Parotid elastography: a potential alternative to replace labial biopsy in classification of patients with primary Sjögren's syndrome?

BACKGROUND: There has been a substantial improvement in classifying patients with primary Sjögren's syndrome (pSS), with the new 2016 ACR/EULAR classification criteria. It was aimed to investigate the potential role of parotid elastography in the classification of patients with pSS, as well as the clinical diagnosis of those who do not otherwise fulfil the criteria. METHOD: This is a cross-sectional analysis of patients with pSS followed up in tertiary out-patient rheumatology clinic. Patients' medical records were retrospectively investigated whether or not clinically diagnosed pSS patients fulfil 2016 ACR/EULAR criteria sets. Elastographic evaluation of parotid and submandibular glands bilaterally was performed when presented for follow-up. Strain ratio, shear wave velocity and Pascal values of the glands were obtained. RESULTS: Clinical data on 179 patients with Sjögren's syndrome were investigated. Ninety-six patients with pSS and 30 gender and age-matched healthy controls were included in the study. Eighty-six percent of the clinically diagnosed patients satisfied the 2016 ACR /EULAR criteria and were considered 'criteria patients', and the remaining were considered 'non-criteria patients'. Both criteria and non-criteria patients had significantly higher parotid strain ratio and submandibular velocity compared with healthy controls (p < 0.001 and p < 0.001 for parotid strain ratio and p < 0.001 and p = 0.016 for submandibular velocity, respectively). Replacing labial gland biopsy findings with parotid strain ratio in the new classification criteria resulted in similar sensitivity and lower specificity, 91.6% and 80%, respectively. CONCLUSION: Parotid shear elastography is an easy and noninvasive method and might be a useful tool for the classification of patients with pSS, especially when labial gland biopsy is not feasible. Key Points • Salivary gland elastography (SGE) is a useful tool for the classification of patients with pSS. • SGE could be performed instead of labial biopsy without changing the diagnostic power of classification criteria.

Perianal fistula mapping at 3 T: volumetric versus conventional MRI sequences.

AIM: To evaluate volumetric contrast-enhanced three-dimensional T1-weighted (CE 3D T1) turbo spin-echo (TSE) with variable flip angle (SPACE), CE 3D T1 volumetric interpolated breath-hold examination (VIBE) sequences with conventional CE-two-dimensional (2D)-T1 and 2D-T2-weighted imaging (WI) sequences in assessing perianal fistulas. METHODS AND MATERIALS: Twenty-three patients with perianal fistula were included in this prospective study and underwent pelvic magnetic resonance imaging (MRI) at 3 T including fat-supressed CE 3D T1 SPACE, CE 3D T1 VIBE, axial and coronal 2D-T1WI together with 2D-T2WI sequences in the axial and coronal planes. Acquisition times were recorded. Performance of each sequence was evaluated in terms of image quality, presence of artefacts, lesion conspicuity, fistula type, presence of abscess, visibility of internal orifice, and number of internal orifices. Results were compared with post-surgical findings defined as the reference standard. RESULTS: Both CE 3D T1 VIBE and CE 3D T1 SPACE were the best sequences to determine fistula type and in terms of image quality, artefacts, and determining locations of internal orifices. The number of internal orifices was detected correctly in 23 (100%) patients for CE 3D T1 SPACE and CE 3D T1 VIBE sequences, in 17 (73.9%) patients on CE-T1WI, and in seven (30.4%) patients on 2D-T2WI. Lesion conspicuity was higher for CE 3D T1 SPACE and CE 3D T1 VIBE sequences compared to the 2D sequences (p<0.05). The overall acquisition time for each 3D sequence was shorter compared to the 2D sequences combined. CONCLUSION: CE 3D T1 SPACE and CE 3D T1 VIBE sequences may outperform conventional 2D sequences in the evaluation of perianal fistulas in terms of visibility and number of internal orifices with a shorter scanning time.