足踝部肌腱的多层CT低剂量三维成像研究

目的 探讨足踝部肌腱的低剂量CT扫描三维成像的可行性和合理性.方法 搜集足踝部骨折的连续病例45例,依序分3组:A组(80 kV、100 mAs)、B组(110 kV、60 mAs)、C组(常规组,130 kV、60 mAs),每组各15例,双侧踝部行6层CT扫描,采集模式1.0 mm ×6.分别测量足底部拇展肌CT值及噪声标准差(SD),记录容积CT剂量指数(CTDIvol)值,盲法评价各病例肌腱VR图像质量.对所获数据进行独立样本的单因素方差分析(ANOVA)方法检验或独立样本非参数检验(Kruskal-Wallis H).结果 A组肌肉平均CT值(71.6±12.0)HU]明显高于B组(66.8±9.2)HU,P=0.010]和C组(66.1±7.1)HU,P=0.004];SD值分别为11.9、9.1、7.0 HU,差异有统计学意义(F=37.124,P=0.000),以A组最大,C组最小;CTDIvol平均值分别为(3.01±0.08)、(4.63±0.11)、(7.02±0.24)mGy,差异有统计学意义(H=39.185,P=0.000),A组最小,C组最大;肌腱VR图像评分分别为(2.3±0.5)、(3.7±0.5)、(4.8±0.4)分,差异有统计学意义(H=72.779,P=0.000),图像质量以A组最差,C组最佳,B组图像质量达到诊断标准以上.结论 6层CT的110 kV与60 mAs组合、1 mm准直足踝部肌腱CT成像有良好图像质量而满足诊断需要.

Abstract：

Objective To study the feasibility and reasonability of low-dose multi-slice CT(MSCT)with three dimensional rendering of the tendons of foot and ankle. The statistical methods including ANOVA and Kruskal-Wallis H was used. Methods Forty-five consecutive patients with fractures of foot and ankle were enrolled and evenly grouped into A (80 kV, 100 mAs), B(110 k V ,60 mAs) and C (130 kV,60 mAs).The MSCT scanning range was 6 slices of 1.0 mm. The CT value and standard deviation (SD) of the muscle and the CTDIvol were recorded. The image quality of volume rendering of the tendons was blindly evaluated.Results The CT value of muscle in group A (71.6 ± 12.0) HU was significantly higher than group B (66.8±9.2) HU, P=0.010]and C(66. 1 ±7. 1) HU, P =0.004]. The SD average values were 11.9, 6. 1 and 7.0 HU for three groups, and there were significant differences among the three groups(F =37. 142, P=0. 0000). Group A had the highest SD value, group C had the lowest SD;CT1DIvol average value were (3.01 ± 0. 08) , (4. 63 ± 0. 11), (7.02 ± 0. 24) mGy respectively, which were significant different among the three groups (H =39. 185, P =0. 000). Group A had the lowest CTDIvol, while group C had the highest CTDIvol. Volume rendering of the tendons was evaluated as 2.3 ± 0. 5、3.7 ± 0. 5、4. 8 ±0. 4, and there were significant differences among the three groups (H = 72. 779, P = 0. 000). Group A had the worst VR images, while group C had the best VR images. All VR images in Group B were good for diagnosis. Conclusion The protocol of 110 kV, 60 mAs, and 1 mm × 6 with three-dimensional volume rendering would be enough for evaluating the tendons of foot and ankle.

Low-dose multi-slice CT with three dimensional rendering of the tendons of foot and ankle

Objective To study the feasibility and reasonability of low-dose multi-slice CT(MSCT)with three dimensional rendering of the tendons of foot and ankle. The statistical methods including ANOVA and Kruskal-Wallis H was used. Methods Forty-five consecutive patients with fractures of foot and ankle were enrolled and evenly grouped into A (80 kV, 100 mAs), B(110 k V ,60 mAs) and C (130 kV,60 mAs).The MSCT scanning range was 6 slices of 1.0 mm. The CT value and standard deviation (SD) of the muscle and the CTDIvol were recorded. The image quality of volume rendering of the tendons was blindly evaluated.Results The CT value of muscle in group A (71.6 ± 12.0) HU was significantly higher than group B (66.8±9.2) HU, P=0.010]and C(66. 1 ±7. 1) HU, P =0.004]. The SD average values were 11.9, 6. 1 and 7.0 HU for three groups, and there were significant differences among the three groups(F =37. 142, P=0. 0000). Group A had the highest SD value, group C had the lowest SD;CT1DIvol average value were (3.01 ± 0. 08) , (4. 63 ± 0. 11), (7.02 ± 0. 24) mGy respectively, which were significant different among the three groups (H =39. 185, P =0. 000). Group A had the lowest CTDIvol, while group C had the highest CTDIvol. Volume rendering of the tendons was evaluated as 2.3 ± 0. 5、3.7 ± 0. 5、4. 8 ±0. 4, and there were significant differences among the three groups (H = 72. 779, P = 0. 000). Group A had the worst VR images, while group C had the best VR images. All VR images in Group B were good for diagnosis. Conclusion The protocol of 110 kV, 60 mAs, and 1 mm × 6 with three-dimensional volume rendering would be enough for evaluating the tendons of foot and ankle.