3,851 Japanese children (2,078 male, and 1,773 female) who were diagnosed as no anatomical and functional heart disease at the pediatric cardiovascular section were enrolled. The age distribution is from 0 month to 18.9 years old and median age is 6 years 7 months.

Statistical method

LMS method.ex

1. Cole TJ, Green PJ. Smoothing reference centile curves: the LMS method and penalized likelihood. Stat Med. 1992;11:1305-1319.

Standard method for ultrasound imaging of coronary artery in childrenex

Cole TJ, Green PJ. Smoothing reference centile curves: The LMS method and penalized likelihood. Stat Med. 1992; 11: 1305-1319.

This standard method for measuring the coronary arterial diameter in children was recommended by the Scientific Committee of the Japanese Society of Kawasaki disease. Followings are the summary of the recommendation.

  • Usually, the patient is examined in a supine, left decubitus or sitting position. The right decubitus position is especially useful to observe the right coronary artery if it is not visible.
  • A sector probe of ≥5 MHz frequency should be used.
  • The focus depth should be set to the coronary artery.
  • The frame rate should be increased to raise time resolution.
  • Low gain, low dynamic range, and near probe distance in ultrasound settings are important factors in accurate measurement of arterial lumen diameter.
  • The coronary artery should be observed at the center of the monitor screen.
  • Echo beam direction should be made at a right angle to the arterial wall where possible.
  • The Coronary arterial diameter should be measured from the trailing edge of the near wall to the leading edge of the far wall intima-lumen interface.ex
  • fig
  • The Measurement of coronary arteries should be done at diastolic cardiac phase (if possible)

How to use

  • At a time, 4,000 and 10 patients’ data are able to estimate using full and light version, respectively.
  • Enter gender (male 1, female 2), height (cm), weight (kg), and coronary arterial diameter (mm) in a same row (patient ID is optional), then BSA and Z score values of their corresponding coronary arterial diameter are calculated automatically.
  • Z=0 means median of the coronary arterial diameter.
  • Ratio means measurement value divided by median of the coronary artery diameter.
  • You can also avail values of Z scores previously reported.ex
  • de Zorzi A, Colan SD, Gauvreau K, Baker AL, Sundel RP, Newburger JW. Coronary artery dimensions may be misclassified as normal in Kawasaki disease. J Pediatr 1998;133:254-258.
    Kurotobi S, Nagai T, Kawakami N, Sano T. Coronary diameter in normal infants, children and patients with Kawasaki disease. Pediatr Int. 2002;44:1-4.
    Tan TH, Wong KY, Cheng TK, Heng JT. Coronary normograms and the coronary-aorta index: objective determinants of coronary artery dilatation. Pediatr Cardiol 2003;24:328-35.
    McCrindle BW, Li JS, Minich LL, Colan SD, Atz AM, Takahashi M, Vetter VL, Gersony WM, Mitchell PD, Newburger JW; Pediatric Heart Network Investigators. Coronary artery involvement in children with Kawasaki disease: risk factors from analysis of serial normalized measurements. Circulation. 2007;116:174-179.
    Olivieri L, Arling B, Friberg M, Sable C. Coronary artery Z score regression equations and calculators derived from a large heterogeneous population of children undergoing echocardiography. J Am Soc Echocardiogr 2009;22:159-164.
    Dallaire F, Dahdah N. New equations and a critical appraisal of coronary artery Z scores in healthy children. J Am Soc Echocardiogr. 2011;24:60-74.
    Newburger JW, Takahashi M, Gerber MA, Gewitz MH, Tani LY, Burns JC, Shulman ST, Bolger AF, Ferrieri P, Baltimore RS, Wilson WR, Baddour LM, Levison ME, Pallasch TJ, Falace DA, Taubert KA; Committee on Rheumatic Fever, Endocarditis and Kawasaki Disease; Council on Cardiovascular Disease in the Young; American Heart Association; American Academy of Pediatrics. Diagnosis, treatment, and long-term management of Kawasaki disease: a statement for health professionals from the Committee on Rheumatic Fever, Endocarditis and Kawasaki Disease, Council on Cardiovascular Disease in the Young, American Heart Association. Circulation. 2004;110:2747-2771.


T Kobayashi, N Sakamoto, and S Fuse on behalf of pediatric coronary artery diameter z score study group.
Corresponding to Tohru Kobayashi, MD, PhD.
E-mail :

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