Unpaired deep learning for pharmacokinetic parameter estimation from dynamic contrast-enhanced MRI without AIF measurements.

DCE-MRI provides information about vascular permeability and tissue perfusion through the acquisition of pharmacokinetic parameters. However, traditional methods for estimating these pharmacokinetic parameters involve fitting tracer kinetic models, which often suffer from computational complexity and low accuracy due to noisy arterial input function (AIF) measurements. Although some deep learning approaches have been proposed to tackle these challenges, most existing methods rely on supervised learning that requires paired input DCE-MRI and labeled pharmacokinetic parameter maps. This dependency on labeled data introduces significant time and resource constraints and potential noise in the labels, making supervised learning methods often impractical. To address these limitations, we present a novel unpaired deep learning method for estimating pharmacokinetic parameters and the AIF using a physics-driven CycleGAN approach. Our proposed CycleGAN framework is designed based on the underlying physics model, resulting in a simpler architecture with a single generator and discriminator pair. Crucially, our experimental results indicate that our method does not necessitate separate AIF measurements and produces more reliable pharmacokinetic parameters than other techniques.

Volume and Permeability of White Matter Hyperintensity on Cognition: A DCE Imaging Study of an Older Cohort With and Without Cognitive Impairment.

BACKGROUND: The impact of blood-brain barrier (BBB) leakage on white matter hyperintensity (WMH) subtypes (location) and its association with clinical factors and cognition remains unclear. PURPOSE: To investigate the relationship between WMH volume, permeability, clinical factors, and cognition in older individuals across the cognitive spectrum. STUDY TYPE: Prospective, cross-sectional. SUBJECTS: A total of 193 older adults with/without cognitive impairment; 128 females; mean age 70.1 years (standard deviation 6.8). FIELD STRENGTH/SEQUENCE: 3 T, GE Dynamic contrast-enhanced, three-dimensional (3D) Magnetization-prepared rapid gradient-echo (MPRAGE T1WI), 3D fluid-attenuated inversion recovery (FLAIR). ASSESSMENT: Periventricular WMH (PWMH), deep WMH (DWMH), and normal-appearing white matter (NAWM) were segmented using FMRIB automatic segmentation tool algorithms on 3D FLAIR. Hippocampal volume and cortex volume were segmented on 3D T1WI. BBB permeability (Ktrans) and blood plasma volume (Vp) were determined using the Patlak model. Vascular risk factors and cognition were assessed. STATISTICAL TESTS: Univariate and multivariate analyses were performed to identify factors associated with WMH permeability. Logistic regression analysis assessed the association between WMH imaging features and cognition, adjusting for age, sex, apolipoprotein E4 status, education, and brain volumes. A P-value <0.05 was considered significant. RESULTS: PWMH exhibited higher Ktrans (0.598 ± 0.509 × 10-3 minute-1) compared to DWMH (0.496 ± 0.478 × 10-3 minute-1) and NAWM (0.476 ± 0.398 × 10-3 minute-1). Smaller PWMH volume and cardiovascular disease (CVD) history were significantly associated with higher Ktrans in PWMH. In DWMH, higher Ktrans were associated with CVD history and cortical volume. In NAWM, it was linked to CVD history and dyslipidemia. Larger PWMH volume (odds ratio [OR] 1.106, confidence interval [CI]: 1.021-1.197) and smaller hippocampal volume (OR 0.069; CI: 0.019-0.253) were independently linked to worse global cognition after covariate adjustment. DATA CONCLUSION: Elevated BBB leakage in PWMH was associated with lower PWMH volume and prior CVD history. Notably, PWMH volume, rather than permeability, was correlated with cognitive decline, suggesting that BBB leakage in WMH may be a consequence of CVD rather than indicate disease progression. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY: Stage 3.

Evaluating the Efficacy of a Novel Hemostatic Powder Compared to Traditional Treatments in Non-Variceal Upper Gastrointestinal Bleeding: A Multicenter, Randomized Non-inferiority Study.

