Comparison of preoperative diagnostic performance between dual-energy CT, conventional CT, and MRI in endometrial cancer.

Purpose: To compare the diagnostic performance of virtual monoenergetic imaging (VMI), computed tomography (CT), and magnetic resonance imaging (MRI) in patients with endometrial cancer (EC). Material and methods: This retrospective study analysed 45 EC patients (mean age: 62 years, range: 44-84 years) undergoing contrast-enhanced CT with dual-energy CT (DECT) and MRI between September 2021 and October 2022. Dual-energy CT generated conventional CT (C-CT) and 40 keV VMI. Quantitative analysis compared contrast-to-noise ratio (CNR) of tumour to myometrium between C-CT and VMI. Qualitative assessment by 5 radiologists compared C-CT, VMI, and MRI for myometrial invasion (MI), cervical invasion, and lymph node metastasis. Sensitivity, specificity, accuracy, and area under the receiver operating characteristic curve (AUC) were calculated and compared for each diagnostic parameter. Results: Virtual monoenergetic imaging showed significantly higher CNR than C-CT (p < 0.001) and a higher sensitivity for MI than C-CT (p = 0.027) and MRI (p = 0.011) but lower specificity than MRI (p = 0.018). C-CT had a higher sensitivity and AUC for cervical invasion than MRI (p = 0.018 and 0.004, respectively). Conclusions: The study found no significant superiority of MRI over CT across all diagnostic parameters. VMI demonstrated heightened sensitivity for MI, and C-CT showed greater sensitivity and AUC for cervical invasion than MRI. This suggests that combining VMI with C-CT holds promise as a comprehensive preoperative staging tool for EC when MRI cannot be performed.

Triple modal treatment comprising with proton beam radiation, hyperthermia, and gemcitabine/nab-paclitaxel for locally advanced pancreatic cancer: a phase I/II study protocol (TT-LAP trial).

BACKGROUND: Locally advanced pancreatic ductal adenocarcinoma (PDAC), accounting for about 30% of PDAC patients, is difficult to cure by radical resection or systemic chemotherapy alone. A multidisciplinary strategy is required and our TT-LAP trial aims to evaluate whether triple-modal treatment with proton beam therapy (PBT), hyperthermia, and gemcitabine plus nab-paclitaxel is a safe and synergistically effective treatment for patients with locally advanced PDAC. METHODS: This trial is an interventional, open-label, non-randomized, single-center, single-arm phase I/II clinical trial organized and sponsored by the University of Tsukuba. Eligible patients who are diagnosed with locally advanced pancreatic cancer, including both borderline resectable (BR) and unresectable locally advanced (UR-LA) patients, and selected according to the inclusion and exclusion criteria will receive triple-modal treatment consisting of chemotherapy, hyperthermia, and proton beam radiation. Treatment induction will include 2 cycles of chemotherapy (gemcitabine plus nab-paclitaxel), proton beam therapy, and 6 total sessions of hyperthermia therapy. The initial 5 patients will move to phase II after adverse events are verified by a monitoring committee and safety is ensured. The primary endpoint is 2-year survival rate while secondary endpoints include adverse event rate, treatment completion rate, response rate, progression-free survival, overall survival, resection rate, pathologic response rate, and R0 (no pathologic cancer remnants) rate. The target sample size is set at 30 cases. DISCUSSION: The TT-LAP trial is the first to evaluate the safety and effectiveness (phases1/2) of triple-modal treatment comprised of proton beam therapy, hyperthermia, and gemcitabine/nab-paclitaxel for locally advanced pancreatic cancer. ETHICS AND DISSEMINATION: This protocol was approved by the Tsukuba University Clinical Research Review Board (reference number TCRB22-007). Results will be analyzed after study recruitment and follow-up are completed. Results will be presented at international meetings of interest in pancreatic cancer plus gastrointestinal, hepatobiliary, and pancreatic surgeries and published in peer-reviewed journals. TRIAL REGISTRATION: Japan Registry of Clinical Trials, jRCTs031220160. Registered 24 th June 2022, https://jrct.niph.go.jp/en-latest-detail/jRCTs031220160 .

