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Objectives: This study aimed to assess the feasibility of pancreatic steatosis quantification by automated whole-volume measurement of the fat fraction of the pancreas on CT in comparison to MRI using proton-density fat fraction (PDFF) techniques. Methods: Fifty-nine patients who underwent both CT and MRI were analyzed. Automated whole-volume measurement of pancreatic fat on unenhanced CT was performed by a histogram analysis with local thresholding. Three sets of CT fat volume fraction (FVF) (%) values with thresholds of −30 Hounsfield unit (HU), −20 HU and −10 HU were compared to MR-FVF (%) values measured on a PDFF map. Results: The median −30 HU CT-FVF, −20 HU CT-FVF, −10 HU CT-FVF and MR-FVF values of the pancreas were 8.6% (interquartile range (IQR), 11.3), 10.5% (IQR, 13.2), 13.4% (IQR, 16.1) and 10.9% (IQR, 9.7), respectively. The −30 HU CT-FVF (%), −20 HU CT-FVF (%) and −10 HU CT-FVF (%) of the pancreas showed a significant positive correlation with the MR-FVF (%) of the pancreas (ρ = 0.898, p < 0.001, ρ = 0.905, p < 0.001, ρ = 0.909, p < 0.001, respectively). The −20 HU CT-FVF (%) displayed reasonable agreement with the MR-FVF (%) with a low absolute fixed bias (mean difference, 0.32%; limit of agreement from −10.1 to 10.7%). Conclusion: The automated whole-volume measurement of the CT fat fraction of the pancreas using the threshold CT attenuation value of −20 HU may be a feasible, non-invasive, and convenient technique for quantifying pancreatic steatosis. Advances in knowledge: CT-FVF value of the pancreas had a positive correlation with the MR-FVF value. The −20 HU CT-FVF may be a convenient technique for quantifying pancreatic steatosis.

Granulocyte colony-stimulating factor (G-CSF)-producing tumors have an aggressive clinical course. Here, we report five cases of G-CSF-producing tumors and review the literature, focusing on imaging findings related to tumor-produced G-CSF. In addition to our cases, we identified 30 previous reports of G-CSF-producing tumors on which 18F-fluorodeoxyglucose positron emission tomography (FDG-PET)/CT, bone scintigraphy, or evaluation of bone marrow MR findings was performed. White blood cell count, serum C-reactive protein, and serum interleukin-6 were elevated in all cases for which these parameters were measured. G-CSF-producing tumors presented large necrotic masses (mean diameter 83.2 mm, range 17–195 mm) with marked FDG uptake (mean maximum standardized uptake value: 20.09). Diffuse FDG uptake into the bone marrow was shown in 28 of the 31 cases in which FDG-PET/CT was performed. The signal intensity of bone marrow suggested marrow reconversion in all seven MRI-assessable cases. Bone scintigraphy demonstrated no significant uptake, except in two cases with bone metastases. Splenic FDG uptake was increased in 8 of 10 cases in which it was evaluated. These imaging findings may reflect the effects of tumor-produced G-CSF. The presence of G-CSF-producing tumors should be considered in patients with cancer who show these imaging findings and marked inflammatory features of unknown origin.

Objective Transmural healing (TH) has been attracting attention as a new therapeutic target for Crohn's disease, but there are few clinical data on TH in Japan. We introduced low-dose computed tomography enterography (CTE) as a monitoring method for Crohn's disease and retrospectively investigated the accuracy of evaluating TH by CTE. Methods Among Crohn's disease patients who underwent low-dose CTE at our hospital from January 2009 to March 2021, 122 patients who underwent colonoscopy or balloon endoscopy within 2 weeks were included. Results of radiological and endoscopic examinations were reviewed independently by radiologists and gastrointestinal endoscopists, respectively. The concordance rate of the diagnosis between CTE and endoscopy was evaluated. Results Twenty-six patients (21.3%) achieved TH, and the kappa index was 0.743. On comparing the TH and non-TH groups, the Crohn's disease activity index (p=0.02), endoscopic healing rate (p0.001), serum albumin (p=0.043), and serum C-reactive protein level (p=0.018) showed significant differences. Among the 122 patients, 69 (56.5%) showed concordance between the diagnosis of CTE and endoscopy, and 22 (18.0%) achieved both TH and endoscopic healing. Conclusion This study provides real-world data on Crohn's disease evaluated with low-dose CTE in Japan. The TH criterion used in this study has a high kappa coefficient and can be used reproducibly in many institutions.

Objective CT enterography/enteroclysis (CTE) is listed in the clinical practice guidelines as a method for diagnosing small bowel bleeding, as is capsule endoscopy (CE), but there are no real-world data yet available on CTE in Japan. This study aimed to investigate the diagnostic ability of CTE and long-term prognosis after CTE in Japan. Patients We conducted a retrospective cohort study of patients suspected of having small bowel bleeding who underwent both CTE and CE within 30 days between April 2008 and March 2019. The number of patients free from rebleeding for up to 24 months was thus determined. Results Seventy-one patients were extracted from the database. The 43 patients (60.6%) with a definite and suspicious source of bleeding in the small bowel were detected by CTE. When the 31 patients with a definite source of bleeding in the small bowel were analyzed, the sensitivity of CTE was 19/31 (61.3%) and that of CE was 24/31 (77.4%), thus indicating no significant difference (p=0.332). However, the sensitivity when CTE and CE were used in combination was 30/31 (96.8%), which was significantly higher than that of CE alone (p=0.0412). No rebleeding was observed in the CTE and CE negative group (p=0.0965). Conclusion The combined use of CTE and CE increased the detection rate of small bowel bleeding. Therefore, in patients with suspected tumor/polyp lesions, not only CE, but also CTE should be performed. This study provides the first real-world data on the diagnostic accuracy of CTE for small bowel bleeding in Japan.

