Transabdominal Transducers Research Articles

Comparison of transrectal and transabdominal transducers for use in fast localized abdominal sonography of horses presenting with colic.

Abdominal ultrasonography is valuable in the diagnosis of equine colic. Fast localized abdominal sonography of horses (FLASH) enables practitioners with limited experience to perform ultrasonography in emergency settings. However, many practitioners only possess rectal format linear array transducers (RFLT). The hypotheses are: (a) A low frequency curvilinear transducer (LFCT) and RFLT will detect free abdominal fluid and abnormal small intestinal loops with similar frequency during FLASH, and (b) there will be a difference between the transducers for detection of gastric abnormalities and nephrosplenic entrapment. The objective is to compare transcutaneous abdominal ultrasonographic detection of abnormalities in horses presenting with colic using a LFCT and RFLT. Twenty-four horses requiring FLASH for investigation of colic were enrolled. Horses that were too painful to undergo transcutaneous abdominal ultrasonographic examination were excluded. A single investigator performed FLASH on all horses using a RFLT, while one of three other clinicians simultaneously performed FLASH using a LFCT. Comparison of abnormal findings between the two transducers was performed using Chi square, Fisher's exact or Wilcoxon tests. The incidence of identification of abnormal findings was similar between the two transducers for all comparisons except the visibility of the left kidney and stomach (kidney LFCT 81.25% vs. RFLT 22.92%, stomach LFCT 87.5% vs. RFLT 62.5%). While there are limitations to using a RFLT to identify nephrosplenic entrapment of the colon and detection of the stomach, it reliably detects other common abnormalities, including peritoneal effusion, lesions of the small intestine, and changes to the wall of the large colon and cecum.

Evaluation fetal heart in the first and second trimester: Results and limitations.

Cardiac heart defects affect nearly 6-12 per 1000 live births in the general population and are more frequent than common trisomies. To assess the efficacy and technical limitations of first-trimester fetal heart evaluation in the 11-14th-weeks' scan and comparison with the second-trimester anatomical exam by ultrasound. Between April 2015 and July 2020, medical records and ultrasound data of 3295 pregnancies who underwent first-trimester fetal anatomy exams by ultrasound were reviewed retrospectively. All ultrasound exams were performed by the same two operators (TUKD, OP) with transabdominal transducers. Fetal situs, four-chamber view, outflow tracts, and three-vessel trachea view are the cornerstones of first-trimester fetal heart examination. Conventional grayscale mode and high-definition power Doppler mode were utilized. The same operators re-examined all cases between the 18 and 23 weeks of gestation by ISUOG guidelines. We performed a combined transvaginal and transabdominal approach for only 101 cases (3.06%). The mean maternal age was 31.28 ± 4.43, the median gestational age at the first-trimester ultrasound exam was 12.4 weeks, and the median CRL was 61.87 mm (range was 45.1-84 mm). Even combined approach situs, cardiac axis, and four-chamber view could not be visualized optimally in 28 cases (0.7%). Outflow tracts were visualized separately in 80% (2636 in 3295) cases. Three vessel-trachea views were obtained in 85.4% (2814 in 3295) cases by high-definition Doppler mode. There were 47 fetuses with cardiac defects in 3295 pregnancies with the known pregnancy outcome. Ten cases had abnormal karyotype results. Thirty-two fetuses with cardiac anomalies (9.7 in 1000 pregnancies) were detected in the first-trimester examination, and the remaining 15 (4.55 in 1000 pregnancies) cases were diagnosed in the second-trimester examination. The prevalence of congenital cardiac anomalies was 14.25 in 1000 pregnancies. Fifteen cases were missed in the first-trimester exam. Also, ten fetuses which had abnormal cardiac findings in the first-trimester exam were not confirmed in the second-trimester exam. Sensitivity, specificity, positive, and negative predictive values were calculated as 65.3%, 99.7%, 66.8%, and 99.67%, respectively. Late first-trimester examination of the fetus is feasible and allows earlier detection of many structural abnormalities of the fetus, including congenital heart defects. Suspicious and isolated cardiac abnormal findings should be re-examined and confirmed in the second-trimester exam. Previous abdominal surgery, high BMI, and subtle cardiac defects can cause missed cardiac abnormalities.