BACKGROUND AND AIMS: Hemostatic powders have been rapidly developed and used to treat gastrointestinal bleeding. We aimed to investigate the non-inferiority of the newly developed hemostatic powder (CEGP-003) compared to conventional endoscopic treatments for non-variceal upper gastrointestinal bleeding (NVUGIB). METHODS: This prospective, multicenter, randomized, open-label, controlled trial was conducted at four referral institutions. We enrolled consecutive patients who underwent emergency endoscopy for NVUGIB. The patients were randomly assigned to either the CEGP-003 or the conventional treatment group. In the CEGP-003 group, the hemostatic powder was applied as a spray. Conventional endoscopic treatments included electrical coagulation and hemoclipping. RESULTS: Between November 2019 and June 2022, 218 patients were enrolled (CEGP-003, 108; conventional, 110). Initial hemostasis was achieved in 104 of 108 patients (96.3%) in the CEGP-003 group and 101 of 110 patients (91.8%) in the conventional treatment group. The CEGP-003 group exhibited a significantly higher re-bleeding rate than the conventional treatment group. Multivariate analysis that age, duodenum and middle 1/3 of stomach, and CEGP-003 use as the initial hemostatic treatment were independent risk factors for re-bleeding. No adverse events were associated with CEGP-003. CONCLUSIONS: CEGP-003 demonstrates promise as an initial endoscopic therapy for NVUGIB, however close monitoring is warranted due to the risk of re-bleeding (Cris.nih.go.kr, number: KCT0004655).

Comparison of Helicobacter pylori eradication rates between 7 and 14 days of tailored therapy according to clarithromycin resistance test: A randomized, multicenter, non-inferiority study.

BACKGROUND: Recently, a simple tailored therapy based on clarithromycin resistance has been implemented as Helicobacter pylori (H. pylori) eradication therapy. Nonetheless, despite the tailored therapy and frequent adverse events, studies on treatment period are lacking. This study aimed to compare the H. pylori eradication rates of 7-day and 14-day tailored therapy regimens according to clarithromycin resistance. MATERIALS AND METHODS: This multicenter, prospective, randomized, noninferiority trial enrolled H. pylori-positive patients who were randomly assigned to 7-day and 14-day regimen groups, depending on the presence or absence of clarithromycin resistance by 23S rRNA gene point mutations. Standard triple therapy (STT) (20 mg rabeprazole, 1 g amoxicillin, and 500 mg clarithromycin twice daily) or bismuth quadruple therapy (BQT) (20 mg rabeprazole twice daily, 500 mg metronidazole thrice daily, 120 mg bismuth four times daily, and 500 mg tetracycline four times daily) was assigned by clarithromycin resistance. Eradication rates and adverse events were evaluated. RESULTS: A total of 314 and 278 patients were included in the intention-to-treat (ITT) and per-protocol (PP) analyses, respectively; however, 31 patients were lost to follow-up, whereas five patients violated the protocol. Both the 7-day and 14-day regimens showed similar eradication rates in the ITT (7-day vs. 14-day: 78.3% vs. 78.3%, p > 0.99) and PP (87.9% vs. 89.1%, p = 0.851) analyses. Non-inferiority was confirmed (p < 0.025). A subgroup analysis according to clarithromycin resistance (clarithromycin resistance rate: 28.7%) revealed no significant difference in eradication rates between the 7-day and 14-day STT (90.0% vs. 90.1%, p > 0.99) and BQT (82.5% vs. 86.5%, p = 0.757). Furthermore, adverse events did not significantly differ between the two groups. CONCLUSIONS: The 7-day triple and quadruple therapy according to clarithromycin resistance showed similar eradication rates, as compared to the 14-day therapy.

Does total omentectomy prevent peritoneal seeding for advanced gastric cancer with serosal invasion?

BACKGROUND: Radical gastrectomy is composed of gastrectomy, lymph node dissection, and omentectomy. Total omentectomy (TO) is expected to reduce the incidence of peritoneal recurrence. We aimed to investigate the necessity of TO for advanced gastric cancer (AGC) with serosal invasion. METHODS: We retrospectively reviewed 310 patients who underwent radical gastrectomy with TO and 93 patients who underwent partial omentectomy (PO) for gastric cancer with serosal invasion between August, 2005 and December, 2017. Finally, 91 patients in the PO group and 91 in the TO group were enrolled based on a 1:1 propensity-score matching analysis. We evaluated surgical and oncological outcomes, including 5-year overall and recurrence-free survival rates. RESULTS: There was no statistically significant difference between the two groups in postoperative complications. Recurrence sites showed similar patterns in both groups, including peritoneal recurrence (PO vs. TO, 18.7% vs. 28.6%; p = 0.188). Five-year overall survival was better in the PO group (p = 0.018), while 5-year recurrence-free survival was similar in both groups (p = 0.066). CONCLUSION: TO might not be an essential part of preventing peritoneal recurrence for AGC with serosal invasion. PO could be considered a radical gastrectomy for T4a gastric cancer.

