The utility of diffusion-weighted MR imaging for differentiating uterine sarcomas from benign leiomyomas

The usefulness of diffusion-weighted (DW) magnetic resonance (MR) imaging for the diagnosis of uterine sarcomas was investigated, as well as whether DW images and quantitative measurement of apparent diffusion coefficient (ADC) values can facilitate differentiating uterine sarcomas from benign leiomyomas. MR images including DW images were obtained in 43 surgically treated patients with 58 myometrial tumors, including seven uterine sarcomas (five leiomyosarcomas and two endometrial stromal sarcomas) and 51 benign leiomyomas (43 ordinary leiomyomas, two cellular leiomyomas and six degenerated leiomyomas). Qualitative analysis of non-enhanced and postcontrast MR images and DW images and quantitative measurement of ADC values were performed for each myometrial tumor. Both uterine sarcomas and cellular leiomyomas exhibited high signal intensity on DW images, whereas ordinary leiomyomas and most degenerated leiomyomas showed low signal intensity. The mean ADC value (10⁻³ mm²/s) of sarcomas was 1.17 ± 0.15, which was lower than those of the normal myometrium (1.62 ± 0.11) and degenerated leiomyomas (1.70 ± 0.11) without any overlap; however, they were overlapped with those of ordinary leiomyomas and cellular leiomyomas. In addition to morphological features on nonenhanced and postcontrast MR sequences, DW imaging and ADC measurement may have a potential ability to differentiate uterine sarcomas from benign leiomyomas.     

MR imaging of uterine inversion

Inversion of the uterus is a postpartum complication that is an obstetric emergency. This report describes a case of inversion of the uterus in which clinical evaluation was inconclusive, and magnetic resonance (MR) of the pelvis revealed findings virtually pathognomonic of incomplete inversion of the uterus with far greater conspicuity than on corresponding ultrasound. The MR findings directly resulted in earlier therapeutic intervention with a possible decrease in morbidity.     

MR imaging of uterine cervical carcinoma

We retrospectively analyzed the magnetic resonance (MR) imaging findings of 20 consecutive patients with primary untreated carcinoma of the cervix who underwent surgery and one patient who underwent percutaneous needle biopsy of enlarged pelvic lymph nodes. Most of the patients were clinical Stage IB. The clinical assessment of the parametria in these patients was more accurate than the MR assessment of the parametria (95 versus 79%). Magnetic resonance was valuable for detecting metastatic pelvic lymphadenopathy. Enlarged pelvic lymph nodes (greater than 1.5 cm in diameter) were demonstrated by MR in all three patients with histologic verification of metastatic lymphadenopathy. In summary, the major therapeutic value of MR in patients with untreated cervical carcinoma is in assessing the pelvic lymph nodes. In patients with clinical Stage IB disease, MR assessment of the parametria does not add useful additional information.     

MR imaging of the uterine cervix: imaging-pathologic correlation.

Magnetic resonance (MR) imaging is useful not only for preoperative staging of gynecologic malignancies but also for prediction of the histopathologic features of a variety of intrapelvic tumors. Familiarity with the specific imaging findings that have been reported for the uterine cervix is a goal of radiologists. The typical MR imaging findings of uterine cervical lesions correspond to the histopathologic features. These lesions can be categorized as epithelial neoplasms, nonepithelial neoplasms, and nonneoplastic diseases. Cervical carcinoma accounts for most cases of malignant lesions and is staged by using the classification system established by the International Federation of Gynecology and Obstetrics. MR imaging allows differentiation between endophytic and exophytic growth and between normal and abnormal findings after hysterectomy and irradiation. Other epithelial neoplasms of the uterine cervix include adenoma malignum, which is a special type of cervical adenocarcinoma, as well as carcinoid tumor and malignant melanoma. Nonepithelial neoplasms of the uterine cervix include malignant lymphoma and leiomyoma. Nonneoplastic diseases of the uterine cervix include cervical pregnancy, cervicitis, nabothian cysts, polyps, and endometriosis.     

