BACKGROUND AND PURPOSE:Bell palsy (BP) is the most common cause of facial nerve (FN) palsy. This study aimed to investigate the diagnostic ability of the 3D double-echo steady-state with water excitation (3D-DESS-WE) sequence to visualize pathologic changes in the FN of patients with BP. MATERIALS AND METHODS:We retrospectively analyzed 30 patients with BP who underwent 3T MRI including 3D-DESS-WE within 30 days of onset and 60 sex- and age (SD, 2) matched controls. Qualitative evaluation of FN signal intensity (SIFN) and thickness (THFN) was performed using a 3-point scale. Quantitative metrics included SIFN and THFN measurements and affected-to-unaffected signal intensity and thickness ratios (SRA/U and TRA/U) in the BP group, and right-to-left ratios in controls. Interobserver agreement, group comparisons, correlations with clinical severity (Yanagihara score), and diagnostic performance were assessed. In a subset of 17 matched pairs, the diagnostic performance of contrast-enhanced (CE) T1WI was assessed, and its agreement with 3D-DESS-WE-based qualitative assessment was evaluated. RESULTS:Qualitative scores for SIFN and THFN were significantly higher in the BP group than in controls (P < .001), with high interobserver agreement (κ = 0.810, 0.788, respectively). When dichotomized (score 0 versus 1-2), qualitative assessments showed good diagnostic performance with a sensitivity and specificity of 0.87 and 0.82 for SIFN, and 0.90 and 0.80 for THFN, respectively. Neither qualitative score correlated significantly with clinical severity. Agreement between 3D-DESS-WE-based and CE T1WI-based qualitative assessments was substantial to almost perfect (κ = 0.766-0.882). In quantitative analysis, both SIFN and THFN were significantly higher on the affected side in the BP group (P < .001), whereas no significant lateral differences were observed in controls. Although SIFN, THFN, and SRA/U did not correlate significantly with clinical severity, TRA/U was significantly inversely correlated with the Yanagihara score (r = -0.413, P = .02), which corresponds to a positive correlation with clinical severity. The Yanagihara score was the only independent predictor of TRA/U in multiple regression analysis (β = -0.425, P = .04). Receiver operating characteristic analysis showed high diagnostic performance: area under the curve = 0.908 for SRA/U and 0.927 for TRA/U. CONCLUSIONS:3D-DESS-WE may be a valuable tool for the routine clinical assessment of BP.

Abstract We report a case of refractory chylous ascites following nephroureterectomy and para-aortic lymphadenectomy for renal pelvic carcinoma, which was successfully treated with percutaneous lymphatic embolization. An 83-year-old man underwent nephroureterectomy with para-aortic lymph node dissection for renal pelvic carcinoma. Postoperatively, > 1000 mL/day of chylous ascites was continuously drained. Despite conservative management, high-output ascites persisted. Transnodal lymphangiography via the inguinal lymph nodes and post-lymphangiographic computed tomography (CT) revealed lymphatic leakage at the nephroureterectomy site. Percutaneous lymphatic embolization was planned as a minimally invasive procedure. Under CT guidance, embolization of a lymphopseudoaneurysm and para-aortic lymph nodes near the leakage site was successfully performed using N-butyl cyanoacrylate. Ascitic fluid output decreased significantly postoperatively, and the drainage tube was removed the following day. This case highlights the importance of post-lymphangiographic CT in identifying actionable lymphatic targets and demonstrates that an anatomically tailored dual-target embolization strategy can achieve effective sealing when central duct access is not feasible.

Pancreatic arteriovenous malformation (PAVM) is a rare vascular anomaly of the gastrointestinal tract, and the coexistence of a pseudoaneurysm is exceptionally uncommon. This report details a case of pseudoaneurysm associated with a massive PAVM that was successfully managed with endovascular therapy. A 67-year-old female patient with a massive PAVM presented with acute back pain. Contrast-enhanced computed tomography revealed a pseudoaneurysm in the pancreatic head accompanied by a surrounding haematoma. Transcatheter arterial embolisation (TAE) was selected as the minimally invasive treatment and the pseudoaneurysm was visualised on angiography. However, identifying the culprit artery was challenging due to the extensive vascular network of the PAVM. Following modification of the local haemodynamics using coil embolisation, the culprit artery became detectable, allowing successful embolisation of the pseudoaneurysm using N-butyl cyanoacrylate (NBCA). This case report highlights the clinical utility of NBCA embolisation combined with flow modification for managing a pseudoaneurysm associated with a massive PAVM, which represents an exceptionally rare vascular anomaly.

