Use of ultrasound elastometry in the diagnosis of pancreatic fibrosis in chronic pancreatitis

Objective. To evaluate the role of EC in the diagnosis of pancreatic fibrosis in CP.

Materials and methods. In Vitebsk Regional Clinical Hospital from 2019 to 2021. in 18 patients with various forms and complications of chronic pancreatitis, a complex correlational diagnosis of pancreatic fibrosis was performed using UE, CT and morphological examination of intraoperative biopsy specimens.

UE the study was performed with an ultrasound transducer with a frequency of 3,5—7,0 MHz in the В-mode using the transabdominal shear wave method in the Shear Wave Elastography (SWE) mode on the GE HEALTHCARE apparatus. The tissue stiffness was assessed on the basis of Young’s modulus of elasticity in the SWE mode according to the nature of the distribution of color mapping in the blue-cyan-yellow-red scale.

Histological examination of intraoperative biopsy specimens is carried out as follows: аfter fixation in 10% neutral formalin solution and standard histological wiring, serial sections were stained with hematoxylin and eosin. After automated staining, the preparations were washed under running water, dehydrated in alcohol, and cleared in carbol-xylene and xylene. The sections were then embedded in Biomount medium and covered with a coverslip. Using light microscopy at x100, x200, x400 magnification, changes in the pancreatic tissue were assessed. Histopreparations were photographed using a computer image analysis system (a Leica DM 2000 microscope with a digital camera and the Leica Aplication Suite, Version 3.6.0 licensed program).

The criteria for assessing the fibrous transformation of the pancreatic parenchyma at CT were: the density of the pancreatic tissue according to Housefield.

Computer morphometry was performed using ImageJ I.52p image processing software.

Results. During a morphological study of biopsy specimens, fibrous changes in the pancreas were identified in 18 cases.

The data obtained after performing the UE correlated with the data of the morphological examination of biopsy specimens. In a comparative assessment of qualitative indicators of the degree of fibrous transformation of the pancreatic parenchyma based on the results of ultrasound, CT and morphology, the sensitivity was 86 %, the specificity was 88 %, and the probability of a correct diagnosis was 81%

Based on the results obtained, we have developed a classification of the degree of density (fibrosis) of pancreatic tissue:

Blue and light blue colors — 0—6,2 kPa — fabric of normal density;

Yellow color— TP—10,9 kPa— medium density fabric;

Red color— 10,9 kPa or more — dense fabric.

Conclusions. Thus, in a comparative assessment of fibrotic changes in the pancreatic parenchyma in CP, according to the results of ultrasound, CT and morphological studies, a high diagnostic efficiency of UE was established and can be used as a non-invasive method for assessing fibrotic changes in the pancreatic tiss

ue.

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