Intervillous blood flow in the third trimester gravid rhesus monkey (Macaca mulatta): use of sonographic contrast agent and harmonic imaging.

A properly implanted and functioning placenta is essential for the normal outcome of pregnancy. As pregnancy advances, an increasing supply of maternal blood, which reaches the intervillous space of the placenta via the spiral arteries, is necessary for continued growth and development of the fetus. Presumably, deficient blood flow to the intervillous space can lead to placental ischaemia and an unfavourable outcome, such as pre-eclampsia. In this study, we used a primate model, where echocontrast-enhanced harmonic imaging was utilized to demonstrate placental intervillous blood flow without visualization of fetal blood circulation within the chorionic villi. We propose that this technique, which requires further assessment of efficacy and safety prior to use in humans, is a potentially useful non-invasive clinical tool for assessing intervillous blood flow in the third trimester of pregnancy.

Transvaginal saline hysterosonography: characteristics distinguishing malignant and various benign conditions.

OBJECTIVE: The objective of this study is to establish criteria for distinguishing endometrial polyps, submucosal leiomyomas, endometrial hyperplasia, and endometrial carcinoma on saline hysterosonography. MATERIALS AND METHODS: Sixty-three saline hysterosonograms with histologic confirmation were retrospectively analyzed. We found 26 endometrial polyps, 16 submucosal leiomyomas, three endometrial hyperplasias, one abnormal endometrium associated with a sloughed polyp, one pseudopolyp, and three endometrial carcinomas; 15 sonograms revealed no abnormality. In two patients, sonography revealed both polyps and submucosal leiomyomas. The sonographic appearance of these abnormalities was analyzed to define criteria for their diagnosis. RESULTS: Twenty-five of 26 polyps were uniformly echogenic with smooth borders and either had a stalk or formed acute angles with underlying endometrium. Sixteen of 16 submucosal leiomyomas showed heterogeneous echogenicity; however, 13 were sessile and three were pedunculated. Endometrial hyperplasia was manifested by wall thickening in two patients and tiny polypoid excrescences in one patient. In all patients with endometrial carcinoma, the endometrial cavities were poorly distensible despite successful cervical os cannulation. All patients with abnormalities other than endometrial carcinoma had fully distensible uterine cavities. CONCLUSION: Malignant and various benign endometrial conditions may be accurately distinguished on saline hysterosonography. Uniformity of echogenicity distinguished all polyps from submucosal leiomyomas, but the angulation formed with the endometrial wall by the intracavitary mass did not distinguish all polyps from submucosal leiomyomas. Lack of distensibility of the endometrial canal is a potential sign of endometrial carcinoma.

Disclosure of results of sonographic examinations to patients by sonologists.

OBJECTIVE: The aim of this study was to assess if patients prefer to talk with a sonologist concerning the results of sonographic examinations. MATERIALS AND METHODS: The study involved outpatients who underwent diagnostic sonography. Technologists offered patients the chance to speak with a sonologist about the results of their sonograms. If requested, a sonologist reviewed the results, and if the study showed an abnormality, its significance was discussed. No treatment recommendations were offered. Patients then filled out a questionnaire. RESULTS: Of the 391 outpatients given the choice, 348 (89%) requested a consultation and 207 of those (60%) returned the completed questionnaire. Of the 207 patients completing the questionnaire, 94% preferred receiving the results from the sonologist rather than from their referring physician. CONCLUSION: We propose a revision of the traditional role of the office-based sonologist to one in which he or she will function as a consultant to both the patient and the patient's physician.

Significance of fetal intracardiac echogenic foci in relation to trisomy 21: a prospective sonographic study of high-risk pregnant women.

OBJECTIVE: The aim of the study was to determine if an association exists between intracardiac echogenic foci in the second-trimester fetus and trisomy 21. SUBJECTS AND METHODS: Over a 2-year period, targeted fetal sonography was performed for various indications in 1593 second-trimester high-risk pregnant women. Presence or absence of echogenic foci was recorded for each fetus. Amniocentesis for karyotype analysis was performed in 901 subjects immediately after sonography. The findings of these 901 subjects formed the basis of this report. RESULTS: Intracardiac echogenic foci were present in the left ventricle of 24 (3%) of the 901 fetuses. Three (13%) of these 24 fetuses had trisomy 21; no chromosomal abnormalities were found in the other 21 fetuses. Karyotype analysis revealed trisomy 21 in 14 (2%) of the remaining 877 fetuses who did not exhibit intracardiac echogenic foci. The sensitivity, specificity, positive predictive values, and negative predictive values for intracardiac echogenic foci in predicting trisomy 21 were 18%, 98%, 13%, and 98%, respectively. The association of intracardiac echogenic foci and trisomy 21 was significant (p < .009) by the two-tailed Fisher's exact test. CONCLUSION: In a high-risk obstetric population, the association between fetal intracardiac echogenic foci and trisomy 21 was statistically significant. Therefore, women carrying fetuses with intracardiac echogenic foci should be informed of the statistical association with trisomy 21.

