Does the Measurement of the Difference of Resistive Indexes in Spleen and Kidney Allow a Selective Assessment of Chronic Kidney Injury?

Abstract

In patients with chronic kidney disease, renal RIs do not selectively indicate organ damage, but also mirror systemic vascular disease. The authors introduced DI-RISK as a potential US marker that may more specifically reflect kidney damage.

Renal Resistive Index

“…This has been examined in patients with chronic kidney disease and in transplant recipients (Figure 2), in whom renal RI correlated with splenic RI. 24,25 In patients with chronic kidney disease, renal and splenic RI showed similar correlations with a host of cardiovascular parameters including carotid intimal-medial thickness and left ventricular hypertrophy. 25 The authors proposed the difference between renal and splenic RI as a more specific marker of renal disease by accounting for systemic effects on renal RI, 25 but the correlation with estimated glomerular filtration rate was weak (0.19).…”

External Validation of the Kidney Failure Risk Equation and Re-Calibration with Addition of Ultrasound Parameters

“…If this holds true, the difference of resistive indices in spleen and kidney (DI-RISK) will eliminate extrarenal determinants and thus yield a more organ-specific ultrasound marker. Cross-sectional studies among healthy volunteers and CARE FOR HOMe study participants seemingly supported our approach, because DI-RISK measurements were independently associated with renal function, but not with markers of extrarenal vascular disease (19).…”

“…However, we and others have objected to the idea that RRI is an organ-specific marker: in clinical studies, RRI is more closely associated with cardiovascular risk factors and with markers of systemic atherosclerosis than with functional and structural renal markers (19,(27)(28)(29). Additionally, experimental data support the assumption that RRI is more strongly associated with systemic vascular changes than with local renal damage (30)(31)(32).…”

“…Two cohorts were used: (1) The Cardiovascular and Renal Outcome in CKD 2-4 Patients-The Fourth Homburg evaluation (CARE FOR HOMe) study recruited patients who visited the outpatient department of Saarland University Medical Center between September 2008 and November 2012 with CKD (GFR categories 2-4) (4,19,20). Excluded were pregnant women, allograft recipients, patients aged ,18 years, and those who were HIV-positive, with clinically apparent infections, active malignancy and/ or acute kidney injury (2).…”

“…A detailed description of ultrasound studies applied in both cohorts has been published previously (12,19). Briefly, in CARE FOR HOMe, ultrasound was performed with a Sequoia C512 unit (Acuson, Thousand Oaks, CA), using a vector probe (model 4V1; 1-4 MHz, Acuson) by trained sonographers who were supervised by a single nephrologist with long-term experience in ultrasound studies.…”