子宫腺肌症的低场MRI表现

目的:探讨子宫腺肌症低场MRI表现及其诊断价值.方法:回顾性分析手术病理证实的35例子宫腺肌症MRI图像,并与病理对照研究.结果:弥漫型子宫腺肌症12例,9例结合带弥漫性均匀或不均匀增厚,3例结合带显示不清,T2WI表现结合带-肌壁弥漫性增厚.呈与结合带信号相近低信号病灶中夹杂点状、短条状或小囊状高信号,T1WI等信号10例、点状或小囊状高信号2例;局限型子宫腺肌症(腺肌瘤)23例26个肿块,后壁14个、前壁10个、底壁2个.紧靠子宫内膜边缘21个、邻近5个,为卵圆形、不规则形或类圆形,边缘模糊22个、较清楚4个.T2WI肿块均与结合带信号相近低信号内夹杂灶性高信号,T1WI肿块呈稍低或等信号,其中9个夹杂少量灶性高信号.结论:①子宫腺肌症的低场MRI表现具有特征性,能够反映本病的病理改变.其形态学特点是结合带-肌壁弥漫性增厚或呈边界不清的肿块,其信号特点是低信号区内混杂灶性高信号(T2WI高信号灶为异位内膜岛,T1WI高信号为出血灶);②矢状T2WI及IRFSET2WI图像对病灶显示最清晰,是子宫腺肌症MRI最佳扫描序列.     

Diffusion-weighted MR imaging of uterine endometrial cancer

PURPOSE: To determine the feasibility of diffusion-weighted (DW) MRI of uterine endometrial cancer and to investigate whether the apparent diffusion coefficient (ADC) values of endometrial cancer differ from those of normal endometrium and whether they differ according to the histologic grade of the tumor. MATERIALS AND METHODS: Study population included 18 consecutive females with surgically proven endometrial cancer and 12 females with pathologically confirmed normal endometrium in cervical cancer patients. Visual evaluation and ADC measurement were performed in endometrial cancer and normal endometrium. RESULTS: All endometrial cancer and the normal endometrium appeared hyperintense on DW images. The mean ADC value (10(-3) mm(2)/second) of endometrial cancer was 0.88 +/- 0.16, which was significantly lower (P < 0.01) than that of normal endometrium (1.53 +/- 0.10). The mean ADC value for each histologic grade was 0.93 +/- 0.16 (G1), 0.92 +/- 0.13 (G2), and 0.73 +/- 0.09 (G3). CONCLUSION: The present study showed that DW imaging is feasible in demonstrating uterine endometrial cancer and ADC measurement has a potential ability to differentiate between normal and cancerous tissue of the endometrium. The ADC values of endometrial cancers of higher grade show tendency to decrease compared to those of lower grade, although estimation of histologic grade based on ADC values seems difficult because of considerable overlap.     

Clinical utility of susceptibility-weighted MR sequence for the evaluation of uterine sarcomas

PurposeHigh intensity intra-tumoral hemorrhagic necrosis on T1-weighted images is a suggestive finding for uterine sarcomas, however, the reported prevalence varies. The purpose of this study is to evaluate the capability of susceptibility-weighted MR sequences (SWS) for the diagnosis of uterine sarcomas.Materials and methodsMR imaging of surgically proven 10 uterine sarcomas and 24 benign leiomyomas were retrospectively evaluated for the presence of high intensity areas on T1-weighted images and signal voids on SWS (T2 star-weighted angiography: SWAN).ResultsHigh intensity areas on T1-weighted images and signal voids on SWS were observed in 40% and 100% of sarcomas, whereas 0% and 4% of leiomyomas, respectively. The accuracy, sensitivity, and specificity for T1-weighted images were 82%, 40%, and 100%, and for SWS were 97%, 100%, and 96%, respectively.ConclusionThe demonstration of intra-tumoral hemorrhage in patients suspected with uterine sarcomas by SWS may provide valuable diagnostic findings.     

