Jeong Woo Kim MD, Presenter: Nothing to Disclose

Chang Hee Lee MD, Abstract Co-Author: Nothing to Disclose

Yang Shin Park MD, Abstract Co-Author: Nothing to Disclose

Jong Mee Lee, Abstract Co-Author: Nothing to Disclose

Jae Woong Choi MD, Abstract Co-Author: Nothing to Disclose

Kyeong Ah Kim MD, Abstract Co-Author: Nothing to Disclose

Cheol Min Park MD, Abstract Co-Author: Nothing to Disclose

To compare the index values made by combination of diffusion parameters between the “reflux” kidney and the “non-reflux” kidney and to evaluate the feasibility of IVIM DWI for predicting vesicoureteral reflux in children with urinary tract infection.

 This retrospective study was approved by our institutional review board and the requirement for informed consent was waived. 83 kidneys from 57 pediatric patients with UTI were included. Kidneys were classified into two groups, “reflux” kidney and “non-reflux” kidney according to the results of voiding cystourethrography(VCUG). DWI using IVIM was performed with eight b factors. ADC, true diffusion coefficient(D), pseudo-diffusion coefficient(D*), and perfusion fraction(f) in the renal pelvises of both “reflux” and “non-reflux” kidneys were measured five times by a radiologist and compared between the two groups. We used the median value of the measurements as the representative value of the measured parameter. Additionally, four indices(D*/ADC, D*/D, f/ADC and f/D) were developed by combining diffusion parameters and four indices were also calculated. ROC curve analyses were performed for each index to evaluate their diagnostic performance and to identify optimal cut-off value to predict the VUR.  

 VURs were detected in 21 kidneys on VCUG. Among ADC- and IVIM-derived parameters, ADC and D were significantly lower in the renal pelvis of the “reflux” kidney than that of the “non-reflux” kidney while D* and f were significantly higher. (p = 0.037, 0.020, 0.010, and <0.001, respectively) Four indices(D*/ADC, D*/D, f/ADC, and f/D) were all significantly higher in the renal pelvis of the “reflux” kidney than that of the “non-reflux” kidney. (p = 0.022, 0.008, <0.001, and <0.001, respectively) In ROC curve analysis, f/D showed the highest AUC (Az = 0.813) with optimal cut-off value of 7.33 and corresponding sensitivity and specificity of 85.7 and 64.5%, respectively.

 Perfusion fraction(f) was significantly higher in the renal pelvis of the “reflux” kidney than that of the “non-reflux” kidney. Our new index, f/D could detect VUR with relatively high sensitivity. In the future, IVIM DWI which is both radiation and contrast media-free, can be used for detecting VUR in children with UTI and further replace VCUG.

Index of VUR in IVIM DW-MRI which is both radiation and contrast media-free can be easily calculated and may be used prior to VCUG study.

Kim, J, Lee, C, Park, Y, Lee, J, Choi, J, Kim, K, Park, C, Predictable Index of Vesicoureteral Reflux (VUR) in Children with Urinary Tract Infection (UTI): Usefulness of Intravoxel Incoherent Motion (IVIM) Diffusion Weighted Magnetic Resonance Imaging (DW-MRI).  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14008706.html