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1.
Clin Radiol ; 79(6): 446-452, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38580482

ABSTRACT

AIM: This study aimed to assess the imaging features of atypical lipomatous tumors (ALTs) and lipoma with fat necrosis. METHODS: This study included patients with histopathologically proven fat necrosis within adipocytic tumors who underwent preoperative imaging. Magnetic resonance imaging (MRI) and/or computer tomography (CT) findings of fat necrosis associated with lipomatous tumors were retrospectively reviewed, emphasizing the "fatty island sign (FIS)." FISs were defined as well-demarcated, focal fat-containing areas surrounded by more thickened septa compared with other intratumoral septa. Imaging findings of FIS were compared between ALT and lipoma. RESULTS: Fat necrosis was histopathologically confirmed in 17 patients (6 ALTs and 11 lipomas). Among them, 18 FISs were observed in 10 lesions (59%). Multiple FISs within a lesion were observed in 4 (40%) patients. The median maximum diameter of the FISs was 37 mm. Hypointense areas within FISs relative to the subcutaneous fat on T1- and T2-weighted images were observed in 8 (80%) and 9 (90%), respectively, whereas hyperintense areas within FISs on fat-suppressed T2-weighted images were observed in 2 (20%). Nonfatty solid components within FISs were observed in 2 (20%). On CT, increased fat attenuation and pure fat attenuation within FISs were observed in 6 (86%) and 1 (14%), respectively. The imaging findings of FIS were not significantly different between ALT and lipoma. CONCLUSION: FISs were observed in 59% of the histologically proven ALT and lipoma patients with fat necrosis. The hypointense areas relative to the subcutaneous fat on T1- and T2-weighted images and increased fat attenuation on CT were usually observed within FISs.


Subject(s)
Fat Necrosis , Lipoma , Magnetic Resonance Imaging , Tomography, X-Ray Computed , Humans , Female , Male , Lipoma/diagnostic imaging , Lipoma/pathology , Middle Aged , Fat Necrosis/diagnostic imaging , Fat Necrosis/pathology , Magnetic Resonance Imaging/methods , Aged , Adult , Retrospective Studies , Tomography, X-Ray Computed/methods
2.
Clin Radiol ; 79(4): e554-e559, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38453389

ABSTRACT

AIM: To compare the radiation dose, image quality, and conspicuity of pancreatic ductal adenocarcinoma (PDAC) in pancreatic protocol dual-energy computed tomography (CT) between two X-ray tubes mounted in the same CT machine. MATERIAL AND METHODS: This retrospective study comprised 80 patients (median age, 73 years; 45 men) who underwent pancreatic protocol dual-energy CT from January 2019 to March 2022 using either old (Group A, n=41) or new (Group B, n=39) X-ray tubes mounted in the same CT machine. The imaging parameters were completely matched between the two groups, and CT data were reconstructed at 70 and 40 keV. The CT dose-index volume (CTDIvol); CT attenuation of the abdominal aorta, pancreas, and PDAC; background noise; and qualitative scores for the image noise, overall image quality, and PDAC conspicuity were compared between the two groups. RESULTS: The CTDIvol was lower in Group B than Group A (7.9 versus 9.2 mGy; p<0.001). The CT attenuation of all anatomical structures at 70 and 40 keV was comparable between the two groups (p=0.06-0.78). The background noise was lower in Group B than Group A (12 versus 14 HU at 70 keV, p=0.046; and 26 versus 30 HU at 40 keV, p<0.001). Qualitative scores for image noise and overall image quality at 70 and 40 keV and PDAC conspicuity at 40 keV were higher in Group B than Group A (p<0.001-0.045). CONCLUSION: The latest X-ray tube could reduce the radiation dose and improve image quality in pancreatic protocol dual-energy CT.


