175 research outputs found

    Pseudoaneurysms complicating organ transplantation: Roles of CT, duplex sonography, and angiography

    Get PDF
    In a retrospective study of proved pseudoaneurysms (PAs) in 15 patients with transplanted organs (11 liver, three kidney, one pancreas), the results of computed tomography (CT), duplex sonography, and angiography were reviewed. Of the 15 cases of PA, eight occurred at the arterial anastomosis and seven were nonanastomotic. Three of the eight anastomotic PAs were caused by infection. Of the seven nonanastomotic PAs, four were caused by percutaneous biopsy, two were caused by infection, and one was of undetermined cause. In nine (60%) of the 15 patients the PAs were incidentally detected at imaging studies performed for other reasons. Diagnosis requires a high degree of suspicion. CT was performed in nine cases and duplex sonography in ten. The diagnosis of PA was made with CT in six (67%) patients and with duplex sonography in five (50%). CT and duplex sonography could not enable diagnosis when the PA was small, when the arterial anastomosis was not included in the field of study, or when enhancement with intravenously administered contrast material was suboptimal. Angiography depicted the PAs in all 15 patients. In three liver transplant recipients with gastrointestinal tract bleeding, the causative PAs were detected only with angiography

    Radiographers supporting radiologists in the interpretation of screening mammography: a viable strategy to meet the shortage in the number of radiologists.

    Get PDF
    BackgroundAn alternative approach to the traditional model of radiologists interpreting screening mammography is necessary due to the shortage of radiologists to interpret screening mammograms in many countries.MethodsWe evaluated the performance of 15 Mexican radiographers, also known as radiologic technologists, in the interpretation of screening mammography after a 6 months training period in a screening setting. Fifteen radiographers received 6 months standardized training with radiologists in the interpretation of screening mammography using the Breast Imaging Reporting and Data System (BI-RADS) system. A challenging test set of 110 cases developed by the Breast Cancer Surveillance Consortium was used to evaluate their performance. We estimated sensitivity, specificity, false positive rates, likelihood ratio of a positive test (LR+) and the area under the subject-specific Receiver Operating Characteristic (ROC) curve (AUC) for diagnostic accuracy. A mathematical model simulating the consequences in costs and performance of two hypothetical scenarios compared to the status quo in which a radiologist reads all screening mammograms was also performed.ResultsRadiographer's sensitivity was comparable to the sensitivity scores achieved by U.S. radiologists who took the test but their false-positive rate was higher. Median sensitivity was 73.3 % (Interquartile range, IQR: 46.7-86.7 %) and the median false positive rate was 49.5 % (IQR: 34.7-57.9 %). The median LR+ was 1.4 (IQR: 1.3-1.7 %) and the median AUC was 0.6 (IQR: 0.6-0.7). A scenario in which a radiographer reads all mammograms first, and a radiologist reads only those that were difficult for the radiographer, was more cost-effective than a scenario in which either the radiographer or radiologist reads all mammograms.ConclusionsGiven the comparable sensitivity achieved by Mexican radiographers and U.S. radiologists on a test set, screening mammography interpretation by radiographers appears to be a possible adjunct to radiologists in countries with shortages of radiologists. Further studies are required to assess the effectiveness of different training programs in order to obtain acceptable screening accuracy, as well as the best approaches for the use of non-physician readers to interpret screening mammography

    Urbanisoituva yliopistokampus informaalin oppimisen mahdollistajana

    Get PDF
    Yliopistokampukset ovat monitoimijaisia ja alati muuttuvia opiskelu-, työ-, asuin- ja harrastusympäristöjä. Niiden muutosprosessi on sidoksissa yliopistojen yhteiskunnallisiin kytkentöihin sekä kaupungin laajenemiseen, tiivistymiseen ja urbanisoitumiseen. Artikkelissa nostetaan keskusteluun yliopistokampus osana ympäröivää kaupunkirakennetta ja julkisena urbaanina tilana, joka voi edistää informaalia oppimista. Esitämme, että on olemassa ainakin Suomessa yleinen yliopistokampustyyppi, jonka kaupungistumisprosessi on kaupunkirakenteellisessa ja toiminnallisessa mielessä vasta alkuvaiheessa. Kutsumme sitä urbanisoituvaksi yliopistokampukseksi. Sitä edustavat artikkelissa käsitellyt Joensuun, Jyväskylän, Tampereen, Turun ja Vaasan keskustojen kampukset. Ne sijaitsevat alueensa keskuskaupungeissa varsin keskeisellä paikalla kaupunkikeskustan ruutukaava-alueen tuntumassa, mutta silti niiden ongelmana on toiminnan hiljeneminen opiskeluaikojen ulkopuolella. Urbanisoitumiseen kytkeytyvien ilmiöiden avulla on mahdollista elävöittää kampusalueen toimintoja ja ympäristöä ja samalla luoda edellytyksiä informaalille oppimiselle. Artikkelissa elävöittämistä pohditaan erityisesti kaupunkirakenteen tiivistymisen, kampusalueen käyttötarkoitusten monipuolistumisen ja puistomaisten viheralueiden kannalta

