MR diagnosis of SCC arising within ovarian cystic teratomas: analysis of mural nodule characteristics.

PURPOSE: This study aims to evaluate and identify magnetic resonance (MR) findings of mural nodules to detect squamous cell carcinoma arising from ovarian mature cystic teratoma (SCC-MCT). METHODS: This retrospective study examined 135 patients (SCC-MCTs, n = 12; and benign MCTs, n = 123) with confirmed diagnoses across five different institutions between January 2010 and June 2022. Preoperative MR images for each patient were independently assessed by two experienced radiologists and analyzed following previously reported findings (PRFs): age, tumor size, presence of mural nodules, size of mural nodule, and the angle between mural nodule and cyst wall (acute or obtuse). Furthermore, this study evaluated four mural nodule features-diffusion restriction, fat intensity, Palm tree appearance, and calcification-and the presence of transmural extension. RESULTS: There were significant differences between the SCC-MCT and benign MCT groups in terms of all PRFs and all mural nodule findings (p < 0.01). Among the PRFs, "tumor size" demonstrated the highest diagnostic performance, with a sensitivity of 83.3% and a specificity of 88.6%. A combination of the aforementioned four mural nodule findings showed a sensitivity and specificity of 83.3% and 97.6%, respectively, for the diagnosis of SCC-MCT. Regarding diagnosis based on a combination of four mural nodule findings, the specificity was significantly higher than the diagnosis based on tumor size (p = 0.021). Based on these mural nodule findings, three SCC-MCT patients without transmural invasion could be diagnosed. CONCLUSION: Mural nodule MR findings had a higher diagnostic performance than PRFs for SCC-MCT and can potentially allow early detection of SCC-MCTs.

Revealing the evolution of local structures in the formation process of alkaline earth metal cation-containing zeolites from glasses.

Alkaline earth metal cations are ubiquitously present in natural zeolites but less exploited in synthetic zeolites due to their low solubility in water, and hence it remains elusive how they contribute to zeolite formation. Herein, harmotome, a PHI-type zeolite with Ba2+, is readily synthesized from a Ba-containing aluminosilicate glass. This glass-to-zeolite transformation process, in particular the structure-regulating role of Ba2+, is investigated by anomalous X-ray scattering and high-energy X-ray total scattering techniques. The results demonstrate that the steady Ba2+-aluminosilicate interactions not only help prevent the precipitation of barium species under alkaline synthetic conditions, but also dictate the local structures with distinct interatomic distances between the Ba2+ and the surrounding aluminosilicate species throughout the transformation process, which lead to the successful formation of harmotome without detectable impurities. This study highlights the usefulness of the comprehensive X-ray scattering techniques in revealing the formation scheme of the zeolites containing specific metal species. In addition, a promising alternative approach to design and synthesize zeolites with unique compositions and topologies by using well-crafted glasses with suitable metal cation dopants is demonstrated.

Fluorescence radial fluctuation enables two-photon super-resolution microscopy.

Despite recent improvements in microscopy, it is still difficult to apply super-resolution microscopy for deep imaging due to the deterioration of light convergence properties in thick specimens. As a strategy to avoid such optical limitations for deep super-resolution imaging, we focused on super-resolution radial fluctuation (SRRF), a super-resolution technique based on image analysis. In this study, we applied SRRF to two-photon microscopy (2P-SRRF) and characterized its spatial resolution, suitability for deep observation, and morphological reproducibility in real brain tissue. By the comparison with structured illumination microscopy (SIM), it was confirmed that 2P-SRRF exhibited two-point resolution and morphological reproducibility comparable to that of SIM. The improvement in spatial resolution was also demonstrated at depths of more than several hundred micrometers in a brain-mimetic environment. After optimizing SRRF processing parameters, we successfully demonstrated in vivo high-resolution imaging of the fifth layer of the cerebral cortex using 2P-SRRF. This is the first report on the application of SRRF to in vivo two-photon imaging. This method can be easily applied to existing two-photon microscopes and can expand the visualization range of super-resolution imaging studies.

