Evaluation of Parathyroid Lesions With Point Shear Wave Elastography

Application of real time shear wave elastography to the differential diagnosis of secondary parathyroid hyperplasia and adenoma

We aimed to explore the value of ultrasonic elastic imaging in the diagnosis of parathyroid hyperplasia and adenoma in patients with secondary hyperparathyroidism and provide more evidence for clinical treatment. Forty patients who were on dialysis and underwent parathyroid surgery were selected All patients underwent routine ultrasound, ultrasound elasticity examination and blood biochemical examination before surgery, including calcium, phosphorus, parathyroid hormone (PTH), etc. According to postoperative results, adenoma group and hyperplasia group were divided into 2 groups. Receiver operating characteristic curve was drawn to evaluate the diagnostic efficacy and combined diagnostic efficacy of each index. The PTH levels significantly differed between the adenoma and hyperplasia groups (P < .001). The volume and blood flow grades significantly differed between the adenoma and hyperplasia groups (P < .001) The minimum of the adenoma group was 14.62 ± 6.79 kPa, mean was 19.42 ± 6.29 kPa, and maximum was 24.25 ± 6.35 kPa which were significantly different from those in the hyperplasia group (P < .05). The combinations of more than 6 indicators in the diagnosis of parathyroid adenoma resulted in an area under the curve of 0.892 (P < .001), and the sensitivity and specificity were 78.9% and 97.4%, respectively. Shear wave elastography can be used as an effective tool to distinguish secondary parathyroid hyperplasia from adenoma. When combined with PTH, conventional ultrasound blood flow grading and volume measurement, it has higher diagnostic efficacy.

Shear wave elastography for differentiating parathyroid neoplasms with malignant diagnosis or uncertain malignant potential from parathyroid adenomas: initial experience

OBJECTIVE

Parathyroid carcinoma (PC) and atypical parathyroid tumor (APT) are rare parathyroid disorders carrying the risk of recurrence of varying degrees. This study aims to explore the value of 2D-shear wave elastography (SWE) in the discrimination of PC/APT among suspicious parathyroid lesions.

METHODS AND MATERIALS

In this prospective study, patients with primary hyperparathyroidism and suspicious parathyroid lesions on ultrasonography (US) were recruited. All the lesions were assessed by SWE before surgery. The velocity (m/s), Young's modulus (Kpa), and elastogram of SWE were compared between pathologically proven parathyroid carcinoma or atypical parathyroid tumor (Group1) and parathyroid adenoma (Group2). All the SWE parameters were displayed at the setting of 50 or 70 kPa. Correlations between SWE and the lesion size as well as biochemical parameters were analyzed.

RESULTS

36 target lesions were enrolled for analysis. The mean shear wave velocity (SWV) between the two groups was 2.4 m/s vs 1.9 m/s, respectively, while the mean Young's modulus was 11.1 kPa vs 18.2 kPa, respectively. The cut-off values are 2.35 m/s and 17.05 kPa correspondingly. The sensitivity and specificity of the selecting cut-off values were 0.56 vs 0.63 and 0.95 vs 1.0 (area under the curve [AUC]: 0.813 vs 0.852 [95% confidence interval (CI): 0.669-0.956 vs 0.720-0.983]; p <  0.001, p <  0.001; respectively). In contrast, the max SWV and Young's modulus showed a better sensitivity of 0.75 and 0.81, respectively. The "colored lesion" and "stiff rim" patterns on the elastogram are more indicated in parathyroid carcinoma and atypical parathyroid tumor, whereas the negative elastogram prevails in parathyroid adenoma. The SWV and Young's modulus of the parathyroid lesions were independent of the tumor size, but the max SWV and Young's modulus slightly correlated with serum parathyroid hormone concentration (PTH) (r = 0.398, p = 0.016; r = 0.396, p = 0.017).

CONCLUSIONS

2D-shear wave elastography plays a useful role in the preoperative assessment of parathyroid lesions with suspicious malignancy. The mean SWV and Young's modulus are advised as the favored diagnostic parameter with the best AUC and excellent specificities, while the max SWV and Young's modulus are more sensitive to distinguish the PC and APT compared with other parameters.

