Quality of Interpretation Of Computed Tomography Images In The Emergency Department

急診部門對電腦斷層圖像之判讀品質研究

李芳年(Fang-Niarn Lee) ； 蔡哲宏(Jeffrey Tsai) ； 顏鴻章(David Yen) ； 羅鴻彰(Hong-Chang Lo) ； 陳啟華(Chii-Hwa Chern) ； 高偉峰(Wei-Fong Kao) ； 胡勝川(Sheng-Chuan Hu) ； 李建賢(Chen-Hsen Lee) ； 張珩(Hang Chang)

《中華民國急救加護醫學會雜誌》 9卷1期 (1998/03) Pp. 1-7

https://doi.org/10.30018/JECCM.199803.0001

摘要

對病人之照護，急診之功能越來越重要，許多急診醫師必需依據自己對放射線影像的判讀來決定病人的初步處置；又影像傳輸提供另一種放射線診斷服務。我們設計此一前瞻性研究，以探討急診醫師對藉由影像傳輸系統處理的腦部電腦斷層圖像判讀之凖確性，及因急診醫師之判讀差異而導致病人處置差異的機率亦同時探討之。
從1995年12月到1996年1月間，有534位病人於台北榮民總醫院急診部進行腦部電腦斷層檢查，其中共有483位病人的腦部電腦斷層圖像成功地經由影像傳輸系統傳輸到急診室。急診醫師對經由影像傳輸系統處理之圖像判讀和放射線醫師對原始軟片判讀結果互做比較。此外，我們亦要求急診醫師判讀經由影像傳輸系統成功處理圖像中的四分之一病例原始軟片，以監拉急診醫師對經由影像傳輸系統處理之圖像和原始軟片間的判讀差異。
執行腦部電腦斷層檢查的三大適應症為：局部神經徵候(37.5%)，神智改變(27.0%)，外傷(22.5%)。其他的原因為頭痛(7.7%)，抽搐(7.1%)及暈眩或嘔吐(5.6 %)。此電腦斷層檢查結果有403例(75.5%)被放射線醫師判讀為陽性結果，其十大異常發現為腦梗塞(53.1%)，皮質下層血管粥狀硬化性腦病變(22.1%)，腦實質出血(16.6%)，腦萎縮(14.9%)，鈣化(12.9%)，腦水腫(8.4%)，頭皮血腫(7.7%)，腦中線偏移(7.4%)，腫塊(6.7%)及蜘珠膜下腔出血(6.2%)。急診醫師和放射線醫師對電腦斷層圖像的判讀差異共有132例(27.3%)，這些差異包含：6例重大假陰性結果(l.2%)，96例些微假陰性結果(19.9%)，17例些微假陽性結果(3.5%)，13例的些微假陰性及假陽性結果(2.7%)及0例重大假陽性結果。急診醫師的判讀誤差主要是：細微腦梗塞，鈣化，皮質下層血管粥狀硬化性腦病變，竇炎及腦萎縮。而6例的重大假陰性結果包括：3例腦梗塞，2例腫塊及l例硬腦膜下血腫塊，但無一病人被處置不當及無一病人有不良預後。而急診醫師對判讀原始軟片結果和判斷影像傳輸系統處理之影像結果之比較，有76例(62.8%)為相同結果，有15例(12.4%)有較多發現，但有30例(24.8%)則反而變差；但影像傳輸系統讓急診醫師能更快的判讀電腦斷層圖像，急診醫師判讀電腦斷層圖像的時間為完成斷層檢查後的2.1+3.0小時，比放射線醫師的判讀時間20.3±22.3小時明顯縮短許多（p值＜0.001）。
急診醫師應接受更多的影像判讀訓練，以防在無神經科或放射線醫師之支援下，仍然能作出正確之決定。

關鍵字

準確性 ； 電腦斷層檢查 ； 急診醫師 ； 判讀 ； 影像傳輸系統 ； 品質

並列摘要

Patient care is increasingly dependent on emergency department services. Teleradiology provides a method of supplementing radiology services. We conducted a prospective study to evaluate the accuracy of interpretation for cranial computed tomography (CT) images transmitted by Picture Archives Communication System (PACS), with the image viewed on a computer screen. In addition, incidents of misinterpretation leading to an alteration in patient care were reviewed.
Five hundred and thirty-four patients undergoing cranial CT scanning in the emergency department (ED) from December 1995 to January 1996 were reviewed. The PACS transmitted 483 patients’ cranial CT images successfully. The interpretations of the PACS transmitted images, by emergency physicians (EPs), were compared with those of the original films, by radiologists. We then asked the EPs to read the original CT films in a randomly selected 25% (121 out of 483) of successfully transmitted cases, in order to compare differences in image reading between original films and PACS images.
The leading three indications for CT scanning were neurologic focal signs (200, 37.5%), altered mental status (144, 27.0%), and trauma (120, 22.5%). The other indications were headache (41, 7.7%), seizure (38, 7.1%) and dizziness, vertigo and/or vomiting (30, 5.6%). The CT scans were reported to be positive by radiologists in 403 cases (75.5%). The top ten abnormalities were infarction (53.1%), subcortical arteriosclerotic encephalopathy, SAE (22.1%), parenchymal hemorrhage (16.6%), brain atrophy (14.9%), calcification (12.9%), cerebral edema (8.4%), scalp hematoma (7.7%), midline shift (7.4%), mass (6.7%), and subarachnoid hematoma (6.2%). Non-concordance between the CT interpretations by the EPs and radiologists were found in 132 cases (27.3%). These non-concordances included 6 major false negatives (1.2%), 96 minor false negatives (19.9%), 17 minor false positives (3.5%), 13 minor false negative + minor false positives (2.7%), and no major false positives. Most of the non-concordant interpretations by EPs were lacunar infarction, calcification, SAE, sinusitis and brain atrophy. The six cases with major false negative included 3 infarctions, 2 masses, and I subdural hematoma, however, no patient was managed inappropriately, and none had an adverse outcome. The same results were achieved in 76 cases (62.8%) when the EPs read the original CT films, as compared to reading the PACS transmitted images. The EPs reported more .findings in 15 cases (12.4%), and less in the other 30 cases (24.8%). The time to interpretation post CT scan was 2.1 ±3.0 hours for EPs, and 20.3 ±22.3 hours for radiologists (p＜0.001).
Misinterpretation of cranial CT scans by EPs is of potential clinical concern, however, no resultant clinical errors were found in this study. We recommend that formal training in CT interpretation be included in residency training and continuing medical education programs for EPs, to ensure important errors are not made during the acute early phase of care.

並列關鍵字

accuracy ； computed tomography ； emergency physicians ； interpretation ； picture archives communication system (PACS) ； quality