直肠筋膜对直肠癌术前分期及术后复发预测的MRI研究

目的:通过MRI评估直肠系膜筋膜受累状态对中下段直肠癌术前分期及其术后复发预测中的价值。方法:对33例中下段直肠癌患者行术前盆腔MRI扫描并于术后随访2年,将MRI表现与术后病理相对照,观察分析直肠系膜筋膜受累状态对术前T分期及预测术后复发的价值。结果:术前MRI显示壁外肿瘤侵犯深度>5mm者16例;直肠系膜浸润程度Ⅰ度14例,Ⅱ度11例,Ⅲ度8例;环周切缘阳性者16例。术后病理:T1期2例,T2期8例,T3期15例,T4期8例。经肠镜证实术后局部复发者7例。术前直肠系膜及筋膜受累状态与术后病理T分期以及肿瘤的术后局部复发均密切相关(P值均<0.05)。结论:通过术前MRI评估直肠系膜及筋膜受累状态有助于更加准确地判断直肠癌术前T分期,为直肠系膜全切手术方式的选择提供更客观的依据,并对预测直肠癌术后局部复发具有重要价值。     

全直肠系膜切除术相关解剖结构的影像学分析

目的 对"全直肠系膜切除术"的相关解剖结构进行影像学探讨.方法 收集MSCT、高分辨力MRI的正常盆腔图像186例(CT 99例,MRI 87例).对直肠系膜、系膜筋膜、Denonvillier's筋膜以及直肠侧韧带进行分析并记录,用SPSS10.0软件对所得数据进行统计学分析.结果 直肠系膜3例显示不清,直肠系膜筋膜显示率CT为93.93%(93/99),MR为94.25%(82/87),二组间无明显统计学差异.Denonvillier's筋膜及直肠侧韧带均无明确显示.结论 MSCT及MRI能很好地显示直肠系膜及系膜筋膜,但不能显示Denonvillier's筋膜及直肠侧韧带结构.     

直肠系膜及筋膜的MR研究

目的 探讨正常直肠系膜及其筋膜的MR表现特点.方法 搜集100例资料按年龄分5组.由2位放射科医生共同观察分析MRI图像,详细记录:①直肠系膜筋膜显示情况;②直肠系膜与盆壁脂肪的信号强度;③各年龄组直肠系膜厚度与盆壁皮下脂肪厚度比值差异.结果 正常直肠前、后、左、右侧直肠系膜筋膜显示率分别为77%、100%、91%、93%.直肠系膜平均信号强度为550.8843,盆壁脂肪平均信号强度为469.8693,按统计学分析,P﹤0.05,直肠系膜信号强度明显高于盆壁脂肪,这种差异大多数肉眼可辨.各年龄组间直肠系膜厚度与盆壁脂肪厚度比值经q检验,P值均﹥0.05,其差异无统计学意义,其95%可信区间为(0.91,1.08).结论 MRI图像能清楚显示直肠系膜及筋膜,后方筋膜显示率高于两侧方及前方筋膜;直肠系膜信号强度高于盆壁脂肪;直肠系膜厚度与盆壁脂肪厚度比值和年龄没有明显关系.     

正常直肠系膜和直肠筋膜的MRI表现

目的 :探讨直肠系膜、直肠筋膜的正常MRI表现。方法 :收集无直肠及周围间隙病变的50例患者的临床和MRI资料,在轴位图像上测量并记录:1精囊腺/子宫体平面上,直肠在直肠周围间隙内的解剖位置;2直肠筋膜显示情况及其厚度;3直肠系膜与盆壁脂肪信号强度比值;4直肠系膜内淋巴结显示情况。结果:精囊腺/子宫体平面上,直肠主要位于直肠筋膜构成的直肠周围间隙内的侧方。直肠筋膜最厚处为(1.94±0.54)mm。直肠系膜与盆壁脂肪信号强度比值为1.02±0.17;直肠系膜脂肪信号强度高于盆壁脂肪信号强度(P0.01)。直肠系膜内正常淋巴结显示率低,其最大径均小于5 mm。结论:MRI能良好显示直肠筋膜及直肠系膜的解剖结构。     

直肠癌全直肠系膜切除术术前影像学评估

目的 行全直肠系膜切除术(TME)探讨影像学对直肠癌病例进行术前评估的价值.方法 术前活检病理证实直肠癌63例,进行CT、MR平扫及增强检查(其中CT 35例,MR 28例).分析直肠系膜筋膜受累情况、筋膜外淋巴结转移及病灶与肛缘间的曲线距离,结果与术后病理相对照.结果 对直肠系膜筋膜受累情况的判断中有2例CT高估,1例MR高估,2组间差异无统计学意义.MR矢状位能清晰显示所有病例的肛缘及肿瘤下缘之间的曲线距离.63例中有37例发现系膜内肿大淋巴结,其中19例病理结果无转移均为反应性增生.16例系膜筋膜外发现肿大淋巴结,其中12例病理结果为转移,4例为反应性增生.结论 MSCT及高分辨力MRI对直肠癌患者拟行TME者的术前评估具有重要价值.     