We report a rare case of squamous cell carcinoma (SCC) arising from a subcutaneous epidermoid cyst in the buttock of an 80-year-old man who presented with a painful mass. MRI revealed a well-defined subcutaneous mass, measuring approximately 10 cm, in the medial aspect of the left buttock, which exhibited internal features typical of an epidermoid cyst. However, MRI also demonstrated a significant finding: a 45-mm solid mural component protruding into the cyst. This solid component exhibited mild high signal intensity on T2-weighted images and heterogeneous signal intensity on DWI, differing from the cystic portion. Color Doppler ultrasound demonstrated internal blood flow within this solid component. Crucially, this solid component was absent on a CT scan performed 2 years prior. Resection and subsequent pathological examination confirmed well-differentiated squamous cell carcinoma (SCC) arising from the epidermoid cyst. This case highlights the importance of considering malignant transformation in epidermoid cysts, especially when imaging findings such as interval development of a solid mural component and internal vascularity are observed.

In the daily clinical practice of radiologists, unexpected lymphadenopathy is frequently encountered, the majority of which is nonneoplastic. The causes of nonneoplastic lymphadenopathy are variable, and nonspecific histologic findings may challenge the accurate diagnosis. Therefore, inferring or identifying the cause based on imaging findings carries substantial clinical relevance. The causes of nonneoplastic lymphadenopathy can be broadly categorized as follows: (a) infections that lead to lymphadenitis; (b) systemic disorders such as sarcoidosis, Kawasaki disease, rheumatoid arthritis, systemic lupus erythematosus, immunoglobulin G4-related disease, Castleman disease, dermatopathic lymphadenopathy, and histiocytosis; (c) iatrogenic causes including drug-induced lymphadenopathy and COVID-19 vaccine-related lymphadenopathy; and (d) miscellaneous causes including congestion from heart failure, foreign body lymphadenopathy from substances such as silicone, epithelial inclusions in lymph nodes, and tumor-associated reactive lymphadenopathy. The distribution of lymphadenopathy, imaging characteristics of the enlarged lymph nodes themselves (eg, necrosis, cystic changes, hypervascularity, or calcification), and additional imaging findings in other organs can help narrow down the differential diagnosis and potentially identify the most likely cause. Even when the underlying cause of lymphadenopathy does not require treatment, establishing the likely cause and correctly excluding malignancy can prevent unnecessary tests and excessive interventions, such as biopsies. Thus, radiologists can play a crucial role in directing the management of such patients and must be familiar with the various conditions that result in nonneoplastic lymphadenopathy, their imaging findings, and their clinical manifestations. The authors provide an overview of these conditions and their imaging appearances and discuss approaches for identifying the cause of nonneoplastic lymphadenopathy based on imaging findings as well as clinical information. ©RSNA, 2025 Supplemental material is available for this article.

Acetabular fractures are usually caused by high-energy trauma, and seizure-induced cases resulting from strong muscle contractions are extremely rare. We report the case of a 90-year-old man with osteoporosis who incurred a nontraumatic acetabular fracture during a seizure. Computed tomography revealed an internal iliac artery injury, which was promptly treated with transcatheter arterial embolization. As such vascular injuries, though rare, require early diagnosis and treatment, radiologists must be aware of the associated imaging findings and management, particularly in cognitively impaired patients.

Adrenal diseases pose significant diagnostic challenges due to the wide range of neoplastic and non-neoplastic pathologies. Radiologists have a crucial role in diagnosing and managing these conditions by, leveraging advanced imaging techniques. This review discusses the vital role of computed tomography (CT), magnetic resonance imaging (MRI), and nuclear medicine in adrenal imaging, and focuses on morphological and functional evaluations. First, the anatomy and physiology of the adrenal glands are described, followed by a discussion on ectopic adrenocortical adenomas and how they develop. The concepts and imaging findings of congenital diseases, such as congenital adrenal hyperplasia (CAH), adrenal rest tumors, and adrenocortical nodular disease, considering recent updates to the WHO Classification of Tumours (5th ed.) terminology are highlighted. The diagnostic value of dynamic contrast-enhanced CT and chemical-shift MRI for identifying adrenocortical adenomas are emphasized, alongside the use of adrenocortical scintigraphy such as 131I-adosterol scintigraphy for diagnosing Cushing’s disease, Cushing’s syndrome (CS), subclinical CS, and ectopic adrenocorticotropic hormone-producing tumors. Systemic complications associated with CS, and the diagnosis and treatment of pheochromocytomas, paragangliomas (PPGLs), and neuroblastomas, will also be discussed focusing on 123I-metaiodobenzylguanidine (MIBG) imaging and 131I-MIBG therapy. Pitfalls in 123I-MIBG imaging and the increasing importance of diagnosing hereditary PPGLs due to increased genetic testing are also be discussed. Additionally, the broad differential diagnosis for adrenal masses—including malignancies like adrenal carcinoma, metastases, and malignant lymphoma, as well as benign conditions like myelolipoma and ganglioneuroma, and complications, such as adrenal hemorrhage, infarction, and infections—will be outlined. The goal of this review was to provide an overview of adrenal diseases that includes the most recent information for radiologists to stay updated on the latest imaging techniques and advancements that can ensure accurate diagnosis and effective management.

