Flow pattern analysis of right ventricular outflow tract in repaired tetralogy of Fallot through 4D flow MRI.

Cardiac magnetic resonance imaging (CMR) often shows discrepancies between right ventricular outflow tract (RVOT) flow and left ventricular outflow tract flow in patients with late-stage repaired tetralogy of Fallot (rTOF), leading to potential errors in pulmonary regurgitation fraction (PRF) assessment. This study aimed to identify the conditions under which RVOT flow can be acutely evaluated using four-dimensional (4D) flow CMR. Twenty-seven consecutive patients with rTOF underwent both two-dimensional phase-contrast (2D PC) and 4D flow CMR between 2016 and 2018, excluding those with peripheral pulmonary artery stenosis, RVOT conduit replacement, unknown surgical method, and an aortic valve regurgitation greater than 20%. Seven healthy controls also underwent only 4D Flow CMR. All healthy controls and fifteen patients with rTOF showed laminar RVOT flow, while seven patients exhibited helical, and four patients exhibited vortical RVOT flow in 4D flow CMR visualization. Flow-volume concordance between the pulmonary artery and aortic flow was significantly lower in patients with rTOF and PRF > 40% in 2D PC CMR. This concordance rate in the suprapulmonary valve was high in both the TOF and control groups, comparing at five RVOT locations in 4D flow CMR. Regarding RVOT flow regurgitation in 4D flow, the whole bulk evaluation exhibited greater variation depending on the flow type compared to the whole pixel-wise evaluation. The study confirmed the flow volume at the upper section of the pulmonary valve as the most accurate correlate of aortic flow volume. Furthermore, the 4D flow CMR using the pixel-wise method demonstrated superior accuracy compared to the traditional bulk flow method.

Preoperative predictive factors for positive peritoneal cytology results in patients with pancreatic ductal adenocarcinomas: a retrospective study.

BACKGROUND: The clinical importance of positive peritoneal cytology results in patients with pancreatic ductal adenocarcinomas remains controversial. We evaluated the prognosis of these patients and the predictive preoperative risk factors for positive peritoneal cytology results. METHODS: We retrospectively reviewed patients who underwent curative-intent surgery at our institution between May 2010 and June 2020. Preoperative risk factors for positive peritoneal cytology results were identified using logistic regression analysis. A scoring model was constructed using the total number of significant independent predictors for positive peritoneal cytology results. RESULTS: Of 233 patients, 18 (7.7%) had positive peritoneal cytology results. The recurrence-free survival and cancer-specific survival were markedly worse in patients with positive peritoneal cytology results than in those with negative peritoneal cytology results (recurrence-free survival: 6.0 months vs. 16.6 months, p = 0.050; cancer-specific survival: 19.4 months vs. 47.5 months, p = 0.034). Tumor location (odds ratio: 3.760, 95% confidence interval: 1.099-11.818, p = 0.023), tumor size > 25 mm (odds ratio: 3.410, 95% confidence interval: 1.031-11.277, p = 0.046), preoperative serosal invasion (odds ratio: 5.193, 95% confidence interval: 1.099-24.531, p = 0.038), and preoperative carcinoembryonic antigen level > 5.6 ng/mL (odds ratio: 3.816, 95% confidence interval: 1.248-10.667, p = 0.019) were identified as significant independent predictive factors. Our predictive model's optimal cutoff and positive predictive values for positive peritoneal cytology results were 3 and 27.9%, respectively. CONCLUSIONS: The indications for curative-intent surgery should be considered carefully in patients with high-risk factors for positive peritoneal cytology results.

Clinical characteristics and predictive factors of postoperative intra-abdominal abscess after distal pancreatectomy.

