Endometriosis, a common but enigmatic disease with many faces: current concept of pathophysiology, and diagnostic strategy

Endometriosis is a benign, common, but controversial disease due to its enigmatic etiopathogenesis and biological behavior. Recent studies suggest multiple genetic, and environmental factors may affect its onset and development. Genomic analysis revealed the presence of cancer-associated gene mutations, which may reflect the neoplastic aspect of endometriosis. The management has changed dramatically with the development of fertility-preserving, minimally invasive therapies. Diagnostic strategies based on these recent basic and clinical findings are reviewed. With a focus on the presentation of clinical cases, we discuss the imaging manifestations of endometriomas, deep endometriosis, less common site and rare site endometriosis, various complications, endometriosis-associated tumor-like lesions, and malignant transformation, with pathophysiologic conditions.


Dynamic contrast-enhanced MR imaging of uterine endometrial carcinoma with/without squamous differentiation

Purpose: Endometrial carcinoma with strong enhancement on dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) is suggestive of high-grade type II endometrial carcinoma. However, low-grade type I endometrial carcinoma may also sometimes show strong enhancement. We hypothesized that squamous differentiation would contribute to the strong enhancement at the early phase on DCE-MRI-like uterine cervical squamous cell carcinoma and compared the DCE-MRI findings of endometrial carcinoma with and without squamous differentiation. Methods: DCE-MRI of endometrial carcinoma including 41 low-grade type I endometrial carcinomas without squamous differentiation (LG), 39 low-grade type I endometrial carcinomas with squamous differentiation (LGSD), and 20 high-grade type II endometrial carcinomas (HG) was retrospectively evaluated. Results: Significant difference in the time-intensity curves was found between LG and HG and LG and LGSD, whereas no significant difference was seen between HG and LGSD. Curve type 3 (initial signal rise which is steeper than that of the myometrium) was more frequent in HG (60%) and LGSD (77%) than in LG (34%). Conclusion: It should be recognized as a pitfall that high-grade type II endometrial carcinoma and low-grade type I endometrial carcinoma with squamous differentiation may show similar early strong enhancement on DCE-MRI.


MR Imaging Findings of Uterine Adenomatoid Tumors.

Adenomatoid tumor is a rare benign genital tract neoplasm of mesothelial origin. Uterine adenomatoid tumors occur in the outer myometrium and may mimic leiomyomas. Because hormonal treatment is not applicable to adenomatoid tumors and laparoscopic enucleation is not easy as myomectomy, it is important to differentiate adenomatoid tumors from leiomyomas for the adequate treatment. The purpose of this study is to evaluate the MRI findings of adenomatoid tumor for the differentiation from leiomyoma. MRI findings of surgically proven 10 uterine adenomatoid tumors in 9 women were retrospectively evaluated with correlation to histopathological findings. All 10 tumors appeared as solid myometrial masses and showed heterogeneous signal intensity with admixture of partially ill-defined slight high-intensity areas containing abundant tubular tumor cells and well-defined myoma-like low-intensity areas reflecting smooth muscle hypertrophy on T2WI including 4 lesions with peripheral ring-like high intensity. High-intensity areas on T2WI tended to show high intensity on diffusion-weighted imaging (DWI) with relatively high apparent diffusion coefficient (ADC), suggesting T2 shine-through effect due to abundant tubules. Intra-tumoral hemorrhage revealed on MRI was rare. Early intense contrast-enhanced areas on dynamic contrast-enhanced study were observed dominantly within the high-intensity areas but rarely within the low-intensity areas on T2WI. The outer myometrial mass with the admixture of well-defined low- and ill-defined high-intensity areas on T2WI may be suggestive of adenomatoid tumor. Peripheral ring-like high intensity on T2WI and DWI may also be suggestive. Dynamic contrast-enhanced MR study may be helpful for the differentiation from leiomyoma.


Magnetic resonance imaging characteristics of polypoid endometriosis and review of the literature.

Polypoid endometriosis is a rare variant of endometriosis and may mimic malignancy. The purpose of this study is to evaluate magnetic resonance (MR) imaging characteristics of polypoid endometriosis for the differential diagnosis with malignancy. MR imaging findings of four histologically proven polypoid endometriosis were retrospectively evaluated with the review of the literature. All polypoid endometriosis exhibited high signal intensity on T2-weighted images reflecting abundant dilated endometrial glands. Peritoneal lesions were surrounded by low signal intensity rim represented the "black rim sign" reflecting endometriotic fibrous adhesion. Two cases arising from endometriotic cysts showed transmural extension (peritoneal extension and myometrial infiltration). Endometriotic hemorrhagic foci were demonstrated in four lesions as high signal intensity on T1-weighted images and/or susceptibility-induced signal voids on susceptibility-weighted MR sequence. Diffusion-weighted images showed high signal intensity with relatively high apparent diffusion coefficient (ADC) due to T2 shine-through effect but no diffusion restriction, and dynamic contrast-enhanced (DCE) MR imaging showed gradually increasing contrast-enhancement pattern like benign pathologies. Polypoid endometriosis may mimic malignancy; however, black rim sign may be a characteristic MR imaging finding for the peritoneal lesions, and no diffusion restriction and gradually increasing contrast-enhancement pattern may reflect its benign nature.

The Journal of Obstetrics and Gynaecology Research


Dynamic contrast-enhanced magnetic resonance imaging of endometrial cancer with/without squamous differentiation


Susceptibility-weighted MR sequence for the evaluation of intra-tumoral hemorrhage: Differentiation of benign and malignant ovarian tumors


The feasibility of reduced field-of-view diffusion-weighted imaging in evaluating bladder invasion of uterine cervical cancer.

Objectives: Uterine cervical cancer with bladder mucosal invasion is classified as FIGO stage IVA with poor prognosis. MRI can rule out the bladder invasion and skipping cystoscopy may be possible; however, high false-positive rate may be problematic. The purpose of this study is to evaluate the diagnostic performance of reduced field-of-view (FOV) diffusion-weighted imaging (DWI) in evaluating bladder mucosal invasion of cervical cancer. Methods: 3T MRI including T2WI and reduced FOV DWI in 15 women with histologically proven cervical cancer (two stage IIIB, six stage IVA, seven stage IVB) were retrospectively evaluated compared with cystoscopic findings. Results: Cystoscopy revealed mucosal invasion in 13 of 15 cases. The border between the tumor and the bladder wall was unclear on T2WI and clear on reduced FOV DWI in all 15 cases. The diagnosis of mucosal invasion on reduced FOV DWI had a sensitivity of 100%, specificity of 50%, accuracy of 93%, PPV of 93%, and NPV of 100%. Conclusions: Addition of reduced FOV DWI may improve the staging accuracy of MRI for cervical cancer in assessing the bladder mucosal invasion. Advances in knowledge: Reduced FOV DWI may improve the staging accuracy of cervical cancer in assessing bladder mucosal invasion with high NPV and PPV, which may be helpful for avoiding unnecessary cystoscopy.


Uterine cervical adenocarcinomas associated with lobular endocervical glandular hyperplasia: MR imaging manifestations


The feasibility of reduced field-of-view DWI in evaluating bladder invasion of uterine cervical cancery


Clinical value of N-acetyl mucinous compounds and lipid peaks in differentiating benign and malignant ovarian mucinous tumors by MR spectroscopy.