The efficacy of deep learning models in the diagnosis of endometrial cancer using MRI: a comparison with radiologists.

PURPOSE: To compare the diagnostic performance of deep learning models using convolutional neural networks (CNN) with that of radiologists in diagnosing endometrial cancer and to verify suitable imaging conditions. METHODS: This retrospective study included patients with endometrial cancer or non-cancerous lesions who underwent MRI between 2015 and 2020. In Experiment 1, single and combined image sets of several sequences from 204 patients with cancer and 184 patients with non-cancerous lesions were used to train CNNs. Subsequently, testing was performed using 97 images from 51 patients with cancer and 46 patients with non-cancerous lesions. The test image sets were independently interpreted by three blinded radiologists. Experiment 2 investigated whether the addition of different types of images for training using the single image sets improved the diagnostic performance of CNNs. RESULTS: The AUC of the CNNs pertaining to the single and combined image sets were 0.88-0.95 and 0.87-0.93, respectively, indicating non-inferior diagnostic performance than the radiologists. The AUC of the CNNs trained with the addition of other types of single images to the single image sets was 0.88-0.95. CONCLUSION: CNNs demonstrated high diagnostic performance for the diagnosis of endometrial cancer using MRI. Although there were no significant differences, adding other types of images improved the diagnostic performance for some single image sets.

Pelvic arterial embolisation with cyanoacrylate during caesarean hysterectomy for placenta accreta.

PURPOSE: To compare n-butyl cyanoacrylate (NBCA) and gelatine sponge (GS) as embolic materials for prophylactic pelvic arterial embolisation during caesarean hysterectomy for placenta accreta spectrum (PAS). MATERIAL AND METHODS: This retrospective study comprised 12 women (age range, 23-42 years; mean, 34.1 years) who underwent caesarean hysterectomy for PAS. Following caesarean delivery, bilateral uterine and non-uterine parasitic arteries were embolized with GS in the first four cases (GS group) and primarily with NBCA mixed with iodized oil in the subsequent eight cases (NBCA group). Procedure time for embolisation and hysterectomy and total blood loss were compared between the two groups using Welch's t-test. RESULTS: Although procedure time for embolisation tended to be longer in the NBCA group than in the GS group (111 ± 47 min versus 71 ± 32 min, p=.11), that for hysterectomy was significantly reduced in the NBCA group when compared to the GS group (158 ± 42 min versus 236 ± 39 min, p=.02). Total blood loss was significantly lower in the NBCA group than in the GS group (1375 ± 565 mL versus 2668 ± 587 mL, p=.01). CONCLUSION: Procedure time for hysterectomy and total blood loss during caesarean hysterectomy can be reduced by using NBCA instead of GS in prophylactic pelvic arterial embolisation for PAS.

Differentiation of carcinosarcoma from endometrial carcinoma on magnetic resonance imaging using deep learning.

Purpose: To verify whether deep learning can be used to differentiate between carcinosarcomas (CSs) and endometrial carcinomas (ECs) using several magnetic resonance imaging (MRI) sequences. Material and methods: This retrospective study included 52 patients with CS and 279 patients with EC. A deep-learning model that uses convolutional neural networks (CNN) was trained with 572 T2-weighted images (T2WI) from 42 patients, 488 apparent diffusion coefficient of water maps from 33 patients, and 539 fat-saturated contrast-enhanced T1-weighted images from 40 patients with CS, as well as 1612 images from 223 patients with EC for each sequence. These were tested with 9-10 images of 9-10 patients with CS and 56 images of 56 patients with EC for each sequence, respectively. Three experienced radiologists independently interpreted these test images. The sensitivity, specificity, accuracy, and area under the receiver operating characteristic curve (AUC) for each sequence were compared between the CNN models and the radiologists. Results: The CNN model of each sequence had sensitivity 0.89-0.93, specificity 0.44-0.70, accuracy 0.83-0.89, and AUC 0.80-0.94. It also showed an equivalent or better diagnostic performance than the 3 readers (sensitivity 0.43-0.91, specificity 0.30-0.78, accuracy 0.45-0.88, and AUC 0.49-0.92). The CNN model displayed the highest diagnostic performance on T2WI (sensitivity 0.93, specificity 0.70, accuracy 0.89, and AUC 0.94). Conclusions: Deep learning provided diagnostic performance comparable to or better than experienced radiologists when distinguishing between CS and EC on MRI.

