484 research outputs found
Vergleich der Dignitätsbestimmung von mammographischem Mikrokalk mit zwei Systemen zur digitalen Vollfeldmammographie unterschiedlicher Detektorauflösung
No full textPurpose. The aim of this retrospective clinical study was to compare the diagnostic accuracy of the novel 50 mu m FFDM (full-field digital mammography) system (DR) with an established 70 mu m system (DR) in the differential diagnosis between benign and malignant clusters of microcalcification (n=50) (BI-RADS (TM) T classification 4/5) and to assess the possible incremental value of the 50 mu m pixel-pitch on specificity. Material and methods. From March 2009 to September 2009, 50 patients underwent full-field digital mammography (FFDM) (detector resolution 70 mu m) (Novation, Siemens, Erlangen, Germany). As there were suspicious signs of microcalcification classified with BI-RADS (TM) 4/5 after diagnosis and preoperative wire localization, control images were made with the new FFDM system (detector: resolution 50 mu m) (Amulet, Fujifilm, Tokyo, Japan) with the same exposure parameters. The diagnosis was determined after the operation by five radiologists with different experience in digital mammography from randomly distributed mediolateral views (monitor reading) whose results were correlated with the final histology of all lesions. Results. Histopathology revealed 19 benign and 31 malignant lesions in 50 patients after open biopsy. The results of the five readers showed a higher sensitivity of the new FFDM system (80.0%) in the ability to recognize malignant microcalcification in comparison to the established system (74.8%). The specificity (75.8 versus 71.6%) was slightly higher for the new system but hese results were not statistically significant (p<0.001). Considering the diagnostic accuracy, the new system (detector: resolution 50 mu m) was also slightly superior to the well-known system (detector: resolution 70 mu m) (80.1% versus 76.4%). Conclusions. Our study has shown that the new full-field digital mammography system using the novel detector compared with the already established FFDM system with respect to the assessment of microcalcification is at least equivalent
Erste Untersuchungen zur Detektion simulierter mammographischer Läsionen
No full textPurpose. The article describes an experimental phantom study of a system for digital full field mammography with a new digital detector with a double plate of pure selenium. Materials and methods. The experiments were carried out with the new full field digital mammography system Amulet from FujiFilm. This system has a new detector (18x24 cm(2)) on the basis of highly purified amorphous selenium (a-Se) with a pixel size of 50 mu m. The x-rays are converted into electric signals in the first plate which are read into the second plate with the help of an optical switch and demonstrated in the form of an image. In this way a better pixel size/volume and signal-to-noise ratio should be achieved. The object of the investigation was the Wisconsin Mammographic Random Phantom, Model 152 A (Technical Performance Mo/Mo, 28 kV, 100 mAs). Five investigators with different experiences in mammography each received three images on a monitor with different random positions of the simulated lesions in the phantom for assessment. The detection rates were compared under the same conditions with the results of two other full field digital mammography systems. Results. The median detection rate for all images and investigators for the new doubled plated a-Se detector with optical switch was 98.7%. For both other systems with a-Si or and a-Se detectors the detection rate was 89.8% or 97.3%, respectively. There were no significant differences in the detection rate of the simulated breast lesions for all three systems considering the interobserver and intraobserver variation. Conclusion. The first phantom study for the detection of simulated breast lesions with the new full field digital mammography system Amulet demonstrates equivalent results with the other systems used in the clinical routine. The trend towards superiority of the new system has to be confirmed in further clinical studies
Comparing the clinical value of spot view mammography with reduced pixel size to monitor zooming by reporting microcalcifications in digital mammography
