Ortendahl  DA; Hylton  N; Kaufman  L; Watts  JC; Crooks  LE; Mills  CM; Stark  DD 《Radiology》1984,153(2):479-488

The response of different magnetic resonance (MR) techniques to tissue parameters - T1, T2, and N(H) - is a determinant of clinical efficacy. The large possible number of imaging techniques and range of variable parameters for each make it difficult to perform exhaustive evaluations in a single patient or even in animal models. In addition, changes in operating magnetic field strength change the relaxation times sufficiently so that the efficacy of a technique at a given field does not imply similar results at another field value. Tools are demonstrated that permit the evaluation of the efficacy of any model of response to tissue parameters, and also allow the investigation of the effects of changing magnetic field. Global maps of signal difference between tissues as well as calculated images are obtainable from a minimally sufficient data set. These tools serve as an important adjunct to experimental work.  相似文献   

  总被引：2，自引：0，他引：2  

Sauser  DD; Nelson  RC; Lavine  MH; Wu  CW 《Radiology》1983,148(3):653

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  总被引：7，自引：0，他引：7  

Stark  DD; Moss  AA; Brasch  RC; deLorimier  AA; Albin  AR; London  DA; Gooding  CA 《Radiology》1983,148(1):101

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  总被引：1，自引：0，他引：1  

Fitzpatrick  JH; Gilboe  DD; Drewes  LR; Betz  AL 《The American journal of physiology》1976,231(6):1840-1846

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Baltaxe  HA; Shaw  DD; Connolly  JF 《Radiology》1980,137(1):53

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E Bartoli  M Molaschi  M Massobrio  P Sismondi  S Sartoris  A Bocci  F Pupita 《Minerva ginecologica》1966,18(5):220-225

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  总被引：3，自引：0，他引：3  

Elizondo  G; Weissleder  R; Stark  DD; Guerra  J; Garza  J; Fretz  CJ; Todd  LE; Ferrucci  JT 《Radiology》1990,174(3):797

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Ozer  H; George  SL; Schiffer  CA; Rao  K; Rao  PN; Wurster-Hill  DH; Arthur  DD; Powell  B; Gottlieb  A; Peterson  BA 《Blood》1993,82(10):2975-2984

We investigated whether recombinant alpha 2b interferon (r alpha 2bIFN) would reduce the proportion of bone marrow Philadelphia chromosome (Ph) cells in chronic-phase chronic myelogenous leukemia (CML) by treating 107 previously untreated patients daily with r alpha 2bIFN at 5 x 10(6)IU/m2 subcutaneously. Patients with complete remission, partial remission, or partial hematologic remission received treatment until progression; those with progressive disease were taken off study and observed for survival. Sixty-three (59%) of the patients achieved at least a partial hematologic remission (24 complete remissions and 39 partial remissions). The median time to response for the 63 responders was 3.4 months, with a median duration of remission of 52 months and with 81% of responders continuing in remission beyond 12 months. The median survival for the 107 patients was 66 months. Of 78 patients with cytogenetic follow-up data, 31 (40%) achieved a partial cytogenetic response (n = 17) or a complete cytogenetic response (n = 14). The percentage of cytogenetic responders among all patients was 29% (31 of 107 patients). The median time to first cytogenetic response was 9 months. A major dose reduction of r alpha 2bIFN (> or = 50%) was required at some time during treatment in 38% of patients, 26% required 10% to 49% dose reductions, and 36% had minor dose reductions of < or = 10%. No association was observed between dose received and the attainment of a cytogenetic response. None of the usual prognostic factors (sex, race, performance status, weight loss, time from diagnosis to treatment, hepatosplenomegaly, age, symptoms, hemoglobin, or platelet, blast, basophil, or white blood cell count) were significantly related to survival. These data provide confirmation that major cytogenetic responses to prolonged administration of subcutaneous r alpha 2bIFN occur in 20% to 38% (95% confidence interval) of chronic- phase Ph-positive patients. Although it is hypothesized that patients achieving major cytogenetic responses to r alpha 2bIFN should have prolonged remission duration and survival compared with nonresponders, analyses of the effect of cytogenetic responders by both \"landmark\" and time-dependent covariate techniques fail to provide statistically significant evidence for an effect of cytogenetic response on remission duration or survival. This may be due in part to an effect size insufficiently large to be detected with the number of patients treated in this study. Thus, confirmation of remission duration or survival benefit, if any, of r alpha 2bIFN therapy in Ph-positive chronic-phase CML must await the outcome of randomized trials comparing IFN with conventional agents.  相似文献   

  总被引：2，自引：0，他引：2  

Weissleder  R; Stark  DD; Rummeny  EJ; Compton  CC; Ferrucci  JT 《Radiology》1988,166(2):423-430

Ferrite, a new magnetic resonance (MR) contrast agent, was evaluated in the detection and diagnosis of splenic lymphoma. Before administration of ferrite, normal rat spleens and spleens with diffuse lymphoma showed similar in vitro relaxation times and in vivo MR imaging signal-to-noise ratios (S/N). After the administration of ferrite (50 mumol Fe/kg), the T2 time of lymphomatous spleen was 27.0 msec +/- 2.9 (mean +/- standard deviation), which was significantly greater than that of normal spleen (10.7 msec +/- 1.5, P less than .005). The S/N of ferrite-enhanced in vivo MR images of lymphomatous spleen was 12.4 +/- 0.9, which was significantly greater than normal (5.7 +/- 0.2, P less than .005). Similar experiments with animal models of micronodular lymphoma also demonstrated that ferrite-enhanced MR imaging can distinguish micronodular lymphoma from normal spleen. Benign splenomegaly, studied with an animal model of erythroid hyperplasia, showed ferrite-enhanced MR tissue characteristics that were indistinguishable from those of normal spleen.  相似文献   

    

Lappas  JC; Maglinte  DD; Kopecky  KK; Cockerill  EM; Lehman  GA 《Radiology》1988,168(1):35-37

In a prospective study, the effect of infusion of a low-density contrast material was evaluated as an adjunct to high-density, double-contrast imaging of the sigmoid colon. After double-contrast barium enema (DCBE) study, 52 consecutive patients with sigmoid diverticulosis received an additional 500-750-mL enema either with water or a 1.5% barium suspension for computed tomography. Rectosigmoid radiographs were evaluated for luminal distention, visualization of the interhaustral space, definition of diverticula, and interpretation of polypoid defects. While double-contrast views were excellent in 21% of patients, improvement in multiple factors by water or 1.5% barium flush resulted in improved sigmoid images in 65% and 75% of patients, respectively. Polyps were confirmed and artifactual defects confidently excluded. Sigmoid flush, particularly with low-density barium, is a simple adjunct to DCBE study that improves visualization of the diverticular sigmoid and increases interpretive confidence.  相似文献