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Biomedical subjects

M Miljan

Publications and source records attributed to M Miljan.

5 recordsLinked to original sources

The assessment of normal early pregnancy by transvaginal color Doppler ultrasonography.

Transvaginal color Doppler was performed in 198 volunteer pregnant women whose menstrual age ranged from the fifth to the twelfth week. In all patients an attempt was made to obtain signals from both uterine arteries, peritrophoblastic/retroplacental vessels, umbilical arteries, fetal aorta, intracranial vessels, and corpus luteum flow. With the combination of color and pulsed Doppler transvaginal sonography, detection of vascular structures was greatly facilitated and the amount of time for examination significantly reduced. Flow velocity waveforms were measured and results were analyzed by calculation of the Resistance Index. During the early stage of pregnancy, we were able to locate both uterine arteries in all cases and continuous diastolic shift signal was found. Flow in the peritrophoblastic/retroplacental area was observed with an overall success rate of 94%. Blood flow in the umbilical artery and fetal aorta was visualized by color Doppler starting from the seventh week. Intracranial blood flow could be visualized starting from the tenth week in some cases. Diastolic flow in these vessels was detectable starting from the twelfth week. Corpus luteum flow was found in 148 cases (75%) and the Resistance Index decreased as pregnancy progressed.

Arteries↗

Transvaginal color Doppler for the assessment of pelvic circulation.

Transvaginal color Doppler was used to analyse a group of 56 patients including 41 with proven pelvic masses and 15 infertility patients with normal pelvic anatomy. All patients were examined by ultrasound before laparoscopy or/and laparotomy. The ultrasonographer had not been informed of other clinical findings and indications for operative treatment. Comparison of blood flow characteristics within uterine fibromas and ovarian malignancies revealed less impedance and higher blood velocity in cases of malignancy. When predicting the malignant nature of pelvic tumors, no false-negative results were encountered, and only one false positive diagnosis of malignancy.

Color↗

Color flow mapping in obstetrics.

Blood flow studies are now used extensively in evaluating fetal peripheral circulation. By using continuous and pulsed Doppler ultrasonic equipment the raw Doppler shifts caused by blood moving in the vessels can be analyzed in different ways. Spectral data can be used to estimate blood velocity and volume in the vessel, and pulsatility characteristics and turbulence. All these data are obtained from very restricted areas within the body so that aiming of the probe is critical, and obtaining data from an area requires long and tedious effort. Color flow mapping which has recently been introduced into clinical practice provides an overview of flow velocities and directions within an area. Color coded flow can be displayed by applying the moving target identification principle (as in radar) to an ultrasonic diagnostic instrument where sound waves are used instead of radio waves. The value of flow mapping has already been recognized in the diagnosis of congenital and acquired heart disease in adults and children. Direct visualization of intracardiac flow provides for a fast and accurate diagnosis of various cardiac defects, such as the ventricular septal defect, without cardiac catheterization. In the present study we have investigated the potential of color flow mapping in obstetrics. 211 pregnant women were examined between the 15th and 40th weeks of pregnancy. 193 of them had normal pregnancies; 18 were abnormal, including 11 cases of insulin dependent diabetes, 2 cases of Rh-immunization, 2 cases of nonimmunologic fetal hydrops, 2 cases of fetal cardiac structural defects and 1 case of intrauterine growth retardation. Intracardiac flow was clearly seen in 78% (35/45) of cases at the gestational age between the 20th and 24th weeks. After the 24th week the heart flow visualization rate gradually decreased to 31% (11/36) before term. In 2 cases of congenital heart abnormality flow mapping enabled clear visualization of reverse flow through the tricuspid valve and diagnosis of valvular insufficiency. The best results in studies of flow in peripheral vessels were obtained from umbilical vessels which were seen in all cases after the 15th week. The flow visualization rate was much lower when the fetal aorta, intrahepatic umbilical vein and internal carotid artery were studied. The comparison between the diameter of the umbilical vein measured on the B-scan and flow width in the same vessel showed no significant difference (t = 0.26; p less than 0.01; N = 209).(ABSTRACT TRUNCATED AT 400 WORDS)

Blood Flow Velocity↗