医学前列腺MRI诊疗再认识.ppt

单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,前列腺MRI诊疗再认识,2012,年首次发表前列腺影像报告和数据系统（,prostate imaging reporting and data system,PI-RADS,）。采用,PI-RADS,规范了前列腺,MRI,报告，具有良好的临床应用价值。,2014,年的北美放射学年会上，美国放射学会、欧洲泌尿生殖放射学会和,AdMeTech,基金会合作开发并发布了第二版,PI-RADS,（,PI-RADS V2,）,PI-RADS,(,前列腺影像报告和数据系统,),PI-RADS V2,中将有临床意义的前列腺癌定义为,Gleason,评分,7,分，伴或不伴体积,0.5 cm,3,【,直径约,0.8cm】,、,包膜外侵犯。,PI-RADS V2,根据前列腺,T,2,WI,、,DWI,及,DCE,的综合表现，对,出现有临床意义前列腺癌的可能性,给出了,评分方法,：,1,分：非常低，极不可能存在；,2,分：低，不可能存在；,3,分：中等，可疑存在；,4,分：高，可能存在；,5,分：非常高，极有可能存在。,PI-RADS,评分,4,或,5,分应考虑活检。,对于,前列腺外周带疾病以,DWI,结果为主,，,例如,DWI,评分为,4,分，,T,2,WI,评分为,2,分，则,PI-RADS,评分为,4,分；,前列腺移行带疾病以,T,2,WI,结果为主,。,1.1,移行带,T2WI,1,2,3,4,5,不均匀中等信号，边界清，,”,Organised Chaos,”【,自己：错落有致征,】,局限性低信号或不均匀有包膜的结节（前列腺增生）,边缘模糊，信号强度不均匀,，包括其他不符合,2,、,4,或,5,分标准者,呈透镜状或边界不清，,均匀中度低信号,，,最大径,1.5cm,【,大小、形态、信号均匀度,/,强度、边缘,】,外周带,T2WI,T2:PI-RADS=1,T2:PI-RADS=2,T2:PI-RADS=4,T2:PI-RADS=5,T2:PI-RADS=4,2.DWI,1,2,3,4,5,ADC,图和高,b,值图像上无异常,ADC,图模糊低信号,。,ADC,图上呈局灶轻、中度低信号,，在高,b,值,DWI,上呈,等、轻度高信号,在,ADC,图上呈局灶明显低信号,，在,高,b,值,DWI,上呈明显高信号,，轴面最大径,=1.5 cm,。,影像表现同,4,分，但最大径,1.5 cm,良恶性,ADC,阈值,0.75-0.95【MR750,建议,0.9】,，最重要的一个阈值,！,3.1,动态增强（,DCE,）,-V1,（弃用）,2,和,3,型曲线，局灶性病变,+1,2,和,3,型曲线，病变不对称,+1,个人建议：加入早期增强速率有一点参考价值,1,2,3,1,型曲线：流入型,2,型曲线：平台型,3,型曲线：流出型,DCE-MRI-V1,DCE:PI-RADS=1,DCE:PI-RADS=2,DCE:PI-RADS=3,3.2,动态增强（,DCE,）,-V2,DCE,阴性,DCE,阳性,1,早期无强化；,2,弥漫性增强，在,T,2,WI,或,DWI,上无相应的局灶性表现；,3,对应病变在,DWI,上显示为前列腺增生特征，呈局灶性增强。具有上述三者之一判定为,DCE,阴性。,局灶性,，早于或与邻近正常前列腺组织同时强化，与,T,2,WI,和（或）,DWI,相应可疑病变符合。,DCE,的主要作用是避免遗漏小的病变,当前列腺,PZ,的,DWI PI-RADS,评分为,3,分时,，,DCE,阴性，其,PI-RADS,评分仍为,3,分，但,DCE,阳性会引起有临床意义前列腺癌相关表现的可能性增加，其,PI-RADS,评分升至,4,分。,DCE,阳性或阴性对,PI-RADS,评分,1,、,2,、,4,、,5,分无影响。,【,自己：,增强形态学被忽视,，如移行带结节强化内部,“黑白错落有致征”与“黑白涂抹征”有价值,】,增生结节,腺癌,“黑白错落有致征”,“黑白涂抹征”,4.MRS,定性分析,-V1,（,V2,未纳入）,1,2,3,4,5,枸橼酸峰超过胆碱峰大于,2,倍,枸橼酸峰高度高于胆碱峰但小于其两倍,胆碱峰和枸橼酸峰高度相等,胆碱峰高于枸橼酸峰但小于其两倍,胆碱峰高度高于枸橼酸峰两倍,B,值：,如果信噪比足够高，,b,值取,1 600 2 000,或更高，更有利于诊断。,PI-RADS V2,中建议，最小,b,值取,100,（而不是,0,），以便减少血流灌注对,ADC,值的影响。,我院,MR750,：,B,值取,100,、,1500,、,2100,三个,B,值。,无,临床意义的前列腺癌,不在,V2,评分范围,（,指病理,Gleason,评,6,分,以下、体积,0.5 cm,3,、,无,包膜外侵犯,），为潜伏癌或偶发癌，大多漏诊：外周带,T2WI/DWI/DCE,均可能显示，移行带仅靠,DWI,，故选择,B,值很重要，要,1500,以上，较低,B,值如,800,的,T2,透过效应严重。