Towards Understanding the Origins of Quantum Indeterminism and Non-Local Quantum Jumps

By Invoking symmetry principle, we present a self-consistent interpretation of the existing quantum theory which explains why our world is fundamentally indeterministic and that why non-local quantum jumps occur. Symmetry principle dictates that the concept of probability is more fundamental than the notion of the wave function in that the former can be derived directly from symmetries rather than have to be assumed as an additional axiom. It is argued that the notion of quantum probability and that of the wavefunction are intimately connected.

Relativity of a Free Will Concept Depending on Both Conscious Indeterminism and Unconscious Determinism

Free will is difficult to classify with respect to determinism or indeterminism, and its phenomenology in consciousness often shows both aspects. Initially, it is felt as unlimited and indeterminate will power, with the potentiality of multiple choices. Thereafter, reductive deliberation is led by determinism to the final decision, which realises only one of the potential choices. The reductive deliberation phase tries to find out the best alternative and simultaneously satisfying vague motivations, contextual conditions and personal preferences. The essential sense of free will is the introduction of personal preferences, which allows a higher diversity of reactions to vague motivations. With an oversimplified model of determinism as a chain of events, incompatibilists define ＂free＂ as ＂undetermined＂ so that determinism becomes incompatible with any free choice between alternatives. In consciousness, free will requires a more complex model of network determinism as well as the consideration of unconsciousness as a causal factor. When ＂free＂ defined as ＂undetermined＂ is applied to the context of consciousness, it should be reinterpreted as ＂unconscious of being determined＂ or not aware of underlying determinism. Lacking information on determinism generates a feeling of ＂free＂ in consciousness and, therefore, gives the impression of indeterminism. Lacking information may be induced by an uncertain future without determined events--an unconscious past with biological reactions suddenly emerging from the unconsciousness or an unknown present unable to distinguish determinism of complex events. Therefore, at the level of human consciousness, the experience of free will is associated with apparent indeterminism although it is based on unconscious determinism. The concepts of compatibilism and incompatibilism are only two different aspects of the same phenomenon and correspond to consciousness and unconsciousness. Nevertheless, they can be considered together with a free will concept based on relativity depending on two different reference frames--the first person＇s experience frame or the Laplace＇s demon frame with knowledge on every molecule of the universe. Only relativity of the free will concept avoids the contradiction between ＂free＂ and ＂unfree＂ for the same phenomenon and could be a compromise for considering compatibilism and incompatibilism equally.

Heisenberg＇s Versus Von Neumann＇s Indeterminism of Quantum Mechanics

Irreducible indeterminism is considered by most physicists as an ontological interpretation of quantum mechanics, which attributes inherent indeterminism to elementary paJcticles. This view was extrapolated by von Neumann from the atomocosm to the entire universe. Heisenberg proposed an epistemic interpretation, postulating that indeterminism stems from ambivalent detection systems, rather than being a characteristic of elementary particles Transformative detection that inherently affects the measured phenomena is responsible for the indeterminism in the atomocosm. As the same does not generally hold true in the macrocosm, this discrepancy has led to the notion of the Heisenberg cut. As explained by Heisenberg＇s microscope example, high-energy light can displace electrons from their atomic shells in the atomocosm, but would not induce the same effect on objects in the macrocosm, thus rendering such detection neutral. Therefore, detection systems are ambivalent in that they can be transformative under the cut and neutral otherwise. Device variation is found under and above the cut and is the essential cause of outcome variability in the macrocosm. Thus, two completely different categories of indeterminism exist simultaneously under the Heisenberg cut, but only one is found above the cut, known as measurement variations of devices. Experimental exploration of elementary paJcticle behaviors is possible only with the help of detection systems. If these systems affect particle characteristics in any way, this would be sufficient to explain the irreducible quantum mechanical indeterminism. Consequently, the true behavior of elementary particles, whether indeterminist or determinist, would never be detectable. Above the cut, on the other hand, variations in device performance are inevitable, due to reducible perturbing factors, inducing measurement wJciation of devices Heisenberg discovered a general principle of ambivalent detection systems, which can also be found in the macrocosm. In the Wilson Cloud Chamber, vapor is an ambivalent detection system, since high-energy charged particles would produce straight tracks, whereas those of lower energy would leave an irregular trace. According to the epistemic interpretation, von Neumann＇s extrapolation of irreducible quantum mechanical indeterminism to the entire universe would not be necessary, thereby avoiding the uncomfortable conclusion that the entire universe is based on indeterminism

