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Objective Abnormal aggregation of tau in the brain is a major contributing factor in various neurodegenerative diseases. Florzolotau (18F) (florzolotau, APN-1607, PM-PBB3) has been shown to be a probe for tau fibrils in an animal model and patients with Alzheimer’s disease and those with non-Alzheimer’s disease tauopathies. The objective of this study is to evaluate the safety, pharmacokinetics, and radiation dose following a single intravenous administration of florzolotau in healthy Japanese subjects. Methods Three healthy male Japanese subjects aged between 20 and 64 were enrolled in this study. Subjects were determined to be eligible based on the screening assessments at the study site. Subjects received a single intravenous dose of 195.0 ± 0.5 MBq of florzolotau and underwent the whole-body PET scan 10 times in total to calculate absorbed doses to major organs/tissues and effective dose. Radioactivities in whole blood and urine were also measured for pharmacokinetic evaluation. Absorbed doses to major organs/tissues and effective dose were estimated using the medical internal radiation dose (MIRD) method. Vital signs, electrocardiography (ECG), and blood tests were done for safety evaluation. Results The intravenous injection of florzolotau was well tolerated. There were no adverse events or clinically detectable pharmacologic effects related to the tracer in any subjects. No significant changes in vital signs and ECG were observed. The highest mean initial uptake at 15 min after injection was in the liver (29.0 ± 4.0%ID), intestine (4.69 ± 1.65%ID), and brain (2.13 ± 0.18%ID). The highest absorbed dose was 508 μGy/MBq of the gallbladder wall, followed by the liver of 79.4 μGy/MBq, the pancreas of 42.5 μGy/MBq, and the upper large intestine of 34.2 μGy/MBq. The effective dose was calculated as 19.7 μSv/MBq according to the tissue weighting factor reported by ICRP-103. Conclusion Florzolotau intravenous injection was well tolerated in healthy male Japanese subjects. The effective dose was determined as 3.61 mSv when 185 MBq florzolotau was given.

Background: Studies using animal experiments have shown secondary neuronal degeneration in the thalamus after cerebral infarction. Neuroimaging studies in humans have revealed changes in imaging parameters in the thalamus, remote to the infarction. However, few studies have directly demonstrated neuronal changes in the thalamus in vivo. The purpose of this study was to determine whether secondary thalamic neuronal damage may manifest as a decrease in central benzodiazepine receptors in patients with cerebral infarction and internal carotid artery or middle cerebral artery disease. Methods: We retrospectively analyzed the data of 140 patients with unilateral cerebral infarction ipsilateral to internal carotid artery or middle cerebral artery disease. All patients had quantitative measurements of 11 C-flumazenil binding potential (FMZ-BP), cerebral blood flow, and cerebral metabolic rate of oxygen using positron emission tomography in the chronic stage. Region of interest analysis was performed using NeuroFlexer—an automated region of interest analysis software using NEUROSTAT. Results: In the thalamus ipsilateral to the infarcts, the values of FMZ-BP, cerebral blood flow, and cerebral metabolic rate of oxygen were significantly lower than those in the contralateral thalamus. Significant correlations were found between the ipsilateral-to-contralateral ratio of FMZ-BP and the ipsilateral-to-contralateral ratio of cerebral blood flow or cerebral metabolic rate of oxygen in the thalamus. Patients with corona radiata infarcts and striatocapsular infarcts had significantly decreased ipsilateral-to-contralateral FMZ-BP ratio in the thalamus compared with those without. The ipsilateral-to-contralateral ratio of FMZ-BP in the thalamus was significantly correlated with the ipsilateral-to-contralateral cerebral metabolic rate of oxygen ratio in the frontal cortex and showed a significant negative correlation with the number of perseverative errors on the Wisconsin Card Sorting Test. Conclusions: Secondary thalamic neuronal damage may manifest as a decrease in central benzodiazepine receptors in patients with cerebral infarction and internal carotid artery or middle cerebral artery disease, which may be associated with frontal lobe dysfunction.

