Computerized Segmentation Method for Nonmasses on Breast DCE-MRI Images Using ResUNet++ with Slice Sequence Learning and Cross-Phase Convolution.

The purpose of this study was to develop a computerized segmentation method for nonmasses using ResUNet++ with a slice sequence learning and cross-phase convolution to analyze temporal information in breast dynamic contrast material-enhanced magnetic resonance imaging (DCE-MRI) images. The dataset consisted of a series of DCE-MRI examinations from 54 patients, each containing three-phase images, which included one image that was acquired before contrast injection and two images that were acquired after contrast injection. In the proposed method, the region of interest (ROI) slice images are first extracted from each phase image. The slice images at the same position in each ROI are stacked to generate a three-dimensional (3D) tensor. A cross-phase convolution generates feature maps with the 3D tensor to incorporate the temporal information. Subsequently, the feature maps are used as the input layers for ResUNet++. New feature maps are extracted from the input data using the ResUNet++ encoders, following which the nonmass regions are segmented by a decoder. A convolutional long short-term memory layer is introduced into the decoder to analyze a sequence of slice images. When using the proposed method, the average detection accuracy of nonmasses, number of false positives, Jaccard coefficient, Dice similarity coefficient, positive predictive value, and sensitivity were 90.5%, 1.91, 0.563, 0.712, 0.714, and 0.727, respectively, larger than those obtained using 3D U-Net, V-Net, and nnFormer. The proposed method achieves high detection and shape accuracies and will be useful in differential diagnoses of nonmasses.

Small-artery-mimicking multi-layered 3D co-culture in a self-folding porous graphene-based film.

In vitro vessel-mimicking models have been spotlighted as a powerful tool for investigating cellular behaviours in vascular development and diseases. However, it is still challenging to create micro-scale tubular tissues while mimicking the structural features of small arteries. Here, we propose a 3D culture model of small vascular tissue using a self-folding graphene-based porous film. Vascular endothelial cells were encapsulated within the self-folding film to create a cellular construct with a controlled curvature radius ranging from 10 to 100 µm, which is comparable to the size of a human arteriole. Additionally, vascular endothelial cells and smooth muscle cells were separately co-cultured on the inner and outer surfaces of the folded film, respectively. The porous wall worked as a permeable barrier between them, affecting the cell-cell communications like the extracellular layer in the artery wall. Thus, the culture model recapitulates the structural features of a small artery and will help us better understand intercellular communications at the artery wall in physiological and pathological conditions.

Use of a deep learning algorithm for non-mass enhancement on breast MRI: comparison with radiologists' interpretations at various levels.

PURPOSE: To evaluate the diagnostic performance of deep learning using the Residual Networks 50 (ResNet50) neural network constructed from different segmentations for distinguishing malignant and benign non-mass enhancement (NME) on breast magnetic resonance imaging (MRI) and conduct a comparison with radiologists with various levels of experience. MATERIALS AND METHODS: A total of 84 consecutive patients with 86 lesions (51 malignant, 35 benign) presenting NME on breast MRI were analyzed. Three radiologists with different levels of experience evaluated all examinations, based on the Breast Imaging-Reporting and Data System (BI-RADS) lexicon and categorization. For the deep learning method, one expert radiologist performed lesion annotation manually using the early phase of dynamic contrast-enhanced (DCE) MRI. Two segmentation methods were applied: a precise segmentation was carefully set to include only the enhancing area, and a rough segmentation covered the whole enhancing region, including the intervenient non-enhancing area. ResNet50 was implemented using the DCE MRI input. The diagnostic performance of the radiologists' readings and deep learning were then compared using receiver operating curve analysis. RESULTS: The ResNet50 model from precise segmentation achieved diagnostic accuracy equivalent [area under the curve (AUC) = 0.91, 95% confidence interval (CI) 0.90, 0.93] to that of a highly experienced radiologist (AUC = 0.89, 95% CI 0.81, 0.96; p = 0.45). Even the model from rough segmentation showed diagnostic performance equivalent to a board-certified radiologist (AUC = 0.80, 95% CI 0.78, 0.82 vs. AUC = 0.79, 95% CI 0.70, 0.89, respectively). Both ResNet50 models from the precise and rough segmentation exceeded the diagnostic accuracy of a radiology resident (AUC = 0.64, 95% CI 0.52, 0.76). CONCLUSION: These findings suggest that the deep learning model from ResNet50 has the potential to ensure accuracy in the diagnosis of NME on breast MRI.

