氣體影像在臨床超音波診斷中的應用

超音波檢查已成為臨床上最常用之影像檢查方法之一，但是遇到氣體存在時，常因氣體產生之高回音而影響深部器官之檢查。雖然氣體對超音波檢查造成干擾，善加利用卻可對超音波診斷有所幫助。在胸腹腔的超音波檢查中，利用自身氣體作為對比，可將氣體聲像歸納4個方面辨認和診斷：1.呆滯氣體：存在於管腔、血管、或實質組織中，具有強回聲的多次反射和聲影聲尾，可見於膽道、膀胱、闌尾、腎盂、子宮等。2.游離氣體：隨體位變換而向高處爬行，或隨心脈搏動原位顫動，獨立於可移動的臟器之外，不隨臟器同步移動，可見於液氣胸和氣腹。3.勾劃出臟器輪廓的氣體聲像：可發現膈肋竇微量積液、肺葉間積液、和透明樣肺不張。腸管內氣體能勾劃出腸管擴張和腸套疊，還能襯托出腸間團塊。4.皮下氣腫：氣體聲衰減所致的近場高度明亮，遠場臟器模糊暗淡的特徵，在微量皮下氣腫時即有顯示。熟悉氣體聲像之變位並善加利用，可以將氣體之干擾變為有用之顯影對比，在某此狀況下，如胃腸穿孔、腸套疊、及臟器的積氣或產氣菌感染，會比放射線檢查更為優越。

關鍵字

氣體；氣體聲像；超音波

並列摘要

Ultrasonography is becoming the imaging modality of choice in many circumstances. But ultrasound imaging is frequently interfered by the presence of air which produces strong echo and causes posterior attenuation. The presence of air within certain organs may or may not be associated with abnormal clinical conditions. Although air causes interference and may be troublesome during ultrasound examinations, sometimes it may be of diagnostic importance. From our observation, 4 patterns of ultrasound images produced by air can be identified: 1) unvarying air in the ducts, vessels, or tissues normally containing no air; 2) free air in the pleural or peritoneal cavities; 3) air in hollow organs or lung which outlines the adjascent structure; 4) subcutaneous air. Familiarity with these air patterns can make the troublesome air become a natural contrast for imaging. In certain conditions, ultrasound examination can be more sensitive and specific than plain radiography.

並列關鍵字

air imaging modalities ； ultrasonography ； air

國際替代計量

氣體影像在臨床超音波診斷中的應用

全文下載

主題瀏覽