Background To resolve drawbacks of navigator triggering (NT) three-dimensional (3D) magnetic resonance cholangiopancreatography (MRCP), several approaches were proposed to obtain 3D MRCP within a single breath-hold (BH). However, reduced field-of-view technique in the phase-encoding direction combined with two-dimensional spatially selective radiofrequency excitation pulses has not yet been applied to 3D BH MRCP. Purpose To investigate the feasibility and the complementary value of 3D BH zoomed MRCP to conventional 3D NT MRCP in patients with branch duct intraductal papillary mucinous neoplasms (BD-IPMNs) of the pancreas. Study type Retrospective. Population A total of 221 patients (116 male and 105 female, median age 73 years) with BD-IPMNs. Field strength/sequence 3.0 T/3D turbo spin echo ASSESSMENT: MR images were analyzed by three radiologists (R.M., H.O., M.T., with 1, 13, and 17 years of experience) to compare blurring and motion artifacts, background suppression, visualization of main pancreatic duct (MPD), conspicuity of BD-IPMN, and overall image quality. Statistical tests Wilcoxon-signed rank, Mann-Whitney U, chi-squared or Fisher's exact tests (P Results Image quality was significantly higher on 3D NT MRCP images than on 3D BH zoomed MRCP (median (interquartile range); background suppression, 4 (4-4) vs. 3 (3-4); visualization of MPD, 4 (3-4) vs. 4 (3-4), conspicuity of BD-IPMN, 4 (3-4) vs. 3 (3-4); and overall image quality, 3 (3-4) vs. 3 (3-3)). However, in 32 (14%) patients, 3D NT MRCP showed a score of 1 or 2 in overall image quality. Regarding the conspicuity of BD-IPMN, a conspicuity score of 1 or 2 was rendered in 31 (14%) patients in 3D NT MRCP group. Conversely, 3D BH zoomed MRCP showed a score of 3 or 4 in 29 (94%) of these 31 patients. Data conclusion 3D BH zoomed MRCP plays a complementary role to 3D NT MRCP, and may improve the conspicuity of BD-IPMNs in patients with irregular breathing pattern. Level of evidence 4 TECHNICAL EFFICACY: Stage 2.

To evaluate the feasibility of High-resolution (HR) magnetic resonance imaging (MRI) of the liver using deep learning reconstruction (DLR) based on a deep learning denoising technique compared with standard-resolution (SR) imaging.This retrospective study included patients who underwent abdominal MRI including both HR imaging using DLR and SR imaging between April 1 and August 31, 2019. DLR was applied to all HR images using 12 different strength levels of noise reduction to determine the optimal denoised level for HR images. The mean signal-to-noise ratio (SNR) was then compared between the original HR images without DLR and the optimal denoised HR images with DLR and SR images. The mean image noise, sharpness and overall image quality were also compared. Statistical analyses were performed with the Friedman and Dunn-Bonferroni post-hoc test.In total, 49 patients were analyzed (median age, 71 years; 25 women). In quantitative analysis, the mean SNRs on the original HR images without DLR were significantly lower than those on the SR images in all sequences (p 0.01). Conversely, the mean SNRs on optimal denoised HR images were significantly higher than those on the SR images in all sequences (p 0.01). In the qualitative analysis, the mean scores for the image noise and overall image quality were significantly higher on optimal denoised HR images than on the SR images in all sequences (p 0.01) except for the mean image noise score in in-phase (IP) images.The use of a deep learning-based noise reduction technique substantially and successfully improved the SNR and image quality in HR imaging of the liver. Denoised HR imaging using the DLR technique appears feasible for use in liver MR examinations compared with SR imaging.

To evaluate the association between a sign and visceral pleural invasion (VPI) of peripheral non–small-cell lung cancer (NSCLC) that does not appear touching the pleural surface. A total of 221 consecutive patients with NSCLC that did not appear touching the pleural surface, ≤ 3 cm in solid tumor diameter, and was surgically resected between January 2009 and December 2015 were included. We focused on the flat distortion of the tumor caused by an arch-shaped linear tag between the tumor and the pleura on CT and named it a bridge tag sign. We evaluated the associations between the clinicopathological features of the tumor, including the bridge tag sign, and VPI. We also evaluated the associations between histopathological findings and the bridge tag sign. The utility of the bridge tag sign in the diagnosis of VPI was statistically assessed. The bridge tag sign was observed in 48 (20.8%) patients. VPI was positive in 9 (4.1%) patients; among these, the bridge tag sign was positive in 8 patients. In multivariate analysis, a bridge tag sign was significantly associated with VPI. The bridge tag sign was associated with longer contact length of the pleura with the tumor and trapezoid type pleural retraction. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of the bridge tag sign in the diagnosis of VPI were 88.9%, 83.5%, 83.7%, 18.6%, and 99.4%, respectively. A bridge tag sign on CT might improve the accuracy of the prediction of VPI. • We present the bridge tag sign which is defined as a flat distortion of an NSCLC tumor by an arch-shaped linear tag between the tumor and chest wall or interlobar fissure. • The bridge tag sign was an independent predictive factor for visceral pleural invasion. • The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of the bridge tag sign in the diagnosis of visceral pleural invasion were 88.9%, 83.5%, 83.7%, 18.6%, and 99.4%, respectively.

