ARFI-Elastography: Clinical Applications in Diffuse or Nodular Thyroid Disease in Children and Adolescents

Research Article

Annals Thyroid Res. 2022; 8(1): 368-372.

ARFI-Elastography: Clinical Applications in Diffuse or Nodular Thyroid Disease in Children and Adolescents

Forster S¹ and Kunze CW²*

¹Departement of Plastic Surgery, University Hospital Rechts der Isar Munich, Germany

²Departement of Radiology, Section of Pediatric Radiology, University Hospital Halle (Saale), Martin-Luther-University Halle-Wittenberg, Germany

*Corresponding author: Kunze CW, Department of Radiology, Section of Pediatric Radiology, University Hospital Halle (Saale), Martin-Luther-University Halle-Wittenberg, Ernst-Grube-Str. 40, 06120 Halle (Saale), Germany

Received: February 14, 2022; Accepted: March 08, 2022; Published: March 15, 2022

Abstract

Elastography is a new step in diagnostic medicine. This technique makes it possible to measure stiffness of the thyroid gland.

Methods: In our study we conducted a cohort study of 141 children and adolescents aged 4-18 years with a suspected or known thyroid disease. Using a Siemens Acuson S3000 we examined thyroid glands both in longitudinal and cross-section.

Results: With increasing tissue changes in the B-Mode of the sonography, the ARFI Velocity increases. This resulted in the average speed of 1.61 +/- 0.36 m/s, however the results of the longitudinal measuring sections proved to be more reliable. It showed a difference between the left and the right lobe, which was particularly noticeable in the cross section measurement. With the increase of vascularization, the ARFI values were initially decreasing and ultimately increasing when vascularization was extreme. A reliable Assessment of clinical presentations using elastography is not possible. The volume of the thyroid gland, TSH, fT4 and sociodemographic factors such as gender, age, weight, height and BMI did not influence the ARFI values.

Conclusion: The ARFI elastography offers a wide range of gain in knowledge in the diagnostics of thyroid gland diseases in children and adolescents. Inflammation, dysfunction and structural diseases of the thyroid gland result in an increase of the ARFI values. During the examination, the examiner should pay attention the surrounding structures and its vascularization. Furthermore, the longitudinally position of the transductor should be carefully selected.

Keywords: Elastography; Thyroid; Children; Sonography

Abbreviations

BMI: Body Mass Index; Corr: Correlation; LQ: Cross-Sectional Sonography of the Left Lobe; LL: Longitudinal-Sectional Sonography of the Left Lobe; M: Mean Value; m/s: Meter Per Second; Max: Maximum; Min: Minimum; RQ: Cross-Sectional Sonography of the Right Lobe; RL: Longitudinal-Sectional Sonography of the Left Lobe; ROI: Region of Interest; SD: Standard Deviation; SF: Standard Error; Sig: Significance; SWE: Shear Wave Velocity; Var: Variance; Vs: Shear Wave Velocity

Introduction

The diagnosis and differentiation of thyroid parenchyma from diffuse or nodular thyroid disease can be challenging, especially in the early stages. Screening tools for thyroid dysfunction such as physical examination, laboratory tests and fine-needle aspiration do not provide accurate, specific and early diagnosis.

Thyroid ultrasound with gray-scale and color Doppler is the most helpful imaging modality to differentiate normal thyroid parenchyma from diffuse or nodular thyroid disease by evaluating glandular size, echogenicity, echotexture, margins, and vascularity.

However the lack of quantifiability made proper diagnostics and follow-ups difficult. Moreover an accurate assessment of tissue consistency was not possible.

Acoustic Radiation Force Impulse (ARFI) filled this gap. ARFI, as a virtual radiologist’s hand, is an imaging technique to directly reveal the physical property of tissue with conventional ultrasound probes (Siemens AG, Erlangen, Germany with a 9L4 transducer). The probe is placed on the neck and no pressure is applied for measurement.

The tissue is mechanically stimulated using short-duration acoustic pulses.

The acoustic pulses generate localized tissue displacements within a defined region of excitation. The displacements induce a lateral shear-wave propagation which is tracked using multiple laterally positioned ultrasound “tracking” beams. By measurement of the time to peak displacement at each lateral location, the shear wave velocity (SWV) within the region of interest can be reconstructed [1].

The stiffer the tissue, the higher the shear wave velocity.

While this method is already being used to examine nodular changes in the thyroid gland, there have been few studies on the examination of diffuse thyroid disease.

This paper shows the results of imaging modality examinations on the thyroid glands of children and adolescents with suspected or already diagnosed diffuse thyroid disease.

Materials and Methods

This cohort study was initiated between February 2015 and June 2016. Informed written consent was obtained from all patients and the study was performed in accordance with the ethical guidelines of the Helsinki Declaration and approved by the local ethics committee of the University of Halle an der Saale.

We examined 141 patients aged between 4 and 18 years (mean age = 12.6 years, 61.7% female and 38.3% male patients). We conducted a cohort study of children and adolescents with a suspected or known thyroid disease (Table 1).