直肠系膜及周围筋膜结构的薄层MRI研究

目的探讨直肠系膜及周围筋膜结构的薄层MRI特点,为直肠癌全直肠系膜切除术(TME)提供客观的影像学依据。方法选取30例健康志愿者行常规T1WI、T2WI、T2W SPAIR及薄层T2WI扫描,比较各序列对系膜及筋膜的显示效果,并分析系膜及筋膜结构的MRI表现。结果薄层T2WI(M=5.0)对系膜及筋膜的评分明显高于T1WI(M=3.0)、T2WI(M=3.0)、T2W SPAIR(M=1.0),差异具有统计学意义(P<0.05)。在薄层T2WI上,30例直肠系膜的显示率为100%,直肠固有筋膜分为前方(与Denonvilliers筋膜难以区分)、后方(与骶前筋膜难以区分)、左方、右方筋膜,其显示率分别为96.7%、100%、96.7%、93.3%。结论薄层T2WI优于常规MRI序列,可较好地显示直肠系膜及筋膜的形态特征,能够为直肠癌TME提供客观的影像学依据。     

表观扩散系数ADC值与直肠癌侵袭性的相关性分析

目的:探讨3.0T磁共振扩散加权成像(DWI)的参数表观扩散系数(ADC)与直肠癌侵袭性之间的相关性.方法:对60例经病理证实的直肠癌患者行常规盆腔MRI及DWI扫描,测量整个肿瘤的ADC值.根据MRI图像及术后病理结果,得到肿瘤的病理类型、分化程度、T1-2(肿瘤局限于肠壁)与T3-4(肿瘤生长突破肠壁);N0(无淋巴结转移)与N1-2(有淋巴结转移);CRM阴性(无直肠系膜筋膜浸润)与CRM阳性(有直肠系膜筋膜浸润)、肿瘤的大体分型、部位、年龄及性别,进行相关性比较.结果:直肠癌的ADC值在分化程度(P-0.000)、T1-2与T3-4(P=0.015)、N0与N1-2(P=0.001)、直肠系膜筋膜受累与未受累(P=0.014)之间的差异均有统计学意义.与肿瘤的大体分型(P=0.971)、部位(P=0.960)、性别(P=0.592)、年龄(r=0.038,P=0.772)之间的差异无统计学意义.结论:直肠癌的ADC值可以作为评价其侵袭性及预后的一个定量指标.     

女性盆腔非生殖系统肿瘤的MRI诊断

目的 探讨女性盆腔非生殖系统肿瘤的MRI特征及诊断要点.方法 回顾性分析15例经手术病理证实的女性盆腔非生殖系统肿瘤的MRI表现,并与术后病理结果进行比较分析.结果 术前MRI检查15例肿物,呈囊实性10例,实性3例,囊性2例,5例误诊为生殖来源肿瘤.15例均经手术病理证实,其中肠道肿瘤6例,腹腔及腹膜后肿瘤5例,其他肿瘤4例;包括小肠系膜间质瘤4例,乙状结肠腺癌1例,阑尾囊腺瘤1例,肠系膜脂肪肉瘤1例,神经鞘瘤2例,纤维瘤病1例,冬眠瘤1例,纱布瘤2例,淋巴囊肿1例及淋巴瘤1例.结论 女性盆腔肿瘤术前MRI检查易诊断为生殖系统来源肿瘤,仔细分析其MRI特征及避免思维定式可减少误诊.     