Objective: Major liver resection is an effective treatment option for patients with liver malignancy. The future liver remnant (FLR) volume and complications after portal vein embolization (PVE) were compared between the ipsilateral right portal vein (PTPE) and transileocolic (TIPE) approaches. Methods: A total of 42 patients (TIPE, n = 22; PTPE, n = 20) underwent right lobectomy after PVE. CT and hepatobiliary scintigraphy were repeated before and after PVE. The blood examination findings and the FLR values (FLRCT: calculated from CT, %FLRCT: FLRCT ratio, %FLRSPECT: FLR ratio using single photon emission CT, FLRCT/BS: FLRCT to body surface ratio) were compared between two approach sites. The complications and mortality were also analyzed after PVE and major right hepatectomy. Results: There were no significant differences in the patient characteristics, blood examination findings or FLR values between two groups. Adequate liver regeneration was observed without significant differences between PTPE and TIPE (increased ratio of FLRCT: 8.7% vs 19.2%, p = 0.15 [25–75 percentile: 17.1–60.4], %FLRCT: 11.2% vs 8.3%, p = 0.25 [6.3–13.3], %FLRSPECT: 15.4% vs 19.2%, p = 0.09 [16.0–22.4], FLRCT/BS: 33.6% vs 47.1%, p = 0.19 [17.2–60.4], respectively), but TIPE required a significantly longer procedure time than PTPE [181.4 min vs 108.7 min, p < 0.01 (103.3–193.5)]. However, one patient was converted to TIPE due to bleeding during PTPE. After right lobectomy, portal vein stenosis or thrombosis was noted in three patients [two with TIPE (9.1%) and one with PTPE (5%)] and three TIPE patients died within 90 days (13.6%) after right hepatectomy. Conclusion: FLR volume significantly increased after PVE, regardless of the approach sites; however, PTPE is a useful technique with a shorter procedure time.

Aim The impact of sustained virologic response (SVR) on surgical outcomes for patients with hepatitis C virus (HCV)‐related hepatocellular carcinoma (HCC) remains controversial. This study aimed to evaluate the influence of SVR on long‐term surgical outcomes after hepatectomy. Methods This multicenter study included 504 patients who underwent curative resection for HCV‐related HCC. Patients with a history of HCC treatment, HBV infection, poor liver function, and tumor with major vascular invasion were excluded. Long‐term surgical outcomes (overall survival [OS] and recurrence‐free survival [RFS]) among patients who achieved SVR before hepatectomy (Pre‐SVR group: 58 patients), after hepatectomy (Post‐SVR group: 54 patients), and without SVR (Non‐SVR group: 186 patients) were compared after adjusting for 13 confounding factors. Using the surgically resected specimens, comparison of the pathological changes in liver fibrosis between the first and second hepatectomy were analyzed. Results Patients with SVR were younger, had better liver function, and less liver fibrosis compared to patients without SVR. Propensity score‐matched OS and RFS were significantly better in Pre‐SVR group than Non‐SVR group (P = .029 and P = .009, respectively). Inverse probability‐weighted OS and RFS were also significantly better in the Post‐SVR group (P = .001 and P = .021, respectively) than in the Non‐SVR group. Histopathological evaluation revealed that only the patients with SVR had regression of liver fibrosis (P, Although the achievement of sustained virologic response (SVR) is essential for improving survival in patients with hepatitis C virus (HCV) infection, its importance on surgical outcomes for HCV‐related hepatocellular carcinoma (HCC) is still controversial. In this multicenter study, we demonstrated the importance of achieving SVR before or after hepatectomy for improving long‐term surgical outcomes. These results can encourage patients with HCV‐related HCC to undergo antiviral therapy regardless of the timing.

This study describes a light-weight wideband spiral antenna that radiates a unidirectional beam. To realise a light-weight antenna, a one-layer thick high-impedance surface reflector (HISR) for a reference spiral antenna is replaced by a two-layer circular HISR (TL-CirHISR). The TL-CirHISR is made of fan-shaped patches printed on a dielectric substrate. It is revealed that a voltage standing wave ratio (VSWR) of