Purpose: To retrospectively evaluate the clinical significance of the peaks of N-acetyl mucinous compounds (NAMC) at 2 ppm and lipid at 1.3 ppm in in-vivo proton magnetic resonance (MR) spectroscopy for distinguishing benign and malignant mucinous tumors in patients with ovarian masses. Methods: MR spectroscopy was performed in patients with pathologically diagnosed mucinous ovarian tumors at 3 T MRI system. The peaks of NAMC, lipid, and total choline compounds (tCho) were classified into three classes in comparison with the noise level by visual estimation. The NAMC concentration was quantified relative to unsuppressed water by using LCModel analysis. Results: A total of 27 ovarian mucinous tumors in 27 patients were included in this study. The NAMC peak was observed in all 27 mucinous tumors, and the lipid peak was observed in 14 of 27 tumors: 1 of 9 benign tumors (11%), and 13 of 18 malignant tumors (11 borderline malignancies and 7 carcinomas) (72%). The presence of the lipid peak for the diagnosis of malignant mucinous tumor showed generally better diagnostic ability than MR imaging, with a sensitivity of 72%, specificity of 89%, accuracy of 78%, PPV of 93%, and NPV of 62%. The concentration of the NAMC in malignant mucinous tumors tended to be higher than that in benign mucinous tumors, but there was no statistically significant difference. Conclusions: The bimodal peaks of NAMC and lipid are suggestive of malignant mucinous tumors, and the presence of the lipid peak may be useful in distinguishing benign from malignant ovarian mucinous tumors.


MRI findings of uterine adenomatoid tumors including diffusion-weighted imaging with pathologic correlation


Clinical value of N-acetyl mucinous compounds and lipid peaks in differentiating benign and malignant ovarian mucinous tumors by MR spectroscopy


Susceptibility-weighted MR sequence for the evaluation of ovarian masses with torsion.

OBJECTIVES: Adnexal torsion is a rare gynecologic emergency caused by twisting of an adnexal mass. Twisted vascular pedicle is the most specific imaging finding for adnexal torsion, however, identification of twisted vascular pedicle can be challenging. The purpose of this study is to evaluate the feasibility of susceptibility-weighted magnetic resonance (MR) sequence (SWS) for the diagnosis of adnexal torsion. METHODS: MR imaging including SWS (SWAN: Susceptibility-weighted angiography) of surgically proven four benign ovarian masses with torsion (one acute and three subacute to chronic torsions) were retrospectively evaluated. Three cystic masses and one solid mass were included in this study. RESULTS: High signal intensity venous thrombus within the twisted vascular pedicle on T1-weighted imaging (T1WI) was detected in three lesions with subacute to chronic torsion (75%) but not in one lesion with acute torsion, whereas susceptibility-induced signal voids within the twisted vascular pedicle on SWAN were detected in all four lesions (100%). CONCLUSIONS: The demonstration of venous thrombus in the twisted vascular pedicle by SWS may be diagnostic for adnexal torsion. ADVANCES IN KNOWLEDGE: SWS can detect blood products sensitively and can reveal venous thrombus in the twisted vascular pedicle, which may be helpful for the diagnosis of adnexal torsion.


Reduced field-of-view diffusion-weighted MR imaging for assessing the local extent of uterine cervical cancer.

BACKGROUND: Recently, the evaluation of the tumor size and local extension of early-stage uterine cervical cancer on magnetic resonance imaging is important for the accurate clinical staging and to determine the indication of less extensive surgery such as fertility sparing radical trachelectomy. PURPOSE: To compare the diagnostic ability of reduced field-of-view diffusion-weighted imaging with those of three-dimensional (3D) contrast-enhanced T1-weighted imaging and T2-weighted imaging for assessing the tumor margin delineation and local extent of uterine cervical cancer. MATERIAL AND METHODS: 3T magnetic resonance images, including T2-weighted imaging, reduced field-of-view diffusion-weighted imaging, and 3D contrast-enhanced T1-weighted imaging, in 27 women with surgically proven cervical cancer (19 FIGO stage IB1, 3 IB2, and 5 IIA1) were retrospectively evaluated. Tumor margins and local tumor extent, including the presence of invasion to parametrium and vagina were evaluated on both sagittal and oblique axial (short axis) images; the results were compared with histologically confirmed tumor extension. RESULTS: Reduced field-of-view diffusion-weighted imaging diagnosed the tumor margins, which was more accurate than T2-weighted imaging ( P<0.001) and slightly better than 3D contrast-enhanced T1-weighted imaging. Reduced field-of-view diffusion-weighted imaging could define the tumor margins well even in small lesions (≤ 20 mm). Histological examination revealed parametrial invasion in two cases (clinically under-staged) and vaginal invasion in four cases. Reduced field-of-view diffusion-weighted imaging could demonstrate local extension of all lesions, which was more accurate than clinical examination and T2-weighted imaging. CONCLUSION: Addition of reduced field-of-view diffusion-weighted imaging may improve the staging accuracy of magnetic resonance imaging for cervical cancer in assessing the local tumor extent.


Clinical utility of susceptibility-weighted MR sequences for the evaluation of adnexal torsion


MR manifestations of polypoid endometriosis: Clinical feasibility of conventional and advanced MR techniques


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

PURPOSE: High 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 METHODS: MR 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). RESULTS: High 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. CONCLUSION: The demonstration of intra-tumoral hemorrhage in patients suspected with uterine sarcomas by SWS may provide valuable diagnostic findings.


Evaluation of Red Degeneration of Uterine Leiomyoma with Susceptibility-weighted MR Imaging


A Case of Uterine Tumor Resembling Ovarian Sex-cord Tumor (UTROSCT) Exhibiting Similar Imaging Characteristics to Those of Ovarian Sex-cord Tumor.


Ovarian Large Cell Neuroendocrine Carcinoma Associated with Serous Carcinoma: Correlation of Pathology with MR Imaging


Evaluating Myometrial Invasion in Endometrial Cancer: Comparison of Reduced Field-of-view Diffusion-weighted Imaging and Dynamic Contrast-enhanced MR Imaging

To compare the diagnostic ability of reduced field-of-view (FOV) diffusion-weighted (DW) magnetic resonance (MR) imaging with that of three-dimensional (3D) dynamic contrast-enhanced (DCE) MR imaging in evaluating the depth of myometrial invasion in patients with endometrial cancer. Three tesla (3T) MR images including T2-weighted imaging, reduced FOV DW imaging and 3D DCE MR imaging in sagittal and oblique axial (short axis) planes in 25 women with surgically proven endometrial cancer were retrospectively evaluated. The depth of myometrial invasion (stage S: < 50% vs stage D: ≥ 50%) on MR imaging was correlated with surgical pathology results. The 25 endometrial cancers included 16 stage S and 9 stage D tumors. The depth of myometrial invasion could be accurately evaluated in 68% of the cases for T2-weighted imaging, 92% for 3D DCE MR imaging, and 96% for reduced FOV DW imaging. In two patients with coexisting adenomyosis, both T2-weighted imaging and 3D DCE MR imaging failed to reveal the deep myometrial invasion, and reduced FOV DW imaging clearly demonstrated the tumor margin in the cases. Combination of reduced FOV DW imaging reading together with T2-weighted imaging improved the assessment of myometrial invasion with a diagnostic accuracy of up to 100%. Addition of reduced FOV DW imaging may improve the staging accuracy of MR imaging for endometrial cancer in assessing the depth of myometrial invasion. Especially, reduced FOV DW imaging has an advantage in assessing the depth of myometrial invasion for patients with coexisting adenomyosis. Reduced FOV DW imaging can be an alternative to 3D DCE MR imaging in evaluating myometrial invasion of endometrial cancer without the use of contrast medium.