Harmonic imaging of porcine intraovarian arteries using sonographic contrast medium: initial findings.

The purpose of this study was to visualize, using harmonic gray-scale imaging, blood flow in porcine intraovarian arteries after intravenous injections of a bubble-based sonographic contrast medium. Five female pigs underwent laparotomy. Surgically isolated ovaries were scanned intraperitoneally by an ultrasound system reconfigured with software changes to accomplish harmonic imaging. The transmission and receiving frequencies were set at 3.75 and 7.5 MHz, respectively. After injection of the sonographic contrast medium (Aerosomes) into a peripheral vein, the ovaries were imaged in the harmonic mode. Ten minutes later, another contrast injection was administered and conventional gray-scale imaging of the ovary performed. In all five pigs, intraovarian arteries were clearly identified upon harmonic imaging as brightly echogenic moving columns. The arterial blood pool appeared brighter during systole than diastole. Upon ultrasound contrast-assisted conventional gray-scale imaging, intraovarian arteries were not visualized in four pigs and poorly visualized in one. We conclude that contrast-assisted harmonic imaging can adequately visualize blood flow in intraovarian arteries of surgically exposed porcine ovaries. Clinically, harmonic imaging may facilitate early detection of tumor-induced angiogenesis in the human ovary.

Color Doppler imaging findings in patients with Budd-Chiari syndrome: correlation with venographic findings.

OBJECTIVE: This study was undertaken to evaluate color Doppler imaging findings in patients with Budd-Chiari syndrome and to compare these findings with results of venography. SUBJECTS AND METHODS: In a prospective study, 21 patients with proved Budd-Chiari syndrome had color Doppler imaging. Sonographic evaluations ware performed to detect appropriately directed flow in the hepatic veins, portal vein, and inferior vena cava. Intrahepatic collaterals were characterized when present. Results of color Doppler imaging were compared with those of angiography in 20 patients. Color Doppler images of the hepatic veins were also obtained in a reference group (20 control subjects, 20 patients with hepatomegaly, and 20 patients with cirrhosis). RESULTS: Color Doppler imaging showed abnormalities of anatomy or flow in one or more of the main hepatic veins in all 21 patients with Budd-Chiari syndrome. Commonly observed abnormalities were visualization of a hepatic vein on real-time sonograms that had no flow or retrograde flow on color Doppler sonograms (11 cases) and no visualization of part or all of a hepatic vein on either real-time or color Doppler sonograms (10 cases). When compared with venographic findings (16 patients), findings on color Doppler sonograms could be used to distinguish patent from occluded hepatic veins in all cases. In our reference group, real-time and color Doppler sonograms showed normal hepatic veins in all control subjects. Real-time sonograms clearly showed hepatic veins in 12 of 20 patients with hepatomegaly; color Doppler sonograms showed flow in the hepatic veins in all 20 of these patients. Among 20 patients with cirrhosis, real-time sonograms showed hepatic veins in only seven; color Doppler imaging confirmed patent veins in 17. Intrahepatic collaterals typical of Budd-Chiari syndrome were observed in 10 of 21 patients with the syndrome. The portal vein was assessed by using color Doppler imaging in all 21 patients with Budd-Chiari syndrome; portograms were available for comparison in 10 patients. Findings were consistent in eight; in two cases, the direction of flow was reversed on color Doppler sonograms compared with portograms. For the inferior vena cava, venographic and sonographic findings correlated in 16 of 20 cases. Color Doppler sonograms did not show a caval web in one patient. CONCLUSION: Abnormalities of the hepatic veins, portal veins, and inferior vena cava detected on color Doppler sonograms in patients with Budd-Chiari syndrome correlate well with findings on venograms.(ABSTRACT TRUNCATED AT 400 WORDS)

Transcervical sonography: an investigational technique for visualization of the embryo.

A catheter-based, miniature ultrasound transducer, operating at a frequency of 12.5 MHz, was introduced transcervically into the uterine cavity of 18 pregnant women about to undergo first-trimester abortion. Transcervical sonography showed the yolk sac and embryonic structures, such as brain vesicles, limb buds, liver, spinal canal, and umbilical cord with blood flow, in eight embryos at 5-8 menstrual weeks of age. As an investigational technique, catheter-assisted transcervical sonography offers a new diagnostic approach to imaging of the first-trimester human embryo.

Sonographic findings after surgical ablation of the endometrium.

