Usefulness Of Resistive Index Research Articles

Immediate complications of hypoxic-ischemic encephalopathy in term neonates with resistive index as prognostic factor

Background: Hypoxemia, a decreased arterial concentration of oxygen, frequently results in hypoxia, or decreased oxygenation to cells or organs. Hypoxic-ischemic encephalopathy (HIE) is a leading cause of neonatal brain injury, morbidity, and mortality globally. In the developed world, incidence is estimated at 1-8 per 1,000 live births, and in the developing world, estimates are as high as 26 per 1,000. The objective of the study is use of resistive index as prognostic factor for immediate neonatal outcome by Doppler ultrasound in birth asphyxia.Methods: 50 babies were subjected to neurosonogram between 12-24 hours of life admitted to tertiary care centre. Resistive index (RI) was measured for all enrolled neonates within 24 hours of life using pulse wave Doppler ultrasound. RI was calculated as: , where S=peak systolic velocity and D=end diastolic velocity. RI was measured for all enrolled neonates within 24 hours of life using pulse wave Doppler ultrasound with 3.5 MHz transducer. RI was calculated as: . A RI between 0.56 and 0.90 was considered normal and neonates were classified as having either normal or abnormal RI.Results: The study conducted states that the mean age taken is 17.12 hours with a p value of 0.82 and the cord pH of mean 6.88 with p value of 0.70 which is suggestive of adverse outcomes in birth asphyxiated babies while the resistive index of cerebral arteries and renal arteries is 0.66 with p value of 0.115 which is statistically significant. The lesser the resistive indices the more severe is the adverse outcome.Conclusions: The immediate consequences of HIE like death, seizures, acute kidney injury which are the parameters in my study has a positive co relation with resistive indices of the cerebral arteries and renal arteries measures respectively.

Usefulness of resistive index on spectral Doppler ultrasonography in the detection of renal cell carcinoma in patients with end-stage renal disease.

Purpose:The aim of this study was to explore the usefulness of the resistive index (RI) on spectral Doppler ultrasonography (US) in the detection of renal cell carcinoma (RCC) in patients with end-stage renal disease (ESRD).Methods:Seventeen ESRD patients with kidneys in which renal masses were suspected in routine US were subjected. They underwent computed tomography scans and additional Doppler US for the characterization of the detected lesions. All underwent radical nephrectomy with the suspicion of RCC. Fourteen patients finally were included. RI measurements were conducted in the region of the suspected renal mass and the background renal parenchyma. The intraclass correlation coefficient was used to assess the reproducibility of the RI measurement. A paired t-test was used to compare the RI values between the renal mass and the background renal parenchyma (P<0.05).Results:The RI values measured at the RCCs were significantly lower than those measured at the background renal parenchyma (0.41-0.65 vs. 0.75-0.89; P<0.001). The intrareader reproducibility proved to be excellent and good for the renal masses and the parenchyma, respectively (P<0.001).Conclusion:RI on spectral Doppler US is useful in detecting RCC in patients with ESRD. The RI values measured at the RCCs were significantly lower than those measured at the background renal parenchyma.

Role of Ultrasound in Managing Rheumatoid Arthritis

Ultrasound (US) is a valid and reliable imaging tool for evaluation of joint and tendon inflammation as well as cartilage and erosions in patients with rheumatoid arthritis (RA). Synovitis is usually scored semiquantitatively for both gray scale synovitis and power Doppler activity, and use of an atlas for US scoring has shown excellent reliability. Several scores are shown to be responsive to medical treatment, but the optimal joint/tendon score is to be explored. Doppler activity may be quantified by use of pixel counts and flow may be examined by use of resistive index. US-guided injections are better tolerated and have increased efficacy, as compared with palpation guidance, and should thus be included in rheumatologic practice. Different methods such as three-dimensional US, contrast-enhanced US and fusion imaging methods are all possible US approaches that may be used in treatment of RA patients in the future.

Use of resistance index for the diagnosis of breast tumours

Aim: To determine whether the resistance index (RI) contributes to the differential diagnosis of breast masses. Patients and methods: In 56 breast tumours colour-coded Doppler sonography was performed and their resistance indices calculated from their spectral Doppler tracings. Histologic evaluation was obtained by excision biopsy. Results: In seven of 28 benign tumours (25%) no lesion was seen on ultrasound. In another seven benign tumours, no intratumoral vessels were demonstrated. The resistance index of the remaining 14 lesions (50%) varied between 0.5 and 0.75 with a mean value of 0.62 (standard deviation 0.08). Ultrasound missed one of 28 carcinomas (3.5%) and in one other tumour (3.5%) no flow was demonstrable. The resistance index of 26 malignant tumours varied between 0.56 and 0.9 with a mean value of 0.7 (standard deviation 0.08). Conclusion: Breast malignancies have higher resistance indices with a wider range as assessed by colour-coded Doppler ultrasound (81% exceed 0.6) than do benign lesions. Due to the considerable overlap of the range of the resistance index, the measurements in any single patient may not be diagnostic. The absence of flow does not definitively exclude malignancy.