Red degeneration of uterine leiomyoma: Clinical utility of susceptibility-weighted MR imaging


Myometrial invasion in endometrial cancer: Comparison of reduced field-of-view diffusion-weighted imaging and dynamic contrast-enhanced magnetic resonance imaging


Comparison of brain tumor contrast-enhancement on T1-CUBE and 3D-SPGR images

T1-Cube (GE HealthCare) is a relatively new 3-dimensional (3D) fast spin-echo (FSE)-based magnetic resonance (MR) imaging sequence that uses a variable flip angle to acquire gap-free volume scans. We compared the gadolinium enhancement characteristics of a heterogeneous population of brain tumors imaged by T1-Cube and then 3D fast spoiled gradient recall acquisition in steady state (3D FSPGR) 3-tesla MR imaging to identify the superior modality for specific diagnostic purposes. We examined 61 lesions from 32 patients using the 2 sequences after administration of gadopentetic acid (Gd-DTPA; 0.1 mmol/kg). Two neuroradiologists independently measured each lesion twice using a region-of-interest (ROI) method. We measured the contrast-to-noise ratio (CNR), the difference in signal intensity (SI) between the tumor and normal white matter relative to the standard deviation (SD) of the SI within the lesion, for both post-contrast 3D FSPGR and post-contrast T1-Cube images of the same tumor and compared modality-specific CNRs for all tumors and in subgroups defined by tumor size, enhancement ratio, and histopathology. The mean CNR was significantly higher on T1-Cube images than 3D FSPGR images for the total tumor population (1.85 ± 0.97 versus 1.12 ± 1.05, P < 0.01) and the histologic types, i.e., metastasis (P < 0.01) and lymphoma (P < 0.05). The difference in CNR was even larger for smaller tumors in the metastatic group (4.95 to 23.5 mm(2)) (P < 0.01). In contrast, mean CNRs did not differ between modalities for high grade glioma and meningioma. Gadolinium enhancement of brain tumors was generally higher when imaged by T1-Cube than 3D FSPGR, and T1-Cube with Gd enhancement may be superior to 3D FSPGR for detecting smaller metastatic tumors.


Clinical application of susceptibility-weighted MR sequences in the female pelvis


Computed diffusion-weighted imaging for differentiating decidualized endometrioma from ovarian cancer

To evaluate the clinical diagnostic ability of computed diffusion-weighted imaging (DWI) for differentiating decidualized endometrioma from ovarian cancer. Computed DWI technique was retrospectively applied to 20 mural nodules in 9 decidualized endometriomas during pregnancy and 20 ovarian cancers. Signal intensities on measured DWI with b values of 800s/mm(2) (DWI800) and on computed DWI with b values of 1500s/mm(2) (cDWI1500) were visually evaluated. Mural nodules of all decidualized endometriomas showed high signal intensity on DWI800 with significantly higher ADC (2.01±0.26×10(-3)mm(2)/s) and low signal intensity on cDWI1500, whereas solid components of all ovarian cancers showed high signal intensity on both DWI800 with lower ADC (1.08±0.20×10(-3)mm(2)/s) and on cDWI1500. Mural nodules in decidualized endometriomas may show high signal intensity on DWI800 due to T2 shine-through effect, and cDWI1500 can distinguish decidualized endometriomas from ovarian cancers by visual evaluation.


A case of polypoid endometriosis with malignant transformation.

Polypoid endometriosis is a benign, rare variant of endometriosis which forms multiple polypoid nodules in the female pelvis mimicking malignant tumors; however, it may rarely cause malignant transformation. We report magnetic resonance imaging findings of a case of polypoid endometriosis with malignant transformation. Multiple high-signal intensity polypoid nodules in the cul-de-sac surrounded by low-signal intensity rim-like fibrous adhesion protruding to the posterior wall of the uterine body were demonstrated on T2-weighted images. The polypoid nodules showed weak contrast enhancement compared with that of uterine myometrium on post-contrast T1-weighted images, and slight high signal intensity on diffusion-weighted images with relatively high mean apparent diffusion coefficient. Reported cases of polypoid endometriosis showed intense contrast enhancement similar to that of uterine myometrium, and weak contrast enhancement similar to that of endometrial carcinoma may be suggestive for malignant transformation of polypoid endometriosis.


Carcinosarcoma of the uterus: MRI findings including diffusion-weighted imaging and MR spectroscopy.

Recently carcinosarcoma has become regarded as a subset of endometrial carcinoma. Because the clinical course of carcinosarcoma is aggressive with poor prognosis, it should be differentiated from endometrial carcinomas for the appropriate surgical management and adjuvant therapy. To clarify the magnetic resonance imaging (MRI) characteristics of uterine carcinosarcoma including diffusion-weighted imaging (DWI) with apparent diffusion coefficient (ADC) measurement and MR spectroscopy (MRS) with quantitative metabolite evaluation. MRI findings of 12 pathologically diagnosed uterine carcinosarcomas obtained on 3T MRI were retrospectively evaluated. The mean and minimum ADCs, and the lipid and choline concentration levels were compared with those of pathologically diagnosed 38 endometrial carcinomas. The mean and minimum ADCs in carcinosarcomas and endometrial carcinomas were not significantly different. The mean ADC of carcinosarcomas was significantly higher than that of higher grade (G2 and G3) endometrial carcinomas. The choline concentration in carcinosarcomas was significantly lower than that in endometrial carcinomas. High lipid peak was observed in 91% of carcinosarcomas and in 24% of endometrial carcinomas. Large, exophytic heterogeneous endometrial mass containing strongly enhanced areas, which may exhibit "tumor delivery", is a suggestive of carcinosarcoma. Relatively high mean ADC and low choline concentration considering its highly malignant nature due to intra-tumoral heterogeneity with necrosis and epithelial cystic components, and the presence of necrosis-associated high lipid peak may be compatible with carcinosarcoma.


MR manifestations of uterine polypoid adenomyoma

Polypoid adenomyoma (PA) is an uncommon benign tumor of the uterus appearing as a submucosal polypoid mass, or rarely as a subserosal polypoid mass. PA should be differentiated from atypical polypoid adenomyoma or malignant uterine tumors. The purpose of our case series is to evaluate magnetic resonance (MR) manifestations of PA for the differential diagnosis. Seven cases with surgically proven PA, five submucosal, and two subserosal, were evaluated. MR imaging findings including contrast enhancement in six cases (four cases with dynamic contrast-enhanced MR study), diffusion-weighted imaging (DWI) in five cases, and susceptibility weighted imaging (SWI) in two cases were retrospectively reviewed. All seven lesions exhibited isointensity compared with the myometrium and 4 of 7 lesions (57%) contained high signal intensity hemorrhagic areas on T1-weighted images. On T2-weighted images, signal intensity was variable and all seven lesions contained cysts. None of five lesions with DWI exhibited high signal intensity compared with the normal myometrium. All six lesions showed intense contrast enhancement similar to that of the myometrium on post-contrast T1-weighted images. Punctate low intensity areas reflecting blood contents were revealed in all two lesions with SWI. Submucosal or subserosal polypoid masses containing hemorrhagic areas, and cysts reflecting functional endometrium and dilatation of endometrial glands are suggestive for PA. Intense contrast enhancement similar to that of the myometrium may be another characteristic finding for PA.


