宫颈癌放射治疗疗效的MRI评价

目的分析宫颈癌放射治疗中与后MRI表现,探讨MRI成像对宫颈癌放射治疗疗效评估的价值。方法23例经病理证实的宫颈癌患者在放射治疗前、中及后不同时间段行盆腔的轴位T1WI,轴位及矢状位T2WI,冠状位SPIR,以及GDDTPA增强后T1WI的轴位、冠状位、矢状位扫描。在MRI图像上观察肿瘤在放射治疗前、后的大小及信号改变。结果外照射结束时,9例肿瘤缩小率在85%以下,14例>85%。T1WI增强扫描7例见肿瘤内出现“无强化区”,其中6例放射治疗结束后有肿瘤残留;16例肿瘤未见“无强化区”,其中13例肿瘤缩小率>85%,仅2例放射治疗后有肿瘤残留。MRI图像上,肿瘤痊愈表现为T2WI、SPIR序列呈低信号,T1WI增强扫描轻微强化或无强化。结论MRI成像可反应肿瘤对射线的疗效。外照射结束时肿瘤容积缩小程度与T1WI增强肿瘤内有无“无强化区”是预测放射治疗效果的重要观测指标。     

MRI在直肠癌术后复发诊断中的价值

目的探讨直肠癌术后复发MRI的诊断价值。方法对48例直肠癌Mile’s术后可疑复发患者,采用常规SE序列行轴位T1WI、T2WI、DWI,矢状位T2WI及冠状位T2压脂盆腔平扫,其中25例行Gd-DTPA增强扫描。MRI检查诊断结果与再次手术、穿刺活检病理或临床随访结果进行比较。结果 32例经再次手术（切除、探查）或穿刺活检病理学检查证实为复发,MRI表现为骶前及会阴部软组织肿块,T1WI呈等、低信号,T2WI呈稍高混杂信号（抑脂序列显示好）,DWI呈高亮信号。复发肿瘤侵犯前列腺8例、精囊腺5例、膀胱7例、骶椎6例,腹股沟及盆腔淋巴结转移18例。另16例随访8个月～2年证实为术后纤维瘢痕,T1WI、T2WI及DWI均表现为低信号,且骶前脂肪间隙清晰。结论 MRI检查在鉴别直肠癌术后复发与纤维瘢痕、明确肿瘤侵犯范围方面,具有重要价值。     

鼻咽癌颅底骨质侵犯的CT与MRI对比检测

目的:研究CT及MRI对鼻咽癌颅底骨侵犯的检测能力及诊断价值。方法:60例鼻咽癌初治患者,于放射治疗前同期进行鼻咽颅底连续横断位CT扫描及FSE轴、冠、矢状位T1WI和轴位T2WIMRI检查,对两者检测结果进行比较。结果:CT、MRI对颅底骨侵犯的阳性检出率在全部患者中为16.7%、53.3%。经检验,P<0.001,有显著性意义。破坏的部位均以斜坡最多见。结论:MRI对鼻咽癌颅底骨侵犯的检测能力优于CT。     

口咽部恶性肿瘤的磁共振成像研究

目的探讨磁共振成像(Magnetic resonance image,MRI)在口咽部恶性肿瘤诊断、疗效评价及术后复发监测中的应用价值。方法收集资料完整的口咽部恶性肿瘤病例30例,术前均行MRI检查,应用标准SE序列平扫及增强扫描,行轴位、矢状位及冠状位的T1WI、T2WI序列扫描,范围从颅底至颈根部。必要时部分病例行MRA检查。结果肿块致口咽腔形态改变,但粘膜表浅的肿瘤MRI不易发现;软组织内肿块表现为T1WI像中等或中低信号、T2WI像中高或高信号;鳞癌一般边界不清信号不均匀,而恶性黑色素及恶性淋巴瘤边界较清楚、内部信号也比较均匀,颌骨中央性癌边界较清信号较均匀;肿块侵犯周围组织结构的状况在MRI像有较好显示,但对血管的显示有时需补充MRA检查;区域淋巴结转移状况的诊断假阴性较高,不能作为排除转移的主要手段;另外,MRI对放化疗效果判断及复发监测有一定价值;同时,Gd-DTPA增强扫描在判断肿瘤性质,区别组织水肿及纤维化与肿瘤复发方面有一定帮助。结论MRI对口咽部恶性肿瘤的定性、定位诊断、疗效评价及术后复发监测具有重要的参考价值。     

