Higher Resistance Index Values Research Articles

Hepatic arterial hemodynamics and model for end-stage liver disease (MELD) scores in chronic liver disease: insights from Doppler ultrasonography

BackgroundDoppler ultrasonography is essential to provide insights into hemodynamic alterations and liver function changes in pre-cirrhotic and cirrhotic patients. Utilizing Doppler examinations, this study aims to explore the correlation between hepatic arterial hemodynamics and Model for end-stage liver disease (MELD) scores in chronic liver disease patients.MethodsA study of 50 chronic liver disease patients included sonographic assessments, measuring liver, portal vein size, and flow. Hepatic artery velocity, resistive index (RI), pulsatility index (PI), and acceleration time (AT) were evaluated. Biochemical parameters (serum bilirubin, creatinine, INR) were used to calculate MELD scores, compared with different Doppler sonographic parameters.ResultsThe study found a mean peak systolic velocity (PSV) of 107.42 ± 48.10, with end-diastolic velocity (EDV) of 26.40 ± 14.68, RI of 0.74 ± 0.06, and PI of 1.47 ± 0.24. The mean MELD score was 19.28 ± 6.09. Correlations between MELD scores and PSV, EDV, RI, PI, and AT did not yield statistically significant correlations. 80% of subjects displayed high RI (> 0.7) values in the hepatic artery, and a significant correlation was found between portal vein thrombosis and hepatic artery PSV and RI (p < 0.05).ConclusionsHepatic artery RI and PSV show a significant correlation with portal vein thrombosis. Doppler ultrasonography, while not directly tied to MELD scores, is valuable for non-invasive liver disease monitoring when invasive methods are impractical. Further research is needed to unravel the relationships between hemodynamic changes, MELD scores, and clinical outcomes in a broader patient population.

Diagnostic value of multi-parameter ultrasound evaluation in sepsis complicated by acute kidney injury

Background This study aimed to discuss the diagnostic value of multi-parameter ultrasound evaluation in sepsis complicated with acute kidney injury (AKI). Methods Patients were divided into an AKI group (n = 50) and a non-injury group (n = 50) based on the presence of AKI. The clinical characteristics were collected, and renal function parameters between the two groups were compared, including 24-h urine volume, serum creatinine, urea, serum cystatin C (CysC), renal parenchymal thickness (RPT), renal artery resistance index (RI), and multi-parameter ultrasound scoring (MPUS). Additionally, logistic regression analysis was conducted to determine the influencing factors of sepsis complicated with AKI. The prediction value was evaluated using a receiver operating characteristic (ROC) curve. Results In the AKI group, creatinine, CysC, urea, MPUS score, RPT, and RI values were significantly higher, while the 24-h urine volume was lower than those in the non-injury group (p < 0.01). Moreover, multivariate logistic analysis indicated that high CysC and RI values were independent risk factors, whereas high 24-h urine volume and low MPUS were independent protective factors for sepsis-induced AKI. The ROC curve demonstrated that RI (AUC = 0.906) was more effective than 24-h urine volume (AUC = 0.797), CysC (AUC = 0.730), and MPUS (AUC = 0.794) in identifying sepsis-induced AKI. Conclusion High RI values increase the risk of sepsis-induced AKI, whereas low MPUS may reduce it. RI showed high diagnosis values for sepsis complicated with AKI.

Color doppler ultrasound analysis of pathological myopia induced changes in retrobulbar blood flow and its relationship with characteristic changes in myopia.