Structural analysis and ionic conduction mechanism of sulfide-based solid electrolytes doped with Br.

Sulfide glasses can exhibit notable ionic conductivity because of annealing-associated crystallization. One well-known example is Li7P3S11. Our research showed that adding bromine (Br) to Li3PS4 sulfide glass results in a similar crystal structure and high ionic conductivity comparable to that of another compound Li10GeP2S12. This structure differs from the PS4 anion framework of Li3PS4. In addition, the ionic conductivity decreases owing to a structural transition to the ß-phase. Herein, we present our findings on the local structure of Li3PS4 sulfide glass and its crystallized glass ceramic with the addition of Br. This analysis relies on the pair distribution function analysis obtained from high-energy X-ray diffraction. Moreover, using the bond valence sum method, we verified that incorporating Br promotes the formation of Li ionic conduction pathways. Our results indicate that precise control over the anion molecular structure by introducing halogens holds promise for achieving high Li-ion conductivity.

＜Editors' Choice＞ Surgical removal of an intracranially migrated acupuncture needle: a case report and literature review.

Acupuncture is a popular alternative therapy worldwide and is generally safe. However, serious acupuncture-related complications can occur. Intracranial complications caused by a migrated acupuncture needle are extremely rare. Herein we report a surgical case of intracranial acupuncture needle migration and discuss the key technical aspects of the procedure. We additionally performed a review of the relevant literature. A 55-year-old woman presented with migration of a broken acupuncture needle via the posterior cervical skin. Computed tomography (CT) showed that the needle migrated intra- and extradurally via the atlanto-occipital junction. CT angiography revealed that the needle tail was located adjacent to the right distal horizontal loop of the vertebral artery. Meanwhile, the needle tip was positioned in the premedullary cistern adjacent to the medulla oblongata via the right lateral medullary cistern. Emergent surgical removal was conducted. Intradural exploration was required as the needle was not found in the epidural space. The needle penetrated the adventitia of the right intradural vertebral artery. We failed to pull out the needle toward the epidural space. After the needle was completely pulled into the intradural space, it was successfully removed without bleeding complication. Postoperative CT showed no evidence of residual needle fragment. The patient was discharged home without any sequelae. To the best of our knowledge, this is the first case of penetrating vertebral artery injury caused by radiologically confirmed acupuncture needle migration. An intracranially migrated needle should be removed urgently to prevent further migration causing brainstem, cranial nerve, and vessel injuries. The surgical strategy should be selected according to needle location and direction.

Actual situation of handling Tokyo 2020 Games-related patients at a designated hospital during COVID-19 pandemic.

In preparation for the Tokyo 2020 Olympic and Paralympic Games, our hospital was responsible for accepting mainly media representatives, marketing partners, and other Games staff. Given that restricting our regular capacity to treat certain groups of patients could potentially result in social losses, to avoid this we made rigorous preparations for the entire hospital to accept Games-related patients. It was rational to set up a single 24-h contact point at the Emergency Department for making the decision on whether to accept the patient or not and for coordinating the patient's medical care. With respect to language support, International Health Care Center staffs were made available as interpreters on weekdays. Multilingual support was available all day via an application run on tablet devices. During a 67-day period, the hospital accepted 31 Games-related patients (mean age 43.4 years, male: female ratio 25:6). Eighteen patients were from Europe, 4 patients each were from North America and Asia, 2 each were from Central America, South America, and Africa, and 1 was from Oceania. The most common cause of visits was COVID-19, but none were severe cases. Other causes were diverse and included moderate and severe conditions. We summarized the challenges and experiences in handling Tokyo 2020 Games-related patients at a designated hospital during the COVID-19 pandemic.

Rapid identification of source of delayed hemobilia following endoscopic metallic stenting for malignant biliary obstruction.

