Development of artificial intelligence-based slow-motion echocardiography and clinical usefulness for evaluating regional wall motion abnormalities.

The diagnostic accuracy of exercise stress echocardiography (ESE) for myocardial ischemia requires improvement, given that it currently depends on the physicians' experience and image quality. To address this issue, we aimed to develop artificial intelligence (AI)-based slow-motion echocardiography using inter-image interpolation. The clinical usefulness of this method was evaluated for detecting regional wall-motion abnormalities (RWMAs). In this study, an AI-based echocardiographic image-interpolation pipeline was developed using optical flow calculation and prediction for in-between images. The accuracy for detecting RWMAs and image readability among 25 patients with RWMA and 25 healthy volunteers was compared between four cardiologists using slow-motion and conventional ESE. Slow-motion echocardiography was successfully developed for arbitrary time-steps (e.g., 0.125×, and 0.5×) using 1,334 videos. The RWMA detection accuracy showed a numerical improvement, but it was not statistically significant (87.5% in slow-motion echocardiography vs. 81.0% in conventional ESE; odds ratio: 1.43 [95% CI: 0.78-2.62], p = 0.25). Interreader agreement analysis (Fleiss's Kappa) for detecting RWMAs among the four cardiologists were 0.66 (95%CI: 0.55-0.77) for slow-motion ESE and 0.53 (95%CI: 0.42-0.65) for conventional ESE. Additionally, subjective evaluations of image readability using a four-point scale showed a significant improvement for slow-motion echocardiography (2.11 ± 0.73 vs. 1.70 ± 0.78, p < 0.001).In conclusion, we successfully developed slow-motion echocardiography using in-between echocardiographic image interpolation. Although the accuracy for detecting RWMAs did not show a significant improvement with this method, we observed enhanced image readability and interreader agreement. This AI-based approach holds promise in supporting physicians' evaluations.

Verification of modified receiver-operating characteristic software using simulated rating data.

ROCKIT, which is a receiver-operating characteristic (ROC) curve-fitting software package, was developed by Metz et al. In the early 1990s, it is a very frequently used ROC software throughout the world. In addition to ROCKIT, DBM-MRMC software was developed for multi-reader multi-case analysis of the difference in average area under ROC curves (AUCs). Because this old software cannot run on a PC with Windows 7 or a more recent operating system, we developed new software that employs the same basic algorithms with minor modifications. In this study, we verified our modified software and tested the differences between the index of diagnostic accuracies using simulated rating data. In our simulation model, all data were generated using target AUCs and a binormal parameter b. In ROC curve fitting with simulated rating data, we varied four factors: the total number of case samples, the ratio of positive-to-negative cases, a binormal parameter b, and the preset AUC. To investigate the differences between the statistical test results obtained from our software and the existing software, we generated simulated rating data sets with three levels of case difficulty and three degrees of difference in AUCs obtained from two modalities. As a result of the simulation, the AUCs estimated by the new and existing software were highly correlated (R > 0.98), and there were high agreements (85% or more) in the statistical test results. In conclusion, we believe that our modified software is as capable as the existing software.

Quantitative Sonographic Assessment of the Quadriceps Femoris Muscle in Healthy Japanese Adults.

OBJECTIVES: The aim of this study was to evaluate the relationships among aging, muscle strength, and image feature analysis of the quadriceps femoris muscle and to evaluate the relationship between aging, muscle strength, and sonographic findings. METHODS: One hundred forty-five healthy volunteers participated in the study. The participants were classified into 6 groups on the basis of sex and age. To assess muscle quality, texture analysis was defined with the following parameters: mean, skewness, kurtosis, inverse difference moment, sum of entropy, and angular second moment. The knee extension force in the sitting position and thickness of the quadriceps femoris muscle were also measured. RESULTS: The quadriceps femoris thickness, skewness, kurtosis, inverse difference moment, angular second moment, and muscle strength were significantly decreased in elderly participants versus those in the younger and middle-aged groups (P < .05). In contrast, the mean and sum of entropy were significantly decreased in the younger group compared with the middle-aged and elderly groups. CONCLUSIONS: Sonography has the capacity to quantitatively assess muscular morphologic changes due to aging and could be a valuable tool for early detection of musculoskeletal disorders.