To analyze changes in retrobulbar blood flow in patients with pathological myopia using color doppler ultrasound (CDU), and to explore the relationship of these changes with the characteristic changes resulting from myopia. One hundred and twenty patients who met the selection criteria in the ophthalmology department of He Eye Specialist Hospital from May 2020 to May 2022 were included in this study. Patients with normal vision (n=40) were considered Group-A, patients with low and moderate myopia (n=40) were considered Group-B, and patients with pathological myopia (n=40) were considered Group-C. All three groups underwent ultrasonography. The peak systolic blood flow velocity (PSV), end-diastolic blood flow velocity (EDV), and resistance index (RI) of the ophthalmic artery, central retinal artery, and posterior ciliary artery were recorded and compared, and the characteristics of these parameters and myopia severity were analyzed. Pathological myopia resulted in significantly lower PSV and EDV of the ophthalmic artery, central retinal artery and posterior ciliary artery and higher RI values than patients with normal vision and low/moderate myopia (P<0.05). Pearson correlation analysis showed that retrobulbar blood flow changes were significantly correlated with age, eye axis, best corrected visual acuity, and retinal choroidal atrophy. CDU can objectively evaluate the retrobulbar blood flow changes in pathological myopia, and such blood flow changes are significantly correlated with the characteristic changes of myopia.

Индекс резистентности внутренних сонных артерий и нейросети мозга при хронической церебральной ишемии

Quantitative assessment of cerebral hemodynamics is important for patients with chronic cerebral ischemia (CCI), as it helps to reveal the pathogenesis of the disease and set the course for effective prevention and treatment. The study was aimed to assess the correlation of the left carotid artery (ICA) resistive index (RI) with cognitive functions and brain network organization based on fMRI data in patients with CCI (51 males and 105 females). The listed above indicators were studied in patients with the left ICA RI values below and above the average (0.54 ± 0.013). The lower, normal physiological ICA resistance levels corresponded to the more successful realization of verbal cognitive functions. In the first group, RI was within normal range (RI = 0.42 ± 0.007), and in the second group RI exceeded normal levels (RI = 0.61 ± 0.01). Variation of the right ICA RI did not correlate with the characteristics of verbal cognitive functions. FMRI data analysis was used to assess the differences in connectivity between various brain regions in the groups with low and high RI. The normal physiological and elevated RI values of the left ICA correlated with differences in the organization of brain networks: normal physiological RI values corresponded to a better organization of hemispheric connections in the basal ganglia and brainstem, and high RI values corresponded to a better organization of connections between the frontal regions and the cerebellum as well as occipital areas of the cerebral cortex. The left ICA RI can be considered as a biomarker of cognitive decline and brain networks reorganization in patients with CCI.

An Analytical Cross-Sectional Study to Assess the Effects of Smoking on Common Carotid Intima-Media Thickness and Resistivity Index Among Current Smokers

Objective: The aim was to assess the structural and hemodynamic effects of smoking on the common carotid arteries (CCAs) in current smokers from Himachal Pradesh. In addition, it was important to determine any association between smoking duration, frequency, pack-years, and the occurrence of common carotid atherosclerosis. Materials and Methods: The study evaluated 50 current smokers for common carotid intima-media thickness (CIMT), plaque presence, and resistive index (RI) with sonography. The findings were compared with 50 healthy control patients, who had never smoked. Results: A positive association was observed between smoking and an increase in CIMT ( P = .001) and occurrence of plaques ( P = .007), with substantially higher mean CIMT values in smokers above 45 years ( P &lt; .05) in both genders ( P &lt; .05). No difference in overall RI was seen in both groups taken as a whole, while higher RI values ( P &lt; .05) were noticed in smokers exclusively above 60 years. A positive association was noted between smoking frequency, pack-years, and an increase in CIMT, RI, and occurrence of plaques. For every unit increase in the number of pack-years and smoking duration, there was a 0.01 unit increase in CIMT among the current smokers. Conclusion: This research provides evidence that smoking has a structural impact on CIMT while its hemodynamic effect is still unclear.