Delayed hemobilia, a rare but potentially fatal complication of endoscopic metallic stenting for malignant biliary obstruction, requires prompt identification of the source of bleeding and subsequent embolization. However, hemobilia is characteristically intermittent, and computed tomography (CT) often fails to show pseudoaneurysms or extravasations. In particular, because the posterior superior pancreaticoduodenal artery (PSPDA) runs alongside the common bile duct for its whole length, it is readily obscured by metallic artifacts in that duct, such as stents, making identification of the source of bleeding by CT difficult. We have encountered three patients with delayed hemobilia from the PSPDA following endoscopic biliary stenting for malignant biliary obstruction in whom no extravasation or pseudoaneurysms were detected by contrast-enhanced CT during bleeding. However, when we identified that the PSPDA had a smaller diameter than in previous CTs in all three cases, we suspected that the PSPDA was the source of the bleeding. No extravasation or pseudoaneurysms were detected with celiac arteriography or superior mesenteric arteriography; however, extravasation and pseudoaneurysms were detected by direct PSPDA angiography. Hemostasis was achieved through embolization. Detecting a large decrease in the diameter of the PSPDA on contrast-enhanced CT during biliary bleeding may help to identify the source of that bleeding.

Poor prognosis of patients with severe COVID-19 admitted to an infectious disease intensive care unit during the pandemic caused by the Delta variant in Japan.

During the surge of coronavirus disease (COVID-19) caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) delta variant, our institution operated an intensive care unit (ICU) for patients with severe COVID-19. The study aim was to determine the survival rate and treatment outcomes of patients with severe COVID-19 treated in the ICU during the surge. A total of 23 consecutive patients with severe COVID-19 were admitted to the ICU between August 5 and October 6, 2021. Patients received multidrug therapy consisting of remdesivir, tocilizumab, heparin, and methylprednisolone. The patients were divided into two groups based on the ordinal scale (OS): a non-invasive oxygen therapy (OS-6) group, and an invasive oxygen therapy (OS-7) group. There were 13 (57%) and 10 (43%) patients in the OS-7 and OS-6 groups, respectively. All patients were unvaccinated. Sixteen patients (70%) were male. The median age was 53 years; the median body mass index (BMI) was 30.3 kg/m2; and the median P/F ratio on admission was 96. The 30-day survival rate was 69% and was significantly poorer in the OS-7 group (54%) than in the OS-6 group (89%; p = 0.05). The prevalence of obesity (p = 0.05) and the Sequential Organ Failure Assessment (SOFA) score on admission (p < 0.01) were significantly higher in the OS-7 group. Seven patients in the OS-7 group (54%) developed bacteremia. A low P/F ratio on admission was a significant unfavorable prognostic factor (hazard ratio: 10.9; p = 0.03). The survival rate was poor, especially in patients requiring invasive oxygen therapy. More measures are needed to improve the treatment outcomes of patients with severe COVID 19.

Trends in endotracheal intubation for patients with COVID-19 by emergency physicians.

Emergency physicians perform endotracheal intubations for patients with COVID-19. However, the trends in the intubation for COVID-19 patients in terms of success rate, complications, personal protective equipment (PPE) information, barrier enclosure use, and its transition have not been established. We conducted a retrospective study of COVID-19 cases that required tracheal intubation at four hospitals in the Tokyo metropolitan area between January 2020 and August 2021. The overall intubation success rate, operator experience, and infection control methods were investigated. We then compared the early and late phases of the pandemic for a period of 8 months each. A total of 211 cases met the inclusion criteria, and 133 were eligible for analysis. The intubation success rate increased from 85% to 94% from early to late phase, although the percentage of intubations performed by emergency medicine residents increased significantly in the late phase (p = 0.03). The percentage of light PPE use significantly increased from 65% to 91% from early to late phase (p < 0.01), whereas the percentage of barrier enclosure use significantly decreased from 26% to 0% (p < 0.01). Furthermore, the infection prevention methods during intubation became more simplified from early to late phase.

Retention of inorganic anions using mesoporous zirconia spheres modified with anion-exchange groups as the stationary phase for ion chromatography.

