29 research outputs found

    Successful flow reduction surgery for a ruptured true posterior communicating artery aneurysm caused by the common carotid artery ligation for epistaxis.

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    [Background]: Carotid artery occlusion can lead to the development of rare true posterior communicating artery (PCoA) aneurysms because of hemodynamic stress on the PCoA. Surgical treatment of these lesions is challenging. [Case Description]: The authors report a case of a true PCoA aneurysm that developed and ruptured 37 years after ligation of the ipsilateral common carotid artery for epistaxis. The lesion was successfully treated with clipping of the distal M1 segment of the middle cerebral artery (MCA) after the occipital artery-radial artery free graft-MCA bypass, which led to extreme reduction in collateral flow through the PCoA. A cortical branch, located just proximal to the obliteration site, functioned as a sufficient flow outlet. The aneurysm shrank, and the patient has been doing well without any symptoms for 5 years after surgery. [Conclusions]: M1 obliteration combined with high-flow extra-intracranial bypass might be a promising option for a true PCoA aneurysm, and therapeutic design that leaves a sufficient flow outlet on the M1 is mandatory to avoid unexpected occlusion of the M1 and its perforators

    Pre-Operative Imaging and Pathological Diagnosis of Localized High-Grade Pancreatic Intra-Epithelial Neoplasia without Invasive Carcinoma

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    Pancreatic ductal adenocarcinoma (PDAC) arises from precursor lesions, such as pancreatic intra-epithelial neoplasia (PanIN) and intraductal papillary mucinous neoplasm (IPMN). The prognosis of high-grade precancerous lesions, including high-grade PanIN and high-grade IPMN, without invasive carcinoma is good, despite the overall poor prognosis of PDAC. High-grade PanIN, as a lesion preceding invasive PDAC, is therefore a primary target for intervention. However, detection of localized high-grade PanIN is difficult when using standard radiological approaches. Therefore, most studies of high-grade PanIN have been conducted using specimens that harbor invasive PDAC. Recently, imaging characteristics of high-grade PanIN have been revealed. Obstruction of the pancreatic duct due to high-grade PanIN may induce a loss of acinar cells replaced by fibrosis and lobular parenchymal atrophy. These changes and additional inflammation around the branch pancreatic ducts (BPDs) result in main pancreatic duct (MPD) stenosis, dilation, retention cysts (BPD dilation), focal pancreatic parenchymal atrophy, and/or hypoechoic changes around the MPD. These indirect imaging findings have become important clues for localized, high-grade PanIN detection. To obtain pre-operative histopathological confirmation of suspected cases, serial pancreatic-juice aspiration cytologic examination is effective. In this review, we outline current knowledge on imaging characteristics of high-grade PanIN

    Profile of the ORION (Osaka emergency information Research Intelligent Operation Network system) between 2015 and 2016 in Osaka, Japan: a population-based registry of emergency patients with both ambulance and in-hospital records

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    Aim: To describe the registry design of the Osaka Emergency Information Research Intelligent Operation Network system (ORION) and its profile of hospital information, patient and emergency medical service characteristics, and in‐hospital outcomes among all patients transported to critical care centers and emergency hospitals in Osaka Prefecture, Japan. Methods: The Osaka Prefecture Government has developed and introduced an information system for emergency patients (the ORION system) that uses a smartphone application (app) for hospital selection by on‐scene emergency medical service personnel and has been accumulating all ambulance records. Since January 2015, medical institutions have obtained information on the diagnosis and outcome of patients transported to medical institutions, and the ORION system merged these data with ambulance records including smartphone app data. Results: From January 2015 to December 2016, 753, 301 eligible patients were registered. The mean age was 58.7 years, and 51.5% of patients were male. After hospital arrival, 39.7% were hospitalized, 58.2% were discharged from hospital, 1.1% changed hospital, and 1.0% died. The most common diagnoses were injury, poisoning, and certain other consequences of external causes. Among the hospitalized patients, 29.2% were continuously hospitalized, 59.0% discharged, 5.2% changed hospital, and 5.8% were dead at 21 days after hospitalization. The most common confirmed diagnosis was diseases of the circulatory system. Conclusion: Using the ORION system developed and operated by Osaka Prefecture since January 2015, we described the epidemiological data of all emergency patients transported to emergency hospitals. Analysis using the ORION database in the future could lead to improvements in the emergency transport system and patient outcomes

    Phantom and clinical evaluation of the Bayesian penalised likelihood reconstruction algorithm Q.Clear without PSF correction in amyloid PET images

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    Abstract Purpose Bayesian penalised likelihood (BPL) reconstruction, which incorporates point-spread-function (PSF) correction, provides higher signal-to-noise ratios and more accurate quantitation than conventional ordered subset expectation maximization (OSEM) reconstruction. However, applying PSF correction to brain PET imaging is controversial due to Gibbs artefacts that manifest as unpredicted cortical uptake enhancement. The present study aimed to validate whether BPL without PSF would be useful for amyloid PET imaging. Methods Images were acquired from Hoffman 3D brain and cylindrical phantoms for phantom study and 71 patients administered with [18F]flutemetamol in clinical study using a Discovery MI. All images were reconstructed using OSEM, BPL with PSF correction, and BPL without PSF correction. Count profile, %contrast, recovery coefficients (RCs), and image noise were calculated from the images acquired from the phantoms. Amyloid β deposition in patients was visually assessed by two physicians and quantified based on the standardised uptake value ratio (SUVR). Results The overestimated radioactivity in profile curves was eliminated using BPL without PSF correction. The %contrast and image noise decreased with increasing β values in phantom images. Image quality and RCs were better using BPL with, than without PSF correction or OSEM. An optimal β value of 600 was determined for BPL without PSF correction. Visual evaluation almost agreed perfectly (κ = 0.91–0.97), without depending on reconstruction methods. Composite SUVRs did not significantly differ between reconstruction methods. Conclusion Gibbs artefacts disappeared from phantom images using the BPL without PSF correction. Visual and quantitative evaluation of [18F]flutemetamol imaging was independent of the reconstruction method. The BPL without PSF correction could be the standard reconstruction method for amyloid PET imaging, despite being qualitatively inferior to BPL with PSF correction for [18F]flutemetamol amyloid PET imaging

    Determination of optimal regularization factor in Bayesian penalized likelihood reconstruction of brain PET images using [ F]FDG and [ C]PiB.

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    The Bayesian penalized likelihood (BPL) reconstruction algorithm, Q.Clear, can achieve a higher signal-to-noise ratio on images and more accurate quantitation than ordered subset-expectation maximization (OSEM). The reconstruction parameter (β) in BPL requires optimization according to the radiopharmaceutical tracer. The present study aimed to define the optimal β value in BPL required to diagnose Alzheimer disease from brain positron emission tomography (PET) images acquired using F-fluoro-2-deoxy-D-glucose ([ F]FDG) and C-labeled Pittsburg compound B ([ C]PiB)
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