子宫腺肌症合并妇科肿瘤的MRI表现

目的：探讨MRI在合并妇科肿瘤的子宫腺肌症中的诊断价值。方法：回顾性分析2003年8月至2004年8月16例子宫腺肌症患者的MRI资料(其中一例为腺肌瘤伴腺肌症)。16例患者行快速自旋回波序列(FRFSE)T1WI、T2WI和T1WI抑脂的多期增强快速扰相梯度回波扫描(FSPGR)，以矢状面，轴位为主，7例伴有冠状位扫描。所有病例均经手术病理证实。结果：弥漫性子宫腺肌症14例。10例在T2WI上表现为子宫结合带弥漫性增厚，厚度10—37mm，平均17mm，呈均匀的低信号，4例病灶内有散在的点状高信号区，其中1例在T1WI仍表现为高信号。局限性腺肌症(腺肌瘤)3例共3个病灶。在T2WI上，表现为卵圆形、类圆形肿块，呈与结合带信号相近的低信号，直径分别为2cm，4cm，7cm；其中2个病灶与周围肌组织分界不清，1个病灶与周围肌组织有较清楚的界限。3个病灶内均有散在的点状高信号区，其中1个病灶在T1WI也呈高信号区。结论：MRI是发现子宫腺肌症较优越的无创伤性检查方法，T2WI矢状位为最佳扫描序列。     

MRI在诊断宫颈癌复发中的价值

目的：探讨MRI在评估诊断宫颈癌复发中的价值。方法：36例经病理证实宫颈癌复发患者,均行盆腔的MRI轴位T1WI、T2WI、SPIR以及GD-DTPA增强扫描后T1WI轴位、矢状位扫描。在不同序列MRI图像上观察复发肿瘤的形态、大小及信号改变。结果：326例病人中出现复发36例,发生率为11%。25例宫颈癌手术后复发病例,MRI可见在阴道残端或盆腔内出现软组织信号肿块影,增强扫描可见肿块明显强化。其中5例可见肿块侵及一侧输尿管,其上方输尿管扩张积水。11例宫颈癌放化疗后复发病例,MRI可见宫颈较前明显增厚,肿块T1WI为略低信号,T2WI为略高信号,增强扫描可见肿块呈不均匀强化。其中2例可见肿块侵及膀胱壁。结论：由于MRI具有非常好的软组织分辨率,MRI成像已成为宫颈癌手术前后或放化疗前后检查和随访最重要的手段,它能够准确判断宫颈癌临床分期,并且可以早期、及时发现肿瘤复发;在评估宫颈癌复发诊断中有重要价值。     

2D和3D MRI结合技术在胰腺癌诊断中的应用

目的探讨多种MRI成像技术和改良增强扫描方案在胰腺癌诊断中的价值。方法对49例胰腺癌患者进行MRI检查,平扫序列分别为T1WI 2D快速小角度单次激发(FLASH)、T1WI 3D屏气容积内插法(VIBE)脂肪抑制、快速自旋回波(TSE)T2WI和T2WI半傅立叶转换单次激发快速自旋回波(HASTE)脂肪抑制MR胰胆管成像(MRCP);增强扫描方法为3D FLASH冠状位与T1WI 3D VIBE横断位交替扫描方式,即动脉期和门静脉期采用冠状位扫描,胰腺期和延迟期采用横断位扫描;最后采用T1WI 2D FLASH完成整个上腹部扫描。冠状位原始图像经最大信号强度投影(MIP)分别获得胰腺周围主要动脉和门静脉影像,用多平面重建技术获得胰腺及周围组织动脉期和门静脉期图像。结果(1)在3D VIBE平扫中,45例肿瘤为低信号,4例为等信号;在2D FLASH序列中,46例肿瘤为低信号,3例为等信号;脂肪抑制TSE T2WI 3例肿瘤为等信号,其余46例均为等和略高信号,并与周围胰腺实质均无明显分界。(2)胰腺期增强扫描,除1例肿瘤为等信号外,其余均呈相对低信号,39例肿瘤周围呈环形强化,其中24例肿瘤门静脉期及延迟期可见边缘结节样和内部分隔样强化。6例延迟强化呈等和略高信号。动脉期肿瘤均未见明显强化。(3)37例手术探查的患者,MRI 磁共振血管成像(MRA)误诊7条血管,包括3例肠系膜上动脉和4例肠系膜上静脉,其余血管均判断正确。结论应用2D和3D MRI结合技术1次检查即可同时了解胰腺肿瘤、胰胆管和血管等多系统的情况,对胰腺癌的术前诊断和手术切除性判断有重要价值。     

