Transvaginal color Doppler study of the uteroplacental circulation in early pregnancy

OBJECTIVE: To compare resistance index (RI) and pulsatility index (PI) values of blood flow in arteries of uteroplacental circulation in normal and threatened abortion first trimester pregnancies. STUDY DESIGN: We have analysed 36 pregnant woman between 5th and 12th weeks of pregnancy--17 patients with threatened abortion as a test group and 19 patients with normal intrauterine pregnancy taken as controls. In all patients transvaginal ultrasonography with pulse color Doppler was performed. The RI and PI values were calculated for blood flow velocity waveforms obtained from uterine artery and its branches--arcuate, radial and spiral arteries. RESULTS: In the test group we have analysed 17 flow velocity waveforms from uterine artery (mean RI 0.852; SD 0.080, mean PI 2.324; SD 0.693), 16 from arcuate artery (mean RI 0.638; SD 0.049, mean PI 1.315; SD 0.064,), 17 from radial artery (mean RI 0.638; SD 0.049, mean PI 1.009; SD 0.177) and 15 from spiral artery (mean RI 0.548; SD 0.068, mean PI 0.804; SD 0.160); in controls we have analysed 16 flow velocity waveforms from uterine artery (mean RI 0.866; SD 0.066, mean PI 2.469; SD 0.618), 17 from arcuate artery (mean RI 0.728; SD 0.123, mean PI 1.352; SD 0.362), 19 from radial artery (mean RI 0.630; SD 0.092, mean PI 1.017; SD 0.261) and 16 from spiral artery (mean RI 0.511; SD 0.100, mean PI 0.760; SD 0.202). CONCLUSION: There was no significant difference in mean RI and PI values between normal and abnormal pregnancies. A gradual statistically significant decrease of RI and PI values during time of pregnancy we have observed only in radial arteries in both groups. For other vessels in the control group the RI and PI values tended to decrease during the time of pregnancy while in the test group some even rose up.     

A monitoring, feedback, and triggering system for reproducible breath-hold MR imaging

OBJECTIVE: To evaluate the diagnostic accuracy and clinical usefulness of high-resolution transvaginal duplex Doppler ultrasound in postpartum and post-abortion patients with excessive hemorrhage who are suspected of having residual trophoblast. METHODS: Forty-eight women with excessive hemorrhage referred for possible residual trophoblastic tissue were evaluated by transvaginal duplex Doppler ultrasonography. Based on two-dimensional imaging, the patients were divided prospectively into groups: women who had an empty uterus with a normal uterine cavity, those with a pure endometrial fluid collection and no echogenic foci, those who had a mixed endometrial fluid collection with foci of echogenicity, and those with intracavitary heterogeneous material with mixed echo patterns of fluid and solid components. In each group, Doppler studies were performed and the resistance index (RI) was calculated. The two-dimensional patterns and Doppler results were correlated with clinical and pathologic follow-up. RESULTS: Twenty-eight subjects had a normal uterine cavity and seven had a pure endometrial fluid collection; all were treated conservatively and none showed later clinical evidence of residual trophoblastic tissue. In 13 women, residual trophoblast was strongly suggested from the images of two-dimensional ultrasonography: Five showed an endometrial fluid collection with some echogenic foci, and eight exhibited intracavitary mixed echogenic material. All underwent curettage, and residual trophoblastic tissue was found in ten of the 13. The mean (+/- standard deviation) RI to flow in the myometrial arteries was 0.54 +/- 0.15 in women without residual trophoblast and 0.35 +/- 0.1 in those with residual trophoblastic tissue (P < .01). CONCLUSION: Our experience suggests that transvaginal duplex Doppler ultrasonography is an effective noninvasive method for evaluating patients with excessive postpartum and post-abortion hemorrhage who are suspected of having residual trophoblastic tissue. Its use enhances the positive preoperative diagnosis of residual trophoblastic tissue and may reduce unnecessary curettage procedures.     

