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病例选自《MayoClinicBodyMRICaseReview》
History55-year-oldwomanwithepistaxis
55岁女性，鼻出血
Fig2.15.1
Fig2.15.2
Fig2.15.3
Fig2.15.4
ImagingFindingsAxialfat-suppressedT2-weightedFSEimage(Figure2.15.1)
demonstratessubtle,ill-definedareasofintermediateincreasedsignalthroughouttheliverthataremoreeasilyvisualizedonDWI(b=s/mm2)(Figure2.15.2).Axialarterial,portalvenous,equilibriumphase,anddelayedhepatobiliaryphase3DSPGRimages(Figure2.15.3)demonstrateheterogeneousnodularhyperenhancementinthearterialphasewithprominentearlyfillinghepaticveins.Thereispersistenthyperenhancementofafewnodularlesionsonthehepatobiliaryphaseimage.Subvolumereformattedaxial(Figure2.15.4A)andcoronal(Figure2.15.4B)arterialphaseMIPimagesemphasizetheextensivenodularhyperenhancementthroughouttheliver,aswellastheenlargedhepaticarteryandhepaticveins,whicharealsodepictedintheVRimage(Figure2.15.4C).Ahepatobiliarycontrastagent(Multihance)wasused;notethecontrastinthehepaticductonthehepatobiliaryphaseimage.
横断位T2WI-FS序列(Figure2.15.1)示肝内多发稍高密度区，边界不清，于DWI(b=s/mm2)序列(Figure2.15.2)显示较清。
肝胆特异性对比剂Multihance增强扫描动脉期、门脉期、平衡期及肝胆相位图(Figure2.15.3)示动脉期病灶不均匀强化，并可见肝内静脉早期充盈。肝胆相位图示肝内部分结节可见持续性强化。
横断位和冠状位MIP(Figure2.15.4A、Figure2.15.4B)更加清晰显示肝内多发强化的结节，同时可以看到扩张的肝内动脉和静脉，VR图像(Figure2.15.4C)可以更加直观地显示。
本病例采用的肝胆特异对比剂Multihance，可以看到肝胆相位期强化的肝内胆管。
Diagnosis
Hereditaryhemorrhagictelangiectasia
遗传性出血性毛细血管扩张症
Comment
HHTisanautosomaldominanthereditarydisordercharacterizedbymultiplesmalltelangiectasiasofskin,mucousmembranes,thegastrointestinaltract,andotherorgans.Recurrentepistaxisisthedominantclinicalsymptominmostpatients;however,moreseriousconsequences,includingcyanosis,hemoptysis,andparadoxicalemboli,usuallyresultfrompulmonaryarteriovenousmalformations.Mutationsinatleast2differentgeneshavebeenassociatedwithHHTandarethoughttobeinvolvedinregulationofangiogenesis.
HHT是一种常染色体显性遗传病，典型表现为皮肤、粘膜、胃肠道及其他组织的多发毛细血管扩张。大多数患者最常见的症状是反复鼻出血，但肺动静脉畸形引起的紫绀、咯血、反常的肺栓塞等表现则更为严重。HHT与至少两种基因突变有关，引起血管生长调节异常。
HepaticinvolvementinHHThasstimulatedmuchinterestinrecentyears.Earlyinvestigationsconcludedthathepaticinvolvementwasrelativelyinfrequent;however,morerecentstudiesusingmultidetectorCTandMRIhavedemonstratedhepaticmanifestationsinasmanyas85%ofpatients.Althoughmostpatientswithhepaticinvolvementareasymptomatic,3clinicalsyndromeshavebeendescribed:high-outputcardiacfailureresultingfromintrahepaticshunts;portalhypertensiondevelopingintheclinicalsettingofarterialportalshunting;andbiliarynecrosis,alsothoughttooccurasaresultofarterial-venousshuntingandconsequentreducedbloodsupplytothebiliarytree.