A zirconia (ZrO2) stationary phase with a chemically fixed silane coupling agent (trimethyl [3-(trimethoxysilyl)propyl]ammonium chloride; TMA), which possesses quaternary ammonium functional groups, is evaluated as a separation column for ion chromatography (IC) of anions. The selectivity for anions varies depending on the amount of TMA immobilized on the ZrO2. The TMA-ZrO2, with an anion-exchange capacity of 17 ± 3 µeq/g, shows an anion-exchange reaction that involves the specific retention of fluoride ion on ZrO2. The TMA-ZrO2 exhibits a decrease of the anion resolution with an increase of the eluent pH and an enhancement of the selective separation of fluoride ion with an increase of the column temperature. Through this study, the TMA-ZrO2 stationary phase shows potential as a new medium for ion separation.

Extracorporeal membrane oxygenation may decrease the plasma concentration of remdesivir in a patient with severe coronavirus disease 2019.

Remdesivir is an antiviral drug that results in clinical improvement after five days of treatment and accelerates recovery by 31%. No studies have discussed the pharmacokinetic analysis of remdesivir in patients with severe COVID-19 requiring extracorporeal membrane oxygenation (ECMO). A 63-year-old American man who underwent mechanical ventilation and ECMO for severe COVID-19 was administered remdesivir for ten days. The loading dosage was 200 mg at 7 PM on day 12 and 100 mg daily at 0:00 PM from day 13-21, administered within 1 h. The pharmacokinetic analysis was performed. The serum creatinine concentration was within the normal range of 0.5-0.7 mg/dL during treatment. According to the pharmacokinetic analysis, the plasma concentrations of remdesivir and GS-441524 4 h after administration (C4) were 662 ng/mL and 58 ng/mL, respectively, and the concentrations 18 h after administration (C18) were 32 ng/mL and 44 ng/mL, respectively. Therefore, the half-life of remdesivir and GS-441524 was 3.2 and 35.1 h, respectively. Monitoring the plasma concentrations of remdesivir and GS-441524 in patients undergoing ECMO may be necessary.

Determination of brain tumor recurrence using 11 C-methionine positron emission tomography after radiotherapy.

We conducted a prospective multicenter trial to compare the usefulness of 11 C-methionine (MET) and 18 F-fluorodeoxyglucose (FDG) positron emission tomography (PET) for identifying tumor recurrence. Patients with clinically suspected tumor recurrence after radiotherapy underwent both 11 C-MET and 18 F-FDG PET. When a lesion showed a visually detected uptake of either tracer, it was surgically resected for histopathological analysis. Patients with a lesion negative to both tracers were revaluated by magnetic resonance imaging (MRI) at 3 months after the PET studies. The primary outcome measure was the sensitivity of each tracer in cases with histopathologically confirmed recurrence, as determined by the McNemar test. Sixty-one cases were enrolled, and 56 cases could be evaluated. The 38 cases where the lesions showed uptake of either 11 C-MET or 18 F-FDG underwent surgery; 32 of these cases were confirmed to be subject to recurrence. Eighteen cases where the lesions showed uptake of neither tracer received follow-up MRI; the lesion size increased in one of these cases. Among the cases with histologically confirmed recurrence, the sensitivities of 11 C-MET PET and 18 F-FDG PET were 0.97 (32/33, 95% confidence interval [CI]: 0.85-0.99) and 0.48 (16/33, 95% CI: 0.33-0.65), respectively, and the difference was statistically significant (P < .0001). The diagnostic accuracy of 11 C-MET PET was significantly better than that of 18 F-FDG PET (87.5% vs. 69.6%, P = .033). No examination-related adverse events were observed. The results of the study demonstrated that 11 C-MET PET was superior to 18 F-FDG PET for discriminating between tumor recurrence and radiation-induced necrosis.

External validation and update of prediction models for unfavorable outcomes in hospitalized patients with COVID-19 in Japan.