Color Doppler ultrasound pulsatile flow signals of thoracic lesions: comparison of lung cancers and benign lesions

Color Doppler ultrasound (US) was performed in 153 patients (including 102 with lung cancer and 51 with benign lesions) to assess pulsatile flow signals in thoracic lesions. The values of resistive index (RI) and pulsatility index (PI) of color Doppler US pulsatile flow signals in lung cancers and benign lesions were measured, analyzed, and compared. In the enrolled 153 patients with thoracic lesions, 61 lung cancers and 34 benign lesions had detectable color Doppler US pulsatile flow signals, and lung cancers had lower RI and PI values than benign lesions (RI: 0.70+/-0.03 vs. 0.79+/-0.04, p < 0.05; PI: 1.61+/-0.15 vs. 2.44+/-0.25, p < 0.005). However, overlapping RI and PI values in lung cancers and benign lesions somewhat limited color Doppler US pulsatile flow signals to differentiate lung cancers from benign lesions. Further analysis of RI and PI values in subgroups of lung cancers [squamous cell carcinoma (SCC, n = 34), adenocarcinoma (AC, n = 18), and small-cell lung cancer (SCLC, n = 6)] and benign lesions [cavitary benign lesions (CBL, n = 8), and noncavitary benign lesions (NCBL, n = 26)] revealed that all different cell types of lung cancers (SCC, AC, and SCLC), indeed, had lower RI and PI values than NCBL (for RI, all p < 0.01; for PI, all p< or =0.001). Moreover, the mean RI and PI values showed a significant incremental decrease from NCBL (mean RI, PI = 0.88, 2.94) toward SCC and AC (for SCC, mean RI, PI = 0.71, 1.68; for AC, mean RI, PI = 0.68, 1.67) and, finally, to SCLC (mean RI, PI = 0.62, 1.05). In contrast, CBL had relatively lower RI and PI values than AC and SCLC (for CBL, mean RI, PI = 0.53, 0.80; both p > 0.05 for RI and PI), and even a significant difference from SCC (p < 0.05 for RI and PI). We conclude that color Doppler US pulsatile flow signal is somewhat limited to differentiate lung cancers from benign lesions, but provides a noninvasive in vivo model to assess the neovascularity intensity of lung cancers.     

Effect of long-term cocaine administration to pregnant ewes on fetal hemodynamics, oxygenation, and growth

OBJECTIVE: To assess uterine and fetal blood flows by Doppler velocimetry and fetal growth and oxygenation in pregnant ewes treated daily with cocaine and to determine whether cocaine impairs fetal cardiac and cerebral reactivity. METHODS: The study groups received 70 mg (n = 7) or 140 mg (n = 7) of cocaine and the control group (n = 7) received placebo injected intramuscularly daily on days 60-134. Hemodynamic data were measured at rest and during two acute hypoxic tests at cesarean delivery performed on day 134. RESULTS: The fetal heart rate (FHR) and umbilical and uterine resistance indices (RIs) were higher in the cocaine groups than in the control group (FHR: 187 +/- 8 and 166 +/- 8 beats per minute at 83 and 123 days, respectively, in controls and 9-11% higher in cocaine groups; umbilical RI: 0.79 +/- 0.06, 0.60 +/- 0.04, and 0.52 +/- 0.06, at 83, 105, and 123 days, respectively, in controls and 11-17% higher in the cocaine groups [P < .01]; and uterine RI: 0.40 +/- 0.05, 0.40 +/- 0.04, and 0.37 +/- 0.04, at 83, 105, and 123 days, respectively, in controls and 13-35% higher in cocaine groups [P < .05]). At delivery on day 134, the following characteristics were found to be different in the cocaine groups: fetal weight (4.03 +/- 0.2 kg in controls and 15-21% lower in the cocaine groups [P < .02]), partial pressure of oxygen (26.5 +/- 1.4 mmHg in controls and 15-16% lower in cocaine groups [P < .05]), umbilical RI (0.40 +/- 0.03 in controls and 11-17% higher in cocaine groups [P < .01]), cerebral RI (0.61 +/- 0.03 in controls and 9-15% lower in cocaine groups [P < .01]), and cerebral-umbilical ratio (1.52 +/- 0.04 in controls and 22-23% lower in cocaine groups [P < .001]). During the hypoxic tests, the cerebral RI (P < .05) and the cerebral-umbilical ratio (P < .05) decreased significantly less in the two cocaine groups. The FHR response was reduced significantly in the two cocaine groups (P < .05). CONCLUSION: Long-term exposure to cocaine induces uterine and fetal blood flow disorders, fetal growth restriction, and hypoxia. It reduces the capability of the cerebral vessels to vasodilate and the heart rate to increase during acute hypoxia.     