Development of a Novel Mild Depolymerization Method of Coal by Combining Oxygen Oxidation and Formic Acid Reduction Reactions.

Depolymerization of coal increases the tar yield in coal pyrolysis and enhances the thermoplasticity of the coal, which makes coal more favorable for producing coke and other value-added products like graphite electrodes, carbon fiber, aromatic chemicals, etc. In this study, the authors have proposed a novel coal depolymerization method that combines the oxidation reactions by molecular oxygen and the following reduction reactions by the coexisting gaseous formic acid to upgrade a bituminous coal at 90-150 °C under atmospheric pressure. The softening and melting performance of the treated coals was enhanced when oxygen and formic acid coexisted in gas phase at 90-130 °C. The amount of low-molecular-weight compounds in the coal treated at 90 °C in air containing formic acid vapor significantly increased by 29.0% of the amount of low-molecular-weight compounds in the raw coal measured by the solvent extraction method. Thus, the authors have succeeded in depolymerizing coal by the treatment under mild conditions, which is expected to contribute to coal's efficient utilization such as increasing the coal extracts and tar yield in the extraction and pyrolysis process, upgrading coal to be more suitable for the raw materials of coke, etc.

Refractory satellite ganglion cyst in the hallux and finger.

Painful ganglion cysts that develop in the hallux and finger usually enlarge progressively to the peripheral direction. Simple resection of satellite ganglion cyst alone has been reported to cause a high rate of recurrence and treatment is often very difficult. The purpose of this study is to evaluate the appropriate surgical treatment for painful satellite ganglion cysts in the hallux and finger and discuss the origin of the ganglion cysts in cases treated surgically at our hospital. We reviewed five cases (three males and two females, ages 55-87 years), three of which occurred in the hallux and two in the finger. In all cases, the preoperative magnetic resonance image showed a large fluid of the flexor tendon sheath. And also, joint effusion was found in the metatarsophalangeal joint and the proximal interphalangeal joint. The first case of the hallux ganglion underwent simple excision of the cyst and had recurrences three times. In the other four cases, the additional synovectomy of the metatarsophalangeal joint and the proximal interphalangeal joint was performed along with ganglion cyst excision. These cases had no recurrence up to 1 year after operation. Recently, there have been reports that tendon sheath ganglions are connected to the ankle, wrist, hallux, and phalangeal joints. Although there are a few cases in our department, satellite ganglion cyst of the hallux and finger possibly originates from adjacent joints. Additional synovectomy of the affected joint should be performed for the excision of satellite ganglion cyst to prevent recurrence.

Recording Saltatory Conduction Along Sensory Axons Using a High-Density Microelectrode Array.

Myelinated fibers are specialized neurological structures used for conducting action potentials quickly and reliably, thus assisting neural functions. Although demyelination leads to serious functional impairments, little is known the relationship between myelin structural change and increase in conduction velocity during myelination and demyelination processes. There are no appropriate methods for the long-term evaluation of spatial characteristics of saltatory conduction along myelinated axons. Herein, we aimed to detect saltatory conduction from the peripheral nervous system neurons using a high-density microelectrode array. Rat sensory neurons and intrinsic Schwann cells were cultured. Immunofluorescence and ultrastructure examination showed that the myelinating Schwann cells appeared at 1 month, and compact myelin was formed by 10 weeks in vitro. Activity of rat sensory neurons was evoked with optogenetic stimulation, and axon conduction was detected with high-density microelectrode arrays. Some conductions included high-speed segments with low signal amplitude. The same segment could be detected with electrical recording and immunofluorescent imaging for a myelin-related protein. The spatiotemporal analysis showed that some segments show a velocity of more than 2 m/s and that ends of the segments show a higher electrical sink, suggesting that saltatory conduction occurred in myelinated axons. Moreover, mathematical modeling supported that the recorded signal was in the appropriate range for axon and electrode sizes. Overall, our method could be a feasible tool for evaluating spatial characteristics of axon conduction including saltatory conduction, which is applicable for studying demyelination and remyelination.

