Ultrasound Machine with Elastography for the Clinic: SE vs SWE, Probes and Single Crystal Technology for Purchase
SE and SWE: Fundamental Differences
According to the EFSUMB classification (Bamber et al., 2013; Săftoiu et al., 2018/2019), elastography is divided into strain technologies (SE) and shear wave methods (SWE). SE displays the relative stiffness of tissues in the form of a black-and-white or colored elastogram. SWE provides a quantitative assessment: cutoff values for liver fibrosis are device-specific and measured in m/s (similar to ARFI) [Diagnostic Ultrasound: Abdomen & Pelvis].
Types of SWE
According to Diagnostic Ultrasound: Abdomen & Pelvis:
| Technology | Features |
|---|---|
| 2D SWE | Real-time analysis of shear wave propagation, multiple ROIs, confidence map, reduced sampling variability, simultaneous HCC screening on clinically available scanners |
| Point SWE (pSWE) | A subset of 2D SWE; a more traditional option without a confidence map |
Limitations of SWE: influence of edema, inflammation, and hepatic congestion, operator dependence [Diagnostic Ultrasound: Abdomen & Pelvis].
What to Look for When Purchasing: Quality Indicators
According to Diagnostic Imaging: Breast (Berg & Leung, 2019), mandatory quality indicators for SWE and strain are a color bar, color overlay, or numerical value for adequate compression control. The elastogram (semi-transparent) should overlay the grayscale image with simultaneous real-time display (side by side or top to bottom).
Diagnostic Efficiency of SWE vs Strain
According to summary data from Diagnostic Imaging: Breast (multiple studies):
| Parameter | SWE | Strain |
|---|---|---|
| Sensitivity | 94% | 80–100% |
| Specificity | 81–91% | 80–95% |
Probes and Single Crystal Technology
The provided excerpts lack specific requirements for probes and data on single-crystal technology transducers [to be clarified].
Criteria for Measurement Reliability
For quantitative liver SWE, the literature discusses reliability criteria and adherence to quality criteria affecting consistency between methods (Ferraioli et al.; Roccarina et al.) — for example, comparing the number of measurements (10, 5, and 3) for ElastPQ-SWE. Specific cutoff values are not provided in the excerpts [to be clarified].
Frequently asked questions
How does SWE differ from strain elastography when choosing a device?
SWE provides a quantitative stiffness assessment in m/s (device-specific cutoff), offers real-time analysis, multiple ROIs, and a confidence map. Strain (SE) displays relative stiffness. According to Diagnostic Imaging: Breast, SWE sensitivity is ~94%, specificity is 81–91%.
What quality indicators should be present in an elastography device?
According to Diagnostic Imaging: Breast — a color bar, color overlay, or numerical value for adequate compression control, as well as simultaneous real-time display of the elastogram and grayscale image.
What is point SWE and does it have limitations?
Point SWE is a subset of 2D SWE, a more traditional option without a confidence map [Diagnostic Ultrasound: Abdomen & Pelvis].
What factors distort SWE results?
Edema, inflammation, and hepatic congestion, as well as operator dependence [Diagnostic Ultrasound: Abdomen & Pelvis].
Are there requirements for single crystal probes in the sources?
The provided excerpts lack specific data on single crystal probe technology [to be clarified].