bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pattern recognition of pelvic masses by gray‐scale ultrasound imaging: the contribution of Doppler ultrasound
Authors: Valentin L 
Published: March 2003

AbstractObjectiveTo determine the extent to which Doppler ultrasound examination contributes to a correct specific diagnosis of a pelvic mass when the preliminary diagnosis is based on subjective evaluation of the gray‐scale ultra‐sound image (pattern recognition).MethodsIn 173 consecutive cases, women scheduled for surgery because of a pelvic mass judged clinically to be of adnexal origin underwent preoperative gray‐scale and color Doppler ultrasound examination. On the basis of subjective evaluation of the gray‐scale ultrasound image, the ultrasound examiner classified each tumor as probably benign or malignant. If possible, a specific diagnosis was made, e.g. ‘endometriosis’ or ‘dermoid cyst’. The confidence with which the diagnosis was made was rated subjectively on a visual analog scale. The diagnosis based on gray‐scale imaging was re‐evaluated after color Doppler examination, the diagnostic confidence after Doppler examination also being rated on a visual analog scale. ‘Malignancy’ was not considered a specific diagnosis.ResultsPattern recognition of the gray‐scale ultrasound image resulted in no unequivocal specific diagnosis in 51% (88/173) of cases, a correct specific diagnosis in 42% (72/173) and an incorrect specific diagnosis in 7% (13/173). Doppler examination added to a correct specific diagnosis in only 5% (8/173) of cases, either by changing an incorrect specific diagnosis to a (more) correct one (five tumors), or by increasing the confidence with which a correct specific diagnosis was made (three tumors). Doppler examination was misleading in one tumor.ConclusionBy using pattern recognition of the gray‐scale ultrasound image, a correct specific diagnosis can be made in almost half of adnexal tumors scheduled for surgery. Subjective assessment of the color content of the tumor scan contributed little to the specific diagnosis of pelvic tumors. Copyright © 1999 International Society of Ultrasound in Obstetrics and Gynecology
Intravascular contrast agent in the ultrasonography of ectopic pregnancy
Authors: Ordén M.‐R. , Gudmundsson S. , Helin H.‐L. , Kirkinen P. 
Published: March 2003

AbstractObjectiveThe aim of this study was to characterize the effect of an intravascular ultrasound contrast agent in the adnexal circulation and to evaluate the applicability of the contrast agent in imaging ectopic trophoblastic blood flow.DesignThirty‐three color Doppler and 13 power Doppler examinations were performed among 30 patients with ectopic pregnancy, first without and then with galactose‐based contrast agent enhancement. The effect of the contrast agent was evaluated both visually (color Doppler) and with computerized power Doppler signal intensity measurements.ResultsThe Doppler signal intensity from the adnexal blood circulation increased within 30 s after antebrachial injection, yielding an effect that was recognizable up to 2–4 min later. There was a clear enhancement of trophoblastic flow after addition of the contrast agent in all except one of the ectopic pregnancies. In 12% of the cases, trophoblastic flow could be imaged only by using the contrast agent. The contrast agent increased the amount of recognizable vascular areas around the trophoblastic mass in 91% of the examinations, resulting in a more complete peritrophoblastic ring. The increase in the mean intensity of the power Doppler signal was 7.8% (p < 0.01).ConclusionThe intravascular ultrasound contrast agent has a recognizable effect on Doppler ultrasonographic examination of the adnexal circulation. It appears to be of help when examining ectopic pregnancies where the finding in color flow imaging is ambiguous. The use of a contrast agent may also facilitate localization of trophoblastic tissue in a hemorrhagic adnexal mass. Copyright © 1999 International Society of Ultrasound in Obstetrics and Gynecology
Assessment of fetal heart rate variability and velocity variability by Doppler velocimetry of the descending aorta at 10–20 weeks of gestation
Authors: Ursem N. T. C. , Clark E. B. , Keller B. B. , Hop W.C.J. , Wladimiroff J. W. 
Published: March 2003