DWI-based MR thermometry: could it discriminate Alzheimer's disease from mild cognitive impairment and healthy subjects?

PURPOSE: The aim of this study is to compare lateral ventricular cerebrospinal fluid (CSF) temperature of the patients with Alzheimer's disease (AD), mild cognitive impairment (MCI), and healthy subjects (HS) using diffusion-weighted imaging (DWI)-based magnetic resonance (MR) thermometry. METHODS: Seventy-two patients (37 AD, 19 MCI, 16 HS) who underwent 3-T MR examination from September 2018 to August 2019 were included in this study. Smoking habits, education level, disease duration, and comorbidity status were recorded. Patients were assessed using Mini-Mental State Examination (MMSE) and the Clinical Dementia Rating (CDR) score. Brain temperatures were measured using DWI-based MR thermometry. Group comparisons of brain temperature were performed using the Pearson chi-square, Mann-Whitney, and Kruskal-Wallis tests. Further analysis was performed using the post hoc Bonferroni test. Receiver operating characteristic (ROC) analysis was also used. RESULTS: A CDR score of 0.5, 1, and 2 was 2 (5.4%), 14 (37.8%), and 21 (56.8%) in AD, respectively. The median MMSE score had significant differences among groups and also in pairwise comparisons. The median CSF temperature (°C) values showed statistically significant difference among groups (HS: 38.5 °C, MCI: 38.17 °C, AD: 38.0 °C). The post hoc Mann-Whitney U test indicated a significant difference between AD patients and HS (p = 0.009). There were no significant CSF temperature differences in other pairwise comparisons. CONCLUSION: Lower CSF temperatures were observed in AD patients than in HS, probably due to decreased brain metabolism in AD. DWI-based MR thermometry as a noninvasive imaging method enabling the measurement of CSF temperatures may contribute to the diagnosis of AD.

The diffusion MRI signature index is highly correlated with immunohistochemical status and molecular subtype of invasive breast carcinoma.

OBJECTIVES: To evaluate the relationship of the signature index (S-index), an advanced diffusion MRI marker, and the immunohistochemical (IHC) status, proliferation rate, and molecular subtype of invasive breast cancers. METHODS: A retrospective study of patients with invasive carcinoma was conducted between 2017 and 2021. All patients underwent dynamic contrast-enhanced MRI and DWI using a 3-T system. For DWI, three b values (0, 200, and 1500 s/mm2) were used to derive the S-index. Three-dimensional ROIs were manually placed over the whole tumor on DWI. Mean and 85th percentile S-index values were compared to the IHC status, proliferation rate, and molecular subtypes of lesions. RESULTS: The study included 153 patients (mean age, 60 ± 13 years) with 160 invasive carcinomas. S-index values were significantly higher in estrogen receptor-positive (mean, p = .005; 85th percentile, p < .001) and progesterone receptor-positive (mean, p = .003; 85th percentile, p < .001) tumors, and significantly lower in human epidermal growth factor receptor 2 (HER2) - positive tumors (mean, p = .023; 85th percentile, p < .001). Mean and 85th percentile S-index values were significantly different among breast cancer subtypes (mean, p = .015; 85th percentile, p = .002), and the AUC of these values for the prediction of IHC status were 0.64 and 0.66 for HER2, and 0.70 and 0.74 for hormone receptors, respectively. CONCLUSIONS: The DWI S-index showed significantly higher values in invasive carcinomas with immunohistochemical status associated with good prognosis, suggesting its usefulness as a noninvasive imaging biomarker to estimate IHC status and orient treatment. KEY POINTS: • The signature index, an advanced diffusion MRI marker, showed good discrimination of immunohistochemical status in invasive breast carcinomas. • The signature index has the potential to differentiate noninvasively invasive breast carcinoma subtypes and appears as an imaging biomarker of prognostic factors and molecular phenotypes.