Syphilis, a bacterial infection caused by Treponema pallidum, is resurging globally. It is classified as acquired or congenital syphilis. Acquired syphilis progresses through primary, secondary, and tertiary stages. Pathologically, acquired syphilis is characterized by vasculopathy, perivascular infiltrates in syphilitic lesions, and reactive lymphadenopathy. Primary and secondary syphilis frequently manifest with cutaneous and mucosal lesions accompanied by extensive lymphadenopathy at the initial sites of sexual contact, such as the genitalia, oropharynx, and anorectum. These manifestations may mimic malignancies. Tertiary syphilis encompasses cardiovascular syphilis, late neurosyphilis, and gummas, each manifesting distinct imaging characteristics. Most acquired cases are suspected on the basis of dermatologic signs and patient history and are confirmed serologically. Imaging findings alone may not be diagnostic and can overlap with those of other infectious, inflammatory, or neoplastic conditions, necessitating clinical correlation and laboratory testing. However, in patients with atypical clinical presentations, imaging has an important role in providing valuable diagnostic clues and guiding appropriate clinical treatment. The incidence of congenital syphilis is also increasing in parallel with the overall increase in syphilis infections. A comprehensive understanding of the diverse imaging manifestations in multiple organ systems is vital for radiologists to accurately diagnose and guide appropriate management in the era of resurgent syphilis. The authors provide an overview of acquired and congenital syphilis, detailing the epidemiologic and pathophysiologic characteristics, diagnostic approaches, clinical courses, and imaging features. ©RSNA, 2025 Supplemental material is available for this article.

PURPOSE:To examine magnetic resonance imaging (MRI) features of mesonephric-like adenocarcinoma (MLA) of the uterine corpus. METHOD:MRI features of 19 patients with pathologically proven MLA of the uterine corpus were retrospectively compared with those of 95 patients with endometrial endometrioid carcinoma (EEC). RESULTS:Most patients with MLA were postmenopausal. Advanced FIGO stages were more common in the MLA than in the EEC group (63.2 % vs. 18.9 %, p < 0.001). On MRI, endophytic growth into the myometrium were more frequent in the MLA than in the EEC group (68.4 % vs. 14.7 %, p = 0.005). The median maximum tumor diameter in the MLA group (52.4 mm) tended to be larger than that in the EEC group (38.9 mm), although the difference was not statistically significant (p = 0.374). The tumor-to-muscle signal intensity ratio (SIR) on fat-suppressed gadolinium-enhanced T1-weighted gradient-echo imaging was higher in the MLA group than in the EEC group. (1.67 vs. 1.36, p = 0.002). The SIR on diffusion-weighted imaging (DWI) was comparable between the two groups (8.35 vs. 6.72, p = 0.330). The apparent diffusion coefficient value was lower in the MLA than in the EEC group (0.69 10-3 mm2/s vs. 0.76 × 10-3 mm2/s, p = 0.003). Coexisting adenomyosis was more frequent in the MLA than in the EEC group (52.6 % vs. 21.1 %, p = 0.034). The concordance rate between MRI and pathology for adenomyosis coexistence was 84.2 % for MLA, 87.4 % for EEC, and 86.8 % overall. MLA of the uterine corpus was identified in two patients, characterized by development independent of and discontinuous from the endometrium, whereas EEC in all patients demonstrated continuity with the endometrium. CONCLUSIONS:MRI of MLA of the uterine corpus typically demonstrates large, diffuse, and endophytic growth into the myometrium, with strong contrast enhancement and more restricted diffusion compared to EEC, with coexisting adenomyosis present in over 50% of patients. Therefore, postmenopausal women with adenomyosis should be carefully evaluated for MLA on MRI, particularly using DWI.