孕产妇颅内静脉窦血栓形成的CT、MRI、MRV、DSA诊断

目的:探讨头部影像学检查诊断孕产妇颅内静脉窦血栓形成(CVST)的价值.材料和方法:回顾性分析6例孕产妇并发CVST患者CT、MRI、MRV、DSA成像的直接和间接征象.6例患者起病后头部CT扫描5例、MRI扫描6例、MRV扫描4例、MRI增强扫描3例、DSA检查1例.结果:6例患者的头部CT、MRI、MRV、DSA成像均有异常表现.表现脑叶皮质及皮质下白质受累间接征象的CT 5例、MRI 6例,其中出血性梗死4例.同时表现纵裂内高密度索带征及高密度三角征直接征像的CT 1例,表现静脉窦流空信号消失、T1为等信号、T2为等及低信号直接征像的MRI 2例.表现受累静脉窦不显影、显影中断、显示不清、或者局部信号缺失的MRV 4例,其中1例表现出两侧静脉分枝显影不均,一侧静脉分枝显影明显减少的征象.显示上矢状窦不显影的DSA 1例.结论:头部CT、MRI、MRV和DSA检查能显示CVST脑组织直接和间接受累征像,MRI+MRV成像可作为诊断CVST的首选检查,CT及MRI+MRV复查能动态观察病情及反映疗效.     

MRS与MRI对前列腺癌与前列腺增生鉴别诊断中的应用

目的:分析前列腺癌和前列腺增生的MRI表现和磁共振波谱成像(magnetic resonance spectroscopy, MRS)代谢特征,探讨MRI和MRS相互结合在前列腺癌和增生鉴别诊断中的价值.方法:分析经手术或穿刺活检证实的26例前列腺癌和32例增生患者的临床资料及MRI、MRS所见.MRI分析前列腺的大小、形态、病变位置、信号特点和肿瘤侵犯程度等.MRS测量枸橼酸盐(Citrate)、胆碱(Choline)、肌酸(Creatine)的峰值、(胆碱 肌酸)/枸橼酸盐[(Cho Cr)/Cit,CC/C]的比值.结果:前列腺癌中有20例在T2WI像上有明显的前列腺癌征象,其中18例侵犯精囊,14例侵犯膀胱,12例侵犯盆腔周围骨组织,5例侵犯直肠,5例盆腔内见多个肿大淋巴结并部分相互融合成团;余6例未见明显的前列腺癌征象.MRS上将前列腺分成六个区,在MRS代谢图上标记出体素(测量点)归入相应分区.每例取4个体素(体素或MRI上疑点),58例中一共取232个体素进行测量,前列腺癌cit峰值均明显下降,Cho峰值均升高,标记出手术或穿刺活检取材癌区的CC/C平均值为2.3730±1.97548,增生的波谱形态和癌相反,CC/C平均值为0.5450±0.48842,两组间差异有统计学意义(t=-4.605,P=0.000<0.05).结论:MRI能对前列腺癌定位,了解侵犯部位及转移情况.MRS能根据MRI提示的病变及可疑部位进行定量分析、显示其代谢情况.MRI与MRS相结合能提高对肿瘤的定性诊断,具有重要的诊断价值.     

前列腺癌内分泌治疗后复发的MRI研究

目的探讨前列腺癌内分泌治疗后复发的MR I征象。方法10例经临床诊断证实的前列腺癌内分泌治疗后复发的病人,在内分泌治疗过程中肿瘤复发前后都进行了MR I检查。对2次MR I图像中前列腺T2信号、体积变化、对周围组织侵犯、扫描范围内的骨转移和淋巴结转移等情况进行对比分析。结果与复发前对比,前列腺体积增大的有7例,体积未见明显变化的有3例。复发后新出现的周围组织侵犯包括精囊腺(3例)、膀胱(2例)、直肠(1例)、盆底肌(1例)。复发后扫描范围内(骨盆至髂血管分叉水平)原有骨转移病灶进展的有3例,新出现转移灶的有4例。新出现髂血管旁肿大淋巴结的有4例,腹股沟肿大淋巴结的有2例。结论MR I检查能提供有助于诊断内分泌治疗后肿瘤复发的多方面影像信息。     

直肠内线圈MR在前列腺癌诊断中作用:肿瘤位置和分期

目的:利用直肠内线圈MR成像显示前列腺癌及进行临床分期。方法:75例前列腺癌,年龄30~81岁,平均年龄为65岁。均经直肠前列腺穿刺活检术获得病理结果。Philips Intera 1.5T Master超导型临床医用磁共振仪,采用标准直肠腔内线圈。对前列腺包膜显示及是否侵犯,精囊侵犯和淋巴结转移进行了分析。结果:直肠内线圈的应用可显著提高前列腺图像的信噪比,可清晰显示前列腺癌病变、局部解剖、包膜、血管神经丛,并能显示前列腺癌转移及盆腔淋巴结转移途径。结论:直肠内线圈可以确定前列腺癌肿瘤的位置,以及包膜和精囊血管侵犯,并有利于分析前列腺癌淋巴结转移的方式。     