Deciding on a Measure of Effect under Indeterminism

Estimating causal effects is a principal goal in epidemiology and other branches of science. Nonetheless, what constitutes an effect and which measure of effect is pre-ferred are unsettled questions. I argue that, under indeterminism, an effect is a change in the tendency of the outcome variable to take each of its values, and then present a critical analysis of commonly used measures of effect and the measures of frequency from which they are calculated. I conclude that all causal effects should be quantified using a unifying measure of effect called the log likelihood ratio (which is the log probability ratio when the outcome is a discrete variable). Furthermore, I suggest that effects should be estimated for all causal contrasts of the causal variable (i.e., expo-sure), on all values of the outcome variable, and for all time intervals between the cause and the outcome. This goal should be kept in mind in practical approximations.

The outcomes and safety of patients undergoing endoscopic retrograde cholangiopancreatography combining a single-use cholangioscope and a single-use duodenoscope:A multicenter retrospective international study

Background: Duodenoscope-related multidrug-resistant organism(MDRO) infections raise concerns. Disposable duodenoscopes have been recently introduced in the market and approved by regulatory agencies with the aim to reduce the risk of endoscopic retrograde cholangiopancreatography(ERCP) associated infections. The aim of this study was to evaluate the outcome of procedures performed with single-use duodenoscopes in patients with clinical indications to single-operator cholangiopancreatoscopy. Methods: This is a multicenter international, retrospective study combining all patients who underwent complex biliopancreatic interventions using the combination of a single-use duodenoscope and a single-use cholangioscope. The primary outcome was technical success defined as ERCP completion for the intended clinical indication. Secondary outcomes were procedural duration, rate of cross-over to reusable duodenoscope, operator-reported satisfaction score(1 to 10) on performance rating of the single-use duodenoscope, and adverse event(AE) rate. Results: A total of 66 patients(26, 39.4% female) were included in the study. ERCP was categorized according to ASGE ERCP grading system as 47(71.2%) grade 3 and 19(28.8%) grade 4. The technical success rate was 98.5%(65/66). Procedural duration was 64(interquartile range 15-189) min, cross-over rate to reusable duodenoscope was 1/66(1.5%). The satisfaction score of the single-use duodenoscope classified by the operators was 8.6 ± 1.3 points. Four patients(6.1%) experienced AEs not directly related to the single-use duodenoscope, namely 2 post-ERCP pancreatitis(PEP), 1 cholangitis and 1 bleeding.Conclusions: Single-use duodenoscope is effective, reliable and safe even in technically challenging procedures with a non-inferiority to reusable duodenoscope, making these devices a viable alternative to standard reusable equipment.

Wave propagation of a functionally graded plate via integral variables with a hyperbolic arcsine function

Several studies on functionally graded materials(FGMs)have been done by researchers,but few studies have dealt with the impact of the modification of the properties of materials with regard to the functional propagation of the waves in plates.This work aims to explore the effects of changing compositional characteristics and the volume fraction of the constituent of plate materials regarding the wave propagation response of thick plates of FGM.This model is based on a higher-order theory and a new displacement field with four unknowns that introduce indeterminate integral variables with a hyperbolic arcsine function.The FGM plate is assumed to consist of a mixture of metal and ceramic,and its properties change depending on the power functions of the thickness of the plate,such as linear,quadratic,cubic,and inverse quadratic.By utilizing Hamilton’s principle,general formulae of the wave propagation were obtained to establish wave modes and phase velocity curves of the wave propagation in a functionally graded plate,including the effects of changing compositional characteristics of materials.

The IDD Transcription Factors:Their Functions in Plant Development and Environmental Response

INDETERMINATE-DOMAIN proteins(IDDs)are a plant-specific transcription factor family characterized by a conserved ID domain with four zinc finger motifs.Previous studies have demonstrated that IDDs coordinate a diversity of physiological processes and functions in plant growth and development,including floral transition,plant architecture,seed and root development,and hormone signaling.In this review,we especially summarized the latest knowledge on the functions and working models of IDD members in Arabidopsis,rice,and maize,particularly focusing on their role in the regulatory network of biotic and abiotic environmental responses,such as gravity,temperature,water,and pathogens.Understanding these mechanisms underlying the function of IDD proteins in these processes is important for improving crop yields by manipulating their activity.Overall,the review offers valuable insights into the functions and mechanisms of IDD proteins in plants,providing a foundation for further research and potential applications in agriculture.

