MO458: Superb Micro-Vascular Imaging: An Innovative Ultrasound Technique for Early Detecting of Renal Damage

Abstract

Abstract BACKGROUND AND AIMS Novel ultrasound (US) methods are required to assess qualitative alterations in renal tissue. Superb microvascular imaging (SMI) is an innovative US technique designed for imaging and better visualization of micro-vascularization unseen with color Doppler US. We assume that SMI will provide sufficient information regarding the severity of chronic kidney disease (CKD) and reflect renal histological alterations. To assess the early detection of kidney dysfunction and renal fibrosis capabilities of SMI imaging in comparison to the reference standard renal biopsy, in order to determine the usefulness of this approach in the early diagnosis of kidney dysfunction and renal fibrosis. METHOD The SMI was performed in patients (n = 52) with CKD stage 2–5, where some of them underwent biopsy-proven chronic renal dysfunction and fibrosis as part of the diagnosis and therapeutic judgment as needed. In addition, biochemical tests were performed in order to determine kidney function (BUN, Serum Creatinine), a urine collection test for the assessment of proteinuria and estimation of GFR by MDRD formula in patients with CKD of various severity and healthy controls (n = 17). In addition, all subjects underwent SMI US imaging, where vascularity is expressed as SMI index (low index reflects low vascularity/fibrosis and vice versa). RESULTS As expected, SMI vascular index was significantly lower in CKD patients as compared with healthy control (72.2 ± 12.9 versus 49.9 ± 16.7 %, P < 0.01). Interestingly, significant correlation between the SMI index and eGFR was found among the CKD patients (r = 0.56, P < 0.001). Similarly, a keen correlation was found between the SCr and SMI index of the diseased subjects (r = −0.54, P < 0.001). Among those who underwent renal biopsy, SMI index corresponds with the histological alterations such as fibrosis and CKD staging. CONCLUSION These findings show that SMI technique could be used due to its diagnostic capacity as a simple and practical method for evaluation of chronic renal histological changes and for the differentiation between CKD grades.