15例前列腺癌侵犯膀胱误诊为膀胱癌的MRI表现

目的分析膀胱受累的前列腺癌的MRI表现,评价MRI对前列腺癌的定性诊断价值,避免伴膀胱受累的前列腺癌误诊为膀胱肿瘤。资料与方法回顾性分析15例行MRI检查前曾误诊为膀胱癌的前列腺癌患者的临床及MRI资料。结果 15例误诊病变MRI均明确诊断为前列腺癌,其中C期10例,D期5例。结论 MRI是诊断前列腺癌良好的影像学方法,特别是当病变累及膀胱时,可很好地避免误诊为膀胱肿瘤,再结合其他检查方法,可提高前列腺癌的诊断准确率。     

Evaluation of T2-weighted and dynamic contrast-enhanced MRI in localizing prostate cancer before repeat biopsy

We assessed the accuracy of T2-weighted (T2w) and dynamic contrast-enhanced (DCE) 1.5-T magnetic resonance imaging (MRI) in localizing prostate cancer before transrectal ultrasound-guided repeat biopsy. Ninety-three patients with abnormal PSA level and negative prostate biopsy underwent T2w and DCE prostate MRI using pelvic coil before repeat biopsy. T2w and DCE images were interpreted using visual criteria only. MR results were correlated with repeat biopsy findings in ten prostate sectors. Repeat biopsy found prostate cancer in 23 patients (24.7%) and 44 sectors (6.6%). At per patient analysis, the sensitivity, specificity, positive and negative predictive values were 47.8%, 44.3%, 20.4% and 79.5% for T2w imaging and 82.6%, 20%, 24.4% and 93.3% for DCE imaging. When all suspicious areas (on T2w or DCE imaging) were taken into account, a sensitivity of 82.6% and a negative predictive value of 100% could be achieved. At per sector analysis, DCE imaging was significantly less specific (83.5% vs. 89.7%, p < 0.002) than T2w imaging; it was more sensitive (52.4% vs. 32.1%), but the difference was hardly significant (p = 0.09). T2w and DCE MRI using pelvic coil and visual diagnostic criteria can guide prostate repeat biopsy, with a good sensitivity and NPV.     

MRI对前列腺癌及邻近受累结构的诊断价值

目的探讨MRI对前列腺癌及邻近受累结构的诊断价值。方法回顺性分析55例经穿刺或F术病理证实的前列腺硝患哲的常规MRI、弥敞加权成像（DWI）及动态增强扫描（DCE）图像,分析前列腺癌及邻近受累结构的图像特点。结果j5例前列腺癌．48例位于外脚带．4例位于中央带．3例同时累及外周带和中央带。所有癌灶于DWI图呈高信号,ADC图呈低信号,前列腺癌ADC值约（0．98±0．15）×10^-3m㎡/s。DCE譬期癌灶信号强度增高,其中41例呈速升速降型．5例呈速升平台型,9例呈速升缓降型。前列腺癌邻近受侵结构：腺周脂肪受侵8例,精囊受侵6例．神经血管束受侵4例．膀胱受侵6例,直肠受侵2例,箍腔淋巴结转移13例．骨转移并5例。结论MRI埘前列腺癌及邻近结构的诊断媳有重婴的诊断价值．为临i床治疗方案的选择具有重要指导意义。     

Improved detection of localized prostate cancer using co-registered MRI and (11)C-acetate PET/CT

Objectives

We aimed to study the ability of contrast enhanced MRI at 1.5 T and ¹¹C-acetate PET/CT, both individually and using fused data, to detect localized prostate cancer.

Methods

Thirty-six men with untreated prostate cancer and negative for metastatic disease on pelvic CT and bone scan were prospectively enrolled. A pelvic ¹¹C-acetate PET/CT scan was performed in all patients, and a contrast enhanced MRI scan in 33 patients (6 examinations using both endorectal coil and surface coils, and 27 examinations using surface coils only). After the imaging studies 10 patients underwent prostatectomy and 26 were treated by image guided external beam radiation treatment. Image fusion of co-registered PET and MRI data was performed based on anatomical landmarks visible on CT and MRI using an advanced in-house developed software package. PET/CT, MRI and fused PET/MRI data were evaluated visually and compared with biopsy findings on a lobar level, while a sextant approach was used for patients undergoing prostatectomy.