Objectives To investigate neuroendocrine carcinoma (NEC) of the uterine cervix cases for MRI features and staging, as well as pathological correlations and survival. Results FIGO was I in 42, II in 14, III in 1, and IV in 5 patients. T2-weighted MRI showed homogeneous slightly high signal intensity and obvious restricted diffusion (ADC map, low intensity; DWI, high intensity) throughout the tumor in most cases, and mild enhancement in two-thirds. In 50 patients who underwent a radical hysterectomy and lymphadenectomy without neoadjuvant chemotherapy (NAC), intrapelvic T staging by MRI overall accuracy was 88.0% with reference to pathology staging, while patient-based sensitivity, specificity, and accuracy for metastatic pelvic lymph node detection was 38.5%, 100%, and 83.3%, respectively. During a mean follow-up period of 45.6 months (range 4.3-151.0 months), 28 patients (45.2%) experienced recurrence and 24 (38.7%) died. Three-year progression-free and overall survival rates for FIGO I, II, III, and IV were 64.3% and 80.9%, 50% and 64.3%, 0% and 0%, and 0% and 0%, respectively. Materials and methods Sixty-two patients with histologically surgery-proven uterine cervical NEC were enrolled. Twelve received NAC. Clinical data, pathological findings, and pretreatment pelvic MRI findings were retrospectively reviewed. Thirty-two tumors were pure NEC and 30 mixed with other histotypes. The NECs were small cell type (41), large cell type (18), or a mixture of both (3). Conclusions Homogeneous lesion texture with obvious restricted diffusion throughout the tumor are features suggestive of cervical NEC. Our findings show that MRI is reliable for T staging of cervical NEC.

A low-profile spiral antenna backed by a circular high-impedance surface (HIS) reflector composed of homogeneous (CirHISRhomo) fan-shaped patch elements is investigated. The total antenna height from the bottom of the CirHISRhomo to the spiral antenna is very small: 0.09 wavelength at a lowest design frequency of 3 GHz. It is revealed that the CirHISRhomo contributes to a constant input impedance and a small axial ratio (AR) across the design frequency range of 3–10 GHz (the fractional bandwidth is approximately 108%). For comparison, the AR for the spiral antenna backed by a conventional perfect electric conducting reflector is also presented. The analysis results are verified by the measured results of the fabricated antenna.

To compare the occurrence of transient respiratory motion artifacts (TRMAs) in multiple arterial phases on abdominal magnetic resonance (MR) images between those obtained using gadobutrol and gadoxetate disodium. Two hundred and fourteen abdominal MR examinations (101 with gadoxetate disodium, 113 with gadobutrol) were evaluated. Dynamic three-dimensional contrast-enhanced T1-weighted imaging (CAIPIRINHA-Dixon-TWIST-VIBE) including single-breath-hold six arterial phase acquisitions was performed on a 3.0-T MRI scanner. The TRMAs frequency and the mean TRMA scores were compared between patients assessed with gadoxetate disodium and those assessed with gadobutrol. In addition, the timing of TRMAs appearing for the first time was also recorded and compared between the two groups. The mean TRMA scores in all arterial phases using gadoxetate disodium were significantly worse than in those using gadobutrol (1.49 ± 0.78 vs. 1.18 ± 0.53, P

There is wide agreement that morphologic features and enhancement kinetics should be evaluated for MRI of the breast, although there has been no clear consensus concerning optimal temporal resolutions. The objective of this study was to investigate the optimal temporal resolution for the kinetic analysis of breast cancers.Thirty-four patients with 34 enhancing lesions of breast cancer who underwent dynamic contrast-enhanced MRI (DCE-MRI) on a 3.0-T scanner were included in this retrospective study. DCE-MRI was performed with an original temporal resolution of 10-s, and the values of pharmacokinetic parameters (Ktrans, Ve, Kep, and area under the curve (AUC)) were compared with selected data of 30-s and 60-s time intervals.Among the 34 lesions, 10 showed a wash out pattern, 16 showed a plateau pattern, and 8 showed a persistent enhancement pattern. The Ktrans value in the wash-out pattern was significantly higher than that of other time-intensity curve patterns (p 0.01). The Kep and AUC also showed significant differences between the wash-out pattern and other types (p 0.01). On comparing the perfusion parameters among different temporal resolutions, simulations showed that only the AUC differed significantly between the data acquired at a 10-s temporal resolution and that acquired at a 60-s time interval (p 0.01). Although the comparison of the AUC between the 30-s and 60-s data also showed significant differences (p = 0.01), there was no significant difference between the 10-s and 30-s data (p = 0.17).DCE-MRI with a temporal resolution of 30-s preserves the kinetic information. Further prospective studies will be needed to investigate the trade-off between temporal and spatial resolution in DCE-MRI.

To determine whether LI-RADS ancillary features predict longitudinal LR-3 observation category changes. This exploratory, retrospective, single-center study with an independent reading center included patients who underwent two or more multiphase CT or MRI examinations for hepatocellular carcinoma assessment between 2011 and 2015. Three readers independently evaluated each observation using CT/MRI LI-RADS v2017, and observations categorized LR-3 using major features only were included in the analysis. Prevalence of major and ancillary features was calculated. After excluding low-frequency (

An 81-year-old woman who had undergone total thyroidectomy for papillary thyroid cancer 12 years earlier was found to have a tumor in the tail of the pancreas. Four years earlier, skin, lung, and mediastinal lymph node metastases had appeared. Computed tomography (CT) showed a mass 26 mm in diameter in the tail of the pancreas. Thereafter, the pancreatic tumor increased in size, while the lung metastases remained stable. Unenhanced CT at the time of first detection showed that the tumor was heterogeneous, with low-attenuation areas indicating fat components. As the tumor grew, the fat components became unclear. Laparoscopic distal pancreatectomy and splenectomy were performed. The tumor was diagnosed as dedifferentiated liposarcoma with a well-differentiated liposarcoma component at the tumor margin. The pancreas is an extremely rare site of primary liposarcoma. In the present case, a pancreatic liposarcoma appeared during follow-up of thyroid cancer, and the changes over time were able to be observed with CT.