ISUOG Practice Guidelines (updated): fetal cardiac screening.

ISUOG Practice Guidelines (updated): fetal cardiac screening.

Normograms in Prenatal Life of Stomach and Urinary Bladder in the Second and Third Trimesters of Pregnancy.

The aim of this study was to prepare normograms for the fetal stomach, urinary bladder, and stomach to urinary bladder index in healthy fetuses. The study was conducted based on the data extracted from the database of our tertiary center in the years 2016-2019. The study group, comprising 867 fetuses, demonstrated normal biometry and normal heart structure, normal heart function, no extracardiac malformations, and no extracardiac anomalies. The stomach to urinary bladder index was analyzed in the study group. The examinations were performed with the use of the following ultrasound machines: Voluson E10, Philips and Voluson Expert, with convex transabdominal transducers. Linear regression analysis based on Microsoft Excel was used for statistical analysis. The average size of the stomach in healthy fetuses between the 14-40th week of gestation was 18 mm (8-40 mm), the average urinary bladder measurement was 17 mm (15-42 mm), and the fetal stomach to urinary bladder index was constant: 1.26 (0.09-3.93). The normograms for the stomach, urinary bladder and the stomach to urinary bladder index prepared based on our study group can contribute to an improvement in the accuracy of examination and provide an unified organization of the description of fetuses. These normograms constitute an additional marker for the assessment of fetal condition. A clear disproportion in the size of the urinary bladder and stomach can be helpful in terms of paying more attention to fetuses with untypical features in screening centers.

Comparative Assessment of Hormonal, Echographic and Spectral Parameters in Chronic Endometritis and Chronic Salpingo-Oophoritis

The purpose of the study was to assess the effectiveness and clinical significance of the use of spectral analysis of molecular markers for an objective assessment of the clinical course of chronic endometritis and salpingo-oophoritis. Materials and methods. The paper presents survey data of 100 women aged 18-47 years with a diagnosis of chronic endometritis and chronic salpingo-oophoritis. Laboratory methods of blood tests were carried out according to the generally accepted methods when patients were admitted for examination. The assessment of the hormonal status was carried out using standard kits from the company "Immunotec" (Czech Republic) on a radioisotope analyzer "Gamma-800" (Narcotest). All subjects underwent ultrasound of the pelvic organs using the Voluson E8 apparatus, using transabdominal transducers of 11 Hz and 18 Hz and a transvaginal transducer with a frequency of 20 Hz and 31 Hz. To study molecular markers, we used the method of molecular Raman spectroscopy. We used a standard two-beam infrared spectrometer "SPECORD-75 IR" in the frequency range of 4000-400 cm-1. Statistical data processing was carried out using Microsoft Excel 2000 and SPSS 10.0.5 software. Results and discussion. The results of our research showed that the use of hormonal and echographic studies, although they are informative methods in the diagnosis of chronic endometritis and salpingo-oophoritis, are not specific enough. One of the important points of pathogenesis, both for acute and chronic inflammatory diseases of the genitals, is the development of endogenous intoxication. A manifestation of acute inflammation against the background of intoxication is a change in the biosynthesis of "acute phase proteins". Spectral analysis of molecular markers allows detecting chronic endometritis / salpingo-oophoritis with higher accuracy (98%), sensitivity (99%) and specificity (97%). Stretching and bending vibrations of -CO and its derivatives are most intensely manifested. At the same time, depending on the pathological process, a shift in the position of the maxima in the absorption spectra was noted. The magnitude of the shift between the wave numbers obtained in patients with endometritis and salpingo-oophoritis was 1000/1500 cm-1, which is important for the identification and differentiation of components in the mixture. Conclusion. For samples of the spectrum of blood plasma in patients with chronic endometritis, characteristic bands with maxima are located in the region of 1510 cm-1, 1520 cm-1, 1535 cm-1. The absorption spectrum corresponds to 0.13-0.18. In patients with chronic salpingo-oophoritis, 1720cm-1 is characteristic for the 1600/1750cm-1 band, but 3420cm-1 for the 3300/3680cm-1 band. In this case, the absorption of waves during this process has significant differences – 0.16-0.25 for the first band and 0.06-0.20 for the second, on average 0.11

ISUOG Practice Guidelines (updated): sonographic examination of the fetal central nervous system. Part 2: performance of targeted neurosonography.