Acute obstruction of the renal collecting system: the intrarenal resistive index is a useful yet time-dependent parameter for diagnosis

The aim of this study was to determine whether the intrarenal resistive index (RI) can be used for the diagnosis of acute obstruction in patients with renal colic and to determine whether the index is time-related. Seventy patients referred to the Emergency Department with acute renal colic and without known associated renal disease underwent duplex Doppler ultrasonography to determine the intrarenal RI at the symptomatic and asymptomatic side. The age range of the patients was 18-72 years. An RI greater than 0.68 and/or an interrenal difference in RI greater than 0.06 and/or an increase in RI of more than 11% compared with the normal side proved reliable cut-off values to diagnose acute renal obstruction. In addition, time dependency of the increase in RI was noted. No significant differences were observed within the first 6 h after the onset of symptoms. From 6 to 48 h, however, the mean RI in the affected kidney (0.70 +/- 0.06; mean +/- SD) was significantly different from that in the normal kidney (0.59 +/- 0.04) (P < 0.001). In the same period the mean difference in RI was 0.08-0.13 (P < 0.001). After 48 h the sensitivity of RI dropped substantially. It is concluded that renal duplex Doppler ultrasonography is useful for diagnosing acute renal obstruction between 6 and 48 h after the onset of symptoms.     

Increased anticardiolipin antibodies are positively related to the uterine artery pulsatility index in unexplained infertility

The objective of the study was to evaluate, in patients with unexplained infertilty, the possible relationship between anticardiolipin antibodies and indices of uterine artery Doppler measurements. A total of 46 infertile women participated in the study and underwent ovarian stimulation. Transvaginal ultrasonography and colour Doppler were performed on the day of embryo transfer and patients were divided on the basis of pulsatility index (PI): group I, PI <2.5; group II, PI 2.5-3.0; and group III, PI >3.0. On the same day that Doppler analysis took place, peripheral blood was obtained and circulating anticardiolipin antibodies were assayed. The response to ovarian stimulation was similar in the three studied groups. No significant differences in oestradiol and ultrasonographic parameters were observed between the groups. A significant increase in anticardiolipin antibodies was observed in those patients with higher resistance to flow at the level of the uterine artery. A significant relationship was found between the uterine artery PI and anticardiolipin immunoglobulin G class (F = 14.35; P = 0.001), and immunoglobulin M class (F = 5.88; P = 0.020). It is concluded that, in unexplained infertility, anticardiolipin antibodies may be involved in uterine vascular modifications and that Doppler flow analysis of uterine arteries may be an important tool in the assessment and management of ovarian stimulation.     

Consistency and validity of patient administered assessment of quality of life by the MOS SF-36; its association with disease activity and damage in patients with systemic lupus erythematosus

BACKGROUND: Detection of renal artery stenoses (RAS) by means of duplex Doppler ultrasound with direct scanning of the main renal arteries is subject to numerous limitations. Using semiquantitative analysis of the Doppler curve, which can be recorded from intrarenal arteries, it is possible to detect RAS unaffected by the problems of direct Doppler scanning of the renal arteries. METHODS: Both angiography of the renal arteries and colour duplex ultrasonography (US) of the intrarenal vessels (interlobar arteries) were performed in 214 patients (53.2 +/- 14.1 years) with severe arterial hypertension. Angiography was used as 'gold standard' in the diagnosis of RAS and the Doppler results were compared with the subsequent findings on angiography. At angiography, the reduction of diameter > 70% was assessed as haemodynamically effective RAS. For the duplex Doppler diagnosis of RAS the following parameters were calculated: (a) resistive index (RI) of each kidney, and (b) side-to-side differences of the resistive indices (delta RI) between the right and left kidney. RESULTS: Angiography demonstrated 59 RAS (> 70%) in 53 patients, including six with bilateral RAS. By means of duplex US we found a significant difference of RI between kidneys with RAS (0.48 +/- 0.11) and without RAS (0.63 +/- 0.08; P < 0.001). In addition, a significant difference of the delta RI was noted in patients with RAS (24.4% +/- 12.5%) and the controls without RAS (3.6% +/- 2.7%). Using a combination of both RI and delta RI, threshold values of RI = 0.45 resp. delta RI = 8% yields a sensitivity of 92.5% and a specificity of 95.7% in the detection of haemodynamically effective RAS. CONCLUSIONS: Colour duplex US with calculation of the RI and delta RI of intrarenal arteries is a valuable non-invasive test assessing the haemodynamic effects of a RAS. Low costs and safety support the use of the Doppler technique in screening for renovascular disease.     