We report a case of a man in his 60s with ROS1 fusion-positive lung adenocarcinoma who developed multiple cystic lesions in both the kidneys and liver during crizotinib treatment. The patient presented with fever, abdominal pain, and oliguria. Contrast-enhanced CT revealed new cystic lesions in both the kidneys and liver, with some showing thick walls, septa, and hyperdense contents. MRI demonstrated heterogeneous signal intensities on T2-weighted images and mixed low to high signal intensities on T1-weighted images. Some cysts displayed T2 hypointense and T1 hyperintense areas along the cyst walls, with diffusion restriction predominantly at the periphery of the masses. Percutaneous drainage of the cysts was performed, and cytology revealed an increase in the number of cells, including neutrophils. However, no malignant cells or microorganisms were detected. Based on these imaging findings and laboratory results, the patient was diagnosed with crizotinib-associated renal and hepatic cysts. Symptoms improved after crizotinib discontinuation, and follow-up imaging showed cyst regression. This is the first report describing MRI findings for crizotinib-associated hepatic cysts. Characteristic MRI findings, such as T2 hypointensity/T1 hyperintensity along the cyst walls and diffusion restriction predominantly at the periphery of the masses, suggesting hemorrhagic components, may help differentiate crizotinib-associated cysts from other lesions, including metastases and abscesses.

To clarify the diagnostic utility and formation of the Mille-feuille sign for ovarian carcinosarcoma (OCS) on MRI, and to evaluate the other MRI findings and serum markers compared to ovarian metastases from colorectal carcinoma (OMCRC). Three blinded radiologists retrospectively reviewed MR images of 12 patients with OCS, 18 with OMCRC, and 40 with primary ovarian carcinoma (POC) identified by the electronic database of radiology reports. The interobserver agreement was analyzed using Fleiss’ kappa test. Their MRI characteristics and tumor markers were compared using Fisher’s exact test and Mann–Whitney’s U test. Receiver operating characteristic curve analyses were used to determine the cutoff points for the ADC value. This study was approved by the institutional ethics committee. Interobserver agreement analysis was moderate or higher for all MRI characteristics. The frequency of Mille-feuille sign was comparable for both OCS and OMCRC groups, and predominantly higher than that of the POC group (p < 0.001, p < 0.001), respectively. Pathologically, the Mille-feuille sign in OCS reflected alternating layers of tumor cells with stroma and necrosis or intraluminal necrotic debris. Compared to OMCRC, intratumoral hemorrhage (p = 0.02), margin irregularity (p = 0.048), unilateral adnexal mass (p = 0.02), and low ADC values (p < 0.01) were more frequently observed and serum CEA levels was significantly lower (p = 0.007) in the OCS group. Under setting of the cutoff value of ADC at 0.871 × 10−3mm2/s, the discriminative ability for OCS showed 66.7

Torsion is the twisting of an object along the axis, and various structures (organs and tumors) in the body can twist. Torsion causes initial lymphatic and venous outflow obstruction, leading to congestive edema, enlargement, venous hemorrhagic infarction, and surrounding edema. It can also cause subsequent arterial obstruction depending on the degree of torsion, leading to ischemia, infarction, necrosis, gangrene, and surrounding inflammation. Therefore, in several cases of torsion, immediate surgical intervention is required to improve blood flow and prevent serious complications. Clinical manifestations of torsion are often nonspecific and can affect individuals of varying ages and sex. Imaging plays an important role in the early diagnosis and management of torsion. Multiple imaging modalities, including US, radiography, CT, and MRI, are used to evaluate torsion, and each modality has its specific characteristics. The imaging findings reflect the pathophysiologic mechanism: a twisted pedicle (whirlpool sign), enlargement of the torsed structures, reduced blood flow, internal heterogeneity, and surrounding reactive changes. The whirlpool sign is a definitive characteristic of torsion . In some cases, despite poor internal enhancement, capsular enhancement is observed on contrast-enhanced CT and MR images and is considered to be associated with preserved capsular arterial flow or capsular neovascularization due to inflammation. Radiologists should be familiar with the pathophysiologic mechanisms, clinical characteristics, and imaging characteristics of torsion in various structures in the body. Since other articles about common organ torsions already exist, the authors of this article focus on the uncommon entities that manifest with torsion. (c) RSNA, 2024 center dot radiographics.rsna.org