Subject(s)
Carcinoma, Pancreatic Ductal , Pancreatic Neoplasms , Radiography, Dual-Energy Scanned Projection , Male , Humans , Aged , Radiographic Image Enhancement/methods , Retrospective Studies , X-Rays , Tomography, X-Ray Computed/methods , Pancreatic Neoplasms/diagnostic imaging , Pancreas/diagnostic imaging , Carcinoma, Pancreatic Ductal/diagnostic imaging , Radiographic Image Interpretation, Computer-Assisted/methods , Radiation Dosage , Radiography, Dual-Energy Scanned Projection/methods
3.
Clin Radiol ; 79(6): e791-e798, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38403540

ABSTRACT

AIM: To evaluate arterial enhancement, its depiction, and image quality in low-tube potential whole-body computed tomography (CT) angiography (CTA) with extremely low iodine dose and compare the results with those obtained by hybrid-iterative reconstruction (IR) and deep-learning image-reconstruction (DLIR) methods. MATERIALS AND METHODS: This prospective study included 34 consecutive participants (27 men; mean age, 74.2 years) who underwent whole-body CTA at 80 kVp for evaluating aortic diseases between January and July 2020. Contrast material (240 mg iodine/ml) with simultaneous administration of its quarter volume of saline, which corresponded to 192 mg iodine/ml, was administered. CT raw data were reconstructed using adaptive statistical IR-Veo of 40% (hybrid-IR), DLIR with medium- (DLIR-M), and high-strength level (DLIR-H). A radiologist measured CT attenuation of the arteries and background noise, and the signal-to-noise ratio (SNR) was then calculated. Two reviewers qualitatively evaluated the arterial depictions and diagnostic acceptability on axial, multiplanar-reformatted (MPR), and volume-rendered (VR) images. RESULTS: Mean contrast material volume and iodine weight administered were 64.1 ml and 15.4 g, respectively. The SNRs of the arteries were significantly higher in the following order of the DLIR-H, DLIR-M, and hybrid-IR (p<0.001). Depictions of six arteries on axial, three arteries on MPR, and four arteries on VR images were significantly superior in the DLIR-M or hybrid-IR than in the DLIR-H (p≤0.009 for each). Diagnostic acceptability was significantly better in the DLIR-M and DLIR-H than in the hybrid-IR (p<0.001-0.005). CONCLUSION: DLIR-M showed well-balanced arterial depictions and image quality compared with the hybrid-IR and DLIR-H.


Subject(s)
Computed Tomography Angiography , Contrast Media , Deep Learning , Radiation Dosage , Whole Body Imaging , Humans , Male , Female , Aged , Prospective Studies , Computed Tomography Angiography/methods , Contrast Media/administration & dosage , Whole Body Imaging/methods , Radiographic Image Interpretation, Computer-Assisted/methods , Algorithms , Middle Aged , Aged, 80 and over , Aortic Diseases/diagnostic imaging
4.
Clin Oncol (R Coll Radiol) ; 35(10): e601-e610, 2023 10.
Article in English | MEDLINE | ID: mdl-37587000

ABSTRACT

AIMS: To evaluate computed tomography (CT) and 18F-fluorodeoxyglucose-positron emission tomography/computed tomography (18F-FDG-PET/CT) findings of invasive non-mucinous adenocarcinoma (INMA) of the lung as a predictor of histological tumour grade according to 2021 World Health Organization (WHO) classification. MATERIALS AND METHODS: This retrospective study included consecutive patients with surgically resected INMA who underwent both preoperative CT and 18F-FDG-PET/CT. A three-tiered tumour grade was performed based on the fifth edition of the WHO classification of lung tumours. CT imaging features and the maximum standardised uptake value (SUVmax) were compared among the three tumour grades. RESULTS: In total, 214 patients with INMA (median age 70 years; interquartile range 65-76 years; 123 men) were histologically categorised: 36 (17%) as grade 1, 102 (48%) as grade 2 and 76 (35%) as grade 3. Pure solid appearance was more frequent in grade 3 (83%) than in grades 1 (0%) and 2 (26%) (P < 0.001). The SUVmax of the entire tumour was higher in grade 3 than in grades 1 and 2 (P < 0.001). Multivariable analysis revealed that pure solid appearance (odds ratio = 94.0; P < 0.001), round/oval shape (odds ratio = 4.01; P = 0.001), spiculation (odds ratio = 2.13; P = 0.04), air bronchogram (odds ratio = 0.40; P = 0.03) and SUVmax (odds ratio = 1.45; P < 0.001) were significant predictors for grade 3 INMAs. CONCLUSION: Pure solid appearance, round/oval shape, spiculation, absence of air bronchogram and high SUVmax were associated with grade 3 INMAs. CT and 18F-FDG-PET/CT were potentially useful non-invasive imaging methods to predict the histological grade of INMAs.


