Strain Wave Elastography Research Articles

The Role of Strain Wave Elastography in The Evaluation of Renal Fibrosis in Patients with Kidney Diseases

Background: A renal biopsy represents the gold standard in the diagnosis, prognosis and management of patients with chronic kidney disease and glomerulonephritis. Strain wave elastography (SE) is a developing technique to assess tissue elasticity. The aim of this study was to correlate between the strain index value of renal parenchyma and degree of renal fibrosis detected with renal biopsy.Method: For 68 patients who were referred for a kidney biopsy, SE test was performed. The Banff scoring system was utilized to classify the IFTA grading of kidney fibrosis that assigns a severity level of mild, moderate, or severe. Receiver operating characteristic curve (ROC) was utilized to correlate between the severity of renal fibrosis and the grade of renal elasticity determined by SE.Results: In total, 38 males and 30 females, the echogenicity, qualitative and semiquantitative elastography showed significant positive correlation with serum creatinine, percentage of fibrosis, G score and tubular atrophy and significant negative correlation with eGFR. ROC curve of SE for diagnosis of interstitial fibrosis shown that echogenicity has sensitivity 100.0%, Specificity 62.5%, positive predictive value (PPV) 75.0%, negative predictive value (NPV) 100.0% with area under curve (AUC) 0.906, while qualitative elastography has sensitivity 77.8%, specificity 75.0%, PPV 77.8%, NPV 75.0% AUC 0.833, semi quantitative elastography has sensitivity 83.3%, specificity 93.8%, PPV 93.8%, NPV 83.3% with AUC 0.915.Conclusion: SE approach is simple to use, and can differentiate between varying stages of renal fibrosis. However, further research is required before it can be frequently used in clinical practice.

Abstract PO1-07-06: Sonographic assessment of breast implants using strain elastography and shear wave elastography in an animal model

Abstract Purpose: To date, MRI remains the gold standard for the diagnosis of breast implant rupture. As MRI is an expensive procedure with limited availability, improvement in sonographic assessment is desirable. A potentially useful tool in this regard is the assessment of tissue stiffness using ultrasound elastography. Strain elastography provides a qualitative analysis by producing a coloured map in the B-mode image comparing the stiffness of adjacent tissues in the region of interest, whereas shear wave elastography provides a quantitative analysis. To evaluate the diagnostic utility of both methods under standardised conditions, we developed an animal model. Under natural conditions, the physiology of the patient (e.g. the amount and stiffness of the breast tissue covering the implant in question) can influence the measurements and alter the data. Therefore, the animal model provides an excellent opportunity to compare ruptured and intact implants of different types and sizes under exactly the same conditions, neglecting individual characteristics of real patients. Methods: An animal model was created by preparing an implant site in a chicken breast, mimicking the layers of tissue typically covering a breast implant after mastectomy (skin, fat, muscle). Different fractured and intact implants were inserted. Measurements were made using strain elastography and shear wave elastography by an investigator with no further experience of breast ultrasound. Implants were scanned in five pre-defined planes in both intact and ruptured conditions. For strain elastography, the resulting images were examined for repetitive patterns. Shear wave elastography data were analysed for significant differences between ruptured and intact implants. Results: The chicken breast animal model produced realistic images and measurements comparable to those of a human breast. Therefore, ruptured and intact implants could be compared under standardised conditions. Statistical analysis showed no significant difference between intact and ruptured implants in shear wave elastography data. However, qualitative analysis using strain wave elastography showed different patterns when comparing intact and ruptured implants in the animal model. Intact implants showed a characteristic three-layer sonographic image at certain levels. Conclusion: Shear wave elastography does not appear to provide reliable data for the evaluation of breast implants, whereas qualitative analysis using strain wave elastography may be a useful tool to improve diagnostic accuracy. Citation Format: Hanna Fritsch, Melisa Celik, Matthias Warm, Fabinshy Thangarajah, Anett Pisek, Christian Eichler. Sonographic assessment of breast implants using strain elastography and shear wave elastography in an animal model [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO1-07-06.

Does Postlong Coronavirus 2019 Disease Affect Renal Stiffness without any Chronic Systemic Disorders?