Overall clinical course of indeterminate dendritic cell tumor patients without skin lesions:A rare case report

BACKGROUND Indeterminate dendritic cell tumor(IDCT)is a rare tumor of immune cells,and IDCT patients without skin lesions are rarely reported.Therefore,the clinical course in this type of patient is unclear,and further research on the underlying pathological mechanisms and appropriate treatments is needed.CASE SUMMARY This study describes a female IDCT patient with bile duct lesions.The strong mimicry of IDCT lesions confused doctors,and consequently,this patient,who had no skin lesions,was first diagnosed with cholangiocarcinoma.Then,she presented with persistent abdominal distension without jaundice.Enlarged mesenteric lymph nodes along with massive ascites were observed in the subsequent imaging examination.However,no tumor cells or pathogens were found in the three subsequent ascites analyses.It took 2 years to reach the correct diagnosis,which was eventually obtained by performing surgery for biopsy of the patient’s abdominal lymph nodes.However,by then,she was already in a cachexic state.Finally,she received a cycle of cyclophosphamide therapy and was advised to visit a hospital specializing in rare diseases.CONCLUSION For IDCT patients without skin lesions,early biopsy is the key to obtaining a correct diagnosis.Moreover,the collective management of IDCT patients is important.Further histological and molecular biology studies based on human specimens are critical for understanding the pathological mechanism of dendritic cell tumors in the future.

Liver histological changes in untreated chronic hepatitis B patients in indeterminate phase

BACKGROUND Studies with large size samples on the liver histological changes of indeterminate phase chronic hepatitis B(CHB)patients were not previously conducted.AIM To assess the liver histological changes in the indeterminate phase CHB patients using liver biopsy.METHODS The clinical and laboratory data of 1532 untreated CHB patients were collected,and all patients had least once liver biopsy from January 2015 to December 2021.The significant differences among different phases of CHB infection were compared with t-test,and the risk factors of significant liver histological changes were analyzed by the multivariate logistic regression analysis.RESULTS Among 1532 untreated CHB patients,814(53.13%)patients were in the indeterminate phase.Significant liver histological changes(defined as biopsy score≥G2 and/or≥S2)were found in 488/814(59.95%)CHB patients in the indete-rminate phase.Significant liver histological changes were significant differences among different age,platelets(PLTs),and alanine aminotransferase(ALT)subgroup in indeterminate patient.Multivariate logistic regression analysis indicated that age≥40 years old[adjust odd risk(aOR),1.44;95%confidence interval(CI):1.06-1.97;P=0.02],PLTs≤150×10^(9)/L(aOR,2.99;95%CI:1.85-4.83;P<0.0001),and ALT≥upper limits of normal(aOR,1.48;95%CI:1.08,2.05,P=0.0163)were independent risk factors for significant liver histological changes in CHB patients in the indeterminate phase.CONCLUSION Our results suggested that significant liver histological changes were not rare among the untreated CHB patients in indeterminate phase,and additional strategies are urgently required for the management of these patients.

Still elusive: Developments in the accurate diagnosis of indeterminate biliary strictures

Indeterminate biliary strictures pose a significant diagnostic dilemma for gastroenterologists.Despite advances in endoscopic techniques and instruments,it is difficult to differentiate between benign and malignant pathology.A positive histological diagnosis is always preferred prior to high risk hepatobiliary surgery,or to inform other types of therapy.Endoscopic retrograde cholangiopancreato-graphy with brushings has low sensitivity and despite significant improvements in instruments there is still an unacceptably high false negative rate.Other methods such as endoscopic ultrasound and cholangioscopy have improved diagnostic quality.In this review we explore the techniques available to aid accurate diagnosis of indeterminate biliary strictures and obtain accurate histology to facilitate clinical management.

Clinical approach to indeterminate biliary strictures:Clinical presentation,diagnosis,and workup

Despite advances in cross-sectional imaging and endoscopic technology,bile duct strictures remain a challenging clinical entity.It is crucial to make an early determination of benign or malignant nature of biliary strictures.Early diagnosis not only helps with further management but also minimizes mortality and morbidity associated with delayed diagnosis.Conventional imaging and endoscopic techniques,particularly endoscopic retrograde cholangiopancreatography(ERCP)and tissue sampling techniques play a key in establishing a diagnosis.Indeterminate biliary strictures(IDBSs)have no definite mass on imaging or absolute histopathological diagnosis and often warrant utilization of multiple diagnostics to ascertain an etiology.In this review,we discuss possible etiologies,clinical presentation,diagnosis,and management of IDBSs.Based on available data and expert opinion,we depict an evidence based diagnostic algorithm for management of IDBSs.Areas of focus include use of traditional tissue sampling techniques such as ERCP with brush cytology,intraductal biopsies,fluorescence in situ hybridization and flow cytometry.We also describe the role of endoscopic ultrasound(EUS)-guided fine needle aspiration and biopsies,cholangioscopy,confocal laser endomicroscopy,and intraductal EUS in management of IDBSs.

