Junko Takahama

Ectopic pregnancy: MRI findings and clinical utility

PurposeTo assess the utility of magnetic resonance imaging (MRI) in patients with clinically suspected ectopic pregnancy (EP).MethodsWe retrospectively reviewed MRIs of 26 consecutive patients who were clinically suspected of having an EP. The diagnostic utility of MRI features of EP was analyzed retrospectively as follows: (1) Direct sign detection of ectopic gestational sac (GS); (2) Indirect signs tubal dilatation with hemosalpinx, adnexal hematoma, and hemorrhagic ascites. The diagnostic accuracy of each sign and their combination was compared to surgical records. The MRI findings of an ectopic GS were reviewed as follows: size, shape, signal intensity, and enhancement pattern.ResultsOf 26 patients, 24 had a tubal pregnancy; 22 of these 24 patients (92%) had a direct sign (sensitivity: 91.3%; specificity: 100%; positive predictive value: 100%). The diagnostic accuracy of the direct sign was 92%; this was more accurate than that of any single indirect sign (39%, 54%, and 50%, respectively). However, the diagnostic accuracy of EP increased to 100% when diagnostic criteria required the presence of a direct sign or at least two indirect signs.ConclusionsMRI is an effective modality for diagnosing EP with a high detection rate of extrauterine GSs. The combination of direct and indirect signs is useful for establishing the correct diagnosis.

Borderline Brenner tumor of the ovary: MRI findings.

Ovarian Brenner tumor is an uncommon epithelial tumor that accounts for 1.5% to 2.5% of all ovarian neoplasms. These tumors are usually benign. Whereas the magnetic resonance imaging features of benign Brenner tumors have been described, reports of malignant findings are limited. We report a case of borderline malignant Brenner tumor that imaged as a cystic lesion with papillary projections and solid elements.

“Sukeroku sign” and “dent internal-capsule sign”—identification guide for targeting the subthalamic nucleus for placement of deep brain stimulation electrodes

IntroductionThe purpose of this study was to assess the usefulness of signs (“Sukeroku sign” and “dent internal-capsule sign”) for the recognition of subthalamic nucleus (STN).Materials and methodsFive Parkinson’s disease cases in which there was a successful placement of deep brain stimulation (DBS) electrodes at the STN were retrospectively reviewed. Five radiologists who were not engaged in localization of STNs in clinical practice were asked to locate the STNs before and after instructions on the signs. We evaluated the deviation between the reader-located points and the location of the DBS electrode for which there had been a successful installation.ResultsAfter instruction, there was a significant reduction in the deviation between the reader-located points and the DBS electrode. The time required for localization was also reduced after the instructions.ConclusionSukeroku sign and dent internal-capsule sign are feasible indicators of STN and seem to be useful in helping to identify the STN.

Polypoid endometriosis of the ureter mimicking fibroepithelial polyps

We present a case of polypoid endometriosis of the ureter that showed bilateral polypoid intraluminal masses in the lower part of the ureter mimicking ureteral fibroepithelial polyps, arising with a background of pelvic endometriosis and a history of gonadotropin releasing hormone (GnRH) therapy. Magnetic resonance imaging revealed the masses to have high signal intensity on T2-weighted imaging. The location and bilaterality of the polypoid intraluminal masses are considered useful points in the differential diagnosis of fibroepithelial polyps.

Prominent signal intensity of T1/T2 prolongation in subcortical white matter of the anterior temporal region on conventional screening MRI of late preterm infants with normal development

PURPOSE This study discusses prominent signal intensity of T(1)/T(2) prolongation of subcortical white matter within the anterior temporal region in premature infant brains that radiologists may encounter when interpreting conventional screening MRIs. MATERIALS AND METHODS T(1)- and T(2)-weighted images of 69 preterm and term infants with no neurological abnormalities or developmental delays were evaluated retrospectively for areas of prominent signal intensity of T(1)/T(2) prolongation in white matter. We measured signal intensities of anterior temporal white matter, deep temporal white matter, frontopolar white matter and subcortical white matter of the precentral gyrus. We accessed chronological changes in signal intensity in the anterior and deep temporal white matter. We also analyzed variance tests among the signal intensity ratios to the ipsilateral thalamus of white matter areas by gestational age. RESULTS There was high frequency of prominent signal intensity of T(1)/T(2) prolongation in the temporal tip, particularly at a gestational age of 36-38 weeks. Signal intensity ratio of the anterior temporal white matter was lower on T(1)-weighted images and higher on T(2)-weighted images, and the finding became less prominent with increasing gestational age. The signal intensity ratios of anterior temporal white matter at a gestational age of 36-37 weeks and 38-39 weeks were significantly different from other regions. CONCLUSION Prominent signal intensity of T(1)/T(2) prolongation of subcortical white matter of the anterior temporal region is seen in normal premature infants, especially those at 36-39 gestational weeks. Although it is a prominent finding, radiologists should understand that these findings do not represent a pathological condition.

