase-conjugate signals are formed. The theoretical analysis on the basis of the scattering theory showed, that in symmetrical reception of scattered radiation with respect to the planes OXZ and OYZ output signal of the photoreceiver contains two high- frequency signal components, which in relation to parameters of the probing and size, can either be in phase or antiphase. Results of numerical modeling are presented: amplitude of high frequency signal, coefficient of phase and polarization matching of mixed waves, the depths of photocurrent modulation and also signal's phase in relation to the angle between the probing beams. Phase method of determining particle's sizes based on the use of two wavelengths probing and symmetrical reception of scattered radiation in which conditions for the formation of phase conjugated high-frequency signals are satisfied is presented.

  18. An experimental study on combined transcatheter hepatic arterial embolization and retrograde hepatic venous embolization

    International Nuclear Information System (INIS)

    Wang Maoqiang; Zhang Jinshan; Xing Zhanhai

    1997-01-01

    The experimental study is aimed at achieving the effect of hepatic tumor and tumor-bearing lobar or segmental resection by using combined transcatheter hepatic arterial embolization and retrograde hepatic venous embolization (THAE-RHVE) in experimental study. THAE-RHVE was carried out in 8 mongrel dogs. Hepatic arterial embolization was performed by injecting lipiodol followed by gelatin sponge particles, following complete occlusion of the hepatic vein with balloon catheter. Retrograde hepatic venous embolization (RHVE) was then performed by injecting a mixture of absolute ethanol and meglumini diatrizoatis (MD) via the inflated balloon catheter. Ethanol and MD were combined with a ratio of 1:1. RHVE alone was performed in 4 dogs as control. The animals were followed up for 1∼8 weeks with liver function test, CT, gross and microscopic examinations. There was no technical failure or procedural complications. Transient elevation of AST and ALT levels was seen immediately in both groups after the procedure. Follow-up CT after 3 weeks showed dense lipiodol accumulation in the embolized lobe or segment and the corresponding portal branches in the THAE-RHVE animals. At 1 week after THAE-RHVE, complete coagulation necrosis was seen at histologic examination in the embolized lobe. The hepatic vein and portal branches of the embolized area had thickened walls and were filled with thrombus. At 2 weeks, granulomatous tissue and inflammatory cell infiltration surrounding the necrotic area could be seen. At 4∼8 weeks, marked atrophy of the embolized lobe was found, and the necrotic area was progressively reducing in size and being replaced by fibrosis. In the control group, incomplete segmental coagulated necrosis was seen and the necrosis area wa smaller than that of THAE-REVE. Hepatic lobectomy or segmentectomy can be achieved with THAE-RHVE. This new method is safe and easy, and may be useful in the treatment of HCC

  19. Diagnostic Indication for Venous Echo-Doppler of the Lower Limbs in the Diagnosis of Thromboembolic; Indicacion de eco-Doppler venosa de extremidades inferiores en el diagnostico de la enfermedad tromboembolica ante una sospecha de tromboembolismo pulmonar

    Energy Technology Data Exchange (ETDEWEB)

    Bolado, A. G.; Barcena, M. V.; Cura, J. L. del; Gorrno, O.; Grande, D. [Hospital de Basurto. Bilbao (Spain)

    2003-07-01

    To study the effectiveness of Doppler echography in the deep venous system of the lower limbs for deep venous thrombosis detection in patients suspected of having pulmonary thromboembolism. There were received 341 consecutive suspected pulmonary thromboembolism patients, all of whom were emergency room attended. All were submitted to CT pulmonary angiography in order to evaluate thrombus presence in the pulmonary tree. Without knowing the results of the previous exploration, we studied 301 of the patients using Doppler echography in deep venous system of the lower limbs in order to evaluate thrombus presence. In the group of CT-detected pulmonary thromboembolism patients, the percentage of Doppler echography-detected deep venous thrombosis was 46.3%, while in the group of non-detected patients this percentage decreased to 4.7%. Additional deep venous system exploration in clinically suspected pulmonary thiolcarbamate patients is useful, since it can increase the detection rate of venous thromboembolic disease, thereby leading to early treatment and prevention of the disease's manifestation in the lungs. Realization of Doppler echography is especially beneficial in those patients who exhibit no factors which predispose them to thromboembolic disease, as well as in patients who have previously had venous thrombosis. This exploration account for 4.7% of non-detected pulmonary embolism patients being added to the ranks of those with thromboembolic disease, an important percentage when taking into consideration the high pulmonary thromboembolism morbimortality rate. (Author) 30 refs.

  20. Planetary Radio Interferometry and Doppler Experiment (PRIDE) for Planetary Atmospheric Studies

    Science.gov (United States)

    Bocanegra Bahamon, Tatiana; Cimo, Giuseppe; Duev, Dmitry; Gurvits, Leonid; Molera Calves, Guifre; Pogrebenko, Sergei

    2015-04-01

    The Planetary Radio Interferometry and Doppler Experiment (PRIDE) is a technique that allows the determination of the radial velocity and lateral coordinates of planetary spacecraft with very high accuracy (Duev, 2012). The setup of the experiment consists of several ground stations from the European VLBI Network (EVN) located around the globe, which simultaneously perform Doppler tracking of a spacecraft carrier radio signal, and are subsequently processed in a VLBI-style in phase referencing mode. Because of the accurate examination of the changes in phase and amplitude of the radio signal propagating from the spacecraft to the multiple stations on Earth, the PRIDE technique can be used for several fields of planetary research, among which planetary atmospheric studies, gravimetry and ultra-precise celestial mechanics of planetary systems. In the study at hand the application of this technique for planetary atmospheric investigations is demonstrated. As a test case, radio occultation experiments were conducted with PRIDE having as target ESA's Venus Express, during different observing sessions with multiple ground stations in April 2012 and March 2014. Once each of the stations conducts the observation, the raw data is delivered to the correlation center at the Joint Institute for VLBI in Europe (JIVE) located in the Netherlands. The signals are processed with a high spectral resolution and phase detection software package from which Doppler observables of each station are derived. Subsequently the Doppler corrected signals are correlated to derive the VLBI observables. These two sets of observables are used for precise orbit determination. The reconstructed orbit along with the Doppler observables are used as input for the radio occultation processing software, which consists of mainly two modules, the geometrical optics module and the ray tracing inversion module, from which vertical density profiles, and subsequently, temperature and pressure profiles of Venus

  1. Deep vein thrombosis of the lower limbs: A retrospective analysis of doppler ultrasound findings

    Directory of Open Access Journals (Sweden)

    Sanjay M Khaladkar

    2014-01-01

    Full Text Available Background: Deep venous thrombosis (DVT of lower limbs is one of the most common cause for the majority of deaths caused by pulmonary embolism. Many medical and surgical disorders are complicated by DVT. Most venous thrombi are clinically silent. B-mode and color Doppler imaging is needed for early diagnosis of DVT to prevent complications and sequalae of DVT. Aim and Objectives: The objectives of the following study were to evaluate the role of Doppler as an imaging modality in diagnosing DVT of lower limbs, to study the spectrum of findings on Doppler ultrasound in patients with DVT. Materials and Methods: Retrospective descriptive analysis of 78 patients of DVT diagnosed on Doppler. Results: Nearly 74% of the patients were males and 26% were females with majority belonging to fifth decade (26%. 75 (96.1% cases showed unilateral while 3 (3.9% cases showed bilateral lower limb involvement. In our study, predominant distribution of thrombus was found to be in above knee region with 69/78 (88.5% patients having thrombus in the superficial femoral vein. Popliteal vein was involved in 54/78 (69.2% patients. Complete thrombosis was observed in 54/78 (69% cases, while partial thrombosis was observed in 24/78 (31% cases. Subacute stage was seen in 42 cases (53.8%, acute stage in 23 cases (29.5% while chronic stage in 13 cases (16.7%. 71 cases (91% had multiple contiguous segmental involvement, whereas 7 cases (9% had isolated vein involvement. Conclusion: Color Doppler is useful in diagnosing DVT in symptomatic and at risk patients and provides a non-invasive method of investigation. It is also helpful in evaluating the site, extent and stage of thrombus.

  2. Uterine Artery Embolization for Retained Products of Conception with Marked Vascularity: A Safe and Efficient First-Line Treatment

    International Nuclear Information System (INIS)

    Bazeries, Paul; Paisant-Thouveny, Francine; Yahya, Sultan; Bouvier, Antoine; Nedelcu, Cosmina; Boussion, Francoise; Sentilhes, Loic; Willoteaux, Serge; Aubé, Christophe

    2017-01-01

    ObjectiveTo report our clinical practice regarding a case series of retained products of conception (RPOC) with marked vascularity (MV) managed with selective uterine artery embolization (UAE) as first-line treatment.MethodsThis was a monocentric, retrospective study of 31 consecutive cases of RPOC with MV diagnosed by Doppler ultrasound in the context of postpartum/postabortal bleeding. The primary outcome was the absence of rebleeding following embolization.ResultsRPOC with MV occurred after abortion in 27 out of 31 patients (87%). The time elapsed between delivery/abortion and UAE ranged from 1 to 210 days (mean 55.7 ± 45 days). Primary clinical success was achieved in 23 women (74.2%) following a single embolization. In total, 27 out of 31 women (87%) had been exclusively managed by UAE with conservative success. Although procedural success was achieved in this number, six women had a further procedure to evacuate RPOC despite procedural success. Large uterine arteriovenous (AV) shunts associated with RPOC were observed in five cases (16.1%), among which two were successfully treated after a single UAE and one after two UAEs, while hysterectomy was performed in the last two cases despite two and three UAE procedures respectively. RPOC was histologically proven in ten cases (32.2%) including four out of five cases of uterine AV shunt.ConclusionRPOC with MV can present with large uterine AV shunt, particularly in case of late management. Uterine artery embolization is an effective and safe first-line treatment, and should be evaluated for this indication in larger prospective trials.

  3. Uterine Artery Embolization for Retained Products of Conception with Marked Vascularity: A Safe and Efficient First-Line Treatment

    Energy Technology Data Exchange (ETDEWEB)

    Bazeries, Paul, E-mail: paul.bazeries@chu-angers.fr; Paisant-Thouveny, Francine; Yahya, Sultan; Bouvier, Antoine; Nedelcu, Cosmina [Centre Hospitalier Universitaire d’Angers, Département d’Imagerie Diagnostique et interventionnelle (France); Boussion, Francoise; Sentilhes, Loic [Centre Hospitalier Universitaire d’Angers, Département de Gynécologie et Obstétrique (France); Willoteaux, Serge; Aubé, Christophe [Centre Hospitalier Universitaire d’Angers, Département d’Imagerie Diagnostique et interventionnelle (France)

    2017-04-15

    ObjectiveTo report our clinical practice regarding a case series of retained products of conception (RPOC) with marked vascularity (MV) managed with selective uterine artery embolization (UAE) as first-line treatment.MethodsThis was a monocentric, retrospective study of 31 consecutive cases of RPOC with MV diagnosed by Doppler ultrasound in the context of postpartum/postabortal bleeding. The primary outcome was the absence of rebleeding following embolization.ResultsRPOC with MV occurred after abortion in 27 out of 31 patients (87%). The time elapsed between delivery/abortion and UAE ranged from 1 to 210 days (mean 55.7 ± 45 days). Primary clinical success was achieved in 23 women (74.2%) following a single embolization. In total, 27 out of 31 women (87%) had been exclusively managed by UAE with conservative success. Although procedural success was achieved in this number, six women had a further procedure to evacuate RPOC despite procedural success. Large uterine arteriovenous (AV) shunts associated with RPOC were observed in five cases (16.1%), among which two were successfully treated after a single UAE and one after two UAEs, while hysterectomy was performed in the last two cases despite two and three UAE procedures respectively. RPOC was histologically proven in ten cases (32.2%) including four out of five cases of uterine AV shunt.ConclusionRPOC with MV can present with large uterine AV shunt, particularly in case of late management. Uterine artery embolization is an effective and safe first-line treatment, and should be evaluated for this indication in larger prospective trials.

  4. Value of the ventilation/perfusion scan in acute pulmonary embolism: Results of the prospective investigation of pulmonary embolism diagnosis (PIOPED)

    International Nuclear Information System (INIS)

    Anon.

    1990-01-01

    To determine the sensitivities and specificities of ventilation/perfusion lung scans for acute pulmonary embolism, a random sample of 933 of 1,493 patients was studied prospectively. Nine hundred thirty-one underwent scintigraphy and 755 underwent pulmonary angiography; 251 (33%) of 755 demonstrated pulmonary embolism. Almost all patients with pulmonary embolism had abnormal scans of high, intermediate, or low probability, but so did most without pulmonary embolism. Of 116 patients with high-probability scans and definitive angiograms, 102 (88%) had pulmonary embolism, but only a minority with pulmonary embolism had high-probability scans. Of 322 with intermediate-probability scans and definitive angiograms, 105 (33%) had pulmonary embolism. Follow-up and angiography together suggest pulmonary embolism occurred among 12% of patients with low-probability scans. Clinical assessment combined with the ventilation/perfusion scan established the diagnosis or exclusion of pulmonary embolism only for a minority of patients--those with clear and concordant clinical and ventilation/perfusion scan findings

  5. Preoperative embolization of facial angiomas

    International Nuclear Information System (INIS)

    Causmano, F.; Bruschi, G.; De Donatis, M.; Piazza, P.; Bassi, P.

    1988-01-01

    Preoperative embolization was performed on 27 patients with facial angiomas supplied by the external carotid branches. Sixteen were males and 11 females; 13 of these angiomas were high-flow arterio-venous (A-V), 14 were low-flow capillary malformations. Fourteen patients underwent surgical removal after preoperative embolization; in this group embolization was carried out with Spongel in 3 cases and with Lyodura in 11 cases. In 12 of these patients the last angiographic examination was performed 3-6 years later: angiography evidenced no recurrence in 8 cases (67%), while in 3 cases (25%) there was capillary residual angioma of negligible size. Treatment was unsuccessful in one patient only, due to the large recurrent A-V angioma. Thirteen patients underwent embolization only, which was carried out with Lyodura in 10 cases, and with Ivalon in 3 cases. On 12 of these patients the last angiographic study was performed 2-14 months later: there was recurrent A-V angioma in 5 patients (42%), who underwent a subsequent embolization; angiography evidenced no recurrence in the other 7 patients (58%). In both series, the best results were obtained in the patients with low-flow capillary angiomas. Embolization and subsequent surgical removal are the treatment of choice for facial angiomas; embolization alone is useful in the management of surgically inacessible vascular malformations, and it can be the only treatment in patients with small low-flow angiomas when distal occlusion of the feeding vessel with Lyodura or Ivalon particles is performed

  6. Moving Target Detection With Compact Laser Doppler Radar

    Science.gov (United States)

    Sepp, G.; Breining, A.; Eisfeld, W.; Knopp, R.; Lill, E.; Wagner, D.

    1989-12-01

    This paper describes an experimental integrated optronic system for detection and tracking of moving objects. The system is based on a CO2 waveguide laser Doppler ra-dar with homodyne receiver and galvanometer mirror beam scanner. A "hot spot" seeker consisting of a thermal imager with image processor transmits the coordinates of IR-emitting, i.e. potentially powered, objects to the laser radar scanner. The scanner addresses these "hot" locations operating in a large field-of-view (FOV) random ac-cess mode. Hot spots exhibiting a Doppler shifted laser signal are indicated in the thermal image by velocity-to-colour encoded markers. After switching to a small FOV scanning mode, the laser Doppler radar is used to track fast moving objects. Labora-tory and field experiments with moving objects including rotating discs, automobiles and missiles are described.

  7. Uterine arterial embolization to treat uterine leiomyoma

    International Nuclear Information System (INIS)

    Wang Huali; Han Lu; Wang Feng

    2002-01-01

    Objective: To assess the clinical effects of uterine arterial embolization on uterine leiomyoma. Methods: The authors treated 21 patients with uterine leiomyoma by Seldinger's uterine arterial embolization. The 4.0 F Cobra catheter was laced into the double uterine arteries with Polyvinyl Alcohol Foam (PVA) particles as the embolization. At 3 and 6 months postoperatively, the authors investigated the effects of the embolization. Results: After uterine arterial embolization, the volume of uterine leiomyoma decreased and menorrhagia was under controlled. The symptoms of anemia and oppression were relieved. The physiologic functions of ovary and uterus were preserved completely. Conclusions: Uterine arterial embolization is an effective and less invasive way to treat uterine leiomyoma

  8. The Test Case of HD 26965: Difficulties Disentangling Weak Doppler Signals from Stellar Activity

    Science.gov (United States)

    Díaz, Matías R.; Jenkins, James S.; Tuomi, Mikko; Butler, R. Paul; Soto, Maritza G.; Teske, Johanna K.; Feng, Fabo; Shectman, Stephen A.; Arriagada, Pamela; Crane, Jeffrey D.; Thompson, Ian B.; Vogt, Steven S.

    2018-03-01

    We report the discovery of a radial velocity signal that can be interpreted as a planetary-mass candidate orbiting the K dwarf HD 26965, with an orbital period of 42.364 ± 0.015 days, or alternatively, as the presence of residual, uncorrected rotational activity in the data. Observations include data from HIRES, PFS, CHIRON, and HARPS, where 1111 measurements were made over 16 years. Our best solution for HD 26965 b is consistent with a super-Earth that has a minimum mass of 6.92 ± 0.79 {M}\\oplus orbiting at a distance of 0.215 ± 0.008 au from its host star. We have analyzed the correlation between spectral activity indicators and the radial velocities from each instrument, showing moderate correlations that we include in our model. From this analysis, we recover a ∼38-day signal, which matches some literature values of the stellar rotation period. However, from independent Mt. Wilson HK data for this star, we find evidence for a significant 42-day signal after subtraction of longer period magnetic cycles, casting doubt on the planetary hypothesis for this period. Although our statistical model strongly suggests that the 42-day signal is Doppler in origin, we conclude that the residual effects of stellar rotation are difficult to fully model and remove from this data set, highlighting the difficulties to disentangle small planetary signals and photospheric noise, particularly when the orbital periods are close to the rotation period of the star. This study serves as an excellent test case for future works that aim to detect small planets orbiting “Sun-like” stars using radial velocity measurements. Some of the data presented herein were obtained at the W.M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W.M. Keck Foundation.

  9. Use of Doppler ultrasound for non-invasive urodynamic diagnosis

    Directory of Open Access Journals (Sweden)

    Hideo Ozawa

    2009-01-01

    Full Text Available Objectives: A totally non-invasive transperineal urodynamic technique using Doppler ultrasonography has been developed. Methods: Since normal urine does not have blood cells, urine was thought not to produce the Doppler effects. However, basic studies confirmed that the decrease of pressure at high velocity (Bernouilli effect caused dissolved gas to form microbubbles, which are detected by Doppler ultrasonography. Subjects sat and the probe was advanced via remote control to achieve gentle contact with the perineal skin. The digital uroflow data signals and the color Doppler ultrasound video images were processed on a personal computer. The flow-velocity curves from two sites; the distal prostatic urethra just above the external sphincter (V1 and the sphincteric urethra (V2 were plotted against time. The parameters of both the pressure-flow studies and the Doppler ultrasound urodynamic studies were compared in men who had various degrees of obstruction. Results: Functional cross-sectional area at prostatic urethra (A1, calculated by Q max /V1, was lower in the group of bladder outlet obstruction (BOO vs. control group. Velocity ratio (VR, which was calculated by V1/V2, was the parameter having the best correlation with BOO index, though A1 had a similar correlation. This method is viable to diagnose the degree of BOO. Conclusions: The development of non-invasive Doppler ultrasound videourodynamics (Doppler UDS will dramatically expand the information on voiding function.

  10. Technique and methods in uterine leiomyoma embolization

    International Nuclear Information System (INIS)

    Helmberger, T.K.; Jakobs, T.F.; Reiser, M.F.

    2003-01-01

    Uterine leiomyomas are the most common benign tumors of the female urogenital tract. Beside the classic surgical treatment options the minimal-invasive embolization therapy of the leiomyomas increasingly gains importance world-wide. Technique, complications, and results of uterine leiomyoma embolization will be presented. After careful evaluation of indications for embolization the procedure is mostly performed under conscious sedation. A single-sided femoral access route together with cross-over technique generally allows for a flow-directed embolization via both uterine arteries. After embolizing the vessels supplying the tumor, the uterine arteries should be still patent. The success rate of embolization of uterine leiomyomas ranges between 85 and 100%, whereas a reduction in size of the tumors in 42 to 83% and a relief of symptoms in up to 96% can be achieved. The total complication rate is about 10% with mainly ''minor complications''. Worldwide only three deaths following embolization of uterine leiomyomas were reported. The high technical and clinical success rate together with a low complication rate make the embolization of uterine leiomyomas a minimally-invasive alternative to the classic treatment. As long term results are not available indication to embolization of uterine leiomyomas must be carefully established in consensus with gynecologists. (orig.) [de

  11. Ultrasound and Doppler examination capabilities in adult portal hypertension type definition

    Directory of Open Access Journals (Sweden)

    N. V. Tumanskaya

    2015-08-01

    Full Text Available Early portal hypertension type diagnostics is an ultimate factor concerning kind and tactics of treatment. Aim. To objectify ultrasound examination capabilities, portal hemodynamics were studied in 97 patients using impulse and color doppler. Methods and results. It was ascertained that impulse and color doppler examination allows to visualize portal vein and its branches’ structural abnormalities, define subhepatic and intrahepatic types of portal hypertension, find thrombosis and characterize its stages. In cirrhosis patients with portal hypertension, homogenous doppler signal was received from the portal vessels lumen, while signs of intraluminar pathology were seen in the case of thrombosis of portal vein. Conclusion. This means that ultrasound examination of portal vein and its branches with impulse and color doppler is informative, non invasive method, which helps to define stages of portal hypertension. Doppler ultrasonography doesn’t have negative effect of ionizing radiation and can be used for the repeated research in the dynamics of disease.

  12. Assessment of resting-state blood flow through anterior cerebral arteries using trans-cranial doppler recordings.

    Science.gov (United States)

    Huang, Hanrui; Sejdić, Ervin

    2013-12-01

    Trans-cranial Doppler (TCD) recordings are used to monitor cerebral blood flow in the main cerebral arteries. The resting state is usually characterized by the mean velocity or the maximum Doppler shift frequency (an envelope signal) by insonating the middle cerebral arteries. In this study, we characterized cerebral blood flow in the anterior cerebral arteries. We analyzed both envelope signals and raw signals obtained from bilateral insonation. We recruited 20 healthy patients and conducted the data acquisition for 15 min. Features were extracted from the time domain, the frequency domain and the time-frequency domain. The results indicate that a gender-based statistical difference exists in the frequency and time-frequency domains. However, no handedness effect was found. In the time domain, information-theoretic features indicated that mutual dependence is higher in raw signals than in envelope signals. Finally, we concluded that insonation of the anterior cerebral arteries serves as a complement to middle cerebral artery studies. Additionally, investigation of the raw signals provided us with additional information that is not otherwise available from envelope signals. Use of direct trans-cranial Doppler raw data is therefore validated as a valuable method for characterizing the resting state. Copyright © 2013 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  13. Volume Change and Liver Parenchymal Signal Intensity in Gd-EOB-DTPA-Enhanced Magnetic Resonance Imaging after Portal Vein Embolization prior to Hepatectomy

    Directory of Open Access Journals (Sweden)

    Ayako Akiba

    2014-01-01

    Full Text Available Purpose. To investigate the liver volume change and the potential of early evaluation by contrast-enhanced magnetic resonance imaging (MRI using gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA after portal vein embolization (PVE. Materials and Methods. Retrospective evaluations of computed tomography (CT volumetry of total liver and nonembolized areas were performed before and 3 weeks after PVE in 37 cases. The percentage of future liver remnant (%FLR and the change ratio of %FLR (%FLR ratio were calculated. Prospective evaluation of signal intensities (SIs was performed to estimate the role of Gd-EOB-DTPA-enhanced MRI as a predictor of hypertrophy in 16 cases. The SI contrast between embolized and nonembolized areas was calculated 1 week after PVE. The change in SI contrast before and after PVE (SI ratio was also calculated in 11 cases. Results. %FLR ratio significantly increased, and SI ratio significantly decreased (both P<0.01. There were significant negative correlations between %FLR and SI contrast and between %FLR and SI ratio (both P<0.01. Conclusion. Hypertrophy in the nonembolized area after PVE was indicated by CT volumetry, and measurement of SI contrast and SI ratio in Gd-EOB-DTPA-enhanced MRI early after PVE may be useful to predict the potential for hepatic hypertrophy.

  14. The clinical study of 2D and power doppler ultrasound in esophagus varix

    International Nuclear Information System (INIS)

    Li Qiang; Zhou Liang; Zhang Yucheng; Yang Minghua; Ruan Fenglian; Lu Haixia; Li Yue

    2008-01-01

    Objective: To study the application of 2D and Power Doppler Ultrasound in diagnosing the abdominal esophageal varicose veins. Methods: 65 patients under suspicion with chronic hepatitis and cirrhosis for esophageal varicose at esophagus in abdomen section were examined by 2D and Power Doppler Ultrasound.Among them, 35 patients suffered from esophageal varicose veins proved by gastroscopy and the rest did not. Results: On the power doppler imaging map, colored blood stream signals were showed in varicose veins while without signals in non-varicose veins.The diagnostic sensitivity and specificity were 91.4% and 100% respectively. On the two-dimensional image chart, non-echoes were represented in varicose veins. The anteroposterior diameter, right-left diameter, as well as the thickness of esophagus wall were larger in patients with varicose veins than those in non varicose veins cases (P<0.01). Conclusion: 2D combined with Power Doppler Ultrasound was of non-invasive, safe, sensitive and high specificity, which is a valuable and practical tool in diagnosing the esophageal varicose veins. (authors)

  15. Golay Complementary Waveforms in Reed–Müller Sequences for Radar Detection of Nonzero Doppler Targets

    Science.gov (United States)

    Wang, Xuezhi; Huang, Xiaotao; Suvorova, Sofia; Moran, Bill

    2018-01-01

    Golay complementary waveforms can, in theory, yield radar returns of high range resolution with essentially zero sidelobes. In practice, when deployed conventionally, while high signal-to-noise ratios can be achieved for static target detection, significant range sidelobes are generated by target returns of nonzero Doppler causing unreliable detection. We consider signal processing techniques using Golay complementary waveforms to improve radar detection performance in scenarios involving multiple nonzero Doppler targets. A signal processing procedure based on an existing, so called, Binomial Design algorithm that alters the transmission order of Golay complementary waveforms and weights the returns is proposed in an attempt to achieve an enhanced illumination performance. The procedure applies one of three proposed waveform transmission ordering algorithms, followed by a pointwise nonlinear processor combining the outputs of the Binomial Design algorithm and one of the ordering algorithms. The computational complexity of the Binomial Design algorithm and the three ordering algorithms are compared, and a statistical analysis of the performance of the pointwise nonlinear processing is given. Estimation of the areas in the Delay–Doppler map occupied by significant range sidelobes for given targets are also discussed. Numerical simulations for the comparison of the performances of the Binomial Design algorithm and the three ordering algorithms are presented for both fixed and randomized target locations. The simulation results demonstrate that the proposed signal processing procedure has a better detection performance in terms of lower sidelobes and higher Doppler resolution in the presence of multiple nonzero Doppler targets compared to existing methods. PMID:29324708

  16. Microcatheter Embolization of Intractable Idiopathic Epistaxis

    International Nuclear Information System (INIS)

    Leppaenen, Martti; Seppaenen, Seppo; Laranne, Jussi; Kuoppala, Katriina

    1999-01-01

    Purpose: To assess the efficacy and safety of microcatheter embolization in the treatment of intractable idiopathic epistaxis. Methods: Thirty-seven patients underwent microcatheter embolization in 1991-1998. We evaluated retrospectively the technical and clinical outcome, the number of complications, the duration of embolization in each case, and the number of blood transfusions needed. All embolizations were done with biplane digital subtraction angiography (DSA) equipment. The procedure was carried out under local anesthesia using transfemoral catheterization, except in one case where the translumbar route was used. Tracker 18 or 10 microcatheters were advanced as far as possible to the distal branches of the sphenopalatine artery. Polyvinyl alcohol (PVA) particles were used for embolization in most cases, while platinum coils or a combination of these two materials were occasionally used. The primary outcome was always assessed immediately by angiography. Follow-up data were obtained from patient records, by interviewing patients on the telephone or by postal questionnaires when necessary. The mean follow-up time was 21 months. Results: The embolization was technically successful in all 37 cases. A curative outcome was achieved in 33 cases (89%). The mean duration of the procedure was 110 min. Four patients (8%) had mild transient complications, but no severe or persistent complications were encountered. Twenty-three patients needed a blood transfusion. Slight rebleeding occurred in three patients during the follow-up; all responded to conservative treatment. One patient suffered two episodes of rebleeding within 2 months after primary embolization. Re-embolizations successfully stopped the bleeding. Conclusion: Embolization is the primary invasive modality for treating intractable idiopathic epistaxis. It proved both safe and effective over a relatively long follow-up

  17. Long-term follow-up after transvenous single coil embolization of patent ductus arteriosus in dogs.

    Science.gov (United States)

    Hildebrandt, N; Schneider, C; Schweigl, T; Schneider, M

    2010-01-01

    Long-term follow-up studies after interventional therapy of patent ductus arteriosus (PDA) in dogs are rare. Transvenous PDA embolization with a single detachable coil is a highly effective method in patients with an angiographically determined PDA≤4.0 mm. Twenty-eight dogs with an angiographic PDA≤4.0 mm were included. Prospective follow-up study after PDA coil embolization. The median follow-up time was 792 days (range, 2-3, 248 days). The rate of complete closure demonstrated by Doppler color flow was 54% at day 3 after intervention and the final cumulative rate was 71%. The rate of complete closure was significantly different between small and moderately sized PDA over the study period (Pclosure, no recanalization was found. Disappearance of the continuous heart murmur was found in 89% after 3 days, and this increased to a final cumulative rate of 96%. Indexed left ventricular internal diameter in diastole (LVDd-I) decreased significantly (Pclosure in all small PDA but a residual shunt with mild hemodynamic consequences was present in half of the moderately sized PDA. Copyright © 2010 by the American College of Veterinary Internal Medicine.

  18. Laser Doppler velocimetry based on the optoacoustic effect in a RF-excited CO{sub 2} laser

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Teaghee; Choi, Jong Woon [Department of Information and Communication, Honam University, Seobong-dong 59-1, Gwansan-gu, Gwangju 506-714 (Korea, Republic of); Kim, Yong Pyung [College of Electronics and Information, Kyunghee University, 1 Seocheon-dong, Giheung-gu, Yongin-si, Gyeonggi-do 446-701 (Korea, Republic of)

    2012-09-15

    We present a compact optoacoustic laser Doppler velocimetry method that utilizes the self-mixing effect in a RF-excited CO{sub 2} laser. A portion of a Doppler-shifted laser beam, produced by irradiating a single wavelength laser beam on a moving object, is mixed with an originally existing laser beam inside a laser cavity. The fine change of pressure in the laser cavity modulated by the Doppler-shifted frequency is detected by a condenser microphone in the laser tube. In our studies, the frequency of the Doppler signal due to the optoacoustic effect was detected as high as 50 kHz. Our measurements also confirmed that the signal varied linearly with the velocity of the external scatterer (the moving object) and the cosine of the angle between the laser beam and the velocity vector of the object.

  19. Reduction of phase-induced intensity noise in a fiber-based coherent Doppler lidar using polarization control

    DEFF Research Database (Denmark)

    Rodrigo, Peter John; Pedersen, Christian

    2010-01-01

    Optimization of signal-to-noise ratio is an important aspect in the design of optical heterodyne detection systems such as a coherent Doppler lidar (CDL). In a CDL, optimal performance is achieved when the noise in the detector signal is dominated by local oscillator shot-noise. Most modern CDL...... systems are built using rugged and cost-efficient fiber optic components. Unfortunately, leakage signals such as residual reflections inherent within fiber components (e.g. circulator) can introduce phaseinduced intensity noise (PIIN) to the Doppler spectrum in a CDL. Such excess noise may be a few orders...

  20. Transcatheter Embolization in the Management of Epistaxis

    Science.gov (United States)

    Dubel, Gregory J.; Ahn, Sun Ho; Soares, Gregory M.

    2013-01-01

    A majority of the population will experience epistaxis at some time in their life. Most cases will be from an anterior source and can be treated with pressure, anterior nasal packing, or cautery. Intractable epistaxis is generally posterior in origin and may require endoscopic cautery, posterior packing, surgical ligation, or embolization. Embolization has been used to treat epistaxis for more than 30 years and success can be achieved in approximately 90% of patients, with major complications occurring in approximately 2%. These excellent results require thorough knowledge of the regional anatomy, familiarity with the equipment and various agents used to achieve this type of embolization, as well as attention to detail and meticulous technique. There remains debate on several aspects of embolization, including the agent of choice, preferred size of the embolic, and the number of vessels to embolize. Advances in endoscopic surgery have evolved to the point that similar success rates for embolization and modern surgical techniques in treating epistaxis may be expected. This detailed review of pertinent vascular anatomy, embolization technique, and surgical alternatives should allow practitioners to formulate treatment algorithms that result in optimal outcomes at their institutions. PMID:24436547

  1. Three-dimensional Doppler ultrasound findings in healthy wrist and finger tendon sheaths

    DEFF Research Database (Denmark)

    Ammitzboll-Danielsen, Mads; Janta, Iustina; Torp-Pedersen, Søren

    2016-01-01

    interpretation of Doppler signals when diagnosing tenosynovitis. Method Forty healthy participants (20 women and 20 men age 23-67 years) without prior history of arthritis, tendon diseases or present pain in their hands were included. Twenty participants had 3D Doppler US of the second and third finger...... participant. No significant difference in feeding vessels was seen between the radial and carpal level in the wrist (p = 0.06) or between the second and third flexor tendon sheath (p = 0.84). Conclusion Doppler findings in or in close proximity to the tendon sheaths were common in wrists and fingers...

  2. Sub-Doppler spectroscopy

    International Nuclear Information System (INIS)

    Hansch, T.W.

    1983-01-01

    This chapter examines Doppler-free saturation spectroscopy, tunable cw sources, and Doppler-free two-photon spectroscopy. Discusses saturation spectroscopy; continuous wave saturation spectroscopy in the ultraviolet; and two-photon spectroscopy of atomic hydrogen 1S-2S. Focuses on Doppler-free laser spectroscopy of gaseous samples. Explains that in saturation spectroscopy, a monochromatic laser beam ''labels'' a group of atoms within a narrow range of axial velocities through excitation or optical pumping, and a Doppler-free spectrum of these selected atoms is observed with a second, counterpropagating beam. Notes that in two-photon spectroscopy it is possible to record Doppler-free spectra without any need for velocity selection by excitation with two counterpropagating laser beams whose first order Doppler shifts cancel

  3. Doppler Tomography

    Science.gov (United States)

    Marsh, T. R.

    I review the method of Doppler tomography which translates binary-star line profiles taken at a series of orbital phases into a distribution of emission over the binary. I begin with a discussion of the basic principles behind Doppler tomography, including a comparison of the relative merits of maximum entropy regularisation versus filtered back-projection for implementing the inversion. Following this I discuss the issue of noise in Doppler images and possible methods for coping with it. Then I move on to look at the results of Doppler Tomography applied to cataclysmic variable stars. Outstanding successes to date are the discovery of two-arm spiral shocks in cataclysmic variable accretion discs and the probing of the stream/magnetospheric interaction in magnetic cataclysmic variable stars. Doppler tomography has also told us much about the stream/disc interaction in non-magnetic systems and the irradiation of the secondary star in all systems. The latter indirectly reveals such effects as shadowing by the accretion disc or stream. I discuss all of these and finish with some musings on possible future directions for the method. At the end I include a tabulation of Doppler maps published in refereed journals.

  4. Transcatheter Embolization of Pseudoaneurysms Complicating Pancreatitis

    International Nuclear Information System (INIS)

    Golzarian, Jafar; Nicaise, Nicole; Deviere, Jacques; Ghysels, Marc; Wery, Didier; Dussaussois, Luc; Gansbeke, Daniel van; Struyven, Julien

    1997-01-01

    Purpose: To evaluate the therapeutic role of angiography in patients with pseudoaneurysms complicating pancreatitis. Methods: Thirteen symptomatic pseudoaneurysms were treated in nine patients with pancreatitis. Eight patients had chronic pancreatitis and pseudocyst and one had acute pancreatitis. Clinical presentation included gastrointestinal bleeding in seven patients and epigastric pain without bleeding in two. All patients underwent transcatheter embolization. Results: Transcatheter embolization resulted in symptomatic resolution in all patients. Rebleeding occurred in two patients, 18 and 28 days after embolization respectively, and was successfully treated by repeated emnbolization. One patient with severe pancreatitis died from sepsis 28 days after embolization. Follow-up was then available for eight patients with no relapse of bleeding after a mean follow-up of 32 months (range 9-48 months). Conclusion: Transcatheter embolization is safe and effective in the management of pseudoaneurysms complicating pancreatitis

  5. Modeling of Doppler frequency shift in multipath radio channels

    Directory of Open Access Journals (Sweden)

    Penzin M.S.

    2016-06-01

    Full Text Available We discuss the modeling of propagation of a quasi-monochromatic radio signal, represented by a coherent pulse sequence, in a non-stationary multipath radio channel. In such a channel, signal propagation results in the observed frequency shift for each ray (Doppler effect. The modeling is based on the assumption that during propagation of a single pulse a channel can be considered stationary. A phase variation in the channel transfer function is shown to cause the observed frequency shift in the received signal. Thus, instead of measuring the Doppler frequency shift, we can measure the rate of variation in the mean phase of one pulse relative to another. The modeling is carried out within the framework of the method of normal waves. The method enables us to model the dynamics of the electromagnetic field at a given point with the required accuracy. The modeling reveals that a local change in ionospheric conditions more severely affects the rays whose reflection region is in the area where the changes occur.

  6. High-frequency Doppler ultrasound transducer for the peripheral circulatory system

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Youngmin; Yang, Jeongwon; Kang, Uk; Kim, Guanghoon [Korea Electrotechnology Research Institute, Ansan (Korea, Republic of)

    2011-12-15

    A Doppler ultrasound transducer was designed and implemented to measure the blood flow velocity in tiny vessels near the skin of hands or feet. The geometric parameters of the transducer for defining the observation volume were derived and implemented with an acoustic window made of polystyrene. The observation volume designed in this study was located 6.5 mm from the transducer, which was comparable to the value predicted geometrically. The two-way insertion loss of the transducer was -11.3 dB on ultrasound frequency of 20 MHz, and the 3-dB bandwidth was approximately 2 MHz. In addition, the Doppler shift in the frequency measured by using a Doppler device composed of the transducer and a Doppler signal processing unit was proportional to the flow velocity generated by a homemade flowing system. Finally, we concluded that the transducer could be applied to measure the blood flow velocity in hands or feet.

  7. High-frequency Doppler ultrasound transducer for the peripheral circulatory system

    International Nuclear Information System (INIS)

    Bae, Youngmin; Yang, Jeongwon; Kang, Uk; Kim, Guanghoon

    2011-01-01

    A Doppler ultrasound transducer was designed and implemented to measure the blood flow velocity in tiny vessels near the skin of hands or feet. The geometric parameters of the transducer for defining the observation volume were derived and implemented with an acoustic window made of polystyrene. The observation volume designed in this study was located 6.5 mm from the transducer, which was comparable to the value predicted geometrically. The two-way insertion loss of the transducer was -11.3 dB on ultrasound frequency of 20 MHz, and the 3-dB bandwidth was approximately 2 MHz. In addition, the Doppler shift in the frequency measured by using a Doppler device composed of the transducer and a Doppler signal processing unit was proportional to the flow velocity generated by a homemade flowing system. Finally, we concluded that the transducer could be applied to measure the blood flow velocity in hands or feet.

  8. Transcatheter arterial embolization for upper gastrointestinal tract bleeding.

    Science.gov (United States)

    Širvinskas, Audrius; Smolskas, Edgaras; Mikelis, Kipras; Brimienė, Vilma; Brimas, Gintautas

    2017-12-01

    Transcatheter arterial embolization is a possible treatment for patients with recurrent bleeding from the upper gastrointestinal tract after failed endoscopic management and is also an alternative to surgical treatment. To analyze the outcomes of transcatheter arterial embolization and identify the clinical and technical factors that influenced the rates of morbidity and mortality. A retrospective analysis was carried out, based on the data of 36 patients who underwent transcatheter arterial embolization for acute nonvariceal upper gastrointestinal bleeding in 2013 to 2015 in our center. An analysis was performed between early rebleeding rates, mortality and the following factors: patient sex, age, number of units of packed red blood cells and packed plasma administered to the patients, length of hospital stay, therapeutic or prophylactic embolization. The technical success rate of the embolization procedure was 100%. There were 15 (41.70%) therapeutic embolizations and 21 (58.3%) prophylactic embolizations. There was a 77.8% clinical success rate. Following embolization, 10 (27.80%) patients had repeated bleeding and 9 (25.0%) patients died. Significant associations were found between rebleeding and prophylactic embolization (OR = 10.53; p = 0.04) and between mortality and prophylactic embolization (OR = 10.53; p = 0.04) and units of packed red blood cells (OR = 1.25; p < 0.01). In our experience, transcatheter arterial embolization is a safe treatment method for acute nonvariceal upper gastrointestinal bleeding and a possible alternative to surgery for high-risk patients.

  9. Percutaneous closure of patent foramen ovale in patients with presumed paradoxical embolism: periprocedural results and midterm risk of recurrent neurologic events.

    Science.gov (United States)

    Balbi, Manrico; Casalino, Laura; Gnecco, Giovanni; Bezante, Gian Paolo; Pongiglione, Giacomo; Marasini, Maurizio; Del Sette, Massimo; Barsotti, Antonio

    2008-08-01

    To report our data on selected patients with previous paradoxical embolism who underwent transcatheter patent foramen ovale (PFO) closure. Between July 2001 and July 2007, percutaneous PFO closure was performed on 128 patients (65 women, mean age: 46 +/- 12.8 years). Patent foramen ovale closure was recommended for secondary prevention in patients with previous transient ischemic attacks (52.5%), stroke (46%), or peripheral embolism (1.5%). Implantation was successful in all patients, and at the end of intervention, complete PFO closure was achieved in 70.3% of them. There were no "major" complications (ie, deaths, device embolization or thrombosis, need for cardiac surgery). The overall incidence of complications (mostly hemorrhagic) was 7%. The mean follow-up period was 32 months. Complete closure had been achieved in 78.4% and in 82.5% of patients at the third month of transesophageal echocardiography examination and at the sixth month of transcranial Doppler examination, respectively. There were no recurrent thromboembolic events during the follow-up period. Percutaneous closure of PFO is a feasible procedure, but it is not a risk-free technique. However, in correctly selected patients (ie, large PFO and those at risk for neurologic relapse), nearly complete PFO closure seems to provide protection from future neurologic ischaemic events at midterm follow-up.

  10. Doppler Radar Vital Signs Detection Method Based on Higher Order Cyclostationary.

    Science.gov (United States)

    Yu, Zhibin; Zhao, Duo; Zhang, Zhiqiang

    2017-12-26

    Due to the non-contact nature, using Doppler radar sensors to detect vital signs such as heart and respiration rates of a human subject is getting more and more attention. However, the related detection-method research meets lots of challenges due to electromagnetic interferences, clutter and random motion interferences. In this paper, a novel third-order cyclic cummulant (TOCC) detection method, which is insensitive to Gaussian interference and non-cyclic signals, is proposed to investigate the heart and respiration rate based on continuous wave Doppler radars. The k -th order cyclostationary properties of the radar signal with hidden periodicities and random motions are analyzed. The third-order cyclostationary detection theory of the heart and respiration rate is studied. Experimental results show that the third-order cyclostationary approach has better estimation accuracy for detecting the vital signs from the received radar signal under low SNR, strong clutter noise and random motion interferences.

  11. Interventional embolization for refractory hyperthyroidism

    International Nuclear Information System (INIS)

    Jiang Guomin; Zhang Yunping; Chen Yaxian; Zhao Jinwei; Yang Weihuai; Chen Jinluo

    2001-01-01

    Objective: To evaluate the clinical effects of the thyroid artery embolization for refractory hyperthyroidism. Methods: Super selective catheterization and interventional embolization of thyroid superior and inferior arteries were performed with PVA microspheres and Gelfoam particles. Changes of function and size of thyroid were investigated after embolization. Results: The procedures were succeeded in all 21 patients. Followed up by 3-12 months, serum level of thyroid hormones dropped significantly (median FT 3 from 17.1 pmol/L to 7.44 pmol/L, median FT 4 from 51.1 pmol/L to 23.3 pmol/L, P< 0.01). The size of thyroid glands decreased remarkably. Symptoms of hyperthyroidism were controlled in 4 patients and were effectively controlled through low dose antithyroid medication in 17 patients. No serious complications occurred. Conclusions: Thyroid artery embolization is a new safe and effective method for refractory hyperthyroidism

  12. Brain 'Embolism' Detected by Magnetic Resonance Imaging During Percutaneous Mitral Balloon Commissurotomy

    International Nuclear Information System (INIS)

    Rocha, Paulo; Qanadli, Salah D.; Strumza, Pierre; Kacher, Safia; Aberkane, Linda; Aubry, Pierre; Rigaud, Michel; Lacombe, Pascal; Raffestin, Bernadette

    1999-01-01

    Purpose: The common finding of thrombi between the bifoil balloons when they were extracted after mitral dilation prompted us to look for evidence of minor brain embolisms using the sensitive technique of BMRI (brain magnetic resonance T2-weighted imaging). Methods: BMRI was performed within 48 hr before and after a percutaneous mitral balloon commissurotomy (PMBC) in each of the 63 patients in this study. Results: There was evidence (hyperintensity foci: HI) of a previous asymptomatic brain embolism in 38 of 63 patients before PMBC and a new HI appeared in 18 of 63 patients after the procedure. New HI signals were found exclusively in the white matter in 8 of 18 patients and in only 3 of 18 were HI signs larger than 1 cm. One patient, with an HI signal >1 cm in the thalamus and another 8; 4, patients from western countries vs the others) were not statistically significant, probably because the number of patients in each subgroup was low. Patients in atrial fibrillation had slightly more (not significant) HI before PMBC (15/20, 75%) than patients in sinus rhythm (23/43, 53%), but after PMBC their HI frequencies were similar (atrial fibrillation: 5/20, 25%; sinus rhythm: 13/43, 30%). Conclusion: Brain microembolism is frequent during PMBC, but is often anatomically limited and free from clinical signs in most cases. Brain embolism seems to be related mainly to the procedure itself and not the features of the patient

  13. Treatment Challenges of a Primary Vertebral Artery Aneurysm Causing Recurrent Ischemic Strokes

    Directory of Open Access Journals (Sweden)

    Davide Strambo

    2017-01-01

    Full Text Available Background. Extracranial vertebral artery aneurysms are a rare cause of embolic stroke; surgical and endovascular therapy options are debated and long-term complication may occur. Case Report. A 53-year-old man affected by neurofibromatosis type 1 (NF1 came to our attention for recurrent vertebrobasilar embolic strokes, caused by a primary giant, partially thrombosed, fusiform aneurysm of the left extracranial vertebral artery. The aneurysm was treated by endovascular approach through deposition of Guglielmi Detachable Coils in the proximal segment of the left vertebral artery. Six years later the patient presented stroke recurrence. Cerebral angiography and Color Doppler Ultrasound well characterized the unique hemodynamic condition developed over the years responsible for the new embolic event: the aneurysm had been revascularized from its distal portion by reverse blood flow coming from the patent vertebrobasilar axis. A biphasic Doppler signal in the left vertebral artery revealed a peculiar behavior of the blood flow, alternately directed to the aneurysm and backwards to the basilar artery. Surgical ligation of the distal left vertebral artery and excision of the aneurysm were thus performed. Conclusion. This is the first described case of NF1-associated extracranial vertebral artery aneurysm presenting with recurrent embolic stroke. Complete exclusion of the aneurysm from the blood circulation is advisable to achieve full resolution of the embolic source.

