title: Age-related changes in liver, kidney, and spleen stiffness in healthy children measured with acoustic radiation force impulse imaging.
abstract: OBJECTIVE
  To evaluate the feasibility and age-related changes of shear wave velocity (SWV) in normal livers, kidneys, and spleens of children using acoustic radiation force impulse (ARFI) imaging.
  
  
  METHODS
  Healthy pediatric volunteers prospectively underwent abdominal ultrasonography and ARFI. The subjects were divided into three groups according to age: group 1: <5 years old; group 2: 5-10 years old; and group 3: >10 years old. The SWV was measured using a 4-9 MHz linear probe for group 1 and a 1-4 MHz convex probe for groups 2 and 3. Three valid SWV measurements were acquired for each organ.
  
  
  RESULTS
  Two hundred and two children (92 male, 110 female) with an average age of 8.1 years (± 4.7) were included in this study and had a successful measurement rate of 97% (196/202). The mean SWVs were 1.12 m/s for the liver, 2.19 m/s for the right kidney, 2.33 m/s for the left kidney, and 2.25 m/s for the spleen. The SWVs for the right and left kidneys, and the spleen showed age-related changes in all children (p<0.001). And the SWVs for the kidneys increased with age in group 1, and those for the liver changed with age in group 3.
  
  
  CONCLUSIONS
  ARFI measurements are feasible for solid abdominal organs in children using high or low frequency probes. The mean ARFI SWV for the kidneys increased according to age in children less than 5 years of age and in the liver, it changed with age in children over 10.
authors: Department of Radiology and Research Institute of Radiological Science, Severance Children's Hospital, Yonsei University, College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752, Republic of Korea. mjl1213@yuhs.ac
authors: Mi-Jung
authors: MJ
authors: Lee
authors: Myung-Joon
authors: MJ
authors: Kim
authors: Kyung Hwa
authors: KH
authors: Han
authors: Choon Sik
authors: CS
authors: Yoon
mesh_terms: D000293:Adolescent; D017677:Age Distribution; D000375:Aging / Q000502:physiology*; D002648:Child; D002675:Child, Preschool; D055119:Elastic Modulus / Q000502:physiology*; D054459:Elasticity Imaging Techniques / Q000706:statistics & numerical data*; D005260:Female; D064368:Healthy Volunteers / Q000706:statistics & numerical data*; D006801:Humans; D007668:Kidney / Q000000981:diagnostic imaging / Q000502:physiology*; D008099:Liver / Q000000981:diagnostic imaging / Q000502:physiology*; D008297:Male; D009928:Organ Specificity / Q000502:physiology; D015203:Reproducibility of Results; D056910:Republic of Korea / Q000453:epidemiology; D012680:Sensitivity and Specificity; D013154:Spleen / Q000000981:diagnostic imaging / Q000502:physiology*