Subject(s)
Adenocarcinoma of Lung , Lung Neoplasms , Male , Humans , Aged , Fluorodeoxyglucose F18 , Positron Emission Tomography Computed Tomography , Retrospective Studies , Adenocarcinoma of Lung/diagnostic imaging , Adenocarcinoma of Lung/surgery , Tomography, X-Ray Computed , Lung Neoplasms/diagnostic imaging , Lung Neoplasms/surgery , Biomarkers , World Health Organization , Lung
5.
Phys Rev Lett ; 128(1): 017701, 2022 Jan 07.
Article in English | MEDLINE | ID: mdl-35061474

ABSTRACT

We propose a nanoscale rotor embedded between two ferromagnetic electrodes that is driven by spin injection. The spin-rotation coupling allows this nanorotor to continuously receive angular momentum from an injected spin under steady current flow between ferromagnetic electrodes in an antiparallel magnetization configuration. We develop a quantum theory of this angular-momentum transfer and show that a relaxation process from a precession state into a sleeping top state is crucial for the efficient driving of the nanorotor by solving the master equation. Our work clarifies a general strategy for efficient driving of a nanorotor.

6.
Clin Radiol ; 77(2): e138-e146, 2022 02.
Article in English | MEDLINE | ID: mdl-34782114

ABSTRACT

AIM: To evaluate the computed tomography (CT) attenuation values, background noise, arterial depiction, and image quality in whole-body dual-energy CT angiography (DECTA) at 40 keV with a reduced iodine dose using deep-learning image reconstruction (DLIR) and compare them with hybrid iterative reconstruction (IR). MATERIAL AND METHODS: Whole-body DECTA with a reduced iodine dose (200 mg iodine/kg) was performed in 22 patients, and DECTA data at 1.25-mm section thickness with 50% overlap were reconstructed at 40 keV using 40% adaptive statistical iterative reconstruction with Veo (hybrid-IR group), and DLIR at medium and high levels (DLIR-M and DLIR-H groups). The CT attenuation values of the thoracic and abdominal aortas and iliac artery and background noise were measured. Arterial depiction and image quality on axial, multiplanar reformatted (MPR), and volume-rendered (VR) images were assessed by two readers. Quantitative and qualitative parameters were compared between the hybrid-IR, DLIR-M, and DLIR-H groups. RESULTS: The vascular CT attenuation values were almost comparable between the three groups (p=0.013-0.97), but the background noise was significantly lower in the DLIR-H group than in the hybrid-IR and DLIR-M groups (p<0.001). The arterial depictions on axial and MPR images and in almost all arteries on VR images were comparable (p=0.14-1). The image quality of axial, MPR, and VR images was significantly better in the DLIR-H group (p<0.001-0.015). CONCLUSION: DLIR significantly reduced background noise and improved image quality in DECTA at 40 keV compared with hybrid-IR, while maintaining the arterial depiction in almost all arteries.


Subject(s)
Aortic Diseases/diagnostic imaging , Computed Tomography Angiography/methods , Deep Learning , Iodine , Radiographic Image Enhancement/methods , Radiographic Image Interpretation, Computer-Assisted/methods , Aged , Aged, 80 and over , Contrast Media , Female , Humans , Male , Middle Aged , Radiography, Dual-Energy Scanned Projection/methods , Whole Body Imaging/methods
7.
Phys Rev Lett ; 127(11): 119902, 2021 Sep 10.
Article in English | MEDLINE | ID: mdl-34558959

ABSTRACT

This corrects the article DOI: 10.1103/PhysRevLett.120.037201.

8.
Clin Radiol ; 76(9): 710.e15-710.e24, 2021 Sep.
Article in English | MEDLINE | ID: mdl-33879322

ABSTRACT

AIM: To evaluate the use of deep-learning-based image reconstruction (DLIR) algorithms in dynamic contrast-enhanced computed tomography (CT) of the abdomen, and to compare the image quality and lesion conspicuity among the reconstruction strength levels. MATERIALS AND METHODS: This prospective study included 59 patients with 373 hepatic lesions who underwent dynamic contrast-enhanced CT of the abdomen. All images were reconstructed using four reconstruction algorithms, including 40% adaptive statistical iterative reconstruction-Veo (ASiR-V) and DLIR at low, medium, and high-strength levels (DLIR-L, DLIR-M, and DLIR-H, respectively). The signal-to-noise ratio (SNR) of the abdominal aorta, portal vein, liver, pancreas, and spleen and the lesion-to-liver contrast-to-noise ratio (CNR) were calculated and compared among the four reconstruction algorithms. The diagnostic acceptability was qualitatively assessed and compared among the four reconstruction algorithms and the conspicuity of hepatic lesions was compared between <5 and ≥5 mm lesions. RESULTS: The SNR of each anatomical structure (p<0.0001) and CNR (p<0.0001) were significantly higher in DLIR-H than the other reconstruction algorithms. Diagnostic acceptability was significantly better in DLIR-M than the other reconstruction algorithms (p<0.0001). The conspicuity of hepatic lesions was highest when using 40% ASiR-V and tended to lessen as the reconstruction strength level was getting higher in DLIR, especially in <5 mm lesions; however, all hepatic lesions could be detected. CONCLUSIONS: DLIR improved the SNR, CNR, and image quality compared with 40% ASiR-V, while making it possible to decrease lesion conspicuity using higher reconstruction strength.