  14. Comparison between Hilbert-Huang transform and scalogram methods on non-stationary biomedical signals: application to laser Doppler flowmetry recordings

    International Nuclear Information System (INIS)

    Roulier, Remy; Humeau, Anne; Flatley, Thomas P; Abraham, Pierre

    2005-01-01

    A significant transient increase in laser Doppler flowmetry (LDF) signals is observed in response to a local and progressive cutaneous pressure application on healthy subjects. This reflex may be impaired in diabetic patients. The work presents a comparison between two signal processing methods that provide a clarification of this phenomenon. Analyses by the scalogram and the Hilbert-Huang transform (HHT) of LDF signals recorded at rest and during a local and progressive cutaneous pressure application are performed on healthy and type 1 diabetic subjects. Three frequency bands, corresponding to myogenic, neurogenic and endothelial related metabolic activities, are studied at different time intervals in order to take into account the dynamics of the phenomenon. The results show that both the scalogram and the HHT methods lead to the same conclusions concerning the comparisons of the myogenic, neurogenic and endothelial related metabolic activities-during the progressive pressure and at rest-in healthy and diabetic subjects. However, the HHT shows more details that may be obscured by the scalogram. Indeed, the non-locally adaptative limitations of the scalogram can remove some definition from the data. These results may improve knowledge on the above-mentioned reflex as well as on non-stationary biomedical signal processing methods

  15. Transcatheter Coil Embolization of Splenic Artery Aneurysm

    International Nuclear Information System (INIS)

    Yamamoto, Satoshi; Hirota, Shozo; Maeda, Hiroaki; Achiwa, Sachiko; Arai, Keisuke; Kobayashi, Kaoru; Nakao, Norio

    2008-01-01

    The purpose of this study was to evaluate clinical results and technical problems of transcatheter coil embolization for splenic artery aneurysm. Subjects were 16 patients (8 men, 8 women; age range, 40-80 years) who underwent transcatheter embolization for splenic artery aneurysm (14 true aneurysms, 2 false aneurysms) at one of our hospitals during the period January 1997 through July 2005. Two aneurysms (12.5%) were diagnosed at the time of rupture. Multiple splenic aneurysms were found in seven patients. Aneurysms were classified by site as proximal (or strictly ostial) (n = 3), middle (n = 3), or hilar (n = 10). The indication for transcatheter arterial embolization was a false or true aneurysm 20 mm in diameter. Embolic materials were fibered coils and interlocking detachable coils. Embolization was performed by the isolation technique, the packing technique, or both. Technically, all aneurysms were devascularized without severe complications. Embolized aneurysms were 6-40 mm in diameter (mean, 25 mm). Overall, the primary technical success rate was 88% (14 of 16 patients). In the remaining 2 patients (12.5%), partial recanalization occurred, and re-embolization was performed. The secondary technical success rate was 100%. Seven (44%) of the 16 study patients suffered partial splenic infarction. Intrasplenic branching originating from the aneurysm was observed in five patients. We conclude that transcatheter coil embolization should be the initial treatment of choice for splenic artery aneurysm

  16. Theoretical study of electromagnetically induced transparency in a five-level atom and application to Doppler-broadened and Doppler-free Rb atoms

    International Nuclear Information System (INIS)

    Bhattacharyya, Dipankar; Ray, Biswajit; Ghosh, Pradip N

    2007-01-01

    We report theoretical studies of a Λ-type five-level atomic system. The density matrix equations are set up and solved numerically to obtain the probe absorption line shape of Rb D 2 transitions for cold (Doppler-free) and room temperature (Doppler-broadened) atoms. Simulated spectra for Doppler-broadened systems lead to four velocity-selective dips along with an electromagnetic induced transparency (EIT) peak as observed earlier from the co-propagating pump-probe spectroscopy of Rb D 2 transitions. Effects of pump power and spontaneous decay rate from the upper levels on the simulated spectra are also studied. For cold atoms a very pronounced EIT peak is observed when the pump frequency is on resonance with one allowed transition. We find that lower pump power leads to a much sharper EIT signal in this case. A simulated dispersion curve shows a rapid variation of the refractive index that may lead to a sharp reduction of the group velocity of photons

  17. Transcatheter embolization therapy of the gastrointestinal hemorrhage

    International Nuclear Information System (INIS)

    Sim, Jae In; Park, Auh Whan; Ryeom, Hun Kyu; Kim, Yong Joo

    1994-01-01

    To evaluate the effectiveness of transcatheter embolization for the treatment of massive gastrointestinal arterial bleeding. The study was based on retrospective analysis of twelve cases(8 men, 4 woman) including two patients with hemobilia in which transcatheter embolization was attempted for the control of massive gastrointestinal bleeding from March 1987 to October 1993. Clinical diagnoses of these patients were peptic ulcer(5), pseudoaneurysm formation(3) following percutaneous transhepatic biliary drainage or traffic accident, stomach cancer(1), typhoid fever(1), duodenal leiomyoma(1) and Osler-Weber-Rendu disease (1). Embolized vessels are as follows: gastroduodenal artery(6), left gastric artery(2), ileocolic artery(2), and hepatic artery(2). Embolization was effective in immediate control of bleeding in all patients. Although five of the six patients who had undergone embolization of the gastroduodenal artery developed rebleeding within 24 hour, only 2 required surgery and none showed serious complication. Embolization therapy is safe and effective initial treatment of choice for life-threatening massive gastrointestinal bleeding

  18. Transcatheter embolization therapy of the gastrointestinal hemorrhage

    Energy Technology Data Exchange (ETDEWEB)

    Sim, Jae In; Park, Auh Whan; Ryeom, Hun Kyu; Kim, Yong Joo [Kyungpook National University Hospital, Daegu (Korea, Republic of)

    1994-05-15

    To evaluate the effectiveness of transcatheter embolization for the treatment of massive gastrointestinal arterial bleeding. The study was based on retrospective analysis of twelve cases(8 men, 4 woman) including two patients with hemobilia in which transcatheter embolization was attempted for the control of massive gastrointestinal bleeding from March 1987 to October 1993. Clinical diagnoses of these patients were peptic ulcer(5), pseudoaneurysm formation(3) following percutaneous transhepatic biliary drainage or traffic accident, stomach cancer(1), typhoid fever(1), duodenal leiomyoma(1) and Osler-Weber-Rendu disease (1). Embolized vessels are as follows: gastroduodenal artery(6), left gastric artery(2), ileocolic artery(2), and hepatic artery(2). Embolization was effective in immediate control of bleeding in all patients. Although five of the six patients who had undergone embolization of the gastroduodenal artery developed rebleeding within 24 hour, only 2 required surgery and none showed serious complication. Embolization therapy is safe and effective initial treatment of choice for life-threatening massive gastrointestinal bleeding.

  19. Thrombolytic therapy in pulmonary embolism.

    LENUS (Irish Health Repository)

    Nagi, D

    2010-01-01

    Massive pulmonary embolism carries a high mortality. Potential treatment includes anticoagulation, thrombolytic therapy and embolectomy. We report a case of deep vein thrombosis leading to progressive massive pulmonary embolism despite appropriate anticoagulation, where thrombolysis with IVC filter placement resulted in a successful outcome.

  20. Investigation of Doppler spectra of laser radiation scattered inside hand skin during occlusion test

    Science.gov (United States)

    Kozlov, I. O.; Zherebtsov, E. A.; Zherebtsova, A. I.; Dremin, V. V.; Dunaev, A. V.

    2017-11-01

    Laser Doppler flowmetry (LDF) is a method widely used in diagnosis of microcirculation diseases. It is well known that information about frequency distribution of Doppler spectrum of the laser radiation scattered by moving red blood cells (RBC) usually disappears after signal processing procedure. Photocurrent’s spectrum distribution contains valuable diagnostic information about velocity distribution of the RBC. In this research it is proposed to compute the indexes of microcirculation in the sub-ranges of the Doppler spectrum as well as investigate the frequency distribution of the computed indexes.

  1. Radiologic diagnosis and treatment of iatrogenic acquired uterine arteriovenous malformation

    International Nuclear Information System (INIS)

    Kwon, Jung Hyeok

    2002-01-01

    To analyze gray-scale US, color and duplex Doppler US, and angiographic findings in patients with acquired uterine arteriovenous malformations (AVMs), and to evaluate the usefulness of these modalities in the diagnosis of this disease and the effect of transcatheter arterial embolization in its treatment. During a recent seven-year period, we diagnosed 21 cases of acquired uterine AVM. Nineteen of these patients had a history of causative D and C (between one and seven D and C procedures per patient), one had a history of causative cesarean section, and one had cervical conization. All patients underwent transabdominal and endovaginal gray-scale, color Doppler, and duplex Doppler US and angiography, with therapeutic embolization of bilateral uterine arteries. The majority underwent follow-up Doppler US after embolization. The gray-scale US morphology of uterine AVMs included subtle myometrial inhomogeneity and multiple distinct, small anechoic spaces in the thickened myometrium or endometrium. Color Doppler US showed a tangle of tortuous vessels with multidirectional, high-velocity arterial flow, which was focally or asymmetrically distributed. Duplex Doppler US depicted a waveform of fast arterial flow with low resistance, while angiography demonstrated a complex tangle of vessels supplied by enlarged uterine arteries, in association with early venous drainage during the arterial phase, and staiss of contrast medium within abnormal vasculature. Where AVMs were combined with a pseudoaneurysm, this finding was observed. Transcatheter arterial embolization provided a complete cure, without recurrence. Color and duplex Doppler US in an appropriate modality for the detection and diagnosis of uterine AVMs and for follow-up after embolization. Transcatheter arterial embolization is a safe and effective method of treating this disease

  2. Radiologic diagnosis and treatment of iatrogenic acquired uterine arteriovenous malformation

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Jung Hyeok [College of Medicine, Keimyung Univ., Taegu (Korea, Republic of)

    2002-05-01

    To analyze gray-scale US, color and duplex Doppler US, and angiographic findings in patients with acquired uterine arteriovenous malformations (AVMs), and to evaluate the usefulness of these modalities in the diagnosis of this disease and the effect of transcatheter arterial embolization in its treatment. During a recent seven-year period, we diagnosed 21 cases of acquired uterine AVM. Nineteen of these patients had a history of causative D and C (between one and seven D and C procedures per patient), one had a history of causative cesarean section, and one had cervical conization. All patients underwent transabdominal and endovaginal gray-scale, color Doppler, and duplex Doppler US and angiography, with therapeutic embolization of bilateral uterine arteries. The majority underwent follow-up Doppler US after embolization. The gray-scale US morphology of uterine AVMs included subtle myometrial inhomogeneity and multiple distinct, small anechoic spaces in the thickened myometrium or endometrium. Color Doppler US showed a tangle of tortuous vessels with multidirectional, high-velocity arterial flow, which was focally or asymmetrically distributed. Duplex Doppler US depicted a waveform of fast arterial flow with low resistance, while angiography demonstrated a complex tangle of vessels supplied by enlarged uterine arteries, in association with early venous drainage during the arterial phase, and staiss of contrast medium within abnormal vasculature. Where AVMs were combined with a pseudoaneurysm, this finding was observed. Transcatheter arterial embolization provided a complete cure, without recurrence. Color and duplex Doppler US in an appropriate modality for the detection and diagnosis of uterine AVMs and for follow-up after embolization. Transcatheter arterial embolization is a safe and effective method of treating this disease.

  3. Transesophageal color Doppler evaluation of obstructive lesions using the new "Quasar" technology.

    Science.gov (United States)

    Fan, P; Nanda, N C; Gatewood, R P; Cape, E G; Yoganathan, A P

    1995-01-01

    Due to the unavoidable problem of aliasing, color flow signals from high blood flow velocities cannot be measured directly by conventional color Doppler. A new technology termed Quantitative Un-Aliased Speed Algorithm Recognition (Quasar) has been developed to overcome this limitation. Employing this technology, we used transesophageal color Doppler echocardiography to investigate whether the velocities detected by the Quasar would correlate with those obtained by continuous-wave Doppler both in vitro and in vivo. In the in vitro study, a 5.0 MHz transesophageal transducer of a Kontron Sigma 44 color Doppler flow system was used. Fourteen different peak velocities calculated and recorded by color Doppler-guided continuous-wave Doppler were randomly selected. In the clinical study, intraoperative transesophageal echocardiography was performed using the same transducer 18 adults (13 aortic valve stenosis, 2 aortic and 2 mitral stenosis, 2 hypertrophic obstructive cardiomyopathy and 1 mitral valve stenosis). Following each continuous-wave Doppler measurement, the Quasar was activated, and a small Quasar marker was placed in the brightest area of the color flow jet to obtain the maximum mean velocity readout. The maximum mean velocities measured by Quasar closely correlated with maximum peak velocities obtained by color flow guided continuous-wave Doppler in both in vitro (0.53 to 1.65 m/s, r = 0.99) and in vivo studies (1.50 to 6.01 m/s, r = 0.97). We conclude that the new Quasar technology can accurately measure high blood flow velocities during transesophageal color Doppler echocardiography. This technique has the potential of obviating the need for continuous-wave Doppler.

  4. Detection of Traveling Ionospheric Disturbances by Medium Frequency Doppler Sounding Using AM Radio Transmissions

    Science.gov (United States)

    Chilcote, M. A.; Labelle, J. W.; Lind, F. D.; Coster, A. J.; Galkin, I. A.; Miller, E.; Weatherwax, A. T.

    2013-12-01

    Nighttime traveling ionosphere disturbances (TIDs) propagating in the lower F region of the ionosphere were detected from time variations in the Doppler shifts of commercial AM radio broadcast stations. Three separately deployed receivers, components of the Intercepted Signals for Ionospheric Science (ISIS) Array software radio instrumentation network, recorded signals from two radio stations during eleven nights in March-April, 2012. Combining these measurements established that variations in the frequencies of the received signals, with amplitudes up to a few tenths of a Hertz, resulted from Doppler shifts produced by the ionosphere. At times, TIDs were detected as large amplitude variations in the Doppler shift with approximately 40-minute period correlated across the array. For one study interval, 0000-0400 UT on April 13, 2012, simultaneous GPS-TEC, digisonde, and superDARN coherent backscatter radar measurements confirmed the detection of TIDs with the same period. Detection of the AM signals at widely spaced receivers allowed the phase velocity and wavelength of the TIDs to be inferred, with some limitations due to differing reflection heights for the different frequencies. These measurements will be compared to phase velocities and wavelengths determined from combining an array of GPS receivers; discrepancies due to the altitude sensitivity of the techniques or other effects will be discussed. These results demonstrate that AM radio signals can be used for detection of nighttime TIDs.

  5. Embolization of carotid artery branch in intractable epistaxis

    International Nuclear Information System (INIS)

    Kordecki, K.; Janica, J.; Lewszuk, A.; Lebkowska, U.; Ustymowicz, A.

    2008-01-01

    Long-term intractable epistaxis results in a series of complications including demise. Unprofessional therapy may account for severe topical and systemic complications. The authors assessed the efficacy and safety of embolization treatment of intractable epistaxis with the use of available embolizing materials. Embolization was performed in 58 patients (39 males aged 24-48 and 19 females aged 26-44) admitted to the ENT Department, Medical University of Bialystok in years 2000 -2005. 65 embolization procedures, including reembolizations, were performed. In 41 procedures (63%) a sponge was used, in 14 (21.6%) PVA, in 10 (15.4%) PVA and coils. In 9 patients, bleeding of a lesser intensity recurred within early hours following the procedure - 84.5% embolization success. On longer follow-up, embolization success was assessed to be 100%. Embolization with the use of proper embolisation materials is an efficient method of arresting spontaneous and posttraumatic epistaxis and may be a safe treatment procedure when performed by experienced medical personnel. (author)

  6. Gas embolism: pathophysiology and treatment

    NARCIS (Netherlands)

    van Hulst, Robert A.; Klein, Jan; Lachmann, Burkhard

    2003-01-01

    Based on a literature search, an overview is presented of the pathophysiology of venous and arterial gas embolism in the experimental and clinical environment, as well as the relevance and aims of diagnostics and treatment of gas embolism. The review starts with a few historical observations and

  7. Versatile mid-infrared frequency-comb referenced sub-Doppler spectrometer

    Science.gov (United States)

    Gambetta, A.; Vicentini, E.; Coluccelli, N.; Wang, Y.; Fernandez, T. T.; Maddaloni, P.; De Natale, P.; Castrillo, A.; Gianfrani, L.; Laporta, P.; Galzerano, G.

    2018-04-01

    We present a mid-IR high-precision spectrometer capable of performing accurate Doppler-free measurements with absolute calibration of the optical axis and high signal-to-noise ratio. The system is based on a widely tunable mid-IR offset-free frequency comb and a Quantum-Cascade-Laser (QCL). The QCL emission frequency is offset locked to one of the comb teeth to provide absolute-frequency calibration, spectral-narrowing, and accurate fine frequency tuning. Both the comb repetition frequency and QCL-comb offset frequency can be modulated to provide, respectively, slow- and fast-frequency-calibrated scanning capabilities. The characterisation of the spectrometer is demonstrated by recording sub-Doppler saturated absorption features of the CHF3 molecule at around 8.6 μm with a maximum signal-to-noise ratio of ˜7 × 103 in 10 s integration time, frequency-resolution of 160 kHz, and accuracy of less than 10 kHz.

  8. Versatile mid-infrared frequency-comb referenced sub-Doppler spectrometer

    Directory of Open Access Journals (Sweden)

    A. Gambetta

    2018-04-01

    Full Text Available We present a mid-IR high-precision spectrometer capable of performing accurate Doppler-free measurements with absolute calibration of the optical axis and high signal-to-noise ratio. The system is based on a widely tunable mid-IR offset-free frequency comb and a Quantum-Cascade-Laser (QCL. The QCL emission frequency is offset locked to one of the comb teeth to provide absolute-frequency calibration, spectral-narrowing, and accurate fine frequency tuning. Both the comb repetition frequency and QCL-comb offset frequency can be modulated to provide, respectively, slow- and fast-frequency-calibrated scanning capabilities. The characterisation of the spectrometer is demonstrated by recording sub-Doppler saturated absorption features of the CHF3 molecule at around 8.6 μm with a maximum signal-to-noise ratio of ∼7 × 103 in 10 s integration time, frequency-resolution of 160 kHz, and accuracy of less than 10 kHz.

  9. Uterine fibroid embolization

    International Nuclear Information System (INIS)

    Totev, M.

    2013-01-01

    Full text: Introduction: Today, after numerous lengthy randomized trials embolization of uterine fibroids has become a standard treatment. Percutaneous embolization of myomas is a micro - invasive surgery, which can be regarded as an alternative to traditional surgery. Although these data 2/3 of the patients were not informed about this treatment option. What you will learn: The uterine embolization is minimal invasive non-surgical procedure. It is an alternative treatment to surgery. Under local anesthesia in the femoral artery puncture reaches the internal iliac artery and uterine arteries. Reached selectively by the catheter and chemicals, which causes clogging, are injected into them. In the vessels that feed fibroids occur a process like an attack, the feeding stops, it starts to shrink and it is replaced by fibrous tissue. The blood vessels of the healthy tissue are different in size and have a plurality of collateral connections as opposed to those of the myoma and thus the blood supply to the normal tissue of the uterus is not distorted. Discussion: Nowadays there are more well- calibrated materials for embolization and those with a particle size of about 700µ are proven as the most successful. The procedure is well tolerated, but after a pain occurs, which has to be covered with anesthetics. Usually pain and metrorrhagia disappear immediately. The fibroids themselves shrink to varying degrees. Hospital stay was significantly shorter than that after surgery, and remained fertile power. Complications are few and rare require further treatment. Multiple nodes are problematic and it is difficult to detect the primary one. A three and six months tracking by MRI is desirable. Conclusion: Embolization of uterine myoma is an established method of treatment primarily on clinical symptoms resulting therefrom. In all patients rapidly disappear metrorrhagia symptoms and morbidity, the volume of the assembly decrease, which together with shorter hospital stays and

  10. Transcranial doppler: Technique and common findings (Part 1

    Directory of Open Access Journals (Sweden)

    Lokesh Bathala

    2013-01-01

    Full Text Available Transcranial Doppler (TCD can be aptly called as the doctor′s stethoscope of the brain. Since its introduction in 1982, by Rune Aaslid, TCD has evolved as a diagnostic, monitoring, and therapeutic tool. During evaluation of patients with acute ischemic stroke, TCD combined with cervical duplex ultrasonography provides physiological information on the cerebral hemodynamics, which is often complementary to structural imaging. Currently, TCD is the only diagnostic tool that can provide real time information about cerebral hemodynamics and can detect embolization to the cerebral vessels. TCD is a noninvasive, cost-effective, and bedside tool for obtaining information regarding the collateral flow across various branches of the circle of Willis in patients with cerebrovascular disorders. Advanced applications of TCD help in the detection of right-to-left shunts, vasomotor reactivity, diagnosis, and monitoring of vasospasm in subarachnoid hemorrhage and as a supplementary test for confirmation of brain death. This article describes the basic ultrasound physics pertaining to TCD insonation methods, for detecting the flow in intracranial vessels in addition to the normal and abnormal spectral flow patterns.

  11. Radio-embolization for hepatocellular carcinoma

    International Nuclear Information System (INIS)

    Raoul, J.L.; Edeline, J.; Pracht, M.; Boucher, E.; Rolland, Y.; Garin, E.

    2011-01-01

    Hepatocellular carcinoma is now a major public health concern. In intermediate stages (one third of hepatocellular carcinoma patients), chemo-embolization is the standard of care despite a poor tolerance and a moderate efficacy. Moreover, despite recent improvements, this technique seems in a dead end. Radio-embolization could be an excellent tool for such patients. Currently 131 I-Lipiodol, 188 Re-Lipiodol, 90 Y-glass or resin microspheres are available. More recent and promising data come from microspheres, but phase II and III studies are needed before drawing any conclusion. In the future, the combination of radio-embolization with systemic chemotherapy or targeted agents (particularly anti-angiogenic drugs) seems very promising. (authors)

  12. Dynamic characteristics of laser Doppler flowmetry signals obtained in response to a local and progressive pressure applied on diabetic and healthy subjects

    Science.gov (United States)

    Humeau, Anne; Koitka, Audrey; Abraham, Pierre; Saumet, Jean-Louis; L'Huillier, Jean-Pierre

    2004-09-01

    In the biomedical field, the laser Doppler flowmetry (LDF) technique is a non-invasive method to monitor skin perfusion. On the skin of healthy humans, LDF signals present a significant transient increase in response to a local and progressive pressure application. This vasodilatory reflex response may have important implications for cutaneous pathologies involved in various neurological diseases and in the pathophysiology of decubitus ulcers. The present work analyses the dynamic characteristics of these signals on young type 1 diabetic patients, and on healthy age-matched subjects. To obtain accurate dynamic characteristic values, a de-noising wavelet-based algorithm is first applied to LDF signals. All the de-noised signals are then normalised to the same value. The blood flow peak and the time to reach this peak are then calculated on each computed signal. The results show that a large vasodilation is present on signals of healthy subjects. The mean peak occurs at a pressure of 3.2 kPa approximately. However, a vasodilation of limited amplitude appears on type 1 diabetic patients. The maximum value is visualised, on the average, when the pressure is 1.1 kPa. The inability for diabetic patients to increase largely their cutaneous blood flow may bring explanations to foot ulcers.

  13. Uterine Fibroid Embolization Can Still Be Improved: Observations on Post-Procedure Magnetic Resonance Imaging

    International Nuclear Information System (INIS)

    Dorenberg, E.J.; Novakovic, Z.; Smith, H.J.; Hafsahl, G.; Jakobsen, J.Aa.

    2005-01-01

    PURPOSE: To evaluate the efficacy and completeness of uterine fibroid embolization (UFE) measured by changes in volume and signal intensity at magnetic resonance imaging (MRI), and to compare with clinical outcome. MATERIAL AND METHODS: 40 women with symptomatic uterine fibroids underwent bilateral uterine artery embolization. At MRI studies, including post-contrast sequences before and repeatedly after treatment, the uterus and dominant fibroids were evaluated for volume, location, and contrast enhancement. Prior to treatment, all myomas showed significant contrast enhancement. The mean uterine volume was 929 ml. Clinical examinations with emphasis on menorrhagia, pelvic pain, and urinary dysfunction were performed before and 6 and 12 months after treatment. RESULTS: UFE was bilaterally successful in 38 patients. After UFE, MRI showed no enhancement of myomas in 30 patients. In 8 patients, post-procedural MRI revealed partially remaining vascularization of fibroids despite angiographically complete embolization of the uterine arteries. On average, uterine volume decreased by 46.2% at 12 months. There was significant improvement of symptoms in the majority of patients, but slightly less improvement in patients with partially remaining vascularization of myomas. CONCLUSION: UFE causes significant volume reduction of myomas and clinical improvement. MRI can reveal remaining vascularization in myomas despite angiographically complete embolization of uterine arteries

  14. Combined embolization and gamma knife radiosurgery for cerebral arteriovenous malformations

    International Nuclear Information System (INIS)

    Guo, W.Y.; Wikholm, G.; Karlsson, B.; Lindquist, C.; Svendsen, P.; Ericson, K.

    1993-01-01

    In a study of 46 patients with cerebral arteriovenous malformations (AVMs) the value of combining embolization and gamma knife radiosurgery was assessed. In 35 patients with large grade III to V AVMs (Spetzler-Martin system) staged combined treatment was planned. In 11 patients, radiosurgery complemented embolization for a residual AVM. The number of embolization sessions ranged from 1 to 7 (median 2). Twenty-six patients needed multiple embolization sessions. In 28 patients the grade of AVMs decreased as a result of embolization. In 16 patients collateral feeding vessels developed after embolization which made delineation of the residual nidus difficult. The time lag between the last embolization and radiosurgery ranged from 1 to 24 months (median 4). Nineteen of 35 large grade III to V AVMs were possible to treat by radiosurgery following embolization. In the 46 patients complications occurred in 9 from embolization and in 2 from radiosurgery. Two patients had transient and 9 had permanent neurologic deficits. It is concluded that embolization facilitates radiosurgery for some large AVMs and therefore this combined treatment has a role in the management of AVMs. (orig.)

  15. Principles of doppler tomography

    International Nuclear Information System (INIS)

    Juhlin, P.

    1992-08-01

    This paper shows how the radon transform can be used to determine vector fields. A scheme to determine the velocity field of a moving fluid by measurements with a continuous doppler signal is suggested. When the flow is confined to a bounded domain, as is the case in most applications, it can be uniquely decomposed into one gradiental and one rotational part. The former vanishes if the fluid is incompressible and source-free, and the latter can be completely reconstructed by the methods proposed in this paper if the domain is simply connected. Special attention is paid to laminar flow in a long cylindrical vessel with circular cross-section. Under such conditions the flow profile becomes parabolic, which makes the vessel recognizable as a typical 'N-shaped' pattern in an image describing the rotation of the velocity field. The vessel yields the same doppler tomographic pattern, no matter how it is sectioned. The ideas presented should be applicable also when studying the flow in blood vessels, even if the flow profile in these is not quite parabolic. The discrepancies only make the 'N-shape' somewhat distorted

  16. Doppler ultrasound scan during normal gestation: umbilical circulation

    International Nuclear Information System (INIS)

    Ruiz, T.; Sabate, J.; Martinez-Benavides, M. M.; Sanchez-Ramos, J.

    2002-01-01

    To determine normal umbilical circulation patterns by means of Doppler ultrasound scan in a healthy gestating population without risk factors and with normal perinatal results, and to evaluate any occurring modifications relative to gestational age by obtaining records kept during pregnancy. One hundred and sixteen pregnant women carrying a single fetus have been studied. These women had no risk factors, with both clinical and analytical controls, as well as ultrasound scans, all being normal. There were performed a total of 193 Doppler ultrasound scans between weeks 15 and 41 of gestation, with blood-flow analysis in the arteries and vein of the umbilical cord. The obtained information was correlated with parameters that evaluate fetal well-being (fetal monitoring and/or oxytocin test) and perinatal result (delivery type, birth weight, Apgar score). Statistical analysis was performed with the programs SPSS 6.0.1 for Windows and EPIINFO 6.0.4. With pulsed Doppler, the umbilical artery in all cases demonstrated a biphasic morphology with systolic and diastolic components and without retrograde blood flow. As the gestation period increased, there was observed a progressive decrease in resistance along with an increase in blood-flow velocity during the diastolic phase. The Doppler ultrasound scan is a non-invasive method that permits the hemodynamic study of umbilical blood circulation. A knowledge of normal blood-flow signal morphology, as well as of the normal values for Doppler indices in relation to gestational age would permit us to utilize this method in high-risk pregnancies. (Author) 30 refs

  17. Mortality and Embolic Potential of Cardiac Tumors

    Energy Technology Data Exchange (ETDEWEB)

    Dias, Ricardo Ribeiro, E-mail: ricardo.dias@incor.usp.br; Fernandes, Fábio; Ramires, Félix José Alvarez; Mady, Charles; Albuquerque, Cícero Piva; Jatene, Fábio Biscegli [Instituto do Coração (InCor) do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, SP (Brazil)

    2014-07-15

    Cardiac tumors are rare, mostly benign with high embolic potential. To correlate the histological type of cardiac masses with their embolic potential, implantation site and long term follow up in patients undergoing surgery. Between January 1986 and December 2011, we retrospectively analyzed 185 consecutive patients who underwent excision of intracardiac mass (119 females, mean age 48±20 years). In 145 patients, the left atrium was the origin site. 72% were asymptomatic and prior embolization was often observed (19.8%). The diagnosis was established by echocardiography, magnetic resonance and histological examination. Most tumors were located in the left side of the heart. Myxoma was the most common (72.6%), followed by fibromas (6.9%), thrombi (6.4%) and sarcomas (6.4%). Ranging from 0.6cm to 15cm (mean 4.6 ± 2.5cm) 37 (19.8%) patients had prior embolization, stroke 10.2%, coronary 4.8%, peripheral 4.3% 5.4% of hospital death, with a predominance of malignant tumors (40% p < 0.0001). The histological type was a predictor of mortality (rhabdomyomas and sarcomas p = 0.002) and embolic event (sarcoma, lipoma and fibroelastoma p = 0.006), but not recurrence. Tumor size, atrial fibrillation, cavity and valve impairment were not associated with the embolic event. During follow-up (mean 80±63 months), there were 2 deaths (1.1%) and two recurrences 1 and 11 years after the operation, to the same cavity. Most tumors were located in the left side of the heart. The histological type was predictor of death and preoperative embolic event, while the implantation site carries no relation with mortality or to embolic event.

  18. Thyroid artery embolization with microspheres for hyperthyroidism

    International Nuclear Information System (INIS)

    Du Yahui; Zhong Chenfu; Chen Weijun; Zhang Ying; Luo Jun; Li Xiaoguang; Cao Junjie; Gan Changli; Cao Junjie; Gan Changli

    2006-01-01

    Objective: To evaluate the method and efficacy of thyroid artery embolization as a new therapy for hyperthyroidism. Methods: Thirteen patients with hyperthyroidism underwent selective thyroid artery embolization. Totally 25 thyroid arteries were embolized with microspheres. The indications for this therapy were as followings: 1) To give hyperthyroid patients having an alternative for surgical and 131 I treatment, and 2) To provide a new method for those clinically being difficult to get control with medicine. Results: Serum level of thyroid hormones dropped significantly[T3 from 2.84-9.0 ng/ml to 0.8-2.2 ng/ml, T4 from 162.9-277.2 ng/ml to 50-126 ng/ml] and symptoms of hyperthyroidism were under control in 12 patients within 1 month after the embolization. One patient remained no change 1 month later and refused to be embolized again. The symptoms of twelve patients were effectively controlled through low dose antithyroid medication for more than 6 months follow up with no serious complications. Conclusion: Thyroid artery embolization with microspheres is an effective alternative for surgical and 131 I treatment of hyperthyroidism. (authors)

  19. Computer-assisted quantitative assessment of power Doppler US: effects of microbubble contrast agent in the differentiation of breast tumors

    International Nuclear Information System (INIS)

    Kettenbach, Joachim; Helbich, Thomas H.; Huber, Sabine; Zuna, Ivan; Dock, Wolfgang

    2005-01-01

    Rationale and objectives: To objectively quantify the effects of a microbubble contrast agent to differentiate breast tumors with power doppler ultrasound and to compare these results with color doppler ultrasound (CD US). Methods: In 47 patients a microbubble contrast agent was injected intravenously. Computer-assisted quantitative assessment of the color pixel density was performed to evaluate the increase in Doppler signals. Results were compared to previously published results of a color Doppler ultrasound study. Results: Peak color pixel density at contrast-enhanced power Doppler ultrasound was higher for carcinomas than for benign tumors (P < 0.03). Time to peak enhancement was shorter in carcinomas than in benign tumors (P < 0.01). For both parameters, diagnostic accuracy of power Doppler ultrasound was 69 and 78%, and for color Doppler ultrasound 62 and 76%, respectively. Conclusions: Quantitative assessment of contrast-enhanced power Doppler ultrasound showed significant differences in malignant and benign breast tumors. Diagnostic accuracy of contrast-enhanced power Doppler ultrasound was higher compared to color Doppler ultrasound

  20. Prognostic factors in bronchial arterial embolization for hemoptysis

    International Nuclear Information System (INIS)

    Kim, Eui Jong; Yoon, Yup; Oh, Joo Hyeong; Lim, Joo Won; Sung, Dong Wook

    1994-01-01

    To find the rebleeding factors in bronchial arterial embolization for treatment of hemoptysis, a retrospective study was performed. Medical records, angiographic findings and embolic materials of 35 patients who had undertaken arterial embolization for control of hemoptysis were reviewed. The period of follow-up for rebleeding was from 3 to 32 months after arterial embolization. We investigated the angiographic findings of extravasation, neovascularity, intervascular shunt, aneurysm and periarterial diffusion. Neovascularity was classified as mild(numerable neovascularity) and severe(innumerable). Rebleeding occurred in 15(43%) among 35 cases. Only two of 11 cases with no past episode of hemoptysis showed recurrence, while 9 of 15 cases who had more than three episodes did. Severe neovascularity were seen in 11 of 15 recurred cases, but seven of 20 non- recurred cases showed severe neovascularity. More than three angiographic findings representing hemoptysis were seen on 11(73%) among recurred 15 cases and seven(35%) among non- recurred 20 cases. The lesion was supplied by more than two different arteries on 8(54%) of the recurred cases, but only three(15%) of the non- recurred cases. Six of seven cases persistent neovascularity after arterial embolization were recurred. The history of repeated hemoptysis, severe neovascularity, variable angiographic findings, and post-embolization persistency of neovascularity were the factors related with the rebleeding after arterial embolization for hemoptysis. Careful and active arterial embolization are required on these conditions

  1. Prognostic factors in bronchial arterial embolization for hemoptysis

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Eui Jong; Yoon, Yup; Oh, Joo Hyeong; Lim, Joo Won; Sung, Dong Wook [Kyung Hee University Hospital, Seoul (Korea, Republic of)

    1994-07-15

    To find the rebleeding factors in bronchial arterial embolization for treatment of hemoptysis, a retrospective study was performed. Medical records, angiographic findings and embolic materials of 35 patients who had undertaken arterial embolization for control of hemoptysis were reviewed. The period of follow-up for rebleeding was from 3 to 32 months after arterial embolization. We investigated the angiographic findings of extravasation, neovascularity, intervascular shunt, aneurysm and periarterial diffusion. Neovascularity was classified as mild(numerable neovascularity) and severe(innumerable). Rebleeding occurred in 15(43%) among 35 cases. Only two of 11 cases with no past episode of hemoptysis showed recurrence, while 9 of 15 cases who had more than three episodes did. Severe neovascularity were seen in 11 of 15 recurred cases, but seven of 20 non- recurred cases showed severe neovascularity. More than three angiographic findings representing hemoptysis were seen on 11(73%) among recurred 15 cases and seven(35%) among non- recurred 20 cases. The lesion was supplied by more than two different arteries on 8(54%) of the recurred cases, but only three(15%) of the non- recurred cases. Six of seven cases persistent neovascularity after arterial embolization were recurred. The history of repeated hemoptysis, severe neovascularity, variable angiographic findings, and post-embolization persistency of neovascularity were the factors related with the rebleeding after arterial embolization for hemoptysis. Careful and active arterial embolization are required on these conditions.

  2. Transcatheter embolization of pseudoaneurysms complicating acute severe pancreatitis

    International Nuclear Information System (INIS)

    Wu Hanping; Liang Huimin; Zheng Chuansheng; Feng Gansheng

    2005-01-01

    Objective: To evaluate the therapeutic roles of transcatheter embolization in patients with pseudoaneurysms complicating acute severe pancreatitis. Methods: Seven patients who suffered from pseudoaneurysms complicating acute severe pancreatitis received abdominal angiography and were treated with transcatheter embolization. The angiographic findings, complications related to the procedure and post- embolization, and rebleeding were observed. Results: The pseudoaneurysms developed at the splenic artery (n=5), right gastroepiploic artery (n=1), and left gastric artery (n=1), respectively. Findings of active bleeding were observed in 3 patients. Six of them were embolized with coils, and the bleedings were stopped immediately. Rebleeding occurred 14-60 days after the embolization in 3 patients, and in one of them, another pseudo aneurysm was observed in repeated angiography and was successfully treated by repeated embolization. No causes of bleeding were found in repeated angiography in the other 2 patients, who died from severe hemorrhage. One pseudo aneurysm was embolized with gelfoam granule. The gastrointestinal bleeding was not controlled and the patient died 3 days later. Procedure related complications occurred in 2 patients. One was celiac trunk rupture during angiography, the other was intima dissecting in splenic artery. Severe post procedure complications occurred in none of the patients. Conclusion: Transcatheter embolization is safe and relatively effective in the management of pseudoaneurysms complicating acute severe pancreatitis. (authors)

  3. Preoperative embolization of gigantic meningioma

    International Nuclear Information System (INIS)

    Wang Hongsheng; Chen Huaqun; Dong Congsong; Li Wenhui; Dai Zhenyu; Chen Guozhi

    2006-01-01

    Objective: To evaluate the clinical efficacy of preoperative embolization in treatment of patients with gigantic meningioma. Methods: Fourteen cases of gigantic meningioma diameter from 6 to 11 cm were measured by CT and MRI scan. DSA manifested that they are vascularizd meningioma and showed the mainly feeding arteries. We used getation sponge to superselectively embilized the feeding arteries. All tumors were performed surgical excision 3-7 days after the embolization. Results: DSA showed the blood supplies in the tumors in 9 cases were completely blocked, and that in 5 cases were dramatically eliminated. All patients were operated 3-7 days after the embolization. During the operations the bleeding were dramatically decreased and the operation time was shortened compared with those in unembolized cases. It helps us remove the tumors easy and quickly from the attachments. No complication occurred during and after the operations. Conclusion: Preoperative embolization of gigantic meningioma is a useful and relatively safe method in helping surgicaly and completely excised of tumor with significant reduction of blood loss and operation time. (authors)

  4. Embolic Brain Infarcts: A Rare Fatal Complication of Preoperative Embolization of a Massive Solitary Fibrous Tumor of the Pleura

    Energy Technology Data Exchange (ETDEWEB)

    Patel, Shreyas R., E-mail: Shrey000@gmail.com; Vachhani, Prasann; Moeslein, Fred [University of Maryland Medical Center, Department of Diagnostic Radiology and Nuclear Medicine (United States)

    2017-02-15

    Solitary fibrous tumor of the pleura (SFTP) is a rare intrathoracic neoplasm, often giant in size and highly vascular, which can make surgical resection very challenging. Preoperative percutaneous embolization before surgical removal can significantly reduce the risk of uncontrollable intraoperative hemorrhage. However, a rare potential life threatening complication could result from embolization of SFTP and must be taken into consideration. This report describes a 69-year-old female with a large right thoracic SFTP, who underwent preoperative angiography and embolization and developed diffuse embolic brain infarcts immediately after the administration of polyvinyl alcohol particles.

  5. The Role of Nonsteroidal Anti-Inflammatory Drugs (NSAIDs in the Management of the Post-Embolization Symptoms after Uterine Artery Embolization

    Directory of Open Access Journals (Sweden)

    Tiago Bilhim

    2010-05-01

    Full Text Available Uterine artery embolization (UAE is usually a very painful procedure. Although pain after the procedure can occur as a single symptom, it usually is associated with other symptoms such as nausea, vomiting, pelvic pain, general malaise, fever and leukocytosis that characterize the post-embolization syndrome. Management of the post-embolization symptoms and of pain in particular, is paramount if UAE is to be performed as an outpatient procedure. Different protocols have used analgesic and/or anti-inflammatory agents to control these symptoms. Nonsteroidal anti-inflammatory drugs (NSAIDs are frequently used in association with analgesic drugs to control post-embolization symptoms. In our institution the patients start oral medication with NSAIDs the day before the procedure and continue it during and after UAE. We also mix NSAIDs with the embolizing particles. This enables a reduction in the inflammation present in the uterine fibroids and helps controlling the pain. The purpose of this paper is to review the importance of NSAIDs in the management of the post-embolization symptoms. We describe the protocol that we use in our institution that enables us to perform the procedure on an outpatient basis with same day discharge and good control of the post-embolization symptoms with oral NSAIDs and analgesics.

  6. Carbon Dioxide Embolism during Laparoscopic Surgery

    Science.gov (United States)

    Park, Eun Young; Kwon, Ja-Young

    2012-01-01

    Clinically significant carbon dioxide embolism is a rare but potentially fatal complication of anesthesia administered during laparoscopic surgery. Its most common cause is inadvertent injection of carbon dioxide into a large vein, artery or solid organ. This error usually occurs during or shortly after insufflation of carbon dioxide into the body cavity, but may result from direct intravascular insufflation of carbon dioxide during surgery. Clinical presentation of carbon dioxide embolism ranges from asymptomatic to neurologic injury, cardiovascular collapse or even death, which is dependent on the rate and volume of carbon dioxide entrapment and the patient's condition. We reviewed extensive literature regarding carbon dioxide embolism in detail and set out to describe the complication from background to treatment. We hope that the present work will improve our understanding of carbon dioxide embolism during laparoscopic surgery. PMID:22476987

  7. Pulmonary Embolism

    Science.gov (United States)

    ... increase the risk for PE, such as: Being bedridden or unable to move around much Having surgery ... of pulmonary embolism (PE) include unexplained shortness of breath, problems breathing, chest pain, coughing , or coughing up ...

  8. Detachable Balloon Embolization of an Arterioportal Fistula Following Liver Biopsy in a Liver Transplant Recipient: A Case Report and Review of Literature

    International Nuclear Information System (INIS)

    Botelberge, Thomas; Vlierberghe, Hans van; Voet, Dirk; Defreyne, Luc

    2005-01-01

    We report a case of an intrahepatic arterioportal fistula in a 61-year-old female liver transplant recipient. The patient presented with massive ascites 7 months after a percutaneous liver biopsy. A large fistula between the right hepatic artery and the right portal vein was diagnosed on color Doppler ultrasound and confirmed on arteriography. The fistula was successfully embolized with the detachable balloon technique and the ascites resolved. Symptomatic intrahepatic arterioportal fistula in a liver transplant recipient following percutaneous biopsy is rare. Clinical manifestations, surgical or endovascular therapy, and outcome are discussed. The literature on this subject is reviewed

  9. Speed of light demonstration using Doppler beat

    Science.gov (United States)

    Bernal, Luis; Bilbao, Luis

    2018-05-01

    From an apparatus previously designed for measuring the Doppler shift using a rotating mirror, an improved, versatile version was developed for speed of light demonstrations in a classroom or a teaching laboratory. By adding a second detector and adequate beam-splitter and mirrors, three different configurations are easily assembled. One configuration is used for time-of-flight measurements between a near and a far detector, allowing one to measure the speed of light provided that the path length between detectors is known. Another variation is the interferometric method obtained by superposing the far and near signals in such a way that a minimum of the combined signal is obtained when the time delay makes the signals arrive out of phase by π radians. Finally, the standard Doppler configuration allows the measurement of the frequency beat as a function of the rotation frequency. The main advantages of the apparatus are (a) the experimental setup is simple and completely accessible to undergraduate students, (b) the light is visible, students can see the rays, which, with the use of appropriate screens, can be blocked at any point along their paths, (c) the experiment can take place entirely within the teaching laboratory or demonstration room (using the interferometric method, the shortest distance to the far mirror was as small as 0.5 m), and (d) different configurations can be built, including some economical setups within the budget of teaching laboratories.

  10. Prophylactic Residual Aneurysmal Sac Embolization with Expandable Hydrogel Embolic Devices for Endoleak Prevention: Preliminary Study in Dogs

    International Nuclear Information System (INIS)

    Hiraki, Takao; Pavcnik, Dusan; Uchida, Barry T.; Timmermans, Hans A.; Yin Qiang; Wu Renghong; Niyyati, Mahtab; Keller, Frederick S.; Roesch, Josef

    2005-01-01

    Objective. To explore the feasibility and efficacy of residual aneurysmal sac (RAS) embolization with the expandable hydrogel embolic device (EHED) in prevention of endoleaks in a surgically created and endoluminally treated abdominal aortic aneurysm (AAA). Methods. In eight dogs, an AAA was created by means of side-to-side anastomosis between the infrarenal abdominal aorta and inferior vena cava (IVC) with ligation of the IVC above and below the anastomotic end, followed by deployment of an endograft with holes. The RAS was then embolized with the EHED. One animal was killed immediately after RAS embolization and one animal died 12 hr after the procedure. Follow-up aortograms were obtained in six animals after 1 day (1 animal), 2 weeks and 6 months (1 animal), and 8 weeks (4 animals). Results. Four animals had no endoleaks on the follow-up aortograms. The remaining two animals with incomplete RAS embolization had moderate type III endoleaks. Type I or II endoleaks were not seen in any animals. Complications included RAS wall penetration by the devices with platinum wires in two animals (nos. 1 and 2), device migration into an aortic circulation through the endograft holes in two animals (nos. 2 and 3) or through distal interstices between the aortic wall and endograft in one animal (no. 8), aortic occlusion in three animals (nos. 3, 7, and 8), and RAS rupture in one animal (no. 7). Histologic examination showed expanded hydrogels occupying the RAS with associated mature or immature organized thrombus, fibrinous thrombus, or degenerate blood cells. Conclusion. RAS embolization was feasible with the EHED, although additional modifications to the device are required to avoid complications. Angiographic and histologic results suggested that RAS embolization with the EHED may help in the prevention of endoleaks

  11. Differences in clinical features and computed tomographic findings between embolic and non-embolic acute ischemic stroke. A quantitative differential diagnosis

    International Nuclear Information System (INIS)

    Takano, Kentaro; Yamaguchi, Takenori; Minematsu, Kazuo; Sawada, Tohru; Omae, Teruo

    1998-01-01

    A diagnosis based on the presumed mechanism of stroke onset is useful for management strategies in acute ischemic stroke. Ninety-two patients with embolic (cardiac or artery-to-artery) and 107 with non-embolic (thrombotic or hemodynamic) stroke were diagnosed on strict cerebral angiographic criteria alone. To clearly discriminate between these two groups, the neurological and computed tomographic (CT) findings were then compared. Rapidity of onset, vomiting, urinary incontinence, level of consciousness, cervical bruit, anisocoria, tongue deviation, sensory disturbance, and CT findings (location of hypodense area, findings of brain edema and hemorrhagic transformation) were discriminatory factors between the two groups (p<0.01). According to these 11 items, we prepared a numerical table for quantitative differential diagnosis. A diagnostic accuracy of 98.9% for embolic and 87.9% for non-embolic stroke in internal verification, and 90.0% and 82.9%, respectively, in external verification was observed. The differences in clinical features and CT findings between embolic and non-embolic stroke may reflect the pathophysiological mechanisms of the occlusive process of cerebral artery as well as the extent and severity of ischemia. (author)

  12. Differences in clinical features and computed tomographic findings between embolic and non-embolic acute ischemic stroke. A quantitative differential diagnosis

    Energy Technology Data Exchange (ETDEWEB)

    Takano, Kentaro; Yamaguchi, Takenori; Minematsu, Kazuo; Sawada, Tohru; Omae, Teruo [National Cardiovascular Center, Suita, Osaka (Japan)

    1998-02-01

    A diagnosis based on the presumed mechanism of stroke onset is useful for management strategies in acute ischemic stroke. Ninety-two patients with embolic (cardiac or artery-to-artery) and 107 with non-embolic (thrombotic or hemodynamic) stroke were diagnosed on strict cerebral angiographic criteria alone. To clearly discriminate between these two groups, the neurological and computed tomographic (CT) findings were then compared. Rapidity of onset, vomiting, urinary incontinence, level of consciousness, cervical bruit, anisocoria, tongue deviation, sensory disturbance, and CT findings (location of hypodense area, findings of brain edema and hemorrhagic transformation) were discriminatory factors between the two groups (p<0.01). According to these 11 items, we prepared a numerical table for quantitative differential diagnosis. A diagnostic accuracy of 98.9% for embolic and 87.9% for non-embolic stroke in internal verification, and 90.0% and 82.9%, respectively, in external verification was observed. The differences in clinical features and CT findings between embolic and non-embolic stroke may reflect the pathophysiological mechanisms of the occlusive process of cerebral artery as well as the extent and severity of ischemia. (author)

  13. Colonic ischemic necrosis following therapeutic embolization

    International Nuclear Information System (INIS)

    Shenoy, S.S.; Satchidanand, S.; Wesp, E.H.; State Univ. of New York, Buffalo

    1981-01-01

    Transcatheter embolization of the middle colic artery for diverticular bleeding was followed by ischemic necrosis in the transverse colon at the site of previous anastomosis and stricture formation. This is a potential complication of intra-arterial embolization for colonic bleeding. (orig.)

  14. Colonic ischemic necrosis following therapeutic embolization

    Energy Technology Data Exchange (ETDEWEB)

    Shenoy, S S; Satchidanand, S; Wesp, E H

    1981-07-15

    Transcatheter embolization of the middle colic artery for diverticular bleeding was followed by ischemic necrosis in the transverse colon at the site of previous anastomosis and stricture formation. This is a potential complication of intra-arterial embolization for colonic bleeding.

  15. The usefulness of Duplex Doppler ultrasound in the angiological and dermatological diagnosis of patients with blue toe syndrome.

    Science.gov (United States)

    Pawlaczyk, Katarzyna; Gabriel, Marcin; Strzelecka-Węklar, Daria A; Krasiński, Zbigniew; Stanisic, Michal; Gabriel, Zofia; Dzieciuchowicz, Łukasz; Adamski, Zygmunt

    2017-10-01

    Peripheral microembolism is one of the most frequent causes of acute limb ischemia. In order to effectively prevent relapses it is essential to localize and eliminate the source of embolism. To evaluate the role of Duplex Doppler ultrasound examination in identifying the causes of blue toe syndrome (BTS). The group of 165 patients with clinical symptoms of BTS on their upper limbs ( n = 16) and lower limbs ( n = 149) was investigated. They all underwent Duplex Doppler ultrasound of the major arteries of the extremities, where ischemic changes occurred. Morphological and functional changes which might be potential sources of microembolism were identified in 146 patients. These changes included significant short-length stenoses or unstable atherosclerotic plaque ( n = 73), true aneurysms ( n = 42) and pseudoaneurysms ( n = 17). In 11 cases, pathology of vascular prostheses in the form of anastomotic aneurysms, infection and residual thrombi after fibrinolysis was detected. In all cases, Duplex diagnosis was confirmed by other imaging and intraoperative tests. Duplex Doppler ultrasound of the arteries in the affected limb with a full length view should be the first-line examination in diagnosing patients with BTS. In the absence of hemodynamic blood flow disturbances in the major arteries in patients with symptoms of BTS, it is advisable to start haematological tests to identify/exclude congenital or acquired thrombophilia.