INTRODUCTION: Most of the currently used prognostic models for COVID-19 are based on Western cohorts, but it is unknown whether any are applicable to patients with COVID-19 in Japan. METHODS: This retrospective cohort study included 160 patients with COVID-19 who were admitted to the National Center for Global Health and Medicine between January 26, 2020 and July 25, 2020. We searched PubMed for prognostic models for COVID-19. The predicted outcome was initiation of respiratory support or death. Performance of the candidate models was evaluated according to discrimination and calibration. We recalibrated the intercept of each model with our data. We also updated each model by adding ß2-microglobulin (ß2MG) to the model and recalculating the intercept and the coefficient of ß2MG. RESULTS: Mean patient age was 49.8 years, 68% were male, 88.7% were Japanese. The study outcomes occurred in 15 patients, including two deaths. Two-hundred sixty-nine papers were screened, and four candidate prognostic models were assessed. The model of Bartoletti et al. had the highest area under receiver operating characteristic curve (AUC) (0.88; 95% confidence interval 0.81-0.96). All four models overestimated the probability of occurrence of the outcome. None of the four models showed statistically significant improvement in AUCs by adding ß2MG. CONCLUSIONS: Our results suggest that the existing prediction models for COVID-19 overestimate the probability of occurrence of unfavorable outcomes in a Japanese cohort. When applying a prediction model to a different cohort, it is desirable to evaluate its performance according to the prevalent health situation in that region.

Preoperative Texture Analysis Using 11C-Methionine Positron Emission Tomography Predicts Survival after Surgery for Glioma.

BACKGROUND: Positron emission tomography with 11C-methionine (MET) is well established in the diagnostic work-up of malignant brain tumors. Texture analysis is a novel technique for extracting information regarding relationships among surrounding voxels, in order to quantify their inhomogeneity. This study evaluated whether the texture analysis of MET uptake has prognostic value for patients with glioma. METHODS: We retrospectively analyzed adults with glioma who had undergone preoperative metabolic imaging at a single center. Tumors were delineated using a threshold of 1.3-fold of the mean standardized uptake value for the contralateral cortex, and then processed to calculate the texture features in glioma. RESULTS: The study included 42 patients (median age: 56 years). The World Health Organization classifications were grade II (7 patients), grade III (17 patients), and grade IV (18 patients). Sixteen (16.1%) all-cause deaths were recorded during the median follow-up of 18.8 months. The univariate analyses revealed that overall survival (OS) was associated with age (hazard ratio (HR) 1.04, 95% confidence interval (CI) 1.01-1.08, p = 0.0093), tumor grade (HR 3.64, 95% CI 1.63-9.63, p = 0.0010), genetic status (p < 0.0001), low gray-level run emphasis (LGRE, calculated from the gray-level run-length matrix) (HR 2.30 × 1011, 95% CI 737.11-4.23 × 1019, p = 0.0096), and correlation (calculated from the gray-level co-occurrence matrix) (HR 5.17, 95% CI 1.07-20.93, p = 0.041). The multivariate analyses revealed OS was independently associated with LGRE and correlation. The survival curves were also significantly different (both log-rank p < 0.05). CONCLUSION: Textural features obtained using preoperative MET positron emission tomography may compliment the semi-quantitative assessment for prognostication in glioma cases.

Corticosteroid therapy for severe COVID-19 pneumonia: optimal dose and duration of administration.

Severe COVID-19 is associated with a hyperinflammatory state, and corticosteroid therapy may be effective. We review the recent literature and discuss the appropriate dose and duration of corticosteroid therapy. Low-dose corticosteroid therapy is often used to treat COVID-19. However, several doses of methylprednisolone (or prednisolone) have been attempted, ranging from about 40 mg/day to 2 mg/kg/day. Doses may need to be adjusted depending on severity. Corticosteroid therapy is generally administered for a short period over several days. However, COVID-19-induced respiratory failure is often prolonged, so longer administration may be considered. Careful monitoring for complications due to corticosteroid therapy is vital.

Metoclopramide versus sumatriptan in the treatment of migraine in the emergency department: a single-center, open-label, cluster-randomized controlled non-inferiority trial.