Structural Comparison between the Right and Left Atrial Appendages Using Multidetector Computed Tomography.

The three-dimensional (3D) structures of the right atrial appendage (RAA) and left atrial appendage (LAA) were compared to clarify why thrombus formation less frequently occurs in RAA than in LAA. Morphological differences between RAA and LAA of 34 formalin-preserved cadaver hearts were investigated. Molds of RAA and LAA specimens were made and the neck areas, volumes of the atrial appendages (AA), and amount of pectinate muscles (PMs) were analyzed using multidetector computed tomography. In RAA, most PMs were connected to one another and formed a "dendritic" appearance and the inner surface area was smaller than in LAA. RAA had smaller volumes and larger neck areas than LAA. The ratios of the neck area/volume were larger and the amounts of PMs were smaller in RAA than in LAA. The volumes, neck areas, and amount of PMs of RAA were significantly correlated with those of LAA. According to the 3D structure, RAA appears to be suited for a more favorable blood flow, which may explain why the thrombus formation is less common in RAA than in LAA. Examining not only LAA but also RAA by transesophageal echocardiography may be useful in high-risk patients of thrombus formation in LAA because the volume, neck area, and amount of PMs of LAA reflect the shape of RAA.

A pilot study to assess Fatty infiltration of the supraspinatus in patients with rotator cuff tears: comparison with magnetic resonance imaging.

The aim of this study was to quantitatively assess the echo intensity of the supraspinatus muscle and compare magnetic resonance imaging and ultrasound findings for 27 patients (12 women, 15 men, 65.8 ± 11.5 y). Tear size and fatty infiltration were determined by magnetic resonance imaging; five stages were assigned based on Goutallier's classification. Gray-scale histogram analysis was used for ultrasound assessment, which was performed in both subcutaneous fat and supraspinatus muscle in three different regions; the echo intensity ratio was the ratio of echo intensity in subcutaneous fat to that in the supraspinatus muscle. Sonograms of 27 shoulders revealed 3 shoulders with a partial tear, and 4 with a small tear, 6 with a medium tear, 6 with a large tear and 4 with a massive tear; 4 shoulders had no tear. Supraspinatus muscle echo intensity and echo intensity ratio were significantly lower in the stage 0 and 1 than in stages 2-4. Our study suggests that ultrasound can quantitatively and objectively assess fatty infiltration in the rotator cuff muscle.

Triterpene alcohols and sterols from rice bran lower postprandial glucose-dependent insulinotropic polypeptide release and prevent diet-induced obesity in mice.

Obesity is now a worldwide health problem. Glucose-dependent insulinotropic polypeptide (GIP) is a gut hormone that is secreted following the ingestion of food and modulates energy metabolism. Previous studies reported that lowering diet-induced GIP secretion improved energy homeostasis in animals and humans, and attenuated diet-induced obesity in mice. Therefore, food-derived GIP regulators may be used in the development of foods that prevent obesity. Rice bran oil and its components are known to have beneficial effects on health. Therefore, the aim of the present study was to clarify the effects of the oil-soluble components of rice bran on postprandial GIP secretion and obesity in mice. Triterpene alcohols [cycloartenol (CA) and 24-methylene cycloartanol (24Me)], ß-sitosterol, and campesterol decreased the diet-induced secretion of GIP in C57BL/6J mice. Mice fed a high-fat diet supplemented with a triterpene alcohol and sterol preparation (TASP) from rice bran for 23 wk gained less weight than control mice. Indirect calorimetry revealed that fat utilization was higher in TASP-fed mice than in control mice. Fatty acid oxidation-related gene expression in the muscles of mice fed a TASP-supplemented diet was enhanced, whereas fatty acid synthesis-related gene expression in the liver was suppressed. The treatment of HepG2 cells with CA and 24Me decreased the gene expression of sterol regulatory element-binding protein (SREBP)-1c. In conclusion, we clarified for the first time that triterpene alcohols and sterols from rice bran prevented diet-induced obesity by increasing fatty acid oxidation in muscles and decreasing fatty acid synthesis in the liver through GIP-dependent and GIP-independent mechanisms.

