Edwards, Phillip K

Objective Endoscopic sleeve gastroplasty (ESG) has gained global adoption but our understanding of its mechanism(s) of action and durability of efficacy is limited. We sought to determine changes in gastric emptying (GE), gastric motility (GM), hormones and eating behaviours after ESG. Design A priori-designed single-centre substudy of a large US randomised clinical trial, adults with obesity were randomised to ESG or lifestyle interventions (LS) alone. We measured GE, hormones and weight loss and assessed eating behaviours. In a subset of ESG patients, we assessed GM. The primary outcome was the change in T1/2 (min) at 3 months, and secondary outcomes were changes in weight, GE, GM, hormones and eating behaviours. We used t-test analyses and regression to determine the association between GE and weight loss. Results 36 (ESG=18; LS=18) participated in this substudy. Baseline characteristics were similar between the two groups. At 3 months, T1/2 was delayed in the ESG group (n=17) compared with the LS group (n=17) (152.3±47.3 vs 89.1±27.9; p<0.001). At 12 months, T1/2 remained delayed in the ESG group (n=16) vs control group (n=14) (137±37.4 vs 90.1±23.4; p<0.001). Greater delays in GE at 3 months were associated with greater weight loss. GM was preserved and fasting ghrelin, glucagon-like peptide 1 and polypeptide YY significantly increased 18 months after ESG. Conclusion ESG promotes weight loss through several key mechanistic pathways involving GE and hormones while preserving GM. These findings further support clinical adoption of this technique for the management of obesity. Trial registration number NCT03406975.

Abstract Background To describe response to therapy of small bowel (SB) Crohn’s disease (CD) at CT or MR enterography (CTE/MRE) in patients on vedolizumab. Methods Patients with SB CD who underwent CTE/MRE exams greater than 12 months apart on vedolizumab therapy were included. Length (in cm) and inflammation severity (EMBARK score) of inflamed SB segments were assessed. Changes in inflammation length of 3.4 cm or greater or inflammation severity of 2 EMBARK points or greater was categorized as response or progression, as appropriate, with development of newly inflamed segments, strictures, or penetrating complications also indicating progression. Patients not meeting the criteria for response or progression were categorized as having stable disease. Results Of 36 SB CD patients, the large majority had prior surgery (86%; 31), anti-TNF use (92%; 33), and internal penetrating (78%; 28) disease. Thirty-two patients had paired baseline and follow-up CTE/MRE exams without interval surgery, with clinical response observed in 24/32 (75%). Based on imaging response criteria, 22% (7/32; 95% CI: 9%–40%) had response, 50% (16/32; 95% CI: 32%–68%) were stable, and 28% (9/32; 95% CI: 14%–47%) had disease progression. Fifty-six percent of (18/32; 95% CI: 38%–74%) patients had clinical improvement with response or stable disease by imaging. Patients with stable disease had shorter median baseline lengths of SB inflammation (P = .012). Proportion of patients with colonic inflammation, perianal disease, or penetrating complications did not change. Conclusions Most patients on vedolizumab for over 12 months demonstrated response or stable SB disease when using objective cross-sectional radiologic imaging criteria using CTE/MRE.

Purpose Using common datasets, to estimate and compare the diagnostic performance of image‐based denoising techniques or iterative reconstruction algorithms for the task of detecting hepatic metastases. Methods Datasets from contrast‐enhanced CT scans of the liver were provided to participants in an NIH ‐, AAPM ‐ and Mayo Clinic‐sponsored Low Dose CT Grand Challenge. Training data included full‐dose and quarter‐dose scans of the ACR CT accreditation phantom and 10 patient examinations; both images and projections were provided in the training data. Projection data were supplied in a vendor‐neutral standardized format ( DICOM ‐ CT ‐ PD ). Twenty quarter‐dose patient datasets were provided to each participant for testing the performance of their technique. Images were provided to sites intending to perform denoising in the image domain. Fully preprocessed projection data and statistical noise maps were provided to sites intending to perform iterative reconstruction. Upon return of the denoised or iteratively reconstructed quarter‐dose images, randomized, blinded evaluation of the cases was performed using a Latin Square study design by 11 senior radiology residents or fellows, who marked the locations of identified hepatic metastases. Markings were scored against reference locations of clinically or pathologically demonstrated metastases to determine a per‐lesion normalized score and a per‐case normalized score (a faculty abdominal radiologist established the reference location using clinical and pathological information). Scores increased for correct detections; scores decreased for missed or incorrect detections. The winner for the competition was the entry that produced the highest total score (mean of the per‐lesion and per‐case normalized score). Reader confidence was used to compute a Jackknife alternative free‐response receiver operating characteristic ( JAFROC ) figure of merit, which was used for breaking ties. Results 103 participants from 90 sites and 26 countries registered to participate. Training data were shared with 77 sites that completed the data sharing agreements. Subsequently, 41 sites downloaded the 20 test cases, which included only the 25% dose data ( CTDI vol = 3.0 ± 1.8 mG y, SSDE = 3.5 ± 1.3 mG y). 22 sites submitted results for evaluation. One site provided binary images and one site provided images with severe artifacts; cases from these sites were excluded from review and the participants removed from the challenge. The mean (range) per‐lesion and per‐case normalized scores were −24.2% (−75.8%, 3%) and 47% (10%, 70%), respectively. Compared to reader results for commercially reconstructed quarter‐dose images with no noise reduction, 11 of the 20 sites showed a numeric improvement in the mean JAFROC figure of merit. Notably two sites performed comparably to the reader results for full‐dose commercial images. The study was not designed for these comparisons, so wide confidence intervals surrounded these figures of merit and the results should be used only to motivate future testing. Conclusion Infrastructure and methodology were developed to rapidly estimate observer performance for liver metastasis detection in low‐dose CT examinations of the liver after either image‐based denoising or iterative reconstruction. The results demonstrated large differences in detection and classification performance between noise reduction methods, although the majority of methods provided some improvement in performance relative to the commercial quarter‐dose images with no noise reduction applied.