,相当数量潜伏癌不发展成临床癌。,PI-RADS,PI-RADS,与“七剑术”对比,项目,PI-RADS,“,七剑术”,1,临床,无,【,纯,mpMRI】,年龄、直肠指检、,PSA,等,2,部位,外周带与移行带分别研究,同左,+,对称与否,+,解剖细节破坏,3,影像,T2WI,大小、形态、信号均匀度与强度、边缘,同左,+,边缘及周围细微结构破坏,DWI-ADC,大小、,ADC,值,同左,+ADC,阈值,+,弥散受限“部位”,+,结合是否强化,DCE,找小病灶、外周带,DWI3,分升级、,TIC,同左,+,早期强化斜率,+,强化内部形态学（黑白错落有致征、黑白涂抹征）,4,动态,无,动态思维贯穿每一项,5,诊断与鉴别,快速入门，大众化易普及,诊断更细，鉴别范围更广，,个性风格强，不易复制,6,治疗与预后,4,、,5,分需活检,同左,+ADC,值反应侵袭性,7,随访,隔几年出新版本,不断优化自己的思维架构，,思维更缜密、新技术更容易与原有技术有机结合使用,PI-RADS,标准很重要，但有缺陷！综合分析法可解决,如何将,PI-RADS,融入自己的思维架构,一、概述、解剖基础（,解剖细节,）,、检查技术,二、将,PI-RADS,精髓融入自己的“七剑术”,一、概述、解剖基础（,解剖细节,）,、检查技术,概述,前列腺癌是男性常见的恶性肿瘤之一。世界范围内，,PCa,患病率居男性恶性肿瘤第,2,位。我国,PCa,的患病率虽然远低于欧美国家，但近年来呈显著增长趋势。根据,2013,年的调查结果，,1998,年至,2008,年我国男性,PCa,患病率年均增加,12.07%,，这与,人口的老龄化、生活水平的提高有关。,近来泌尿学专家对活检前的前列腺,MRI,检查和,MRI,导引下前列腺穿刺活检非常热门。,约,30%,前列腺癌,PSA,在正常范围内。,个人建议,3T-MRI,平扫可作为筛查项目之一,，有可疑异常，马上增强。,解剖基础,基础决定高度！,权威书籍或论文的解剖概念也混乱,强调前列腺的解剖细节（如下面一组病例）,3T-MR750,高分辨率提供了最先进的武器,一组病例提示：,T2WI+DWI+DCE,与单纯,T2WI,相比，并不能提高前列腺,移行带癌,的检出率和定位准确率。,PI-RADS v2,刘树伟主编的,断层解剖学,仅用“区”，未用“带”,个人建议：仅用“带”细分。,如要用中央带,+,移行带，则两者,=,中央区？但少数论著中央区,=,中央带。中央腺体,=,内腺,=,移行带（,+,尿道周围腺），中央腺体易误为含有中央带（如上文）。,Ex vivo T2-weighted image,(4700/42)of the specimen,obtained at,9.4 T,shows highly cellular,compact dark tissue in the central gland(arrows)surrounding the urethra(U).(h)Photograph of a whole-mount reconstructed histologic section(original magnification,2;hematoxylin-eosin HE stain)of the midgland shows a,large volume of tumor in the transition zone,(outlined in green).Note the excellent,correlation with the ex vivo image in g and the in vivo image in c,which show cancer of high cellular density in the transition zone,前列腺小囊为苗勒氏管盲端,35,P-,周围带,C-,中央带,T-,移行带,A-,前肌纤维质,U,-,尿道,S-,精囊,e -,射精管,V-,精阜,冠状层面，中央带呈八字形，更后层面呈,Y,字形,外周带明显高信号提示早期增生？因前列腺小管受压、分泌液潴留,精阜,射精管,前列腺分区（本科室应统一，建议只用“带”）,前列腺组织结构,纤维肌肉基质区,1/3,腺体部分,2/3,外周带,70%,中央带,25%,移行带,5%-10%,尿道周围区,1%,中央带,起于精阜水平，向头侧方向扩展，直径逐渐增大，是前列腺基底部主要构成成分。由于,中央带内含较多致密的平滑肌组织,，,信号较低,且均匀，注意与,MT,鉴别,。,移行带位于尿道的前、外侧，从精阜水平伸到膀胱颈水平，在横轴位上呈马蹄形。,正常前列腺外周带的腺泡沿着尿道呈放射状分布，腺体和腺管结构丰富,。,诸,前列腺管开口于精阜周围的尿道,。,前列腺表面覆盖有两层被膜,，,内层称前列腺囊,，,为一坚韧的纤维肌性组织,，紧包于前列腺表面。,外层称前列腺筋膜,，为盆脏筋膜在前列腺囊周围增厚而成。,前列腺血管,动脉,：膀胱下,A,、阴部内,A,、直肠下,A.,膀胱下动脉是前列腺的主要血液供应来源,。