In the last few years, coronavirus disease 2019 (COVID-19) has changed human lifestyle, behavior, and perception of life. This disease is caused by severe acute respiratory syndrome coronavirus 2 (SARS-COV-2). In the literature, there are limited studies about the late renal effects of COVID-19 that reflect the systemic involvement of this disease. In the present study, we aimed to compare sonoelastographic changes in both kidneys between patients who had totally recovered from COVID-19 and healthy individuals using strain wave elastography (SWE). This study was conducted between June 2021 and May 2022 in Kahramanmaraş City Hospital Department of Radiology. File and archive records were retrospectively evaluated. Basic demographic, laboratory, and renal ultrasonography (USG) and sonoelastographic findings were screened and noted. Two groups were defined to compare sonoelastographic findings. Post-long COVID-19 group had 92 post-long COVID-19 patients, and the comparator group had 9 healthy individuals". Both groups' demographic, laboratory, and ultrasound-elastographic findings were assessed. The post-long COVID-19 group had a higher renal elastographic value than the comparator group (1.52 [0.77-2.3] vs. 0.96 [0.54-1.54], p<0.001). There were no statistically significant differences between the two groups in terms of age (p=0.063), gender (p=0.654), or body mass index (BMI) (p=0.725), however, there was a significant difference observed between the two groups in the renal strain ratio (RSR). According to an ROC analysis, an RSR cutoff of >1.66 predicted post-long COVID-19 with 44.9% sensitivity and 81.9% specificity. (AUC=0.655, p<0.001). A separate ROC analysis was performed to predict post-long COVID-19 with a BMI cutoff of <33.52, kg/m2 sensitivity of 92.4% and specificity of 17% (AUC=0.655, p<0.001). We demonstrated that renal parenchymal stiffness increases with SWE in post-long COVID-19 patients.

Sonographic Assessment of Breast Implants Using Strain Elastography and Shear Wave Elastography in an Animal Model.

To date, magnetic resonance imaging (MRI) remains the gold standard for diagnosing breast implant rupture. As MRI is an expensive procedure with limited availability, the improvement of sonographic assessment is desirable. A potentially useful tool in this regard is elastography. To evaluate the diagnostic benefits of strain elastography and shear wave elastography under standardized conditions we developed an animal model. An animal model was created by preparing an implant site in a chicken breast, imitating tissue layers covering a breast implant after mastectomy. Different broken and intact implants were inserted. Thereby, measurements were performed using strain elastography and shear wave elastography. For strain elastography, the resulting images were investigated on repeated patterns. The data generated by shear wave elastography were analyzed for significant differences between the ruptured and intact implants. The animal model using chicken breast generated realistic images and measurements comparable to those of a human breast. Hence, ruptured and intact implants could be compared under standardized conditions. Statistical analysis showed no significant difference between intact and ruptured implants with respect to the data generated by shear wave elastography. Qualitative analysis using strain wave elastography showed different patterns between intact and ruptured implants in the animal model. Intact implants showed a characteristic sonographic image of three layers in certain levels. Shear wave elastography does not seem to produce reliable data for the evaluation of breast implants, whereas qualitative analysis using strain elastography might be a useful tool to improve diagnostic accuracy.

