Faster R-CNN-Based Glomerular Detection in Multistained Human Whole Slide Images

The detection of objects of interest in high-resolution digital pathological images is a key part of diagnosis and is a labor-intensive task for pathologists. In this paper, we describe a Faster R-CNN-based approach for the detection of glomeruli in multistained whole slide images (WSIs) of human renal tissue sections. Faster R-CNN is a state-of-the-art general object detection method based on a convolutional neural network, which simultaneously proposes object bounds and objectness scores at each point in an image. The method takes an image obtained from a WSI with a sliding window and classifies and localizes every glomerulus in the image by drawing the bounding boxes. We configured Faster R-CNN with a pretrained Inception-ResNet model and retrained it to be adapted to our task, then evaluated it based on a large dataset consisting of more than 33,000 annotated glomeruli obtained from 800 WSIs. The results showed the approach produces comparable or higher than average F-measures with different stains compared to other recently published approaches. This approach could have practical application in hospitals and laboratories for the quantitative analysis of glomeruli in WSIs and, potentially, lead to a better understanding of chronic glomerulonephritis

Heart wall is thicker on postmortem computed tomography than on antemortem [corrected] computed tomography: the first longitudinal study.

OBJECTIVE: To evaluate the postmortem changes of the heart wall on postmortem (PM) computed tomography (CT) in comparison with those on ante mortem CT (AMCT), and in comparison with the pathological findings, obtained in the same patients. MATERIALS AND METHODS: We studied 57 consecutive patients who had undergone AMCT, PMCT, and pathological autopsy in our tertiary care hospital between April 2009 and December 2010. PMCT was performed within 20 hours after death, followed by pathological autopsy. The cardiac chambers were measured at five sites on both AMCT and PMCT by two board-certified radiologists who were not provided with clinical information. The differences in heart wall thickness between AMCT with and without contrast medium, between AMCT and PMCT, and between PMCT and pathological anatomy were evaluated statistically. Confounding factors of postmortem change such as gender, presence of arteriosclerosis, the organ related to cause of death, age, and elapsed time since death were examined statistically. RESULTS: No significant differences were observed on AMCT in comparison of contrasted and non-contrasted images. The heart wall was significantly thicker on PMCT than on AMCT (p < 0.0001) at all five measurement sites. The heart wall was significantly thicker on PMCT than on pathology specimens when measured in accordance with pathological standard mensuration. However, no significant difference was observed between PMCT measurements and those of pathology specimens at any site when the papillary muscles and epicardial fat were included. No significant association was found between postmortem change in heart wall thickness and gender, presence of arteriosclerosis, the organ related to cause of death, age, or elapsed time since death. CONCLUSION: This is the first longitudinal study to confirm greater thickness of heart wall on postmortem images compared with ante mortem images, in the same patients. Furthermore, the postmortem changes on CT were supported by the pathological findings

Comparison of attenuation of striated muscle between postmortem and antemortem computed tomography: results of a longitudinal study.

OBJECTIVE: We evaluated the postmortem changes of striated muscle by comparing computed tomography (CT) images obtained postmortem and antemortem in the same patients. MATERIALS AND METHODS: We studied 33 consecutive patients who underwent antemortem CT, postmortem CT, and pathological autopsy in our tertiary care hospital between April 2009 and December 2010. Postmortem CT was performed within 20 h after death and was followed by pathological autopsy. Pathological autopsy confirmed the absence of muscular diseases such as amyotrophic lateral sclerosis, muscular dystrophy, myositis, and myasthenia, in all of the patients. The CT attenuation values of four cardiac muscle sites (anterior wall of the left ventricle, left ventricular free wall, posterior wall of the left ventricle, and the ventricular septum) and two skeletal muscle sites (the pectoralis major muscle and the erector spinae muscle) were compared between antemortem and postmortem CT using paired t test. RESULTS: Striated muscle had significantly greater attenuation on postmortem CT than on antemortem CT (P<0.001) in all six tissue sites. No significant association was found between postmortem change in the CT attenuation of striated muscle and gender, age, or elapsed time since death. CONCLUSION: This is the first longitudinal study to show hyperattenuation of striated muscle on postmortem CT images compared with antemortem CT images in the same patients

Brain Swelling and Loss of Gray and White Matter Differentiation in Human Postmortem Cases by Computed Tomography.