Background: Studies using animal models have shown that cerebral hypoperfusion causes hyperphosphorylation of tau protein, leading to neuronal damage. However, the relationship between hypoperfusion and tau deposition in humans is unclear. Hence, we aimed to determine whether cerebral hypoperfusion leading to decreased blood flow relative to metabolic demand [increased oxygen extraction fraction (OEF), misery perfusion] is associated with increased tau deposition in patients with atherosclerotic internal carotid artery or middle cerebral artery disease. Methods: We prospectively evaluated the distribution of tau aggregate deposition using positron emission tomography and 18 F-florzolotau (PMPBB3 [1-fluoro-3-((2-((1E,3E)-4-(6-(methylamino)pyridine-3-yl)buta-1,3-dien-1-yl)benzo[d]thiazol-6-yl)oxy)propan-2-ol)]) in 8 patients with atherosclerotic disease of the internal carotid artery or middle cerebral artery. The standardized uptake value ratio of 18 F-florzolotau at 100 to 110 minutes after injection was calculated using the cerebellar cortex as a reference region and was correlated with OEF obtained from 15 O-gas positron emission tomography in the middle cerebral artery distributions. Results: Significant decreases in cerebral blood flow and cerebral metabolic rate of oxygen and increases in OEF were found in the hemisphere ipsilateral to the arterial lesion. 18 F-florzolotau standardized uptake value ratio in this region was also greater than that in the contralateral hemisphere. In the ipsilateral hemisphere, 18 F-florzolotau standardized uptake value ratio positively correlated with OEF values. Conclusions: This pilot study with a small sample size suggests that increases in OEF–misery perfusion–may be associated with increased tau aggregates deposition in atherosclerotic internal carotid artery or middle cerebral artery disease.

Alcohol flushing reaction (AFR) is known as one of the risks for esophageal squamous cell cancer, and scientists have been elucidating this issue. However, little attention has been given to relevant imaging features. This study aims to investigate whether physiological 18F-fluorodeoxyglucose (FDG) uptake patterns in vertebrae are associated with drinking habits or AFR. Japanese male patients who underwent FDG positron emission computed tomography for evaluation of their known or suspected malignancies or inflammatory diseases were asked about their drinking habits and AFR. Altogether, 192 patients, 139 every-day drinkers and 53 non-drinkers were evaluated. Comparing the FDG uptake between that in the thoracic region and that in the lumbar region, vertebral uptake was visually classified into four patterns: Ld, dominant in lumbar region; TL, almost equal in both regions; BL, slightly higher in thoracic region (borderline pattern); Td, dominant in thoracic region. The uptake patterns were evaluated according to drinking habit (every-day drinker or non-drinker), AFR (flusher or non-flusher), and the combination of these two factors (habit/reaction: every-day drinker/flusher, every-day drinker/non-flusher, non-drinker/flusher, or non-drinker/non-flusher). There were 95 flushers (51 every-day drinkers and 44 non-drinkers) and 97 non-flushers (88 every-day drinkers and 9 non-drinkers). Ld, TL, BL, and Td patterns were observed in 0, 109 (56.8%), 31 (16.1%), and 52 (27.1%) patients, respectively. Td and BL patterns were more frequently observed in every-day drinkers compared with non-drinkers (p = 0.0467). Though the uptake patterns did not differ between flushers and non-flushers (p = 0.116), the Td pattern was more frequently observed in every-day drinkers/flushers (51%) compared with every-day drinkers/non-flushers (20.5%), non-drinkers/flushers (13.6%), and non-drinkers/non-flushers (22.2%) (p = 0.0014). The Td pattern was observed in patients with various diseases, with higher frequency in esophageal cancer, head and neck cancer, and lung cancer compared with other diseases. In conclusion, drinking habits and AFR were related to the vertebral uptake pattern with decreased uptake in the lumbar region in Japanese male patients.