Properties of lead deposits in cell walls of radish (Raphanus sativus) roots.

Various mechanisms are involved in detoxification of heavy metals such as lead (Pb) in plant cells. Most of the Pb taken up by plants accumulates in their roots. However, the detailed properties of Pb complexes in roots remain unclear. We have investigated the properties of Pb deposits in root cell walls of radish (Raphanus sativus L.) seedlings grown on glass beads bed containing Pb pellets, which are the source of Pb-contamination in shooting range soils. Pb deposits were tightly bound to cell walls. Cell wall fragments containing about 50,000 ppm Pb were prepared from the roots. After extracting Pb from the cell wall fragments using HCl, Pb ions were recombined with the Pb-extracted cell wall fragments in a solution containing Pb acetate. When the cell wall fragments were treated with pectinase (E.C. 3.2.1.15) and were chemically modified with 1-ethyl-3-dimethylamino-propylcarboimide, the Pb-rebinding ability of the treated cell wall fragments decreased. When acid-treated cell wall fragments were incubated in a solution containing Pb(2+) and excess amounts of a chelating agent, Pb recombined with the cell wall fragments were measured to estimate the affinity between Pb(2+) and the cell wall fragments. Our data show that Pb(2+) binds to carboxyl groups of cell walls. The source of the carboxyl groups is suggested to be pectic compounds. A stability constant of the Pb-cell wall complex was estimated to be about 10(8). The role of root cell walls in the mechanism underlying heavy metal tolerance was discussed.

Basic concepts and development of an all-purpose computer interface for ROC/FROC observer study.

In this study, we initially investigated various aspects of requirements for a computer interface employed in receiver operating characteristic (ROC) and free-response ROC (FROC) observer studies which involve digital images and ratings obtained by observers (radiologists). Secondly, by taking into account these aspects, an all-purpose computer interface utilized for these observer performance studies was developed. Basically, the observer studies can be classified into three paradigms, such as one rating for one case without an identification of a signal location, one rating for one case with an identification of a signal location, and multiple ratings for one case with identification of signal locations. For these paradigms, display modes on the computer interface can be used for single/multiple views of a static image, continuous viewing with cascade images (i.e., CT, MRI), and dynamic viewing of movies (i.e., DSA, ultrasound). Various functions on these display modes, which include windowing (contrast/level), magnifications, and annotations, are needed to be selected by an experimenter corresponding to the purpose of the research. In addition, the rules of judgment for distinguishing between true positives and false positives are an important factor for estimating diagnostic accuracy in an observer study. We developed a computer interface which runs on a Windows operating system by taking into account all aspects required for various observer studies. This computer interface requires experimenters to have sufficient knowledge about ROC/FROC observer studies, but allows its use for any purpose of the observer studies. This computer interface will be distributed publicly in the near future.

Dietary 1-monoolein decreases postprandial GIP release by reducing jejunal transport of glucose and fatty acid in rodents.

