| 1. |
- Laurini, Ricardo, et al.
(författare)
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Placental histology and fetal blood flow in intrauterine growth retardation
- 1994
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Ingår i: Acta Obstetricia et Gynecologica Scandinavica. - 1600-0412. ; 73:7, s. 529-534
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE. To define the histological lesions in the placenta associated with abnormal blood flow findings and to evaluate their possible clinical significance. DESIGN. A prospective blind study. SETTING. A clinical study at a teaching hospital, Malmo General Hospital, University of Lund, Sweden, morphological studies of placentas being performed at the Institute of Pathology, University of Lausanne, Switzerland. MATERIAL. Thirty-seven pregnancies where intrauterine growth retardation (IUGR) was suspected. METHODS. Blood velocimetry of the fetal descending aorta, umbilical artery and vein, and the maternal arcuate artery, using 2.5 MHz pulsed wave Doppler ultrasound. Histological examination of at least five random samples from each placenta. MAIN OUTCOME MEASURES. Frequency of small-for-gestational age (SGA) newborns (birth weight < or = mean -2 s.d.) and of operative delivery for fatal distress. RESULTS. Only the presence of placental infarction was significantly associated with IUGR and with intrauterine findings of abnormal blood velocity in the fetal descending aorta and umbilical artery. CONCLUSION. Placental infarction would seem to be a valuable morphological marker of uteroplacental vascular disease related to IUGR and impaired fetal and umbilical blood flow.
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| 2. |
- Maesel, A, et al.
(författare)
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Fetal cerebral blood flow velocity during labor and the early neonatal period
- 1994
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Ingår i: Ultrasound in Obstetrics & Gynecology. - : Wiley. - 1469-0705 .- 0960-7692. ; 4:5, s. 372-376
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Tidskriftsartikel (refereegranskat)abstract
- This study was performed to elucidate circulatory changes in the fetal cerebral circulation during uncomplicated labor and in early neonatal life. Eighteen healthy term singleton fetuses were followed longitudinally during labor. Using the transabdominal approach, and the color Doppler technique, the middle cerebral artery was identified and Doppler flow velocity waveforms recorded between and during uterine contractions. Neonatal recordings were made by insonating the middle cerebral artery from the temporal region before and immediately after the cutting of the umbilical cord, and at 1 hour and 1 day after birth. The recorded Doppler signals were evaluated for pulsatility index, heart rate, peak systolic flow velocity, end-diastolic flow velocity and time-averaged maximum velocity. There was no change in the pulsatility index between and during contractions (1.39 +/- 0.36 and 1.40 +/- 0.39, respectively, mean +/- SD). A significant decrease in the pulsatility index compared to fetal values was seen 4 min after birth (1.06 +/- 0.30, p < 0.01). One hour after birth, the pulsatility index values increased significantly (1.52 +/- 0.25, p < 0.001), to fall again between I hour and 1 day after birth (0.95 +/- 0.26, p < 0.001). Mechanical compression of the skull, blood gas changes and a decrease in ductal shunting may all have contributed to these changes. The present study has shown physiological neonatal circulatory adaptation and onset of breathing to cause manifest changes in cerebral blood flow velocity.
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| 3. |
- Sladkevicius, Povilas, et al.
(författare)
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Blood flow velocity in the uterine and ovarian arteries during menstruation
- 1994
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Ingår i: Ultrasound in Obstetrics & Gynecology. - : Wiley. - 1469-0705 .- 0960-7692. ; 4:5, s. 421-427
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Tidskriftsartikel (refereegranskat)abstract
- Eleven healthy women with regular menstrual cycles were examined with a combination of two-dimensional real-time ultrasound and color and spectral Doppler techniques on the 7th day after follicular rupture, and on the 1st, 2nd, 3rd and 4th days of menstrual bleeding. Both uterine arteries, arteries in the stroma and hila of both ovaries, in the wall of the largest follicle of the non-dominant ovary and in the wall of the corpus luteum were examined with the Doppler technique. The pulsatility index (PI) and the time-averaged maximum velocity were calculated. In the uterine arteries, the PI was highest on the first day of menstrual bleeding (median PI 3.2 for the dominant and 3.0 for the non-dominant uterine artery), after which it decreased to its lowest values on the second day (median PI 2.1 and 1.8, respectively) and third day (median PI 2.2 and 2.1, respectively). The time-averaged maximum velocity reached its highest value on the second and third days of menstruation. The corpus luteum was still visible on the first day of menstrual bleeding in all women, and on the second day in five. It was indistinguishable on the third and fourth days of menstruation in all women. In the dominant ovary, the time-averaged maximum velocity of flow in the arteries in the ovarian hilum decreased during menstrual bleeding and was lower during menstruation than in the preceding luteal phase. In the non-dominant ovary, neither the PI nor the time-averaged maximum velocity manifested any consistent changes during the period studied. We conclude that substantial changes in PI and time-averaged maximum velocity occur in the uterine arteries and in the arteries of the dominant ovary during menstruation.