Stone removal using endoscopic papillary large balloon dilation (EPLBD) is extremely effective. However, limited research exists regarding the risk factors for perforation of the duodenal papilla and bile duct, which may be fatal. We aimed to investigate the risk factors for perforation during EPLBD + stone removal. We included patients who underwent EPLBD + stone removal at four medical facilities between January 2008 and December 2018. We retrospectively analyzed the risk factors for perforation and their relationship between overdilation and adverse events. Overdilation was defined as a ratio of the balloon diameter to the diameter of the bile duct that exceeded 100%. The diameter of the distal bile duct was measured using the diameter of the intrapancreatic bile duct at a point 10 mm toward the liver from the narrow distal segment on a cholangiogram. We included 310 patients (177 males; median age: 79 years [range: 46–102 years]). Perforation occurred in five patients (1.6%). Multivariate analysis indicated that no surrounding-pancreas (half or less of the circumference of the intrapancreatic bile duct was surrounded by the pancreatic parenchyma) was a significant risk factor (perforation rate: 8.3%, p = 0.011, odds ratio: 12.7 [95% confidence interval: 1.8–90.5]). No significant difference was found between the overdilation and non-overdilation groups regarding the occurrence of pancreatitis, bleeding, and cholangitis. Perforation rate in patients with no surrounding pancreas + overdilation was 16.7% (2/12). Patients with perforation underwent conservative therapy, which improved their conditions. EPLBD + stone removal should be avoided in patients with no surrounding pancreas. Overdilation is not a risk factor for adverse procedural events; however, it should be limited in patients with surrounding pancreas.

A schwannoma is a tumor originating from Schwann cells. It is occasionally observed in the abdominal viscera in the form of a submucosal tumor derived from the gastric or duodenal muscularis propria. To date, only a few studies have reported on pancreatic schwannomas. Furthermore, very few patients are preoperatively diagnosed with pancreatic schwannoma because of the lack of established imaging characteristics distinguishing this type of schwannoma from other conditions. We herein report the first English publication of pancreatic schwannoma in which surgery was avoided because a pathological diagnosis was made solely on the basis of endoscopic ultrasound-guided fine-needle aspiration findings.

We study a simple, self-dual, rational, and C 2 -cofinite vertex operator algebra of CFT-type whose simple current modules are graded by Z 2 k . Based on those simple current modules, a vertex operator algebra associated with a Z 2 k -code is constructed. The classification of irreducible modules for such a vertex operator algebra is established. Furthermore, all the irreducible modules are realized in a module for a certain lattice vertex operator algebra.

We herein report the first case of metastatic pancreatic leiomyosarcoma derived from the urinary bladder diagnosed by an endoscopic ultrasound-guided fine-needle biopsy (EUS-FNB) in a 65-year-old woman. The patient had undergone total cystectomy for bladder leiomyosarcoma. Four years thereafter, a nodule was observed in her left lung on chest computed tomography. Suspecting primary lung cancer, pulmonologists at our hospital recommended a thoracoscopic lung biopsy, which the patient refused. Five years post-cystectomy, fluorodeoxyglucose positron emission tomography revealed enlargement of the left lung nodule and a new mass in the pancreatic head. She was referred to our department for the pathological diagnosis of a pancreatic head mass by an EUS-FNB. The EUS-FNB yielded adequate pancreatic tissue for an immunohistochemical analysis. A diagnosis of metastatic pancreatic lesion originating from the urinary bladder was made. In atypical pancreatic tumors, the utilization of an EUS-FNB and immunohistochemical analysis can help establish an accurate diagnosis.

BACKGROUND Information on whether a fine-needle biopsy (FNB) needle can improve histopathological specimen quality or the amount of core tissue collected in the diagnosis of subepithelial lesions (SELs) remains insufficient. In this study, we aimed to compare the procedure outcomes and adequacy of histopathological specimens of fine-needle aspiration (FNA) and FNB needles in endoscopic ultrasound-guided tissue acquisition (EUS-TA) using sample isolation processing by stereomicroscopy (SIPS) in patients with SELs. METHODS We performed a retrospective comparison of SEL cases registered in two previously conducted prospective studies. Of 61 cases, we identified 56 cases of SELs that involved the muscularis propria layer. Of these, 27 patients who underwent EUS-TA using a 22-gauge FNA needle between July 2016 and December 2017, and 29 patients who underwent the procedure using a 22-gauge FNB needle between March 2018 and January 2019 were included in the FNA and FNB group, respectively. RESULTS Patient background characteristics did not differ between the groups. The technical success rate was 100% in both groups. The median adequacy score was significantly higher in the FNB group than in the FNA group (P