Preoperative Diagnosis of a Torsioned Accessory Spleen.

We report a case of a 12-year-old boy with an accessory spleen torsion. He presented with left-sided abdominal pain after trauma. A 4 cm oval mass without contrast enhancement was detected on contrast-enhanced computed tomography (CT), and ultrasound (US) showed a 4 cm oval mass below the spleen. The mass mainly consisted of high echoes similar to the spleen; the central part showed irregularly low echoes. Subsequent follow-up daily US examinations showed gradual expansion of the central low echoes with conspicuous hyperechoic dots. Discontinuation of the branch from the splenic artery to the mass was observed, both, on US and CT. These findings led to the diagnosis of a hemorrhagic infarct caused by torsion of the accessory spleen. Laparoscopy showed adherence of the accessory spleen to the omentum and colon by twisting four times around its axis. It was resected and confirmed the diagnosis of a torsioned accessory spleen.

Endoleak detection after endovascular aneurysm repair using unenhanced MRI with flow suppression technique: Feasibility study in comparison with contrast-enhanced CT.

OBJECTIVES: To evaluate the feasibility of unenhanced motion-sensitized-driven equilibrium (MSDE)-prepared balanced turbo field echo (BTFE) sequences for detecting endoleaks after endovascular aneurysm repair (EVAR). METHODS: Forty-six patients treated with EVAR for aortic and/or iliac arterial aneurysms underwent contrast-enhanced CT and MSDE-prepared BTFE sequences with and without flow suppression. Two independent observers reviewed these sequences and their subtraction images and assigned confidence levels for detecting endoleaks. Relative contrast values were calculated by dividing signal intensities by those of paraspinal muscles. CT provided the reference standard. RESULTS: CT showed types I and II endoleaks in one and ten patients, respectively. Areas under receiver operating characteristic curves were 0.92 and 0.97 for observers 1 and 2, respectively. Sensitivity, specificity, accuracy, positive predictive value and negative predictive value of both observers were 91 (10/11), 91(32/35), 91 (42/46), 77 (10/13) and 97 % (32/33), respectively. Relative contrast values of endoleaks and flowing blood significantly decreased by flow suppression on MSDE-prepared BTFE images (P = 0.002 and P < 0.0001 respectively), and were significantly higher than those of the excluded aneurysms on subtraction images (P = 0.003 and P = 0.001, respectively). CONCLUSIONS: Unenhanced MSDE-prepared BTFE sequences are feasible for detecting endoleaks. KEY POINTS: • Flow suppression significantly reduces endoleak signals on MSDE-prepared BTFE images. • Subtraction images of MSDE-prepared BTFE sequences ± flow suppression demonstrate endoleaks. • MSDE-prepared BTFE sequences indicate high diagnostic values (>90 %) except PPV (77 %). • MSDE-prepared BTFE sequences need further refinement to reduce false positives. • Endoleaks can be detected without contrast injection using MSDE-prepared BTFE sequences.

Uterine cervical cancer volumetry using T2- and diffusion-weighted MR images in patients treated by primary surgery and neoadjuvant chemotherapy.