No full textPurpose: Evaluation of the diagnostic value of breast specimen imaging with a digital mammographic system using a detector system with changeable pixel size compared to standard mode imaging in different monitor display modes. Materials and Methods: Using the digital mammographic system SenoScan (Fischer Imaging, Denver, USA), 50 diagnostic breast specimens with microcalcifications were visualized in both standard mode (pixel size 54 pm) and high resolution mode (pixel size 27 pm). The resulting radiographs were displayed 1:1 on a monitor. Standard mode images (pixel size 54 mu m) were additionally displayed in a 2:1 mode. A total of 5 readers with different mammographic experience analyzed the type of the microcalcifications on the basis of the different display modes. The images were presented randomly. The findings were subsequently compared to the histology. Results: The high resolution mode yielded slightly but not significantly better results than the standard mode on average for all 5 readers. Compared to a sensitivity of 80% and a specificity of 72% (PPV=74%, NPV=78%) in the standard mode, the high resolution mode provided a sensitivity of 86% and a specificity of 74% (PPV = 77%, NPV = 83%). The standard mode images on a 2:1 monitor display yielded 84% and 74% (PPV = 76%, NPV = 82%). Conclusion: The high resolution mode did not significantly increase the sensitivity and specificity of the microcalcification reading. A similar improvement was achieved by the 2:1 display mode, i.e. digital monitor zooming. For the clinical situation this means that there is no diagnostic advantage from using a high resolution target view with this mammographic system
Supplemental material for Initial clinical results with a fusion prototype for mammography and three-dimensional ultrasound with a standard mammography system and a standard ultrasound probe
No full textSupplemental material for Initial clinical results with a fusion prototype for mammography and three-dimensional ultrasound with a standard mammography system and a standard ultrasound probe by Julius Emons, Marius Wunderle, Arndt Hartmann, Marcus Radicke, Claudia Rauh, Michael Uder, Paul Gass , Peter A Fasching, Hanna Langemann, Matthias W Beckmann, Rüdiger Schulz-Wendtland and Sebastian M Jud in Acta Radiologica</p
Induktion und Reparatur von strahleninduzierten DNA-Doppelstrangbrüchen in Blutlymphozyten von Patienten nach Angiografieuntersuchungen - Ansatz einer biologischen Dosimetrie
No full textObjectives The use of ionizing radiation for diagnostic, therapeutic and scientific pur-poses in medical application results in a potential mutagen radiation exposure for patients and operators. In the following thesis the radiation exposure in diagnostic and interventional angiography as a subfield of radiology is considered with comparatively high radiation exposure. The effective biological effect of radiation is measured by determination of DNA double-strand breaks (DNA-DSB). The purpose of this study is to establish the gamma-H2AX immunofluorescence microscopy to measure DNA-DSB in peripheral blood lymphocytes in a first collective of patients undergoing angiographic procedures and medical staff. Materials and Methods We examined the induction of DNA-DSB in blood lymphocytes of 19 patients undergoing different angiographic procedures as well as three operators doing interventional procedures. Individual DSB yields were visualized by detecting the phosphorylated variant of the histone H2AX in lymphocytes with the use of immunofluorescence microscopy. The biological radiation dose to the patients was determined by comparing the in-vivo DSB yields after angiography to values of individual in-vitro-irradiated samples for every patient. To imitate the examination conditions of angiographic procedures we used in-vitro fractioned irradiation. Therefore the cumulative dose (50mGy) was split in fractionated single doses (10 • 5mGy). The effect of the chemotherapeutic epirubicin was tested in-vitro. Results In all patients we saw an induction of DNA-DSB in blood lymphocytes after angiographic procedures. The maximum number of DNA-DSB occurs 15 minutes after irradiation (0.03 – 1.5 DSB /cell), thereafter a rapid loss of the gamma-H2AX foci was observed due to repair procedures. When regarding specific examination regions of the patients separately, the number of DNA-DSB showed a linear correlation to the dose area product (DAP) (e.g. pelvic and leg arteries: R = 0,92 and renal arteries R = 0,99). Compared to a fractionated in-vitro irradiation a single x-ray exposure led to a 30% reduction of the maximum DSB yield with the same total dose. Epirubicin showed a dose dependent induction of DNA-DSB itself. There was no induction of DNA-DSB in blood samples of medical operators dur-ing one working day. Conclusions Gamma-H2AX immunofluorescence