Endoscopic retrograde cholangiopancreatography (ERCP) is associated with complications such as post-ERCP pancreatitis (PEP). Protease inhibitors, including nafamostat mesylate (NM), have been evaluated for prophylaxis against PEP. We describe the first multicenter randomized controlled trial assessing the prophylactic efficacy of NM against PEP. In this multicenter prospective study, we aimed to enroll 800 patients aged ≥ 20 years with a planned ERCP between December 2012 and March 2019. The primary outcome was the incidence and severity of PEP in patients who did not receive NM (non-NM) versus those who did (NM; 20 mg). Secondary outcomes included the incidence of PEP by NM initiation (pre- and post-ERCP), risk factors for PEP, and NM-related adverse events. Only 441 of the planned 800 patients were enrolled (non-NM: n = 149; NM: n = 292 [pre-ERCP NM: n = 144; post-ERCP NM: n = 148]). Patient characteristics were balanced at baseline with no significant differences between groups. PEP occurred in 40/441 (9%) patients (non-NM: n = 15 [10%]; NM: n = 25 [9%]), including 17 (12%) and eight (8%) in the pre-ERCP and post-ERCP NM groups, respectively. In the NM group, the incidence of PEP was lower in the low-risk group than in the high-risk group. Pancreatic injection and double-guidewire technique were independent risk factors for PEP. NM-related adverse events of hyperkalemia occurred in two (0.7%) patients. We found no evidence for the prophylactic effect of NM against PEP, regardless of the timing of administration; however, further studies are needed.

Aim Amyloid-β (Aβ) accumulation, accelerated by traumatic brain injury (TBI), may play a crucial role in neurodegeneration in chronic-stage TBI. The injury type could influence Aβ dynamics because of TBI's complex, heterogeneous nature. We, therefore, investigated spatial patterns of amyloid deposition according to injury type after TBI using 5-(5-(2-(2-(2-[F]-fluoroethoxy)ethoxy)ethoxy)benzofuran-2-yl)-N-methylpyridin-2-amine (18F-FPYBF-2) positron emission tomography (PET). Methods Altogether, 20 patients with chronic TBI [12 with focal injury, 8 with diffuse axonal injury (DAI)] underwent 18F-FPYBF-2 PET, structural magnetic resonance imaging (MRI), and neuropsychological examination. Additionally, 50 healthy controls underwent either 18F-FPYBF-2 PET (n=30) or structural MRI (n=20). Results Standardized uptake value ratio (SUVR) on PET images and regional brain volumes were measured in four cortical (frontal, parietal, occipital, temporal) and subcortical (combined caudate, putamen, pallidum, thalamus) regions. Patients with DAI showed significantly increased (compared with controls) SUVR in occipital and temporal cortices and decreased brain volume in occipital cortex (corrected p < 0.05). Although patients with focal injury showed decreased SUVR in all regions except occipital cortex, there were no significant differences (compared with controls) in the SUVR in any regions. There were no significant correlations between increased SUVR and neuropsychological impairments in patients with DAI. Conclusion Varying spatial patterns of amyloid deposition suggest amyloid pathology diversity depending on the injury type in chronic-TBI patients.

We study simple current extensions of tensor products of two vertex operator algebras satisfying certain conditions. We establish the relationship between the fusion rule for the simple current extension and the fusion rule for a tensor factor. In a special case, we construct a chain of simple current extensions. We discuss certain irreducible twisted modules for the simple current extension as well., 20 pages; an assumption is removed; some materials are deleted

False-positive bone lesions (bone pseudometastases) have been often reported in patients with esophageal cancer (EsoC). This study aimed to evaluate the vertebral 2-deoxy-2-[18F] fluoro-d-glucose (FDG) accumulation pattern in patients with newly diagnosed esophageal cancers and other malignancies (OtherT) to elucidate the possible mechanism that causes bone pseudometastasis. FDG positron emission tomography/computed tomography performed for 90 patients with EsoC, and 112 patients with OtherT was retrospectively evaluated. The uptake pattern in the thoracic (Th) and lumbar (L) vertebrae was visually assessed regarding predominance (TL, Th ≒ L; Td, Th > L; Ld, L > Th), main intensity compared with the uptake in the blood pool (BP) (Grade 1 BP), and homogeneity (homogeneous, heterogeneous, marginal, or spotty). The patterns between EsoC and OtherT and between Th and L were compared. TL, Td, and Ld patterns were observed in 51.1%, 48.9%, and 0% in EsoC and 79.7%, 20.3%, and 0% in OtherT. Though Grade 2 was most frequently observed in both groups, the ratio of Grade 3 in Th and Grade 1 in L was significantly higher in EsoC than in OtherT. Heterogeneous and spotty patterns were more frequently observed in L and in EsoC, and these were strongly associated with Td pattern. Td pattern was frequently seen, especially in EsoC, and was strongly associated with a heterogeneous or marginal pattern in the L. Heterogeneous marrow distribution with declined lumbar uptake is suspected as the mechanism of bone pseudometastasis.

