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81.
Short-Ti inversion-recovery pulse sequence: analysis and initial experience in cancer imaging 总被引:2,自引:0,他引:2
Inversion recovery (IR), commonly considered a pulse sequence capable of producing T1-weighted images with excellent display of normal anatomy, is versatile: The null point and peak time provide a useful, succinct summary of the properties of IR and its capacity for producing both T1- and T2-weighted images. Shortening of the inversion time (TI) and creation of a short-TI inversion-recovery (STIR) pulse sequence increases sensitivity to malignancy and other abnormalities by making the effects of prolonged T1 and T2 on signal intensity additive and by nulling the signal from fat. The authors examined over 300 patients with various malignancies and compared STIR images with T1- and T2-weighted images obtained at 0.5 T. In 43 cases, signal-difference-to-noise ratios (SD/Ns) were calculated between tumor, fat, and muscle. In general, STIR images demonstrated tumor as a conspicuously high-intensity area in a background of muted, discernible anatomic detail. The good contrast achieved with STIR sequences between tumor and fat (SD/N = 18.1) and tumor and muscle (SD/N = 12.9) consolidated into a single image the information contained separately on T1- and T2-weighted images, which facilitates efficient detection and localization of malignancy. 相似文献
82.
Rosenberg ZS; Jahss MH; Noto AM; Shereff MJ; Cheung Y; Frey CC; Norman A 《Radiology》1988,167(2):489-493
Computed tomography (CT) was performed in 42 patients with 49 clinically suspected tears of the posterior tibial tendon. Twenty-eight of the 49 suspected tears were subsequently surgically explored and repaired. Three patterns of tendon abnormalities were recognized on CT scans: type I-intact, hypertrophied, heterogeneous tendon; type II-attenuated tendon; and type III-absence of a portion of a tendon. Types I and II correlated with partial rupture seen during surgery, and type III correlated with complete rupture of the tendon. CT findings were accurate in 96% of the patients who underwent surgery. In four cases (14%), tendon rupture was seen on CT scans, but the extent of the injury was underestimated and the rupture was misclassified. Reactive periostitis of the distal tibia was seen in 71% of diseased tendons and may represent an important factor in the diagnosis of tendon rupture. 相似文献
83.
OBJECTIVES: The paper gives an overview on the components and the polymer chemical aspects of currently used self-etching enamel-dentin primers/adhesives. In addition, the contribution of new adhesives monomers and cross-linkers exhibiting enhanced hydrolytic stability than methacrylates to improve the performance of single-bottle adhesives is discussed. SOURCES: Information from original scientific papers or reviews about enamel-dentin adhesives, the patent literature concerning dental adhesives and manufacturer information of commercial self-etching adhesives were included in this review. DATA: The most efficient self-etching enamel-dentin adhesives are based on strongly acidic adhesive monomers, containing dihydrogenphosphate, phosphonic acids or carboxylic acid groups. Serious problems of single-bottle water-based, strongly acidic self-etching enamel-dentin adhesives arise both from the hydrolytic instability of the methacrylate monomers used and the side reaction of the applied initiator components. CONCLUSIONS: The stability of the self-etching enamel-dentin adhesives can be improved by using new acrylic ether phosphonic acids or mono- or difunctional acrylamides, while more stable and compatible components have to be developed in the future. 相似文献
84.
Axel Stäbler M.D. Richard G. H. Baumeister M.D. Ulrike Szeimies Ulrich Fink M.D. Hermann Berger M.D. 《Skeletal radiology》1994,23(2):103-106
Post-traumatic ulnar carpal translocation is a rare, severe ligamentous injury to the wrist. Radiologic findings include widening of the radiocarpal joint space at the radial styloid process and ulnar displacement of the carpus. Less than 50% of the lunate articulates with the radius in the neutral position; the lunate is tilted dorsally with palmar subluxation due to a ruptured radioscapholunate (RSL) ligament. This malposition should be called rotatory palmar subluxation of the lunate (RPSL), by analogy to rotatory subluxation of the scaphoid (RSS). In contrast to dorsiflexed intercalated segment instability (DISI), in RPSL the RSL ligament is ruptured and, in the majority of cases, the scapholunate ligament remains intact. A prompt diagnosis should lead to successful treatment. 相似文献
85.
86.
