MR imaging findings of massive perivillous fibrin deposition of the placenta: A case report.

Massive perivillous fibrin deposition (MPFD) of the placenta is characterized by the obliteration of the villous trophoblast with extensive deposition of fibrinoid material in the intervillous space. Here, we describe the MRI findings of a case of MPFD. The placenta demonstrates linear and geographical hypointensity on T2-weighted imaging, which is suggested to mainly reflect fibrin deposition. This finding should be noted, particularly in patients with miscarriage in their past history.

Amide proton transfer imaging in differentiation of type II and type I endometrial carcinoma: a pilot study.

PURPOSE: This study aimed at evaluating the efficacy of amide proton transfer (APT) imaging in differentiation of type II and type I uterine endometrial carcinoma. MATERIALS AND METHODS: Thirty-three patients diagnosed with uterine endometrial carcinoma, including 24 with type I and 9 with type II carcinomas, underwent APT imaging. Two readers evaluated the magnetization transfer ratio at 3.5 ppm [MTRasym (3.5 ppm)] in each type of carcinoma. The average MTRasym (APTmean) and the maximum MTRasym (APTmax) were analyzed. The receiver operating characteristic (ROC) curve analysis was performed. RESULTS: The APTmax was significantly higher in type II carcinomas than in type I carcinomas (reader1, p = 0.004; reader 2, p = 0.014; respectively). However, APTmean showed no significant difference between type I and II carcinomas. Based on the results reported by reader 1, the area under the curve (AUC) pertaining to the APTmax for distinguishing type I from type II carcinomas was 0.826, with a cut-off, sensitivity, and specificity of 9.90%, 66.7%, and 91.3%, respectively. Moreover, based on the results reported by reader 2, the AUC was 0.750, with a cut-off, sensitivity, and specificity of 9.80%, 62.5%, and 87.5%, respectively. CONCLUSION: APT imaging has the potential to determine the type of endometrial cancer.

Magnetic resonance imaging findings of endosalpingiosis: a case report.

Endosalpingiosis is characterized by the presence of glands lined by benign tubal-type epithelium outside the fallopian tube. It is usually an incidental finding and rarely occurs as a tumor-like mass lesion. Here, we describe the magnetic resonance imaging findings of endosalpingiosis that presented as a paraovarian multicystic lesion. It exhibited iso to low intensity on T1-weighted images and inhomogeneous high intensity on T2-weighted images. The septa presented relatively iso to slight high intensity on T2-weighted images and strong contrast enhancement on dynamic contrast-enhanced imaging. Endosalpingiosis should be considered as a differential diagnosis in cases of paraovarian multicystic lesions along the uterine serosa.

CT and MR imaging findings of bilateral ovarian metastasis from renal cell carcinoma: a case report.

Secondary ovarian involvement by renal cell carcinoma rarely occurs. Here, we describe the computed tomography and magnetic resonance imaging findings of bilateral ovarian metastases from renal cell carcinoma that demonstrated heterogeneous strong contrast enhancing tumors with flow voids around and within the tumors. In addition, the apparent diffusion coefficients of the malignant tumors were high. These findings were similar to those of renal cell carcinomas at primary and other metastatic sites.

MR imaging findings of unusual leiomyoma and malignant uterine myometrial tumors: what the radiologist should know.

Uterine sarcomas account for less than 1% of gynecological malignancies and 2-5% of all uterine malignancies. Such sarcomas mainly include leiomyosarcoma (LMS) and endometrial stromal sarcoma (ESS). Additionally, inflammatory myofibroblastic tumor (IMT) and endometrial carcinoma arising in adenomyosis can occur as uterine myometrial tumors. Their differentiation from leiomyoma (LM), particularly degenerated LM and the malignant tumors, is challenging, but preoperative diagnosis is very important for the patient's management. We demonstrate the useful and compulsory findings to differentiate between uterine myometrial malignant tumors and degenerated LM with an unusual appearance.

Ovarian solid tumors: MR imaging features with radiologic-pathologic correlation.

Ovarian solid tumors have variable histological types including benign and malignant tumors. In addition, non-neoplastic lesions sometimes show a tumor-like appearance. It is important to differentiate benign from malignant tumors. In general, low signal intensity (SI) on T2-weighted imaging (T2WI), low SI on diffusion-weighted imaging (DWI), and gradual increased pattern on dynamic contrast-enhanced magnetic resonance (MR) imaging are known to be suggestive of a benign tumor. Conversely, there are some cases in which these rules do not apply. We should, therefore, strive for a greater understanding of these exceptional cases. Several tumors show characteristic findings on MR imaging reflecting pathologic features, which leads to the correct diagnosis. Additionally, MR imaging provides important information other than the nature of tumors, such as secondary uterine changes. Furthermore, clinical findings and laboratory examination data also help in determining the correct diagnosis.

