心脏多层螺旋CT增强扫描对电极穿孔的诊断价值

Assessment of Lead Perforation Using Cardiac Multi-slice Computed Tomography Contrast Enhancement Scan

【目的】探讨心脏起搏器或植入型心律转复除颤器导线穿孔患者心脏多层螺旋CT增强扫描的影像学表现和诊断价值。【方法】分析经临床、多种影像学检查及手术探查等证实的10例导线穿孔患者的心脏CT表现,判断导线穿孔与否、穿孔位置、有否合并心包积液、有无对比剂漏出至心包腔内、导线及其头端伪影。【结果】10例患者中仅1例胸部X线可明确诊断,6例超声心动图结合新发心包积液及起搏器程控参数诊断导线穿孔。心脏CT检查含常规CT增强扫描5例,序贯式心电门控CT增强扫描及随后的延迟增强扫描5例,CT诊断明确导线穿孔5例,可疑导线穿孔5例。穿孔位于右心尖7例,右室膈面2例,右心房后上壁1例。少至大量心包积液8例,无心包积液2例。5例行延迟增强扫描,均未发现对比剂延迟外漏至心包腔。10例行常规CT增强扫描患者(含5例心电门控扫描后的延迟增强扫描),所有患者导线及导线头端均产生运动伪影;9例患者导线产生中、重度金属伪影,1例患者导线未产生金属伪影;8例患者导线头端产生中、重度金属伪影,2例患者导线头端产生轻度金属伪影。5例行心电门控CT增强扫描患者,导线及导线头端均未产生运动伪影;2例患者导线产生轻度金属伪影,3例患者导线未产生金属伪影;4例患者导线头端产生轻度金属伪影,1例患者导线头端产生中度金属伪影。【结论】多层螺旋CT增强扫描有助于明确导线穿孔,尤其是心电门控增强扫描因减轻导线及其头端的运动伪影和金属伪影,可提高诊断准确率。

[Objective] To assess the imaging features and diagnostic value of muhi-slice computed tomography （CT） enhanced scanning in patients with cardiac lead perforation. [Methods] Cardiac CT findings in 10 cases with pacemaker or implantable cardioverter-defibrillators lead perforation were analyzed, including the efficacy of CT for visualization of lead perforation, the precise location of the perforated lead tips, and the streaking artifacts and acoustic shadowing from the metallic lead. [Results] Five patients received conventional CT enhanced scan alone, and another 5 received ECG-gated enhanced scan followed by delayed enhancement. Among the 10 cases, only 1 case can be confirmed lead perforation by chest x-ray, and echocardiographic findings are equivocal in 6 patients. By CT scan, 5 cases with probable and another 5 with definitelead perforation were documented, with 7 perforating in right ventricular apex, 2 in right ventricular diaphragmatic surface, and 1 inright atrial posterior wall.There were 8 cases with small to large pericardial effusion, 2 cases with no pericardial effusion. There was no contrast-medium found external leakage to the pericardial cavity in 5 patients with delayed enhancement scan. Among 10 patients accepted conventional CT scan（including 5 cases with delayed enhancement following ECG gating）, all cases produced motion artifacts of wired and lead tip, 9 cases with moderate to severe metal artifacts of wired, 1 case with no metal artifact of wired, and 8 with moderate to severe metal artifacts of lead tip, 2 with mild metal artifacts of lead tip. Meanwhile, among 5 patients with ECG-gated scan, there was no case with motion artifact of wired and lead tip, 2 cases with mild metal artifacts of wired, 3 cases with no metal artifact of wired, 4 cases with mild metal artifacts of lead tip, 1 case with moderate metal artifact of lead tip. [Conclusion] Multi-slice CT can be a helpful adjunct to other imaging facilities in the diagnosis of lead perforation. Contrast-enhanced CT scan with ECG gatingmay improve the diagnostic accuracy due to its reduction of artifacts of lead and its tip.