ISUOG Practice Guidelines (updated): sonographic examination of the fetal central nervous system. Part 2: performance of targeted neurosonography.

Integration of nuchal translucency screening into the first-trimester fetal anatomy scan: the time has come.

Integration of nuchal translucency screening into the first-trimester fetal anatomy scan: the time has come.

ISUOG Safety Committee Position Statement on safe performance of obstetric and gynecological scans and equipment cleaning in context of COVID-19.

ISUOG Safety Committee Position Statement on safe performance of obstetric and gynecological scans and equipment cleaning in context of COVID-19.

153. Spiral arterial blood flow during pregnancy; a systematic review and meta-analysis

Objectives To evaluate the physiological adaptation of blood flow in human uterine spiral arteries throughout the course of normotensive and hypertensive pregnancies based on existing literature. Methods A systematic literature review and meta-analysis on the change of arterial uterine spiral arteries, measured by Doppler ultrasonography, was conducted. Literature search was performed in Pubmed, EMBASE and Cochrane Library. The search was limited to papers published in English. Both first and second selection were performed by two independent researchers. Weighted means of the Doppler indices were calculated for the three pregnancy trimesters. Results Seven longitudinal prospective and four cross-sectional studies were included with publication dates ranging from 1995 to 2015. Ultrasound measurements were performed at certain gestational ages using transvaginal or transabdominal transducers. In normotensive pregnancies, pulsatility index (PI) decreased from 0.76 (95% CI: 0.65–0.86) in the first trimester to 0.51 (95% CI: 0.45–0.57) (p Conclusions PI and RI in uterine spiral arteries both decreased with advancing gestational age with the largest decrease between the first and second trimester. This is in concordance with previous histological hypertrophic decidual vasculopathy- and Doppler uterine artery findings. Longitudinal studies examining comprehensively the predictive value of spiral artery Doppler for hypertensive pregnancies are yet to be determined.

OP08.10: Comparison of microbial contamination of transabdominal versus transvaginal transducers

OP08.10: Comparison of microbial contamination of transabdominal versus transvaginal transducers

Early Pregnancy Scanning for Fetal Anomalies—The New Standard?

For many years, significant efforts have been made toward attempts at early detection of chromosomal and structural malformations, to lower the rate of these defects in newborns. Traditionally, the main ultrasound examination during pregnancy was performed in the second trimester, using transabdominal transducers. The development of high-frequency and high-resolution (5 to 9 MHz; 6 to 12 MHz) transvaginal probes along with substantial improvements in image and signal processing have opened new possibilities for the investigation of early pregnancy. Up until the recent past, many defects were considered unidentifiable early in pregnancy. A large number of those can now be diagnosed already in the first trimester. Early detection of fetal anomalies enables karyotyping by chorionic villus sampling and, in those patients in whom findings are abnormal, simpler procedures for termination of pregnancy may be performed. This may reduce physical and psychological morbidity associated with second-trimester abortions.

The petrous portion of the temporal bone can be demonstrated by transvaginal ultrasound at 14–16 weeks of gestation