Combined use of T2-weighted and diffusion-weighted 3-T MR imaging for differentiating uterine sarcomas from benign leiomyomas

The objective of our study was to compare diffusion-weighted imaging (DWI) alone and DWI combined with T2-weighted MRI for the differentiation of uterine sarcomas from benign leiomyomas. T2-weighted imaging and DWI were performed in 103 patients with 103 myometrial tumours, including 8 uterine sarcomas and 95 benign leiomyomas on 3-T MR imaging. The signal intensity (SI) of the tumour on T2-weighted images was quantified as the tumour–myometrium contrast ratio (TCR) by using the following formula: (SI_tumour − SI_myometrium)/SI_myometrium. The TCR or apparent diffusion coefficient (ADC) value alone and then the ADC value combined with T2-weighted imaging were evaluated for differentiation between sarcomas and leiomyomas. The mean ADC value of sarcomas was 0.86 ± 0.11 × 10⁻³ m²/s, which was significantly lower than that of leiomyomas 1.18 ± 0.24 × 10⁻³ m²/s; however, there was a substantial overlap. The mean TCR of sarcomas was 0.66 ± 0.71, which was significantly higher than that of the leiomyomas, –0.37 ± 0.34; however, again, there was a considerable overlap. When ADC was less than 1.05 × 10⁻³ mm²/s and TCR was greater than 0 this condition was considered to confirm a sarcoma; a combination of ADC and TCR achieved a significant improvement without any overlap between sarcomas and leiomyomas (sensitivity 100%, specificity 100%). Our preliminary results indicate that combined DWI and T2-weighted MR imaging is better than DWI alone in the differentiation of uterine sarcomas from benign leiomyomas.     

Gadolinium-enhanced MR imaging in the evaluation of uterine fibroids treated with uterine artery embolization.

OBJECTIVE: The purpose of this study was to determine whether tumor volume reduction can be predicted by the infarction rate of uterine fibroids as seen on gadolinium-enhanced MR images obtained immediately after uterine artery embolization. MATERIALS AND METHODS: In our study, 36 women with symptomatic uterine fibroids successfully underwent uterine artery embolization. Unenhanced and enhanced MR imaging was performed before the procedure and repeated at 1 week, 4 months, and 1 year after the procedure. We retrospectively reviewed enhanced MR images of uterine fibroids after uterine artery embolization. At 4 months after uterine artery embolization, we compared the rate of tumor volume reduction in patients with completely infarcted dominant fibroids with the rate of tumor volume reduction in patients with partially infarcted fibroids. RESULTS: Enhanced MR images obtained 1 week after uterine artery embolization revealed that 100% infarction rates of the dominant uterine fibroids were achieved in 33 women (92%), and 70--90% infarction rates were seen in the remaining three (8%). They also revealed that of a total of 204 fibroids in these patients, 100% infarction was achieved in 199 fibroids (98%). Enhanced MR images obtained 4 months after uterine artery embolization showed that tumor volume reduction of the completely infarcted dominant fibroids (n = 23) was 60% +/- 18%, whereas that of the partially infarcted fibroids (n = 5) was 35% +/- 27% (p = 0.0367). CONCLUSION: Gadolinium-enhanced MR imaging is a useful diagnostic technique for uterine fibroids after uterine artery embolization because it assesses the degree of infarction in the embolized fibroids, which corresponds to the subsequent tumor volume reduction.     

MR imaging of uterine leiomyomas and their complications

Magnetic resonance (MR) imaging in eight patients with uterine leiomyomas and in eight normal female volunteers clearly depicted the size, shape, and position of the corpus uteri and demonstrated adjacent anatomic structures to good advantage in transaxial, coronal, and sagittal planes. Spin echo (SE) with short repetition time (TR) and short echo time (TE) values was judged best for overall delineation of anatomic structures. Longer TR and TE times were used to differentiate myometrium from endometrium. Detection and characterization of complications of uterine myomas were facilitated by the use of multislice/multiecho SE techniques, but in general TE values greater than 60 ms were not needed to differentiate endometrium from myometrium and in most cases did not improve the MR depiction of abnormalities. Calculated T1 and T2 relaxation times from this preliminary study do not demonstrate a clear advantage in further characterizing uterine abnormalities.     

Preliminary experience with gadolinium-enhanced dynamic MR imaging for uterine neoplasms.

