9 patients received the angiography found 10 renal arterial stenosid or obstruction among 100 patients during 1/1995 - 3/1998. The results showed that the level of the arterial stenosid by ultrasound was quite suitable with this by the angiography. All patients received an operation for connecting the renal artery or thrombosis removal were postoperative examined by the color ultrasound Doppler and long-term monitored.
Ultrasonography ; Renal Artery Obstruction

Nowadays, diagnosis of renal artery stenosis by renal angiography is gradually supplied by techniques of noninterference, include: Colour Doppler ultrasound, CT angiography in helical with MIP, magnetic resonance angiography. In the all, the colour Doppler ultrasound is the best method for diagnosis of renal artery atenosis in the near future
Ultrasonography ; Renal Artery Obstruction

The study was conducted from January 1996 to March 1998 in B¹ch Mai Hospital. Participants were 100 hypertensive patients who have suspected renal artery stenosis after screening using clinical examination. Age of participants ranged from 9 to 50. All participants underwent colour ultrasonography and measurements are evaluated. Results showed that among 18 renal arteries of 9 patients, who received ultrasonography and angiography, 10 arteries were stenosed or occluded. 1 renal artery had suspected stenosis showed in ultrasonography, but not in angiography. So Doppler ultrasonography produced 1 false positive result, 10 true positive results, 7 true negative results and none false negative. This procedure gave high 100% of sensivity, 87.5% of speciality, positive prediction value is 90.9%, negative prediction value is 100%. Doppler ultrasonography can be used for post-operative examination and for patient following-up
Renal Artery Obstruction ; Ultrasonography

The measurement of parameter of the aorta, renal left and right arteries of 40 normal people with ages of 20 - 40 has shown that the parameters of indicators of Doppler in the normal Vietnamese were an insignificant different from these in normal English, French. The parameters of Vp, Vd and Vm were different between the left and right, and between proximal and distal position of the renal artery. The parameters of ACT, RI, PI, ATR, RAR were not different between right and left as well as position of the renal artery
ultrasonography ; Renal Artery

The author studied 104 renal arteries of healthy people and 106 renal arteries of hypertension patients by color Duplex ultrasound and DSA, and then compared these findings. Results: color Duplex ultrasound can detect 96% of renal arteries. Ultrasound can be used to study renal arteries with 3 positions gave high rate of detection: anterior abdominal position 96%, right subcostal position 94%, and translumbar position 98%
ultrasonography ; Renal Artery ; Hypertension ; diagnosis

In stenosis of a segmental branch or among multiple renal arteries, Doppler sampling of intrarenal arteries in the upper, mid and lower poles demonstrates strikingly different waveform patterns that might otherwise be overlooked. We report a case of segmental branch renal artery stenosis in which a pulsus parvus et tardus waveform was observed in a segmental branch of a renal artery. In this case, systematic analysis of Doppler waveforms of intrarenal arteries at more than three different locations facilitated a rapid and confident diagnosis of seg-mental branch renal artery stenosis.
Adult ; Case Report ; Female ; Human ; Renal Artery/ultrasonography ; Renal Artery Obstruction/*ultrasonography ; Support, Non-U.S. Gov't ; *Ultrasonography, Doppler

PURPOSE: The goal of this study was to evaluate the effect of vascular compliance, resistance, and pulse rate on the resistive index (RI) by using an electrical circuit model to simulate renal blood flow. METHODS: In order to analyze the renal arterial Doppler waveform, we modeled the renal blood-flow circuit with an equivalent simple electrical circuit containing resistance, inductance, and capacitance. The relationships among the impedance, resistance, and compliance of the circuit were derived from well-known equations, including Kirchhoff's current law for alternating current circuits. Simulated velocity-time profiles for pulsatile flow were generated using Mathematica (Wolfram Research) and the influence of resistance, compliance, and pulse rate on waveforms and the RI was evaluated. RESULTS: Resistance and compliance were found to alter the waveforms independently. The impedance of the circuit increased with increasing proximal compliance, proximal resistance, and distal resistance. The impedance decreased with increasing distal compliance. The RI of the circuit decreased with increasing proximal compliance and resistance. The RI increased with increasing distal compliance and resistance. No positive correlation between impedance and the RI was found. Pulse rate was found to be an extrinsic factor that also influenced the RI. CONCLUSION: This simulation study using an electrical circuit model led to a better understanding of the renal arterial Doppler waveform and the RI, which may be useful for interpreting Doppler findings in various clinical settings.
Compliance ; Computer Simulation ; Electric Impedance ; Heart Rate ; Jurisprudence ; Pulsatile Flow ; Renal Artery ; Renal Circulation ; Ultrasonography, Doppler

