1Takane Village Clinic, 2Department of Clinical Pathology, Jichi Medical School
Ultrasonography, Spleen, Infants, Children, Normal range
We studied the normal range of splenic size in infants and children (0-5 years old) with real-time ultrasound scanners (TOSHIBA SAL-32B and ALOKA SSD-210DX, 5 MHz linear array transducer). The subjects were devided into four age groups: 0-1 month old, 3-4 m., 5-11 m., and 1-5 year old. Splenotomogram was taken by left intercostal scanning in the right lateral decubitus. Spleen Index (SI) was measured in 278 cases (male: 140, female: 138). SI was defined as "a×b" according to Koga's method, in which "a" was the maximum line of the longitudinal section of the spleen and "b" was the perpendicular line to "a" through the splenic hilum. In all age groups, SI correlated with the age, body length (BL), body weight (BW) and body surface area (BSA). SI/BW negatively correlated with those four parameters in every age groups. But no significant correlation was found between either SI/BL or SI/BSA and the four parameters. The average SI increased with age, whereas average SI/BW decreased with age. The average SI/BL showed no correlation with age. The average SI/BSA was significantly larger in a 0-1 m. group than other age groups, in which its average was relatively constant irrespective of age. The above results were similar to the data in Aimi's study on the spleen at the autopsy. Thus, SI/BSA was considered as the best index of the splenic size for infants and children. SI/BSAs of more than 5.0×10-3 in 0-1 m., and more than 4.1×10-3 in 3 m.- 5 y. indicate splenomegaly.