To determine imaging findings of pancreatic adenocarcinomas incidentally detected on contrast-enhanced multiphasic dynamic computed tomography (CT) obtained during the follow-up for other diseases. From January 2007 to December 2018, 14 patients with pancreatic adenocarcinomas incidentally detected on CT obtained during the follow-up for other diseases (incidental group) and 105 patients with pancreatic adenocarcinomas symptomatically detected on ultrasound or CT (non-incidental group) were included. Imaging characteristics of the tumor were compared between the two groups. Additionally, imaging findings prior to the detection of a tumor on previous CT images in the incidental group were also assessed. In cancers of the pancreas body/tail, there was a significantly smaller tumor size (median, 17 mm vs. 42 mm, p

Purpose To evaluate the association of the pancreatic exocrine function estimated by cine-dynamic magnetic resonance cholangiopancreatography (MRCP) using a spatially selective inversion-recovery (IR) pulse with the pancreatic endocrine function estimated by the T1 relaxation time of the pancreatic parenchyma and HbA1c values. Materials and methods Forty-three patients with suspected hepatobiliary or pancreatic diseases were included. Patients were classified into three groups: HbA1c U tests. Results Both the mean secretion grade and frequency of the pancreatic secretory inflow had a significant negative correlation with the T1 relaxation time of the pancreatic parenchyma (r = − 0.335, p = 0.028 and r = − 0.305, p = 0.047, respectively) and HbA1c values (r = − 0.308, p = 0.044 and r = − 0.313, p = 0.041, respectively). Both the mean secretion grade and frequency of the pancreatic secretory inflow in the elevated HbA1c (prediabetes and diabetes) group were significantly lower than those in the normal group (p = 0.030 and p = 0.029, respectively). Conclusion The pancreatic exocrine function estimated by cine-dynamic MRCP was significantly lower in patients with prediabetes and diabetes than in controls. Cine-dynamic MRCP with a spatially selective IR pulse may be useful for the early diagnosis of pancreatic exocrine insufficiency in patients with pancreatic endocrine insufficiency.

PURPOSE To evaluate the image quality of ultra-high-resolution CT (U-HRCT) in the comparison among four different reconstruction methods, focusing on the gastric wall structure, and to compare the conspicuity of a three-layered structure of the gastric wall between conventional HRCT (C-HRCT) and U-HRCT. METHOD Our retrospective study included 48 patients who underwent contrast-enhanced U-HRCT. Quantitative analyses were performed to compare image noise of U-HRCT between deep-learning reconstruction (DLR) and other three methods (filtered back projection: FBP, hybrid iterative reconstruction: Hybrid-IR, and Model-based iterative reconstruction: MBIR). The mean overall image quality scores were also compared between the DLR and other three methods. In addition, the mean conspicuity scores for the three-layered structure of the gastric wall at five regions were compared between C-HRCT and U-HRCT. RESULTS The mean noise of U-HRCT with DLR was significantly lower than that with the other three methods (P

This paper presents the antenna characteristics of a spiral antenna backed by a circular high-impedance surface reflector (CirHISR) composed of a fan-shaped patch element. The fan-shaped patch element is arrayed symmetrically. The antenna height between the spiral antenna and the bottom surface of the CirHISR is 0.09 wavelength (9.0 mm) at the lowest operating frequency of 3 GHz. Input impedance and axial ratio are analyzed using FEKO based on the method of moment and compared to that of a spiral antenna with a CirHISR asymmetric array using a fan-shaped patch element. It is found that good antenna characteristics are obtained across a frequency range of 3 GHz to 10 GHz (a fractional bandwidth of 108%). Similar antenna characteristics are also found between the spiral with the CirHISR symmetric patch array and that of the asymmetric one.