Methods of identification of parathyroid glands in thyroid surgery: A literature review

Intra-operative identification and preservation of parathyroid glands is an important but challenging aspect of thyroid surgery. Failure to do so may lead to transient or permanent hypocalcaemia, where the latter represents a serious complication causing life-long morbidity. It would be beneficial, therefore, if a simple and reliable modality can be developed to assist in the identification of parathyroid glands intra-operatively. The aim of this literature review is to provide an overview of intra-operative modalities used to identify parathyroid glands with a particular focus on near-infrared autofluorescence (NIRAF). Twenty-seven studies were considered relevant in this literature review. Several modalities have been used to aid parathyroid gland identification, including Raman spectroscopy, indocyanine green angiography, and NIRAF. NIRAF technology allows parathyroid glands to spontaneously give off light (autofluorescence) when exposed to near-infrared light at a wavelength of 785 nm, creating a contrast between tissues to allow intra-operative differentiation. Studies utilising NIRAF technology were able to identify 76.3%-100% of parathyroid glands intra-operatively. Furthermore, two randomised controlled trials comparing NIRAF and white light showed that the use of NIRAF was able to significantly increase the mean number of parathyroid glands detected and reduce the incidence of post-operative hypocalcaemia. NIRAF is an emerging tool that has been shown to increase the number of intra-operative parathyroid gland identification and reduce the rate of post-operative hypocalcaemia in a safe and reproducible manner. Future trials are needed to evaluate the real-life impact of NIRAF technology in outcomes of patients following thyroid surgery.

Evaluation of the Stiffness of Thyroid Parenchyma With Shear Wave Elastography Using a Free-Region of Interest Technique in Graves Disease

OBJECTIVES

The first aim was to evaluate the stiffness of thyroid parenchyma with shear wave elastography (SWE) in patients with Graves disease (GD) and compare the elastographic values with those of asymptomatic volunteers. The second aim was to evaluate whether there was a correlation between SWE values and grayscale ultrasound (US) and laboratory parameters.

METHODS

In this prospective study, the thyroid gland parenchyma of 50 patients whose clinical and laboratory findings were indicative for GD and 54 asymptomatic participants with normal laboratory values was examined by SWE. Grayscale US images of the thyroid and submandibular gland were recorded. The volume of the thyroid gland was measured. Elastographic measurements were performed with a free region of interest. The quantitative SWE values (meters per second and kilopascals) of the patient and control groups were compared. A correlation analysis between the SWE values and grayscale US and laboratory parameters was performed.

RESULTS

The median (range) SWE values of the thyroid gland in patients with GD were significantly higher than those of the control group [17.34 (12.58-56.15) versus 12.05 (7.72-23.67) kPa and 2.28 (1.83-4.12) versus 1.92 (1.55-2.61) m/s; P < .001 for both comparisons]. When 14.5 kPa or 2.115 m/s was designated as the cutoff value, GD could be diagnosed with a high sensitivity and specificity. We showed a negative weak correlation between the SWE values and parenchymal echogenicity in the GD group.

CONCLUSIONS

Shear wave elastography can be used as an effective imaging method with high sensitivity and specificity rates in the diagnosis of GD.

Evaluation of perforating venous insufficiency with shear wave elastography: a preliminary study

PURPOSE

The aim of this study was to investigate the efficacy of shear wave elastography (SWE) in the diagnosis of perforating vein insufficiency, and to determine the applicability of these measurements.

METHODS

A total of 140 symptomatic patients with a total of 280 lower extremities were investigated. All patients presented with venous insufficiency (VI) symptoms, and received Doppler ultrasound assessment to determine VI and SWE measurements. The SWE values were measured in the adjacent perivenous tissue of the largest Cockett's perforating vein (PV) of both lower extremities, at the level where they pass the fascia. The Cockett's PV diameter and the presence of reflux in Cockett's PV and the great saphenous vein were compared with SWE values in perivenous tissue of PVs.

RESULTS

The SWE values of the perforating vein insufficiency group were significantly higher than those of the normal PV without insufficiency group (P < 0.001). A significant and positive relation was seen between increased PV diameter and SWE values (P < 0.001) and there was a significant relationship between the presence of perforating vein insufficiency and increase in PV diameter. A statistically significant increase was detected in SWE values for the PV for those with reflux in the great saphenous vein (P < 0.001). The best cut-off values that can be used to detect perforating vein insufficiency were found 34.600 for kPa and 3.375 for m/s.

CONCLUSION

SWE may be used effectively in addition to conventional Doppler ultrasound examination in diagnosing and following perforating vein insufficiency.

