Subtransmission overhead lines mechanical monitoring for fast detection of damaging events

Different harmful events affecting high voltage overhead lines (OHLs) cause changes in the mechanical tension (tensile strength) of conductors. A mechanical monitoring of OHLs, therefore, can provide useful additional information (compared with the information provided by the widely used SCADA systems) about the power system state. The tension measurements combined with a few environmental measurements (air temperature, wind speed) can be used for an automatic (fast) detection of different events and for their approximate location along an OHL, reducing the impact of these events. Referring to 132-150 kV sub-transmission OHLs, this paper proposes some original algorithms, based on the mechanical monitoring of OHLs, for the automatic detection of the following events: conductor breaking, fall of trees on the conductors, ice/snow sleeve accretion on the conductors, strands breaking and galloping. The proposed algorithms require a limited number of sensors placed along the OHLs for measurements of the conductor tension and weather-related quantities

Surgical complications after pancreatic transplantation: A computed tomography imaging pictorial review

pancreatic transplantation should start with the evaluation of the arterial Y-graft, the venous anastomosis and the duodenojejunostomy. With regard to complications, CT allows for the identification of vascular complications, such as thrombosis or stenosis of blood vessels supplying the graft, the detection of pancreatic fluid collections, including pseudocysts, abscesses, or leaks, the assessment of bowel complications (anastomotic leaks, ileus or obstruction), and the identification of bleeding. The aim of this pictorial review is to illustrate CT findings of surgical-related complications after pancreatic transplantation. The knowledge of surgical techniques is of key importance to understand postoperative anatomic changes and imaging evaluation. Therefore, we first provide a short summary of the main techniques of pancreatic transplantation. Then, we provide a practical imaging approach to pancreatic transplantation and its complications providing tips and tricks for the prompt imaging diagnosis on CT.Pancreatic transplantation is considered by the American Diabetes Association and the European Association for the Study of Diabetes an acceptable surgical procedure in patients with type 1 diabetes also undergoing kidney transplantation in pre-final or end-stage renal disease if no contraindications are present. Pancreatic transplantation, however, is a complex surgical procedure and may lead to a range of postoperative complications that can significantly impact graft function and patient outcomes. Postoperative computed tomography (CT) is often adopted to evaluate perfusion of the transplanted pancreas, identify complications and as a guide for interventional radiology procedures. CT assessment afte

Intraductal papillary mucinous neoplasms of the pancreas: Uncommon imaging presentation, evolution and comparison of guidelines

Pancreatic cystic lesions are often asymptomatic, incidentally detected and include a range of entities with varying degrees of concern for malignancy. Among these, intraductal papillary mucinous neoplasms (IPMN) are considered premalignant pancreatic lesions, with a broad pathological spectrum ranging from lesions without dysplasia, which can be managed conservatively, to malignant lesions that require surgical resection. The increasing use of CT and MRI has led to increased recognition of this entity incidentally, with branch-duct IPMN representing the most common subtype and the most challenging lesions in terms of patient management. The main imaging modality involved in diagnosis and surveillance of IPMN is MRI. Radiologists play an important role in the management of patients with IPMN, including lesion detection, characterization, follow-up and prognostication, allowing early MRI identification of features that are concerning for malignancy. The main aim of this pictorial review is to illustrate MRI features of IPMN and to discuss risk stratification scores based on different guidelines, with a main focus on branch-duct IPMN. The secondary aims include the presentation of common and uncommon imaging evolution of BD-IPMN as well as the discussion on current controversies on the appropriate management of IPMN