Postprandial secretion of insulin and glucose-dependent insulinotropic polypeptide (GIP) is differentially regulated by not only dietary carbohydrate but also fat. Recent studies have shown that the ingestion of diacylglycerol (DAG) results in lower postprandial insulin and GIP release than that of triacylglycerol (TAG), suggesting a possible mechanism for the antiobesity effect of DAG. The structural and metabolic characteristics of DAG are believed to be responsible for its beneficial effects. This study was designed to clarify the effect of 1-monoacylglycerol [oleic acid-rich (1-MO)], the characteristic metabolite of DAG, on postprandial insulin and GIP secretion, and the underlying mechanism. Dietary 1-MO dose dependently stimulated whole body fat utilization, and reduced high-fat diet-induced body weight gain and visceral fat accumulation in mice, both of which are consistent with the physiological effect of dietary DAG. Although glucose-stimulated insulin and GIP release was augmented by the addition of fat, coingestion of 1-MO reduced the postprandial hormone release in a dose-dependent manner. Either glucose or fatty acid transport into the everted intestinal sacs and enteroendocrine HuTu-80 cells was also reduced by the addition of 1-MO. Reduction of either glucose or fatty acid transport or the nutrient-stimulated GIP release by 1-MO was nullified when the intestine was pretreated with sodium-glucose cotransporter-1 (SGLT-1) or fatty acid translocase (FAT)/CD36 inhibitor. We conclude that dietary 1-MO attenuates postprandial GIP and insulin secretion by reducing the intestinal transport of the GIP secretagogues, which may be mediated via SGLT-1 and FAT/CD36. Reduced secretion of these anabolic hormones by 1-MO may be related to the antiobesity effect of DAG.

Hydroxypropylated distarch phosphate versus unmodified tapioca starch: fat oxidation and endurance in C57BL/6J mice.

An RS4-type resistant starch is a chemically modified starch that shows reduced availability in comparison to the corresponding unmodified starch. Hydroxypropylated distarch phosphate (HDP) is an RS4-type resistant starch that increases energy expenditure and prevents high-fat diet-induced obesity through increased hepatic fatty acid oxidation. The aim of this study was to clarify the acute effects of HDP from tapioca starch (HPdTSP) on physical performance in mice. Male C57BL/6J mice were used to examine the effects of a single administration of 2 mg/g body weight HPdTSP or unmodified tapioca starch (TS) on postprandial responses in serum metabolic parameters, running endurance capacity on a treadmill, whole-body energy metabolism during exercise, activity of enzymes involved in fatty acid oxidation, liver and gastrocnemius muscle glycogen content, and serum glucose, insulin, non-esterified fatty acid, lactate, and triglyceride levels after exercise. Running time to fatigue was significantly greater in HPdTSP mice than in TS mice. Furthermore, HPdTSP maintained higher fat oxidation and this was associated with a greater activity of enzymes in fatty acid oxidation in the muscle during exercise. The blood lactate and serum insulin levels after exercise was significantly lower in HPdTSP mice than in TS mice. Liver glycogen was significantly higher in HPdTSP mice than in TS mice. These results suggest that acute oral administration of the RS4-type resistant starch, HPdTSP, maintained higher fat oxidation and reduced liver glycogen consumption during exercise and increased running endurance capacity in mice.

Quantitative analysis of vascularization in the finger joints in patients with rheumatoid arthritis using three-dimensional volumetric ultrasonography with power Doppler.

This study aimed to compare the intraobserver and interobserver reliability of three-dimensional (3D) and two-dimensional (2D) power Doppler ultrasonography (PDUS) and to assess the relationship between 3D PDUS and clinical parameters in patients with rheumatoid arthritis (RA). Bilateral second/third metacarpophalangeal joints and second/third proximal interphalangeal joints in 33 patients were examined by both 2D and 3D PDUS. Each joint was given a separate 2D PDUS subjective score (range, 0-3) in a standard manner. The 2D PDUS index is the sum of the scores of all eight joints assessed. 3D PDUS voxel signals were quantitatively analyzed by using computerized voxel counts. Intraobserver reliability was high for both examinations (2D PDUS: ICC = 0.957, 95% confidence interval = 0.818-0.999; 3D PDUS: ICC = 0.998, 95% confidence interval = 0.998-1.000). Interobserver reliability was also high (2D PDUS: ICC = 0.993, 95% confidence interval = 0.806-0.988; 3D PDUS: ICC = 0.999, 95% confidence interval = 0.999-1.000). A significant correlation was found between the 2D PDUS index and 3D PDUS voxel count (r = 0.795; p < 0.001). The 3D PDUS voxel count showed significant correlation with 28 joints Disease Activity Score (DAS28)-erythrocyte sedimentation rate (r = 0.448, p < 0.01) and DAS28-C-reactive protein (r = 0.383, p < 0.05). Our study indicates that the measurement of 3D PDUS may be a valuable tool for predicting disease activity.

