Doppler sonography of renal obstruction: value of venous impedance index measurements.

OBJECTIVE: Arterial resistive index values have poor sensitivity and specificity for alterations in renal perfusion induced by collecting system obstruction. We aimed to determine whether the intrarenal venous impedance index values could be useful in evaluating renal parenchymal compliance in cases of obstruction and in differentiating acute obstruction from chronic cases. METHODS: Fifteen patients with acute renal colic having unilateral stone disease and another 15 patients having unilateral chronic obstruction due to various causes were evaluated sonographically. The diagnosis was confirmed either by computed tomography or intravenous urography in all cases. Fifteen subjects with normal kidneys were investigated as a control group. All patients were examined prospectively by conventional and Doppler sonography. The impedance indices and peak flow signals of the interlobar arteries and veins of both kidneys were calculated from spectral Doppler waveforms in all 3 groups. RESULTS: The mean venous impedance index on the acutely obstructed side was lower than the index on the unobstructed side: 0.25 +/- 0.07 and 0.53 +/- 0.3 (mean +/- SD), respectively (P = .005). The mean venous impedance index on the acutely obstructed side was less than the indices both on the chronically obstructed side and in the control subjects (P > .0001). In acute cases, the mean arterial resistive index on the obstructed side was higher than the index on the unobstructed side: 0.62 +/- 0.06 and 0.57 +/- 0.06, respectively (P = .001). No statistically significant difference was detected between other parameters evaluated for the test and control groups. CONCLUSIONS: Renal venous impedance index values may be helpful in evaluating renal hemodynamics in obstruction and in differentiating acute obstruction from chronic cases when used in conjunction with the arterial resistive index.     

Corpus luteum blood flow in normal and abnormal early pregnancy: evaluation with transvaginal color and pulsed Doppler sonography.

One hundred and thirteen (66.5%) women in this study had a normal intrauterine pregnancy with ages ranging 6 to 12 weeks of gestation. Fifty-seven (33.5%) patients were admitted to the hospital owing to clinically suspected abnormal early pregnancy. Dilatation and curettage were done on all women and tissue sample sent to the pathologist for a final diagnostic. Diagnosis of ectopic pregnancy was made on laparoscopy. Both ovaries were examined carefully by color Doppler in sonography in all patients. Color flow was used as a guide for pulsed Doppler exploration. Corpus luteum blood flow was defined as random, usually semilunar in appearance, dispersed vessels with very low impedance to blood flow. The resistive index and pulsatility index were calculated. Overall detection rate of corpus luteum blood flow in normal pregnancies was higher for the left ovary (62.6%) than for the right ovary (37.4%) (P < 0.01). The mean resistive and pulsatility indices from corpus luteum blood flow were not influenced by gestational age in normal pregnancy. The overall mean value for for resistive index was 0.452 +/- 0.04 and for pulsatility index 0.636 +/- 0.09. The overall detection rate of corpus luteum in abnormal pregnancies also was higher for the left ovary (56.7%) than for the right ovary (43.4%) (P < 0.01). The mean resistive indices from corpus luteum blood flow in patients with missed abortion was higher than in women with normal pregnancy (P < 0.01). Both resistive and pulsatility indices were higher in patients with incomplete or threatened abortion in comparison with normal pregnancy (P < 0.01). No statistically significant difference was seen in the case of anembryonic, molar, or ectopic pregnancy.     

Resistive indices in the evaluation of infants with obstructive and nonobstructive pyelocaliectasis.

Diagnosing obstructive uropathy by renal resistive indices calculated from duplex Doppler sonographic waveforms has been supported as well as challenged in the radiology literature relating to adults. Despite reports of normally higher resistive indices in children as compared to adults, two studies have documented high sensitivity and specificity of renal Doppler sonography in the diagnosis of obstructive uropathy in children, using the same discriminatory criterion of a resistive index of 0.7 or greater as used in adults. We evaluated 43 infants with significant or bilateral pyelocaliectasis secondary to both obstructive and unobstructive uropathy and found no significant difference in the mean resistive indices or the mean difference in resistive indices of two kidneys in one patient. We conclude that Doppler sonography in infants has no value in differentiating obstructive from nonobstructive pyelocaliectasis.     

