A multi-centre polyp detection and segmentation dataset for generalisability assessment.

Polyps in the colon are widely known cancer precursors identified by colonoscopy. Whilst most polyps are benign, the polyp's number, size and surface structure are linked to the risk of colon cancer. Several methods have been developed to automate polyp detection and segmentation. However, the main issue is that they are not tested rigorously on a large multicentre purpose-built dataset, one reason being the lack of a comprehensive public dataset. As a result, the developed methods may not generalise to different population datasets. To this extent, we have curated a dataset from six unique centres incorporating more than 300 patients. The dataset includes both single frame and sequence data with 3762 annotated polyp labels with precise delineation of polyp boundaries verified by six senior gastroenterologists. To our knowledge, this is the most comprehensive detection and pixel-level segmentation dataset (referred to as PolypGen) curated by a team of computational scientists and expert gastroenterologists. The paper provides insight into data construction and annotation strategies, quality assurance, and technical validation.

Plasma α-Glutathione S-Transferase in Patients with Chronic Mesenteric Ischemia and Median Arcuate Ligament Syndrome.

Background: Chronic mesenteric ischemia (CMI) due to either atherosclerosis of the mesenteric arteries or median arcuate ligament syndrome (MALS) is an underdiagnosed entity. The etiology of MALS and its existence have been debated and questioned. We aimed to identify plasma biomarkers indicating mesenteric ischemia in patients with CMI and MALS. Methods: Plasma α-glutathione S-transferase (α-GST), intestinal fatty acid-binding protein (I-FABP), citrulline, and ischemia modified albumin (IMA) were analyzed in fifty-eight patients with CMI (Group A, n=44) and MALS (Group B, n=14) before and after revascularization. The plasma levels of these potential biomarkers were compared with those of healthy individuals (Group C, n=16). Group comparison was performed with the Mann-Whitney U-test. Cross-tabulation and its derivatives were obtained. Receiver operating characteristic (ROC) curves and area under the curve (AUC) were calculated. Results: Plasma levels of α-GST were significantly raised in the patients with CMI (7.8 ng/mL, p<0.001) and MALS (8.4 ng/mL, p<0.001), as compared with the control Group C (3.3 ng/mL). The threshold for normal median plasma α-GST levels of 4 ng/mL yielded a sensitivity of 93% and 86%, specificity of 86% and 88%, respectively, for the diagnosis of CMI due to atherosclerosis and MALS. AUC of ROC curves was 0.96 (p<0.0001) for CMI and 0.85 (p<0.002) for MALS. The patient groups did not differ from the healthy controls in any other biomarkers. Conclusion: Plasma α-GST levels are elevated in CMI and MALS patients. Elevated plasma levels of α-GST suggest ischemia as the etiology of MALS.

Early Identification of Chronic Mesenteric Ischemia with Endoscopic Duplex Ultrasound.

Introduction: Due to diagnostic delay, chronic mesenteric ischemia (CMI) is underdiagnosed. We assumed that the patients suspected of CMI of the atherosclerotic origin or median arcuate ligament syndrome (MALS) could be identified earlier with endoscopic duplex ultrasound (E-DUS). Patients and Methods: Fifty CMI patients with CTA-verified stenosis of either ≥50% and ≥70% of celiac artery (CA) and superior mesenteric artery (SMA) were examined with E-DUS and transabdominal duplex ultrasound (TA-DUS). Peak systolic velocities (PSV) of ≥200cm/s and ≥275cm/s for CA and SMA, respectively, were compared with CTA. Subgroup analysis was performed for the patients with (n=21) and without (n=29) prior revascularization treatment of CMI. The diagnostic ability of E-DUS and TA-DUS was tested with crosstabulation analysis. Receiver operating characteristics (ROC) curve analysis was performed, and the area under the curve (AUC) was calculated to investigate the test accuracy. Results: In the patients with ≥70% stenosis, E-DUS had higher sensitivity than TA-DUS (91% vs 81% for CA and 100% vs 92% for SMA). AUC for SMA ≥70% in E-DUS was 0.75 and with TA-DUS 0.68. The sensitivity of E-DUS for CTA-verified stenosis ≥70% for CA was 100% in the patients without prior treatment. E-DUS demonstrated higher sensitivity than TA-DUS for both arteries with stenosis ≥50% and ≥70% in the treatment-naive patients. Conclusion: E-DUS is equally valid as TA-DUS for the investigation of CMI patients and should be used as an initial diagnostic tool for patients suspected of CMI.