Incidence and adverse clinical events of primary sclerosing cholangitis with ulcerative colitis.

PURPOSE: The aim of this study was to conduct a nationwide population-based study to estimate the incidence of primary sclerosing cholangitis in patients with ulcerative colitis (UC-PSC) and investigate healthcare use, medication use, surgery, cancer, and death as adverse clinical events of UC-PSC. METHODS: We identified incident cases of UC with (UC-PSC) or without PSC (UC-alone) between 2008 and 2018 using health insurance claims data in Korea. Univariate (crude hazard ratio (HR)) and multivariate analyses were performed to compare the risk of adverse clinical events between groups. RESULTS: A total of 14,406 patients with UC using population-based claims data were detected in the cohort. Overall, 3.38% (487/14,406) of patients developed UC-PSC. During a mean follow-up duration of approximately 5.92 years, the incidence of PSC in patients with UC was 185 per 100,000 person-years. The UC-PSC group showed statistically more frequent healthcare use (hospitalization and emergency department visits: HRs, 5.986 and 9.302, respectively; P < .001), higher immunomodulator and biologic use (azathioprine, infliximab, and adalimumab: HRs, 2.061, 3.457, and 3.170, respectively; P < .001), and higher surgery rate (operation for intestinal obstruction, and colectomy: HRs, 9.728 and 2.940, respectively; P < .001) than did the UC-alone group. The UC-PSC group also showed significantly higher colorectal cancer and biliary tract cancer (HRs, 2.799 and 36.343, respectively; P < .001) and mortality (HR, 4.257) rates than did the UC-alone group. CONCLUSION: Patients with UC-PSC have higher risks of colorectal cancer, biliary tract cancer, and death than do patients with UC-alone. Although considered a rare disease, managing this complex and costly disease requires recognition of the impact of increased burden on healthcare services.

Feasibility of endoscopic resection and impact of endoscopic ultrasound-based surveillance on colorectal subepithelial tumors.

BACKGROUND: Owing to the rising number of screening endoscopies and instrumental advances in endoscopic ultrasound (EUS), colorectal subepithelial tumors (SETs) are being increasingly detected. We aimed to determine the feasibility of endoscopic resection (ER) and the impact of EUS-based surveillance on colorectal SETs. METHODS: The medical records of 984 patients with incidentally detected colorectal SETs between 2010 and 2019 were retrospectively reviewed. Overall, 577 colorectal SETs underwent ER, and 71 colorectal SETs underwent serial colonoscopy for > 12 months. RESULTS: The mean tumor size (± standard deviation) of 577 colorectal SETs for which ER was performed was 7.0 ± 5.7 (median, 55; range, 1-50) mm; 475 tumors were located in the rectum and 102, in the colon. En bloc resection was achieved in 560/577 treated lesions (97.1%), and complete resection was achieved in 516/577 (89.4%). ER-related adverse events occurred in 15/577 (2.6%) patients. SETs originating from the muscularis propria showed a higher risk of ER-related adverse events and perforation than SETs arising from the mucosal or submucosal layer (odds ratio [OR] 19.786, 95% confidence interval [CI] 4.556-85.919; P = 0.002 and OR 141.250, 95% CI 11.596-1720.492; P = 0.046, respectively). Seventy-one patients were followed up after EUS without any treatment for > 12 months, during which three showed progression; eight, regression; and sixty, no changes. CONCLUSIONS: ER for colorectal SETs showed excellent efficacy and safety. Additionally, colorectal SETs without high-risk features in surveillance with colonoscopy showed an excellent prognosis.

Analysis of risk factors affecting long-term survival in elderly patients with advanced gastric cancer.