Subject(s)
Abdominal Neoplasms/diagnostic imaging , Contrast Media , Deep Learning , Radiographic Image Enhancement/methods , Radiographic Image Interpretation, Computer-Assisted/methods , Tomography, X-Ray Computed/methods , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Prospective Studies , Radiography, Abdominal/methods
9.
Nat Commun ; 11(1): 3009, 2020 Jun 15.
Article in English | MEDLINE | ID: mdl-32541678

ABSTRACT

Hydrodynamic motion can generate a flux of electron-spin's angular momentum via the coupling between fluid rotation and electron spins. Such hydrodynamic generation, called spin hydrodynamic generation (SHDG), has recently attracted attention in a wide range of fields, especially in spintronics. Spintronics deals with spin-mediated interconversion taking place on a micro or nano scale because of the spin-diffusion length scale. To be fully incorporated into the interconversion, SHDG physics should also be established in such a minute scale, where most fluids exhibit a laminar flow. Here, we report electric voltage generation due to the SHDG in a laminar flow of a liquid-metal mercury. The experimental results show a scaling rule unique to the laminar-flow SHDG. Furthermore, its energy conversion efficiency turns out to be about 105 greater than of the turbulent one. Our findings reveal that the laminar-flow SHDG is suitable to downsizing and to extend the coverage of fluid spintronics.

10.
Clin Radiol ; 75(4): 320.e17-320.e23, 2020 04.
Article in English | MEDLINE | ID: mdl-31879024

ABSTRACT

AIM: To evaluate the value of virtual monochromatic images (VMIs) at lower energy levels in fast-voltage-switching dual-energy computed tomography (DECT) for assessing pancreatic ductal adenocarcinoma (PDAC). MATERIALS AND METHODS: The institutional review board approved this prospective study. Written informed consent was obtained from all patients. Seventy-four consecutive patients with PDAC underwent dynamic contrast-enhanced DECT. Two radiologists reviewed eight energy levels (40, 45, 50, 55, 60, 65, 70, and 75 keV) of the pancreatic parenchymal phase VMIs. CT attenuation of the PDAC and pancreatic parenchyma, background noise, signal-to-noise ratio (SNR) of the pancreas, tumour-to-pancreas contrast-to-noise ratio (CNR), major and minor axes of PDAC, and qualitative tumour conspicuity were compared among the VMIs at eight energy levels. RESULTS: CT attenuation of PDAC and pancreatic parenchyma, background noise, SNR, and CNR peaked on VMIs at 40 keV with statistically significant difference (p<0.0001) and gradually decreased with increasing energy levels. The reproducibility in measuring tumour size was better on VMIs at 40 keV (28.8 and 29.2 mm of major axis in readers 1 and 2, respectively) and tended to be overestimated at higher energy levels (29.8 and 30.9 mm of major axis at 75 keV in readers 1 and 2, respectively). Qualitative tumour conspicuity was also significantly superior on VMIs at 40 keV than at all other energy levels (p<0.0001). CONCLUSION: VMIs at 40 keV demonstrated significantly increased SNR of the pancreas, CNR, and tumour conspicuity and high reproducibility in measuring tumour size for assessing PDAC.