To resolve drawbacks of navigator triggering (NT) three-dimensional (3D) magnetic resonance cholangiopancreatography (MRCP), several approaches were proposed to obtain 3D MRCP within a single breath-hold (BH). However, reduced field-of-view technique in the phase-encoding direction combined with two-dimensional spatially selective radiofrequency excitation pulses has not yet been applied to 3D BH MRCP.To investigate the feasibility and the complementary value of 3D BH zoomed MRCP to conventional 3D NT MRCP in patients with branch duct intraductal papillary mucinous neoplasms (BD-IPMNs) of the pancreas.Retrospective.A total of 221 patients (116 male and 105 female, median age 73 years) with BD-IPMNs.3.0 T/3D turbo spin echo ASSESSMENT: MR images were analyzed by three radiologists (R.M., H.O., M.T., with 1, 13, and 17 years of experience) to compare blurring and motion artifacts, background suppression, visualization of main pancreatic duct (MPD), conspicuity of BD-IPMN, and overall image quality.Wilcoxon-signed rank, Mann-Whitney U, chi-squared or Fisher's exact tests (P 0.05).Image quality was significantly higher on 3D NT MRCP images than on 3D BH zoomed MRCP (median (interquartile range); background suppression, 4 (4-4) vs. 3 (3-4); visualization of MPD, 4 (3-4) vs. 4 (3-4), conspicuity of BD-IPMN, 4 (3-4) vs. 3 (3-4); and overall image quality, 3 (3-4) vs. 3 (3-3)). However, in 32 (14%) patients, 3D NT MRCP showed a score of 1 or 2 in overall image quality. Regarding the conspicuity of BD-IPMN, a conspicuity score of 1 or 2 was rendered in 31 (14%) patients in 3D NT MRCP group. Conversely, 3D BH zoomed MRCP showed a score of 3 or 4 in 29 (94%) of these 31 patients.3D BH zoomed MRCP plays a complementary role to 3D NT MRCP, and may improve the conspicuity of BD-IPMNs in patients with irregular breathing pattern.4 TECHNICAL EFFICACY: Stage 2.

To determine the consistency of major hepatocellular carcinoma (HCC) features between CT and MRI based on Liver Imaging Reporting and Data System (LI-RADS) v2018 and to investigate the additional value on gadoxetic acid-enhanced MRI.Patients who underwent dynamic CT and gadoxetic acid-enhanced MRI within 1 month were investigated. Two radiologists evaluated the presence of major HCC features and categorized observations using LI-RADS v2018 algorithm. In addition, each observation was recorded as hyper-, iso-, or hypo-intensity on hepatobiliary-phase (HBP) images.Sixty-one patients with 110 observations were identified. Among 88 observations classified as LR-3, 4 or 5, arterial phase hyper-enhancement and washout appearance showed higher frequencies on CT than on MRI (75.0% vs. 58.0%, P 0.001, and 60.2% vs. 44.3%, P = 0.014, respectively). Of the 59 LR-3 observations categorized on MRI, 70.0% of observations with hypo-intensity on HBP images were HCCs, whereas 89.5% of observations with iso- or hyper-intensity on HBP images were non-HCCs (P 0.001) CONCLUSION: The frequencies of arterial phase hyper-enhancement and washout appearances were higher on CT than on gadoxetic acid-enhanced MRI. For LR-3 observations, adding the hepatobiliary-phase hypo-intensity to major features improved the diagnostic performance of MRI in distinguishing HCCs from non-HCC lesions.

BACKGROUND Reduced field-of-view diffusion-weighted imaging (rDWI) with tilted two-dimensional radiofrequency (RF) excitation planes has not yet been applied to the imaging of the pancreas although the utility of this technique which allows the acquisition of high-quality images without aliasing artifacts in the phase-encoding direction has been evaluated for brain and spinal cord imaging. PURPOSE To evaluate the visual image quality of the pancreas by tilting the excitation plane (tilted rDWI) in comparison to conventional DWI (cDWI) and rDWI without using the tilted excitation plane. STUDY TYPE Retrospective. POPULATION Thirty-two patients evaluated for suspected pancreatobiliary diseases. FIELD STRENGTH/SEQUENCE Echo-planar imaging DWI (cDWI, rDWI, and tilted rDWI) acquired at 3 T. ASSESSMENT Images from each DWI sequence were analyzed by five radiologists to compare image quality (conspicuity of pancreatic edges, interslice signal homogeneity, overall image quality, and conspicuity of focal pancreatic lesions) and artifacts (presence of blurring or ghosting artifacts, susceptibility artifacts, and aliasing artifact). STATISTICAL TESTS Shapiro-Wilk test was performed to assess whether data were normally distributed. Friedman test followed by Bonferroni-adjusted Wilcoxon signed-rank test for post hoc analysis was performed to compare image quality and artifact scores. RESULTS The mean scores for conspicuity of pancreatic edges (3.36 vs. 2.37), interslice signal homogeneity (3.14 vs. 2.81), presence of ghosting artifacts (3.32 vs. 2.66), susceptibility artifacts (3.06 vs. 2.30), and aliasing artifacts (3.90 vs. 2.34), and overall image quality (3.49 vs. 2.36) were significantly higher in the tilted rDWI than in the rDWI (P

Purpose This study aimed to examine MRI features and staging of neuroendocrine carcinoma (NEC) of the endometrium and evaluate survival. Materials and methods Clinical data, pathological, and preoperative pelvic MRI findings in 22 patients with histologically surgery-proven endometrial NEC were retrospectively reviewed. Tumors were pure NEC (n = 10) or mixed histotype (n = 12), with 13 large and nine small cell type. Results International Federation of Gynecology and Obstetrics (FIGO) staging was I, II, III, and IV in 6, 2, 12, and 2 patients, respectively. In 13 (76.4%) of 17 patients with pathological deep myometrial invasion, MRI showed abnormal diffusely infiltrative high T2 signal intensity throughout the myometrium with loss of normal uterine architecture. All tumors had restricted diffusion (apparent diffusion coefficient map low signal intensity, diffusion weighted imaging high signal intensity). Accuracy of T staging by MRI for all cases was 81.8%, with reference to pathology staging, while patient-based sensitivity, specificity, and accuracy for detecting metastatic pelvic lymph nodes was 60.0%, 100%, and 77.8%, respectively. Two intrapelvic peritoneal dissemination cases were detected by MRI. During follow-up (mean 30.4, range 3.3-138.4 months), 16 patients (72.7%) experienced recurrence and 12 (54.5%) died of disease. Two-year disease-free and overall survival rates for FIGO I, II, III, and IV were 66.7% and 83.3%, 50% and 100%, 10% and 33.3%, and 0% and 0%, respectively. Conclusion Abnormal diffusely infiltrative high T2 signal intensity throughout the myometrium with normal uterine architecture loss and obvious restricted diffusion throughout the tumor are suggestive features of endometrial NEC. Pelvic MRI is reliable for intrapelvic staging of affected patients.