The first three weeks assessed by transvaginal color Doppler

Transvaginal color Doppler has made possible to study ovarian and uterine perfusion in non-pregnant and pregnant patients, thus advancing the understanding of the early human development. RI of follicular blood flow starts decreasing prior to ovulation reaching its nadir at ovulation. It is considered that apart from hormonal factors the angiogenesis is also involved. The mature corpus luteum shows increased blood flow velocity in relation to preovulatory follicle. Comparing RI values of luteal blood flow of normal and ectopic pregnancy no difference was found. But in threatened, incomplete and missed abortions the resistance and pulsatility indices were significantly higher than in normal pregnancy. The follow up of the luteal flow might have a prognostic value in a group of patients with threatened abortion. In women with spontaneous cycles the day preceding the ovulation impedance to uterine flow velocity starts decreasing. Alterations in flow velocity patterns of the radial and spiral arteries in spontaneous ovulatory cycles are paralleling blood flow dynamics of the uterine arteries. In stimulated cycles RI increases the day before ovulation in both the uterine arteries and their branches. It seems that endometrial perfusion presents more accurate noninvasive assay of uterine receptivity than uterine artery perfusion alone. Endometrial receptivity is maximum during the time of peak luteal function during which implantation is most likely to occur. During the pregnancy impedance to blood flow decrease from the main uterine to the spiral arteries as well as with the advancing gestational age. The spiral arteries in pregnancy become the vessels with completely different haemodynamic characteristics in relation to other arteries of uteroplacental circulation. Color Doppler adds new information on perfusion and pathophysiological changes connected with the ectopic trophoblast implantation.     

A study for predicting toxemia of pregnancy by the diastolic notch in pulsed Doppler flow velocity waveforms of the uterine arteries--quantitative analysis of the diastolic notch as uterine arterial index (UTAI)

To investigate the ability of measurement of the diastolic notch in Doppler flow velocimetry to predict development of toxemia of pregnancy, analysis of uteroplacental and fetal blood flow waveforms was performed. The waveforms were analyzed by calculating the resistance index (RI) and the pulsatility index (PI) and were investigated whether diastolic notches existed or not. In the prospective study, the uterine arterial index (UTAI; an index introduced to evaluate the degree of diastolic notch quantitatively) was also calculated. RETROSPECTIVE STUDY: The waveforms in the uterine arteries, the umbilical artery and the fetal vessel (inferior vena cava, descending aorta and middle cerebral artery) were measured in 153 pregnant women. PROSPECTIVE STUDY: Uterine artery velocimetry was performed at 16-23 weeks' gestation in 387 pregnant women. RESULT 1: Subjects with a diastolic notch had significantly higher rates of development of toxemia of pregnancy. Indexes of the fetal blood flow waveforms had no significant correlations with the development of toxemia of pregnancy. RESULT 2: UTAI showed an equivalently high negative predictive value (98.1%) and higher positive predictive value (17.6%) than RI (98.2%, 10.2% respectively) and PI (98.7%, 12.7% respectively). CONCLUSION: UTAI measurement was more useful for predicting toxemia of pregnancy than RI or PI.     

Catch me if you can: are catechol- and indoleamine genes pleiotropic QTLs for common mental disorders?