Mucosa-associated lymphoid tissue (MALT) lymphoma commonly arises from chronic inflammation or autoimmune diseases, such as Sjögren syndrome (SjS). Although rare, amyloid deposition in MALT lymphoma has been reported. We present a rare case of parotid gland MALT lymphoma in a 49-year-old woman, in whom preoperative diagnosis was challenging due to atypical imaging findings resulting from amyloid deposits. MRI showed T2-hypointense and T1-iso- to slightly hyperintense masses in the left parotid gland and right sublingual gland, with predominant marginal contrast enhancement and no significant diffusion restriction. Additionally, atrophy and fatty replacement of the parenchyma were noted in bilateral parotid glands, suggesting SjS. Left superficial parotidectomy was performed and pathological findings confirmed MALT lymphoma with extensive amyloid deposition. Histopathological findings of the resected parotid gland parenchyma also suggested SjS. MALT lymphoma should be considered in the differential diagnosis of multiple salivary gland masses in patients with suspected SjS. If MRI reveals atypical imaging findings for malignant lymphoma, particularly T2-hypointensity with no significant diffusion restriction, the possibility of amyloid deposition in MALT lymphoma should be considered.

Struma ovarii is a monodermal teratoma characterized by the presence of >50% thyroid tissue. It is mostly benign; therefore, preoperative diagnosis is important. It usually manifests as a multilocular cystic mass but rarely as a predominantly solid mass. On magnetic resonance imaging (MRI), solid-appearing struma ovarii showed early signal intensity enhancement on dynamic gadolinium-enhanced T1-weighted images, which histopathologically indicates the presence of thyroid tissue with abundant blood vessels. The Ovarian-Adnexal Reporting and Data System (O-RADS) MRI score is a validated classification worldwide for characterizing adnexal lesions. Based on the morphology, signal intensity, and enhancement of any solid tissue on the MRI, the scoring system can be used to classify adnexal lesions into five categories from score one (no adnexal mass) to score five (high risk of malignancy). An adnexal solid mass with a higher signal intensity than that of the myometrium 30-40 seconds after gadolinium (Gd) injection on non-dynamic contrast-enhanced (non-DCE) MRI was assigned a score of 5 (high risk of malignancy). We present a case of solid-appearing struma ovarii with a higher signal intensity than that of the myometrium 30 seconds after Gd injection on non-DCE MRI, and it was classified as score five preoperatively. Therefore, a total abdominal hysterectomy with bilateral salpingo-oophorectomy was performed despite the presence of a benign ovarian mass. When an adnexal mass with a higher signal intensity than that of the myometrium 30-40 seconds after Gd injection on non-DCE MRI is encountered, struma ovarii should be included in the differential diagnosis, despite the O-RADS MRI score of five and management of the situation should be discussed.

Menkes disease is an X-linked disorder of copper metabolism caused by mutations in the ATP7A gene, and female carriers are usually asymptomatic. We describe a 7-month-old female patient with severe intellectual disability, epilepsy, and low levels of serum copper and ceruloplasmin. While heterozygous deletion of exons 16 and 17 of the ATP7A gene was detected in the proband, her mother, and her grandmother, only the proband suffered from Menkes disease clinically. Intriguingly, X chromosome inactivation (XCI) analysis demonstrated that the grandmother and the mother showed skewing of XCI toward the allele with the ATP7A deletion and that the proband had extremely skewed XCI toward the normal allele, resulting in exclusive expression of the pathogenic ATP7A mRNA transcripts. Expression bias analysis and recombination mapping of the X chromosome by the combination of whole genome and RNA sequencing demonstrated that meiotic recombination occurred at Xp21-p22 and Xq26-q28. Assuming that a genetic factor on the X chromosome enhanced or suppressed XCI of its allele, the factor must be on either of the two distal regions derived from her grandfather. Although we were unable to fully uncover the molecular mechanism, we concluded that unfavorable switching of skewed XCI caused Menkes disease in the proband.

Hemochromatosis is a primary or secondary pathological condition characterized by the deposition of excess iron in the body tissues, which can eventually lead to cellular damage and organ dysfunction. Although excess iron deposition in the central nervous system is rare, involvement of the choroid plexus, pituitary gland, cortical surfaces, and basal ganglia has been reported to date. This case report describes 2 cases of transfusion-induced hemochromatosis involving the choroid plexus and pituitary gland, which were diagnosed by magnetic resonance imaging (MRI). In both cases, gradient echo (GRE) sequences, such as T2 star-weighted image and susceptibility-weighted imaging demonstrated markedly low signal intensity in the choroid plexus. Furthermore, the pituitary gland showed low signal intensity on T2-weighted images in Patient 2. Because these low signal intensities were not seen prior to red blood cell transfusion, they were diagnosed with transfusion-induced hemochromatosis. Brain MRI with GRE sequences was useful in detecting iron deposition in the choroid plexus. Considering that iron deposition in the body tissues can lead to irreversible organ damage, MRI with GRE sequences should be considered for patients with suspected iron overload.