PURPOSE: The postoperative mortality rate of distal pancreatectomy is lower than that of pancreaticoduodenectomy, although persistent complications may occur after distal pancreatectomy. Fluid collection (FC) is frequently observed after distal pancreatectomy; however, FC may occasionally progress to postoperative intra-abdominal abscess (PIAA), which requires conservative or progressive interventional treatment. This study aimed to compare the status between patients with or without PIAA, identify predictive factors for PIAA and clinically relevant postoperative pancreatic fistula, and investigate the clinical characteristics of patients with PIAA with interventional drainage. METHODS: We retrospectively reviewed data of patients who underwent distal pancreatectomy between January 2012 and December 2019 at two high-volume centers, where hepatobiliary-pancreatic surgeries were performed by expert specialist surgeons. Logistic regression analysis was performed to determine the predictive factors for PIAA. RESULTS: Overall, 242 patients were analyzed, among whom 49 (20.2%) had PIAA. The median postoperative period of PIAA formation was 9 (range: 3-49) days. Among the 49 patients with PIAA, 25 (51.0%) underwent percutaneous ultrasound, computed tomography, or endoscopic ultrasound-guided interventions for PIAA. In the univariate analysis, preoperative indices representing abdominal fat mass (i.e., body mass index, subcutaneous fat area, and visceral fat area) were identified as predictive factors for PIAA; in the multivariate analysis, C-reactive protein (CRP) level (continuous variable) on postoperative day (POD) 3 (odds ratio: 1.189, 95.0% confidence interval: 1.111 - 1.274; P < 0.001) was the only independent and significant predictive factor for PIAA. CONCLUSIONS: CRP level on POD 3 was an independent and significant predictive factor for PIAA after distal pancreatectomy.

Clinical utility of the Vesical Imaging-Reporting and Data System for muscle-invasive bladder cancer between radiologists and urologists based on multiparametric MRI including 3D FSE T2-weighted acquisitions.

OBJECTIVES: To investigate the clinical utility of the Vesical Imaging-Reporting and Data System (VI-RADS) by comparing its diagnostic performance for muscle-invasive bladder cancer (MIBC) between radiologists and urologists based on multiparametric MRI, including three-dimensional (3D) fast spin-echo (FSE) T2-weighted acquisitions. METHODS: This study included 66 treatment-naïve patients (60 men, 6 women; mean age 74.0 years) with pathologically proven bladder cancer who underwent multiparametric MRI, including 3D FSE T2-weighted imaging, before transurethral bladder tumour resection between January 2010 and November 2018. The MRI scans were categorised according to the five-point VI-RADS score by four independent readers (two board-certified radiologists and board-certified urologists each), blinded to the histopathological findings. The VI-RADS scores were compared with the postoperative histopathological diagnosis. Interobserver agreement was assessed using weighted kappa coefficients. ROC analysis and generalised estimating equations were used to evaluate the diagnostic performance. RESULTS: Forty-nine (74.2%) and 17 (25.8%) tumours were confirmed to be non-MIBC and MIBC, respectively, based on pathological examination. The interobserver agreement was good-to-excellent between all pairs of readers (range, 0.73-0.91). The urologists' sensitivity/specificity values for DCE-MRI VI-RADS scores were significantly lower than those of radiologists. No significant differences were observed for the overall VI-RADS score. The AUC for the overall VI-RADS score was 0.94, 0.92, 0.89, and 0.87 for radiologists 1 and 2 and urologists 1 and 2, respectively. CONCLUSIONS: The VI-RADS score, based on multiparametric MRI including 3D FSE T2-weighted acquisitions, can be useful for radiologists and urologists to determine the bladder cancer muscle invasion status preoperatively. KEY POINTS: • VI-RADS (using multiparametric MRI including 3D FSE T2-weighted acquisitions) achieves good to excellent interobserver agreement and has similar diagnostic performance for detecting muscle invasion by both radiologists and urologists. • The diagnostic performance of the overall VI-RADS score is high for both radiologists and urologists, particularly due to the dominant effect of diffusion-weighted imaging on the overall VI-RADS score. • The sensitivity and specificity values of the T2WI VI-RADS scores for four readers in our study (using 3D FSE T2-weighted acquisitions) were similar (with slightly higher specificity values) to previously published results (using 2D FSE T2-weighted acquisitions).