Factors that Differentiate between Endometriosis-associated Ovarian Cancer and Benign Ovarian Endometriosis with Mural Nodules

Purpose: Mural nodules and papillary projections can be seen in benign ovarian endometriosis (OE) and malignant transformation of OE (endometriosis-associated ovarian cancer [EAOC]), which can pose a challenging diagnostic dilemma to clinicians. We identify the preoperative imaging characteristics helpful to the differential diagnosis between benign OE with mural nodules and EAOC. Materials and Methods: This was a retrospective study of 82 patients who were diagnosed pathologically to have OE with mural nodules (n = 42) and malignant transformations of these tumors (n = 40) at the Nara Medical University Hospital from January 2008 to January 2015. All patients were assessed with contrast-enhanced MRI before surgery. Patient demographics, and clinical and pathologic features were analyzed to detect the significant differences between the two groups. Results: Histological examinations of resected OE tissue specimens revealed that a majority (78.6%) of the mural nodular lesions were retracted blood clots. We found that the patients with malignant mural nodules, when compared to those with benign nodules, were older, had larger cyst diameters and larger mural nodule sizes, and were more likely to exhibit a taller than wider lesion. They were also more likely to present with various signal intensities on T1-weighted images (T1WI), high-signal intensity on T2-weighted images (T2WI), a lower proportion of shading on T2WI, and were more likely to show an anterior location of the cyst. In the multivariate logistic regression analysis, “Height” (>1.5 cm) and “Height-Width ratio (HWR)” (>0.9) of mural nodules, maximum diameter of the cyst (>7.9 cm), and age at diagnosis (>43 years) were independent predictors to distinguish EAOC from OE with mural nodules. Conclusion: The “Height” and “HWR” of the mural nodules in the cyst may yield a novel potential diagnostic factor for differentiating EAOC from benign OE with mural nodules.

Transverse Relaxation Rate of Cyst Fluid Can Predict Malignant Transformation of Ovarian Endometriosis

Purpose: Heme and iron accumulation due to repeated hemorrhage in endometriosis may contribute to a pivotal role in carcinogenesis. We evaluate the clinical application of MR relaxometry in a series of ovarian endometriosis (OE) and endometriosis-associated ovarian cancer (EAOC). Materials and Methods: A prospective study of diagnostic accuracy was conducted among 82 patients (67 OE and 15 EAOC) to compare MR relaxometry and biochemical measurement of cyst fluid total iron concentration. Transverse relaxation rate R2 value was determined using a single-voxel, multi-echo MR sequence (HISTO) by a 3T-MR system. Phantom experiments were also performed to assess the correlation between the ex vivo R2 values and total iron concentrations. Results: Both the results of phantom experiments and in vivo human data confirmed that in vivo R2 values were highly correlated with total iron concentrations. Compared to OE, EAOC exhibit decreased in vivo R2 values and total iron levels, regardless of their age, menopausal status and cyst size. The use of in vivo R2 values retained excellent accuracy in distinguishing EAOC versus OE (sensitivity and specificity: 86% and 94%). Conclusions: We have demonstrated that MR relaxometry provides a noninvasive predictive tool to discriminate between EAOC and OE.

MRI Findings of Inverted Urothelial Papilloma of the Bladder

OBJECTIVE The objective of this study was to characterize MRI findings of inverted urothelial papilloma of the bladder. MATERIALS AND METHODS Data pertaining to 16 patients with 18 pathologically proven inverted urothelial papillomas of the bladder who had undergone MRI were retrospectively collected from seven institutions. The shape and surface characteristics of the tumors were evaluated using T2-weighted MR images. In addition, the signal intensity of inverted urothelial papillomas was visually assessed on T1-weighted, T2-weighted, and DW images and on early and delayed phase contrast-enhanced images. RESULTS The shape of the 18 inverted urothelial papillomas of the bladder was classified as polypoid with a stalk for 16 tumors (89%) and polypoid without a stalk for two tumors (11%). All stalks were surrounded by urine in the bladder. A total of 15 of the tumor surfaces (83%) were nonpapillary and three (17%) were papillary. All 12 of the inverted urothelial papillomas for which evaluable T1-weighted images were available were isointense with the bladder wall. The lesions had a slightly higher signal intensity than the bladder wall in 15 of the patients (83%) and showed isointensity with the bladder wall in three patients (17%). A total of three patients (17%) had tiny hyperintense foci noted on T2-weighted images. All 16 of the inverted urothelial papillomas examined by DWI had very high signal intensity. All 13 of the lesions for which early phase images were obtained using dynamic contrast-enhanced MRI showed strong enhancement. When compared with early phase images, delayed phase images of the same 13 lesions showed that enhancement was stronger in two lesions (15%), similar in six lesions (46%), and weaker in five lesions (38%). CONCLUSION On MRI, the typical appearance of inverted urothelial papillomas of the bladder is a polypoid shape with a nonpapillary surface and a thin short stalk surrounded by urine. Cystic foci are also occasionally seen within the tumor.

