Handheld, Portable Ultrasound in the Neonatal Intensive Care Nursery: A New, Inexpensive Tool for the Rapid Diagnosis of Common Neonatal Problems Vladimir Burdjalov, MD Pinchi Srinivasan, MD Stephen Baumgart, MD Alan R. Spitzer, MD INTRODUCTION Ultrasound diagnosis has become a crucial adjunct to neonatal intensive care since its introduction approximately two decades ago. 1 Because of the fragile nature of the newborn infant ( particularly the critically ill, very - low - birth - weight baby ), transport to other areas of the hospital for CT or MR imaging is often difficult. For infants who require mechanical ventilation, warming, and other specialized neonatal intensive care support, the problem of patient mobility becomes even more complex and hazardous. 2 Because ultrasound equipment can be brought to the bedside and does not expose babies to additional radiation, it is often the preferred initial study for imaging in neonates. Until recently, however, ultrasound units were large and complicated to use, and required extensive expertise in the acquisition of images. Moreover, the machines themselves were prohibitively expensive. As a result, ultrasound units were typically purchased by hospitals, were maintained in the radiology department ( which provided the technical support ), and were a limited resource shared among many hospital departments with differing needs. In many instances ( particularly at night and on weekends ), ultrasound imaging has not always been immediately available to the neonatal intensive care unit (NICU). Common neonatal management decisions that might benefit from immediate ultrasound evaluations have often been deferred until the next day, contributing to physician frustration, parental anxiety, and hospital cost. Furthermore, and most importantly, the care of the infant may be adversely affected. Recently, a new portable ultrasound unit and transducer specifically designed for neonatal care has been introduced. This device is accompanied by imaging software that has been simplified for bedside use in the NICU. The purpose of this report is to illustrate several potential uses for this diagnostic capability. METHODS The portable ultrasound unit for this study was designed by Sonosite (Bothell, WA). The handheld unit is shown in Figure 1 and weighs 5.4 lb (2.5 kg), measuring only 13.3Â7.6Â2.5 in. The device is powered by either AC current from a wall outlet, or rechargeable (DC) battery. The screen on the handheld unit is 4.3Â3.1 in., and has a high-quality image resolution. This portable unit can be docked into a mobile station equipped with a larger screen for viewing by several individuals or for teaching purposes. The device also has pulsed wave Doppler, directional color power Doppler, and tissue harmonic imaging capability. The transducer used for neonatal image acquisition is a C11 7 - to 4 - MHz transducer with a derated spatial peak, with temporal average intensity of 49.0 mW/ cm 2 . The C11 transducer has a radius curve of the array of 11 mm. The applicable thermal index value for the transducer is 0.50, with a mechanical index of 0.52. The derated pulse average intensity at maximal mechanical index is listed at 33.9 mW/cm 2 . Sonosite has developed proprietary software for image acquisition and definition. The software allows for enlargement of the image and selection of varying degrees of ultrasound depth and image resolution. The four available types of examinations that can be The use of ultrasound imaging in the neonatal intensive care unit ( NICU ) has become an essential part of the evaluation and delivery of care for most neonates. Until recently, ultrasound machines were large, expensive, and often not immediately available, particularly at night and during weekends. Additionally, serial studies to define the evolution of an acute clinical situation were often not practical because of the dedicated time required and the expense involved. The recent introduction into our NICU of a high - quality, reasonably priced, and completely portable neonatal ultrasound unit ( Sonosite, Bothell, WA ) has now made it possible for neonatologists to rapidly obtain the hour - by - hour information that can be extremely helpful in the evaluation of a critically ill neonate. This paper illustrates some of the capabilities of this simplified device, and the value of having continuous on - site ultrasound availability in the NICU. Journal of Perinatology (2002) 22, 478 – 483 doi:10.1038/sj.jp.7210782 Department of Pediatrics, Division of Neonatology, SUNY - Stony Brook, Stony Brook, NY, USA. Address correspondence and reprint requests to Alan R. Spitzer, MD, Department of Pediatrics, SUNY - Stony Brook, HSC T11 - 060, Stony Brook, NY 11794 - 8111, USA. Special Article & & & & & & & & & & & & & & 478 Journal of Perinatology 2002; 22:478 – 483 #2002 Nature Publishing Group All rights reserved. 0743-8346/02 $25 www.nature.com / jp