The purpose of this study was to evaluate the brain by postmortem computed tomography (PMCT) versus antemortem computed tomography (AMCT) using brains from the same patients. We studied 36 nontraumatic subjects who underwent AMCT, PMCT, and pathological autopsy in our hospital between April 2009 and December 2013. PMCT was performed within 20 h after death, followed by pathological autopsy including the brain. Autopsy confirmed the absence of intracranial disorders that might be related to the cause of death or might affect measurements in our study. Width of the third ventricle, width of the central sulcus, and attenuation in gray matter (GM) and white matter (WM) from the same area of the basal ganglia, centrum semiovale, and high convexity were statistically compared between AMCT and PMCT. Both the width of the third ventricle and the central sulcus were significantly shorter in PMCT than in AMCT (P < 0.0001). GM attenuation increased after death at the level of the centrum semiovale and high convexity, but the differences were not statistically significant considering the differences in attenuation among the different computed tomography scanners. WM attenuation significantly increased after death at all levels (P<0.0001). The differences were larger than the differences in scanners. GM/WM ratio of attenuation was significantly lower by PMCT than by AMCT at all levels (P<0.0001). PMCT showed an increase in WM attenuation, loss of GM-WM differentiation, and brain swelling, evidenced by a decrease in the size of ventricles and sulci

Computational Pipeline for Glomerular Segmentation and Association of the Quantified Regions with Prognosis of Kidney Function in IgA Nephropathy

The histopathological findings of the glomeruli from whole slide images (WSIs) of a renal biopsy play an important role in diagnosing and grading kidney disease. This study aimed to develop an automated computational pipeline to detect glomeruli and to segment the histopathological regions inside of the glomerulus in a WSI. In order to assess the significance of this pipeline, we conducted a multivariate regression analysis to determine whether the quantified regions were associated with the prognosis of kidney function in 46 cases of immunoglobulin A nephropathy (IgAN). The developed pipelines showed a mean intersection over union (IoU) of 0.670 and 0.693 for five classes (i.e., background, Bowman’s space, glomerular tuft, crescentic, and sclerotic regions) against the WSI of its facility, and 0.678 and 0.609 against the WSI of the external facility. The multivariate analysis revealed that the predicted sclerotic regions, even those that were predicted by the external model, had a significant negative impact on the slope of the estimated glomerular filtration rate after biopsy. This is the first study to demonstrate that the quantified sclerotic regions that are predicted by an automated computational pipeline for the segmentation of the histopathological glomerular components on WSIs impact the prognosis of kidney function in patients with IgAN

Ante mortem and postmortem measurements of the heart of a 60-year-old man.

<div><p>(a) Multiplanar reconstruction image of ante mortem CT.</p> <p>(b) Multiplanar reconstruction image of postmortem CT.</p> <p>(c) Photograph of the pathological cross-sectional slice.</p> <p>All three of these images represent the same plane.</p> <p>Solid lines represent measurements without including papillary muscles or epicardial fat, according to conventional methods. Dotted lines represent measurements with papillary muscles and epicardial fat.</p> <p>A, anterior wall of the left ventricle; F, left ventricular free wall; P, posterior wall of the left ventricle; S, ventricular septum; R, right ventricular wall.</p></div

Intestinal perforation after nivolumab immunotherapy for a malignant melanoma: a case report

Abstract Background Nivolumab is a monoclonal antibody against programmed death 1 and has become a standard treatment of advanced melanoma because of its durable response and survival benefits. In this report, we present a case of severe intestinal perforation after nivolumab immunotherapy for malignant melanoma. Case presentation A 73-year-old man with stage IV malignant melanoma underwent nivolumab therapy. The patient presented to our hospital because of a progressing abdominal pain. Radiological evaluation revealed evidence of free intraperitoneal air. Therefore, we diagnosed the patient as having an intestinal perforation, which was successfully resolved after surgical treatment. Conclusion Although intestinal perforation after nivolumab immunotherapy is rare, it can be severe and requires early diagnosis and emergency surgery to ensure a favorable prognosis