Although the first approach for peptic ulcer bleeding is endoscopic hemostasis, quick determination of a hemostatic strategy is important in patients with vitals indicating shock. However, the unsuccessful factors for endoscopic treatment have yet to be sufficiently examined. We aimed to investigate the factors for unsuccessful endoscopic hemostasis in severe peptic ulcer bleeding.Unsuccessful factors were retrospectively investigated in 150 eligible patients who underwent endoscopic hemostasis for shock-presenting peptic ulcer bleeding at our critical care center between April 2007 and March 2021.There were 123 and 27 cases of successful and unsuccessful endoscopic hemostasis, respectively. Causative diseases included gastric ulcer bleeding in 124 patients (82.7%) and duodenal ulcer bleeding in 26 patients (17.3%). Shock index (SI) (1.46When these factors (SI ≥ 1.53, exposed blood vessel diameter ≥1.9 mm identified on CE-CT, duodenal ulcer bleeding, and Forrest Ia) are present in patients with severe peptic ulcer bleeding, non-endoscopic hemostasis, such as interventional radiology (IVR) and surgery, should be considered.

We evaluated the usefulness of a newly developed system with which the total amount of whitish cores in endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-FNAB) samples is automatically calculated (automated multiband imaging system [AMUS]).From 30 prospectively enrolled patients suspected of having pancreatic cancer, four EUS-FNAB specimens per patient were obtained. Following AMUS calculations, two specimens were prepared after stereomicroscopy-guided manual division into whitish and reddish sections (isolation group), and the other two were prepared without such division (no-isolation group). The relation of the AMUS results pertaining to the length of the manually measured whitish cores (stereo-microscopically visible white core [SVWC]) and the sample suitability for pathologic evaluation were analyzed.Histological diagnostic accuracy was 90%; median SVWC length, 14 mm; and median area of whitish core calculated using the AMUS, 13 mmAMUS is a simple on-site verification procedure for determining the appropriate sampling tissue quantity for high diagnostic accuracy.

A 70-year-old woman had spontaneous resolution of an embolism in her right middle cerebral artery (MCA) (day 1); another embolism occurred in her left MCA (day 3), which was promptly removed. On day 5, F-FDG PET/CT performed for staging mediastinal lymphoma showed marked FDG accumulation in the left MCA territory, whereas a defect was seen in the right insular region. Eventually, bilateral lesions developed irreversible infarction. Anaerobic metabolism and/or inflammation in acute-phase infarction were the supposed mechanism for the increased accumulation of FDG in her left MCA territory.

BACKGROUND Post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (PEP) is new onset acute pancreatitis after ERCP. This complication is sometimes fatal. As such, PEP should be diagnosed early so that therapeutic interventions can be carried out. Serum lipase (s-Lip) is useful for diagnosing acute pancreatitis. However, its usefulness for diagnosing PEP has not been sufficiently investigated. AIM This study aimed to retrospectively examine the usefulness of s-Lip for the early diagnosis of PEP. METHODS We retrospectively examined 4192 patients who underwent ERCP at our two hospitals over the last 5 years. The primary outcomes were a comparison of the areas under the receiver operating characteristic (ROC) curves (AUCs) of s-Lip and serum amylase (s-Amy), s-Lip and s-Amy cutoff values based on the presence or absence of PEP in the early stage after ERCP via ROC curves, and the diagnostic properties [sensitivities, specificities, positive predictive values (PPV), and negative predictive value (NPV)] of these cutoff values for PEP diagnosis. RESULTS Based on the eligibility and exclusion criteria, 804 cases were registered. Over the entire course, PEP occurred in 78 patients (9.7%). It occurred in the early stage after ERCP in 40 patients (51.3%) and in the late stage after ERCP in 38 patients (48.7%). The AUCs were 0.908 for s-Lip [95% confidence interval (CI): 0.880-0.940, P < 0.001] and 0.880 for s-Amy (95%CI: 0.846-0.915, P < 0.001), indicating both are useful for early diagnosis. By comparing the AUCs, s-Lip was found to be significantly more useful for the early diagnosis of PEP than s-Amy (P = 0.023). The optimal cutoff values calculated from the ROC curves were 342 U/L for s-Lip (sensitivity, 0.859; specificity, 0.867; PPV, 0.405; NPV, 0.981) and 171 U/L for s-Amy (sensitivity, 0.859; specificity, 0.763; PPV, 0.277; NPV, 0.979). CONCLUSION S-Lip was significantly more useful for the early diagnosis of PEP. Measuring s-Lip after ERCP could help diagnose PEP earlier; hence, therapeutic interventions can be provided earlier.