Susceptibility-weighted MRI of extra-ovarian endometriosis: preliminary results

Extra-ovarian endometriosis (EOE) usually appears as solid masses mimicking neoplasms both clinically and radiologically. Detection of blood products within a lesion may be suggestive of its endometriotic nature. We present a descriptive study of MR imaging findings that include susceptibility-weighted imaging (SWI) for patients with EOE. Eight pathologically proven EOE (3 bowel, 2 bladder and 3 abdominal wall) were evaluated. Fat-saturated T1-weighted images (fsT1WI) and SWI were obtained using 1.5T MR imaging. Images were reviewed for the presence of signal voids on SWI and of high-intensity foci on fsT1WI. High-intensity foci reflecting subacute hemorrhage were detected in 4 of 8 lesions (50%) on fsT1WI, whereas signal voids reflecting acute to chronic hemorrhage were detected in all 8 lesions (100%) on SWI. SWI is a sensitive MRI technique which demonstrates hemorrhage of varying chronicity in patients with EOE and may improve future MRI characterization of EOE.


Susceptibility-weighted Imaging of Ovarian Torsion: A Case Report

We report findings of magnetic resonance imaging including susceptibility-weighted imaging (SWI) of the subacute torsion of an ovarian fibrothecoma in a patient with renal dysfunction. Although venous thrombosis within the vascular pedicle mimicked a malignant tumor, showing high signal intensity on T2-weighted images and diffusion-weighted imaging, we diagnosed ovarian torsion on SWI without the administration of contrast medium, aided by the prominent susceptibility-induced signal void caused by the thrombosis.


Magnetic Resonance Manifestations of Villoglandular Papillary Adenocarcinoma of the Uterine Cervix with a Fern-leaf-like Appearance.

Villoglandular papillary adenocarcinoma (VGPA) is a rare subtype of cervical adenocarcinoma that generally affects young women and has a favorable prognosis. Its preoperative diagnosis is important to avoid excessive surgery. We report the magnetic resonance (MR) findings of a case in which the cervical tumor showed a fern-leaf-like appearance on high resolution T2-weighted images obtained at 3 tesla. MR imaging clearly showed this pathological feature that may suggest this disease.


Clear cell adenocarcinoma arising from clear cell adenofibroma of the ovary: value of DWI and DCE-MRI.

Clear cell adenofibroma (CCAF) is a rare surface epithelial-stromal tumor of the ovary and recently considered another precursor of clear cell adenocarcinoma (CCA) other than endometrioma. We report magnetic resonance (MR) findings of a borderline CCAF that contained a small CCA focus. The tumor manifested a characteristic "black sponge" appearance. The CCA focus showed high signal intensity on diffusion-weighted imaging (DWI) and early enhancement on dynamic contrast-enhanced (DCE) MR imaging (DCE-MRI), and the CCAF components showed low signal intensity on DWI and gradually increasing contrast enhancement on DCE-MRI.


In vivo proton MR spectroscopy in uterine abscesses.

Journal of Magnetic Resonance Imaging : JMRI


Preliminary observations and clinical value of lipid peak in high-grade uterine sarcomas using in vivo proton MR spectroscopy.

To retrospectively evaluate the clinical significance of the lipid peak in in vivo proton magnetic resonance spectroscopy (MRS) for the diagnosis of high-grade uterine sarcomas. MRS was performed in patients with 38 pathologically diagnosed uterine corpus tumours (26 leiomyomas and 12 sarcomas) at 3 T. Single-voxel MRS data were collected from a single square volume of interest that encompassed the tumours. The concentrations of lipid and total choline compounds (tCho) were classified as high, low or none. High lipid peaks were observed in all 12 sarcomas and not in benign leiomyomas except for 1 lipoleiomyoma. All 26 leiomyomas and 10 of the 12 sarcomas showed tCho peaks, whereas 2 sarcomas with massive necrosis showed no tCho peak. The presence of a high lipid peak for the diagnosis of sarcoma had a sensitivity of 100 %, specificity of 96 %, positive predictive value of 92 % and negative predictive value of 100 %. The high lipid peaks in high-grade malignant tumours may be observed in both viable and necrotic areas, and may be useful in distinguishing uterine sarcomas from benign leiomyomas. · High lipid peak on MR spectroscopy is suggestive of uterine sarcomas. · Lipid peak is observed in both viable and necrotic areas in sarcomas. · MR spectroscopy may be useful in distinguishing uterine sarcomas from benign leiomyomas.


Ovarian adenofibromas and cystadenofibromas: magnetic resonance imaging findings including diffusion-weighted imaging.

Ovarian adenofibromas (AF) and cystadenofibromas (CAF) belong to the surface epithelial-stromal tumors, and may appear as solid, or solid and cystic masses mimicking ovarian cancers. To evaluate the capability of magnetic resonance imaging (MRI) including diffusion-weighted imaging (DWI) with apparent diffusion coefficient (ADC) measurement for the diagnosis of ovarian AF/CAF. Magnetic resonance manifestations of 13 cases of ovarian AF/CAF were retrospectively evaluated. DWI was obtained in all 13 lesions, and mean ADC values in 11 lesions were compared with those in solid portions of 27 ovarian cancers. Results Neither case with AF/CAF revealed high signal intensity on DWI, whereas all ovarian cancers showed high signal intensity on DWI. The ADC values in the solid portions of AF/CAF were significantly higher than those of ovarian cancers (P < 0.001). A cut-off value of 1.20 × 10(-3) mm(2)/s for AF/CAF had a sensitivity of 82%, specificity of 93%, positive predictive value of 82%, and negative predictive value of 93%. DWI with ADC measurement may be helpful in differentiating AF/CAF from ovarian cancers.


Preliminary observations and diagnostic value of lipid peak in ovarian thecomas/fibrothecomas using in vivo proton MR spectroscopy at 3T.

To retrospectively evaluate the significance of lipid peak in in vivo proton magnetic resonance (MR) spectroscopy for the diagnosis of ovarian thecomas/fibrothecomas in patients with solid gynecologic tumors exhibiting totally or partially low signal intensity on T2-weighted images. MR spectroscopy was performed in patients with pathologically diagnosed gynecologic tumors at 3T MRI. Single-voxel MR spectroscopy data were collected from a single square volume of interest that encompassed the gynecologic masses. The lipid concentration level was classified into three classes (high; low; none). A total of 20 gynecologic tumors in 20 patients were evaluated in this study. High lipid peak was observed in all seven thecomas/fibrothecomas, whereas low lipid peak was observed in only one fibroma in 13 nonthecomatous tumors (six benign ovarian tumors and seven subserosal uterine leiomyomas). The presence of lipid peak for the diagnosis of thecomas/fibrothecomas had a sensitivity of 100%, specificity of 92%, positive predictive value of 88%, and negative predictive value of 100%. The high lipid peak reflecting abundant intracellular lipid contents is considered a specific metabolite concentration for thecomas/fibrothecomas. Demonstration of high lipid peak may contribute to the diagnosis of thecomas/fibrothecomas in distinguishing from other benign ovarian fibrous tumors or subserosal uterine leiomyomas.


Primary carcinoid tumor of the ovary: Magnetic resonance imaging characteristics with pathologic correlation

Ovarian carcinoid tumor is a rare neoplasm that may appear as a solid mass or often combined with teratomas or mucinous tumors. We report 2 cases associated with mucinous cystadenomas and describe their magnetic resonance imaging characteristics. On T(2)-weighted images, the tumors appeared as multilocular cystic masses with hypointense solid components as a result of abundant fibrous stroma induced by serotonin. Demonstration of prominent hypervascularity of the tumors following contrast administration on dynamic study may be the clue to differential diagnosis.


Preliminary observations and clinical value of N-acetyl resonances in ovarian tumours using in-vivo proton MR spectroscopy at 3T.