Effects of Hypoplastic Fetal Umbilical Artery on Doppler Findings For Common Iliac Arteries

Background: The umbilical cord contains two arteries and one vein. Normally, the diameters of umbilical arteries are close in size, but this may vary, as one umbilical artery may be considerably smaller or more hypoplastic than the other. Objectives: This study aimed to investigate the effect of hypoplastic umbilical arteries on Doppler ultrasonography (US) findings for the common iliac arteries (CIAs), such as the pulsatility index (PI) and resistive index (RI) values, and to investigate the associations between hypoplastic fetal umbilical arteries and placental, umbilical cord, and fetal pathologies. Patients and Methods: Doppler US was performed on 165 pregnant women between 18 and 22 weeks of gestation, and again between 27 and 37 weeks of gestation. The umbilical artery diameters and both CIA flow parameters (PI and RI) were measured during these visits. The presence of a diameter difference of greater than 25% (95th percentile) between the two umbilical arteries was accepted as a hypoplastic umbilical artery. Results: Eleven of the 165 patients (6.7%) demonstrated a hypoplastic umbilical artery. Second-trimester US showed median dominant and non-dominant CIA PI values of 1.43 and 1.60 (P = 0.062), respectively, and median dominant and non-dominant CIA RI values of 0.80 and 0.85 (P < 0.001), respectively, in the hypoplastic umbilical artery group. Third-trimester US showed median dominant and non-dominant CIA PI values of 1.24 and 1.66 (P = 0.062), respectively, and median dominant and non-dominant CIA RI values of 0.73 and 0.82 (P = 0.002), respectively, in the hypoplastic umbilical artery group. We did not observe an association between hypoplastic umbilical arteries and placental, umbilical cord, or fetal pathologies. Conclusion: Our study revealed that the hypoplastic umbilical artery group’s non-dominant CIA had higher RI values than the contralateral dominant CIA.

Comparative B-mode and Doppler renal ultrasonography with histopathological findings in dogs positive for canine visceral leishmaniasis.

Morphological parameters and renal flow were assessed and measured in six clinically healthy dogs with negative serological and parasitological examinations for canine visceral leishmaniasis (CVL) and six dogs with CVL-positive serological and parasitological tests and asymptomatic condition of the disease. Kidney length and diameter were measured and compared with the aorta/kidney ratio. Alterations in flow were measured using the flow velocity (cm/s) and resistance index (RI). Renal function was assessed by serum biochemical examination (urea, creatine, total proteins, albumin, and globulin) and urinalysis. CVL-positive animals presented heterogeneous kidney echotexture, reduced vascular flow, hypoperfusion, lesser visualization of the arcuate arteries, high RI values (1.06 ± 0.28 for the right kidney and 1.10 ± 0.30 for the left kidney), reduced diastolic flow, and high systolic peak. They also presented positive creatine/RI correlation and between the renal artery vascular flow and kidney diameter. Histopathological analysis of CVL-positive animals was compatible and confirmed hemodynamic changes observed by Doppler ultrasound. The findings in the present study showed that Doppler ultrasonography is a valid method to assess and detect alterations in flow in renal pathological processes with kidney vascular damage, as in the case of leishmaniasis, and can help in the diagnosis of animals with this infection. Microsc. Res. Tech. 79:637-645, 2016. © 2016 Wiley Periodicals, Inc.

Initial kidney graft resistance index and the long-term cardiovascular mortality in transplanted patients: a paired grafts analysis.

Cardiovascular complications remain the most frequent cause of death in kidney transplant recipients. We analysed the prognostic value of early measured resistance index (RI) in the aspect of long-term cardiovascular mortality. In order to eliminate potential donor-related confounders, we analysed the mortality of recipients, transplanted with organs procured from the same donor, in whom the initial RI values substantially differed. Doppler sonography was performed in 725 consecutive kidney graft recipients early after transplantation. We identified 133 pairs (266 patients) who received their kidney grafts from the same donor and their initial RI values differed by >0.1. During 109 ± 37 months of follow-up after transplantation, 84 patients lost their graft and 29 died, 14 of them due to cardiovascular causes. Two groups of paired patients with higher RI and lower RI did not differ significantly with respect to their age, BMI, HLA mismatch and cold ischaemia time. There were more patients with diabetes in the higher RI group (14.3 versus 6.8%). Survival analysis revealed a higher mortality for cardiovascular (8.3 versus 2.3%, P = 0.02) and all causes (14.3 versus 7.5%, P = 0.06) among patients with higher initial RI values. In the Cox regression model, not including age, a higher RI value was a strong predictor of cardiovascular death (HR = 4.88), independent of previous cardiovascular episodes (HR = 6.78). Both these variables lost its significance as a predictors after inclusion of age in the regression model. Increased intrarenal resistance index in the early posttransplant period may help to identify the recipients with increased cardiovascular risk.