Lowering the threshold of alanine aminotransferase for enhanced identification of significant hepatic injury in chronic hepatitis B patients

BACKGROUND The clinical and histological features of chronic hepatitis B(CHB)patients who fall into the"grey zone(GZ)"and do not fit into conventional natural phases are unclear.AIM To explore the impact of varying the threshold of alanine aminotransferase(ALT)levels in identifying significant liver injury among GZ patients.METHODS This retrospective analysis involved a cohort of 1617 adult patients diagnosed with CHB who underwent liver biopsy.The clinical phases of CHB patients were determined based on the European Association for the Study of the Liver 2017 Clinical Practice Guidelines.GZ CHB patients were classified into four groups:GZ-A(HBeAg positive,normal ALT levels,and HBV DNA≤10^(7) IU/mL),GZ-B(HBeAg positive,elevated ALT levels,and HBV DNA<10^(4) or>10^(7) IU/mL),GZC(HBeAg negative,normal ALT levels,and HBV DNA≥2000 IU/mL),and GZ-D(HBeAg negative,elevated ALT levels,and HBV DNA≤2000 IU/mL).Significant hepatic injury(SHI)was defined as the presence of notable liver inflammation(≥G2)and/or significant fibrosis(≥S2).RESULTS The results showed that 50.22%of patients were classified as GZ,and 63.7%of GZ patients developed SHI.The study also found that lowering the ALT treatment thresholds to the American Association for the Study of Liver Diseases 2018 treatment criteria(35 U/L for men and 25 U/L for women)can more accurately identify patients with significant liver damage in the GZ phases.In total,the proportion of patients with ALT≤40 U/L who required antiviral therapy was 64.86%[(221+294)/794].When we lowered the ALT treatment threshold to the new criteria(30 U/L for men and 19 U/L for women),the same outcome was revealed,and the proportion of patients with ALT≤40 U/L who required antiviral therapy was 75.44%[(401+198)/794].Additionally,the proportion of SHI was 49.1%in patients under 30 years old and increased to 55.3%in patients over 30 years old(P=0.136).CONCLUSION These findings suggest the importance of redefining the natural phases of CHB and using new ALT treatment thresholds for better diagnosis and management of CHB patients in the GZ phases.

Role of artificial intelligence in the characterization of indeterminate pancreatic head mass and its usefulness in preoperative diagnosis

Artificial intelligence(AI)has been used in various fields of day-to-day life and its role in medicine is immense.Understanding of oncology has been improved with the introduction of AI which helps in diagnosis,treatment planning,management,prognosis,and follow-up.It also helps to identify high-risk groups who can be subjected to timely screening for early detection of malignant conditions.It is more important in pancreatic cancer as it is one of the major causes of cancer-related deaths worldwide and there are no specific early features(clinical and radiological)for diagnosis.With improvement in imaging modalities(computed tomography,magnetic resonance imaging,endoscopic ultrasound),most often clinicians were being challenged with lesions that were difficult to diagnose with human competence.AI has been used in various other branches of medicine to differentiate such indeterminate lesions including the thyroid gland,breast,lungs,liver,adrenal gland,kidney,etc.In the case of pancreatic cancer,the role of AI has been explored and is still ongoing.This review article will focus on how AI can be used to diagnose pancreatic cancer early or differentiate it from benign pancreatic lesions,therefore,management can be planned at an earlier stage.

The Origin of Nonlinear Dynamics Involving Complexity in Modern Sciences

This paper reveals the origin of nonlinear dynamics and presents a solution for nonlinear systematic problems based on other science. Generally, physical phenomena are divided into linear static logical problems and nonlinear dynamic systematic problems, but all scientists have solved both problems using the same algebraic logical solution in statistical physics based on determinism such as chaos theory. Surprisingly, this is a contradiction and a serious mistake because there is a perfect solution such as the system analysis theory existing in other science. Unfortunately, it has developed in the 20th century by engineers. Thus, classical physicists could not solve it. Meanwhile, the author achieved the systematic solution for many unsolved nonlinear systematical, further, proved the research result through simulation using specially designed simulation device. Thus, this is a revolutionary achievement because it can easily solve the unsolved nonlinear dynamics that exists in all fields of science. Ironically most determinists do not welcome and reject it. However, it has no matter, it will be separated from current physics and other scientists studied it in the second physics. Therefore, it would be contributed to solve the unsolved nonlinear dynamics in complex science.

