同一个体3.0T与1.5T乳腺MR扩散加权成像的图像质量比较

目的比较3.0 T与1.5 T MR正常乳腺组织扩散加权成像(DWI)的图像质量,从而评价3.0 T乳腺MRDWI的可行性。方法对44名女性乳腺受检者分别在3.0 T MR与1.5 T MR上行DWI。3.0 T DWI应用选择性水激励(Water excitation)技术行脂肪抑制,1.5 T DWI应用频率选择脂肪饱和(Fatsat)技术行脂肪抑制,b值均为0,1000 s/mm2,其他参数相同。比较3.0 T及1.5 T乳腺MR DWI图像的主观质量评分,测量并计算3.0 T及1.5 T乳腺MR DWI乳腺组织信噪比(SNR)及表观扩散系数(ADC)值,进行统计学分析。结果 3.0 T乳腺MR DWI的图像质量平均评分为(3.07±0.79),主观质量评分达到3分(可以诊断)及以上者为34名,占总检查例数的77.27%。1.5 T乳腺MR DWI的图像质量平均评分为(3.23±0.52),主观质量评分达到3分及以上者为42例,占总检查例数的95.45%。两者比较差异无统计学意义(P=0.1615,>0.05)。3.0 T乳腺MR DWI的乳腺组织SNR为(52.28±19.34),1.5 T乳腺MR DWI的乳腺组织SNR为(49.97±17.99)。3.0 T乳腺MR DWI图像乳腺组织平均SNR略高于1.5 T,但二者差异无统计学意义(P=0.5500,>0.05)。3.0 T MR DWI的平均ADC值为(1.80±0.44)×10-3mm2/s,1.5 T MR DWI的平均ADC值为(1.73±0.32)×10-3 mm2/s,两者比较差异无统计学意义(P=0.0652,>0.05)。结论 DWI可用于3.0 T MR乳腺成像,图像质量可以达到1.5 T MR DWI的效果,且ADC值与1.5 T的ADC值无明显差异。

Quality Assessment of Diffusion Weighted Imaging in Normal Breast: Intraindividual Comparison of 3.0 T and 1.5 T MRI

Objective To compare the image quality of normal breast DWI at 3.0 T and 1.5 T MRI.Methods Forty four female underwent breast DWI using both 3.0 T and 1.5 T MRI.DWI was performed using water excitation at 3.0 T MRI and FATSAT at 1.5 T MRI with the same b value of 0,1000 s/mm2.Image quality score,signal to noise ratio(SNR) and apparent diffusion coefficient(ADC) at 3.0 T and 1.5 T were compared and analyzed.Results Average score of the image quality at 3.0 T was(3.07±0.79).There were 34 cases(77.27%) had subjective quality score of 3 and above(high quality image).Average score of the image quality at 1.5 T MR was(3.23±0.52).There were 42 cases(95.45%) had subjective quality score of 3 and above.There was no significant difference of DWI image quality score between 3.0 T and 1.5 T(P=0.1615,>0.05).Average SNR of the breast DWI was 52.28±19.34 at 3.0 T and 49.97±17.99 at 1.5 T.There was no significant difference of SNR value between 3.0 T and 1.5 T(P=0.5500,>0.05).Average ADC value of the breast DWI was(1.80±0.44)×10-3mm2/s at 3.0 T and(1.73±0.32)×10-3mm2/s at 1.5 T.There was no difference between them(P=0.0652,>0.05).Conclusion DWI can be used at 3.0 T with the same high image quality as at 1.5 T.