Usefulness of gadopentetate dimeglumine in magnetic resonance (MR) imaging of uterine neoplasms was evaluated in 53 patients with endometrial carcinoma and 15 patients with cervical carcinoma. T1- and T2-weighted MR images were obtained before the contrast material was administered. After a bolus injection of gadopentetate dimeglumine, dynamic MR images were acquired, followed by static T1-weighted images. Gadolinium-enhanced MR images revealed relatively small endometrial carcinomas in the uterine cavity as high signal intensity in four cases and invasion of the myometrium as low signal intensity in 20 cases. In eight cases, endometrial tumors showed irregular, early enhancement compared with that of the myometrium on dynamic images; these cases were associated with poor prognosis. Tumor extension into the lower part of the uterus, parametrium, and paracervical fat was well seen on enhanced images in cases of cervical carcinoma. The authors believe that gadolinium-enhanced MR imaging will prove helpful in the staging of uterine neoplasms.     

Staging uterine cervical carcinoma with low-field MR imaging

PURPOSE: To assess the validity of low-field MR in staging cervical cancer compared to clinical staging. MATERIAL AND METHODS: A total of 95 women entered the study over a 3-year period. MR examinations with a 0.1 T resistive magnet using a body coil and clinical staging according to the FIGO recommendations (1988) were performed within 2 weeks from clinical diagnosis. T1- and T2-weighted sequences were obtained in transversal and sagittal acquisitions, and an additional T1 before and after contrast (randomisation to 0.1 or 0.3 mmol/kg b.w. gadodiamide). Treatment decisions on surgery or radiation therapy were made solely on the clinical staging. RESULTS: Sixty-one patients were found to be eligible for surgery. In 5 women, the pathological results revealed a more advanced stage of the disease than assessed by clinical staging. MR correctly staged 4 of the 5 but otherwise tended to overstate the disease. Contrast enhancement significantly reduced this trend (p<0.05) regardless of the contrast medium dose used. Divided into two groups, an operable (less than stage 2b) and an inoperable group (more than stage 2a), the clinical staging correctly classified 57 patients (accuracy 92%) compared to 52 patients with MR using contrast enhancement (accuracy 84%). The specificity was no higher than 31%, whereas the reproducibility of the MR assessment was fairly good with kappa values around 0.65 for both intra- and inter-observer variations. Conclusion: In the present set-up, clinical assessment was superior to low-field MR in staging cervical cancer. When using contrast enhancement, the staging accuracies of low-field MR were comparable to the ones reported for techniques with higher tesla values, whereas the specificity and reproducibility errors were lower. The method, therefore, needs to be optimised.     

磁共振扩散加权成像应用对子宫内膜恶性肿瘤的鉴别价值

 目的 比较不同病理类型子宫内膜恶性肿瘤(腺癌、鳞癌及间质肉瘤)的表观扩散系数(apparent diffusion coefficient ,ADC)值是否有区别,探讨磁共振扩散加权成像对子宫恶性肿瘤的临床应用价值。方法 收集手术后经病理证实为子宫恶性肿瘤患者102例(子宫内膜腺癌36例,宫颈腺癌4例、宫颈鳞癌47例、子宫内膜间质肉瘤15例),以及怀疑有其他盆腔病变的女性患者47例(26例卵巢囊肿、21例子宫肌瘤),所有患者术前均行盆腔磁共振扫描(包括常规序列及DWI,DWI选择b值为700 s/mm²),分析不同病理类型子宫恶性肿瘤与正常子宫内膜ADC值之间以及不同病理类型子宫恶性肿瘤ADC值之间的差异。结果 子宫内膜腺癌、鳞癌、内膜间质肉瘤及正常子宫内膜的ADC值分别为:(1.032±0.14) s/mm²、(1.063±0.21) s/mm²、(0.89±0.26)s/mm²、(1.55±0.13) s/mm²。统计分析结果显示:子宫内膜腺癌、鳞癌及肉瘤与正常子宫内膜的ADC值之间的差异有统计学意义(均P<0.05),腺癌与鳞癌的ADC值之间的差异无统计学意义(P>0.05),腺癌与肉瘤、鳞癌与内膜间质肉瘤的ADC值之间的差异有统计学意义(均P<0.05)。子宫内膜恶性肿瘤的ADC值明显低于正常子宫内膜,起源不同的子宫恶性肿瘤的ADC值之间有差异。子宫内膜间质肉瘤的ADC值明显低于腺癌与鳞癌。结论 ADC值有助于子宫内膜恶性肿瘤的量化,对内膜间质肉瘤与腺癌和鳞癌有鉴别诊断价值。     