,膀胱下动脉在进入前列腺前又分为支,，,即前列腺被膜动脉和尿道前列腺动脉,。前列腺外腺组的血供，主要由前列腺被膜动脉承担；尿道周围的腺体组织和前列腺深部组织，由尿道前列腺动脉供给。,静脉,：髂内,V,；与骶骨、腰椎和髂翼的静脉有交通；通过直肠上,V,汇入肝门静脉（可肝转移），因此，前列腺癌有腰骶部和髂部浸润时，为早期转移表现。,淋巴,：髂内、髂外,T2WI,：,中央带及移行带腺体少，肌肉及间质致密，信号低,；外周带腺体丰富，呈高信号,外科假包膜,:,移行带与外周带之间有时可见低信号条状影，为受压的外周带和中央带形成。,前列腺包膜：外周带外周低信号、厚度约,1mm,的、由纤维肌肉组织构成的,T1,中等信号包膜。,影像解剖前列腺,MR,正常前列腺的,MRI,表现,中央带,T2WI,呈低信号，部分等信号；,【,自己观察到：多数情况下，,DWI,及,DCE,与外周带相似,】,。,尿道周围腺体,T2WI,呈低信号。,52,前肌纤维质,移行带,周围带,中央带,与,CA,鉴别,SLICE-5,53,周围带（,P,）,中央带（,C,）,精囊（,S,）,前肌纤维质,尿道,正中矢状面,C,P,S,54,中央带,C,周围带,P,移行带,T,C,P,T,B,旁正中矢状面,55,周围带,中央带,精阜,精囊,冠状面,P,C,中央带,C,C,注意：,中央带,ADC,值低，约,1.0,，与癌有交叉,正常前列腺T1WI,神经血管束,静脉,检查技术,前列腺,MRI扫描前准备,患者,适度充盈膀胱,。膀胱过度充盈会引起波动伪影，膀胱排空后不利于观察前列腺与膀胱壁的关系及膀胱壁受累情况。,胃肠道内容物对前列腺图像质量影响严重,保证检查时,直肠内清洁,。,若先行前列腺穿刺活检，则穿刺活检与,MRI,检查至少间隔,6,周,以上。,线圈的中心正对耻骨联合，下腹部垫以海绵垫，并,束紧前后片线圈,压迫,小腹以抑制呼吸运动,，不需要前片线圈的支架,。,男性前列腺规范化扫描方案,1,3-pl Loc,三平面定位,2,Asset Calibration,校准扫描,3,Ax T2 fs FRFSE,横断面,脂肪抑制,T2,扫描,4,Ax DWI b=100,、,1500,、,2100,横断面,DWI,扫描,5,Ax T1WI Full FOV,大范围横断面,T1,扫描,6,OCor fs T2 FRFSE,冠状面脂肪抑制,T2,扫描,7,OS,ag,fs T2 FRFSE,矢状面脂肪抑制,T2,扫描,8,Ax LAVA Mask,横断面,LAVA,蒙片,9,Dyn Ax LAVA+C,横断面,LAVA,动态增强,10,Sag LAVA+C,矢状面,LAVA,增强,邻近前列腺包膜有异常信号时，应加扫轴位,T2WI,不压脂序列。,不压脂,T2WI,：,Histopathologic findings confirmed extracapsular extension,Ax DWI技术：,PI-RADS V2,中建议，,最小,b,值取,100,s/mm,2,（而不是,0,），以便减少血流灌注对,ADC,值的影响,常规,B,值,1500,，或增加一个更高,B,值（,2000,以上，只要信噪比允许），有利诊断,。,一般情况下复制横断面,T2,定位像，注意，由于弥散序列使用,ASSET,，必须手动调节,FOV,大小，超过盆腔结构大小。,必须添加局部匀场。频率编码为左右方向。若膀胱充满尿液，将会引起弥散图像伪影。,早期病灶最好用,HR-DWI-,小,FOV,Pitfall IX(,lack of suppression of benign prostate tissue on standard high-b-value diffusion-weighted images,):Impact of ultrahigh b values for tumor conspicuity in 61-year-old man who underwent prostate MRI after previous prostate biopsy showing Gleason 3+4 tumor in one core from left midgland peripheral zone.,A,T2-weighted image shows focal region of decreased signal intensity(,arrow,)in region of biopsy-proven tumor in left peripheral zone.,B,Diffusion-weighted image at,b=1000 s/mm2,shows diffuse hyperintensity throughout peripheral zone bilaterally(,arrows,).Left peripheral zone lesion is therefore not readily