microscopy is a reliable and sensitive method to measure the induction and repair of DNA-DSB caused by ionizing radiation during angiographic procedures. The estimation of the biological radiation dose of each patient is possible by a comparison of the in-vivo DNA damage level with the number of DSBs induced by a fractioned in-vitro irradiation imitating the examination conditions and avoiding under estimation of the real radiation damage.Hintergrund und Ziele Der Einsatz von ionisierender Strahlung im Rahmen von diagnostischen, therapeutischen und wissenschaftlichen Zwecken in der Medizin führt zu einer potenziell mutagenen Strahlenexposition für Patienten und Anwender. Im Folgenden wird die Strahlenexposition in der diagnostischen und interventionellen Angiografie als Teilbereich der Radiologie mit relativ hoher Strahlenexposition betrachtet. Die tatsächlich biologisch wirksame Strahlendosis wird anhand der Induktion von DNA-Doppelstrangbrüchen (DNA-DSB) quantifiziert. Ziel der nachfolgenden Arbeit ist es, die Methode der gamma-H2AX-Immunfluoreszenzfärbung zur Detektion von DNA-DSB in peripheren Blutlymphozyten bei Angiografieuntersuchungen zu etablieren und erste Patienten, sowie ärztliche Mitarbeiter zu untersuchen. Methode Untersucht wird die Induktion von DNA-DSB in Blutlymphozyten von 19 Angiografiepatienten und drei interventionellen Radiologen bzw. Kardiologen. Die individuelle Anzahl an DNA-DSB wird durch den Nachweis der phosphorylierten Variante des Histons gamma-H2AX in Blutlymphozyten mittels der indirekten Immunfluoreszenzmikroskopie gemessen. Die biologische Strahlendosis der Patienten wird durch einen Vergleich der in-vivo DNA-DSB nach der Angiografieuntersuchung mit den Werten nach einer in-vitro Bestrahlung der jeweiligen Patientenprobe ermittelt. Zur in-vitro Nachahmung der Bestrahlungsbedingungen der Angiografieuntersuchungen wird eine fraktionierte Bestrahlung durchgeführt, dabei wird die Gesamtdosis (50 mGy) auf mehrere nacheinander applizierte Einzeldosen (10 x 5 mGy) aufgeteilt. Der Effekt des Chemotherapeutikums Epirubicin wird in-vitro getestet. Ergebnisse Bei allen Patienten wurde eine Induktion von DNA-DSB in Blutlymphozyten infolge einer Angiografieuntersuchung nachgewiesen. Die größte Anzahl an DNA-DSB tritt 15 Minuten nach Bestrahlungsende auf (0,03-1,5 DSB/Zelle). Innerhalb kurzer Zeit nahm die Zahl der induzierten DNA-DSBs reparaturbedingt wieder deutlich ab. Betrachtet man die unter-schiedlichen Untersuchungsregionen der Patienten getrennt voneinander wird eine lineare Abhängigkeit zwischen den induzierten DNA-DSB und dem Dosisflächenprodukt (DFP) deutlich (z.B. Becken-Bein-Angiografie R(BBA)=0,92 und Nierenarterien R(NA)=0,99). Die aus der fraktionierten Bestrahlung gewonnenen Daten zur Induktion der DNA-DSB liegen dreißig Prozent unter den Werten einer Einzelbestrahlung bei identischer Gesamtdosis. Epirubicin induziert konzentrationsabhängig selbst DNA-DSB. Bei den die Untersuchung durchführenden Ärzten konnte während eines Arbeitstages keine Induktion an DNA-DSB im Vergleich zur Kontrolluntersuchung vor der Intervention nachgewiesen werden. Schlussfolgerungen Die gamma-H2AX-Immunfluoreszensfärbung ist eine zuverlässige und sensitive Methode zum Nachweis der Induktion und Reparatur von DNA-DSBs infolge ionisierender Strahlung bei Angiografieuntersuchungen. Zur Abschätzung der biologischen Strahlendosis der Patienten kann die Anzahl an DNA-DSBs mit der einer fraktionierten in-vitro Bestrahlung verglichen werden, um die Untersuchungsbedingungen nachzuahmen und eine Unterschätzung des reellen Strahlenschadens zu vermeiden
Paraduodenal pancreatitis as diagnostic challenge: clinical and morphological features of patients with pancreatic pathology involving the pancreatic groove
No full textBackground Paraduodenal pancreatitis (PP) is an inflammation involving the groove zone, delimited by the duodenum lumen, bile duct, and the head of the pancreas. This area may also be involved during acute pancreatitis (AP). The differential diagnosis is clinically relevant, since PP generallypersists, whereas AP resolves. Hence, we compared a cohort of patients with PP and AP involving the groove area. Methods We retrospectively evaluated patients with pathology involving the groove area. The primary aim was to define the diagnostic features of PP compared to non-PP pancreatitis involving the groove area. PP was diagnosed by imaging, while AP was diagnosed according to the revised Atlanta classification and the clinical course, to exclude chronic pancreatitis. Results The study population consisted of 37 