    Pregnancy-Associated Breast Disease: Radiologic Features and Diagnostic Dilemmas

    Get PDF
    In this paper, we evaluate the radiological features of pregnancy-associated breast lesions and discuss the difficulties in diagnosis by imaging. We selected patients who were diagnosed with pregnancy-associated breast lesions during the previous 5 years. All patients complained of palpable lesions in the breast and underwent ultrasonographic (US) examination, the first choice for examination of pregnancy-related breast lesions. Any suspicious lesions found by the US were recommended for a US-guided core biopsy, US-guided fine needle aspiration (FNA), or surgery. Various breast lesions were detected during pregnancy and lactation, including breast cancer, mastitis and abscesses, lactating adenoma, galactoceles, lobular hyperplasia, and fibroadenomas. The imaging features of pregnancy-associated breast lesions did not differ from the features of non-pregnancy-associated breast lesions; however, some pregnancy-associated benign lesions had suspicious sonographic features. A US-guided core biopsy was necessary for differentiating benign from malignant. In patients with breast cancer, the cancer was often advanced at the time of diagnosis. In conclusion, various pregnancy-related breast lesions were detected and the imaging of these lesions had variable findings. Breast ultrasound could be an excellent imaging modality for diagnosis and differentiation between benign and malignant lesions. However, when the imaging results are suspicious, a biopsy should be performed to obtain a pathologic diagnosis

    A clinical case of a patient with probable cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) from Chuvashia

    Get PDF
    Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) syndrome is a congenital small-vessel disease running with recurrent lacunar infarcts and leading to gradually progressive subcortical, pseudobulbar, and cerebellar syndromes and dementia. Neuroimaging reveal multiple lacunar infarcts in the basal ganglia, thalamus, pons Varolii, and cerebral hemispheric white matter, as well as cerebral atrophy. The specific feature of the disease is white matter lesion adjacent to the temporal horns of the lateral ventricles and to the external capsules. The paper describes a patient with CADASIL syndrome. The latter runs a progressive course and includes the following neurological disorders: cognitive, pyramidal, extrapyramidal, and axial ones. This clinical case was differentially diagnosed with multiple sclerosis, including with consideration for neuroimaging findings. The CADASIL syndrome is a rare potentially menacing neurological condition that is observed in young patients and requires a detailed examination using current diagnostic techniques

    Dispersive flies optimisation and medical imaging

    Get PDF
    One of the main sources of inspiration for techniques applicable to complex search space and optimisation problems is nature. This paper introduces a new metaheuristic—Dispersive Flies Optimisation (DFO)—whose inspiration is beckoned from the swarming behaviour of flies over food sources in nature. The simplicity of the algorithm facilitates the analysis of its behaviour. A series of experimental trials confirms the promising performance of the optimiser over a set of benchmarks, as well as its competitiveness when compared against three other well-known population based algorithms. The convergence-independent diversity of DFO algorithm makes it a potentially suitable candidate for dynamically changing environment. In addition to diversity, the performance of the newly introduced algorithm is investigated using the three performance measures of accuracy, efficiency and reliability and its outperformance is demonstrated in the paper. Then the proposed swarm intelligence algorithm is used as a tool to identify microcalcifications on the mammographs. This algorithm is adapted for this particular purpose and its performance is investigated by running the agents of the swarm intelligence algorithm on sample mammographs whose status have been determined by the experts. Two modes of the algorithms are introduced in the paper, each providing the clinicians with a different set of outputs, highlighting the areas of interest where more attention should be given by those in charge of the care of the patients