BACKGROUND: Tumor volumetry with magnetic resonance imaging (MRI) is very common; however, the accuracy of such measures remains unclear, especially after treatment. PURPOSE: To determine the accuracy of preoperative volume measurements of uterine cervical carcinomas resected with and without neoadjuvant chemotherapy (NAC) on T2-weighted (T2W) and diffusion-weighted (DWI) MRI. MATERIAL AND METHODS: Twenty-nine consecutive patients with surgically confirmed uterine cervical carcinoma were included in this study. MRI scans were performed before preoperative treatment in 17 patients and after two courses of NAC in 12 patients. In all patients, T2W images and DWI were obtained to measure the tumor diameters. The maximum diameter of the surgical specimens was macroscopically measured. The correlation coefficients between the measured tumor size using T2W imaging and DWI and the size measured on the surgical specimens were calculated for all specimens. RESULTS: The correlation coefficient of the three-dimensional (3D) tumor volume measurement using T2W imaging and DWI was 0.97 in the primary surgery group and was 0.96 in the NAC group. The 3D tumor volume measurement using MRI and the measurement of the actual surgical specimen was 0.55 for T2WI and 0.48 for DWI in the primary surgery group and 0.88 for T2WI and 0.95 for DWI in the NAC group. CONCLUSION: T2WI and DWI can provide accurate 3D tumor volume measurements of uterine cervical carcinomas in patients with and without preoperative chemotherapy, suggesting that tumor volumetry using 3 T MRI after uterus-preserving treatment is feasible.

Diagnostic imaging analysis to differentiate struma ovarii from mucinous carcinomas, encompassing T2*-based imaging, diffusion-weighted imaging, and dynamic contrast-enhanced imaging.

PURPOSE: To clarify the differences between struma ovarii (SO) and mucinous carcinomas (MC) on CT and MRI, including T2*-based images, diffusion-weighted images (DWI), and time-intensity curve (TIC) patterns, which have not been previously reported. METHODS: We retrospectively compared the presence of low intensity on T2-weighted and T2*-based images, high intensity on T1-weighted images, hyperattenuation on non-contrast CT, TIC pattern, T2 ratio, T1 ratio, CT value, and apparent diffusion coefficient (ADC) value in 15 patients with SO and 27 patients with MC. RESULTS: SO exhibited a significantly higher frequency of low intensity on T2-weighted and T2*-based images, and hyperattenuation on non-contrast CT than MC (P < 0.001, <0.001, and 0.006, respectively). The T2 ratios and CT attenuation of the locules were also significantly different (P < 0.001, and 0.006, respectively). In SO, sites of low intensity on T2-weighted and T2*-based images and sites of hyperattenuation on CT images always coincided. Regarding the TIC pattern, most SO showed a high-risk pattern, with a significant difference (P = 0.003). The ADC values of SO were significantly lower, and only one case of SO showed high signal intensity on DWI. CONCLUSION: SO were more frequently with low intensity on T2-weighted and T2*-based images, and hyperattenuation on non-contrast CT, and showed high-risk TIC patterns without diffusion restriction. ADVANCES IN KNOWLEDGE: SO shows a high-risk TIC pattern, but can be specifically diagnosed in combination with the lack of diffusion restriction and loculi with marked hypointensity on T2-weighted and T2*-based images consistent with hyperattenuation on non-contrast CT.

Imaging findings in inflammatory disease of the genital organs.

This review focuses on inflammatory diseases of female and male genital organs and discusses their epidemiology, pathogenesis, clinical presentation, and imaging findings. The female section covers pelvic inflammatory disease (PID) primarily caused by sexually transmitted infections (STIs) that affect the uterus, fallopian tubes, and ovaries. Unusual causes such as actinomycosis and tuberculosis have also been explored. The male section delves into infections affecting the vas deferens, epididymis, testes, prostate, and seminal vesicles. Uncommon causes such as tuberculosis, and Zinner syndrome have also been discussed. In addition, this review highlights other conditions that mimic male genital tract infections such as vasculitis, IgG4-related diseases, and sarcoidosis. Accurate diagnosis and appropriate management of these inflammatory diseases are essential for preventing serious complications and infertility. Imaging modalities such as ultrasound, magnetic resonance imaging, and computed tomography play a crucial role in diagnosis. Understanding the diverse etiologies and imaging findings is vital for the effective management of inflammatory diseases of the genital organs.

