Carcinoma of the cervix: dynamic MR imaging.

Dynamic magnetic resonance (MR) imaging was performed to evaluate eight normal uteri and 29 cervical carcinomas. After rapid injection of gadopentetate dimeglumine, dynamic images were obtained every 30 seconds with the spin-echo (SE) technique in the sagittal plane or the fast low-angle shot (FLASH) technique in the axial plane. In the normal uterus, initial slight enhancement of the junction between endometrium and myometrium was followed by enhancement of the uterine myometrium. Cervical carcinoma was readily distinguished from the cervical stroma and myometrium in the early dynamic phase (30-60 seconds). Tumor-cervix contrast in the early dynamic phase was significantly more marked with the dynamic SE technique than with T2-weighted or contrast material-enhanced T1-weighted imaging (P less than .01). For the evaluation of parametrial invasion, the dynamic FLASH study showed better contrast than did T2-weighted images. Among 18 patients who underwent surgery, accurate assessment of the degree of stromal invasion and tumor size was possible with dynamic MR images in 14 patients (78%), T2-weighted images in 11 (61%), and postcontrast T1-weighted images in seven (39%).     

比较3.0T MRI平扫及增强扫描对宫颈癌分期的价值

目的：通过与手术病理分期对比,比较MRI平扫及增强扫描在宫颈癌分期中的价值。方法：搜集75例经手术病理证实的宫颈癌患者,由2位工作经验丰富的放射科医师共同对其MRI平扫及增强图像进行评价,包括肿瘤位置、大小、边界清晰度、信号特征、对周围组织的侵犯情况,并分别根据MRI平扫及增强表现对所有患者进行分期,以手术病理分期为金标准,比较两种分期方法对宫颈癌总体分期准确性,各期别分期准确性差异。结果：MRI增强扫描显示肿瘤边界明显较MRI平扫清晰（P〈0．001）;MRI增强及平扫对宫颈癌总体分期准确度分别为85．3％、77．3％,在对宫颈癌Ia、Ⅱa、Ⅱb各期别分期评判中,MRI增强准确度分别为89．3％、85．3％、96．0％,MRI平扫准确度分别为84．0％、77．3％、93．3％,统计学分析表明MRI平扫及增强扫描在宫颈癌总体分期及Ig、Ⅱa、Ⅱb各期别分期准确性差异均无统计学意义（P均〉0．05）。结论：在宫颈癌分期方面,MRI增强准确性优于MRI平扫,但两者差异无统计学意义。     

Carcinoma of the cervix: value of MR imaging in detecting parametrial involvement

In patients with cervical carcinoma, precise knowledge of parametrial tumor extension affects the therapeutic decision between surgery and radiation therapy. The purpose of this prospective study was to determine the efficacy of MR imaging in detecting the presence or absence of parametrial invasion in patients with cervical cancer thought clinically to be confined to the cervix. Twenty-five consecutive patients were included in the study. All patients underwent radical hysterectomy or total abdominal hysterectomy and had detailed histologic evaluation of the parametrium. Ten had pathologic evidence of parametrial invasion; in the remaining 15, no parametrial invasion was identified pathologically. MR findings were compared with pathologic findings in all cases. For determining parametrial involvement, MR imaging had an accuracy of 88%, a sensitivity of 100%, and a specificity of 80%. Our results suggest that MR imaging is a reliable means of assessing parametrial invasion by cervical cancer.     

磁共振弥散加权成像在子宫内膜癌的初步研究

目的 探讨磁共振弥散加权成像(diffusion weighted imaging,DWI)在子宫内膜癌中的诊断价值.方法 正常妇女子宫45例,子宫内膜癌(endometrial carcinoma,EC) 35例,均进行横断面、矢状面常规MRI扫描及不同b值下(b=500、800、1 000 s/mm2)横断面及矢状位扩散加权成像,分别测量正常子宫体3层结构和子宫内膜癌病灶的信噪比(signal to noise ratio,SNR)及表观扩散系数(appareent diffusion coefficient,ADC)值,膀胱的信号强度比(signal intensity ratio,SIR),并进行比较.结果 正常子宫三层结构的T2WI图像信号强度有差异,内膜层信号度最高,结合带最低;在DWI图像上内膜信号强度分别高于结合带和外带,结合带和外带的差异肉眼不易分辨.正常对照组子宫同一层组织在不同b值下所得ADC值之间差异无统计学意义(P>0.05);宫体内膜与结合带ADC值之间差异无统计学意义(P>0.05),而宫体内膜与肌层、结合带与肌层ADC值之间差异有统计学意义(P<0.01).扩散图像中肿瘤SNR随着b值增加而逐渐下降.b=500 s/mm2时,正常子宫内膜与子宫内膜癌ADC值之间的差异无统计学意义(P>0.05); b=800、1 000 mm2/s时,正常子宫内膜ADC分别为(1.541±0.148)×10-3mm2/s和(1.530±0.119)×10-3mm2/s,均高于EC病灶的(0.984±0.162) ×10-3mm2/s和(0.775±0.153)×10-3 mm2/s,两者之间的差异有统计学意义(F=32.919,P<0.01).但高分化子宫内膜样腺癌和中分化子宫内膜样腺癌的ADC值之间在不同b值间无统计学意义(P＞0.1).结论 b=800 s/mm2和1 000 s/mm2是子宫内膜癌成像的较佳b值.ADC值对鉴别正常子宫体内膜与子宫内膜癌有一定的参考价值,但对于鉴别不同分化程度的子宫内膜样腺癌仍有一定困难.     

