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.

MR imaging findings of primary ovarian carcinoid: A novel finding of T1 hyperintense solid tissue.

Ovarian carcinoid is a rare well-differentiated neuroendocrine tumor resembling those arising in the gastrointestinal tract. We present a case of ovarian carcinoid with magnetic resonance imaging (MRI) findings. A 50-year-old woman with genital bleeding and severe constipation was referred to our hospital. On MR imaging, a left ovarian tumor showed iso to high signal intensity on T1-weighted images (T1WI), relatively low signal intensity on T2WI, and slightly high signal intensity on diffusion-weighted images. Additionally, the tumor demonstrated early and delayed strong contrast enhancement on dynamic contrast-enhanced images. The tumor was pathologically diagnosed with ovarian strumal carcinoid. High signal intensity on T1WI should be recognized as the MRI findings in ovarian carcinoids.

Image Quality and Lesion Detection of Multiplanar Reconstruction Images Using Deep Learning: Comparison with Hybrid Iterative Reconstruction.

Background: We assessed and compared the image quality of normal and pathologic structures as well as the image noise in chest computed tomography images using "adaptive statistical iterative reconstruction-V" (ASiR-V) or deep learning reconstruction "TrueFidelity". Methods: Forty consecutive patients with suspected lung disease were evaluated. The 1.25-mm axial images and 2.0-mm coronal multiplanar images were reconstructed under the following three conditions: (i) ASiR-V, lung kernel with 60% of ASiR-V; (ii) TF-M, standard kernel, image filter (Lung) with TrueFidelity at medium strength; and (iii) TF-H, standard kernel, image filter (Lung) with TrueFidelity at high strength. Two radiologists (readers) independently evaluated the image quality of anatomic structures using a scale ranging from 1 (best) to 5 (worst). In addition, readers ranked their image preference. Objective image noise was measured using a circular region of interest in the lung parenchyma. Subjective image quality scores, total scores for normal and abnormal structures, and lesion detection were compared using Wilcoxon's signed-rank test. Objective image quality was compared using Student's paired t-test and Wilcoxon's signed-rank test. The Bonferroni correction was applied to the P value, and significance was assumed only for values of P < 0.016. Results: Both readers rated TF-M and TF-H images significantly better than ASiR-V images in terms of visualization of the centrilobular region in axial images. The preference score of TF-M and TF-H images for reader 1 were better than that of ASiR-V images, and the preference score of TF-H images for reader 2 were significantly better than that of ASiR-V and TF-M images. TF-M images showed significantly lower objective image noise than ASiR-V or TF-H images. Conclusion: TrueFidelity showed better image quality, especially in the centrilobular region, than ASiR-V in subjective and objective evaluations. In addition, the image texture preference for TrueFidelity was better than that for ASiR-V.

Clinical Utility of Diffusion-Weighted Imaging in Gynecological Imaging: Revisited.

ABSTRACT: Diffusion-weighted imaging (DWI) is an increasingly valuable sequence in daily clinical practice, providing both functional and morphological information. The use of DWI can help quantify diffusion using the apparent diffusion coefficient, which reflects the physiological features of the tissue and tumor microcirculation. This knowledge is crucial for understanding and interpreting gynecological imaging. This article reviews the clinical utility of DWI for gynecological imaging, highlighting its ability to aid in the detection of endometrial and cervical cancers, as well as tumor extension and metastasis. In addition, DWI can easily detect the solid components of ovarian cancer (including dissemination), assist in the diagnosis of adnexal torsion, and potentially show bone marrow status. Apparent diffusion coefficient measurement is useful for differentiating between endometrial lesions, uterine leiomyomas, and sarcomas, and may provide important information for predicting the prognosis of gynecological cancers.

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.