Comparison of Benign, Borderline, and Malignant Ovarian Seromucinous Neoplasms on MR Imaging.

PURPOSE: This study aimed to compare MRI findings among benign, borderline, and malignant ovarian seromucinous neoplasms. METHODS: We retrospectively analyzed MRI data from 24 patients with ovarian seromucinous neoplasms-seven benign, thirteen borderline, and six malignant. The parameters evaluated included age, tumour size, morphology, number, height, apparent diffusion coefficient (ADC) values, T2 ratios, time-intensity curve (TIC) descriptors, and TIC patterns of the mural nodules. Additionally, we examined the T2 and T1 ratios of the cyst contents, tumour markers, and the presence of endometriosis. We used statistical tests, including the Kruskal-Wallis and Fisher-Freeman-Halton exact tests, to compare these parameters among the three aforementioned groups. RESULTS: The cases showed papillary architecture with internal branching in 57% of benign, 92% of borderline, and 17% of malignant cases. Three or fewer mural nodules were seen in 57% of benign, 8% of borderline, and 17% of malignant cases. Compared to benign and borderline tumours, mural nodules of malignant neoplasms had significantly increased height (P = 0.015 and 0.011, respectively), lower means ADC values (P = 0.003 and 0.035, respectively). The mural nodules in malignant cases also demonstrated significantly lower T2 ratios than those in the benign cases (P = 0.045). Most neoplasms displayed an intermediate-risk TIC pattern, including 80% benign, 83% borderline, and 60% malignant neoplasms, and no significant differences were observed. CONCLUSION: Most benign and borderline tumours exhibited a papillary architecture with an internal branching pattern, whereas this feature was less common in malignant neoplasms. Additionally, benign tumours had fewer mural nodules compared to borderline tumours. Malignant neoplasms were characterized by mural nodules with increased height and lower ADC values than those in benign and borderline tumours. Interestingly, all three groups predominantly exhibited an intermediate-risk TIC pattern, emphasizing the complexity of diagnosing seromucinous neoplasms using MRI.

Imaging approaches for the diagnosis of genetic diseases affecting the female reproductive organs and beyond.

This review aims to provide an overview of neoplastic lesions associated with genetic diseases affecting the female reproductive organs. It seeks to enhance our understanding of the radiological aspects in diagnosing genetic diseases including hereditary breast and ovarian cancer syndromes, Lynch syndrome, Peutz-Jeghers syndrome, nevoid basal cell carcinoma syndrome, and Swyer syndrome, and explores the patterns and mechanisms of inheritance that require elucidation. Additionally, we discuss the imaging characteristics of lesions occurring in other regions due to the same genetic diseases.

Noninvasive visualization of endoleaks after endovascular aortic aneurysm repair through unenhanced MRI with motion-sensitized driven equilibrium preparation: Phantom experiments.