Preoperative and Intraoperative Methods of Parathyroid Gland Localization and the Diagnosis of Parathyroid Adenomas

Accurate pre-operative determination of parathyroid glands localization is critical in the selection of minimally invasive parathyroidectomy as a surgical treatment approach in patients with primary hyperparathyroidism (PHPT). Its importance cannot be overemphasized as it helps to minimize the harmful side effects associated with damage to the parathyroid glands such as in hypocalcemia, severe hemorrhage or recurrent laryngeal nerve dysfunction. Preoperative and intraoperative methods decrease the incidence of mistakenly injuring the parathyroid glands and allow for the timely diagnosis of various abnormalities, including parathyroid adenomas. This article reviews 139 studies conducted between 1970 and 2020 (49 years). Studies that were reviewed focused on several techniques including application of carbon nanoparticles, carbon nanoparticles with technetium sestamibi (99m Tc-MIBI), Raman spectroscopy, near-infrared autofluorescence, dynamic optical contrast imaging, laser speckle contrast imaging, shear wave elastography, and indocyanine green to test their potential in providing proper parathyroid glands' localization. Apart from reviewing the aforementioned techniques, this study focused on the applications that helped in the detection of parathyroid adenomas. Results suggest that applying all the reviewed techniques significantly improves the possibility of providing proper localization of parathyroid glands, and the application of indocyanine green has proven to be the 'ideal' approach for the diagnosis of parathyroid adenomas.

Assessment of thyroid gland elasticity with shear-wave elastography in Hashimoto's thyroiditis patients

PURPOSE

We aimed to investigate the use and effectiveness of Shear-Wave Elastography (SWE) in Hashimoto's Thyroiditis (HT) diagnosis and compare the SWE values in HT patients with asymptomatic volunteers.

METHODS

The thyroid gland parenchyma of 74 patients whose clinical and laboratory findings and ultrasonography (US) features were indicative of HT and 75 healthy, asymptomatic participants with normal laboratory values were examined using SWE. Their thyroid parenchymal echoes and thyroid gland volume were measured using B-mode US examination. Elastographic measurements were made by plotting the boundaries of thyroid gland by hand, using Free Region of Interest (ROI). The quantitative SWE values [meters/second (m/s) and kilopascal (kPa)] were compared betweent the patients and the controls. The correlation analyses between the SWE measurements and the autoantibodies [Anti-thyroid peroxidase antibody (TPOAbs) and anti-thyroglobulin antibodies (TgAbs)], thyroid-stimulating hormone (TSH), freetriiodothyronine (fT3), free-thyroxine (fT4), and thyroglobulin levels were performed.

RESULTS

The mean thyroid SWE measurement values of HT group were significantly higher than the asymptomatic group (p < 0.001). This study proposes 29.45 kPa or 2.77 m/s as a sensitive-spesific cut-off value for HT. We revealed significant positive association between SWE values and TgAb levels, gland volume, TgAb, TPOAb levels, and a significant negative association between SWE and echogenicity (p < 0.001).

CONCLUSION

In the assessment of HT, SWE is a highly sensitive imaging method to estimate the degree of fibrosis and to provide objective numerical values.

Shear Wave Elastography versus Strain Elastography in Diagnosing Parathyroid Adenomas

OBJECTIVES

The aim of the study was to compare elastographic means in parathyroid adenomas, using shear wave elastography and strain elastography.

METHODS

This prospective study examined 20 consecutive patients diagnosed with primary hyperparathyroidism and parathyroid adenoma, confirmed by biochemical assay, technetium-99 sestamibi scintigraphy, and pathology report, after parathyroid surgery. All patients were examined on conventional 2B ultrasound, 2D shear wave elastography, and strain elastography. We determined using 2D shear wave elastography (SWE) the elasticity index (EI) in parathyroid adenoma, thyroid parenchyma, and surrounding muscle and examined using strain elastography the parathyroid adenoma, and determined the strain ratio with the thyroid tissue and muscle tissue.

RESULTS

All patients had positive sestamibi scintigraphy and underwent surgery, with confirmation of parathyroid adenoma in all cases. The mean parathormone (PTH) value before surgery was 153.29 pg/ml (36.5, 464.8) and serum calcium concentration was 10.5 mg/dl (9, 11.5). We compared using 2D-SWE and strain elastography parathyroid adenoma with thyroid tissue and with surrounding muscle. The mean EI measured by SWE in parathyroid adenoma was 4.74 ± 2.74 kPa and in thyroid parenchyma was 11.718 ± 4.206 kPa (mean difference = 6.978 kPa, p < 0.001), and the mean EI value in muscle tissue was 16.362 ± 3.829 kPa (mean difference = 11.622, p < 0.001). Using ROC analysis, we found that an EI below 7 kPa correctly identifies parathyroid tissue. We evaluated parathyroid adenomas using strain elastography by color mapping and strain ratio as a semiquantitative measurement; however, we could not find any statistical correlation comparing the strain ratio obtained from the parathyroid adenoma with the thyroid tissue (p=0.485).

