Accelerating the phase demodulation process for heterodyne Φ-OTDR using spatial phase shifting.

An effective orthogonal signal generation method for heterodyne-detection-based phase-sensitive optical time-domain reflectometer systems is proposed to accelerate the phase demodulation process. The demodulation principle is based on the spatial phase shifting technique. By exploiting the relative phase difference between adjacent spatial sampling channels, the orthogonal signal is easily obtained from basic algebra calculations. The simulation and experimental results showed that the proposed method achieved >100% computation speed improvement compared with the conventional methods, with a slight trade-off in phase demodulation performance. Therefore, the proposed method is potentially beneficial for the distributed acoustic sensing technology for reducing the computation complexity of phase demodulation procedures.

Pretreatment ultrasound-based deep learning radiomics model for the early prediction of pathologic response to neoadjuvant chemotherapy in breast cancer.

OBJECTIVES: To investigate the predictive performance of the deep learning radiomics (DLR) model integrating pretreatment ultrasound imaging features and clinical characteristics for evaluating therapeutic response after neoadjuvant chemotherapy (NAC) in patients with breast cancer. METHODS: A total of 603 patients who underwent NAC were retrospectively included between January 2018 and June 2021 from three different institutions. Four different deep convolutional neural networks (DCNNs) were trained by pretreatment ultrasound images using annotated training dataset (n = 420) and validated in a testing cohort (n = 183). Comparing the predictive performance of these models, the best one was selected for image-only model structure. Furthermore, the integrated DLR model was constructed based on the image-only model combined with independent clinical-pathologic variables. Areas under the curve (AUCs) of these models and two radiologists were compared by using the DeLong method. RESULTS: As the optimal basic model, Resnet50 achieved an AUC and accuracy of 0.879 and 82.5% in the validation set. The integrated DLR model, yielding the highest classification performance in predicting response to NAC (AUC 0.962 and 0.939 in the training and validation cohort), outperformed the image-only model and the clinical model and also performed better than two radiologists' prediction (all p < 0.05). In addition, predictive efficacy of the radiologists was improved under the assistance of the DLR model significantly. CONCLUSION: The pretreatment US-based DLR model could hold promise as a clinical guidance for predicting NAC response of patients with breast cancer, thereby providing benefit of timely treatment strategy adjustment to potential poor NAC responders. KEY POINTS: • Multicenter retrospective study showed that deep learning radiomics (DLR) model based on pretreatment ultrasound image and clinical parameter achieved satisfactory prediction of tumor response to neoadjuvant chemotherapy (NAC) in breast cancer. • The integrated DLR model could become an effective tool to guide clinicians in identifying potential poor pathological responders before chemotherapy. • The predictive efficacy of the radiologists was improved under the assistance of the DLR model.

Quantitative demodulation of distributed low-frequency vibration based on phase-shifted dual-pulse phase-sensitive OTDR with direct detection.

Phase-sensitive optical time-domain reflectometry (Φ-OTDR) has been proposed for distributed vibration sensing purpose over recent years. Emerging applications, including seismic and hydroacoustic wave detection, demand accurate low-frequency vibration reconstruction capability. We propose to use the direct-detection Φ-OTDR configuration to achieve quantitative demodulation of external low-frequency vibrations by phase-shifted dual-pulse probes. Simultaneous pulsing and phase shifting modulation is realized with a single acousto-optic modulator to generate such probes, relaxing the need for an additional optical phase modulator. In the experiments, vibrations with frequency as low as 0.5 Hz are successfully reconstructed with 10 m spatial resolution and 35 dB signal-to-noise ratio. Excellent linearity and repeatability are demonstrated between the optical phase demodulation results and the applied vibration amplitudes. The proposed method is capable of quantitative demodulation of low-frequency vibrations with a cost-effective system configuration and high computation efficiency, showing potential for commercial applications of distributed seismic or hydroacoustic wave acquisition.

Ultra-low sampling resolution technique for heterodyne phase-OTDR based distributed acoustic sensing.

Phase-sensitive optical time-domain reflectometry (Φ-OTDR) based on heterodyne detection is widely used for its simple structure and high signal-to-noise ratio (SNR). However, the large amount of raw data of Φ-OTDR places a heavy burden on the storage device and also limits the transferability of the data. In this Letter, we propose an ultra-low sampling resolution technique to solve the data storage problem in heterodyne Φ-OTDR. Experimental results show that the optical phase variations induced by external vibrations can be successfully demodulated from the 1-bit-resolution raw data, and a vibration SNR of 58.03 dB is achieved. In addition, this work also reveals that a data acquisition device with extremely low sampling resolution is sufficient for heterodyne Φ-OTDR, signifying that the cost of the system can be further decreased.

