特发性肝动静脉畸形的影像学表现

Imaging Manifestations of Idiopathic Hepatic Arteriovenous Malformation

目的探讨特发性肝动静脉畸形(idiopathic hepatic arteriovenous malformation,IHAVM)的多层螺旋CT(multi-detector row spiral CT,MDCT)和磁共振成像(magnetic resonance imaging,MRI)的表现特征,并评价它们的诊断价值。方法收集2009年1月至2010年6月期间我院诊断的19例IHAVM患者资料,其中行MDCT检查9例,行MRI检查10例。回顾性观察分析其CT和MRI影像表现,特别是增强扫描的强化特征。结果①MDCT表现特征:9例患者病灶平扫均表现为等密度;增强后动脉期呈明显血管样或小结节样强化,门脉期强化持续,但程度降低,逐渐呈等密度改变。4例出现动脉期静脉分支早显,6例病变边缘出现片状或楔形的动脉期一过性强化。②MRI表现特征:10例患者病灶动脉早期均表现为病灶内出现小结节样、团状或条状强化,动脉晚期持续强化,门脉期强化程度降低,呈等信号或稍高信号改变,平衡期呈等信号改变。7例病灶边缘出现动脉期异常的一过性强化区,5例出现门静脉或肝静脉分支早显。结论多期增强MDCT和MRI扫描均能直观、准确地显示IHAVM病变的部位、大小、血供等细节情况,影像特征明显,具有较高的诊断价值。

Objective To investigate the imaging features of idiopathic hepatic arteriovenous malformation（IHAVM）on multi-detector row spiral CT（MDCT）and magnetic resonance imaging（MRI）.Methods Nineteen patients with IHAVM between January 2009and June 2010were included for retrospective analysis of the imaging findings on MDCT（n=9）and MRI（n=10）,especially the imaging features of IHAVM on contrast-enhanced dynamic scans.Results All IHAVM lesions in 9patients were isodense in plain scan of MDCT,and showed marked small nodular or linear enhancement with similar intensity to vascular enhancement in arterial phase,and the enhancement continued to persist to portal phase but with reduced enhancement degree.Early visualization of venous tributaries in arterial phase was present in 4cases,and wedge-shaped or lamellar transient hepatic parenchyma enhancement in arterial phase in the edge of the lesion was observed in 6cases.In 10patients with MRI scan,the enhancement patterns of IHAVM were quite similar to the findings on MDCT,with early visualization of venous tributaries in arterial phase in 5cases and wedge-shaped transient hepatic parenchyma enhancement in arterial phase in the edge of the IHAVM lesion in 7cases.Conclusion Contrast-enhanced multi-phase MDCT and MRI scans can depict the morphologic and hemodynamic characteristics of IHAVM,thus they are very valuable for the diagnosis of IHAVM.