ISSN:1053-1807    

DOI:10.1002/jmri.1880060102

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1996

数据来源: WILEY

摘要:

AbstractThis article is a summary of the workgroup on Audience/Funding at the recent Society of Magnetic Resonance Workshop on Efficacy and Effectiveness of Imaging: An Evaluation of Methodologies.

ISSN:1053-1807    

DOI:10.1002/jmri.1880060103

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1996

数据来源: WILEY

ISSN:1053-1807    

DOI:10.1002/jmri.1880060104

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1996

数据来源: WILEY

摘要:

AbstractMRI development in the United States is reviewed from 1983 to the present with the intent of projecting future utilization and reimbursement. Since 1992, a decreasing rate of new installations and an aging installed base have markedly lowered the ratio between fixed and variable costs, thereby improving the ability to project cost per study. Variable costs are now estimated to average $175 to $200 per examination, up sharply from earlier reports. Actual costs per study usually exceed $400, even for high volume sites. Major cost contributors are reviewed and methods for identifying impediments to efficient operation are suggested.

ISSN:1053-1807    

DOI:10.1002/jmri.1880060105

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1996

数据来源: WILEY

摘要:

AbstractNew technologies, such as magnetic resonance imaging, are frequently cited as major contributors to the growth of national health care expenditure. The cost‐effectiveness of this modality is commonly challenged, and the lack of health economic documentation increases the level of criticism. Some common methods for evaluating imaging methods with regard to efficacy, cost, and benefits are, therefore, reviewed. Limitations in the assessment of diagnostic imaging are discussed, together with some suggestions as to which methodological approaches may be useful in this field of researc

ISSN:1053-1807    

DOI:10.1002/jmri.1880060106

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1996

数据来源: WILEY

摘要:

AbstractTo evaluate the quality of clinical research studies of magnetic resonance angiography (MRA), the authors reviewed studies of carotid, renal, and lower extremity MRA published in English during 1991‐1994. The purpose, design, and implementation of the study, and the type of statistical information presented, were evaluated. The results were compared with those of previous studies that assessed the quality of MRI research. Fifty‐nine studies of renal (n=10), carotid (n=29), and lower extremity (n=20) MRA were identified; 30 met the inclusion criteria for the analysis. In these papers, presentation of a reference standard was routine, observer blinding was usual, information often was given about patient selection and exclusion, sample sizes were always given, and parameter estimates and statistical analyses were common. However, evidence of research planning was not routine, measurement of interobserver variability was occasional, variability of parameter estimates was usually not estimated, and validation of statistical assumptions was uncommon. On balance the authors conclude that the scientific quality of recent investigations of MRA is better than that of older studies of

ISSN:1053-1807    

DOI:10.1002/jmri.1880060107

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1996

数据来源: WILEY

摘要:

AbstractWe compared two imaging techniques, spiral CT arterial portography (CTAP) and MR imaging, for diagnostic accuracy, procedural cost, and effect on management of 26 patients referred for hepatic surgery for suspected limited malignant liver disease. CTAP and MR imaging were done within a 1‐week period (19 within 24 hours); the results of the studies were interpreted prospectively by separate reviewers. Surgical data were evaluated in conjunction with imaging data in 10 patients. Lesion detection and segmental involvement were determined and sensitivity and specificity were calculated. Procedural cost was determined from hospital billing codes. Effect on patient management was determined by the referring oncologic surgeon. CTAP and MR imaging showed 185 and 176 true‐positive malignant lesions, 15 and zero false‐positive malignant lesions, zero and 18 true‐negative malignant lesions, and 13 and 22 falsenegative malignant lesions, respectively. CTAP and MR imaging showed 107 and 105 true‐positive segments, 11 and zero false‐positive segments, 80 and 91 true‐negative segments, and four and six false‐negative segments, respectively. There was a significant difference in specificity of segmental involvement between MR imaging (1.0 ± 0) compared with CTAP (0.88 ± 0.05),P=.03. Total procedural cost was $3,499 for CTAP and $1,224 for MR imaging. CTAP findings did not change patient management over MR imaging findings in any patient, whereas MR imaging findings resulted in a change in patient management over CTAP findings in seven patients (P=.015). The results of our study suggest that MR imaging has higher diagnostic accuracy and greater effect on patient management than CTAP does and is 6

ISSN:1053-1807    

DOI:10.1002/jmri.1880060108

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1996

数据来源: WILEY

摘要:

AbstractSeventy‐five patients (41 women and 34 men, 20‐85 years old) with clinically suspected deep venous thrombosis (DVT) were examined with MR imaging and sonography. In 26 patients, the final diagnosis was acute femoropopliteal DVT. The sensitivity of MR imaging for detecting this disease was 100% with a 95% confidence interval (CI) of 87‐100%; the specificity was 100% with a CI of 92‐100%; and the accuracy was 96% with a CI of 89‐99%. The correspond‐ ing sensitivity of sonography was 77% with a CI of 53‐92%; the specificity was 98% with a CI of 89‐100%; and the accuracy was 83% with a CI of 72‐90%. In four of the 75 patients, MR images revealed thrombus of the pelvis (n=1) or calf (n=3) without femoropopliteal involvement. The estimated prevalence of isolated calf and/or pelvic DVT was 5% with a CI of 1‐13%. MR imaging is significantly more sensitive (P=.02) and accurate (P<.01) than sonography in the detection of lower extremity DVT, but there was no difference in the specificity of MR imaging and that of

ISSN:1053-1807    

DOI:10.1002/jmri.1880060109

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1996

数据来源: WILEY

摘要:

AbstractIn this essay the author makes predictions on how the future of MRI will develop for the short term, the intermediate term, and the long term; these periods of time are defined as the present to the next 3 years, 3 to 5 years, and beyond 5 years, respectively. For each time period, general scientific trends and specific applications are presented. Despite about 15 years of extensive scientific research and significant application to clinical imaging, there continue to be many opportunities for additional technical development in MRI as its role in clinical use and the extent of its scientific significance expand.

ISSN:1053-1807    

DOI:10.1002/jmri.1880060110

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1996

数据来源: WILEY

摘要:

AbstractAs clinical MRI has evolved, there have been numerous arguments for the use of different field strengths. Those favoring high magnetic field (1.5 T and above) include higher signal‐to‐noise ratio, capability for MR spectroscopy, and other forms of functional MRI, high speed imaging, and high resolution imaging. However, cost remains a significant limitation to the wider dissemination of high field MRI. There are definite cost advantages (capital, operating, siting) to the use of lower field MRI. Much debate has occurred over the past decade regarding the relative diagnostic benefits of high field MRI versus lower field MRI, but few randomized, controlled clinical trials have compared diagnostic accuracy of MRI at various field strengths. In this article, we review the physical principles of the field strength dependence of MRI in relation to image quality. The assessment of the importance of field strength in MR is incomplete without some analysis of diagnostic accuracy versus field strength. Such analysis is difficult to accomplish in an unbiased manner. The use of receiver‐operator‐characteristic (ROC) analysis is probably the best available method to measure diagnostic accuracy of various imaging methods without bias. An ROC study of diagnostic accuracy of 0.5 T versus 1.5 T MRI, examining several common clinical categories, has recently been conducted at our institution. Results from this study demonstrate diagnostic equivalence between these two field strengths in at least two common clinical disease categories (MS and internal derangement of the knee). These results are discussed and related to results from previous field strength

ISSN:1053-1807    

DOI:10.1002/jmri.1880060111

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1996

数据来源: WILEY