Transcranial color Doppler imaging of brain arteriovenous malformations in adults

This study was performed to investigate the utility of transcranial color Doppler sonography in evaluating adult cerebral arteriovenous malformations. Twelve patients with such malformations underwent sonography. Spectral Doppler sonographic assessment included peak systolic velocity, end diastolic velocity, and resistive index within the intracranial and extracranial vessels. Color Doppler sonography was used to visualize the site of shunting. Paired and unpaired Student's t-tests were used to determine significance of spectral findings. The nidus was seen in eight of 10 pial malformations. The nidi in two patients were located in the parietal region and not visualized. When compared with the corresponding contralateral artery, feeding arteries (identified in all 10 of the pial lesions) demonstrated diminished resistive indices (P = 0.09). Similarly, the end diastolic velocity was increased in all feeding arteries (P = 0.03). When compared with published normal values, the peak systolic and end diastolic velocities were significantly elevated and the resistive indices were low (P < 0.0003). Transcranial color Doppler sonography depicted the nidi of pial arteriovenous malformations in 80% of cases. Feeding arteries demonstrated abnormal peak systolic velocity, end diastolic velocity, and resistive index in all cases when compared with published values. Transcranial color Doppler sonography is not a good screening tool due to limited acoustical window, but it may be useful for noninvasive study of the physiology of arteriovenous malformations as they are treated.     

Renal duplex Doppler sonography in asymptomatic women during pregnancy

The purpose of this study was to establish the normal range of the renal RI in pregnant women. Maternal renal RIs were calculated in 61 asymptomatic pregnant patients with at least unilateral pyelocaliectasis. A mean RI was calculated for each kidney. Overall, the mean RI was 0.61 +/- 0.05. The renal RI was > or = 0.70 in 4% (5/121) of kidneys with no statistically significant difference between the mean right (0.62 +/- 0.06) and left (0.60 +/- 0.04) kidney RIs. There was no correlation between trimester of pregnancy or degree of pyelocaliectasis and RI.     

多普勒超声评价正常妊娠及妊娠并输尿管结石孕妇肾内动脉血流指数变化

多普勒超声观测Ａ组３０名健康非孕妇女、Ｂ组１４０名正常孕妇及Ｃ组１２例妊娠并输尿管结石孕妇肾内动脉血流指数（ＲＩ、ＰＩ、Ｓ／Ｄ）。结果：Ｂ组１０９名（１１８只肾）有肾积水；无论有无肾积水Ｂ组肾ＲＩ、ＰＩ、Ｓ／Ｄ值与Ａ组无显著差异（Ｐ＞０．０５），除Ｂ组４只积水肾ＲＩ＞０．７（３％）外，Ａ、Ｂ组肾ＲＩ均＜０．７，且Ａ、Ｂ组左、右侧肾ＲＩ差值均＜０．１；Ｂ组积水肾ＲＩ、ＰＩ、Ｓ／Ｄ值高低与肾积水程度及孕周无关（Ｐ＞０．０５）。Ｃ组输尿管梗阻侧肾ＲＩ、ＰＩ、Ｓ／Ｄ均显著高于Ａ、Ｂ组与对侧健肾（Ｐ＜０．００１），梗阻侧肾ＲＩ均＞０．７且与对侧健肾ＲＩ差值＞０．１。结果表明：多普勒超声观测肾动脉血流指数变化对诊断妊娠合并机械性输尿管梗阻有重要意义     