The aim of this study was to determine the effect of a short-term ethinyl estradiol/levonorgestrel medication on blood flow in the uterine arteries in postmenopausal women in a prospective placebo-controlled double-blind study. Twenty-one healthy postmenopausal woman at least 2 years after menopause received 60 micrograms ethinyl estradiol (EE) for 14 days followed by 40 micrograms EE plus 125 micrograms levonorgestrel (LNG) for 12 days (total treatment period 26 days). Sonographically, uterine volume, endometrial thickness, and blood flow in the uterine arteries [as reflected by pulsatility (PI) and resistance indices (RI)] were measured. Uterine size increased from 44 to 80 mL (day 14, p < 0.001) and 87 mL (day 26, p = NS). Endometrium grew from 3 to 8 mm (day 14, p < 0.001) and 11 mm (day 26, p = NS). Uterine arterial PI fell from 2.76 to 1.37 (day 14, p < 0.001) and 1.34 (day 26, p = NS), whereas RI fell from 0.9 to 0.68 (day 14 and day 26, p < 0.001). In conclusion, short-term treatment with LNG does not antagonize the vascular effect of EE on the uterine arteries as reflected by PI and RI. This result might have clinical significance in the selection of the progestin used in hormonal replacement therapy.     

Intrarenal hemodynamic abnormalities in diabetic nephropathy measured by duplex Doppler sonography

Intrarenal hemodynamics were studied by duplex Doppler sonography in 112 inpatients with type II diabetes mellitus (DM; 65 males, 47 females, 58 +/- 13 years old). The resistive index (RI) and pulsatility index (PI) of the interlobar arteries were calculated. The patients were divided into four groups: group I consisted of patients with urinary albumin excretion (UAE) < 20 micrograms/min (N = 42), group II with 20 < or = UAE < 200 (N = 28), group III with UAE > or = 200 (N = 25), and group IV with serum creatinine > or = 1.5 mg/dl (N = 17). Both RI and PI values in groups II, III, and IV were significantly higher than those in the controls (age- and sex-matched healthy persons, N = 37; P < 0.001), and those in group IV were significantly higher than those in groups I, II, and III (P < 0.0001). Multiple regression analysis revealed that RI values in DM patients were significantly affected by creatinine clearance, age, and duration of diabetes (R2 = 0.554, P < 0.0001). When intima-medial thickness (IMT) of the femoral and carotid arteries were measured by B-mode ultrasonography, RI values were significantly correlated with both the femoral and carotid arterial IMT. These results demonstrate that intrarenal hemodynamic abnormalities are present in type II DM patients with nephropathy, and that intrarenal hemodynamics are affected by decreased glomerular function and also probably by advanced arteriosclerosis.     

The effects of a copper-intrauterine device on the uterine artery blood flow in regularly menstruating women

The aim of the study was to evaluate the effect of a copper-intrauterine device (IUD) on uterine artery blood flow during the midluteal phase and on the first day of the menstrual cycle using pulsed colour Doppler ultrasonography. Twenty-one regularly menstruating women (18-45 years) who were willing to use copper-IUD contraception participated in the study. The patients were first examined without the IUD in the midluteal phase 6-9 days before the expected onset of menstruation and on the first day of menstruation, after which the IUD was inserted. Three months later the patients were examined again on the corresponding cycle days. The patients estimated the level of dysmenorrhoeic pain with a scoring system. Transvaginal ultrasonography with colour flow imaging was used to measure the pulsatility index (PI) in the uterine arteries. There were no significant changes in the uterine artery blood flow after the insertion of the IUD during menstruation or in the midluteal phase. In patients with increased IUD-related pain during menstruation (n = 5), however, there was a decrease in PI (2.87 +/- 0.52 versus 2.41 +/- 0.23, P = 0.05) after IUD insertion. The decrease in the mean PI was present in all five patients. In conclusion, copper-IUD does not induce any major changes in the resistance of the uterine artery blood flow, although during menstruation in patients with increased menstrual pain after IUD insertion there seems to be a decrease in the uterine artery PI.     