Huge uterine leiomyoma with adenomyotic cysts mimicking uterine sarcoma on MR imaging

Magnetic resonance imaging of a 39-year-old woman who presented with an abdominal mass revealed a tumor with hemorrhagic lesions extending from the intrauterine space to the subserosa. Hysterectomy was performed for probable uterine sarcoma. The histological examination diagnosed uterine leiomyoma with severe myxoid degeneration and without malignant components. Hemorrhagic lesions were diagnosed as adenomyotic cysts, resulting in findings similar to those of a uterine sarcoma.     

含软骨基质型肉瘤的MR钆喷替酸葡甲胺增强和扩散加权成像特点

Objective To study the Gadolinium-enhanced MRI and diffusion weighted imaging (DWI) characteristics of the chondroid matrix-forming sarcomas.Methods Contrast-enhanced MRI and DWI were performed in 14 eases of chondroid matrix-forming sarcomas (10 chondrosarcomas,4 chondroblastic esteosarcomas) and 13 cases of other types of osteosarcomas.DWI was obtained with a single-shot echo-planar imaging (EPI) sequence using a 1.5 T MR imager with two different b values of 0 and 700 s/mm2.The apparent diffusion coefficient (ADC) values were obtained in GE Functiontool software.The contrast-enhancement pattern was evaluated and the ADC values of ehondroid matrix-forming sarcomas was compared with that of other types of asteosarcoma.Independent sample t-test was performed to evaluate the difference of ADC values between the group of chondroid matrix-forming sarcoma and the group of other types of osteosarcoma.In addition, nonparametrie test was used to assess the difference of ADC values between the chondrosareoma and the chondroblastic osteosarcoma.P value less than 0.05 was considered to represent a statistical significance.Results For 14 eases of ehondroid matrix-forming sarcomas, peripheral enhancement was found in all cases, septonodular enhancement was identified in 12 cases.While 13 eases of other types of osteosarcowas demonstrated heterogeneous enhancement.The mean ADC value of chondroid matrix-forming sarcomas [(2.56 ±0.35) × 10 -3 mm2/s] was significantly higher than that of other types of osteosarcoma [( 1.16±0.20) × 10-3 mm2/s] (t = 12.704,P <0.O1 ).There was no significant difference in the ADC value between the chondrosarcoma and the chondroblastie osteesarcama(Z =0.507 ,P =0.959).Conclusion Contrast-enhanced MRI and DWI can improve differentiation between chondroid matrix-forming sarcomas and other types of osteosarcomas.     

含软骨基质型肉瘤的MR钆喷替酸葡甲胺增强和扩散加权成像特点

目的 评价含软骨基质型肉瘤的MR Gd-DTPA增强和DWI特点.方法 在1.5 T MR机上对14例含软骨基质型肉瘤(10例软骨肉瘤和4例成软骨型骨肉瘤)和13例其他类型骨肉瘤行MR Gd-DTPA增强和DWI.DWI采用单次激发平面回波成像(SS-EPI)序列,b值分别取0、700 s/mm2,在GE Functool后处理软件上测定肿瘤的ADC值.评价肿瘤的MRI对比强化特点,并比较ADC值差异.含软骨基质型肉瘤与其他类型骨肉瘤的ADC值两组间比较采用独立样本t检验;软骨肉瘤与成软骨型骨肉瘤的ADC值两组间采用秩和检验.结果 在14例含软骨基质型肉瘤中,间隔结节状强化者有12例,边缘强化有14例.13例其他类型骨肉瘤均表现为不均匀强化.含软骨基质型肉瘤的平均ADC值[(2.56±0.35)×10-3mm2/s]高于其他类型骨肉瘤的平均ADC值[(1.16±0.20)×10-3 mm2/s](t=12.704,P<0.01);软骨肉瘤的ADC值与成软骨型骨肉瘤的ADC值的差异无统计学意义(Z=0.507,P=0.959).结论 Gd-DTPA增强MRI和DWI对区别含软骨基质型肉瘤与其他类型骨肉瘤有一定价值.