Demarcation Line Determination for Diagnosis of Gastric Cancer Disease Range Using Unsupervised Machine Learning in Magnifying Narrow-Band Imaging.

BACKGROUND AND AIMS: It is important to determine an accurate demarcation line (DL) between the cancerous lesions and background mucosa in magnifying narrow-band imaging (M-NBI)-based diagnosis. However, it is difficult for novice endoscopists. We aimed to automatically determine the accurate DL using a machine learning method. METHODS: We used an unsupervised machine learning approach to determine the DLs. Our method consists of the following four steps: (1) an M-NBI image is segmented into superpixels using simple linear iterative clustering; (2) the image features are extracted for each superpixel; (3) the superpixels are grouped into several clusters using the k-means method; and (4) the boundaries of the clusters are extracted as DL candidates. The 23 M-NBI images of 11 cases were used for performance evaluation. The evaluation investigated the similarity of the DLs identified by endoscopists and our method, and the Euclidean distance between the two DLs was calculated. For the single case of 11 cases, the histopathological examination was also conducted to evaluate the proposed system. RESULTS: The average Euclidean distances for the 11 cases were 10.65, 11.97, 7.82, 8.46, 8.59, 9.72, 12.20, 9.06, 22.86, 8.45, and 25.36. The results indicated that the proposed method could identify similar DLs to those identified by experienced doctors. Additionally, it was confirmed that the proposed system could generate pathologically valid DLs by increasing the number of clusters. CONCLUSIONS: Our proposed system can support the training of inexperienced doctors as well as enrich the knowledge of experienced doctors in endoscopy.

Benefits of linked color imaging for recognition of early differentiated-type gastric cancer: in comparison with indigo carmine contrast method and blue laser imaging.

BACKGROUND AND AIM: Linked color imaging (LCI) is a novel endoscopy system, which enhances slight differences in mucosal color. However, whether LCI is more useful than other kinds of image-enhanced endoscopy (IEE) in recognizing early gastric cancer remains unclear. This study aimed to evaluate LCI efficacy compared with the indigo carmine contrast method (IC), and blue laser imaging-bright (BLI-brt) in early differentiated-type gastric cancer recognition. METHODS: We retrospectively analyzed early differentiated-type gastric cancer, which were examined by all four imaging techniques (white light imaging, IC, LCI, BLI-brt) at Asahi University Hospital from June 2014 to November 2018. Both subjective evaluation (using ranking score: RS) and objective evaluation (using color difference score: CDS) were adopted to quantify early differentiated-type gastric cancer recognition. RESULTS: During this period, 87 lesions were enrolled in this study. Both RS and CDS of LCI were significantly higher (p < 0.01) than those of IC and BLI-brt. Both RS and CDS of BLI-brt had no significant difference compared with those of IC. Subgroup analysis revealed that LCI was especially useful in post-Helicobacter pylori eradication patients and flat or depressed lesions compared with IC and BLI-brt. CONCLUSIONS: LCI appears to be more beneficial for the recognition of early differentiated-type gastric cancer in endoscopic screenings than IC and BLI-brt from the middle to distant view.

Recurrence of Cutaneous and Lymph Node Metastases 12 Years after Radical Total Gastrectomy for Stage IIA Gastric Cancer.

We herein report a rare case of cutaneous and lymph node metastases that recurred 12 years after radical total gastrectomy for stage IIA gastric cancer. A 62-year-old man had undergone total gastrectomy for stage IIA gastric cancer 12 years earlier without postoperative adjuvant chemotherapy. At 12 years after the surgery, he was admitted for left jugular swelling. Computed tomography revealed supraclavicular lymph node swelling and precordial subcutaneous edema. The lymph node specimens and cutaneous biopsies indicated late recurrence of the gastric cancer. Concurrent chemoradiotherapy was administered effectively, but after eight months, the patient died due to deterioration in his general condition.

Successful treatment of unresectable advanced rectal cancer with liver metastases by hemostasis re-irradiation of the rectal cancer and palliative low-dose whole-liver radiation therapy: a case report.