Migraine is a common disease seen in the emergency department (ED). Triptans, which are recommended in therapeutic guidelines for migraine, have some contraindications and possible severe side effects. Metoclopramide, which is commonly used as an antiemetic, also seems to have pain-relieving effects for migraine. In this article, we will introduce a study in progress, which investigates whether metoclopramide 10 mg intravenously (IV) is non-inferior to sumatriptan 3 mg subcutaneously (SQ) as migraine treatment in the ED. This study is a single-center, open-label, cluster-randomized controlled trial of 80 patients with migraine attacks to investigate the non-inferiority of metoclopramide to sumatriptan. The patients will be cluster-randomized monthly into metoclopramide 10 mg IV and sumatriptan 3 mg SQ arms. The primary outcome will be change in Numerical Rating Scale score for headache at 1 h after baseline. In discussion, if our hypothesis is confirmed, metoclopramide can be considered as first-line medication for migraine attacks in ED settings.

Halo artifacts of indwelling urinary catheter by inaccurate scatter correction in 18F-FDG PET/CT imaging: incidence, mechanism, and solutions.

BACKGROUND: Halo artifacts from urinary catheters can occur due to inaccurate scatter correction, and the artifacts affect the tumor visibility in 18F-FDG PET/CT images. We investigated the incidence rate and the mechanisms of halo-artifact generation and explored several scatter correction techniques to prevent artifacts. METHODS: We conducted patient and phantom studies. (1) We retrospectively reviewed the cases of patients who had undergone 18F-FDG PET/CT scans. To determine the frequency of halo-artifact generation, we used the patients' PET images with a standard scatter correction based on a tail-fitted single-scatter simulation (TF-SSS) using 4-mm voxel µ-maps (TFS 4-mm). (2) We performed phantom studies to evaluate the effects of a urine catheter and two scatter correction techniques, i.e., TF-SSS with 2-mm voxel µ-maps (TFS 2-mm) and a Monte Carlo-based single-scatter simulation (MC-SSS) using 4-mm voxel µ-maps (MCS 4-mm). The average standardized uptake values (SUVs) were measured for axial PET images. (3) Using the patients' data, we investigated whether TFS 2-mm and MCS 4-mm can eliminate the artifacts in the clinical images. RESULTS: (1) There were 61 patients with urinary catheters; in five (8.2%), halo artifacts were observed in the TFS 4-mm PET images. (2) The phantom study clearly reproduced the halo artifacts in the TFS 4-mm PET images. The halo artifacts were generated when urine moved in the interval between the CT and PET imaging, and when the urinary catheter was placed in a circular shape. The SUVs for the TFS 4-mm and TFS-2mm PET images were underestimated at the halo-artifact regions, whereas the SUVs for the MCS 4-mm PET images were close to the true values. (3) The halo artifacts disappeared in the TFS 2-mm PET images in 4/5 patients but not 1/5 patient, whereas the halo artifacts were completely absent in the MCS 4-mm PET images in 5/5 patients. CONCLUSIONS: These data suggest that halo artifacts are caused if the PET images do not correspond to the physical material in the µ-maps, which induces the scatter correction error. With the MC-SSS, it was possible to accurately estimate the scatter without generating halo artifacts.

Current state of drug analysis in Japanese emergency departments: a nationwide survey.

