Doppler Ultrasound

Both resting tachycardia and irregular ventricular rhythm may contribute to impaired cardiac performance in atrial fibrillation (AF). This study assesses the relation between resting heart rate and beat-to-beat changes in left ventricular (LV) ejection and filling in patients with normal and impaired LV systolic function. Beat-to-beat variation in LV outflow and inflow velocity-time integral was measured using pulsed Doppler ultrasound in 39 patients with chronic AF and normal (n ‫؍‬ 22) or impaired (n ‫؍‬ 17) LV systolic function. Aortic velocity-time integral variability increased with mean heart rate (p ‫؍‬ 0.003) even though RR interval variability decreased (p <0.001). Aortic velocity-time integral was more sensitive to the duration of both the preceding (p <0.001) and prepreceding (p <0.001) RR intervals at higher heart rates. These relations were similar for patients with normal and impaired LV systolic function. The sensitivity of the filling velocity-time integral to RR interval variability also increased with heart rate (p <0.001). However, at higher heart rates the filling velocity-time integral (p ‫؍‬ 0.009 ) and filling time (p ‫؍‬ 0.005) were less sensitive to change in RR intervals in patients with impaired LV function. We conclude that beat-to-beat stroke volume variability in AF increases with heart rate. Stroke volume variability was not influenced by LV systolic function.

Malfunction of permanent vascular accesses remains a cause of frequent and costly morbidity in patients receiving chronic hemodialysis (CHD). Several recommendations for routine monitoring of these permanent vascular accesses for incipient failure have been proposed. In this study, multiple indicators of incipient vascular access dysfunction, including &amp;amp;amp;quot;venous&amp;amp;amp;quot; and &amp;amp;amp;quot;arterial&amp;amp;amp;quot; pressures at serial blood flows (200 ml/min, 300 ml/min, and 400 ml/min), percent urea recirculation, Doppler ultrasound, and access blood flow by ultrasound dilution technique were simultaneously evaluated in a total of 220 vascular accesses in 170 chronic hemodialysis patients in two separate study periods (6 months apart). The rate of thrombosis was determined within the subsequent 12 weeks of each study period to assess the short-term predictive power of access thrombosis. During the period of follow-up, there were 34 thrombotic events in 172 polytetrafluoroethylene (PTFE) grafts and only one thrombotic event in 48 arterio-venous fistulas (AVF). Therefore, the statistical analysis was limited to the PTFE grafts. When grafts with thromboses were compared to those without thrombosis by univariate analysis, access blood flow measured either by ultrasound dilution technique (875 +/- 426 ml/min with thrombosis vs. 1193 +/- 677 ml/min without thrombosis, P = 0.001) or by Doppler ultrasound (762 +/- 420 ml/min with thrombosis vs. 1171 +/- 657 ml/min without thrombosis, P = 0.001) were significantly different in the two groups. There was good correlation (r = 0.79, P = 0.0001) between the blood flows determined by both techniques. The grade of stenosis determined by ultrasound was also a statistically significant predictor (P = 0.02). &amp;amp;amp;quot;Venous&amp;amp;amp;quot; and &amp;amp;amp;quot;arterial&amp;amp;amp;quot; pressures were numerically similar and were not statistically different between the accesses that did and those that did not thrombose. When multivariate analysis was used, there was a significantly increased risk of thrombosis only with decreasing access blood flow determined by ultrasound dilution techniques after adjusting for other confounding variables. When the average blood flow of all grafts (1134 ml/min) is considered as the reference access blood flow (relative risk of 1.0), the relative risk of a PTFE thrombotic event within the subsequent 12 weeks was 1.23 at a blood flow 950 ml/min, 1.67 at a blood flow of 650 ml/min and to 2.39 at a blood flow of 300 ml/min. In summary, access blood flow measured by either Dilution or Doppler is a reliable indicator of subsequent short-term thrombosis risk. Other proposed methods of evaluating access dysfunction were not useful in our patients. If simple to use, cost-effective devices to measure dialysis access blood flow become readily available, the measurement of access blood flow will likely become the method of choice for screening of PTFE vascular access dysfunction in hemodialysis patients.