A 72-year-old man was admitted to the hospital with fatigue. Colonoscopy revealed a 50 × 50 mm rectal tumor with bleeding. Based on close inspection, he was diagnosed with unresectable advanced rectal cancer with multiple liver metastases. Chemotherapy was administered as 10 cycles of bevacizumab + mFOLFOX6 and 7 cycles of bevacizumab + FOLFIRI. Nine months later, he presented with hematochezia and progression of anemia. It was difficult to stop the bleeding via endoscopy. He underwent radiation therapy (39 Gy in 13 fractions), and hemostasis was confirmed. Then, further chemotherapy was performed with 3 cycles of bevacizumab + FOLFIRI and 2 cycles of TAS102. However 14 months after the initial visit, he presented with right hypochondralgia and abdominal fullness due to the progression of multiple liver metastases. Palliative low-dose whole-liver radiation therapy (WLRT) (30 Gy in 10 fractions) was performed. He developed Grade 2 nausea, but his right hypochondralgia reduced, liver dysfunction improved, and he successfully completed radiotherapy. At approximately the same time his anemia progressed, and colonoscopy revealed recurrent bleeding from the tumor. Re-irradiation (15 Gy in 5 fractions) of the rectal tumor was carried out and a blood transfusion was performed for the bleeding. He was discharged after confirmation the anemia had not progressed. Few reports have been published on the use of both palliative re-irradiation to stop bleeding from rectal cancer and palliative low-dose WLRT. Based on our experience with this case, we believe that palliative radiotherapy can be useful in treating patients with a poor prognosis.

Potential of automatic diagnosis system with linked color imaging for diagnosis of Helicobacter pylori infection.

BACKGROUND AND AIM: It is necessary to establish universal methods for endoscopic diagnosis of Helicobacter pylori (HP) infection, such as computer-aided diagnosis. In the present study, we propose a multistage diagnosis algorithm for HP infection. METHODS: The aims of this study are to: (i) to construct an interpretable automatic diagnostic system using a support vector machine for HP infection; and (ii) to compare the diagnosis capability of our artificial intelligence (AI) system with that of endoscopists. Presence of an HP infection determined through linked color imaging (LCI) was learned through machine learning. Trained classifiers automatically diagnosed HP-positive and -negative patients examined using LCI. We retrospectively analyzed the new images from 105 consecutive patients; 42 were HP positive, 46 were post-eradication, and 17 were uninfected. Five endoscopic images per case taken from different areas were read into the AI system, and used in the HP diagnosis. RESULTS: Accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of the diagnosis of HP infection using the AI system were 87.6%, 90.4%, 85.7%, 80.9%, and 93.1%, respectively. Accuracy of the AI system was higher than that of an inexperienced doctor, but there was no significant difference between the diagnosis of experienced physicians and the AI system. CONCLUSIONS: The AI system can diagnose an HP infection with significant accuracy. There remains room for improvement, particularly for the diagnosis of post-eradication patients. By learning more images and considering a diagnosis algorithm for post-eradication patients, our new AI system will provide diagnostic support, particularly to inexperienced physicians.

A case of phlegmonous gastritis with hepatic portal venous gas caused by Aeromonas hydrophila successfully treated with medication.

A 74-year-old woman was admitted to the hospital with epigastric pain, severe nausea and vomiting, and diarrhea that had started 3 days previously. She had eaten raw Ayu fish 4 days before admission. An abdominal contrast-enhanced computed tomography scan revealed the presence of gas in the portal vein and remarkable thickening of the gastric wall. In many cases, the gas in the portal vein indicates the existence of intestinal necrosis. Esophagogastroduodenoscopy showed a submucosal tumor-like elevation in the gastric corpus. She was diagnosed with sepsis and phlegmonous gastritis (PG) with hepatic portal venous gas (HPVG) caused by Aeromonas hydrophila, which was detected in her stool. The patient was treated with antibiotics and discharged from the hospital 23 days after admission in a stable condition. When caused by PG, HPVG is not necessarily considered a poor prognostic factor and is expected to be treatable with medication. However, patients should be closely monitored for signs of a life-threatening pathology such as intestinal necrosis.

