Area Diagnostica per Immagini, UOC Radiologia, University Hospital Foundation "A. Gemelli", Catholic University of the Sacred Hearth, Rome, Italy.
Eur Rev Med Pharmacol Sci. 2017 Oct;21(20):4477-4486.
The purpose of this pictorial essay is to describe anatomic variants and congenital anomalies of portal venous system and related liver parenchymal alterations. The imaging findings of some of these entities have been previously described in other articles, however this work encompasses all congenital anomalies of portal venous system with attention to their features on various imaging modalities; in particular we illustrated with detailed pictures all the main portal vein variants, congenital extra- and intra-hepatic porto-systemic venous shunts and portal vein aneurysm. Variants of portal branches and intrahepatic portosystemic shunts are quite uncommon, however, when present, they should be recognized before performing surgery or interventional procedures. Congenital absence of the portal vein is an important finding as the complete loss of portal perfusion predisposes the liver to focal or diffuse hyperplastic or dysplastic changes. Portal vein aneurysm is a rare clinical entity that can affect intra- and extra-hepatic portal branches; although usually asymptomatic, thrombosis can occur. Awareness of congenital variants of portal venous system among radiologists should allow a more confident diagnosis and permit an accurate planning of surgical procedures and percutaneous interventions; identification of portal system anomalies also suggest an accurate evaluation of associated hepatic parenchymal anomalies such as nodular regenerative hyperplasia, focal nodular hyperplasia (FNH), and adenomas with high risk of malignant transformation.
本图文集旨在描述门静脉系统的解剖变异和先天性异常及其相关的肝实质改变。这些病变中的一些影像学表现之前已在其他文章中描述过，但本作品涵盖了门静脉系统的所有先天性异常，并重点介绍了它们在各种影像学模式下的特征；特别是，我们用详细的图片说明了所有主要的门静脉变异、先天性肝内外门体静脉分流和门静脉瘤。门静脉分支和肝内门体静脉分流的变异并不常见，但当它们存在时，在进行手术或介入治疗之前应该识别出来。门静脉完全缺失是一个重要的发现，因为门静脉完全丧失灌注会使肝脏容易发生局灶性或弥漫性增生或发育不良改变。门静脉瘤是一种罕见的临床实体，可以影响肝内外门静脉分支；尽管通常无症状，但可能会发生血栓形成。放射科医生对门静脉系统先天性变异的认识，应能更自信地诊断，并能准确规划手术和经皮介入；门静脉系统异常的识别也提示需要准确评估相关的肝实质异常，如结节性再生性增生、局灶性结节性增生（FNH）和腺瘤，这些异常有恶性转化的高风险。