BACKGROUND: Factors predicting postoperative complications after gastrectomy for elderly patients with gastric cancer have been analyzed in several previous studies. However, there is limited research available on risk factors related to long-term survival. AIMS: This study aimed to analyze factors affecting long-term survival after curative gastrectomy in elderly patients with advanced gastric cancer. METHODS: This study included patients aged > 75 years with histologically confirmed advanced gastric cancer stage II or greater. Before analysis, risk factors were categorized into four groups: baseline characteristics, underlying diseases, surgical and pathologic factors, and nutritional factors. RESULTS: The mean follow-up duration was 71.0 months. The 5-year overall survival and disease-specific survival rates were 51.5% and 58.3%, respectively. Kaplan-Meier curves showed that patients who were female and overweight had significantly longer survival rates than those who were male and underweight. Elderly patients who underwent a total gastrectomy had poorer survival rates than those who underwent a distal gastrectomy. Multivariate analysis demonstrated that tumor stage, extent of gastrectomy, overweight status and overall complication were independent risk factors for overall survival. DISCUSSION: Our study show that the overweight patients, the extent of gastrectomy, tumor stage and overall complications are significant risk factors affecting long-term survival. CONCLUSIONS: Therefore, surgeons may be cautious in performing total gastrectomy in elderly gastric cancer patients. Additionally, it is important to focus on improving nutritional status and mitigating overall complications.

Safety evaluation of curative gastrectomy for gastric cancer patients who underwent liver transplantation: a comparative study with conventional gastrectomy for gastric cancer patients.

BACKGROUND: We aimed to examine the technical and oncological safety of curative gastrectomy for gastric cancer patients who underwent liver transplantation. METHODS: In this study, we compared the surgical and oncological outcomes of two groups. The first group consisted of 32 consecutive patients who underwent curative gastrectomy for gastric cancer after liver transplantation (LT), while the other group consisted of 127 patients who underwent conventional gastrectomy (CG). In addition, a subgroup analysis was performed to evaluate the impact of the background differences and the surgical outcomes on the involvement of a specialized liver transplant surgery team. RESULTS: The mean operative time was significantly longer in the LT group (p < 0.05). Furthermore, there were more frequent cases of postoperative transfusion in the LT group compared to the CG group (p < 0.05). However, there were no significant differences in the overall complications between the groups (25.00 vs 23.62%, p = 0.874). The 5-year overall survival rates of the LT and CG groups were 76.7% and 90.1%, respectively (p < 0.05). The results of the subgroup analysis demonstrated no statistically significant difference in various early surgical outcomes, such as time to transfusion during surgery, first flatus, time to first soft diet, postoperative complications, hospital stay after surgery, and the number of harvested lymph nodes except for operation time. CONCLUSIONS: Despite one's medical history of undergoing LT, our study demonstrated that curative gastrectomy could be a surgically safe treatment for gastric cancer. However, further study should be conducted to identify the reason gastric cancer patients who underwent liver transplant surgery have lower overall survival rate.

Correlations between H2 Permeation and Physical/Mechanical Properties in Ethylene Propylene Diene Monomer Polymers Blended with Carbon Black and Silica Fillers.

H2 permeation in peroxide-crosslinked EPDM blended with carbon black (CB) and silica fillers was studied at pressures ranging from 1.2 MPa to 90 MPa via the volumetric analysis technique. H2 uptake in the CB-filled EPDM revealed dual-sorption behaviors via Henry's law and the Langmuir model, which were attributed to H2 absorption by the polymer chains and H2 adsorption at the filler interfaces, respectively. Additionally, single-sorption mechanisms were observed for neat EPDM and silica-blended EPDM according to Henry's law, indicating H2 absorption by the polymer chain. The linear decreases in the diffusivity with filler content for the silica-blended EPDMs were attributed to increases in the diffusion paths caused by the filler. Exponential decreases in the diffusivity with increasing filler content and in the permeation with the physical/mechanical properties for CB-filled EPDMs were caused by decreases in the fractional free volume due to increased densities for the EPDM composites. Moreover, good filler-dependent correlations between permeability and density, hardness, and tensile strength were demonstrated for EPDMs used as sealing materials for O-rings. From the resulting equation, we predicted the permeation value without further measurements. Thus, we can select EPDM candidates satisfying the permeation guidelines used in hydrogen infrastructure for the future hydrogen economy.

