Survivors of critical illness experience significant skeletal muscle weakness and physical disability, which can persist for at least 5 years.^1,2 Muscle wasting contributes substantially to weakness acquired in the intensive care unit (ICU),^1,3 but its time course and underlying pathophysiological mechanisms remain poorly characterized and understood. In health, muscle mass is maintained through balanced protein breakdown and synthesis.⁴ For wasting to occur, breakdown must be increased relative to synthesis.

Thematic Section Chairperson 1 Introduction F. Piscaglia – C. Nolsøe 2 Generalities D. Cosgrove 3 Equipment H. P. Weskott 4 Investigator’s training O. H. Gilja 5 Terminology F. Piscaglia 6 Safety G. ter Haar 7 Paediatric C. Nolsøe 8 Pancreas M. D’Onofrio 9 Endoscopic CEUS C. F. Dietrich 10 Gastrointestinal tract O. H. Gilja 11 Spleen O. Catalano 12 Kidney M. Bertolotto 13 Vesicoureteral reflux M. Bertolotto 14 Scrotum P. S. Sidhu 15 Abdominal Trauma O. Catalano 16 Lung and pleural lesions G. Mathis 17 Vascular D. Clevert 18 Cerebral vessels G. Seidel 19 Inflammatory joint diseases A. S. Klauser 20 Intracavitary A. Ignee 21 Lymphnodes M. Hocke 22 Tumour response assessment E. Leen 23 Breast D. Cosgrove 24 Adrenals H. P. Weskott 25 Emerging CEUS applications and future perspectives A Gynecology D. Timmerman B Perineum C. F. Dietrich C Urinary Bladder F. M. Drudi D Transplanted Kidney M. Bertolotto E Prostate Cancer J. M. Correas F Aorto-caval fistula D. Clevert G Free Tissue Transplants E. M. Jung H Extrahepatic Biliary System C. F. Dietrich 26 Use of CEUS in patients with renal failure J. M. Correas – T. Albrecht 27 Technical Appendix F. Piscaglia – C. Nolsøe

The updated version of the EFSUMB guidelines on the application of non-hepatic contrast-enhanced ultrasound (CEUS) deals with the use of microbubble ultrasound contrast outside the liver in the many established and emerging applications.

We present here the first update of the 2013 EFSUMB (European Federation of Societies for Ultrasound in Medicine and Biology) Guidelines and Recommendations on the clinical use of elastography, focused on the assessment of diffuse liver disease. The first part (long version) of these Guidelines and Recommendations deals with the basic principles of elastography and provides an update of how the technology has changed. The practical advantages and disadvantages associated with each of the techniques are described, and guidance is provided regarding optimization of scanning technique, image display, image interpretation, reporting of data and some of the known image artefacts. The second part provides clinical information about the practical use of elastography equipment and the interpretation of results in the assessment of diffuse liver disease and analyzes the main findings based on published studies, stressing the evidence from meta-analyses. The role of elastography in different etiologies of liver disease and in several clinical scenarios is also discussed. All of the recommendations are judged with regard to their evidence-based strength according to the Oxford Centre for Evidence-Based Medicine Levels of Evidence. This updated document is intended to act as a reference and to provide a practical guide for both beginners and advanced clinical users.

Background: Quadriceps weakness and loss of muscle mass predict mortality in chronic obstructive pulmonary disease (COPD). It was hypothesised that a reduced quadriceps cross-sectional area could be detected by ultrasound in patients with COPD compared with healthy subjects, and that measurements relate to strength and fat-free mass (FFM). Methods: Rectus femoris muscle cross-sectional area (RF_CSA) was measured by ultrasound and whole-body FFM estimated using electrical bioimpedance. Quadriceps strength was measured by maximum voluntary contraction and twitch tension (TwQ) following magnetic femoral nerve stimulation. Results: 26 healthy volunteers of mean (SD) age 63 (9) years and 30 patients with COPD of mean (SD) age 67 (9) years and percentage predicted forced expiratory volume in 1 s (FEV₁) 48.0 (20.8)% with a similar FFM (46.9 (9.3) kg vs 46.1 (7.3) kg, p = 0.193) participated in the study. Mean RF_CSA was reduced in patients with COPD by 25% of the mean value in healthy subjects(−115 mm²; 95% CI −177 to −54, p = 0.001) and was related to MRC dyspnoea scale score, independent of FFM or sex. Maximum voluntary contraction strength was linearly related to RF_CSA in patients with COPD (r = 0.78, p<0.001). TwQ force per unit of RF_CSA was similar in both healthy individuals and those with COPD (mean (SD) 17 (4) g/mm² vs 18 (3) g/mm², p = 0.657). Voluntary contraction strength per unit of RF_CSA was dependent on central quadriceps activation and peripheral oxygen saturation in COPD. Conclusion: Ultrasound measurement of RF_CSA is an effort-independent and radiation-free method of measuring quadriceps muscle cross-sectional area in patients with COPD that relates to strength.

“How to perform contrast-enhanced ultrasound (CEUS)” provides general advice on the use of ultrasound contrast agents (UCAs) for clinical decision-making and reviews technical parameters for optimal CEUS performance. CEUS techniques vary between centers, therefore, experts from EFSUMB, WFUMB and from the CEUS LI-RADS working group created a discussion forum to standardize the CEUS examination technique according to published evidence and best personal experience. The goal is to standardise the use and administration of UCAs to facilitate correct diagnoses and ultimately to improve the management and outcomes of patients.