Why Free Will Is Logically Not Possible within Naturalism

One of the most intriguing problems of philosophy and of mankind is the question whether humans have a free will. This question is heavily disputed between natural scientists and especially neuroscientists, who deny free will, and philosophers and other groups, who insist on free will. It is perplexing that both sides base their premise on the same precondition, namely naturalism. We will prove that naturalism automatically leads to physicalism, to materialism, and to reductionism. We will also prove here that it is logically not possible to have a free will if naturalism is true. Free will definitely requires an additional substance, a non-material soul, which cannot be part of our universe. This must not be in contradiction to our current knowledge of natural sciences.

Role of digital single-operator cholangioscopy in the diagnosis and treatment of biliary disorders

Due to the need for improvement in the diagnosis and minimally invasive therapy of the bile duct disorders new technologies for cholangioscopy have been recently developed. Per-oral cholangioscopy has become an important diagnostic and therapeutic tool leading to avoidance of aggressive and unnecessary surgery in many clinical scenarios. This paper focuses on the newly developed SpyGlass DS technology, its advantages, and the technique of single-operator cholangioscopy(SOC), biliary indications and possible adverse events. We also review the available literature; discuss the limitations and future expectations.Digital SOC(D-SOC) is a useful technique, which provides endoscopic imaging of the biliary tree, optical diagnosis, biopsy under direct vision and therapeutic interventions. The implementations are diagnostic and therapeutic. Diagnostic indications are indeterminate biliary strictures, unclear filling defects, staging of cholangiocarcinoma, staging of ampullary tumors(extension into the common bile duct), unclear bile duct dilation, exploring cystic lesions of the biliary tree,unexplained hemobilia, posttransplant biliary complications. Therapeutic indications are lithotripsy of difficult stones, retrieval of migrated stents, foreign body removal, guide wire placement, transpapillary gallbladder drainage and endoscopic tumor ablative therapy. Most studied and established indications are the diagnosis of indeterminate biliary stricture and intraductal lithotripsy of difficult stones. The adverse events are not different and more common compared to those of Endoscopic retrograde cholangiopancreatography(ERCP)alone. D-SOC is a safe and effective procedure, adjunct to the standard ERCP and the newly available digital technology overcomes many of the limitations of the previous generations of cholangioscopes.

Indeterminate pulmonary nodules in colorectal cancer

AIM:To investigate the clinicopathologic parameters of pulmonary metastasis in colorectal cancer(CRC) patients after lung operation of indeterminate pulmonary nodules(IPNs).METHODS:From a prospective database of CRCpatients,40 cases that underwent lung operation between November 2008 and December 2012 for suspicious metastatic pulmonary nodules on chest computed tomography(CT)were enrolled.The decision to perform a lung operation was made if the patient met the following criteria:(1)completely resected or resectable primary CRC;(2)completely resectable IPNs;(3)controlled or controllable extrapulmonary metastasis;and(4)adequate general condition and pulmonary function to tolerate pulmonary operation.Lung operation was performed by a thoracic surgeon without CT-guided biopsy for pathologic confirmation.RESULTS:A total of 40 cases of lung resection was performed in 29 patients.Five patients underwent repeated lung resection.The final pathology result showed metastasis from the CRC in 30 cases(75%)and benign pathology in 10 cases(25%).The primary tumor site was the rectum in 26/30(86.6%)cases with pulmonary metastasis,but only 3/10(30%)cases in the benign group had a primary rectal cancer(P=0.001).Positron emission tomography(PET)-CT was performed for 22/30(73.4%)patients in the lung metastasis group and for 6/10(60.0%)patients in the benign group.PET-CT revealed hot uptake of18fluorine 2-fluoro-2-deoxy-D-glucose with all IPNs in both groups.The group with pulmonary metastasis had a higher incidence of primary rectal cancer(P=0.001),a more advanced tumor stage(P=0.011),and more frequent lymphatic invasion of tumor cells(P=0.005).Six cases with previous liver metastasectomy were present in the lung metastasis group.Serum carcinoembryonic antigen levels before lung operation were not elevated in any of the patients.CONCLUSION:The stage and location of the primary tumor and tumor cell infiltration of lymphatics provide useful indicators for deciding on lung resection of IPNs in CRC.