Quantification of intratumoral collagen and elastin fibers within hepatocellular carcinoma tissues finds correlations with clinico-patho-radiological features.

AIM: Emerging evidence suggests a promising role for tumor stromal factors in characterizing patients with various types of malignancies, including hepatocellular carcinoma (HCC). We quantified the amount of collagen and elastin fibers in HCC samples with the aim of clarifying the clinico-patho-radiological significance of fiber deposition in HCC. METHODS: We computed the amount of collagen and elastin fibers using digital image analysis of whole-slide images of Elastica van Gieson-stained tissues from 156 surgically resected HCCs. Furthermore, we assessed the correlations between the fiber content of HCC samples and clinical, pathological, and radiological features, including immunohistochemistry-based molecular subtypes and immunosubtypes. RESULTS: The intratumoral area ratio of collagen in HCC tissues (median 3.4%, range 0.1-22.2%) was more than threefold that of elastin (median 0.9%, range 0.1-9.0%); there was a strong positive correlation between the amounts of collagen and elastin. Higher levels of combined collagen and elastin were significantly associated with the confluent multinodular macroscopic tumor type, the absence of a fibrous capsule, intratumoral steatosis, scirrhous tumor stroma, dense inflammatory-cell infiltrates, and the biliary/stem cell markers-positive HCC subtype. The associations of higher collagen levels with radiological findings, including heterogeneous enhancement and persistent enhancement on dynamic computed tomography, were significant. In contrast, the associations of radiological findings with elastin fibers were not significant. Intratumoral fibrous stroma in HCC comprised septum-like and perisinusoidal fibrosis; these two forms represented distinct distribution patterns of fibers and fibroblasts. CONCLUSION: Quantitative analysis suggested that stromal fiber-rich HCCs likely represent a distinct clinico-patho-radiological entity.

Urgent distal pancreatectomy for intraperitoneal hemorrhage due to the spontaneous rupture of a pancreatic metastatic tumor from synovial sarcoma: a case report.

BACKGROUND: Synovial sarcoma is a soft tissue malignancy that frequently affects the extremities, adjacent to the large joints. Synovial sarcoma has a high rate of distant metastasis; however, pancreatic metastasis is extremely rare, and to our knowledge, there has been no report of bleeding due to spontaneous tumor rupture. This study reports the case of a patient with synovial sarcoma pancreatic metastasis causing tumor rupture and bleeding, which was successfully managed with emergent distal pancreatectomy. CASE PRESENTATION: A 27-year-old woman underwent extensive resection of the primary tumor and partial lung resection after chemotherapy for left femoral synovial sarcoma and multiple lung metastases 4 years prior. During the follow-up, a 35-mm tumor was noted in the pancreatic tail on abdominal computed tomography (CT), and no other distant metastases were detected via positron emission tomography CT. Laparoscopic distal pancreatectomy was scheduled for pancreatic metastasis of synovial sarcoma. However, before the scheduled pancreatectomy could be conducted, the patient visited the emergency department because of abdominal pain that occurred after consuming a small amount of alcohol, and CT showed ascites with high CT values and leakage of contrast media. She was diagnosed with intra-abdominal hemorrhage due to a ruptured metastatic pancreatic tumor, and an emergency operation was performed. In total, 1500 mL of blood was evacuated from the abdomen, and the bleeding pancreatic tail tumor was resected. Histopathological findings revealed synovial sarcoma metastasis and a ruptured tumor capsule, and tumor cells were observed in the hematoma. After discharge on postoperative day 18, the patient was carefully monitored and confirmed to be in relapse-free survival, without chemotherapy, at 6 months post-surgery. CONCLUSIONS: While the rate of tumor growth varies depending on the grade of the tumor, the possibility of rupture should be considered even in metastatic pancreatic tumors. In the case of pancreatic tumor rupture with stable circulation, radiological evaluation for oncology is necessary, and primary resection may be compatible with resectable cases.

Myocardial T1 values in healthy volunteers measured with saturation method using adaptive recovery times for T1 mapping (SMART1Map) at 1.5 T and 3 T.

