In a previous study, we applied patch classification, a fiber estimation method, on macro-images of paper obtained using a digital camera; these macro-images were obtained from a limited number of materials. The method efficiently classified these images by dividing them into image patches. However, this method did not analyze the entire macro-image. Therefore, to extend the application of this patch-based paper fiber classification method to entire macro-images, we propose a method wherein EfficientNet is applied for fiber estimation in macro-images; the type of fiber of each image patch was estimated in two stages. The first stage was patch fiber classification 1 (PFC 1), wherein image patches were classified into three fibers, yielding PFC results for the patches comprising a macro-image. If more than 80% of the patches were determined to be of the same fiber by a majority vote, these results would be used as the paper fiber estimation (PFE) results for the macro-image. If less than 80% were classified to be of the same fiber under PFC 1, then patch fiber classification 2 (PFC 2), wherein the patches between two fibers were classified, was performed. Then, by majority, the PFC 2 results would be used as the estimation results. We targeted three fibers, namely kõzo, mitsumata, and gampi; and we used 1179 macro-images (393 for each fiber). The fiber estimation accuracy for the macro-images was evaluated using three-fold cross-validation. We achieved an accuracy of 87.6% in estimating fibers in the macro-images of paper using the proposed method.
The body cavity region contains organs and is an essential region for skeletal muscle segmentation. This study proposes a method to segment body cavity regions using U-Net with focus on the oblique abdominal muscles. The proposed method comprises two steps. First, the body cavity is segmented using U-Net. Subsequently, the abdominal muscles are identified using recognition techniques. This is achieved by removing the segmented body cavity region from the original computerized tomography (CT) images to obtain a simplified CT image for training. In this image, the visceral organ regions are masked by the body cavity; ensuring that the organs therein are excluded from the segmentation target in advance which has been a primary concern in the conventional method of skeletal muscle segmentation. The segmentation accuracies of the body cavity and oblique abdominal muscle in 16 cases were 98.50% and 84.89%, respectively, in terms of the average dice value. Furthermore, it was observed that body cavity information reduced the number of over-extracted pixels by 36.21% in the segmentation of the oblique abdominal muscles adjacent to the body cavity, improving the segmentation accuracy. In future studies, it could be beneficial to examine whether the proposed simplification of CT images by segmentation of body cavities is also effective for abdominal musculoskeletal muscles adjacent to body cavities divided by tendon ends, such as the rectus abdominis.
Supervised learning for image segmentation requires annotated images. However, image annotation has the problem that it is time-consuming. This problem is particularly significant in the erector spinae muscle segmentation due to the large size of the muscle. Therefore, this study considers the relationship between the number of annotated images used for training and segmentation accuracy of the erector spinae muscle in torso CT images. We use Bayesian U-Net, which has shown high accuracy in thigh muscle segmentation, for the segmentation of the erector spinae muscle. In the network training, we limit the number of slices for each case and the number of cases to 100%, 50%, 25%, and 10%. In the experiment, we use 30 torso CT images, including 6 cases for the test dataset. Experimental results are evaluated by the mean Dice value of the test dataset. Using 100% of the slices per case, the segmentation accuracy with 100%, 50%, 25%, and 10% of the cases was 0.934, 0.927, 0.926, and 0.890, respectively. On the other hand, using 100% of the cases, the segmentation accuracy with 100%, 50%, 25%, and 10% of the slices per case was 0.934, 0.934, 0.933, and 0.931, respectively. Furthermore, the segmentation accuracy with 100% of the cases and 10% of the slices per case was higher than that of the previous method. We showed that it is feasible to achieve high segmentation accuracy with a limited number of annotated images by selecting several slices from a limited number of cases for training.
Mammary gland density is used as one of the measures in managing the risk of breast cancer. It can be divided into four categories. In addition, mammography is used for population-based breast cancer screening in Japan. However, mass and calcification are assumed to be hidden in the shadow of the mammary gland as displayed by the mammogram when patients showing heterogeneously dense or extremely dense in the mammary gland density category are scanned with mammography. Therefore, it is necessary to recommend an examination suitable for each category of mammary gland density. In one example, a doctor recommends ultrasonography in addition to mammography for patients with dense breasts. However, mammary gland density is distinguished visually using subjective judgment. Against such a background, we have worked on an automatic classification of mammary gland densities using a deep learning technique. Moreover, we investigated the effect of image resolution on the classification results in the automatic classification of mammary gland density with deep learning. The resolution was varied from 1/100 (474 × 354) to 1/3600 (79 × 59) using 1106 cases of resolution 4740 × 3540 (pixels) obtained with Fuji Computed Radiography (FCR) by Fujifilm Co. Ltd. As a result, the accuracy of automatic classification of mammary gland density exceeded 90% up to a resolution of 1/400 (237 × 177), and was 89% even at the lowest resolution of 1/3600 (79 × 59).
