| 1. |
- Dubiel, M, et al.
(författare)
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Blood redistribution in the fetal brain during chronic hypoxia
- 2002
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Ingår i: Ultrasound in Obstetrics & Gynecology. - : Wiley. - 1469-0705 .- 0960-7692. ; 20:2, s. 117-121
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Tidskriftsartikel (refereegranskat)abstract
- Background Studies on blood flow velocity in the fetal middle cerebral artery have revealed signs of brain sparing in chronic hypoxia. These signs of brain sparing can disappear in the terminal case, but whether this applies to the whole brain or only parts of it is unknown. Methods Velocity waveforms of the middle cerebral, anterior cerebral and posterior cerebral arteries were recorded in 221 pregnancies complicated by pregnancy-induced hypertension. The presence of brain sparing (pulsatility index < 2 standard deviations) was noted and correlated to outcome of pregnancy, including emergency operative intervention and/or neonatal distress. Results Signs of brain sparing in the anterior cerebral artery were found in 90 fetuses, and in the middle cerebral and posterior cerebral arteries in 52 and 65, respectively. Signs of brain sparing in the anterior cerebral artery showed the strongest relationship to adverse perinatal outcome. The anterior cerebral artery was the only vessel in which signs of brain sparing were predictive of perinatal mortality. Conclusions Velocimetry of the anterior cerebral artery appears to be superior to that of the middle cerebral and posterior cerebral arteries as a means to predict adverse perinatal outcome. Anterior cerebral artery brain sparing may therefore be less transitory than sparing in the middle cerebral and posterior cerebral arteries, possibly suggesting that the frontal lobes are spared longer than the lateral and occipital regions of the fetal brain.
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| 2. |
- Epstein, Elisabeth, et al.
(författare)
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An algorithm including results of gray-scale and power Doppler ultrasound examination to predict endometrial malignancy in women with postmenopausal bleeding.
- 2002
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Ingår i: Ultrasound in Obstetrics & Gynecology. - : Wiley. - 1469-0705 .- 0960-7692. ; 20:4, s. 370-376
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To determine if power Doppler ultrasound examination of the endometrium can contribute to a correct diagnosis of endometrial malignancy in women with postmenopausal bleeding and endometrium >/= 5 mm. METHODS: Eighty-three women with postmenopausal bleeding and endometrium >/= 5 mm underwent gray-scale and power Doppler ultrasound examination using predetermined, standardized settings. Suspicion of endometrial malignancy at gray-scale ultrasound examination (endometrial morphology) was noted, and the color content of the endometrium at power Doppler examination was estimated subjectively (endometrial color score). Computer analysis of the most vascularized area of the endometrium was done off-line in a standardized manner. Stepwise multivariate logistic regression analysis was carried out to determine which subjective and objective ultrasound and power Doppler variables satisfied the criteria to be included in a model to calculate the probability of endometrial malignancy. RESULTS: Endometrial thickness, vascularity index (vascularized area/endometrial area), and use of hormone replacement therapy (HRT) satisfied the criteria to be included in the model used to calculate the 'objective probability of endometrial malignancy'. Endometrial morphology, endometrial color score and HRT use satisfied the criteria to be included in the model to calculate the 'subjective probability of malignancy'. Endometrial thickness >/= 10.5 mm had a sensitivity with regard to endometrial cancer of 0.88 and a specificity of 0.61. At a fixed sensitivity of 0.88, the specificity of the 'objective probability of malignancy' (0.81) was superior to all other ultrasound and power Doppler variables (P = 0.001-0.02). The 'objective probability of malignancy' detected more malignancies at endometrium 5-15 mm than endometrial morphology (5/7 vs. 1/7, i.e. 0.71 vs. 0.14; P = 0.125) with a similar specificity (49/57 vs. 51/57, i.e. 0.86 vs. 0.89). CONCLUSION: Power Doppler ultrasound can contribute to a correct diagnosis of endometrial malignancy, especially if the endometrium measures 5-15 mm. The use of regression models including power Doppler results to estimate the risk of endometrial cancer deserves further development.
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| 3. |
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| 4. |
- Epstein, Elisabeth, et al.