Hyperthermia enhances radiosensitivity of colorectal cancer cells through ROS inducing autophagic cell death.

Hyperthermia (HT) enhances the anti-cancer effects of radiotherapy (RT), but the precise biochemical mechanisms involved are unclear. This study was aim to investigate if mild HT sensitizes colorectal cancer cells to RT through reactive oxygen species (ROS)-inducing autophagic cell death in a mice model of HCT116 human colorectal cancer. HCT116 mice model were randomly divided into five groups: mock group, hyperthermia group (HT), radiotherapy group (RT), HT + RT group, and HT + RT +N-acetyl L-cysteine (NAC) group (HT + CT + NAC). After four weeks of treatment, cancer growth inhibition, rate and mitochondrial membrane potential were measured with MTT and JC-1 assays, respectively, while ROS were estimated fluorimetrically. The relationship of these parameters to expressions of autophagy-related genes Beclin1, LC3B, and mTOR was analyzed. Gene expression was measured by Real-Time polymerase chain reaction (RT-PCR). There were significant increases in ROS levels and mitochondrial membrane potential in the HT + RT group. ROS levels in the HT + RT group increased more significantly than in any other group. In contrast, ROS levels in the HT + RT + NAC group were significantly decreased relative to the HT + RT group. The number of autophagic bodies in HT + RT group was higher than that of mock group. There were significant increases in the expression of Beclin1 and LC3B genes, while mTOR expression was significantly decreased in the HT + CT group. Treatment with NAC reversed the pattern of these changes. These results indicate that HT enhances the radiosensitivity of colorectal cancer cells to RT through ROS inducing autophagic cell death.

Endoscopic retrograde cholangiopancreatography for diagnosing and treating pediatric biliary and pancreatic diseases.

BACKGROUND: This study evaluated the safety and effectiveness of endoscopic retrograde cholangiopancreatography (ERCP) in pediatric patients with biliary and pancreatic diseases. A retrospective analysis was conducted on 57 ERCP procedures performed in 41 children, primarily for treating pancreatic diseases. The overall success rate was 91.2%, with no major complications observed. Post-ERCP pancreatitis (PEP) occurred in 8.8% of cases. Follow-up examinations over one year showed no recurrence of biliary or pancreatic diseases. Notably, endoscopic treatment led to a significant increase in body mass index (BMI). These findings demonstrate the valuable role of ERCP in managing such conditions. AIM: To evaluate the safety and efficacy of ERCP for the management of biliary and pancreatic diseases in pediatric patients. METHODS: We conducted a retrospective analysis of data from children aged 1-18 years who underwent ERCP for biliary and pancreatic diseases at Beijing Children's Hospital between January 2021 and December 2022. The collected data included procedure time, endoscopic treatment, success rate, and postoperative complications. RESULTS: Forty-one children underwent 57 ERCP procedures, including 14 with biliary duct disease and 27 with pancreatic disease. The mean age of the patients was 7.48 ± 3.48 years. Biliary duct-related treatments were performed 18 times, and pancreatic disease treatments were performed 39 times. ERCP was primarily used to treat pediatric pancreatic diseases [68.4% (39/57) of the procedures]. The overall success rate was 91.2% (52/57 patients). PEP was noted in five patients (8.8%, 5/57), and no instances of bleeding, perforation, or cholangitis were observed. The patients were followed up for over one year, and no recurrence of biliary or pancreatic diseases was detected. Importantly, BMI significantly increased after endoscopic treatment compared to that before treatment (P = 0.001). CONCLUSION: The high success rate and lack of major complications support the valuable role of ERCP in the management of pediatric biliary and pancreatic diseases in the pediatric population.

[Evaluation of carotid artery elasticity in patients with obstructive sleep apnea syndrome using quantitative arterial stiffness technique].