Bilateral Ovarian Tumors on MRI: How Should We Differentiate the Lesions?

BACKGROUND: We investigated the distinguishing pathological features of bilateral ovarian tumors using magnetic resonance (MR) imaging. METHODS: Eighty-six patients with bilateral ovarian tumors on MR imaging were evaluated. The pathological diagnosis was investigated, and the results were subjected to statistical analysis using Mann-Whitney U test, Fisher's exact test, Chi-squared test and receiver operating characteristic (ROC) curve to determine the features useful for the differentiation of distinct types of lesions. RESULTS: The diagnosis of bilateral ovarian tumors was confirmed in eighty-one patients and the majority of the lesions were further classified into serous carcinoma (n = 36), mature teratoma (n = 20) and metastasis (n = 12). We assessed the existence of factors useful for the MR imaging differentiation between metastasis and serous carcinoma or primary malignant ovarian tumors. Cancer antigen (CA) 125 serum level and maximum tumor diameter were significantly different between metastasis and serous carcinoma and similarly, between metastasis and primary malignant ovarian tumors. MR imaging morphology, ascites and peritoneal implants did not show any significant difference between the different types of lesions. CONCLUSION: Within our patient cohort, most bilateral ovarian tumor lesions were determined to be serous carcinoma, mature teratoma or metastasis. CA 125 serum level and maximum tumor diameter are useful markers for the differentiation between metastasis and serous carcinoma or primary malignant ovarian tumors.

Evaluation of Parkinson's disease by neuromelanin-sensitive magnetic resonance imaging and 123I-FP-CIT SPECT.

Background Both neuromelanin-sensitive magnetic resonance imaging (NmMRI) and 123I-FP-CIT single photon emission computed tomography (SPECT) (DaTSCAN) assist the diagnosis of Parkinson's disease (PD). However, there have been few studies investigating a correlation between them. Purpose To correlate the utility of NmMRI and DaTSCAN and to evaluate the relationship between both imaging findings and the Unified PD rating scale part III (UPDRS III) score for the diagnosis and management of PD. Material and Methods Seventeen patients with PD who underwent both NmMRI and DaTSCAN were included. We measured the volume of the neuromelanin-positive substantia nigra pars compacta (SNc volume) on NmMRI and measured the specific binding ratio (SBR) on DaTSCAN. The asymmetry index (AI) of the SNc volume and SBR were also calculated. We evaluated the relationship between the UPDRS III score and the SNc volume and SBR, respectively. Results The SNc volume showed a significant correlation with the SBR. The AIs of them also showed a significant correlation. Both the mean of the bilateral SBR and the mean of the bilateral SNc volume showed significant negative correlations with the UPDRS III score. However, the correlation between the SBR and the UPDRS III score was stronger than that between the SNc volume and the UPDRS III score. Conclusion Both NmMRI and DaTSCAN are helpful for PD diagnosis. However, we conclude that DaTSCAN is more suitable for the evaluation of the clinical motor severity and would be more useful for the management of PD patients than NmMRI.

The spectrum of imaging appearances of müllerian duct anomalies: focus on MR imaging.

Müllerian duct anomalies (MDAs) are the result of incomplete development, vertical or lateral fusion, or absorption of the müllerian ducts. The range of anomalies includes uterovaginal agenesis or hypoplasia, unicornuate uterus, uterus didelphys, bicornuate uterus, septate uterus, and arcuate uterus. Correct diagnosis and classification of these anomalies are essential because pregnancy outcomes and treatment options vary between the types of anomaly. Furthermore, early identification of MDAs helps to avoid prolonged symptomatic periods and the complications that may subsequently arise, such as infertility, endometriosis, and neoplasm. Although many of these abnormalities are initially diagnosed by ultrasound or hysterosalpingography, MR imaging is the most accurate noninvasive modality available for classification of the various anomalies because of its better anatomic assessment compared with other diagnostic modalities. Familiarity with the wide variety of MDA presentations can help in the planning of appropriate treatment.

Volume Measurement by Diffusion-Weighted Imaging in Cervical Cancer.

