半剂量对比剂增强双反转恢复序列臂丛成像研究

目的:研究低剂量对比剂增强3D-DIR-SPACE序列在臂丛神经磁共振成像中的可行性。方法:研究分为两组,第一组建议剂量0.2 mL/kg行3D-STIR-SPACE扫描(对照组),第二组低剂量0.1 mL/kg行3D-DIR-SPACE扫描(研究组),两组均行2D-STIR实图重建扫描。在2D-STIR实图像上测量计算神经、血管、淋巴的SI、SNR(将信号相近的淋巴与血管定义为组织1,将信号低于淋巴的血管定义为组织2),统计神经与组织1/2间的差异,比较神经在3D-DIR/STIR-SPACE平扫下的CNR且行统计学分析,比较低剂量下3D-DIR-SPACE与建议剂量下3D-STIR-SPACE在增强后的评分,行统计学分析。结果:神经与组织1、组织2在2D-STIR图像上的SI分别为274±37.49、654.20±145.85、267±49.56,SNR分别为267.83±65.62、638.17±202.90、261.03±71.83,神经与组织1在SI、SNR上有明显差异(P1=0.00),神经与组织2在SI、SNR上无明显差异(P2=0.77/0.93)。3D-STIR/DIR-SPACE在臂丛平扫中的CNR分别为89.85±50.36、72.02±34.63,没有明显差异(P=0.06),低剂量下3D-DIR-SPACE与建议剂量下3D-STIR-SPACE在增强后的评分分别为4.55±0.50、4.72±0.45,无统计学差异(P=0.10)。结论:低剂量对比剂增强3D-DIR-SPACE扫描在降低剂量的同时能获得达到诊断效果的图像质量。

A study of half dose contrast-enhanced with double inversion recovery sequence in the imaging of brachial plexus

Objective:To evaluate the feasibility of low dose contrast-enhanced three-dimensional double inversion time inversion recovery sampling perfection with application optimized contrasts using different flip angle evolution(3D-DIR-SPACE)in the MR imaging of brachial plexus.Methods:The patients were divided into two groups.The first group was recommended a dose of 0.2mL/kg with three-dimensional short inversion time inversion recovery sampling perfection with application optimized contrasts using different flip angle evolution(3D-STIR-SPACE)scanning(control group),and the second group,a low dose of contrast of 0.1mL/kg with 3D-DIR-SPACE(experimental group).Both groups were performed two-dimensional short inversion time inversion recovery(2D-STIR)scanning and image reconstruction.The signal intensity(SI)and signal to noise ratio(SNR)of nerves,blood vessels,lymph were measured and calculated on 2D-STIR images(the lymph and blood vessels with similar signals were defined as tissue 1,and the blood vessels with signals below lymph were defined as tissues2).Statistical differences were analyzed between nerve,tissues1 and 2.The contrast to noise ratio(CNR)of nerves on 3D-DIR and STIR-SPACE without contrast were also compared,as well as the enhanced scores of 3D-DIR-SPACE and 3D-STIR-SPACE at low dose.Results:The SI of nerve,tissue 1 and 2 on 2D-STIR images were 274±37.49,654.20±145.85 and 267±49.56,respectively,and the SNR were 267.83±65.62,638.17±202.90 and 261.03±71.83,respectively.There were significant differences in SI and SNR between nerves and tissues 1(P1=0.00).There were no significant differences in SI and SNR between nerves and tissues 2(P2=0.77/0.93).The CNR of 3D-STIR/DIR-SPACE in brachial plexus without contrast were 89.85±50.36 and 72.02±34.63,respectively(P=0.06).The enhanced scores of 3D-DIR-SPACE at low dose and 3D-STIR-SPACE at the recommended doses were 4.55±0.50 and 4.72±0.45,respectively(P=0.10).Conclusions:Low dose of contrast-enhanced 3D-DIR-SPACE protocol can achieve comparable image quality with reducing contrast agents,comparing traditional 3D-STIR-SPACE with normal contrast dose of contrast.