Visual Assessment of Coronary Calcifications on Diagnostic Chest CT Improves Diagnostic Accuracy of Tl-201 CZT SPECT Myocardial Perfusion Imaging

評估診斷性胸部電腦斷層中冠狀動脈的是否鈣化可提高單光子斷層心肌灌注掃描的診斷準確性

陳宏杰(Hong-Jie Chen) ； 張雁翔(Yen-Hsiang Chang) ； 黃永成(Yung-Cheng Huang) ； 徐健欽(Chien-Chin Hsu)

《核子醫學暨分子影像雜誌》 33卷1期 (2020/03) Pp. 17-27

https://doi.org/10.6332/ANMMI.202003_33(1).0003

摘要

Background: Single photon emission tomography (SPECT) myocardial perfusion imaging (MPI) can provide valuable diagnostic and prognostic information in patients with known or suspected coronary artery disease (CAD). Recently, the development of cadmium-zinc-telluride (CZT) SPECT MPI provided satisfactory sensitivity but suboptimal specificity for detecting CAD. Coronary artery calcification (CAC) is a useful CAD indicator when assessed by dedicated calcium scoring computed tomography (CT) scan. Simultaneous CAC scoring with CZT SPECT MPI offered incremental diagnostic and prognostic information over CZT SPECT alone using Tc-99m sestamibi. The aim of this study is to assess diagnostic implications of CAC incorporated with Thallium (Tl)-201 CZT SPECT MPI. Methods: We retrospectively analyzed patients who underwent invasive coronary angiography (ICA) within 6 months of SPECT MPI. Patients who received diagnostic chest CT within 6 months prior to ICA were included (n = 126). The MPI and CT images were interpreted by experienced nuclear medicine physicians and radiologists without knowledge of clinical history. For assessing the location and severity of perfusion defects, 17 segmentation scores and a 5-point scale were used. The global summed stress score (SSS) was calculated by adding all scores in 17 segments on stress images. MPI results were considered abnormal when SSS ≥ 4. Identification of any calcified region (HU ＞ 130) within coronary artery territories on non-contrasted CT scan was defined as CAC positive. A coronary stenosis ≥ 50% on ICA was considered obstructive CAD. Results: The specificity of MPI plus CAC were higher than in MPI alone (86% vs 71%; p = 0.004). The sensitivity showed no significant difference between MPI plus CAC and MPI alone (75% vs 78%; p = 0.5). Positive predictive value (PPV) of MPI plus CAC is 86% but only 76% in MPI alone (p ＜ 0.001). Negative predictive value (NPV) showed no significant difference (75% vs 73%; p = 1.0). Both SSS and CAC were independent factors predicting obstructive CAD. Conclusions: CAC provides additional diagnostic values by improving the specificity of Tl-201 CZT SPECT MPI.

關鍵字

chest CT ； coronary artery disease ； CZT ； myocardial perfusion imaging ； Tl-201

並列摘要

目的：單光子斷層掃描（single photon emission computed tomography, SPECT）心肌灌注成像（myocardial perfusion imaging, MPI）可為患有或疑似冠心病（coronary artery disease, CAD）的患者提供有價值的診斷和預後。最近，cadmium-zinc-telluride（CZT）SPECT MPI的發展提供了令人滿意的靈敏度，但檢測CAD的特異性卻欠佳。利用電腦斷層掃描進行鈣化評估時，冠狀動脈鈣化（CAC）的評分是有效的CAD指標。結合CAC評分和Tc- 99m sestamibi CZT SPECT MPI的評估相較於單獨使用使用CZT SPECT可以提供更多有關診斷和預後資訊。此研究目的為評估CAC對於鉈201（Tl-201）CZT SPECT MPI 的診斷意義。方法：回溯性分析在接受SPECT MPI後6個月內進行了心導管（invasive coronary angiography, ICA）的患者。同時在ICA前6個月內接受診斷性 胸部電腦斷層掃描（computed tomography, CT）檢查的患者（n = 126）。MPI和CT影像由未知病患病史的核醫科醫師和放射科醫師判讀。為了評估灌注缺陷的位置和嚴重性，使用了17個分區評分和5分制量表。通過將壓力相上17個分區中的所有得分相加來計算總壓力相分數（summed stress score, SSS）。當SSS大於4分時，MPI的結果判定為異常。在無顯影胸部CT掃描中，冠狀動脈區域內有任何鈣化區域（HU ＞ 130）則定義為CAC陽性。心導管檢查中冠狀動脈管徑狹窄大於50%則認定為阻塞性CAD。結果：使用MPI加上CAC判定的特異性高於單獨使用MPI檢查（86% vs. 71%; p = 0.004）。MPI加上CAC判定和單獨使用MPI之間的敏感性則沒有顯著差異（75% vs. 78%; p = 0.500）。MPI加上CAC的陽性預測值為86%，但單獨使用MPI僅為76%（p ＜ 0.001）。陰性預測值無顯著差異（75% vs. 73%; p = 1.000）。SSS和CAC都是預測阻塞性CAD的獨立因子。結論：可以透過CAC的判定改善Tl-201 CZT SPECT MPI的特異性提供了附加的診斷價值。

並列關鍵字

心肌灌注掃描 ； 胸部電腦斷層掃描 ； 冠心病 ； 鉈-201 ； CZT