To retrospectively evaluate the clinical significance of N-acetyl resonances at 2 ppm in in-vivo proton magnetic resonance (MR) spectroscopy for distinguishing mucinous and non-mucinous tumours in patients with ovarian masses. MR spectroscopy was performed in patients with pathologically diagnosed ovarian tumours at 3T-MR imaging. Single-voxel MR spectroscopy data were collected from a single square volume of interest that encompassed the ovarian masses. The metabolite resonance peak areas at 2 ppm were quantified relative to unsuppressed water using a software package (LCModel). A total of 32 ovarian lesions in 32 patients were evaluated in this study. High metabolite peak at 2 ppm was observed in all nine mucinous tumours (9.71 +/- 7.46 mM), whereas low peak was observed in 14 of 23 non-mucinous tumours (3.12 +/- 1.42 mM) (p < 0.001). Using a cut off value of 4.45 mM for mucinous tumours had a sensitivity of 89%, specificity of 86%, PPV of 80%, and NPV of 92%. Proton MR spectroscopy with quantitative evaluation of the metabolite at 2 ppm concentration, which may suggest the presence of mucinous material containing N-acetyl mucinous compounds, can provide helpful information in distinguishing mucinous and non-mucinous ovarian tumours. Key Points MR spectroscopy helps distinguish mucinous from non-mucinous ovarian tumours. High N-acetyl resonance at 2 ppm is observed in ovarian mucinous tumours. Thus MR spectroscopy could improve management of these patients.


Magnetic resonance manifestations of hyperreactio luteinalis

Hyperreactio luteinalis (HL) is a rare benign physiological ovarian enlargement associated with gestational trophoblastic disease or pregnancy, and may mimic neoplasm. We evaluated magnetic resonance findings of HL to distinguish from neoplasm by using diffusion-weighted imaging with apparent diffusion coefficient (ADC) measurement. Magnetic resonance manifestations of 15 cases of HL in 8 women (mean age, 32 years) were retrospectively evaluated. Diffusion-weighted imaging (b = 0 and 800 seconds/mm²) was obtained in 11 cases of HL, and ADC was compared with that in solid portions of 18 ovarian cancers. All cases of HL appeared as multilocular cystic masses with septations mimicking mucinous cystic tumors. Intervening ovarian stroma exhibited hyperintensity on diffusion-weighted imaging. The ADC in ovarian stroma in HL was significantly higher than that in solid portions of ovarian cancers. Ovarian stroma in HL may mimic solid tumorous components in mucinous tumors; however, high ADC reflecting edematous, luteinized stroma may be helpful for the diagnosis of HL.


Differentiation of benign and malignant uterine corpus tumors by using proton MR spectroscopy at 3T: preliminary study.

To retrospectively evaluate the diagnostic ability of magnetic resonance (MR) spectroscopy for distinguishing benign and malignant lesions in patients with uterine corpus tumours at MR imaging. Pelvic MR spectroscopy was performed in patients with pathologically diagnosed benign and malignant uterine corpus tumours at 3T-MR imaging. Single-voxel MR spectroscopy data were collected from a single square volume of interest that encompassed the uterine corpus lesion. The total choline compounds (tCho) resonance peak areas were quantified relative to unsuppressed water using a software package. Patients who fulfilled the criteria for estimates of acceptable reliability were included. A total of 32 patients (age range, 24-76 years) with 32 lesions were evaluated in this study. The median lesion size at MR imaging was 50 mm (range, 19-218 mm). A tCho peak was present in all 32 lesions including 14 malignant lesions (9.21 ± 2.21 mM), and 18 benign lesions (4.59 ± 2.22 mM) (p < 0.0001). Using a cut-off value of 7.00 mM for malignant lesions had a sensitivity of 93%, specificity of 83%, PPV of 81% and NPV of 94%. Proton MR spectroscopy with quantitative evaluation of tCho concentration can provide helpful information in distinguishing benign and malignant uterine corpus tumours.


Adenomyosis: Usual and Unusual Imaging Manifestations, Pitfalls, and Problem-solving MR Imaging Techniques.

Adenomyosis is a common nonneoplastic gynecologic disease characterized by the presence of ectopic endometrium within the myometrium. On T2-weighted magnetic resonance (MR) images, typical adenomyosis appears as an ill-demarcated low-signal-intensity lesion with uterine enlargement. However, various physiologic or pathologic states such as amount of functional endometrial tissue, phase of the menstrual cycle, endogenous hormonal abnormality, and exogenous hormonal stimulation may affect the MR imaging appearance of adenomyosis and may result in a tumorlike appearance. Problem-solving MR imaging techniques used in diagnosis of adenomyosis include diffusion-weighted imaging, susceptibility-weighted imaging, hydrogen 1 MR spectroscopy, cine MR imaging, and high-resolution MR imaging at 3 T. Adenomyotic lesions that show high signal intensity relative to the outer myometrium on T2-weighted images mimic malignancies such as leiomyosarcoma and endometrial stromal sarcoma. In these cases, a relatively high apparent diffusion coefficient at diffusion-weighted imaging and a low choline peak at MR spectroscopy are suggestive of a benign lesion. Small hemorrhagic foci suggestive of an adenomyotic lesion are well demonstrated as signal voids at susceptibility-weighted imaging. Cine MR imaging is useful in differentiating transient myometrial contraction from focal adenomyosis. High-resolution MR imaging at 3 T demonstrates anatomically detailed structures and may improve diagnostic accuracy in differentiating adenomyosis from its mimics, such as low-grade endometrial stromal sarcoma.


Manifestations of the Female Reproductive Organs on MR Images: Changes Induced by Various Physiologic States.

Unlike other reproductive organs, the uterus and ovaries are known to undergo dynamic morphologic changes according to various physiologic states. It is vitally important for radiologists when diagnosing gynecologic disorders to understand how normal female reproductive organs appear on magnetic resonance (MR) images for a given physiologic state. The authors focused on the effects of the menstrual cycle, pregnancy, and aging on MR images of normal female reproductive organs. During menstruation, the zonal architecture of the uterine corpus may be indistinct and the ovarian stroma may shrink and have lower signal intensity on both T2- and diffusion-weighted (DW) images. During periovulation, the ovarian stroma may be reach its maximum size and have high signal intensity on both T2- and DW images. Functional cysts may often be seen in ovaries of reproductive age and usually spontaneously shrink, whereas surface-epithelial inclusion cysts may be commonly seen in postmenopausal ovaries. Pregnancy-related changes, such as decidual changes in ectopic endometrial tissue and hyperreactio luteinalis in ovaries, may mimic gynecologic tumors and must be correctly diagnosed to avoid unnecessary and excessive surgical intervention. The authors offer some clues that may be helpful for making the differential diagnosis when evaluating MR images of female reproductive organs. Radiologists should, as much as practicably possible, check the physiologic states of patients before interpreting MR images.


Diffusion-weighted magnetic resonance imaging of ovarian tumors: differentiation of benign and malignant solid components of ovarian masses.

We evaluated the feasibility of diffusion-weighted imaging (DWI) with apparent diffusion coefficient (ADC) measurement in differentiating benign and malignant ovarian tumors. Surgically proven 49 ovarian tumors (39 malignant/borderline malignant and 10 benign) were examined. The solid portion of all 39 malignant tumors showed homogeneous or heterogeneous high intensity on DWI, whereas only 3 of the 10 benign tumors (3 thecomas) showed high intensity. The mean (SD) ADC value in the 39 malignant tumors (1.03 [0.19]) was significantly lower than that in 10 benign tumors (1.38 [0.30]). A relatively low ADC (1.08-1.20) in the 3 thecomas may reflect their abundant cellular nature, and the presence of low intensity on T2-weighted images was suggestive for benign fibrous tumor. Low intensity on DWI with high ADC may suggest benign lesions; however, it may be occasionally difficult to differentiate benign and malignant lesions only on the basis of DWI.