patients (32 men, age 56.9 +/- 9.1 years), 25 with a diagnosis of PP (23 men, mean age 54.9 +/- 8.5 years), and 12 (9 men, mean age 61.2 +/- 9.2 years) with AP involving the groove. All 25 patients with PP and 4 (33.3%) with AP reported a history of alcohol abuse, 23 patients (92%) with PP, and 3 (25%) with AP had a history of smoking. On imaging, PP patients presented a signifi & Oslash;tly thicker duodenal wall compared to the AP group (P=0.010). Chronic pancreatitis in the body/tail and exocrine insufficiency was prevalent in PP (P<0.001 and P=0.02). The medial displacement of the gastroduodenal artery was more frequent in the PP group (P=0.011). Conclusion PP has a different clinical and imaging profile compared to AP involving the groove area
The potential of predictive and prognostic breast MRI (P2-bMRI)
No full textMagnetic resonance imaging (MRI) is an important part of breast cancer diagnosis and multimodal workup. It provides unsurpassed soft tissue contrast to analyse the underlying pathophysiology, and it is adopted for a variety of clinical indications. Predictive and prognostic breast MRI (P2-bMRI) is an emerging application next to these indications. The general objective of P2-bMRI is to provide predictive and/or prognostic biomarkers in order to support personalisation of breast cancer treatment. We believe P2-bMRI has a great clinical potential, thanks to the in vivo examination of the whole tumour and of the surrounding tissue, establishing a link between pathophysiology and response to therapy (prediction) as well as patient outcome (prognostication). The tools used for P2-bMRI cover a wide spectrum: standard and advanced multiparametric pulse sequences; structured reporting criteria (for instance BI-RADS descriptors); artificial intelligence methods, including machine learning (with emphasis on radiomics data analysis); and deep learning that have shown compelling potential for this purpose. P2-bMRI reuses the imaging data of examinations performed in the current practice. Accordingly, P2-bMRI could optimise clinical workflow, enabling cost savings and ultimately improving personalisation of treatment. This review introduces the concept of P2-bMRI, focusing on the clinical application of P2-bMRI by using semantic criteria
New insights on accretion in supergiant fast X-ray transients from XMM-Newton and INTEGRAL observations of IGR J17544-2619
No full textXMM–Newton observations of the supergiant fast X-ray transient IGR J17544?2619 are reported and placed in the context of an analysis of archival INTEGRAL/IBIS data that provide a refined estimate of the orbital period at 4.9272?±?0.0004?d. A complete outburst history across the INTEGRAL mission is reported. Although the new XMM–Newton observations (each lasting ?15 ks) targeted the peak flux in the phase-folded hard X-ray light curve of IGR J17544?2619, no bright outbursts were observed, the source spending the majority of the exposure at intermediate luminosities of the order of several 1033?erg?s?1 (0.5–10 keV) and displaying only low level flickering activity. For the final portion of the exposure, the luminosity of IGR J17544?2619 dropped to ?4?×?1032?erg?s?1 (0.5–10 keV), comparable with the lowest luminosities ever detected from this source, despite the observations being taken near to periastron. We consider the possible orbital geometry of IGR J17544?2619 and the implications for the nature of the mass transfer and accretion mechanisms for both IGR J17544?2619 and the supergiant fast X-ray transients (SFXTs) population. We conclude that accretion under the ‘quasi-spherical accretion’ model provides a good description of the behaviour of IGR J17544?2619 and suggests an additional mechanism for generating outbursts based upon the mass accumulation rate in the hot shell (atmosphere) that forms around the neutron star under the quasi-spherical formulation. Hence, we hope to aid in explaining the varied outburst behaviours observed across the SFXT population with a consistent underlying physical model
Evaluation des Liver Imaging Reporting and Data System in einem Kollektiv von Hochrisikopatienten für ein hepatozelluläres Karzinom mit extrahepatischem Tumor
No full textLI-RADS is a worldwide established algorithm for diagnosing liver lesions in patients at high risk for hepatocellular carcinoma (HCC). The guidelines explicitly point out that the algorithm can also be used in patients with an extrahepatic primary tumor. Therefore in this study the accuracy of
LI-RADS is investigated in patients with a diagnosed liver lesion and an extrahepatic primary tumor.
