肝脏局灶性结节性增生与甲胎蛋白阴性肝癌患者MRI和CT表现

Differential diagnosis of magnetic resonance imaging and CT between hepatic focal nodular hyperplasia and hepatocellular carcinoma with negative alpha-fetoproteins

目的总结肝脏局灶性结节性增生（FNH）与甲胎蛋白（AFP）阴性肝癌患者CT和MRI表现。方法对2008年1月至2012年1月武警重庆总队医院经手术病理证实的37例FNH和25例AFP阴性肝癌患者的MRI和CT平扫及动态增强表现以及部分特异性造影剂钆贝葡胺（Gd—BOPTA）延迟扫描表现结合临床资料进行回顾性分析和总结。结果37例FNH患者中，27例行CT检查，其中19例行三期动态增强扫描，8例仅行平扫；27例29个病灶中，25例27个病灶（93．1％，27／29）CT平扫呈稍低密度；19例21个病灶中，15例17个病灶（81．0％，17／21）增强扫描动脉期明显强化且均匀；12例14个病灶（66．7％，14／21）增强扫描门脉期呈等密度；12例14个病灶（66．7％，14／21）增强扫描延迟期呈等密度，3例3个病灶（14．3％，3／21）增强扫描延迟期呈低密度，3例3个病灶（14．3％，3／21）增强扫描延迟期呈稍高密度；11例12个病灶（57．1％，12／21）可见中央星状瘢痕，10例11个病灶（91．7％，11／12）可见瘢痕延迟强化。25例AFP阴性肝癌患者中，20例行CT检查，其中5例仪行平扫；20例21个病灶中，16例17个病灶（80．9％，17／21）CT平扫呈低密度，4例4个病灶（19．O％，4／21）CT平扫呈等密度；15例16个病灶中，12例12个病灶（75．0％，12／16）动脉期明显不均匀增强；13例14个病灶（87．5％，14／16）门脉期迅速降低为低密度；9例10个病灶（62．5％，10／16）延迟期出现假包膜，多无中央星状瘢痕，5例5个病灶（31．3％，5／16）可见出血坏死，5例5个病灶（31．3％，5／16）可见门静脉癌栓形成。37例FNH患者中，3I例行MRI平扫及增强扫描。31例33个病灶中，FNH在T1像多呈略低信号（28／33，84．8％），T2像多呈略高信号（30／33，90．9％）；27例29个病灶（29／33，87．9％）增强扫描动脉期明显均匀强化；23例25个病灶（75．8％，25／33）增强扫描门脉期及延迟期呈等信号，6例6个病灶（18．2％，6／33）增强扫描门脉期及延迟期呈低信号，2例2个病灶增强扫描门脉期及延迟期呈高信号（2／33，6．1％），12例12个病灶（36．4％，12／33）可见长12信号中央瘢痕，延迟强化；21例23个病灶Gd-BOPTA延迟60～120rain扫描，20例22个病灶（95．7％，22／23）均呈等信号。25例AFP阴性肝癌患者中，23例行MRI平扫及增强扫描；23例25个病灶中，肝癌在T1像呈略低信号（20／25，80．0％），他像呈略高信号（84．0％，21／25）；18例19个病灶（76．0％，19／25）增强扫描动脉期不均匀强化；16例17个病灶（68．O％，17／25）增强扫描门脉期迅速廓清为低信号，2例3个病灶（12．O％，3／25）增强扫描门脉期为等信号；15例17个病灶（68．0％，17／25）可见假包膜，未见中央瘢痕；5例5个病灶（20．0％，5／25）可见门静脉癌栓形成；15例15个病灶（15／15，100％）Gd—BOPTA延迟60—120min扫描均呈低信号。结论肝脏FNH和AFP阴性肝癌患者CT和MRI表现各有其特点，联合应用多种检查方法可提高两者诊断准确率，减少误诊率。