apparent.,C,Diffusion-weighted image at,b=1500 s/mm2,shows greater suppression of signal intensity throughout peripheral zone with subsequent greater conspicuity of area of hyperintensity in region of left peripheral zone tumor(,arrow,),几年前上海市一,3T-HDxt,用,B,值,800,，太多良性也明显高信号，,MR750,已改用,1500,扫描其他注意事项,矢状位：,尖部,是前列腺癌的好发部位，,底部的精囊腺根部是前列腺癌包膜外侵犯的好发部位。,动态增强扫描一般不建议使用,SCIC,信号强度均匀性纠正技术。,T2WI,也不用,SCIC,二、将PI-RADS精髓融入自己的“七剑术”,、临床,PSA,值,正常,:,10ng/ml,可疑者,1/3,有癌，异常者,2/3,有癌,PSA20ng/ml,很少能幸免于前列腺癌,结合,TPSA,、,FPSA,、,FPSA/TPSA,、,PSAD,等,诊断,P,Ca,的敏感性为,75%,，而特异性仅,40,%,约,30%,前列腺癌,PSA,在正常范围,内,游离前列腺特异抗原,（,fPSA）,近来研究发现血清中,PSA,以不同的分子形式存在，血清中有少量未结合的,PSA,称游离,PSA。,它对区分,BPH,和前列腺癌有重要意义，测定,fPSA,可提高,PSA,诊断前列腺癌的特异性，结果认为,fPSA,比率,25，,则可基本排除前列腺癌,。,如,tPAS,小于,4,，则,fPSA,比率无意义。,、部位,前列腺癌来源于前列腺的腺泡或导管上皮,前列腺癌：外周带,68%,，移行带,24%,，中央带,8%,病变,分布对称否,大约有,83,-85%,的前列腺癌呈多发性,。,PI-RADS,将移行带和外周带分开独立评分（见前）,Prostate cancer in a 43-year-old man,with a Gleason score of 4+3 and a PSA level of 90.5 ng/mL.Endorectal MR imaging was performed at 3.0 T.(a)T2-weighted image(4860/109)shows a voxel of interest(square)in the left peripheral zone.Although the left peripheral zone is enlarged compared with the right peripheral zone,it has no focal dark areas.There are patchy dark abnormalities in the right peripheral zone.(b)MR spectroscopic spectrum from the voxel of interest shows a markedly elevated level of choline(Cho)(arrow)that is almost equal to the citrate(Ci)peak.Elevation of choline level with a decrease in citrate level is the spectral signature of prostate cancer.Cr=creatine.(c)Color DCE MR map shows a large area of high permeability(,Ktran,s,)occupying the entire left peripheral zone(arrows).(d)Axial image from a,SPECT,study with 111Inlabeled prostate monoclonal antibody(capromab pendetide ProstaScint;Cytogen,Princeton,NJ)shows avid uptake in the entire left prostate(arrow),a finding compatible with a large-volume prostate cancer.As seen in this case,some aggressive prostate cancers,even of large volume,may appear isointense on T2-weighted images;thus,morphologic imaging alone may not be able to show these tumors.Functional MR imagingMR spectroscopy and DCE MR imagingas well as antibody imaging accurately depicted this large prostate cancer.,外周带两侧不对称提示病变,多发性,、影像（,PI-RADS,的应用,；解剖细节）,1,、,PI-RADS,的应用：,大小、形态、信号均匀度与强度、边缘（见前述评分法）。