Barthez P Y, Bais R J, Vernooij J C M
Division of Diagnostic Imaging, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 10, NL-3508 TD, Utrecht, The Netherlands.
Vet Radiol Ultrasound. 2007 Sep-Oct;48(5):457-9. doi: 10.1111/j.1740-8261.2007.00278.x.
The purpose of this study was to determine if variation in the ultrasound beam angle would affect cartilage thickness measurement performed with B-mode ultrasonography. Transverse sections of six fresh equine middle phalanges were obtained from necropsy. Ultrasonographic images of the proximal articular cartilage were obtained in a water bath, in a plane parallel and adjacent to the section plane using a 5-10 MHz linear transducer. Static images were acquired for all six bone specimens with an ultrasound beam angle of 0 degree, 30 degrees, 45 degrees, and 60 degrees. Proximal articular cartilage thickness was measured on ultrasonographic images and on the bone specimen at the same level. A linear mixed-effects model was used to compare articular cartilage thickness measured on specimen and on ultrasonographic images using different ultrasound beam angle. Mean +/- SD cartilage thickness was 1.82 +/- 0.35 mm on bone specimens, 1.72 +/- 0.29 with a 0 degrees angle, 1.99 +/- 0.34 with 30 degrees, 2.06 +/- 0.34 with 45 degrees, and 2.3 +/- 0.38 with 60 degrees. There was a significant difference between macroscopic measurements and ultrasonographic measurements performed with ultrasound angles at 30 degrees, 45 degrees, and 60 degrees. There was a significant increase in cartilage thickness when the ultrasound beam angle decreased (P = 0.0157; R2 = 0.969). Cartilage thickeness measured on ultrasonographic images varies with the ultrasound beam angle and may not be accurate because ultrasound speed in cartilage may be different than the speed used by the ultrasonographic unit for distance calculation.
本研究的目的是确定超声束角度的变化是否会影响用B型超声进行的软骨厚度测量。从尸检中获取了六个新鲜马中节指骨的横切面。使用5-10MHz线性换能器，在与切面平行且相邻的平面内，于水浴中获取近端关节软骨的超声图像。对所有六个骨标本，分别以0度、30度、45度和60度的超声束角度采集静态图像。在超声图像和同一水平的骨标本上测量近端关节软骨厚度。使用线性混合效应模型比较在不同超声束角度下，在标本和超声图像上测量的关节软骨厚度。骨标本上软骨厚度的平均值±标准差为1.82±0.35mm，0度角时为1.72±0.29，30度时为1.99±0.34，45度时为2.06±0.34，60度时为2.3±0.38。在30度、45度和60度超声角度下进行的宏观测量和超声测量之间存在显著差异。当超声束角度减小时，软骨厚度显著增加（P = 0.0157；R2 = 0.969）。在超声图像上测量的软骨厚度随超声束角度而变化，可能不准确，因为软骨中的超声速度可能与超声设备用于距离计算的速度不同。
