MR features of fluid-fluid levels in ovarian masses

To evaluate retrospectively the frequency and imaging features of fluid-fluid levels (FFLs) in pathologically proven ovarian masses on magnetic resonance (MR) images. The authors reviewed the preoperative MR findings of 556 ovarian masses in 428 patients. Presence, numbers, and signal intensities (SI) of FFLs were analyzed. In non-teratomas, we assessed whether SI of the FFLs of benign masses and malignant neoplasms differed using the χ² test. FFLs were observed in 66 of 556 ovarian masses (11.9%) on MR images, fat-fluid levels were observed in 11 of 80 teratomas, and FFLs attributed to hemorrhage in 54 of 476 non-teratomas and one twisted teratoma. Non-neoplastic cystic lesions were most common non-teratomas to contain FFLs (27/197, 13.7%), followed by malignant neoplasms (23/177, 13.0%). Benign neoplasms rarely contained FFLs (4/102, 3.9%); those that did were commonly associated with complications such as torsion or inflammation. A hypointense supernatant layer together with a hyperintense dependent layer on T1-weighted images (T1WIs) was significantly more common in malignant neoplasms than in benign masses (P < 0.0001). FFLs occurred in various ovarian masses ranging from benign to malignant neoplasms on MR images. In non-teratomas, a hypointense supernatant layer and a hyperintense dependent layer on T1WIs may favor a diagnosis of malignancy.     

Immature teratoma of the ovary: correlation of MR imaging and pathologic findings

The objectives of this study were to describe MR imaging findings of immature teratoma and to correlate imaging findings with histopathologic findings. The MR findings of ten patients (age range 12–29 years, mean age 19.0 years) with pathologically proven immature teratoma were retrospectively reviewed for tumor size, presence and characteristics of fatty content, presence and characteristics of solid components, and presence of ascites and implants. The MR findings were compared with gross (n=3) and microscopic (n=10) findings. Comparisons between relative amounts of solid components and histologic grades were evaluated by Spearman rank-order correlation. On MR images all lesions appeared to be fat-containing tumors with solid components consisting of numerous cysts of various sizes. Solid tissue exhibited a wide variety of signal intensities on T2-weighted images. Punctate foci of fat were identified in all lesions, whereas fatty fluid was observed only in two. Predominant fluid content exhibited signal intensities similar to simple fluid in nine lesions. Ascites was observed in six lesions, and peritoneal dissemination in three. Pathologic studies confirmed scattered foci of adipose tissue in the solid portions of all cases, and revealed numerous cystic structure formations in these solid components. The correlation coefficient between the amount of solid tissue and the tumor grade was not significant (r_s=0.266). The MR images of immature teratoma tended to show aqueous fluids and the solid components consisting of numerous cysts with punctate foci of adipose tissue, whereas predominant fluid is sebaceous fluid in the vast majority of mature cystic teratomas. Electronic Publication     

继发性卵巢腺癌的CT和MR影像特点及诊断价值

目的:探讨继发性卵巢腺癌的CT和MR影像学征象及诊断价值。方法:收集有明确病理诊断的继发性卵巢腺癌29例,其中有完整CT资料者21例,有完整MR资料者8例。CT采用常规四期扫描(平扫、动脉期、静脉期、延迟期)。扫描范围包括肝顶部至耻骨联合下水平。MR采用常规轴、矢、冠平扫及增强扫描。体线圈、呼吸门控技术。影像征象与病理结果相对照,进行回顾性分析。结果:原发灶为胃癌的10例,结肠癌12例,直肠癌6例,胆管癌1例。双侧卵巢腺癌13例,单侧卵巢腺癌16例,共42个病灶。其中I型占14.3%、Ⅱa型占4.7%、Ⅱb型占9.5%、 c型占28.6%、Ⅲ型占42.9%。肿块多数分界清楚(71.4%),出现瘤内囊19%,腹水征34.5%,淋巴结转移发生率69%等。结论:继发性卵巢腺癌为单侧或双侧卵巢发生的Ⅱc型或Ⅲ型肿块。囊实性分界清楚或肿瘤内出现瘤内囊;增强后实性成分明显强化;高的淋巴结转移发生率;合并少量或无明显腹水等征象均为其特点。掌握并擅于利用各种影像学检查方法的优势,将达到对疾病的更加准确的诊断。     

Prevalence of ovarian adrenal rest tumours and polycystic ovaries in females with congenital adrenal hyperplasia: results of ultrasonography and MR imaging

