Aorta and main pulmonary artery segmentation using stacked U-Net and localization on non-contrast-enhanced computed tomography images.

BACKGROUND: The contact between the aorta, main pulmonary artery (MPA), main pulmonary vein, vena cava (VC), and esophagus affects segmentation of the aorta and MPA in non-contrast-enhanced computed tomography (NCE-CT) images. PURPOSE: A two-stage stacked U-Net and localization of the aorta and MPA were developed for the segmentation of the aorta and MPA in NCE-CT images. METHODS: Normal-dose NCE-CT images of 24 subjects with chronic thromboembolic pulmonary hypertension (CTEPH) and low-dose NCE-CT images of 100 subjects without CTEPH were used in this study. The aorta is in contact with the ascending aorta (AA) and MPA, the AA with the VC, the aortic arch (AR) with the VC and esophagus, and the descending aorta (DA) with the esophagus. These contact surfaces were manually annotated. The contact surfaces were quantified using the contact surface ratio (CSR). Segmentation of the aorta and MPA in NCE-CT images was performed by localization of the aorta and MPA and a two-stage stacked U-Net. Localization was performed by extracting and processing the trachea and main bronchus. The first stage of the stacked U-Net consisted of a 2D U-Net, 2D U-Net with a pre-trained VGG-16 encoder, and 2D attention U-Net. The second stage consisted of a 3D U-Net with four input channels: the CT volume and three segmentation results of the first stage. The model was trained and tested using 10-fold cross-validation. Segmentation of the entire volume was evaluated using the Dice similarity coefficient (DSC). Segmentation of the contact area was also assessed using the mean surface distance (MSD). The statistical analysis of the evaluation underwent a multi-comparison correction. CTEPH and non-CTEPH cases were classified based on the vessel diameters measured from the segmented MPA. RESULTS: For the noncontact surfaces of AA, the MSD of stacked U-Net was 0.31 ± 0.10 mm (p < 0.05) and 0.32 ± 0.13 mm (p < 0.05) for non-CTEPH and CTEPH cases, respectively. For contact surfaces with a CSR of 0.4 or greater in AA, the MSD was 0.52 ± 0.23 mm (p < 0.05), and 0.68 ± 0.29 mm (p > 0.05) for non-CTEPH and CTEPH cases, respectively. MSDs were lower than those of 2D and 3D U-Nets for contact and noncontact surfaces; moreover, MSDs increased slightly with larger CSRs. However, the stacked U-Net achieved MSDs of approximately 1 pixel for a wide contact surface. The area under the receiver operating characteristic curve for CTEPH and non-CTEPH classification using the right main pulmonary artery (RMPA) diameter was 0.97 (95% confidence interval [CI]: 0.94-1.00). CONCLUSIONS: Segmentation of the aorta and MPA on NCE-CT images were affected by vascular and esophageal contact. The application of stacked U-Net and localization techniques for non-CTEPH and CTEPH cases mitigated the impact of contact, suggesting its potential for diagnosing CTEPH.

Influence of Pitch on Surface Dose Distribution and Image Noise of Computed Tomography Scans.

This study evaluated the effect of pitch on 256-slice helical computed tomography (CT) scans. Cylindrical water phantoms (CWP) were measured using axial and helical scans with various pitch values. The surface dose distributions of CWP were measured, and reconstructed images were obtained using filtered back-projection (FBP) and iterative model reconstruction (IMR). The image noise in each reconstructed image was decomposed into a baseline component and another component that varied along the z-axis. The baseline component of the image noise was highest at the center of the reconstructed image and decreased toward the edges. The normalized 2D power spectra for each pitch were almost identically distributed. Furthermore, the ratios of the 2D power spectra for IMR and FBP at different pitch values were obtained. The magnitudes of the components varying along the z-axis were smallest at the center of the reconstructed image and increased toward the edge. The ratios of the 3D power spectra on the fx axis for IMR and FBP at different pitch values were obtained. The results showed that the effect of the pitch was related to the component that varied along the z-axis. Furthermore, the pitch had a smaller effect on IMR than on FBP.

Characteristics of patients who were able to switch from benzodiazepine hypnotics to lemborexant.

OBJECTIVES: There is little evidence of insomnia treatment, especially exit strategies for hypnotics. We examined on the characteristics of patients who were able to switch from benzodiazepine hypnotics to lemborexant. METHODS: Insomnia was assessed using the Athens Insomnia Scale. Efficacy outcome assessment was the Clinical Global Impressions-Improvement scale. RESULTS: Eighty patients switched from benzodiazepine hypnotic monotherapy to lemborexant and 57 patients who continued the use of benzodiazepine hypnotics. The switched group had a significantly lower benzodiazepine hypnotic diazepam equivalent and a significantly shorter dosing period than the continued group (p < 0.001 for all). The mean Athens Insomnia Scale total score of the switched group was a significant improved (5.8 ± 3.3 to 4.0 ± 3.3; p < 0.05). The mean Clinical Global Impressions-Improvement score of the switched group was 3.3 ± 0.7. CONCLUSION: Our findings suggest that when administering benzodiazepine hypnotics, shortening the administration period, as much as possible, allows a smooth switch to safe long-term maintenance therapy using lemborexant, without exacerbating insomnia.

The effect of lemborexant for insomnia disorder.