Subject(s)
Adenocarcinoma/diagnostic imaging , Carcinoma, Pancreatic Ductal/diagnostic imaging , Pancreatic Neoplasms/diagnostic imaging , Radiography, Dual-Energy Scanned Projection/methods , Tomography, X-Ray Computed/methods , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Prospective Studies , Reproducibility of Results , Signal-To-Noise Ratio
11.
Clin Radiol ; 74(12): 976.e19-976.e25, 2019 Dec.
Article in English | MEDLINE | ID: mdl-31551148

ABSTRACT

AIM: To evaluate how computed tomography (CT) and magnetic resonance imaging (MRI) characteristics can be used to differentiate immunohistochemically confirmed mediastinal Müllerian cysts (MMCs) from bronchogenic cysts (BCs). MATERIALS AND METHODS: Sixteen patients with histopathologically and immunohistochemically confirmed mediastinal cysts (four with MMCs and 12 with BCs) were included in this study. CT and MRI images were reviewed retrospectively and the location, size, CT attenuation, and MRI signal intensity of the two pathologies were compared. RESULTS: On review of CT images, cysts could be located to the anterior mediastinum in four BCs, middle mediastinum in three MMCs and seven BCs, and posterior mediastinum in one MMC and one BC. Contact with a vertebral body was observed in 4/4 MMCs (100%) and 6/12 BCs (50%). The ratios of minimum-to-maximum diameter (0.57±0.09 versus 0.74±0.11, p<0.01), CT attenuation (7.8±6 versus 44.3±12 HU, p<0.01), and cyst-to-spinal cord signal intensity ratios (SIRs) on T1-weighted images (0.56±0.2 versus 1.31±0.4, p<0.01) were significantly lower for MMCs than BCs. No significant differences in maximum diameter, minimum diameter, and SIRs on T2-weighted images were found between MMCs and BCs. CONCLUSION: In characterising mediastinal cysts in a middle-aged female patient, contact with a vertebral body, flattened configuration, hypodensity on CT, and hypointensity compared to spinal cord on T1-weighted images are features that are specific to MMCs.


Subject(s)
Bronchogenic Cyst/diagnostic imaging , Mediastinal Cyst/diagnostic imaging , Adult , Aged , Aged, 80 and over , Bronchogenic Cyst/diagnosis , Diagnosis, Differential , Female , Humans , Magnetic Resonance Imaging , Male , Mediastinal Cyst/diagnosis , Mediastinum/diagnostic imaging , Middle Aged , Tomography, X-Ray Computed , Young Adult
12.
Int Endod J ; 52(9): 1327-1343, 2019 Sep.
Article in English | MEDLINE | ID: mdl-31002379

ABSTRACT

AIM: To investigate whether glycosaminoglycans (GAGs) binding to high-dose LL37 eliminates its cytotoxicity to dental pulp cells (hDPCs) whilst retaining undiminished antimicrobial and LPS-neutralizing abilities. METHODOLOGY: hDPCs were stimulated with varying concentrations of LL37, and their cell viability was analysed by MTT. Then, high-dose LL37 (10 µmol L-1 ) was bound to varying concentrations of three GAGs, heparin, chondroitin sulphate and hyaluronic acid, and their cytotoxic effects on hDPCs and antimicrobial effects were evaluated and compared. Furthermore, the LPS-neutralizing ability of heparin (5 µg mL-1 )-LL37 (10 µmol L-1 ) complexes, which were found to be less cytotoxic for hDPCs with undiminished antimicrobial ability, was investigated. Statistical analysis was performed using one-way analysis of variance (anova), followed by Dunnett's test. P values below 0.05 were considered significant. RESULTS: LL37 significantly reduced the cell viability of hDPCs in a dose-dependent manner (P < 0.01). LL37 (10 µmol L-1 ) binding to heparin within a limited concentration range (2~6 µg mL-1 ) eliminated the cytotoxicity for hDPCs (P < 0.01) whilst exerting potent antimicrobial effects against Streptococcus mutans, Streptococcus sobrinus, Streptococcus salivarius, Aggegatibacter actinomycetemcomitans and Escherichia coli. LL37 (10 µmol L-1 ) binding to chondroitin sulphate exhibited similar functions (P < 0.01); however, the effective chondroitin sulphate concentration was highly restricted (3 µg mL-1 ). LL37 (10 µmol L-1 ) binding to hyaluronic acid was unable to abrogate the cytotoxicity of LL37 even at higher concentrations (10 and 100 µg mL-1 ). Moreover, exogenous addition of LPS dose-dependently reduced the amount of LL37 precipitated with the heparin-LL37 agarose beads (P < 0.01), and the released LL37 simultaneously neutralized the pro-inflammatory ability of LPS in macrophages (P < 0.01). CONCLUSIONS: Heparin-LL37 complexes generated at suitable concentration ratios are easy to make, are less cytotoxic and are broad-range antimicrobial materials that can neutralize LPS by providing LL37 in accordance with the amount of free LPS. They may be a potential treatment to save dental pulp tissue from the acute inflammation exacerbated by invading bacteria and the LPS they release.


