心脏黏液瘤多模态成像特点及诊断模式

目的探究心脏黏液瘤（CM）多模态成像特点及其多模态诊断模式。 方法回顾性研究2016年7月至2019年8月在阜外医院行二维经胸超声心动图检查初诊为CM的178例患者，以病理结果为金标准，将研究对象分为CM组和非CM组，根据超声心动图特点将CM组划分为典型CM组和非典型CM组。分析归纳各组患者的临床特征，二维经胸超声心动图、多层螺旋计算机断层摄影术（MSCT）和心脏磁共振成像（CMR）特点，采用t检验、χ²检验或Fisher确切概率法比较组间差异。 结果178例初诊为CM的患者中有160例患者行手术治疗和病理检查（89.9%），病理证实CM患者150例，10例为非CM患者：低度恶性纤维黏液肉瘤1例，未分化多形性肉瘤1例，血管肉瘤1例，血管瘤2例，脂肪瘤2例，血栓3例。二维经胸超声心动图、MSCT、CMR诊断准确性分别为93.8%、96.3%、100%。典型CM组合并高血压和心房颤动的比例低于非典型CM组（25.4% vs 53.1%；2.5% vs 18.8%），差异具有统计学意义（χ²=8.978、9.027，P均=0.003）；典型CM组左心房前后径、二尖瓣舒张早期峰值流速显著大于非典型CM组［（39.21±6.34）mm vs （35.92±5.72）mm；（1.59±1.67）m/s vs （0.90±0.25）m/s］，差异具有统计学意义（t=2.357、2.040，P=0.020、0.043）；二维经胸超声心动图成像显示，非典型CM组平均长径显著小于典型CM组［（34.81±17.43）mm vs （45.99±16.73）mm］，瘤蒂或基底宽度显著大于典型CM组［（13.02±7.28）mm vs （9.97±4.73）mm］，差异具有统计学意义（t=3.324、-2.506，P=0.001、0.014），非典型CM的分布、附着部位、形态、活动度、瘤蒂存在情况以及房室瓣口梗阻情况与典型CM比较差异均具有统计学意义（P均＜0.05）；MSCT成像显示CM以低密度为主，中等混杂密度比例和存在强化的比例高于典型CM，但差异无统计学意义（P均＞0.05）；CMR成像显示非典型CM T1、T2加权像信号强度与典型CM类似（P均＞0.05）。非CM占位平均长径小于典型CM，但差异没有统计学意义（P＞0.05），平均短径与典型CM类似，瘤蒂或基底的宽度显著大于典型CM［（13.35±6.80）mm vs （9.97±4.73）mm］，差异具有统计学意义（t=-2.026，P=0.046）；非CM占位分布情况、附着情况、形态、瘤蒂存在情况及活动度与典型CM差异均具有统计学意义（P均＜0.05）。综合以上分析，非CM占位超声心动图特点更接近非典型CM。非CM占位的MSCT以混杂密度为主，与典型CM差异有统计学意义（P＜0.05），部分存在强化（P＞0.05）。非CM占位T1加权像以等信号和高信号为主，T2加权像以高信号为主，1/2患者存在早期灌注、延迟强化，与典型CM的CMR特点差异均无统计学意义（P均＞0.05）。 结论基于CM多模态成像特点，心脏多模态影像学检查应综合应用：超声心动图评估可疑CM的典型性，对考虑为非典型CM的心脏占位进一步行心脏CT和CMR检查评估占位良恶性及组织类型，有效提高CM诊断效能，降低误诊率，有助于做好术前规划。

Multimodality imaging for diagnosis of cardiac myxoma

ObjectiveTo investigate the multimodality imaging features of cardiac myxoma (CM) and explore the multimodality diagnosis model of CM. MethodsOne hundred and seventy-eight patients who were initially screened for CM by two-dimensional transthoracic echocardiography at Fuwai Hospital from July 2016 to August 2019 were retrospectively included in our study. Using pathological results as the gold standard, the subjects were divided into either a CM group or a non-CM group.The CM group was further divided into a typical CM subgroup and an atypical CM subgroup according to the characteristics of echocardiography. The clinical characteristics and the imaging features of echocardiography, multi-slice computed tomography (MSCT), and cardiac magnetic resonance imaging (CMR) were compared between groups by t-test, chi-squared test, or Fisher's exact test. ResultsOf the 178 patients with an initial diagnosis of CM, 160 (89.9%) underwent surgical treatment and pathological examination (89.9%); 150 patients were diagnosed with CM, 1 with low-grade fibromyxoid sarcoma, 1 with undifferentiated pleomorphic sarcoma, 1 with angiosarcoma, 2 with hemangioma, 2 with lipoma, and 3 with thrombosis. The diagnostic accuracies of echocardiography, MSCT, and CMR were 93.8 %, 96.3%, and 100%, respectively. The proportions of patients with hypertension and atrial fibrillation in the typical CM subgroup were significantly lower than those of the atypical CM subgroup (25.4% vs 53.1%, χ²=8.978, P=0.003; 2.5% vs 18.8%; χ²=9.027, P=0.003); the left atrial anteroposterior diameter and the early diastolic peak flow velocity of the mitral valve were significantly higher in the typical CM subgroup than in the atypical CM subgroup (39.21±6.34) mm vs (35.92±5.72) mm, t=2.357, P=0.020; (1.59±1.67) m/s vs (0.90±0.25) m/s; t=2.040; P=0.043]. The average long diameter of atypical CM was significantly smaller than that of typical CM (34.81±17.43) mm vs (45.99±16.73) mm; t=3.324, P=0.001], and the width of tumor pedicle or base was significantly larger than that of typical CM (13.02±7.28) mm vs (9.97±4.73) mm; t=-2.506, P=0.014]. The distribution, attachment site, morphology, mobility, presence of tumor pedicle, and presence of atrioventricular valve orifice obstruction in atypical CM were significantly different from those in typical CM (P＜0.05 for all). Low-attenuation was the main MSCT feature of atypical CM, and the proportion of patients with medium or mixed attenuation and enhancement was higher than that of typical CM, but the difference was not statistically significant (P＞0.05). The signal intensity of atypical CM on T1 and T2 weighted images was similar to that of typical CM (both P＞0.05). The average long diameter of the non-CM masses was smaller than that of typical CM, but the difference was not statistically significant (P＞0.05). The average short diameter was similar to the typical CM, and the width of the tumor pedicle or base was significantly larger than that of the typical CM (13.35±6.80) mm vs (9.97±4.73) mm; t=-2.026, P=0.046]. The distribution, attachment site, morphology, presence of tumor pedicle, and mobility of non-CM masses were significantly different from those of typical CM (P＜0.05 for all). Based on the above analysis, the echocardiographic characteristics of non-CM masses were similar to those of atypical CM. The main MSCT feature of non-CM masses was mixed attenuation, which was different from that of typical CM (P＜0.05). The non-CM masses were iso-hyperintense on T1-weighted images and hyperintense on T2-weighted images, and showed enhancement at about one-half of cases on first-pass perfusion imaging and late gadolinium enhancement imaging, which did not show significant difference from those of typical CM (P＞0.05 for all). ConclusionBased on the multimodality imaging features of CM, echocardiography should be used to discriminate typical CM from atypical CM and further cardiac CT and CMR are used to distinguish between malignant and benign tumors and to assess histological types of cardiac masses considered as atypical CM, which can improve the diagnostic efficiency of CM, reduce the misdiagnosis rate, and contribute to preoperative planning.