Neonates and premature babies represent the most vulnerable patient groupowing to their limited ability to negotiate their “unfamiliar” life after delivery.Therefore， a special environment using incubators is set up to provide homeo-stasis， for example， temperature.“Minimal handling” is one of the majorstrategies in neonatology， and every action must be balanced between possi-ble harms and benefits.
　　Almost 40 years have passed since the introduction of ultrasound in clini-cal use.Starting with obstetrics， many areas of the body can be scanned safelyby ultrasound； the most common investigations involve abdominal， urinarytract， gynecological， and obstetric sonography as well as echocardiography.Children differ in many respects from adults， including in their psychology，communication， circulation， body composition， and proportions， to name justa few.Depending on age， a variable， usually considerable， amount of theskeleton is not calcified but consists of cartilage.This presents new chal-lenges and possibilities for ultrasound.Owing to the reduced craniocaudalchest length compared to adults， the upper abdominal organs are less coveredby the rib cage， and in combination with， for example， the small amount ofintestinal fat content， high-quality images with excellent resolution can be obtained easily.In addition， Doppler ultrasound makes it possible to detect，monitor， and quantify flow.Therefore， challenging applications， like brain ultrasound and spinal or hip sonography， are possible.Even better， all inves-tigations can be conducted bedside， including those involving the use ofincu-bators， making ultrasound the perfect imaging tool in neonatology.
　　Considering the high frequency oflung diseases in premature babies due to their inherent immaturity， it is a logical step to evaluate and describe the potential of lung ultrasound.For several years chest ultrasound was used for the evaluation of pleural effusions， consolidation， surfactant deficiency states，and pneumothorax detection.Enthusiastic pediatricians and radiologists used ultrasound also to guide interventions and insertions of peripheral lines； in particular， correct， central positioning can be monitored noninvasively by ultrasound using a subcostal approach.
　　In children， Prof.Dr.Erich Sorantin has been applying ultrasound to all body regions for more than 30 years， and the challenges of lung ultrasound have always attracted him.Dr.Jing Liu and Hai-ying Cao were the first neo-natologist and radiologist， respectively， to develop this technology in China under the auspices of Prof.Sorantin starting in 2011.They gained extensive experience in this field through long-term clinical practice with a large number of patients， so the time has come to promote this technology by means of a neonatallung ultrasound monograph.
　　This book tries to close the gap between clinical needs and sporadic lung ultrasound publications.For the first time this book provides a comprehen-sive overview of several typical， neonatal lung diseases and includes patho-physiology and clinical findings in combination with lung ultrasound.Moreover， care was taken to embed lung ultrasound findings in the clinical management of vulnerable patients.
　　The book is intended to be read by physicians of all（sub）specialties inter-ested in the imaging and management of neonatal lung diseases including neonatologists and pediatricians， pediatric radiologists， and intensive care and emergency room doctors.Furthermore， the authors believe strongly that using lung ultrasound will reduce the number of chest films in susceptible patients， thereby preventing their exposure to radiation and protecting them from the harmful effects of radiation.
　　We want to thank Dr.Clark Zhe Wu， professor at the University of Electronic Science and Technology of China， who provided much help in English editing and ultrasound physics.His invaluable assistance helped to improve the quality of the book.