Cervical carcinoma with full-thickness stromal invasion: efficacy of dynamic MR imaging in the assessment of parametrial involvement

The purpose of this study was to investigate the efficacy of dynamic MR imaging in the assessment of parametrial involvement by cervical carcinoma with full-thickness stromal invasion on thin-section oblique axial T2-weighted images. Dynamic MR images of 24 patients with cervical carcinoma with full-thickness stromal invasion on thin-section oblique axial T2-weighted images were evaluated with pathologic correlation. Dynamic MR imaging was performed using a turboFLASH, 3D-FISP, or 2D-FLASH technique. The imaging planes of dynamic MR imaging were oblique axial planes of the uterine cervix. Dynamic MR imaging was performed twice, once for the early phase (40 to 60 sec after the administration of contrast media) and once for the late phase (5 min). Contrast enhancement of the tumor was divided into six types. Type I, cervical stroma with low signal intensity surrounding a tumor with high signal intensity, was seen in the early phase of dynamic MR imaging; type II-RR, the hyperintense rim was seen from the early phase to the late phase; type II-RO, the hyperintense rim was seen in the early phase only; type II-OR, the hyperintense rim was seen in the late phase only; type II-O, the hyperintense rim was not seen at all; and type III, tumor invasion with high signal intensities was seen beyond the cervical stroma in the early phase of dynamic MR imaging. The numbers for each type of cervical carcinoma on dynamic MR images were as follows: type I, four parametrial sites; type II-RR, 0; type II-RO, 0; type II-OR, 13; type II-O, 14; and type III, one. Three-dimensional diameters (transverse, craniocaudal, and anteroposterior) of the primary tumor were measured using dividers. All parametrial sites of type I and type II-OR showed no parametrial involvement. One parametrial site of type III and three parametrial sites of type II-O showed parametrial involvement, and 11 of type II-O showed no parametrial involvement. None of the patients showed type I-RR or type II-RO. When type I and type II-OR were categorized as criteria of no parametrial involvement and type III and transverse diameters of 3.5 cm or over classified as type II-O were categorized as criteria of parametrial involvement, the rate of diagnostic accuracy was 95.8%. Dynamic MR imaging is considered to be substantially useful in the assessment of parametrial involvement with cervical carcinoma with full-thickness stromal invasion by thin-section oblique axial T2-weighted images.     

MR imaging findings of uterine endometrial stromal sarcoma: differentiation from endometrial carcinoma

Endometrial stromal sarcoma (ESS) is a rare malignant neoplasm of the uterus. We retrospectively analyzed pelvic MR imaging in 8 cases of ESS to determine the characteristic MR findings of ESS. Magnetic resonance images of 8 cases of ESS were evaluated for findings including the size, margin of the tumor, nodular lesions at the tumor margin, intramyometrial worm-like nodular extension, multiple nodular mass formation, hemorrhage, and necrosis in the tumor. The degree of contrast enhancement was also analyzed. The MR imaging findings of 21 consecutive cases of endometrial carcinoma (EC) were also evaluated and compared with those of ESS. The mean and the standard deviation of the maximum diameter of ESS and EC were 8.80 ± 4.99 and 3.93 ± 2.47 cm, respectively. Increased enhancement in at least a part of the tumor was observed in five of the six analyzed ESS cases and in 2 of 12 analyzed EC cases. The irregular margin, nodular lesions at the margin, intramyometrial nodular extension, and multiple nodular mass formation were more frequently seen in cases of ESS than in cases of EC. Magnetic resonance imaging can play a role in both diagnosing ESS as well as in differentiating ESS from EC. Received: 17 December 1999 Revised: 18 May 2000 Accepted: 22 May 2000     

肝细胞癌在MR扩散加权成像与动态增强成像中的影像表现

信号;2个T1WI平扫等信号的病变,各期增强仍然呈等信号,DWI表现为高信号,其中1个病理证实为再生结节.1个肝硬化再生结节T1WI平扫及DWI均为高信号,动脉期明显强化,门静脉及平衡期为等信号.结论 多数HCC在MR动态增强图像上表现为动脉期明显强化,部分小HCC可表现为等信号.Gd-DTPA动态增强与DWI结合可能有助提高HCC的诊断准确性.     

