Strain elastography for noninvasive assessment of liver fibrosis: A prospective study with histological comparison

Evaluation of Usability and Efficacy of Strain Elastography Method Concurrently with Preoperative Ultrasonography in Cases of Hydatid Cyst

Background

Hydatid cysts (HCs), which are among the cystic lesions of the liver, are frequently encountered in endemic areas. Routine imaging modalities are sometimes insufficient to differentiate HC types, and ultrasound (US) elastography has just begun to be used for this purpose. In this study, the effectiveness of the strain elastography (SE) method in preoperative HC cases was investigated, and the relationship between HC types and elastography values was evaluated.

Methods

HC cases that underwent SE simultaneously with preoperative US between January 2019 and February 2021 were evaluated retrospectively, and 75 cases were included in the study. In addition to elastography data, cyst typing according to the World Health Organization (WHO) classification was also available.

Results

Thirty cases were male and 45 cases were female, the median age was 48 years, and the interquartile range was 41 years. According to the WHO classification, 15 cases were Type I, 27 cases were Type II, and 33 cases were Type III HC. Median strain ratio (SR) values were 5.69 (4.07-14.47) for Type I, median 1.49 (1.26-1.74) for Type II, and median 0.21 (0.13-0.30) for Type III, and there was a highly significant relationship between HC types and SR values (P < 0.001). There was also a very strong (-) directional correlation between HC type and strain rate (P < 0.001, Spemann rho (ρ): -0.928).

Conclusion

US elastography is a new modality in the diagnosis of HC types, and there are few studies available. In this study, unlike the literature, it is the first time that HC typing and discrimination have been used using the SE technique, which is remarkable.

Application of strain elastography ultrasound to the endometrium of normal women

BACKGROUND

While there is a scarcity of studies utilizing strain elastography (SE) for the endometrium, commonly used gynecologic ultrasound instruments are equipped with built-in elastography modalities, primarily SE. With the objective of facilitating comprehensive examinations for gynecologic patients on a single ultrasound instrument, we undertook this study. Therefore, our aim was to study the value of SE ultrasonography in the assessment of endometrial elasticity in normal women.

METHODS

Three hundred and twenty normal women were recruited at our hospitals from November 2021 to December 2022. Each volunteer underwent a transvaginal two-dimensional (2D) and SE ultrasound during either the endometrial proliferative or secretory phase. The 2D ultrasound indices obtained included endometrial thickness, echo type (type A, B, and C), and blood flow grading (grades 0, 1, 2, and 3). SE indices obtained included endometrial strain values, myometrial strain values, and endometrial strain ratios. Differences in endometrial ultrasound indices between different menstrual cycles and different age groups were compared.

RESULTS

Comparison of 2D ultrasound parameters revealed that endometrial thickness in the proliferative phase endometrium group was smaller than that in the secretory phase endometrium group, with a statistically significant difference. Additionally, there was a statistically significant difference in endometrial echo types between the two groups, while the disparity in endometrial blood flow grading was not significant. Regarding SE parameters, the median and mean values of endometrial strain ratio in the proliferative phase endometrium group were smaller than those in the secretory phase endometrium group, showing a statistically significant difference. However, there were no significant differences observed between the two groups in endometrial strain and myometrial strain in the fundus. Furthermore, there were no significant differences in any of the endometrial ultrasound indices among the different age groups.

CONCLUSIONS

SE can reflect changes in endometrial stiffness in different menstrual cycles and is an important tool for assessing endometrial softness.