The aim of the investigation was to assess the prevalence of ovarian adrenal rest tumours and polycystic ovaries in female patients with congenital adrenal hyperplasia (CAH). Thirteen female CAH patients (median age 19.8 years, range 14.8–23.5 years) underwent transvaginal (n=6) or transabdominal (n=7) ultrasonography by a gynaecologist and MR imaging (n=13) of the ovaries (pre and post contrast-enhanced T1- and T2-weighted images). Ovarian adrenal rest tumours were defined as small hypoechoic and multifocal nodules on ultrasound and isointense lesions on T1- and hypointense on T2-weighted MR images (derived from characteristics of testicular adrenal rest tumours). Polycystic ovaries were defined as the presence of 10 follicles arranged peripherally around or scattered throughout increased stroma. No ovarian adrenal rest tumours were found either on ultrasound, or by MR imaging. Polycystic ovaries were found in 2 of the 13 patients (15.4%), both with ultrasound and MR. No ovarian adrenal rest tumours were detected in these female CAH patients, which suggests that ovarian adrenal rest tumours in CAH females are rare. The prevalence of polycystic ovaries corresponded to that in the general population. From these results, we would suggest that routine ovarian imaging in CAH females is not indicated. However, when ovarian dysfunction is present, ovarian imaging is advised, first by ultrasonography, to detect ovarian adrenal rest tumours or polycystic ovaries.     

Solid and papillary epithelial neoplasm of the pancreas: CT and MR findings

Solid and papillary epithelial neoplasm of the pancreas is a very rare low-grade malignant neoplasm with only 126 cases reported in the literature and seen mostly in young female patients. Surgical excision means cure in cases before malignant degeneration developed. Its characteristic findings are typical location in the tail of the pancreas, peripheral capsule formation, hypodensity on CT images, and hyperintense internal signal characteristics on T1-weighted MR images secondary to hemorrhage and accumulation of methemoglobine molecule. These findings are enough for the preoperative diagnosis that may lead to early surgery and cure. We present the CT and MR findings of this very rare neoplasm in a case report.     

MR Imaging of Pregnancy Luteoma: a Case Report and Correlation with the Clinical Features

We report here on a 26-year-old pregnant female who developed hirsutism and virilization during her third trimester along with a significantly elevated serum testosterone level. Abdominal US and MR imaging studies were performed, and they showed unique imaging features that may suggest the diagnosis of pregnancy luteoma in the clinical context. After the delivery, the serum testosterone level continued to decrease, and it returned to normal three weeks postpartum. The follow-up imaging findings were closely correlated with the clinical presentation.     

The role of magnetic resonance imaging and ultrasound in patients with adnexal masses

AIMS: To evaluate the accuracy of ultrasonography (US) and magnetic resonance imaging (MRI) in characterizing adnexal masses, and to determine which patients may benefit from MRI. METHODS: We prospectively studied 72 women (mean age 53 years, range 19 to 86 years) with clinically suspected adnexal masses. A single experienced sonographer performed transabdominal and transvaginal greyscale spectral and colour Doppler examinations. MRI was carried out on a 1.5T system using T1, T2 and fat-suppressed T1-weighted sequences before and after intravenous injection of gadolinium. The adnexal masses were categorized as benign or malignant without knowledge of clinical details, according to the imaging features which were compared with the surgical and pathological findings. RESULTS: For characterizing lesions as malignant, the sensitivity, specificity and accuracy of MRI were 96.6%, 83.7% and 88.9%, respectively, and of US were 100%, 39.5% and 63.9%, respectively. MRI was more specific (p<0.05) than US. Both MRI and US correctly diagnosed 17 (24%) cases with benign and 28 (39%) cases with malignant masses. MRI correctly diagnosed 19 (26%) cases with benign lesion(s), which on US were thought to be malignant. The age, menopausal status and CA-125 levels in these women made benign disease likely, but US features were suggestive of malignancy (large masses and solid-cystic lesions with nodules). CONCLUSION: MRI is more specific and accurate than US and Doppler assessment for characterizing adnexal masses. Women who clinically have a relatively low risk of malignancy but who have complex sonographic features may benefit from MRI.     

Role of diffusion MRI and proton magnetic resonance spectroscopy in characterization of ovarian neoplasms

Introduction

Adnexal masses are a common clinical problem and considered as the leading indication for gynecological surgery. The ovary and adnexal structures are relatively difficult to image with any technology. Magnetic resonance spectroscopy (MRS) can detect metabolic changes. As molecular changes often precede morphologic alterations, sensitivity is expected to improve by MRS. Diffusion weighted magnetic resonance imaging (DW-MRI) is sensitive to molecular diffusion which is due to random microscopic translational motion of molecules (known as Brownian motion). In the event of morphologic evaluation of cystic ovarian tumors, whether benign or malignant, DW-MR imaging and calculated apparent diffusion coefficient (ADC) values would be useful for evaluation.