Sonographic appearances of desmoid tumors.

The medical records of 16 patients (9 female and 7 male; age range, 5-66 years) with 24 lesions that had a histologic diagnosis of desmoid tumors were reviewed at our institution. Six cases were extra-abdominal, 4 intra-abdominal, and 6 in the abdominal wall. Lesions ranged from 1.5 to 18.0 cm in diameter (mean, 6.8 cm). All lesions were solid masses, which appeared hypoechoic, isoechoic, or hyperechoic with homogeneous or heterogeneous echogenicity. Posterior acoustic enhancement was seen in 18 lesions. No lesions showed central necrosis. Most lesions had substantial flow and high resistive index values (>0.70). Sonography can show a desmoid tumor's site, size, contour, margin, echogenicity, homogeneity, vascularity, and resistive index value in detail.

A3.13 The high resistance index values are decreased in systemic lupus erythematosus patients – risk factors and clinical association

BackgroundHigh resistance index (HRI), evaluated on the basis of Doppler spectrum of popliteal arteries, enables detection of subclinical changes in small vessels in systemic lupus erythematosus (SLE) patients.ObjectiveTo evaluate the...

Renal Duplex Sonographic Evaluation of Type 2 Diabetic Patients

The purpose of this study was to evaluate the renal volume and intrarenal hemodynamics with duplex sonography in a group of diabetic patients with normal renal function in comparison to nondiabetic controls. The renal volume and resistive index (RI) of segmental arteries were assessed by duplex sonography in 88 diabetic patients (44 male and 44 female; median age, 58 years [range, 37-69 years]) and 73 nondiabetic control participants (48 male and 25 female; median age, 53 years [range, 27-75 years]) without renal artery stenosis. Both renal volume and RI values in the diabetic patients were significantly higher compared to the controls (mean volume ± SD: diabetic patients, 197.3 ± 47.6 mL; controls, 162.5 ± 35.2 mL; P < .0001; RI: diabetic patients, 0.70 ± 0.05; controls, 0.59 ± 0.06; P < .0001). Renal hypertrophy was present even in diabetic patients without proteinuria (renal volume: patients without proteinuria, 198.3 ± 45.9 mL; controls, 162.5 ± 35.2 mL; P < .005). Patients with higher RI values had significantly greater proteinuria (RI <0.75, 15.9 mg/g [range, 4.2-1718.9 mg/g]; RI >0.75, 37.9 mg/g [range, 11.34-2087.0 mg/g]; P < .02). Changes in renal volume and hemodynamics are detectable on sonography in diabetic patients. Those changes are also present in patients without proteinuria or signs of renal atherosclerosis and with both normal and increased glomerular filtration rates. These results indicate a potential role of duplex sonography in the early identification of morphologic and hemodynamic renal changes in type 2 diabetic patients.

Correlation between the Resistive Index Values of Renal and Orbital Arteries

Background: Resistive index (RI) is an indirect measurement of blood flow resistance that can be used to evaluate vascular damage. Aims: The purpose of this study is to evaluate the association between RI values of orbital and intrarenal arteries by means of Doppler ultrasonography (US). Methods: We evaluated 103 diabetic patients. As a control group, 30 subjects were examined. The patients were divided into two groups. Group 1 consisted of patients with urinary albumin excretion (UAE) <300 mg/day and estimated glomerular filtration rate (eGFR) levels >90 ml/min (n = 50); Group 2 had a UAE >300 mg/day and/or eGFR levels between 89 and 60 ml/min (n = 53). The association between RI values obtained with Doppler US of the ophthalmic artery, central retinal artery, posterior ciliary artery and intrarenal arteries were calculated. Results: Both orbital and intrarenal arterial RI values in Group 1 and Group 2 were higher than the control group (p = 0.001); furthermore, values were higher in Group 2 than in Group 1 (p = 0.0004/0.029/0.036, p = 0.016, respectively). A positive correlation was found between orbital and intrarenal arterial RI values in Group 2 (r = 0.475, 0.285, 0.363, p < 0.01, respectively). Conclusion: Both orbital and renal arterial RI values were shown to be higher than the control group. Further, a trend towards higher RI values was observed with renal disease. RI may be useful as one of the markers for early diagnosis and follow-up of diabetic nephropathy and retinopathy.