Background: Infection by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can lead not only to respiratory symptoms but also to neurologic symptoms with various levels of severity. After the worldwide prevalence of Omicron variant, severe neurological manifestations of coronavirus disease 2019 (COVID-19) such as febrile seizure, demyelinating disease, and cerebrovascular disease, have been reported. However, reports of acute encephalopathy in patients with COVID-19 are quite limited. Especially in terms of cytokine storminducing hemorrhagic shock and encephalopathy syndrome (HSES), there is no case reported related to COVID-19.Case presentation: We describe the case of an 8-year-old girl who presented with fatal HSES associated with pediatric SARS-CoV-2 infection. Status epilepticus occurs after the onset of fever and diarrhea and lasted for at least an hour. Unconsciousness was followed by circulatory failure and ultimately leading to death within 2 days after the fever onset. Analysis of forty-eight cytokines and chemokines measured in three consecutive serum samples revealed that interferon (IFN)-c, interleukin (IL)-6, IL-10, IL -17A, tumor necrosis factor (TNF)-a, IL-8, Interferon gamma inducible protein (IP)-10, and Monocyte chemoattractant protein (MCP)-1, were increased within an hour after the onset of impaired consciousness. Conclusion: Here, we describe a case of fatal fulminant encephalopathy with rapid progression because of HSES associated with COVID-19. High levels of cytokines and chemokines observed in this case may be because of the SARS-CoV-2-associated cytokine storm. This study is the first COVID-19-associated case of HSES.(c) 2023 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

Complete androgen insensitivity syndrome (CAIS) and Mayer-Rokitansky-Küster-Hauser syndrome (MRKHS) share common clinical features such as female phenotype, vaginal hypoplasia, and primary amenorrhea. Magnetic resonance imaging (MRI) is performed to investigate the cause of primary amenorrhea. However, the MRI features are also similar in both disorders. They are ultimately diagnosed by chromosome testing, but there is a possibility of misdiagnosis if chromosome testing is not performed. This study aimed to identify MRI features that are useful for differentiating CAIS from MRKHS. This multicenter retrospective study included 12 patients with CAIS and 19 patients with MRKHS. Three radiologists blindly evaluated the following features: (1) detection of vagina, (2) detection of nodular and cystic structures in the lateral pelvis; undescended testicles and paratesticular cysts in CAIS and rudimentary uteri and ovaries in MRKHS, (3) their location, (4) number of cysts in the cystic structures, and (5) signal intensity on diffusion-weighted images (DWI) and apparent diffusion coefficient (ADC) values of the nodular structures. Statistical comparisons were performed using Mann–Whitney U and Fisher’s exact tests. Compared with MRKHS, the CAIS group showed significantly detectable vagina, more ventrally located nodular and cystic structures, fewer cysts within the cystic structures, and nodular structures with higher signal intensity on DWI and lower ADC values. MRI features of detectable vagina, location of nodular and cystic structures, number of cysts within the cystic structures, signal intensity on DWI and ADC values of the nodular structures were useful in differentiating CAIS from MRKHS.

This study aimed to clarify associations between subacute hematoma on placental magnetic resonance imaging (MRI), antenatal bleeding, and preterm deliveries in patients with placenta previa (PP) without placenta accreta spectrum (PAS). This retrospective study investigated 78 consecutive patients with PP (median age, 34.5 years; interquartile range [IQR], 31–37 years) who underwent placental MRI in the third trimester. Patients with PAS detected intraoperatively or pathologically were excluded. Two radiologists evaluated the presence of subacute hematomas and their locations on placental MRI. We examined associations between presence of subacute hematoma and antenatal bleeding, emergency cesarean section (CS), hysterectomy, gestational age (GA) at delivery, birth weight, and amount of blood loss at CS. We also examined the association between perinatal outcome and subacute hematoma location: marginal, retro-placental, or intra-placental. Inter-observer agreement for the detection of subacute hematoma was calculated using kappa analysis. Subacute hematomas were identified on MRI in 39 of the 78 patients (50.0