## 7 Conclusions  
SWE techniques have increasingly been used in children with several etiologies of diffuse liver disease. Each technique has its strong points, including feasibility, reproducibility, acceptable number of false positive or negative results. TE is quick to perform and very little cooperation is needed. It is also the most studied method since it was the first available on the market. Point SWE and 2D-SWE techniques are available on conventional high-end ultrasound machines and have the advantage of allowing the morphological assessment of the liver in B-mode as well.  
Studies have shown that all SWE techniques are feasible in children at any age with acceptable reliability. LSMs values seem age-dependent, with children of age 12 or more having values similar to adults. The majority of studies have shown that girls have significantly lower LSMs than boys of the same age; however some studies did not confirm this finding. SWE is feasible also in babies but confounding factors such as the probe choice, sedation, or food intake need to be taken into account when interpreting the results.  
As reported in adults, LSMs obtained in the right liver lobe are lower than those obtained in the left lobe, and measurements should be performed in the right lobe whenever possible. The majority of studies have shown that LSMs are not influenced by the BMI.  
The intra-operator reproducibility of LSMs by 2D-SWE was found to be excellent and the breathing does not seem to affect the results. Three 2D-SWE acquisitions can be enough for hepatic LSMs in children older than 6 years old regardless of breathing status or hepatic pathology. More acquisitions seem needed for children under the age of five during free breathing.  
Ultrasound elastography is a reliable non-invasive method to monitor liver fibrosis in pediatric patients. However, for some pathologies, such as biliary atresia, the evidence is still limited. As shown in adults, inflammation is a confounding factor when assessing fibrosis severity and care should be taken when interpreting the results. Elastographic techniques cannot discriminate between contiguous stages of fibrosis (F0 vs. F1; F1 vs. F2). Moreover, as reported in adults, LSMs for the same stage of fibrosis vary according to different etiologies of liver disease and different values are obtained with different ultrasound systems.  
Due to the scarce comparative data between serology and elastography techniques in children, a definite conclusion regarding which is the best cannot be drawn. Neither non-invasive elastographic techniques nor laboratory scores allow a determination of the presence and the degree of inflammation, necrosis, iron or copper deposits.  
We acknowledge the discussion with [PERSON], Giessen, Germany. We acknowledge the support of the Bad Mergentheimer Leberzentrum e.V.  
[PERSON], speaker for: Hitachi Medical Systems, Siemens Healthineers, Mindray Medical Systems, Supersonic, GE, Bracco, Pentax, Olympus, Fuji, Boston Scientific, AbbVie, Falk, Novvartis, [PERSON]: Philips Healthcare, Canon Medical Systems, Hitachi Medical Systems, Mindray Medical Systems. [PERSON]: I have received financial support (congress travel grant or speaker fees) from Philips, Abbvie, Zeniro. [PERSON]: I have received financial support (congress travel grants, speaker fees) from: Philips, General Electric, Abbvie, AstraZeneca, Zeniro. [PERSON]: I have received financial support (congress travel grant or speaker fees) from Philips, Siemens, General Electric, Abbvie, Zeniro, Bristol Meyers Squibb. [PERSON] and [PERSON] declare no conflict of interest.