in march 2013 , cases infected with a novel reassortant avian - origin influenza a ( h7n9 ) virus emerged in china and had high mortality . that month , a patient with h7n9 influenza was admitted to our hospital , and daily lung ultrasound was performed . a 54-year - old woman , who ran a convenience store beside a poultry market , complained of cough and high fever for 4 days . her temperature was 38.6c , and she had a heart rate of 113 beats per minute and a respiratory rate of 26 breaths per minute . her white blood cell count was 2.7  10/l , and neutrophil , lymphocyte , and monocyte levels were 72.4% , 22% , and 5.2% , respectively . her partial pressure of oxygen in arterial blood was 72 mm hg , and her fraction of inspiratory oxygen ( fio2 ) was 40% . avian - origin influenza a ( h7n9 ) virus was confirmed from the pharyngeal swabs by real - time reverse transcriptase - polymerase chain reaction . treatment with oseltamivir ( 150-mg capsule taken by mouth twice a day ) was initiated , and she was admitted to an isolated room in the infectious diseases department . bothell , wa , usa ) with c60 convex probe ( 2 to 5 mhz ) was performed , and the lung ultrasound score ( lus )   was recorded , and both effectively reflected the progression of pneumonia ( figure 1 ) . dynamic changes of chest computed tomography ( ct ) , radiography , and lung ultrasound in a patient with h7n9 influenza . ( a - c ) ct showed pneumonia in the left upper lung , with partial consolidation on admission . ( d - f ) lung ultrasound corresponding to ct in ( a - c ) showed multiple abutting b2 lines , and some regions presented a tissue pattern ( arrow ) . ( g - i ) ct on day 6 after admission showed that the pneumonia was partially absorbed . ( j - l ) lung ultrasound corresponding to ct in ( g - i ) showed that the number of b lines was obviously decreased , and the consolidation disappeared . ( m - o ) ct on day 9 after admission showed that the size of the lesion was obviously reduced . ( p - r ) lung ultrasound corresponding to ct in ( m - o ) indicated that only the a line and few b lines were visible . ( s - u ) chest radiography on days 1 , 3 , and 6 after admission showed no obvious change of the pneumonia . ( v ) dynamic changes of lung ultrasound score ( lus ) ( total of 48 for normal lung ) . the onset of h7n9 influenza in this case was manifested by hyperpyrexia and flu - like symptoms and progressed to lobar pneumonia 4 days later . chest radiograph is the routine tool for assessment of pneumonia , but its sensitivity and accuracy were not so good . ct is regarded as the gold standard , but its application is limited in cases with this new emerging virus since strict protection should be followed to avoid person - to - person transmission . ultrasound has many advantages , including convenience , rapidness , non - invasiveness , availability for repeated examination , and absence of radiation . the right lung presented an a line with few isolated b lines , whereas the left lung presented multiple abutting b lines and consolidation . when the patient improved , both b lines and the area of consolidation were decreased and the lus was synchronously increased . this case highlights that ultrasound can be an adjutant to chest radiography and ct in caring for patients with h7n9 influenza . written informed consent was obtained from the patient for publication of this letter and accompanying images .
h7n9 influenza is a new emerging infection and has high mortality . 
 both chest radiography and computed tomography ( ct ) had some limitations in assessing such patients . 
 we performed daily lung ultrasound in a patient with h7n9 influenza . 
 lung ultrasound and lung ultrasound score showed high consistency with ct and the progression of pneumonia . 
 ultrasound can be adjutant to chest radiography and ct in caring for patients with h7n9 influenza .