摘要
目的:探讨腰椎DWI的不同b值对图像质量及ADC值的影响,选择3.0T磁共振鉴别腰椎良、恶性压缩骨折的最适b值。方法:31例压缩骨折的患者45个椎体,分为良性组(17例共23个椎体,由外伤或骨质疏松引起)和恶性组(14例共22个椎体,转移瘤或原发性恶性骨肿瘤),行矢状面DWI序列扫描,测定b值分别为300、400、500、600、700和800 s/mm2时病变椎体的对比度比(CR)、对比信噪比(CNR)和表观弥散系数值(ADC)。比较良性组和恶性组在各个b值下的CR、CNR和ADC值。结果:不同b值下CR分别为0.71±0.41、0.58±0.44、0.49±0.36、0.40±0.34、0.33±0.30和0.27±0.26,b值为300 s/mm2时最高,CNR值分别为9.03±4.25、7.27±5.81、6.41±4.43、4.83±4.08、4.21±3.64、3.42±3.24,b值为300 s/mm2时最大;良、恶性压缩骨折组间的CR、CNR值无统计学差异(P>0.05)。b值为300、400、500和600 s/mm2时,良、恶性压缩骨折椎体组间ADC值均有统计学差异(P<0.05);其中b值为300 s/mm2时,ADC值良性组为1.75±0.41,恶性组为1.11±0.33,两组间差异最大。结论:DWI图像上病变信号强度不能鉴别良恶性腰椎压缩骨折。使用较小b值的DWI图像在鉴别腰椎良、恶性压缩骨折上也许更有价值。
Objective： To explore the optimal b value in diffusion-weighted imaging（DWl） of MRI for differential diagnosis of benign and malignant vertebral fractures. Methods： Thirty-one consecutive patients with vertebral compression fractures un- derwent sagittal DWI with different b values. The group included 17 patients with 23 benign vertebral fractures due to osteo- porosis and/or trauma and 14 patients with 22 malignant vertebral fractures due to malignancy. The quality of the images was analyzed by measurement of the contrast ratio（CR） and the contrast SNR（CNR）. Apparent diffusion coefficient（ADC） values were also calculated. The CR, CNR and ADC values in various b value were compared between benign group and malignant groups. Results： The mean CR of the images ranged from 0.71±0.41 at the b value of 300s/mm2 to 0.27±0.26 at the b value of 800 s/mm2. The mean CNR of the images ranged from 9.03±4.25 at the b value of 300 s/mm2 to 3.42±3.24 at the b value of 800 s/mm2. The CR and CNR of DWI with the b value of 300 s/mm2 were significantly different from that with other b val- ues（P〈0.05）. The CR values and CNR values between the benign fractures and malignant fractures were not statistically differ- ent. The mean ADC values of malignant fractures were significantly lower than those of benign ones on DWI with b values from 300 s/mm2 to 600 s/mm2. Conclusions： When DWI with multiple b values are used to differentiate benign from malignant vertebral compression fractures, smaller b value may be better.
出处
《中国临床医学影像杂志》
CAS
2013年第6期409-413,共5页
Journal of China Clinic Medical Imaging
关键词
腰椎
骨折
磁共振成像
Lumbar vertebrae
Fractures
Magnetic resonance imaging