A case of metastatic malignant melanoma of the ovary with a multilocular cystic appearance on MR imaging.

Ovarian metastasis from malignant melanoma is rare and usually appears as a solid ovarian mass. We report a case of ovarian metastasis from cutaneous malignant melanoma that proved to be a diagnostic dilemma. The ovarian metastasis exhibited a multilocular cystic appearance on magnetic resonance imaging, mimicking a mucinous ovarian tumor with massive ascites.


Diffusion-weighted magnetic resonance imaging of endometrial cancer: differentiation from benign endometrial lesions and preoperative assessment of myometrial invasion.

Uterine endometrial cancer is the most common gynecologic malignancy, and benign endometrial hyperplasia or polyps should be differentiated from endometrial cancer. In evaluating endometrial cancer on magnetic resonance imaging (MRI), the assessment of the depth of myometrial invasion is important because it closely correlates with the patient's prognosis. To verify the feasibility of diffusion-weighted magnetic resonance imaging (DWI) to distinguish benign and malignant endometrial lesions, and to evaluate myometrial invasion of endometrial cancer. Sixty-seven endometrial lesions including 45 cancers and 22 benign lesions (hyperplasia and polyps) were evaluated by DWI with apparent diffusion coefficient (ADC) measurement. The staging accuracies of DWI and gadolinium-enhanced T1-weighted images in the assessment of myometrial invasion were evaluated in 33 patients with endometrial cancer. The ADC values (x10(-3) mm(2)/s) in cancer and benign lesions were 0.84+/-0.19 and 1.58+/-0.36, respectively (P<0.01). The staging accuracy (superficial or deep myometrial invasion) was 94% for DWI and 88% for gadolinium-enhanced T1-weighted images. Coexisting adenomyosis and infiltrative myometrial invasion caused staging errors on gadolinium-enhanced T1-weighted images, whereas DWI could demonstrate the tumor extent correctly. DWI provides helpful information in evaluating benign and malignant endometrial lesions.


Hyperintense uterine myometrial masses on T2-weighted magnetic resonance imaging: differentiation with diffusion-weighted magnetic resonance imaging.

The objective was to determine whether diffusion-weighted imaging (DWI) might be useful in differentiating uterine leiomyomas exhibiting hyperintensity on T2-weighted images from malignant lesions. Thirty-four uterine myometrial lesions including 7 malignant tumors and 27 leiomyomas (6 cellular leiomyomas [CLM] and 21 degenerated leiomyomas [DLM]) were evaluated. The apparent diffusion coefficients (ADC) in cellular portions of the lesions were measured (10(-3) mm2/s). All malignant tumors showed high signal intensity on DWI with low ADC (mean [SD], 0.79 [0.26]), which was significantly lower (P < 0.01) than that in benign leiomyomas (1.51 [0.33]). The ADC in CLM (1.18 [0.16]) was significantly lower (P < 0.01) than that in DLM (1.60 [0.30]) and higher (P < 0.05) than that in malignant tumors. It was difficult to differentiate malignant tumors from leiomyomas on the basis of signal intensity on DWI; however, the ADC measurement may be helpful to distinguish malignant tumors, CLM, and DLM.


Adenosarcoma of the uterus: magnetic resonance imaging characteristics.

Adenosarcoma of the uterus is a rare tumor containing benign glandular epithelial and malignant mesenchymal elements. Typical adenosarcoma is a low-grade tumor, presents as a large polypoid mass occupying the endometrial cavity, and may protrude into the vaginal cavity. The presence of small hyperintense cysts scattered within the mass on T(2)-weighted imaging, reflecting glandular epithelial components, and relatively low signal intensity on high b-value diffusion-weighted imaging, reflecting its low-grade nature, may be characteristic findings.


Clear cell adenocarcinoma of the female urethra: magnetic resonance imaging

Clear cell adenocarcinoma of the female urethra is a rare malignant tumor arising from urethral diverticulum or paraurethral ducts and glands, and extends to the submucosa surrounding the urethra. In the advanced stage, the tumor may involve adjacent organs such as the vagina, and may mimic gynecologic malignancy. We report 2 cases in which magnetic resonance imaging could reveal their urethral origin by detecting the normal urethra within the mass as targetlike appearance on axial T2-weighted image.


Diffusion-weighted magnetic resonance imaging of urinary epithelial cancer with upper urinary tract obstruction: preliminary results

BACKGROUND: Various malignant tumors of the body show high signal intensity on diffusion-weighted magnetic resonance imaging (DWI). In the genitourinary region, DWI is expected to have a role in detecting urinary epithelial cancer noninvasively. PURPOSE: To demonstrate the feasibility of DWI for the diagnosis of urinary epithelial cancer with upper urinary tract obstruction. MATERIAL AND METHODS: Twenty upper urinary tract cancers in 16 patients were evaluated by high-b-value DWI (b=800 s/mm(2)). The signal intensity was visually evaluated, and the apparent diffusion coefficients (ADCs) were measured. RESULTS: All urinary epithelial cancers showed high signal intensity on DWI. The ADC in cancerous lesions was 1.31+/-0.27 x 10(-3) mm(2)/s, which was significantly lower than that of the lumens of the ureter or renal pelvis (3.32+/-0.44 x 10(-3) mm(2)/s; P<0.001). Maximum intensity projection images of DWI in combination with static-fluid MR urography provided three-dimensional entire urinary tract imaging with the extension of tumors. CONCLUSION: DWI is useful in the tumor detection and in evaluating the tumor extension of urinary epithelial cancer in patients with upper urinary tract obstruction.


Susceptibility-weighted MRI of endometrioma: preliminary results

OBJECTIVE: Susceptibility-weighted MRI combines magnitude and phase information from fully velocity-compensated gradient-echo sequences and depicts as signal voids the susceptibility effects caused by local inhomogeneity of the magnetic field. Our objective, based on MRI of 60 pathologically proven ovarian cystic lesions, including 42 endometriomas and 18 nonendometrial cysts, was to evaluate hemosiderin deposition within the walls of endometriomas on susceptibility-weighted MR images. Two radiologists blinded to the final diagnosis retrospectively reviewed the images in consensus. CONCLUSION: On susceptibility-weighted MR images, punctate or curved linear signal voids along the cyst wall were observed in 39 endometriomas (92.9%) and in no nonendometrial cysts. The signal voids were more prominent on 3-T than on 1.5-T images, reflecting the higher sensitivity of 3-T MRI to magnetic susceptibility effects. Thirty-two endometriomas (76.2%) met definitive MRI criteria, that is, hyperintensity on T1-weighted images and hypointensity on T2-weighted images, and 41 endometriomas (97.6%) were correctly diagnosed with susceptibility-weighted MRI.


Ovarian fibromatosis: magnetic resonance imaging findings with pathologic correlation

Ovarian fibromatosis is a rare benign nonneoplastic condition with ovarian enlargement in young women and characterized by a proliferation of collagen-producing spindle cells surrounding normal ovarian structures. We reported magnetic resonance findings of a case that the affected ovarian parenchyma with follicles was surrounded by very low intense thick fibrous tissue on T2-weighted images such as "black garland" around the ovary. The magnetic resonance findings well reflected the pathological feature of the disease and may be diagnostic.