Objective -To investigate the differential diagnosis between hepatic focal nodular hyperplasia （FNH） and hepatocellular carcinoma （HCC） with negative alpha-fetoproteins （AFP）. Methods Imaging materials of magnetic resonance imaging （MRI） and plain CT scan and dynamic contrast-enhanced scan as well as specific contrast agent gadobenate dimeglumin muhihanee （Gd-BOPTA） delayed scan were retrospectively analysed and summarized together with the clinical materials of 37 patients with FNH and 25 patients with AFP negative hepatocellular carcinoma proven by pathology in CQ Municipal CAPF Hospital from January 2008 to January 2012. Results Twenty-seven of 37 patients with FNH did CT scan, 19 cases did three phase dynamic enhanced scan and 8 cases did plain CT scan only ; in 29 lesions of 27 cases, 27 lesions in 25 cases （93, 1% ,27/29） were low density in CT plain scan; in 21 lesions of 19 cases, 17 lesions in 15 cases （81.0%, 17/21 ） showed obvious and homogeneous enhancement in arterial phase, 14 lesions in 12 cases （66.7%, 14/21） showed isodensity in portal venous phase; 14 lesions in 12 cases （66.7% ,14/21） showed isodensity in delay phase, 3 lesions in 3 cases （14.3% ,3/21 ） showed low density in delay phase,3 lesions in 3 cases （ 14.3% ,3/21 ） showed high density in delay phase, 12 lesions in 11 cases （57.L1%, 12/21 ） showed the central stellate scar, 11 lesions in i0 cases （91.7%, 11/12） showed enhancement in delay phase. 20 of 25 HCC patients with negative AFP did CT scan, 5 cases did plain CT scan only; in 21 lesions of 20 cases, 17 lesions in 16 cases （80.9% ,17/21 ） were low density in CT plain scan, 4 lesions in 4 cases （19.0% ,4/21 ） were isodensity; in 16 lesions of 15 cases, 12 lesions in 12 cases （75.0 % , 12/16） showed intense but inhomogeneous enhancement in arterial phase, 14 lesions in 13 cases （87.5%, 14/16） reduced to low density rapidly in portal venous phase, 10 lesions in 9 cases （62.5 %, 10/16） had pseudocapsule in delay phase, almost without the central stellate scar, 5 lesions in 5 cases （31.3% ,5/16） showed hemorrhage and necrosis, 5 lesions in 5 cases （31.3% ,5/16） showed the portal vein tumor thrombus. 31 of 37 FNH patients did MRI plain scan and enhanced scan. In 33 lesions of 31 cases, the majority of FNH showed hypointense on T1WI （84.8% ,28/33） and hyperintense on T2WI （90.9%, 30/33） in MRI plain scan, 29 lesions in 27 cases （87. 9%, 29/33） showed obvious and homogeneous enhancement, 25 lesions in 23 cases （75.8% , 25/33 ） showed equisignal in portal venous phase and delay phase, 6 lesions in 6 cases （18.2 % ,6/33） showed low signal in portal venous phase and delay phase, 2 lesions in 2 cases （6.1% ,2/33 ） showed high signal in portal venous phase and delay phase, 12 lesions in 12 cases （36. 4 %, 12/33 ） showed central scar with high signal on T2WI and delay enhancement; 23 lesions in 21 cases did the 60-120 min delay scan of gadobenate dimeglumin multihance （Gd-BOPTA）, 22 lesions in 20 cases （95.7% ,22/23 ） showed equisignal. 23 of 25 HCC patients with negative AFP did MRI plain scan and enhanced scan ; in 25 lesions of 23 cases, the majority of HCC showed hypointense on T1WI （80.0% ,20/25 ） and hyperintense on T2WI （84.0% ,21/25） in MRI plain scan, 19 lesions in 18 cases （76.0% ,19/25 ） showed unhomogeneous enhancement in arterial phase, 17 lesions in 16 cases （68.0% , 17/25 ） showed low signal in portal venous phase rapidly, 3 lesions in 2 cases （ 12.0% ,3/25） showed equisignal in portal venous phase, 17 lesions in 15 cases （68. 0 %, 17/25 ） had pseudocapsule in the delay scan without central scar, 5 lesions in 5 cases （20.0% ,5/25） had portal vein tumor thrombus ; 15 lesions in 15 cases （ 100%, 15/15 ） were low signal in the 60-120 min delay scan of gadobenate dimeglumin multihance （Gd-BOPTA）. Conclusions CT and MRI of FNH and HCC with negative AFP have their own characteristics. The combined application of various examination methods can improve diagnostic accuracy and reduce the misdiagnosis rate of both diseases.