MRI直接用于颅内肿瘤治疗计划设计的可行性探讨

目的通过检测MRI的空间几何失真程度大小,研究其直接用于放疗计划设计的可行性。方法自制油脂管按每15°间隔辐射状排列置于泡沫模体内,制成模体1;自制油脂管按2.7cm间距网格状排列置于泡沫模体内,制成模体2。以Marconi1.5T超导型磁共振仪采用头部FSET2WI序列,分别对2个模体行平行于辐射状和网格状油脂管冠位面扫描和垂直于上述各面的横断位扫描,然后进行冠状面DRR重建。将获得的图像分为不同大小的5个视窗范围,测量直接扫描图像和DRR图像的边界绝对位置误差并计算其几何畸变率。结果对直接扫描的MRI,在11cm×11cm的视窗范围内,其边界最大位置误差基本为零;在22cm×22cm视窗内,其边界最大位置误差仅为1.1mm;在27.5cm×27.5cm的视窗范围内,其边界最大位置误差为1.4mm。对冠状面DRR重建图像,在16.5cm×16.5cm的视窗范围内,其边界最大位置误差<1.0mm;在22cm×22cm视窗范围内,其边界最大位置误差为1.4mm;在27.5cm×27.5cm的视窗范围内,其边界最大位置误差为2.0mm。结论对高场强的磁共振仪,在假定组织为均匀密度的前提下,MRI可以直接用于颅内肿瘤的放疗计划设计。     

螺旋CT结肠仿真内镜对结肠肿瘤术前评估

目的　探讨螺旋 CT结肠仿真内镜 (CCVE)术前对结肠肿瘤诊断、鉴别诊断、肿瘤数目、大小、部位、受侵范围及淋巴结转移等评估的临床应用价值。方法　对 38例临床诊断为结肠肿瘤的患者进行螺旋 CT结肠仿真内镜检查 ,扫描范围包括盲肠、全部结肠及直肠以 1mm间隔重建 ,之后进行图像后处理及显示原始的横断位、2 D结肠横断位、冠状位、矢状位 ,任意平面的图像及 3D结肠图像。结果　 CCVE可以准确显示病变的位置、数目、大小、淋巴结肿大以及腹部器官有否转移等情况 ,从而对结肠肿瘤患者进行正确的术前评估。结论　 CCVE是一种无创伤性的检查方法 ,对结肠肿瘤的术前评估有着重要参考价值 ,有利于治疗方案的选择。     

MRI在侵袭性垂体腺瘤术前评估中的价值及临床意义

目的探讨MRI在侵袭性垂体腺瘤术前评估中的价值及临床意义。方法回顾性分析经手术病理证实的侵袭性垂体腺瘤36例,所有病例均接受3．0TMRIT1wI冠状位、矢状位,T2WI冠状位平扫及T1WI冠状位、矢状位和横轴位增强扫描。结果肿瘤以等T1、等或稍长他信号为主,增强扫描后均匀或不均匀强化。肿瘤向周围组织侵犯表现为颈动脉包绕,海绵窦受累;鞍底下陷,部分肿瘤突人蝶窦;突破鞍隔等。MRI示海绵窦4级受侵的有24侧,3级受侵的有27侧,术中均证实海绵窦受侵犯,颈内动脉部分或完全受包绕。结论MRI可在术前正确评估垂体腺瘤的侵袭性及侵袭范围,对手术方式以及术后治疗方案的选择具有重要的临床意义。     