AbstractObjectivesDetermination of gestational age‐related modulations in fetal heart rate and descending aorta blood flow velocity in the early human fetus and comparison of aortic variability data with data obtained from the umbilical artery. It is hypothesized that these modulations present in the umbilical artery also occur in the descending aorta.MethodsDoppler studies of descending aorta velocity waveforms were performed at 10–20 weeks in 55 normal pregnant women. In 24 of the 55 women, Doppler recordings from both the descending aorta and the umbilical artery were collected. Absolute values and variability of fetal heart rate, peak systolic and time‐averaged velocities were determined from flow velocity waveforms of at least 18 s in duration.ResultsFrom 10 to 20 weeks of gestation, the descending aorta peak systolic and time‐averaged velocities increased, whereas the fetal heart rate decreased. The descending aorta peak systolic variability also increased. However, the time‐averaged velocity variability and fetal heart rate variability remained constant during the study period. In the subset of 24 women, the fetal heart rate variability and velocity variability data from the descending aorta and umbilical artery were not significantly different.ConclusionsReproducible fetal heart rate and velocity variability data can be derived from the descending aorta and umbilical artery. The increase in heart rate variability observed in the umbilical artery was not seen in recordings obtained from the descending aorta. Different fetal activity states may be the underlying mechanism for these heart rate variability discrepancies. Copyright © 1999 International Society of Ultrasound in Obstetrics and Gynecology
F79Real‐time three‐dimensional fetal echocardiography
Authors: Tutschek B. , Buck T. , Reihs T. , Staiger H. F. , Henrich W. , Bender H. G. , Erbel R. 
Published: March 2003

BackgroundFetal echocardiography employs high resolution two‐dimensional ultrasound (2DE) to detect structural heart disease. Three‐dimensional echocardiography (3DE) using reconstruction of a series of 2D images of the fetal heart has been hampered by technical problems. Real‐time 3DE (rt3DE) acquires volume data sets rather than 2D images.MethodThe rt3DE system (Volumetrics, Durham) uses a 2.5‐MHz matrix phased‐array transducer scanning a pyramidal volume. A multipanel screen displays cross‐sectional images of the same volume in real‐time: two perpendicular 2D images that can be freely oriented throughout 3‐D space plus up to three calculated sections not obtainable by 2DE.Resultsrt3DE could visualize the fetal heart satisfactorily. Due to real‐time volumetric scanning gating with the fetal cardiac cycle was not necessary. The image quality with regard to resolution was inferior to current high end 2D machines, but is bound to improve with technology. Volumes can also include color Doppler, but at the cost of low frame rates.ConclusionWith advancing technology volume rather than 2D data acquisition may emerge as a standard in fetal echocardiography. While examining one or two technically and physically optimized 2D views, the entire pyramidal volume surrounding these planes is acquired in real time. The dissociation of rapid data acquisition from its interpretation may be advantageous, enabling ‘virtual scanning’ for different aspects even without the patient present.
Combined ultrasound biometry, serum markers and age for Down syndrome risk estimation
Authors: Bahado‐Singh R.O. , Oz A.U. , Gomez K. , Hunter D. , Copel J. , Baumgarten A. , Mahoney M.J. 
Published: March 2003

Objective To compare Down syndrome screening efficiency of the standard serum triple analyte screen to that of a four‐component screen consisting of ultrasound biometry and serum markers in the second trimester.Methods The Down syndrome screening efficiency of the triple screen, i.e. alpha‐fetoprotein (AFP), unconjugated estriol (E3), hCG and maternal age, was compared with the four‐marker algorithm, i.e. humerus length, nuchal thickness, AFP and hCG plus maternal age. A quadrivariate Gaussian algorithm was used to calculate individual Down syndrome odds. Receiver operating characteristic (ROC) curves plotting sensitivity against false‐positive rate were constructed for each algorithm and the areas under the curves were compared to determine which was superior. Sensitivity and false‐positive rates at different Down syndrome risk thresholds were also compared.Results There were 46 cases of Down syndrome (1.9%) with 2391 normal singleton pregnancies in a referral population in which triple screen, fetal biometry and karyotype had been done. The gestational age range for the study was 14–24 completed weeks. The median maternal age for the study group was 35.0 years (14.0–46.0 years). The areas (SE) under the ROC curves were 0.75(0.04) and 0.93(0.02) for the standard triple and the four‐marker screen, respectively (P < 0.001). At a 10% false‐positive rate, detection was 45.7% for the triple and 80.4% for the four‐marker screen.Condusions A new algorithm combining humerus length and nuchal thickness measurement with serum AFP, hCG and maternal age substantially improved Down syndrome screening efficiency compared with the traditional triple screen. The model appears promising and should be evaluated in an independent data set.
Prenatal diagnosis of intrahepatic arteriovenous shunts
Authors: Tseng J. J. , Chou M. M. , Lee Y. H. , Ho Esther S. C. 
Published: March 2003