Gastrointestinal endoscopy biopsy derived proteomic patterns predict indeterminate colitis into ulcerative colitis and Crohn's colitis

Patients with indeterminate colitis(IC) are significantly younger at diagnosis with onset of symptoms before the age of 18 years with significant morbidity in the interim. The successful care of IC is based on microscopic visual predict precision of eventual ulcerative colitis(UC) or Crohn's colitis(CC) which is not offered in 15%-30% of inflammatory bowel disease(IBD) patients even after a combined state-of-the-art classification system of clinical, visual endoscopic, radiologic and histologic examination. These figures have not changed over the past 3 decades despite the introduction of newer diagnostic modalities. The patient outcomes after restorative proctocolectomy and ileal pouch-anal anastomosis may be painstaking if IC turns into CC. Our approach is aiming at developing a single sensitive and absolute accurate diagnostic test tool during the first clinic visit through endoscopic biopsy derived proteomic patterns. Matrix-assisted-laser desorption/ionization mass spectrometry(MS) and/or imaging MS technologies permit a histology-directed cellular test of endoscopy biopsy which identifies phenotype specific proteins, as biomarker that would assist clinicians more accurately delineate IC as beingeither a UC or CC or a non-IBD condition. These novel studies are underway on larger cohorts and are highly innovative with significances in differentiating a UC from CC in patients with IC and could lend mechanistic insights into IBD pathogenesis.

Endoscopic ultrasonography can diagnose distal biliary strictures without a mass on computed tomography

AIM:To assess the diagnostic ability of endoscopic ultrasonography(EUS)for evaluating causes of dista biliary strictures shown on endoscopic retrograde chol angiopancreatography(ERCP)or magnetic resonance cholangiopancreatography(MRCP),even without iden tifiable mass on computed tomography(CT). METHODS:The diagnostic ability of EUS was retro spectively analyzed and compared with that of routine cytology(RC)and tumor markers in 34 patients with distal biliary strictures detected by ERCP or MRCP a Dokkyo Medical School Hospital from December 2005 to December 2008,without any adjacent mass or ec centric thickening of the bile duct on CT that could cause biliary strictures.Findings considered as benign strictures on EUS included preservation of the normasonographic layers of the bile duct wall,irrespective of the presence of a mass lesion.Other strictures were considered malignant.Final diagnosis of underlying diseases was made by pathological examination in 18 cases after surgical removal of the samples,and by clinical follow-up for>10 mo in 16 cases. RESULTS:Seventeen patients(50%)were finally di- agnosed with benign conditions,including 6"normal" subjects,while 17 patients(50%)were diagnosed with malignant disease.In terms of diagnostic ability,EUS showed 94.1%sensitivity,82.3%specificity,84.2% positive predictive value,93.3%negative predictive value(NPV)and 88.2%accuracy for identifying ma- lignant and benign strictures.EUS was more sensi- tive than RC(94.1%vs 62.5%,P=0.039).NPV was also better for EUS than for RC(93.3%vs 57.5%,P= 0.035).In addition,EUS provided significantly higher sensitivity than tumor markers using 100 U/mL as the cutoff level of carbohydrate antigen 19-9(94.1%vs 53%,P=0.017).On EUS,biliary stricture that was fi- nally diagnosed as malignant showed as a hypoechoic, irregular mass,with obstruction of the biliary duct and invasion to surrounding tissues. CONCLUSION:EUS can diagnose biliary strictures caused by malignant tumors that are undetectable on CT.Earlier detection by EUS would provide more therapeutic options for patients with early-stage pancreaticobiliary cancer.

Current endoscopic approach to indeterminate biliary strictures

Biliary strictures are considered indeterminate when basic work-up, including transabdominal imaging and endoscopic retrograde cholangiopancreatography with routine cytologic brushing, are non-diagnostic. Indeterminate biliary strictures can easily be mischaracterized which may dramatically affect patient's outcome. Early and accurate diagnosis of malignancy impacts not only a patient's candidacy for surgery, but also potential timely targeted chemotherapies. A significant portion of patients with indeterminate biliary strictures have benign disease and accurate diagnosis is, thus, paramount to avoid unnecessary surgery. Current sampling strategies have suboptimal accuracy for the diagnosis of malignancy. Emerging data on other diagnostic modalities, such as ancillary cytology techniques, single operator cholangioscopy, and endoscopic ultrasonography-guided fine needle aspiration, revealed promising results with much improved sensitivity.