(författare)
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Transvaginal sonography, saline contrast sonohysterography and hysteroscopy for the investigation of women with postmenopausal bleeding and endometrium > 5 mm
- 2001
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Ingår i: Ultrasound in Obstetrics & Gynecology. - : Wiley. - 1469-0705 .- 0960-7692. ; 18:2, s. 157-162
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: To determine the ability of transvaginal ultrasound, with or without saline infusion, to detect focally growing lesions in the uterine cavity in women with postmenopausal bleeding and endometrium > 5 mm, and to determine the accuracy of conventional ultrasound, saline contrast sonohysterography and diagnostic hysteroscopy under general anesthesia to diagnose endometrial polyps, submucous myomas and uterine malignancy. DESIGN: In a prospective study, 105 women with postmenopausal bleeding and endometrium > 5 mm underwent conventional ultrasound examination and saline contrast sonohysterography. Diagnostic and operative hysteroscopy under general anesthesia was then performed. The presence of focally growing lesions and the type of lesion (endometrial polyp, submucous myoma, malignancy or unclear focal lesion) were noted at ultrasound examination and at hysteroscopy. RESULTS: There was almost perfect agreement (96%) between saline contrast sonohysterography and hysteroscopy in the diagnosis of focally growing lesions. Saline contrast sonohysterography and hysteroscopy both had a sensitivity of approximately 80% with regard to diagnosing endometrial polyps (false-positive rates of 24% and 6%, respectively), whereas conventional ultrasound missed half of the polyps (sensitivity, 49%; false-positive rate, 19%). Hysteroscopy was superior to both saline contrast sonohysterography and conventional ultrasound with regard to discriminating between benign and malignant lesions (sensitivity, 84%, 44%, and 60%; false-positive rate, 15%, 6% and 10%, respectively). The risk of malignancy was increased seven-fold (odds ratio, 7.3; 95% confidence interval, 1.9-27.8) in women with distension difficulties at saline contrast sonohysterography, and two thirds of the women with a poorly distensible uterine cavity had a malignant diagnosis. CONCLUSION: Saline contrast sonohysterography is as good as hysteroscopy at detecting focally growing lesions in the uterine cavity in women with postmenopausal bleeding. However, neither hysteroscopy nor saline contrast sonohysterography can reliably discriminate between benign and malignant focal lesions. Distension difficulties at saline contrast sonohysterography should raise a suspicion of malignancy.
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| 5. |
- Gardiner, H, et al.
(författare)
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Ventriculovascular physiology of the growth-restricted fetus
- 2001
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Ingår i: Ultrasound in Obstetrics & Gynecology. - : Wiley. - 1469-0705 .- 0960-7692. ; 18:1, s. 47-53
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: To examine the mechanisms by which intrauterine growth restriction may influence later cardiovascular risk by comparing the ventriculovascular physiology of gestational age- and weight-matched growth-restricted and normal fetuses. DESIGN: A prospective longitudinal observational study of 20 normal fetuses studied from 20 weeks to term at monthly intervals was compared with a growth-restricted cohort examined in the interval between diagnosis and delivery. The last values before delivery of the growth-restricted cohort were compared with the normal cohort in two analyses matched for weight and for gestation. Arterial and venous vessel wall physiology and aortic pulse wave velocity were examined longitudinally in the thoracic descending aorta and inferior vena cava using an ultrasonic phase-locked echo-tracking system. Serial echocardiographic examinations were performed assessing structure, ventricular dimensions, function and Doppler flows. RESULTS: There was a linear increase in cardiac preload and relative pulse amplitude in the inferior vena cava with gestation. In normal fetuses, the aortic pulse wave velocity, maximum incremental and late decremental velocities increased with gestation whilst the relative pulse amplitude decreased reflecting falling distal impedance. In both age- and weight-matched analyses, the growth-restricted fetuses showed significantly reduced values reflecting the chronic fetal ventriculovascular responses to increased placental impedance. Pulse wave velocity increased with gestation and was significantly less in the growth-restricted cohort. CONCLUSIONS: Growth restriction is associated with abnormal ventriculovascular physiology that represents a successful adaptive response to raised placental impedance and reduction in wall stress as evidenced by the lower fetal pulse wave velocity in growth-restricted fetuses. However, whilst fetal adaptive mechanisms may aid survival they may result in cerebral and vascular abnormalities that prejudice later cardiovascular health.
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| 6. |
- Hofstaetter, C, et al.