Digital workflow for mini-implant-assisted rapid palatal expander fabrication-a case report.

BACKGROUND: Non-surgical mini-implant assisted rapid palatal expansion, or midfacial skeletal expansion, is a paradigm-shifting concept that in recent years has expanded the envelope of orthopedic movement in the transverse direction for adult patients. Although adding mini-screws to a rapid palatal expander is not complicated, accurate and successful expansion strongly depends on the device's position and its relation to the resisting structures of the maxillofacial complex. CASE PRESENTATION: This article presents a digital workflow to locate the optimal position of the Midfacial Skeletal Expander (MSE) device in a CBCT-combined intraoral scan file and describes how to transfer the MSE position intra-orally with properly sized bands during the device fabrication. The complete digital workflow of MSE fabrication and its application for a Class III orthognathic surgical case is presented in detail. CONCLUSIONS: This report describes a completely digital process that can accurately position the MSE device according to the orientation and morphology of maxillary basal bone, which is crucial in adult cases demand maxillary expansion.

Sandwich spatial saturation for neuromelanin-sensitive MRI: Development and multi-center trial.

Neuromelanin (NM)-sensitive MRI using a magnetization transfer (MT)-prepared T1-weighted sequence has been suggested as a tool to visualize NM contents in the brain. In this study, a new NM-sensitive imaging method, sandwichNM, is proposed by utilizing the incidental MT effects of spatial saturation RF pulses in order to generate consistent high-quality NM images using product sequences. The spatial saturation pulses are located both superior and inferior to the imaging volume, increasing MT weighting while avoiding asymmetric MT effects. When the parameters of the spatial saturation were optimized, sandwichNM reported a higher NM contrast ratio than those of conventional NM-sensitive imaging methods with matched parameters for comparability with sandwichNM (SandwichNM: 23.6 ± 5.4%; MT-prepared TSE: 20.6 ± 7.4%; MT-prepared GRE: 17.4 ± 6.0%). In a multi-vendor experiment, the sandwichNM images displayed higher means and lower standard deviations of the NM contrast ratio across subjects in all three vendors (SandwichNM vs. MT-prepared GRE; Vendor A: 28.4 ± 1.5% vs. 24.4 ± 2.8%; Vendor B: 27.2 ± 1.0% vs. 13.3 ± 1.3%; Vendor C: 27.3 ± 0.7% vs. 20.1 ± 0.9%). For each subject, the standard deviations of the NM contrast ratio across the vendors were substantially lower in SandwichNM (SandwichNM vs. MT-prepared GRE; subject 1: 1.5% vs. 8.1%, subject 2: 1.1 % vs. 5.1%, subject 3: 0.9% vs. 4.0%, subject 4: 1.1% vs. 5.3%), demonstrating consistent contrasts across the vendors. The proposed method utilizes product sequences, requiring no alteration of a sequence and, therefore, may have a wide practical utility in exploring the NM imaging.

Choroid Plexus Volume and Permeability at Brain MRI within the Alzheimer Disease Clinical Spectrum.

Background Mounting evidence suggests that the choroid plexus (CP) plays an important role in the pathophysiology of Alzheimer disease (AD), but its imaging profile in cognitive impairment remains unclear. Purpose To evaluate CP volume, permeability, and susceptibility by using MRI in patients at various stages of cognitive impairment. Materials and Methods This retrospective study evaluated patients with cognitive symptoms who underwent 3.0-T MRI of the brain, including dynamic contrast-enhanced (DCE) imaging and quantitative susceptibility mapping (QSM), between January 2013 and May 2020. CP volume was automatically segmented using three-dimensional T1-weighted sequences; the volume transfer constant (ie, Ktrans) and fractional plasma volume (ie, Vp) were determined using DCE MRI, and susceptibility was assessed using QSM. The effects of CP volume, expressed as the ratio to intracranial volume, on cognition were evaluated using multivariable linear regression adjusted for age, sex, education, apolipoprotein E ε4 allele status, and volumetric measures. Results A total of 532 patients with cognitive symptoms (mean age, 72 years ± 9 [SD]; 388 women) were included: 78 with subjective cognitive impairment (SCI), 158 with early mild cognitive impairment (MCI), 149 with late MCI, and 147 with AD. Among these, 132 patients underwent DCE MRI and QSM. CP volume was greater in patients at more severe stages (ratio of intracranial volume × 103: 0.9 ± 0.3 for SCI, 1.0 ± 0.3 for early MCI, 1.1 ± 0.3 for late MCI, and 1.3 ± 0.4 for AD; P < .001). Lower Ktrans (r = -0.19; P = .03) and Vp (r = -0.20; P = .02) were negatively associated with CP volume; susceptibility was not (r = 0.15; P = .10). CP volume was negatively associated with memory (B = -0.67; standard error of the mean [SEM], 0.21; P = .01), executive function (B = -0.90; SEM, 0.31; P = .01), and global cognition (B = -0.82; SEM, 0.32; P = .01). Conclusion Among patients with cognitive symptoms, larger choroid plexus volume was associated with severity of cognitive impairment in the Alzheimer disease spectrum. Published under a CC BY 4.0 license. Online supplemental material is available for this article. See also the editorial by Chiang in this issue.