Use of colour and spectral Doppler ultrasound examination in gynaecology

Objective: To review and sum up the published literature on gynecological Doppler ultrasound examination. Methods: Publications on gynecological Doppler ultrasound examination already known by the author, publications found in the bibliographic database Medline, and publications found in the reference lists of available studies were read, and relevant information was extracted and summarized. Results: Reference data representative of normal findings at transvaginal color and spectral Doppler ultrasound examination of the uterine and ovarian arteries have been established in healthy pre- and post-menopausal women and in normal early pregnancies. Blood flow velocities in the uterine and ovarian arteries change during the normal menstrual cycle and are very different in pre- and post-menopausal women. Lower blood flow velocities and higher pulsatility index (PI) values have been recorded in the ovarian arteries after the menopause. Uterine artery blood flow velocities increase and uterine artery PI values and resistance index (RI) values decrease with gestational age in the first trimester. There is not yet an established role of the gynecological Doppler ultrasound examination in clinical practice. It remains unclear whether the gynecological Doppler ultrasound examination contributes substantially to the clinical management of early pregnancy complications or infertility problems, to the differential diagnosis of pelvic masses or uterine pathology. Conclusions: Large prospective studies-preferably randomized controled trials-are needed to determine the clinical value of the gynecological Doppler ultrasound examination. Copyright 1997 Elsevier Science Ireland Ltd.     

Vascular patterns of gestational trophoblastic tumors by color Doppler ultrasound

BACKGROUND: Destruction of uterine vasculature is a common phenomenon in gestational trophoblastic tumors. The authors categorized such uterine vasculature by color Doppler ultrasound and studied its clinical significance. METHODS: Color Doppler ultrasound was performed in 28 patients with gestational trophoblastic tumors. The vascular morphologic manifestations were recorded, and the peak systolic velocity and resistance index of uterine artery were calculated. Serum beta-human chorionic gonadotropin (hCG) levels were measured periodically to monitor chemotherapy response. Seventeen uneventful postmole uteri were used as controls. Two-tailed Student's t-test and Fisher's exact test were used for statistical analysis. RESULTS: The gestational trophoblastic tumors were categorized as diffuse type (N = 7), lacunar type (N = 16), and compact type (n = 5) according to their vascular patterns. The mean serum beta-hCG level at diagnosis in diffuse type lesions (6608 +/- 6320 mIU/mL) was significantly lower than in the lacunar type (40462 +/- 39735 mIU/mL; P = 0.04) and compact type (212114 +/- 205126 mIU/mL; P = 0.02), whereas the level in compact type lesions was significantly higher than in the lacunar type (P = 0.003). Lacunar type lesions exhibited a significantly lower uterine artery resistance index (0.51 +/- 0.13) than diffuse type (0.66 +/- 0.10; P = 0.03) or compact type lesions (0.70 +/- 0.06; P = 0.02). All lesions exhibited significantly higher peak systolic velocity than control subjects (P < 0.001); however, no significant difference was observed among them. Brief courses (< 5 cycles) of chemotherapy cured more diffuse type (6 of 7) than lacunar type (3 of 15, P = 0.006) or compact type lesions (0 of 5, P = 0.008). Histopathologic diagnosis was available for 11 lesions. They were invasive mole in seven lacunar type lesions and choriocarcinoma in four compact type lesions. CONCLUSION: Vascular morphologic patterns of gestational trophoblastic tumors by color Doppler ultrasound correlated well with beta-hCG levels, uterine hemodynamics, chemotherapy response, and possibly the histopathologic diagnosis.     

Effect of dehydroepiandrosterone sulfate on uterine artery flow velocity waveforms in term pregnancy

OBJECTIVE: To investigate the interrelation between estrogen synthesis by the fetoplacental unit and uteroplacental hemodynamics in term pregnancy. METHODS: Transvaginal color Doppler flow imaging and pulsed Doppler ultrasonographic assessments were made on ten normal full-term pregnant women before and 3, 5, 10, 30, and 60 minutes after the administration of a 200-mg intravenous dose of dehydroepiandrosterone sulfate (DHAS) in 20 mL of 5% dextrose. Ten normal full-term pregnant women received 20 mL of 5% dextrose as controls. The pulsatility index (PI) values for the uterine artery, heart rate, and mean arterial pressure were recorded. Plasma estradiol (E2) was measured before and 10 minutes after the infusion. RESULTS: In the DHAS group, uterine artery PI decreased from baseline by 26% (P < .05) after 5 minutes, and the mean reduction was 36% (P < .05) after 10 minutes and 15% (P < .05) after 30 minutes. The PI returned to the baseline value 60 minutes later. In the control group, there was no change in uterine artery PI. No change was found in heart rate or mean arterial blood pressure in the control or DHAS groups. The mean plasma E2 increased from 22.3 +/- 6.6 to 56.2 +/- 24.1 ng/mL (P < .05) 10 minutes after the infusion in DHAS subjects, whereas there was no significant change in plasma E2 in the controls. CONCLUSION: Dehydroepiandrosterone sulfate induces a significant decrease in the uterine artery PI, which suggests a possible decrease in uterine vascular impedance in term pregnancy.     

