ISSN:0899-3459    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

The appropriate role for magnetic resonance imaging (MRI) as an adjunct technique to mammography in the detection, diagnosis, staging, and therapy management of breast cancer has been the subject of much current research. The clinical application determines the choice of imaging technique. Time restraints due to the rapid kinetics of contrast enhancement require that trade-offs be made between spatial and temporal resolution, with a resulting effect on sensitivity and specificity. This article discusses some general requirements and recommendations for breast MRI techniques, including dedicated radiofrequency coils, pulse sequence specifications and image quality considerations, fat-suppression techniques, methods of contrast administration, and image postprocessing and interpretation.

ISSN:0899-3459    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

In the past decade, most studies have shown that in selected indications of breast imaging, the overall accuracy can be improved by the additional use of contrast-enhanced magnetic resonance imaging (MRI). The sensitivity of contrast-enhanced MRI for invasive malignancy is >98%: reported specificity, however, ranges from 37% to 97%. This range of values is predominantly caused by different patient preselection and interpretation criteria. Other factors, such as technique (e.g., choice of pulse sequence and echo time, slice thickness, reduction in artifacts, dosage of contrast agent, and methods for elimination of fat signal), hormonal influences (menstrual cycle and hormonal replacement therapy), and levels of verification, influence the accuracy and reproducibility of contrast-enhanced MRI. An appropriate application of MRI is highly desirable because of the increased costs of imaging, increased rates of biopsy due to false-positive results, and possibility of false-negative results caused by technical failures and interpretation errors. We present an overview of the sensible application and interpretation of contrast-enhanced MRI of the breast based on our experience and on published data.

ISSN:0899-3459    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Contrast-enhanced magnetic resonance imaging (MRI) is being used increasingly as a complementary diagnostic modality in breast imaging of preselected patients. The exclusion of multicentricity before surgery and the differentiation between a scar and a carcinoma are well-accepted indications of this method. Problems result when suspicious lesions found with MRI cannot be visualized with mammography or ultrasonography. In these cases, MRI-based guidance systems are needed to guide needle biopsy or allow localization of the lesion before surgery. At our institution. 167 MR-guided interventions (35 percutaneous biopsies and 132 preoperative localizations) have been performed with the use of different types of add-on devices during the past 3 years. Percutaneous biopsy (31 fine needle aspiration and four core biopsies) revealed 24 benign and 8 malignant lesions, 3 biopsies were insufficient. Histologic examination after MR-guided wire localization showed benign findings in 68 lesions (52%) and malignancy in 64 lesions (48%). Technical aspects, experiences, advantages, and disadvantages of our system as well as those of other devices are reported and discussed. MR-compatible equipment for interventions of the breast is demonstrated. In conclusion, we perform MR-guided interventions of the breast routinely in indicated cases at a rate of −3–5% for all patients undergoing diagnostic contrast-enhanced MRI of the breast.

ISSN:0899-3459    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

For many solid carcinomas, high-resolution cross-sectional imaging has changed cancer staging, the evaluation of therapeutic response, the detection of recurrence, and even how therapy is selected and performed. Such imaging has not yet had similar effects on breast cancer. Evaluations of therapeutic response in breast carcinomas have been impeded by the current limited methods of evaluating breast tumor size and extent: clinical palpation, ultrasonography, and mammography. The use of magnetic resonance imaging (MRI) of the breast in the evaluation of breast tumors brings the advantages of high-resolution cross-sectional imaging to breast cancer staging and treatment evaluation and is likely to greatly enhance research efforts in this complex disease. MRI of the breast has evolved to be the most accurate noninvasive technique for local staging of breast cancer. MRI is most accurate in measuring tumor size and detecting multicentric disease. These staging characteristics affect the selection of therapy and initial determination of prognosis; therefore. MRI of the breast can change the assessment of fundamental parameters on which treatment is selected. Because clinical trials of new cancer treatments are predicated on proper and accurate characterization of the tumor, MRI also should affect how clinical trials are performed and evaluated.

ISSN:0899-3459    

出版商:OVID    

年代:1998

数据来源: OVID