MRI对子宫内膜癌术前分期的应用价值

子宫内膜癌又称子宫体癌,是指原发于子宫内膜的上皮恶性肿瘤,是女性生殖系统最常见的恶性肿瘤之一。治疗前准确估计分期、病理分级、淋巴结转移有助于合理选择治疗方案及判断预后。磁共振成像（magnetic resonance imaging,MRI）具有多方位、多角度、多序列成像、组织分辨力高及软组织对比度好等特点,可准确显示盆腔及子宫的解剖结构,并且对病变范围、肌层浸润深度较准确定位,从而可指导临床制定正确的治疗方案。本研究对42例子宫内膜癌行高场强MRI检查,并与手术后病理结果进行对比分析,以期探讨MRI在子宫内膜癌术前分期中的应用价值。     

动态增强MRI在子宫内膜癌的诊断及分期中的应用

目的 评价动态增强MRI在子宫内膜癌的诊断及分期中的价值.方法 回顾性分析38例经手术病理证实的子宫内膜癌的T1WI、T2WI和动态增强表现,并依据FIGO分期原则,将术前MRI分期与术后病理结果进行比较.结果 大部分肿瘤T1WI与子宫肌信号相近,T2WI呈等或稍高信号,动态增强早期显示子宫内膜下强化带25例,不出现内膜下强化带者,肌层内表面不规则12例,光滑1例.动态增强延迟期36例子宫内膜癌呈轻至中等强化,强化程度低于子宫肌层,2例明显强化.与手术病理比较,动态增强MRI分期判断Ⅰ期子宫内膜癌正确率为84.2%;Ⅱ期正确率为92.1%.结论 动态增强MRI在子宫内膜癌的诊断及分期中有较高的价值,应列为术前常规序列检查.     

Use of preoperative MR imaging in the management of endometrial carcinoma: cost analysis

PURPOSE: To compare the cost of magnetic resonance (MR) imaging and its ability to direct the use of lymph node dissection with the cost and ability of conventional surgery for the staging of endometrial carcinoma. MATERIALS AND METHODS: Preoperative MR images of 25 patients who underwent hysterectomy for endometrial carcinoma were retrospectively evaluated. MR imaging results were compared with those of intraoperative gross dissection of the uterus and final histopathologic examination. Medicare reimbursements for two scenarios were compared in each patient. In the MR imaging scenario, the necessity for lymph node dissection was based on MR imaging results and histologic findings at biopsy. In the actual scenario, lymph node dissection was performed at the surgeon's discretion on the basis of findings at gross dissection of the uterus and histologic examination at biopsy. RESULTS: The cost of the MR imaging scenario, as defined by Medicare reimbursements, was 1% ($1, 265/$148,500) less than that of the actual scenario. In the MR imaging scenario, all patients who required lymph node dissection received it, and 86% of the lymph node dissections performed were necessary. In the actual scenario, one necessary lymph node dissection was not performed, and only 31% of the lymph node dissections performed were necessary. CONCLUSION: Staging with MR imaging has costs and accuracy similar to those of the current method of staging with intraoperative gross dissection of the uterus. In addition, MR imaging decreases the number of unnecessary lymph node dissections.     

MR imaging findings and patterns of spread in secondary tumor involvement of the uterine body and cervix

OBJECTIVE: Our study sought to describe the MR imaging features and the patterns of spread in secondary tumor involvement of the uterus by nonuterine tumors. CONCLUSION: Direct extension of an adjacent tumor to the uterus is the most common pattern of secondary tumor involvement. Concomitant invasion of other pelvic organs is also typical. Although less common, hematogenous or lymphatic metastases to the uterus are encountered in clinical practice. Metastases should be added to the differential diagnosis of apparently malignant masses in the uterine body or cervix, especially in patients with metastatic disease or in patients whose uterus shows a preserved shape with involvement by an infiltrative heterogeneously enhancing process.     

MR staging of endometrial carcinoma

Endometrial cancer is the second most common gynaecological malignancy. The usual presentation with post-menopausal bleeding results in an early diagnosis in most cases and thus there is opportunity for cure. Magnetic resonance (MR) imaging is pivotal in the decision-making process regarding treatment options. We present a review of the magnetic resonance (MR) findings to illustrate its role in the staging of endometrial cancer.     

Myometrial invasion by endometrial carcinoma: assessment by MR imaging.