Purpose To examine the frequency and patterns of renal parenchymal retention of iodinated contrast agent during follow-up computed tomography (CT) performed one day after undergoing contrast-enhanced CT and to evaluate the association with the renal function before and after contrast-enhanced CT. Materials and Methods This retrospective study included 55 patients who underwent follow-up CT the day after contrast-enhanced CT had been performed. Two radiologists categorized the retention patterns on a scale of 0–6 (0: no retention, 1: diffuse parenchymal, 2: diffuse cortical, 3: subcapsular tiny nodular, 4: cortical wedge-shaped, 5: medullary focal, 6: renal pelvic). In addition, we collected the patients’ clinical data, including the development of contrast-induced nephropathy (CIN). Results A total of 37 patients (67 %) showed retention of contrast agent in the kidney (retention group), while 18 did not (non-retention group). A diffuse parenchymal pattern and renal pelvis pattern were the most common. High levels of creatinine (Cre) and blood urea nitrogen (BUN) before contrast-enhanced CT were significantly associated with the retention in the kidney (p = 0.018, 0.006, respectively). The frequency of the development of CIN was significantly higher (p = 0.021) in the retention group (10/37) than in the non-retention group (0/18). A diffuse parenchymal pattern and diffuse cortical pattern were significantly more common in patients with CIN than in those without CIN (p = 0.003, p = 0.045, respectively). Conclusion Renal parenchymal retention of iodinated contrast agent the day after contrast-enhanced CT was a frequently recognized finding and was associated with renal dysfunction. This finding, especially diffuse parenchymal and cortical patterns, may be a potential biomarker of CIN development.

Although it is important to quantify the degree of fatty degeneration of the pancreas, it is difficult to make such a quantification using conventional computed tomography (CT). The present study evaluated the feasibility of pancreatic fat quantification by dual-energy CT (DECT) compared with T2*-corrected six-point Dixon magnetic resonance imaging (MRI). Twenty-eight patients who underwent both DECT (100 and 150 kVp) and Dixon MRI without the use of contrast agents were analyzed. The region of interest (ROI) was placed at the head and body/tail of the pancreas on fat volume fraction (FVF) maps generated using the multi-material decomposition (MMD) algorithm on DECT. The FVF (%) of pancreatic parenchyma measured by DECT (CT-FVF) was compared with that measured on FVF maps calculated using Dixon MRI (MR-FVF) using the Spearman rank correlation coefficient. The median CT-FVF (%) values of the head and body/tail of the pancreas on DECT were 14.2% (range 0.1–81.2%) and 9.4% (range 0–40.8%), respectively. The median MR-FVF (%) values of the head and body/tail of the pancreas on Dixon MRI were 12.2% (range 1.2–80.9%) and 8.1% (range 0.3–43.7%), respectively. CT-FVF (%) measured by DECT showed a significant correlation with the MR-FVF (%) measured by Dixon MRI in the head of the pancreas (ρ = 0.631, P

A questionnaire survey was conducted regarding the prognosis for pancreatic cancer at 8 major hospitals in Yamaguchi Prefecture. A total of 552 patients with pancreatic cancer who underwent radical surgery between 1997 and 2016 were identified. Five of them survived for more than 10 years. Among the 5 patients, none was treated with neoadjuvant chemotherapy: 4 underwent PD and 1 underwent DP-CAR. Two of them were treated with adjuvant chemotherapy. No complications occurred during their postoperative courses. All of them had no recurrence and survived. Here, we reported the longterm postoperative survival of patients with pancreatic cancer with literature review.

This paper presents a fully digital transmitting and receiving module (FDTR-MOD) for a future active electrically scanned array (AESA). The FDTR-MOD is composed of a fully digital transmitting and receiving circuit (FDTR-circuit) mounted in a novel stack module package (SMP). The interface signal of the FDTR-MOD is digitized by operating analog-to-digital converters (ADCs), digital-to-analog converters (DACs), and phase lock loop (PLL) for each antenna element. The prototypes of the SMP and FDTR-circuit are made and measured. It is found that the SMP has good RF characteristics. It is also found that the standard deviation of synchronization is 0.21 degree in receiving circuits and 0.31 degree in transmitting and receiving circuits of the FDTR-circuit.