AIM: In 1999, the Japanese Society for Clinical Toxicology proposed 15 toxicants that would be useful for analysis: methanol, barbiturates, benzodiazepines, bromovalerylurea, tricyclic acid, acetaminophen, salicylic acid, theophylline, organic phosphorus pesticides, carbamate pesticides, glufosinate, paraquat, arsenic, cyanide, and methamphetamine. We aimed to reveal the current state of drug analysis for acute poisoning in the emergency department of Japanese hospitals. METHODS: From 1 April, 2017, we undertook a questionnaire survey in the emergency departments of 546 hospitals designated as educational institutions for emergency physicians. RESULTS: Responses were obtained from 246 hospitals (45.1%). Among drug abuse screening kits for qualitative testing, 80.9% used the Triage Drugs of Abuse Panel and 7.3% used Instant-View M-1. Analytical results have always been immediately obtained by 2.8% of facilities for methanol, 19.5% for barbiturates, 2.4% for benzodiazepines, 0.8% for bromovalerylurea, 1.2% for tricyclic acid, 12.2% for acetaminophen, 4.1% for salicylic acid, 44.3% for theophylline, 2.0% for organic phosphorus pesticides, 1.6% for carbamate pesticides, 1.2% for glufosinate, 2.4% for paraquat, 0.8% for arsenic, 1.2% for cyanide, and 1.2% for methamphetamine. CONCLUSION: In the treatment of acute poisoning, drug analysis is important for both clinical judgment and academic verification. However, many of the 15 toxicants proposed to be useful for analysis in 1999 are not yet immediately analyzed in the emergency department of Japanese hospitals. Furthermore, it is necessary to develop inexpensive testing systems and to provide insurance points for testing so that analysis can be carried out by emergency departments.

Clinical characteristics of stonefish "Oni-daruma-okoze" envenomation in Japan.

AIM: Stonefish, known in Japan as "Oni-daruma-okoze" (Synanceia verrucosa Block et Schneider), inhabit the waters surrounding the Okinawa/Amami districts. By far, habubites have been limited to these areas mainly due to climatic conditions. Due to changes promoted by global warming and increasing tourism, concerns regarding the potential for stonefish envenomation as well as jellyfish stings on the main island of Japan are increasing. However, few studies of stonefish envenomation have been reported in Japan. The current study aimed to comprehensively examine for the first time the clinical characteristics of stonefish envenomation in Japan. METHODS: We administered retrospective questionnaire surveys between January 2013 and December 2017 to determine patient characteristics, treatment, and clinical outcomes of stonefish envenomation. We compared patient characteristics between tourists and non-tourists. RESULTS: Over the 5-year study period, 15 patients were identified from four hospitals. More than 70% of stonefish envenomation cases occurred in the northern part of Okinawa Main Island. All patients recovered well, including four patients with severe stonefish envenomation. In two severe cases, the length of hospitalization was more than 1 week (8-9 days). Antivenom was not given. There were no significant differences between tourists and non-tourists with regard to baseline characteristics. CONCLUSIONS: During a 5-year period, 15 cases of stonefish envenomation occurred in Japan. The patients recovered well without treatment with antivenom.

A convolutional neural network-based system to classify patients using FDG PET/CT examinations.

BACKGROUND: As the number of PET/CT scanners increases and FDG PET/CT becomes a common imaging modality for oncology, the demands for automated detection systems on artificial intelligence (AI) to prevent human oversight and misdiagnosis are rapidly growing. We aimed to develop a convolutional neural network (CNN)-based system that can classify whole-body FDG PET as 1) benign, 2) malignant or 3) equivocal. METHODS: This retrospective study investigated 3485 sequential patients with malignant or suspected malignant disease, who underwent whole-body FDG PET/CT at our institute. All the cases were classified into the 3 categories by a nuclear medicine physician. A residual network (ResNet)-based CNN architecture was built for classifying patients into the 3 categories. In addition, we performed a region-based analysis of CNN (head-and-neck, chest, abdomen, and pelvic region). RESULTS: There were 1280 (37%), 1450 (42%), and 755 (22%) patients classified as benign, malignant and equivocal, respectively. In the patient-based analysis, CNN predicted benign, malignant and equivocal images with 99.4, 99.4, and 87.5% accuracy, respectively. In region-based analysis, the prediction was correct with the probability of 97.3% (head-and-neck), 96.6% (chest), 92.8% (abdomen) and 99.6% (pelvic region), respectively. CONCLUSION: The CNN-based system reliably classified FDG PET images into 3 categories, indicating that it could be helpful for physicians as a double-checking system to prevent oversight and misdiagnosis.