癌的,信号改变：,细胞密度增加、腺管结构消失。,2,、解剖细节（,3T-MR,的最大优势）,破坏,外周带低信号的形态,线状、楔形、地图状、弥漫性倾向于良性,下例,T2WI,外周带基本对称弥漫不均匀信号减低（部分中度减低），,DWI,等及少部分轻度高信号（,3,分），,DCE,中度强化（,+,）。,【PI-RADS 4,分,】,。,病理为腺癌。,自己认为：,外周带弥漫性伴有中度以上强化应为待定、或可疑（,+,）,。,前列腺腺癌：本例,67,岁，,DWI,呈等信号,少部分轻度高信号，,ADC1.0,，,TIC,呈,2,型,(a)Transverse and(b)coronal T2-weighted MR images in 59-year-old patienttreated with high-intensity focused ultrasound shows thickened prostatic capsule(arrow)and,extensive tissue fibrosis around the prostate(arrowhead,).There is,diffusely decreased volume in the peripheral zone,with benign prostatic hyperplasia in the transition zone.,前列腺外周带也可见增生,60-year-old man with,peripheral prostate cancer,with negative MR spectroscopy(MRS)imaging results and positive findings from T2-weighted imaging(T2WI),diffusion-weighted imaging(DWI),and dynamiccontrast-enhanced(DCE)MRI images.Patients prostate-specific antigen(PSA)level was 3.90 ng/mL,and his free-to-total PSA ratio was 7.5%.,A,Axial T2WI scan shows low-signal-intensity nodular lesion(,arrow,)within left peripheral zone,suspicious for cancer.,B,DCE-MRI images shows,curve type 3,from region of interest of lesion(,arrow,)suspicious for cancer.,C,MRS image shows,normal metabolic curve,within voxel from lesion(,arrow,).,D,Apparent diffusion coefficient map from DWI shows,restricted diffusion from lesion,(,arrow,),suspicious for malignant tumor.Biopsy was positive for prostate cancer within peripheral zone.,不典型类楔形,MRS,正常,ADC,明显低信号,59-year-old man with,prostate cancer,.,A,Axial T2-weighted MR image shows subtle decrease in,right peripheral zone subcapsula,r T2 signal intensity(,arrow,).,B,Apparent diffusion coefficient(ADC)map from diffusion-weighted imaging shows decreased ADC(,arrow,)corresponding to area in,A,aiding visualization of abnormality.MRI-ultrasound fusion biopsy showed Gleason 3+4 tumor in this region.,少见区域发生的,Pca,2,、,解剖细节,破坏,-,破坏具动态感，特异性强,真包膜,：外隆,/,外侵，包膜增厚,/,僵直,/,接触面积，向内收缩,外科包膜,：跨界,前肌纤维质,：受侵,中央带,：受侵。