Purpose: The purpose for this research study was to develop the most efficiently
reliable and accurate method to determine the presence of blockage in the lower
limb arteries without any ambiguity. Blockage in the lower limb arteries comes due
to the problems like the fats deposition or cholesterol rich substances inside the
arterial walls. These problems cause the reduction in the arterial radius by
narrowing the arteries.
Method: For this purpose the method was adopted with the fact that, change in the
arterial radius arises due to presence of blockage inside the arterial walls which
affects the speed or velocity of the flowing blood through that particular artery and
hence produce a change in the waveform pattern of the received echoes. The
method is the combine study of changing waveform pattern and changing speed or
velocity of the blood flowing through the particular artery. 10 cases of different
ages and sex were taken into consideration by using Doppler ultrasound technique.
Results: Results showed blockage in many cases but with varying degree of
blockage. Some cases showed normal or early blockage and some show late or well
blocked artery. Also some normal cases were taken for study, so as to evident the
effectiveness of this method to determine the absence of blockage.
Conclusion: It was concluded that waveform pattern comparison along with the
velocity comparison method is most careful, very accurate and appreciable
indicator for the determination of existence of blockage in lower limb arteries.

Background Doppler US to measure abdominal blood flow velocities (ABFV) is increasingly used to investigate intestinal haemodynamics in several clinical conditions in neonates. Studies that provide reference values of ABFV during the entire neonatal period are currently lacking. Objective To make available normal reference values of ABFV and Doppler indices in the coeliac trunk and superior mesenteric artery during the first month of life in term and healthy preterm infants. Materials and methods ABFV were obtained with colour Doppler US in 69 neonates (12 term, 57 preterm) divided into four gestational age groups (25-28 weeks, 29-32 weeks, 33-36 weeks, and 37-41 weeks). Results ABFV increased with increasing gestational and postnatal age. We also provide normal reference values of ABFV and Doppler indices to compare with measurements of abdominal blood flow changes during the neonatal period for diagnostic, therapeutic and prognostic purposes.

Background This retrospective analysis evaluated the clinical and radiologic results of transcatheter arterial embolization (TAE) in the treatment of significant hemobilia. The imaging findings, embolization technique, complications, and efficacy are described. Methods Thirty-two consecutive patients (21 male, 11 female, age range 8–61 years) who were referred to the radiology department for severe or recurrent hemobilia were treated by TAE. Causes of hemobilia were liver trauma (n = 19; iatrogenic in six and road traffic accident in 13), vasculitis (n = 6), vascular malformations (n = 2), and hepatobiliary tumors (n = 5). Iatrogenic liver trauma was secondary to cholecystectomy in those six patients. Four of five hepatobiliary tumors were inoperable malignant tumors and one was a giant cavernous hemangioma. Arterial embolization was done after placing appropriate catheters as close as possible to the bleeding site. Embolizing materials used were Gelfoam, polyvinyl alcohol particles or steel coils, alone or in combination. Postembolization angiography was performed in all cases to confirm adequacy of embolization. Follow-up color Doppler ultrasound and contrast-enhanced computed tomography was done in all patients. Results Ultrasonic, computed tomographic, and angiographic appearances of significant hemobilia were assessed. Angiogram showed the cause of bleeding in all cases. Three patients with liver trauma due to accidents required repeat embolization. Eight patients required surgery due to failed embolization (continuous or repeat bleeding in four patients, involvement of the large extrahepatic portion of hepatic artery in two, and coexisting solid organ injuries in two). Severity of hemobilia did not correlate with grade of liver injury. All 13 patients with blunt hepatic trauma showed the cause of hemobilia in the right lobe. No patient with traumatic hemobilia showed an identifiable cause in the left lobe. There were no clinically significant side effects or complications associated with TAE except one gallbladder infarction, which was noted at surgery, and cholecystectomy was performed with excision of the hepatic artery aneurysm. Conclusion TAE is a safe and effective interventional radiologic procedure in the nonoperative management of patients who have significant hemobilia.

Systolic pulmonary arterial pressure was determined serialiy over the first 10 days of life in 33 babies with hyaline membrane disease by measuring the peak velocity of pansystolic tricuspid valve regurgitation, using Doppler ultrasound, and applying the Bernoulli equation. Results are presented in age groups 0-12, 13-36, 37-72, and 73-96 hours respectively. The incidence of tricuspid valve regurgitation was 92, 97, 80, and 64% (falling to 35% by day 10) compared with 53, 50, 31, and 0% in 17 healthy premature infants.