AbstractA case of mixed intrahepatic arteriovenous shunts in a fetus diagnosed at 35 weeks' gestation is presented. Color Doppler ultrasonography in the fetal liver demonstrated complicated vascular connections fed by the hepatic arterial branches and drained into the portal and middle hepatic veins. Pulsed Doppler ultrasonography identified a high cardiac output state by the detection of increased flow velocities of the great vessels. The contribution of Doppler ultrasonography to hemodynamic changes is highlighted. The management is briefly discussed. Copyright © 2000 International Society of Ultrasound in Obstetrics and Gynecology
Three‐dimensional targeting: a new three‐dimensional ultrasound technique to evaluate needle position during breast biopsy
Authors: Weismann C. F. , Forstner R. , Prokop E. , Rettenbacher T. 
Published: March 2003

AbstractObjectiveTo evaluate the role of three‐dimensional (3D) ultrasound (US) following needle breast biopsy under two‐dimensional (2D) needle guidance.MethodsA total of 188 core‐needle biopsies and 24 fine‐needle aspiration biopsies were 3D US correlated after typical ‘freehand’ US needle guidance. All cases were examined with a linear 3D US volume scanner (5–13 MHz, Voluson 530D, Medison‐Kretztechnik, Zipf, Austria). After core‐needle stroke or localization of fine needle, a 3D US data volume set was acquired and a multiplanar analysis performed. This needle position check in all three planes is called ‘3D targeting’. 66 women with a mean age of 51 years (range, 27∼80 years) showed 77 breast lesions (55 solid lesions, 22 cysts) with a mean diameter of 1.5 (range, 0.3∼5.0) cm.ResultsIn 49 women with 55 solid breast lesions, 16 lesions were malignant and 39 lesions benign. In 53 solid breast lesions 188 core‐needle biopsies were performed (mean 3.6 biopsies/lesion). After core‐needle biopsy 23 lesions (16 malignant, seven benign) were surgically removed. In 22 cases final histology confirmed results of the core‐needle specimen. In one case a core‐needle specimen of a 5 mm lesion showed atypical lobular hyperplasia. The definitive histology after surgery was invasive lobular carcinoma. Twenty‐two cysts and two benign solid lesions were punctured with a fine needle followed by aspiration biopsy. The overall sensitivity of core‐needle results in this study was 94% (specificity 100%, accuracy 0.98, positive predictive value 1, negative predictive value 0.97). In 117 core‐needle strokes of benign (21) and malignant (12) lesions 3D targeting prospectively revealed 95 lesion hits, Twelve marginal lesion hits and nine out‐of‐lesion hits. In one case after the initial large core‐needle path a 5‐mm lesion was disguised by air bubbles, therefore 3D targeting failed during the second biopsy procedure.Conclusion3D US combined with 3D targeting technique is a reliable and objective tool demonstrating exact spatial positioning of core and fine needle during biopsy procedure. Copyright © 2000 International Society of Ultrasound in Obstetrics and Gynecology
Networking of three dimensional sonography volume data
Authors: Kratochwil A. , Lee A. , Schoisswohl A. 
Published: March 2003

