超声双重造影诊断直肠间质瘤的价值

The value of double contrast-enhanced unltrasonography in the diagnosis of rectal gastrointestinal stromal tumors

目的探讨经直肠超声双重造影对直肠间质瘤的诊断价值及临床意义。方法回顾性分析2013年10月至2015年3月在浙江省人民医院住院并经手术及病理证实的11例直肠间质瘤患者临床资料。分析患者直肠腔内灌注胃肠声学造影剂后肿块灰阶超声特征,及患者静脉内注射微泡造影剂后病灶微循环灌注特点。按照肿瘤直径和核分裂象计数对胃肠道间质瘤进行分级,包括极低度危险性、低度危险性、中度危险性和高度危险性。其中极低度危险性与低度危险性为低危组,中度危险性与高度危险性为高危组。对照超声表现与病理类型,评估不同危险度间质瘤的不同超声表现。结果 11例直肠间质瘤中,低危组7例(63.6%),超声表现为肿瘤直径<5 cm,形态规则,呈圆形或类圆形,内部低回声为主,整体均匀低增强,液化坏死少见;高危组4例(36.4%),表现为体积≥5 cm,形态不规则,呈圆形或类圆形,也可呈分叶状,内部回声不均匀,整体不均匀高增强,见丰富或粗大血管,液化坏死区常见。直肠间质瘤的生物学行为与病灶大小、内部有无液化坏死、超声造影增强模式有关,与病灶边界、形态无关。超声双重造影对直肠间质瘤诊断准确率为90.9%(10/11);超声灌注造影对直肠间质瘤诊断准确率为72.7%(8/11)。结论超声双重造影可对直肠间质瘤定性并评估其危险性,具有一定的临床价值。

Objective To investigate the role of double contrast-enhanced ultrasonography （DCUS） in the diagnosis of rectal gastrointestinal stromal tumors （GISTs）. Methods In eleven patients with rectal GISTs before surgery, gastrointestinal ultrasound contrast agent were injected into rectal lumen and tumor’s two dimensional ultrasound features were analyzed. Microbubbles were injected into the vein to investigate the feature of lesion microcirculation perfusion. After the surgery, according to the tumor diameter and mitotic count, rectal GISTs were classified as very low-risk, low-risk, intermediated-risk and high-risk tumors. The very low-risk and low-risk tumors were grouped together as one group while the intermediated-risk and high-risk tumors were grouped together as another group. According to ultrasound performance and pathological type, ultrasonic features of rectal GISTs with different risk levels were estimated. Results Among all rectal GISTs cases, 63.6%（7/11） were low-risk. Under DCUS, the tumor diameter was less than 5 cm, with regular round, hypoechogenicity, uniform low enhancement and less internal liquefaction necrosis. For the 36.4%（4/11） high-risk cases, under DCUS, the tumor diameter was≥5 cm, with irregular round or lobulation, mixed hyperechogenicity and hypoechogenicity, nonuniform high enhancement, large blood vessel and common liquefied necrosis region. The biological behavior of rectal GISTs was relevant to lesion size, liquefaction necrosis and enhancement mode of ultrasound contrast and irrelevant to the bound and shape of lesion. The accuracy of DCUS and contrast-enhanced ultrasonography were 90.9%（10/11） and 72.7%（8/11） respectively. Conclusions DCUS is considered as an effective tool in diagnosingrectal GISTs and can get useful information of the biological characteristics. It has great value for the diagnosis and treatment of rectal GISTs.