CONCLUSION

Ultrasound elastography is a helpful tool in identifying parathyroid adenomas. A cutoff value below 7 kPa can be used in 2D-SWE. Color maps in strain elastography without adding strain ratio can be used, parathyroid adenoma being identified as score 1 in the Rago criteria.

Shear Wave Elastography in Diagnosing Secondary Hyperparathyroidism

This study evaluates the diagnostic value of two-dimensional shear wave elastography (2 D-SWE) technique in the evaluation of hyperplastic parathyroid glands in cases with secondary and tertiary hyperparathyroidism. A total of 59 patients (end-stage renal disease, under supplemental dialysis program) with visible parathyroid hyperplastic glands on ultrasound, confirmed by biochemical assay and scintigraphy, were enrolled; they were examined on grayscale ultrasound and 2 D shear wave elastography. We determined the elasticity index (EI) in the parathyroid gland, thyroid parenchyma and surrounding muscles, and the elasticity ratio of hyperplastic parathyroid glands compared to muscle, specifically sternocleidomastoid muscle. Patients presented fibrocystic bone disease with secondary hyperparathyroidism induced by end-stage chronic kidney disease; being on prolonged chronic dialysis therapy, they had positive sestamibi scintigraphy and high values of serum parathormone (1141.04 pg/mL). Nodules placed posterior to the thyroid capsule that were cystic, had a hypoechoic aspect, and were homogenous with an independent afferent artery were found. Mean EI in the parathyroid gland was 7.83 kPa, the median value in thyroid parenchyma was 13.76 kPa, and mean muscle EI value was 15.78 kPa. The observed mean parathyroid/muscle SWE ratio was 0.5356 and the value for parathyroid/normal thyroid parenchyma was 0.5995. Using receiver operating characteristic (ROC) analysis, we found that EI below 9.74 kPa correctly identifies parathyroid tissue, with a sensitivity of 94.8%, specificity of 90.7%, and accuracy of 92.26% when compared to normal thyroid tissue. Compared with the muscle tissue, we identified that EI below 9.98 kPa has a sensitivity, specificity, and accuracy of 93.8%, 90.7%, and 91.75%, respectively. Ultrasound elastography is a helpful tool in identifying parathyroid hyperplasia in patients with chronic kidney disease. A cutoff value of 9.98 kPa can be used in 2 D-SWE for accurate diagnosis of parathyroid disease.

Ultrasound elastography score and strain index in different parathyroid lesions

BACKGROUND

Despite significant improvement in imaging quality and advanced scientific knowledge, it may still sometimes be difficult to distinguish different parathyroid lesions. The aims of this prospective study were to evaluate parathyroid lesions with ultrasound elastography and to determine whether strain index can help to differentiate parathyroid lesions.

METHODS

Patients with biochemically confirmed hyperparathyroidism and localised parathyroid lesions in ultrasonography were included. All patients underwent B-mode US and USE examination. Ultrasound elastography scores and strain index of lesions were determined. Strain index was defined as the ratio of strain of the thyroid parenchyma to the strain of the parathyroid lesion.

RESULTS

Data of 245 lesions of 230 patients were analysed. Histopathologically, there were 202 (82.45%) parathyroid adenomas, 26 (10.61%) atypical parathyroid adenomas, and 17 (6.94%) cases of parathyroid hyperplasia. Median serum Ca was significantly higher in atypical parathyroid adenoma patients than parathyroid hyperplasia patients (P = 0.019) and median PTH was significantly higher in APA compared to PA patients (P < 0.001). In 221 (90.2%) of the parathyroid lesions, USE score was 1 or 2. The median SI of atypical parathyroid adenomas was significantly higher than parathyroid adenomas and hyperplasia lesions (1.5 (0.56-4.86), 1.01 (0.21-8.43) and 0.91 (0.26-2.02), respectively, P = 0.003).

CONCLUSION

Our study revealed that SI of parathyroid lesions as well as serum calcium, parathyroid hormone levels, and B-mode US features may help to predict the atypical parathyroid adenoma. Ultrasound elastography can be used to differentiate among parathyroid lesions and guide a surgical approach.