Purpose

The aim of this study is to evaluate the role of diffusion MRI & proton magnetic resonance spectroscopy (H-MRS) in diagnosis of ovarian neoplasms.

Subjects and methods

This study included 20 patients, their ages ranged from 20 to 72 years. In all cases, diagnosis was proven by surgical and pathological examination. Trans-abdominal ultrasound (n = 20) and trans-vaginal ultrasound (n = 11) were included in our routine protocol to obtain baseline information preceding MR examination. The routine MR examination protocol included: T1WI, T2WI, and post contrast fat suppressed T1WI. Diffusion weighted imaging (DWI) was done to all patients at b0, b500, b1000 and ADC values were calculated. MRS was performed in all cases using multi-voxel point resolved surface coil spectroscopy (PRESS sequence) for volume localization.

Results

Fourteen cases (70%) had benign ovarian masses while the remaining six cases (30%) had malignant masses. High lipid peak was detected in all three cases of mature cystic teratoma. All cases of simple serous cysts showed choline and creatine signals that were higher than the average noise level but lower than the two fold higher noise level. Sharp choline peak was detected in all malignant ovarian masses (except a case of metastases under chemotherapy) as well as the case of fibroma. Creatine signal was detected in all benign and malignant masses except two cases of mature cystic teratoma and cases of endometrioma. Lactate signal was detected only in cases of hemorrhagic cysts, mature cyst teratoma and one case of endometrioma and not obtained in any of malignant lesions except dysgerminoma. High NAA signal was detected in dysgerminoma and all three cases of mature cystic teratomas. The mean Cho/Cr ratio was significantly higher in malignant than benign ovarian masses (<0.05), there was no significant difference in mean and lowest ADC values between malignant and benign lesions.

Conclusion

Proton MRS using Cho/Cr ratio added useful information for the diagnosis of different ovarian neoplasms. Direct visual assessment of DWI of ovarian lesions is not useful in differentiating benign from malignant ovarian lesions; determining the threshold of the ADC for diagnosing cystic ovarian tumors is difficult because of their large variance. Further experience with a larger and more biologically variable range of tumors is recommended.     

Dynamic contrast enhanced MRI in correlation with diffusion weighted (DWI) MR for characterization of ovarian masses

Introduction

Ovarian tumors; are the second most common gynecological tumor and are the fifth commonest tumor in women. It is desirable to preoperatively differentiate benign from malignant tumor to decide whether surgery is required, and which type of surgery is appropriate avoiding unnecessary surgery, adding dynamic contrast and diffusion weighted to conventional images can help in differentiation of benign ovarian tumor from malignant. DWI depends on the fact that water molecules can diffuse freely in low cellular environment, while tissue hyper cellularity causes its restriction. As a result, malignant ovarian tumors due to its hypercellular nature show restriction of diffusion, unlike most benign tumors. This study aims at reviewing and emphasizing the role of dynamic contrast enhanced MRI and diffusion-weighted MR in characterization of ovarian lesions.

Patients and methods

This study was performed on 30 patients referred to the radiology department from surgical department by ovarian masses. Pelvic MR with DWI was done for all patients, DCE-MR was done for 29 out of 30 patients. Twenty-five patients underwent surgery with pathologic correlation. Five patients were put under regular follow up US for 3 months.

Results

The sensitivity of MRI was 99.9% while that of DWI was 100%. The specificity was higher for DWI (75%) compared to conventional MRI (58.3%), as well as the accuracy which was 73.9% for MRI while that of DWI was 86.9%. The mean ADC values for malignant lesions were (0.84 × 10⁻³ ± 0.1 SD mm²/s), while that for benign lesions were (1.8 × 10⁻³ ± 0.5 SD mm²/s), with cut off 1.2 × 10⁻³ and p value = 0.005. Mature teratomas showed restricted diffusion with ADC values 0.8 × 10⁻³ mm²/s (false positive), due to mixed cellularity of the teratoma. Hemorrhagic cysts and endometriomas showed high signal not only on diffusion images but also on corresponding ADC map and ADC values 1.3–1.4 × 10⁻³ (T2 Shine-through). Sensitivity of MRI was 99.9% while that of DCE-MRI was 60%. The specificity was higher for DCE 91% compared to conventional MRI sequences 58.3%, as well as the accuracy which was 73.9% for MRI while that of DCE was 77% and so addition of DCE to the MRI is expected to increase the specificity and the accuracy of examination.