RS4-type resistant starch prevents high-fat diet-induced obesity via increased hepatic fatty acid oxidation and decreased postprandial GIP in C57BL/6J mice.

Chemically modified starches (CMS) are RS4-type resistant starch, which shows a reduced availability, as well as high-amylose corn starch (HACS, RS2 type), compared with the corresponding unmodified starch. Previous studies have shown that RS4 increases fecal excretion of bile acids and reduces zinc and iron absorption in rats. The aim of this study was to investigate the effects of dietary RS4 supplementation on the development of diet-induced obesity in mice. Weight- and age-matched male C57BL/6J mice were fed for 24 wk on a high-fat diet containing unmodified starch, hydroxypropylated distarch phosphate (RS4), or HACS (RS2). Those fed the RS4 diet had significantly lower body weight and visceral fat weight than those fed either unmodified starch or the RS2 diet. Those fed the RS4 diet for 4 wk had a significantly higher hepatic fatty acid oxidation capacity and related gene expression and lower blood insulin than those fed either unmodified starch or the RS2 diet. Indirect calorimetry showed that the RS4 group exhibited higher energy expenditure and fat utilization compared with the RS2 group. When gavaged with fat (trioleate), RS4 stimulated a lower postprandial glucose-dependent insulinotropic polypeptide (GIP; incretin) response than RS2. Higher blood GIP levels induced by chronic GIP administration reduced fat utilization in high-fat diet-fed mice. In conclusion, dietary supplementation with RS4-type resistant starch attenuates high-fat diet-induced obesity more effectively than RS2 in C57BL/6J mice, which may be attributable to lower postprandial GIP and increased fat catabolism in the liver.

Automated analysis of breast parenchymal patterns in whole breast ultrasound images: preliminary experience.

PURPOSE: A computerized classification scheme to recognize breast parenchymal patterns in whole breast ultrasound (US) images was developed. A preliminary evaluation of the system performance was performed. METHODS: Breast parenchymal patterns were classified into three categories: mottled pattern (MP), intermediate pattern (IP), and atrophic pattern (AP). Each classification was defined as proposed by an experienced physician. A total of 281 image features were extracted from a volume of interest which was automatically segmented. Canonical discriminant analysis with stepwise feature selection was employed for the classification of the parenchymal patterns. RESULTS: The classification scheme accuracy was computed to be 83.3% (10/12 cases) in MP cases, 91.7% (22/24 cases) in IP cases, 92.9% (13/14 cases) in AP cases, and 90.0% (45/50 cases) in all the cases. CONCLUSIONS: The feasibility of an automated ultrasonography classifier for parenchymal patterns was demonstrated with promising results in whole breast US images.

Coingestion of acylglycerols differentially affects glucose-induced insulin secretion via glucose-dependent insulinotropic polypeptide in C57BL/6J mice.

The precise role of fat in postprandial glycemia and insulinemia has not been thoroughly researched because postprandial blood glucose and concurrent insulin secretion are largely assumed to be proportional to carbohydrate intake. Recent studies have suggested that dietary fat differentially regulates the postprandial insulin response. To explore this, we examined the effects of coadministered fat on glucose-induced glycemia and insulinemia in C57BL/6J mice. The insulin response to glucose was augmented by the addition of glycerol trioleate (TO) in a dose-dependent manner, which was associated with enhanced glucose transport from the circulation to muscle and adipose tissues. To investigate the mechanism underlying fat-induced hyperinsulinemia, we examined the release of the incretin hormones glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1. TO increased GIP secretion, whereas glucagon-like peptide-1 secretion was unaffected. TO-induced hyperinsulinemia was significantly attenuated by the pretreatment of mice with a specific GIP antagonist. Diacylglycerol (DAG) promoted lower postprandial GIP and triglyceride responses and, when ingested with glucose, a lower insulin response compared with triacylglycerol of a similar fatty acid composition. Pluronic L-81, an inhibitor of chylomicron formation, reduced not only the triglyceride response but also TO-induced GIP secretion, indicating that the lower GIP response after DAG ingestion may be associated with retarded chylomicron formation in the small intestine. We conclude that dietary fat augments glucose-induced insulinemia via gut-derived GIP and, thereby, influences postprandial nutrient metabolism in mice. DAG promotes a lower GIP and thereby reduced insulin responses compared with triacylglycerol, which may differentially influence postprandial energy homeostasis.

