1.5 T MRI全身类PET的正常表现

Normal appearance of whole-body PET-like imaging at 1.5T MRI

目的探讨1.5 T MRI全身"类PET"的正常表现。材料与方法对40名不同年龄组健康志愿者行1.5 T MR全身"类PET"成像,在AW4.6工作站上经Functool和3D-MIP后处理,获得最大信号强度投影、黑白反转及伪彩"类PET"图像,观察正常组织结构的信号,分析椎体、椎间盘信号信号与年龄的相关性。结果 (1)脂肪、肌肉、两肺、肝脏、胃肠道、脑脊液呈低信号;(2)脑、脊髓、头颈部腺体、脾脏、胆囊、生殖腺以及椎间盘呈高信号;(3)椎体在儿童中呈高信号,在60岁以上健康志愿者中主要呈低信号;(4)椎体和椎间盘信号与年龄呈负相关(r=-0.6917,P<0.05;r=-0.7562,P<0.05)。结论正确认识"类PET"的正常表现将有利于对病变的诊断。

Objective： To investigate the normal appearance of whole-body PET-like imaging at 1.5 T MR scanner. Materials and Methods：Forty healthy volunteers with different age underwent whole-body PET-like MR examination at 1.5 T scanner. The data was reformatted using Functool and 3D-MIP software at AW4.6 workstation. Then, maximum intensity projection （MIP）, inverted-gray-scale and pseudocolor processing PET-like images were obtained. Signal of the normal tissue was observed. Correlation between age and signal of lumbar vertebrae and intervertebral discs was analyzed. Results：（1） Fat, muscle, lungs, liver, gastrointestinal tract, and cerebrospinal fluid showed hypointensity. （2） Brain, spinal cord, glands of head and neck, spleen, gallbladder, genital gland, and intervertebral discs showed hyperintensity. （3） Vertebral body showed hyperintensity in children and mainly hypointensity in healthy volunteers over 60 years of age. （4） There were significant negative correlation between age and signal of lumbar vertebrae （r=-0.6917,P〈0.05） and intervertebral discs （r=-0.7562,P〈0.05）. Conclusions： It will be beneifcial for diagnosis after correctly understanding normal appearance of PET-like images.