Objectives: To establish normative data for ophthalmic artery Doppler parameters throughout a healthy pregnancy, to investigate the possible correlation between these Doppler measurements and gestational age, and to test intraobserver variability. Methods: A prospective cross-sectional study was performed to assess various Doppler parameters in 276 healthy women between 20 and 39 weeks of gestation. The following measurements were obtained: pulsatility and resistance indices (PI, RI), peak systolic velocity (PSV), peak diastolic velocity (PDV), end diastolic flow velocity (EDFV), and peak ratio (PR). Quantile regression was used to estimate reference values throughout pregnancy and P b 0.05 was considered significant. The intraclass correlation coefficient (Intra-CC) was used to calculate intraobserver variability. Results: The 5th and 95th prediction intervals for each gestational age are presented. No significant correlation was detected between Doppler indices and gestational age. Intra-CC was excellent (0.996). Conclusions: Reference values were generated for ophthalmic artery Doppler measurements, and they did not vary significantly during healthy pregnancy.

A common clinical practice during single-point Doppler analysis is to measure the centerline maximum velocity and to recover the time-averaged flow rate by exploiting an assumption on the shape of velocity profile (a priori formula), either a parabolic or a flat one. In a previous study, we proposed a new formula valid for the peak instant linking the maximum velocity and the flow rate by including a well-established dimensionless fluid-dynamics parameter (the Womersley number), in order to account for the hemodynamics conditions (Womersley number-based formula). Several in silico tests confirmed the reliability of the new formula. Nevertheless, an in vivo confirmation is missing limiting the clinical applicability of the formula. An experimental in vivo protocol using cine phase-contrast MRI (2-D PCMRI) technique has been designed and applied to ten healthy young volunteers in three different arterial districts: the abdominal aorta, the common carotid artery, and the brachial artery. Each PCMRI dataset has been used twice: 1) to compute the value of the blood flow rate used as a gold standard and 2) to estimate the flow rate by measuring directly the maximum velocity and the diameter (i.e., emulating the intravascular Doppler data acquisition) and by applying to these data the a priori and the Womersley number-based formulae. All the in vivo results have confirmed that the Womersley numberbased formula provides better estimates of the flow rate at the peak instant with respect to the a priori formula. More precisely, mean performances of the Womersley number-based formula are about three times better than the a priori results in the abdominal aorta, five times better in the common carotid artery, and two times better in the brachial artery.

Objective: To analyze the association between umbilical cord cardiac troponin I (cTnI), obstetric Doppler, and birth acidemia. Method: This prospective observational study was conducted on 58 singleton pregnancies at 3 Brazilian hospitals. Umbilical and middle cerebral artery Doppler velocimetry were performed 24 h prior to birth. At delivery, cord blood was collected for pH, blood gas analysis, and cTnI measurement. Results: Cardiac troponin I ≥ 0.20 ng/mL was detected in 5 neonates (8.6%). Centralization was recorded in 12 fetuses; 4 of these (33.3%) had detectable cTnI compared with 1/46 (2.2%) fetuses with normal Doppler (P = 0.005). Acidemia was present in 60% of the neonates with detectable cTnI, compared with 15% of the neonates with undetectable cTnI (P = 0.042). Conclusion: Centralization and birth acidemia are associated with detectable cTnI in cord blood supporting the possibility of myocardial ischemia in these fetuses.

The lack of knowledge of the beam-flow angle represents one of the major sources of uncertainty in Doppler measurements. Not only are some new, appealing applications of the Doppler technique prevented, but some basic clinical procedures are made more difficult than desirable. This paper reports on the Doppler angle ambiguity problem and on the classic solutions so far proposed in order to overcome the related limitations. The main features of a recently introduced dual-beam method are described. Starting from the classic problem of measuring the true velocity in a single sample volume, the application to the measurement of full velocity profiles is discussed. Combination of this method with a new multi-channel multi-gate system is shown capable of contributing to arterial mechanics investigations by allowing the simultaneous measurement of wall shear rate and wall distension in major human arteries. Finally the feasibility of accurate volumetric flow measurements is discussed, and work-in-progress is reported