Conclusion

Combination of DWI and DCE to conventional MRI improves the specificity of MRI and thus increasing radiologist’s confidence in image interpretation which will finally reflect on patients’ outcome and prognosis.     

Preoperative staging of cervical carcinoma with MR imaging: a reappraisal of diagnostic accuracy and pitfalls

The purpose of this study was to assess the diagnostic accuracy and pitfalls of MR imaging in preoperative staging of cervical cancer. Magnetic resonance imaging was performed to determine the tumor staging for 41 patients with cervical carcinoma emphasizing tumor size, parametrial invasion, vaginal invasion, and lymph node metastases. According to the correlation of MR findings with surgical-pathological features, there was less than 5 mm discrepancy in the size in 29 of 34 tumors (85.3%) that were larger than 1 cm. In assessing parametrial invasion, vaginal invasion and lymph node metastases, MR imaging had an accuracy of 95, 83, and 86%, respectively. In determining stage of disease and differentiating operable (< or =stage IIA) from advanced disease (> or =stage IIB), MR imaging had an accuracy of 82.9 and 93%. Pitfalls leading to staging errors included difficulties in differentiating cancer foci from surrounding tissue edema and detecting microscopic tumor extension. Magnetic resonance imaging is accurate in the evaluation of parametrial invasion and differentiation of operable from advanced disease. The ability of MR imaging to detect microscopic extra-cervical tumor extension and differentiate cancer foci from surrounding tissue edema is not as reliable.     

卵巢子宫内膜异位囊肿低场MR表现及诊断价值

目的:探讨卵巢子宫内膜异位囊肿的低场MRI表现及其诊断价值。方法:回顾性分析24例卵巢子宫内膜异位囊肿MRI和B超检查,全部病例手术病理证实。结果:24例32个卵巢病变共63个卵巢子宫内膜异位囊肿,单侧16例,双侧8例;21个卵巢为单发囊肿,11个卵巢为多发囊肿共42个囊肿,其中8个卵巢大囊肿周围伴有小囊肿,5个囊肿内有分隔;T1WI及T2WI均呈高信号23(36.5%)个囊肿,T1WI高信号而T2WI呈低信号19(30.2%)个囊肿,呈混杂信号17(27.0%)个囊肿,T1WI呈等或低信号而T2WI呈高信号4个囊肿;囊肿边缘光滑6个,边缘部分毛糙不清19个,边缘完全毛糙不清38个。低场MR术前诊断63个卵巢子宫内膜异位囊肿,60个与病理相符,3个病理诊断为囊腺瘤;B超术前诊断卵巢子宫内膜异位囊肿50个,未定性8个,未发现病变5个。结论:MRI和B超对卵巢子宫内膜异位囊肿的诊断检出率100%(63/63)、95%(60/63),特异性95%(60/63)、79%(50/63),低场MR对卵巢子宫内膜异位囊肿的诊断明显优于B超。     

Hemodynamics of ovarian veins: MR angiography in women with uterine leiomyomata

Purpose

The passive reflux into ovarian veins (OVs) is well known as a common finding in normal asymptomatic women. The purpose of this study was to investigate the hemodynamics of OVs in women with myomatous uterus.

Materials and methods

Thirty-two women with symptomatic uterine leiomyomata underwent time-of-flight MR (TOF-MR) angiography, including venography and arteriography, and contrast-enhanced MRI. The frequency of reflux into OVs on TOF-MR angiography was retrospectively assessed with uterine volume, and compared to that of normal women in previous publication. The statistical evaluation was performed using Fisher's exact test.

Results

The mean uterine volume was 932 ± 612 ml (range, 301–2627 ml). The reflux into left OVs was observed in 4 of 32 women (13%) and that into right OVs was noted in 0 of 32 women (0%). These rates were significantly lower than those of normal asyptomatic women in the previous publication (p < 0.05). The reflux into OVs was observed in 0 of 19 women (0%) with 600 ml or larger myomatous uterus, whereas it was noted in 4 of the remaining 13 women (31%) with less than 600 ml myomatous uterus, with significant difference between the two groups (p = 0.02).

Conclusions

We found that reflux into OVs was infrequent in the vast majority of women with myomatous uterus, especially those with larger uterus due to leiomyomata on the basis of TOF-MR angiography. These findings suggested myomatous uterus could affect the flow direction of OVs, and passive reflux into OVs might be prevented due to the influence of antegrade flow of OVs.     