In patients with early-stage endometrial cancer, preoperative knowledge of myometrial tumor extension has important prognostic and therapeutic implications. The purpose of this prospective study was to determine the sensitivity and specificity of MR imaging for assessing the depth of myometrial invasion in patients with endometrial cancer that clinically was thought to be confined to the uterine corpus. Sixty-five consecutive patients were included in the study. All patients had MR imaging before radical surgery. MR imaging findings were compared with microscopic pathologic findings in all cases. On MR images and at histologic analysis, myometrial invasion was classified as absent (tumor confined to the endometrium), superficial (less than 50% of myometrial thickness), or deep (50% or more of myometrial thickness). At histologic examination, tumor limited to the endometrium was proved in 14 cases, superficial myometrial invasion by tumor was present in 34 cases, and deep tumor invasion was demonstrated in 17 cases. In determining the presence of tumor confined to the endometrium, MR imaging had a sensitivity of 57% and a specificity of 96%. In the assessment of tumor with superficial myometrial invasion, MR imaging had a sensitivity and a specificity of 74%, whereas in assessing deep myometrial penetration, the sensitivity and specificity of MR were 88% and 85%, respectively. Errors in MR interpretation when determining myometrial tumor spread were more frequently overestimations rather than underestimations. Our results indicate that MR imaging is useful for the preoperative assessment of myometrial invasion in patients with proved endometrial cancer.     

Local-regional staging of endometrial carcinoma: role of MR imaging in surgical planning

PURPOSE: To assess magnetic resonance (MR) imaging in depicting the depth of myometrial infiltration, cervical invasion, and presence of enlarged lymph nodes in patients with endometrial adenocarcinoma compared with surgicopathologic findings. MATERIALS AND METHODS: Thirty-seven consecutive patients with endometrial carcinoma were included in this prospective study. All patients underwent MR imaging and surgery. Qualitative image analysis included the depth of myometrial infiltration, infiltration of the uterine cervix, and presence of enlarged lymph nodes. Quantitative image analysis included tumor and myometrium contrast-to-noise ratios during different phases of dynamic imaging. MR imaging findings were compared with surgicopathologic findings. Sensitivity, specificity, diagnostic accuracy, and positive and negative predictive values of MR imaging in depicting myometrial and cervical infiltration and in lymph node assessment were calculated. RESULTS: Respective sensitivity, specificity, diagnostic accuracy, and positive and negative predictive values in assessing myometrial infiltration were 87%, 91%, 89%, 87%, and 91%; those for cervical infiltration, 80%, 96%, 92%, 89%, and 93%; and those for lymph node assessment, 50%, 95%, 90%, 50%, and 95%. There was significant agreement between MR imaging and surgicopathologic findings in assessment of myometrial invasion (P <.001). Myometrial and cervical invasion and lymph node enlargement were correctly assessed with MR imaging in 28 (76%) of 37 patients. Quantitative analysis showed a significant improvement in tumor and myometrium contrast-to-noise ratios during the equilibrium phase compared with the arterial and precontrast phases (P <.001). CONCLUSION: MR imaging coupled with contrast material-enhanced dynamic MR imaging is highly accurate in local-regional staging of endometrial carcinoma; more challenging is the assessment of pelvic and lumboaortic lymph nodes.     

Endometrial polyps: MR imaging features and distinction from endometrial carcinoma

PURPOSE: To determine the magnetic resonance (MR) imaging characteristics of endometrial polyps and the accuracy of MR imaging in distinguishing endometrial polyps from endometrial carcinomas in a case-control study. MATERIALS AND METHODS: Cross-referencing pathology records with MR studies from two institutions disclosed 35 patients with surgically proved endometrial polyp or carcinoma after controlling for tumor size. All MR examinations were performed at 1.5 T with T2-weighted fast spin-echo sequences in multiple planes. Three independent readers blinded to histologic diagnoses and clinical data scored each image for the presence of several defined findings. RESULTS: A central fibrous core (low signal intensity on T2-weighted images) and intratumoral cysts (high signal intensity on T2-weighted images) were seen more frequently in endometrial polyps than in carcinomas; myometrial invasion and necrosis showed high predictive value for carcinomas. The readers' responses showed a mean sensitivity of 79%, specificity of 89%, accuracy of 86%, positive predictive value of 82%, and negative predictive value of 88% for diagnosis of carcinoma. The mean area under the receiver operating characteristic curve for the three readers was 0.87 for the diagnosis of carcinoma. CONCLUSION: MR images can help to distinguish most polyps from endometrial carcinomas on the basis of morphologic features. Accuracy does not appear to be sufficient to obviate biopsy, partly because carcinomas and polyps frequently coexist.     

MR功能成像在子宫内膜癌的术前分期中的价值

子宫内膜癌术前准确分期对治疗方案的选择,尤其是手术方案的选择有很重要的影响,MRI是目前最准确的术前分期方法之一.综述MR动态增强成像及扩散加权成像在子宫内膜癌术前分期中的价值,并就其各自的适用范围、技术优势和局限性进行探讨.