University Hospital Heidelberg, Department of Otorhinolaryngology, Heidelberg, Germany.
Otol Neurotol. 2010 Apr;31(3):440-6. doi: 10.1097/MAO.0b013e3181d2775f.
A-mode ultrasound scanning with coded signals allows bone thickness measurements at the site of bone-anchored hearing aid surgery as compared to computed tomographic scanning and mechanical measurements.
Adequate bone thickness is a prerequisite for successful, long-lasting osseointegration of titanium fixtures for bone-anchored hearing aids. Computed tomography can be used to measure bone thickness but has several drawbacks.
Bone thickness was measured at the site of bone-anchored hearing aids surgery in 28 formaldehyde-preserved human cadaver temporoparietal bones. Four blinded investigators used a hand-held, A-mode ultrasound system with direct coupling at 2.25 MHz transducer using coded signals (SonoPointer) and repeated the measurements twice. Comparisons were made with high-resolution computed tomographic scanning and mechanical micrometer caliper measurements.
There was significant anatomical variation in the temporoparietal bones. Computed tomography was in good agreement with the mechanical reference. All specimens could be measured by the SonoPointer. The mean difference between the mechanical control and ultrasound scanning averaged for all measurements by all investigators was 0.3 mm (standard deviation, 1.2 mm). Trained ultrasound experts yielded better results (mean difference, 0.3 mm; standard deviation, 1.0 mm). Agreement was best for bone thickness up to 5 mm. Outliers occurred in bones thicker than 7.5 mm.
The SonoPointer is a promising, noninvasive, hand-held tool for real-time measurement of bone thickness in bone-anchored hearing aid surgery, especially for children. Even disregarding the absolute thickness reading, the SonoPointer could be used to search intraoperatively for a local maximum of bone thickness.
与计算机断层扫描和机械测量相比，编码信号的 A 型超声扫描可在骨锚式助听器手术部位进行骨厚度测量。
足够的骨厚度是钛植入物成功、长期骨整合的必要条件骨锚式助听器。计算机断层扫描可用于测量骨厚度，但有几个缺点。
在 28 个福尔马林保存的人尸颞顶骨的骨锚式助听器手术部位测量了骨厚度。四名盲法研究者使用手持式 A 型超声系统，在 2.25 MHz 换能器上使用编码信号（SonoPointer）直接耦合，并重复测量两次。将其与高分辨率计算机断层扫描和机械测微计测量进行比较。
颞顶骨存在显著的解剖学变异。计算机断层扫描与机械参考值吻合良好。所有标本均可用 SonoPointer 进行测量。所有研究者对所有测量结果的机械对照和超声扫描的平均差异为 0.3 毫米（标准差为 1.2 毫米）。经过培训的超声专家得出了更好的结果（平均差异为 0.3 毫米，标准差为 1.0 毫米）。对于厚度达 5 毫米的骨，一致性最好。在厚度超过 7.5 毫米的骨中出现离群值。
SonoPointer 是一种有前途的、非侵入性的、手持式工具，可用于实时测量骨锚式助听器手术中的骨厚度，特别是对于儿童。即使不考虑绝对厚度读数，SonoPointer 也可用于术中搜索局部骨厚度最大值。