Comparison of Standard D2 and Limited Lymph Node Dissection in Elderly Patients with Advanced Gastric Cancer.

BACKGROUND: Knowledge on the optimal extent of lymphadenectomy among elderly patients with advanced gastric cancer is limited. This study was designed to compare standard D2 and limited lymphadenectomy for evaluating the appropriate extent of lymphadenectomy. PATIENTS AND METHODS: We retrospectively reviewed patient's data based on a prospectively collected gastric cancer registry. The inclusion criteria were age above 75 years and histologically confirmed stage II or more advanced gastric cancer. In this study, 103 patients who underwent limited lymph node dissection and 134 patients who underwent standard D2 lymph node dissection were included to evaluate surgical and oncological outcomes using propensity score matching (PSM) analysis. RESULTS: The mean age after PSM was approximately 78 years in both groups. The Charlson Comorbidity Index was 5.81 ± 0.87 and 5.75 ± 0.76, respectively, and 12.5% of the patients in both groups had American Society of Anesthesiologists scores of more than 3. The limited lymphadenectomy group showed a shorter operation time and fewer retrieved lymph. However, other surgical outcomes and pathological data were not significantly different between the groups. No postoperative mortality within 30 days was observed. There were no significant differences in overall complications between the groups. The 3-year overall survival rates of the limited and standard lymphadenectomy groups were 58.3% and 73.6%, respectively. The 3-year recurrence-free survival rate of the limited lymphadenectomy group was lower than that of the standard lymphadenectomy group; however, the difference was not statistically significant. CONCLUSIONS: Standard D2 lymphadenectomy has better oncological outcomes in elderly patients with advanced gastric cancer.

Contrast-Enhanced Fluid-Attenuated Inversion Recovery in Neuroimaging: A Narrative Review on Clinical Applications and Technical Advances.

While contrast-enhanced fluid-attenuated inversion recovery (FLAIR) has long been regarded as an adjunct sequence to evaluate leptomeningeal disease in addition to contrast-enhanced T1-weighted imaging, it is gradually being used for more diverse pathologies beyond leptomeningeal disease. Contrast-enhanced FLAIR is known to be highly sensitive to low concentrations of gadolinium within the fluid. Accordingly, recent research has suggested the potential utility of contrast-enhanced FLAIR in various kinds of disease, such as Meniere's disease, seizure, stroke, traumatic brain injury, and brain metastasis, in addition to being used for visualizing glymphatic dysfunction. However, its potential applications have been reported sporadically in an unorganized manner. Furthermore, the exact mechanism for its superior sensitivity to low concentrations of gadolinium has not been fully understood. Rapidly developing magnetic resonance technology and unoptimized parameters for FLAIR may challenge its accurate application in clinical practice. This review provides the fundamental mechanism of contrast-enhanced FLAIR, systematically describes its current and potential clinical application, and elaborates on technical considerations for its optimization. LEVEL OF EVIDENCE: 3 TECHNICAL EFFICACY STAGE: 5.

Magnetic susceptibility in the deep gray matter may be modulated by apolipoprotein E4 and age with regional predilections: a quantitative susceptibility mapping study.