The temporal bone consists of four components: the squamous, petromastoid and tympanic portions, and the styloid process. The petrous part houses the auditory apparatus1. This mass of bone is wedged between the sphenoid and occipital bones in the cranial base1. Complete agenesis of the petrous portion of the temporal bone occurs in Michel aplasia2, a congenital malformation associated with congenital hearing loss. Here we describe, for the first time, the sonographic appearance of the petrous part of the temporal bone in normal pregnancies, between 14 and 16 weeks of gestation, using transvaginal sonography (TVS). Approval for the study was given by the Institutional Review Board (Helsinki Committee Protocol). Thirty-four consecutive pregnant women, between 14 and 16 weeks of gestation, were examined after giving written informed consent to take part in the study. All patients were studied during a routine fetal anomaly scan using TVS, with an endocavitary 5–9-MHz transducer (Voluson 730 Expert; GE Medical Systems, Milwaukee, WI, USA). Patients were included in the study if there was a single fetus without evident or suspected fetal malformations and no family history of congenital hearing loss. The fetal head was assessed in transverse sections with the parotid gland first identified as an echoic structure located medial to the external ear; the petrous bone (an annular echogenic structure located medial and superior to the parotid gland) was then identified and measured in its largest anteroposterior diameter (Figure 1, Videoclip S1). The largest of three measurements was documented. The petrous bone was measured on at least one side of the head in each fetus. The examination time was not prolonged in order to permit measurement of the petrous bone (beyond the short time needed for the measurement itself) and no special attempt was made to measure the bone on both sides. However, bilateral measurements were obtained when both sides were visualized easily. Measurement of the petrous bone (calipers) at 15 weeks of gestation. Ant., anterior; Post., posterior; E, eye. In all 34 fetuses the petrous bone was visualized and measured on at least one side, and in eight patients the petrous bones were visualized and measured bilaterally. The median anteroposterior diameter of the petrous bone was 4.5 (range, 3.5–6.1) mm, and the mean ( ± SD) anteroposterior diameter was 4.59 ± 0.53 mm. This is the first report to describe the normal appearance of the fetal petrous bone. The ability to visualize the petrous bone raises the possibility of prenatal diagnosis of congenital malformations of the inner ear, such as Michel aplasia2. Congenital hearing loss owing to malformation of the inner ear is classified into several types3-5. Some of these malformations are associated with malformations of the temporal bone, specifically the petrous portion, which is reported to be malformed in about 20% of cases of congenital deafness4. We measured the petrous bone at 14–16 weeks of gestation because at later gestational ages measurement of the bone is more difficult and time-consuming. However, we now measure the normal petrous bone at up to 40 weeks of gestation. TVS was used because this is the standard technique used in our institution for a routine fetal anomaly scan at the gestational age considered. However, the petrous bone can also be visualized using transabdominal transducers at 14–16 weeks. SUPPORTING INFORMATION ON THE INTERNET The following supporting information may be found in the online version of this article: Videoclip S1 Videoclip showing measurement of the petrous bone in a 15-week fetus. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article. M. Odeh*, E. Ophir*, J. Bornstein*, * Department of Obstetrics and Gynecology, Western Galilee Hospital, Nahariya, Rappaport Faculty of Medicine, Technion, Haifa, Israel

OP19.11: The distance between fetal umbilical cord insertion and symphisis pubis In utero indication for congenital bladder extrophy

Congenital Bladder Extrophy (CBE) is a severe and rare malformation never diagnosed at early second trimester. Our aim was to measure the distance between fetal Umbilical Cord Insertion (UCI) and the Symphysis Pubis (SP) in order to enhance fetal diagnosis of CBE. A prospective cross sectional study was performed on normal singleton pregnancies between 13 to 23 weeks gestation. The distance between the fetal UCI and SP was measured in a mid sagittal plain using an high resolution transvaginal and trans abdominal transducers. Adequate measurements were obtained in 150 fetuses. The distance of between fetal UCI to SP was found to have good correlation with gestational age and was expressed by regression equations and correlation coefficient, were found to be highly statistically significant (P < 0.0001). The normal mean (+/− SD) for each gestational week was defined. In two fetuses one in 14 wks' and the other in 22 wks' in whom no bladder could be visualized although the kidneys appeared normal the UCI to SP distance was found below the 5 percentile for gestational age. The present data contribute significantly to the inutero diagnosis of CBE.