  16. High-frequency dual mode pulsed wave Doppler imaging for monitoring the functional regeneration of adult zebrafish hearts

    Science.gov (United States)

    Kang, Bong Jin; Park, Jinhyoung; Kim, Jieun; Kim, Hyung Ham; Lee, Changyang; Hwang, Jae Youn; Lien, Ching-Ling; Shung, K. Kirk

    2015-01-01

    Adult zebrafish is a well-known small animal model for studying heart regeneration. Although the regeneration of scars made by resecting the ventricular apex has been visualized with histological methods, there is no adequate imaging tool for tracking the functional recovery of the damaged heart. For this reason, high-frequency Doppler echocardiography using dual mode pulsed wave Doppler, which provides both tissue Doppler (TD) and Doppler flow in a same cardiac cycle, is developed with a 30 MHz high-frequency array ultrasound imaging system. Phantom studies show that the Doppler flow mode of the dual mode is capable of measuring the flow velocity from 0.1 to 15 cm s−1 with high accuracy (p-value = 0.974 > 0.05). In the in vivo study of zebrafish, both TD and Doppler flow signals were simultaneously obtained from the zebrafish heart for the first time, and the synchronized valve motions with the blood flow signals were identified. In the longitudinal study on the zebrafish heart regeneration, the parameters for diagnosing the diastolic dysfunction, for example, E/Em < 10, E/A < 0.14 for wild-type zebrafish, were measured, and the type of diastolic dysfunction caused by the amputation was found to be similar to the restrictive filling. The diastolic function was fully recovered within four weeks post-amputation. PMID:25505135

  17. The color Doppler ultrasonography in in the diagnosis of deep vein thrombosis

    International Nuclear Information System (INIS)

    Ameneiro Perez, Santiago; Alvarez Sanchez, Jose A.; Rodriguez Villalonga, Luis; Borras Migues, Marisela; Quinnones Castro, Mayda

    2004-01-01

    The paper was aimed at evaluating the accuracy of color Doppler ultrasonography, a noninvasive method, in the diagnosis of deep vein thrombosis of the lower limbs, comparing it to the results of the cruel and costly diagnostic g olden rule , that is, phlebography. Methods: Color Doppler ultrasonography served to assess 102 patients clinically suspected of deep vein thrombosis of the lower limbs, taking into account the following criteria: vein compressibility, echographic images, color, Vein Doppler signal modulation after several maneuvers and distal compression. Sensitivity, specificity, positive and negative predictive values and diagnostic efficacy were estimated for each criteria, taking the phlebography as a reference. Results: Total or partial lack of vein compressibility combined with the vein flow evaluation is the ultrasonographic criterion that reveals higher degree of sensitivity, specificity and efficacy (0,98; 0,95 and 0,97 respectively. Color Doppler ultrasonography is a highly effective noninvasive diagnostic method that detects deep vein thrombosis in proximal areas of the lower limbs

  18. Detection of Transient Signals in Doppler Spectra

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Signal processing is used to detect transient signals in the presence of noise. Two embodiments are disclosed. In both embodiments, the time series from a remote...

  19. Transcatheter embolization of renal neoplasms. A comparison of the merits of the radio-active infarct implant versus total embolization with inert material

    International Nuclear Information System (INIS)

    Lang, E.K.; Pisco, J.M.

    1980-01-01

    Transcatheter embolization with radio-active infarct particles and inert embolic material has been proposed for adjuvant therapy in the management of renal cell carcinoma. Transcatheter embolization with inert embolic material has been advocated in preparation for surgical resection of renal tumours. Embolization with radio-active infarct particles is undertaken to deliver a tumouricidal dose to the primary neoplasm. The resultant interstitial implant offers the advantage of a high dose to the primary tumour, choice of time of delivery of the radiant energy by selection of a radio-isotope with appropriate half-life, and limitation of the integral dose to the patient by selection of appropriate physical characteristics of the radio-isotope utilized. Transcatheter embolization with radio-active infarct particles is advocated either as definitive therapy for clearly inoperable neoplasms, or in hope to make an initially inoperable neoplasm operable. (Auth.)

  20. A temible complication of ischemic stroke: pulmonary embolism

    Directory of Open Access Journals (Sweden)

    Linda Iurato

    2015-12-01

    Pulmonary embolism is a major contributor to in-hospital death after stroke. Although the rate of clinically overt pulmonary embolism after stroke has been estimated to be less than 1%, pulmonary emboli account for up to 50% of early deaths after stroke. In daily practice, the clinical burden of pulmonary embolism in patient with stroke is, however, underestimated since the clinical symptoms of stroke may obscure the recognition of this complication. The aim of this article is to describe the clinical and therapeutic aspects of pulmonary embolism as complication after stroke.

  1. Dynamic MR imaging of hepatoma treated by transcatheter arterial embolization therapy

    International Nuclear Information System (INIS)

    Yamashita, Y.; Yoshimatsu, S.; Sumi, M.; Harada, M.; Takahashi, M.

    1993-01-01

    The effect of transcatheter arterial chemo-embolization theory (TACE) for hepatoma was evaluated with dynamic MR imaging with Gd-DTPA in 37 patients (44 tumors). TACE was performed using Lipiodol/cis-platinum and gelatin sponge (or microspheres) as an embolic material. All patients were examined with dynamic CT and MR imaging before and after treatment. On conventional spin echo images, changes of signal intensity after treatment varied regardless of presence of Lipiodol. Dynamic MR imaging revealed changes of tumor vascularity before and after treatment. On histologic correlation, areas of persistent tumor enhancement on dynamic MR imaging corresponded to areas of viable tumor cells while areas of nonenhancement corresponded to areas of necrosis. Dynamic MR imaging was superior in contrast resolution and was not influenced by the presence of Lipiodol compared with dynamic CT, and therefore residual viable tumors were better defined by dynamic MR imaging. (orig.)

  2. Attenuated Vector Tomography -- An Approach to Image Flow Vector Fields with Doppler Ultrasonic Imaging

    International Nuclear Information System (INIS)

    Huang, Qiu; Peng, Qiyu; Huang, Bin; Cheryauka, Arvi; Gullberg, Grant T.

    2008-01-01

    The measurement of flow obtained using continuous wave Doppler ultrasound is formulated as a directional projection of a flow vector field. When a continuous ultrasound wave bounces against a flowing particle, a signal is backscattered. This signal obtains a Doppler frequency shift proportional to the speed of the particle along the ultrasound beam. This occurs for each particle along the beam, giving rise to a Doppler velocity spectrum. The first moment of the spectrum provides the directional projection of the flow along the ultrasound beam. Signals reflected from points further away from the detector will have lower amplitude than signals reflected from points closer to the detector. The effect is very much akin to that modeled by the attenuated Radon transform in emission computed tomography.A least-squares method was adopted to reconstruct a 2D vector field from directional projection measurements. Attenuated projections of only the longitudinal projections of the vector field were simulated. The components of the vector field were reconstructed using the gradient algorithm to minimize a least-squares criterion. This result was compared with the reconstruction of longitudinal projections of the vector field without attenuation. If attenuation is known, the algorithm was able to accurately reconstruct both components of the full vector field from only one set of directional projection measurements. A better reconstruction was obtained with attenuation than without attenuation implying that attenuation provides important information for the reconstruction of flow vector fields.This confirms previous work where we showed that knowledge of the attenuation distribution helps in the reconstruction of MRI diffusion tensor fields from fewer than the required measurements. In the application of ultrasound the attenuation distribution is obtained with pulse wave transmission computed tomography and flow information is obtained with continuous wave Doppler

  3. The PARAFAC-MUSIC Algorithm for DOA Estimation with Doppler Frequency in a MIMO Radar System

    Directory of Open Access Journals (Sweden)

    Nan Wang

    2014-01-01

    Full Text Available The PARAFAC-MUSIC algorithm is proposed to estimate the direction-of-arrival (DOA of the targets with Doppler frequency in a monostatic MIMO radar system in this paper. To estimate the Doppler frequency, the PARAFAC (parallel factor algorithm is firstly utilized in the proposed algorithm, and after the compensation of Doppler frequency, MUSIC (multiple signal classification algorithm is applied to estimate the DOA. By these two steps, the DOA of moving targets can be estimated successfully. Simulation results show that the proposed PARAFAC-MUSIC algorithm has a higher accuracy than the PARAFAC algorithm and the MUSIC algorithm in DOA estimation.

  4. The effect of blood acceleration on the ultrasound power Doppler spectrum

    Science.gov (United States)

    Matchenko, O. S.; Barannik, E. A.

    2017-09-01

    The purpose of the present work was to study the influence of blood acceleration and time window length on the power Doppler spectrum for Gaussian ultrasound beams. The work has been carried out on the basis of continuum model of the ultrasound scattering from inhomogeneities in fluid flow. Correlation function of fluctuations has been considered for uniformly accelerated scatterers, and the resulting power Doppler spectra have been calculated. It is shown that within the initial phase of systole uniformly accelerated slow blood flow in pulmonary artery and aorta tends to make the correlation function about 4.89 and 7.83 times wider, respectively, than the sensitivity function of typical probing system. Given peak flow velocities, the sensitivity function becomes, vice versa, about 4.34 and 3.84 times wider, respectively, then the correlation function. In these limiting cases, the resulting spectra can be considered as Gaussian. The optimal time window duration decreases with increasing acceleration of blood flow and equals to 11.62 and 7.54 ms for pulmonary artery and aorta, respectively. The width of the resulting power Doppler spectrum is shown to be defined mostly by the wave vector of the incident field, the duration of signal and the acceleration of scatterers in the case of low flow velocities. In the opposite case geometrical properties of probing field and the average velocity itself are more essential. In the sense of signal-noise ratio, the optimal duration of time window can be found. Abovementioned results may contribute to the improved techniques of Doppler ultrasound diagnostics of cardiovascular system.

  5. Doppler velocity measurements from large and small arteries of mice

    Science.gov (United States)

    Reddy, Anilkumar K.; Madala, Sridhar; Entman, Mark L.; Michael, Lloyd H.; Taffet, George E.

    2011-01-01

    With the growth of genetic engineering, mice have become increasingly common as models of human diseases, and this has stimulated the development of techniques to assess the murine cardiovascular system. Our group has developed nonimaging and dedicated Doppler techniques for measuring blood velocity in the large and small peripheral arteries of anesthetized mice. We translated technology originally designed for human vessels for use in smaller mouse vessels at higher heart rates by using higher ultrasonic frequencies, smaller transducers, and higher-speed signal processing. With these methods one can measure cardiac filling and ejection velocities, velocity pulse arrival times for determining pulse wave velocity, peripheral blood velocity and vessel wall motion waveforms, jet velocities for the calculation of the pressure drop across stenoses, and left main coronary velocity for the estimation of coronary flow reserve. These noninvasive methods are convenient and easy to apply, but care must be taken in interpreting measurements due to Doppler sample volume size and angle of incidence. Doppler methods have been used to characterize and evaluate numerous cardiovascular phenotypes in mice and have been particularly useful in evaluating the cardiac and vascular remodeling that occur following transverse aortic constriction. Although duplex ultrasonic echo-Doppler instruments are being applied to mice, dedicated Doppler systems are more suitable for some applications. The magnitudes and waveforms of blood velocities from both cardiac and peripheral sites are similar in mice and humans, such that much of what is learned using Doppler technology in mice may be translated back to humans. PMID:21572013

  6. CT findings of cerebral fat embolism

    International Nuclear Information System (INIS)

    Mashiyama, Shoji; Kawakami, Kiyoshi; Ohtsuki, Taisuke; Ishibashi, Takao.

    1986-01-01

    A case of cerebral fat embolism following multiple bone fractures is presented. A 27-year-old patient was admitted to our clinic 50 minutes after a traffic accident. He was somnolent on admission, but his consciousness level was gradually raised and respiratory symptoms (dyspnea, bloody sputum) appeared with petechiae of his conjunctiva and chest. We diagnosed cerebral fat embolism. On CT scan we found multiple high-density areas, which gradually turned into multiple low-density areas. Subsequent cerebral atrophy and subdural effusion developed one month after the injury. This patient showed a typical clinical course and CT findings of cerebral fat embolism. (author)

  7. Treatment of acute renal artery embolism

    International Nuclear Information System (INIS)

    Fava, C.; Grosso, M.; Malara, D.; Barile, C.

    1987-01-01

    The possible ways of treating renal artery embolisms are reviewed with an examination of their advantages and defects. Surgical treatment has a fairly high mortality rate but quickly cures any type of vascular occlusion and will cures any type of vascular occlusion and will cure any concomitant problems such as arterial stenosis. Medical treatement with anticoagulant or mortality rate and is effective even on narrow blood vessels but the response varies according to the type of thromboembolic damage and the way the drugs are administred. Recently developed forms of radiological treatment are also examined. A personal technique successfully applied to an embolism in a patient with only one functioning kidney is described. It consists of a two-stepmechanical and pharmacological attack. First the occluded artery was opened by means of a balloon catheter that was pushedbeyond the embolism and withdrawn into the aorta after inflation of the balloon. Thrombolytic drugs (Urokinase) were then infused through the catheter into the bed of the renal artery in order to cure the secondary thrombosis found, as is generally the case, downstream of the embolism. The technique appears ideal for the treatment of patients with embolisms and total involvement of the renal parenchyma, especially when their general condition makes surgery inadvisable

  8. [Selective embolization to treat obstetric hemorrhage].

    Science.gov (United States)

    Ferrer Puchol, M D; Lanciego, C; Esteban, E; Ciampi, J J; Edo, M A; Ferragud, S

    2014-01-01

    To describe cases of obstetric hemorrhage that have called for selective intra-arterial embolization and the different embolization techniques used. To assess the clinical outcomes and postprocedural fertility. We studied 27 women with obstetric hemorrhage. In 24 patients, embolization was performed by catheterizing both uterine arteries and in 2 patients only one uterine artery was catheterized (pseudoaneurysm). The materials used for embolization consisted of Spongostan in 17/27, particles in 9/27, and coils in 1/27. Clinical follow-up included an analysis of early and late complications and of postprocedural fertility. Hemorrhage was classified as primary (25/27) or secondary (2/27). The cause of bleeding was vaginal delivery (20), cesarean sections (5), abortion (1), and cervical ectopic pregnancy (1). The initial technical success rate was 100% and the clinical success rate was 92.6% (25 of the 27 patients). Bleeding ceased and the outcome was satisfactory in 25 patients. During clinical follow-up ranging from one to seven years, 23 patients had normal menstruation and 6 patients completed 7 full-term pregnancies. Intra-arterial embolization for obstetric hemorrhage leads to good outcomes and few complications and it preserves fertility. Copyright © 2011 SERAM. Published by Elsevier Espana. All rights reserved.

  9. Preoperative embolization of hypervascular head and neck tumours

    International Nuclear Information System (INIS)

    Gupta, A. K.; Purkayastha, S.; Bodhey, N. K.; Kapilamoorthy, T. R.; Kesavadas, C.

    2007-01-01

    Full text: The embolization of vascular tumours of the head and neck has become an important adjunct to the surgical treatment of these tumours. A vascular tumour in the head and neck region in a surgically treatable patient may be a candidate for embolization. Palliative embolization may be the sole treatment for high risk patients. Reducing intraoperative bleeding may shorten surgery time thus decreasing morbidity and mortality. The purpose of this study is to assess the efficacy of embolization as an adjunct to surgery or as a curative measure in the management of hypervascular head and neck tumours. We retrospectively reviewed the records of 46 consecutive patients 27 men and 16 women; mean age, 37.8 years) with 48 hypervascular head and neck tumours that had undergone preoperative transarterial, direct puncture or combined mode of embolization. Diagnosis of tumours was made on the basis of findings of imaging studies. The 46 patients underwent embolization either through transarterial route, by direct puncture technique or both direct puncture and arterial route. The devascularization reached 90-95% with the use of NBCA. The amount of devascularization reached by transarterial particle embolization is a little lesser. One patient (carotid body tumour) developed mild unilateral seventh, ninth and 10th cranial nerve palsy after transarterial embolization, transient hemiparesis was seen in another patient (nasopharyngeal angiofibroma). Both patients improved completely with steroids and had no deficit on follow up. One patient developed delayed glue migration into the middle cerebral artery territory 6 h after the procedure with no reported increase in size of the lesion in the following 5 years. Preoperative embolization of hypervascular tumour of head and neck region appears to be safe and improves the chance of complete removal during surgery with minimal blood loss

  10. Magneto-optic Doppler analyzer: a new instrument to measure mesopause winds

    Science.gov (United States)

    Williams, Bifford P.; Tomczyk, Steven

    1996-11-01

    The magneto-optic Doppler analyzer (MODA) is a new type of passive optical instrument that one can use to measure the Doppler shift of the sodium nightglow emitted at approximately 91 km near the mesopause. From this measurement, horizontal wind signatures are inferred. The MODA is based on a sodium vapor magneto-optic filter that provides inherent wavelength stability at a low cost. The instrument has been used to take nightly zonal and meridional wind measurements since October 1994 at Niwot Ridge, Colorado (40 N, 105 W). We obtained an internally consistent wind signal and measured the semidiurnal tide for several seasons.

  11. Numerical study of glare spot phase Doppler anemometry

    Science.gov (United States)

    Hespel, C.; Ren, K. F.; Gréhan, G.; Onofri, F.

    2008-03-01

    The phase Doppler anemometry has (PDA) been developed to measure simultaneously the velocity and the size of droplets. When the concentration of particles is high, tightly focused beams must be used, as in the dual burst PDA. The latter permits an access to the refractive index of the particle, but the effect of wave front curvature of the incident beams becomes evident. In this paper, we introduce a glare spot phase Doppler anemometry which uses two large beams. The images of the particle formed by the reflected and refracted light, known as glare spots, are separated in space. When a particle passes through the probe volume, the two parts in a signal obtained by a detector in forward direction are then separated in time. If two detectors are used the phase differences and the intensity ratios between two signals, the distance between the reflected and refracted spots can be obtained. These measured values provide information about the particle diameter and its refractive index, as well as its two velocity components. This paper is devoted to the numerical study of such a configuration with two theoretical models: geometrical optics and rigorous electromagnetism solution.

  12. Two different embolic agents in the treatment of uterine arterial embolization for symptomatic fibroids

    International Nuclear Information System (INIS)

    Shi Hongjian; Huang Youhua; Xu Qiang; Shen Tao; Chen Jing; Wu Xiaosong; Jiang Lei; Dong Weihua

    2008-01-01

    Objective: To compare the efficacy and safety of dextran microspheres and polyvinyl alcohol particles in the uterine arterial embolization (UAE)for symptomatic uterine leiomyomata. Methods: Forty women (mean aged 38.5 years, ranged 28-44 years)with symptomatic myomas were randomly divided into two groups with 20 patients in each, PVA (polyvinyl alcohol particles, 355-500 μm)was used as embolic agents in group A and dextran microspheres(Sephadex G-50, 100-300 μm)in group B. The mean diameter of fibroids was 6.5 cm (range, 3-12 cm)with symptoms of menorrahgia, bulk-related symptoms, dysmenorrhea and infertility. Analgesics, anti-infection and rehydration treatments were used after the procedure. The hospital stay, post-embolization syndromes, follow-up materials were reviewed and compared. Results: The hospital stay and the post embolization pain showed no obvious difference between the two groups, simultaneously with no serious complications. The average follow-up duration was 9 months (range, 6-24 months). The average volumes of uterus and fibroid in group A and B decreased gradually during follow-up: 53.4%, 55% and 48.6%, 40.9%, respectively. Conclusion: Dextran microspheres is as the same effective and safe as PVA particles for UAE, but rather cheaper than latter. Further prospective study is warranted. (authors)

  13. Ultrasonography with color Doppler and power Doppler in the diagnosis of periapical lesions

    International Nuclear Information System (INIS)

    Goel, Sumit; Nagendrareddy, Suma Gundareddy; Raju, Manthena Srinivasa; Krishnojirao, Dayashankara Rao Jingade; Rastogi, Rajul; Mohan, Ravi Prakash Sasankoti; Gupta, Swati

    2011-01-01

    To evaluate the efficacy of ultrasonography (USG) with color Doppler and power Doppler applications over conventional radiography in the diagnosis of periapical lesions. Thirty patients having inflammatory periapical lesions of the maxillary or mandibular anterior teeth and requiring endodontic surgery were selected for inclusion in this study. All patients consented to participate in the study. We used conventional periapical radiographs as well as USG with color Doppler and power Doppler for the diagnosis of these lesions. Their diagnostic performances were compared against histopathologic examination. All data were compared and statistically analyzed. USG examination with color Doppler and power Doppler identified 29 (19 cysts and 10 granulomas) of 30 periapical lesions accurately, with a sensitivity of 100% for cysts and 90.91% for granulomas and a specificity of 90.91% for cysts and 100% for granulomas. In comparison, conventional intraoral radiography identified only 21 lesions (sensitivity of 78.9% for cysts and 45.4% for granulomas and specificity of 45.4% for cysts and 78.9% for granulomas). There was definite correlation between the echotexture of the lesions and the histopathological features except in one case. USG imaging with color Doppler and power Doppler is superior to conventional intraoral radiographic methods for diagnosing the nature of periapical lesions in the anterior jaws. This study reveals the potential of USG examination in the study of other jaw lesions

  14. Transcatheter embolization for treatment of acute lower gastrointestinal bleeding

    International Nuclear Information System (INIS)

    Uflacker, R.

    1987-01-01

    Treatment of lower gastrointestinal bleeding was attempted in 13 patients by selective embolization of branches of the mesenteric arteries with Gelfoam. Bleeding was adequately controlled in 11 patients with active bleeding during the examination. One patient improved after embolization but bleeding recurred within 24 hours and in another patient the catheterization was unsuccessful. Five patients with diverticular hemorrhage were embolized in the right colic artery four times, and once in the middle colic artery. Three patients had embolization of the ileocolic artery because of hemorrhage from cecal angiodysplasia, post appendectomy, and leukemia infiltration. Three patients had the superior hemorrhoidal artery embolized because of bleeding from unspecific proctitis, infiltration of the rectum from a carcinoma of the bladder, and transendoscopic polypectomy. One patient was septic and bled from jejunal ulcers. Ischemic changes with infarction of the large bowel developed in two patients and were treated by partial semi-elective colectomy, three and four days after embolization. Four other patients developed pain and fever after embolization. Transcatheter embolization of branches of mesenteric arteries in an effective way to control acute lower gastrointestinal bleeding, but still has a significant rate of complications that must be seriously weighed against the advantages of operation. (orig.)

  15. Contrast-enhanced power Doppler US in the characterization of renal masses

    International Nuclear Information System (INIS)

    Ascenti, G.; Zimbaro, G.; Mazziotti, S.; Visalli, C.; Racchiusa, S.; Vinci, S.; Scribano, E.

    2000-01-01

    Purpose of this work is to report the results of a prospective study investigating the potentials of contrast-enhanced power Doppler in the diagnosis of expansive renal lesions. From 1997 to October 30, 1999, it was studied the case of 59 expansive renal lesions (28 malignant, 31 benign) in 48 patients (mean age 55 years, range 10-79) with power Doppler US before and after the administration of an echo-enhancing agent (Levovist, Schering AG, Berlin Germany). Were found 5 patterns of vascular architecture of the lesions, both before and after contrast agent administration, following the classification by Jinzaki e Coll. Power Doppler US showed vascular structures in 34 patients. The administration of Levovist revealed vessels in 12/25 lesions which had none at baseline studies and in 6 cases vascularity was particularly evident. Color signals were enhanced in all the 34 vascularized lesions, which allowed better definition of vascular patterns. The characterization of vascular patterns with baseline power Doppler US helped improve diagnostic accuracy compared to gray-scale US (58% versus 32%) for hyperechoic lesions, complex cysts and pseudomasses. Independent of contrast agent administration, the integration of gray-scale and power Doppler modes increased diagnostic accuracy even further (76% correct diagnoses). In our series, the US contrast agent did not increase the diagnostic accuracy of power Doppler in the differential diagnosis of hyperechoic renal lesions; conversely, Levovist can be advantageous for the characterization of suspected pseudomasses and complex cysts [it

  16. Transarterial embolization in head and neck lesions

    International Nuclear Information System (INIS)

    Chang, Kee Hyun; Han, Man Chung

    1985-01-01

    The transarterial embolization procedures have been performed in a total of 38 patients with head and neck lesions, including 5 carotid-cavernous fistulas, 1 internal carotid aneurysm, 10 meningiomas, 16 nasopharyngeal angiofibromas, 1 post-traumatic epistaxis and 5 other vascular tumors, over the 18 months-period. Six cases of C-C fistula and ICA aneurysm were treated with the detachable balloon catheter technique. The meningiomas, angiofibromas and all other lesions were embolized with superselection of the branches of the external carotid artery such as the internal maxillary, the middle meningeal, the ascending pharyngeal the facial or other branches, using Berenstein superselective catheters or conventional angiographic catheters. The PVA (polyvinyl alcohol foam) and/or Gelfoam particles were used as embolic materials in these cases. Most of the lesions were successfully embolized with minor transient complications such as pain, headache, vomiting, fever and etc. But in 4 cases occurred the serious complications; one cerebral hemorrhage, two cerebral infarctions, and one acute laryngeal edema. The selection of the embolic materials and the catheters, and the complications are briefly discussed

  17. Transcatheter arterial embolization for traumatic bleeding control

    International Nuclear Information System (INIS)

    Ryu, Choon Wook; Lee, Sang Kwon; Suh, Kyung Jin; Kim, Tae Heon; Kim, Yong Joo; Kang, Duck Sik

    1989-01-01

    Angiography is essential for the detection of bleeding vessels in traumatic vascular injury. Immediately after the diagnosis, transcatheter embolization can be performed for the control of bleeding effectively and easily with proper use of embolic materials. Transcatheter embolization is believed to be the treatment of choice when emergency control is needed, where surgical approach is difficult and in those who are poor candidate for surgery. We have tried bleeding control in 18 cases of trauma over recent 4 years. The results were as follows; 1. Causes of bleeding(cases): Blunt or penetrating trauma (10), latrogenic trauma (8), (Postoperative (5), Needle biopsy (2), Percutaneous hepatic procedure (1)) 2. Embolized vessels: Renal artery branches (8), Hepatic artery branches (2), Arteries supplying chest wall (2), External carotid artery branches (3), Internal carotid artery (1), Circumflex humeral artery (1), Internal iliac artery branches (1). 3. Embolic agents: Gelfoam cubes (16), Stainless steel coils (3), Detachable latex balloon (1). 4. Successful bleeding control was achieved in 17 cases and reduction of the amount of bleeding in one case without significant complications

  18. Transarterial embolization in head and neck lesions

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Kee Hyun; Han, Man Chung [College of Medicine, Seoul National University, Seoul (Korea, Republic of)

    1985-06-15

    The transarterial embolization procedures have been performed in a total of 38 patients with head and neck lesions, including 5 carotid-cavernous fistulas, 1 internal carotid aneurysm, 10 meningiomas, 16 nasopharyngeal angiofibromas, 1 post-traumatic epistaxis and 5 other vascular tumors, over the 18 months-period. Six cases of C-C fistula and ICA aneurysm were treated with the detachable balloon catheter technique. The meningiomas, angiofibromas and all other lesions were embolized with superselection of the branches of the external carotid artery such as the internal maxillary, the middle meningeal, the ascending pharyngeal the facial or other branches, using Berenstein superselective catheters or conventional angiographic catheters. The PVA (polyvinyl alcohol foam) and/or Gelfoam particles were used as embolic materials in these cases. Most of the lesions were successfully embolized with minor transient complications such as pain, headache, vomiting, fever and etc. But in 4 cases occurred the serious complications; one cerebral hemorrhage, two cerebral infarctions, and one acute laryngeal edema. The selection of the embolic materials and the catheters, and the complications are briefly discussed.

  19. Cerebral fat embolism

    International Nuclear Information System (INIS)

    Sakamoto, Toshihisa; Sawada, Yusuke; Yukioka, Tetsuo; Nishide, Kazuyuki; Yoshioka, Toshiharu

    1982-01-01

    A case of cerebral fat embolism is reported. A 18-year-old patient with multiple bone fractures was in semiconma immediately after an injury. Brain CT showed no brain swelling or intracranial hematoma. Hypoxemia and alcoholemia were noted on admission, which returned to normal without improvement of consciousness level. In addition, respiratory symptoms with positive radiographic changes, tachycardia, pyrexia, sudden drop in hemoglobin level, and sudden thrombocytopenia developed. These symptoms were compatible with Gurd's criteria of systemic fat embolism. Eight days after injury, multiple low density areas appeared on CT and disappeared within the subsequent two weeks, and subdural effusion with cerebral atrophy developed. These CT findings were not considered due to cerebral trauma. Diagnosis of cerebral fat embolism was made. The subdural effusion was drained. Neurologic and pulmonary recoveries took place slowly and one month following the injury the patient became alert and exhibited fully coordinated limb movement. The CT scans of the present case well corresponded with hitherto reported pathological findings. Petechiae in the white matter must have developed on the day of injury, which could not be detected by CT examination. It is suggested that some petechial regions fused to purpuras and then gradually resolved when they were detected as multiple low density areas on CT. CT in the purpuras phase would have shown these lesions as high density areas. These lesions must have healed with formation of tiny scars and blood pigment which were demonstrated as the disappearance of multiple low density areas by CT examination. Cerebral atrophy and subsequent subdural effusion developed as a result of demyelination. The patient took the typical clinical course of cerebral fat embolism and serial CT scans served for its assessment. (author)

  20. Doppler Processing with Ultra-Wideband (UWB) Radar Revisited

    Science.gov (United States)

    2018-01-01

    REPORT TYPE Technical Note 3. DATES COVERED (From - To) December 2017 4. TITLE AND SUBTITLE Doppler Processing with Ultra-Wideband (UWB) Radar...unlimited. 13. SUPPLEMENTARY NOTES 14. ABSTRACT This technical note revisits previous work performed at the US Army Research Laboratory related to...target considered previously is proportional to a delayed version of the transmitted signal, up to a complex constant factor. We write the received

  1. The relationship between tumor markers and pulmonary embolism in lung cancer.

    Science.gov (United States)

    Xiong, Wei; Zhao, Yunfeng; Xu, Mei; Guo, Jian; Pudasaini, Bigyan; Wu, Xueling; Liu, Jinming

    2017-06-20

    Tumor markers (TMs) and D-Dimer are both hallmarks of severity and prognosis of lung cancer. Tumor markers could be related to pulmonary embolism (PE) in lung cancer. The number of abnormal tumor markers of lung cancer patients with pulmonary embolism (3.9 ± 1.1vs1.6 ± 0.6,P 0.005) was more than that in patients without pulmonary embolism. TMs panel (P trend tumor markers, TMs panel (OR5.98, P Tumor markers were compared between lung cancer patients complicated with pulmonary embolism and those without pulmonary embolism Then the correlation between each tumor marker as well as panel of combined TMs and D-Dimer as well as pulmonary embolism were analyzed for patients with pulmonary embolism. There is a relationship between tumor markers and pulmonary embolism in patients with lung cancer. The panel of combined tumor markers is a valuable diagnostic marker for pulmonary embolism in lung cancer.

  2. Dual-Doppler Feasibility Study

    Science.gov (United States)

    Huddleston, Lisa L.

    2012-01-01

    When two or more Doppler weather radar systems are monitoring the same region, the Doppler velocities can be combined to form a three-dimensional (3-D) wind vector field thus providing for a more intuitive analysis of the wind field. A real-time display of the 3-D winds can assist forecasters in predicting the onset of convection and severe weather. The data can also be used to initialize local numerical weather prediction models. Two operational Doppler Radar systems are in the vicinity of Kennedy Space Center (KSC) and Cape Canaveral Air Force Station (CCAFS); these systems are operated by the 45th Space Wing (45 SW) and the National Weather Service Melbourne, Fla. (NWS MLB). Dual-Doppler applications were considered by the 45 SW in choosing the site for the new radar. Accordingly, the 45th Weather Squadron (45 WS), NWS MLB and the National Aeronautics and Space Administration tasked the Applied Meteorology Unit (AMU) to investigate the feasibility of establishing dual-Doppler capability using the two existing systems. This study investigated technical, hardware, and software requirements necessary to enable the establishment of a dual-Doppler capability. Review of the available literature pertaining to the dual-Doppler technique and consultation with experts revealed that the physical locations and resulting beam crossing angles of the 45 SW and NWS MLB radars make them ideally suited for a dual-Doppler capability. The dual-Doppler equations were derived to facilitate complete understanding of dual-Doppler synthesis; to determine the technical information requirements; and to determine the components of wind velocity from the equation of continuity and radial velocity data collected by the two Doppler radars. Analysis confirmed the suitability of the existing systems to provide the desired capability. In addition, it is possible that both 45 SW radar data and Terminal Doppler Weather Radar data from Orlando International Airport could be used to alleviate any

  3. The clinical course of patients with suspected pulmonary embolism

    NARCIS (Netherlands)

    van Beek, E. J.; Kuijer, P. M.; Büller, H. R.; Brandjes, D. P.; Bossuyt, P. M.; ten Cate, J. W.

    1997-01-01

    BACKGROUND: The outcome of patients with suspected pulmonary embolism is known to a limited extent only. OBJECTIVE: To address this limited knowledge in a cohort in whom pulmonary embolism was proved or ruled out. METHODS: Consecutive patients with clinically suspected pulmonary embolism underwent

  4. Endosonographic and color doppler flow imaging alterations observed within irradiated rectal cancer

    International Nuclear Information System (INIS)

    Alexander, Archie A.; Palazzo, Juan P.; Ahmad, Neelofur R.; Liu, J.-B.; Forsberg, Flemming; Marks, John

    1996-01-01

    Purpose: To correlate the endosonographic and color Doppler flow imaging alterations observed in irradiated rectal cancers with the pathologic features of radiation response, and to evaluate the potential impact of altered blood flow on the integrity of the surgical anastamosis. Methods and Materials: Endosonography with color and pulsed wave Doppler was performed on 20 rectal cancer masses before and after high dose preoperative radiation (XRT). Pre- and post-XRT observations included comparing alterations in tumor size, sonographic echotexture, color Doppler flow, and pulsatility indices. Comparisons were made with pathologic findings in the irradiated specimens and with the incidence of anastomotic failure. Results: Compared to pre-XRT observations, irradiated rectal cancers decreased in size and became either mixed in echogenicity with less apparent color Doppler flow (16 of 20) or unchanged in color Doppler flow and echotexture (4 of 20). Those with less flow (16 of 20) were imaged later (mean = 90.2 ± 12.1 days) than those without change in color Doppler flow (mean = 21.7 ± 2.7 days). Pathologically, the group of four without change in color Doppler signal had features of acute inflammation which were not observed in 16 of 20 imaged later. Based on pulsatility index measurements, both high and low resistance vessels were detected and confirmed by immunohistochemical staining, and features of postradiation obliterative vasculitis were observed. Only one primary anastomosis in 14 patients with decreased flow failed. Conclusions: The sonographic and color Doppler flow imaging alterations observed within irradiated rectal cancer correlated with changes of postradiation obliterative vasculitis. The apparent diminished local blood flow within high and low resistance vessels post-XRT did not result in an increased incidence of anastomotic failures

  5. Control of haematuria with superselective embolization

    Energy Technology Data Exchange (ETDEWEB)

    Vlahos, L.; Gouliamos, A.; Kalovidouris, A.; Colias, S.; Papacharalambous, X.; Papavasiliou, C. (Athens Univ. (Greece). Dept. of Radiology)

    1991-02-01

    Fifteen patients with severe haematuria due to causes other than malignant disease were seen between 1981 and 1989. Arteriography was done in an attempt to treat these patients with superselective embolization. In 7 patients, the cause of bleeding was due to injuries of iatrogenic origin and of the remaining 8, 2 had been in a car accident, 2 had knife stabwounds, 3 angiomatous malformations and 1 tuberous sclerosis. Twelve of the 15 patients were treated successfully with superselective embolization with steel coils. We consider angiography followed by superselective embolization to be the method of choice for the diagnosis and treatment of haematuria due to renal injury or other benign conditions. (orig.).

  6. Particle sizing experiments with the laser Doppler velocimeter: Final report

    Energy Technology Data Exchange (ETDEWEB)

    Giel, T.V. Jr.; Son, J.Y.

    1988-06-01

    Measurement techniques for in-situ simultaneous measurements of particle size distributions and particle velocities using the dual beam laser Doppler velocimeter (LV) were analytically and experimentally investigated. This investigation examined the different signal characteristics of the LV for determination of particle size and particle velocity, simultaneously. The different size related signal components were evaluated not only singularly but also as simultaneous measurements to determine which characteristic, or combination of characteristics, provided the best measure of particle size. The evaluation concentrated on the 0.5 to 5 ..mu..m particle size range, in which the LV light scattering characteristics are complex often non-monotonic functions of the particle size as well as functions of index of refraction, the laser light wavelength, laser intensity and polarization, and the location and response characteristics of the detector. Different components of the LV signal were considered, but analysis concentrated on Doppler phase, visibility and scatter-intensity because they show the greatest promise. These signals characteristics were initially defined analytically for numerous optical configurations over the 0.5 to 5 ..mu..m diameter range with 0.1 ..mu..m segmentation, for refractive index values from 1.0 to 3.0 with absorptive (imaginary) components varied form 0 to 1.0. Collector orientation and effective f/No., as well as fringe spacing, beam polarization and wavelength, were varied in this analytical evaluation. 18 refs., 42 figs., 5 tabs.

  7. Potentialities of embolization of life threatening hemorrhages

    International Nuclear Information System (INIS)

    Moskvichev, V.G.

    1985-01-01

    The author analysed experience in the embolization of the abdominal vessels in 79 patients with diseases and lesions of the peritoneal cavity and retroperitoneal space accompanied by life threatening hemorrhage. In 51 cases embolization was used as an independent method of hemorrhage arrest and in 28 cases for patients' preoperative preparation. A hemostatic sponge combined with a superselective administration of 150-200 ml of aminocaproic acid was used as an emboilizing material. Complications attributed to embolization were noted in 5 patients: pancreatitis, subdiaphragmatic abscess, paranephritis, ischemia of the gluteal soft tissues, sciatic neuritis. An analysis has shown that urgent embolization of the abdominal vessels in diseases and lesions of the organs of the peritoneal cavity and retroperitoneal space accompanied by massive hemorrhage, can be used as an independent method for hemorrhage arrest

  8. Ultrasonography with color Doppler and power Doppler in the diagnosis of periapical lesions

    Science.gov (United States)

    Goel, Sumit; Nagendrareddy, Suma Gundareddy; Raju, Manthena Srinivasa; Krishnojirao, Dayashankara Rao Jingade; Rastogi, Rajul; Mohan, Ravi Prakash Sasankoti; Gupta, Swati

    2011-01-01

    Aim: To evaluate the efficacy of ultrasonography (USG) with color Doppler and power Doppler applications over conventional radiography in the diagnosis of periapical lesions. Materials and Methods: Thirty patients having inflammatory periapical lesions of the maxillary or mandibular anterior teeth and requiring endodontic surgery were selected for inclusion in this study. All patients consented to participate in the study. We used conventional periapical radiographs as well as USG with color Doppler and power Doppler for the diagnosis of these lesions. Their diagnostic performances were compared against histopathologic examination. All data were compared and statistically analyzed. Results: USG examination with color Doppler and power Doppler identified 29 (19 cysts and 10 granulomas) of 30 periapical lesions accurately, with a sensitivity of 100% for cysts and 90.91% for granulomas and a specificity of 90.91% for cysts and 100% for granulomas. In comparison, conventional intraoral radiography identified only 21 lesions (sensitivity of 78.9% for cysts and 45.4% for granulomas and specificity of 45.4% for cysts and 78.9% for granulomas). There was definite correlation between the echotexture of the lesions and the histopathological features except in one case. Conclusions: USG imaging with color Doppler and power Doppler is superior to conventional intraoral radiographic methods for diagnosing the nature of periapical lesions in the anterior jaws. This study reveals the potential of USG examination in the study of other jaw lesions. PMID:22223940

  9. Ultrasonography with color Doppler and power Doppler in the diagnosis of periapical lesions

    Directory of Open Access Journals (Sweden)

    Sumit Goel

    2011-01-01

    Full Text Available Aim: To evaluate the efficacy of ultrasonography (USG with color Doppler and power Doppler applications over conventional radiography in the diagnosis of periapical lesions. Materials and Methods: Thirty patients having inflammatory periapical lesions of the maxillary or mandibular anterior teeth and requiring endodontic surgery were selected for inclusion in this study. All patients consented to participate in the study. We used conventional periapical radiographs as well as USG with color Doppler and power Doppler for the diagnosis of these lesions. Their diagnostic performances were compared against histopathologic examination. All data were compared and statistically analyzed. Results: USG examination with color Doppler and power Doppler identified 29 (19 cysts and 10 granulomas of 30 periapical lesions accurately, with a sensitivity of 100% for cysts and 90.91% for granulomas and a specificity of 90.91% for cysts and 100% for granulomas. In comparison, conventional intraoral radiography identified only 21 lesions (sensitivity of 78.9% for cysts and 45.4% for granulomas and specificity of 45.4% for cysts and 78.9% for granulomas. There was definite correlation between the echotexture of the lesions and the histopathological features except in one case. Conclusions: USG imaging with color Doppler and power Doppler is superior to conventional intraoral radiographic methods for diagnosing the nature of periapical lesions in the anterior jaws. This study reveals the potential of USG examination in the study of other jaw lesions.

  10. Time-frequency analysis of laser Doppler flowmetry signals recorded in response to a progressive pressure applied locally on anaesthetized healthy rats

    International Nuclear Information System (INIS)

    Humeau, Anne; Koitka, Audrey; Abraham, Pierre; Saumet, Jean-Louis; L'Huillier, Jean-Pierre

    2004-01-01

    The laser Doppler flowmetry technique has recently been used to report a significant transient increase of the cutaneous blood flow signal, in response to a local non-noxious pressure applied progressively on the skin of both healthy humans and rats. This phenomenon is not entirely understood yet. In the present work, a time-frequency analysis is applied to signals recorded on anaesthetized healthy rats, at rest and during a cutaneous pressure-induced vasodilation (PIV). The comparison, at rest and during PIV, of the scalogram relative energies and scalogram relative amplitudes in five bands, corresponding to five characteristic frequencies, shows an increased contribution for the endothelial related metabolic activity in PIV signals, till 400 s after the beginning of the progressive pressure application. The other subsystems (heart, respiration, myogenic and neurogenic activities) contribute relatively less during PIV than at rest. The differences are statistically significant for all the relative activities in the interval 0-200 s following the beginning of the pressure. These results and others obtained on patients, such as diabetics, could increase the understanding of some cutaneous pathologies involved in various neurological diseases and in the pathophysiology of decubitus ulcers

  11. Time-frequency analysis of laser Doppler flowmetry signals recorded in response to a progressive pressure applied locally on anaesthetized healthy rats

    Energy Technology Data Exchange (ETDEWEB)

    Humeau, Anne [Groupe ISAIP-ESAIP, 18 rue du 8 mai 1945, BP 80022, 49180 Saint Barthelemy d' Anjou Cedex (France); Koitka, Audrey [Laboratoire de Physiologie et d' Explorations Vasculaires, Centre Hospitalier Universitaire d' Angers, 49033 Angers Cedex 01 (France); Abraham, Pierre [Laboratoire de Physiologie et d' Explorations Vasculaires, Centre Hospitalier Universitaire d' Angers, 49033 Angers Cedex 01 (France); Saumet, Jean-Louis [Laboratoire de Physiologie et d' Explorations Vasculaires, Centre Hospitalier Universitaire d' Angers, 49033 Angers Cedex 01 (France); L' Huillier, Jean-Pierre [Ecole Nationale Superieure d' Arts et Metiers (ENSAM), Laboratoire Procedes-Materiaux-Instrumentation (LPMI), 2 boulevard du Ronceray, BP 3525, 49035 Angers Cedex (France)

    2004-03-07

    The laser Doppler flowmetry technique has recently been used to report a significant transient increase of the cutaneous blood flow signal, in response to a local non-noxious pressure applied progressively on the skin of both healthy humans and rats. This phenomenon is not entirely understood yet. In the present work, a time-frequency analysis is applied to signals recorded on anaesthetized healthy rats, at rest and during a cutaneous pressure-induced vasodilation (PIV). The comparison, at rest and during PIV, of the scalogram relative energies and scalogram relative amplitudes in five bands, corresponding to five characteristic frequencies, shows an increased contribution for the endothelial related metabolic activity in PIV signals, till 400 s after the beginning of the progressive pressure application. The other subsystems (heart, respiration, myogenic and neurogenic activities) contribute relatively less during PIV than at rest. The differences are statistically significant for all the relative activities in the interval 0-200 s following the beginning of the pressure. These results and others obtained on patients, such as diabetics, could increase the understanding of some cutaneous pathologies involved in various neurological diseases and in the pathophysiology of decubitus ulcers.

  12. Laser Doppler flowmetry in endodontics: a review.

    Science.gov (United States)

    Jafarzadeh, H

    2009-06-01

    Vascular supply is the most accurate marker of pulp vitality. Tests for assessing vascular supply that rely on the passage of light through a tooth have been considered as possible methods for detecting pulp vitality. Laser Doppler flowmetry (LDF), which is a noninvasive, objective, painless, semi-quantitative method, has been shown to be reliable for measuring pulpal blood flow. The relevant literature on LDF in the context of endodontics up to March 2008 was reviewed using PubMed and MEDLINE database searches. This search identified papers published between June 1983 and March 2008. Laser light is transmitted to the pulp by means of a fibre optic probe. Scattered light from moving red blood cells will be frequency-shifted whilst that from the static tissue remains unshifted. The reflected light, composed of Doppler-shifted and unshifted light, is returned by afferent fibres and a signal is produced. This technique has been successfully employed for estimating pulpal vitality in adults and children, differential diagnosis of apical radiolucencies (on the basis of pulp vitality), examining the reactions to pharmacological agents or electrical and thermal stimulation, and monitoring of pulpal responses to orthodontic procedures and traumatic injuries. Assessments may be highly susceptible to environmental and technique-related factors. Nonpulpal signals, principally from periodontal blood flow, may contaminate the signal. Because this test produces no noxious stimuli, apprehensive or distressed patients accept it more readily than current methods of pulp vitality assessment. A review of the literature and a discussion of the application of this system in endodontics are presented.

  13. Fpga based L-band pulse doppler radar design and implementation

    Science.gov (United States)

    Savci, Kubilay

    As its name implies RADAR (Radio Detection and Ranging) is an electromagnetic sensor used for detection and locating targets from their return signals. Radar systems propagate electromagnetic energy, from the antenna which is in part intercepted by an object. Objects reradiate a portion of energy which is captured by the radar receiver. The received signal is then processed for information extraction. Radar systems are widely used for surveillance, air security, navigation, weather hazard detection, as well as remote sensing applications. In this work, an FPGA based L-band Pulse Doppler radar prototype, which is used for target detection, localization and velocity calculation has been built and a general-purpose Pulse Doppler radar processor has been developed. This radar is a ground based stationary monopulse radar, which transmits a short pulse with a certain pulse repetition frequency (PRF). Return signals from the target are processed and information about their location and velocity is extracted. Discrete components are used for the transmitter and receiver chain. The hardware solution is based on Xilinx Virtex-6 ML605 FPGA board, responsible for the control of the radar system and the digital signal processing of the received signal, which involves Constant False Alarm Rate (CFAR) detection and Pulse Doppler processing. The algorithm is implemented in MATLAB/SIMULINK using the Xilinx System Generator for DSP tool. The field programmable gate arrays (FPGA) implementation of the radar system provides the flexibility of changing parameters such as the PRF and pulse length therefore it can be used with different radar configurations as well. A VHDL design has been developed for 1Gbit Ethernet connection to transfer digitized return signal and detection results to PC. An A-Scope software has been developed with C# programming language to display time domain radar signals and detection results on PC. Data are processed both in FPGA chip and on PC. FPGA uses fixed

  14. Acquire uterine vascular malformation: Clinical outcome of transarterial embolization

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Chae Hoon [Dept. of Radiology, Gangneung Asan Hospital, Gangneung (Korea, Republic of); Yang, Seung Boo; Goo, Dong Erk; Kim, Yong Jae; Lee, Jae Myung; Lee, Woong Hee [Dept. of Radiology, Soonchunhyang University Gumi Hospital, Gumi (Korea, Republic of)

    2017-02-15

    To evaluate clinical outcomes of transarterial embolization of bilateral uterine arteries (UAE) in patients with acquired uterine vascular malformation (UVM). This retrospective study was performed on the medical records of all 19 patients who underwent transarterial embolization of bilateral UAE for the treatment of symptomatic UVMs from January 2003 to June 2011. Embolization was performed via the unilateral femoral artery approach with a catheter and angiographic techniques. Clinical success was defined as definitive resolution of abnormal vaginal bleeding. Post-procedural complications included all adverse events related to the embolization procedure. A total of 20 procedures were performed in 19 patients. One patient required repeat embolization because of incomplete embolization related to prominent high flow malformation. Clinically, in all patients, bleeding was controlled immediately after embolization. No complications occurred in all patients during the follow up period. In all patients who underwent successful UAE, menstrual cycles were normally restored within 1-2 months. Normal pregnancy with term delivery was observed in two of the 19 cases. Transarterial bilateral UAE is a safe and effective treatment in patients with vaginal bleeding caused by acquired UVM, and it allows the possibility of future pregnancy.

  15. Acquire uterine vascular malformation: Clinical outcome of transarterial embolization

    International Nuclear Information System (INIS)

    Kang, Chae Hoon; Yang, Seung Boo; Goo, Dong Erk; Kim, Yong Jae; Lee, Jae Myung; Lee, Woong Hee

    2017-01-01

    To evaluate clinical outcomes of transarterial embolization of bilateral uterine arteries (UAE) in patients with acquired uterine vascular malformation (UVM). This retrospective study was performed on the medical records of all 19 patients who underwent transarterial embolization of bilateral UAE for the treatment of symptomatic UVMs from January 2003 to June 2011. Embolization was performed via the unilateral femoral artery approach with a catheter and angiographic techniques. Clinical success was defined as definitive resolution of abnormal vaginal bleeding. Post-procedural complications included all adverse events related to the embolization procedure. A total of 20 procedures were performed in 19 patients. One patient required repeat embolization because of incomplete embolization related to prominent high flow malformation. Clinically, in all patients, bleeding was controlled immediately after embolization. No complications occurred in all patients during the follow up period. In all patients who underwent successful UAE, menstrual cycles were normally restored within 1-2 months. Normal pregnancy with term delivery was observed in two of the 19 cases. Transarterial bilateral UAE is a safe and effective treatment in patients with vaginal bleeding caused by acquired UVM, and it allows the possibility of future pregnancy

  16. Prevention and treatment of complications for thyroid-arterial embolization

    International Nuclear Information System (INIS)

    Yang Jijin; Yuan Min; Tian Jianming; Chen Wei; Yang Chaoai; Hao Qiang; Zou Dajing; Wang Yongchun

    2003-01-01

    Objective: To investigate the complications of thyroid-arterial embolization and their prevention and treatment. Methods: 61 cases of thyroid disorders received the therapy of thyroid-arterial embolization were retrospectively studied. The complications of arterial embolization during or after the procedure were analyzed. How to prevent and deal with these complications were discussed. Results: Sensitivity to contrast media occurred in 1 case and surgical arterial injury in 2. After embolization thyroid storm occurred in 1 patient and all other complications including headache (23 cases), toothache (11 cases), neckache (13 cases), hoarseness (37 cases) were caused by non-target arterial embolization with the most serious one of cerebral infarction (1 case) and another eyelid ptosis (1 case). The cerebral infarct one was treated with some vasodilating drugs and anti-coagulant, all others were given anti-symptomatics or no special treatment. Conclusions: Proper treatment should be ready during thyroid arterial embolization and given in time with occurrence of complications

  17. Distal Embolic Protection for Renal Arterial Interventions

    International Nuclear Information System (INIS)

    Dubel, Gregory J.; Murphy, Timothy P.