Doppler sonography in the diagnosis of urinary tract obstruction by stone

PURPOSE: This study was conducted to evaluate the accuracy of Doppler sonography in renal colic due to obstruction and to assess whether the resistance index (RI) and interrenal RI difference (DeltaRI) are time-dependent parameters. SUBJECTS AND METHODS: Obstructed and unobstructed contralateral kidneys in 28 patients with renal colic and normal kidneys in 27 control subjects were prospectively evaluated with Doppler sonography. Mean RI, mean DeltaRI, and duration of pain were evaluated. Statistical analysis was done using paired and independent t-tests. RESULTS: Mean RIs of the control-group, obstructed, and contralateral kidneys were 0.60, 0.71, and 0.61, respectively; mean DeltaRI values of the obstructed and control-group kidneys were 0.10 and 0.03, respectively. Differences in mean RI between obstructed and contralateral or control-group kidneys were statistically significant (p < 0.001). There was a statistically significant difference in DeltaRI between patients and controls (p < 0.001). The difference between the RI values of kidneys with low-grade (0.70) and high-grade obstructions (0.72) was not statistically significant. The difference between the DeltaRI values of kidneys with low-grade (0.08) and high-grade obstructions (0.13) was statistically significant (p < 0.05). Differences in the mean RI and mean DeltaRI values between 3 groups of patients categorized according to the duration of pain were not statistically significant. CONCLUSIONS: Along with gray-scale sonography and intravenous urography, Doppler sonography can be used in the evaluation of renal obstruction. RI and DeltaRI are not time-dependent parameters.     

Renal Venous Doppler Sonography in Preeclampsia

Objective. The elevation in blood pressure associated with preeclampsia appears to be associated with a shift in the renal pressure natriuresis curve. Pressure natriuresis is modulated by renal medullary pressure. In obstructive uropathy, Doppler sonography has been used to indicate changes in renal venous impedance, possibly measuring alterations in medullary pressure and compliance in this condition. The hypothesis tested in this study was that an elevation in renal venous pulsation may occur in preeclampsia compared with normal pregnancy. Methods. Seven patients with clinical evidence of preeclampsia were referred for fetal well‐being confirmation by sonography in the third trimester. Seven pregnant patients without renal disease or hypertension reviewed in the third trimester served as a control group. Doppler studies of the interlobar arteries and veins of both kidneys were performed, with a total of 14 kidneys imaged per group. Arterial and venous impedance indices were obtained. The impedance indices for the patients were compared by the Student t test. Results. No significant difference was noted between the arterial resistive indices. The mean venous impedance index for the hypertensive patients was 0.50 ± 0.12, and that for the control patients was 0.37 ± 0.06 (P = .003). Conclusions. Preeclampsia in the third trimester appears to be associated with altered medullary venous pulsation, possibly indicating reduced medullary pressure.     

Changes of renal resistive index in response to hydration and diuretic administration in normal subjects and in patients with small ureteral stone.

The renal resistive index has been measured before and after hydration and administration of diuretics in persons with normal kidneys and in kidneys with small ureteral stone, either obstructing or nonobstructing, to assess induced flow changes and to identify features differentiating obstructing from nonobstructing stones. In normal kidneys the resistive index was normal (mean, 0.62+/-0.03); no changes in the resistive index occurred within 15 to 60 min after hydration alone, whereas the resistive index rose within 15 min after hydration plus administration of diuretics and then returned to initial values within 30 min. In both cases the resistive index decreased below basal values after 75 to 90 min. Similar changes were observed in kidneys with a nonobstructing ureteral stone. In kidneys with an obstructing ureteral stone the resistive index was higher than in normal subjects (mean, 0.73+/-0.02, P<0.01), increased further within 15 min after hydration and administration of diuretics (P<0.01), and remained higher than basal values during the following 90 min. In conclusion, different resistive index changes have been observed in response to hydration and diuretics in normal and obstructed kidneys. Duplex Doppler sonography and diuresis duplex Doppler sonography seem promising diagnostic tools to identify obstructing stones.     