Endoscopic retrograde cholangiopancreatography (ERCP) in patients with surgically altered anatomy must be performed by a highly experienced endoscopist. The challenges are accessing the afferent limb in different types of reconstruction, cannulating a papilla with a reverse orientation, and performing therapeutic interventions with uncommon endoscopic accessories. The development of endoscopic techniques has led to higher success rates in this group of patients. Device-assisted ERCP is the endoscopic procedure of choice for high success rates in short-limb reconstruction; however, these success rate is lower in long-limb reconstruction. ERCP assisted by endoscopic ultrasonography is now popular because it can be performed independent of the limb length; however, it must be performed by a highly experienced and skilled endoscopist. Stent deployment and small stone removal can be performed immediately after ERCP assisted by endoscopic ultrasonography, but the second session is needed for other difficult procedures such as cholangioscopy-guided electrohydraulic lithotripsy. Laparoscopic-assisted ERCP has an almost 100% success rate in long-limb reconstruction because of the use of a conventional side-view duodenoscope, which is compatible with standard accessories. This requires cooperation between the surgeon and endoscopist and is suitable in urgent situations requiring concomitant cholecystectomy. This review focuses on the advantages, disadvantages, and outcomes of various procedures that are suitable in different situations and reconstruction types. Emerging new techniques and their outcomes are also discussed.

OBJECTIVES We investigated clinical characteristics of patients with extremely increased or decreased physiologic F-FDG uptake of the liver and their prognosis. METHODS One thousand four hundred eighty-seven PET/CT scans of patients with known or suspected malignancy were retrospectively analyzed. A spherical volume of interest (3 cm in diameter) was set on the right lobe of the liver to calculate the SUVmean. Scans with extremely high (SUVmean >97.5th percentile) and low (SUVmean

Purpose of the report False-positive bone lesions mimicking bone metastases (bone pseudometastasis) on F-FDG PET/CT have often been reported in patients with esophageal cancer. We aimed to evaluate the prevalence and features of these lesions in Japanese patients with esophageal cancer. Methods In this retrospective study, we analyzed 83 FDG PET/CT studies for initial staging of esophageal cancer, and extracted patients with 1 or more localized high uptake sites with no subsequent progression, which were therefore judged to be bone pseudometastasis. The FDG PET/CT imaging features of the bone pseudometastasis were evaluated, and other available imaging and clinical features reviewed. Results Of the 83 patients, 7 had bone pseudometastasis. All 7 were males diagnosed with squamous cell cancer, of which 5 had T1a tumors. Bone pseudometastasis showed normal or ill-defined hyperdense (nonosteolytic) sites compared with the surrounding area on the CT. Additionally, accumulation in the upper vertebral levels of each case was contiguously high compared with the lumbar spines (we named this finding "contiguous accumulation"). On MRI, these findings were visualized as low signals on T1-weighted imaging (T1WI) and T2WI images but were unclear on fat-suppressed T2WI images. Conclusions Among all PET/CT performed for staging of esophageal cancer, 8.3% demonstrated bone pseudometastasis characterized by heterogeneous distribution with severe fatty degeneration of bone marrow accompanied by contiguous accumulation. Caution is required during diagnoses of bone lesions in esophageal cancer patients in Japan to prevent inappropriate therapeutic choices.