BACKGROUND: The aim of this paper was to evaluate the validity of tumor volume measurement using diffusion-weighted (DW) imaging in cervical cancer. METHODS: In this retrospective study, 22 patients, who underwent preoperative 3.0 T MR examinations with DW imaging were evaluated. Tumor volume measurement by oblique axial (short axis to the uterine cervix) T2-weighted imaging was performed by manually outlining the tumor on the monitor. The area of tumor in each slice was multiplied by the slice profile (slice thickness plus intersection gap), and the total tumor volume was calculated by summation of these obtained volumes. Meanwhile, one experienced radiological technologist generated three-dimensional DW images of cervical cancer using a volume-rendering algorithm at a computer workstation, and tumor volume was automatically calculated in the workstation. Analysis via the intraclass correlation coefficient (ICC) and Bland-Altman plots were used to assess the validity and reliability of these methods. RESULTS: Between tumor volumes measured by T2-weighted imaging methods and DW imaging methods, the ICC was excellent (0.962). The 95% limits of agreement of volume measurement were -52.7 and 35.7 mL (mean difference, -8.5 mL). In regards to intra-observer variability, the ICC was excellent (0.963). The 95% limits of agreement of volume measurement were -42.2 and 47.4 mL (mean difference, 2.6 mL). CONCLUSION: DW imaging can be used to measure cervical cancer volume.

The Mechanism Causing High-signal Intensity on Diffusion-weighted Imaging in Adnexal Torsion: Two Case Reports.

We report two cases with adnexal torsion to assess the mechanism of very strong signal intensity in ovarian lesions on DW imaging using MR imaging such as T2*-weighted imaging. MR imaging findings of the cases suggest that the very strong signal intensity on DW imaging is contributed to cytotoxic edema with or without vasogenic edema, as well as oxyhemoglobin or extracellular methemoglobin.

Evaluation of Fetal Thyroid with 3D Gradient Echo T1-weighted MR Imaging.

PURPOSE: The characteristics of fetal thyroid on magnetic resonance (MR) imaging, including normal thyroid and disorders other than goiter have not been fully evaluated. Our aim was to assess fetal thyroid using three dimensional (3D) gradient echo (GRE) T1-weighted MR imaging and to examine the usefulness of this modality. MATERIALS AND METHODS: The study included 27 3D GRE T1-weighted images from 26 fetuses. The largest possible region of interest (ROI) within the thyroid at the slice level depicting the thyroid was manually defined and three circular ROIs on neck muscle were manually defined on the image slices showing the highest signal intensity (SI) of the thyroid. Maximum and mean thyroid-to-muscle SI ratios (SIRs) were then calculated as SIR = maximum or mean thyroid SI/muscle SI. RESULTS: The thyroid could not be identified in two cases. Fetal thyroid function was normal in 17 cases, and there were 7 cases of hypothyroidism (6 transient and 1 thyroid dysgenesis). There was no linear relationship between mean and maximum SIR and gestational age. The mean and maximum SIR in the cases of normal fetal thyroid were 1.85 ± 0.20 and 2.61 ± 0.39, and the mean and maximum SIR in fetal hypothyroidism were 1.58 ± 0.20 and 2.13 ± 0.37. Mean (P = 0.0088) and maximum (P = 0.0221) SIR values were significantly different between euthyroid and hypothyroid fetuses. CONCLUSION: Thyroid SIR measurement provided useful information regarding fetal thyroid function.

Apparent diffusion coefficient (ADC) measurement in ovarian tumor: Effect of region-of-interest methods on ADC values and diagnostic ability.

PURPOSE: To investigate the difference in apparent diffusion coefficient (ADC) measurements of differently shaped regions of interest (ROIs) in ovarian tumors, and to investigate the diagnostic ability of differently shaped ROIs in differentiating benign from malignant ovarian tumors. MATERIALS AND METHODS: Fifty-four patients with ovarian tumors with a solid component were evaluated. The patients underwent magnetic resonance (MR) examinations including diffusion-weighted imaging using a 3.0T MR system. Two readers measured ADCs using four ROI methods: freehand, square, round, and five small round ROIs. The interclass correlation coefficient (ICC) and repeated-measures analysis of variance were used to assess their measurement reliability and to compare ADCs for each ROI method. Receiver operating characteristic curve analysis and unpaired t-test on each ROI were used to differentiate benign and malignant ovarian tumors and assess the diagnostic ability. RESULTS: All ROI methods except the square ROI (0.56) showed good or excellent correlations (0.70-0.91). Minimum and mean ADC values differed significantly between the ROIs (P < 0.05). When using the freehand ROI, the minimum and mean ADC values were the lowest and highest, respectively. The optimal cutoff minimum and mean ADC values of each ROI for differentiating benign and malignant tumors were 0.81-1.06 × 10(-3) mm(2) /s and 1.15-1.52 × 10(-3) mm(2) /s, respectively. The areas under the curve showed no significant differences among the ADCs in the different ROI methods (P > 0.05). Minimum and mean ADCs from all ROIs showed significant differences between benign and malignant tumors (P < 0.05). CONCLUSION: The ROI shape influences ADC values and the optimal cutoff ADC values for differentiating benign from malignant ovarian tumors.