To determine whether LI-RADS ancillary features predict longitudinal LR-3 observation category changes.This exploratory, retrospective, single-center study with an independent reading center included patients who underwent two or more multiphase CT or MRI examinations for hepatocellular carcinoma assessment between 2011 and 2015. Three readers independently evaluated each observation using CT/MRI LI-RADS v2017, and observations categorized LR-3 using major features only were included in the analysis. Prevalence of major and ancillary features was calculated. After excluding low-frequency ( 5%) features, inter-reader agreement was assessed using intraclass correlation coefficient (ICC). Major and ancillary feature prediction of observation upgrade (to LR-4 or higher) or downgrade (to LR-1 or LR-2) on follow-up imaging was assessed using logistic regression.141 LR-3 observations in 79 patients were included. Arterial phase hyperenhancement, washout, restricted diffusion, mild-moderate T2 hyperintensity, and hepatobiliary phase hypointensity were frequent enough for further analysis (consensus prevalence 5.0-66.0%). ICCs for inter-reader agreement ranged from 0.18 for restricted diffusion to 0.48 for hepatobiliary phase hypointensity. On follow-up, 40% (57/141) of baseline LR-3 observations remained LR-3. 8% (11/141) were downgraded to LR-2, and 42% (59/141) were downgraded to LR-1. A small number were ultimately upgraded to LR-4 (2%, 3/141) or LR-5 (8%, 11/141). None of the assessed major or ancillary features was significantly associated with observation category change. Longer follow-up time was significantly associated with both observation upgrade and downgrade.While numerous ancillary features are described in LI-RADS, most are rarely present and are not useful predictors of LR-3 observation category changes.

Purpose To investigate the clinical value of measuring the ECV fraction of the pancreas by DECT in association with an impaired glucose tolerance (IGT) estimated by the hemoglobin A1C (HbA1C) value in patients with or without cirrhosis. Materials and Methods This retrospective study included patients who underwent contrast-enhanced dynamic CT with dual-energy mode between March 2018 and February 2019. The ECV fraction of the pancreas was calculated from iodine map images created from equilibrium-phase contrast-enhanced DECT images. The cross-sectional areas of the pancreas were also measured. Results In total, 51 patients were analyzed (median age, 69 years old; 22 women). The ECV fraction of the pancreas showed a significant negative correlation with the HbA1c value in the cirrhotic group (ρ=-0.346, p = 0.048), while there was no significant correlation in the non-cirrhotic group (ρ=-0.086, p = 0.734). In the elevated HbA1C group, the ECV fraction of the pancreas in the cirrhotic patients (median, 0.247; interquartile range [IQR], 0.098) was significantly lower than that in the non-cirrhotic patients (0.332, IQR 0.113) (p = 0.024). In the elevated HbA1C group, the cross-sectional area of the pancreas was significantly larger in the cirrhotic patients than that in the non-cirrhotic patients (median [IQR]; 2945 [904] vs. 1885 [909] mm2, p = 0.019). Conclusion A reduction in the ECV fraction of the pancreas measured by DECT as well as the enlargement of the pancreatic parenchyma was observed in cirrhotic patients with IGT. These findings suggest that the measurement of the pancreatic ECV fraction by DECT may help clarify the pathophysiology of IGT in patients with cirrhosis.

This letter presents a low-profile spiral antenna with an extremely thin magnetodielectric substrate (MagDS), which is backed by a conducting plane. A MagDS thickness of 0.1 mm (0.0001 λ at 300 MHz) provides a purely input resistance with an axial ratio of less than 3 dB across a wide frequency range. Using this thickness value, the radiation characteristics are analyzed. It is revealed that a VSWR of less than 2 and an axial ratio of less than 3 dB are obtained across a frequency range of 300–1000 MHz (fractional bandwidth: 108%). It should be emphasized that the total antenna height from the bottom conducting plane to the antenna top surface is very small: 0.061 λ at 300 MHz. Simulated results are confirmed by experimental work.

In recent years, liver cancer has become the fourth-largest number of deaths in the world. Surgery is a typical treatment for liver cancer. Therefore, advance information about the number and size of cancer is important for surgery. Multi-phase CT images are well known diagnostic method. By extracting the region of the liver and the region of cancer from the obtained CT image, the shape can be finally restored in 3D. In this paper, as a preliminary step to construct an image analysis method for efficiently extracting cancerous regions in multi-phase CT, we propose a method of obtaining a rectangular region as a rough cancerous region of interest. As a method, after preprocessing the input image, using Faster R-CNN, the region of interest including the cancer region is extracted as a rectangle. As a result of applying this method to 11 cases of arterial phase of multi-phase CT, the detection performance was different depending on the network model adopted for backbone part.

This paper describes the antenna characteristics of a spiral antenna with a circular high-impedance surface (HIS) reflector (CirHISR). The CirHISR consists of a fan-shaped patch element array printed on the top surface of a circular dielectric substrate, and a perfect electric conducting reflector printed on the bottom surface of the circular dielectric substrate. The aspect ratio of each fan-shaped patch element, which is defined by the ratio of patch width to patch length, is approximately one. The axial ratio characteristics are analyzed using FEKO software based on the Method of Moment. Good axial ratio is obtained across a frequency range of 3 GHz to 10 GHz, where the antenna height is 0.9 cm (0.09 wavelengh at the lowest analysis frequency). In addition, other antenna characteristics, including VSWR, gain, and radiation efficiency are recognized.