BACKGROUND: Lemborexant has a low dependence potential, less muscle relaxant effect, and less effect on cognitive function. However, there have been no naturalistic reports in Japan clarifying the effect of lemborexant on insomnia disorder. We retrospectively examined the effectiveness of treatment with lemborexant. METHODS: Insomnia was assessed using the Athens Insomnia Scale (AIS). Efficacy outcome assessment was the Clinical Global Impressions-Improvement scale (CGI-I). RESULTS: We analyzed 150 patients (male/female = 57/93) in total. The mean subject age and mean duration of illness were 47.8 ± 19.9 years and 4.2 ± 7.2 years, respectively. The average dose of lemborexant was 5.9 ± 2.0 mg. The mean AIS total score was a significant improved (6.6 ± 3.7-3.9 ± 3.3) (p < 0.01). The mean CGI-I score was 3.2 ± 0.8. The 24-week continuation rates for lemborexant were 86.7%. CONCLUSION: Similar to the results obtained in previous studies, the CGI-I score, which is one of the objective indicators evaluated by the therapist, and the AIS, which is one of the subjective evaluations of patients, improved as well. The results of this study suggest that lemborexant may be safe and effective in patients with insomnia in real-world clinical practice.

Continuation rate for asenapine and brexpiprazole treatment in patients with schizophrenia.

INTRODUCTION: The current study sought to compare the treatment continuation rates of asenapine and brexpiprazole while specifically investigating the factors influencing this index and the clinical efficacy of brexpiprazole. METHODS: Retrospective study on patients with schizophrenia who were prescribed either asenapine (n = 73) or brexpiprazole (n = 136), as part of their routine medical care. RESULTS: The treatment continuation rates for asenapine and brexpiprazole were 19.0% and 38.6% at 52 weeks, with that of brexpiprazole found to be significantly higher than that of asenapine (p = .002). Moreover, age was found to be a significant factor affecting the treatment continuation rate for brexpiprazole (p = .03). Additionally, patients with a longer continuation duration had significantly lower Clinical Global Impression-Severity of Illness (CGI-S) scale scores compared to those who discontinued early (p = .04). The continuation rate was also significantly higher for those who began using the drug as outpatients compared to those first administered the drug as inpatients (p = .04). Furthermore, disease duration, CGI-S scale, and continuation duration significantly affected the clinical efficacy of brexipiprazole (p < .05 for all). CONCLUSIONS: The continuation rate for brexpiprazole increases as the age of the patient increases, as disease severity decreases, and if the patient first uses the drug as an outpatient. Shorter disease duration and longer drug administration may lead to improved clinical efficacy. These results suggest that brexpiprazole is an effective treatment option for maintenance therapy of schizophrenia.

Radiation Dose Reduction for Computed Tomography Localizer Radiography Using an Ag Additional Filter.

OBJECTIVE: This study aimed to assess the potential of an Ag additional filter attached to the bow tie filter of a computed tomography (CT) scanner to reduce the radiation dose in CT localizer radiography. METHODS: Radiation doses in CT localizer radiography with Cu and Ag additional filters were evaluated based on dose measurements and Monte Carlo simulations. Image quality evaluations of an adult torso phantom were performed, and the automatic exposure control performance was evaluated in terms of the water-equivalent thickness estimated from CT localizer radiographs. RESULTS: With the Ag additional filter, effective doses were approximately 72% to 75% lower than those with the Cu additional filter. The image quality and water-equivalent thickness with the Ag additional filter were similar to those with the Cu additional filter. CONCLUSIONS: The Ag additional filter helped significantly reduce radiation doses in CT localizer radiography while maintaining image quality and performance.

Comparisons of the effects of second-generation antipsychotics long-acting injections on treatment retention according to severity of patient condition.

INTRODUCTION: There have been no naturalistic reports in Japan clarifying the difference of second-generation antipsychotics (SGA) long-acting injections (LAIs) on treatment retention according to severity of patient condition. METHODS: This study aimed to investigate the difference in treatment retention between SGA LAIs according to severity of patient condition. RESULTS: This study demonstrated that, although AOM patients had better rates of treatment retention compared to PP and RLAI for mild cases, the reverse was true for moderate to severe cases. CONCLUSION: Because treatment retention rates can differ for each SGA LAI based on the severity of the patient's condition.

The p53 activator overcomes resistance to ALK inhibitors by regulating p53-target selectivity in ALK-driven neuroblastomas.

Anaplastic lymphoma kinase (ALK) is an oncogenic receptor tyrosine kinase that is activated by gene amplification and mutation in neuroblastomas. ALK inhibitors can delay the progression of ALK-driven cancers, but are of limited use owing to ALK inhibitor resistance. Here, we show that resistance to ALK inhibitor in ALK-driven neuroblastomas can be attenuated by combination treatment with a p53 activator. Either ALK inhibition or p53 activator treatment induced cell cycle arrest, whereas combination treatment induced apoptosis, and prevented tumour relapse both in vitro and in vivo. This shift toward apoptosis, and away from cell-cycle arrest, in the presence of an ALK inhibitor and a p53 activator, is mediated by inhibition of the ALK-AKT-FOXO3a axis leading to a specific upregulation of SOX4. SOX4 cooperates with p53 to upregulate the pro-apoptotic protein PUMA. These data therefore suggest a novel combination therapy strategy for treating ALK-driven neuroblastomas.