Myocardial T1 mapping is clinically valuable for assessing the myocardium, and modified look-locker inversion-recovery (MOLLI) approaches have been commonly used for measuring myocardial T1 values. To date, several other sequences have been developed for measuring myocardial T1 values, and saturation-recovery-based sequences have been shown to be less dependent on various factors, such as T2 times and magnetization transfer, than inversion-recovery techniques. Systematic differences in T1 values between different sequences have been reported; therefore, definition of the normal range of native T1 values is required before clinical usage can begin. The purpose of this study was to evaluate the reference range and sex dependency of native T1 values in the myocardium measured using one such saturation-recovery sequence, i.e., saturation method using adaptive recovery times for cardiac T1 mapping (SMART1Map). Myocardial T1 values were compared between SMART1Map and MOLLI in 24 young healthy volunteers at 1.5 T and 3 T, and differences in the T1 values between the sexes were assessed. The mean native T1 values in the myocardium were significantly longer with SMART1Map than MOLLI [1530.4 ± 49.2 vs 1222.1 ± 48.9 ms at 3 T (p < 0.001) and 1227.3 ± 41.9 ms vs 1014.8 ± 49.4 ms at 1.5 T (p < 0.001)]. A significant difference between the sexes was observed in the T1 values obtained using each sequence, excluding SMART1Map at 3 T. The SMART1Map has a potential advantage to overcome the shortcoming of MOLLI, which underestimates T1 values; however, the sex-dependent difference remains obscure using SMART1Map.

The impact of the mesorectal apparent diffusion coefficient value on surgical difficulty in laparoscopic anterior resection for rectal cancer.

PURPOSE: We aimed to clarify the impact of the apparent diffusion coefficient (ADC) value of the mesorectum from preoperative magnetic resonance imaging (MRI) on surgical difficulty in laparoscopic anterior resection (Lap-AR) for rectal cancer. METHODS: In total, 67 patients who had undergone curative Lap-AR for rectal cancer in our hospital from January 2008 to March 2015 and had preoperative MRI findings available were included. We randomly calculated the average ADC in three regions of the mesorectum at the level of the upper edge of the superior border of the femur. Univariate and multivariate analyses were performed to evaluate the correlation between the patients' clinicopathological characteristics, including the ADC value and short-term surgical outcomes. RESULTS: The univariate analysis revealed that a lower ADC value was associated with a significantly increased operative blood loss (p = 0.008) and prolonged operative time (p < 0.001). The multivariate analysis adjusted for the body mass index, anal verge, tumor location, covering stoma, clinical T factor and conversion revealed that the ADC value was an independent risk factor for a prolonged operative time (R2 = 0.6003, p < 0.001). Furthermore, the multivariate analysis adjusted for the body mass index, anal verge, covering stoma, clinical T factor and conversion revealed that the ADC value was an independent risk factor for an increased blood loss (R2 = 0.4345, p = 0.008). CONCLUSION: A lower ADC value of the mesorectum might be a predictor of surgical difficulty in Lap-AR for rectal cancer.

Silent navigator-triggered silent MRI of the abdomen.

PURPOSE: To develop and demonstrate the feasibility of a silent respiratory navigator technique for prospective triggering, which was incorporated into a three-dimensional radial zero-echo-time sequence for respiratory navigated silent abdominal imaging. METHODS: A nonselective hard excitation radiofrequency pulse was used for the navigator sequence with a derated readout gradient, to avoid generation of high levels of acoustic noise. The acquired navigator signals were processed in real time and used for prospective triggering of the zero-echo-time sequence. Ten healthy volunteers were scanned using the proposed and conventional techniques at 1.5 T. An acoustic noise measurement with A-weighted continuous equivalent sound pressure level was also performed. RESULTS: The sound pressure-level values of the background noise, zero-echo-time imaging, conventional, and silent navigators were 68.3, 68.4, 102.5, and 69.4 dBA, respectively. Excellent correlation with correlation coefficients greater than 0.9 was observed between the bellows signals and displacement values calculated from the navigators. Sharpness of the portal vein of both conventional and silent navigator-triggered images was significantly higher than those of nontriggered images. CONCLUSIONS: The silent navigator-triggered zero-echo-time technique is feasible and might improve image quality and workflow of abdominal MRI of patients who are prone to acoustic noise. Magn Reson Med 79:2170-2175, 2018. © 2017 International Society for Magnetic Resonance in Medicine.

