Diagnostic Value of Different 3-D Shear Wave Elastography Sections in the Diagnosis of Thyroid Nodules

Evaluation of ovarian stiffness and its biological mechanism using shear wave elastography in polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a common endocrine disorder with various contributing factors. Shear wave elastography (SWE) is a contemporary noninvasive imaging technique that reports on the elasticity of tissues. This study aimed to evaluate ovarian stiffness in patients with PCOS using transvaginal SWE, and investigate the potential biological mechanisms underlying increased ovarian stiffness. Patients with PCOS and healthy controls underwent transvaginal 2D ultrasound and SWE to measure the number of follicles, ovarian volume, and ovarian elasticity. Multivariate logistic regression analysis was conducted to identify risk factors for PCOS. A rat model of PCOS was established to further investigate the biological basis of increased ovarian stiffness. Histological analysis, enzyme-linked immunosorbent assay, quantitative reverse transcription-polymerase chain reaction, western blotting, transcriptomics, and proteomics were performed to assess alterations in fibrosis and basement membrane (BM) gene expression. The results demonstrated that patients with PCOS (n = 59) showed an increased number of follicles, ovarian volume, and SWE (mean and max) compared with controls (n = 56; P < 0.001). The number of follicles, ovarian volume, and SWE_mean were identified as independent risk factors for PCOS (P < 0.05). SWE_mean ≥ 12.5 kPa demonstrated an area under the curve of 0.816 for PCOS diagnosis and was positively correlated with AMH levels (r = 0.6776, P < 0.0001). In the rat model, increased ovarian stiffness was associated with significant fibrosis and altered expression of fibrosis-related markers. Transcriptomic and proteomic analyses revealed that BM gene alterations were correlated with ovarian stiffness, which was further validated using PCOS patient data from the Gene Expression Omnibus database. In conclusion, SWE is a valuable technique for diagnosing PCOS by detecting increased ovarian stiffness, which may be associated with alterations in the expression of BMs, thereby mediating ovarian fibrosis.

Non-invasive evaluation of testicular torsion using ultrasound shear wave elastography: an experimental study

PURPOSE

The goal of this study was to examine changes in testicular stiffness at various intervals after the induction of testicular torsion, as well as to assess the predictive value of testicular stiffness for testicular spermatogenesis after torsion.

METHODS

Sixty healthy male rabbits were randomly assigned to one of three groups: complete testicular torsion, incomplete testicular torsion, or control. All rabbits underwent preoperative and postoperative scrotal ultrasonography, including shear wave elastography (SWE), at predetermined intervals. Changes in SWE values were analyzed and compared using repeatedmeasures analysis of variance. To assess the diagnostic performance of SWE in determining the degree of spermatogenic function impairment, the areas under the receiver operating characteristic curves (AUCs) were calculated.

RESULTS

SWE measurements in both central and peripheral zones of the testicular parenchyma affected by torsion demonstrated significant negative correlations with spermatogenesis, with coefficients of r=-0.759 (P<0.001) and r=-0.696 (P<0.001), respectively. The AUCs of SWE measurements in the central or peripheral zones of the torsed testicular parenchyma were 0.886 (sensitivity, 83.3%; specificity, 100%) and 0.824 (sensitivity, 83.3%; specificity, 73.3%) for distinguishing between hypospermatogenesis and spermatogenic arrest, respectively (P=0.451, DeLong test).

CONCLUSION

Variations in the stiffness of both central and peripheral regions of the testicular parenchyma correlate with the extent and duration of torsion, exhibiting a specific pattern. The "stiff ring sign" is the characteristic SWE finding associated with testicular torsion. SWE appears to aid in the non-invasive determination of the extent of spermatogenic damage in torsed testes.

Diagnostic value of ACR TI-RADS combined with three-dimensional shear wave elastography in ACR TI-RADS 4 and 5 thyroid nodules

BACKGROUND

Three-dimensional shear wave elastography (3D-SWE) is a promising method in distinguishing benign and malignant thyroid nodules. By combining with conventional method, it may further improve the diagnostic value. The study aimed to assess the diagnostic value of American College of Radiology (ACR) thyroid imaging reporting and data system (TI-RADS) combined with 3D-SWE in ACR TI-RADS 4 and 5 thyroid nodules.

METHODS

All nodules were examined by conventional ultrasonography, ACR TI-RADS classification, and 3D-SWE examination. Conventional ultrasonography was used to observe the location, size, shape, margin, echogenicity, taller-than-wide sign, microcalcification, and blood flow of thyroid nodules, and then ACR TI-RADS classification was performed. The Young's modulus values (3D-C-Emax, 3D-C-Emean, and elastography standard deviation [3D-C-Esd]) were measured on the reconstructed coronal plane images. According to the receiver operating characteristic (ROC) curve, the best diagnostic efficiency among 3D-C-Emax, 3D-C-Emean, and 3D-C-Esd was selected and the cut-off threshold was calculated. According to the surgical pathology, they were divided into benign group and malignant group. And appropriate statistical methods such as t -test and Mann-Whitney U test were used to compare the difference between the two groups. On this basis, 3D-SWE combined with conventional ACR TI-RADS was reclassified as combined ACR TI-RADS to determine benign or malignant thyroid nodules.

RESULTS

Of the 112 thyroid nodules, 62 were malignant and 50 were benign. The optimal cut-off value of three-dimensional maximum Young's modulus in coronal plane (3D-C-Emax) was 51.5 kPa and the area under the curve (AUC) was 0.798. The AUC, sensitivity, specificity, and accuracy of conventional ACR TI-RADS were 0.828, 83.9%, 66.0%, and 75.9%, respectively. The AUC, sensitivity, specificity, and accuracy of combined ACR TI-RADS were 0.845, 90.3%, 66.0%, and 79.5%, respectively. The difference between the two AUC values was statistically significant.

CONCLUSIONS

Combined ACR TI-RADS has higher diagnostic efficiency than conventional ACR TI-RADS. The sensitivity and accuracy of combined ACR TI-RADS showed significant improvements. It can be used as an effective method in the diagnosis of thyroid nodules.