子宫颈癌术前磁共振成像诊断与术后病理分期对比分析

 目的　探讨磁共振成像（MRI）术前分期的准确性与病理分期的准确性,以及对子宫颈癌治疗方式的指导价值。方法　回顾性分析50例子宫颈癌患者（鳞癌47例,腺癌2例,鳞腺癌1例）的临床及MRI资料。所有患者行平扫及增强扫描,23例行三期动态增强扫描。38例经手术治疗的患者,对术前MRI分期与术式的选择及术后病理分期进行对照分析。结果　33例MRI分期为Ⅰ～ⅡA期子宫颈癌分期准确率约为82.35 %,患者行子宫全切术及盆腔淋巴结清扫术。ⅢA～ⅣB期的诊断准确率约100 %。MRI对子宫颈癌分期总的准确率约为84.21 %。结论　MRI能多方位显示子宫颈癌病灶及其侵犯范围,术前分期具有较高的准确性,有利于术前评估、手术方式的制定及治疗方案的选择。     

腰椎间盘突出症2D-FIESTA Cine成像的临床应用

目的 评价2D-FIESTA cine成像在腰椎间盘突出症中的临床应用价值.方法 18例腰椎间盘突出症患者分别行矢状位SE T1WI,快速SE(FSE)T2WI,脂肪抑制FSE T2WI(fat saturation FSE T2WI,FS-FSE T2WI)及2D-FIESTA(fast imaging employing steady-state acquisition,FIESTA)cine.回顾性分析18例经手术病理或随访证实腰椎间盘突出症的2D-FIESTA cine表现,并与其他常规序列的MR扫描时间进行比较.结果 18例腰椎间盘突出症患者,共33个椎间盘受累.在SE T1WI上,病变均呈低信号,FS-FSE T2WI、FSE T2WI和FIESTA呈中等信号或低信号.2D-FIESTA cine除可动态显示突出椎间盘的情况,并可清楚显示受压的脊神经.2D-FIESTA的扫描时间仅为T2WI的13.3%;为T1WI的17.9%.2D-FIESTA的扫描时间比常规MRI扫描时间短(P＜0.001).结论 2D-FIESTA cine能清楚提供诊断腰椎间盘突出症的有价值的表现,是常规MR检查的有效补充.     

磁共振扩散加权成像对子宫内膜癌的诊断价值

目的 应用高场强磁共振对子宫内膜癌进行扩散加权成像(DWI),并探讨其对子宫内膜癌的诊断价值.方法 应用3.0T磁共振扫描仪,对临床怀疑为子宫内膜癌的50例患者(病理证实子宫内膜癌35例,子宫内膜不典型增生10例,分泌期子宫内膜4例,萎缩性子宫内膜1例)以及41例正常志愿者行常规扫描和DWI,DWI选择b值为1000 s/mm~2.观察子宫内膜癌、正常子宫内膜和子宫内膜不典型增生在DWI图像上的差异,并分析三者间以及不同分化程度子宫内膜样腺癌之间表观扩散系数(ADC)值的差异.结果 与周围正常肌层相比,子宫内膜癌、子宫内膜不典型增生和正常子宫内膜在DWI图像上均呈明显高信号.子宫内膜癌、子宫内膜不典型增生和正常子宫内膜的ADC值分别为(1.08±0.23)×10~(-3)mm~2/s、(1.29±0.21)×10~(-3) mm~2/s和(1.41±0.21)×100~(-3)mm~2/s.统计分析结果显示,子宫内膜癌和正常子宫内膜的ADC值之间以及子宫内膜癌与子宫内膜不典型增生的ADC值之间的差异均有统计学意义(均P＜0.05),但高分化子宫内膜样腺癌和中分化子宫内膜样腺癌的ADC值之间的差异无统计学意义(P=0.109).结论 DWI对检出子宫内膜病变非常敏感,能够鉴别子宫内膜癌、子宫内膜不典型增生和正常子宫内膜,但对于鉴别不同分化程度的子宫内膜样腺癌仍有一定的困难.     

