肝脏血管系统与肝内占位病灶的MR三维重建与融合

Three-dimensional Reconstruction and Image Fusion between Liver Focal Lesions and Dynamic Contrast-enhanced Magnetic Resonance Angiography

背景与目的:肝内血管和肝内占位病灶解剖关系的确立,直接影响到治疗计划的选择。本研究利用三维动态增强磁共振血管造影(threedimensionaldynamiccontrastenhancedmagneticresonanceangiography,3DDCEMRA)序列重建肝门及肝内血管系统并与肝内的占位病灶进行融合,探讨其对临床治疗的指导作用。方法:利用上腹部3DDCEMRA扫描技术,采用最大密度投影(maximumintensityprojection,MIP)和表面容积再现(surfaceshadeddisplay,SSD)的方法重建血管及肝内占位病灶,并将两者融合及三维重建,共27例得到理想图像,包括血管瘤2例,局灶性结节增生3例,腺瘤1例,巨结节性再生结节2例,肝囊腺癌2例,肝细胞癌17例;其中23例有手术证实,4例有数字减影血管造影(digitalsubstractionangiography,DSA)对照。结果:肿块与血管的显示及相互关系包括:肝内血管系统主分支未见异常5例,可见由肝动脉发出的供血动脉6例,肝内血管主干受压移位13例,肝内血管主干受侵6例,门静脉或下腔静脉内癌栓11例。9例合并有肝硬化门脉高压症的表现。MIP法在显示重建血管的级数方面高于SSD法。结论:肝脏血管系统和肝内占位病灶的三维重建和融合技术可较好地显示病灶和血管的立体解剖关系,有助于临床医生确定能否手术及手术的方式、范围。

BACKGROUND ＆ OBJECTIVES. Identifying the correlation of focal lesions to the liver vessel system is a key factor in selecting treatment patterns for focal hepatic diseases. This study was to evaluate the feasibility of 3-dimensional reconstruction and the fusion image between the 3-dimensional dynamic contrast-enhanced magnetic resonance angiography （3D DCE MRA） and the focal hepatic lesions, and further, explore the clinical application of this method. METHODS： 3D DCE-MRA and conventional magnetic resonance imaging （MRI） were performed. The angiography and focal hepatic lesions were reconstructed with maximum intensity projection （MIP） and surface shaded display （SSD）, and then fused together. Of the 25 cases with evaluable images, 2 were hemangioma, 3 were focal nodular hyperplasis, 1 was hepatocellular adenoma, 2 were macroregenerative nodule, 2 were hepatobiliary cystadenocarcinoma, and 17 were hepatocellular carcinoma; 21 were confirmed by operation resection, and 4 received digital subtraction angiography （DSA）. RESULTS= The anatomic relationship between the lesions and the vessels were well shown. Of the 27 cases, 5 showed normal vessel branching, 6 showed feeding arteries from the hepatic artery, 11 showed compressed and shifted trunks of the vessels, 6 showed tumor invaded vessels, and 11 showed the tumor embolism in the portal vein or the inferior vena cave; 9 also showed MRI signs of portal hypertension. MIP was prior to SSD in demonstrating small branches of the hepatic vessels. CONCLUSION： The 3-dimensional reconstruction and fusion images between 3D DCE-MRA and the focal hepatic lesions by using MIP and SSD can easily display the anatomic relationship between the focal hepatic lesions and the hepatic vessels, and thus can help the surgeons to localize lesions, minimize operating time and decide the extent of surgical resection.