OBJECTIVE: To explore the changes and clinical value of carotid elasticity index in patients with obstructive sleep apnea syndrome (OSAS) by quantitative arterial stiffness (QAS) technique. METHODS: Seventy-two OSAS patients were divided into 2 groups according to whether there was coexisting hypertension. Of them, there were 37 OSAS patients without hypertension (OSAS1 group) and 35 OSAS patients with hypertension (OSAS2 group). In addition, forty healthy volunteers were recruited as the normal control group. We measured the arterial elastic parameters including vascular expansibility (VE), compliance coefficient (CC), stiffness index (ß) and pulse wave velocity (PWV) through QAS analysis technique. The difference of the parameters among the groups was analyzed. In the OSAS group, polysomnograph (PSG) data were recorded and analyzed including apnea-hypopnea index (AHI), minimal pulse oxyhemoglobin saturation (miniSpO(2)), time spent below oxygen saturation of 90% (Ts90%) and oxygen desaturation index (ODI). Correlations and regression were calculated between indices of oxygen saturation and PWV. RESULTS: Compared with normal control group, in OSAS1 and OSAS2 groups, VE and CC were significantly lower, but ß and PWV was significantly higher (P < 0.05). Compared with OSAS1 group, CC in OSAS2 group decreased but ß and PWV increased significantly (P < 0.05). In the OSAS group, PWV was correlated positively with systolic blood pressure, AHI, ODI and age (r = 0.285 - 0.542, all P < 0.05). Through stepwise multiple linear regression analysis, age and ODI were the significant variables to determine PWV. CONCLUSION: The decreases in arterial elasticity are present in OSAS patients. These changes are more evident in OSAS patients with hypertension. QAS technique plays an important role in analyzing the arterial elasticity accurately and could be used as a quantitative mean to evaluate early atherosclerosis.

Endoscopic retrograde cholangiopancreatography in the treatment of pancreaticopleural fistula in children.

BACKGROUND: Pancreaticopleural fistula (PPF) is a rare disease, especially in children. Conservative treatment and surgery are traditional therapies, but surgery is invasive. The emergence of endoscopic retrograde cholangiopancreatography (ERCP) has provided a new noninvasive treatment for PPF and may become the first choice for children with PPF. AIM: To explore the treatment response to ERCP for PPF in children. METHODS: Seven children with PPF were hospitalized in the Gastroenterology Department of Beijing Children's Hospital from December 2007 to May 2019. Data on these seven patients' clinical characteristics, diagnosis, treatments, and outcomes were analyzed, and their treatment responses following surgery and ERCP were compared. The correlation between the length of hospital stay and conservative treatment was analyzed. Peer-reviewed articles written in English and Chinese published from January 2009 to December 2019 were obtained from various open data sources and reviewed. RESULTS: The seven patients comprised three boys and four girls with a mean age of 6.57 ± 3.26 years. The main symptoms were chest tightness and pain (n = 4), intermittent fever (n = 3), dyspnea (n = 3), and abdominal pain (n = 1), and all patients had bloody pleural effusion. All seven patients were diagnosed with PPF by magnetic resonance cholangiopancreatography, and all were initially treated conservatively for a mean of 34.67 ± 22.03 d with a poor response. Among five patients who underwent ERCP, one required surgery because of intubation failure; thus, the success rate of ERCP was 80%. Two patients were successfully treated with surgery (100%). The postoperative hospital stay of the two patients treated by surgery was 20 and 30 d, respectively (mean of 25 d), and that of the four patients treated by ERCP ranged from 12 to 30 d (mean of 19.25 ± 8.85 d). The recovery time after ERCP was short [time to oral feeding, 4-6 d (mean, 5.33 ± 1.15 d); duration of closed thoracic drainage, 2-22 d (mean, 13.3 d)]. Analysis of previous cases of PPF published worldwide during the past decade showed that the treatment success rate of ERCP is not lower than that of surgery. There was no significant difference in the postoperative hospital stay between surgery (16 ± 10.95 d) and ERCP (18.7 ± 6.88 d, P > 0.05). A positive linear correlation was found between the overall hospital stay and ERCP intervention time (R 2 = 0.9992). CONCLUSION: ERCP is recommended as the first-choice treatment for PPF in children. ERCP should be performed as early as possible if conditions permit.

Laparoscopic Hyperthermic Intraperitoneal Perfusion Chemotherapy for Patients With Malignant Ascites Secondary to Unresectable Gastric Cancer.