Subject(s)
Anti-Infective Agents , Cells, Cultured , Dental Pulp , Heparin , Humans , Lipopolysaccharides
13.
Clin Radiol ; 74(6): 490.e1-490.e6, 2019 06.
Article in English | MEDLINE | ID: mdl-30914207

ABSTRACT

AIM: To evaluate the potential value of magnetic resonance imaging (MRI) for predicting postoperative pancreatic fistula (POPF) in patients with pancreatic cancer (PC) and non-pancreatic cancer (non-PC). MATERIAL AND METHODS: This retrospective study was approved by the institutional review board and written informed consent was waived. Forty patients underwent pancreatoduodenectomy due to PC (n=31) and non-PC (n=9). The pancreas-to-muscle signal intensity ratio (SIR) on three-dimensional (3D)- fast field echo (FFE) T1-, in- and opposed-phase T1-, and T2-weighted images, as well as the apparent diffusion coefficient (ADC) value of the pancreas were measured. The frequency of POPF and MRI measurements were compared between patients with PC and non-PC. The MRI measurements were also compared with the grade of pancreatic fibrosis on pathological findings, fat deposition, and interstitial oedema. RESULTS: The frequency of POPF was significantly higher in patients with non-PC than in those with PC (p=0.0067), with an odds ratio of 10.4. The SIR on 3D-FFE T1-weighted images was significantly higher in patients with non-PC (p=0.0001) and those with POPF (p=0.017) than in those with PC and those without POPF, respectively. Multiple regression analysis demonstrated that the SIR on 3D-FFE T1-weighted image was independently associated with the grade of pancreatic fibrosis (p<0.0001). CONCLUSION: The frequency of POPF was significantly higher in patients with non-PC than in those with PC was inversely related to the grade of pancreatic fibrosis. The SIR on 3D-FFE T1-weighted image might be a potential imaging biomarker for predicting POPF.


Subject(s)
Magnetic Resonance Imaging/methods , Pancreatic Diseases/diagnostic imaging , Pancreatic Diseases/pathology , Pancreatic Fistula/diagnostic imaging , Postoperative Complications/diagnostic imaging , Aged , Aged, 80 and over , Diagnosis, Differential , Female , Fibrosis , Humans , Male , Middle Aged , Pancreas/diagnostic imaging , Pancreas/pathology , Pancreas/surgery , Pancreatic Diseases/surgery , Pancreatic Fistula/pathology , Pancreatic Neoplasms/diagnostic imaging , Pancreatic Neoplasms/pathology , Postoperative Complications/pathology
14.
Clin Radiol ; 73(10): 907.e9-907.e14, 2018 10.
Article in English | MEDLINE | ID: mdl-29895387

ABSTRACT

AIM: To perform radiology-pathology correlation of the inchworm sign on diffusion-weighted imaging (DWI) in patients with endometrial cancer. MATERIALS AND METHODS: Consecutive patients (345) with histopathologically proven endometrial cancer who underwent preoperative magnetic resonance imaging (MRI), including DWI images, and hysterectomy were included in the present study. The inchworm sign was defined as a hypointense stalk between hyperintense endometrial cancer and hypointense myometrium on DWI images. A genitourinary pathologist reviewed the resected specimen at the site of the inchworm sign. RESULTS: The inchworm sign on DWI images was observed in 32 (9.3%) patients. On T2-weighted images, areas of hypointense stalk on DWI images showed hypointensity in 31 (97%) patients and hyperintensity in one (3%). Among them, the depth of myometrial invasion at histopathology was superficial (<50% myometrial invasion) in 28 (87.5%) patients and deep (≥50% myometrial invasion) in four (12.5%). As a result of histopathological investigation, the hypointense stalk of the inchworm sign was mainly composed of various degrees of stromal proliferation, including smooth muscle cells and metaplastic fibromuscular stroma, with or without intervening endometrial cancer. CONCLUSION: The inchworm sign of endometrial cancer on DWI images usually indicated superficial myometrial invasion and was caused by a stalk composed of stromal proliferation with or without intervening endometrial cancer.