Ulrike Lueken Ulrich Seidl Lena V?lker Elisabeth Schweiger Andreas Kruse Johannes Schr?der 《The American journal of geriatric psychiatry》2007,15(5):376-385
OBJECTIVE: Apathy is among the most frequent neuropsychiatric symptoms in dementia, particularly Alzheimer disease. The Apathy Evaluation Scale (AES) has been widely employed for assessing apathy in different patient groups. To further facilitate the usage of the AES, an abbreviated version was constructed. METHOD: On basis of a sample of 356 nursing home residents, a cross-validation procedure was carried out to develop a brief version of the AES. According to a thorough clinical examination, 85% of the residents were demented, 8% presented with mild cognitive impairment, whereas 7% did not present any cognitive deficits. After subdividing the patient group into two matched samples, the first subsample was used to identify problematic items due to defined psychometric and content-related criteria. The original 18-item scale was thus reduced to 10 items. Psychometric properties of the shortened version were subsequently reassessed in the second subsample. RESULTS: The short version demonstrated favorable psychometric properties that could be confirmed by cross-validation with the second sample. Correlations with the original full-length version were high (r = 0.97 for both subsamples); the shortened scale yielded no substantial losses regarding internal consistency or construct validity (correlations with the respective subscales of the Neuropsychiatric Inventory). CONCLUSION: The frequency of apathetic symptoms in the nursing home residents included confirms the clinical importance of apathy for understanding dementia. Given this specific patient population, setting, and mode of data collection, the short-version AES seems to be a valuable and time-efficient instrument for assessing apathy. 相似文献
87.
Robert F Bonvini Ulrich Sigwart Vitali Verin 《Catheterization and cardiovascular interventions》2007,69(2):274-276
We report the case of a 36-year-old woman admitted for cryptogenic stroke, in whom the Patent Foramen Ovale (PFO) diameter measurement, with a purpose built sizing balloon, performed before the closure procedure, was complicated with the rupture of the inter-atrial septum generating an Atrial Septal Defect (ASD) with a significant left-to-right shunt. This kind of complication may not be easy to handle, changing the initial procedural strategy from PFO to ASD closure technique requiring specific material and operator's technical skill. 相似文献
88.
Prof. Dr. Bernhard Schmitt Prof. Dr. Michael Albani Priv.-Doz. Dr. Thomas Bast Prof. Dr. Ulrich Brandl Prof. Dr. Rudolf Korinthenberg Prof. Dr. Gerhard Kurlemann Prof. Dr. Bernd Neubauer Prof. Dr. Ulrich Stephani Dr. Markus Wolff 《Zeitschrift für Epileptologie》2007,20(3):113-119
Zusammenfassung
Der richtige Zeitpunkt für das Absetzen der Antiepileptika (AE) im Kindesalter ist unbekannt. Anl?sslich ihrer Jahrestagung
haben die Mitglieder des K?nigsteiner Arbeitskreises (KA) eigene und publizierte Absetzstrategien diskutiert. Da Studien zu
diesem Thema rar und widersprüchlich sind, wurde beschlossen, die Diskussionsergebnisse im Sinne einer Meinungs?u?erung zu
publizieren.
Bei Neugeborenen besteht übereinstimmung, AE innerhalb von 2 bis 12 Wochen nach dem letzten Anfall abzusetzen. Bei BNS-Epilepsie
wird Vigabatrin nach 6 bis 12 und Sultiam nach 6 bis 36 Monaten abgesetzt. Nach erfolgreicher Steroidtherapie setzt die Mehrheit
des KA die AE-Therapie für zwei Jahre fort. Für die Rolando-Epilepsie sind 1 bis 3 Jahre Anfallsfreiheit ausreichend, auch
wenn fokale Spike-Waves persistieren. Im Falle einer symptomatisch fokalen Epilepsie ist die Grunderkrankung mitentscheidend
für das Absetzen. Die Behandlung der Absencen-Epilepsie kann nach zwei Jahren beendet werden, w?hrend bei myoklonisch- astatischer
Epilepsie meist eine 2- bis 5-j?hrige Anfallsfreiheit vorausgesetzt wird. Konsens besteht darüber, dass die Juvenile- Myoklonus-Epilepsie
ein sehr hohes Rückfallrisiko birgt. Dennoch ziehen einzelne neurop?diatrische Mitglieder einen Absetzversuch nach 2- bis
3-j?hriger Anfallsfreiheit in Betracht. Die überwiegende Mehrheit des KA führt aber bei gesicherter Diagnose keinen Absetzversuch
durch. Bezüglich der Absetzgeschwindigkeit wird ein langsames (3 bis 12 Monate) Ausschleichen favorisiert. Nur zwei Mitglieder
praktizieren ein rascheres Absetzen (<3 Monaten). Das EEG spielt für die Entscheidung eine untergeordnete Rolle und bleibt
auf bestimmte Epilepsieformen (z. B. Absencen-Epilepsie) beschr?nkt.
Das vorliegende Papier gibt die Meinung des KA wieder und eignet sich nicht im Sinne einer Leitlinie. Für die Entscheidung
AE abzusetzen, ist immer eine individuelle Abw?gung von Grunderkrankung, Epilepsieform und psychosozialen Umst?nde erforderlich.
相似文献
89.
90.