PURPOSE: To examine the relationship between apolipoprotein E gene (APOE) mutation status and iron accumulation in the deep gray matter of subjects with cognitive symptoms using quantitative susceptibility mapping (QSM). METHODS: A total of 105 patients with cognitive symptoms were enrolled. QSM data were generated from 3D gradient-echo data using an STI Suite algorithm. A region of interest-based analysis with QSM was performed in the deep gray matter. Differences between APOE4 carriers and non-carriers were assessed by analysis of covariance. Multiple regression analysis was performed to identify the factors associated with magnetic susceptibility. RESULTS: Clinical characters such as age, education, MMSE, vascular risk burden, and systolic blood pressure differ between APOE4 carrier and non-carrier groups. The APOE4 carrier group had higher magnetic susceptibility values than the non-carrier group, with significant differences in the caudate (p = 0.004), putamen (p < 0.0001), and globus pallidus (p < 0.0001) which imply higher iron accumulation. In a multiple regression analysis, APOE4 status was found to be a predictor of magnetic susceptibility value in the globus pallidus (p = 0.03); age for magnetic susceptibility value in the caudate nucleus (p = 0.0064); and age and hippocampal atrophy for magnetic susceptibility value in the putamen (p < 0.05). CONCLUSION: Our study demonstrates that magnetic susceptibility in globus pallidus is related to APOE4 status while those of caudate and putamen are related to other factors including age. It suggests that brain iron accumulation in the deep gray matter is modulated by APOE4 and age with differential regional predilection.

Colonoscopy Insertion in Patients with Gastrectomy: Does Position Impact Cecal Intubation Time?

BACKGROUND: A history of abdominal surgery is associated with difficulty in colonoscopy insertion. Few studies have reported effective colonoscopy insertion for patients who underwent abdominal surgery due to stomach cancer. AIM: We aimed to compare the impact of supine position (SP) and left lateral position (LLP) as the starting position of colonoscopy insertion in patients who underwent abdominal surgery due to stomach cancer. METHODS: This was a prospective, randomized controlled trial. Patients undergoing colonoscopy for screening or post-polypectomy surveillance after gastrectomy due to stomach cancer were enrolled and randomized to the SP or LLP group as the starting position of colonoscopy insertion. All colonoscopic examinations were performed with a transparent cap. The primary outcome was to compare the cecal intubation time between the two groups. RESULTS: A total of 224 patients were enrolled. The mean cecal intubation time was not significantly different between the SP and LLP groups (364.5 s versus 306.9 s; p = 0.105). In patients with a lower body mass index (< 21 kg/m2) or who underwent gastrectomy within three years, the mean cecal intubation time of the LLP group was shorter than the SP group. In the multivariate analysis for the factors affecting to increase in the cecal intubation time (> 5 min), the starting position was not an independent factor. CONCLUSION: Either the SP or LLP could serve as a possible starting position of colonoscopy insertion for patients who underwent abdominal surgery due to stomach cancer.

Novel temperature-responsive hydrogel injected to the incision site for postoperative pain relief in laparoscopic abdominal surgery: a single-blind, randomized, pivotal clinical trial.

BACKGROUND: A temperature-responsive hydrogel (PF-72; TGel Bio, Inc., Ltd, Seoul, Korea), developed as a sustained drug delivery device, can be mixed with ropivacaine to reduce pain in the incision area. The hydrogel is soluble at low temperatures (2-8 °C) and is converted into a gel at high temperatures (> 30 °C). We aimed to evaluate whether the administration of ropivacaine using PF-72 at incision sites reduces pain until 72 h postoperatively in patients undergoing laparoscopic stomach or colorectal surgery. METHODS: Patients were randomly assigned to the control group (0.75% ropivacaine) or PF-72 group (PF-72 mixed with 0.75% ropivacaine). Before surgical incision closure, 0.75% ropivacaine or PF-72 mixed with 0.75% ropivacaine was injected into the subcutaneous fat and muscle of all incisions. Postoperative pain was evaluated by the Numerical Rating Scale (NRS, 0 = no pain, 10 = most severe pain) for wound pain at 3, 6, 24, 48, and 72 h after the end of surgery. RESULTS: Ninety-nine patients (control, n = 51; PF-72, n = 48) were included in the analysis. The areas under the curve of NRS for wound pain until 72 h in the control group and the PF-72 group were 188.7 ± 46.1 and 135.3 ± 49.9 h, respectively (P < 0.001). The frequency of the administration of rescue analgesics in the general ward was similar between the two groups. CONCLUSION: PF-72 mixed with 0.75% ropivacaine reduced postoperative pain until 72 h in patients undergoing laparoscopic surgery. Although the study population was not large enough for safety evaluation, no adverse events associated with PF-72 were observed.

