Shen Wei, Chen Jun, Kwak Sofia, Punyanitya Mark, Heymsfield Steven B
Obesity Research Center, St Luke's-Roosevelt Hospital and Institute of Human Nutrition, Columbia University College of Physicians and Surgeons, New York, USA.
Int J Pediatr Obes. 2011 Apr;6(2):149-56. doi: 10.3109/17477166.2010.486833. Epub 2010 Jun 7.
Magnetic Resonance Imaging (MRI) is increasingly being used in children to quantify adipose tissue (AT) and skeletal muscle (SM) in vivo. It is unclear whether the every 5 cm whole body MRI protocol used in adults is appropriate when applied in children. Whole body MRI continuous 1 cm thick slices were acquired in 73, aged 5-17-year-old healthy children. Images were segmented into subcutaneous (SAT), visceral (VAT), intermuscular AT (IMAT), and SM. The percentage difference between volumes measured by the continuous protocol and volumes estimated with protocols of different between-slice intervals (i.e., interval = 2, 3, 4 and 5 cm) was larger with an increase in interval size, depot size, weight and body mass index percentile. For group comparisons, studies will require less than 5.4% more subjects if an every 5 cm protocol is used for equivalent power as the every 1 cm protocol. For individual subject comparisons, interval protocols can be used to reliably distinguish between subjects who differ in SM or SAT volume by 0.14 to 0.64 L (i.e., 1 to 5% of SM or SAT volume) or more, or in VAT or IMAT volume by 0.06 to 0.21 L (i.e., 10 to 30% of VAT or IMAT volume) or more. The every 5 cm image acquisition protocol can be considered as accurate as the contiguous protocol for group comparisons in children, as well as for comparison of SM and SAT among individual children. However, a smaller slice interval protocol would be more accurate for comparison of VAT or IMAT among individual children.
磁共振成像（MRI）越来越多地用于儿童体内脂肪组织（AT）和骨骼肌（SM）的量化。尚不清楚成人使用的每5厘米全身MRI方案应用于儿童时是否合适。对73名5至17岁的健康儿童进行了全身MRI检查，获取了连续1厘米厚的切片。图像被分割为皮下脂肪（SAT）、内脏脂肪（VAT）、肌间脂肪（IMAT）和骨骼肌。随着切片间隔、脂肪储存量、体重和体重指数百分位数的增加，连续方案测量的体积与不同切片间隔（即间隔 = 2、3、4和5厘米）方案估计的体积之间的百分比差异增大。对于组间比较，如果使用每5厘米方案与每1厘米方案具有同等效力，则研究所需的受试者数量将减少不到5.4%。对于个体受试者比较，间隔方案可用于可靠地区分骨骼肌或皮下脂肪体积相差0.14至0.64升（即骨骼肌或皮下脂肪体积的1%至5%）或更多，或内脏脂肪或肌间脂肪体积相差0.06至0.21升（即内脏脂肪或肌间脂肪体积的10%至30%）或更多的受试者。对于儿童组间比较以及个体儿童之间骨骼肌和皮下脂肪的比较，每5厘米图像采集方案可被视为与连续方案一样准确。然而，较小的切片间隔方案对于个体儿童之间内脏脂肪或肌间脂肪的比较将更准确。