Clinical stage I carcinoma of the uterine cervix value of preoperative magnetic resonance imaging in assessing parametrial invasion

AIMS AND BACKGROUND: The purpose of this prospective study was to assess the efficacy of different MR imaging techniques in the evaluation of parametrial tumor invasion in patients with early stage cervical cancer. METHODS: A total of 73 consecutive patients, clinically considered to have invasive tumor (<3 cm in diameter) confined to the cervix, underwent MR imaging studies at 1 T, according to the following protocol: fast spin-echo (FSE) T2-weighted, gadolinium-enhanced SE T1-weighted, and fat-suppressed gadolinium-enhanced SE T1-weighted sequences. Images obtained with each sequence were evaluated for parametrial invasion with the use of histopathologic findings as the standard of reference. RESULTS: In the assessment of tumor infiltration of the parametrium, with FSE T2-weighted images accuracy was 83%, with SE T1-weighted gadolinium-enhanced images was 65%, and with SE T1-weighted gadolinium-enhanced fat-suppressed images was 72%. The difference between the accuracy rate achieved with FSE T2-weighted images and those obtained with the other two MR sequences was statistically significant (P <0.05). The high negative predictive value (95%) for the exclusion of parametrial tumor invasion was the principal contributor to the staging accuracy obtained with FSE T2-weighted imaging. CONCLUSIONS: Unenhanced FSE T2-weighted imaging is a reliable method for determining the degree of tumor invasion in patients with early stage cervical cancer. Our data suggest that contrast-enhanced sequences, even with the use of the fat suppression technique, have limited value in assessing tumor extension.     

胰头癌与胰头慢性胰腺炎的MR诊断与鉴别诊断

目的探讨胰头癌及胰头慢性胰腺炎的MR诊断与鉴别诊断。方法回顾性分析24例胰头癌及3例胰头慢性胰腺炎的MR表现。全部27例病人均行常规及压脂SET1WI序列、常规及压脂FSET2WI序列扫描。8例胰头癌及3例胰头慢性炎症患者行压脂SET1WI序列增强扫描。T2WI序列发现胰管扩张时行MRCP共24例,其中胰头癌23例,慢性胰腺炎1例。结果24例胰头癌于常规SET1WI序列呈低(n=8)或稍低(n=16)信号,于常规FSET2WI序列可表现为高(n=8)、稍高(n=5)、等(n=10)或低(n=1)信号,于压脂FSET2WI序列可表现为高(n=11)、等(n=11)或稍低(n=2)信号,于压脂SET1WI序列均呈低信号。23例胰头癌于MRCP均可见典型的“双管征”、胆总管扩张及远端截断。8例胰头癌无明显强化。3例胰头慢性胰腺炎于常规SET1WI序列呈稍低或等信号,于常规FSET2WI序列均呈高信号。2例于压脂SET1WI及FSET2WI序列分别呈等信号及稍高信号,另1例则分别呈低信号及混杂信号,MRCP可见胆总管轻度扩张伴胰管近端不规则扩张。3例慢性胰炎均呈不同程度强化。结论胰头癌与胰头慢性胰腺炎均于多个序列表现出信号的多样性,均可见异常强化,绝大多数胰头癌及部分胰头慢性胰腺炎有异常的MRCP表现。联合使用多种序列特别是平扫及增强压脂SET1WI序列及MRCP,可能鉴别胰头癌与胰头慢     