AbstractThree‐dimensioned (3D) sonography enables the examiner to store, instead of copies from single B‐scan planes, a volume consisting of 300 scan planes. The volume is displayed on a monitor in form of three orthogonal planes – longitudinal, axial and coronal. Translation and rotation facilitates anatomical orientation and provides any arbitrary plane within the volume to generate organ optimized scan planes. Different algorithms allow the extraction of different information such as surface, or bone structures by maximum mode, or fluid filled structures, such as vessels by the minimum mode. The volume may contain as well color information of vessels.The digitized information is stored on a magnetic optical disc. This allows virtual scanning in absence of the patient under the same conditions as the volume was primarily stored. The volume size is dependent on different, examiner‐controlled settings. A volume may need a storage capacity between 2 and 16 MB of 8‐bit gray level information.As such huge data sets are unsuitable for network transfer, data compression is of paramount interest. 100 stored volumes were submitted to JPEG, MPEG, and bi‐orthogonal wavelet compression. The original and compressed volumes were randomly shown on two monitors. In case of noticeable image degradation, information on the location of the original and compressed volume and the ratio of compression was read. Numerical values for proving compression fidelity as pixel error calculation and computation of square root error have been unsuitable for evaluating image degradation. The best results in recognizing image degradation were achieved by image experts. The experts disagreed on the ratio where image degradation became visible in only 4% of the volumes.Wavelet compression ratios of 20 : 1 or 30 : 1 could be performed without discernible information reduction. The effect of volume compression is reflected both in the reduction of transfer time and in storage capacity. Transmission time for a volume of 6 MB using a normal telephone with a data flow of 56 kB/s was reduced from 14 min to 28 s at a compression rate of 30 : 1. Compression reduced storage requirements from 6 MB uncompressed to 200 kB at a compression rate of 30:1. This successful compression opens new possibilities of intra‐ and extra‐hospital and global information for 3D sonography. The key to this communication is not only volume compression, but also the fact that the 3D examination can be simulated on any PC by the developed 3D software. PACS teleradiology using digitized radiographs transmitted over standard telephone lines.Systems in combination with the management systems of HIS and RIS are available for archiving, retrieval of images and reports and for local and global communication. This form of tele‐medicine will have an impact on cost reduction in hospitals, reduction of transport costs. On this fundament worldwide education and multi‐center studies becomes possible. Copyright © 2000 International Society of Ultrasound in Obstetrics and Gynecology
Ultrasonic diagnosis of ureteral injury after laparoscopically‐assisted vaginal hysterectomy
Authors: Hung M. J. , Huang C. H. , Chou M. M. , Liu F. S. , Ho E. S. C. 
Published: March 2003

AbstractUreteral injuries are uncommon but serious complications of laparoscopically‐assisted vaginal hysterectomy. The ureter is particularly at risk for inadvertent injury when the cardinal‐uterosacral ligament complex is coagulated and divided below the uterine vessels. We present two recent cases which describe the application of transabdominal ultrasound including color Doppler mapping in the diagnosis of ureteral injury after laparoscopically‐assisted vaginal hysterectomy. Transabdominal ultrasound including color Doppler mapping has great diagnostic potential as a method for non‐invasive evaluation of post‐operative ureteral conditions. Ultrasonic triads (absence of a ureteric jet, ascites, and the presence or absence of hydronephrosis) are capable of differentiating diagnosis of complete, partial, or nonobstructive surgical ureteral injuries. Copyright © 2000 International Society of Ultrasound in Obstetrics and Gynecology
Fetal adrenal artery velocimetry measurements in appropriate‐for‐gestational age and intrauterine growth‐restricted fetuses
Authors: Tekay A. , Jouppila P. 
Published: March 2003

AbstractObjectiveTo investigate adrenal artery blood flow in the fetus.Design and methodSixty‐two appropriate‐for‐gestational‐age (AGA) and 20 intrauterine growth‐restricted (IUGR) fetuses were recruited to this cross‐sectional study between 22 and 42 weeks of pregnancy in a tertiary referral fetal medicine unit of a university hospital.EndpointsDoppler velocimetry of the fetal adrenal, umbilical (UA), renal and middle cerebral arteries (MCA). Pulsatility index (PI), resistance index (RI), peak systolic velocity (PSV), time‐averaged maximum velocity (TAMXV) and cerebroplacental ratio (MCA RI/UA RI; CPR). Obstetric outcome.ResultsThe adrenal artery was detected in 82% of the fetuses. All flow velocity waveforms obtained from the adrenal artery indicated low impedance blood flow. No significant changes in PI, RI, PSV and TAMXV occurred with advancing gestation. The blood flow parameters of the adrenal artery did not differ between AGA and IUGR fetuses. In five IUGR fetuses with signs of redistribution of cardiac output in favor of the brain, the adrenal artery velocimetry results were unremarkable. The adrenal artery PI, RI, PSV and TAMXV values were higher in female fetuses than in male fetuses (P < 0.05). A relationship was observed between the velocity measurements and the estimated fetal weight (P < 0.01).ConclusionsThe fetal adrenal artery could be readily detected. We observed no redistribution of blood flow in favor of the fetal adrenals in IUGR fetuses which were not severely compromised. Copyright © 2000 International Society of Ultrasound in Obstetrics and Gynecology
Prenatal diagnosis of intrahepatic communications of the umbilical vein with atypical arteries (A–V fistulae) in two cases of trisomy 21 using color Doppler ultrasound
Authors: Hartung J. , Chaoui R. , Kalache K. , Tennstedt C. , Bollmann R. 
Published: March 2003