OBJECTIVE: Endometrial ablation is a new surgical technique that is an alternative to hysterectomy in women with dysfunctional uterine bleeding. The endometrium is either coagulated or resected in an attempt to render the patient amenorrheic. Because of the newness of the procedure, no report of radiologic findings after endometrial ablation has been published. Accordingly, the sonographic appearance of the uterus after endometrial ablation is described. MATERIALS AND METHODS: Using transvaginal sonography, we examined a select group of 16 women, seven of whom were symptomatic after endometrial ablation. All patients had a preoperative diagnosis of menorrhagia not responsive to conventional hormonal therapy and no evidence of cancer. RESULTS: In the seven symptomatic patients, sonography showed that postoperatively two had hematometra, one had a nonviable intrauterine pregnancy, and four had residual islands of functioning endometrial tissue alone or in combination with hematometra. In nine asymptomatic patients, postoperative sonography showed seven had normal findings except for leiomyomata and two had residual islands of functioning endometrial tissue. CONCLUSION: Sonographic examination of the uterus after endometrial ablation provides a method for evaluating symptomatic patients and for identifying any remaining endometrium that could later become symptomatic.

Color Doppler imaging of the hepatic vasculature.

Duplex sonography added a new dimension to real-time sonographic imaging and can be used to characterize flow dynamics. Unfortunately, duplex sonography also has significant drawbacks, most of which are the result of the limited sampling ability of pulse-gated technology and the inability to provide a global display of Doppler information. Sonographic imaging of intraabdominal vessels has improved markedly with the advent of color Doppler techniques. This article reviews the use of color Doppler sonography in the evaluation of hepatic vessels. The complementary role of Doppler spectral analysis is also considered.

A new electronically enhanced biopsy system: value in improving needle-tip visibility during sonographically guided interventional procedures.

Sonographically guided fine-needle biopsy procedures are hampered by poor visibility of the needle tip. This study was performed to evaluate a new system for placing needles under sonographic guidance. The Biosponder needle (Advanced Technology Laboratories, Bothell, WA) incorporates a specialized stylet with a passive sensor at its tip. When an ultrasound pulse is detected by the sensor, an electrical signal is transmitted to the sonographic unit by a battery-powered electronic module connected to the stylet and to the scanner. This signal is converted into a bright, flashing marker on the screen at the precise location of the needle tip. The Biosponder system, which uses 20- or 22-gauge needles, was compared with a 20-gauge Turner needle (Cook, Bloomington, IN) in 18 patients with masses or fluid collections and two patients requiring nephrostomy tube placement. The tip of the Turner needle could not be localized precisely in any patient. The shaft of the Turner needle was seen clearly in 13 patients, poorly in three, and was not visualized at all in four patients. Excluding four instances of mechanical failure, the Biosponder system allowed precise localization of the needle tip in every patient and was consistently rated as easier to use than the Turner needle. We conclude that the Biosponder needle, with its precise tip localization and ease of use, is a valuable tool for sonographically guided needle placement.

Endoluminal catheter-assisted transcervical US of the human embryo. Work in progress.

To enhance visualization of anatomic structures of the human embryo, the authors used a commercially available catheter-based ultrasound (US) transducer (12.5 MHz) introduced through the cervix and into the endometrial cavity of seven women about to undergo voluntary termination of first-trimester pregnancy. The authors term this technique endoluminal catheter-assisted transcervical (ELCAT) sonography. In none of the patients did the US catheter rupture the fluid-filled chorionic/amniotic cavity. The duration of pregnancy ranged from 5.2 to 10.0 menstrual weeks. The most prominent anatomic structures visualized were the heart and neural tube. As an investigational technique, ELCAT US can be used to image anatomic structures of the developing human embryo.

Diagnosis of portal vein thrombosis: value of color Doppler imaging.

This study was undertaken to determine the accuracy of color Doppler imaging in the diagnosis of portal vein thrombosis. Two hundred fifteen patients were studied with color Doppler imaging to determine patency of the main portal vein. Sonographic findings were confirmed in 75 patients, aged 19 to 66 years. Correlation with angiography was obtained in 13 patients, and surgical correlation was obtained in the remaining 62. Nine patients had portal vein thrombosis on the basis of these gold standards. Sonograms were classified as showing either patency or thrombosis, depending on the ability to show color flow within the main portal vein. Agreement between sonography and angiography or surgery was found in 69 patients (61 patent, eight thrombosed). One patient with a patent portal vein at sonography was found to have a thrombosed vessel at surgery, whereas five patients without portal venous flow at sonography had patent vessels at angiography (one patient) or surgery (four patients). Overall sensitivity and specificity for detection of portal vein thrombosis were 89% and 92%, with an accuracy of 92%, a false-negative rate of 0.11, a negative predictive value of 0.98, and a positive predictive value of 0.62. We postulate that the majority of errors in our study occurred in vessels that, although patent, had only sluggish flow, which could not be resolved because of technical limitations. We conclude that color Doppler imaging is a valuable screening procedure for the assessment of portal vein patency. If the sonogram shows a patent portal vein, no further studies are required. However, a lack of demonstrable flow does not always indicate thrombosis, and other imaging studies should be performed for confirmation.