Uterine endometrial carcinoma with DNA mismatch repair deficiency: magnetic resonance imaging findings and clinical features

PurposeThe purpose of this study was to identify the magnetic resonance imaging (MRI) features of uterine endometrial carcinoma (EC) with DNA mismatch repair (MMR) deficiency.Materials and methodsThis was a retrospective study approved by our institutional review board. The study included 118 patients pathologically diagnosed as having EC in our institution from April 2014 to December 2016. Of 118 patients, 8 were excluded because of insufficient data. Immunohistochemical analysis of MMR was performed retrospectively to observe the expressions of MLH1, MSH2, MSH6, and PMS2. A tumor with MMR deficiency was detected in 17 of 110 cases (15%). Clinical background characteristics and MRI findings were reviewed. These findings were compared between MMR deficiency group and the other group as a control group. Statistical significance was determined using the Fisher’s exact test and the Mann–Whitney U test, as appropriate.ResultsThe clinical background characteristics of patients with EC with MMR deficiency were not significantly different from those of other patients. On MRI, the tumor was significantly more often located in the lower uterine site (MMR(−) vs. MMR(+): 29.4 vs. 8.9% [p = 0.0366]).ConclusionEC with MMR deficiency tends to be located lower in the uterus, though most other findings were not significantly different from those of EC without MMR deficiency.

Uterine carcinosarcoma including angiosarcoma: A short case report

To the Editor: We describe a case of uterine carcinosarcoma, mainly composed of angiosarcoma as a mesenchymal element. The patient was an 82-year-old woman who complained of vaginal bleeding. Smear cytology of the endometrium did not detect any malignant cells. Magnetic resonance imaging and computed tomography of the pelvis revealed a mass in the anterior wall of the uterus. Total transabdominal hysterectomy and salpingo-oophorectomy were carried out. Grossly, the tumor occupied the almost whole myometrium without tumorous lesion at the endometrial surface, suggesting that it was of myometrial origin. The patient died 7 months after the operation, attributed to intra-abdominal neoplastic spread and multiple lung metastases. An autopsy was not conducted. The uterine cavity of the resected uterus was filled with bloody materials. The endometrium was thin with partial erosion with hemorrhage and necrosis. The cut surfaces of the uterus showed the thickened anterior wall with hemorrhagic nodules (Fig. 1a and Fig. S2d), and the tumor measured 5 × 6 × 4.5 cm in size. The tumor did not showa polypoid growth protruding into the uterine cavity, which is a typical feature of uterine CS. Histologically, it was a biphasic tumor consisted of mesenchymal component mainly composed of angiosarcoma and epithelial component. The angiosarcoma were immunopositive for Factor VIII, CD31, CD34, and Erythroblast transformation specific related gene (ERG). Anothermesenchymal component demonstrated features of undifferentiated sarcoma (Fig. S1). On the other hand, the epithelial component showed poorly differentiated carcinoma consisted of various-sized nests of polygonal cells with atypical round nuclei and eosinophilic cytoplasm, focally showed squamous differentiation positive for cytokeratin, p63 and p40 and negative for ER, PgR, synaptophysin, and chromogranin A by immunohistochemistry (Fig. S1). The tubular structures were immunoreactive for CEA and also contained Periodic-acid-Schiff stain and Alcian blue-positive secretion, suggesting glandular differentiation. Both the epithelial and mesenchymal components were immunohistochemically negative for hCG. The results of the immunohistochemical studies are summarized in Table S1. Venous invasion of the angiosarcoma was diffusely distributed in the myometrium, and the epithelial component also revealed vascular and lymphatic invasion. Transitions from the epithelial component to angiosarcoma were seen in several foci (Fig. S2a–c). For other findings, multiple adenomyotic foci were widely distributed throughout the myometrium and inside the tumor (Fig. 1b–d), leading to a diagnosis of carcinosarcoma associated with adenomyosis, FIGO Stage IIIC. Some of them had irregular architecture with nuclear enlargement. These