肝脏局灶性结节性增生的超声造影与增强磁共振成像的增强表现对比研究

Comparative study of contrast-enhanced ultrasound and contrast-enhanced magnetic resonance imaging in liver focal nodular hyperplasia

目的:分析与比较肝脏局灶性结节性增生(focal nodular hyperplasia,FNH)的超声造影(contrast-enhanced ultrasound,CEUS)与增强磁共振成像(contrast-enhanced magnetic resonance imaging,CEMRI)的增强表现及特点,以期提高FNH影像学诊断的准确率。方法:纳入74例经手术切除病理学检查证实为肝脏FNH的患者,患者均在术前接受CEUS及CEMRI检查。对FNH病灶在CEUS和CEMRI的表现进行对比分析。结果:共选取74例肝脏FNH患者的74个FNH病灶。CEUS动脉期所有FNH病灶均表现为快速高回声增强(100.0%),凭借CEUS动态实时观察的优势,其中45.9%(34/74)的病灶呈泉涌状增强,21.6%(16/74)的病灶呈轮辐状增强。32.4%(24/74)的病灶中央发现未增强的瘢痕,另外在78.4%(58/74)病灶外周发现扭曲的滋养动脉。根据病灶在CEUS各时期的增强-消退的变化,33.8%(25/74)呈"快进慢出",59.5%(44/74)呈"快进同出",6.8%(5/74)呈"快进快出"。CEMRI显示所有FNH病灶动脉期均表现为相对肝实质的高增强(100.0%),根据病灶在CEMRI各时期的增强-消退的变化,50.0%(37/74)呈"快进慢出",39.2%(29/74)呈"快进同出",10.8%(8/74)呈"快进快出"。59.5%(44/74)的病灶在动脉期出现未增强的中央瘢痕,且在延迟期缓慢强化。29.7%(22/74)在病灶外周发现扭曲的滋养动脉。本组CEUS的诊断准确率达90.5%(67/74),CEMRI的诊断准确率达87.8%(65/74)(P>0.05)。结论:FNH在CEUS和CEMRI两种影像学表现上均具有一定特征,CEUS能够动态实时地显示FNH的泉涌状增强及轮辐状增强,并可发现FNH的中央瘢痕及外周滋养动脉,CEMRI能够更完整地显示FNH病灶,对中央瘢痕更敏感。结合两种影像学方法各自的成像特性及共性,可提高FNH诊断准确率,有助于指导临床治疗方法的选择。

Objective:To analyze and compare the imaging characteristics of contrast-enhanced ultrasound(CEUS)and contrastenhanced magnetic resonance imaging(CEMRI)for improving the accuracy in diagnosis of liver focal nodular hyperplasia(FNH).Methods:Seventy-four patients with liver FNH confirmed by surgical resection were enrolled in this study.All patients underwent CEUS and CEMRI before surgery.The imaging features in CEUS and CEMRI of FNH lesions were retrospectively analyzed and compared.Results:A total of 74 FNH lesions were selected from 74 patients with FNH.All FNH lesions in the CEUS arterial phase showed rapid hyperechoic enhancement(100.0%).With the advantage of CEUS dynamic real-time observation,spring-like enhancement was observed in 45.9%(34/74)lesions,and 21.6%(16/74)showed a spoke-like enhancement.An unenhanced central scar was found in 32.4%(24/74)lesions,and a distorted peripheral feeding artery was found in 78.4%(58/74)lesions.According to the changes in enhancement and regression of lesions in CEUS,33.8%(25/74)showed"fast-in and slow-out",and 59.5%(44/74)showed"fast-in and synchronous-out",6.8%(5/74)showed"fast-in and fast-out".CEMRI showed that all FNH lesions were hyperenhancement(100%)relative to the liver parenchyma.According to the changes of enhancement and regression of the lesions at various stages of CEMRI,50%(37/74)showed"fast-in and slow-out",39.2%(29/74)showed"fast-in and synchronous-out",and 10.8%(8/74)showed"fast-in and fast-out".An unenhanced central scar was found in 59.5%(44/74)of the lesions during arterial phase,with slowly enhancing in delayed phase.A distorted feeding artery was found in periphery of 29.7%(22/74)lesions.The diagnostic accuracy of CEUS was 90.5%(67/74),the diagnostic accuracy of CEMRI was 87.8%(65/74)(P>0.05).Conclusion:FNH has certain characteristics in both CEUS and CEMRI imaging.CEUS has the advantage of characterize spring-like enhancement and spoke-like enhancement of FNH in real time,and central scar and peripheral feeding artery of FNH can also be observed,while CEMRI is more sensitive to detect central scars.Combination of the two imaging methods can improve diagnostic accuracy of FNH and help guide the selection of clinical treatment.