(författare)
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Venous Doppler velocimetry in the surveillance of severely compromised fetuses
- 2002
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Ingår i: Ultrasound in Obstetrics & Gynecology. - : Wiley. - 1469-0705 .- 0960-7692. ; 20:3, s. 233-239
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Tidskriftsartikel (refereegranskat)abstract
- Objective To investigate whether venous Doppler velocimetric signs of cardiac decompensation might predict fetal demise in severely compromised fetuses. Material and methods This was a prospective study involving 154 growth-restricted fetuses, 37 of which were found to have reversed flow in the umbilical artery (BFC III). Doppler velocimetry of the right hepatic vein and ductus venosus were investigated serially and the presence of umbilical venous pulsations also registered. Only the final examination prior to birth or fetal demise was accepted for analysis and related to obstetric outcome defined as gestational age at birth, birth weight and perinatal mortality. In cases of BFC III the venous velocimetry of 15 nonsurviving fetuses was compared to that of the 22 survivors. Results There was a significant correlation between venous blood velocity and placental vascular resistance. In the right hepatic vein there was a significant decrease in peak systolic and end-systolic velocities and an increase of maximum velocity during atrial contraction and pulsatility (P < 0.05). A decrease of all velocities and increase of pulsatility were noted in the ductus venosus (P < 0.05). A reversed flow in the ductus venosus was found in 9/37 fetuses and double umbilical venous pulsations in 16/37 fetuses. However, the hepatic vein seemed to be a better predictor of impending mortality than the ductus venosus. Changes in diastolic venous blood velocity and a double pulsation in the umbilical vein were closely related to perinatal mortality, although these parameters did not provide a useful threshold to optimize the timing of delivery. Conclusion Diastolic venous velocimetry changes significantly in severely compromised fetuses. These changes might be of great clinical value in deciding on the timing of delivery to minimize damage to the fetus and newborn.
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| 7. |
- Källén, Karin
(författare)
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Mid-trimester ultrasound prediction of gestational age: advantages and systematic errors
- 2002
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Ingår i: Ultrasound in Obstetrics & Gynecology. - : Wiley. - 1469-0705 .- 0960-7692. ; 20:6, s. 558-563
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Tidskriftsartikel (refereegranskat)abstract
- Objective To detect possible sources of bias in ultrasound prediction of gestational age. Subjects and Methods Using the Swedish Medical Birth Registry, 571 617 women were identified who were delivered between 1990 and 1997 and who had obtainable information on last menstrual period and expected date of delivery according to ultrasound. Results Male fetuses were more likely than females to be judged older than the last menstrual period date suggested at early fetometry. The estimated magnitude of the systematic error by infant gender corresponded to 1.5 days. Similarly, the fetuses of young women, multiparous women, smokers and women with low educational level were at increased risk of being smaller than expected at ultrasound examination in early pregnancy. A strong association was seen between adjustments of expected date of delivery -7 days or more and small-for-gestational age according to ultrasound at birth. Compared to singleton pregnancies, twin pregnancies were more likely to be judged more progressed at ultrasound fetometry than the last menstrual period date suggested. Conclusions Compared to last menstrual period estimates, routine ultrasound measurements to predict date of delivery are comparatively reliable but systematic errors are inherent in the method. The erroneous adjusted dates may be due to incorrect measurements or systematic bias (e.g. gender), but they are also likely to reflect early growth restriction (e.g. in the case of maternal smoking and small-for-gestational age). Further studies are needed to investigate whether the systematic errors in ultrasound prediction of gestational age could lead to suboptimal obstetric management in adjusted pregnancies.
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| 8. |
- 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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| 9. |
- 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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| 10. |
- Sladkevicius, Povilas, et al.
(författare)
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Interobserver agreement in the results of Doppler examinations of extrauterine pelvic tumors
- 1995
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Ingår i: Ultrasound in Obstetrics & Gynecology. - : Wiley. - 1469-0705 .- 0960-7692. ; 6:2, s. 91-96
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to evaluate interobserver agreement in the results of Doppler measurements of peak systolic velocity (PSV), time-averaged maximum velocity (TAMXV) and the color content of tumor scans in extrauterine pelvic tumors. The results of transvaginal color and spectral Doppler examinations of 66 extrauterine pelvic masses obtained by two observers experienced in ultrasonography were compared. Each observer aimed to obtain the highest possible Doppler shift from arteries in the wall, septa and solid parts of each tumor. Tumor vascularization was assessed in terms of the 'tumor color score', i.e. the color content of the Doppler scan as rated for the tumor as a whole by each observer on a visual analog scale. The tumors were classified according to arbitrarily chosen cut-off limits for the tumor color score, the highest tumor TAMXV and the highest tumor PSV. Inter-class correlation coefficient values for TAMXV and PSV were < or = 0.75, whereas that for tumor color score was 0.89. Interobserver agreement was complete for the detection of color in tumors (Kappa value 1.0), excellent for the recording of arterial Doppler shift spectra from tumors (Kappa value 0.82), and moderate or good for classifying tumors based on cut-off limits for TAMXV, PSV (Kappa values ranging from 0.44 to 0.67) and tumor color score (Kappa values ranging from 0.59 to 0.66).(ABSTRACT TRUNCATED AT 250 WORDS)
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