The Effects of Hydrogen Gas Inhalation on Adverse Left Ventricular Remodeling After Percutaneous Coronary Intervention for ST-Elevated Myocardial Infarction　- First Pilot Study in Humans.

BACKGROUND: Hydrogen gas inhalation (HI) reduced infarct size and mitigated adverse left ventricular (LV) remodeling in a rat model of acute myocardial infarction (AMI). We designed a prospective, open-label, rater-blinded clinical pilot study in patients experiencing ST-elevated MI (STEMI).Methods and Results:The 20 patients with an initial diagnosis of STEMI were assigned to either an HI group (1.3% H2with 26% oxygen) or a control group (26% oxygen). There were no HI-related severe adverse events. In the full analysis set, the cardiac salvage index as evaluated using cardiac magnetic resonance imaging at 7 days after primary percutaneous coronary intervention (PCI), showed no significant between-group difference (HI: 50.0±24.3%; control: 60.1±20.1%; P=0.43). However, the improvement from day 7 in the HI group was numerically greater than that in the control group in some of the surrogate outcomes at 6-month follow-up, including the LV stroke volume index (HI: 9.2±7.1 mL/m2; control: -1.4±7.2 mL/m2; P=0.03) and the LV ejection fraction (HI: 11.0%±9.3%; control: 1.7%±8.3%; P=0.11). CONCLUSIONS: The first clinical study has shown that HI during PCI is feasible and safe and may also promote LV reverse remodeling at 6 months after STEMI. The study was not powered to test efficacy and a further large-scale trial is warranted. (Clinical trials registration: UMIN00006825).

Quantitative assessment of fatty infiltration and muscle volume of the rotator cuff muscles using 3-dimensional 2-point Dixon magnetic resonance imaging.

BACKGROUND: In patients with rotator cuff tears, muscle degeneration is known to be a predictor of irreparable tears and poor outcomes after surgical repair. Fatty infiltration and volume of the whole muscles constituting the rotator cuff were quantitatively assessed using 3-dimensional 2-point Dixon magnetic resonance imaging. METHODS: Ten shoulders with a partial-thickness tear, 10 shoulders with an isolated supraspinatus tear, and 10 shoulders with a massive tear involving supraspinatus and infraspinatus were compared with 10 control shoulders after matching age and sex. With segmentation of muscle boundaries, the fat fraction value and the volume of the whole rotator cuff muscles were computed. After reliabilities were determined, differences in fat fraction, muscle volume, and fat-free muscle volume were evaluated. RESULTS: Intra-rater and inter-rater reliabilities were regarded as excellent for fat fraction and muscle volume. Tendon rupture adversely increased the fat fraction value of the respective rotator cuff muscle (P < .002). In the massive tear group, muscle volume was significantly decreased in the infraspinatus (P = .035) and increased in the teres minor (P = .039). With subtraction of fat volume, a significant decrease of fat-free volume of the supraspinatus muscle became apparent with a massive tear (P = .003). CONCLUSION: Three-dimensional measurement could evaluate fatty infiltration and muscular volume with excellent reliabilities. The present study showed that chronic rupture of the tendon adversely increases the fat fraction of the respective muscle and indicates that the residual capacity of the rotator cuff muscles might be overestimated in patients with severe fatty infiltration.

Repair of congenital 'disconnected uterus': a new female genital anomaly?