Color Doppler sonographic appearance of renal perforating vessels in subjects with normal and impaired renal function

PURPOSE: The purpose of this study was to assess the prevalence and color Doppler sonographic characteristics of perforating vessels-small arteries and veins connecting the intrarenal vasculature with the capsular plexus-in healthy subjects, in hypertensive patients, and in patients with renal failure due to hypertensive nephroangiosclerosis or ischemic nephropathy. METHODS: Fifteen healthy subjects 24-34 years old, 15 healthy subjects 68-80 years old, 25 hypertensive patients, 25 patients with hypertension and chronic renal failure (15 mild, 10 severe), and 12 patients with hypertension and chronic renal failure and acute renal insufficiency due to ischemic nephropathy underwent color Doppler sonography of both kidneys. RESULTS: The few perforating arteries in healthy and hypertensive patients had various resistance indices and flow toward the capsule. Perforating veins in these patients were much more common than perforating arteries. Perforating arteries with a lower mean resistance index than the mean interlobar resistance index and flow toward the capsule were detected in 76% of kidneys in the patients with mild chronic renal failure and in 20% of those in patients with severe chronic renal failure. Only a few perforating veins were seen in patients with chronic renal failure. In 64% of the kidneys with renal artery stenosis detected in the patients with chronic renal failure complicated by acute renal insufficiency, there were perforating arteries with flow toward the kidney and a mean resistance index higher than the mean interlobar resistance index. CONCLUSIONS: Perforating vessels are recognizable using color Doppler sonography both in healthy subjects and in patients with renal failure. The prevalence and flow characteristics of perforating vessels differ between healthy subjects, patients with mild and with severe chronic renal failure, and patients with chronic renal failure complicated by acute renal insufficiency caused by renal artery stenosis.     

Intrarenal Doppler ultrasonography: which vessel should be investigated?

The aim of our study was to determine whether the site of intrarenal Doppler measurement influences diagnosis of renal artery stenosis. In an experimental test, three sheep with variable degrees of renal artery stenosis were investigated. In each animal, the resistive index from renal segmental arteries correlated better with mean pressure gradient (r = 0.85, 0.71, 0.85) and had lower standard deviation (s = 0.02 to 0.05) than resistive index from interlobar arteries (r = 0.48, 0.54, 0.61) (s = 0.03 to 0.11). In two animals the difference was significant (correlation: P < or = 0.01, P = 0.13, P < or = 0.05; standard deviation: P < or = 0.01, P < or = 0.34, P < or = 0.05). For detecting renal artery stenosis, vessels within the renal sinus should be used for Doppler sampling.     

Echo-enhanced Doppler sonography of focal nodular hyperplasia of the liver.

Lesions of focal nodular hyperplasia are hypervascular, benign focal liver lesions whose differentiation from other focal liver lesions is of significant clinical relevance. The purpose of this study was to investigate the echo-enhancing agent SHU 508A (Levovist) in the evaluation of focal nodular hyperplasia with Doppler sonography. We examined 49 patients with 71 lesions of focal nodular hyperplasia in the liver with gray scale and power Doppler sonography. In all patients Levovist was administered intravenously in a concentration of 300 to 400 mg galactose per milliliter. Visualization of the feeding vessels and the vascularity of the lesions were evaluated, and the resistive indices in the feeders and the hepatic arteries were assessed. In comparison with unenhanced power Doppler sonography, echo-enhanced power Doppler sonography yields a higher sensitivity in the detection of the feeding artery (97% versus 82%) in focal nodular hyperplasia and in the depiction of the radial vascular architecture in such lesions, especially those located in the left lobe of the liver. Lesions less than 3 cm in diameter do not consistently show a characteristic vascular architecture with echo-enhanced Doppler sonography. The resistive index of the tumor-feeding artery (mean, 0.51 +/- 0.09) is significantly (P < 0.0001) lower than that of the hepatic artery (mean, 0.65 +/- 0.06) and decreases as the size of the focal nodular hyperplasia increases. The administration of Levovist may improve the signal-to-noise ratio and thus visualization of the vascular architecture in focal nodular hyperplasia. Lesions located in the left lobe of the liver, which commonly are subject to disturbing motion artifacts in color Doppler sonography, will significantly benefit from the administration of Levovist. Echo-enhanced power Doppler sonography, however, is not capable of depicting a characteristic vascular pattern in small (< or = 3 cm) lesions of focal nodular hyperplasia that would guarantee a specific diagnosis.     