Mobile arm supports: evidence-based benefits and criteria for use.

BACKGROUND/OBJECTIVE: To collect data from therapists regarding criteria for use and activities that individuals with C4-C5 tetraplegia can perform using a mobile arm support (MAS) that they otherwise could not. Reasons for nonuse, equipment design limitations, and therapist training needs were also studied. METHODS: A modified Delphi approach was used to conduct an e-mail survey for which the response to each question was analyzed and used to formulate the subsequent question. SETTING: Rehabilitation centers. PARTICIPANTS: Eighteen occupational therapists (most affiliated with 1 of the federally designated Model Spinal Cord Injury Systems) with extensive experience in the treatment of individuals with spinal cord injury (SCI). RESULTS: The key physical prerequisite for successful use of the MAS was at least minimal strength of the deltoid and biceps muscles; 92% of respondents indicated that they would fit an MAS for motivated patients having very weak (<2/5) biceps and deltoid muscles. According to the therapists, 100% (n = 30) of their clients were able to perform at least 1 activity using a MAS that they were unable to perform without the device. These activities included (in descending frequency) eating, page turning, driving a power wheelchair, brushing teeth, keyboarding, writing, name signing, drawing, painting, scratching nose, playing board games, accessing electronic devices, drinking, and grooming. Equipment design limitations included increased wheelchair width and problems managing the arms while reclining. CONCLUSIONS: Mobile arm supports allow persons with C4-C5 tetraplegia to engage in activities that they otherwise cannot perform with their arms.

Children-robot interaction: a pilot study in autism therapy.

We present here a pilot study of child-robot interactions, in which we discuss developmental origins of human interpersonal communication. For the past few years, we have been observing 2- to 4-year-old children with autism interacting with Keepon, a creature-like robot that is only capable of expressing its attention (directing its gaze) and emotions (pleasure and excitement). While controlled by a remote experimenter, Keepon interacted with the children with its simple appearance and actions. With a sense of curiosity and security, the children spontaneously approached Keepon and engaged in dyadic interaction with it, which then extended to triadic interactions where they exchanged with adult caregivers pleasure and surprise they found in Keepon. Qualitative and quantitative analysis of these unfolding interactions suggests that autistic children possess the motivation to share mental states with others, which is contrary to the commonly held position that this motivation is impaired in autism. We assume Keepon's minimal expressiveness helped the children understand socially meaningful information, which then activated their intact motivation to share interests and feelings with others. We conclude that simple robots like Keepon would facilitate social interaction and its development in autistic children.

Effect of additional auditory and visual stimuli on continuous performance test (noise-generated CPT) in AD/HD children -- usefulness of noise-generated CPT.

The continuous performance test (CPT) is designed to measure sustained attention quantitatively. Several CPTs are used clinically. We have made changes to the conventional type of visual CPT, by displaying auditory and visual noise along with target or non-target stimuli. By influencing the recognition of the subjects in this way, the changes were intended to increase the sensitivity of detection of inattention and impulsiveness, to make CPT more useful for diagnosis, and to examine the effect of noise on AD/HD children during CPT performance. Its usefulness for AD/HD diagnosis and the reaction of AD/HD children to noise were examined using newly developed computer software. Using this CPT analysis, a significant difference was observed in all measurements, except mean reaction time, between the control and AD/HD groups, showing that it was useful as a supplementary diagnostic method for AD/HD, and was more useful in the younger age group than in the older age group, as the same for conventional CPTs. As compared to no-noise sessions, commission and omission errors both increased significantly in auditory and visual noise sessions. Thus, analyzing the changes in measurements during noise sessions will improve the diagnosis of inattention and combined AD/HD subtypes. Furthermore, it was suggested that analysis of the effects of noise on AD/HD children will benefit their handling in an educational environment. Since omission errors were decreased in AD/HD children by noise during the CPT performance as compared to the control group, noise may induce attention in AD/HD children. The present study presents new findings on the responses to noise of AD/HD children during the CPT.