Congenital uterine anomaly is a female genital disorder caused by developmental anomaly of the Müllerian ducts. In this report, we present a case of repair of congenital 'disconnected uterus' between the cervix and the body of the uterus. The case did not correspond to the consensus classifications that have been proposed for congenital uterine anomaly. The patient was a young woman whose chief complaints were not having first menstruation and experiencing monthly severe lower abdominal pain. Magnetic resonance imaging showed that the uterine body was separated from the uterine cervix. Uteroplasty was conducted to anastomose the separated uterus. Periodic menstruation started 1 month after surgery and abdominal pain was improved. Performance of uteroplasty in this case was extremely significant and greatly improved the quality of life of the patient.

The efficacy of preoperative positron emission tomography-computed tomography (PET-CT) for detection of lymph node metastasis in cervical and endometrial cancer: clinical and pathological factors influencing it.

OBJECTIVE: We studied the diagnostic performance of (18)F-fluoro-2-deoxy-d-glucose-positron emission tomography/computed tomography in cervical and endometrial cancers with particular focus on lymph node metastases. METHODS: Seventy patients with cervical cancer and 53 with endometrial cancer were imaged with (18)F-fluoro-2-deoxy-D-glucose-positron emission tomography/computed tomography before lymphadenectomy. We evaluated the diagnostic performance of (18)F-fluoro-2-deoxy-D-glucose-positron emission tomography/computed tomography using the final pathological diagnoses as the golden standard. RESULTS: We calculated the sensitivity, specificity, positive predictive value and negative predictive value of (18)F-fluoro-2-deoxy-D-glucose-positron emission tomography/computed tomography. In cervical cancer, the results evaluated by cases were 33.3, 92.7, 55.6 and 83.6%, respectively. When evaluated by the area of lymph nodes, the results were 30.6, 98.9, 55.0 and 97.0%, respectively. As for endometrial cancer, the results evaluated by cases were 50.0, 93.9, 40.0 and 95.8%, and by area of lymph nodes, 45.0, 99.4, 64.3 and 98.5%, respectively. The limitation of the efficacy was found out by analyzing it by the region of the lymph node, the size of metastatic node, the historical type of tumor in cervical cancer and the prevalence of lymph node metastasis. CONCLUSION: The efficacy of positron emission tomography/computed tomography regarding the detection of lymph node metastasis in cervical and endometrial cancer is not established and has limitations associated with the region of the lymph node, the size of metastasis lesion in lymph node and the pathological type of primary tumor. The indication for the imaging and the interpretation of the results requires consideration for each case by the pretest probability based on the information obtained preoperatively.

Retroperitoneal low-flow vascular malformations: characteristic MRI findings correlated with histopathological findings.

PURPOSE: To evaluate the MRI findings of retroperitoneal low-flow vascular malformations (RLVMs) correlated with histopathological findings. METHODS: Two radiologists reviewed the MRI findings of 4 RLVMs (3 with capillary malformations and 1 with a venous malformation). First, they evaluated the visibility, signal intensities, and signal homogeneity of each lesion on non-fat-suppressed breath-hold T2-weighted single-shot fast spin-echo (non-FS SSFSE) images and fat-suppressed T2-weighted fast spin-echo (FS T2-weighted FSE) images. Second, the kinetic patterns and the internal enhancement patterns were analyzed for each lesion on multi-phasic contrast-enhanced (CE) images. After these image analyses, the MRI findings were correlated with the histopathological findings. RESULT: Histopathologically, the 4 RLVMs did not exhibit remarkable degeneration and were present in the retroperitoneal fat tissue without clear capsules. On the non-FS SSFSE images, 3 of the 4 RLVMs could not be discriminated from the surrounding retroperitoneal fat tissue (invisible), and the remaining lesion was barely visible with an indistinct margin. On the FS T2-weighted FSE images, however, all the RLVMs were clearly visualized as homogeneous high-signal intensities. On the multi-phasic CE images, all the capillary malformations exhibited fast enhancement, while a venous malformation showed slow enhancement. Furthermore, the RLVMs tended to exhibit a centripetal filling pattern. CONCLUSION: The RLVMs blended in with the surrounding retroperitoneal fat tissue on non-FS SSFSE images, like phantoms, whereas they were clearly visualized on FS T2-weighted FSE images. On multi-phasic CE images, the RLVMs tended to exhibit a centripetal filling pattern. These imaging features may be useful diagnostic clues for RLVMs.