Medical Radiology: Current Progress

Recently, medical radiology has undergone significant improvements in patient management due to advancements in image acquisition by the last generation of machines, data processing, and the integration of artificial intelligence. In this way, cardiovascular imaging is one of the fastest-growing radiological subspecialties. In this study, a compressive review was focused on addressing how and why CT and MR have gained a I class indication in most cardiovascular diseases, and the potential impact of tissue and functional characterization by CT photon counting, quantitative MR mapping, and 4-D flow. Regarding rectal imaging, advances in cancer imaging using diffusion-weighted MRI sequences for identifying residual disease after neoadjuvant chemoradiotherapy and [18F] FDG PET/MRI were provided for high-resolution anatomical and functional data in oncological patients. The results present a large overview of the approach to the imaging of diffuse and focal liver diseases by US elastography, contrast-enhanced US, quantitative MRI, and CT for patient risk stratification. Italy is currently riding the wave of these improvements. The development of large networks will be crucial to create high-quality databases for patient-centered precision medicine using artificial intelligence. Dedicated radiologists with specific training and a close relationship with the referring clinicians will be essential human factors

Contrast-enhanced ultrasound of the spleen: an introduction and pictorial essay

A wide variety of pathologies can produce focal lesions within the spleen. These are being more frequently encountered as imaging technology improves. It is vital that radiologists are aware of these pathologies to enable accurate diagnosis. The role of ultrasound contrast in splenic disease will be discussed and illustrated with cases likely to be encountered by general and abdominal radiologists

Real time contrast enhanced ultrasonography in detection of liver metastases from gastrointestinal cancer

Background: Contrast enhanced ultrasound (CEUS) is an imaging technique which appeared on the market around the year 2000 and proposed for the detection of liver metastases in gastrointestinal cancer patients, a setting in which accurate staging plays a significant role in the choice of treatment. Methods: A total of 109 patients with colorectal (n = 92)or gastric cancer prospectively underwent computed tomography (CT) scan and conventional US evaluation followed by real time CEUS. A diagnosis of metastases was made by CT or, for lesions not visibile at CT, the diagnosis was achieved by histopathology or by a malignant behavior during follow-up. Results: Of 109 patients, 65 were found to have metastases at presentation. CEUS improved sensitivity in metastatic livers from 76.9% of patients (US) to 95.4% (p < 0.01), while CT scan reached 90.8% (p = n.s. vs CEUS, p < 0.01 vs US). CEUS and CT were more sensitive than US also for detection of single lesions (87 with US, 122 with CEUS, 113 with CT). In 15 patients (13.8%), CEUS revealed more metastases than CT, while CT revealed more metastases than CEUS in 9 patients (8.2%) (p = n.s.). Conclusion: CEUS is more sensitive than conventional US in the detection of liver metastases and could be usefully employed in the staging of patients with gastrointestinal cancer. Findings at CEUS and CT appear to be complementary in achieving maximum sensitivity. © 2007 Piscaglia et al; licensee BioMed Central Ltd

The Viscoelastic Properties of Passive Eye Muscle in Primates. II: Testing the Quasi-Linear Theory

We have extensively investigated the mechanical properties of passive eye muscles, in vivo, in anesthetized and paralyzed monkeys. The complexity inherent in rheological measurements makes it desirable to present the results in terms of a mathematical model. Because Fung's quasi-linear viscoelastic (QLV) model has been particularly successful in capturing the viscoelastic properties of passive biological tissues, here we analyze this dataset within the framework of Fung's theory

The Viscoelastic Properties of Passive Eye Muscle in Primates. I: Static Forces and Step Responses

The viscoelastic properties of passive eye muscles are prime determinants of the deficits observed following eye muscle paralysis, the root cause of several types of strabismus. Our limited knowledge about such properties is hindering the ability of eye plant models to assist in formulating a patient's diagnosis and prognosis. To investigate these properties we conducted an extensive in vivo study of the mechanics of passive eye muscles in deeply anesthetized and paralyzed monkeys. We describe here the static length-tension relationship and the transient forces elicited by small step-like elongations. We found that the static force increases nonlinearly with length, as previously shown. As expected, an elongation step induces a fast rise in force, followed by a prolonged decay. The time course of the decay is however considerably more complex than previously thought, indicating the presence of several relaxation processes, with time constants ranging from 1 ms to at least 40 s. The mechanical properties of passive eye muscles are thus similar to those of many other biological passive tissues. Eye plant models, which for lack of data had to rely on (erroneous) assumptions, will have to be updated to incorporate these properties