Results

When using biopsy samples as method of reference, the sensitivity, specificity and accuracy for visual detection of prostate cancer on a lobar level by contrast enhanced MRI was 85%, 37%, 73% and that of ¹¹C-acetate PET/CT 88%, 41%, 74%, respectively. Fusion of PET with MRI data increased sensitivity, specificity and accuracy to 90%, 72% and 85%, respectively.

Conclusions

Fusion of sequentially obtained PET/CT and MRI data for the localization of prostate cancer is feasible and superior to the performance of each individual modality alone.     

Comparison of MRI with CT for the radiotherapy planning of prostate cancer: a feasibility study

This feasibility study was performed to evaluate the suitability of MRI in defining appropriate pelvic radiotherapy treatment volumes, and to compare MRI sequences with CT for prostate cancer radiotherapy. Five patients with localized prostate cancer, imaged with four MRI sequences (spin echo (SE) T1, turbo SE (TSE) T2, high resolution TSE (HR) T2, and FLASH 3D (F3D)), compared with their corresponding CT planning scans. Segmentation ability of the following pelvic structures: prostatic apex (PA), prostate, rectum, bladder and seminal vesicles (SV), were evaluated by three independent observers. They used a five point grading scale based on the anatomical definition of the organ boundary, tissue contrast and multiplanar display. Results were averaged for the group and for each sequence. There was no significant interobserver variation in the assessed scores (p > 0.1). The average scores (+/- 1 SD) for all pelvic structures assessed by each imaging sequence were CT 1.3 +/- 0.6; SE T1 2.4 +/- 0.9; TSE T2 2.4 +/- 0.7; HR T2 2.2 +/- 0.7 and F3D 3.4 +/- 0.6. Compared with CT, the average MR score for each assessed pelvic structure was higher with a trend for all transaxial MR sequences to provide improved segmentation of the PA and rectum. The F3D sequence scored highest as it provided multiplanar views and avoided the problem of partial volume averaging. MRI, compared with CT, appears to provide improved definition of pelvic treatment volumes but further work is required to confirm this and to address the issues of MRI associated distortion and dosimetry before MRI can be used routinely for pelvic radiotherapy planning.     

Endorectal 3D T2-weighted 1 mm-slice thickness MRI for prostate cancer staging at 1.5 Tesla: Should we reconsider the indirects signs of extracapsular extension according to the D’Amico tumor risk criteria?

Purpose

To evaluate the accuracy of a 3D-endorectal 1 mm-thick slices MRI acquisition for local staging of low, intermediate and high D’Amico risk prostate cancer (PCa).

Materials and methods

178 consecutive patients underwent a multiparametric MRI protocol prior to radical prostatectomy (RP). T2W images were acquired with the 3D sampling perfection with application optimized contrasts using different flip angle evolutions (SPACE) sequence (5 mn acquisition time). Direct and indirect MRI signs of extracapsular extension (ECE) were evaluated to predict the pT stage. The likelihood of SVI (seminal vesicle invasion) was also assessed.

Results

Histology showed ECE and SVI in 38 (21%) and 12 (7%) cases, respectively. MRI sensitivity and specificity to detect ECE were 55 and 96% if direct signs of ECE were used and 84 and 89% (p < 0.05), if both direct and indirect signs were combined. D’Amico criteria did not influence MRI performance. Sensitivity and specificity for SVI detection were 83% and 99%.

Conclusions

3D data sets acquired with the SPACE sequence provides a high accuracy for local staging of prostate cancer. The use of indirect signs of ECE may be recommended in low D’Amico risk tumors to optimise patient selection for active surveillance or focal therapy.     

Diagnostic imaging in male pelvic disorders]

This article reviews the imaging findings of male pelvic disorders, especially those of prostate disease. Magnetic resonance imaging (MRI) provides excellent anatomical detail, and is useful to stage prostate cancer and to understand the process of anomaly. However, failure to detect capsular invasion remains a significant weakness in prostate cancer. It is important to understand the limits and contributions of MRI to the staging of prostate cancer, and to perform the appropriate examination.     

前列腺癌的MRI诊断

目的探讨前列腺癌的MRI诊断价值方法回顾性分析30例经手术与病理证实的前列腺癌MRI表现及分期,并与临床病理对照结果前列腺癌80%发生于外周带,T2WI在高信号的前列腺周边带内出现异常结节状低信号,或者前列腺带状结构破坏,周边带与中央带界线消失86.7%的前列腺癌发现已位于C、D期结论磁共振对诊断前列腺癌及其分期具有重要意义