    Early onset lactating adenoma and the role of breast MRI: a case report

    Get PDF
    <p>Abstract</p> <p>Introduction</p> <p>Lactating adenoma is a benign condition, representing the most prevalent breast lesion in pregnant women and during puerperium; in this paper, a case of a woman with lactating adenoma occurring during the first trimester of pregnancy is reported. There have been no reports in the literature, according to our search, focusing on magnetic resonance imaging findings in cases of lactating adenomas. Also the early onset of the lesion during the first trimester of pregnancy is quite unusual and possibly unique.</p> <p>Case presentation</p> <p>We report the case of a primiparous 30-year-old Caucasian woman, who noted an asymptomatic lump within her left breast during the 9<sup>th </sup>week of gestation, slightly increasing in size over the next few weeks. Ultrasound demonstrated a hypoecoic solid mass, hypervascularized and measuring 4 cm. On magnetic resonance imaging, performed in the first month after delivery, the lesion appeared as an ovoidal homogeneous mass, with regular margins and a significant contrast enhancement indicative of a giant adenoma.</p> <p>Conclusion</p> <p>Magnetic resonance imaging could play an important role in the differential diagnosis of pregnancy-related breast lumps, particularly during puerperium, thus avoiding unnecessary surgical biopsies.</p

    Совершенствование научно-методических подходов в области метрологического обеспечения технологий контроля герметичности на опасных производственных объектах

    Get PDF
    In this article the analysis of metrological assurance of control technologies integrity subject to the rules of safety at hazardous production facilities. Deals with the scientific and methodological aspects of the evaluation of threshold sensitivity of control systems integrity using controlled leaks, containing in its composition of standard samples for reproduction of units of volumetric and mass flow of gas, which expands the scope of their applicability.В настоящей статье проводится анализ метрологического обеспечения технологий контроля герметичности с учетом правил безопасности на опасных производственных объектах. Рассматриваются научные и методические аспекты оценки пороговой чувствительности систем контроля герметичности с использованием контрольных течей, содержащих в своем составе стандартные образцы воспроизведения единиц объемного и массового расходов газа, что расширяет сферу их применимости

    Prospective screening study of 0.5 Tesla dedicated magnetic resonance imaging for the detection of breast cancer in young, high-risk women

    Get PDF
    BACKGROUND: Evidence-based screening guidelines are needed for women under 40 with a family history of breast cancer, a BRCA1 or BRCA2 mutation, or other risk factors. An accurate assessment of breast cancer risk is required to balance the benefits and risks of surveillance, yet published studies have used narrow risk assessment schemata for enrollment. Breast density limits the sensitivity of film-screen mammography but is not thought to pose a limitation to MRI, however the utility of MRI surveillance has not been specifically examined before in women with dense breasts. Also, all MRI surveillance studies yet reported have used high strength magnets that may not be practical for dedicated imaging in many breast centers. Medium strength 0.5 Tesla MRI may provide an alternative economic option for surveillance. METHODS: We conducted a prospective, nonrandomized pilot study of 30 women age 25–49 years with dense breasts evaluating the addition of 0.5 Tesla MRI to conventional screening. All participants had a high quantitative breast cancer risk, defined as ≥ 3.5% over the next 5 years per the Gail or BRCAPRO models, and/or a known BRCA1 or BRCA2 germline mutation. RESULTS: The average age at enrollment was 41.4 years and the average 5-year risk was 4.8%. Twenty-two subjects had BIRADS category 1 or 2 breast MRIs (negative or probably benign), whereas no category 4 or 5 MRIs (possibly or probably malignant) were observed. Eight subjects had BIRADS 3 results, identifying lesions that were "probably benign", yet prompting further evaluation. One of these subjects was diagnosed with a stage T1aN0M0 invasive ductal carcinoma, and later determined to be a BRCA1 mutation carrier. CONCLUSION: Using medium-strength MRI we were able to detect 1 early breast tumor that was mammographically undetectable among 30 young high-risk women with dense breasts. These results support the concept that breast MRI can enhance surveillance for young high-risk women with dense breasts, and further suggest that a medium-strength instrument is sufficient for this application. For the first time, we demonstrate the use of quantitative breast cancer risk assessment via a combination of the Gail and BRCAPRO models for enrollment in a screening trial
    corecore