Nuclear magnetic resonance in the diagnosis of breast cancer.
ABSTRACT We believe that the preponderance of evidence suggests that MRI is less accurate than conventional mammography in the diagnosis of primary cancer of the breast. Thus, it currently has no established place in algorithms for the evaluation of patients suspected of having breast cancer. MRI could be used to evaluate masses with mammographically smooth, well-defined margins, since high signal intensity (greater than fat) in a T2-weighted image is a highly specific indicator of benignancy in such lesions. However, most of these masses are cysts and can be reliably and less expensively identified as such by sonography. Nonetheless, MRI might be used to re-evaluate a smooth, well-defined mass if sonography has failed to identify the lesion as a cyst. MRI might be particularly useful in this regard if a lesion is difficult to evaluate by other modalities because it is located adjacent to the chest wall, is deep within a very large breast, or is obscured by a breast prosthesis. MRI with Gd-DTPA may be useful in evaluating radiographically dense breasts or in differentiating breast malignancies from irregular dysplastic or scar tissue. However, further investigation of this technique is needed. It has been hoped that in vivo measurement of T1 and T2 or in vivo NMR spectroscopy might improve the accuracy of noninvasive diagnosis of cancer of the breast. However, there is currently no credible evidence that in vivo measurements of relaxation times provide useful indexes for the diagnosis of breast cancer. In vivo NMR spectroscopy of nuclei other than P may ultimately provide reliable criteria for noninvasive diagnosis of breast cancer in humans, but the technique is currently in its infancy.
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ABSTRACT: Single slice MR images were obtained from 9 normal breasts, 17 breasts with benign tumors, and 11 breasts with malignant tumors using an interleaved (mixed) spin echo (SE) inversion-recovery (IR) imaging sequence. SE and IR MR images were synthesized with variable repetition, echo and inversion times from the mixed sequence data. These images were used to qualitatively evaluate the contrast possibilities available when imaging the breast with MR imaging. Proton T1 and T2 relaxation times were determined for normal breast tissues and malignant and benign breast tumors from pure T1 and T2 images calculated using the mixed sequence data. The mean T1 value in benign tumors of 1,049.02 +/- 40.31 was found to be significantly longer (p < 0.0001) than the mean value of malignant tumors (876.09 +/- 27.83) and normal tissues (795.64 +/- 21.12). The value of T2 in benign tumors (89.15 +/- 8.33) was significantly longer (p < 0.01) than the value of T2 in normal tissues (62.82 +/- 4.06). The mixed sequence can be applied to improve image contrast between malignant tumors, benign tumors, and normal tissues of the breast and can potentially differentiate between these tissues in vivo.Acta Radiologica 07/1993; 34(4):356-61. DOI:10.1080/02841859309173257 · 1.35 Impact Factor
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ABSTRACT: A dynamic contrast-enhanced MRI technique for whole breast examinations is presented. The fast kinetics of tissue response during and after constant-rate intravenous infusion of gadolinium diethylenetriaminopentaacetic acid was resolved using a strongly T1-weighted saturation recovery TurboFLASH sequence that makes it possible to acquire signal-time courses sequentially from 15 adjacent slices with a temporal sampling rate of 21 s. On the basis of the mathematically established and experimentally verified linear relationship between the measured saturation recovery TurboFLASH signal variation and the gadolinium diethylenetriaminopentaacetic acid concentration in the tissue, the signal-time courses were analyzed within the framework of pharmacokinetic modeling. In our study, the tissue response was parameterized adequately using an open linear two-compartment model. With this approach, the tissue specific information contained in the signal-time course can be described using only two parameters: an amplitude A, reflecting the degree of MR signal enhancement, and an exchange parameter k21, characterizing vascular permeability and perfusion of the tissue. A clearly arranged representation of the large amount of data (480 saturation recovery TurboFLASH breast images/examination) was accomplished by means of color coding of the computed parameters, resulting in one color-coded pharmacokinetic parameter map/cross-section.Magnetic Resonance in Medicine 04/1995; 33(4):506-14. DOI:10.1002/mrm.1910330408 · 3.40 Impact Factor
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ABSTRACT: Both benign and malignant breast lesions may exhibit intense contrast enhancement when imaged using gadolinium-enhanced MRI. We propose a quantitative approach for fitting dynamic signal intensity (SI) data that may distinguish benign from malignant lesions. We studied 78 lesions in 75 women (18 malignancies, 16 fibroadenomas, and 44 other benign breast lesions) to determine the potential of this model for decreasing false-positive MR results. Twenty-eight lesions showed no enhancement; all were benign. One lesion showed a complex pattern not amenable to region-of-interest analysis and was considered a false positive. SI versus time data for the remaining 49 lesions were fit to the proposed model. We found that one parameter, M, the normalized slope of the SI enhancement profile evaluated at half the maximal signal intensity, seemed to be highly correlated with malignancy and offered improved discrimination between malignant and benign lesions compared to a previously published two-point slope method.Journal of Magnetic Resonance Imaging 09/1996; 6(5):743-52. DOI:10.1002/jmri.1880060507 · 2.79 Impact Factor