In a three-stage selection process, 33 study participants were selected for the retrospective study from a collective of 9247 patients who received a liver MRI at the University Hospital Erlangen between September 1, 2008 and August 31, 2018. Two experienced radiologists evaluated the MRIs of these patients in 2 rounds each with LI-RADS. The intra- and interreader reliability of the categories and characteristics of LI-RADS and the distribution of the histological findings among the categories were evaluated.
The liver lesions in the patients were 20 HCCs, 6 CCCs and 3 benign lesions. 4 were metastases from extrahepatic tumors located on the skin (melanoma), in the stomach, the breast and in the esophagus. The sensitivity for LR-5, LR-TIV and LR-M was 63,75%, for LR-4, LR-5, LR-TIV und LR-M 90,0% and for LR-3, LR-4, LR-5, LR-TIV und LR-M 100%. The positive predictive value for LR-5 was 95,56%. The interreader reliability for the categories of LI-RADS resulted in
α = 0.83. The intrareader reliability for APHE was
κ = 0.51 (R1), κ = 0.59 (R2), for washout κ = 0.76 (R1),
κ = 0.70 (R2) and for enriching capsule (κ = 0.81 (R1), κ = 0.75 (R2).
The study showed good results for the accuracy of LI-RADS in patients with a liver lesion and an extrahepatic primary tumor. With the algorithm, metastases of extrahepatic tumors can be distinguished from HCCs with a high degree of certainty.LI-RADS ist weltweit ein etablierter Algorithmus zur Befundung von Leberläsionen bei Hochrisikopatienten für ein hepatozelluläres Karzinom (HCC). In den Richtlinien wird explizit darauf hingewiesen, dass der Algorithmus auch bei Patienten mit einem extrahepatischen Primärtumor angewendet werden kann. In dieser Studie wurde daher die Genauigkeit von LI-RADS bei Patienten mit diagnostizierter Leberläsion und extrahepatischem Primärtumor untersucht.
In einem dreistufigen Selektionsprozess wurden für die retrospektive Studie 33 Studienteilnehmer aus einem Kollektiv von 9247 Patienten ausgewählt, die im Zeitraum vom 01.09.2008 bis 31.08.2018 am Universitätsklinikum Erlangen ein Leber-MRT erhalten haben. Zwei erfahrene Radiologen werteten die MRTs dieser Patienten in je 2 Durchgängen mit LI-RADS aus. Es wurden die Intra- und Interreader-Reliabilität der Kategorien und Merkmale von LI-RADS sowie die Verteilung der histologischen Befunde auf die Kategorien evaluiert.
Bei den Leberläsionen der Patienten handelte es sich um 20 HCCs, 6 CCCs und 3 benigne Läsionen. 4 waren Metastasen extrahepatischer Tumore, die an der Haut (Melanom), im Magen, der Mamma und im Ösophagus lokalisiert waren. Die Sensitivität für LR-5,
LR-TIV und LR-M betrug 63,75%, für LR-4, LR-5, LR-TIV und
LR-M 90,0% für LR-3, LR-4,
LR-5, LR-TIV und LR-M 100,0%. Der positiv prädiktive Wert für die Kategorie LR-5 ergab 95,56% Die Interreader-Reliabilität für die Kategorien von LI-RADS ergab
α = 0,83. Die Intrareader-Reliabilität für APHE war
κ = 0,51 (R1), κ = 0,59 (R2), für washout κ = 0,76 (R1),
κ = 0,70 (R2) und für anreichernde Kapsel κ = 0,81 (R1), κ = 0,75 (R2).
Die Studie zeigte gute Ergebnisse für die Genauigkeit von LI-RADS bei Patienten mit einer Leberläsion und einem extrahepatischen Primärtumor. Mit dem Algorithmus können Metastasen extrahepatischer Tumore mit einer hohen Sicherheit von HCCs unterschieden werden
The history of creation of the program imitators of industrial plants at study process
No full textРассматриваются вопросы использования программных имитаторов промышленного контроллера и установок, управляемых им.Problem of use of program imitators of industrial controller and plants are uder consideration
- …