Three different indices, the A/B ratio, the pulsatility index (PI) and the Pourcelot ratio (PR), are in common use for quantitative analysis of umbilical artery Doppler ultrasound waveforms. A detailed examination of the similarities and differences between these indices, together with the expected errors for each, was undertaken to enable informed comparisons and choices to be made. The indices were calculated from 133 last trimester recordings using an objective and very reliable computer analysis technique. The PI is more difficult to calculate than the other two quantities and the extra computation does not provide any extra information. The A/B ratio appears the simplest index to use but the values are not normally distributed. With the PR a normal distribution of values can be assumed. A theoretical consideration of errors showed that none of the indices is intrinsically less error prone for last trimester waveforms overall. The errors in the A/B ratio increase as the value of the index increase, whereas the converse holds for the PI and PR.

Optical methods are most popular speed measurement techniques due to its non-destructive and non-contact in nature. Speed measurement by optical techniques are suitable for all sizes of objects. In this experiment, we dealt with transverse speed measurement and Doppler shift measurement for the speed of train and rotating wheel. Fast rotating wheel in transverse speed measurement provided beat frequency of 1.87 MHz while our calculated beat frequency and fringes period were 2.47 MHz and 8.72 um, respectively. For slow moving wheel, the beat frequency was ~91 KHz and the calculated velocity for rotating wheel was 0.03392 m/s using the Doppler shift technique. The beat frequency for the moving train ranges from 266.304 KHz to 923.913 KHz for train speed of 0.068 m/s and 0.26 m/s.

A numerical model that can produce pulsed Doppler signals for nonaxial, pulsatile flow is presented. The model takes into account both hemodynamic and acoustic factors that affect the Doppler signal, such that a wide range of flow patterns and arbitrary transducer types can be simulated. The physics of blood flow is modeled by solving the Navier-Stokes equations utilizing a finite element technique, and the acoustic field is modeled using the acoustic impulse response method. The model was validated by comparison to the Womersley theory. The median deviation was 3.45%. Doppler signals from flow through a 50% stenosis were also simulated. The calculated spectra demonstrated the changing flow patterns from jets and vortices. This new computer model can be used to test spectral analysis tools on simulated Doppler signals, whose underlying flow patterns are of clinical importance.

partners has for women involved in committed relationships. In this report, we will (a) briefly review the only two previous studies on this topic, both of which were undertaken with highly distressed populations, and (b) discuss the results and implications of a survey designed to assess the attitudes of a broader, more diverse population of women. Results suggest that highly negative evaluations of a partner's pornography use are not representative of women in general, but that such evaluations do characterize about one third of women surveyed. One -way ANOVAs revealed that more negative evaluations were associated with being married to the pornography user and with higher levels of usage on his part Significance of Pornography 3 Romantic Partners' Use of Pornography: It's Significance for Women "[My husband] was going online constantly without letting me know. I hated it. He watches [pornography] tapes without me too...and magazines...you name it. It makes me feel really fat and ugly and like he'd rather masturbate to those images than have the real thing sometimes. I've asked and asked him not to, but he says he doesn't get it enough from me. Which confuses me because he never comes to me for sex to start out with! If something is going to happen I am the one to start everything. It's like he's afraid of the rejection so he goes with something that is a "sure" thing. I find it degrading to think that he's turned on by those women more, but on the other hand if he invited me in to watch a movie I wouldn't hate it so much...at least I wouldn't feel left out and like he's trying to hide something from me. It's almost like he's cheating on me. A terrible feeling." (Member, Expecting mother's chat group)

Diagnostic ultrasound has been in use in clinical obstetrics for close to half-a-century. However, in the literature, examination of the placenta appears to be treated with less attention than the fetus or the pregnant uterus. This is somewhat unexpected, given the obvious major functions this organ performs during the entire pregnancy. Examination of the placenta plays a foremost role in the assessment of normal and abnormal pregnancies. A methodical sonographic evaluation of the placenta should include: location, visual estimation of the size (and, if appearing abnormal, measurement of thickness and/or volume), implantation, morphology, anatomy, as well as a search for anomalies, such as additional lobes and tumors. Additional assessment for multiple gestations consists of examining the intervening membranes (if present). The current review considers the various placental characteristics, as they can be evaluated by ultrasound, and the clinical significance of abnormalities of these features. Numerous and varied pathologies of the placenta can be detected by routine ultrasound. It is incumbent on the clinician performing obstetrical ultrasound to examine the placenta in details and in a methodical fashion because of the far reaching clinical significance and potentially avoidable severe consequences of many of these abnormalities.