,其它结构破坏：含典型,增生结节的假包膜破坏、纤维肌性分隔破坏、尿道、精阜、射精管、精囊腺根部、中央沟、苗勒氏管囊肿、血管神经束,等,巨大的移行带增生结节，压迫中央带变薄，使之参与形成外科包膜。,外周带低信号分隔,：呈,放射状围绕尿道排列,+,少量网状分布，窄窗宽容易观察,。,移行带的,解剖细节应用,癌与增生难鉴别时，反过来研究增生,。,常规窗,+,窄窗（移行带与外周带用不同的窄窗）。,移行带增生内部信号：高信号腺体增生与坏死的区别；低信号间质增生（纤维平滑肌增生）与瘤实质的区别。,移行带增生：边缘,T2WI,无“擦木炭画征”，内部有“黑白错落有致征”,。,DCE,结节内部强化 有“黑白错落有致征”,正常及增生的,解剖细节应用,移行带均匀低信号结节：边缘是否规则完整、模糊，与其他间质增生信号是否一样；,内部低信号的程度，用窄窗宽观察,【,注意不同设备不同参数的正常表现,】,外周带：轻度低信号、边缘模糊，似磨玻璃样（窄窗宽可见更低信号分隔）：慢性炎症,间质增生结节：,DWI,轻中度高信号（,ADC,多在,0.9-1.3,），而癌,DWI,明显高信号、,ADC,多小于,0.9,手术病理证实为前列腺增生,窄窗宽更好显示结节内部细节,低信号间质（平滑肌为主）增生结节周边环绕高信号提示良性高些？,主要应结合,DWIADC,本例该结节,DWI,中等高,S,，,ADC,约,1.0,。,T2WI+DWI,应评,3,分,低信号结节与同侧增生间质信号相似或轻度降低,，偏向良性，如,中度降低则偏向,MT,T2WI,评,3,分,DWI,评,5,分，,总的,T2WI,应,升为,4,分,移行带癌,T2WI,：,较均匀低信号,边缘模糊,擦木炭画征,DWI,高信号，,ADC,降低,DCE,流出型,平台型,MRS,Cho/Cr,升高，,Cit,降低,擦木炭画征,前列腺前部穿刺活检易漏诊,61-year-old man with prostate cancer(prostate-specific antigen level,6.6 ng/mL).,A,Axial T2-weighted image shows faint hypointense lesion(,arrow,)in right anterior prostate gland.Score of 3 was assigned on T2-weighted image alone because lesionis indistinguishable from anterior fibromuscular stroma.,B,On apparent diffusion coefficient(ADC)map,lesion(,arrow,)shows hypointensity.Consequently,score of 5 was assigned to interpretation of T2-weighted image and ADC map.,C,Photograph of histologic step section reveals prostate cancer(,outlined areas,)in right anterior prostate gland.,Comparison of,cancerous anterior fibromuscular stroma and noncancerous anterior fibromuscular stroma,.,A,and,B,67-year-old man with anterior prostate cancer.T2-weighted image(,A,)and apparent diffusion coefficient(ADC)map(,B,)show hypointense lesions(,arrows,)in middle of anterior prostate gland.,C,and,D,68-year-old man with noncancerous anterior fibromuscular stroma.Although T2-weighted image(,C,)shows hypointense lesion(,arrows,C,)in middle of anterior prostate gland,ADC map(,D,)does not show hypointensity in corresponding area(,arrows,D,).,71-year-old man with,bilateral peripheral and transition zone cancer with extracapsular extension,(Gleason score,7;baseline prostate-specific antigen level,5.64 ng/mL).,A,Photograph of histopathologic specimen shows