Does cerebrospinal fluid pulsation affect diffusion-weighted imaging thermometry? A study in healthy volunteers.

Diffusion-weighted imaging (DWI)-based thermometry offers potential as a noninvasive method for measuring temperatures deep inside the human brain. However, DWI might be influenced by the pulsatile flow of cerebrospinal fluid (CSF). This study aimed to investigate the influence of such pulsations on DWI thermometry in healthy individuals. A total of 104 participants (50 men, 54 women; mean [± standard deviation] age, 44.2 ± 14.3 years; range 21-69 years) were investigated. DWI-based brain temperature (TDWI ) was acquired at three speeds (maximum and minimum speeds of ascending flow and random timing at the cerebral aqueduct) of CSF pulsation using a 3-T magnetic resonance imaging scanner. Magnetic resonance spectroscopy (MRS)-based temperature (TMRS ) at the thalamus was also obtained as a reference standard for brain temperature. The three different CSF pulsatile flows were monitored by heart rate during the scan. The difference between reference temperature and brain temperature (ΔT = TDWI - TMRS ) along with the three CSF speeds were statistically compared using Student's matched pair t-test. No significant difference in ΔT was evident among CSF speeds (p > 0.05). No significant linear correlation between ΔT and CSF flow speed at the cerebral aqueduct was observed. Using DWI thermometry with clinical acquisition settings, which utilizes mean values within thresholds, no effect of CSF pulsation speed was observed in the estimation of ΔT.

Deep Multi-Objective Learning from Low-Dose CT for Automatic Lung-RADS Report Generation.

Radiology report generation through chest radiography interpretation is a time-consuming task that involves the interpretation of images by expert radiologists. It is common for fatigue-induced diagnostic error to occur, and especially difficult in areas of the world where radiologists are not available or lack diagnostic expertise. In this research, we proposed a multi-objective deep learning model called CT2Rep (Computed Tomography to Report) for generating lung radiology reports by extracting semantic features from lung CT scans. A total of 458 CT scans were used in this research, from which 107 radiomics features and 6 slices of segmentation related nodule features were extracted for the input of our model. The CT2Rep can simultaneously predict position, margin, and texture, which are three important indicators of lung cancer, and achieves remarkable performance with an F1-score of 87.29%. We conducted a satisfaction survey for estimating the practicality of CT2Rep, and the results show that 95% of the reports received satisfactory ratings. The results demonstrate the great potential in this model for the production of robust and reliable quantitative lung diagnosis reports. Medical personnel can obtain important indicators simply by providing the lung CT scan to the system, which can bring about the widespread application of the proposed framework.

Temperature Measurement by Diffusion-Weighted Imaging.

Diffusion-weighted imaging (DWI) thermometry is a magnetic resonance-based imaging tool that allows the noninvasive measurement of brain core temperature. Although only applicable to cerebrospinal fluid, it is thought to be potentially useful in assessing the thermal pathophysiology of the brain in both patients and healthy subjects. The objective of this article is to provide a concise but thorough review of the basic physical principles and the principal applications of DWI thermometry as a potential method to elucidate the pathophysiology of several brain diseases and neurologic syndromes.

Low-grade IVH in preterm infants causes cerebellar damage, motor, and cognitive impairment.

