EARLY POSTOPERATIVE ULTRASONOGRAPHY ROLE FOR AV FISTULA FAILURE PREDICTION IN HEMODIALYSIS PATIENTS.

Doppler ultrasonography is the main modality for imaging of hemodialysis AV ?stula as it is safe and non-invasive. This study is to measure the Arterio-venous (AV) ?stula blood ?ow during early postoperative period (0–7days) and assess its role in AV ?stula failure prediction. Doppler ultrasonography was used to estimate the blood ?ow in the AV ?stula of 50 patients at (0–7days) after the ?stula was made. The blood ?ow in ?stula during early postoperative period for ?stula failure was evaluated, and long term failure was predicted. Blood ?ow rates Method measured in arteriovenous ?stula created in upper extremity were measured in ?rst week and sixth week post-operative. Results After follow up evaluation out of 50 patients, 40 ?stulas considered to be matured; 10 considered failed. 30% failure were males and 70% were female. In early post operative period, cut off was set at 182 ml/min and the sensitivity of blood ?ow for prediction of ?stula failure is 98%, speci?city 90 %, PPV 95% and NPV 90%. Measurements of the AV ?stula blood Conclusion ?ow in proximal artery and draining vein with its diameter of lumen were noted in the early postoperative period has a role predicting AV ?stula failure. There is risk of failure if the blood ?ow less than 182 ml/min (day 0–7)

Objective Ultrasonographic Findings for Diagnosis of Liver Cirrhosis: A Comparison between Images Obtained with Low Frequency and High Frequency Probes on a PACS

PURPOSE: We aimed to evaluate objective ultrasonography (US) findings for diagnosis of liver cirrhosis and to correlate the utility between the use of the low frequency and high frequency probes for images analyzed on the picture archiving and communications system (PACS). MATERIALS AND METHODS: A total of 87 patients participated in the study; 19 patients that had a clinically proven normal liver and 68 patients that had biopsy-proven chronic liver disease were evaluated with the use of US for the status of the liver. Multiple variables such as a 'smooth surface,' 'irregular nodular surface,' 'homogeneous echotexture,' 'heterogeneous appearance mixed with hypoechoic and hyperechoic echotexture' and 'hypoechoic honeycomb like echotexture' were evaluated based on images obtained with the use of both low frequency and high frequency probes by two observers. The diagnoses obtained after US were correlated with the histological results using assess agreement as statistical method. The concordance rate was calculated to correlate the utility between the use of the low frequency and high frequency probes. RESULTS: An 'irregular nodular surface' showed high interobserver agreement for the diagnosis of liver cirrhosis on images obtained with the low frequency probe (kappa= 0.61). In addition, 'hypoechoic honeycomb' showed high interobserver agreement on images obtained with the high frequency probe (kappa= 0.60). The use of the low frequency probe was associated with more accuracy for the diagnosis of liver cirrhosis (73%). CONCLUSION: Objective US findings for the diagnosis of liver cirrhosis are an 'irregular nodular surface' on images obtained with use of a low frequency probe and a 'hypoechoic honeycomb' on images with use of a high frequency probe.

Detection of Segmental Branch Renal Artery Stenosis by Doppler US: A Case Report

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.

Vesicoureteral Reflux in Children: Comparison of Contrast - Enhanced Voiding Ultrasonography with Radiographic Voiding Cystourethrography: Preliminary Report

PURPOSE: To compare the usefulness of contrast-enhanced voiding ultrasonography(US) with that of radiographic voiding cystourethrography(VCUG) for the diagnosis of vesicoureteral reflux(VUR) in children. MATERIALS AND METHODS: Ninety-five kidney-ureter units of 47 patients referred for investigation of VUR underwent contrast-enhanced voiding US followed by radiographic VCUG. After baseline US examination of the urinary tract, residual urine in the bladder was drained through an inserted Foley catheter and the bladder was gravity filled at a height of 1 m with normal saline. A galactose-based, microbubble-containing echo-enhancing agent (Levovist; Schering, Berlin, Germany) was then administered. The amount of this was approximately 10% of bladder capacity, and VUR was diagnosed when microbubbles appeared in the ureter or pelvo-calyceal system. Using radiographic VCUG as a reference point, the accuracy with which contrast-enhanced voiding US detected VUR was calculated. RESULTS: In 87 of 95 kidney-ureter units (91.6%), the two methods showed similar results regarding the diagnosis or exclusion of VUR, which was detected by both in 12 units, but by neither in 75. VUR was shown to occur in a total of 20 units, but in eight of these by one method only. In two units, VUR detected by contrast-enhanced voiding US was not demonstrated by radiographic VCUG; in six units, the reverse was true. In the detection of VUR, contrast-enhanced voiding US showed a sensitivity of 66.7%, a specificity of 97.4%, a positive predictive value of 85.7%, and a negative predictive value of 92.6%. CONCLUSION: Contrast-enhanced voiding US is highly specific and has high positive and negative predictive values; its sensitivity, however, is not sufficiently high. The modality appears to be a useful diagnostic tool for the detection of VUR without exposure to ionizing radiation, though to be certain of its value, more experience of its use is first required.

Hepatic Hemangiomas: Spectrum of US Appearances on Gray-scale, Power Doppler, and Contrast-Enhanced US

Because US plays a key role in the initial evaluation of hepatic hemangiomas,knowledge of the entire spectrum of US appearances of these tumors is impor-tant. Most hemangiomas have a distinctive US appearance, and even with those with atypical appearances on conventional gray-scale US, specific diagnoses can be made using pulse-inversion harmonic US with contrast agents. In this essay,we review the spectrum of US appearances of hepatic hemangiomas on conven-tional gray-scale, power Doppler, and pulse-inversion harmonic US with contrast agents.

Sonographic Measurement of the Normal Gallbladder Size in the Korean Children

PURPOSE: While normal ultrasound measurement of the gallbladder (GB) is well established in adults, little attention has been focused on the normal measurement of the pediatric gallbladder. Normal parameters of the pediatric gallbladder may be significant to establish disease criteria, because some gallbladder diseases are only accompanied by changes in gallbladder size. We therefore wish to document the normal ultrasonic parameters of the pediatric gallbladder. MATERIAL AND METHOD: Five hundred and ten children with normal clinical findings andlaboratory data were included in this study. Ultrasonography was performed as a part of a health screening examination from the Dec. 1994 to Feb. 1995. Sonographic parameters included gallbladder size, volume, and clinical parameters such as age, height, weight, and body surface area were noted stastical significance between the sonographic and clinical parameters was analyzed through correlation and regression analysis. RESULTS: The patient age was ranged from 0 to 16 years, and the male : female ratio was 1.5 : 1. The longitudinal length of GB showed significant positive correlation with patient age(0.504), height(r=0.527), body weight(r=0.492), and bodsurface(r=0.522)(p <0.0001). The result of correlation analysis and regression analysis to the volume of gallbladder was also significant(r : 0.403-0.515, p <0.0001). The correlation analysis to the transverse length of gallbladder shows relatively low correlation coefficiency(r=0.290-0.398), however, the result of regresion analysis shows significance(p <0.0001). The range of mean value of gallbladder size according to age was 3.32(+/-0.73)-6.81(+/-1.05)cm in longitudinal length, 1.10(+/-0.37)-2.01(+/- 0.57)cm in transverse length, and2.46(+/-1.66)-15.35(+/-8.18)cm3 in volume. CONCLUSION: The mean values of pediatric gallbladder may be an useful index for the clinical application to vanior gallbladder disease.