    2008-01-01

    Distal or embolic protection has intuitive appeal for its potential to prevent embolization of materials generated during interventional procedures. Distal protection devices (DPDs) have been most widely used in the coronary and carotid vascular beds, where they have demonstrated the ability to trap embolic materials and, in some cases, to reduce complications. Given the frequency of chronic kidney disease in patients with renal artery stenosis undergoing stent placement, it is reasonable to propose that these devices may play an important role in limiting distal embolization in the renal vasculature. Careful review of the literature reveals that atheroembolization does occur during renal arterial interventions, although it often goes undetected. Early experience with DPDs in the renal arteries in patients with suitable anatomy suggests retrieval of embolic materials in approximately 71% of cases and renal functional improvement/stabilization in 98% of cases. The combination of platelet inhibition and a DPD may provide even greater benefit. Given the critical importance of renal functional preservation, it follows that everything that can be done to prevent atheroembolism should be undertaken including the use of DPDs when anatomically feasible. The data available at this time support a beneficial role for these devices

  18. Uterine artery embolization to treat uterine fibroids

    International Nuclear Information System (INIS)

    Machan, L.; Martin, M.

    2001-01-01

    The first reported application of uterine artery embolization, in 1979, was to treat life-threatening hemorrhage after a failed hysterectomy. Since then, uterine artery embolization has been used very successfully to control acute or delayed post-partum hemorrhage, post-surgical hemorrhage and hemorrhage from ectopic pregnancy, to treat uterine arteriovenous malformations and as prophylaxis before high-risk surgery, such as cesarean delivery in women with placenta previa. In contrast to these proven but underutilized applications, uterine embolization for fibroids has, in a short time, achieved significant notice in the lay press and is being widely offered. Ravina and colleagues, first reported uterine fibroid shrinkage after embolization for the treatment of acute bleeding. Since then, his group has performed over 100 procedures with up to a 6-year follow-up. The cumulative clinical success rate for the treatment of abnormal uterine bleeding due to fibroids is reported to be approximately 85% and for treatment of pain or pressure symptoms, about 75%. Six-month follow-up sonography reveals an average reduction of fibroid size of approximately 40%. However, to date, no studies have compared patients who undergo embolization with a nontreatment cohort or with surgical intervention. (author)

  19. Uterine artery embolization to treat uterine fibroids

    Energy Technology Data Exchange (ETDEWEB)

    Machan, L.; Martin, M. [Univ. of British Columbia Hospital, Dept. of Radiology, Vancouver, BC (Canada)

    2001-06-01

    The first reported application of uterine artery embolization, in 1979, was to treat life-threatening hemorrhage after a failed hysterectomy. Since then, uterine artery embolization has been used very successfully to control acute or delayed post-partum hemorrhage, post-surgical hemorrhage and hemorrhage from ectopic pregnancy, to treat uterine arteriovenous malformations and as prophylaxis before high-risk surgery, such as cesarean delivery in women with placenta previa. In contrast to these proven but underutilized applications, uterine embolization for fibroids has, in a short time, achieved significant notice in the lay press and is being widely offered. Ravina and colleagues, first reported uterine fibroid shrinkage after embolization for the treatment of acute bleeding. Since then, his group has performed over 100 procedures with up to a 6-year follow-up. The cumulative clinical success rate for the treatment of abnormal uterine bleeding due to fibroids is reported to be approximately 85% and for treatment of pain or pressure symptoms, about 75%. Six-month follow-up sonography reveals an average reduction of fibroid size of approximately 40%. However, to date, no studies have compared patients who undergo embolization with a nontreatment cohort or with surgical intervention. (author)

  20. Heart disease in patients with pulmonary embolism.

    Science.gov (United States)

    Pesavento, Raffaele; Piovella, Chiara; Prandoni, Paolo

    2010-09-01

    Several heart diseases are promoters of left-side cardiac thrombosis and could lead to arterial embolism. The same mechanism may be responsible for right-side cardiac thrombosis and therefore be a direct source of pulmonary embolism. Yasuoka et al. showed a higher incidence of perfusion defects in lung scan in patients with spontaneous echocontrast in the right atrium than in those without it (40% and 7% respectively; P=0.006). We recently assessed the prevalence of heart diseases in 11.236 consecutive patients older than 60 years discharged from Venetian hospitals with a diagnosis of pulmonary embolism. We observed a higher prevalence of all-cause heart diseases (odds ratio 1.26; 95% confidence interval, 1.13-1.40) in patients with a diagnosis of pulmonary embolism alone (secondary or unprovoked) compared with those discharged with a diagnosis of pulmonary embolism associated with deep vein thrombosis, generating the hypothesis that some specific heart diseases in older patients could themselves be a possible source of pulmonary emboli. Further prospective studies are required to confirm these findings, which have the potential to open new horizons for the interpretation and management of venous thromboembolic disease.

  1. Contrast-enhanced power Doppler US of hepatocellular carcinomas: Quantitative analysis

    International Nuclear Information System (INIS)

    Kim, Ah Young; Choi, Byung Ihn; Kim, Tae Kyoung; Lee, Kyoung Ho; Han, Joon Koo

    1999-01-01

    To determine peak time and duration of contrast enhancement of nodular hepatocellular carcinoma (HCC) on contrast-enhancement power Doppler ultrasound (US) with Levovist by quantitative analysis. Twenty eight patients with nodular HCC were prospectively evaluated with power Doppler US by one examiner. Serial images were obtained before and after injection of 300 mg/mL US contrast agent (SH U 508 A, Levovist, Schering) with the injection rate of 0.2 mL/sec. Power Doppler signals on obtained digital images were quantified using 'Ultrasound Imaging Tool Version 1.0' (Seoul, Korea). The grade, peak time and duration of contrast enhancement of the tumors were analyzed. For nodular HCCs, mean peak enhancement time was 60 seconds after injection of Levovist (mean enhanced area 41.6 ± 28.6 %). These tumoral enhancement decreased from 90 seconds and returned to near baseline state at 5 minutes after injection of Levovist. Maximum enhanced areas (%) were variable at a range of 8-98.5% and mean maximum enhanced area was 46.4 ± 28.6%. On contrast-enhanced power Doppler US with Levovist, nodular HCCs showed peak contrast enhancement (41.6± 28.6) at 60 seconds after injection of contrast agent. This tumoral enhancement nearly disappeared at 5 minutes after injection of contrast agent.

  2. Pulmonary Embolism as the Initial Presentation of Testicular Carcinoma

    Science.gov (United States)

    Berber, Ilhami; Erkurt, Mehmet Ali; Ulutas, Ozkan; Ediz, Caner; Nizam, Ilknur; Kırıcı Berber, Nurcan; Unlu, Serkan; Koroglu, Reyhan; Koroglu, Mustafa; Akpolat, Nusret

    2013-01-01

    Objective. The risk of pulmonary embolism is well recognized as showing an increase in oncological patients. We report a case presenting with pulmonary embolism initially, which was then diagnosed with testicular cancer. Clinical Presentation and Intervention. A 25-year-old man was admitted to the emergency department with a complaint of dyspnoea. Thoracic tomography, lung ventilation/perfusion scintigraphy, and an increased D-dimer level revealed pulmonary embolism. For the aetiology of pulmonary embolism, a left orchiectomy was performed and the patient was diagnosed with a germinal cell tumour of the testicle. Conclusion. In this paper, we present a patient for whom pulmonary embolism was the initial presentation, and a germinal cell tumour was diagnosed later during the search for the aetiology. PMID:24383024

  3. Follow-up of cerebral aneurysm embolization with hydrogel embolic system: Systematic review and meta-analysis.

    Science.gov (United States)

    Serafin, Zbigniew; Di Leo, Giovanni; Pałys, Alicja; Nowaczewska, Magdalena; Beuth, Wojciech; Sardanelli, Francesco

    2015-10-01

    Hydrogel embolic system (HES) for endovascular treatment of cerebral aneurysms was developed to reduce the risk of aneurysm recurrence and the rate of retreatment. The aim of this systematic review was to verify the efficacy of HES, also in comparison to bare platinum coils (BPC). A systematic literature search was performed by two independent reviewers for articles published until January 31st, 2013 on the follow-up recurrence rate of intracranial aneurysm embolization with hydrogel-coated coils. Thirteen articles on the use of HES for embolization of cerebral aneurysms were included in this study, for a total of 1683 embolized aneurysms. Significant heterogeneity was found regarding patient populations, methods of aneurysm coiling, follow-up schedules, and recurrence definitions. The pooled rate of initial complete aneurysm occlusion was 55% (95%CI, 38-70%); 59% (95%CI, 43-74%) in the subgroup of aneurysms treated with the use of HES. The pooled total recurrence rate was 19% (95%CI, 15-24%); 17% (95%CI, 14-22%) in the HES-treated subgroup. The pooled major recurrence rate was 12% (95%CI, 8-18%); 11% (95%CI, 7-16%) in the HES-treated subgroup. Comparing both types of coils, the pooled odds ratio for total recurrence was 0.63 (95%CI, 0.45-0.88; p=0.008) in favor of HES. Embolization of cerebral aneurysms using HES seems to result in a lower rate of recurrence than that obtained using BPC, which is in line with the only randomized controlled trial. High-quality prospective studies are needed to define specific indications for the use of hydrogel-coated coils. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  4. Control of haematuria with superselective embolization

    International Nuclear Information System (INIS)

    Vlahos, L.; Gouliamos, A.; Kalovidouris, A.; Colias, S.; Papacharalambous, X.; Papavasiliou, C.

    1991-01-01

    Fifteen patients with severe haematuria due to causes other than malignant disease were seen between 1981 and 1989. Arteriography was done in an attempt to treat these patients with superselective embolization. In 7 patients, the cause of bleeding was due to injuries of iatrogenic origin and of the remaining 8, 2 had been in a car accident, 2 had knife stabwounds, 3 angiomatous malformations and 1 tuberous sclerosis. Twelve of the 15 patients were treated successfully with superselective embolization with steel coils. We consider angiography followed by superselective embolization to be the method of choice for the diagnosis and treatment of haematuria due to renal injury or other benign conditions. (orig.) [de

  5. Devascularization of Head and Neck Paragangliomas by Direct Percutaneous Embolization

    International Nuclear Information System (INIS)

    Ozyer, Umut; Harman, Ali; Yildirim, Erkan; Aytekin, Cuneyt; Akay, Tankut Hakki; Boyvat, Fatih

    2010-01-01

    Preoperative transarterial embolization of head and neck paragangliomas using particulate agents has proven beneficial for decreasing intraoperative blood loss. However, the procedure is often incomplete owing to extensive vascular structure and arteriovenous shunts. We report our experience with embolization of these lesions by means of direct puncture and intratumoral injection of n-butyl cyanoacrylate (NBCA) or Onyx. Ten patients aged 32-82 years who were referred for preoperative embolization of seven carotid body tumors and three jugular paragangliomas were retrospectively analyzed. Intratumoral injections were primarily performed in four cases with multiple small-caliber arterial feeders and adjunctive to transarterial embolization in six cases with incomplete devascularization. Punctures were performed under ultrasound and injections were performed under roadmap fluoroscopic guidance. Detailed angiographies were performed before and after embolization procedures. Control angiograms showed complete or near-complete devascularization in all tumors. Three tumors with multiple small-caliber arterial feeders were treated with primary NBCA injections. One tumor necessitated transarterial embolization after primary injection of Onyx. Six tumors showed regional vascularization from the vasa vasorum or small-caliber branches of the external carotid artery following the transarterial approach. These regions were embolized with NBCA injections. No technical or clinical complications related to embolization procedures occurred. All except one of the tumors were surgically removed following embolization. In conclusion, preoperative devascularization with percutaneous direct injection of NBCA or Onyx is feasible, safe, and effective in head and neck paragangliomas with multiple small-caliber arterial feeders and in cases of incomplete devascularization following transarterial embolization.

  6. Uterine Artery Anatomy Relevant to Uterine Leiomyomata Embolization

    International Nuclear Information System (INIS)

    Gomez-Jorge, Jackeline; Keyoung, Andrew; Levy, Elliot B.; Spies, James B.

    2003-01-01

    To categorize the anatomic variants of uterine arteries, and determine the incidence of menopausal symptoms where the tubo-ovarian branches were seen prior to embolization. Between July 1997 and June 2000, 257 (n = 257) uterine fibroid embolizations were performed at our institution. Arteriograms were retrospectively evaluated. Uterine arteries were classified into groups: type I (the uterine artery as first branch of the inferior gluteal artery), type II (the uterine artery as second or third branch of the inferior gluteal artery), type III (the uterine artery, the inferior gluteal and the superior gluteal arteries arising as a trifurcation), type IV (the uterine artery as first branch of the hypogastric artery), inconclusive, or not studied. Tubo-ovarian branches were recorded if visualized prior to and/or after embolization. Menopausal symptoms were recorded (n = 175 at 3 months, n = 139 at 6 months, n = 98 at 1 year, n = 22 at 2 years) using written questionnaires. Five hundred and fourteen uterine arteries (n = 514) were evaluated. There were 38% classifiable types, 23% inconclusive, and 39% not studied. Classification was as follows: type I, 45%; type II, 6%; type III, 43%; type IV, 6%. Among 256 patients, tubo-ovarian arteries were seen in 36 prior to embolization, but not afterwards. In this group, 25 patients reported transient menopausal symptoms (hot flashes, amenorrhea). Five patients did not report any menopausal symptoms. Six patients did not answer the questionnaires. Type I is the most common type of anatomy, followed by type III. The tubo-ovarian arteries may be visualized prior to and/or after embolization. The embolization was monitored to avoid embolization of the tubo-ovarian branches. Menopausal symptoms were transient all patients when the tubo-ovarian branches were seen prior to embolization

  7. A fiber optic Doppler sensor and its application in debonding detection for composite structures.

    Science.gov (United States)

    Li, Fucai; Murayama, Hideaki; Kageyama, Kazuro; Meng, Guang; Ohsawa, Isamu; Shirai, Takehiro

    2010-01-01

    Debonding is one of the most important damage forms in fiber-reinforced composite structures. This work was devoted to the debonding damage detection of lap splice joints in carbon fiber reinforced plastic (CFRP) structures, which is based on guided ultrasonic wave signals captured by using fiber optic Doppler (FOD) sensor with spiral shape. Interferometers based on two types of laser sources, namely the He-Ne laser and the infrared semiconductor laser, are proposed and compared in this study for the purpose of measuring Doppler frequency shift of the FOD sensor. Locations of the FOD sensors are optimized based on mechanical characteristics of lap splice joint. The FOD sensors are subsequently used to detect the guided ultrasonic waves propagating in the CFRP structures. By taking advantage of signal processing approaches, features of the guided wave signals can be revealed. The results demonstrate that debonding in the lap splice joint results in arrival time delay of the first package in the guided wave signals, which can be the characteristic for debonding damage inspection and damage extent estimation.

  8. Gallblader varices in children with portal cavernoma: duplex-Doppler and color Doppler ultrasound studies

    International Nuclear Information System (INIS)

    Muro, D.; Sanguesa, C.; Lopez, A.

    1998-01-01

    To determine the prevalence of varices in the gallbladder wall, observed by duplex-Doppler and color Doppler ultrasound, in children with cavernoma of the portal vein. Nineteen patients with portal hypertension were studied prospectively by duplex-Doppler and color Doppler ultrasound: 12 of the patients had developed a cavernoma of the portal vein. The presence of peri vesicular varices was assessed in the group of patients with portal cavernoma. Duplex-Doppler and color Doppler ultrasound disclosed the presence of varices in gallbladder wall in nine of the 12 patients (75%). The varices appeared as anechoic and serpiginous areas, and Doppler ultrasound revealed slowed venous flow. However, the three patients in whom gallbldder varices were not detected presented collateral gastric ciculation and spontaneous splenorenal shunt. Gallbladder varices are common in children with portal vein cavernoma; they present hepatopetal flow. Their developments is not related to the size of the portal cavernoma, the presence of spontaneous portosystemic shunts, or endoscopic obliteration of gastric and esophageal varices. The detection of gallbladder varices in patients with portal hypertension who are to undergo biliary surgery is highly important for the surgeon, helping to avoid perioperative complications. (Author) 15 refs

  9. Facial Palsy Following Embolization of a Juvenile Nasopharyngeal Angiofibroma.

    Science.gov (United States)

    Tawfik, Kareem O; Harmon, Jeffrey J; Walters, Zoe; Samy, Ravi; de Alarcon, Alessandro; Stevens, Shawn M; Abruzzo, Todd

    2018-05-01

    To describe a case of the rare complication of facial palsy following preoperative embolization of a juvenile nasopharyngeal angiofibroma (JNA). To illustrate the vascular supply to the facial nerve and as a result, highlight the etiology of the facial nerve palsy. The angiography and magnetic resonance (MR) imaging of a case of facial palsy following preoperative embolization of a JNA is reviewed. A 13-year-old male developed left-sided facial palsy following preoperative embolization of a left-sided JNA. Evaluation of MR imaging studies and retrospective review of the angiographic data suggested errant embolization of particles into the petrosquamosal branch of the middle meningeal artery (MMA), a branch of the internal maxillary artery (IMA), through collateral vasculature. The petrosquamosal branch of the MMA is the predominant blood supply to the facial nerve in the facial canal. The facial palsy resolved since complete infarction of the nerve was likely prevented by collateral blood supply from the stylomastoid artery. Facial palsy is a potential complication of embolization of the IMA, a branch of the external carotid artery (ECA). This is secondary to ischemia of the facial nerve due to embolization of its vascular supply. Clinicians should be aware of this potential complication and counsel patients accordingly prior to embolization for JNA.

  10. Bronchial Artery Embolization for Massive Hemoptysis: a Retrospective Study

    Directory of Open Access Journals (Sweden)

    Ali Fani

    2013-05-01

    Full Text Available   Introduction: To assess the efficacy and safety of bronchial artery embolization in the treatment of massive hemoptysis.   Materials and Methods: A retrospective study on 46 patients (26 males and 20 females who were referred to the Razavi Hospital from April 2009 to May 2012 with massive hemoptysis and had bronchial artery embolization procedures. General characteristics of the patients including age, gender, etiology, and thorax computed tomograms, findings of bronchial angiographic, results of the embolization, complications related to bronchial artery embolization and clinical outcome during follow-up were reviewed. Results: The etiology included previous pulmonary tuberculosis in 20 cases, previous tuberculosis with bronchiectasis in 16 cases, bronchiectasis in 6 cases, and active pulmonary tuberculosis in one case. No identifiable causes could be detected in three patients. Moreover, massive hemoptysis was successfully and immediately controlled following the embolization procedure in all patients. One patient developed recurrent hemoptysis during one month following the procedure and was treated by re-embolization. No major procedure–related complication such as bronchial infarction was identified However none of the patientsexperienced neurological complications. Conclusion: Bronchial artery embolization is a safe and effective means of controlling massive hemoptysis and should be regarded as the first-line treatment for this condition.

  11. Challenges in noise removal from Doppler spectra acquired by a continuous-wave lidar

    DEFF Research Database (Denmark)

    Angelou, Nikolas; Foroughi Abari, Farzad; Mann, Jakob

    2012-01-01

    are presented. A method for determining the background noise spectrum without interrupting the transmission of the laser beam is described. Moreover, the dependency between the determination of the threshold of a Doppler spectrum with low signal-to-noise ratios and the characteristics of the wind flow......This paper is focused on the required post processing of Doppler spectra, acquired from a continuous-wave coherent lidar at high sampling rates (400 Hz) and under rapid scanning of the laser beam. In particular, the necessary steps followed for extracting the wind speed from such Doppler spectra...... are investigated and a systematic approach for removing the noise is outlined. The suggested post processing procedures are applied to two sample time series acquired by a short-range WindScanner during one second each....

  12. Thyroid artery embolization for hyperthyroidism

    International Nuclear Information System (INIS)

    Li Jingyu; Zhang Xinguo; Xu Liyang; Liu Ming; Zhang Yongtian; Jin Weiya

    2001-01-01

    Objective: To evaluate the method and result of thyroid artery embolization as a new therapy for hyperthyroidism. Methods: Twenty-two patients with hyperthyroidism underwent selective thyroid artery embolization. Totally 52 thyroid arteries were embolized with microspheres. The indications to this therapy were following: hyperthyroid patients having indications to surgical and 131 I therapy, clinically being difficult to complete the preparation for subtotal thyroidectomy and having high risk for surgical process because of their huge thyroid gland. Results: Serum level of thyroid hormones dropped significantly [median T3 from 8.8 nmol/L (4.3-43.0 nmol/L) to 4.0 nmol/L (1.1-9.2 nmol/L), median T4 from 206.4 nmol/L (77.4-748.2 nmol/L) to 144.5 nmol/L (25.8-279.9 nmol/L), P 131 I treatment of hyperthyroidism. A long term follow-up study is still needed

  13. Myocardial Infarction as a Complication of Bronchial Artery Embolization

    Energy Technology Data Exchange (ETDEWEB)

    Labbé, Hugo, E-mail: hugo.labbe.1@ulaval.ca [Université Laval, Department of Medicine (Canada); Bordeleau, Simon [Université Laval, Department of Emergency Medicine (Canada); Drouin, Christine [Université Laval, Department of Anesthesiology and Critical Care Medicine (Canada); Archambault, Patrick [Université Laval, Department of Emergency Medicine (Canada)

    2017-03-15

    Bronchial artery embolization is now a common treatment for massive pulmonary hemoptysis if flexible bronchoscopy at the bedside failed to control the bleeding. Complications of this technique range from benign chest pain to devastating neurological impairments. We report the case of a 41-year-old man who developed an ST elevation myocardial infarction during bronchial artery embolization, presumably because of coronary embolism by injected particles. In this patient who had no previously known coronary artery disease, we retrospectively found a communication between the left bronchial artery and the circumflex coronary artery. This fistula was not visible on the initial angiographic view and likely opened because of the hemodynamic changes resulting from the embolization. This case advocates for careful search for bronchial-to-coronary arterial fistulas and the need for repeated angiographic views during embolization procedures.

  14. Video-assisted open supraclavicular sympathectomy following air embolism.

    Science.gov (United States)

    Shpolyanski, G; Hashmonai, M; Rudin, M; Abaya, N; Kaplan, U; Kopelman, D

    2012-01-01

    Air embolism is a relatively rare complication of thoracoscopic surgery. Open supraclavicular sympathectomy was indicated to overcome the risk of re-embolization. A novel video-assisted technique was performed. conclusions: The previously prevalent open supraclavicular sympathectomy is a good choice for avoiding air embolism. Laparoscopic instrumentation and technology can be used to improve open procedures, especially when exposure and visibility are limited. Sometimes we should remember to use the experience of our teachers.

  15. Identification of anomalous Doppler resonance effect during current ramp down in HT-7 tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Li Erzhong, E-mail: rzhonglee@ipp.ac.c [Institute of Plasma Physics, Chinese Academy of Science, Hefei 230031 (China); Hu Liqun; Ling Bili; Liu Yong; Ti Ang; Zhou Reijie; Lu Hongwei; Gao Xiang [Institute of Plasma Physics, Chinese Academy of Science, Hefei 230031 (China)

    2010-09-21

    The abrupt steep jump of electron cyclotron emission (ECE) signals during current ramp-down has been observed and explained by an anomalous Doppler resonance effect (ADR). The identifying process of ADR was presented based on the fast Fourier transform (FFT) technique. The threshold value for triggering a steep jump on ECE signals has been identified under different discharge conditions.

  16. The use of intraoperative monitoring and treatment of symptomatic microemboli in carotid artery stenting: case report and discussion

    Energy Technology Data Exchange (ETDEWEB)

    Rangi, P.S.; Clifton, A. [St Georges Hospital, Department of Neuroradiology, Atkinson Morley Wing, Tooting, London (United Kingdom); Markus, H.S.; Punter, M.N.M. [St Georges University of London, Centre for Clinical Neuroscience, Cranmer Terrace, London (United Kingdom)

    2007-03-15

    Carotid artery stenting is a recently introduced treatment in symptomatic atherosclerotic carotid artery disease with acceptable complication rates. The major risk is perioperative embolic stroke. Transcranial Doppler ultrasonography (TCD) can be used to identify embolic signals and guide therapy. We present a case of symptomatic embolization in a 72-year-old female following carotid stent deployment complicated by haemodynamic changes. Despite concurrent dual antiplatelet medication significant symptomatic embolization occurred even after restoration of the blood pressure, and modulation of the rate of embolization was achieved using dextran-40 guided by TCD monitoring. The patient recovered from an initially profound hemiparesis and dysphasia to minor sensory changes. Microemboli are common following carotid artery stenting and there appears to be a threshold phenomenon associated with prolonged embolization and progression to cerebral infarction. TCD can be used to detect particulate microemboli and therefore may be useful in guiding antithrombotic therapy in this setting. Dextran-40 has been shown to reduce the embolic load following carotid endarterectomy and was used to good effect in this patient in terms of both embolic load and clinical outcome. This is the first case of embolization following carotid stenting successfully treated with dextran-40, and offers a further option for therapeutic intervention in microembolism detected by TCD and stresses the importance of perioperative monitoring of embolic load for postoperative stroke risk. (orig.)

  17. Amniotic fluid embolism

    Directory of Open Access Journals (Sweden)

    Kiranpreet Kaur

    2016-01-01

    Full Text Available Amniotic fluid embolism (AFE is one of the catastrophic complications of pregnancy in which amniotic fluid, fetal cells, hair, or other debris enters into the maternal pulmonary circulation, causing cardiovascular collapse. Etiology largely remains unknown, but may occur in healthy women during labour, during cesarean section, after abnormal vaginal delivery, or during the second trimester of pregnancy. It may also occur up to 48 hours post-delivery. It can also occur during abortion, after abdominal trauma, and during amnio-infusion. The pathophysiology of AFE is not completely understood. Possible historical cause is that any breach of the barrier between maternal blood and amniotic fluid forces the entry of amniotic fluid into the systemic circulation and results in a physical obstruction of the pulmonary circulation. The presenting signs and symptoms of AFE involve many organ systems. Clinical signs and symptoms are acute dyspnea, cough, hypotension, cyanosis, fetal bradycardia, encephalopathy, acute pulmonary hypertension, coagulopathy etc. Besides basic investigations lung scan, serum tryptase levels, serum levels of C3 and C4 complements, zinc coproporphyrin, serum sialyl Tn etc are helpful in establishing the diagnosis. Treatment is mainly supportive, but exchange transfusion, extracorporeal membrane oxygenation, and uterine artery embolization have been tried from time to time. The maternal prognosis after amniotic fluid embolism is very poor though infant survival rate is around 70%.

  18. Noncontact Detection and Analysis of Respiratory Function Using Microwave Doppler Radar

    Directory of Open Access Journals (Sweden)

    Yee Siong Lee

    2015-01-01

    Full Text Available Real-time respiratory measurement with Doppler Radar has an important advantage in the monitoring of certain conditions such as sleep apnoea, sudden infant death syndrome (SIDS, and many other general clinical uses requiring fast nonwearable and non-contact measurement of the respiratory function. In this paper, we demonstrate the feasibility of using Doppler Radar in measuring the basic respiratory frequencies (via fast Fourier transform for four different types of breathing scenarios: normal breathing, rapid breathing, slow inhalation-fast exhalation, and fast inhalation-slow exhalation conducted in a laboratory environment. A high correlation factor was achieved between the Doppler Radar-based measurements and the conventional measurement device, a respiration strap. We also extended this work from basic signal acquisition to extracting detailed features of breathing function (I : E ratio. This facilitated additional insights into breathing activity and is likely to trigger a number of new applications in respiratory medicine.

  19. Apoptotic study in Graves disease treated with thyroid arterial embolization

    International Nuclear Information System (INIS)

    Zhao Wei; Gao Bulang; Yi Genfa

    2009-01-01

    The objective of this study was to investigate apoptosis in the thyroid of Graves disease (GD) induced by thyroid arterial embolization. Forty one patients with clinically and laboratorily ascertained GD were treated with thyroid arterial embolization and followed up for 3-54 months following embolization. Prior to embolization and at 1, 3, 6, 12 and 36 months following embolization, thyroid autoimmune antibodies were tested respectively, including thyroid stimulating antibody (TSAb), thyroglobulin antibody (TGAb) and thyroid microsomal antibody (TMAb). Thyroid biopsy was performed under the guidance of computed tomography for immunohistochemistry examination using semi-quantity analysis. The positive staining of Fas and FasL was mostly in the cytoplasma and cell membrane, the positive expression of Bax was mainly in the cytoplasma, and no positive expression of P53 was detected in the thyroid cells before embolization. After arterial embolziation, the positive cell number and staining degree of these genes were both greater than before embolization. The treatment method of thyroid arterial embolization can effectively enhance the positive expression of pro-apoptotic genes of Fas, FasL, Bax, Bcl-2 and P53 in GD thyroid, thus promoting apoptosis of GD thyroid and helping restore the thyroid size and function to normal conditions. (author)

  20. Paradoxical embolism: Experiences from a single center

    Directory of Open Access Journals (Sweden)

    Hong-Liang Zhang

    2017-06-01

    Full Text Available Objective: To present our treatment experiences and the follow-up data of patients with paradoxical embolism (PDE. Methods: The clinical characteristics, management, and follow-up data of all included patients who were diagnosed with PDE at Fuwai Hospital from January 1994 to October 2015 were recorded. Results: Twelve patients were included; all had a pulmonary embolism, and 8 had deep venous thrombosis. The artery embolisms involved the cerebral artery (7 patients, renal artery (2 patients, mesentery artery (2 patients, popliteal artery (1 patient, descending aorta thrombus (1 patient, and thrombus-straddled patent foramen ovale (PFO (1 patient. PFO was found in 3 cases. One patient underwent thrombectomy and PFO closure; Six patients received thrombolysis; and 3 patients were implanted with a vena cava filter. Long-term anticoagulation with warfarin was recommended for each patient. One patient died from ventricular fibrillation despite cardiopulmonary resuscitation. Eleven patients were discharged with improvements. No late mortality occurred in 8 patients with a complete follow-up of 10.6–17.7 years. One had a recurrent deep venous thrombosis. No patient had a recurrent pulmonary or arterial embolism. Two patients changed their treatment from warfarin to aspirin; others remained on warfarin. Only 1 case had an occasional gum bleeding. Conclusions: PDE treatment including thrombolysis, anticoagulation, and embolectomy should be individualized. We recommend long-term anticoagulation therapy to prevent the recurrence of PDE, especially to those with an intracardiac communication or persistent risk factors for re-thrombosis. Keywords: Paradoxical embolism, Pulmonary embolism, Deep venous thrombosis, Patent foramen ovale

  1. Avaliação dos tumores hepáticos ao Doppler Doppler evaluation of liver tumors

    Directory of Open Access Journals (Sweden)

    Márcio Martins Machado

    2004-10-01

    Full Text Available Os avanços recentes na ultra-sonografia têm ampliado a possibilidade de detecção de tumores hepáticos. Isto tem auxiliado na perspectiva de melhora do prognóstico destes pacientes, à medida que novas técnicas terapêuticas têm surgido. Neste artigo os autores relatam achados ao Doppler que podem auxiliar na identificação e caracterização dos tumores hepáticos, avaliando dados do Doppler colorido, pulsado e do Doppler de amplitude ("power Doppler". Fazem, também, referência a novas modalidades de imagem, como o uso da harmônica.Recent advances in ultrasound have optimized the detection of liver tumors and helped to improve the prognosis of patients with this condition as newly developed and improved therapeutic modalities have been established. The authors review important Doppler findings which may help in the identification and characterization of some hepatic tumors through the evaluation of color Doppler, pulsed Doppler and power Doppler features. New imaging methods such as the use of harmonics imaging are also reviewed.

  2. Can catheter-directed thrombolysis be applied to acute lower extremity artery embolism after recent cerebral embolism from atrial fibrillation?

    International Nuclear Information System (INIS)

    Si, T.-G.; Guo, Z.; Hao, X.-S.

    2008-01-01

    Purpose: To assess the feasibility and efficacy of catheter-directed thrombolysis with recombinant tissue plasminogen activator (rt-PA) for acute limb embolism in patients with recent cerebral embolism due to atrial fibrillation. Materials and methods: Eight patients (six men, two women; mean age 63.5 years) with acute embolic occlusion of two left common iliac arteries, four femoral arteries (three left; one right), and two right popliteal arteries were treated. All patients had a history of recent cerebral embolism (mean 6 days, range 5-15 days) and all had a history of atrial fibrillation (duration 5-10 years). Catheter-directed thrombolysis started a few hours (mean 6.2 h; range 3-10 h) after the onset of arterial embolism. Two 5 mg boluses of rt-PA were injected into the proximal clot through a 5 F end-hole catheter and, subsequently, two additional boluses of 5 mg rt-PA were injected into the emboli. In patients with residual emboli, infusion with rt-PA (1 mg/h) was continued. Percutaneous transluminal angioplasty was performed in three patients, and a stent was deployed in one patient. Results: Technical success was achieved in all patients. Clinical success rate was 87.5% (7/8). The one clinical failure was secondary to chronic occlusion of outflow runoff vessels. The mean duration of continuous rt-PA infusion was 3.6 h, the mean total dose of rt-PA administered was 23.6 mg (range 20-28 mg). There was no significant change in stroke scale scores during thrombolysis and no intracerebral haemorrhage was found at computed tomography (CT) after thrombolysis. Minor complications included haematomata at puncture sites (6/8), bleeding around the vascular sheath (2/8), and haematuria (1/8). During the follow-up period of 3-6 months, one patient suffered from recurrent cerebral embolism and died. Conclusions: Catheter-directed thrombolysis with rt-PA is an option for acute lower extremity arterial embolism in patients with recent cerebral embolism and a history of

  3. Can catheter-directed thrombolysis be applied to acute lower extremity artery embolism after recent cerebral embolism from atrial fibrillation?

    Energy Technology Data Exchange (ETDEWEB)

    Si, T.-G. [Department of interventional treatment, Tianjin medical university cancer Hospital and Institution, Tianjin (China); Guo, Z. [Department of interventional treatment, Tianjin medical university cancer Hospital and Institution, Tianjin (China)], E-mail: dr.guozhi@yahoo.com.cn; Hao, X.-S. [Department of interventional treatment, Tianjin medical university cancer Hospital and Institution, Tianjin (China)

    2008-10-15

    Purpose: To assess the feasibility and efficacy of catheter-directed thrombolysis with recombinant tissue plasminogen activator (rt-PA) for acute limb embolism in patients with recent cerebral embolism due to atrial fibrillation. Materials and methods: Eight patients (six men, two women; mean age 63.5 years) with acute embolic occlusion of two left common iliac arteries, four femoral arteries (three left; one right), and two right popliteal arteries were treated. All patients had a history of recent cerebral embolism (mean 6 days, range 5-15 days) and all had a history of atrial fibrillation (duration 5-10 years). Catheter-directed thrombolysis started a few hours (mean 6.2 h; range 3-10 h) after the onset of arterial embolism. Two 5 mg boluses of rt-PA were injected into the proximal clot through a 5 F end-hole catheter and, subsequently, two additional boluses of 5 mg rt-PA were injected into the emboli. In patients with residual emboli, infusion with rt-PA (1 mg/h) was continued. Percutaneous transluminal angioplasty was performed in three patients, and a stent was deployed in one patient. Results: Technical success was achieved in all patients. Clinical success rate was 87.5% (7/8). The one clinical failure was secondary to chronic occlusion of outflow runoff vessels. The mean duration of continuous rt-PA infusion was 3.6 h, the mean total dose of rt-PA administered was 23.6 mg (range 20-28 mg). There was no significant change in stroke scale scores during thrombolysis and no intracerebral haemorrhage was found at computed tomography (CT) after thrombolysis. Minor complications included haematomata at puncture sites (6/8), bleeding around the vascular sheath (2/8), and haematuria (1/8). During the follow-up period of 3-6 months, one patient suffered from recurrent cerebral embolism and died. Conclusions: Catheter-directed thrombolysis with rt-PA is an option for acute lower extremity arterial embolism in patients with recent cerebral embolism and a history of

  4. Contrast-enhanced power Doppler US in the characterization of renal masses; Power Doppler con mezzo di contrasto nella caratterizzazione delle masse renali

    Energy Technology Data Exchange (ETDEWEB)

    Ascenti, G.; Zimbaro, G.; Mazziotti, S.; Visalli, C.; Racchiusa, S.; Vinci, S.; Scribano, E. [Messina Univ., Messina (Italy). Ist. di Scienze Radiologiche

    2000-09-01

    Purpose of this work is to report the results of a prospective study investigating the potentials of contrast-enhanced power Doppler in the diagnosis of expansive renal lesions. From 1997 to October 30, 1999, it was studied the case of 59 expansive renal lesions (28 malignant, 31 benign) in 48 patients (mean age 55 years, range 10-79) with power Doppler US before and after the administration of an echo-enhancing agent (Levovist, Schering AG, Berlin Germany). Were found 5 patterns of vascular architecture of the lesions, both before and after contrast agent administration, following the classification by Jinzaki e Coll. Power Doppler US showed vascular structures in 34 patients. The administration of Levovist revealed vessels in 12/25 lesions which had none at baseline studies and in 6 cases vascularity was particularly evident. Color signals were enhanced in all the 34 vascularized lesions, which allowed better definition of vascular patterns. The characterization of vascular patterns with baseline power Doppler US helped improve diagnostic accuracy compared to gray-scale US (58% versus 32%) for hyperechoic lesions, complex cysts and pseudomasses. Independent of contrast agent administration, the integration of gray-scale and power Doppler modes increased diagnostic accuracy even further (76% correct diagnoses). In our series, the US contrast agent did not increase the diagnostic accuracy of power Doppler in the differential diagnosis of hyperechoic renal lesions; conversely, Levovist can be advantageous for the characterization of suspected pseudomasses and complex cysts. [Italian] Scopo di questo articolo e' quello di riportare i risultati di uno studio prospettico finalizzato ad individuare le potenzialita' del power Doppler con mdc ecografico nella caratterizzazione delle lesioni espansive del rene. Dal 1997 al 30 ottobre 1999 sono state studiate 59 lesioni renali (28 maligne, 31 benigne) in 48 pazienti (eta' media 55 anni, intervallo 10

  5. Animal models of cerebral arterial gas embolism

    NARCIS (Netherlands)

    Weenink, Robert P.; Hollmann, Markus W.; van Hulst, Robert A.

    2012-01-01

    Cerebral arterial gas embolism is a dreaded complication of diving and invasive medical procedures. Many different animal models have been used in research on cerebral arterial gas embolism. This review provides an overview of the most important characteristics of these animal models. The properties

  6. The selective external carotid arterial embolization treatment of uncontrollable epistaxis

    International Nuclear Information System (INIS)

    Yao Qunli; Liu Yizhi; Ni Caifang

    2004-01-01

    Objective: To evaluate the selective external carotid arterial embolization of uncontrollable epistaxis. Methods: 27 procedures of super-selective external carotid arterial embolization were performed with absorbable gelfoam by using Seldinger's method in 26 cases with uncontrollable epistaxis. Results: 27 procedures of super-selective intra-arterial embolization of uncontrollable epistaxis were all successful without any serious complication. Conclusions: Selective external carotid arterial embolization is safe, effective and successful in the treatment of severe epistaxis. (authors)

  7. Inferior phrenic artery embolization in the treatment of hepatic neoplasms

    International Nuclear Information System (INIS)

    Duprat, G.; Charnsangavej, C.; Wallace, S.; Carrasco, C.H.

    1988-01-01

    Twenty-nine inferior phrenic artery embolizations were performed in 20 patients with primary or metastatic hepatic neoplasms. All patients had interruption of their hepatic arteries by previous infusion of chemotherapy, hepatic arterial embolization or surgical ligation. In one patient, bilateral pleural effusions developed following embolization of the inferior phrenic artery. No other severe complications occurred. Inferior phrenic artery embolization is a safe procedure and permits the continuation of transcatheter treatment of hepatic neoplasms. (orig.)

  8. Inferior phrenic artery embolization in the treatment of hepatic neoplasms

    Energy Technology Data Exchange (ETDEWEB)

    Duprat, G.; Charnsangavej, C.; Wallace, S.; Carrasco, C.H.

    Twenty-nine inferior phrenic artery embolizations were performed in 20 patients with primary or metastatic hepatic neoplasms. All patients had interruption of their hepatic arteries by previous infusion of chemotherapy, hepatic arterial embolization or surgical ligation. In one patient, bilateral pleural effusions developed following embolization of the inferior phrenic artery. No other severe complications occurred. Inferior phrenic artery embolization is a safe procedure and permits the continuation of transcatheter treatment of hepatic neoplasms.

  9. Joint angle and Doppler frequency estimation of coherent targets in monostatic MIMO radar

    Science.gov (United States)

    Cao, Renzheng; Zhang, Xiaofei

    2015-05-01

    This paper discusses the problem of joint direction of arrival (DOA) and Doppler frequency estimation of coherent targets in a monostatic multiple-input multiple-output radar. In the proposed algorithm, we perform a reduced dimension (RD) transformation on the received signal first and then use forward spatial smoothing (FSS) technique to decorrelate the coherence and obtain joint estimation of DOA and Doppler frequency by exploiting the estimation of signal parameters via rotational invariance techniques (ESPRIT) algorithm. The joint estimated parameters of the proposed RD-FSS-ESPRIT are automatically paired. Compared with the conventional FSS-ESPRIT algorithm, our RD-FSS-ESPRIT algorithm has much lower complexity and better estimation performance of both DOA and frequency. The variance of the estimation error and the Cramer-Rao Bound of the DOA and frequency estimation are derived. Simulation results show the effectiveness and improvement of our algorithm.

  10. Microembolus Detection by Transcranial Doppler Sonography: Review of the Literature

    Directory of Open Access Journals (Sweden)

    Vlasta Vuković-Cvetković

    2012-01-01

    Full Text Available Transcranial Doppler can detect microembolic signals which are characterized by unidirectional high intensity increase, short duration, random occurrence, and a “whistling” sound. Microembolic signals have been detected in a number of clinical settings: carotid artery stenosis, aortic arch plaques, atrial fibrillation, myocardial infarction, prosthetic heart valves, patent foramen ovale, valvular stenosis, during invasive procedures (angiography, percutaneous transluminal angioplasty, surgery (carotid, cardiopulmonary bypass, orthopedic, and in certain systemic diseases. Microembolic signals are frequent in large artery disease, less commonly detected in cardioembolic stroke, and infrequent in lacunar stroke. This article provides an overview about the current state of technical and clinical aspects of microembolus detection.

  11. Partial thyroid arterial embolization for the treatment of hyperthyroidism

    International Nuclear Information System (INIS)

    Brzozowski, Krzysztof; Piasecki, Piotr; Zięcina, Piotr; Frankowska, Emilia; Jaroszuk, Andrzej; Kamiński, Grzegorz; Bogusławska-Walecka, Romana

    2012-01-01

    Background: Hyperactive thyroid gland in patients that are unable to tolerate or accept standard therapy is a common clinical problem. Aim of the study was to evaluate effectiveness of partial thyroid arterial embolization in patients with hyperthyroidism. Material/methods: From May 2004 to November 2005 partial thyroid gland embolization was performed in 15 patients. Mean thyroid gland volume was 162 ml. Embolization of one to three thyriod arteries was performed with the mixture of Histoacryl and Lipiodol. Selective angiography was performed after embolization to ensure that the targeted arteries were completely occluded. Follow-up study covered 12 patients. Results: The embolization procedure was well tolerated by all patients. Three days after embolization fT3 and fT4 levels were higher than before the procedure. Further laboratory tests showed quick reversal to near-normal or normal levels of thyroid hormones. 12 weeks follow-up showed: normal serum levels of fT3, fT4 and TSH in 9 of 12 patients (75%), hyperthyroidism in 3 of 12 patients (25%), goiter volume reduction of approximately 32% of its original volume (from 13 to 76.3%), mean thyroid gland volume of 94 ml. One year after embolization 7 of 12 patients required thyreostatic drugs. At two and four years follow-up thyreostatics doses were significantly lower and thyroid tissue was fibrotic. Conclusions: Based on our results the treatment of the thyroid gland goiters using arterial thyroid gland partial embolization may be offered as an effective alternative for patients who will not or cannot accept standard therapy.

  12. Arterial embolization for the treatment of hemoptysis

    International Nuclear Information System (INIS)

    Wang Yaoheng; Xiao Enhua

    2009-01-01

    Hemoptysis is a life-threatening clinical emergency. Many diseases can cause hemoptysis and the blood vessels supplying the bleeding site are complicated and varied. Using endovascular embolization to treat hemoptysis has many advantages. It is safe to apply this technique in a great variety of indications with less contraindications. Besides,this technique is minimally-invasive and takes hemostatic effect immediately with less complications. Therefore, endovascular embolization has become the therapy of first choice for hemoptysis. This paper aims to make a comprehensive review in the respects of embolic materials, technical points, short-term and long-term effectiveness and related complications, etc.. (authors)

  13. Doppler evaluation of valvular stenosis

    International Nuclear Information System (INIS)

    Kisslo, J.; Krafchek, J.; Adams, D.; Mark, D.B.

    1986-01-01

    One of the reasons why use of Doppler echocardiography is growing rapidly is because of its utility in detecting the presence of valvular stenosis and in estimating its severity. Detection of the presence of stenotic valvular heart disease using Doppler echocardiography was originally described over 10 years ago. It has been demonstrated that Doppler blood velocity data could be used to estimate the severity of a stenotic lesion. This chapter discusses the evaluation of valvular stenois using Doppler

  14. Uterine artery embolization for adenomyosis without fibroids

    Energy Technology Data Exchange (ETDEWEB)

    Kim, M.D. E-mail: mdkim@cha.ac.kr; Won, J.W.; Lee, D.Y.; Ahn, C.-S

    2004-06-01

    AIM: To evaluate the potential usefulness of transcatheter uterine artery embolization as a treatment for symptomatic adenomyosis in patients without uterine fibroids. MATERIALS AND METHODS: Uterine artery embolization using polyvinyl alcohol particles sized 250-710 mm was performed in 43 patients (mean; 40.3 years, range; 31-52 years) with dysmenorrhoea, menorrhagia, or bulk-related symptoms (pelvic heaviness, urinary frequency) due to adenomyosis without fibroids. All patients underwent pre-procedural and 3.5 months (range 1-8 months) follow-up magnetic resonance imaging (MRI) with contrast enhancement. Clinical symptoms were also assessed at the time of MRI before and after embolization. RESULTS: Significant improvement of dysmenorrhoea (95.2%) and menorrhagia (95.0%) was reported in most patients. Contrast-enhanced MRI revealed non-enhancing areas suggesting coagulation necrosis of adenomyosis in 31 patients (72.1%), decreased size without necrosis in 11 patients (25.6%), and no change in one patient (2.3%). The mean volume reduction of the uteri after uterine artery embolization was 32.5% (from 321.7{+-}142.9 to 216.7{+-}130.1 cm{sup 3}). CONCLUSION: Transcatheter uterine artery embolization is an effective therapy for the treatment of symptomatic pure adenomyosis, and may be a valuable alternative to hysterectomy.

  15. Uterine artery embolization for adenomyosis without fibroids

    International Nuclear Information System (INIS)

    Kim, M.D.; Won, J.W.; Lee, D.Y.; Ahn, C.-S.

    2004-01-01

    AIM: To evaluate the potential usefulness of transcatheter uterine artery embolization as a treatment for symptomatic adenomyosis in patients without uterine fibroids. MATERIALS AND METHODS: Uterine artery embolization using polyvinyl alcohol particles sized 250-710 mm was performed in 43 patients (mean; 40.3 years, range; 31-52 years) with dysmenorrhoea, menorrhagia, or bulk-related symptoms (pelvic heaviness, urinary frequency) due to adenomyosis without fibroids. All patients underwent pre-procedural and 3.5 months (range 1-8 months) follow-up magnetic resonance imaging (MRI) with contrast enhancement. Clinical symptoms were also assessed at the time of MRI before and after embolization. RESULTS: Significant improvement of dysmenorrhoea (95.2%) and menorrhagia (95.0%) was reported in most patients. Contrast-enhanced MRI revealed non-enhancing areas suggesting coagulation necrosis of adenomyosis in 31 patients (72.1%), decreased size without necrosis in 11 patients (25.6%), and no change in one patient (2.3%). The mean volume reduction of the uteri after uterine artery embolization was 32.5% (from 321.7±142.9 to 216.7±130.1 cm 3 ). CONCLUSION: Transcatheter uterine artery embolization is an effective therapy for the treatment of symptomatic pure adenomyosis, and may be a valuable alternative to hysterectomy

  16. Improvement of vertical velocity statistics measured by a Doppler lidar through comparison with sonic anemometer observations

    Science.gov (United States)

    Bonin, Timothy A.; Newman, Jennifer F.; Klein, Petra M.; Chilson, Phillip B.; Wharton, Sonia

    2016-12-01

    Since turbulence measurements from Doppler lidars are being increasingly used within wind energy and boundary-layer meteorology, it is important to assess and improve the accuracy of these observations. While turbulent quantities are measured by Doppler lidars in several different ways, the simplest and most frequently used statistic is vertical velocity variance (w'2) from zenith stares. However, the competing effects of signal noise and resolution volume limitations, which respectively increase and decrease w'2, reduce the accuracy of these measurements. Herein, an established method that utilises the autocovariance of the signal to remove noise is evaluated and its skill in correcting for volume-averaging effects in the calculation of w'2 is also assessed. Additionally, this autocovariance technique is further refined by defining the amount of lag time to use for the most accurate estimates of w'2. Through comparison of observations from two Doppler lidars and sonic anemometers on a 300 m tower, the autocovariance technique is shown to generally improve estimates of w'2. After the autocovariance technique is applied, values of w'2 from the Doppler lidars are generally in close agreement (R2 ≈ 0.95 - 0.98) with those calculated from sonic anemometer measurements.

  17. The Cognitive Doppler.

    Science.gov (United States)

    Kozoil, Micah E.

    1989-01-01

    Discusses the learning needs of students in the concrete operational stage in mathematics. Identifies the phenomenon of reduced cognitive performance in an out-of-class environment as the "Cognitive Doppler." Suggests methods of reducing the pronounced effects of the Cognitive Doppler by capitalizing on the students' ability to memorize…

  18. Doppler ultrasound exam of an arm or leg

    Science.gov (United States)

    Peripheral vascular disease - Doppler; PVD - Doppler; PAD - Doppler; Blockage of leg arteries - Doppler; Intermittent claudication - Doppler; Arterial insufficiency of the legs - Doppler; Leg pain and ...

