Restricted diffusion MRI as a functional biomarker for the assessment of acute calcular upper urinary tract obstruction: initial experience

Heba M Abou El Atta,Haytham Shebel,Amal Abdelsattar Sakrana

doi:10.1186/s43055-021-00620-z

Abstract

BackgroundAcute renal obstruction due to stone is a prevalent scenario. The diffusion-weighted magnetic resonance imaging (DWI) of the kidneys provides a noninvasive information on renal function. Our objective is to prospectively assess the potential role of DWI to predict the signal changes of a kidney with acute calcular obstruction.ResultsChi-square and Fissure exact tests were used to assess the association of diffusion signal changes among patients and control groups. Cohen's Kappa test was run to determine the degree of agreement between the two radiologists. An independent sample t-test was performed to assess the significant difference among ADC values between the two groups. Restricted signals of the obstructed kidneys showed a statistically significant difference when compared with contralateral unobstructed kidney and control group with p value (0.001) and (0.01), respectively. Furthermore, there is a moderate agreement between the two radiologists K = 0.7, p = 0. 001. There is no statistically significant difference in ADC values when comparing the obstructed kidney and the contralateral unobstructed kidney of the patient group or with the control group p value (0.06) and (0.05), respectively.ConclusionRestricted signals of the obstructed kidney by DWI may be a helpful tool in diagnosing acute unilateral renal obstruction and can affect its management; however, it needs further validation by more studies.

Highlights

Acute renal obstruction due to stone is a prevalent scenario
An independent sample t-test was performed to assess the significant difference among apparent diffusion coefficient (ADC) values between the two groups
Forty patients referred from the urology department due to acute renal colic; 18 patients were included in this study based on our inclusion criteria All patients presented with renal colic had ureteric stones with an average mean diameter of 3 mm, range (2–5 mm), 12 cases in the distal ureter, and 6 cases in the proximal ureter

Summary

Introduction

Acute renal obstruction due to stone is a prevalent scenario. Our objective is to prospectively assess the potential role of DWI to predict the signal changes of a kidney with acute calcular obstruction. Acute obstructive uropathy is a commonly encountered condition occurring in a broad group population. One of the most prevalent causes of acute obstruction is a renal stone. Unilateral ureteral stone obstruction is affecting up to 15% of the population [1]. With this unilateral obstruction, serum creatinine is not affected unless the condition became bilateral. The kidneys have functional, morphological, and biochemical changes; these changes can lead to renal function loss. Early diagnosis and intervention can preserve the affected kidney [2, 3]

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