Ultrasound Shear Wave Elastography and Doppler Sonography to Assess the Effect of Hydration on Human Kidneys: A Preliminary Observation

To assess the feasibility of ultrasound imaging in depicting the changes in kidney size, hemodynamics and cortex viscoelasticity after hydration, we prospectively performed 2-D ultrasound shear wave elastography (SWE) and Doppler sonography of bilateral kidneys in 30 volunteers. Kidney length, cortex shear wave velocity (SWV), shear wave dispersion (SWD), interlobar artery peak systolic velocity (PSV), end-diastolic velocity (EDV) and resistive index (RI) were measured before and 60 min after with and without drinking water (1 L). The differences in kidney length, SWV, PSV, EDV and color pixel intensity before and after hydration were significant (p < 0.001), whereas these differences were not significant without hydration (p > 0.05). SWD and RI did not significantly differ with or without hydration. Inter- and intra-observer reliability in performing SWE and Doppler sonography was good. The use of Doppler sonography and ultrasound SWE to evaluate the effect of hydration on kidney size, hemodynamics and viscoelasticity seem to be feasible.     

Value of Doppler ultrasound in early detection of diabetic kidney disease: A systematic review and meta-analysis

The diagnosis of diabetic kidney disease can be delayed by limitations of primary biomarkers, which are microalbuminuria and estimated glomerular filtration rate. A number of Doppler ultrasound studies have associated an increase in intrarenal vascular resistance with the disease, which makes ultrasound a potential adjunct tool for early diagnosis. However, there is inadequate evidence to establish the effectiveness of including Doppler ultrasound in the diagnostic process. This systematic review was therefore conducted to determine the value of using Doppler ultrasound in early detection of diabetic kidney disease. Electronic literature searches were carried out in PubMed, CINAHL, Web of Science and EMBASE. All published prospective studies with records of intrarenal Doppler ultrasound, microalbuminuria and estimated glomerular filtration rate were obtained, and their relationship as parameters for diabetic kidney disease assessed. The meta-analysis of Doppler ultrasound versus albuminuria shows insignificant statistical difference between high resistive index of ≥ 0.7 and albuminuria, with the resistive index being the favoured parameter on the forest plot, making Doppler ultrasound highly comparable with albuminuria for the detection of diabetic kidney disease. Again, there was a significant statistical difference between high intrarenal resistive index of ≥ 0.7 and low estimated glomerular filtration rate of < 60 mL/min/1.73 m², with the resistive index being the favoured parameter on the forest plot, making Doppler ultrasound a superior parameter compared with estimated glomerular filtration rate for early detection of diabetic kidney disease.     

Color Doppler sonographic mapping of pulmonary lesions: evidence of dual arterial supply by spectral analysis.