  19. DSA diagnosis and embolization therapy of gastrointestinal hemorrhage

    International Nuclear Information System (INIS)

    Zhou Ruming; Qiu Shuibo; Liu Minhua; Yang Huijun; Zhuang Shaoyu

    2006-01-01

    Objective: To evaluate the effect of digital subtraction angiography and transcatheter embolization for gastrointestinal hemorrhage. Methods: Twenty patients with gastrointestinal hemorrhage received celiac arteries, superior mesenteric arteries and inferior mesenteric arteries angiography. Superselective angiography were performed when the arteries were suspicious by clinic or angiogrraphy. Ten patients with definite diagnosis and manifestation of hemorrhagic arteries by angiography were embolized after superselective catheterization with gelfoam particles, gelfoam particles and coils, polyvinyl alcohol particles. Results: The positive signs were observed in 13 cases. The DSA features including contrast medium accumulation in the gastrointestinal tract outside vascular, aneurysm, tumorous vascularization and staining, artery affect and local vasospasm. The bleedings were stopped immediately in 8 patients. No rebleeding and intestinal ischaemia or necrosis were observed in 30 days. One patient died in the second day after embolization from multiple organ failure. Rebleeding occurred 3 days after embolization in another patient, and was recovered after surgical operation. Conclusion: DSA is more effective for the diagnosis of gastrointestinal vascular malformation and tumors complicating acute bleeding. Transcatheter embolization is effective and safe to control the hemorrhage. (authors)

  20. MDCT angiography and transcatheter embolization in management ...

    African Journals Online (AJOL)

    Hassan Abdelsalam

    2015-12-18

    Dec 18, 2015 ... 14 patients did not have a MDCT and proceeded straight to angiography;. 6 of them showed active bleeding on angiography. Conclusion: MDCT is an excellent technique before angiography and embolization in cases with acute gastrointestinal bleeding. Transcatheter embolization is an effective tool for ...

  1. Amniotic fluid embolism and isolated coagulopathy: atypical presentation of amniotic fluid embolism.

    LENUS (Irish Health Repository)

    Awad, I T

    2012-02-03

    A 41-year-old multigravida presented at 32 weeks of gestation with polyhydramnios and an anencephalic fetus. Abnormal bleeding as a result of disseminated intravascular coagulation complicated an emergency Caesarean section for severe abdominal pain thought to be due to uterine rupture. Massive transfusion with blood products was necessary and the abdomen packed to control bleeding. The patient was transferred to the intensive care unit where she made a slow but complete recovery. Amniotic fluid embolism with atypical presentation of isolated coagulopathy is the likely diagnosis in this case. The case serves to demonstrate that amniotic fluid embolism may present with symptoms and signs other than the classical pattern of dyspnoea, cyanosis and hypotension.

  2. The clinical presentation of pulmonary embolism

    International Nuclear Information System (INIS)

    Otto, A.C.; Dunn, M.; Van der Merwe, B.; Katz, M.

    2004-01-01

    Full text: Introduction: Pulmonary embolism is often misdiagnosed by many clinicians because of confusion with pulmonary infarction. According to present literature, the latter seldomly occurs, thus pleuritic pain and hemoptysis are usually absent. The purpose of our study was to re-evaluate the clinical presentation of pulmonary embolism with specific reference to the presence of pulmonary hypertension and pulmonary infarction. Materials and methods: Ethical committee approval was obtained to study fifteen patients with abnormal lung perfusion and high probability for pulmonary embolism retrospectively. Clinical data will be presented in table format. Appropriate symptoms and signs not mentioned was considered absent. Specific investigations not available was considered not done. Results: Will be displayed in table format. The main findings can be summarized as follows: 1. Dyspnea was present in all the patients; 2. Pleuritic pain and hemoptysis was absent in all the patients; 3. None of the patients had clinical signs of pulmonary hypertension or infarction; 4. The available special investigations confirmed the above mentioned findings. Conclusion: The absence of pulmonary infarction and pulmonary hypertension with submassive pulmonary embolism (<60% of pulmonary vascular bed occluded) was reconfirmed and should be emphasized more in clinical practice. (author)

  3. The selective angiographic diagnosis and endovascular embolization treatment of severe epistaxis

    International Nuclear Information System (INIS)

    Zhang Xiquan; Lu Yonghong; Sun Jinghua; Guo Deqiang; Li Yuzhen; Wei Aihua

    2002-01-01

    Objective: To evaluate selective angiographic diagnosis and embolization of severe epistaxis in 57 cases. Methods: 41 cases with spontaneous haemorrhage, 11 cases with traumatic haemorrhage, 3 cases with haemorrhage of nasopharyngeal fibroangioma, and 2 case with haemorrhage of nasopharyngeal carcinoma were included in the study. Selective angiographic diagnosis and embolization of epistaxis were performed with absorbable gelatin sponge or balloon or spring coil by using Seldinger's method. Results: 59 procedure of angiographic diagnosis and embolization were performed in 57 cases. Both maxillaris internal artery embolization was performed in 6 cases. After embolization, satisfactory results were achieved immediately in 55 cases. After 6 months to 2 years' follow-up, no haemorrhage recurred. In 4 cases with traumatic haemorrhage in the face, simple maxillaris internal artery embolization was performed in 2 cases. Conclusion: Selective angiographic diagnosis and embolization are safe, effective, and successful method of choices in the treatment of severe epistaxis

  4. [Doppler ultrasound evaluation of aortic insufficiency using half-pressure time. Absence of arterial rigidity influence].

    Science.gov (United States)

    Kalotka-Bratek, H; Drobinski, G; Klimczak, K; Busquet, P; Fraysse, J B; Bejean-Lebuisson, A; Grosgogeat, Y

    1989-02-01

    In 20 patients with pure aortic regurgitation we studied the relationship between the severity of regurgitation, as assessed haemodynamically by the percentage of leakage (%L), and the half-pressure (T 1/2 P) and half-velocity (T 1/2 V) times, as obtained from doppler aortic blood velocity curves, taking into account the rigidity of the systemic vascular circuit characterized by the pressure wave propagation velocity (PWPV). The systemic arterial circuit was supple in 14 patients (PWPV less than 7.5 m/sec) and rigid in 6 patients (PWPV greater than 7.5 m/sec). The regression slopes between %L and T 1/2 P and between %L and T 1/2 V were calculated with their confidence limits in the 14 patients with supple arteries. The 6 patients with rigid arteries fitted into this nomogram, thus demonstrating that systemic arterial rigidity makes no difference in the relationship between %L and doppler indices. The half-velocity and half-pressure times measured by doppler ultrasound were acquired from a velocity signal directly determined by the aortic regurgitation, without any detectable effect of vascular circuit rigidity. Being equivalent by nature to the signal decrease time constant, they are independent of the absolute protodiastolic value of diastolic pressure gradient or blood flow velocity. For this reason these two doppler parameters are reliable to evaluate the severity of aortic regurgitation.

  5. Detection of a stochastic background of gravitational radiation by the Doppler tracking of spacecraft

    International Nuclear Information System (INIS)

    Mashhoon, B.; Grishchuk, L.P.

    1980-01-01

    The possibility of detection of an isotropic background gravitational radiation of a stochastic nature by the method of Doppler tracking of spacecraft is considered. In the geometrical optics limit, the general formula for the frequency shift of an electromagnetic signal in the gravitational radiation field is discussed, and it is shown to be gauge (or rather Lie) independent. A detailed examination of the propagation of a free electromagnetic wave in a gravitational radiation field shows that no resonance phenomena can be expected. Thus, the results valid in the geometrical optics limit are also approximately valid for any gravitational radiation spectrum dominated by wavelengths large compared to that of the electromagnetic signal. The ''Doppler noise'' due to a stochastic background is evaluated, and it is shown to depend on the total energy density of the background and a parameter that is a characteristic of the aradiation spectrum and the detection system used. A background gravitational radiation with an energy density comparable to the electromagnetic (approx.3 K) background and a spectrum dominated by wavelengths > or approx. =1 AU may be detectable in the near future by the Doppler tracking of interplanetary spacecraft

  6. Percutaneous N-Butyl cyanoacrylate embolization of a pancreatic pseudoaneurysm after failed attempts of transcatheter embolization

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ri Hyeon; Yoo, Roh Eul; Kim, Hyo Cheol [Seoul National University Medical Research Center, and Clinical Research Institute, Seoul National University Hospital, Seoul (Korea, Republic of)

    2014-10-15

    One common complication after major pancreatic surgery is bleeding. Herein we describe a case of pancreatic pseudoaneurysm which developed after pylorous preserving pancreaticoduodenectomy for common bile duct cancer. Three attempts of transcatheter embolization failed since feeders to the pseudoaneurysm had unfavorable anatomy. Direct percutaneous N-butyl cyanoacrylate injection was performed under fluoroscopy-guidance and the pseudoaneurysm was successfully treated. Percutaneous fluoroscopy-guided direct N-butyl cyanoacrylate injection may be a useful alternative when selective transcatheter embolization fails or is technically challenging.

  7. Radio Science from an Optical Communications Signal

    Science.gov (United States)

    Moision, Bruce; Asmar, Sami; Oudrhiri, Kamal

    2013-01-01

    NASA is currently developing the capability to deploy deep space optical communications links. This creates the opportunity to utilize the optical link to obtain range, doppler, and signal intensity estimates. These may, in turn, be used to complement or extend the capabilities of current radio science. In this paper we illustrate the achievable precision in estimating range, doppler, and received signal intensity of an non-coherent optical link (the current state-of-the-art for a deep-space link). We provide a joint estimation algorithm with performance close to the bound. We draw comparisons to estimates based on a coherent radio frequency signal, illustrating that large gains in either precision or observation time are possible with an optical link.

  8. Pathophysiology of spontaneous venous gas embolism

    Science.gov (United States)

    Lambertsen, C. J.; Albertine, K. H.; Pisarello, J. B.; Flores, N. D.

    1991-01-01

    The use of controllable degrees and durations of continuous isobaric counterdiffusion venous gas embolism to investigate effects of venous gas embolism upon blood, cardiovascular, and respiratory gas exchange function, as well as pathological effects upon the lung and its microcirculation is discussed. Use of N2O/He counterdiffusion permitted performance of the pathophysiologic and pulmonary microstructural effects at one ATA without hyperbaric or hypobaric exposures.

  9. Bayesian Classifier for Medical Data from Doppler Unit

    Directory of Open Access Journals (Sweden)

    J. Málek

    2006-01-01

    Full Text Available Nowadays, hand-held ultrasonic Doppler units (probes are often used for noninvasive screening of atherosclerosis in the arteries of the lower limbs. The mean velocity of blood flow in time and blood pressures are measured on several positions on each lower limb. By listening to the acoustic signal generated by the device or by reading the signal displayed on screen, a specialist can detect peripheral arterial disease (PAD.This project aims to design software that will be able to analyze data from such a device and classify it into several diagnostic classes. At the Department of Functional Diagnostics at the Regional Hospital in Liberec a database of several hundreds signals was collected. In cooperation with the specialist, the signals were manually classified into four classes. For each class, selected signal features were extracted and then used for training a Bayesian classifier. Another set of signals was used for evaluating and optimizing the parameters of the classifier. Slightly above 84 % of successfully recognized diagnostic states, was recently achieved on the test data. 

  10. Carefully calibrated microsphere embolization of tumors and AVMs

    International Nuclear Information System (INIS)

    Laurent, A.; Wassef, M.; Beaujeux, R.; Hodes, J.E.; Gobin, P.Y.; Schenker, C.; Bouchez, B.; Brette, M.D.; Aymard, A.; Cophignon, J.; Merland, J.J.

    1990-01-01

    This paper evaluates the efficacy of a new type of uniformly calibrated microsphere for embolization of various pathologies. Fourteen tumors (five intracranial, eight extracranial, one spine), and seven facial arteriovenous malformations (AVMs) (nose, lip, and scalp) were embolized preoperatively. Angiographic, surgical devascularization, and histologic findings were correlated with the spheres' size. In the second part of the study, spinal cord (n = 22) and intracerbral (n = 14) AVM, Weber-Osler-Rendu disease (n = 2), and epistaxis (n = 1) embolization was angiographically evaluated

  11. METABOLIC DISORDERS AND PULMONARY EMBOLISM

    Directory of Open Access Journals (Sweden)

    O. Ya. Vasiltseva

    2015-01-01

    Full Text Available The purpose of the study. To examine the contribution of diabetes and obesity in the development of pulmonary embolism on the based data of the Register of new hospital of pulmonary embolism (PE in hospitals inTomsk(2003–2012. Material and Methods. The medical history and records of autopsies of patients treated in hospitals in the city ofTomsk, 2003–2012, and anatomopathological and/or instrumental examination revealed pulmonary embolism have been subjected to studies. We used the classification of diabetes mellitus proposed by the WHO in1999 inour work, because the register including data (2003–2012. The degree of obesity was assessed according to WHO classification (1997. Statistical analysis of the results was carried out with the help of software for computer Statistica for Windows, version 8.0. The Shapiro–Wilk and Kolmogorov–Smirnov tests was used to determine the nature of the distribution of the data. The ho mogeneity of the population variance was assessed using Fisher's exact test andLeuventest. The Mann– Whitney test was used when comparing two independent samples to determine the significance of differences. The analysis was conducted by means of qualitative characteristics contingency tables using Pearson χ 2 . The odds ratio was calculated to assess the association between a specific outcome and the risk. Data are presented as M ± SD factor. The significance level of p for all procedures used by the statistical analysis was taken to be 0.05. It was considered statistically significant level of p < 0.05. The results of the study. In intermediate urbanized city ofWestern Siberia,Tomsk, established register of hospital pulmonary embolism (2003–2012. The register included 751patients whose in vivo and / or postmortem revealed pulmonary embolism (PE. The data histories and autopsy reports was analyze. The type 2diabetes was diagnosed in 205 patients. The type 2 diabetes moderate had 29%. Diabetes severe suffer 82

  12. Pulmonary embolism and pelvic-lower limb deep venous thrombosis: initial experience with magnetic resonance angiography

    International Nuclear Information System (INIS)

    Jiang Tao; Qiu Chuanya; Jiang Hua

    2004-01-01

    Objective: To evaluate the usefulness of combined three-dimensional (3D) and two-dimensional (2D) contrast enhanced magnetic resonance angiography (CE-MRA) for checking the thrombus embolism of different positions within single examination on the pulmonary artery and pelvic-lower limb deep veins. Methods: Fifteen patients with suspected pulmonary embolism and pelvic-lower limb deep venous thrombosis (DVT) were evaluate with combined 3D MRA and 2D CE-MRA. 3D spoiled gradient-recalled-echo bolus chase MR angiograms were obtained in four stations from the pulmonary artery to the ankle. Thereafter, 3D CE MRA was reversely scanned from the ankle to the pelvic. 2D contrast-enhanced MRI was obtained in pelvis, thigh, and calf. Pulmonary CT angiography (CTA) and/or DSA were performed in 15 patients, and duplex ultrasonography of lower-limb vein was performed in 12 patients. Results: Of the 15 cases, acceptable imaging of pulmonary vessel was acquired with 3D CE-MRA in 12 cases. The signal intensity was lower in the deep iliac vein and lower extremities than that in the artery, but vein frame was distinct after post processing. The artery and deep vein were clearly revealed with contrast enhanced FSPGR sequence in 15 cases. 3D CD-MRA imaging disclosed pulmonary embolism in fourteen patients and pelvis-lower limb DVT with multi-place involvement in nine patients. 2D contrast-enhanced MR imaging proved DVT in pelvis-lower limb. 2D contrast-enhanced FSPGR sequence was a complementation of 3D CE-MRA and it had larger scan field. Thrombus presented as low signals and eccentral or intraluminal filling defect. Local caliber of vein thrombus in 6 cases was evidently broadened. Conclusion: Within only one MR examination procedure, it is capable of examining the pulmonary embolism and DVT of pelvis-lower limb with combined 3D MRA and 2D contrast enhanced MR. The results are promising as a non-invasion 'on-stop shopping' tool in the evaluation of thromboembolic disease

  13. Laser Doppler perfusion imaging with a complimentary metal oxide semiconductor image sensor

    NARCIS (Netherlands)

    Serov, Alexander; Steenbergen, Wiendelt; de Mul, F.F.M.

    2002-01-01

    We utilized a complimentary metal oxide semiconductor video camera for fast f low imaging with the laser Doppler technique. A single sensor is used for both observation of the area of interest and measurements of the interference signal caused by dynamic light scattering from moving particles inside

  14. Spacecraft Doppler tracking with possible violations of LLI and LPI: a theoretical modeling

    International Nuclear Information System (INIS)

    Deng Xue-Mei; Xie Yi

    2014-01-01

    Currently two-way and three-way spacecraft Doppler tracking techniques are widely used and play important roles in control and navigation of deep space missions. Starting from a one-way Doppler model, we extend the theory to two-way and three-way Doppler models by making them include possible violations of the local Lorentz invariance (LLI) and the local position invariance (LPI) in order to test the Einstein equivalence principle, which is the cornerstone of general relativity and all other metric theories of gravity. After taking the finite speed of light into account, which is the so-called light time solution (LTS), we make these models depend on the time of reception of the signal only for practical convenience. We find that possible violations of LLI and LPI cannot affect two-way Doppler tracking under a linear approximation of LTS, although this approximation is sufficiently good for most cases in the solar system. We also show that, in three-way Doppler tracking, possible violations of LLI and LPI are only associated with two stations, which suggests that it is better to set the stations at places with significant differences in velocities and gravitational potentials to obtain a high level of sensitivity for the tests

  15. Dynamic Gesture Recognition with a Terahertz Radar Based on Range Profile Sequences and Doppler Signatures.

    Science.gov (United States)

    Zhou, Zhi; Cao, Zongjie; Pi, Yiming

    2017-12-21

    The frequency of terahertz radar ranges from 0.1 THz to 10 THz, which is higher than that of microwaves. Multi-modal signals, including high-resolution range profile (HRRP) and Doppler signatures, can be acquired by the terahertz radar system. These two kinds of information are commonly used in automatic target recognition; however, dynamic gesture recognition is rarely discussed in the terahertz regime. In this paper, a dynamic gesture recognition system using a terahertz radar is proposed, based on multi-modal signals. The HRRP sequences and Doppler signatures were first achieved from the radar echoes. Considering the electromagnetic scattering characteristics, a feature extraction model is designed using location parameter estimation of scattering centers. Dynamic Time Warping (DTW) extended to multi-modal signals is used to accomplish the classifications. Ten types of gesture signals, collected from a terahertz radar, are applied to validate the analysis and the recognition system. The results of the experiment indicate that the recognition rate reaches more than 91%. This research verifies the potential applications of dynamic gesture recognition using a terahertz radar.

  16. Doppler flowmetry in preeclampsia.

    Science.gov (United States)

    Zahumensky, J

    2009-01-01

    The purpose of this study was to summarize the new published data on the Doppler flowmetry in preeclampsia. We summarize the new published data on the Doppler flowmetry in uteroplacental, fetoplacental and fetal circulation in preeclampsia. The present review summarized the results of clinical research on the Doppler flowmetry in the screening of risk of preclampsia, in the diagnosis of preclampsia and in the fetal risk in preclampsia (Ref. 19). Full Text (Free, PDF) www.bmj.sk.

  17. TEACHING PHYSICS: An experiment to demonstrate the principles and processes involved in medical Doppler ultrasound

    Science.gov (United States)

    Andrews, D. G. H.

    2000-09-01

    Doppler ultrasound is widely used in medicine for measuring blood velocity. This paper describes an experiment illustrating the principles of medical Doppler ultrasound. It is designed with A-level/undergraduate physics students in mind. Ultrasound is transmitted in air and reflected from a moving target. The return signal is processed using a series of modules, so that students can discover for themselves how each stage in the instrument works. They can also obtain a quantitative value of the speed of the target.

  18. The serpentine mitral valve and cerebral embolism

    Directory of Open Access Journals (Sweden)

    Ker James

    2011-02-01

    Full Text Available Abstract Valvular strands, well-delineated filiform masses, attached to cardiac valve edges are associated with cerebral embolism and stroke. Strokes, caused by emboli from valvular strands, tend to occur among younger persons. In this case report a valvular strand, giving a peculiar serpentine appearance to the mitral valve is described. This mitral valvular strand was the only explanation for an episode of cerebral embolism, presenting with a transient right sided hemiparesis. It is proposed that a randomized study involving combined treatment with aspirin and clopidogrel is warranted in young patients with valvular strands, presenting with a first episode of cerebral embolism.

  19. A feasability study of color flow doppler vectorization for automated blood flow monitoring.

    Science.gov (United States)

    Schorer, R; Badoual, A; Bastide, B; Vandebrouck, A; Licker, M; Sage, D

    2017-12-01

    An ongoing issue in vascular medicine is the measure of the blood flow. Catheterization remains the gold standard measurement method, although non-invasive techniques are an area of intense research. We hereby present a computational method for real-time measurement of the blood flow from color flow Doppler data, with a focus on simplicity and monitoring instead of diagnostics. We then analyze the performance of a proof-of-principle software implementation. We imagined a geometrical model geared towards blood flow computation from a color flow Doppler signal, and we developed a software implementation requiring only a standard diagnostic ultrasound device. Detection performance was evaluated by computing flow and its determinants (flow speed, vessel area, and ultrasound beam angle of incidence) on purposely designed synthetic and phantom-based arterial flow simulations. Flow was appropriately detected in all cases. Errors on synthetic images ranged from nonexistent to substantial depending on experimental conditions. Mean errors on measurements from our phantom flow simulation ranged from 1.2 to 40.2% for angle estimation, and from 3.2 to 25.3% for real-time flow estimation. This study is a proof of concept showing that accurate measurement can be done from automated color flow Doppler signal extraction, providing the industry the opportunity for further optimization using raw ultrasound data.

  20. Transcatheter Arterial Embolization for Primary Postpartum Hemorrhage: Predictive Factors of Need for Embolic Material Conversion of Gelatin Sponge Particles to N-Butyl Cyanoacrylate

    Energy Technology Data Exchange (ETDEWEB)

    Tanahashi, Yukichi; Goshima, Satoshi, E-mail: gossy@par.odn.ne.jp [Gifu University Hospital, Department of Radiology (Japan); Kondo, Hiroshi [Teikyo University School of Medicine, Department of Radiology (Japan); Ando, Tomohiro; Noda, Yoshifumi; Kawada, Hiroshi; Kawai, Nobuyuki [Gifu University Hospital, Department of Radiology (Japan); Kotoku, Junichi [Teikyo University School of Medicine, Department of Radiological Technology, Faculty of Medical Technology (Japan); Furui, Shigeru [Teikyo University School of Medicine, Department of Radiology (Japan); Matsuo, Masayuki [Gifu University Hospital, Department of Radiology (Japan)

    2017-02-15

    PurposeTo identify predictive factors for embolic material conversion to N-butyl cyanoacrylate (NBCA) for the treatment of primary postpartum hemorrhage (PPH) after failed transcatheter arterial embolization (TAE) using gelatin sponge (GS).Materials and MethodsInstitutional review board approval was obtained. We retrospectively studied 62 consecutive women with primary PPH who underwent TAE between January 2006 and March 2015. Five of them were excluded for the following: cardiopulmonary arrest at arrival (n = 1), uterine inversion (n = 1), and hysterectomy after TAE (n = 3). Remaining 57 women (age range, 21–43 years; mean, 32.6 years) comprised study population. TAE was initially performed using GS in all cases and then converted to NBCA after two embolizations using GS with persistent hemodynamic instability or vaginal bleeding. The patients’ background, uterine height, vital signs, laboratory tests, disseminated intravascular coagulation score, and details of procedure were reviewed. Univariate and multivariate analyses were performed to determine factors related to embolic material conversion.ResultsTechnical success rate was 100%. Fourteen patients (25%) needed embolic material conversion to NBCA. Univariate analysis showed that uterine height, systolic blood pressure (sBP), and hemoglobin level were significantly related to embolic material conversion to NBCA (P = 0.029, 0.030, and 0.042). Logistic regression analysis showed that uterine height (odds ratio, 1.37; P = 0.025) and sBP (odds ratio, 0.96; P = 0.003) were associated with embolic material conversion to NBCA.ConclusionUterine height and sBP can be predictive factors for embolic material conversion to NBCA for the treatment of PPH.Level of EvidenceLevel 4, Case Control Study.

  1. Transcatheter Arterial Embolization for Primary Postpartum Hemorrhage: Predictive Factors of Need for Embolic Material Conversion of Gelatin Sponge Particles to N-Butyl Cyanoacrylate

    International Nuclear Information System (INIS)

    Tanahashi, Yukichi; Goshima, Satoshi; Kondo, Hiroshi; Ando, Tomohiro; Noda, Yoshifumi; Kawada, Hiroshi; Kawai, Nobuyuki; Kotoku, Junichi; Furui, Shigeru; Matsuo, Masayuki

    2017-01-01

    PurposeTo identify predictive factors for embolic material conversion to N-butyl cyanoacrylate (NBCA) for the treatment of primary postpartum hemorrhage (PPH) after failed transcatheter arterial embolization (TAE) using gelatin sponge (GS).Materials and MethodsInstitutional review board approval was obtained. We retrospectively studied 62 consecutive women with primary PPH who underwent TAE between January 2006 and March 2015. Five of them were excluded for the following: cardiopulmonary arrest at arrival (n = 1), uterine inversion (n = 1), and hysterectomy after TAE (n = 3). Remaining 57 women (age range, 21–43 years; mean, 32.6 years) comprised study population. TAE was initially performed using GS in all cases and then converted to NBCA after two embolizations using GS with persistent hemodynamic instability or vaginal bleeding. The patients’ background, uterine height, vital signs, laboratory tests, disseminated intravascular coagulation score, and details of procedure were reviewed. Univariate and multivariate analyses were performed to determine factors related to embolic material conversion.ResultsTechnical success rate was 100%. Fourteen patients (25%) needed embolic material conversion to NBCA. Univariate analysis showed that uterine height, systolic blood pressure (sBP), and hemoglobin level were significantly related to embolic material conversion to NBCA (P = 0.029, 0.030, and 0.042). Logistic regression analysis showed that uterine height (odds ratio, 1.37; P = 0.025) and sBP (odds ratio, 0.96; P = 0.003) were associated with embolic material conversion to NBCA.ConclusionUterine height and sBP can be predictive factors for embolic material conversion to NBCA for the treatment of PPH.Level of EvidenceLevel 4, Case Control Study

  2. Evaluation of a liquid embolization agent (Onyx) for transcatheter embolization for renal vascular lesions

    Energy Technology Data Exchange (ETDEWEB)

    Rennert, Janine; Herold, T.; Schreyer, A.G.; Jung, E.M.; Mueller-Wille, R.; Zorger, N. [Inst. fuer Roentgendiagnostik, Klinikum der Univ. Regensburg (Germany); Banas, B.; Feuerbach, S. [Medizinische Klinik, Nephrologie, Univ. Regensburg (Germany); Lenhart, M. [Klinik fuer Diagnostische und Interventionelle Radiologie, Sozialstiftung Bamberg (Germany)

    2009-10-15

    Purpose: to evaluate the therapeutic outcome after endovascular treatment of renal vascular lesions using the liquid embolization agent, Onyx. Materials and methods: between 2004 and 2008 nine patients with renal vascular lesions were treated with transcatheter arterial embolization using Onyx. The renal vascular lesions consisted of 4 AV-fistulas, a pseudoaneurysm, bleeding from a single subsegmental artery, diffuse parenchymal bleeding after trauma, septic embolizations and multiple aneurysms in endocarditis. All patients underwent selective angiography of the renal artery. A dimethyl sulfoxide (DMSO)-compatible microcatheter was used and Onyx was injected. The technical and clinical success rate, examination time and procedure-related complications were documented. Results: the overall technical and clinical success rate was 100%. One patient had to be treated twice due to recurrent bleeding after an accidental puncture with a drainage catheter. No loss of viable renal tissue occurred in 4 cases. In 4 patients mild to moderate parenchyma loss was noted. In one patient having diffuse renal bleeding, occlusion of the main renal artery was performed. No procedure-related complications were noted. The mean examination time was 16.17 min when treating with Onyx alone and 60 min when using a combination of Onyx and coils. Within an average follow-up period of 21 months, no recurrent renal bleeding or recurrent AV-fistulas occurred. Conclusion: Onyx is an effective embolization agent for the treatment of renal vascular lesions. It allows controlled and quick application with low complication rates and a short examination time as a standalone agent or in combination with coils. (orig.)

  3. Doppler radar flowmeter

    Science.gov (United States)

    Petlevich, Walter J.; Sverdrup, Edward F.

    1978-01-01

    A Doppler radar flowmeter comprises a transceiver which produces an audio frequency output related to the Doppler shift in frequency between radio waves backscattered from particulate matter carried in a fluid and the radiated radio waves. A variable gain amplifier and low pass filter are provided for amplifying and filtering the transceiver output. A frequency counter having a variable triggering level is also provided to determine the magnitude of the Doppler shift. A calibration method is disclosed wherein the amplifier gain and frequency counter trigger level are adjusted to achieve plateaus in the output of the frequency counter and thereby allow calibration without the necessity of being able to visually observe the flow.

  4. Pulmonary Cement Embolism following Percutaneous Vertebroplasty

    Directory of Open Access Journals (Sweden)

    Ümran Toru

    2014-01-01

    Full Text Available Percutaneous vertebroplasty is a minimal invasive procedure that is applied for the treatment of osteoporotic vertebral fractures. During vertebroplasty, the leakage of bone cement outside the vertebral body leads to pulmonary cement embolism, which is a serious complication of this procedure. Here we report a 48-year-old man who was admitted to our hospital with dyspnea after percutaneous vertebroplasty and diagnosed as pulmonary cement embolism.

  5. Experimental study of vascular embolization with homemade second-level Copper coil

    International Nuclear Information System (INIS)

    Jiang Hua; Wang Jiaping; Li Yingchun; Tong Yuyun; Yang Qing; Yan Dong; Ding Lili; Yuan Shuguang

    2013-01-01

    Objective: To evaluate the embolic effect of homemade copper coil in rabbits. Methods: Seventeen New Zealand Big Ear Rabbit was included in this study. After conventional anesthesia, one common carotid artery or subclavian artery was embolized with second-level copper coated platinum microcoils (experimental group) through a 3F catheter, and the other common carotid artery or subclavian artery was embolized with second-level platinum micro-coils (control group) as control. Angiography was processed to observe the extent of vascular occlusion 10 min, 30 min, 3 d, 1 w, 2 w, 4 w, 6 w, and 12 w after embolization respectively. The rabbits were sacrificed to observe thrombosis and pathological change of the embolic artery 3 days, 1 w, 2 w, 4 w, 6 w and 12 w after the embolization. Vascular occlusion and thrombosis were compared between experimental group and the control group by using the exact probability method and rank sum test for statistical analysis. Results: Embolization experiment was successfully implemented in 15 of 17 rabbits. Twenty-one second-level copper coated platinum micro-coils were used in the experimental group, while 19 second-level platinum micro-coils were used in the control group. Ten min and 30 min after embolization, angiography showed that vascular embolization effect was not significantly different between the two groups. The vascular embolization effect of the experiment group was superior to control group 3 d, 1, 2, 4, 6 and 12 w after embolization (P < 0.05). Pathological examination showed that there were a lot of blood clots around the copper coil and in the proximal and distal arterial lumen. Only a small amount of blood clots was found around the platinum coil in the control group. For every time point of observation, thrombosis was more severe in the experiment group than that in the control group (P < 0.05). Conclusion: Second-level copper coated coil can be released with 4F catheter to embolize the vessel, showing good physical

  6. Evaluation of factors influencing arterial Doppler waveforms in an in vitro flow phantom

    Energy Technology Data Exchange (ETDEWEB)

    Sung, Chang Kyu [Dept. of Radiology, SMG-SNU Boramae Medical Center, Seoul National University College of Medicine, Seoul (Korea, Republic of); Lee, Kyoung Ho [Dept. of Radiology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam (Korea, Republic of); Kim, Seung Hyup [Dept. of Radiology and the Institute of Radiation Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2017-01-15

    The aim of this study was to investigate factors that influence arterial Doppler waveforms in an in vitro phantom to provide a more accurate and comprehensive explanation of the Doppler signal. A flow model was created using a pulsatile artificial heart, rubber or polyethylene tubes, a water tank, and a glass tube. Spectral Doppler tracings were obtained in multiple combinations of compliance, resistance, and pulse rate. Peak systolic velocity, minimum diastolic velocity, resistive index (RI), pulsatility index, early systolic acceleration time, and acceleration index were measured. On the basis of these measurements, the influences of the variables on the Doppler waveforms were analyzed. With increasing distal resistance, the RI increased in a relatively linear relationship. With increasing proximal resistance, the RI decreased. The pulsus tardus and parvus phenomenon was observed with a small acceleration index in the model with a higher grade of stenosis. An increase in the distal resistance masked the pulsus tardus and parvus phenomenon by increasing the acceleration index. Although this phenomenon occurred independently of compliance, changes in the compliance of proximal or distal tubes caused significant changes in the Doppler waveform. There was a reverse relationship between the RI and the pulse rate. Resistance and compliance can alter the Doppler waveforms independently. The pulse rate is an extrinsic factor that also influences the RI. The compliance and distal resistance, as well as proximal resistance, influence the pulsus tardus and parvus phenomenon.

  7. Infiltrating a thin or single-layer opal with an atomic vapour: Sub-Doppler signals and crystal optics

    Science.gov (United States)

    Moufarej, Elias; Maurin, Isabelle; Zabkov, Ilya; Laliotis, Athanasios; Ballin, Philippe; Klimov, Vasily; Bloch, Daniel

    2014-10-01

    Artificial thin glass opals can be infiltrated with a resonant alkali-metal vapour, providing novel types of hybrid systems. The reflection at the interface between the substrate and the opal yields a resonant signal, which exhibits sub-Doppler structures in linear spectroscopy for a range of oblique incidences. This result is suspected to originate in an effect of the three-dimensional confinement of the vapour in the opal interstices. It is here extended to a situation where the opal is limited to a few- or even a single-layer opal film, which is a kind of bidimensional grating. We have developed a flexible one-dimensional layered optical model, well suited for a Langmuir-Blodgett opal. Once extended to the case of a resonant infiltration, the model reproduces quick variations of the lineshape with incidence angle or polarization. Alternately, for an opal limited to a single layer of identical spheres, a three-dimensional numerical calculation was developed. It predicts crystalline anisotropy, which is demonstrated through diffraction on an empty opal made of a single layer of polystyrene spheres.

  8. Improvement of Renal Functions After Embolization of Renal AVF in a Patient Who had been on Dialysis for 5 Years

    International Nuclear Information System (INIS)

    Ulusoy, Şükrü; Özkan, Gülsüm; Dinç, Hasan; Kaynar, Kübra; Öztürk, Mehmet Halil; Gül, Semih; Kaplan, Safiye Tuba

    2011-01-01

    Recently, ultrasound-guided percutaneous renal biopsy has been used in the diagnosis of renal diseases. Development of an arteriovenous fistula (AVF), which is one of the post-biopsy complications, is not frequently encountered. AVFs are usually asymptomatic; however, they may lead to serious outcomes. We report a 21-year-old patient, who had been on dialysis for 5 years. Due to high blood pressure (230/160 mmHg) and a thrill in the lumbar area detected on physical examination, Doppler examination was performed and a renal AVF was detected. Because the patient had a history of renal biopsy 5 years previously, the fistula was thought to be secondary to the biopsy. After embolization of the AVF, renal functions improved enough to terminate dialysis treatment.

  9. A proposed angioarchitecture grading system related to embolization of brain arteriovenous malformations

    International Nuclear Information System (INIS)

    Fang Bing; Wang Yirong; Li Tielin; Duan Chuanzhi

    2007-01-01

    Objective: To analyze the risk of embolization of brain AVMs, study the angioarchitectural factors affecting the difference of embolization level, and to establish the angioarchitecture grading system for embolization of brain AVMs. Methods: The clinical data, angioarchitectural features, embolism complication and embolism level were retrospectively analyzed. Multivariate statistical analysis was performed to determine if any of the variables was predictive of a poor outcome of embolization (death or permanent neurological deficit), and if any of the variables was predictive of the percentage obliteration achieved by embolization. Based on the above results, we established the angioarchitecture grading system. Results: Endovascular procedures for embolization were performed 324 times in 189 patients during an 11-year period. Embolization was performed using N-butyl cyanoacrylate. In those patients, 3 (1.6%) died and 5(2.6%) had a permanent neurological deficit as a result of the embolization. The AVMs were given a score from 0 to 5 based on the size, number of the first grade feeding artery, and number of the second grade feeding artery. The assigned scores were as follows: nidus size (AVF=0, <30 mm=1, ≥30 mm=2), number of the first grade feeding artery (1=0, 2-3=1, ≥4=2)and number of the second grade feeding artery(≤3=0, ≥4=1). Angiographic results based on percentage obliteration were grouped into four categories: complete, 80%-99%, 50%-79%, and 0%-50%. In the AVMs with angioarchitecture scores 0-1, 24(77.4% )of 31 were fully embolised, with scores of 4-5, none of the 101 were fully embolised, 82(81.2%)were below 50% embolization percentage. The correlation between the angioarchitecture grading system and the embolization percentage was strong (κ= 0.736, P<0.05). Conclusions: The angioarchitecture grading system predicts the embolization percentage perfectly. The lower the scores, the higher the possibility of fully embolization is; the higher the scores

  10. Improving the results of transarterial embolization of type 2 endoleaks with the embolic polymer Onyx.

    Science.gov (United States)

    Wojtaszek, Mikolaj; Wnuk, Emilia; Maciag, Rafal; Solonynko, Bohdan; Korzeniowski, Krzysztof; Lamparski, Krzysztof; Rowinski, Olgierd

    2016-01-01

    Type 2 endoleaks (T2E) occur in 10 to 20% of patients after endovascular abdominal aortic aneurysm repair (EVAR) and remain a significant clinical issue. To evaluate the efficacy and clinical outcomes of transarterial treatment of persistent type II endoleaks after EVAR using the liquid embolic Onyx. From February 2012 to August 2015 transarterial T2E embolization was attempted in 22 patients (21 men, median age: 73, range: 62-88 years). Indications for treatment included an increase in the diameter of the aneurysm sac above 5 mm and a persistent endoleak observed for more than 6 months. Mean time from EVAR to endoleak treatment was 43 months (range: 2-125 months). Primary technical success was achieved in 17 (77.3%) patients and secondary technical success in 81.8%, with 0% in-hospital mortality. The mean procedure time was 95 ±48 min, with an average fluoroscopy time of 54 ±25 min. The mean amount of Onyx used was 7.5 ±6.6 ml. Clinical success was seen in 17/21 patients with follow-up imaging (80.9%). Mean follow-up time was 17 months (range: 3-38 months). Onyx has been shown to effectively stabilize previous aneurysm growth as a result of the T2E in the majority of our patients. Transarterial embolization of T2E can be significantly improved as compared to previously reported results by using liquid embolic polymers such as Onyx.

  11. Transcatheter arterial embolization for congenital renal arteriovenous malformation

    International Nuclear Information System (INIS)

    Zhou Jun; Hu Tingyang; Yuan Jianhua; Yu Wenqiang

    2008-01-01

    Objective: To evaluate the effectiveness of transcatheter arterial embolization for congenital renal arteriovenous malformation. Methods: Seven cases of congenital renal arteriovenous malformation causing gross hematuria were retrospectively studied. All of 7 cases were demonstrated by means of angiography and then the catheter was placed superselectively into the involved arterial end of the malformation undertaking embolization with gelfoam, dehydrated ethanol, coils, etc. Results: All the malformations of the 7 cases were successfully embolized with stoppage of gross hematuria within 24 hours. No serious complications occurred except lumbago, fever, gastrointestinal reaction for one week. There was no recurrence of haematuria and the renal function was also normal in all cases during the follow-up for 36 to 98 months. Conclusions: Transcatheter renal arterial angiography and embolization are the important and effective management for the diagnosis and treatment of congenital renal arteriovenous malformation. (authors)

  12. Differences in time-domain and spectral indexes of skin-surface laser-Doppler signals between controls and breast-cancer subjects.

    Science.gov (United States)

    Hsiu, Hsin; Chen, Chao-Tsung; Hung, Shuo-Hui; Chen, Guan-Zhang; Huang, Yu-Ling

    2018-04-13

    There is an urgent need to improve the early diagnosis of breast cancer. The present study applied spectral and beat-to-beat analyses to laser-Doppler (LDF) data sequences measured on the skin surface on the back of the right hands, with the aim of comparing the different peripheral microcirculatory-blood-flow (MBF) perfusion condition between breast-cancer and control subjects. ECG and LDF signals were obtained simultaneously and noninvasively from 23 breast-cancer patients and 23 age-matched control subjects. Time-domain beat-to-beat indexes and their variability parameters were calculated. Spectral indexes were calculated using the Morlet wavelet transform. The beat-to-beat LDF pulse width and its variability were significantly smaller in cancer patients than in the controls. The energy contributions of endothelial-, neural-, and myogenic-related frequency bands were also significantly smaller in cancer patients. The present study has revealed significant differences in the beat-to-beat and spectral indexes of skin-surface-acquired LDF signals between control subjects and breast-cancer patients. This illustrates that LDF indexes may be useful for monitoring the changes in the MBF perfusion condition induced by breast cancer. Since the breast-cancer patients were at TNM stages 0- 2, the present findings may aid the development of indexes for detecting breast cancer.

  13. Electrocardiographic findings in Emergency Department patients with pulmonary embolism.

    Science.gov (United States)

    Richman, Peter B; Loutfi, Hassan; Lester, Steven J; Cambell, Patricia; Matthews, Jessica; Friese, Jeremy; Wood, Joseph; Kasper, David; Chen, Frederick; Mandell, Mark

    2004-08-01

    To assess the pre-study, null hypothesis that there is no difference in the electrocardiogram (EKG) findings for Emergency Department (ED) patients who rule in vs. rule out for suspected pulmonary embolism, a retrospective review of a cohort of patients with pulmonary embolism and their controls was conducted in an academic, suburban ED. Patients who were evaluated in the ED during a one-year study period for symptoms suggestive of pulmonary embolism were eligible for inclusion. All patients with pulmonary embolism and sex- and age-matched controls comprised the final study groups. Two board-certified cardiologists reviewed each patient's EKG. There were 350 eligible patients identified; 49 patients with pulmonary embolism and 49 controls were entered into the study. The most common rhythm observed in both groups was normal sinus rhythm (67.3% cases vs. 68.6 % controls; p = 1.0). Abnormalities believed to be associated with pulmonary embolism occurred with similar frequency in both case and control groups (sinus tachycardia [18.8 % vs. 11.8%, respectively; p = 0.40]), incomplete right bundle branch block (4.2% vs. 0.0%, respectively; p = 0.24), complete right bundle branch block (4.2% vs. 6.0, respectively; p = 1.0), S1Q3T3 pattern (2.1 vs. 0.0, respectively; p = 0.49), S1Q3 pattern (0.0 vs. 0.0), and extreme right axis (0.0 vs. 0.0). New EKG changes were identified more frequently for patients with pulmonary embolism (33.3% vs. 12.5% controls; p = 0.03), but specific findings were rarely different between cases and controls. In our cohort of ED patients, we did not identify EKG features that are likely to help distinguish patients with pulmonary embolism from those who rule out for the disease.

  14. Spatial weighting of Doppler reactivity feedback

    International Nuclear Information System (INIS)

    Carew, J.F.; Diamond, D.J.; Todosow, M.

    1977-12-01

    The spatial weighting of the local Doppler feedback implicit in the determination of the core Doppler feedback reactivity has been investigated. Using a detailed planar PDQ7-II PWR model with local fuel-temperature feedback, the core Doppler spatial weight factor, S, has been determined for various control patterns and power levels. Assuming power-squared weighting of the local Doppler feedback, a simple analytic expression for S has been derived and, based on comparison with the PDQ7-II results, provides a convenient and accurate representation of the Doppler spatial weight factor. The sensitivity of these results to variations in the fuel rod heat transfer coefficients, fuel loading and the magnitude of the Doppler coefficient has also been evaluated. The dependence of the local Doppler coefficient on moderator temperature, boron concentration and control rod density has been determined and found to be weak. Selected comparisons with vendor analyses have been made and indicate general agreement

  15. Anterior mediastinal paraganglioma: A case for preoperative embolization

    Directory of Open Access Journals (Sweden)

    Shakir Murtaza

    2012-07-01

    Full Text Available Abstract Background Paraganglioma is a rare but highly vascular tumor of the anterior mediastinum. Surgical resection is a challenge owing to the close proximity to vital structures including the heart, trachea and great vessels. Preoperative embolization has been reported once to facilitate surgical treatment. Case presentation We report a case of anterior mediastinal paraganglioma that was embolized preoperatively, and was resected without the need for cardiopulmonary bypass and without major bleeding complications. Conclusion We make a case to further the role of preoperative embolization in the treatment of mediastinal paragangliomas.

  16. Multipoint photonic doppler velocimetry using optical lens elements

    Science.gov (United States)

    Frogget, Brent Copely; Romero, Vincent Todd

    2014-04-29

    A probe including a fisheye lens is disclosed to measure the velocity distribution of a moving surface along many lines of sight. Laser light, directed to the surface and then reflected back from the surface, is Doppler shifted by the moving surface, collected into fisheye lens, and then directed to detection equipment through optic fibers. The received light is mixed with reference laser light and using photonic Doppler velocimetry, a continuous time record of the surface movement is obtained. An array of single-mode optical fibers provides an optic signal to an index-matching lens and eventually to a fisheye lens. The fiber array flat polished and coupled to the index-matching lens using index-matching gel. Numerous fibers in a fiber array project numerous rays through the fisheye lens which in turn project many measurement points at numerous different locations to establish surface coverage over a hemispherical shape with very little crosstalk.

  17. Embolization techniques in severe obstetrical and nonmalignant vaginal hemorrhage

    International Nuclear Information System (INIS)

    Sniderman, K.W.; Shewchun, J.; Colapinto, R.F.; Odurny, A.; Rosenthal, D.

    1988-01-01

    Fifteen of 16 patients with vaginal hemorrhage following vaginal delivery (n=2), cesarian section (n=2), vaginal hysterectomy (n=1), abdominal hysterctomy (n=10), or vaginal trachelectomy (n=1) were treated with transcatheter embolotherapy when conservative methods failed. Pelvic and/or hypogastric arteriography showed a bleeding point in 15 patients. Unilateral hypogastric embolization stopped the bleeding in 12 and was unsuccessful in one; recurrent bleeding in four patients was managed with contralateral embolization. Bilateral synchronous embolizations were performed in one patient. One of two patients with continued bleeding following hypogastric artery ligation was treated with collateral artery embolization. No serious complications occurred. In this patient population, the authors recommend therapeutic embolotherapy as the treatment of choice

  18. Embolization with the Amplatzer Vascular Plug in TIPS Patients

    International Nuclear Information System (INIS)

    Pattynama, Peter M. T.; Wils, Alexandra; Linden, Edwin van der; Dijk, Lukas C. van

    2007-01-01

    Vessel embolization can be a valuable adjunct procedure in transjugular intrahepatic portosystemic shunt (TIPS). During the creation of a TIPS, embolization of portal vein collaterals supplying esophageal varices may lower the risk of secondary rebleeding. And after creation of a TIPS, closure of the TIPS itself may be indicated if the resulting hepatic encephalopathy severely impairs mental functioning. The Amplatzer Vascular Plug (AVP; AGA Medical, Golden Valley, MN) is well suited for embolization of large-diameter vessels and has been employed in a variety of vascular lesions including congenital arteriovenous shunts. Here we describe the use of the AVP in the context of TIPS to embolize portal vein collaterals (n = 8) or to occlude the TIPS (n = 2)

  19. A Rare Case of Jejunal Arterio-Venous Fistula: Treatment with Superselective Catheter Embolization with a Tracker-18 Catheter and Microcoils

    International Nuclear Information System (INIS)

    Sonnenschein, Martin J.; Anderson, Suzanne E.; Lourens, Steven; Triller, Juergen

    2004-01-01

    Arterio-venous fistulas may develop spontaneously, following trauma or infection, or be iatrogenic in nature. We present a rare case of a jejunal arterio- venous fistula in a 35-year-old man with a history of pancreatic head resection that had been performed two years previously because of chronic pancreatitis. The patient was admitted with acute upper abdominal pain, vomiting and an abdominal machinery-type bruit. The diagnosis of a jejunal arterio-venous fistula was established by MR imaging. Transfemoral angiography was performed to assess the possibility of catheter embolization. The angiographic study revealed a small aneurysm of the third jejunal artery, abnormal early filling of dilated jejunal veins and marked filling of the slightly dilated portal vein (13-14 mm). We considered the presence of segmental portal hypertension. The patient was treated with coil embolization in the same angiographic session. This case report demonstrates the importance of auscultation of the abdomen in the initial clinical examination. MR imaging and color Doppler ultrasound are excellent noninvasive tools in establishing the diagnosis. The role of interventional radiological techniques in the treatment of early portal hypertension secondary to jejunal arterio-venous fistula is discussed at a time when this condition is still asymptomatic. A review of the current literature is included

  20. Quantification of Postmembrane Gaseous Microembolization During Venoarterial Extracorporeal Membrane Oxygenation.

    Science.gov (United States)

    Jiao, York; Gipson, Keith E; Bonde, Pramod; Mangi, Abeel; Hagberg, Robert; Rosinski, David J; Gross, Jeffrey B; Schonberger, Robert B

    Prolonged use of venoarterial extracorporeal membrane oxygenation (VA ECMO) may be complicated by end-organ dysfunction. Although gaseous microemboli (GME) are thought to damage end organs during cardiopulmonary bypass, patient exposures to GME have not been well characterized during VA ECMO. We therefore performed an observational study of GME in adult VA ECMO patients, with correlation to clinical events during routine patient care. After institutional review board (IRB) approval, we used two Doppler probes to detect GME noninvasively in extracorporeal membrane oxygenation (ECMO) circuits on four patients for 15 hours total while also recording patient care events. We then conducted in vitro trials to compare Doppler signals with gold-standard measurements using an Emboli Detection and Classification EDAC quantifier (Luna Innnovations, Inc. Roanoke, VA) (Terumo Cardiovascular, Ann Arbor, MI) during simulated clinical interventions. Correlations between Doppler and EDAC data were used to estimate GME counts and volumes represented by clinical Doppler data. A total of 503 groups of Doppler peaks representing GME showers were observed, including 194 statistically larger showers during patient care activities containing 92% of total Doppler peaks. Intravenous injections accounted for an estimated 68% of GME and 88% of GME volume, whereas care involving movement accounted for an estimated 6% of GME and 3% of volume. Overall estimated embolic rates of 24,000 GME totaling 4 μl/hr rivals reported GME rates during cardiopulmonary bypass. Numerous GME are present in the postmembrane circuit during VA ECMO, raising concern for effects on microcirculation and organ dysfunction. Strategies to detect and minimize GME may be warranted to limit embolic exposures experienced by VA ECMO patients.