Doppler ultrasound is an emerging technology that has the potential to increase the diagnostic, monitoring, and predictive capabilities of equine theriogenologists and researchers. The technology is based on Doppler-shift frequencies, wherein the ultrasound frequency of echoes from moving red cells is increased or decreased as the cells move toward or away from the transducer. In spectral mode, the blood flow in a specific vessel can be assessed by placing a sample-gate cursor on the image of the lumen of the vessel. In addition, an angle cursor can be used to represent the angle of intersection of the ultrasound beams with the direction of blood flow (Doppler angle). The Doppler-shift frequency and the Doppler angle are used by the instrument for computing blood velocity. The focused results from placement of a sample gate in an artery are displayed by a spectrum that represents the changing velocities over time in association with the pulses of cardiac cycles. Peak systolic, end diastolic, and time-averaged maximum velocities are computed and shown for a selected cardiac cycle. Doppler indices (resistance index, RI; pulsatility index, PI) are ratios that are computed from various points on the spectrum. The indices are relatable to the hemodynamics of the tissue supplied by the artery. Increasing RI or PI values indicate increasing resistance and decreasing perfusion of the distal tissues. In color-flow mode, Doppler-shift frequencies are obtained from areas delineated by the operator on the B-mode image and are transformed and expressed as color-coded spots representing areas of blood flow. Vascular perfusion of a structure can be quantitated by the number of colored pixels in an image or can be estimated subjectively by the extent of the colored spots. The Doppler technology has the potential for providing information on the status and future success of a structure. However, realization of the expected potential will depend on future experience and research.

ULTRASONOGRAPHIC EVALUATION OF OVULATION STIGMA AND PROGNOSIS OF GROWTH OUTCOMES OF THE DOMINANT FOLLICLE.
O.V. Bulavenko, V.V.Doschechkyn
Abstract
Study objective: To study the relationship of ultrasonographic changes in the walls of the dominant follicle with the outcomes of its growth – ovulation or persistence.
Study design: Prospective cross-sectional study. Patients, Methods, Settings: Upon results of sonographic one cycle pre-assessment, 96 women from subfertile couples were distributed into two groups. Main group – 78 women with documented ovulation. Comparison group consisted of eighteen women with various clinical forms of follicle persistence. Ovulation stigma identification was performed by transvaginal ultrasonography using the technique of Mobile Hydroacoustic Window (TVS+MHAW) with standard 6–10 MHz probes. Three sources of fluid were used for the building of mobile hydroacoustic window: antral fluid, contents of ovulation stigma and the fluid located close to ovary apex. Subtle structures of follicle walls were assessed at the interface of liquid and dense medium in the area of ovary apex.
Results, Discussion: In 52 cases (66.6%) two main types of ovulation stigma – Large Bleb-type and Small Flat-type were identified, in 48 (61.5%) and 4 (5.1%) cases, accordingly. In the rest of 26 (33.3%) ovulating women it was not possible to identify the stigma sonographically. In 18 (18.8%) cases anovulatory cycles were presented: LUF in 10 (10.4%) cases, follicular regression in 6 (6.3%) and hemorrhagic cysts developed in two cases (2.1%). Local thinning of follicular walls in the area of stigma (91%), appearance of small amount of fluid near the ovary apex (93.6%) and elongated or cone-like shape of the pre-ovulatory follicle (59%) were the most prevalent sonographic signs of stigma formation. Stages of sonographic changes of the structure of forming ovulation stigma were detected and described. New sonographic sign of ovulation stigma, – the phenomenon of Constriction Ring (30.8%), characterizing the closing stage of stigma formation was described. Mean growth and regression rates were calculated for dominant follicles. The increase of dominant follicle size beyond 28.5 mm is connected to high risk of its anovulation or persistence. It should also be taken into account that ovulation can occur at any stage of stigma formation, also without its sonographic appearance.
Conclusion: The study of phenotypic features of stigma formation by means of TVS + MHAW can be useful for timing of OPU in IVF natural cycles and prediction of high risk of follicle persistence/regression at intrauterine insemination