PURPOSE: To optimize imaging parameters for balanced turbo field echo (BTFE) sequence combined with motion-sensitized driven equilibrium (MSDE) preparation for endoleak detection and type classification in phantom experiments. MATERIALS AND METHODS: We prepared four phantoms: a pulsatile flow generator with an aortic aneurysm model simulating no endoleak, and a type-1, type-2, and type-3 endoleak. Throughout the experiments, MSDE-BTFE images with and without flow suppression were obtained at 1.5 T and subtraction images were used for image evaluation. The no-endoleak phantom was imaged using different MSDE-BTFE sequences to optimize the k-space trajectory and evaluate the use of electrocardiogram gating. The relative contrast between flowing saline and background was calculated. Then all phantoms were imaged to determine the optimal velocity encoding (VENC) for endoleak detection and type classification. Three independent observers performed the image evaluation. Consistencies between the interpreted and true results were analyzed using kappa statistics. RESULTS: The 3D low-high k-space trajectory with electrocardiogram gating provided the highest relative contrast. Low VENCs of 2-10 cm/s and high VENCs of 20 cm/s showed perfect consistency in endoleaks detection and type classification, respectively. CONCLUSION: MSDE-BTFE sequences of appropriate VENCs has potential for endoleak detection and type classification, without contrast material.

Diversity in size and signal intensity in multilocular cystic ovarian masses: new parameters for distinguishing metastatic from primary mucinous ovarian neoplasms.

PURPOSE: To differentiate primary mucinous ovarian neoplasms from metastatic ones with MR using diversity in size and signal intensity of multilocular cystic masses. MATERIALS AND METHODS: Twenty-eight cases of primary malignant or borderline mucinous malignant neoplasms and 14 metastatic ovarian tumors were retrospectively reviewed. We analyzed whether the tumor was unilateral or bilateral, the diversity in the size and signal intensity of each loculus in multilocular tumors, namely the size ratio of the smallest/largest loculus (size diversity ratio), and the standard deviation of the signal intensity at the level with the most varying signal on T2-weighted images within tumors (signal diversity ratio). We performed statistical analysis using the Mann-Whitney U-test. RESULTS: Bilateral tumors were more commonly observed among metastatic tumors than primary mucinous tumors (2/28 in primary versus 11/14 in metastatic, P < 0.01). The size diversity ratio was higher in primary mucinous tumors than in metastatic tumors (mean, 50.2 versus 23.2; P < 0.01). The signal diversity ratio was also higher in primary mucinous tumors than in metastatic tumors (334.3 versus 231.2; P < 0.01). CONCLUSION: Bilateral tumors were more common among metastatic tumors, which tended to be composed of cysts of uniform sizes and signal intensities compared with those of primary mucinous tumors.

Differences in the position of endometriosis-associated and non-associated ovarian cancer relative to the uterus.

BACKGROUND: Preoperative assessment of the histological type of ovarian cancer is essential to determine the appropriate treatment strategy. Tumor location may be helpful in this regard. The purpose of this study was to compare the position of endometriosis-associated (EAOCs) and non-associated (non-EAOCs) ovarian cancer relative to the uterus using MRI. METHODS: This retrospective study included patients with pathologically confirmed malignant epithelial ovarian tumors who underwent MRI at our hospital between January 2015 and January 2023. T2-weighted images of the sagittal and axial sections of the long axis of the uterine body were used for the analysis. Three blinded experienced radiologists independently interpreted the images and assessed whether the ovarian tumor was attached to the uterus, and the angle between the uterus and the tumor was measured. The presence of attachment and the measured angles were compared for each histology. In addition, the angles between EAOCs, including endometrioid carcinomas (ECs) and clear cell carcinomas (CCCs), were compared with non-EAOCs. RESULTS: In total, 184 women (mean age, 56 years; age range, 20-91 years) were evaluated. High-grade serous carcinomas (HGSCs) were significantly smaller than the others and had significantly less uterine attachment than CCCs (p < 0.01 for all readers). According to the mean of the measured angles, CCCs were positioned significantly more posteriorly than HGSCs and mucinous carcinomas (p < 0.02), and EAOCs were positioned significantly more posteriorly to the uterus than non-EAOCs (p < 0.01). CONCLUSION: HGSCs are often not attached to the uterus, and EAOCs are positioned more posteriorly to the uterus than non-EAOCs. CRITICAL RELEVANCE STATEMENT: High-grade serous carcinomas were often not attached to the uterus, and endometriosis-associated ovarian cancers were positioned more posteriorly to the uterus than non-endometriosis-associated ovarian cancers. KEY POINTS: • The position of the ovarian tumor can be determined using MRI. • High-grade serous carcinomas had less attachment to the uterus. • Endometriosis-associated cancers were positioned more posteriorly to the uterus. • The location of ovarian tumors is helpful in estimating histology.