This paper describes an observational study for the geometrical properties of hydrometeors during a refreezing process initiated by a winter storm in the northern Kanto Plain, Japan, on 29 January 2016, in which a subfreezing layer developed below a melting layer. The observations by using dual-polarization radar showed consistency between high values of differential reflectivity ZDR signals in midair and ice-pellet reports at the surface. The high ZDR was indicative of the sideways-oriented particles with a small axis ratio. The low ZDR signals in midair corresponded with the reports of rain or rain/ice-pellet mixtures. Observations by using a two-dimensional video disdrometer (2DVD) near the ground showed different microphysics corresponding to high ZDR and low ZDR periods. The high ZDR periods of 2DVD observations indicated that the hydrometeors exhibited dual modes of fall velocities, namely, fast-falling and slow-falling modes. The fast-falling particles were found to be deformed ice pellets with long sideways orientations that contributed to the high ZDR. The slow-falling particles were also deformed ice pellets but with a variety of orientations. This feature was rather close to that of general dry conditions of ice particles in the atmosphere. Meanwhile, the low ZDR periods of 2DVD observations indicated that the hydrometeors exhibited a single mode of fall velocity close to the terminal velocity of raindrops, but with a more spherical shape compared to raindrops. Hence, it is suggested that the high ZDR signal occurs during freezing between the initial stage of spherical ice forming and completely freezing stage of ice pellets with a variety of orientations.

The patient was a 69-year-old female with a chief complaint of yellow staining of her urine. A detailed physical examination and laboratory tests were carried out, and as a result, her condition was diagnosed as unresectable advanced extrahepatic cholangiocarcinoma with liver metastases. Chemotherapy using gemcitabine + cisplatin was initiated, and computed tomography after six cycles revealed that the liver metastases had disappeared, and that a partial response was achieved in the primary tumor. After tan cycles, a pylorus-preserving pancreaticoduodenectomy was performed as conversion surgery, and as a result, a pathological complete response was achieved in the primary tumor. After the primary lesion was resected, we were able to start an adjuvant chemotherapy immediately. Approximately 19 months have passed since the surgery, and the patient is currently alive and recurrence-free. If an improvement of the outcomes of chemotherapy in unresectable advanced biliary tract carcinomas is achieved in the future, there could be an increase in the number of treatment-responsive cases like the one reported in this study. Accumulating a large number of cases successfully treated by conversion surgery, and conducting a detailed analysis of the postoperative course, may help design adequate treatment strategies.

Biliary cannulation failure is a major problem during endoscopic retrograde cholangiopancreatography. It remains unclear how duodenal papilla morphology affects biliary cannulation. Therefore, we proposed a new classification system for the duodenal papilla based on oral protrusion pattern (ratio of the length of the oral protrusion to the transverse diameter of the papilla) and papilla pattern. To retrospectively compare biliary cannulation results with regard to classification and operator experience. We analyzed 589 naive major duodenal papillae. Our classification system comprised oral protrusion pattern, classified as small (Protrusion-S), regular (Protrusion-R), or large (Protrusion-L), and the papilla pattern, classified as annular (Papilla-A), unstructured (Papilla-U), longitudinal (Papilla-LO), isolated (Papilla-I), or gyrus (Papilla-G). Intra-evaluator concordance and the results of biliary cannulation were analyzed. The following oral protrusion pattern classifications were observed: Protrusion-S, 11.7%; Protrusion-R, 77.9%; and Protrusion-L, 10.4%. The following papilla patterns were observed: Papilla-A, 67.1%; Papilla-U, 7.0%; Papilla-LO, 7.5%; Papilla-I, 1.2%; Papilla-G, 15.6%; and unclassified, 1.7%. Intra-evaluator concordance value (Fleiss kappa) was 0.788 for oral protrusion pattern and 0.750 for papilla pattern. A logistic regression analysis of cannulations performed by an experienced endoscopist identified Protrusion-L as a significant risk factor for difficult cannulation (odds ratio 2.956; 95% confidence interval 1.115–7.84; p = 0.029). Multivariate analysis confirmed Protrusion-L as an independent risk factor for difficult biliary cannulation (odds ratio 3.772; 95% confidence interval 1.359–10.464; p = 0.011). We propose a new general classification system for the duodenal papilla. Protrusion-L is a significant risk factor for difficult biliary duct cannulation.

