- 學位論文
超音波動態影像於腕隧道症候群之診斷
Ultrasound Dynamic Imaging for the Diagnosis of Carpal Tunnel Syndrome
摘要
腕隧道症候群是在上肢當中最常見之周邊神經病變，其特徵為當正中神經通過腕隧道的時候遭到擠壓而導致的正中神經功能不良。此一疾病已被廣為確認與工作相關之肌肉骨骼系統疾病以及職場失能有相關性。然而這一疾病的正確診斷標準還未確立，傳統上腕隧道症候群主要是以病患臨床特徵以及理學發現來診斷。對於輕度到中度嚴重度之腕隧道症候群病人或是模稜兩可的狀況而言，神經傳導檢查通常有利於診斷且被視為目前腕隧道症候群診斷的黃金標準。當我們要計畫進行正中神經壓迫腕隧道減壓手術前，應該先安排神經傳導檢測以確定腕隧道症候群疾病之嚴重度以及將來術後之預後。目前已經有足夠的證據顯示高解析度超音波影像已被確立可用來當做腕隧道症候群的診斷工具之一。對比於神經傳導檢查，超音波動態影像可針對位於腕隧道內的正中神經本身的形態及動態變化提供解剖學方面的訊息，同時亦可以確認導致正中神經受壓迫之周圍組織的異常病灶組成。為了處理治療有症狀的腕隧道症候群病人，對臨床醫師而言關於此一疾病充分的知識了解是極為重要的，故在這篇論文當中為了提供患有腕隧道症候群疾病的病人適當之處置，針對腕隧道症候群這一疾病關於臨床、解剖、病理、診斷以及治療等方面進行了廣泛的回顧。這篇論文的目的係採用分析超音波動態影像技術，於手指握拳攤掌運動期間進行正中神經橫向位移模式之量測，想要來區別正常個體以及腕隧道症候群病人。我們先擷取正中神經運動時的橫向超音波影像，再利用斑點追蹤演算法來計算正中神經於橫向橈尺平面在B模式超音波影像上的橫向位移再加以平均，而我們使用的斑點追蹤演算法是以漸層區塊總和金字塔演算法為基礎而來。於單一手指攤掌握拳週期內各個不同時間點之平均橫向位移向量加以累積會得到一個時間累積橫向位移向量圖，之後再以二次元多項式方程式進行曲線校正回歸。校正回歸後的曲線即可視為某一正中神經的橫向滑移模式。根據校正回歸後的曲線再以電腦計算出其判定係數R平方、曲度curvature及最大位移amplitude，分別各代表此校正回歸的優良與否、變異性以及最大位移數值。接下來進一步使用箱形圖、接收者操作特徵曲線及模糊聚類法來進行統計學分析。手指運動期間正中神經在正常個體身上比輕度或嚴重腕隧道症候群患者的橫向滑移較大且有較陡峭的校正回歸曲線。正中神經於腕隧道內在不同時間點的橫向滑移變化與有無腕隧道症候群以及其嚴重程度發現有其關聯性。正中神經於手指運動時經計算出所代表的橫向位移模式證明有助於在腕隧道症候群病人當中定量估算正中神經功能不良。利用超音波動態影像技術整合發展正中神經之橫向滑移模式可視為診斷腕隧道症候群之新典範，同時超音波動態影像亦可以當做評估診斷腕隧道症候群的早期檢查工具，因其具有較好的設備可親近性、病患接受度，較低的花費，可偵測組織結構異常以及相似於神經傳導檢測的敏感性及特異性等優點。
並列摘要
Carpal tunnel syndrome (CTS), the most common peripheral neuropathy of the upper extremities, is characterized by entrapment of the median nerve as it travels through the carpal tunnel and the resulting nerve dysfunction. It is widely recognized as a factor in most cases of work-related musculoskeletal disorders and job disability. An accurate diagnostic standard for CTS is not yet established, and CTS is traditionally diagnosed on the basis of the patient’s clinical features and physical findings. For mild to moderate CTS or equivocal cases, nerve conduction studies (NCS) are useful to confirm the diagnosis and are usually considered the current gold standard in CTS diagnosis. If carpal tunnel release for median nerve compression is scheduled, NCS should be performed to assess the grade of CTS severity and predict surgical outcome. There is now sufficient evidence supporting high-resolution ultrasonography as a diagnostic tool in CTS. Complementary to NCS, ultrasound dynamic imaging can not only offer further anatomical clues on morphological and kinematic changes of the median nerve inside the carpal tunnel, but can also provide information on abnormal lesions of adjacent structures that may compromise the median nerve. A thorough knowledge of the disease is essential for clinicians to manage patients with symptomatic CTS, and the clinical, anatomical, pathogenic, diagnostic, and therapeutic aspects of CTS are comprehensively reviewed in this thesis to provide appropriate management of symptomatic subjects with CTS disorder. The aim of this thesis was to develop a technique that distinguishes between normal subjects and CTS patients by estimating the transverse sliding patterns of the median nerve during finger movements through analysis of ultrasound dynamic images. After acquisition of transverse ultrasound images of median nerve movement, a speckle-tracking algorithm based on a multilevel block-sum pyramid algorithm and averaging was applied in B-mode images to determine the lateral displacements of the median nerve in the radial-ulnar plane. Temporally cumulative lateral displacements were obtained by accumulation of all of the averaged lateral displacements at separate acquisition times within a single flexion–extension cycle of finger movement. The fitted curve acquired with a second-order polynomial function was considered the transverse sliding pattern of the median nerve. The goodness, variation, and maximum value of the fit were evaluated by computation of the R2 value, curvature, and amplitude of the fitted curves, respectively. Statistical analysis was performed using Box plots, the receiver operating characteristic (ROC) curve, and a fuzzy c-means clustering algorithm. Compared with individuals with mild or severe CTS, the transverse sliding of the median nerve during finger movements in normal subjects was greater and had a steeper fitted curve. Temporal changes in transverse sliding of the median nerve within the carpal tunnel correlated with both the presence of CTS and its severity. The representative transverse sliding patterns of the median nerve during finger movements allowed quantitative estimation of median nerve dysfunction in CTS patients. Incorporation of the transverse sliding patterns of the median nerve revealed by ultrasound dynamic imaging represents a new paradigm in the diagnosis of CTS. Ultrasound dynamic imaging should be advocated as the preliminary assessment method in CTS due to greater equipment accessibility and patient acceptability, reduced cost, and the ability to detect morphological abnormalities with similar sensitivity and specificity to NCS.