Gastroscopy assisted laser Doppler flowmetry and visible light spectroscopy in patients with chronic mesenteric ischemia.

Mucosal pathology due to chronic mesenteric ischemia (CMI) is rarely seen during upper endoscopy. Combining Laser Doppler Flowmetry (LDF) and Visible Light Spectroscopy (VLS) may aid in detection of CMI at an early stage. We aimed to investigate the utility of LDF and VLS in detecting microcirculatory changes in patients with CMI during upper endoscopy. In a single center, prospective study, 104 patients were evaluated for mesenteric ischemia during a 24 months period. Patients with a consensus diagnosis of CMI (n = 40) were examined with LDF and VLS. Thirty-two were successfully treated and had a definitive diagnosis of CMI. Results were compared with controls (n = 38) with normal intestinal circulation evaluated with duplex ultrasonography (DUS). Treatment response was evaluated clinically and with DUS at 1 month and with VLS and LDF at 3 months. A significant reduction in mucosal capillary hemoglobin oxygen saturation (SO2) was found in CMI patients compared to controls before treatment: mean ± SD: 67 ± 9%, 81 ± 4%, respectively (p < .001). A significant reduction was also seen for the relative hemoglobin (rHb) amount, flow and velocity (p < .001). The sensitivity of SO2 measured by VLS for diagnosing CMI was 94% and the specificity 72% (cut-off 78%), calculated with ROC curve analysis. A combination of SO2 and rHb increased the test sensitivity and specificity to 97% and 79%, respectively. Conclusion: CMI patients have significantly reduced microcirculation in the stomach and duodenum compared to controls. The results suggest that VLS should be included when performing an upper endoscopy in patients with suspected CMI.

Trends in management and outcome of cystic pancreatic lesions - analysis of 322 cases undergoing surgical resection.

Background: Several guidelines for the management of cystic pancreatic lesions (CPL) exists. From 2013, Oslo University Hospital adapted the European consensus guidelines (ECG) in the decision-making as to whether patients should be advised to have resection or observation for CPL. The aims of the study were to assess changes over time in the workup and diagnostic accuracy of resected CPL, and the short-term surgical outcome. Methods: Preoperative radiological workup, clinicopathological characteristics, and perioperative outcomes were retrospectively reviewed in three consecutive time periods (early: 2004-2008, intermediate: 2009-2012, late: 2013-2016). The rate of concordance between the ECG recommendations for resection (ECG+) or observation (ECG-) and the final histological diagnosis were assessed. Results: A total of 322 consecutive patients underwent resection for CPL (early: n = 89, intermediate: n = 108, late: n = 125). The most common diagnoses were intraductal papillary mucinous neoplasia (IPMN, 36.0%), serous cystic neoplasm (SCN, 23.9%), mucinous cystic neoplasm (10.6%), pseudocyst (9.6%), solid pseudopapillary neoplasm (7.8%), and cystic pancreatic neuroendocrine tumour (5.3%). The proportion of ECG+ CPL undergoing surgery increased significantly (42.7% vs. 60.7% vs. 70.4%, p < .001). The relative proportion of patients undergoing resection for SCN decreased (38.2% vs. 21.3% vs. 16.0%), whereas it increased for IPMN (31.5% vs. 30.6% vs. 44.0%). The use of magnetic resonance imaging and endoscopic ultrasound increased. There were no differences in postoperative severe complications (23.0% vs. 23.6%) or 90-day mortality (2.3% vs. 0.8%) between ECG+ and ECG- patients. Conclusion: Several changes in the management of CPL were revealed during time. Adherence to guidelines is important in order to avoid unnecessary surgery for CPL.

Pancreatic MRI for the surveillance of cystic neoplasms: comparison of a short with a comprehensive imaging protocol.