Fibrolipomatous hamartoma with macrodactyly and carpal tunnel syndrome.

A 26-year-old man presented with congenital left thumb macrodactyly. MRI showed diffuse enlargement of the left median nerve from the wrist to the digits, with particularly severe swelling of the thumb; US revealed the median nerve swelling comprised enlarged hypoechoic nerve bundles and increased hyperechoic areas around the nerve bundles. These typical cable-like and spaghetti-like appearances led to the diagnosis of fibrolipomatous hamartoma (FLH). Only debulking was performed for cosmetic reasons and enlarged nerves contiguous to the skin of the distal phalanx were cauterized and dissected. The diagnosis of FLH was confirmed pathologically. FLH is a rare, congenital disorder characterized by anomalous overgrowth of fibroadipose tissue between and around nerve bundles. Patients with median nerve involvement often present with carpal tunnel syndrome. Once its characteristic image is obtained, biopsy is not necessary.

A case of Pseudo-Meigs' syndrome due to Brenner tumor.

A 65-year-old woman with suspected ascites-associated abdominal distention had elevated CA125 levels. Contrast-enhanced computed tomography to search for the cause of the ascites showed bilateral pleural effusions, ascites, and an ovarian tumor. On magnetic resonance imaging the tumor exhibited a lobulated structure and markedly low signal intensity on both T1- and T2-weighted imaging, with no restrictions on diffusion-weighted images. Progressive enhancement was observed at tumor margins. Meigs syndrome due to fibroma was suspected, and total hysterectomy, bilateral salpingo-oophorectomy, and partial omentectomy were performed. Postoperatively, the pleural effusion and ascites resolved promptly without specific treatment. On pathological examination, the ovarian tumor was diagnosed as a benign Brenner tumor with scattered nests of transitional epithelium within a large amount of stroma. Based on the clinical course, the patient was diagnosed with pseudo-Meigs' syndrome due to a Brenner tumor.

A case of renal involvement in juvenile xanthogranulomatosis.

Juvenile xanthogranuloma (JXG) is a type of non-Langerhans cell histiocytosis that rarely involves other than the skin. Here, we present detailed ultrasound (US) findings, including a contrast study, of a rare JXD renal lesion. A 42-year-old woman with JXG had chronic kidney disease. Ultrasound showed multiple cystic masses with fine internal septa in both kidneys. Contrast-enhanced US revealed early staining and late washout consistent with the internal septa inside the masses and led us to suspect cystic renal cell carcinomas in both kidneys. Left nephrectomy was performed for diagnostic purposes. Microscopic examination revealed a foamy component with Touton-type giant cells by histiocytosis; CD68 and S100 were positive, and CD1a was negative, leading the diagnosis of JXD. The US findings of extracutaneous lesions on JXA are variable and can be cystic, and when arising in the kidney may resemble cystic renal cell carcinoma.

Mucinous tumors arising from ovarian teratomas as another source of pseudomyxoma peritoneii: MR findings comparison with ovarian metastases from appendiceal mucinous tumors.