OATP1B3 expression is strongly associated with Wnt/ß-catenin signalling and represents the transporter of gadoxetic acid in hepatocellular carcinoma.

BACKGROUND & AIMS: In the current era of emerging molecular targeted drugs, it is necessary to identify before treatment the specific subclass to which a tumour belongs. Gadoxetic acid is a liver-specific contrast agent that is preferentially taken up by hepatocytes. Therefore, gadoxetic acid-enhanced magnetic resonance imaging (EOB-MRI) should provide precise molecular information about hepatocellular carcinomas (HCCs). The aim of this study was to investigate the transporters of gadoxetic acid in HCC comprehensively and to analyse the molecular regulatory mechanism of such transporters. METHODS: Expression levels of transporters, transcriptional factors and Wnt target genes in clinical samples were examined by quantitative real-time reverse transcription polymerase chain reaction and immunohistochemistry. LiCl treatment of the HCC cell line KYN-2 was conducted in vitro to assess the effects of Wnt signalling activity. RESULTS: Comprehensive analyses of transporter mRNAs and protein expressions revealed that the organic anion transporting polypeptide 1B3 (OATP1B3) had the strongest correlation with tumour enhancement in hepatobiliary-phase images of EOB-MRI. Association analysis with OATP1B3 expression revealed significant correlation with the expression of Wnt/ß-catenin target genes. Further, LiCl treatment induced OATP1B3 mRNA expression in KYN-2 cells, indicating a strong association between OATP1B3 expression and Wnt/ß-catenin signalling. The sensitivity and specificity to predict Wnt/ß-catenin-activated HCC using tumour enhancement in EOB-MRI were 78.9% and 81.7%, respectively. CONCLUSIONS: OATP1B3 was confirmed as the most important transporter mediating HCC enhancement in EOB-MRI. OATP1B3 expression showed a strong association with the expression of Wnt/ß-catenin target genes, therefore, OATP1B3-upregulated HCC likely represents a specific subclass of Wnt/ß-catenin-activated HCC.

Fast abdominal magnetic resonance elastography with simultaneous encoding of three-dimensional displacements.

Three-dimensional (3D) magnetic resonance elastography (MRE) is more accurate than two-dimensional (2D) MRE; however, it requires long-term acquisition. This study aimed to reduce the acquisition time of abdominal 3D MRE using a new sample interval modulation (short-SLIM) approach that can acquire all three motions faster while reducing the prolongation of echo time and flow compensation. To this end, two types of phantom studies and an in vivo test of the liver in three healthy volunteers were performed to compare the performances of conventional spin-echo echo-planar (SE-EPI) MRE, conventional SLIM and short-SLIM. One phantom study measured the mean amplitude and shear modulus within the overall region of a homogeneous phantom by changing the mechanical vibration power to assess the robustness to the lowered phase-to-noise ratio in short-SLIM. The other measured the mean shear modulus in the stiff and background materials of a phantom with an embedded stiffer rod to assess the performance of short-SLIM for complex wave patterns with wave interference. The Spearman's rank correlation coefficient was used to assess similarity of elastograms in the rod-embedded phantom and liver between methods. The results of the phantom study changing the vibration power indicated that there was little difference between conventional MRE and short-SLIM. Moreover, the elastogram pattern and the mean shear modulus in the rod-embedded phantom in conventional SLIM and short-SLIM did not change for conventional MRE; the liver test also showed a small difference between the acquisition techniques. This study demonstrates that short-SLIM can provide MRE results comparable to those of conventional MRE. Short-SLIM can reduce the total acquisition time by a factor of 2.25 compared to conventional 3D MRE time, leading to an improvement in the accuracy of shear modulus estimation by suppressing the patient movements.

Retroperitoneal leiomyosarcoma mimicking an ovarian tumor diagnosed using a negative ovarian pedicle sign.

