乳房X光攝影微鈣化群之電腦三度空間定位

Three-dimensional Localization of Microcalcifications on X-ray Mammograms

李三剛(San-Kan Lee) ； 楊勝智(Sheng-Chih Yang) ； 詹寶珠(Pau-Choo Chung) ； 羅見順(Chien-Shun Lo) ； 楊晴雯(Ching-Wen Yang) ； 李覃(Tain Lee) ； 張建褘(Chein-I Chang)

《中華放射線醫學雜誌》 26卷3期 (2001/06) Pp. 107-118

摘要

乳房的腫瘤常須要以細胞學或病理組織的檢查結果決定治療處置的方式，對於觸摸不到的腫塊尤其是由乳房X光攝影偵測到的微鈣化病灶，僅能靠頭腳相與斜側相來判斷病灶的所在位置，然而有些病例存在多個微鈣比群，或是影像不清時，並不容易經由兩張影像來定位出微鈣化群的位置，於是得探用穿刺鐵絲定位以找出正確的位置。像這樣的步驟，得花費不少的人力、物力，並且X光具有幅射性，增加定位的穿刺次數，等於是增加攝影的次數，將對病患的健康有礙，也相對的耗費醫療資源。針對此點我們設計一套微鈣化群的電腦輔助定位系統，經由輸入頭腳相與斜側相兩張影像，藉由電腦影像處理技術重建出病人的乳房立體三度空間模型，並標示出微鈣化群的位置與分佈範圍，以協助醫師在術前減少切片穿刺的次數，並顯示出病灶的正確位置，提供手術時參考。
本系統使用一部乳房X光攝影數位化設備，配合相連線之個人電腦做為輸出，顯示乳房三維立體架構。流程中包含微鈣化群的電腦自動偵測判斷、頭腳相與斜側相的微鈣化群校準、乳頭自動偵測等影像處理技術，才能正確地顯示微鈣化群的所在位置與分佈範圍。經由詳細的測試，此一設計軟體可將頭腳相與斜側相所得到的微鈣化群位置，藉系統校準、對應、座標轉換後，將其標示在已知的乳房三維模形中，此位置可經由虛擬實境建構語言(Virtual Reality Modeling Language)瀏覽器瀏覽。

關鍵字

微鈣化群 ； 乳房X光攝影 ； 定位 ； 三度空間

並列摘要

Breast tumors require the results of a cytology or pathology examination in order to decide on further management. For non-palpable breast rumors, especially mammography-detectable microcalcifications, the location of the lesion can be determined only from craniocaudal (CC) and mediolateral oblique (MLO) views on mammograms. However, in a case with multiple clusters of microcalcifications or when the image quality is not optimal, it is not easy to localize the microcalcifications using these 2 views. One has to use wire localization to identify the exact site. With this procedure, much manpower and materials must be expended; even the radiation dose of X-rays will be increased due to an increased number of exposures required for needle localization. This is not only hazardous to patients, but also wastes valuable medical resources. To solve this problem, we designed a computer-aided localization system for microcalcifications. After inputting the CC and MLO views of mammograms and with the aid of computer image-processing techniques, a 3-dimensional (3D) breast model was reconstructed to demonstrate and delineate the exact site and distribution of microcalcifications. This model can be used to assist doctors in reducing the number of punctures needed for a biopsy preoperatively, and in demonstrating the exact location of a lesion for reference during operations.
The hardware of this system includes equipment necessary to obtain digital images of X-ray mammograms and to network with the personal computer which is also used as an output device to demonstrate the 3D structures of the breast. The flowchart of this software consists of special image-processing techniques of auto-detection and determination of clustered microcalcifications, adjustments for clustered microcalcifications on CC and MLO views, and auto-detection of the nipple, in order to accurately demonstrate the location and distribution of clustered microcalcifications. After delicate testing, the location of the clustered microcalcifications detected from CC and MLO views can be well demonstrated on the constructed 3D model after system calibration, comparison, and axis transformation from the designed software. The exact location of the lesion can be viewed with a virtual reality modeling language viewer.

並列關鍵字

Microcalcification ； X-ray mammography ； Localization ； 3-dimensional