OBJECTIVE: Within pulmonary lesions, flow signals of pulmonary arteries can be discriminated from flow signals of central bronchial and peripheral bronchial arteries on color Doppler sonography. Our aim was to evaluate the evidence and frequency of different arterial supplies of pleural-based pulmonary lesions using qualitative and quantitative color Doppler sonography. METHODS: Forty-one patients with roentgenologically confirmed pleural-based pulmonary lesions were investigated by color Doppler sonography. The following parameters were investigated: (1) qualitative color Doppler sonographic evidence of vascularization, (2) quantitative color Doppler sonographic evidence of arterial flow signals (resistive index and pulsatility index), and (3) number of different arterial flow signals in 1 lesion by color Doppler sonographic mapping. RESULTS: We found no vascularization in 5 patients, sparse vascularization in 21, and pronounced vascularization in 15. Quantitative color Doppler sonographic parameters were as follows: mean pulmonary artery resistive index, 1.2; mean central bronchial artery resistive index, 0.5; mean peripheral bronchial artery resistive index, 0.7; mean pulmonary artery pulsatility index, 7.8; mean central bronchial artery pulsatility index, 0.7; and mean peripheral bronchial artery pulsatility index, 1.6. There was a significant difference between all types of flow signals for resistive and pulsatility index values but not between pulmonary and peripheral bronchial arteries (P = .068). In 41 patients, 57 different arterial flow signals were determined; 19 (46%) of these patients had 2 or more different arterial flow signals in a lesion. There was no significant difference between benign and malignant lesions regarding the number of flow signals. CONCLUSIONS: Evidence of at least a dual arterial supply can be found on quantitative color Doppler sonography in almost 50% of pulmonary lesions. A single spectral analysis is not suitable for characterization of the arterial supply of pulmonary lesions.     

Three-dimensional power Doppler vascular sampling: a new method for predicting ovarian cancer in vascularized complex adnexal masses.

OBJECTIVE: The purpose of this study was to explore the role of a new concept ("vascular sampling") as a third step to discriminate benign and malignant lesions in B-mode and color Doppler sonographically suggestive adnexal masses. METHODS: Forty-five women (mean age, 52.3 years; range, 17-82 years) with the diagnosis of complex adnexal masses on B-mode sonography were evaluated using 3-dimensional power Doppler sonography. Four women had bilateral masses. After a morphologic reevaluation was done, color pulsed Doppler sonography was used to obtain flow velocity waveforms, and velocimetric indices were calculated (resistive index, pulsatility index, and peak systolic velocity). Thereafter, 3-dimensional power Doppler sonography was used to assess vascularization of highly suggestive areas (gross papillary projections, solid areas, and thick septations), meaning a focused assessment ("sampling") of a suggestive area of the tumor. With a virtual organ computer-aided analysis program, vascular indices (vascularization index, flow index, and vascular flow index) were automatically calculated. A definitive histologic diagnosis was obtained in each case. RESULTS: Forty masses (82%) were malignant and 9 (18%) were benign. Morphologic evaluation revealed 10 (20%) unilocular solid masses, 20 (41%) multilocular solid masses, and 19 (39%) mostly solid masses. Blood flow was found in all cases. Median vascularization index (15.5% versus 8.2%; P = .002), flow index (33.6 versus 20.8; P = .007), and vascular flow index (5.2 versus 2.3; P = .001) were significantly higher in malignant tumors. No differences were found in resistive index (0.43 versus 0.45; P = .770), pulsatility index (0.62 versus 0.65; P = .694), and peak systolic velocity (15.6 versus 12 cm/s; P = .162). CONCLUSIONS: Three-dimensional power Doppler vascular sampling seems to be a promising tool for predicting ovarian cancer in vascularized complex adnexal masses. It could be better than conventional color pulsed Doppler imaging.     

Influence of posture change on intrarenal arterial resistive index measurement

BACKGROUND: We investigated the influence of posture change on intrarenal arterial resistive index measurement in 80 subjects (38 male, 42 female). METHODS: Three interlobar arteries in the superior, middle, and inferior parts of the right kidney in each subject were examined by color Doppler ultrasound in two different positions (left lateral decubitus and supine). Based on the movement of the kidney caused by posture change, 23 subjects were classified as having a highly mobile kidney (group I) and the other 57 subjects were classified as not having a highly mobile kidney (group II). RESULTS: Fifty-eight kidneys (72.5%), 19 in group I (82.6%) and 39 in group II (68.4%), showed higher resistive index values in the lateral decubitus position than in the supine position. The influence of posture change on resistive index measurement was significant ( p < 0.001 for all subjects, p < 0.01 for group I, p < 0.05 for group II). The ranges of resistive index differences caused by posture change were 0-0.13 for group I and 0-0.11 for group II. The difference in resistive index caused by posture change was not significant between groups. CONCLUSION: Posture change is a potential confounding factor for intrarenal resistive index measurement.     