Shear wave elastography in the diagnostics of parathyroid adenomas-new application of the method

PURPOSE

Shear wave elastography (SWE) was described as valuable tool in the diagnostics of distinct types of thyroid lesions, thyroiditis and several other non-thyroidal conditions, such as liver inflammation and fibrosis or diagnostics of breast lesions. The aim of the current study was to assess the appearance of parathyroid adenomas in SWE and to check prospectively if SWE can be valuable additional tool in the diagnostics of pathologically enlarged parathyroids.

METHODS

Patients with parathyroid adenomas confirmed by histopathology were included. Subjects with benign thyroid lesions were enrolled to the control group. Elasticity of parathyroid adenomas and benign thyroid nodules was measured and compared.

RESULTS

Sixty five patients with parathyroid adenomas and 35 patients with 51 benign thyroid nodules were included. Parathyroid adenomas where significantly more elastic than benign thyroid nodules-mean elasticity of the lesion was 5.2 ± 7.2 vs. 24.3 ± 33.8 kPa, respectively. Relative mean elasticity (in comparison with surrounding thyroid tissue) was 0.30 ± 0.36 and 2.8 ± 3.9, respectively.

CONCLUSIONS

SWE can be useful tool in the diagnostics of parathyroid adenomas. Enlarged parathyroids are significantly more elastic than benign thyroid lesions. Low elasticity of the lesion constitutes feature with high negative prognostic value, allowing for reliable exclusion of suspicion of parathyroid adenomas.

Experience of Using Shear Wave Elastography Imaging in Superficial Venous Insufficiency of the Lower Extremity

We investigated the effectiveness of shear wave elastography (SWE) in patients with lower extremity superficial venous insufficiency (VI). A total of 138 symptomatic patients, 51 asymptomatic volunteers, and a total of 359 lower extremities (257 symptomatic, 102 asymptomatic) were examined. All participants underwent Doppler ultrasound (US) evaluation to determine VI and SWE measurements performed by manually drawing vein wall and perivenous tissue with free region of interest at the great saphenous vein (GSV) and small saphenous vein (SSV). The GSV, SSV diameter, VI, and volume flow of reflux were compared with the SWE values. The SWE values of the symptomatic group for GSV and SSV were significantly higher than those of the asymptomatic control group regardless of whether VI was detected by Doppler US (P < 0.001). There was a statistically significant increase in SWE values for the symptomatic group who were diagnosed as having reflux in GSV and SSV (P < 0.001). A significant positive correlation between increased GSV, SSV diameter, and SWE values was seen (P < 0.001). Venous insufficiency can be diagnosed with a 84.7% sensitivity and 84.2% specificity when 2655 m/s was designated as cutoff value, and with a 85.4% sensitivity and 84.2% specificity when 22,350 kPa was designated as the cutoff value in GSV. Venous insufficiency can be diagnosed with a 84.3% sensitivity and 82.4% specificity when 2845 m/s was designated as cutoff value, and with a 85.7% sensitivity and 84.4% specificity when 27,100 kPa was designated as the cutoff value in SSV. Shear wave elastography may be used effectively in addition to conventional Doppler US examination in diagnosing and following VI.

2D-Shear Wave Elastography in the Evaluation of Parathyroid Lesions in Patients with Hyperparathyroidism

BACKGROUND AND AIMS

2D-shear wave elastography (2D-SWE) is a relatively new elastographic technique. The aim of the present study is to determine the values of the elasticity indexes (EI) measured by 2D-SWE in parathyroid benign lesions (adenomas or hyperplasia) and to establish if this investigation is helpful for the preoperative identification of the parathyroid adenoma.

MATERIAL AND METHODS

The study groups were represented by 22 patients with primary or tertiary hyperparathyroidism, diagnosed by specific tests, and 43 healthy controls, in whom the thyroid parenchyma was evaluated, in order to compare the EI of the thyroid tissue with those of the parathyroid lesions.

RESULTS

The mean EI measured by 2D-SWE in the parathyroid lesions was 10.2 ± 4.9 kPa, significantly lower than that of the normal thyroid parenchyma (19.5 ± 7.6 kPa; p = 0.007), indicating soft tissue. For a cutoff value of 12.5 kPa, the EI assessed by 2D-SWE had a sensitivity of 93% and a specificity of 86% (AUC = 0.949; p < 0.001) for predicting parathyroid lesions.

CONCLUSION

A value lower than 12.5 kPa for the mean EI measured by 2D-SWE can be used to confirm that the lesion/nodule is a parathyroid adenoma.