Keywords:
Kidney, Abdomen, Ultrasound, Elastography, Diagnostic procedure, Pathology, Tissue characterisation
Authors:
G. Cardenas, D. I. Herquinigo, P. Romanque, A. Inostroza, L. Toro, I. Gacitua, M. Alvo, L. Michea, P. Segura; Santiago/CL
DOI:
10.26044/ecr2019/C-3712
Aims and objectives
Chronic kidney disease (CKD) is a global public health problem,
with a high rate of complications and expense.
CKD is defined as abnormalities of renal structure or function present for 3 months.
The term comprises a group of pathologies,
being a progressive and irreversible syndrome that begins asymptomatically,
leads to renal dysfunction,
and results finally in renal failure.
It is a common condition,
though is potentially treatable if diagnosed early.
The degree of renal fibrosis predicts the prognosis of CKD.
Several novel therapeutic strategies are being developed for fibrosis treatment.
Therefore,
it is imperative to accurately assess the degree of renal fibrosis noninvasively to identify those patients who can benefit from treatment.
Currently,
the gold standard for diagnosis of fibrosis is renal biopsy; however,
biopsy is an invasive procedure not exempt of risk and not optimal for repeat assessment of progression.
Acoustic Radiation Force Impulse (ARFI) elastography is a non-invasive method for the evaluation of tissue fibrosis using a mechanical pulse and an ultrasonic pulse to generate shear waves in tissue in order to measure its elasticity.
An ultrasound probe generates a focused strain pulse,
which can induce tissue deformation in the region of interest (ROI).
As a result,
shear waves are generated and subsequently propagate away from the ROI.
The same transducer monitors the propagation of the shear waves and displays their velocity (m/sec) on the screen.
Under the principle of ARFI,
compression of the organ parenchyma induces a smaller strain in firmer tissues than in softer ones,
with the propagation speed increasing with the severity of fibrosis (1).
ARFI is currently used to study liver fibrosis and it has been proposed to estimate kidney stiffness in several clinical scenarios,
including allograft study prior to transplant and CKD,
with variable results (2).
The aim of this study is to explore whether acoustic radiation force impulse (ARFI) imaging assessment of renal tissue stiffness may serve as a non-invasive biomarker in predicting the histologic presence of renal fibrosis.