FRI0380 Assessment of submandibular gland qualitative changes using shear wave elastography in patients with sjÖgren's syndrome. (12th June 2018) - Hashimoto, N.
Abstract : Background: We have reported that the submandibular gland ultrasonography (SGUS) is a useful noninvasive and inexpensive procedure for the evaluation of the structural changes of salivary gland (SG) in Sjögren's syndrome (SS), International Symposium on SS 2002, EULAR 2009, EULAR 2012 . EULAR 2015 However, our previously study demonstrated that although SGUS findings were useful for the diagnosis of SS with low salivary flow they were not for early-stage SS with normal salivary flow. EULAR 2016 Recently, ultrasound elastography has been reported to be a new tool to evaluate tissue stiffness and diagnose tumour. Objectives: The aim of this study was to examine the usefulness of SGUS using US staging and PD grading score in combination with shear wave elastography (SWE) in patients with SS. Methods: Fifty-eight patients who fulfilled the American College of Rheumatology (ACR)/European League Against Rheumatism (EULAR) classification criteria for SS were studied. SS patients were divided into three groups according to salivary flow using gum test (VL/SS:<5 mL/10 min. (n=21), L/SS: 5–10 mL/10 min. (n=27) and N/SS: ≧10 mL/10 min. (n=10)). All patients were examined SGUS by a single investigator who was blinded to device (TUS-A300; Canon Medical Systems, Tokyo, Japan) with a linear transducer (7.5–10MHz). The examination consisted of conventional B-mode US (US staging score), pulsed wave Doppler US (PD grading score) and SWE with quantitative assessment. US staging scores were assessed by glandular size, inhomogeneity and contrast of diagastric muscle (stage 0 to 3). PD grading scores were graded by pulsed wave pattern in pulsed wave Doppler US at the internal SG facial arteries (grade 0 to 2). With the region-of-interest (ROI) placed over the stiffest areas of the lesion on SWE, the quantitative mean of the elasticity values were measured by shear wave velocity (Vs: m/s) and elasticity (E: kPa) for each lesion. Results: The US staging scores of SS patients were 0.0% in stage 0; 17.2% in stage 1; 8.6% in stage 2; 74.1% in stage 3. The PD grading scores of SS patients were 20.7% in grade 0, 17.2% in grade 1, 62.1% in grade 2. The US staging and grading scores were significantly lower in N/SS patients (1.40±0.70, 0.10±0.32) than in L/SS (2.74±0.66, p<0.001, 1.59±0.69, p<0.001) and in VL/SS (2.91±0.30, p<0.001, 1.81±0.40, p<0.001) patients. The elasticity value measure by Vs and E were significantly higher in N/SS patients than in VL/SS patients (Vs: 1.90 vs 1.56 m/s, p<0.05, E: 11.2 vs 7.57 kPa, p<0.05). The Vs and E were significantly decreased as US staging score (stage 1 vs 3: 1.91 vs 1.62 m/s, p<0.05, 11.3 vs 8.21 kPa, p<0.05) and PD grading score (grade 0 vs 2: 1.90 vs 1.61 m/s, p<0.05, 11.1 vs 8.13 kPa, p<0.05) increased. Conclusions: The present study demonstrated that the tissue elasticity was increased due to inflammation and high viscosity in the SG at the early stage, but was decreased due to structural changes in the SG at the advanced stage of the disease. The SWE may be a useful tool for elucidation of early stage pathological changes of the SG when salivary gland functions are not impaired in SS. Disclosure of Interest: None declared