Vivek Kishor Pargaonkar MBBS, Presenter: Nothing to Disclose

Sudhakar K, Abstract Co-Author: Nothing to Disclose

Prospective evaluation of diagnostic efficacy of acoustic radiation force impulse(ARFI) imaging to test the elasticity of renal parenchyma by measuring the shear wave velocity(SWV) which might be used to detect chronic kidney disease(CKD).

Fifty patients(age range 18-78yrs)with CKD were enrolled.Seventy three subjects(age range 18-71 yrs) without clinical, biochemical or ultrasound evidence of renal disease were also included & served as control group.An ARFI value, expressed as speed (m/s) of wave propagation through the tissue,was calculated for each patient by calculating the mean of values obtained in both kidneys.The results were compared with the subjects in the control group.The potential influencing factors & measurement reproducibility were evaluated.Correlations between SWV & laboratory tests were analyzed in CKD patients.Receiver-operating characteristic curve (ROC) analyses were performed to assess the diagnostic performance of ARFI.P value < 0.05 was considered statistically significant.

The mean SWV in control group was 2.93±0.58m/s,while 1.95±0.21,1.6±0.62,1.78±0.42,1.81±0.36 & 1.63±0.27m/s for stage 1,2,3,4 and 5 CKD patients respectively.The SWV was significantly higher for subjects in the control group compared with each stage in CKD patients.ARFI could not predict different stages of CKD.The SWV of subjects in control group differed significantly between men & women(2.82±0.61vs3.08±0.50m/s,P=0.025,n=73).In CKD group also, the mean SWV was higher in women compared to men(1.83±0.32vs.1.71±0.40m/s,P=0.35,n=50).The SWV showed negative correlation with age in the control as well as CKD group.The Inter-observer agreement expressed as intraclass coefficient correlation was 0.65(95% CI 0.4368-0.8054, P=< 0.05,n=40).In CKD patients, SWV correlated to e-GFR(r=0.113,p=0.435),urea nitrogen (r=-0.155,p=0.283), and creatinine (r=-0.240,p=0.093).ROC analyses indicated that the area under the ROC curve was 0.974 (95% CI: 0.952-0.997,P< 0.001).The cut-off value for predicting CKD was 1.85m/s(sensitivity 97.3 %,specificity 64%).

A significant difference in the SWV in the control group compared to CKD group by ARFI indicates its potential role in the detection of CKD.

ARFI can be a potential diagnostic,prognostic,simple,inexpensive,easily available,repeatable and accurate tool for non invasive evaluation of CKD.

Pargaonkar, V, K, S, Non Invasive Evaluation of Elasticity of Renal Parenchyma by Acoustic Radiation Force Impulse Imaging.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14002679.html