BACKGROUND: To compare the efficacy of 3 chemotherapeutic combinations for laparoscopic hyperthermic intraperitoneal perfusion chemotherapy (HIPPC) in the treatment of malignant ascites secondary to unresectable gastric cancer (GC). MATERIALS AND METHODS: From January 2010 to December 2013, 38 GC patients were randomly divided into 3 groups and treated by laparoscopic HIPPC with 1 of the 3 following chemotherapy combinations: raltitrexed (Ra) with oxaliplatin (L-OHP), Ra with cisplatin (DDP), and Ra with mitomycin C (MMC). Perioperative complications, patients' quality of life, and survival were recorded and compared among the 3 groups. RESULTS: The intraoperative course was successful in all patients, and no perioperative death or complication related to laparoscopic HIPPC was documented. The median follow-up period was 9 months and the median survival was 7.5 months for all patients. Patients in the Ra/L-OHP group had a median survival of 8.7 months, the Ra/DDP group had a median survival of 5.6 months, and the Ra/MMC group had a median survival of 7.5 months. Patients' median survival in the Ra/L-OHP group and Ra/MMC group is significantly longer than Ra/DDP group (P<0.05). No significant difference was found in total remission rate of ascites, increase in the Karnofsky performance scale, and incidence rate of port-site metastases among the 3 groups. CONCLUSIONS: Laparoscopy-assisted HIPPC provide modest yet encouraging efficacy for malignant ascites secondary to disseminated GC. Our preliminary data indicate that the chemotherapeutical combination of Ra/L-OHP and Ra/MMC might be more beneficial compared with Ra/DDP in terms of patients' survival.

Ultrasound-based radiomics nomogram: A potential biomarker to predict axillary lymph node metastasis in early-stage invasive breast cancer.

PURPOSE: To establish a radiomics nomogram integrating clinical factors and radiomics features from ultrasound for the preoperative diagnosis axillary lymph node (ALN) status in patients with early-stage invasive breast cancer (EIBC). MATERIALS AND METHODS: Between September 2016 and December 2018, four hundred twenty-six ultrasound manually segmented images of patients with EIBC were enrolled in our retrospective study, which were divided into a primary cohort (n = 300) and a validation cohort (n = 126). A radiomics signature was built with the least absolute shrinkage and selection operator (LASSO) algorithm in the primary cohort. Multivariable logistic regression analysis was used to establish a radiomics nomogram model based on radiomics signature and clinical variables. The performance of nomogram was quantified with respect to discrimination and calibration. The radiomics model was further evaluated in the internal validation cohort. RESULTS: The radiomics signature, consisted of fourteen selected ALN-status-related features, achieved moderate prediction efficacy with an area under the curve (AUC) of 0.78 and 0.71 in the primary and validation cohorts respectively. The radiomics nomogram, comprising tumor size, US-reported LN status and radiomics signature, showed good calibration and favorite performance for ALN detection (AUC 0.84 and 0.81 in the primary and validation cohort). The decision curve which was demonstrated the radiomics nomogram displayed good clinical utility. CONCLUSION: The radiomics nomogram could hold promise as a non-invasive and reliable tool in predicting ALN metastasis and may facilitate to develop more effective preoperative decision-making.

Laparoscopic Hyperthermic Intraperitoneal Perfusion Chemotherapy for Patients with Malignant Ascites Secondary to Unresectable Gastric Cancer.

BACKGROUND: To compare the efficacy of three chemotherapeutic combinations for laparoscopic hyperthermic intraperitoneal perfusion chemotherapy (HIPPC) in the treatment of malignant ascites secondary to unresectable gastric cancer (GC). MATERIALS AND METHODS: From January 2010 to December 2013, 38 GC patients were randomly divided into three groups and treated by laparoscopic HIPPC with one of the three following chemotherapy combinations: raltitrexed (Ra) with oxaliplatin [trans-(±)-diaminocyclohexane oxalatoplatinum (l-OHP)], Ra with cisplatin (DDP), and Ra with mitomycin C (MMC). Perioperative complications, patients' quality of life, and survival were recorded and compared among the three groups. RESULTS: The intraoperative course was successful in all patients, and no perioperative death or complication related to laparoscopic HIPPC was documented. The median follow-up period was 9 months, and the median survival was 7.5 months for all patients. Patients in the Ra/l-OHP group had a median survival of 8.7 months, the Ra/DDP group had a median survival of 5.6 months, and the Ra/MMC group had a median survival of 7.5 months. Patients' median survival in the Ra/l-OHP group and Ra/MMC group was significantly longer than in the Ra/DDP group (P < .05). No significant difference was found in total remission rate of ascites, increase in the Karnofsky Performance Scale, and incidence rate of port-site metastases among the three groups. CONCLUSIONS: Laparoscopy-assisted HIPPC provides modest yet encouraging efficacy for malignant ascites secondary to disseminated GC. Our preliminary data indicate that the chemotherapeutic combination of Ra/l-OHP and Ra/MMC might be more beneficial compared with Ra/DDP in terms of patients' survival.