Diagnostic ultrasound has been in use in clinical obstetrics for close to half-a-century. However, in the literature, examination of the placenta appears to be treated with less attention than the fetus or the pregnant uterus. This is somewhat unexpected, given the obvious major functions this organ performs during the entire pregnancy. Examination of the placenta plays a foremost role in the assessment of normal and abnormal pregnancies. A methodical sonographic evaluation of the placenta should include: location, visual estimation of the size (and, if appearing abnormal, measurement of thickness and/or volume), implantation, morphology, anatomy, as well as a search for anomalies, such as additional lobes and tumors. Additional assessment for multiple gestations consists of examining the intervening membranes (if present). The current review considers the various placental characteristics, as they can be evaluated by ultrasound, and the clinical significance of abnormalities of these features. Numerous and varied pathologies of the placenta can be detected by routine ultrasound. It is incumbent on the clinician performing obstetrical ultrasound to examine the placenta in details and in a methodical fashion because of the far reaching clinical significance and potentially avoidable severe consequences of many of these abnormalities.

Frequent advances in transducer design, electronics, computers, and signal processing have improved the quality of ultrasound images to the extent that sonography is now a major mode of imaging for the clinical diagnosis of breast cancer. Breast ultrasound is routinely used for differentiating cysts and solid nodules with high specificity. In combination with mammography, ultrasound is used to characterize solid masses as benign or malignant. There is growing interest in using Doppler ultrasound and contrast agents for measuring tumor blood flow and for imaging tumor vascularity. Ease of use and real-time imaging capability make breast ultrasound a method of choice for guiding breast biopsies and other interventional procedures. Breast ultrasound is used in many forms. B-mode is the most common form of imaging for the breast, although compound imaging and harmonic imaging are being increasingly applied to better visualize breast lesions and to reduce image artifacts. These developments, together with the formulation of a standardized lexicon of solid mass features, have improved the diagnostic performance of breast ultrasound. Several approaches that are currently being investigated to further improve performance include: (1) computer-aided-diagnosis; (2) the assessment of tumor vascularity and tumor blood flow with Doppler ultrasound and contrast agents; and (3) tissue elasticity imaging. In the future, ultrasound will play a greater role in differentiating benign from malignant masses and in the diagnosis of breast cancer.

La thrombose veineuse ovarienne est une pathologie rare mais potentiellement mortelle.

Son diagnostic repose essentiellement sur les techniques d’imagerie, en particulier le CT et la résonance magnétique. Ces deux techniques d’imagerie sont en effet extrêmement sensibles et spécifiques dans cette situation.

Avec un traitement précoce associant antibiotiques et anticoagulants, les complications sont devenues exceptionnelles.

Tissue-mimicking phantoms that are currently available for routine biomedical applications may not be suitable for high-temperature experiments or calibration of thermal modalities. Therefore, design and fabrication of customized thermal phantoms with tailored properties are necessary for thermal therapy studies. A multitude of thermal phantoms have been developed in liquid, solid, and gel forms to simulate biological tissues in thermal therapy experiments. This article is an attempt to outline the various materials and techniques used to prepare thermal phantoms in the gel state. The relevant thermal, electrical, acoustic, and optical properties of these phantoms are presented in detail and the benefits and shortcomings of each type are discussed. This review could assist the researchers in the selection of appropriate phantom recipes for their in vitro study of thermal modalities and highlight the limitations of current phantom recipes that remain to be addressed in further studies.

Zusammenfassung

Grundlagen:  Ziel der vorliegenden Studie war es, die Sensitivitäts- und Spezifitätsindizes des Gebärmutterarterien-Dopplers (UAD) bei der Prädiktion von Präeklampsien und fetalen Wachstumsrestriktionen (FGR) zu überprüfen.
Methodik Im Rahmen von 76 zwischen 1995 und 2014 veröffentlichten Studien wurden 298.329 pränatale Doppleruntersuchungen bei Erstgebärenden mit Einlingsschwangerschaften im ersten und frühen zweiten Trimester durchgeführt. Auf der Grundlage der Sensitivitäts- und Spezifitätsindizes wurde die Stichprobe in Bezug auf die wesentlichen klinischen Endpunkte der Kohorte in vier Gruppen stratifiziert.

