Preoperative diagnosis of breast diseases by dynamic MR mammography: Cut-off point establishment for signal intensity ratio

Abstract

We have demonstrated that the dynamic study for breast lesions by magnetic resonance imaging(MRI)can differentiate benign from malignant lesions objectively.The cases were 57 histopathologically appraised breast lesions, including 20 cases of breast cancer, 28 cases of mastopathy, 8 cases of fibroadenoma and 1 caseof intraductal papillomatosis. We plotted time-signal intensity ratio curves and then determined 95% confidence intervals, plotting the signal intensity ratio for both breast cancer and mastopathy every 30 seconds during dynamic magnetic resonance mammography(MRM)after gadolinium-diethylenetriamine pentaacetic acid(Gd-DTPA)administration, and further established cut-off points to differentiate between them. We then tried of estimate objectively the benign-malignant differentiation to breast lesions by confirming their signal intensity ratio to be more or less than the cut-off points. We advocate this procedure, and call it the " dynamic ratio method. " As a result, we found highly significant differences between breast cancer and mastopathy at 30 and 60 seconds after Gd-DTPA administration(P < 0.0001). We also confirmed that the cut-off point for the dynamic ratio method was equivalent to 1.4 and 1.8 times the precontrast signal intensity value at30 and 60 seconds after administration of Gd-DTPA respectively. By performing this dynamic ratio method preoperatively we can assess objectively not only the malignancy of breast lesions, but also neighboring infiltration, extending intraductal component, and lymph node metastasis. Furthermore, the dynamic ratio method provides detailed information for selecting the appropriate region for breast conserving surgery preoperatively, and can be expected to reduce unnecessary biopsies of benign cases. The dynamic ratio method had a sensitivity of 95.0%, a specificity of 81.1% and a positive predictive value of 73.1%. Also, for detectinginvasive ductal carcinoma, the sensitivity of the dynamic ratio method was 100.0%.

Dynamic magnetic resonance imaging of cervical lymph nodes in patients with oral cancer: utility of the small region of interest method in evaluating the architecture of cervical lymph nodes

“…Thus, the specifi city of time-intensity curves with respect to histopathological characteristics may be further increased by taking into account high and low maximum contrast index values in future analyses of time-intensity curves obtained using the small ROI method. For the preoperative diagnosis of breast lesions using dynamic magnetic resonance mammography, Tsuchiya et al 1 selected a signal intensity ratio cutoff point to distinguish benign and malignant tumors, and also to detect surrounding infi ltration and lymph node metastasis. The selection of a cutoff point for time-intensity curves obtained using the small ROI method might lead to increased accuracy in the detection of cervical lymph node metastasis, which would further demonstrate the usefulness of detecting metastases by the small ROI method.…”

“…Studies using this form of imaging to diagnose lymph node metastasis are limited to those on the diagnosis of metastatic lymph nodes in breast cancer. 1 To our knowledge, there are no published reports on the use of dynamic MRI to examine the cervical lymph nodes.…”

“…In some instances, however, this imaging results in signals of the same intensity even though the histological character of the samples differs. Dynamic MRI, which allows the evaluation of hemodynamics in lesions through continuous acquisition following intravenous injection of contrast medium and observation over time, is considered useful in such instances [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] and has been reported to allow the differential diagnosis of benign and malignant tumors based on time-intensity curves. [2][3][4][5][6][7][11][12][13][14][15][16] Reports vary, however, regarding the differentiation of benign from malignant tumors using time-intensity curves, and there are as yet no fi xed diagnostic criteria.…”

Performance Assessment of Phased-Array Coil in Breast MR Imaging

“…Breast MR imaging now plays an important role in breastconserving therapy because of its superior ability to depict tumor mass as well as peritumoral inˆltra-tion such as extensive intraductal components. 5 Successful MR imaging of breast cancer requires high spatial resolution and good image uniformity. PAC technology allows for simultaneous acquisition and subsequent compiling of data from a multitude of closely positioned receiving coils; moreover, it oŠers the SNR and resolution of a small surface coil over a FOV normally associated with body coil imaging with no increase in imaging time.…”