A rare case of ovarian hemangioma in a 30-year-old nulligravid woman

A 30-year-old nulligravid woman with a history of polycystic ovarian syndrome presented for evaluation of left adnexal mass. The patient was referred to the gynecologic oncology clinic after endorsing signs of abdominal pain for a month and the pelvis ultrasound demonstrated hypoechoic solid mass in the left ovary. Magnetic resonance imaging with T1- and T2-weighted images demonstrated progressive centripetal “filling-in” of the mass suggesting a unique variation of malignant ovarian mass, similar to what is seen in hepatic hemangioma. Upon resection of the ovarian mass, pathology reported that the mass was filled with numerous small blood vessels with single later of endothelial cells confirming the diagnosis of ovarian hemangioma, capillary-type—a rare finding.     

Primary leiomyoma of the ovary: a case report

The imaging features of primary ovarian leiomyoma have seldom been described because of the very low prevalence of the tumor. Herein we present a case report on its magnetic resonance imaging features. Both T1- and T2-weighted images revealed a low-signal-intensity mass, which was well circumscribed and sharply demarcated from the uterus. Magnetic resonance imaging was useful in distinguishing it from a malignant ovarian tumor and uterine leiomyoma. Received 10 October 1997; Revision received 2 February 1998; Accepted 4 February 1998     

A thickened or indistinct junctional zone on T2-weighted MR images in patients with endometrial carcinoma: pathologic consideration based on microcirculation

Thickened or indistinct junctional zone (JZ) is a problematic finding in staging endometrial carcinoma. We studied the incidence, pathological cause of this condition correlated to microcirculation, and the utility of dynamic contrast MRI for differential diagnosis. T2-weighted images were analyzed in 119 cases with endometrial carcinoma. The enhancement of the JZ during the dynamic contrast MRI, histopathological causes, and the density of arterioles in the JZ were retrospectively analyzed in cases with thickened or indistinct JZ. The MRI histopathological correlation of all 31 patients with a thickened or indistinct JZ were analyzed, in which it was corresponded to myometrial cancer invasion only in 22%. The sensitivity of a poor early enhancement pattern on dynamic study for detecting myometrial invasion was 71.4%, the specificity was 100%, and the overall accuracy was 92.5%. Although only weak relationship between the contrast enhancement and the arteriole density was revealed, the arteriole density within the JZ with cancer invasion was significantly decreased. Poor enhancement of JZ in early dynamic phase was correlated with the decreased density of arterioles within the myometrium which was invaded by endometrial carcinoma. Dynamic contrast study should be performed in staging endometrial carcinoma especially when JZ was thickened or indistinct.     

Nasopharyngeal teratoma: CT and MR findings

Teratomas of the nasopharynx occur usually in neonates. We present a case of teratoma which was discovered in an adult, and which relapsed after 34 years. The conventional radiograms, CT, MR, and histologic appearances are described. Received 3 January 1996; Revision received 1 March 1996; Accepted 4 March 1996     

A new computer-aided diagnostic tool for non-invasive characterisation of malignant ovarian masses: results of a multicentre validation study

Objectives

To prospectively assess an innovative computer-aided diagnostic technology that quantifies characteristic features of backscattered ultrasound and theoretically allows transvaginal sonography (TVS) to discriminate benign from malignant adnexal masses.

Methods

Women (n?=?264) scheduled for surgical removal of at least one ovary in five centres were included. Preoperative three-dimensional (3D)-TVS was performed and the voxel data were analysed by the new technology. The findings at 3D-TVS, serum CA125 levels and the TVS-based diagnosis were compared with histology. Cancer was deemed present when invasive or borderline cancerous processes were observed histologically.

Results

Among 375 removed ovaries, 141 cancers (83 adenocarcinomas, 24 borderline, 16 cases of carcinomatosis, nine of metastases and nine others) and 234 non-cancerous ovaries (107 normal, 127 benign tumours) were histologically diagnosed. The new computer-aided technology correctly identified 138/141 malignant lesions and 206/234 non-malignant tissues (98% sensitivity, 88% specificity). There were no false-negative results among the 47 FIGO stage I/II ovarian lesions. Standard TVS and CA125 had sensitivities/specificities of 94%/66% and 89%/75%, respectively. Combining standard TVS and the new technology in parallel significantly improved TVS specificity from 66% to 92% (p?<?0.0001).

Conclusions

Computer-aided quantification of backscattered ultrasound is a highly sensitive for the diagnosis of malignant ovarian masses.