BACKGROUND: Few studies have examined the effect of low-grade intraventricular hemorrhage (IVH) on the white matter in the cerebellum and its association with neurodevelopment. We evaluated cerebellar white matter at term-equivalent age (TEA) in preterm infants with low-grade IVH. Furthermore, we assessed neurodevelopmental outcomes at 3 years of age to examine the influence of low-grade IVH on neurodevelopment. METHODS: Thirteen infants with low-grade IVH and 26 without IVH, born at <30 weeks' postmenstrual age (PMA), were enrolled in this study. Diffusion tensor imaging (DTI) parameters, including fractional anisotropy (FA) and apparent diffusion coefficient (ADC) in the middle and superior cerebellar peduncles (SCP), were measured. Neurodevelopmental outcomes at three years of age were assessed and the correlation between DTI parameters and developmental quotient (DQ) was analyzed. RESULTS: Preterm infants with IVH showed lower FA values (P < 0.01) and higher ADC values (P < 0.05) in the SCP at TEA than the no-IVH group. Lower Postural-Motor and Cognitive-Adaptive DQ at 3 years of age were observed in the IVH compared to the no-IVH group. A significant correlation between the FA values in the SCP at TEA and the Posture-Motor DQ was observed at three years of age (P = 0.043, r = 0.50). CONCLUSIONS: These data suggest that low-grade IVH in preterm infants affects the SCP at TEA and that impaired cerebellar white matter correlates with poor motor development at three years of age.

Correction to: Reply to the letter: N-Butyl Cyanoacrylate-Lipiodol Mixture for Endovascular Purpose: Polymerization Kinetics Differences Between In Vitro and In Vivo Experiments.

We would like to correct one of the references that was listed incorrectly in our article.

Novel Tetrafunctional Probes Identify Target Receptors and Binding Sites of Small-Molecule Drugs from Living Systems.

Significant advancement of chemoproteomics has contributed to uncovering the mechanism of action (MoA) of small-molecule drugs by characterizing drug-protein interactions in living systems. However, cell-membrane proteins such as G protein-coupled receptors (GPCRs) and ion channels, due to their low abundance and unique biophysical properties associated with multiple transmembrane domains, can present challenges for proteome-wide mapping of drug-receptor interactions. Herein, we describe the development of novel tetrafunctional probes, consisting of (1) a ligand of interest, (2) 2-aryl-5-carboxytetrazole (ACT) as a photoreactive group, (3) a hydrazine-labile cleavable linker, and (4) biotin for enrichment. In live cell labeling studies, we demonstrated that the ACT-based probe showed superior reactivity and selectivity for labeling on-target GPCR by mass spectrometry analysis compared with control probes including diazirine-based probes. By leveraging ACT-based cleavable probes, we further identified a set of representative ionotropic receptors, targeted by CNS drugs, with remarkable selectivity and precise binding site information from mouse brain slices. We anticipate that the robust chemoproteomic platform using the ACT-based cleavable probe coupled with phenotypic screening should promote identification of pharmacologically relevant target receptors of drug candidates and ultimately development of first-in-class drugs with novel MoA.

Alteration of brain temperature and systemic inflammation in Parkinson's disease.

OBJECTIVES: Parkinson's disease (PD) is known to be related to various factors, including neuroinflammation, increased oxidative stress, and brain temperature alteration. We aimed to evaluate the correlation between these factors using diffusion-weighted imaging (DWI) thermometry and blood tests of systemic inflammation. METHODS: From July 2012 to Jun 2017, 103 patients with PD (44 men and 59 women; mean age, 60.43 ± 9.12 years) and 106 sex- and age-matched healthy volunteers (48 men and 58 women; mean age, 58.16 ± 8.45 years) retrospectively underwent magnetic resonance DWI thermometry to estimate brain intraventricular temperature (Tv). Subjects were divided into three subgroups in light of their ages. The tested inflammatory markers included plasma nuclear DNA, mitochondrial DNA, apoptotic leukocytes, and serum adhesion molecules. The correlations among the Tv values, clinical severity, and systemic inflammatory markers were then calculated. RESULTS: The PD patients did not show a natural trend of decline in Tv with age. Comparisons among the different age groups revealed that the younger PD subjects had significantly lower Tv values than the younger controls, but the older subjects had no significant group differences. Overall, the PD patients exhibited lower Tv values than the controls, as well as increased oxidative stress. The brain temperature showed positive correlations with inflammatory markers, including plasma nuclear DNA and L-selectin levels, in all the subjects. CONCLUSIONS: Possible pathophysiological correlations between systemic inflammation and brain temperature were indicated by the results of this study, a finding which may aid us in investigating the underlying pathogenesis of PD.