PURPOSE: Incorrect positioning of umbilical artery catheter (UAC) results in an increased incidence of complications and erroneous pressure measurements. We radiologically localized major aortic branches and calculated the length of catheter from umbilicus to celiac artery, renal artery and aortic bifurcation for optimal positioning of UAC. To determine the neonatal body measurement that best predicts optimal UAC lengths, we studied three commonly used parameters-birth weight (BW), total body length (TBL) and shoulder-umbilicus length (SUL). METHODS: Fifty one high type of UAC were routinely identified by sonographic scanning from the epigastrium in longitudinal projection and 42 low type of UAC from the flank in coronal projection. The distances from the catheter tip to the celiac artery, the renal artery and to the aortic bifurcation were measured by electronic calipers and were compared with the length of the catheter from umbilicus to the tip on the chest anteroposterior radiograph. RESULTS: The celiac arteries originated from T10-T12, renal arteries Ll-L2, and aortic bifurcations L3-L5. There was positive correlation between BW, TBL or SUL and the length of catheter to the celiac artery (r2=0.476, 0.749 or 0.753), to the renal artery (r2= 0.785, 0.847 or 0.720), and to the aortic bifurcation (r2=0.714, 0.809 or 0.747). CONCLUSION: Although any one of the three parameters can be used clinically, we prefer the TBL and SUL parameters for its reliability and usefulness in emergency settings. The use of a new distribution plot of origins of major branches and regression equations for calculation of the lengths may help deciding the optimal position of UAC.
Catheters* ; Celiac Artery ; Emergencies ; Humans ; Incidence ; Infant, Newborn* ; Renal Artery ; Thorax ; Ultrasonography* ; Umbilical Arteries* ; Umbilicus

PURPOSE: This study was performed to observe the utilization of ultrasonography in locating the position of UAC and to compare the position with anatomical landmarks seen on radiography. METHODS: Optimal position is when the catheter tip is located between T6-T10 or L3-L5 by anteroposterior radiography (AP-R) and above the diaphragm by cross-table lateral radiography (CTL-R). Ultrasonographic studies used a Hewlett Packard Sonos 1000 with 5 MHz scanner, the distance from the catheter tip to the origin of the celiac artery in high position and the distance from the catheter tip to the origin of the renal arteries and to the aortic bifurcation in low position were measured. RESULTS: In 23 of 36 newborns, high type UAC was properly positioned by AP-R, but ultrasonographic examination showed that 3 UAC were malpositioned under 5mm above the origin of the celiac artery. Detection of properly positioned UAC by AP-R had a sensitivity of 80% and specificity of 72.7%. In 19 of 28 newborns, high type UAC was properly positioned by CTL-R, but ultrasonographic examination showed that 2 UAC were malpositioned under 5mm above the origin of the celiac artery. Detection of properly positioned UAC by CTL-R had a sensitivity of 81% and specificity of 71.4%. In 15 of 20 newborns, low type UAC was properly positioned by AP-R, and ultrasonographic examination showed that 1 UAC was malpositioned below the aortic bifurcation. Detection of properly localized UAC by AP-R had a sensitivity of 77.8% and specificity of 50%. CONCLUSION: Ultrasonographic catheter localization is a noninvasive technique that uses no ionizing radiation and has no known deterimental side effects, and allows direct visualization of the pertinent vascular anatomy, providing more information than traditional radiography.
Catheters* ; Celiac Artery ; Diaphragm ; Humans ; Infant, Newborn ; Radiation, Ionizing ; Radiography* ; Renal Artery ; Sensitivity and Specificity ; Ultrasonography*

BACKGROUNDSome individuals have multiple renal arteries. Severe stenosis in one of the arteries may cause refractory hypertension. The detection of stenosis within one of the multiple renal arteries usually required invasive procedures, such as computed tomographic angiography (CTA) and magnetic resonance angiography (MRA). This study reported the application of color Doppler sonography (CDS) in the detection of severe stenosis in one of the multiple arteries.

METHODSPatients with multiple renal arteries and one of the arteries with severe stenosis were retrospectively studied. Peak systolic velocities (PSV) of renal arteries and the intrarenal CDS patterns were collected and compared. The diagnosis was confirmed by digital subtraction angiography (DSA).

RESULTSFour children with multiple renal arteries and one of the arteries with stenosis were investigated. They were admitted due to refractory hypertension. CDS screening identified two renal arteries in one kidney of each patient with one of the two renal arteries having stenosis > 70%. The PSV of the stenosed arteries were much higher, and the intrarenal CDS patterns supplied by the stenosed arteries changed into T-P patterns.

CONCLUSIONNon-invasive CDS technology may be a useful method to identify severe stenosis in one of multiple renal arteries in young patients.

Adolescent ; Child ; Female ; Humans ; Male ; Renal Artery ; abnormalities ; Renal Artery Obstruction ; diagnostic imaging ; Ultrasonography, Doppler, Color ; methods