Ergebnisse:  Die Korrelationen der diagnostischen Spezifität (r = 0,728) und Indizes bilateraler postsystolischer Inzisuren (r = 0,803) bei der FGR deuten auf eine Abhängigkeit der UAD-Genauigkeit sowohl vom Plazentabett als auch vom Screeningmodus hin.

Schlussfolgerungen:  Die prädiktive Sensitivität des UAD erhöhte sich nach 16 Wochen + 3 Tagen (115 Tagen) Gestation. Der stärkste prädiktive Parameter für Präeklampsien und FGR war der Index plazentaseitiger Gebärmutterarterien-Resistenz, wobei die höchsten Mittelwerte bei einer Mittellinienlage der Plazenta erzielt wurden (OR 0,9).
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AIM: To determine sensitivity and cut-off indices of the Uterine Artery Doppler (UAD) in prediction of preeclampsia and fetal growth restriction (FGR).

METHODS: Seventy-six studies published in 1995-2014, present 298,329 prenatal Doppler screenings preformed in nullipara in the 1st and early 2nd trimesters of singleton pregnancies. The sample is stratified into four groups based on the Doppler sensitivity and specificity indices pertaining to the major clinical endpoints of the cohort.

RESULTS: The FGR diagnostic specificity (r = 0.728) and bilateral notching index (r = 0.803) correlations indicate that the UAD accuracy depends on the placental bed and the screening mode.

CONCLUSIONS: Predictive sensitivity of the UAD increases after 16 weeks + 3 days (115 days) of gestation. The best predictive parameter of preeclampsia and FGR is the placental-side uterine artery resistance index (RI) which confers to the highest means when the placenta is on the midline (OR 0.9).

Artículo original Resumen Antecedentes: la placentación anormal es una de las principales características de la preeclampsia. Se debe a una falla en la invasión trofoblástica de las arterias espirales maternas, que condiciona el aumento de las resistencias vasculares y la disminución de la perfusión útero-placentaria. Objetivo: determinar la relación entre la velocimetría Doppler de la arteria umbilical y el resultado perinatal adverso en pacientes con preeclampsia severa. material y método: estudio prospectivo, observacional y transversal. Se incluyeron pacientes entre 27 y 33 semanas de gestación, con preeclampsia severa tratadas de manera conservadora entre enero de 2004 y enero de 2006. La velocimetría de la arteria umbilical con ultrasonido Doppler pulsado con transductor convexo de 3.5 MHz se midió cada semana. Los resultados del último Doppler, en los siete días previos a la interrupción del embarazo, se relacionaron con el resultado perinatal. Las gestaciones se interrumpieron por indicación materna o fetal (prueba sin estrés ominosa o perfil biofísico fetal de 4 o menor). El Doppler se consideró anormal cuando el índice de pulsatilidad estaba por arriba del percentil 95 para la edad gestacional, o bien un perfil de onda de la arteria umbilical con flujo diastólico final ausente o reverso. El análisis estadístico se realizó con la prueba de la c 2 y t de Student. Resultados: se estudiaron 43 pacientes: 21 (49%) tuvieron Doppler normal y 22 (52%) anormal. En el segundo grupo 13 (59%) pacientes tuvieron índice de pulsatilidad mayor del percentil 95 para la edad gestacional, 7 (32%) flujo diastólico ausente y 2 (9%) flujo reverso. Los recién nacidos con Doppler anormal tuvieron menor peso (1,174 vs 1,728 gramos), Apgar a los 5 minutos menor, mayor ingreso a terapia intensiva (86.4 vs 43%) y mayor morbilidad neonatal, comparados con los que tuvieron Doppler normal (p < 0.05). Cuando el Doppler fue normal la mortalidad perinatal fue de cero, mientras que con un resultado anormal hubo seis muertes, de las que dos ocurrieron con flujo diastólico presente (15%), dos con flujo diastólico ausente (28%) y dos con reverso (100%). Conclusiones: el Doppler anormal de la arteria umbilical se asocia con resultado perinatal adverso y es un factor pronóstico importante de morbilidad y mortalidad perinatal. Palabras clave: Doppler de la arteria umbilical, preeclampsia severa, resultado perinatal.