Intraoperative Resistance Index Measured With Transsonic Flowmeter on Kidney Graft Artery Can Predict Early and Long-term Graft Function

Introduction Resistive index (RI) measured by Doppler sonography in the early period after kidney transplantation is a well-known predictor of kidney transplant outcome. The purpose of this study was to analyze the impact of RI values calculated intraoperatively in renal allograft artery using transit time flowmetry (TTF) on both early and long-term kidney graft function. Material and Methods TTF was performed on 72 patients who received kidney grafts fed by a single artery. TTF was performed before wound closure. We excluded patients with an early acute rejection (n = 8), an early graft loss (n = 2), or primary graft nonfunction (n = 1). Recipients were divided into RI tertile groups. The initial kidney graft function was defined as immediate (IGF), slow or delayed. Kidney graft estimated glomerular filtration rate (eGFR) was analyzed upon long-term follow-up. Results Patients with a low RI (< 0.57) showed the highest incidence of immediate graft function (65% versus 5.3%), whereas the high RI group (> 0.70). Show the most frequent rate of delayed graft function (52.6% versus 15%). Recipients with low RI values displayed significantly better eGFR (by at least 12 mL/min/1.73 m 2) than those with medium or high RI values at all analyzed times; subjects with medium or high RI showed similar eGFR at 48-months. Conclusion An high RI value measured intraoperatively was a valuable predictor of inferior early and long-term kidney graft function.

Comparison between Doppler Ultrasound and Biopsy Findings in Patients with Suspected Kidney Transplant Rejection

Introduction: The role of Doppler ultrasound in diagnosing kidney allograft rejections is controversial. Our goal in this study was to investigate the utility of Doppler-measured resistive index (RI) as a screening tool for kidney transplant rejection. Methods: We retrospectively studied a random sample of 188 kidney transplanted patients who had Doppler-ultrasound examination followed within two weeks by transplant biopsy. We evaluated the specificity and sensitivity of Doppler ultrasound in diagnosing rejection at different RI thresholds, using the reported biopsy findings as the gold standard. Results: The RI values of the study population had a mean value of 0.7 ± 0.11 (mean ± SD) and a range of 0.4-1.0. There was no significant difference in the mean RI between patients with biopsy proven rejection and patients without rejection (0.68±0.09 versus 0.71±0.12, P = 0.16). The sensitivity and specificity of Doppler-measured RI in diagnosing rejection was highly variable depending on the chosen cut-off value, ranging between 4.1-98.6% and 2.6-92.2% respectively. Acceptable specificity was only achieved at the expense of very low sensitivity. Acute tubular necrosis (ATN) and interstitial edema (IE) were associated with higher RI values than other pathological entities, while very low RI values had high specificity and low sensitivity for transplanted renal artery stenosis (TRAS). Conclusion: Doppler-measured RI lacks accuracy in diagnosing transplanted kidney rejection, resulting in poor utility of this test as a screening tool for rejection. Keywords: Doppler Ultrasound; Rejection; Resistive Index (RI); Transplant kidney

Vascular resistance in the prostate evaluated by colour Doppler ultrasonography: is benign prostatic hyperplasia a vascular disease?