  1. [Paradoxical brain embolism mediated through a pulmonary arteriovenous malformation with hereditary hemorrhagic telangiectasia in a Japanese patient].

    Science.gov (United States)

    Takeda, June; Todo, Kenichi; Yamamoto, Shiro; Yamagami, Hiroshi; Kawamoto, Michi; Kohara, Nobuo

    2012-01-01

    We report a case of paradoxical brain embolism mediated through a pulmonary arteriovenous malformation (PAVM) with hereditary hemorrhagic telangiectasia (HHT). A 25-year-old right handed man was admitted to our hospital after sudden headache and visual field abnormality. In neurologic examinations, he had left superior-quadrantanopsia. Laboratory findings showed iron deficiency anemia. Diffusion weighted images disclosed a high-signal-intensity area in the right occipito-temporal lobe, and intraarterial digital subtraction cerebral angiography revealed occlusion of the right posterior cerebral artery. Transesophageal echocardiography revealed continuous right-to-left shunt. We confirmed his history of spontaneous recurrent epistaxis and the first-degree relatives with epistaxis or PAVM. A contrast enhanced CT scan of the chest revealed a PAVM. The diagnosis of paradoxical brain embolism mediated through the PAVM with HHT was, thus, established. The PAVM was occluded by using embolization coils successfully. In Asian countries, the prevalence of PAVM with HHT is thought to be lower than in European countries. We should carefully take medical and family histories, especially epistaxis, in a young stroke patient.

  2. Treatment of Rectal Hemorrhage by Coil Embolization

    International Nuclear Information System (INIS)

    Dobson, Craig Charles; Nicholson, Anthony A.

    1998-01-01

    Four patients, aged 54-84 years, presenting with life-threatening rectal bleeding from the superior hemorrhoidal artery, underwent percutaneous fibered platinum coil embolization via coaxial catheters. Pre-procedure sigmoidoscopy had failed to identify the source of hemorrhage, because the rectum was filled with fresh blood. Embolization was technically and clinically successful in all four patients. Subsequent sigmoidoscopy confirmed the diagnoses in three patients as a solitary rectal ulcer, iatrogenic traumatic ulceration following manual evacuation, and a rectal Dieulafoy's lesion. The other case was angiographically seen to be due to a rectal angiodysplasia. Embolization is an effective procedure in life-threatening superior hemorrhoidal arterial bleeding when endoscopic treatment fails, and should be preferred to rectosigmoid resection

  3. Right Gastric Artery Embolization Prior to Treatment with Yttrium-90 Microspheres

    International Nuclear Information System (INIS)

    Cosin, Octavio; Bilbao, Jose Ignacio; Alvarez, Sergio; Luis, Esther de; Alonso, Alberto; Martinez-Cuesta, Antonio

    2007-01-01

    Purpose. Intra-arterial infusion of yttrium-90 microspheres is a form of radiation treatment for unresectable hepatic neoplasms. Misdeposition of particles in the gastroduodenal area such as the right gastric artery (RGA) may occur with serious consequences. We present a series of patients who underwent a detailed vascular study followed by RGA embolization. Special emphasis is placed on anatomic variations and technical considerations .Methods. In a 1 year period, 27 patients were treated. Initial vascular evaluation was performed, with careful attention to anatomic variants or extrahepatic arterial supply, especially to the gastroduodenal area. Embolization of such arteries was planned if needed. RGA embolization was performed antegradely from the hepatic artery or retrogradely via the left gastric artery (LGA). Postprocedural follow-up included clinical interview and gastroscopy if necessary. Results. RGA embolization was performed in 9 patients presenting with primary (n = 3) or metastatic liver tumors (n 6). Six patients underwent antegrade RGA embolization and 3 had embolization done retrogradely via the LGA. Retrograde access was chosen for anatomic reasons. None of the patients complained of gastroduodenal symptoms. Conclusion. RGA embolization can help minimize the gastroduodenal deposition of radioactive particles. RGA embolization should routinely be carried out. The procedure can be performed, with similar technical success, by both anterograde and retrograde approaches

  4. Ultrasonic colour Doppler imaging

    DEFF Research Database (Denmark)

    Evans, David H; Jensen, Jørgen Arendt; Nielsen, Michael Bachmann

    2011-01-01

    Ultrasonic colour Doppler is an imaging technique that combines anatomical information derived using ultrasonic pulse-echo techniques with velocity information derived using ultrasonic Doppler techniques to generate colour-coded maps of tissue velocity superimposed on grey-scale images of tissue...... anatomy. The most common use of the technique is to image the movement of blood through the heart, arteries and veins, but it may also be used to image the motion of solid tissues such as the heart walls. Colour Doppler imaging is now provided on almost all commercial ultrasound machines, and has been...

  5. Doppler-shift estimation of flat underwater channel using data-aided least-square approach

    Directory of Open Access Journals (Sweden)

    Weiqiang Pan

    2015-03-01

    Full Text Available In this paper we proposed a dada-aided Doppler estimation method for underwater acoustic communication. The training sequence is non-dedicate, hence it can be designed for Doppler estimation as well as channel equalization. We assume the channel has been equalized and consider only flat-fading channel. First, based on the training symbols the theoretical received sequence is composed. Next the least square principle is applied to build the objective function, which minimizes the error between the composed and the actual received signal. Then an iterative approach is applied to solve the least square problem. The proposed approach involves an outer loop and inner loop, which resolve the channel gain and Doppler coefficient, respectively. The theoretical performance bound, i.e. the Cramer-Rao Lower Bound (CRLB of estimation is also derived. Computer simulations results show that the proposed algorithm achieves the CRLB in medium to high SNR cases.

  6. Doppler-shift estimation of flat underwater channel using data-aided least-square approach

    Science.gov (United States)

    Pan, Weiqiang; Liu, Ping; Chen, Fangjiong; Ji, Fei; Feng, Jing

    2015-06-01

    In this paper we proposed a dada-aided Doppler estimation method for underwater acoustic communication. The training sequence is non-dedicate, hence it can be designed for Doppler estimation as well as channel equalization. We assume the channel has been equalized and consider only flat-fading channel. First, based on the training symbols the theoretical received sequence is composed. Next the least square principle is applied to build the objective function, which minimizes the error between the composed and the actual received signal. Then an iterative approach is applied to solve the least square problem. The proposed approach involves an outer loop and inner loop, which resolve the channel gain and Doppler coefficient, respectively. The theoretical performance bound, i.e. the Cramer-Rao Lower Bound (CRLB) of estimation is also derived. Computer simulations results show that the proposed algorithm achieves the CRLB in medium to high SNR cases.

  7. Pulmonary embolism presenting with ST segment elevation in inferior leads

    Directory of Open Access Journals (Sweden)

    Muzaffer Kahyaoğlu

    2017-03-01

    Full Text Available Acute pulmonary embolism is a form of venous thromboembolism that is widespread and sometimes mortal. The clinical presentation of pulmonary embolism is variable and often nonspecific making the diagnosis challenging. In this report, we present a case of pulmonary embolism characterized by ST segment elevation in inferior leads without reciprocal changes in the electrocardiogram.

  8. An improvement of wind velocity estimation from radar Doppler spectra in the upper mesosphere

    Directory of Open Access Journals (Sweden)

    S. Takeda

    2001-08-01

    Full Text Available We have developed a new parameter estimation method for Doppler wind spectra in the mesosphere observed with an MST radar such as the MU radar in the DBS (Doppler Beam Swinging mode. Off-line incoherent integration of the Doppler spectra is carried out with a new algorithm excluding contamination by strong meteor echoes. At the same time, initial values on a least square fitting of the Gaussian function are derived using a larger number of integration of the spectra for a longer time and for multiple heights. As a result, a significant improvement has been achieved with the probability of a successful fitting and parameter estimation above 80 km. The top height for the wind estimation has been improved to around 95 km. A comparison between the MU radar and the High Resolution Doppler Imager (HRDI on the UARS satellite is shown and the capability of the new method for a validation of a future satellite mission is suggested.Key words. Meteorology and atmospheric dynamics (middle atmosphere dynamics – Radio science (remote sensing; signal processing

  9. Model experiments on imaging subsurface fracture permeability by pulsed Doppler borehole televiewer; Pulse doppler borehole televiewer ni yoru kiretsu tosuisei hyoka ni kansuru model jikken

    Energy Technology Data Exchange (ETDEWEB)

    Inagaki, Y; Niitsuma, H [Tohoku University, Sendai (Japan). Faculty of Engineering

    1996-05-01

    This paper reports model experiments to evaluate flow rates of fluids passing through a fracture by using a Doppler borehole televiewer (DBHTV). A supersonic transducer disposed on a well axis transmits transmission pulses, and a transducer receives scattered waves generated by particulates in water and waves reflected on a well wall. This signal is applied with time gating to extract only the scattered waves from particulates in the vicinity of the well wall. Deriving spectra in the recorded Doppler signal obtains flow velocity components in the direction of the well radius. A model was made with a polyvinylchloride pipe with a diameter of 14.6 cm to simulate a well, to which an aluminum pipe with an inner diameter of 2 mm is connected to be used as a simulated fracture, and mud water is circulated in the pipe. The result of deriving a passed flow volume in this model by integrating flow rate distribution derived by using the above method to a predetermined range in the vicinity of the fracture showed a good proportional relationship with actual flow rate in the simulated fracture. 1 ref., 7 figs.

  10. Prevention and management of the complications during embolizing intracranial aneurysm with GDC

    International Nuclear Information System (INIS)

    Zhong Ming; Tan Xianxi; Wang Junlu; Hu Wenhao; Fan Lianghao

    2002-01-01

    Objective: To sum up the experience of embolization of intracranial aneurysm with Guglielmi detachable coil (GDC) and to discuss how to prevent and manage the complications during the endovascular treatment. Methods: 108 patients with intracranial aneurysm were embolized with GDC. 24 accident out of 20 patients during embolization were reviewed. Results: Among the 24 accidents, there were 10 aneurysm rupture, 5 over- embolization 5 coils end protruding to parent artery, and 4 thrombosis. Once the aneurysm ruptures, neutralizing heparin and continuing embolization was administered. Among 10 cases of aneurysm ruptures, 4 were death, 1 was severe deformity, 1 was mild deformity. Thrombolysis, heparinisation and raising blood pressure were used to control over-embolization, coil protrusion, and thrombosis. Among 5 cases of over-embolization, 1 died, 4 recovered. Among 5 cases of coils end protruding, 1 was severe deformity, 1 was mild deformity. Among 4 cases of embolization, 1 died, 1 was led sensory aphasics. The accidents resulted in 5 deaths (4.6%), 4 permanent neurological deficits (3.7%). Conclusion: The correct management of the complications during the treatment, the better understanding of the aneurysm and its parent artery angio-anatomy and the improved skill of embolizing technique are helpful to reduce the accidents and increase the cure rate

  11. Thrombolytic and anticoagulation treatment in a rat embolic stroke model

    DEFF Research Database (Denmark)

    Rasmussen, Rune Skovgaard; Overgaard, K; Meden, P

    2003-01-01

    OBJECTIVES: The effects of pentasaccharide (PENTA), given alone or combined with thrombolysis using recombinant tissue plasminogen activator (rt-PA), on infarct size and clinical outcome were evaluated in a rat embolic stroke model. MATERIALS AND METHODS: Ninety-two rats were embolized unilateral...... alone or combined with rt-PA did not significantly increase mortality or tendency for hemorrhage.......OBJECTIVES: The effects of pentasaccharide (PENTA), given alone or combined with thrombolysis using recombinant tissue plasminogen activator (rt-PA), on infarct size and clinical outcome were evaluated in a rat embolic stroke model. MATERIALS AND METHODS: Ninety-two rats were embolized unilaterally...

  12. Retrograde Transvenous Ethanol Embolization of High-flow Peripheral Arteriovenous Malformations

    International Nuclear Information System (INIS)

    Linden, Edwin van der; Baalen, Jary M. van; Pattynama, Peter M. T.

    2012-01-01

    Purpose: To report the clinical efficiency and complications in patients treated with retrograde transvenous ethanol embolization of high-flow peripheral arteriovenous malformations (AVMs). Retrograde transvenous ethanol embolization of high-flow AVMs is a technique that can be used to treat AVMs with a dominant outflow vein whenever conventional interventional procedures have proved insufficient. Methods: This is a retrospective study of the clinical effectiveness and complications of retrograde embolization in five patients who had previously undergone multiple arterial embolization procedures without clinical success. Results: Clinical outcomes were good in all patients but were achieved at the cost of serious, although transient, complications in three patients. Conclusion: Retrograde transvenous ethanol embolization is a highly effective therapy for high-flow AVMs. However, because of the high complication rate, it should be reserved as a last resort, to be used after conventional treatment options have failed.

  13. Chronic recurrent hemoptysis: effectiveness of bronchial artery embolization in 25 patients

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jong Ik; Shim, Hyung Jin; Wang, Chi Hyung; Hyun, Yu; Kim, Yang Soo; Kim, Young Goo; Kim, Kun Sang [Chungang University College of Medicine, Seoul (Korea, Republic of)

    1994-09-15

    Bronchial artery embolization has been effective in the treatment of massive hemoptysis. The purpose of this study was to report the effectiveness of bronchial artery embolization in patients with chronic recurrent hemoptysis intractable to medical treatment. This study included 25 patients who were admitted for treatment of chronic recurrent hemoptysis with bronchial artery embolization. Chronic recurrent hemoptysis was defined as condition in tractable to medical treatment persistently and occurring over two times per two months The target vessels for embolization were selected in consideration of the results of aortography as well as the finding of chest radiography and bronchoscopy. After selective arteriography for embolization by using 5-French Simmons catheter, embolic agents(mainly polyvinyl alcohol(PVA) and additionally gelfoam and coils) were released through the catheter. The results of the embolization were assessed with review of medical records. The cases of the hemoptysis were pulmonary tuberculosis(n=12.48%), bronchiectasis(n=6.24%), aspergilloma(n=3.12%), chronic obstructive pulmonary disease(n=2.8%), chronic bronchitis(n=1.4%) and lung abscess(n=1.4%). Selective embolization was carried out in 49 sites(42 in bronchial artery and 7 in nonbronchial systemic collaterals). Early success rate within 2 months was 96%. After long-term follow up study (6-30 months, average 15 months), complete remission was 72%, partial remission 12% and recurrence 12% respectively. During and after embolization, major complications such as spinal cord injury or bronchial wall necrosis was not found. Minor complications were chest pain, shoulder pain and chilling sense, which were relieved spontaneously within a few days. High success rate and relatively low recurrence with no significant complication were achieved with bronchial artery embolization in the patients complaining of chronic recurrent hemoptysis.

  14. Applicability of liquid radiopaque polyurethane for transcatheter embolization

    International Nuclear Information System (INIS)

    Novak, D.; Wieners, H.; Rueckner, R.

    1983-01-01

    Polyurethane Bayer was tested as an occlusive agent for experimental embolization in postmortem and postnephrectomy kidneys which served as a tumor model. Coaxial and balloon catheters were used for the embolization. To make polyurethane radiopaque, the material was labeled with different water-soluble, oily and solid contrast agents. Best results were achieved with oily contrast materials, e.g., Pantopaque. We found that polyurethane can easily be injected during a predetermined working time of 8-10 min. The embolization results in a complete, permanent, and homogeneous occlusion of the proximal arterial branches and small peripheral vessels. (orig.)

  15. Detection of Moving Targets Based on Doppler Spectrum Analysis Technique for Passive Coherent Radar

    Directory of Open Access Journals (Sweden)

    Zhao Yao-dong

    2013-06-01

    Full Text Available A novel method of moving targets detection taking Doppler spectrum analysis technique for Passive Coherent Radar (PCR is provided. After dividing the receiving signals into segments as pulse series, it utilizes the technique of pulse compress and Doppler processing to detect and locate the targets. Based on the algorithm for Pulse-Doppler (PD radar, the equipollence between continuous and pulsed wave in match filtering is proved and details of this method are introduced. To compare it with the traditional method of Cross-Ambiguity Function (CAF calculation, the relationship and mathematical modes of them are analyzed, with some suggestions on parameters choosing. With little influence to the gain of targets, the method can greatly promote the processing efficiency. The validity of the proposed method is demonstrated by offline processing real collected data sets and simulation results.

  16. Differential doppler heterodyning technique

    DEFF Research Database (Denmark)

    Lading, Lars

    1971-01-01

    Measuring velocity without disturbing the moving object is possible by use of the laser doppler heterodyning technique. Theoretical considerations on the doppler shift show that the antenna property of the photodetector can solve an apparent conflict between two different ways of calculating...

  17. Coil occlusion of residual shunts after surgical closure of patent ductus arteriosus.

    Science.gov (United States)

    Fujii, Yoko; Keene, Bruce W; Mathews, Kyle G; Atkins, Clarke E; Defrancesco, Teresa C; Hardie, Elizabeth M; Wakao, Yoshito

    2006-12-01

    OBJECTIVE; To describe use of coil embolization to occlude residual flow through a patent ductus arteriosus (PDA) after incomplete surgical ligation. Clinical study. Dogs (n=4) with continuous murmur after surgical ligation of PDA. After PDA ligation, residual ductal flow through the PDA was visible on color-flow Doppler examination and left ventricular end-diastolic diameter remained increased. Coil embolization by an arterial approach was performed to achieve complete occlusion of the PDA. Embolization coils were delivered without complications and hemodynamically successful occlusion was achieved. Doppler-visible flow resolved in 2 dogs within 3 months after embolization. Left ventricular end-diastolic diameter indexed to body weight decreased in all dogs. Transcatheter coil embolization appears to be a safe and minimally invasive procedure for complete occlusion of residual PDA flow after incomplete surgical ligation. Transcatheter coil embolization should be considered for correction of hemodynamically significant residual shunts in dogs that have incomplete PDA occlusion after open surgical ligation.

  18. Transarterial embolization for hematuria caused by renal arteriovenous malformations or fistulae

    International Nuclear Information System (INIS)

    Meng Xiaoxi; Liu Shiyuan; Dong Weihua; Dong Sheng; Jia Ningyang; Xiao Xiangsheng

    2008-01-01

    Objective: To evaluate the efficacy and safety of transarterial embolization for hematuria caused by renal arteriovenous malformation or fistulae. Methods: Seven patients with gross hematuria caused by renal arterial abnormalities were retrospectively reviewed, of which three had congenital renal arteriovenous malformations and the other four had non-neoplastic acquired renal arteriovenous fistulae. All patients were confirmed by renal arterial angiography and undergone embolization with various embolic materials. Results: Embolization was successfully carried out in all cases. Gross hematuria disappeared one to seven days after the procedure. No severe complications were encountered. No recurrence occurred within 12 to 36 months of follow-up. Conclusions: Transarterial embolization is safe and effective for hematuria caused by renal arteriovenous malformations or fistulae. (authors)

  19. Embolic Protection using the WIRION Embolic Protection System with JetStream Atherectomy in a Patient with Superficial Femoral Artery Chronic total Occlusion.

    Science.gov (United States)

    Shammas, Nicolas W

    2017-06-01

    Distal embolization is a common occurrence with peripheral arterial interventions and is more frequent with the use of atherectomy devices. We report the first case of JetStream atherectomy (Boston Scientific, Maple Grove, MN) with the use of the novel WIRION embolic protection system filter. The procedure was performed successfully with no distal embolizations beyond the filter and with no complications in the delivery or retrieval of the filter. The pros and cons of the off label use of this filter with JetStream atherectomy are discussed.

  20. New thermoreversible liquid embolic agent for embolotherapy: technical report

    International Nuclear Information System (INIS)

    Takao, Hiroyuki; Murayama, Yuichi; Ebara, Masaki; Ishibashi, Toshihiro; Saguchi, Takayuki; Irie, Koreaki; Abe, Toshiaki; Yoshioka, Hiroshi; Mori, Yuichi; Vinuela, Fernando

    2009-01-01

    To evaluate potential feasibility of new liquid embolic agent, thermoreversible gelation polymer (TGP), for embolotherapy. TGP is a liquid polymer that was originally developed as a cell culture medium for tissue engineering. TGP becomes liquid at temperatures lower than the sol-gel transition temperature (TT) and becomes a gel at temperatures higher than the TT. The TT can be adjusted from 10 C to 40 C, allowing gelation at body temperature without solvent. The renal arteries in six swine were embolized with TGP. Angiographic evaluations were obtained 0, 3 h, and 14 days after embolization. The animals were sacrificed at day 14 after angiogram. All renal arteries were successfully embolized with TGP using cooling catheter. No acute and chronic clinical complication was observed. Follow-up angiogram demonstrated complete or near complete occlusion of renal arteries. No untoward inflammatory response was observed in acute and chronic specimen. This embolic material has potential feasibility to be used in the treatment of cerebral arteriovenous malformations, aneurysms, or hyper vascular tumors. (orig.)

  1. Permanent Cortical Blindness After Bronchial Artery Embolization

    Energy Technology Data Exchange (ETDEWEB)

    Doorn, Colette S. van, E-mail: cvandoorn@gmail.com; De Boo, Diederick W., E-mail: d.w.deboo@amc.uva.nl [Academic Medical Centre, Department of Radiology (Netherlands); Weersink, Els J. M., E-mail: e.j.m.weersink@amc.uva.nl [Academic Medical Centre, Department of Pulmonology (Netherlands); Delden, Otto M. van, E-mail: o.m.vandelden@amc.uva.nl; Reekers, Jim A., E-mail: j.a.reekers@amc.uva.nl; Lienden, Krijn P. van, E-mail: k.p.vanlienden@amc.uva.nl [Academic Medical Centre, Department of Radiology (Netherlands)

    2013-12-15

    A 35-year-old female with a known medical history of cystic fibrosis was admitted to our institution for massive hemoptysis. CTA depicted a hypertrophied bronchial artery to the right upper lobe and showed signs of recent bleeding at that location. Bronchial artery embolization (BAE) was performed with gelfoam slurry, because pronounced shunting to the pulmonary artery was present. Immediately after BAE, the patient developed bilateral cortical blindness. Control angiography showed an initially not opacified anastomosis between the embolized bronchial artery and the right subclavian artery, near to the origin of the right vertebral artery. Cessation of outflow in the bronchial circulation reversed the flow through the anastomosis and allowed for spill of embolization material into the posterior circulation. Unfortunately the cortical blindness presented was permanent.

  2. Posttranscatheter embolization computed tomography in hepatocellular carcinoma

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    Yasumori, K; Tamura, S; Hasuo, K; Kudo, S; Uchino, A; Nishitani, H; Onitsuka, H; Kawanami, T; Kawahira, K; Ono, M

    1984-12-01

    The postcontrast CT scans and angiography of 26 lesions in 23 patients with hepatomas who underwent transcatheter arterial embolization therapy were reviewed. Newly developed low density and high density areas and gas were noted on CT scans of the tumors after embolization in 100, 8 and 58% of the lesions, respectively. The CT findings of residual tumors correlated well with those of follow-up angiography. When discrete smooth round low density zones were observed on CT, there was no residual neovascularity on follow-up arteriography. When there were nodular or thick septum-like structures in low density lesions, arteriography revealed residual tumor vascularity in the lesions. CT proved useful not only in evaluating the effects of embolization, but also in providing important information about residual tumors.

  3. Diagnostic value of dual section helical CT in suspected acute pulmonary embolism

    International Nuclear Information System (INIS)

    Marangoni, Alberto A.; Torrecillas, Maria D.; Marchegiani, Silvio H.; Surur, Alberto

    2003-01-01

    Purpose: To asses the role of Dual Section Helical Computed Tomography (DSHCT) in patients with clinically suspected acute pulmonary embolism (APE). Material and Methods: A retrospective evaluation of 102 patients (57 male, 45 female; age range: 30-83 years; mean: 56 years) with high suspicion of APE studied by DSHCT, was carried out. From the medical records we analyzed clinical parameters, blood gases, D-dimer, risk factors and other imaging examinations. US Doppler of the inferior limbs was performed in 58/102 patients (57%). Results. 52 patients (51%) had APE on DSHCT. Scans of the other 50 patients (49%) were negative for APE. In 39/50 cases (78%) without evidence of APE, DSHCT detected ancillary thoracic findings such as atelectasia (n=11), pulmonary consolidation/edema (n=10), interstitial lung disease (n=8), pleural effusion (n=6), emphysema (n=2), nodules (n=2). 11 cases (22%) DSHCT showed no abnormal features. In this group, with persistent clinical symptoms, angio MRI showed 2 additional cases of APE (false negatives on DSHCT). On DSHCT 51/52 patients (98%) with APE showed satisfactory filling of iodinate contrast in segmental pulmonary arteries, and 45/52 patients (87%) in sub segmental arteries. On DSHCT 36 patients showed bilateral APE, and 7 had isolated peripheral APE. In 7/12 patients DSHCT demonstrated deep venous thrombosis (DVT) of the inferior limbs. In other 27/58 cases (47%) US Doppler was positive for DVT. Conclusion: DSHCT can be effectively used to rule out suspected APE and also provides additional information in patients without APE. In addition DSHCT also contributes to demonstrate deep venous thrombosis. (author)

  4. Laser Doppler flowmetry for measurement of laminar capillary blood flow in the horse

    Science.gov (United States)

    Adair, Henry S., III

    1998-07-01

    Current methods for in vivo evaluation of digital hemodynamics in the horse include angiography, scintigraphy, Doppler ultrasound, electromagnetic flow and isolated extracorporeal pump perfused digit preparations. These techniques are either non-quantifiable, do not allow for continuous measurement, require destruction of the horse orare invasive, inducing non- physiologic variables. In vitro techniques have also been reported for the evaluation of the effects of vasoactive agents on the digital vessels. The in vitro techniques are non-physiologic and have evaluated the vasculature proximal to the coronary band. Lastly, many of these techniques require general anesthesia or euthanasia of the animal. Laser Doppler flowmetry is a non-invasive, continuous measure of capillary blood flow. Laser Doppler flowmetry has been used to measure capillary blood flow in many tissues. The principle of this method is to measure the Doppler shift, that is, the frequency change that light undergoes when reflected by moving objects, such as red blood cells. Laser Doppler flowmetry records a continuous measurement of the red cell motion in the outer layer of the tissue under study, with little or no influence on physiologic blood flow. This output value constitutes the flux of red cells and is reported as capillary perfusion units. No direct information concerning oxygen, nutrient or waste metabolite exchange in the surrounding tissue is obtained. The relationship between the flowmeter output signal and the flux of red blood cells is linear. The principles of laser Doppler flowmetry will be discussed and the technique for laminar capillary blood flow measurements will be presented.

  5. Radioembolization: Is Prophylactic Embolization of Hepaticoenteric Arteries Necessary? A Systematic Review

    Energy Technology Data Exchange (ETDEWEB)

    Borggreve, Alicia S., E-mail: alicia.borggreve@gmail.com; Landman, Anadeijda J. E. M. C., E-mail: ajemclandman@gmail.com; Vissers, Coco M. J., E-mail: coco.vissers@hotmail.com; De Jong, Charlotte D., E-mail: charlotte-dejong@live.nl; Lam, Marnix G. E. H., E-mail: m.lam@umcutrecht.nl [University Medical Center Utrecht, Division of Radiology and Nuclear Medicine (Netherlands); Monninkhof, Evelyn M., E-mail: e.monninkhof@umcutrecht.nl [University Medical Center Utrecht, Julius Center for Health Sciences and Primary Care (Netherlands); Prince, Jip F., E-mail: jipfprince@gmail.com [University Medical Center Utrecht, Division of Radiology and Nuclear Medicine (Netherlands)

    2016-05-15

    PurposeTo study the effectiveness of prophylactic embolization of hepaticoenteric arteries to prevent gastrointestinal complications during radioembolization.MethodsA PubMed, Embase and Cochrane literature search was performed. We included studies assessing both a group of patients with and without embolization.ResultsOur search revealed 1401 articles of which title and abstract were screened. Finally, eight studies were included investigating 1237 patients. Of these patients, 456 received embolization of one or more arteries. No difference was seen in the incidence of gastrointestinal complications in patients with prophylactic embolization of the gastroduodenal artery (GDA), right gastric artery (RGA), cystic artery (CA) or hepatic falciform artery (HFA) compared to patients without embolization. Few complications were reported when microspheres were injected distal to the origin of these arteries or when reversed flow of the GDA was present. A high risk of confounding by indication was present because of the non-randomized nature of the included studies.ConclusionIt is advisable to restrict embolization to those hepaticoenteric arteries that originate distally or close to the injection site of microspheres. There is no conclusive evidence that embolization of hepaticoenteric arteries influences the risk of complications.

  6. Radioembolization: Is Prophylactic Embolization of Hepaticoenteric Arteries Necessary? A Systematic Review

    International Nuclear Information System (INIS)

    Borggreve, Alicia S.; Landman, Anadeijda J. E. M. C.; Vissers, Coco M. J.; De Jong, Charlotte D.; Lam, Marnix G. E. H.; Monninkhof, Evelyn M.; Prince, Jip F.

    2016-01-01

    PurposeTo study the effectiveness of prophylactic embolization of hepaticoenteric arteries to prevent gastrointestinal complications during radioembolization.MethodsA PubMed, Embase and Cochrane literature search was performed. We included studies assessing both a group of patients with and without embolization.ResultsOur search revealed 1401 articles of which title and abstract were screened. Finally, eight studies were included investigating 1237 patients. Of these patients, 456 received embolization of one or more arteries. No difference was seen in the incidence of gastrointestinal complications in patients with prophylactic embolization of the gastroduodenal artery (GDA), right gastric artery (RGA), cystic artery (CA) or hepatic falciform artery (HFA) compared to patients without embolization. Few complications were reported when microspheres were injected distal to the origin of these arteries or when reversed flow of the GDA was present. A high risk of confounding by indication was present because of the non-randomized nature of the included studies.ConclusionIt is advisable to restrict embolization to those hepaticoenteric arteries that originate distally or close to the injection site of microspheres. There is no conclusive evidence that embolization of hepaticoenteric arteries influences the risk of complications.

  7. Color Doppler Score: A New Approach for Monitoring a Large Placental Chorioangioma

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    Maria Angelica Zoppi

    2014-01-01

    Full Text Available We employed color Doppler score as an innovative approach for the prenatal diagnosis and monitoring of a large placental chorioangioma case diagnosed at 26 weeks and the subjective semiquantitative assessment of the vascularization. The blood flow was assessed by a color Doppler score based on the intensity of the color signal with the following value ranges: (1 no flow, (2 minimal flow, (3 moderate flow, and (4 high vascular flow. Weekly examinations were programmed. Initially, a color Doppler score 3 was assigned, remaining unchanged at the following two exams and decreasing to Score 2 in the following 2 exams and to Score 1 thereafter. The ultrasonographic scan showed an increase of the mass size at the second and third exams and was followed by an arrest of the growth persisting for the rest of the pregnancy. Some hyperechogenic spots inside the mass appeared at the end. Expectant management was opted for, and the delivery was at 39, 2 weeks and maternal and fetal outcomes were favourable. The color Doppler score employed for assessment of vascularization in successive examinations proved to be an important tool for the prediction of the chorioangioma involution, and this new approach of monitoring allowed effective surveillance and successful tailored management.

  8. Pulmonary fat embolism: a case report

    International Nuclear Information System (INIS)

    Douvlou, E.; Vakhnina-Vassila, O.; Vlahou, I.; Petrocheilou, G.; Markantonatos, D.; Petinelli, A.; Stathopoulou, S.; Kokkinis, C.

    2012-01-01

    Full text: Introduction: Fat embolism is a clinical syndrome that usually occurs from the first to third day after a bone fracture or/and an orthopaedic surgery. The target organs are the lungs and more rarely the brain and the skin. Objectives and tasks: The aim of this presentation is to discuss the imaging diagnostic criteria of lung fat embolism in CT on the occasion of a case. Material and methods: A 30-years-old male patient was admitted to the Orthopaedic Department after a motorbike accident. A fracture of the head of his right femur was diagnosed and the patient underwent a surgery 3 days later. During the first postoperative day, the patient presented severe dyspnoea, tachycardia, a significant fall of PO 2 (59 mmHg) and a parallel increase in d-Dimmers (7.8 mg/l). The patient was then referred for a chest CT scan. Results: Contrast enhanced CT excluded the presence of thrombus in the pulmonary arteries and raised the diagnosis of lung fat embolism (septal thickening with a nodular pattern and diffuse ground-glass opacities along with the presence of small quantity of bilateral pleural effusions). Conclusion: Chest CT prior and the use of intravenous contrast media after is the most reliable diagnostic method to confirm or exclude pulmonary fat embolism syndrome

  9. The role of lung imaging in pulmonary embolism

    Science.gov (United States)

    Mishkin, Fred S.; Johnson, Philip M.

    1973-01-01

    The advantages of lung scanning in suspected pulmonary embolism are its diagnostic sensitivity, simplicity and safety. The ability to delineate regional pulmonary ischaemia, to quantitate its extent and to follow its response to therapy provides valuable clinical data available by no other simple means. The negative scan effectively excludes pulmonary embolism but, although certain of its features favour the diagnosis of embolism, the positive scan inherently lacks specificity and requires angiographic confirmation when embolectomy, caval plication or infusion of a thrombolytic agent are contemplated. The addition of simple ventilation imaging techniques with radioxenon overcomes this limitation by providing accurate analog estimation or digital quantitation of regional ventilation: perfusion (V/Q) ratios fundamental to understanding the pathophysiologic consequences of embolism and other diseases of the lung. ImagesFig. 1Fig. 2Fig. 3Fig. 4Fig. 5Fig. 6Fig. 7p495-bFig. 8Fig. 9Fig. 10Fig. 11Fig. 12Fig. 13 PMID:4602128

  10. Embolization of Spontaneous Hemarthrosis Post Total Knee Replacement

    International Nuclear Information System (INIS)

    Given, M. F.; Smith, P.; Lyon, S. M.; Robertson, D.; Thomson, K. R.

    2008-01-01

    Spontaneous nonhemophiliac hemarthrosis is an unusual entity, which has been little described. We present three cases of spontaneous recurrent hemarthrosis post total knee replacement (TKR) and successful management with embolization. Three male patients were referred to our service for angiography and treatment of recurrent hemarthrosis post TKR. In all three patients antegrade ipsilateral common femoral artery punctures and selective angiography of the geniculate branches were performed with a microcatheter. Abnormal vasculature was noted in all cases. Subsequent embolization was performed with Contour (Boston Scientific, Target Vascular, Cork, Ireland) embolization particles (150-250 and 250-355 μm) in two patients and microcoils in the third (TornadoR; Cook Inc., Bloomington, IN, USA). Technical success was 100%. One patient had a recurrence of symptoms requiring a repeat procedure 6 months later. No complications were encountered. Selective angiography and particle embolization is an effective technique for management of this unusual but problematic postoperative sequelae.

  11. Intratumoral vascularity of experimentally induced VX2 carcinoma : comparison of power doppler sonography and microangiography

    International Nuclear Information System (INIS)

    Park, Kil Sun; Won, Hyung Jin; Seo, Joon Beom; Kim, Tae Kyoung; Han, Joon Koo; Choi, Byung Ihn

    1997-01-01

    To evaluate the usefulness and limitations of power Doppler sonography in determining the tumor vascularity Power Doppler sonography was performed on VX2 carcinomas present in rabbit thighs, and the findings were compared with those of microangiography in an almost identical plane. Tumor vascularity was qualitatively analysed on the basis of tumor vessel distribution and density, and the presence of thick and thin vesels;for a comparison of tumor vascularity as seen on microangiography, tumor blood flow signals shown by power Doppler sonography were graded 3, 2, 1, 0. For quantitative analysis, a comparison was made of the percentage of tumor area occupied by vessels, as shown in each study. Data analysis utilized the Wilcoxon signed-rank test and Spearman correlation test. Mean tumor vascularity scores, as seen on power Doppler sonography and relating to tumor vessel distribution and density, and the presence of thick and thin vessels, were 2.87, 2.73, 2.93 and 2.73, respectively. The means and medians of the percentages of tumor area occupied by vessels were 22.7% and 23.5% and 36.4% and 34.7% on microangiography and power Doppler sonography, respectively. Thus, there was good correlation between these two modes. Power doppler sonography could demonstrate the tumor vascularity on microangiography relatively well but tend to overestimate it

  12. Investigation on the clinical practice of transcatheter embolization for acute gastrointestinal hemorrhage

    International Nuclear Information System (INIS)

    Gao Bin; Xu Shengde; Cheng Bing; Peng Qiong; Hong Ci; Xu Guozhong; Wang Tao

    2002-01-01

    Objective: To study the tactics, methods and relevant factors of transcatheter embolization for acute gastrointestinal hemorrhage. Methods: Fifteen patients with acute gastrointestinal hemorrhage were embolized by one of the methods of Polyvinyl Alcohol (PVA), gelfoam or metal coils. Four of the fifteen patients were upper gastrointestinal hemorrhage, the other cases were lower gastrointestinal hemorrhage which were embolized using coaxial microcatheter. Results: Fourteen of the fifteen patients were treated successfully by these methods. There were total 17 times of embolization for 16 parts, the success rate reached 94. 1%. The other one revealed an infarction of intestine after the embolization and was cured by resection. One of the fifteen patients appeared a recurrent hemorrhage 3 months later, and confirmed to be a hemangiolymphangioma. Two patients with malignant tumor were operated upon selectively. The other patient of intestinal hemorrhage was embolized successfully by using a metal coil after shock. Leiomyoma complicated with large area of bleeding was finally proven by operation. Conclusions: Transcatheter embolization for acute massive gastrointestinal hemorrhage is safe and efficient under different choice of methods. The key of success is the right selection of embolized target artery and dosage of emboli

  13. Juvenile nasopharyngeal angiofibroma with skull base invasion : intratumoral direct puncture embolization

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    Shin, Hye Young; Kim, Sun Yong; Suh, Jung Ho; Park, Kee Hyun [Ajou Univ., Suwon (Korea, Republic of). Coll. of Medicine

    1998-04-01

    The purpose of this study is to demonstrate the utility and efficacy of percutaneous direct glue embolization for juvenile nasopharyngeal angiofibromas with skull base invasion. In nine cases of juvenile nasopharyngeal angiofibromas with invasion of the skull base, embolization under general anethesia was performed. Using an 18G spinal needle, direct puncture were made via the transnasal or mandibular sciatic notch. A glue-lipiodol mixture (1:1 -1:3) was injected slowly for 15 to 30 seconds under fluoroscopic control; the number of post-embolization angiography and the distribution of embolic materials was assessed on CT within 1-3 days. The mass was surgically removed 3 to 7 days after embolization. Direct glue embolization of juvenile angiofibroma with skull base invasion appears to be a simple and safe procedure. The technique could be used for other hypervascular lesions in the base of the skull or parapharyngeal space. (author). 19 refs., 1 tab., 2 figs.

  14. Juvenile nasopharyngeal angiofibroma with skull base invasion : intratumoral direct puncture embolization

    International Nuclear Information System (INIS)

    Shin, Hye Young; Kim, Sun Yong; Suh, Jung Ho; Park, Kee Hyun

    1998-01-01

    The purpose of this study is to demonstrate the utility and efficacy of percutaneous direct glue embolization for juvenile nasopharyngeal angiofibromas with skull base invasion. In nine cases of juvenile nasopharyngeal angiofibromas with invasion of the skull base, embolization under general anethesia was performed. Using an 18G spinal needle, direct puncture were made via the transnasal or mandibular sciatic notch. A glue-lipiodol mixture (1:1 -1:3) was injected slowly for 15 to 30 seconds under fluoroscopic control; the number of post-embolization angiography and the distribution of embolic materials was assessed on CT within 1-3 days. The mass was surgically removed 3 to 7 days after embolization. Direct glue embolization of juvenile angiofibroma with skull base invasion appears to be a simple and safe procedure. The technique could be used for other hypervascular lesions in the base of the skull or parapharyngeal space. (author). 19 refs., 1 tab., 2 figs

  15. Transarterial embolization for postoperative massive hemorrhage in patients with abdominal tumors

    International Nuclear Information System (INIS)

    Wang Zhiwei; Shi Haifeng; Sun Hao; Zhou Kang; Li Xiaoguang; Pan Jie; Zhang Xiaobo; Liu Wei; Yang Ning; Jin Zhengyu

    2010-01-01

    Objective: To discuss the feasibility and effectiveness of transarterial embolization for the management of postoperative massive hemorrhage in patients with abdominal tumors. Methods: Between January 2004 and December 2009 in authors' hospital transarterial embolization for postoperative massive hemorrhage was performed in thirteen patients with abdominal tumors. The clinical data and the technical points were retrospectively analyzed. Results: Of 13 patients,the bleeding was completely controlled in 10 after single embolization procedure. Re-bleeding occurred in the other 3 patients, and angiography showed the new bleeding arteries. Trans arterial embolization was carried out again, and the bleeding was successfully stopped in 2 patients. The remaining one patient had to be treated with surgery as the microcatheter could not be super-selectively placed into the bleeding vessel. The overall clinical success rate of trans arterial embolization for postoperative massive hemorrhage was 92% (12 /13). No severe complications occurred. Conclusion: Trans arterial embolization is a safe and effective treatment for postoperative massive hemorrhage in patients with abdominal tumors. (authors)

  16. Urgent surgical management for embolized occluder devices in childhood: single center experience

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    Gokaslan Gokhan

    2012-12-01

    Full Text Available Abstract Background In this study, we sought to analyze our experience in urgent surgical management for embolized cardiac septal and ductal occluder devices resulting from trans-catheter closure of atrial septal defect, ventricular septal defect and patent ductus arteriosus in childhood patient group. Methods We retrospectively reviewed 9 patients (aged 2–15 years who underwent urgent surgery due to cardiac septal and ductal occluder embolization between January 2007 and December 2010. Congenital defects were atrial septal defect (n = 6, ventricular septal defect (n = 1, and patent ductus arteriosus (n = 2. Risk factors for device embolization and urgent surgical management techniques for embolized device removal were discussed. Results Removal of embolized devices in all cases and repair of damaged tricuspid valve in 2 patients were performed. Inevitably, all congenital defects were closed or ligated up to the primary defect. Total circulator arrest necessitated in 1 patient with ascending aortic device embolization. All operations were completed successfully and no hospital mortality or morbidity was encountered. Conclusions Although closure of left to right shunting defects by percutaneous occluder devices has a lot of advantages, device embolization is still a major complication. If embolized device retrieval fails with percutaneous intervention attempts, surgical management is the only method to remove embolized devices. In this circumstance, to provide an uneventful perioperative course, urgent management strategies should be well planned.

  17. Outcome of acute nonvariceal gastrointestinal haemorrhage after nontherapeutic arteriography compared with embolization

    International Nuclear Information System (INIS)

    Defreyne, Luc; Vanlangenhove, Peter; Decruyenaere, Johan; Van Maele, Georges; De Vos, Martine; Troisi, Roberto; Pattyn, Piet

    2003-01-01

    In acute nonvariceal gastrointestinal (GI) bleeding, immediate arteriographic haemostasis is presently assumed to be a therapeutic advantage. This study assesses whether the risk of a delayed haemostasis, caused by arteriographic findings precluding embolization, might influence patient outcome. We performed a 5.5-year retrospective database search to find all patients referred for arteriography to arrest acute nonvariceal GI bleeding with embolization. The embolized and nonembolized patients were compared for differences in baseline characteristics and bleeding parameters. In both groups the outcome of all endoscopic or surgical interventions after catheterization was included in the follow-up. Clinical success (at 30 days, after all therapy) and in-hospital mortality in the embolized and nonembolized group were compared. We retrieved 63 nonembolized bleedings in 58 patients and 49 embolized bleedings in 49 patients. In the nonembolized group, transfusion need and haemodynamic instability were significantly less severe. Forty-two of 63 (66%) nonembolized bleedings persisted requiring haemostasis by surgery (n=23), endoscopy (n=13) or supportive transfusions. Thirteen of 49 (27%) embolized bleedings recurred and were managed by surgery (n=7), endoscopy (n=3) or transfusion. Overall clinical success rate was 88.9% (56 of 63) in the nonembolized and 87.8% (43 of 49) in the embolized group. Mortality rate was 17.2% (10 of 58) in the nonembolized vs 30.6% (15 of 49) in the embolized patients (P=0.115). Whether or not arteriographic findings afforded the opportunity to embolize, outcome of acute nonvariceal GI bleeding did not differ significantly; however, patients undergoing embolization were more critically bleeding and ill. (orig.)

  18. Patient-exposure data for doppler ultrasound

    International Nuclear Information System (INIS)

    Stewart, H.F.; Silvis, P.X.; Smith, S.W.

    1986-01-01

    In recent years ultrasound imaging and Doppler blood flow measurements have become important tools for use in diagnostic medicine. Commercial pulse-echo imaging equipment was first introduced into commerce in 1963. The first commercial continuous wave Doppler unit was introduced to the marketplace in 1966. As equipment improved and applications developed, the industry experienced rapid growth in the 1970s. One of the more recent growth areas in the application of diagnostic ultrasound has been the use of pulsed Doppler equipment for cardiac applications. Prior to 1976, some continuous wave Doppler ultrasound was used for cardiovascular diagnosis. However, only a single manufacturer marketed a pulsed Doppler clinical instrument for cardiac or peripheral vascular diagnosis. Currently, many continuous wave and pulsed Doppler instruments are commercially available for both peripheral vascular and cardiac diagnosis. This chapter (1) briefly reviews current safety guidelines, regulations, and recommendations for diagnostic ultrasound; (2) discusses the patient-exposure intensities associated with Doppler ultrasound medical equipment and compare these levels of exposure with intensities from other medical ultrasound devices; and (3) considers some of the current information as it relates to the safety of diagnostic ultrasound

  19. Coherent optical transients observed in rubidium atomic line filtered Doppler velocimetry experiments

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    Fajardo, Mario E., E-mail: mario.fajardo@eglin.af.mil; Molek, Christopher D.; Vesely, Annamaria L. [Air Force Research Laboratory, Munitions Directorate, Ordnance Division, Energetic Materials Branch, AFRL/RWME, 2306 Perimeter Road, Eglin AFB, Florida 32542-5910 (United States)

    2015-10-14

    We report the first successful results from our novel Rubidium Atomic Line Filtered (RALF) Doppler velocimetry apparatus, along with unanticipated oscillatory signals due to coherent optical transients generated within pure Rb vapor cells. RALF is a high-velocity and high-acceleration extension of the well-known Doppler Global Velocimetry (DGV) technique for constructing multi-dimensional flow velocity vector maps in aerodynamics experiments [H. Komine, U.S. Patent No. 4,919,536 (24 April 1990)]. RALF exploits the frequency dependence of pressure-broadened Rb atom optical absorptions in a heated Rb/N{sub 2} gas cell to encode the Doppler shift of reflected near-resonant (λ{sub 0} ≈ 780.24 nm) laser light onto the intensity transmitted by the cell. The present RALF apparatus combines fiber optic and free-space components and was built to determine suitable operating conditions and performance parameters for the Rb/N{sub 2} gas cells. It yields single-spot velocities of thin laser-driven-flyer test surfaces and incorporates a simultaneous Photonic Doppler Velocimetry (PDV) channel [Strand et al., Rev. Sci. Instrum. 77, 083108 (2006)] for validation of the RALF results, which we demonstrate here over the v = 0 to 1 km/s range. Both RALF and DGV presume the vapor cells to be simple Beer's Law optical absorbers, so we were quite surprised to observe oscillatory signals in experiments employing low pressure pure Rb vapor cells. We interpret these oscillations as interference between the Doppler shifted reflected light and the Free Induction Decay (FID) coherent optical transient produced within the pure Rb cells at the original laser frequency; this is confirmed by direct comparison of the PDV and FID signals. We attribute the different behaviors of the Rb/N{sub 2} vs. Rb gas cells to efficient dephasing of the atomic/optical coherences by Rb-N{sub 2} collisions. The minimum necessary N{sub 2} buffer gas density ≈0.3 amagat translates into a

  20. Preoperative embolization in the treatment of vascular metastatic lesions of the spine

    International Nuclear Information System (INIS)

    Gellad, F.E.; Nourmohammadi, N.; Numaguchi, Y.; Sadato, H.; Levine, A.M.