COMPARISON OF STRAIN ELASTOGRAPHY AND SHEAR WAVE ELASTOGRAPHY FOR DIFFERENTIATING MALIGNANT FROM BENIGN BREAST MASSES

To compare the diagnostic performance of shear wave and strain elastography in distinguishing benign and malignant breast lesions. A prospective study carried out from 20th March 2020 to 20th March 2021 at department of Radiology of Sahiwal, Multan, Lahore. The study included women who were lined for surgical excision or core needle biopsy and were examined using B-mode ultrasound and shear and strain wave elastography. A total of 30 female patients with 40 breast lesions were included in the study. Lesions were categorized on B-mode ultrasound as 3 BI-RADS 3, 18 BI-RADS 4A, 5 BI-RADS 4B, 7 BI-RADS 4C, and 7 BI-RADS 5. After performing a B-mode Ultrasound examination, US elastography was done. A 14-MHz transducer was used to obtain high-resolution images. For comparing the diagnostic performance of both, an area under the ROI curve (AUC) from data sets of shear and strain wave elastography was compared. The McNemar test was used for the comparison of sensitivity and specificity of both data sets. Mean age of the participants was 48.4 years (21-80years). 24 out of 40 lesions were benign while 16 were malignant. B mode US imaging showed the diameter of the lesion ranged from 0.5 to 5.2 cm. There was no significant difference between specificity and sensitivity of elastographic images. 6 breast masses showed discrepant results. After category 4a BI-RADs were selectively downgraded on the bases of cutoff values, AUCs showed improvement. Diagnostic performance of shear wave and strain elastography in distinguishing malignant and benign lesions is the same. Combining both has better diagnostic performance than using each individually.

Strain Wave Elastography Imaging for the Evaluation of Pancreas in Healthy Volunteers

Strain Wave Elastography Imaging for the Evaluation of Pancreas in Healthy Volunteers

Strain wave elastography in response assessment to neo-adjuvant chemotherapy in patients with locally advanced breast cancer.

The study was conducted to study the role of strain wave elastography in evaluating the response to neo-adjuvant chemotherapy (NACT) in patients with locally advanced breast cancer (LABC). In this Institutional review board approved study, 86 patients of LABC were investigated with strain wave elastography. Females receiving NACT had the affected breast scanned by strain wave elastography before each cycle of chemotherapy and immediately before surgery by two independent observers. Changes in elastographic parameters (size ratio, strain ratio) were documented and then compared to clinical and pathologic tumor response as evaluated after mastectomy. Elastographic strain ratio parameters demonstrated high sensitivity and moderate specificity for determining response even after the first cycle of neo-adjuvant chemotherapy [97.7% sensitivity (Sn), 68.7% specificity (Sp)]. Elastographic size ratio parameters showed moderate sensitivity and specificity for response detection after second and third cycle of neo-adjuvant chemotherapy (Sn, Sp: after second cycle of NACT Sn 83.3% Sp 80%; after third cycle of NACT Sn 77.8% Sp 100%). Strain ratio is the earliest predictor of treatment response in patients of LABC. Serial imaging with elastography has the potential to predict treatment response early during the course of NACT, which may prove vital in management of patients with breast cancer. Strain wave elastography is a powerful tool to predict chemoresponse early during the course of management, thereby providing an optimal window to change treatment protocols.

Strain wave elastography for evaluation of renal parenchyma in chronic kidney disease.

Chronic kidney disease (CKD) is an important and costly health problem in developed countries and has a tendency to progress to end-stage renal disease regardless of the aetiology. This progress ends in interstitial fibrosis, which decreases the elasticity of tissue. Elastography is a developing technique to assess tissue elasticity. The aim of this study was to determine the difference of strain index (SI) value of renal parenchyma between patients with CKD and healthy individuals. In addition, SI differences of inter-stages were studied. Toshiba (Toshiba Medical Systems Corporation, Otawara, Japan) Aplio™ 500 ultrasound device and 3.5- to 5.0-MHz convex probe were used for the elastography examinations. A total of 58 patients with CKD from nephrology and endocrinology clinics (30 males and 28 females; mean age, 56.14 ± 11.60 years) and 40 normal healthy individuals (19 males and 21 females; mean age, 51.70 ± 11.71 years) were included in this prospective study. The mean SI of normal healthy individuals and patients with CKD (regardless of stages) was 0.42 ± 0.30 and 1.81 ± 0.88, respectively (p < 0.001). SI values were not statistically significant among the CKD stages (except CKD Stages 1 and 3). The area under the receiver operating characteristic curve was 0.956 for SI. The optimal cut-off value for the prediction of CKD was 0.935 (sensitivity, 88% and specificity, 95%). SI value of sonoelastography can be used to differentiate patients with CKD and healthy individuals. Sonoelastography is an acceptable technique to approach patients with CKD, but we have not shown that it can reliably differentiate different stages. Determining a cut-off SI value between normal and diseased renal parenchyma can help in the diagnosis of CKD.