Vloga ultrazvočne preiskave s kontrastnim sredstvom in elastografije pri ugotavljanju okvare presajene ledvice

Vičič, Eva (author), Ključevšek, Damjana (mentor), Arnol, Miha (comentor)

Namen in hipoteze: Opredeliti vlogo ultrazvočne preiskave z ultrazvočnim kontrastnim sredstvom (UZ-KS) in dvodimenzionalne elastografije s strižnimi valovi (2D-ESV) pri ugotavljanju okvare presajene ledvice. Preverjali smo tri hipoteze. (1) Vrednosti parametrov UZ-KS presajene ledvice v bolusni tehniki so statistično značilno povezane s histomorfološko okvaro ledvice, ocenjeno po Banffskih merilih. (2) Vrednosti 2D-ESV presajene ledvice so statistično značilno povezane s histomorfološko okvaro ledvice, ocenjeno po Banffskih merilih. (3) V primeru, da so preiskovane vrednosti parametrov UZ-KS in 2D-ESV normalne, lahko trdimo, da v presajeni ledvici ni prišlo do klinično pomembne histomorfološke okvare. Metode: 64 preiskovancev je bilo vključenih v prospektivno opazovalno raziskavo. Pri vseh preiskovancih smo odvzeli kri za laboratorijske preiskave, opravili dinamični UZ-KS s kvantifikacijo pretoka presajene ledvice, 2D-ESV in ledvično biopsijo. Rezultati: 28 preiskovancev je imelo z biopsijo ugotovljene minimalne histomorfološke spremembe presadka (skupina MS), 36 pa je imelo klinično pomembno okvaro (KPO), od teh 12 rejekcijske spremembe (RS) in 24 nerejekcijske spremembe (NRS). Kvantifikacija pretoka v presajeni ledvici je pokazala, da je čas do maksimalnega signala (TTP) med sredico in skorjo (?TTPm-c) v skupinah RS in NRS značilno krajši (5,77 in 5,92 s) v primerjavi s skupino MS (7,94 s). Poleg tega je bil TTP v sredici v skupini RS značilno krajši (27,75 s) v primerjavi s skupino MS (32,26 s). Tudi v podskupini preiskovancev 1 leto po presaditvi je bil ?TTPm-c krajši v skupini KPO (5,67 s) v primerjavi s skupino MS (7,67 s). Ploščina pod krivuljo ROC za ?TTPm-c je bila 0,69 v skupini vseh preiskovancev in 0,71 v skupini preiskovancev z biopsijo presajene ledvice po enem letu. V analizo 2D-ESV je bilo vključenih 53 preiskovancev, od katerih je 42 imelo klinično nepomembno in 11 klinično pomembno fibrozo. Vrednosti 2D-ESV se niso razlikovale med obema skupinama, so pa bile vrednosti v skorji statistično značilno nižje pri preiskovancih z višjim indeksom telesne mase (ITM ? 25 kg/m2). Zaključki: Kvantifikacija pretoka presajene ledvice z UZ-KS je pokazala, da je ?TTPm-c obetajoč napovedni parameter klinično pomembne okvare presadka, saj je bil značilno krajši v skupinah s KPO v primerjavi s skupino MS. 2D-ESV v naši raziskavi ni razlikovala med klinično pomembno in nepomembno fibrozo presadka. Vrednosti 2D-ESV v skorji so statistično značilno nižje pri preiskovancih z ITM ? 25 kg/m2.

• Language: Slovenian
• Keywords: ultrazvok, kvantifikacija, ultrazvočno kontrastno sredstvo, krivulja čas-intenzivnost, elastografija, presaditev ledvice, okvara presajene ledvice, fibroza
• Work type: Doctoral dissertation
• Organization: MF - Faculty of Medicine
• Year: 2022
• PID: 20.500.12556/RUL-137905
• COBISS.SI-ID: 124950019
• Publication date in RUL: 05.07.2022

Secondary language

• Language: English
• Title: The role of contrast enhanced ultrasound and elastography for the assessment ob kidney allograft dysfunction

Abstract

Objective and hypotheses: To assess the role of quantitative contrast-enhanced ultrasound (CEUS) and two-dimensional shear-wave elastography (2D-SWE) for the differentiation of kidney allografts with significant histopathological injury. Three hypotheses were explored. (1) Quantitative CEUS parameters of kidney allografts are associated with histopathological changes based on the Banff criteria. (2) 2D-SWE values of kidney allografts are associated with histopathological changes based on the Banff criteria. (3) When quantitative CEUS parameters and 2D-SWE values of kidney allografts are normal, we can conclude that no significant histopathological injury occurred in the kidney allograft. Methods: 64 patients were enrolled in this prospective observational study. Biopsies were performed following CEUS, 2D-SWE, and blood examination. Results: 28 biopsy specimens had minimal changes (MC group), while 36 had significant injury (SI group). Of these, 12 had rejection (RI group) and 24 non-rejection injury (NRI group). In RI and NRI groups, temporal difference in time to peak (TTP) between medulla and cortex (ΔTTPm-c) was significantly shorter compared to the MC group (5.77, 5.92, and 7.94 s, respectively). Additionally, RI group had significantly shorter medullary TTP compared to the MC group (27.75 vs. 32.26 s, respectively). In a subset of 41 patients with protocol biopsy at 1-year post-transplant, ΔTTPm-c was significantly shorter in the SI compared to the MC group (5.67 vs. 7.67 s, respectively). Area under receiver operating characteristic curves (AUROCs) for ΔTTPm-c was 0.69 in all patients and 0.71 in patients with protocol biopsy. 53 patients were included in the 2D-SWE analysis. Of these, 42 had biopsy proven clinically insignificant fibrotic changes (IF group) and 11 had clinically significant fibrotic changes (SF group). 2D-SWE values did not differ between the two groups. However, patients with higher body mass index (BMI 䁥 25 kg/m2) had significantly lower cortical 2D-SWE values (16,78 kPa vs 19,22 kPa, respectively). Conclusions: RI and NRI groups had shorter ΔTTPm-c compared to the MC group. AUROCs for both patient groups were good, making ΔTTPm-c a promising CEUS parameter for distinguishing patients with significant histopathological injury. 2D-SWE could not differentiate between patients with clinically significant and clinically insignificant fibrotic changes. 2D-SWE values were significantly lower in patients with BMI 䁥 25 kg/m2.

• Keywords: dynamic contrast-enhanced ultrasound, quantification, time-intensity curve, elastography, kidney transplantation, kidney allograft injury, fibrosis