背景：不同頻率的超音波探頭之解析度不同，曲線陣列探頭可吻合枕骨下緣至頸部的弧度，有潛力用於 测量枕骨與頸椎之距離。因此筆者欲探討腹部超音波常用之2〜5 MHz曲線陣列探頭掃瞄影像之横向解析度-作為進一步使用此工具的基礎。目的：檢测2 ~ 5 MHz曲線型探頭於自製假體模型之解析度。並以此探頭及游 標卡尺測量一標準長方體塑膠物 > 比較測量結果之差異。實驗方法：自製的假體系統，以7根石墨棒（直徑為 0.5 mm)兩兩相隔不同之距離（0.5, 1, 2, 3, 4, 5 mm) ’測試探頭在深度1 cm與3 cm之横向解析度’再使用超音 波测量一塑膠立方體在探頭下6個不同位置時的長度，比較超音波测量結果與游標卡尺測量結果之差異。結果： 當假體模型置於1 cm及3 cm深處時，兩根石墨棒距離相距1 mm及以上時,才可以肉眼清楚辨識超音波影像 中有兩根石墨棒。使用超音波量得之假體模型長度與游標卡尺量得長度差異小於0.65 lmm ,量測誤差小於2%。 結論：可探用2 ~5 MHz曲線型探頭來测量大於1 mm之距離。生物體的距離大於此解析度，將可運用超音波影像量测。（物理治療2016;41(4):264-270)

Background: The curvilinear probe with lower frequency (2-5 MHz) provides much poor resolution chan the linear probe with higher frequency (7-12 MHz). A2-5 MHz curvilinear array transducer which commonly used in abdominal scanning is relatively suitable for measuring the distance of an object with a curvy surface. Its shape fits the curvature of the spine, and has potential to measure the segmental distance between occipital bone and vertebrae. Before adapting this new measurement method for segmental bony distance, the lateral resolution and accuracy of a curvilinear array transducer need to be tested, Purposes： To evaluate the lateral resolution and accuracy of the ultrasonography with a 2- 5 MHz curvilinear array transducei using a designed phantom system. Methods: Seven fine graphite sticks (diameter: 0.5 mm) were placed in a row at a difference distance of 0.5 mm> 1 mm, 2 mm, 3 mm, 4 mm, 5 mm at bottom of a tank filled with water. The graphite phantom system was placed 1 cm and 3 cm below a 2-5 MH/ curvilinear array transducer to study the lateral resolution. A plastic phantom was placed in 6 different positions under the probe. The lengths of this plastic phantom those measured by curvilinear probe. Tlie measurements from ultrasonography and Vernier calliper were cornpared. Results: Using the ultrasound scanning images obtained from 2-5 MHz curvilinear array transducer, it is unable to identify two objects with interval of 0.5mm ac the depth of 1 or 3 cm. While the interval was larger than 1 mm, the ultrasound image of two graphite sticks could be identified-Tlie difference of phantom lengths obtained from 2-5 MHz curvilinear array transducer and Vernier caliper is less than 0.65 mm, the measurement tolerance is less than 2%. Conclusions: Distance larger chan 1mm can be identified by using the ultrasound seanning images obtained from 2-5 MHz curvilinear array transducer. Ultrasound image could be a potential tool for measurement of the segmental bony distance. (FJPT 20l6;4l(4);264-270)