Subject(s)
Carcinoma, Endometrioid/pathology , Endometrial Neoplasms/pathology , Adult , Aged , Aged, 80 and over , Diffusion Magnetic Resonance Imaging , Female , Humans , Middle Aged , Neoplasm Invasiveness , Retrospective Studies
15.
Phys Rev Lett ; 120(3): 037201, 2018 Jan 19.
Article in English | MEDLINE | ID: mdl-29400496

ABSTRACT

We theoretically investigate the fluctuation of a pure spin current induced by the spin Seebeck effect and spin pumping in a normal-metal-(NM-)ferromagnet(FM) bilayer system. Starting with a simple ferromagnet-insulator-(FI-)NM interface model with both spin-conserving and non-spin-conserving processes, we derive general expressions of the spin current and the spin-current noise at the interface within second-order perturbation of the FI-NM coupling strength, and estimate them for a yttrium-iron-garnet-platinum interface. We show that the spin-current noise can be used to determine the effective spin carried by a magnon modified by the non-spin-conserving process at the interface. In addition, we show that it provides information on the effective spin of a magnon, heating at the interface under spin pumping, and spin Hall angle of the NM.

16.
Clin Radiol ; 73(6): 594.e1-594.e6, 2018 06.
Article in English | MEDLINE | ID: mdl-29459139

ABSTRACT

AIM: To compare right adrenal vein (RAV) visualisation and contrast enhancement degree on adrenal venous phase images reconstructed using adaptive statistical iterative reconstruction (ASiR) and model-based iterative reconstruction (MBIR) techniques. MATERIAL AND METHODS: This prospective study was approved by the institutional review board, and written informed consent was waived. Fifty-seven consecutive patients who underwent adrenal venous phase imaging were enrolled. The same raw data were reconstructed using ASiR 40% and MBIR. The expert and beginner independently reviewed computed tomography (CT) images. RAV visualisation rates, background noise, and CT attenuation of the RAV, right adrenal gland, inferior vena cava (IVC), hepatic vein, and bilateral renal veins were compared between the two reconstruction techniques. RESULTS: RAV visualisation rates were higher with MBIR than with ASiR (95% versus 88%, p=0.13 in expert and 93% versus 75%, p=0.002 in beginner, respectively). RAV visualisation confidence ratings with MBIR were significantly greater than with ASiR (p<0.0001, both in the beginner and the expert). The mean background noise was significantly lower with MBIR than with ASiR (p<0.0001). Mean CT attenuation values of the RAV, right adrenal gland, IVC, and hepatic vein were comparable between the two techniques (p=0.12-0.91). Mean CT attenuation values of the bilateral renal veins were significantly higher with MBIR than with ASiR (p=0.0013 and 0.02). CONCLUSION: Reconstruction of adrenal venous phase images using MBIR significantly reduces background noise, leading to an improvement in the RAV visualisation compared with ASiR.


Subject(s)
Adrenal Glands/blood supply , Veins/diagnostic imaging , Adrenal Glands/diagnostic imaging , Adult , Aged , Aged, 80 and over , Computed Tomography Angiography/methods , Hepatic Veins/diagnostic imaging , Humans , Image Processing, Computer-Assisted/methods , Middle Aged , Models, Theoretical , Multidetector Computed Tomography/methods , Prospective Studies , Renal Veins/diagnostic imaging , Vena Cava, Inferior/diagnostic imaging , Young Adult
17.
Phys Rev Lett ; 119(7): 077202, 2017 Aug 18.
Article in English | MEDLINE | ID: mdl-28949686

ABSTRACT

We demonstrate the generation of alternating spin current (SC) via spin-rotation coupling (SRC) using a surface acoustic wave (SAW) in a Cu film. Ferromagnetic resonance caused by injecting SAWs was observed in a Ni-Fe film attached to a Cu film, with the resonance further found to be suppressed through the insertion of a SiO_{2} film into the interface. The intensity of the resonance depended on the angle between the wave vector of the SAW and the magnetization of the Ni-Fe film. This angular dependence is explicable in terms of the presence of spin transfer torque from a SC generated via SRC.