Fetal echocardiography at the time of the nuchal translucency scan

The fetal heart is not studied routinely in the first trimester because of technical and time limitations. Our aim was to assess the feasibility of performing a fetal cardiac study in pregnancies referred for nuchal translucency (NT) screening, using high-frequency linear transabdominal transducers with a specific ultrasound preset. A single trained operator assessed the fetal heart in pregnancies with a fetal crown-rump length (CRL) of 60-84 mm that had been referred for NT screening. A 15- or 6-MHz transabdominal linear transducer with a specific preset suitable mainly for color-flow mapping was used to confirm or refute normal cardiac anatomy rather than to establish a specific diagnosis. Fetuses having an increased risk for congenital heart disease were referred to a tertiary center for a further examination within 1 week. This group consisted of all fetuses with NT > 95(th) centile and those in which a family history or the initial heart scan increased the risk. A total of 608 fetuses with a median CRL of 65 mm was examined between 2003 and 2005. A cardiac scan was performed successfully in 456 (75%) using a 15-MHz linear transducer alone, and the additional use of a 6-MHz transducer allowed diagnostic images to be obtained in a further 152. Normal cardiac anatomy was assessed confidently within 10 min in 517/608 (85%) pregnancies; in 85 (14%) a longer time was needed and six patients were rescheduled within 2 weeks because of non-diagnostic images at the initial scan. In 571/608 (94%) the risk for congenital heart disease (CHD) was not increased and the heart was considered normal at initial echocardiography; this was confirmed by later scans and at postnatal follow-up. In 37/608 (6%) fetuses the risk for CHD was increased (35 for NT > 95(th) centile and two for family history). In this group normal heart anatomy was described in 34 fetuses and confirmed by subsequent specialist echocardiography. Cardiac defects were suspected in three fetuses (all with increased NT) and confirmed by a fetal cardiologist in each case. A trained operator can perform a fetal heart study during the NT screening test using transabdominal high-resolution transducers in an acceptable length of time.

Sonographic examination of the fetal central nervous system: guidelines for performing the ‘basic examination’ and the ‘fetal neurosonogram’

Sonographic examination of the fetal central nervous system: guidelines for performing the ‘basic examination’ and the ‘fetal neurosonogram’

Prenatal ultrasound diagnosis of Down syndrome. After major malformations, soft markers, nuchal translucency and skeletal signs, a new vascular sign?

Prenatal ultrasound diagnosis of Down syndrome. After major malformations, soft markers, nuchal translucency and skeletal signs, a new vascular sign?

Future Prospects for SonoVue and CPS

Though long considered unlikely because of the resonance pattern of agents such as SonoVue, high frequency applications for small parts and intracavitary applications now seem very promising. Excellent non-linear signals can be obtained at 7 MHz and higher using recently developed CPS software, and preliminary results suggest that this may prove useful for assessing superficial lymph nodes, the thyroid and parathyroid, breast masses and many superficial masses including those in the skin. Some other potentially useful "fringe" applications of the now-familiar transabdominal transducers with CPS are the pancreas, gall bladder and spleen, though these have not been investigated formally as yet.

Does 3D sonography present new perspectives for gynecology and obstetrics?

3D-sonography opens a new chapter of ultrasound-imaging. The aim of our study was, to summarise our preliminary experiences in the clinical application of this method. One-hundred and fifty patients were investigated with the use of transabdominal transducers. The scanning is performed after targeting the three-dimensional region by the volume box. The three planes are displayed simultaneously on the screen. Analysis can be performed on any possible plane within the stored volume (tomography). Surface imaging and transparent imaging can be calculated and displayed by a work-station. Three-dimensional ultrasound makes complete imaging and documentation of sonographically investigated structures feasible. The possibility of arbitrarily often repeatable systematic analyses without risk for the patient seems to be the more important advantage than statistical simultaneous imaging. Plastic imaging of structures, especially of foetuses, in the surface and transparent modes has been made possible for the first time. Biometry can also be measured in three dimensions (volumetry). Volume documentation provides the possibility of arbitrarily repeatable "real-time" scanning. By this means, any plane can be reanalyzed, remeasured and reassessed. This kind of documentation provides advantages in clinical, scientific, didactic and legal aspects. The first experiences with this new method seem to be promising. Further studies have to be conducted to evaluate the diagnostic significance of 3D-sonography in our field of specialisation.

Introduction to Transvaginal Imaging

Transvaginal sonography provides improved resolution and avoidance of intervening anatomic structures that can degrade the image. In this article, transvaginal transducers are described and compared with transabdominal transducers. The sagittal and coronal views used in transvaginal sonography are described. Advantages and disadvantages of transvaginal sonography are considered. Safety considerations of the decreased attenuation path to the fetus are dealt with.

Comparison Between Endovaginal and Transabdominal Transducers for Measuring Ovarian Volume

Comparison Between Endovaginal and Transabdominal Transducers for Measuring Ovarian Volume