AbstractWe report on two cases of the prenatal diagnosis of arterio‐venous communication between the intra‐abdominal umbilical vein and atypical arteries. The diagnosis was made by color and spectral Doppler and ‘color power angiography’. Both cases presented with hydrops fetalis, one at 14 and the other at 31 weeks of gestation. In the first case, color Doppler demonstrated an atypical arterial vessel connecting the umbilical vein with the aorta; the ductus venosus was patent. Echocardiography showed a so‐called atrioventricular canal. In the second case, a complex intrahepatic vascular malformation was found. Color Doppler demonstrated communications between the umbilical vein and the hepatic artery and an atypical artery; the ductus venosus was patent. In the latter case polyhydramnios, duodenal atresia and macroglossia were additionally detected. In both cases, fetal karyotyping revealed trisomy 21. The first case resulted in a missed abortion, the second in a stillbirth. All findings were confirmed on autopsy.Of interest is that both fetuses were affected with trisomy 21. The increasing use of color Doppler in prenatal diagnosis, especially in hemodynamically compromised fetuses, will help to determine the actual incidence of complex vascular malformations of the umbilical vein and to elucidate the impact of such malformations on fetal outcome. Copyright © 2000 International Society of Ultrasound in Obstetrics and Gynecology
Sono‐endoscopic delineation of the placental vascular equator prior to selective fetoscopic laser ablation in twin‐to‐twin transfusion syndrome
Authors: Thilaganathan B. , Gloeb D. J. , Sairam S. , Tekay A. 
Published: March 2003

AbstractObjectiveTo assess the safety and efficacy of a new fetoscopic technique in the management of twin‐to‐twin transfusion syndrome.Study designProspective study of fetoscopic treatment and outcome in 10 pregnancies complicated by severe twin‐to‐twin transfusion syndrome before 24 weeks' gestation. The sono‐endoscopic approach was used to identify the placental vascular equator and photocoagulate any vessels crossing this threshold.ResultsThe mean gestation at treatment was 20 weeks and 3 days. An average of three to four vessels were ablated during each procedure, with a mean operative time of 24 min (range, 14–31 min). The overall survival rate was 55% (11 of 20) with at least one survivor in 70% (seven of 10) of pregnancies.ConclusionsFetoscopic laser ablation is a safe and effective form of treatment in the management of severe twin‐to‐twin transfusion syndrome. This technique, where vessels crossing the placental vascular equator are identified and photocoagulated fetoscopically, is an alternative to the non‐selective and selective methods described previously. This new approach is associated with a shorter operating time, less damage to the normal placental surface vasculature and with survival results that are at least as promising as previously reported techniques. Copyright © 2000 International Society of Ultrasound in Obstetrics and Gynecology
Reference values of fetal peak systolic blood flow velocity in the middle cerebral artery at 19–40 weeks of gestation
Authors: Kurmanavicius J. , Streicher A. , Wright E. M. , Wisser J. , Müller R. , Royston P. , Huch R. , Huch A. , Zimmermann R. 
Published: March 2003

AbstractObjectivesThe objectives of this prospective study were (i) to establish new reference values of peak systolic blood flow velocity measurement in the fetal middle cerebral artery (MCA‐PSV) following validated methodological guidelines and (ii) to develop a method to calculate Z‐scores of MCA‐PSV.Patients and MethodsCross‐sectional data were obtained from 331 pregnant women between 19 and 40 weeks' gestation. Reference ranges for MCA‐PSV were constructed and for each measurement linear regression models were fitted separately to the mean and standard deviations (SD) as a function of gestational age. An application to calculate Z‐scores was developed. A comparison was made between the reference ranges produced in our study and those of a previous one.ResultsA new chart, table of centiles and regression equations of MCA‐PSV are presented. Comparison of our reference ranges with ones produced in a previous study showed similar 5th centile values. However, the values for the 50th and 95th centiles between 19 and 28 gestational weeks were lower in our study.ConclusionsWe have constructed reference ranges for MCA‐PSV which, because they are derived from a larger number of examinations in the 15–20‐week period and because the methodological flaws of the previously published study have been eliminated, we consider to be more accurate and therefore more useful for clinical practice. Copyright © 2001 International Society of Ultrasound in Obstetrics and Gynecology