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| 4. |
- Sladkevicius, Povilas, et al.
(författare)
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Endometrial thickness and Doppler velocimetry of the uterine arteries as discriminators of endometrial status in women with postmenopausal bleeding: a comparative study
- 1994
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Ingår i: American Journal of Obstetrics and Gynecology. - 1097-6868. ; 171:3, s. 722-728
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Our purpose was to compare the ability of transvaginal Doppler ultrasonographic examination with that of gray-scale ultrasonographic examination to discriminate between benign and malignant and between normal and pathologic endometrium in women with postmenopausal bleeding. STUDY DESIGN: One hundred thirty-eight consecutive women scheduled for curettage because of postmenopausal bleeding underwent transvaginal ultrasonography, including color and spectral Doppler techniques, within 8 days preceding the operation. The thickness of the endometrium was measured. Doppler signals of the maximum blood flow velocity obtained from the two main uterine arteries and subendometrial and intraendometrial arteries were evaluated for pulsatility index and time-averaged maximum velocity. The results of the examinations were compared with the histologic diagnosis of the curettage specimen. RESULTS: Receiver-operator characteristic curves showed endometrial thickness to be a better discriminator between normal and pathologic and between benign and malignant endometrium than any Doppler variable, 14 mm being the optimal threshold value for differentiating between benign and malignant endometrium (sensitivity 88%, specificity 81%). CONCLUSION: Measurement of endometrial thickness with transvaginal ultrasonography is a better method for discriminating between benign and malignant or normal and pathologic endometrium than is Doppler velocimetry of the uterine arteries.
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| 5. |
- Valentin, Lil, et al.
(författare)
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Limited contribution of Doppler velocimetry to the differential diagnosis of extrauterine pelvic tumors
- 1994
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Ingår i: Obstetrics and Gynecology. - 1873-233X. ; 83:3, s. 425-433
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To compare the ability of transvaginal color and spectral Doppler and that of gray-scale ultrasound examination to discriminate between benign and malignant extrauterine pelvic tumors. METHODS: One hundred forty-nine consecutive women scheduled for laparotomy because of an extrauterine pelvic mass underwent ultrasound examination, including color and spectral Doppler techniques, within 8 days before a planned operation. Based on the gray-scale ultrasound image, each tumor was classified as a unilocular cyst, multilocular cyst, unilocular cyst with solid parts, multilocular cyst with solid parts, or solid tumor. Doppler signals of the maximum blood flow velocity of tumor vessels were evaluated for pulsatility index (PI) and peak systolic and time-average maximum velocity. The results of gray-scale imaging and Doppler velocimetry were related to the final diagnosis, which in most cases was based on histology of the specimen. RESULTS: None of the 88 unilocular or multilocular cysts without solid parts were malignant, compared to 28 malignancies (46%) among the 61 tumors with solid components. The PI was significantly lower, and the peak systolic and time-average maximum blood flow velocities significantly higher, in the malignant than in the benign tumors. However, this was true only of the multilocular cysts with solid parts; the PI and blood flow velocity results overlapped completely between benign and malignant solid tumors. According to receiver operating characteristic curves, the ultrasound morphology of the tumors was a better discriminator between benign and malignant tumors than any of the Doppler variables. Ultrasound morphology correctly identified all the malignant tumors, with a false-positive rate of 27%. Discrimination was slightly improved if PI and blood flow velocity were used for discriminating between benign and malignant multilocular cysts with solid parts. With this approach, all the malignant tumors were detected with a false-positive rate of 17-23%, depending on which Doppler variable and which cutoff level was used. CONCLUSION: The present technique of Doppler velocimetry has a limited contribution to the differential diagnosis of extrauterine pelvic tumors.
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