Stiffness estimated by strain elastography reflects canine testicular spermatogenesis and histology

Ultrasound elastography was proposed for the evaluation of testicular focal lesions, but no studies verified the agreement between the whole histological architecture of the testis and the stiffness measured by elastography. The present study explored the use of strain elastography in the evaluation of testis with normal or abnormal spermatogenesis, classified based on epididymal sperm attributes, and the consistency between elastographic parameters and the testicular histological feature. Strain elastography was performed during the routine andrological examination in 22 dogs presented for elective orchiectomy. Epididymal sperm attributes and testicular histology were analyzed after orchiectomy. Based on the epididymal sperm characteristics, testes were classified according to normal or abnormal spermatogenesis, and strain elastographic attributes were compared between groups. Possible correlations between strain elastography and histological features were also explored. Consistent with the literature in humans, testes with abnormal spermatogenesis were stiffer (mean strain elastographic index 3.6 ± 0.6) compared with normal testes (mean strain elastographic index 1.9 ± 0.2; P < 0.01). The strain elastographic index was negatively correlated with the area occupied by seminiferous tubules (Pearson's rho = -0.716; P = 0.0003), the mean diameter (Pearson's rho = -0.742; P = 0.0002), and thickness of the seminiferous tubule (Pearson's rho = -0.728; P = 0.0002). Surprisingly, no correlations were found between the area occupied by connective tissue in histological sections and elastographic attributes, suggesting that the increased stiffness was not related to the increased amount of connective tissue. This study demonstrated that strain elastography could be used to support the andrological examination, but measurements should be acquired in specific regions to be reliable.

The severity of portal hypertension by a non-invasive assessment: acoustic structure quantification analysis of liver parenchyma

Background

Acoustic structure quantification (ASQ) has been applied to evaluate liver histologic changes by analyzing the speckle pattern seen on B-mode ultrasound. We aimed to assess the severity of portal hypertension (PHT) through hepatic ultrasonography.

Methods

Sixty patients diagnosed with PHT and underwent surgical treatment with portosystemic shunts were enrolled. Portal pressure (PP) was measured intraoperatively. Patients were divided into subgroups according to the severity of gastroesophageal varices and Child–Pugh class. Three difference ratio (C_m²) values on ASQ histogram mode were analyzed for their relationships with PP, degree of gastroesophageal varices and Child–Pugh liver function. Thirty healthy volunteers matched with the patients for gender and age were enrolled as controls. Comparisons among groups and correlation of the parameters with PP were analyzed. Area under the receive operating characteristic curve was used to evaluate the predicting value of ASQ parameters.

Results

In the patients, the ASQ parameters peak C_m² (C_m²_max), mean C_m² (C_m²_mean) and the highest occurred C_m² value of the obtained red curve (R_maxC_m²) were all greatly increased (P < 0.0001, P < 0.0001, P = 0.027). Multiple comparisons indicated that, regardless of Child–Pugh class and degree of gastroesophageal varices, the patients had significantly increased C_m²_max and C_m²_mean compared with the controls (all P < 0.0001). No differences among subgroups were observed. C_m²_max was significantly statistically correlated with PP (r = 0.3505, P < 0.01), degree of varices (r = 0.4998, P < 0.0001). Youden’s index for C_m²_max with a cut-off value of 140.3 for predicting the presence of PHT, gastroesophageal varices and liver function equal to or worse than Child–Pugh class B were 0.8, 0.91 and 0.84, respectively.

Conclusions

ASQ analysis of ultrasonographic images may have a role in the evaluation of the severity of PHT by detecting liver histologic changes in the speckle pattern caused by cirrhosis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12880-022-00817-2.

Ultrasound-based liver elastography: current results and future perspectives

Chronic liver disease affects 185 million population worldwide. It encompasses a heterogenous disease spectrum, but all can lead to the development of liver fibrosis. The degree of liver fibrosis is not only a prognosticator, but has also been used to guide the treatment strategy and to evaluate treatment response. Traditionally, staging of liver fibrosis is determined on histological analysis using samples obtained from an invasive liver biopsy. Ultrasound-based liver elastography is a non-invasive method of assessing diffuse liver disease in patients with known chronic liver disease. The use of liver elastography has led to a significant reduction in the number of liver biopsies performed to assess the severity of liver fibrosis and a liver biopsy is now reserved for only select sub-groups of patients. The aim of this review article is to discuss the key findings and current evidence for ultrasound-based elastography in diffuse liver disease as well as the technical challenges and to evaluate the potential research direction.