To evaluate prostatic vascular resistance by measuring the resistive index (RI), and flow velocity using colour Doppler ultrasonography (CDUS), in normal prostates and in patients with benign prostatic hyperplasia (BPH) or prostate cancer, as BPH is considered to be a result of urogenital ageing and studies suggest that hyperplasia in the stromal and glandular compartments might be induced by stromal growth secondary to hypoxia, which in turn results from abnormal blood flow patterns. Ninety-two men (22 with normal prostates, 45 with BPH and 25 with prostate cancer; mean age 56 years) were prospectively evaluated by CDUS. The RI values for the peripheral, central and transition zones were assessed by one investigator. The diagnosis of BPH and prostate cancer was established from histological findings. The mean (sd) RI in the transition zone was significantly higher only in patients with BPH, at 0.77 (0.05), vs 0.65 (0.05) in the other two groups. In the peripheral and central zones there was no significant difference in the RI among the three groups. Arterial CDUS flow velocity was increased in the transition zone of patients with BPH, but not in the peripheral and central zones. The present results support the hypothesis that an age-related impairment of blood supply to the lower urinary tract might have a role in the development of BPH. Although prostate cancer cannot be excluded by measuring RI, high RI values (>0.75) in the transition zone are indicative of BPH.

Resistive index in febrile urinary tract infections: predictive value of renal outcome.

In the absence of specific symptomatology in children, the early diagnosis of acute pyelonephritis is a challenge, particularly during infancy. In an attempt to differentiate acute pyelonephritis from lower urinary tract infection (UTI), we measured intrarenal resistive index (RI). We evaluated its ability to predict renal involvement as assessed by dimercaptosuccinic acid (DMSA) scintigraphy. In total 157 patients admitted to the pediatric department of the Sişli Etfal Hospital with clinical signs of febrile UTI were included in the study. The children were divided into groups according to their age at the time of ultrasonography (US). RI was measured from the renal arteries with Doppler US in the first 72 h in all 157 children. Renal involvement was assessed by (99m)Tc-DMSA scintigraphy in the first 7 days after admission. The examination was repeated at least 6 months later if the first result was abnormal. All available patients with an abnormal scintigraphy underwent voiding cystourethrography 4-6 weeks after the acute infection. All patients with vesicoureteral reflux and scarred kidneys were excluded from the study. DMSA scintigraphy demonstrated abnormal changes in 114 of 157 children and was normal in the remaining 43 children. Of these 114 children, 104 underwent repeat scintigraphy, of whom 77 showed partially or totally reversible lesion(s). Of these 77 children, 17 children (22%) with vesicoureteral reflux were excluded. Thus, we compared the 43 children with lower UTI with the 60 children with definite acute pyelonephritis at admission. Kidneys with changes of acute pyelonephritis had a mean RI of 0.744+/-0.06 in infants, 0.745+/-0.03 in preschool children, and 0.733+/-0.09 in patients of school age with upper UTI. However, the mean RI was 0.703+/-0.06 in infants, 0.696+/-0.1 in preschool children, and 0.671+/-0.09 in school-aged patients with lower UTI. The mean RI values were significantly higher in patients with upper UTI ( P<0.001). There was a highly significant correlation between RI values and the severity of the renal lesion as ranked by DMSA scintigraphy ( P<0.001). When the cut-off RI value was 0.715, there was an 80% sensitivity and a 89% specificity for diagnosing upper UTI. Refluxing kidneys and scarred kidneys also had higher RI values. In conclusion, RI values were increased significantly in children with febrile UTI when renal parenchymal involvement (assessed by DMSA scintigraphy) was present. Our results also support the view that the children with high RI values are at a high risk of reflux, scarring, or both, which was frequently observed in febrile UTI. This might allow identification of patients at risk for severe renal lesions that require more aggressive therapy, investigation, and follow-up than those with lower UTI.

Doppler sonography in congenital ureteropelvic junction obstruction and multicystic dysplastic kidneys.