Diagnostic performance of endoscopic ultrasonography-guided fine-needle biopsy in upper gastrointestinal subepithelial tumors measuring 2-5 cm in size.

BACKGROUND: Subepithelial tumors (SETs) in the upper gastrointestinal (GI) tract are frequently discovered during upper endoscopy, and their management is determined based on size and histopathological diagnosis. We aimed to evaluate the diagnostic performance of endoscopic ultrasonography-guided fine-needle biopsy (EUS-FNB) in upper GI SETs of 2-5 cm in size. METHODS: We included 63 patients who underwent EUS-FNB for upper GI SETs of 2-5 cm in size between January 2013 and February 2020. The diagnostic yield of EUS-FNB, ability of EUS-FNB in discriminating malignant from non-malignant lesions, and histopathological concordance between EUS-FNB specimens and resected specimens were evaluated. RESULTS: Successful acquisition of macroscopic tissue cores was possible in all 63 cases, and the diagnostic yield of EUS-FNB was 92.1% (58/63). The sensitivity, specificity, and accuracy of EUS-FNB in discriminating malignant from non-malignant lesions were 100% (95% confidence interval [CI] 85.3-100%), 87.8% (95% CI 79.9-87.8%), and 92.1% (95% CI 81.8-92.1%), respectively. Of the 26 SETs that were endoscopically or surgically resected after EUS-FNB, the histopathological concordance rate between the EUS-FNB specimens and resected specimens was 100% (24/24), except in two cases of inadequate results with EUS-FNB specimens. CONCLUSION: EUS-FNB provides high diagnostic yield and high capability in discriminating malignant from non-malignant lesions in upper GI SETs of 2-5 cm in size.

Association between mucin phenotype and lesion border detection using acetic acid-indigo carmine chromoendoscopy in early gastric cancers.

BACKGROUND: For successful treatment of early gastric cancers (EGCs), it is crucial to define the horizontal border of the lesion with high accuracy. Acetic acid-indigo carmine (AI) chromoendoscopy has been used to determine the horizontal border in EGCs, but this technique is less potent in certain situations. Mucin phenotype in gastric cancers refers to biological differences in precursor lesions and differences in histopathologic findings, and it might affect AI chromoendoscopy findings. We aimed to investigate the association between mucin phenotype and AI chromoendoscopy findings in EGCs. METHODS: We prospectively evaluated 126 lesions in 126 patients with endoscopically diagnosed EGCs. Conventional endoscopy and AI chromoendoscopy findings of these lesions before treatment were prospectively analyzed. The border distinction between the lesion and surrounding mucosa was classified as distinct or indistinct on conventional endoscopy and AI chromoendoscopy, respectively. Mucin phenotypes were classified as gastric, intestinal, gastrointestinal, or null type by immunohistochemistry. RESULTS: The lesion borders were distinct in 46.8% (59/126) of the lesions assessed using conventional endoscopy and in 73.0% (92/126) of those assessed with AI chromoendoscopy (p < 0.001). The border distinction rate of differentiated-type cancers on AI chromoendoscopy was significantly higher than that on conventional endoscopy (66/71 [93.0%] vs. 34/71 [47.9%], p < 0.001), but the border distinction rate of undifferentiated-type cancers on AI chromoendoscopy was not different from that on conventional endoscopy (26/55 [47.3%] vs. 25/55 [45.5%], p = 0.848). Compared with conventional endoscopy, AI chromoendoscopy identified borders in a significantly higher percentage of gastric, intestinal, and gastrointestinal mucin types; however, there was no difference in AI chromoendoscopy findings according to the mucin phenotype (p = 0.271). CONCLUSION: AI chromoendoscopy was effective in horizontal border delineation in differentiated-type EGCs, but not in undifferentiated-type EGCs. Mucin phenotype had no effect on border distinction using AI chromoendoscopy.