High-b-value diffusion-weighted magnetic resonance imaging of pancreatic cancer and mass-forming chronic pancreatitis: preliminary results

BACKGROUND: Mass-forming chronic pancreatitis may mimic a pancreatic cancer on dynamic computed tomography (CT) and magnetic resonance (MR) imaging, and preoperative differential diagnosis is often difficult. Recently, the usefulness of diffusion-weighted MR imaging (DWI) in the diagnosis of pancreatic cancer has been reported in several studies. PURPOSE: To determine whether high-b-value DWI can distinguish pancreatic cancer from benign mass-forming chronic pancreatitis. MATERIAL AND METHODS: Twenty pancreatic cancers and four cases of mass-forming chronic pancreatitis were evaluated by high-b-value DWI (b=800 s/mm(2)). The signal intensity on DWI was visually evaluated, and the isotropic apparent diffusion coefficients (ADCs) were measured. RESULTS: All twenty pancreatic cancers showed high signal intensity (18 showed very high, two showed slightly high) on DWI. None of the mass-forming chronic pancreatitis cases showed very high intensity (three showed iso to low, one showed slightly high) on DWI. The ADCs in the pancreatic cancer and mass-forming chronic pancreatitis were 1.38 +/- 0.32 x 10(-3) mm(2)/s and 1.00 +/- 0.18 x 10(-3) mm(2)/s, respectively (P < 0.05). CONCLUSION: On high-b-value DWI, most pancreatic cancers showed very high signal intensity, and may hence be distinguished from benign mass-forming chronic pancreatitis based on our preliminary results.


Magnetic resonance manifestations of endometrial cysts at 3 T compared with 1.5 T

OBJECTIVE: To evaluate the feasibility of magnetic resonance (MR) imaging at 3 T compared with 1.5 T while focusing on the shading sign of endometrial cysts on T2-weighted images. METHODS: Fifteen ovarian endometrial cysts in 10 patients underwent pelvic MR scans on 3-T and 1.5-T scanners. Fast spin-echo T2-weighted images were obtained. The images were evaluated qualitatively for the presence of the shading sign. Quantitative evaluation was performed by comparing the cyst-to-muscle signal intensity ratio at 3 T and that at 1.5 T. RESULTS: The signal intensity of the cysts was lower at 3 T than that at 1.5 T by visual evaluation. In 2 lesions, the shading sign was demonstrated at 3 T but was not at 1.5 T. The cyst-to-muscle signal intensity ratio at 3 T was significantly lower than that at 1.5 T. CONCLUSION: Magnetic resonance imaging at 3 T is useful for the diagnosis of endometrial cysts with better demonstration of the shading sign on T2-weighted images.


BACKGROUND: The objective of this article is to define the imaging characteristics of ancient schwannoma, which is a rare variant of benign schwannoma with degenerative changes, arising in the female pelvis simulating ovarian tumors. METHODS: Eleven surgically proven ancient schwannomas of the female pelvis were evaluated retrospectively on the basis of CT and MR findings. RESULTS: Typical intra-pelvic schwannoma was a neurologically asymptomatic large mass, which may situate at presacral or lateral pelvic region with the continuity to the nerve or neural foramen. Ancient schwannomas manifested as encapsulated solid masses with random or eccentric cystic areas, or as cystic masses with marginal crescent-shaped or nodular solid components. Hemorrhagic changes and calcifications were often observed on MRI and CT respectively. To detect ipsilateral normal ovary and to demonstrate centripetal displacement of the adjacent rectum or iliac vessels were helpful to diagnose the tumor as an extra-ovarian mass situated at the extraperitoneal region. CONCLUSIONS: Diagnosis of ancient schwannoma before surgical treatment is important and should be made by its characteristic clinical and imaging findings.


A case of polypoid endometriosis: MR pathological correlation

We report a case of polypoid endometriosis and correlate the MRI findings with the pathological findings. The polypoid endometriosis appeared as multiple polypoid masses protruding into the adjacent pelvic organs, including the uterus and rectum. The masses were found to show hyperintensity on T(2) weighted images, which was similar to the signal intensity of the uterine endometrium, reflecting the presence of abundant endometrial-type glands. The masses were also surrounded by hypointense rim-like structures on T(2) weighted images. These structures were confirmed by pathology to correspond with fibrous tissues arising from endometriosis. These features, together with an intense enhancement similar to the adjacent uterus, may be a diagnostic clue to this rare entity.


Malignant Brenner tumor with transition from benign to malignant components: computed tomographic and magnetic resonance imaging findings with pathological correlation

We report computed tomographic and magnetic resonance findings of an ovarian malignant Brenner tumor with transition from benign to malignant components. The tumor was demonstrated as a cystic mass with solid mural components. The benign component contained dense calcifications on computed tomography and showed very low intensity on T2-weighted images, whereas the malignant component showed high intensity. The admixture of 2 components may well reflect the pathological feature and may be a diagnostic clue to malignant Brenner tumor.


Magnetic Resonance Manifestations of Decidualized Endometriomas During Pregnancy

OBJECTIVE: Decidual changes of endometrial tissue in endometriomas during pregnancy may manifest as mural nodules and mimic malignant transformation. We evaluated magnetic resonance findings of decidualized ovarian endometriomas for the differentiation from malignant transformation. METHODS: Magnetic resonance manifestations of 5 decidualized ovarian endometriomas were evaluated. High b-value diffusion-weighted images were performed in 3 cases. RESULTS: The mural nodules were demonstrated as linear, small nodular, broad-based nodular, or polypoid structures, which showed prominent hyperintensity on T2-weighted images and on diffusion-weighted images similar to normal endometrium or placenta. The apparent diffusion coefficient of decidualized mural nodules was significantly higher than that of malignant mural nodules of 7 ovarian cancers. CONCLUSIONS: Endometrioma with prominent hyperintense mural nodules on T2-weighted images in a pregnant woman is highly suggestive for decidualized endometriomas. Diffusion-weighted images with the apparent diffusion coefficient measurement may help the diagnosis of this rare entity.


Malignant transformation of pelvic endometriosis: MR imaging findings and pathologic correlation

Malignant transformation is a rare complication of endometriosis. Endometriosis-associated ovarian cancers are seen more often in younger women than are ovarian cancers without endometriosis, and early detection is important to improve the prognosis and preserve fertility. However, normal decidual change of the ectopic endometrium in an endometrioma during pregnancy must be differentiated from malignant transformation. The finding that is most important for a diagnosis of malignant change is the presence of one or more contrast material-enhanced mural nodules within a cystic mass at magnetic resonance (MR) imaging. Dynamic subtraction MR imaging is useful in depicting small contrast-enhanced nodules within the hyperintense endometrioma on T1-weighted images. Intracystic coagulate may mimic a mural nodule; the absence of contrast enhancement is the diagnostic clue to its benignity. Enlargement of the endometrioma and the disappearance of shading within the mass on T2-weighted images are suggestive of malignant transformation.


Cerebral hyperperfusion in a patient with eclampsia with perfusion-weighted magnetic resonance imaging

The patient was a 25-year-old Japanese woman with postpartum eclampsia, in whom magnetic resonance imaging (MRI) was performed ten hours after convulsion. The patient improved within three days. Diffusion-weighted images showed a high apparent diffusion coefficient (ADC), and perfusion-weighted images obtained by the multi-slice flow-sensitive alternating inversion recovery (FAIR) method showed hyperperfusion, which was suggestive of vasogenic edema, on the parietal and occipital subcortical white matter, corresponding with transient hyperintensities on T2-weighted images. MR angiography (MRA) revealed no signs of vasospasm. These findings suggested hyperperfusion-induced vasogenic edema without cerebrovascular spastic change in the early stage of eclampsia. The FAIR method is considered a useful technique for perfusion-weighted MRI, especially useful to evaluate the cerebral perfusion of emergency patients such as those with eclampsia.