The accurate diagnosis of severe congenital ureteropelvic junction obstruction (UPJO) and the indications for surgical intervention are a matter of debate. Differential diagnosis from, for example, congenital cystic kidney malformations is important. In the present study we analysed the value of Doppler sonography (DS) for assessment of obstruction in congenital UPJO and its usefulness for differential diagnosis. A total of 138 infants and children were examined. Forty-three healthy infants and 24 children who had had a pyeloplasty at least 1 year previously served as control groups. Seventy-one children with UPJO and cystic kidney malformations underwent DS in addition to the usual examinations of intravenous urography and scintigraphy. Resistive Index (RI) was measured in both kidneys. Twenty infants showed decompensated UPJO and had needed an operation. Preoperatively all showed significantly increased RI (RI = 74%), which returned to normal after operation (RI = 68.3%). Thirty-nine children with UPJO could be managed conservatively, showing compensated obstruction on diuretic renography. On DS they had normal and symmetrical RI values (RI = 67%). Eleven children had multicystic dysplastic kidneys; 4 underwent nephrectomy. On DS all showed either absence of perfusion signals or very low flow velocities with very high RI values (RI = 90-100%) in the renal vessels. One child was found to be suffering from a cystic nephroma. DS was able to reveal quite normal vessel distribution in renal parenchyma with slightly elevated RI values (RI = 80%). Our results indicate that DS a non-invasive, non-ionising method of investigation, may serve as an additional functional parameter for defining accurately the degree of obstruction in UPJO.(ABSTRACT TRUNCATED AT 250 WORDS)

The relationship of uterine and umbilical Doppler resistance to fetal and placental protein synthesis in the second trimester

The relation of uteroplacental and umbilical Doppler resistance index (RI) to peripheral levels of alphafetoprotein (AFP), human chorionic gonadotrophin (hCG), human placental lactogen (HPL), Schwangerswaft protein (SP1), pregnancy-associated placental protein A (PAPP-A) and insulin-like growth factor binding protein 1 (IGP-BP1) at 16-24 weeks was established in a cross-sectional study of 183 unselected singleton pregnancies. There was an association between high values of uteroplacental RI and high hCG levels, and high umbilical RI values with high hCG and HPL levels. Thus, in the mid-trimester, the levels of some placental proteins seem to be related to placental resistance.

Evaluation of risk factors for the development of nonmalignant diseases of the cervix

The relation of uteroplacental and umbilical Doppler resistance index (RI) to peripheral levels of alphafetoprotein (AFP), human chorionic gonadotrophin (hCG), human placental lactogen (HPL), Schwangerswaft protein (SP1), pregnancy-associated placental protein A (PAPP-A) and insulin-like growth factor binding protein 1 (IGP-BP1) at 16–24 weeks was established in a cross-sectional study of 183 unselected singleton pregnancies. There was an association between high values of uteroplacental RI and high hCG levels, and high umbilical RI values with high hCG and HPL levels. Thus, in the mid-trimester, the levels of some placental proteins seem to be related to placental resistance.

Relationship of utero- and fetoplacental blood flow velocity wave forms with pathomorphological placental findings.

Pulsed Doppler examinations were performed in 143 risk pregnancies. The resistance index (RI) values of the uteroplacental vessels and umbilical artery on the last examination before delivery were correlated to specific patterns of morphological placental findings. The sensitivity and specificity of Doppler blood flow velocity wave forms to predict placental disease as well as the significant relationships were calculated. Impaired uteroplacental perfusion is correlated with: disturbances in growth, such as reduced weight and reduced basal area (p < 0.005, p < 0.05); disturbances in villous maturation, such as prematurity or a reduction in intermediate sized villi (p < 0.05, p < 0.01), and circulation disorders, such as acute or chronic infarcts (p < 0.05), villous fibrosis (p < 0.005) or microfibrin deposits (p < 0.05). Villous immaturity was not correlated to either pathological utero- or fetoplacental blood flow. Except for acute infarcts, all these findings as well as endangiopathy of truncal arteries are also combined with high RI values in umbilical arteries (p < 0.005) possibly reflecting the 'down-stream impedance' of the fetoplacental circulation.