    1989-01-01

    Preoperative embolization of metastatic renal and thyroid carcinomas of the spine is an adjuvant technique that decreases significantly the intraoperative blood loss and resultant morbidity. This paper reports on twenty-one patients with spinal cord compression secondary to metastatic renal and thyroid disease who underwent preoperative spinal arteriography for embolization. Sixteen patients were embolized, two patients twice for recurrent tumor. None of the patients developed postangiographic or embolization complications. The procedures were performed with a digital subtraction technique. Gelfoam particles or lvalon powder was used. If Gelfoam is the embolic material used, surgery should be performed within 24 hours to prevent recanalization

  1. Microcoil Embolization for Acute Lower Gastrointestinal Bleeding

    International Nuclear Information System (INIS)

    D'Othee, Bertrand Janne; Surapaneni, Padmaja; Rabkin, Dmitry; Nasser, Imad; Clouse, Melvin

    2006-01-01

    Purpose. To assess outcomes after microcoil embolization for active lower gastrointestinal (GI) bleeding. Methods. We retrospectively studied all consecutive patients in whom microcoil embolization was attempted to treat acute lower GI bleeding over 88 months. Baseline, procedural, and outcome parameters were recorded following current Society of Interventional Radiology guidelines. Outcomes included technical success, clinical success (rebleeding within 30 days), delayed rebleeding (>30 days), and major and minor complication rates. Follow-up consisted of clinical, endoscopic, and pathologic data. Results. Nineteen patients (13 men, 6 women; mean age ± 95% confidence interval = 70 ± 6 years) requiring blood transfusion (10 ± 3 units) had angiography-proven bleeding distal to the marginal artery. Main comorbidities were malignancy (42%), coagulopathy (28%), and renal failure (26%). Bleeding was located in the small bowel (n = 5), colon (n 13) or rectum (n = 1). Technical success was obtained in 17 patients (89%); 2 patients could not be embolized due to vessel tortuosity and stenoses. Clinical follow-up length was 145 ± 75 days. Clinical success was complete in 13 (68%), partial in 3 (16%), and failed in 2 patients (11%). Delayed rebleeding (3 patients, 27%) was always due to a different lesion in another bowel segment (0 late rebleeding in embolized area). Two patients experienced colonic ischemia (11%) and underwent uneventful colectomy. Two minor complications were noted. Conclusion. Microcoil embolization for active lower GI bleeding is safe and effective in most patients, with high technical and clinical success rates, no procedure-related mortality, and a low risk of bowel ischemia and late rebleeding

  2. Superselective uterine artery embolization for the control and prevention of obstetric hemorrhage

    International Nuclear Information System (INIS)

    Song Li; Tong Xiaoqiang; Wang Jian; Yang Min; Lv Yongxing; Zou Yinghua

    2008-01-01

    Objectives: To evaluate the efficacy of superselective uterine artery embolization for treatment and prevention of obstetric hemorrhage. Methods: Between April 2004 and December 2007, 47 consecutive patients underwent uterine artery embolization to control or prevent hemorrhage, including 20 patients for preventing hemorrhage before abortion and 27 for controlling obstetric hemorrhage. Results: Bilateral uterine artery embolization was performed in all cases except one for abnormal vascular anatomy receiving unilateral approach. Within 10 days after embolization, curettage abortion or uterine-incision delivery was done without hysterectomy, and hemorrhage during abortion was less with average of 54 ml. Conclusions: The high success rate, effectiveness and possibility of preserving reproductive function have made uterine artery embolization the technique of choice to control obstetric hemorrhage, and prophylactic embolization, can prevent hemorrhage before abortion. (authors)

  3. Preoperative Direct Puncture Embolization of Advanced Juvenile Nasopharyngeal Angiofibroma in Combination with Transarterial Embolization: An Analysis of 22 Consecutive Patients

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    Lv Mingming, E-mail: lvmingming001@163.com; Fan, Xin-dong, E-mail: fanxindong@yahoo.com.cn [Shanghai Jiao Tong University School of Medicine, Department of Radiology, Ninth People' s Hospital (China); Su Lixin, E-mail: sulixin1975@126.com [Shanghai Jiao Tong University School of Medicine, Department of Oral and Maxillofacial Surgery, Ninth People' s Hospital (China); Chen Dong, E-mail: chenjsun@public8.sta.net.cn [Shanghai Jiao Tong University School of Medicine, Department of Otolaryngology, Ninth People' s Hospital (China)

    2013-02-15

    ObjectiveThis study was designed to evaluate the clinical application of preoperative auxiliary embolization for juvenile nasopharyngeal angiofibroma (JNA) by direct puncture embolization (DPE) of the tumor in combination with transarterial embolization (TAE). The study included 22 patients. An 18-gauge needle was used to puncture directly into the tumor, and 20-25 % N-butyl cyanoacrylate was injected under the guidance of fluoroscopy after confirming the placement of the needle into the JNA and no leaking into the surrounding tissue. Tumors were obstructed later via TAE. The supplying arteries of JNA were from branches of the internal carotid and external carotid arteries. Control angiography showed the obliteration of contrast stain in the entire tumor mass and the distal supplying arteries disappeared after DPE in combination with TAE. Surgical resection was performed within 4 days after embolization and none of the patients required blood transfusion. The use of DPE in combination with TAE was a safe, feasible, and efficacious method. It can devascularize effectively the JNAs and reduce intraoperative bleeding when JNAs are extirpated.

  4. Preoperative Direct Puncture Embolization of Advanced Juvenile Nasopharyngeal Angiofibroma in Combination with Transarterial Embolization: An Analysis of 22 Consecutive Patients

    International Nuclear Information System (INIS)

    Lv Mingming; Fan, Xin-dong; Su Lixin; Chen Dong

    2013-01-01

    ObjectiveThis study was designed to evaluate the clinical application of preoperative auxiliary embolization for juvenile nasopharyngeal angiofibroma (JNA) by direct puncture embolization (DPE) of the tumor in combination with transarterial embolization (TAE). The study included 22 patients. An 18-gauge needle was used to puncture directly into the tumor, and 20–25 % N-butyl cyanoacrylate was injected under the guidance of fluoroscopy after confirming the placement of the needle into the JNA and no leaking into the surrounding tissue. Tumors were obstructed later via TAE. The supplying arteries of JNA were from branches of the internal carotid and external carotid arteries. Control angiography showed the obliteration of contrast stain in the entire tumor mass and the distal supplying arteries disappeared after DPE in combination with TAE. Surgical resection was performed within 4 days after embolization and none of the patients required blood transfusion. The use of DPE in combination with TAE was a safe, feasible, and efficacious method. It can devascularize effectively the JNAs and reduce intraoperative bleeding when JNAs are extirpated.

  5. Digital spectrometer for coincidence measurement of Doppler broadening of positron annihilation radiation

    International Nuclear Information System (INIS)

    Cizek, J.; Vlcek, M.; Prochazka, I.

    2010-01-01

    High-resolution digital coincidence Doppler broadening spectrometer equipped with two high-purity Ge detectors and two-channel 12-bit fast digitizer was developed and tested in this work. Two configurations were compared: (i) semi-digital setup which uses active analogue shaping of detector pulses prior to digitization to improve signal-to-noise ratio, and (ii) pure-digital setup which samples detector pulses directly. Software procedure developed for analysis of sampled waveforms, i.e. precise determination of energy of detected photon and rejection of distorted pulses, is described. Performance of digital coincidence spectrometer was compared with traditional analogue setup connected to the same detectors. It was found that digital spectrometer enables to achieve better energy resolution than in traditional analogue setup. Moreover, in digital configuration one has better control over shape of the signal. This allows efficient elimination of undesired distorted or damaged waveforms and to obtain spectrum of better clarity. The superior parameters of new digital coincidence Doppler broadening spectrometer are demonstrated by benchmark measurements of well defined Fe and Al specimens and also by the detection of rare annihilation in flight events.

  6. Uterine artery embolization for uterine leiomyomas: impact on serum level of sex hormones

    International Nuclear Information System (INIS)

    Fu Shouzhong; Dai Feng; Zhang Lihua; Ding Wei; Wang Xiaowei; Wang Xiaoyan; Wang Jianhua

    2007-01-01

    Objective: To investigate the impact of uterine artery embolization (UAE) for leiomyomas of uterus on serum level of sex hormones. Methods: UAE were performed on 31 patients with leiomyomas of uterus. Changes of menses were followed up within 3-6 months after UAE. Serum levels of sex hormones, including FSH, LH, Prog, E2 were tested before and 3 months or 6 months after UAE; and simultaneously with recording the tumor size and the changes of blood dynamics by color Doppler. Results: Twenty-five patients (80.6%)with menorrhagia resumed normal after UAE, and a transient menstrual disorder occurred in 4 patients (12.9%). Only 2 patients (0.06%)aged 45 years and 49 years became menopausal following the procedure. Serum levels of sex hormones showed no significant difference before and 3 months or 6 months after UAE (P>0.05)in 31 patients. Conclusion: UAE is an effective treatment for uterine leiomyomas and possesses no influence on serum levels of sex hormones. However, for patients aged 45 or older, there is possibility of menopause. (authors)

  7. Arterial embolization therapy of traumatic renal hemorrhage

    International Nuclear Information System (INIS)

    Wu Changxu; Chen Xiaolin; Huang Changhai; Pu Ge

    2000-01-01

    Objective: To study the angiographic manifestations and arterial embolizatin for traumatic renal hemorrhage when conservative treatment had failed. methods: 5 cases, all male, ranging in age from 12-29 years. All cases had history of injury. the main symptoms included severe abdominal pain, hematuria or coffee colored urine, rapid heart rate, hypotension. 3 suffered hemorrhagic shock. All cases underwent angiographic exam and the diagnosis was confirmed. Embolization materials were mainly self-blood clot and gelfoam. Results: Symptoms in all cases subsided quickly after embolization. Blood pressure recovered to normal within 12 hours; Hematuresis and abdominal pain disappeared or reduced in 1-2 days. One month later, intravenous urographic exam revealed recovered function of the injured kidneys. Conclusion: Renal arterial embolization in treating traumatic renal hemorrhage can control the bleeding while preserving the injured kidneys

  8. Doppler tomography in fusion plasmas and astrophysics

    DEFF Research Database (Denmark)

    Salewski, Mirko; Geiger, B.; Heidbrink, W. W.

    2015-01-01

    Doppler tomography is a well-known method in astrophysics to image the accretion flow, often in the shape of thin discs, in compact binary stars. As accretion discs rotate, all emitted line radiation is Doppler-shifted. In fast-ion Dα (FIDA) spectroscopy measurements in magnetically confined plasma......, the Dα-photons are likewise Doppler-shifted ultimately due to gyration of the fast ions. In either case, spectra of Doppler-shifted line emission are sensitive to the velocity distribution of the emitters. Astrophysical Doppler tomography has lead to images of accretion discs of binaries revealing bright...... and limits, analogies and differences in astrophysical and fusion plasma Doppler tomography and what can be learned by comparison of these applications....

  9. Coil Migration after Transarterial Coil Embolization of a Splenic Artery Pseudoaneurysm

    Directory of Open Access Journals (Sweden)

    Bezawit D. Tekola

    2013-11-01

    Full Text Available A 48-year-old man with a history of splenic artery pseudoaneurysm requiring transarterial embolization 3 months earlier presented to the emergency department with abdominal pain and fever. Computed tomography showed evidence of embolization coil fragments within the gastrointestinal tract. Upper endoscopy showed a large gastric ulcer with numerous embolization coils extruding into the gastric lumen. The patient underwent partial gastrectomy, distal pancreatectomy and resection of the splenic artery pseudoaneurysm. This case illustrates a rare delayed complication of transarterial embolization of a splenic artery pseudoaneurysm.

  10. Selective arterial embolization in the management of symptomatic renal angiomyolipomas

    Energy Technology Data Exchange (ETDEWEB)

    Mourikis, Dimitrios; Chatziioannou, Achilles; Antoniou, Aristidis; Kehagias, Dimitrios; Gikas, Dimitrios; Vlahos, Lambros

    1999-12-01

    Current management of renal angiomyolipomas (AMLs) include observation, transcatheter embolization and partial or total nephrectomy. Patients symptoms and size of the lesion are the determinants for the choice of the treatment. In general symptomatic or greater than 8 cm masses require intervention. A retrospective study of five patients presented with symptomatic lesions and treated with selective transcatheter embolization, over a 3 year period was performed in our hospital. A total of eight embolizations were performed, all on an emergency basis due to retroperitoneal bleeding or significant hematuria. Surgical intervention was necessary in one case, due to massive rebleeding on the fourth post-procedural day. Two patients rebled within 6 months and 2 years respectively, and were managed successfully with additional embolization. The remaining two patients are still asymptomatic 26 and 18 months after the successful initial result. Experience with this procedure is reported on with emphasis to the clinical outcome. It is believed that selective arterial embolization should be the standard initial therapy for symptomatic renal AMLs.

  11. Selective arterial embolization in the management of symptomatic renal angiomyolipomas

    International Nuclear Information System (INIS)

    Mourikis, Dimitrios; Chatziioannou, Achilles; Antoniou, Aristidis; Kehagias, Dimitrios; Gikas, Dimitrios; Vlahos, Lambros

    1999-01-01

    Current management of renal angiomyolipomas (AMLs) include observation, transcatheter embolization and partial or total nephrectomy. Patients symptoms and size of the lesion are the determinants for the choice of the treatment. In general symptomatic or greater than 8 cm masses require intervention. A retrospective study of five patients presented with symptomatic lesions and treated with selective transcatheter embolization, over a 3 year period was performed in our hospital. A total of eight embolizations were performed, all on an emergency basis due to retroperitoneal bleeding or significant hematuria. Surgical intervention was necessary in one case, due to massive rebleeding on the fourth post-procedural day. Two patients rebled within 6 months and 2 years respectively, and were managed successfully with additional embolization. The remaining two patients are still asymptomatic 26 and 18 months after the successful initial result. Experience with this procedure is reported on with emphasis to the clinical outcome. It is believed that selective arterial embolization should be the standard initial therapy for symptomatic renal AMLs

  12. Uterine arterial embolization for uterine leiomyoma: efficacy and clinical outcome

    International Nuclear Information System (INIS)

    Park, Jeong Seon; Lee, Do Yon; Kim, Yong Tae; Park, Ki Hyun; Park, Yong Won; Cho, Jae Sung; Kim, Myung Jun; Won, Je Hwan; Kang, Byung Chul

    1999-01-01

    To determine the efficacy and clinical outcome of uterine arterial embolization as a new approach to the management of uterine leiomyomas. Uterine arterial embolization was performed in 21 patients aged 26-62(mean, 42) years. Twenty of these had menorrhagia, dysmenorrhea, and mass-related symptoms (low abdominal discomfort, backache, urinary frequency, etc.) and one was diagnosed incidentally. Bilateral uterine arteries were selected individually and polyvinyl alcohol and/or gelfoam was used as an embolic material. Nineteen patients were followed up after embolization. Seventeen (89.5 %)reported satisfactory improvement of symptoms and follow-up sonography three months later showed a 58.5 % reduction in mean myoma volume. In 17 patients (89.5 %), the menstrual cycle returned to normal. All patients experienced pain after the procedure and other complications were vaginal bleeding (26.3 %) and fever (23.8 %). Uterine arterial embolization represents a new approach to the management of uterine leiomyoma-related symptoms. Further investigations and long-term follow-up are, however, enquired

  13. Uterine arterial embolization for uterine leiomyoma: efficacy and clinical outcome

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jeong Seon; Lee, Do Yon; Kim, Yong Tae; Park, Ki Hyun; Park, Yong Won; Cho, Jae Sung; Kim, Myung Jun [Yonsei Univ. College of Medicine, Seoul (Korea, Republic of); Won, Je Hwan [Ajou Univ. College of Medicine, Suwon (Korea, Republic of); Kang, Byung Chul [Ewha Womans Univ. College of Medicine, Seoul (Korea, Republic of)

    1999-09-01

    To determine the efficacy and clinical outcome of uterine arterial embolization as a new approach to the management of uterine leiomyomas. Uterine arterial embolization was performed in 21 patients aged 26-62(mean, 42) years. Twenty of these had menorrhagia, dysmenorrhea, and mass-related symptoms (low abdominal discomfort, backache, urinary frequency, etc.) and one was diagnosed incidentally. Bilateral uterine arteries were selected individually and polyvinyl alcohol and/or gelfoam was used as an embolic material. Nineteen patients were followed up after embolization. Seventeen (89.5 %)reported satisfactory improvement of symptoms and follow-up sonography three months later showed a 58.5 % reduction in mean myoma volume. In 17 patients (89.5 %), the menstrual cycle returned to normal. All patients experienced pain after the procedure and other complications were vaginal bleeding (26.3 %) and fever (23.8 %). Uterine arterial embolization represents a new approach to the management of uterine leiomyoma-related symptoms. Further investigations and long-term follow-up are, however, enquired.

  14. Emergency treatment by intravascular embolization in traumatic carotid cavernous fistula

    International Nuclear Information System (INIS)

    Tang Jun; Sun Zengtao; Liu Zuoqin; Liu Yanjun; Li Fengxin

    2006-01-01

    Objective: To discuss the method of intervenfional intravascular treatment in traumatic carotid cavernous fistula (TCCF) and the significance of clinical application in emergency. Methods: In 297 eases of TCCF, 36 cases were treated by interventional intravascular embolization by detachable balloon, embolization orificium or occlusion in one side of carotid artery. In the 36 cases, serious epistaxis occurred in 22 eases, cortical vein inflow in 9 cases, intracranial hemorrhage in 3 cases, aggravation of eyesight in 3 cases, and limb dysfunction in 2 cases. Results: Fistula was successfully embolized and internal carotid artery remained patent in 19 cases. Complete embolization of orificium or internal carotid artery was achieved in 17 eases. The serious epistaxias in 22 cases and intracranial hemorrhage in 3 cases stopped. Eyesight recovered in 2 eases and improved in 1 case. Limb dysfunction improved evidently in 2 cases. Conclusion: Intravascular embolization treatment is the first therapeutic choice for TCCF, especially in emergency. It is necessary, safe and effective. (authors)

  15. QUALITY OF LIFE IN PATIENTS AFTER MASSIVE PULMONARY EMBOLISM

    Directory of Open Access Journals (Sweden)

    Dragan Kovačić

    2004-04-01

    Full Text Available Background. Pulmonary embolism is a disease, which has a 30% mortality if untreated, while an early diagnosis and treatment lowers it to 2–8%. Health related quality of life (HRQL of patients who survived massive pulmonary embolism is unknown in published literature. In our research we tried to apply experience of foreign experts in estimation of quality of life in some other diseases to the field of massive pulmonary embolism.Patients and methods. Eighteen patients with shock or hypotension due to massive pulmonary embolism, treated with thrombolysis, between July 1993 and November 2000, were prospectively included in the study. Control group included 18 gender and age matched persons. There were no significant differences regarding demographic data between the groups. The HRQL and aerobic capacity of patients and control group were tested with short questions and questionnaires (Veterans brief, self administered questionnaire (VSAQ, EuroQuality questionnaire (EQ, Living with heart failure questionnaire (LlhHF. With LlhHF physical (F-LlhHF and emotional (E-LlhHF HRQL was assessed at hospitalization and 12 months later.Results. One year after massive pulmonary embolism aerobic capacity (–9.5%, p < 0.017 and HRQL (EQ (–34.5%, F-LlhHF (–85.4%, E-LlhHF (–48.7% decreased in massive pulmonary embolism group compared to aerobic capacity 6 months before massive pulmonary embolism and HRQL. Heart rate before thrombolysis correlated with aerobic capacity (r = 0.627, p < 0.01, EQ (r = 0.479, p < 0.01 and F-LlhHF (r = 0.479, p = 0.04 1 year after massive pulmonary embolism. Total pulmonary resistance at 12 hours after start of treatment correlated with aerobic capacity at 1 year (r = 0.354, p < 0.01.With short question (»Did you need any help in everyday activities in last 2 weeks?« we successfully separated patients with decreased HRQL in EQ (74.3 ± 20.8 vs. 24.5 ± 20.7, p < 0.001 and F-LlhHF (21.7 ± 6.7 vs. 32.8 ± 4.3, p < 0.01, but we

  16. Diversity combining in laser Doppler vibrometry for improved signal reliability

    International Nuclear Information System (INIS)

    Dräbenstedt, Alexander

    2014-01-01

    Because of the speckle nature of the light reflected from rough surfaces the signal quality of a vibrometer suffers from varying signal power. Deep signal outages manifest themselves as noise bursts and spikes in the demodulated velocity signal. Here we show that the signal quality of a single point vibrometer can be substantially improved by diversity reception. This concept is widely used in RF communication and can be transferred into optical interferometry. When two statistically independent measurement channels are available which measure the same motion on the same spot, the probability for both channels to see a signal drop-out at the same time is very low. We built a prototype instrument that uses polarization diversity to constitute two independent reception channels that are separately demodulated into velocity signals. Send and receive beams go through different parts of the aperture so that the beams can be spatially separated. The two velocity channels are mixed into one more reliable signal by a PC program in real time with the help of the signal power information. An algorithm has been developed that ensures a mixing of two or more channels with minimum resulting variance. The combination algorithm delivers also an equivalent signal power for the combined signal. The combined signal lacks the vast majority of spikes that are present in the raw signals and it extracts the true vibration information present in both channels. A statistical analysis shows that the probability for deep signal outages is largely decreased. A 60 fold improvement can be shown. The reduction of spikes and noise bursts reduces the noise in the spectral analysis of vibrations too. Over certain frequency bands a reduction of the noise density by a factor above 10 can be shown

  17. Bletilla colloid as a vascular embolization agent: experimental studies

    International Nuclear Information System (INIS)

    Zheng Chuansheng; Feng Gansheng; Zhang Yanfang

    1998-01-01

    Purpose: To study the efficacy, safety and related characteristics of bletilla colloid as a vascular embolization agent. Materials and methods: The authors prepared bletilla colloid as a vascular embolization agent from the stem tubers of bletilla of Chinese medicinal herb. Related characteristics of bletilla colloid were studied. In four pigs hepatic arterial embolization was performed with the bletilla colloid. Results: The bletilla colloid was a homogenous viscous colloid whose relative viscosity was 2324.6 mm 2 /s. It was easily injected through 4-F catheter and hyperattenuating under fluoroscopy, meanwhile, with good histocompatibility and hemo-compatibility, without pyrogenetic response and toxicity. In vitro, the mixture of bletilla colloid and MMC did not produce separation and suspension phenomena but released 50% of MMC at 1.8h and 100% at 3.4h. The bletilla colloid mainly embolized peripheral arteries, maintaining occlusion for 5 weeks and without formation of collateral circulation. The injuries of normal hepatic tissues were slight, without hepatic cytonecrosis. Conclusions: Bletilla colloid, safe and effective in use with angioembolic function and characteristics of carrier and slow-release, is a potential peripheral embolization agent

  18. Design of an integrated photo detector circuit for laser doppler blood flow monitoring

    NARCIS (Netherlands)

    Nieland, J.; Nieland, J.; van Kranenburg, H.; Wallinga, Hans; Serov, Alexander; Steenbergen, Wiendelt; de Mul, F.F.M.

    1999-01-01

    A method to measure the blood perfusion of tissue is to apply photons to tissue and measure the frequency shift of the Doppler shifted photons.. To avoid the use of fibers, a chip was designed which contains photodetectors and electronic circuitry to amplify the signal. This IC serves as an

  19. Transcatheter embolization for high blood flow vascular malformations of oral maxillofacial region

    International Nuclear Information System (INIS)

    Sun Zengtao; Liu Zuoqin; Li Jijun; Tang Jun; Shang Jianqiang; Chen Jie

    2007-01-01

    Objective: To explore the treatment and efficiency of high blood flow vascular malformations of oral maxillofacial region with super-selective arterial embolization. Methods: 18 cases underwent angiography of the head and neck before treatment and then followed by super-selective catheterization with microcatheter to embolize the feeding vessels of the vascular malformations with PVA. 8 cases underwent surgical excision within 72 hours after the embolization and the other 10 cases passed through the arterial radical emboliztion treatment. Results: Technical success ratio reached 100% with no complications causing skin necrosis or incorrect arterial embolization else where in the skull. All 8 cases undergone preoperative embolization showed obviously less bleeding, easier removal of the mass and reduction of operation time. 10 cases with radical arterial embolization manifested reduction of swelling and improvement of organ function within 1 to 24 months after the procedure. 5 patients were cured with only once operation, 4 cases with twice operation and 1 with the thrice. Conclusions: Aterial embolization is a safe and effective method in the treatment of high blood flow vascular malformations of oral maxillofacial region. (authors)

  20. Renal aneurysm and arteriovenous fistula; Management with transcatheter embolization

    Energy Technology Data Exchange (ETDEWEB)

    Savastano, S.; Feltrin, G.P.; Miotto, D.; Chiesura-Corona, M. (Padua Univ. (Italy). Ist. di Radiologia Padua Univ. (Italy). Ist. di Fisioterapia)

    1990-01-01

    Embolization was performed in six patients with renal artery aneurysms (n=2) and arteriovenous fistulas (AVF) (n=5). The aneurysms were observed in one patient with fibromuscular dysplasia and in another with Ehlers-Danlos syndrome. All the AVFs were intraparenchymal and secondary to iatrogenic trauma. Elective embolization was performed in five patients with good clinical results at follow-up between 1 and 9 years. Because of rupture of the aneurysm emergency embolization was attempted without success in the patient with Ehlers-Danlos syndrome, and nephrectomy was carried out. A postembolization syndrome complicated three procedures in which Gelfoam and polyvinyl alcohol were used; in two of these cases unexpected reflux of the particulate material occurred, resulting in limited undesired ablation of the ipsilateral renal parenchyma. Embolization is the most reliable and effective treatment for intrarenal vascular abnormalities since it minimizes the parenchymal damage. (orig.).

  1. Revascularization of brain arteriovenous malformations after embolization with brucrylate

    International Nuclear Information System (INIS)

    Fournier, D.; Centre Hospitalier Universitaire, 49 - Angers; Terbrugge, K.; Lasjaunias, P.; Hopital de Bicetre, 94 - Le Kremlin-Bicetre; Rodesch, G.

    1990-01-01

    Between 1984 and 1988, 52 brain arteriovenous malformations (AVMs) were embolized in the Radiology Department of the Toronto Western Hospital. 9 were localized in the occipital lobe. There was angiographic follow-up ranging from one to four years. Two embolized AMVs, both occipital, showed revascularisation at 6 months and two years respectively. In one case the embolization had resulted in a complete obliteration of the AVM. In the other, the nidus was reduced by 95%. It is suggested that the occipital lobe, because of its rich vascularity, is more prone than other parts of the brain to produce intense collateralization leading indirectly to resupply of embolized AVMs. Existence of these collaterals may also explain the rarity of visual defects in occipital AVMs. These cases confirm the need for post therapeutic angiographic controls to assess the stability of the results obtain. (orig.)

  2. Clinical value of pre-operative embolization of maxillary artery for nasopharyngeal angiofibroma

    International Nuclear Information System (INIS)

    Zhu Wenke; Shan Hong; Zhu Kangshun; Jiang Zabo; Guan Shouhai; Huang Mingsheng; Li Zhengran; Shen Xinying

    2004-01-01

    Objective: To assess the clinical value of pre-operative embolization for nasopharyngeal angiofibroma. Methods: 13 patients with nasopharyngeal angiofibroma confirmed by surgery and biopsy were retrospectively analysed. Bilateral carotid artery angiography was performed for demonstration of the arterial supply of tumor. According to the size and different caliber of arteries, embolization were separately undertaken by different types of coil via 4.1 or 5F Head-Hunter catheter. The embolization efficacy, embolization was evaluated by amount of blood loss. Results: After coil embolization, no complication happened ranging 1-4 days (mean 2 days) in all 13 patients and then all the tumor masses were totally resected with mean blood loss of (584.6 ± 379.4) ml (range 250-1500 ml). Conclusions: Preoperative coils embolization is safe, reliable with less complication especially for reducing intraoperative blood loss and promoting the prognosis. (authors)

  3. Evaluation of arterial embolization therapy of hepatocellular carcinoma by computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Ohishi, H; Ohue, S; Ide, K [Nara Medical Univ., Kashihara (Japan)

    1981-11-01

    The therapeutic effect of arterial embolization performed to 18 patients with hepatocellular carcinoma was evaluated by means of computed tomography (CT). 1) After embolization, the tumor was observed to have been reduced in size in all the cases. The relative attenuation coefficients of the tumor region to surrounding liver tissue was decreased at initial stage after arterial embolization, however, it showed a tendency of more elevation than the initial stage in the cases performed follow-up CT. The decrease of the attenuation values at the initial stage suggests the ischemic necrosis, while its elevation is considered attributable to subsequent histologic change and tumor shrinkage. 2) The follow-up CT examination after the arterial embolization on hepatocellular carcinoma provides significant facility for evaluation of its effectiveness and judgement of the time for the repeat arterial embolization.

  4. Parametric Investigation of Laser Doppler Microphones

    Science.gov (United States)

    Daoud, M.; Naguib, A.

    2002-11-01

    The concept of a Laser Doppler Microphone (LDM) is based on utilizing the Doppler frequency shift of a focused laser beam to measure the unsteady velocity of the center point of a flexible polymer diaphragm that is mounted on top of a hole and subjected to the unsteady pressure. Time integration of the velocity signal yields a time series of the diaphragm displacement, which can be converted to pressure from knowledge of the sensor's deflection sensitivity. In our APS/DFD presentation last year, the stringent frequency resolution requirement of these new sensors and methods to meet this requirement were discussed. Here, the dependence of the sensor characteristics (sensitivity, bandwidth, and noise floor) on various significant parameters is investigated in detail by calibrating the sensor in a plane wave tube in the frequency range of 50 - 5000 Hz. Parameters investigated include sensor diaphragm material and thickness, sensor size, damping of the diaphragm motion and laser beam spot size. The results shed light on the operating limits of the new sensor and demonstrate its ability to conduct high-spatial-resolution measurements in typical high-Reynolds-number test facilities. Moreover, calibrated LDM sensors were used to conduct measurements in a separating/reattaching flow and the results are compared to classical electret-type microphones with a similar sensing diameter.

  5. Adaptive Spectral Doppler Estimation

    DEFF Research Database (Denmark)

    Gran, Fredrik; Jakobsson, Andreas; Jensen, Jørgen Arendt

    2009-01-01

    . The methods can also provide better quality of the estimated power spectral density (PSD) of the blood signal. Adaptive spectral estimation techniques are known to pro- vide good spectral resolution and contrast even when the ob- servation window is very short. The 2 adaptive techniques are tested......In this paper, 2 adaptive spectral estimation techniques are analyzed for spectral Doppler ultrasound. The purpose is to minimize the observation window needed to estimate the spectrogram to provide a better temporal resolution and gain more flexibility when designing the data acquisition sequence...... and compared with the averaged periodogram (Welch’s method). The blood power spectral capon (BPC) method is based on a standard minimum variance technique adapted to account for both averaging over slow-time and depth. The blood amplitude and phase estimation technique (BAPES) is based on finding a set...

  6. Evaluation of cutaneous blood flow responses by 133Xe washout and a laser-Doppler flowmeter

    International Nuclear Information System (INIS)

    Engelhart, M.; Kristensen, J.K.

    1983-01-01

    A new method for noninvasive measurement of cutaneous blood flow is laser-Doppler flowmetry. The technique is based on the fact that laser light is back-scattered from the moving red blood cells, with Doppler-shifted frequencies; these impulses lead to photodetectors and are converted to flow signals. In this work we used a new system with a low noise level. Comparison was made between this technique and the atraumatic epicutaneous 133 Xe technique for measurement of cutaneous blood flow during reactive hyperemia and orthostatic pressure changes. The laser-Doppler flowmeter seems to measure blood flow in capillaries as well as in arteriovenous anastomoses, while the 133 Xe method probably measures only capillary flow. A calibration of the laser-Doppler method against the 133 Xe method would appear to be impossible in skin areas where arteriovenous anastomoses are present. The changes in blood flow during reactive hyperemia, orthostatic pressure changes, and venous stasis were found to be parallel as measured by the two methods in skin areas without shunt vessels. The laser-Doppler flowmeter would appear to be a useful supplement to the 133Xe washout method in cutaneous vascular physiology, but it is important to keep in mind that different parameters may be measured

  7. OBESITY AS A RISK FACTOR FOR PULMONARY EMBOLISM

    Directory of Open Access Journals (Sweden)

    O. Ya. Vasiltseva

    2014-01-01

    Full Text Available The aim of the study. Based on the data of the Register of new cases of hospital pulmonary embolism (PE in hospitals in Tomsk (2003–2012, to explore the contribution of obesity to the development of venous thromboembolism.Material and Methods. Study were subjected to medical history and records of autopsies of patients treated in hospitals in Tomsk in 2003–2012, who at patologoanatomic and/or instrumental study revealed pulmonary embolism. The degree of obesity was assessed according to WHO criteria (1997. Statistical processing of the results was carried out using the software package for PC Statistica 8.0 for Windows. To test the normality of the distribution of quantitative traits using the Shapiro–Wilk test and the Kolmogorov–Smirnov with the adjusted Lillieforsa. Check the equality of the population variance was performed using Fisher's exact test and Cochran. Was considered statistically significant level of p < 0.05.The results of the study. In Western Siberia, Tomsk, a register of hospital pulmonary embolism (2003–2012. In the register included 720 patients with in vivo and/or post mortem revealed pulmonary embolism (PE. Analyzed data from medical records and autopsy reports. Revealed statistically significant differences in BMI (p = 0.033 and the presence of obesity (p = 0.002 in patients with pulmonary embolism, holding medical and surgical beds. As of medical, surgical and among patients with thromboembolism, obesity is significantly more common in women than men (p = 0.050 and p = 0.041 respectively. According to the study, obesity grade 1 or 2 alone (at the isolated presence of the patient is not significantly increased the odds of a massive thromboembolism. However, grade 3 obesity increased the odds of a massive pulmonary embolism by more than 2.7 times (OR = 2.708, CI: 1,461–5,020.

  8. Optical characteristics of modified fiber tips in single fiber, laser Doppler flowmetry

    Science.gov (United States)

    Oberg, P. Ake; Cai, Hongming; Rohman, Hakan; Larsson, Sven-Erik

    1994-02-01

    Percutaneous laser Doppler flowmetry (LDF) and bipolar surface electromyography (EMG) were used simultaneously for measurement of skeletal muscle (trapezius) perfusion in relation to static load and fatigue. On-line computer (386 SX) processing of the LDF- and EMG- signals made possible interpretation of the relationship between the perfusion and the activity of the muscle. The single fiber laser Doppler technique was used in order to minimize the trauma. A ray-tracing program was developed in the C language by which the optical properties of the fiber and fiber ends could be simulated. Isoirradiance graphs were calculated for three fiber end types and the radiance characteristics were measured for each fiber end. The three types of fiber-tips were evaluated and compared in flow model measurements.

  9. The diagnosis and treatment of two kinds of pulmonary embolism complications after interventional therapy

    International Nuclear Information System (INIS)

    Su Hongying; Xiao Liang; Zhong Hongshan; Xu Ke; Zheng Yanbo; Lu Zaiming

    2008-01-01

    Objective: To summarize the different types, clinical manifestation, treatment and prognosis of pulmonary embolism after interventional therapy in order to promote the diagnosis and treatment for the severe complication. Methods: The cases of pulmonary embolism complications after interventional therapy were collected from three hospitals between 1998 and 2005. The patients were divided into two types of iodized oil and thrombus pulmonary embolism according to the different types of the embolus. The experience of the clinical manifestation, diagnosis and treatment were summarized. Results: Ten patients with pulmonary embolism complication after interventional therapy were collected, including five with thrombus pulmonary embolism and four with iodized oil pulmonary embolism. All 5 cases of the thrombus pulmonary embolism suffered burst dyspnea and apsychia, two died and the others recovered or turned better. Aggravating dyspnea without shock occurred in the five iodized oil pulmonary embolism cases, 1 to 3 days after interventional therapy. The symptoms disappeared 15 to 50 days after combined therapy including majorly oxygen supply therapy. Conclusion: Pulmonary embolism is an emergent and severe complication after interventional therapy including acute thrombus pulmonary embolism without deep vein thrombosis which can be effectively treated be effectively treated with maintaining effective circulation and thrombolysis; and iodized oil pulmonary embolism with slow onsets could disappear within 1 month after combined therapy with mainly oxygen supplying therapy. The diagnosis and antidiastole mainly rely on enhancement of CT scan. (authors)

  10. Embolism of high energy firearm projectile

    Directory of Open Access Journals (Sweden)

    Jaime Álvarez Soler

    2016-12-01

    Full Text Available The embolism of a projectile is very rare and out of the normal context, so the cor-oner in front of a wound projectile firearm must make a very judicious and careful analysis to recover the projectile and/or its fragments. This case presents evidence how modern military high-velocity weapons have a high kinetic energy which is transferred to body tissues, so including their fragments and parts of the projectile can cause serious injury and embolism, requiring a great effort scientific and in-terdisciplinary to give technical support to justice.

  11. Uterine Fibroid Embolization (UFE)

    Science.gov (United States)

    ... or gynecologist. top of page What are the benefits vs. risks? Benefits Uterine fibroid embolization, done under local anesthesia , is ... risk of infection. The chance of infection requiring antibiotic treatment appears to be less than one in ...

  12. Clinical application of partial splenic embolization with PVA particles for hypersplenism in cirrhosis

    International Nuclear Information System (INIS)

    Zhu Kangshun; Shan Hong; Li Zhengran; Meng Xiaochun; Shen Xinying; Huang Mingsheng; Jiang Zaibo; Guan Shouhai

    2004-01-01

    Objective: To evaluate the efficacy and complications of partial splenic embolization (PSE) using polyvinyl alcohol (PVA) particles as embolic material for hypersplenism in cirrhosis. Methods: 50 patients with hypersplenism and cirrhosis were treated with PSE and followed up for 1 years. According to the difference of the embolic material in PSE, 41 patients were divided into 2 groups. Group A: 22 patients with gelfoam cubes as the embolic material of PSE. Group B: 19 patients with PVA as the embolic material of PSE. The follow-up indices included peripheral blood cells counts (white blood cell (WBC), platelet (PLT) and red blood cell (RBC)) and the complications associated with PSE. Results: In group A and group B, WBC and PLT counts kept significantly higher in number than pre-embolization from 2 weeks to 1 years after PSE (P 0.05). RBC counts did not show significant changes after PSE within 1 year follow-up (P>0.05). The most frequent side-effects were abdominal pain and fever. The degree and duration of abdominal pain were higher and longer in group B than those in group A, but the occurrence rate of fever was lower in group B. The occurrence rate of severe complications showed no significant differences for both groups. The increase of embolization degree may aggravate post-embolization side-effects and raise the incidence of complications. Conclusions: PVA may be used as the embolic material of PSE with embolization degree ranging from 50% to 70% which may alleviate hypersplenism in patients with cirrhosis, relieve post-embolization syndrome and decrease the incidence of severe complications

  13. Central venous cannulation: are routine chest radiographs necessary after B-mode and colour Doppler sonography check?

    International Nuclear Information System (INIS)

    Lanza, Cecilia; Fabrizzi, Giancarlo; Russo, Marco

    2006-01-01

    After the insertion of a central venous catheter, a chest radiograph is usually obtained to ensure correct positioning of the catheter tip. To determine in a paediatric population whether B-mode and colour Doppler sonography after central venous access is useful to evaluate catheter position, thus obviating the need for a postprocedural radiograph. A prospective study of 107 consecutive central venous access procedures placed in a paediatric intensive care unit was performed. At the end of the procedure, B-mode and colour Doppler sonography were used to assess catheter position and check for complications. A postprocedural chest radiograph was obtained in all patients. In 96 patients postprocedural B-mode and colour Doppler sonography showed colour Doppler signals within the vena cava. Among the 11 patients predicted to have a potential complication, there was one pneumothorax and ten malpositions. Chest radiography showed a total of 13 complications - 1 pneumothorax and 12 malpositions. The concordance between colour Doppler sonography and chest radiography was 98.1% in the detection of catheter position; sonography had a sensitivity of 84.6% and a specificity of 100%. The close concordance between B-mode and colour Doppler sonography and chest radiography justifies the more frequent use of sonography to evaluate catheter position because ionizing radiation is eliminated. Chest radiography may then be performed only when there is suspected inappropriate catheter tip position after sonography. (orig.)

  14. Evaluation of the activity of synovitis in patients with rheumatoid arthritis: Value of power Doppler ultrasonography

    International Nuclear Information System (INIS)

    Ahn, Joong Mo; Lim, Hyo Keun; Kim, Seung Hoon; Kim, Sung Hyun; Koh, Eun Mi; Kim, Jin Seok; Cha, Hoon Suk

    2001-01-01

    To correlate the grades on power Doppler ultrasonography with clinical disease activity indices and acute phase reactant values for assessing the activity of synovitis in patients with rheumatoid arthritis. Twenty patients with rheumatoid arthritis diagnosed on the basis of American College of power Doppler ultrasonography. Two experienced radiologists evaluated, in consensus, the power Doppler signals as follows: grade I=no flow or minimal flow, grade 2=mild flow, grade 3=moderate flow and grade 4= marked flow. The clinical disease activity indices consisted of the counts of tender joints and swollen joints, patient's assessment of pain, patient's global assessment of disease activity, physician's globe assessment of disease activity and patient's assessment of physical function. Acute-phase reactants included CRP and ESR. The grades on power Doppler ultrasonography were correlated with clinical disease activity indices as well as acute-phases reactant values by a use of Spearman rank correlation coefficient. The grades on power Doppler ultrasonography showed a statistically significant correlation with tender joint count (rs=.835; p<.05), swollen joint count (rs=.833; p<.05), physician's global assessment of disease activity (rs=.857; p<.05), CRP (rs=.838; P<.05) and ESR (rs=.838; p<.05). The power Doppler ultrasonography is an useful diagnostic modality for assessing the activity of synovitis in patients with rheumatoid arthritis.

  15. Evaluation of aortogenic embolic stroke using multi-detector row CT (MDCT)

    International Nuclear Information System (INIS)

    Mizuno, Masanori; Ooura, Kazumasa; Yamaguchi, Mao; Katsura, Noriyuki; Terayama, Yasuo

    2010-01-01

    Transesophageal cardioechography is one of the useful tools for detecting aortic arteriosclerosis causing aortogenic cerebral embolism. However, it is difficult to perform this method to all of the patients because of the technical difficulties due to patient's condition, especially the severity of atherosclerosis. To avoid the unexpected and adverse events, we are routinely applying multi-detector row CT (MDCT) to those patients. Among 10 cerebral embolic patients with unidentified embolic origin, MDCT revealed arteriosclerotic changes in aorta inducing mobile thrombus in 3 cases. The above data indicates that MDCT is safe and useful tool for diagnosis of aortogenic embolic stroke. (author)

  16. Doppler waveform study as indicator of change of portal pressure after administration of octreotide

    Science.gov (United States)

    Haider, Shahbaz; Hussain, Qurban; Tabassum, Sumera; Hussain, Bilal; Durrani, Muhammad Rasheed; Ahmed, Fayyaz

    2016-01-01

    Objective: To estimate the effect of portal pressure lowering drug ‘octreotide’, by observing the Doppler waveform before and after the administration of intravenous bolus of octreotide and thus to assess indirectly its efficacy to lower the portal pressure. Methods: This quassi experimental study was carried out in Medical Department in collaboration with Radiology Department of Jinnah Postgraduate Medical Center Karachi Pakistan from September 10, 2015 to February 5, 2016. Cases were selected from patients admitted in Medical Wards and those attending Medical OPD. Diagnosis of cirrhosis was confirmed by Clinical Examination and Lab & Imaging investigation in Medical Department. Doppler waveform study was done by experienced radiologist in Radiology Department before and after administration of octreotide. Doppler signals were obtained from the right hepatic vein. Waveform tracings were recorded for five seconds and categorized as ‘monophasic’, ‘biphasic’ and ‘triphasic’. Waveform changes from one waveform to other were noted and analyzed. Results: Significant change i.e. from ‘monophasic’ to ‘biphasic’ or ‘biphasic’ to ‘triphasic’ was seen in 56% cases while ‘monophasic’ to ‘triphasic’ was seen in 20% cases. No change was seen in 24% cases. Improvement in waveform reflects lowering of portal vein pressure. Conclusion: Non invasive Hepatic vein Doppler waveform study showed improvement in Doppler waveform after administration of octreotide in 76% cases. Doppler waveform study has the potential of becoming non invasive ‘follow up tool’ of choice for assessing portal pressure in patients having variceal bleed due to portal hypertension. PMID:27648043

  17. Fat embolism syndrome: a review of the literature | Mustapha ...

    African Journals Online (AJOL)

    Fat embolism syndrome is a serious manifestation of fat embolism phenomenon characterized clinically by triad of dyspnoea, petechiae and mental confusion and usually follows long bone fractures. Its classic presentation consists of an asymptomatic interval followed by pulmonary and neurologic manifestations combined ...

  18. Treatment of non-neoplastic renal hemorrhage with segmental embolization of renal artery

    International Nuclear Information System (INIS)

    Zhu Bing

    2007-01-01

    Objective: To explore the value of segmental embolization of renal artery in dealing with non- neoplastic renal hemorrhage. Methods: Four cases of non-neoplastic hemorrhage, including 2 with bleeding after renal acupuncture biopsy, 2 with bleeding after nephrolithotomy and 1 with congenital renal arteriovenous malformation, were treated with superselective segmental embolization of renal artery. 2 were embolized with coil, 1 with alcohol plus coil and 1 with PVA parcels. Results: Hematuria disappeared in 1-3 days. There was no recurrence in 7-45 months follow up and no complications induced by embolization. Conclusion: It is a safe and reliable therapy to treat non-neoplastic renal hemorrhage with segmental embolization of renal artery. (authors)

  19. Poststenotic flow disturbance in the dog aorta as measured with pulsed Doppler ultrasound.

    Science.gov (United States)

    Talukder, N; Fulenwider, J T; Mabon, R F; Giddens, D P

    1986-08-01

    Blood flow velocity was measured in the dog aorta distal to mechanically induced constrictions of various degrees of severity employing an 8-MHz pulsed Doppler ultrasound velocimeter and a phase-lock loop frequency tracking method for extracting velocity from the Doppler quadrature signals. The data were analyzed to construct ensemble average velocity waveforms and random velocity disturbances. In any individual animal the effect of increasing the degree of stenosis beyond approximately 25 percent area reduction was to produce increasing levels of random velocity disturbance. However, variability among animals was such that the sensitivity of random behavior to the degree of stenosis was degraded to the point that it appears difficult to employ Doppler ultrasound measurements of random disturbances to discriminate among stenoses with area reductions less than approximately 75 percent. On the other hand, coherent vortex structures in velocity waveforms consistently occurred distal to mild constrictions (25-50 percent area reduction). Comparison of the phase-lock loop Doppler ultrasound data with simultaneous measurements using invasive hot-film anemometry, which possesses excellent frequency response, demonstrates that the ultrasound method can reliably detect those flow phenomena in such cases. Thus, the identification of coherent, rather than random, flow disturbances may offer improved diagnostic capability for noninvasively detecting arteriosclerotic plaques at relatively early stages of development.

  20. Embolization Coils Migrating and Being Passed per Rectum After Embolization of a Splenic Artery Pseudoaneurysm, 'The Migrating Coil': A Case Report

    International Nuclear Information System (INIS)

    Shah, Numan A.; Akingboye, Akinfemi; Haldipur, Nandon; Mackinlay, James Y.; Jacob, George

    2007-01-01

    Acute or chronic blood loss from pseudoaneurysms of the splanchnic artery in chronic pancreatitis poses diagnostic and management challenges. Arteriographic examination offers both diagnostic and therapeutic options, with success rates of 76%-100% for both modalities. In cases of failure of embolization, repeat embolization is also an option. Surgical intervention is advocated for rebleeding and failure of embolization. Evidence-based guidelines regarding the optimal treatment modality for this condition are lacking. There has been a reported case of dislodgement of coil into the stomach through a gastropseudocystic fistula. We report the case of a migrating steel-wire coil through the gastrointestinal tract and splenic artery pseudoaneurysm. We highlight the potential complications of pseudoaneurysm and other available therapeutic management options

  1. Percutaneous Access via the Recanalized Paraumbilical Vein for Varix Embolization in Seven Patients

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Yeon Jin; Kim, Hyo Cheol; Hur, Sae Beom; Jae, Hwan Jun; Chung, Jin Wook [Dept. of Radiology, Seoul National University College of Medicine, Seoul National University Hospital, Seoul (Korea, Republic of); Kim, Young Whan [Dept. of Radiology, Dongsan Hospital, Keimyung University College of Medicine, Daegu (Korea, Republic of)

    2014-10-15

    To evaluate the feasibility of percutaneous access via the recanalized paraumbilical vein for varix embolization. Between July 2008 and Jan 2014, percutaneous access via the recanalized paraumbilical vein for varix embolization was attempted in seven patients with variceal bleeding. Paraumbilical vein puncture was performed under ultrasonographic guidance, followed by introduction of a 5-Fr sheath. We retrospectively evaluated the technical feasibility, procedure-related complications, and clinical outcomes of each patient. Recanalized paraumbilical vein catheterization was performed successfully in all patients. Gastroesophageal varix embolization was performed in six patients, and umbilical varix embolization was performed in one patient. Embolic materials used are N-butyl cyanoacrylate (n = 6) and coil with N-butyl cyanoacrylate (n = 1). There were no procedure-related complications. One patient underwent repeated variceal embolization 6 hours after initial procedure via recanalized paraumbilical vein, due to rebleeding from gastric varix. Percutaneous access via the paraumbilical vein for varix embolization is a simple alternative in patients with portal hypertension.

  2. Pathological evaluation of thyroid glands in Graves' disease after thyroid arteries embolization

    International Nuclear Information System (INIS)

    Zhuang Wenquan; Xiao Haipeng; Cheng Wei; Yang Jianyong; Chen Guorui; Ling Qibo

    2003-01-01

    Objective: To study the pathological morphology of thyroid specimen after thyroid arteries embolization. In order to select appropriate size of embolizing granules, the diameters of thyroid arteries in Graves' disease were measured. Methods: Multiple slides of embolized thyroid tissues from superior pole, body and inferior pole of the resected thyroid glands were made. After being embedded and stained, pathological morphology was observed and diameters of arteries in various parts of thyroid glands were measured under microscopy. Results: Pathological examination of thyroid glands showed that superior and inferior thyroid arteries and most of their branches were embolized with ischemic necrosis and fibrosis in the embolized thyroid tissue. Follicular epithelium appeared as flat or cubic shapes with colloid reduction. Average diameter of main branches of superior artery was 440-550 μm and that of inferior artery was 300-375 μm. The diameters of capillary network in the thyroid body was 120-250 μm, and the non-embolized ones was 40-110 μm. The diameter of isthmus was 130-150 μm. Conclusions: Pathological morphology of Graves' disease after thyroid arteries embolization showed that the excretion of thyroid glands would be decreased and equivalents to subtotal thyroidectomy

  3. Transcatheter arterial embolization as therapy of renal angiomyolipomas: The evolution in 15 years of experience

    International Nuclear Information System (INIS)

    Chatziioannou, A.; Gargas, D.; Malagari, K.; Kornezos, I.; Ioannidis, I.; Primetis, E.; Moschouris, H.; Gouliamos, A.; Mourikis, D.