Objetivo: Demostrar que el índice relativo de impedancia entre el ductus arterioso y la arteria pulmonar fetal puede ser utilizado como prueba diagnóstica de embarazo pretérmino, término y postérmino. Método: Se incluyeron 134 gestantes, 52 de pretérmino, 65 de término y 17 de postérmino, a cuyos fetos se les obtuvo mediante ultrasonido Doppler pulsado las ondas de velocidad de flujo en el ductus arterial y la arteria pulmonar.

Objectives. To present our experience with the results of three different methods of treatment of idiopathic varicoceles. Methods. A total of 301 patients with 417 varicoceles were retrospectively assigned into three groups according to the method of treatment. Group 1 included 94 patients with 131 varicoceles treated by open surgery. Group 2 consisted of 120 patients with 163 varicoceles treated by percutaneous retrograde sclerotherapy, and in group 3, 87 patients with 123 varicoceles were treated by laparoscopic varicocelectomy. Of all patients, 222 (73.8%) were closely followed up with clinical and Doppler ultrasound examinations 6 and 12 months after the treatment. Seminal analysis was carried out before treatment and repeated in 172 patients with subfertility or infertility 4 to 6 months after treatment. Results. Patients in the three treatment groups were balanced regarding the different variables. The mean operative time was significantly shorter among patients with open surgery. The cost of sclerotherapy is one fourth to one fifth that of surgery and the cost of laparoscopy is double. Sclerotherapy was successful in 96 (82.8%) of 116 left varicoceles and in only 24 (51%) of 47 right varicoceles. The recurrence rate at follow-up was not significantly different among the three groups. The recurrence rate increased progressively with the increase of varicocele size from grade I to grade III in all groups. The overall incidence of postoperative complications was significantly higher among patients with open surgery. Postoperative spermiogram showed a significant increase in the density and motility and a significant reduction in the percentage of abnormal forms in all groups. The pregnancy rate was approximately similar in all groups. Conclusions. First, sclerotherapy is best used for isolated left-sided varicoceles. Second, laparoscopy is the treatment of choice for bilateral varicoceles. Finally, open surgery still has a role in isolated right-sided varicoceles and in left-sided cases with failed sclerotherapy. UROLOGY 52: 294-300, 1998.

Recent increases in the pressure output of diagnostic ultrasound scanners have led to an interest in establishing thresholds for bioeffects in many organs including the lungs of mammals. Damage may be mediated by inertial cavitation, yet there have been no such direct observations in viva. To explore the hypothesis of cavitation-based bioeffects from diagnostic ultrasound, research has been performed on the thresholds of damage in rat lungs exposed to 4.0~MHz pulsed Doppler and color Doppler uItrasound. A 30-MHz active cavitation detection scheme complementing these studies provides the first direct evidence of cavitation in vivo from diagnostic ultrasound pulses.

Purpose: At present, thereis little scientific evidence that postexercise manual massage has any effect on the factors associated with the recovery process. The purpose of this study was to compare the effects of massage against a resting control condition upon femoral artery blood flow (FABF), skin blood flow (SKBF), skin (SKT), and muscle (MT) temperature after dynamic quadriceps exercise. Methods: Thirteen male volunteers participated in 3 X 2-min bouts of concentric quadriceps exercise followed by 2 X 6-min bouts of deep effleurage and petrissage massage or a control (rest) period of similar duration in a counterbalanced fashion. Measures of FABF, SKBF, SKT, MT, blood lactate concentration (BLa), heart rate (HR), and blood pressure (BP) were taken at baseline, immediately after exercise, as well as at the midpoint and end of the massage/rest periods. Data were analyzed by two-way ANOVA. Results: Significant main effects were found for all variables over time due to effects of exercise. Massage to the quadriceps did not significantly elevate FABF (end-massage 760 t 256 vs end-control 733 t 161 mL.min-), MT, BL, HR, and BP over control values (P > 0.05). SKBF (end-massage 150 ± 49 vs end control 6 t 4 au) SKT (end-massage 32.2 t 0.9 vs end-control 31.1 t 1.3°C) were elevated after the application of massage compared with the control trial (P < 0.05). Conclusion: From these data it is proposed that without an increase in arterial blood flow, any increase in SKBF is potentially diverting flow away from recovering muscle. Such a response would question the efficacy of massage as an aid to recovery in postexercise settings.