Giubbini Raffaele Mario Tarquinio, Gabanelli Sara, Lucchini Silvia, Merli Giuseppe, Puta Erinda, Rodella Carlo, Motta Federica, Paghera Barbara, Rossini Pierluigi, Terzi Arturo, Bertagna Francesco
Chair of Nuclear Medicine, University of Brescia, Spedali Civili di Brescia, Italy.
Nucl Med Commun. 2011 Nov;32(11):1026-32. doi: 10.1097/MNM.0b013e32834b4575.
Attenuation correction (AC) has been shown to improve the accuracy of myocardial perfusion single photon emission computed tomography (SPECT) for the detection and evaluation of patients with coronary artery disease. Attenuation artifacts, because of diaphragmatic attenuation, frequently affect the evaluation of the inferior wall, especially in male patients.
The aim of this study was to evaluate the value of AC for the assessment of infarct size in coronary artery disease patients after inferior myocardial infarction.
Gated-SPECT with Tc-labeled compounds with AC by hybrid SPECT/computed tomography (CT) was performed in 56 male patients with documented previous inferior myocardial infarction. Both corrected and uncorrected SPECT images were processed after motion and scatter correction by ordered-subset expectation maximization iterative reconstruction. When needed, a manual realignment between SPECT and computed tomography (CT) sections was performed. Uncorrected and corrected SPECT images were analyzed for perfusion using a 5-point segmental scoring scale from 0 (normal) to 4 (absent). Summed stress score (SSS), summed rest score (SRS), and summed difference score (SDS) of the inferior left ventricle wall (inferoseptal, inferior, infero-apical and infero-lateral segments) were determined and compared with the regional wall motion score as determined by uncorrected gated-SPECT.
The SSS, SRS, SDS for attenuation-uncorrected and attenuation-corrected studies were 14.02 ± 7.9, 9.51 ± 7, 4.5 ± 3.2 and 9.39 ± 7.1, 5.6 ± 6.1, 3.8 ± 2.8, respectively. Differences were statistically significant (P<0.0001) for SSS and SRS but not for SDS. The regional summed rest score of the inferior wall (SRS of inferior segments) showed a better correlation with the regional summed wall motion score of the same segments: R²=0.50 in comparison to uncorrected SRS, R²=0.46.
The combination of diaphragmatic attenuation and inferior myocardial infarction determines an artifactual overestimation of infarct size of inferior infarcts. The AC regional perfusion score (SRS) correlates with the regional wall motion score of the inferior wall. AC does not affect the detection and size of residual ischemia (SDS).
已证实衰减校正（AC）可提高心肌灌注单光子发射计算机断层扫描（SPECT）检测和评估冠状动脉疾病患者的准确性。由于膈肌衰减导致的衰减伪影经常影响下壁的评估，尤其是在男性患者中。
本研究旨在评估AC在评估下壁心肌梗死后冠状动脉疾病患者梗死面积方面的价值。
对56例有下壁心肌梗死病史的男性患者进行门控SPECT检查，使用锝标记化合物，并通过SPECT/计算机断层扫描（CT）进行AC。经有序子集期望最大化迭代重建进行运动和散射校正后，对校正和未校正的SPECT图像进行处理。必要时，对SPECT和计算机断层扫描（CT）层面进行手动重新对齐。使用从0（正常）到4（无灌注）的5分节段评分量表分析未校正和校正后的SPECT图像的灌注情况。确定左心室下壁（下间隔、下壁、下尖段和下侧壁节段）的总应力评分（SSS）、总静息评分（SRS）和总差异评分（SDS），并与未校正的门控SPECT确定的节段壁运动评分进行比较。
未进行衰减校正和进行衰减校正研究的SSS、SRS、SDS分别为14.02±7.9、9.51±7、4.5±3.2和9.39±7.1、5.6±6.1、3.8±2.8。SSS和SRS差异有统计学意义（P<0.0001），但SDS差异无统计学意义。下壁的区域总静息评分（下节段的SRS）与相同节段的区域总壁运动评分显示出更好的相关性：与未校正的SRS相比，R²=0.50，R²=0.46。
膈肌衰减和下壁心肌梗死共同导致下壁梗死面积的人为高估。AC区域灌注评分（SRS）与下壁的区域壁运动评分相关。AC不影响残余缺血的检测和范围（SDS）。