18.
Clin Radiol ; 72(10): 901.e13-901.e19, 2017 Oct.
Article in English | MEDLINE | ID: mdl-28673448

ABSTRACT

AIM: To compare contrast enhancement and image quality between renovascular computed tomography (CT) images with adaptive statistical iterative reconstruction (ASiR) and that with model-based iterative reconstruction (MBIR). MATERIAL AND METHODS: This retrospective study was approved by the institutional review board and written informed consent was waived. Twenty-five consecutive patients who underwent renovascular CT were enrolled in this study. The same raw projection data were reconstructed using ASiR 40%, 100%, and MBIR. Background noise, CT attenuation, and signal-to-noise ratio (SNR) of the renal vessels and kidneys, and image quality were compared among the three reconstruction techniques. RESULTS: Mean background noise was significantly lower with MBIR at the first and second phases than those with ASiR 40% and 100% (p<0.0001). Mean CT attenuation of the abdominal aorta, renal artery, and renal cortex obtained at the first phase and those of the renal vein and renal medulla at the second phase were comparable among the three techniques (p=0.051-1.00). Mean SNRs of the abdominal aorta, renal artery, renal cortex, renal vein, and renal medulla were significantly higher with MBIR than with ASiR 40% or 100% (both p<0.0001). The depiction of the renal artery and vein as well as image quality significantly improved with MBIR compared with those with ASiR 40% and 100% (p<0.0001-0.0016). CONCLUSION: Reconstruction of renovascular CT images with MBIR significantly reduces background noise, leading to an improvement in SNR and image quality compared with that using ASiR.


Subject(s)
Image Processing, Computer-Assisted/methods , Kidney/blood supply , Kidney/diagnostic imaging , Radiographic Image Enhancement/methods , Radiographic Image Interpretation, Computer-Assisted/methods , Tomography, X-Ray Computed/methods , Adult , Aged , Aged, 80 and over , Aorta, Abdominal/diagnostic imaging , Female , Humans , Kidney Medulla/diagnostic imaging , Male , Middle Aged , Renal Artery/diagnostic imaging , Renal Veins/diagnostic imaging , Reproducibility of Results , Retrospective Studies , Signal-To-Noise Ratio
19.
Soft Matter ; 11(35): 7053-8, 2015 Sep 21.
Article in English | MEDLINE | ID: mdl-26249035

ABSTRACT

We have developed a novel lipid-bearing DNA that forms hairpin modules, including a single RNA monomer; this can be used to create micrometer-sized structures from nanometer-sized building blocks during breakage at the RNA site. In the presence of divalent metal ions and heat stimulation, we observed transition of the self-assembly, which results in the formation of a three-dimensional network structure. To our knowledge, this is also the first report of heat-induced micrometer-sized molecular self-assembly of molecules that carry biological information.


Subject(s)
DNA/chemistry , Lipids/chemistry , Hot Temperature , Inverted Repeat Sequences , Magnesium/chemistry , RNA/chemistry
20.
Oncogene ; 34(9): 1141-9, 2015 Feb 26.
Article in English | MEDLINE | ID: mdl-24662825

ABSTRACT

Dlg5 has been reported to participate in cancer progression; however, its role in prostate cancer still remains poorly understood. In this study, we demonstrate that Dlg5 is frequently downregulated in prostate cancer. We show here that Dlg5 is involved in the regulation of cell migration and cancer cell invasion. Knockdown of endogenous Dlg5 markedly increased prostate cancer cell migration and invasion. Our studies, for the first time, demonstrate the interaction between Dlg5 and Girdin, an actin-binding Akt substrate. Importantly, we found that levels of Akt-mediated Girdin phosphorylation (p-Girdin-Ser1416) are increased in Dlg5-depleted cells. Small interfering RNA directed against Girdin and wortmannin treatment, which was found to reduce Girdin phosphorylation, impaired the effect of Dlg5 depletion on cell migration. Taken together, our findings demonstrate that Dlg5 interacts with and inhibits the activity of Girdin, thereby suppressing the migration of prostate cancer cells.


Subject(s)
Membrane Proteins/genetics , Membrane Proteins/metabolism , Microfilament Proteins/metabolism , Prostatic Neoplasms/pathology , Tumor Suppressor Proteins/genetics , Tumor Suppressor Proteins/metabolism , Vesicular Transport Proteins/metabolism , Androstadienes/pharmacology , Cell Line, Tumor , Cell Movement/drug effects , Gene Knockdown Techniques , Humans , Male , Microfilament Proteins/genetics , Neoplasm Invasiveness/genetics , Neoplasm Invasiveness/pathology , Phosphorylation/drug effects , Prostatic Neoplasms/genetics , Prostatic Neoplasms/metabolism , Signal Transduction , Vesicular Transport Proteins/genetics , Wortmannin
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