Correlation of resistive index of main renal artery and inter-lobar artery with degree of hydronephrosis.

Objective: To study the correlation of resistive index of main renal artery and inter-lobar artery with degree of hydronephrosis. For the purpose of this study data collection was carried through different research works conducted previously regarding hydronephrosis and its effects on the resistivity index of renal arteries. Study Design: Systemic Review. Setting: Radiology Research Section, University of Lahore. Period: September 2018 to May 2020. Material & Methods: Research was conducted with the help of keywords. One hundred and three articles were found at initial stage. A table was designed for data collection purpose including the information such as author of article, year of research, type of hydronephrosis, number of patients, and the resistive index of renal arteries. The data included both male and female patients of any age suffering from hydronephrosis of any origin and no area or time limitation was applied. Results: Pooling results of this systematic review depicts that the researchers conducted various researches addressing the cause of hydronephrosis, the effect of type of hydronephrosis on the resistive index, difference between resistivity index of obstructive and non-obstructive hydronephrosis, level of obstruction and its effect on RI of the renal artery, factors that influence RI other than renal in origin but not a single research conducted on human subject represents the correlation of different grades or degrees of hydronephrosis with either main renal artery or inter-lobar arteries. Out of 17 articles, 8 (47%) articles discuss the resistive index for both obstructive and non-obstructive hydronephrosis while remaining 9 (53%) articles discuss only the mean resistive index for the obstructed kidney. Conclusion: Although renal resistive index is the parameter which is influenced by a variety of other factors such as age of patient, plasma renin level, and the simultaneous presence of certain diseases like hypertension, cardiac diseases, diabetes mellitus, and renal disorders. The presence of any of these factors may rise the RI values even if there is no renal obstruction. Yet different research mainly shows that the values of RI are high i.e. >0.70 in case of obstructed kidney while generally the values of RI are <0.70 in case of none obstructed kidney.