背景：鉈-201心肌灌注單光子射出電腦斷層掃描為目前偵測冠狀動脈心臟疾病極重要的非侵襲性檢查項目之一，然而結果並不令人滿意，主因為光子於射出過程會受到身體組織衰減，影響了診斷的正確性，本研究探討非一致性衰減校正和無衰減校正鉈-201心肌灌注造影在偵測冠狀動脈心臟疾病之臨床診斷差異性。
方法；100位冠狀動脈心臟疾病高危險群的病患，採用潘西丁(persantin)藥理剌激後。再靜脈注射2 mCi (74 MBq) 鉈-201氯化亞鉈製劑，給藥後5分鐘及3小時各進行一次造影以資比較、造影以ADAC vcrtcx plus雙頭攝影機及兩條掃描式釓-153線射源進行之。影像重組使用反覆式最大可能重建的數學模式處理，經衰減圖處理者為非一致性衰減校正(non-uniform attenuation correction, AC)影像；未經衰減圖處理者為無衰減校正 (non-attenuation correction,NC)影像。影像結果以左心室水平、垂直及短軸方向三種斷層切面顯示。以卡方檢定法評估非一致性衰減校正和無衰減校正之臨床診斷差異性，P<0.05設為顯著差異。
結果：100位病人當中，43位男性中的23位，以及57位女性中的28位有明顯差異(P值分別為0.0006及0.0047)。
結論：本研究結果顯示AC與NC之間有很大的臨床診斷差異。

Background: Thallium-201 myocardial perfusion single photon emission computed tomography (SPECT) is a valuable tool for the detection and localization of coronary artery disease (CAD). However, it is regarded as less satisfactory. Particularly, the diagnostic accuracy is limited by irregular intrathoracic photon attenuation. The aim of thisstudy was to compare non-uniform attenuation correction (AC) and non-attenuation correction (NC) for the detection of CAD patients.
Methods: One hundred CAD patients were enrolled to undergo myocardial perfusion SPECT. Persantin-induced stress study and redistribution study were performed 5 min and 3 h, respectively, after administration of 2 mCi (74MBq) thallium-201 thallous chloride. All images were acquired with a dual-head gamma camera (ADAC vertex plus), equipped with L-shape positioned detectors and two scanning gadolinium-153 line sources, Images were reconstructed using iterative maximum-likelihood algorithm with and without AC. Thereafter, horizontal and vertical as well as short axis slices of the left ventricle were displayed in the usual manner. The significance of difference between AC and NC studies were analyzed by the use of a bivariate chi-square test. The significance level was set at P<0.05.
Results: Among 100 patients studied, 23 of 43 males and 28 of 57 females showed significant difference between AC and NC, with P = 0.0006 and P= 0.0047, respectively.
Conclusion: The results of this study reveal significant diagnostic difference between AC and NC.