Computer-aided diagnosis: the emerging of three CAD systems induced by Japanese health care needs.

The aim of this paper is to describe three emerging computer-aided diagnosis (CAD) systems induced by Japanese health care needs. CAD has been developing fast in the last two decades. The idea of using a computer to help in medical image diagnosis is not new. Some pioneer studies are dated back to the 1960s. In 1998, the first U.S. FDA (Food and Drug Administration) approved commercial CAD system, a film-digitized mammography system, was launched by R2 Technologies, Inc. The success was quickly repeated by a number of companies. The approval of Medicare CAD reimbursement in the U.S. in 2001 further boosted the industry. Today, CAD has its significance in the economy of the medical industry. FDA approved CAD products in the field of breast imaging (mammography, ultrasonography and breast MRI) and chest imaging (radiography and CT) can be seen. In Japan, as part of the "Knowledge Cluster Initiative" of the government, three computer-aided diagnosis (CAD) projects are hosted at the Gifu University since 2004. These projects are regarding the development of CAD systems for the early detection of (1) cerebrovascular diseases using brain MRI and MRA images by detecting lacunar infarcts, unruptured aneurysms, and arterial occlusions; (2) ocular diseases such as glaucoma, diabetic retinopathy, and hypertensive retinopathy using retinal fundus images; and (3) breast cancers using ultrasound 3-D volumetric whole breast data by detecting the breast masses. The projects are entering their final development stage. Preliminary results are presented in this paper. Clinical examinations will be started soon, and commercialized CAD systems for the above subjects will appear by the completion of this project.

Development of a fully automatic scheme for detection of masses in whole breast ultrasound images.

Ultrasonography has been used for breast cancer screening in Japan. Screening using a conventional hand-held probe is operator dependent and thus it is possible that some areas of the breast may not be scanned. To overcome such problems, a mechanical whole breast ultrasound (US) scanner has been proposed and developed for screening purposes. However, another issue is that radiologists might tire while interpreting all images in a large-volume screening; this increases the likelihood that masses may remain undetected. Therefore, the aim of this study is to develop a fully automatic scheme for the detection of masses in whole breast US images in order to assist the interpretations of radiologists and potentially improve the screening accuracy. The authors database comprised 109 whole breast US imagoes, which include 36 masses (16 malignant masses, 5 fibroadenomas, and 15 cysts). A whole breast US image with 84 slice images (interval between two slice images: 2 mm) was obtained by the ASU-1004 US scanner (ALOKA Co., Ltd., Japan). The feature based on the edge directions in each slice and a method for subtracting between the slice images were used for the detection of masses in the authors proposed scheme. The Canny edge detector was applied to detect edges in US images; these edges were classified as near-vertical edges or near-horizontal edges using a morphological method. The positions of mass candidates were located using the near-vertical edges as a cue. Then, the located positions were segmented by the watershed algorithm and mass candidate regions were detected using the segmented regions and the low-density regions extracted by the slice subtraction method. For the removal of false positives (FPs), rule-based schemes and a quadratic discriminant analysis were applied for the distribution between masses and FPs. As a result, the sensitivity of the authors scheme for the detection of masses was 80.6% (29/36) with 3.8 FPs per whole breast image. The authors scheme for a computer-aided detection may be useful in improving the screening performance and efficiency.