OBJECTIVES: The study aims were to evaluate: (1) whether a short-protocol (SP) MRI for the surveillance of pancreatic cystic neoplasms (PCN) provides equivalent clinical information as a comprehensive-protocol (CP), and (2) the cost reduction from substituting CP with SP for patient surveillance. METHODS: This retrospective study included 154 consecutive patients (median age: 66, 52 % men) with working-diagnosis of PCN and available contrast-enhanced MRI/MRCP. Three radiologists evaluated independently two imaging sets (SP/CP) per patient. The CP included: T2-weighted (HASTE/MRCP), DWI and T1-weighted (chemical-shift/pre-/post-contrast) images [acquisition time (AT) ≈ 35 min], whereas the SP included: T2-weighted HASTE and T1-weighted pre-contrast images (AT ≈ 8 min). Mean values of largest cyst/main pancreatic duct diameter (DC/DMPD) were compared. Agreement regarding presence/absence of cystic/MPD mural nodules (MNC/MNMPD), inter-observer agreement and cost differences between SP/CP were calculated. RESULTS: For DC and DMPD, mean values with SP/CP were 21.4/21.7 mm and 3.52/3.58 mm, while mean differences SP-CP were 0.3 mm (p = 0.02) and 0.06 mm (p = 0.12), respectively. For presence/absence of MNC and MNMPD, SP/CP coincided in 93 % and 98 % of cases, respectively. Inter-observer agreement was strong for SP/CP. SP-cost was 25 % of CP-cost. CONCLUSIONS: For the surveillance of PCN, short-protocol MRI provides information equivalent to the more time-consuming and costly comprehensive-protocol. KEY POINTS: • Pancreatic cystic neoplasms (PCN) are increasingly diagnosed in the general population. • Multiple imaging controls are recommended for the surveillance of patients with PCN. • Short and comprehensive MRI-protocols are equivalent for decision-making in PCN under surveillance. • Evaluation of imaging risk factors in PCNs is comparable with both MRI-protocols. • Use of the short MRI-protocol may rationalise healthcare resources.

Opportunities of improvement in the management of pancreatic and periampullary tumors.

Abstract Objective. The first objective of the present study was to identify opportunities of improvement for clinical practice, assessed by local quality indicators, then to analyze possible reasons why we did not reach defined treatment quality measures. The second objective was to characterize patients, considered unresectable according to present criteria, for future arrangement of interventional studies with improved patient selection. Material and methods. Prospective observational cohort study from October 2008 to December 2010 of patients referred to the authors' institution with suspected pancreatic or periampullary neoplasm. Results. Of 330 patients, 135 underwent surgery, 195 did not, 129 due to unresectable malignancies. The rest had benign lesions. Perioperative morbidity rate was 32.6%, mortality 0.7%. Radical resection (R0) was obtained in 23 (41.8%) of 55 patients operated for pancreatic adenocarcinoma and 6.3% underwent reconstructive vascular surgery. Diagnostic failure/delay resulted in unresectable carcinoma, primarily misconceived as serous cystic adenoma in two patients. One resected lesion turned out to be focal autoimmune pancreatitis. One case with misdiagnosed cancer was revised to be a pseudoaneurysm. Palliative treatment was offered to 144 patients with malignant tumors, 62 due to locally advanced disease and all pancreatic adenocarcinomas. Conclusions. Quality improvement opportunities were identified for patient selection and surgical technique: Too few patients underwent reconstructive vascular surgery. The most important quality indicators are those securing resectional, radical (R0) surgery. Altogether 143 patients (57.9%) of those with malignant tumors were found unresectable, most of these patients are eligible for inclusion in future interventional studies with curative and/or palliative intention.

[A 68-year-old woman with iron deficiency anemia]. / En 68 år gammel kvinne med blødningsanemi.

A 68-year-old woman with iron deficiency anemia (due to gastrointestinal bleeding) was evaluated. Over a period of two years she received iron supplementation perorally and intravenously, as well as multiple blood transfusions, but the hemoglobin level did not exceed 10 g/dL. The investigations included upper endoscopy, duodenoscopy with side optical view, ileocolonoscopy, capsule endoscopy, antegrad single-balloon enteroscopy and conventional angiography of the abdominal vessels. Upper and lower endoscopies were performed repeatedly. The only consistent finding was linear erosions of the gastric mucosa in a large hiatal hernia at the level of the diaphragm. The association between large hiatal hernias and iron deficiency anemia was first described in the 1930s. The bleeding source is thought to be erosions or ulcerations in the hiatal hernia, as described by Cameron & Higgins in 1986. These lesions are analogous to the finding in our patient. The recognized treatment options are iron supplementation, proton pump inhibition and fundoplication. In our case we decided to start treatment with pantoprazole. Her hemoglobin level had normalized within an observational period of three months.