Retroperitoneal leiomyosarcoma (RPLMS) is rare and usually presents as a large abdominal mass with poor clinical symptoms. Radiological findings of an RPLMS arising in the pelvis of a woman resemble those of adnexal tumors. Herein, we present a case of RPLMS mimicking an adnexal tumor which was differentiated from having an ovarian origin as the right ovarian vein was passing through the tumor but there was no direct vascular connection with the tumor. Therefore, it is important to identify the ovarian vein to distinguish between these tumors.

Biliary findings assist in predicting enlargement of intraductal papillary mucinous neoplasms of the pancreas.

BACKGROUND & AIMS: There is controversy over the optimal management strategy for patients with branch-duct type intraductal papillary mucinous neoplasms of the pancreas (BD-IPMNs), precursors to pancreatic cancer. We aimed to identify factors associated with the presence of BD-IPMNs and changes in their diameter. METHODS: Two separate analyses were conducted in a cohort of patients who underwent magnetic resonance cholangiopancreatography (MRCP) in a single year (2006). MRCP findings and clinical outcomes of these patients were followed for a maximum of 6 years. We evaluated initial MRCP findings and demographics associated with the presence of BD-IPMNs at baseline and increase in BD-IPMN diameter over time. RESULTS: During the follow-up period, 154 patients developed BD-IPMN and 322 patients did not. Older age, diabetes mellitus, gallbladder adenomyomatosis, and absence of gallstones were associated with the presence of BD-IPMNs at baseline. Increases in diameter of BD-IPMNs were associated with 3 baseline factors: BD-IPMN diameter greater than 17 mm, gallbladder adenomyomatosis, and a common bile duct diameter less than 5.5 mm. Patients with BD-IPMNs could be stratified into 4 groups with varying risk for the enlargement of BD-IPMNs over time: those with 3 risk factors (hazard ratio [HR], 11.4; 95% confidence interval [CI], 3.4-37.8), 2 risk factors (HR, 4.7; 95% CI, 1.7-12.8), or 1 risk factor (HR, 3.1; 95% CI, 1.2-8.2) compared with those without risk factors. CONCLUSIONS: For patients with BD-IPMNs, careful follow-up evaluation is particularly important for those with BD-IPMN >17 mm in size, common bile duct diameter <5.5 mm, or gallbladder adenomyomatosis.

Preoperative and intraoperative assessment of myometrial invasion in endometrial cancer: comparison of magnetic resonance imaging and frozen sections.

OBJECTIVE: To compare the diagnostic characteristics of the evaluation of myometrial invasion (MI) retrospectively between preoperative magnetic resonance imaging (MRI) and intraoperative frozen sections. DESIGN: A retrospective study. SETTING: University hospital. SAMPLE: 201 women diagnosed with endometrial carcinoma. METHODS: All women underwent preoperative MRI and 111 of them also underwent intraoperative frozen section assessment. The final pathological evaluation was used as the definitive diagnosis. MAIN OUTCOME MEASURES: In women who underwent MRI and frozen sections (n = 111), the accuracies of detection of MI and of deep invasion (defined as ≥50% invasion) were compared. RESULTS: The accuracy, sensitivity, and specificity of MRI for detection of MI were 65.8, 58.8, and 88.5%, and those in frozen sections were 90.1, 90.6, and 88.5%, respectively. The accuracy and sensitivity of frozen sections were significantly higher (p < 0.001, p < 0.001), whereas the specificity of the two methods did not differ (p = 1.000). The accuracy, sensitivity, and specificity of MRI for detection of deep invasion were 83.8, 69.2, and 88.2%, and those of frozen sections were 93.7, 73.1, and 100.0%, respectively. The accuracy and specificity of frozen sections were significantly higher (p = 0.007 and p < 0.001, respectively), whereas sensitivity did not show a significant difference (p = 0.999). CONCLUSION: In assessment of MI, the accuracy of frozen sections was significantly higher than that of MRI. Since the diagnostic characteristics differ between two methods, additional intraoperative frozen sections are recommended for more accurate assessment of MI when MRI is negative for the presence of any MI or positive for the presence of deep invasion.