A case of adenomyomatous polyp of the uterus associated with tamoxifen therapy

A case of adenomyomatous polyp of the uterine endometrium is reported. The patient was 64-year-old woman treated with tamoxifen. Ultrasonography demonstrated a heterogeneous hyperechoic mass with small cystic spaces in the uterus. On magnetic resonance imaging (MRI), a thick stalk with many thin restiform branches within a large solid and cystic endometrial mass showed dendriform low intensity on T2-weighted images and intense enhancement on contrast-enhanced T1-weighted images. The prominent dendriform central fibrous core on MRI reflected a thick stalk originating from the myometrium with numerous branches containing abundant smooth muscle fibers, and may represent the pathologic feature of adenomyomatous polyp.


Pathologies of the uterine endometrial cavity and unusual manifestations and pitfalls on

The endometrial cavity may demonstrate various imaging manifestations such as normal, reactive, inflammatory, and benign and malignant neoplasms. We evaluated usual and unusual magnetic resonance imaging (MRI) findings of the uterine endometrial cavity, and described the diagnostic clues to differential diagnoses. Surgically proven pathologies of the uterine endometrial cavity were evaluated retrospectively with pathologic correlation. The pathologies included benign endometrial neoplasms such as endometrial hyperplasia and polyp, malignant endometrial neoplasms such as endometrial carcinoma and carcinosarcoma, endometrial-myometrial neoplasm such as endometrial stromal sarcoma, pregnancy-related lesions in the endometrial cavity such as gestational trophoblastic diseases (hydatidiform mole, invasive mole and choriocarcinoma) and placental polyp, myometrial lesions simulating endometrial lesions such as submucosal leiomyoma and some adenomyosis, endometrial neoplasms simulating myometrial lesions such as adenomyomatous polyp and endometrial lesions arising in the hemicavity of a septate/bicornate uterus, and fluid collections in the uterine cavity (hydro/hemato/pyometra). It is important to recognize various imaging findings in these diseases, in order to make a correct preoperative diagnosis.


Imaging findings of urachal mucinous cystadenocarcinoma associated with pseudomyxoma peritonei.

Pseudomyxoma peritonei is an uncommon neoplastic condition in which gelatinous fluid-like materials are observed in the peritoneal cavity caused by the dissemination of mucinous adenocarcinoma. Although ruptured appendiceal mucocele is the most common cause, tumors arising from other organs may also cause pseudomyxoma peritonei. We report the imaging findings of an extremely rare case of urachal mucinous adenocarcinoma associated with pseudomyxoma peritonei on computed tomography and magnetic resonance imaging with histopathologic correlation.


Difference of signal change by a language task on autistic patients using functional MRI

OBJECTIVE: Cerebral function with a language task was evaluated by functional magnetic resonance imaging (MRI), and the differences of activated pattern and signal changes were compared between autistic patients and normal controls. METHODS: Ten autistic and ten normal subjects were tested by fMRI with a language task requiring the attribution of complex mental states. Activation maps analyzed between two groups were generated and the asymmetry indexes calculated by the quotient of activated pixels of the right frontal lobe divided by those of the left frontal lobe were statistically compared by unpaired t-test. RESULTS: Both the autistic and the normal subjects showed activation at the bilateral prefrontal cortical areas and the ventral occipito-temporal regions. However, the autistic patients demonstrated more activation at the right frontal lobe than the normal controls. Thus it was considered that in the autistic patients the right-hemisphere was more dominant for the language task than that of the normal controls. The result is consist to the theory that autism is related to early left-hemisphere dysfunction. CONCLUSIONS: We considered that fMRI may be a useful non-invasive method to evaluate the cerebral functional abnormality in autistic patients.

The Journal of Medical Investigation : JMI


A case of urachal xanthogranuloma containing a calculus: CT and MRI findings

We report a rare case of an urachal xanthogranuloma containing a urinary calculus, which was considered to have originated from vesicourachal diverticulum. The patient was a 66-year old woman with hematuria and pyuria. Computed tomography (CT) revealed a midline-situated supravesical cavitary mass containing a calculus. Sagittal images of magnetic resonance imaging (MRI) revealed continuity of the mass with the umbilicus. Fatty components of the xanthogranuloma showed low attenuation on CT and hyperintensity on T1-weighted images of MRI. The presence of a large calculus in the vesicourachal diverticulum may have caused continuous irritation resulting in the xanthogranulomatous formation.


Magnetic resonance imaging and proton MR spectroscopy of the brain in a patient with carbohydrate-deficient glycoprotein syndrome type I.

This is a report on a case of carbohydrate-deficient glycoprotein syndrome (CDGS) with neurological deficits. Magnetic resonance (MR) images showed remarkable atrophy of the cerebellum and brainstem, and hypointensity was seen in the pallidum on diffusion-weighted images (DWI), suggesting deposits of metal substances. In the cerebellum, proton MR spectroscopy (MRS) showed decreased concentrations of N-acetylaspartate and a complex of glutamine and glutamate (Glx) while the concentration of myo-inositol was increased, indicating neuronal impairment and gliosis. In the parietal lobe, there was an increased concentration of Glx, possibly reflecting dysfunction caused by liver injury.

Journal of Magnetic Resonance Imaging : JMRI


Magnetic resonance imaging and spectroscopy in a patient with treated methylmalonic acidemia.

Magnetic resonance imaging (MRI) and proton magnetic resonance spectroscopy (proton MRS) findings before and after carnitine therapy in a patient with methylmalonic acidemia (MMA) are evaluated. The hyperintensity on T2-weighted image and diffusion-weighted image and the decreased apparent diffusion coefficient of bilateral basal ganglia were normalized in parallel with normalization of the elevated lactate levels and the decreased N-acetyl-aspartate levels, corresponding to improvement of clinical symptoms. MRI and proton MRS may serve as a suitable, noninvasive modality for monitoring treated MMA.


Localized pseudomyxoma peritonei in the female pelvis simulating ovarian carcinomatous peritonitis.

Two cases of localized pseudomyxoma peritonei in the female pelvic cavity associated with a ruptured appendiceal mucocele and ovarian involvement that mimicked ovarian carcinomatous peritonitis were evaluated. Subtle omental irregularity adjacent to the cecum may suggest the hidden appendiceal origin reflecting localized carcinomatous peritonitis caused by the occult rupture of the mucocele. Mucinous fluid-like materials were localized in the pelvic cavity with scalloping of the uterus, which may be the diagnostic finding of pseudomyxoma peritonei.


Ovarian cystadenofibromas: characteristic magnetic resonance findings with pathologic correlation

Ovarian cystadenofibroma is a benign tumor and may appear as a multilocular cystic mass with solid nodular components mimicking malignant ovarian tumor. Preoperative diagnosis is required to avoid excess surgical procedure. We report characteristic magnetic resonance imaging (MRI) findings of 2 cases with pathologic correlation. On T2-weighted images, the solid components of the tumors showed very low intensity, in which very high intense tiny cysts were present reflecting dense fibrous stromal proliferation with scattered small cystic glandular structures. This "black sponge"-like appearance was considered to be diagnostic.