Penile bulb imaging

PURPOSE: Because of the apparent relationship between potency loss and radiation doses to the erectile bodies, there is increasing rationale for incorporating penile bulb dosimetry into treatment planning and posttreatment evaluation. Because the location and shape of the penile bulb have not been described in detail on various imaging modalities, we herein describe the anatomic boundaries of the penile bulb on computed tomography (CT), magnetic resonance imaging (MR), and transrectal ultrasound (TRUS), before and after brachytherapy. METHODS AND MATERIALS: Nonenhanced axial CT images were taken on a CTi CT Scanner (General Electric Medical Systems, Milwaukee, WI) with the patient in the supine position. Settings were at 300 ma, 140 kvp, 4-s scan time per slice, and collimation of 3 mm with data obtained at 3-mm intervals. Nonenhanced MR images were obtained with a 1.5 Tesla Signa Horizon LX Scanner using fast spin-echo T1-weighted (TR/TE, 466/20) and T2-weighted (TR/TE, 8000/90) images, with a slice thickness of 2 mm and an interslice gap of 0.5 mm. TRUS images were obtained with a Siemens SONOLINE Prima ultrasound machine at 6.0 MHz and a Winston-Barzell stepper unit. RESULTS: The penile bulb is best visualized on T2-weighted MR images in the axial, sagittal, and coronal planes, appearing as an oval-shaped, hyperintense midline structure. On axial CT imaging, the bulb of the penis is typically readily identifiable, bounded by the paired crura laterally, the corpora spongiosum anteriorly, and the levator ani posteriorly. The penile bulb is typically well visualized on transverse TRUS, but usually only faintly seen on sagittal TRUS. The bulb is partially obscured on postimplant CT and MR images, presumably because of implant-related edema. Bulb volumes vary markedly from patient to patient, ranging from 5.6 to 12.4 cc (median: 8.1 cc). CONCLUSION: Closer attention to penile erectile tissue doses should lead to improved external beam radiation and brachytherapy delivery. It will benefit the radiation oncology community to become familiar with these imaging findings, so that penile bulb dosimetry can be incorporated into our daily practice.     

胆管癌的磁共振成像表现及其临床意义

目的：通过磁共振成像(MR)征象与手术对照分析，探讨胆管癌的MR特点。方法：27例患行常规轴位SE，12加权成像和呼吸门控FSE，12加权成像，并做冠状位：MRCP成像，所有患经手术和病理证实，分析病灶信号特征、形态、范围，并与术中所见进行比较。结果：16例肝门型胆管癌在磁共振成像上多呈放射状(89％)，术中所见病灶沿胆管浸润生长，且病灶范围比MRI所见大。所有胆管癌病灶在TIWI上均呈低信号(100％)，4例肝内胆管癌在T2WI上为混杂信号，11例肝门型胆管癌在，T2WI上呈等(61％)或稍高信号(39％)，2例壶腹癌在T2WI上呈低信号。在MRCP上所有病人表现为胆道梗阻。16例(89％)：MRCP分型与临床分型一致。结论：胆管癌在磁共振成像上有较特征性表现，且能提供病变准确部位，但对病变范围估计不足，MRCP用于肝门型胆管癌临床分型是可行的。     

Endometrium-myometrium Ratio: A Newly Proposed Diagnostic Parameter on Magnetic Resonance Imaging Assessment of Myometrial Invasion by Endometrial Cancer

In order to improve the accuracy of magnetic resonance (MR)imaging assessment of myometrial invasion by endometrial cancer,the usefulness of a new diagnostic parameter, the endometriummyometrium(EM) ratio has been evaluated. EM ratio is the proportion ofthe widest length of endometrium to the length of myometriummeasured at the same line, this being vertical to the parallelof the long axis of the uterine body in the sagittal plane ofthe MR images. Myometrial invasion was defined as a value ofthe EM ratio > 1 , and the tumor was limited to the endometriumfor values < 1 . In 25 consecutive patients, both the EMratio-based assessment and the well-established junctional zone-basedasessment with T2-weighted MR imaging and enhanced MR imagingwith gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA)were compared with the results from pathological examinationsof postoperative specimens. In identifying moymetrial invasionby endometrial cancer, the sensitivity of the EM ratio-basedassessment was better than that of the junctional zone-basedassessment. The overall sensitivity of the former was 96% inboth the T2-weighted and enhanced MR imaging with Cd-OTPA, whereasthat of the latter was 84% in the T2-weighted MR imaging and72% (P<0.05) in the enhanced MR imaging. The use of the EMratio with MR imaging improves the ability to assess myometrialinvasion by endometrial cancer.