cancer(,outlined area,)in bilateral anterior peripheral and transition zones.Extensive extracapsular extension(,blue,)was found.,B,On axial T2-weighted image,cancer(,arrow,)with homogeneously low signal intensity is seen in anterior aspect of prostate.Associated findings of contour bulging and indistinct margin indicate possibility of extracapsular extension.,C,On axial apparent diffusion coefficient(ADC)map,ADC value of cancer(,outlined area,)is 0.77 103mm2/S.,移行带低信号结节,：,BPH,与,Pca,内部：窄窗观察（与同侧邻近结节信号接近或仅轻度降低，或存在黑白相间），增强黑白错落有致征，为,BPH,。均匀则待定,假包膜：完整更倾向于,BPH,，少数,Pca,也可。,周围高信号环绕：更倾向于,BPH,？,Pca,也可。,周围解剖细节破坏，则为,Pca,。,DWI,：,Pca,的,DWI,高信号大于,BPH,，,ADC,有交叉，间质增生结节,ADC,多为,0.9-1.3,Dyn-CE,：只分阳性与阴性。,减少活检,，,保护前列腺,，,应避免检出无临床意义的前列腺癌,移行带,Pca,的,MRI,平扫表现,早期移行带前列腺癌，所示病灶呈弥漫性低信号，外周带信号依然正常。这一例病灶已经出现了膀胱和精囊的侵犯征象。,Biopsy-proved,adenocarcinoma,in a 72-year-old man.(a)Axial T2-weighted MR image shows a low-signal-intensity lesion in the right lobe of the prostate(arrow).(b)ADC map shows a low ADC value in the lesion(arrow),a finding indicative of decreased diffusion.A targeted biopsy was performed.,Prostatic cancer,in 68-year-old man with prostate-specific antigen level of 19.3 ng/mL and negative findings on endorectal sonography-guided biopsy.Stage is T2b.No suspicious findings were seen on digital rectal examination or endorectal sonography.A and B,Axial and sagittal T2-weighted images(TR/TE,5,000/155 and 4,700/119;echo-train length,8)show uniform hypointense area with irregular margin in anterior location of inner gland,which,extends toward anterior fibromuscular stroma,(arrows).Heterogeneous decreased intensity area is seen in right peripheral zone.C,Contrast-enhanced T1-weighted image(600/20)with fat suppression shows homogeneous enhancement of lesion at inner gland and enhancement of both peripheral zones.D,Histopathologic specimen obtained at corresponding level reveals moderately differentiated adenocarcinoma in anterior position of inner gland(arrow).Tumor size is 35 15 mm.Two small tumor foci indicating prostatic intraepithelial neoplasia are seen in background of both peripheral zones(arrowheads),70-year-o