Color Doppler imaging and plasma levels of endothelin-1 in low-tension glaucoma

Endothelin-1 (ET-1) is a potent vasoconstrictor peptide produced by vascular endothelin cells There are reports in the literature that ET-1 plasma levels are raised in low tension glaucoma (LTG). ET-1 plasma concentration and Color Doppler Imaging (CDI) evaluation in ophthalmic and posterior ciliary arteries were measured in 15 LTG patients and in 15 healthy subjects. The blood flow index recorded for the ophthalmic artery in normal subjects was a PSV of 36.646 +/- 6.611 cm/sec with RI of 0.717 +/- 0.019 while in the LTG patients it was 32.961 +/- 3.045 cm/sec (p < 0.003) with RI of 0.789 +/- 0.018 (p < 0.001). For the posterior ciliary arteries in the same two groups, we obtained a PSV of 13.878 +/- 4.149 cm/sec vs 8.720 +/- 1.645 cm/sec (p < 0.001) and an RI of 0.679 +/- 0.039 vs 0.722 +/- 0.024 (p < 0.001). The plasma ET-1 level in normal subjects was 1.720 +/- 0.174 pg while in LTG patients it was 2.947 +/- 0.217 pg (p < 0.001). On the basis of our experience, we think that GON and the visual field damage found in LTG can be attributed to an alteration in the endothelial self-regulating sections and consequent vascular insufficiency, particularly pronounced in the posterior ciliary arteries which, since it is these that provide the blood supply to the optic nerve head, leads to irreversible functional damage.     

Blood-flow velocities in the extraocular vessels in normal volunteers

PURPOSE: To determine normal values of blood-flow velocities in extraocular vessels. METHODS: In one eye each in 189 healthy adult volunteers, blood-flow velocities in the ophthalmic artery (OA), central retinal artery (CRA), central retinal vein (CRV), short lateral posterior ciliary artery (LPCA), and short medial posterior ciliary artery (MPCA) were measured by color Doppler imaging. In the arteries, peak systolic velocity (PSV), end diastolic velocity (EDV), and resistivity index (RI) were calculated. In the CRV, maximal and minimal blood-flow velocities were measured. Influence of age, gender, blood pressure, and heart rate on blood-flow velocities and the resistivity index were analyzed. RESULTS: Mean outcomes +/- S.D. cm/sec were as follows: in the OA, PSV was 39.2 +/- 5.3, EDV was 9.1 +/- 2.5, and RI was 0.77 +/- 0.05. In the CRA, PSV was 11.0 +/- 1.8, EDV was 3.3 +/- 0.9, and RI was 0.71 +/- 0.05. In the short LPCA, PSV was 11.2 +/- 1.7, EDV was 3.7 +/- 1.0, and RI was 0.68 +/- 0.06. In the short MPCA, PSV was 11.2 +/- 11.7, EDV was 3.6 +/- 0.9, and RI was 0.68 +/- 0.05. In the CRV, mean maximal velocity was 4.5 +/- 0.9, and mean minimal velocity was 3.3 +/- 0.7. Age, gender, systolic blood pressure, diastolic blood pressure, and heart rate had no consistent statistically significant influence on the measured and calculated variables. CONCLUSION: Normal values for blood-flow velocities in the extraocular vessels serve as a basis in deciding whether a measured value of a patient is normal or abnormal.     