Objective: The origin of pseudomyxoma peritoneii (PMP) has been established as low-grade appendiceal mucinous tumors (AMT). However, intestinal-type ovarian mucinous tumors are known as another source of PMP. Recently, it is advocated that ovarian mucinous tumors causing PMP originates from teratomas. However, AMTs are often too small to detect on imaging; then, differentiating metastatic ovarian tumors of AMT from ovarian teratoma-associated mucinous tumors (OTAMT) is important. Therefore, this study investigates the MR characteristics of OTAMT compared to the ovarian metastasis of AMT. Methods: MR findings of six pathologically confirmed OTAMT were retrospectively analyzed compared to ovarian metastases of low-grade appendiceal mucinous neoplasms (LAMN). We studied the existence of PMP, uni- or bilateral disease, the maximum diameter of ovarian masses, the number of loculi, a variety of sizes and signal intensity of each content, the existence of the solid part, fat, calcification within the mass, and appendiceal diameters. All the findings were statistically analyzed using the Mann-Whitney test. Results: Four of the six OTAMT showed PMP. OTAMT showed unilateral disease, had a larger diameter, more frequent intratumoral fat, smaller appendiceal diameter than those in AMT, and they were statistically significant (p < .05). On the other hand, the number, variety of size, signal intensity of loculi, and the solid part, calcification within the mass did not differ from each other. Conclusion: Both OTAMT and ovarian metastasis of AMT appeared as multilocular cystic masses with relatively uniform signal and size of loculi. However, a larger unilateral disease with intratumoral fat and smaller size of the appendix may suggest OTAMT. Advances in knowledge: OTAMT can be another source of PMP, as AMT. MR characteristics of OTAMT were very similar to ovarian metastases of AMT; however, in cases with PMP combined with fat-containing multilocular cystic ovarian mass, we can diagnose them as OTAMT, not PMP caused by AMT.

Prospective intraindividual comparison of unenhanced magnetic resonance imaging vs contrast-enhanced computed tomography for the planning of endovascular abdominal aortic aneurysm repair.

OBJECTIVE: This study clarified whether unenhanced magnetic resonance imaging (MRI) is an alternative to contrast-enhanced computed tomography (CT) for aortoiliac arterial measurement before endovascular abdominal aortic aneurysm repair (EVAR). METHODS: The institutional review board approved this prospective study. Twenty patients being considered for EVAR underwent MRI using a steady-state free-precession sequence in a 1.5-T system and contrast-enhanced CT within 4 weeks of each other. Two independent observers reviewed MRI and CT in random order using vessel analysis software and measured seven diameters, four lengths, and the angle of the aortoiliac arteries. The intermodality, interobserver, and intraobserver agreements were assessed for each measurement by intraclass correlation coefficients (ICCs) and the Altman-Bland method. Additionally, the observers independently recorded the number of bilateral renal arteries, decided EVAR suitability, and selected the main endograft on each modality. RESULTS: Intermodality ICCs for observers A and B showed ranges of 0.83 to 0.99 and 0.70 to 0.98; interobserver ICCs for MRI and CT showed ranges of 0.73 to 0.99 and 0.65 to 0.99; and intraobserver ICCs for MRI and CT showed ranges of 0.59 to 0.99 and 0.59 to 0.99. In intermodality, interobserver, and intraobserver comparisons, mean differences in diameters were included within the range -1 to +1 mm, excluding three of seven diameters on CT in interobserver comparison and one of seven on CT in intraobserver comparison. Mean differences in lengths were included within the range -5 to +5 mm, excluding one of four lengths in observer B in intermodality comparison and one of four on MRI and CT in interobserver comparison. All mean differences in angles were included within the range -5° to +5°. Both observers detected all 40 bilateral main renal arteries on MRI and CT. Of the 13 accessory renal arteries, observers A and B detected four (31%) and nine (69%), respectively, on MRI; in contrast, both observers detected 11 (85%) on CT. The observers independently determined that the same seven patients were suitable for EVAR on MRI and CT. Of the seven selected main endografts, seven and six diameters and five and six lengths agreed exactly between MRI and CT for observers A and B, respectively. CONCLUSIONS: Although contrast-enhanced CT remains the gold standard for preoperative EVAR planning, unenhanced MRI with steady-state free-precession sequence can be an alternative modality for patients with contraindications for CT, such as renal impairment, because the intermodality agreement for preoperative measurements is as good as interobserver and intraobserver agreement.