Open AccessAssessment of renal allograft fibrosis by acoustic radiation force impulse quantification – a pilot study
Author(s) -
Syversveen Trygve,
Brabrand Knut,
Midtvedt Karsten,
Strøm Erik H.,
Hartmann Anders,
Jakobsen Jarl A.,
Berstad Audun E.
Publication year - 2011
Publication title -
transplant international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.998
H-Index - 82
eISSN - 1432-2277
pISSN - 0934-0874
DOI - 10.1111/j.1432-2277.2010.01165.x
Subject(s) - medicine , acoustic radiation force , chronic allograft nephropathy , fibrosis , intraclass correlation , renal transplant , urology , nuclear medicine , coefficient of variation , kidney transplantation , transplantation , radiology , ultrasound , psychometrics , clinical psychology , statistics , mathematics
Summary Chronic allograft nephropathy characterized by interstitial fibrosis and tubular atrophy is a major cause of renal transplant failure. Acoustic radiation force impulse (ARFI) quantification is a promising noninvasive method for assessing tissue stiffness. We evaluated if the method could reveal renal transplant fibrosis. In a prospective study, 30 adult renal transplant recipients were included. ARFI quantification, given as shear wave velocity (SWV), of the renal cortex was performed by two observers. SWV was compared to grade of fibrosis (0–3) in biopsies. The median SWV was 2.8 m/s (range: 1.6–3.6), 2.6 m/s (range: 1.8–3.5) and 2.5 m/s (range: 1.6–3) for grade 0 ( n = 12), 1 ( n = 10) and grades 2/3 ( n = 8) fibrosis respectively. SWV did not differ significantly in transplants without and with fibrosis (grade 0 vs. grade 1, P = 0.53 and grade 0 vs. grades 2/3, P = 0.11). The mean intraobserver coefficient of variation was 22% for observer 1 and 24% for observer 2. Interobserver agreement, expressed as intraclass correlation coefficient was 0.31 (95% CI: −0.03 to 0.60). This study does not support the use of ARFI quantification to assess low‐grade fibrosis in renal transplants. ARFI quantification in its present stage of development has also high intra‐ and interobserver variation in renal transplants.