Maternal renal artery blood flow velocimetry in normal and hypertensive pregnancies

OBJECTIVE: To investigate the effect of normal pregnancy and hypertensive disorders of pregnancy on the maternal renal artery Doppler blood flow velocity indices. METHODS: The patient material consisted of 30 normal pregnant women, 29 women with pregnancy induced hypertension, 43 women with preeclampsia and 22 pregnant women with chronic hypertension. Blood flow velocities in the segmental renal arteries from the right kidney were analysed by pulsed and color Doppler. The systolic/diastolic (s.d.) ratio, resistance index (RI) and pulsatility index (PI) were used for Doppler waveform analysis. RESULTS: In all of the groups of hypertensive pregnant women renal artery Doppler indices were significantly lower compared to the normal pregnant women group. There was a significant negative relationship between renal artery PI and mean arterial pressure in the preeclampsia group and in the chronic hypertension group. CONCLUSION: The present results demonstrate that the mechanism of renal autoregulation in preeclampsia might be altered, leaving glomerulus unprotected from increased blood pressure. It seems that the concept of renal vasoconstriction in preeclampsia might be disputed and needs further investigation.     

Value of transcranial Doppler indices in predicting raised ICP in infantile hydrocephalus. A study with review of the literature

Cerebral hemodynamic changes in infants with progressive hydrocephalus have been studied with the transcranial Doppler (TCD) technique. Several authors have referred to the correlation between the hemodynamic changes and increased intracranial pressure (ICP). Despite conflicting conclusions on the value of pulsatility index (PI) and resistance index (RI) measurements for monitoring infantile hydrocephalus, these pulsatility indices are the most commonly used for this purpose. Although clinical signs of raised ICP are highly variable and unreliable in infants, assumptions have been made in most of the studies about the presence of elevated ICP on the basis of the patient's clinical state. Few studies have reported on actual ICP values, however, and a direct relationship between ICP and TCD changes has never been adequately demonstrated. In the present study, this relationship was investigated in long-term simultaneous TCD/ICP measurements, in an attempt to develop a noninvasive method of monitoring the effect of ICP on intracranial hemodynamics. Two groups of data sets were established. Group I consisted of pre- and postoperative (shunt implantation) TCD/ICP measurements. Group II were long-term simultaneous TCD/ICP recordings showing significant ICP variations. In most of the postoperative measurements there was a decrease in the average PI and RI values. The correlation between PI or RI and ICP in the long-term simultaneous recordings, however, was generally poor. The risk of obtaining false positive or false negative PI or RI values in short-term measurements was also demonstrated. It can be concluded from our results, besides the wide range of reference values for the Doppler indices and extracranial influences upon them, that the present Doppler indices are inadequate for monitoring the complex intracranial dynamic responses in patients with raised ICP.     

Color Doppler ultrasonography in retinitis pigmentosa. Preliminary study

PURPOSE: Retinitis pigmentosa is a bilateral retinal degeneration. The primary disorder is still debated. METHODS: We performed a prospective investigation of the ocular circulation directly by color Doppler imaging (CDI). A total of 28 eyes of 14 patients (8 men and 6 women, affected with retinitis pigmentosa) were recruited for this study. For each case were evaluated protosystolic velocity and the resistive index of the ophthalmic artery, central retinal artery, posterior ciliary arteries and choroid. These values, furthermore, have been compared with a control group. RESULTS: The results of the CDI in the group of RP and in the CG were: in the OA: PSV 31.177 +/- 5.119 cm/sec vs 36.700 +/- 3.152 cm/sec (p < 0.007); RI 0.713 +/- 0.058 vs 0.717 +/- 0.019 (p < 0.0839); in the CRA PSV 7.075 +/- 1.611 cm/sec vs 12.710 +/- 2.795 cm/sec (p < 0.001); RI 0.560 +/- 0.062 vs 0.550 +/- 0.051 (p < 0.234); in the PCA: PSV 8.569 +/- 3.408 cm/sec vs 14.100 +/- 2.571 cm/sec (p < 0.001) with RI 0.634 +/- 0.090 vs 0.681 +/- 0.045 (p < 0.145). In the CHO: PSV 12.312 +/- 2.327 cm/sec vs 16.170 +/- 1.846 cm/sec (p < 0.001) with RI 0.581 +/- 0.072 vs 0.638 +/- 0.050 (p < 0.065). CONCLUSION: Our results suggest that in the affected eyes there is a statistically significant reduction in blood flow in ophthalmic and ciliary arteries. These data offer new views on the retinitis cause of pigmentosa and possible therapeutics to be studied.