    2012-01-01

    Objective: This study aims at presenting the evolution of the embolization technique in treating renal angiomyolipomas (AMLs) either diagnosed in patients with acute bleeding or discovered accidentally. Methods: Ten patients with renal AMLs have been through thirteen selective transcatheter arterial embolizations for 15 years. Two patients had tuberous sclerosis complex (TSC) with bilateral tumors and were embolized twice. Four embolic materials were employed: PVA particles, Gianturco coils, microspheres and microcoils. Catheterization was achieved by means of 5F Cobra 2 catheters and coaxial microcatheter systems. Results: On an emergency basis, embolization was a first-line treatment. In one case, surgery was necessary; in two patients, a second embolization was performed. When treatment was preventive, a single embolization proved to be sufficient, as well. There was no significant deterioration of the serum creatinine levels in the post-embolization period. Conclusion: Selective arterial embolization is a rather safe and effective technique to treat AMLs both urgently and preventively. Different embolic materials can be employed. Microspheres and microcatheters stand for new promising materials

  4. Palliative embolization of hemorrhages in extensive head and neck tumors

    International Nuclear Information System (INIS)

    Rzewnicki, Ireneusz; Kordecki, Kazimierz; Łukasiewicz, Adam; Janica, Jacek; Puławska-Stalmach, Magdalena; Kordecki, Justyn Ksawery; Łebkowska, Urszula

    2012-01-01

    A lot has changed in terms of intervention technique, indications and embolic agents since Duggan introduced embolization to management of postraumatic epistaxis in 1970. Embolization is used in treatment of spontaneous and traumatic epistaxis, palliative tumors and vascular defects, as well as vascularized tumors and juvenile nasopharyngeal angiofibromas. The possibility of simultaneous visualization of pathology and implementation of therapy is one of its greatest advantages. Authors analyzed the efficacy of selective embolization treatment of haemorrhage in advanced head and neck tumors. Seventy-six patients with such tumors treated at the Department of Otolaryngology in Bialystok between1999 and 2011 were examined. Embolization of bleeding vessel within the tumor was effective (hemorrhage was stopped) in 65 patients (86%). Although the method is highly efficient, it is still associated with complications. Fourteen patients suffered from headaches that lasted for several days and six from face edema. Rebleeding was rare. Unfortunately, there was one case of hemiparesis. We conclude that superselective endovascular treatment deserves to be considered alongside standard options for the palliative or preoperative management of acute hemorrhage from advanced head and neck cancers

  5. Peripheral hepatic arterial embolization with cross-linked collagen fibers

    International Nuclear Information System (INIS)

    Daniels, J.R.; Kerlan, R.K. Jr.; Dodds, L.; McLaughlin, P.; La Berge, J.M.; Harrington, D.; Daniels, A.M.; Ring, E.J.

    1986-01-01

    Hepatic artery embolization with a nonimmunogenic, cross-linked collagen preparation (Angiostat, collagen for embolization, Target Therapeutics) was studied in mongrel dogs. Flow-directed technique was used to achieve complete distal arterial occlusion. Serial liver function evaluation demonstrated marked alterations at 48 to 72 hours, partial correction at 1 week, and resolution of abnormalities by 1 month. Restoration of large-vessel blood flow was angiographically demonstrable at 1 week. Recanalization, achieved by migration of endothelial cells around the collagen, resulted in complete restoration of normal hepatic vascular and tissue anatomy at 1 month. Repeated embolization at biweekly intervals was well tolerated

  6. Coil embolization of an enlarging fusiform myxomatous cerebral aneurysm

    Directory of Open Access Journals (Sweden)

    Frances Lazarow, MD

    2018-04-01

    Full Text Available Myxomatous cerebral aneurysms are rare sequelae of cardiac atrial myxoma. These aneurysms are generally fusiform, multiple, and distal. Pathogenesis and evolution of these aneurysms is still debated. There are currently no guidelines on the management of aneurysms secondary to atrial myxoma. We present a case of a 52-year-old man with multiple fusiform aneurysms 3 years after resection of a left atrial myxoma. One of these aneurysms was followed with cerebral angiography and showed substantial interval enlargement. This aneurysm was subsequently embolized. All aneurysms were stable 6 months post-embolization. Keywords: Myxomatous aneurysm, Fusiform, Coil embolization

  7. State and development of uterine myoma embolization in Germany

    International Nuclear Information System (INIS)

    Jakobs, T.F.; Helmberger, T.K.; Reiser, M.F.

    2003-01-01

    To evaluate the current situation and implementation of embolization of uterine leiomyomas into the treatment concept in women with symptomatic uterine leiomyomas in Germany. A questionnaire addressing the clinical background of uterine myomas, recommended treatment concepts, preclinical evaluation, technical approach and complications was sent to 164 departments of gynecology and radiology in Germany. 33 radiological departments and 19 gynecological departments submitted a completed questionnaire. Only 7 departments of radiology reported to have own experience with embolization of uterine leiomyomas, while only 2 departments of gynecology considered embolization as an alternative treatment option in patients with symptomatic leiomyomas. 18/33 radiological departments offer this treatment option but get no patient referrals. Agreement was found concerning the indications for treatment, preclinical evaluation by ultrasound and MRI, preferable location of treatable fibroids, technical approach and pain management. The embolization of uterine leiomyomas in patients with symptomatic myomas is regardless of the well documented high efficacy and low complication rate not yet an established treatment option in Germany. Interventional radiologists and gynecologists have to evaluate the indications for the embolization of uterine leiomyomas together before the procedure is advised to the patient, because it seems mandatory to add this procedure to the standard armamentarium of treatment options in uterine myomas. (orig.) [de

  8. Embolization of Isolated Lumbar Artery Injuries in Trauma Patients

    International Nuclear Information System (INIS)

    Sofocleous, Constantinos T.; Hinrichs, Clay R.; Hubbi, Basil; Doddakashi, Satish; Bahramipour, Philip; Schubert, Johanna

    2005-01-01

    Purpose. The purpose of the study was to evaluate the angiographic findings and results of embolotherapy in the management of lumbar artery trauma. Methods. All patients with lumbar artery injury who underwent angiography and percutaneous embolization in a state trauma center within a 10-year period were retrospectively reviewed. Radiological information and procedural reports were reviewed to assess immediate angiographic findings and embolization results. Long-term clinical outcome was obtained by communication with the trauma physicians as well as with chart review. Results. In a 10-year period, 255 trauma patients underwent abdominal aortography. Eleven of these patients (three women and eight men) suffered a lumbar artery injury. Angiography demonstrated active extravasation (in nine) and/or pseudoaneurysm (in four). Successful selective embolization of abnormal vessel(s) was performed in all patients. Coils were used in six patients, particles in one and gelfoam in five patients. Complications included one retroperitoneal abscess, which was treated successfully. One patient returned for embolization of an adjacent lumbar artery due to late pseudoaneurysm formation. Conclusions. In hemodynamically stable patients, selective embolization is a safe and effective method for immediate control of active extravasation, as well as to prevent future hemorrhage from an injured lumbar artery

  9. Therapeutic embolization in pulmonary hemorrhage

    International Nuclear Information System (INIS)

    Gasparini, D.

    1989-01-01

    The author's purpose was to evaluate the efficacy of therapeutic embolization in pulmonary hemorrage performed with fibrin foam (Spongostan) suspended in sclerosing agents (hidroxy-poliethoxy-dodecano 3%, or natrium morruate 5%), and electrocoagulation (Bitrol, spa) as an alternative to surgery. Twenty patients were embolized: 17 with fibrin foam and sclerosing agents only, 2 with the addition of electrocoagulation and a Gianturco coil respectively, and 1 with electrocoagulation alone. The follow-up ranges from 3 to 42 months (average 22). A patient affected by aspergilloma died a few days after hemoptysis. The patient treated by electrocoagulation alone suffers from periodical hematic expectoration (spitting). The remaining 18 patients have not shown any pathological findings. In 2 cases the arterial occlusion was confirmed by angiography, while in 1 case partial arterial recanalization was observed. Such a finding was due to the vessel dimensions and to hyperflux values. In similar cases, obstruction must be completed different techniques (e.g. Gianturco coils, electrocoagulation, detachable balloons, etc.). The absence of flux resulting from embolization improves electrocoagulation efficiency, which should be considered as the technique of choice. Even though additional trials are needed, the techniques have proven quite reliable and suitable to replace surgery in low-aggression lesions

  10. Asymptomatic and symptomatic embolic events in infective endocarditis: associated factors and clinical impact.

    Science.gov (United States)

    Monteiro, Thaíssa S; Correia, Marcelo G; Golebiovski, Wilma F; Barbosa, Giovanna Ianini F; Weksler, Clara; Lamas, Cristiane C

    Embolic complications of infective endocarditis are common. The impact of asymptomatic embolism is uncertain. To determine the frequency of emboli due to IE and to identify events associated with embolism. Retrospective analysis of an endocarditis database, prospectively implemented, with a post hoc study driven by analysis of data on embolic events. Data was obtained from the International Collaboration Endocarditis case report forms and additional information on embolic events and imaging reports were obtained from the medical records. Variables associated with embolism were analyzed by the statistical software R version 3.1.0. In the study period, 2006-2011, 136 episodes of definite infective endocarditis were included. The most common complication was heart failure (55.1%), followed by embolism (50%). Among the 100 medical records analyzed for emboli in left-sided infective endocarditis, 36 (36%) were found to have had asymptomatic events, 11 (11%) to the central nervous system and 28 (28%) to the spleen. Cardiac surgery was performed in 98/136 (72%). In the multivariate analysis, splenomegaly was the only associated factor for embolism to any site (pinfective endocarditis of the mitral valve (p<0.05, OR 3.5, 95% CI 1.23-10) and male gender (p<0.05, OR 3.2, 95% CI 1.04-10). Splenectomy and cardiac surgery did not impact on in-hospital mortality. Asymptomatic embolism to the central nervous system and to the spleen were frequent. Splenomegaly was consistently associated with embolic events. Copyright © 2017 Sociedade Brasileira de Infectologia. Published by Elsevier Editora Ltda. All rights reserved.

  11. Agent-based station for on-line diagnostics by self-adaptive laser Doppler vibrometry

    Science.gov (United States)

    Serafini, S.; Paone, N.; Castellini, P.

    2013-12-01

    A self-adaptive diagnostic system based on laser vibrometry is proposed for quality control of mechanical defects by vibration testing; it is developed for appliances at the end of an assembly line, but its characteristics are generally suited for testing most types of electromechanical products. It consists of a laser Doppler vibrometer, equipped with scanning mirrors and a camera, which implements self-adaptive bahaviour for optimizing the measurement. The system is conceived as a Quality Control Agent (QCA) and it is part of a Multi Agent System that supervises all the production line. The QCA behaviour is defined so to minimize measurement uncertainty during the on-line tests and to compensate target mis-positioning under guidance of a vision system. Best measurement conditions are reached by maximizing the amplitude of the optical Doppler beat signal (signal quality) and consequently minimize uncertainty. In this paper, the optimization strategy for measurement enhancement achieved by the down-hill algorithm (Nelder-Mead algorithm) and its effect on signal quality improvement is discussed. Tests on a washing machine in controlled operating conditions allow to evaluate the efficacy of the method; significant reduction of noise on vibration velocity spectra is observed. Results from on-line tests are presented, which demonstrate the potential of the system for industrial quality control.

  12. Agent-based station for on-line diagnostics by self-adaptive laser Doppler vibrometry.

    Science.gov (United States)

    Serafini, S; Paone, N; Castellini, P

    2013-12-01

    A self-adaptive diagnostic system based on laser vibrometry is proposed for quality control of mechanical defects by vibration testing; it is developed for appliances at the end of an assembly line, but its characteristics are generally suited for testing most types of electromechanical products. It consists of a laser Doppler vibrometer, equipped with scanning mirrors and a camera, which implements self-adaptive bahaviour for optimizing the measurement. The system is conceived as a Quality Control Agent (QCA) and it is part of a Multi Agent System that supervises all the production line. The QCA behaviour is defined so to minimize measurement uncertainty during the on-line tests and to compensate target mis-positioning under guidance of a vision system. Best measurement conditions are reached by maximizing the amplitude of the optical Doppler beat signal (signal quality) and consequently minimize uncertainty. In this paper, the optimization strategy for measurement enhancement achieved by the down-hill algorithm (Nelder-Mead algorithm) and its effect on signal quality improvement is discussed. Tests on a washing machine in controlled operating conditions allow to evaluate the efficacy of the method; significant reduction of noise on vibration velocity spectra is observed. Results from on-line tests are presented, which demonstrate the potential of the system for industrial quality control.

  13. Utility of pharmacologic provocative neurological testing before embolization of occipital lobe arteriovenous malformations.

    Science.gov (United States)

    Tawk, Rabih G; Tummala, Ramachandra P; Memon, Muhammad Z; Siddiqui, Adnan H; Hopkins, L Nelson; Levy, Elad I

    2011-01-01

    Endovascular treatment is an established option for treatment of cerebral arteriovenous malformations (AVMs). However, embolization has been associated with postprocedural neurological complications. We sought to evaluate the usefulness of intra-arterial pharmacologic provocative (superselective Wada) testing before embolization of occipital lobe AVMs. We performed a retrospective review of cases of occipital AVMs that were embolized at our institution (Millard Fillmore Gates Hospital) while the patient was under conscious sedation. Visual field testing was performed before and after superselective Wada testing and again after embolization. After microcatheterization of the target feeding pedicle, amobarbital (or, occasionally, methohexital) was administered, followed immediately by neurological testing. If the provocative test results were negative, the evaluated feeder was embolized with a liquid agent. Complications were categorized as transient or permanent neurological deficit, visual field loss, ischemic or hemorrhagic stroke, and death. Thirteen patients with occipital AVMs underwent 39 Wada tests of 34 pedicles before embolization during 26 endovascular treatment sessions. Patients were treated under conscious sedation with local anesthesia. The mean age of these patients was 43.5 years (range 16-62 years); 6 were women. Testing induced a neurological deficit in six patients. A positive test result led us to abort embolization attempts in four pedicles. In the two remaining cases, advancement of the catheter tip distally within the feeding pedicle allowed us to proceed with embolization after initial test failure. Neither patient developed a visual field deficit after embolization. Despite passing the Wada test before embolization, one other patient had a visual deficit that was detected a few hours after the procedure; this deficit lessened but was permanent. No further ischemic complications and no hemorrhagic complications occurred. Pharmacologic

  14. Ethanol embolization of arteriovenous malformations: results and complications of 33 cases

    International Nuclear Information System (INIS)

    Jeon, Yong Hwan; Do, Young Soo; Shin, Sung Wook; Liu, Wei Chiang; Cho, Jae Min; Lee, Min Hee; Kim, Dong Ik; Lee, Byung Boong; Choo, Sung Wook; Choo, In Wook

    2003-01-01

    To assess the effectiveness of ethanol embolization for the treatment of arteriovenous malformation (AVM), and the complications, if any, arising. Thirty-three patients with AVMs underwent 145 staged sessions of ethanol embolization. AVMs were located in an upper extremity (n=14), a lower extremity (n=10), the pelvis (n=7), the thorax (n=1), or the abdomen (n=1). Eighty-five transcatheter embolizations and 60 direct percutaneous puncture embolizations were performed, and seven patients underwent additional coil embolization of the dilated outflow vein. The therapeutic effectiveness of embolization was evaluated in terms of the extent to which an AVM was obliterated between baseline and the final angiogram. Complications were classified as minor or major. In 13 patients (39%), AVMs were totally obliterated. In eight patients (24%), more than 75% were obliterated; in three (9%), the proportion was 50-75%; and in four (12%), less than 50%. Five patients (15%), were not treated. The reasons for failure were the difficulty of approaching the nidus due to previous surgical ligation or coil embolization of the feeding artery, the subcutaneous location of an AVM, post-procedural infection, and massive bleeding during the follow-up period. Twenty-one minor complications such as focal skin necrosis or transient nerve palsy developed during 145 sessions of (an incidence of 14%), but these were relieved by conservative treatment. The five major complications arising (3%) were cerebral infarction, urinary tract infection, acute renal failure due to rhabdomyolysis, permanent median nerve palsy, and infection. Ethanol embolization by direct percutaneous puncture or using a transcatheter technique is an effective approach to the treatment of an AVM. However, to overcome the considerable number of complications, arising, further investigation is required

  15. Ethanol embolization of arteriovenous malformations: results and complications of 33 cases

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Yong Hwan; Do, Young Soo; Shin, Sung Wook; Liu, Wei Chiang; Cho, Jae Min; Lee, Min Hee; Kim, Dong Ik; Lee, Byung Boong; Choo, Sung Wook; Choo, In Wook [School of Medicine, Sungkyunkwan Univ., Seoul (Korea, Republic of)

    2003-10-01

    To assess the effectiveness of ethanol embolization for the treatment of arteriovenous malformation (AVM), and the complications, if any, arising. Thirty-three patients with AVMs underwent 145 staged sessions of ethanol embolization. AVMs were located in an upper extremity (n=14), a lower extremity (n=10), the pelvis (n=7), the thorax (n=1), or the abdomen (n=1). Eighty-five transcatheter embolizations and 60 direct percutaneous puncture embolizations were performed, and seven patients underwent additional coil embolization of the dilated outflow vein. The therapeutic effectiveness of embolization was evaluated in terms of the extent to which an AVM was obliterated between baseline and the final angiogram. Complications were classified as minor or major. In 13 patients (39%), AVMs were totally obliterated. In eight patients (24%), more than 75% were obliterated; in three (9%), the proportion was 50-75%; and in four (12%), less than 50%. Five patients (15%), were not treated. The reasons for failure were the difficulty of approaching the nidus due to previous surgical ligation or coil embolization of the feeding artery, the subcutaneous location of an AVM, post-procedural infection, and massive bleeding during the follow-up period. Twenty-one minor complications such as focal skin necrosis or transient nerve palsy developed during 145 sessions of (an incidence of 14%), but these were relieved by conservative treatment. The five major complications arising (3%) were cerebral infarction, urinary tract infection, acute renal failure due to rhabdomyolysis, permanent median nerve palsy, and infection. Ethanol embolization by direct percutaneous puncture or using a transcatheter technique is an effective approach to the treatment of an AVM. However, to overcome the considerable number of complications, arising, further investigation is required.

  16. Power Doppler flow mapping and four-dimensional ultrasound for evaluating tubal patency compared with laparoscopy.

    Science.gov (United States)

    Soliman, Amr A; Shaalan, Waleed; Abdel-Dayem, Tamer; Awad, Elsayed Elbadawy; Elkassar, Yasser; Lüdders, Dörte; Malik, Eduard; Sallam, Hassan N

    2015-12-01

    To study the accuracy of four-dimensional (4D) ultrasound and power Doppler flow mapping in detecting tubal patency in women with sub-/infertility, and compare it with laparoscopy and chromopertubation. A prospective study. The study was performed in the outpatient clinic and infertility unit of a university hospital. The sonographic team and laparoscopic team were blinded to the results of each other. Women aged younger than 43 years seeking medical advice due to primary or secondary infertility and who planned to have a diagnostic laparoscopy performed, were recruited to the study after signing an informed consent. All of the recruited patients had power Doppler flow mapping and 4D hysterosalpingo-sonography by injecting sterile saline into the fallopian tubes 1 day before surgery. Registering Doppler signals, while using power Doppler, both at the tubal ostia and fimbrial end and the ability to demonstrate the course of the tube especially the isthmus and fimbrial end, while using 4D mode, was considered a patent tube. Out of 50 recruited patients, 33 women had bilateral patent tubes and five had unilateral patent tubes as shown by chromopertubation during diagnostic laparoscopy. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy for two-dimensional power Doppler hysterosalpingography were 94.4%, 100%, 100%, 89.2%, and 96.2%, respectively and for 4D ultrasound were 70.4%, 100%, 100%, 70.4%, and 82.6%, respectively. Four-dimensional saline hysterosalpingography has acceptable accuracy in detecting tubal patency, but is surpassed by power Doppler saline hysterosalpingography. Power Doppler saline hysterosalpingography could be incorporated into the routine sub-/infertility workup. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  17. Radar micro-doppler signatures processing and applications

    CERN Document Server

    Chen, Victor C; Miceli, William J

    2014-01-01

    Radar Micro-Doppler Signatures: Processing and applications concentrates on the processing and application of radar micro-Doppler signatures in real world situations, providing readers with a good working knowledge on a variety of applications of radar micro-Doppler signatures.

  18. Radiologic findings of cerebral septic embolism

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jee Young; Kim, Sang Joon; Kim Tae Hoon; Kim, Seung Chul; Kim, Jae Seung; Pai, Hyun Joo [Dankook Univ., Seoul (Korea, Republic of). Coll. of Medicine; Kim, Dong Ik [Yonsei Univ., Seoul (Korea, Republic of). Coll. of Medicine; Chang, Kee Hyun [Seoul National Univ. (Korea, Republic of). Coll. of Medicine; Choi, Woo Suk [Kyung Hee Univ., Seoul (Korea, Republic of). Coll. of Medicine

    1998-01-01

    To determine the MR and CT findings which differentiate cerebral septic embolism from thrombotic infarction. Cerebral septic embolism was confirmed by blood culture in six patients and autopsy in two. The number, size, distribution, contrast enhancement, and hemorrhage of the lesions, as seen on MR and CT, were retrospectively analyzed, and four patients were followed up for between one week and seven months. In a total of eight patients, infective endocarditis (n=5) and sepsis (n=3) caused cerebral septic embolism. The number, of lesions was 3 {approx} 7 in six patients, over 10 in one, and innumerable in one: these varied in size from punctate to 6 cm and were distributed in various areas of the brain. Gyral infarction was noted in five patients: non-enhancing patchy lesions involving the basal ganglia or white matter were found in five, tiny isolated nodular or ring-enhancing small lesions involving the cortex and white matter in three, peripheral rim-enhancing large lesions in one, and numerous enhancing nodules disseminated in the cortex in one. Hemorrhage had occurred in six. follow-up studies in four patients showed that initial lesions had enlarged in two and regressed in two: new lesions had appeared in two. Multiple lesions of different sizes and various patterns which include gyral infarction, patchy or nodular lesion in the cortex, white mater of basal ganglia, and isolated small ring-like or nodular enhancement or frequent hemorrhage are findings which could be helpful in the radiologic diagnosis of cerebral septic embolism. (author). 8 refs., 5 figs.

  19. Radiologic findings of cerebral septic embolism

    International Nuclear Information System (INIS)

    Lee, Jee Young; Kim, Sang Joon; Kim Tae Hoon; Kim, Seung Chul; Kim, Jae Seung; Pai, Hyun Joo; Kim, Dong Ik; Chang, Kee Hyun; Choi, Woo Suk

    1998-01-01

    To determine the MR and CT findings which differentiate cerebral septic embolism from thrombotic infarction. Cerebral septic embolism was confirmed by blood culture in six patients and autopsy in two. The number, size, distribution, contrast enhancement, and hemorrhage of the lesions, as seen on MR and CT, were retrospectively analyzed, and four patients were followed up for between one week and seven months. In a total of eight patients, infective endocarditis (n=5) and sepsis (n=3) caused cerebral septic embolism. The number, of lesions was 3 ∼ 7 in six patients, over 10 in one, and innumerable in one: these varied in size from punctate to 6 cm and were distributed in various areas of the brain. Gyral infarction was noted in five patients: non-enhancing patchy lesions involving the basal ganglia or white matter were found in five, tiny isolated nodular or ring-enhancing small lesions involving the cortex and white matter in three, peripheral rim-enhancing large lesions in one, and numerous enhancing nodules disseminated in the cortex in one. Hemorrhage had occurred in six. follow-up studies in four patients showed that initial lesions had enlarged in two and regressed in two: new lesions had appeared in two. Multiple lesions of different sizes and various patterns which include gyral infarction, patchy or nodular lesion in the cortex, white mater of basal ganglia, and isolated small ring-like or nodular enhancement or frequent hemorrhage are findings which could be helpful in the radiologic diagnosis of cerebral septic embolism. (author). 8 refs., 5 figs

  20. Preoperative embolization in surgical treatment of spinal metastases

    DEFF Research Database (Denmark)

    Clausen, Caroline; Dahl, Benny; Frevert, Susanne Christiansen

    2015-01-01

    PURPOSE: To assess whether preoperative transcatheter arterial embolization of spinal metastases reduces blood loss, the need for transfusion with allogeneic red blood cells (RBCs), and surgery time in the surgical treatment of patients with symptomatic metastatic spinal cord compression. MATERIALS......L) versus 902 mL (SD, 416 mL). CONCLUSIONS: Preoperative embolization in patients with symptomatic spinal metastasis independent of primary tumor diagnosis did not reduce intraoperative blood loss and allogeneic RBC transfusion significantly but did reduce the surgery time. A small reduction...... instrumentation and randomly assigned to either preoperative embolization (n = 23) or a control group (n = 22). The primary outcome was intraoperative blood loss. Secondary outcomes were perioperative blood loss, allogeneic RBC transfusion, and surgery time. Analyses were performed by intention-to-treat. RESULTS...

  1. Management of thromboembolism-in-transit with pulmonary embolism

    Directory of Open Access Journals (Sweden)

    V S Ellensen

    2017-10-01

    Full Text Available We present a rare complication of deep venous thrombosis with pulmonary embolism that threatened the patient with systemic embolization. A 36-year-old female was referred to the hospital after five days of progressive shortness of breath and chest pain. Preceding onset of symptoms, she had undergone surgery leading to reduced physical activity and had just returned from vacation by a long flight. Investigations with transthoracic and transesophageal echocardiography revealed a thromboembolism-in-transit across a patent foramen ovale. Thoracic CT showed submassive bilateral pulmonary embolism. Hemodynamic parameters were stable. The patient was treated surgically with extraction of the thrombus, closure of the foramen ovale and removal of the bilateral pulmonary emboli. She was discharged after an uneventful hospital stay.

  2. Application of a laser Doppler vibrometer for air-water to subsurface signature detection

    Science.gov (United States)

    Land, Phillip; Roeder, James; Robinson, Dennis; Majumdar, Arun

    2015-05-01

    There is much interest in detecting a target and optical communications from an airborne platform to a platform submerged under water. Accurate detection and communications between underwater and aerial platforms would increase the capabilities of surface, subsurface, and air, manned and unmanned vehicles engaged in oversea and undersea activities. The technique introduced in this paper involves a Laser Doppler Vibrometer (LDV) for acousto-optic sensing for detecting acoustic information propagated towards the water surface from a submerged platform inside a 12 gallon water tank. The LDV probes and penetrates the water surface from an aerial platform to detect air-water surface interface vibrations caused by an amplifier to a speaker generating a signal generated from underneath the water surface (varied water depth from 1" to 8"), ranging between 50Hz to 5kHz. As a comparison tool, a hydrophone was used simultaneously inside the water tank for recording the acoustic signature of the signal generated between 50Hz to 5kHz. For a signal generated by a submerged platform, the LDV can detect the signal. The LDV detects the signal via surface perturbations caused by the impinging acoustic pressure field; proving a technique of transmitting/sending information/messages from a submerged platform acoustically to the surface of the water and optically receiving the information/message using the LDV, via the Doppler Effect, allowing the LDV to become a high sensitivity optical-acoustic device. The technique developed has much potential usage in commercial oceanography applications. The present work is focused on the reception of acoustic information from an object located underwater.

  3. Percutaneous Mechanical Thrombectomy Treatment of Acute Superior Mesenteric Artery Embolism

    Directory of Open Access Journals (Sweden)

    Z. Zhang

    Full Text Available : Objective/Background: This report presents a superior mesenteric artery (SMA embolism managed by percutaneous mechanical thrombectomy (PMT. Methods: A 61 year old woman diagnosed with SMA embolism was admitted. Emboli were found in the middle and distal segments of the SMA on abdominal computed tomography angiography. Under local anaesthesia, a 6 F Rotarex system was used to remove the emboli via left brachial artery access. Emboli were successfully removed and patency was restored to the SMA and its branches. Results: Post-operatively, the patient's symptoms were significantly relieved. No post-operative complications were observed and no discomfort was documented during follow-up. Conclusion: Endovascular treatment of SMA embolism using PMT is a feasible and alternative option. Keywords: Acute mesenteric ischaemia, Embolism, Endovascular treatment, Percutaneous mechanical thrombectomy, Superior mesenteric artery

  4. Uterine artery embolization for uterine fibroids: mid-long term follow up

    International Nuclear Information System (INIS)

    Guo Wenbo; Yang Jianyong; Chen Wei; Zhuang Wenquan; Li Lijuan; Zhu Yunxiao

    2006-01-01

    Objective: To evaluate the mid-long term effects of uterine fibroids embolization. Methods: Uterine artery embolization (UAE) was performed in 110 patients with uterine fibroids with follow up of 48-72 months. All the patients were examined with transvaginal color ultrasound. 51 cases were embolized with mixed liquor of lipiodol and pingyangmycin and another 59 cases with polyvinyl alcohol particles (350-700 μm, in diameter). The mid-long term clinical effects, complications, change of serum sexual hormone, pregnancy and delivery after UAE were observed. Results; Bilateral uterine artery embolization was performed in 110 cases with following outcomes in improvements of menorrhagia in 93/94 (98.9%) and the bulked-related symptoms in 26/26 (100%), decrease of the volumes of uterus 51.5% ± 3.1% (t value 2.861, P<0.01) and fibroids 64.2% ± 6.6% (t value 2.664, P<0.01). No statistical differences in serum levels of luteinizing, follicle stimulating hormone and estradiol before and after the uterine artery embolization were found. All events included abdominal pain in 6/110 (5.5%), fever in 90/110 (81.8%), colporrhagia in 95/110 (86.4%), haematuria in 11/110 (10.0%), non-targeted embolization of bladder in 1/110 (0.9%), transient amenorrhea in 3/110 (2.7%), permanent amenorrhea due to ovarian failure in 3/110 (2.7%), failure of embolization in 1/110 (0.9%) and recurrence after uterine fibroids embolization in 4/110 (3.6%). There were 7 times of pregnancies in 5 patients, including 4 times of deliveries in 4 patients, and one patient accepted artificial abortion 3 times, but with no fibroids recurrences or enlargement under ultrasound follow up. Conclusion: The mid-long term effects of uterine fibroids embolization are positive, stable and safe, but with a low recurrence rate slight ovarian functional change and still safe for pregnancy and delivery. (authors)

  5. Microcatheter embolization of hemorrhages

    International Nuclear Information System (INIS)

    Seppaenen, Seppo K.; Leppaenen, Martti J.; Pimenoff, Georg; Seppaenen, Janne M.

    1997-01-01

    Purpose. To evaluate the efficacy of embolotherapy using microcatheters in patients with hemorrhage from various locations. Methods. Among 29 patients there were 13 with severe epistaxis, 7 with gastrointestinal bleeding, 4 with hemorrhage in the kidney, 4 with bleeding in pelvic organs and 1 with bleeding in the shoulder region. In all cases, a Tracker-18 or Tracker-10 microcatheter was advanced coaxially through a 4.1 Fr guiding catheter in order to reach the bleeding site as distally as possible. Polyvinyl alcohol microparticles and/or platinum microcoils were used as embolic material. Results. The bleeding was stopped in 90% (26 of 29) of cases. In 66% of cases the treatment was curative, in 7% preoperative, and in 17% palliative. There were 3 clinical failures. Conclusion. Microcatheter embolization is an effective and safe means of managing different kinds of hemorrhage of various causes from a variety of sites

  6. The experimental study of selective arterial embolization in the lumbar spine of dogs

    International Nuclear Information System (INIS)

    Ni Caifang; Xu Ming; Liu Yizhi; Ding Yi; Yang Huilin; Tang Tiansi

    2002-01-01

    Objective: To establish the model of acute spinal infarction, to evaluate the relative factors affecting results in spinal embolization, and to provide the theoretical basis with the preoperative embolization of spinal tumors. Methods: Through the SAE of the lumbar arteries, the neuro-function of the posterior legs of dogs, MRI findings, and pathologic changes of the spinal specimen were observed in 12 dogs. The embolizing agents was gelfoam (GF). Results: The significant ischemia changes of spinal column and the corresponding muscles at the occluding spinal after embolizing more than one segmental arteries occurred in 9 dogs, but there were no paraplegia or obvious changes in 3 dogs having been embolized single lumbar arteries no matter they sent out the radiculomedullary artery (RA) or not. Paraplegia occurred in one dog after embolizing the multisegmental arteries. Conclusion: (1) The method of SAE in dog can be used to set up the experimental model of the acute ischemia of spine. (2) The occlusion in single-segmental arteries can not result in the infarction of the whole spine. (3) The serious complication may result from embolizing multisegmental spinal arteries (especially sending out RA). (4) The protecting embolization should be carried out in order to decrease the reaction during SAE in spine

  7. Embolization of intracranial dural arteriovenous fistulas using PHIL liquid embolic agent in 26 patients

    DEFF Research Database (Denmark)

    Lamin, S.; Chew, H. S.; Chavda, S.

    2017-01-01

    BACKGROUND AND PURPOSE: The introduction of liquid embolic agents has revolutionized endovascular approach to cranial vascular malformations. The aim of the study was to retrospectively assess the efficacy and safety of Precipitating Hydrophobic Injectable Liquid (PHIL), a new nonadhesive liquid......: This was a retrospective multicenter study. Twenty-six consecutive patients with dural arteriovenous fistulas (de novo or previously treated) treated by injection of PHIL only or with PHIL in combination with other embolization products (such as Onyx or detachable coils) were included in the study. Recruitment started......, 3 were retreated with PHIL and 1 achieved angiographic cure. An adverse event was seen in 1 patient who developed worsening of preexisting ataxia due to acute thrombosis of the draining vein. CONCLUSIONS: PHIL appears to be safe and effective for endovascular treatment of cranial dural arteriovenous...

  8. A Pedestrian Detection Scheme Using a Coherent Phase Difference Method Based on 2D Range-Doppler FMCW Radar

    Science.gov (United States)

    Hyun, Eugin; Jin, Young-Seok; Lee, Jong-Hun

    2016-01-01

    For an automotive pedestrian detection radar system, fast-ramp based 2D range-Doppler Frequency Modulated Continuous Wave (FMCW) radar is effective for distinguishing between moving targets and unwanted clutter. However, when a weak moving target such as a pedestrian exists together with strong clutter, the pedestrian may be masked by the side-lobe of the clutter even though they are notably separated in the Doppler dimension. To prevent this problem, one popular solution is the use of a windowing scheme with a weighting function. However, this method leads to a spread spectrum, so the pedestrian with weak signal power and slow Doppler may also be masked by the main-lobe of clutter. With a fast-ramp based FMCW radar, if the target is moving, the complex spectrum of the range- Fast Fourier Transform (FFT) is changed with a constant phase difference over ramps. In contrast, the clutter exhibits constant phase irrespective of the ramps. Based on this fact, in this paper we propose a pedestrian detection for highly cluttered environments using a coherent phase difference method. By detecting the coherent phase difference from the complex spectrum of the range-FFT, we first extract the range profile of the moving pedestrians. Then, through the Doppler FFT, we obtain the 2D range-Doppler map for only the pedestrian. To test the proposed detection scheme, we have developed a real-time data logging system with a 24 GHz FMCW transceiver. In laboratory tests, we verified that the signal processing results from the proposed method were much better than those expected from the conventional 2D FFT-based detection method. PMID:26805835

  9. A Pedestrian Detection Scheme Using a Coherent Phase Difference Method Based on 2D Range-Doppler FMCW Radar

    Directory of Open Access Journals (Sweden)

    Eugin Hyun

    2016-01-01

    Full Text Available For an automotive pedestrian detection radar system, fast-ramp based 2D range-Doppler Frequency Modulated Continuous Wave (FMCW radar is effective for distinguishing between moving targets and unwanted clutter. However, when a weak moving target such as a pedestrian exists together with strong clutter, the pedestrian may be masked by the side-lobe of the clutter even though they are notably separated in the Doppler dimension. To prevent this problem, one popular solution is the use of a windowing scheme with a weighting function. However, this method leads to a spread spectrum, so the pedestrian with weak signal power and slow Doppler may also be masked by the main-lobe of clutter. With a fast-ramp based FMCW radar, if the target is moving, the complex spectrum of the range- Fast Fourier Transform (FFT is changed with a constant phase difference over ramps. In contrast, the clutter exhibits constant phase irrespective of the ramps. Based on this fact, in this paper we propose a pedestrian detection for highly cluttered environments using a coherent phase difference method. By detecting the coherent phase difference from the complex spectrum of the range-FFT, we first extract the range profile of the moving pedestrians. Then, through the Doppler FFT, we obtain the 2D range-Doppler map for only the pedestrian. To test the proposed detection scheme, we have developed a real-time data logging system with a 24 GHz FMCW transceiver. In laboratory tests, we verified that the signal processing results from the proposed method were much better than those expected from the conventional 2D FFT-based detection method.

  10. Usefulness of dynamic MR imaging for the evaluation of transcatheter arterial embolization for hepatocellular carcinoma

    International Nuclear Information System (INIS)

    Kyomasu, Yoshinori; Nakayama, Masafumi; Kawakami, Mutsumi; Mashima, Yasuoki; Ichinose, Akira; Endou, Kazuo; Chiba, Kazuo; Tanno, Munehiko; Yamada, Hideo

    1992-01-01

    Thirteen patients with hepatocellular carcinoma (HCC) were studied with dynamic MR imaging in addition to conventional T 1 - and T 2 -weighted and enhanced T 1 -weighted images before and after the treatment of HCC by transcatheter arterial embolization (TAE). Dynamic MR imaging was performed using GRASS (gradient recalled acquisition in the steady state) sequences. The imaging was started at 10 seconds after rapid injection of Gd-diethylenetriaminepentaacetic acid (Gd-DTPA) with 6s breath hold. Thereafter about 12 images were obtained during 6s breath-holding with 20 seconds intervals. On T 1 - and T 2 -weighted images, signal intensity at the tumor tended to increase during the early period after TAE and to decrease later. Intensities of the HCC, however, were heterogeneous. Differentiation among embolic area, necrosis, viable cells and recurrent area, was often difficult only by conventional images. Dynamic GRASS images could clearly demonstrate an embolic area as a region without contrast enhancement. While recurrent tumor could be diagnosed as an area with early enhancement at the arterial phase. Development of the collateral circulation and dominancy of tumor feeding vessels after TAE could also be deduced on dynamic MR images together with enhanced T 1 -weighted images. The dynamic MR imaging was concluded to be a potentially useful procedure for the clinical evaluation of HCC after TAE. (author)

  11. Digital angiography in pulmonary embolism

    International Nuclear Information System (INIS)

    Bjoerk, L.

    1986-01-01

    Pulmonary digital subtraction angiography was diagnostic in 98.3% of patients with possible acute pulmonary embolism. The procedure was well tolerated even in severely ill patients. A large image intensifier made simultaneous imaging of both lungs possible reducing the number of contrast injections necessary. Small volumes of low iso-osmolar concentration of modern contrast media were used. There was no need for catherization of the pulmonary artery. Theoretical considerations and our limited experience indicate that this will reduce the number of complications compared with conventional pulmonary angiography. The procedure is rapidly performed and the diagnostic accuracy high. This makes digital subtraction angiography cost effective. Digital pulmonary angiography can be recommended as the primary diagnostic method in most patients with possible pulmonary embolism. (orig.)

  12. Contrast-enhanced power Doppler ultrasonography of the metacarpophalangeal joints in rheumatoid arthritis

    DEFF Research Database (Denmark)

    Szkudlarek, Marcin; Court-Payen, Michel; Strandberg, Charlotte

    2003-01-01

    The aim of this study was to examine, with dynamic contrast-enhanced MRI as the reference, if contrast-enhanced power Doppler ultrasonography (CE PDUS) of rheumatoid arthritis (RA) metacarpophalangeal (MCP) joints provides additional information for evaluation of synovial inflammation compared...... with PDUS. One MCP joint in each of 15 RA patients and 3 healthy control persons were examined with PDUS before and after intravenous bolus Levovist contrast injection. Corresponding rates of early synovial enhancement (RESE), previously shown to be closely related to histopathological synovitis, were...... calculated from dynamic contrast-enhanced MR images obtained the same day. Prior to ultrasonography, the joint was evaluated clinically. Levovist increased the flow signal in 7 of 9 joints with pre-contrast flow-signal and in 0 of 9 without pre-contrast signal. No healthy controls showed CE PDUS signal...

  13. Analysis of monochromatic signals by using data from the detector of Allegro gravitational waves

    International Nuclear Information System (INIS)

    Oliveira, Fernanda Gomes de

    2010-01-01

    The present work is developed in the searching for monochromatic gravitational waves signals in ALLEGRO's data. We have two procedures for data analysis based on the periodogram of Welch, which a method for the detection of monochromatic signals in the middle of noise which basically makes power spectrum estimates using averaged modified periodograms. By using this method it was possible to obtain a power spectrum for the data which reinforce peaks due to monochromatic signals. The two procedures of analysis for the years 1997 and 1999, were focused on monitoring a peak that appears in the spectral density of ALLEGRO's detector, so called 'mystery mode' (near 887 Hz). We look for variations in the frequency of the mystery mode that agree with the variation of the Doppler effect. In the rst analysis we have used by the variation of daily and annual Doppler shift. For the second one, we have only searched annual Doppler shift. We have applied the periodogram of Welch in both tests in the raw data of the detector in the search for a real signal and we found some peaks that can be candidates of gravitational radiation only the second analysis. In order to test the method we used in both analysis a simulated gravitational wave signal modulated by the Doppler effect injected in the data. We detected in both methods the artificial signal of GW simulated. Therefore we have reason to conclude that both methods are efficient in the search for monochromatic signals. (author)

  14. MR Venography of Deep Veins: Changes with Uterine Fibroid Embolization

    International Nuclear Information System (INIS)

    Katsumori, Tetsuya; Kasahara, Toshiyuki; Tsuchida, Yoko; Nara, Yoshinori

    2009-01-01

    Deep veins (DVs) can be compressed by a uterus enlarged with fibroids. The purpose of this study was to assess the degree of luminal narrowing of DVs caused by a myomatous uterus, and the change in DV narrowing in women with symptomatic fibroids after embolization using time-of-flight (TOF)-magnetic resonance venography (MRV). Twenty-nine consecutive women with symptomatic uterine fibroids underwent TOF-MRV and pelvic MRI before and 4 months after embolization. Based on the TOF-MRV, we evaluated the luminal narrowing of three DVs, including the inferior vena cava, and the bilateral common and external iliac veins, and divided the findings into three grades. The scores for each DV were added for each patient (lowest, 0; highest, 6). DV scores and symptom severity (SS) scores were compared between the baseline and 4 months after embolization using the paired t-test. The relationship between DV scores and uterine volume was investigated using Pearson's test. DV scores decreased significantly, from 1.52 ± 1.70 at baseline to 0.93 ± 1.56 at 4 months after embolization (p = 0.004). The uterine volume decreased from 948 ± 647 mL at baseline to 617 ± 417 mL at 4 months after embolization (p < 0.001). DV score correlated with uterine volume (r = 0.856, p < 0.001). SS scores decreased from 54.5 ± 14.6 at baseline to 26.8 ± 15.4 at 4 months after embolization (p < 0.001). In conclusion, the degree of luminal narrowing of DVs caused by a uterus with fibroids is correlated with the uterine volume. Uterine artery embolization may induce an improvement of luminal narrowing of DVs due to a reduction of the myomatous uterus volume.

  15. Endothelial cell proliferation in swine experimental aneurysm after coil embolization.

    Directory of Open Access Journals (Sweden)

    Yumiko Mitome-Mishima

    Full Text Available After coil embolization, recanalization in cerebral aneurysms adversely influences long-term prognosis. Proliferation of endothelial cells on the coil surface may reduce the incidence of recanalization and further improve outcomes after coil embolization. We aimed to map the expression of proliferating tissue over the aneurysmal orifice and define the temporal profile of tissue growth in a swine experimental aneurysm model. We compared the outcomes after spontaneous thrombosis with those of coil embolization using histological and morphological techniques. In aneurysms that we not coiled, spontaneous thrombosis was observed, and weak, easily detachable proliferating tissue was evident in the aneurysmal neck. In contrast, in the coil embolization group, histological analysis showed endothelial-like cells lining the aneurysmal opening. Moreover, immunohistochemical and morphological analysis suggested that these cells were immature endothelial cells. Our results indicated the existence of endothelial cell proliferation 1 week after coil embolization and showed immature endothelial cells in septal tissue between the systemic circulation and the aneurysm. These findings suggest that endothelial cells are lead to and proliferate in the former aneurysmal orifice. This is the first examination to evaluate the temporal change of proliferating tissue in a swine experimental aneurysm model.

  16. Preop endovascular embolization in juvenile nasal angiofibroma management

    Directory of Open Access Journals (Sweden)

    M. V. Nersesyan

    2018-01-01

    Full Text Available Introduction. Juvenile nasal angiofibroma (JNA is an aggressively expanding fibro-vascular benign tumor, which occurs in male adolescents. Surgical management of JNA is considered as one of the most difficult in rhinology, because it very often has accompanied with profuse, streaming bleeding. Endovascular embolization has successfully used for reducing the operative blood loss since 2000th. Nevertheless, there is no consensus in the literature about its expediently using because of complications, which may occur.Objective is to evaluate the effectiveness of selective angiography and endovascular embolization in reducing bleeding when removal of JNA of different stages.Materials and methods. In the N.N. Burdenko National Medical Research Center of Neurosurgery 134 patients with JNA had been treated surgically.Results. 110 patients with JNA, who underwent embolization, managed to perform total, subtotal or partial devascularization of the tumor. Total devascularization was achieved in JNA blood supply variant only from the external carotid artery (ECA system from 1 or 2 sides  (in primary patients or in patients who had not previously been embolized (n = 39; subtotal devascularization, if the blood supply was carried out from the ECA system, internal carotid artery (ICA on the 1 side (n = 52 and partial, if there was blood supply from the ECA and significant from the ICA system from 2 sides (in patients with relapse after previous embolization with microspirals or the ECA ligations from 1 or 2 sides, as well as with giant JNA (n = 19. Since the vast majority of patients admitted to our clinic were previously operated on, and JNA blood supply in relapses was more pronounced, we performed the comparison of the degree of tumor devascularization depending on its blood supply in primary patients and patients with relapse. It turned out, as could be expected, that with the primary JNA often managed  to execute a total devascularization than with JNA

  17. Cerebral Fat Embolism: Diffusion-weighted Magnetic Resonance Imaging Findings

    International Nuclear Information System (INIS)

    Ryu, C.W.

    2005-01-01

    PURPOSE: To demonstrate the diffusion-weighted (DWI) magnetic resonance imaging (MRI) findings, and the follow-up MRI findings, of cerebral fat embolism in the acute stage. MATERIAL AND METHODS: The initial DWI and clinical findings of six patients with cerebral fat embolism were retrospectively evaluated. The finding of DWI with a b-value of 1000 s/mm 2 (b=1000) was compared with that of DWI with a b-value of 0 s/mm 2 (b=0). In three patients who underwent follow-up MRI, the interval change of the lesion on T2-weighted images was investigated. RESULTS: The characteristic DWI finding of cerebral fat embolism in the acute stage was multiple, hyperintense, dot-like lesions disseminated in the brain. These lesions were distributed dominantly in the bilateral border-zone areas. Some lesions had an ancillary location including the cortex, deep white matter, basal ganglia, and cerebellum. The lesions were more intense and numerous in DWI (b=1000) than in DWI (b=0). The findings on the follow-up T2-weighted images were multiple confluent hyperintense lesions in the white matter with progression since the initial MRI. CONCLUSION: DWI could be a sensitive tool for detecting cerebral fat embolism in the acute phase. It is recommended that DWI be included in the initial evaluation of cerebral fat embolism with MRI

  18. Management of Severe Hemoptysis from Pulmonary Aspergilloma Using Endovascular Embolization

    International Nuclear Information System (INIS)

    Corr, Peter

    2006-01-01

    Purpose. To determine the effectiveness of endovascular embolization as a temporizing measure in the management of severe hemoptysis caused by intracavitary pulmonary aspergilloma. Methods. Patients presenting with hemoptysis, estimated to be more than 300 ml in the preceding 24 hr, in whom a radiological diagnosis of pulmonary aspergilloma was made on chest radiographs and/or computed tomography of the chest were subjected to bronchial and systemic arteriography and embolization using triacryl microspheres. Results. Twelve patients with upper lobe intracavitary aspergillomas were managed with embolization. In 11 patients hemoptysis stopped within 24 hr and with no recurrence over the next 4 weeks. In 1 patient hemoptysis persisted and an upper lobe lobectomy was performed. Conclusion. Embolization of bronchial and systemic arteries is an effective method for treating acute severe hemoptysis from intracavitary aspergillomas, allowing the patient time to recover for definitive surgical management

  19. A micro-Doppler sonar for acoustic surveillance in sensor networks

    Science.gov (United States)

    Zhang, Zhaonian

    Wireless sensor networks have been employed in a wide variety of applications, despite the limited energy and communication resources at each sensor node. Low power custom VLSI chips implementing passive acoustic sensing algorithms have been successfully integrated into an acoustic surveillance unit and demonstrated for detection and location of sound sources. In this dissertation, I explore active and passive acoustic sensing techniques, signal processing and classification algorithms for detection and classification in a multinodal sensor network environment. I will present the design and characterization of a continuous-wave micro-Doppler sonar to image objects with articulated moving components. As an example application for this system, we use it to image gaits of humans and four-legged animals. I will present the micro-Doppler gait signatures of a walking person, a dog and a horse. I will discuss the resolution and range of this micro-Doppler sonar and use experimental results to support the theoretical analyses. In order to reduce the data rate and make the system amenable to wireless sensor networks, I will present a second micro-Doppler sonar that uses bandpass sampling for data acquisition. Speech recognition algorithms are explored for biometric identifications from one's gait, and I will present and compare the classification performance of the two systems. The acoustic micro-Doppler sonar design and biometric identification results are the first in the field as the previous work used either video camera or microwave technology. I will also review bearing estimation algorithms and present results of applying these algorithms for bearing estimation and tracking of moving vehicles. Another major source of the power consumption at each sensor node is the wireless interface. To address the need of low power communications in a wireless sensor network, I will also discuss the design and implementation of ultra wideband transmitters in a three dimensional

  20. Renal Angiomyolipoma: Mid- to Long-Term Results Following Embolization with Onyx

    Energy Technology Data Exchange (ETDEWEB)

    Thulasidasan, Narayanan, E-mail: narayanant@doctors.net.uk; Sriskandakumar, Srividhiya; Ilyas, Shahzad; Sabharwal, Tarun [Guy’s & St Thomas’ NHS Foundation Trust, Department of Interventional Radiology (United Kingdom)

    2016-12-15

    PurposePercutaneous transcatheter embolization is currently the preferred treatment for ruptured or enlarging renal angiomyolipoma (AML), although the optimum choice of embolic material has not yet been established. We present mid- to long-term outcomes following embolization of AMLs with Onyx.Materials and MethodsTen AMLs in seven patients (including two with tuberous sclerosis) were embolized with Onyx. Patients were followed-up clinically, with tumour size and renal function measured pre- and post-procedure.ResultsMean pre-treatment AML size was 63.4 mm (range 42–100). Mean clinical follow-up was 431.4 days (range 153–986) and imaging follow-up 284.2 days (range 30–741). There was no haemorrhage from treated lesions within the follow-up period. Of patients who had cross-sectional imaging pre- and post-procedure, mean decrease in AML size of 22 mm was seen after Onyx embolization (p = 0.0058, 95 % CI 9.13–34.87). No significant difference between serum creatinine was seen pre- and post-procedure (p = 0.54, 95 % CI 8.63–4.85).ConclusionsOnyx embolization of renal AMLs is effective in the medium to long term, with theoretical benefits in safety and durability of result.