Do ultrasonic contrast agents artificially increase maximum Doppler shift? In vivo study of human common carotid arteries.

The aim of this study was to establish whether an increase of maximum Doppler shift occurs in the human common carotid artery after the administration of Levovist, an ultrasonographic echo enhancer. Twenty common carotid arteries of 10 patients were examined. Spectral Doppler waveform examinations were performed before and after administration of Levovist using an Acuson 128 XP 10 and a 7.0 MHz transducer probe. Time averaged mean velocity, peak velocity, maximum Doppler shift, and spectral Doppler indices (pulsatility index, resistive index, systolic-diastolic ratio) were assessed. No significant changes in any of the measured parameters, including maximum Doppler shifts, peak velocity (P = 0.35, Wilcoxon rank sum test), pulsatility indices (P = 0.70), resistive indices (P = 0.98), or other spectral indices, were found. We conclude that an increase in Doppler shift does not inevitably occur after the administration of a signal enhancer when examining the human common carotid artery.     

Doppler sonography of the inferior mesenteric artery: a preliminary study.

The purposes of this study were to look for the inferior mesenteric artery in patients undergoing abdominal sonography, to determine in what percentage of patients it is visible, and to characterize Doppler flow patterns of the inferior mesenteric artery in fasting patients without intestinal vascular disease. The inferior mesenteric artery was sought in 100 consecutive fasting adults (mean age, 54 years; 63 women, 37 men), as follows: the infrarenal aorta was scanned in a transverse plane; the origin of the inferior mesenteric artery was identified on the left anterolateral surface of the aorta; the inferior mesenteric artery was then traced caudally along the left side of the aorta. The inferior mesenteric artery and the superior mesenteric artery were studied with Doppler sonography in 50 different subjects without clinical or Doppler sonographic evidence of abdominal vascular disease (mean age, 44.9 years; 17 men, 33 women). Pulsed Doppler samples were taken within the inferior mesenteric artery in sagittal planes. The resistive index was calculated from the superior mesenteric artery and the inferior mesenteric artery. The inferior mesenteric artery was detected in all but eight patients (92%). In seven patients obesity prevented visualization. The eighth patient had undergone abdominal surgery on the previous day, limiting the sonographic examination. The diastolic flow in the inferior mesenteric artery was less than that in the superior mesenteric artery in all patients. The resistive index was 0.959 +/- 0.045 in the inferior mesenteric artery and 0.856 +/- 0.046 in the superior mesenteric artery (P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)     

多普勒超声诊断急性输尿管梗阻的实验研究

本研究利用多普勒超声对８例左侧输尿管结扎与８例正常对照家犬在术后２４小时内行双肾内动脉及肾脏超声（ＵＳ）观测，测取双肾内动脉阻力指数（ＲＩ），并与ＵＳ结果对比。结果表明，实验组梗阻侧肾ＲＩ在输尿管梗阻后８小时开始上升，且显著高于对照组肾ＲＩ（Ｐ＜０．００１），实验组双肾ＲＩ差值（＞０．１）显著高于对照组双肾ＲＩ差值（＜０．１）（Ｐ＜０．００１），在输尿管梗阻后８小时，实验组健侧肾ＲＩ显著低于对照组及术前ＲＩ（Ｐ＜０．００１），有１例家犬ＲＩ升高时ＵＳ未显示集合区扩张（１３％）。我们认为多普勒超声对诊断急性输尿管梗阻有重要意义。