The skeletal muscle exists in the whole body and can be observed in many cross sections in various tomographic images. Skeletal muscle atrophy is due to aging and disease, and the abnormality is difficult to distinguish visually. In addition, although skeletal muscle analysis requires a technique for accurate site-specific measurement of skeletal muscle, it is only realized in a limited region. We realized automatic site-specific recognition of skeletal muscle from whole-body CT images using model-based methods. Three-dimensional texture analysis revealed imaging features with statistically significant differences between amyotrophic lateral sclerosis (ALS) and other muscular diseases accompanied by atrophy. In recent years, deep learning technique is also used in the field of computer-aided diagnosis. Therefore, in this initial study, we performed automatic classification of amyotrophic diseases using deep learning for the upper extremity and lower limb regions. The classification accuracy was highest in the right forearm, which was 0.960 at the maximum (0.903 on average). In the future, methods for differentiating more kinds of muscular atrophy and clinical application of ALS detection by analyzing muscular regions must be considered.
Amyotrophic lateral sclerosis (ALS) causes functional disorders such as difficulty in breathing and swallowing through the atrophy of voluntary muscles. ALS in its early stages is difficult to diagnose because of the difficulty in differentiating it from other muscular diseases. In addition, image inspection methods for aggressive diagnosis for ALS have not yet been established. The purpose of this study is to develop an automatic analysis system of the whole skeletal muscle to support the early differential diagnosis of ALS using whole-body CT images. In this study, the muscular atrophy parts including ALS patients are automatically identified by recognizing and segmenting whole skeletal muscle in the preliminary steps. First, the skeleton is identified by its gray value information. Second, the initial area of the body cavity is recognized by the deformation of the thoracic cavity based on the anatomical segmented skeleton. Third, the abdominal cavity boundary is recognized using ABM for precisely recognizing the body cavity. The body cavity is precisely recognized by non-rigid registration method based on the reference points of the abdominal cavity boundary. Fourth, the whole skeletal muscle is recognized by excluding the skeleton, the body cavity, and the subcutaneous fat. Additionally, the areas of muscular atrophy including ALS patients are automatically identified by comparison of the muscle mass. The experiments were carried out for ten cases with abnormality in the skeletal muscle. Global recognition and segmentation of the whole skeletal muscle were well realized in eight cases. Moreover, the areas of muscular atrophy including ALS patients were well identified in the lower limbs. As a result, this study indicated the basic technology to detect the muscle atrophy including ALS. In the future, it will be necessary to consider methods to differentiate other kinds of muscular atrophy as well as the clinical application of this detection method for early ALS detection and examine a large number of cases with stage and disease type.
The iliac muscle is an important skeletal muscle related to ambulatory function. The muscles related to ambulatory function are the psoas major and iliac muscles, collectively defined as the iliopsoas muscle. We have proposed an automated recognition method of the iliac muscle. Muscle fibers of the iliac muscle have a characteristic running pattern. Therefore, we used 20 cases from a training database to model the movement of the muscle fibers of the iliac muscle. In the recognition process, the existing position of the iliac muscle was estimated by applying the muscle fiber model. To generate an approximation mask by using a muscle fiber model, a candidate region of the iliac muscle was obtained. Finally, the muscle region was identified by using values from the gray value and boundary information. The experiments were performed by using the 20 cases without abnormalities in the skeletal muscle for modeling. The recognition result in five cases obtained a 76.9% average concordance rate. In the visual evaluation, overextraction of other organs was not observed in 85% of the cases. Therefore, the proposed method is considered to be effective in the recognition of the initial region of the iliac muscle. In the future, we will integrate the recognition method of the psoas major muscle in developing an analytical technique for the iliopsoas area. Furthermore, development of a sophisticated muscle function analysis method is necessary.
In aging societies, it is important to analyze age-related hypokinesia. A psoas major muscle has many important
functional capabilities such as capacity of balance and posture control. These functions can be measured by its cross
sectional area (CSA), volume, and thickness. However, these values are calculated manually in the clinical situation. The
purpose of our study is to propose an automated recognition method of psoas major muscles in X-ray torso CT images.
The proposed recognition process involves three steps: 1) determination of anatomical points such as the origin and
insertion of the psoas major muscle, 2) generation of a shape model for the psoas major muscle, and 3) recognition of the
psoas major muscles by use of the shape model. The model was built using quadratic function, and was fit to the
anatomical center line of psoas major muscle. The shape model was generated using 20 CT cases and tested by 20 other
CT cases. The applied database consisted of 12 male and 8 female cases from the ages of 40's to 80's. The average value
of Jaccard similarity coefficient (JSC) values employed in the evaluation was 0.7. Our experimental results indicated that
the proposed method was effective for a volumetric analysis and could be possible to be used for a quantitative
measurement of psoas major muscles in CT images.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.