Pancreatic granular cell tumors (GCTs) are rare and making an imaging diagnosis of pancreatic GCT is difficult because it has no definite characteristics on contrast-enhanced computed tomography (CE-CT) or magnetic resonance imaging (MRI) owing to varying findings. We report about a 32-year-old woman who presented with an incidental finding of a pancreatic tumor with a past history of excision of a right forearm GCT nodule 12 years ago. CE-CT revealed a 23-mm-sized homogeneous low enhancement tumor in the arterial phase in the pancreatic body. Abdominal MRI revealed a lobulated hypointense mass in T1WI and high signal in DWI. Endoscopic ultrasonography (EUS) revealed that the tumor was oval, hypoechoic with posterior echo enhancement, and had a well-defined border. Although EUS-guided fine needle aspiration revealed benign granular cells of the pancreas, she underwent laparoscopic surgery because the metastatic tumor from the past lesion was not excluded. The pathological finding was benign GCT of the pancreas and it was considered as an original lesion. In the previous reports, most of the resected cases were considered to be pancreatic cancer or neuroendocrine tumor preoperatively. Compared to CE-CT and MRI, EUS imaging and EUS-FNA are more reliable diagnosis tools for pancreatic GCT. Although malignant GCT accounts for approximately 1-2% of all cases, surgical resection or strict follow-up should be considered because it is difficult to predict its biological behavior.

Endoscopic transmural drainage is performed for symptomatic peripancreatic fluid collections (PPFCs). Long-term transmural double-pigtail stent (DPS) placement is useful in preventing recurrences. There are few reports on the long-term safety of DPS placement. Thus, this study aimed to examine the complications of long-term indwelling DPS for PPFCs. Among 53 patients who underwent endoscopic ultrasound-guided transmural drainage for symptomatic PPFCs between April 2006 and March 2017, those followed up for over one year were included. Complications of long-term indwelling DPS were examined retrospectively. This study enrolled 36 patients [30 men, median age 54 years (range 22–82)]. Walled-off necrosis was present in 22 cases (including 9 disconnected pancreatic duct syndrome cases) and pancreatic pseudocysts, in 14 cases. The median stenting period was 20.9 (range 0.8–142.3) months, and median observation period was 56.2 (range 12.4–147.1) months. Colon perforation due to DPS occurred in 3 cases (8.3%), at 5.8, 17.1, and 33.7 months after indwelling DPS placement; 2 cases developed perforation from the serosal side. In 1 case, the patient was treated surgically, and in 2 cases, the patients underwent endoscopic removal of the stent and showed improvement with conservative treatment. Long-term indwelling transmural DPS for symptomatic PPFCs poses a risk of intestinal perforation. Thus, if possible, it may be better to avoid long-term placement.

Background and Objectives: Balloon enteroscopy-assisted ERCP (BE-ERCP) has become the first-line therapy for biliopancreatic anastomotic strictures. However, it is not always successful, and salvage methods have not been established. This study aimed to evaluate the outcomes of EUS-guided transanastomotic drainage using a forward-viewing (FV) echoendoscope. Patients and Methods: Of eight cases wherein BE-ERCP treatment failed due to severe or complete benign anastomotic stricture, seven cases underwent EUS-guided choledochojejunostomy, and EUS-guided pancreaticojejunostomy was applied in one case after intubating an FV echoendoscope into the anastomotic site. Results: The success rate of reaching the target site was 100% (8/8) for patients after modified Child resection. The median time to reach the anastomosis was 5 min (range: 3–17 min), and the technical success rate for drainage was 75% (6/8). The median total procedure time was 33.5 min (range: 22–45 min) for six successful cases. Cautery dilatation catheters were necessary to dilate the puncture site in all cases, and no early complications were observed. During the follow-up period (median: 13.3 months [range: 6.5–60.3]), recurrence of the stricture occurred in one case, and a stent-free status was achieved after 6–12 months of stent placement in five cases. Conclusions: EUS-guided transanastomotic drainage using an FV echoendoscope is a feasible and safe rescue technique for the management of benign severe biliopancreatic anastomotic strictures.