Is the Cessation of Blood Flow Faster than the Polymerization of an n-Butyl Cyanoacrylate-Lipiodol Mixture? An In Vitro Phantom Study.

PURPOSE: To compare the polymerization time of n-butyl cyanoacrylate (NBCA) and lipiodol mixture in a static model and a pulsating flow model simulating embolization procedure of small caliber arteries. MATERIALS AND METHODS: The polymerization time of NBCA-lipiodol mixture was measured by the morphological changes of a glue droplet in a petri dish. For the flow model, we used a 2-mm-inner-diameter polyvinyl alcohol tube connected to a pulsation pump. Bovine serum was supplied from the pump and circulated into the system at 30 ml/min and 60 bpm. A 0.64-mm-inner-diameter silicon microcatheter was inserted into this system, and then, 0.5 ml of glue was injected into the tube. The flow cessation time was defined as the time it took to stop the serum draining from the end of the tube. Six samples of 100, 66, 50, 40, 33, and 20 vol% NBCA were assessed. RESULTS: The median polymerization times for each concentration were 0.12, 3.72, 12.30, 27.41, 57.68, and 63.67 s, respectively. The median flow cessation times were 0.28, 0.78, 1.43, 3.75, 4.50, and 9.29 s, respectively. The flow cessation time was significantly shorter than the polymerization time for all samples except for 100 vol% cyanoacrylate (p < 0.05). CONCLUSION: The flow cessation time of cyanoacrylate glue was significantly shorter than the polymerization time in an in vitro experiment. The injected glue possibly stops the blood flow before the completion of polymerization in the vascular system.

Whole-tumor histogram analysis of DWI and QSI for differentiating between meningioma and schwannoma: a pilot study.

PURPOSE: To investigate whether whole-tumor histogram analyses of diffusivity measurements derived from q-space imaging (QSI) improves the differentiation between meningioma and schwannoma. MATERIALS AND METHODS: Fifteen extra-axial tumors (11 meningiomas and 4 schwannomas) with MR examinations from April 2011 to May 2013 were included. Three-dimensional regions of interest (ROI) encompassed the whole tumor, including cystic areas. Histogram analyses of mean displacement (MD) derived from QSI and apparent diffusion coefficient (ADC) for the ROI were performed at mean, the five percentiles of MDn and ADCn (n = 5, 25, 50, 75, 95th), kurtosis, and skewness. To determine the diagnostic ability of MDn and ADCn, we also compared the area under the curve (AUC) on receiver operating characteristic (ROC) analysis. RESULTS: Histogram analyses revealed significant differences between meningioma and schwannoma in MD75, ADC25, ADC50, ADC75, and kurtosis of ADC. The ROC analysis of kurtosis of ADC and MD75 resulted in an AUC of 1.0 and 0.96, respectively. There were no significant differences between the AUC of MD75 and that of kurtosis of ADC (p = 0.41). CONCLUSION: The histogram analyses of MD and ADC derived from QSI were both equally useful in differentiating between intracranial meningioma and schwannoma.

Effects of different fat-suppression methods on T1 values in dynamic contrast-enhanced magnetic resonance imaging: a phantom study.

Dynamic contrast-enhanced MRI may yield variable longitudinal-relaxation time (T1) values depending on the precision of the fat-suppression (FS) technique. This study aimed to investigate the influences of FS methods on T1 value measurements on phantoms containing test tubes filled with mixtures of five volumes of fat, six amounts of contrast agent, and water. Volumetric interpolated images were obtained using several FS methods and flip angles. T1 maps were created based on the variable flip angle approach. The T1 values of water obtained by point-resolved single-voxel spectroscopy (SVS) were used as reference values. Notably, FS methods were shown to have substantial effects on the measurement of T1 values. Among the tested FS methods, the Dixon (water) method produced T1 values most similar to SVS, which can be considered as a reference value for clinical practice.