Comparison of dynamic contrast-enhanced MRI parameters of breast lesions at 1.5 and 3.0 T: a pilot study.

OBJECTIVE: To compare dynamic contrast-enhanced (DCE) MRI parameters from scans of breast lesions at 1.5 and 3.0 T. METHODS: 11 patients underwent paired MRI examinations in both Philips 1.5 and 3.0 T systems (Best, Netherlands) using a standard clinical fat-suppressed, T1 weighted DCE-MRI protocol, with 70-76 s temporal resolution. Signal intensity vs time curves were fit with an empirical mathematical model to obtain semi-quantitative measures of uptake and washout rates as well as time-to-peak enhancement (TTP). Maximum percent enhancement and signal enhancement ratio (SER) were also measured for each lesion. Percent differences between parameters measured at the two field strengths were compared. RESULTS: TTP and SER parameters measured at 1.5 and 3.0 T were similar; with mean absolute differences of 19% and 22%, respectively. Maximum percent signal enhancement was significantly higher at 3 T than at 1.5 T (p = 0.006). Qualitative assessment showed that image quality was significantly higher at 3 T (p = 0.005). CONCLUSION: Our results suggest that TTP and SER are more robust to field strength change than other measured kinetic parameters, and therefore measurements of these parameters can be more easily standardized than measurements of other parameters derived from DCE-MRI. Semi-quantitative measures of overall kinetic curve shape showed higher reproducibility than do discrete classification of kinetic curve early and delayed phases in a majority of the cases studied. ADVANCES IN KNOWLEDGE: Qualitative measures of curve shape are not consistent across field strength even when acquisition parameters are standardized. Quantitative measures of overall kinetic curve shape, by contrast, have higher reproducibility.

Characterizing early contrast uptake of ductal carcinoma in situ with high temporal resolution dynamic contrast-enhanced MRI of the breast: a pilot study.

Improvements in the reliable diagnosis of preinvasive ductal carcinoma in situ (DCIS) by dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) are needed. In this study, we present a new characterization of early contrast kinetics of DCIS using high temporal resolution (HiT) DCE-MRI and compare it with other breast lesions and normal parenchyma. Forty patients with mammographic calcifications suspicious for DCIS were selected for HiT imaging using T(1)-weighted DCE-MRI with ∼7 s temporal resolution for 90 s post-contrast injection. Pixel-based and whole-lesion kinetic curves were fit to an empirical mathematical model (EMM) and several secondary kinetic parameters derived. Using the EMM parameterized and fitted concentration time curve for subsequent analysis allowed for calculation of kinetic parameters that were less susceptible to fluctuations due to noise. The parameters' initial area under the curve (iAUC) and contrast concentration at 1 min (C(1 min)) provided the highest diagnostic accuracy in the task of distinguishing pathologically proven DCIS from normal tissue. There was a trend for DCIS lesions with solid architectural pattern to exhibit a negative slope at 1 min (i.e. increased washout rate) compared to those with a cribriform pattern (p < 0.04). This pilot study demonstrates the feasibility of quantitative analysis of early contrast kinetics at high temporal resolution and points to the potential for such an analysis to improve the characterization of DCIS.

Detection of in situ mammary cancer in a transgenic mouse model: in vitro and in vivo MRI studies demonstrate histopathologic correlation.

Improving the prevention and detection of preinvasive ductal carcinoma in situ (DCIS) is expected to lower both morbidity and mortality from breast cancer. Transgenic mouse models can be used as a 'test bed' to develop new imaging methods and to evaluate the efficacy of candidate preventive therapies. We hypothesized that despite its microscopic size, early murine mammary cancer, including DCIS, might be accurately detected by MRI. C3(1) SV40 TAg female mice (n=23) between 10 and 18 weeks of age were selected for study. Eleven mice were subjected to in vitro imaging using a T(2)-weighted spin echo sequence and 12 mice were selected for in vivo imaging using a T(1)-weighted gradient echo, a T(2)-weighted spin echo and high spectral and spatial resolution imaging sequences. The imaged glands were carefully dissected, formalin fixed and paraffin embedded, and then H&E stained sections were obtained. The ratio of image-detected versus histologically detected cancers was obtained by reviewing the MR images and H&E sections independently and using histology as the gold standard. MR images were able to detect 12/12 intramammary lymph nodes, 1/1 relatively large (approximately 5 mm) tumor, 17/18 small (approximately 1 mm) tumors and 13/16 ducts distended with DCIS greater than 300 microm. Significantly, there were no false positives--i.e., image detection always corresponded to a histologically detectable cancer in this model. These results indicate that MR imaging can reliably detect both preinvasive in situ and early invasive mammary cancers in mice with high sensitivity. This technology is an important step toward the more effective use of non-invasive imaging in pre-clinical studies of breast cancer prevention, detection and treatment.

What is the role of cytopathologists in stereotaxic needle biopsy diagnosis of nonpalpable mammographic abnormalities?

The popularity of screening mammography has led to increased detection of mammographic lesions that require pathologic diagnosis. Stereotaxic needle biopsy techniques to sample such lesions can be used to either identify those lesions that require excision from those that can be followed, or to confirm a mammographic impression of malignancy prior to excision. Stereotaxic core biopsy (SCBX) and stereotaxic fine needle aspiration (SFNA) have rarely been directly compared. For this review we undertook a uniform re-analysis of the data that was presented in the published studies of SFNA and/or SCBX. The main endpoint was the negative predictive value (NPV) that measures the frequency that a benign diagnosis is truly benign. There was variability in NPV (likely due to sampling methods) and specific aspects of sampling techniques are discussed. The NPV was compared to indicators of selection of lesions to biopsy (frequency of invasive cancer in the study population), mammographic characteristics (masses or microcalcifications), and the reported nondiagnostic rates. The general conclusion is that SFNA and SCBX are equivalent in accuracy, with considerable variability that reflects the types of lesions that are selected for biopsy and the thoroughness of sampling. For SFNA studies, nondiagnostic rates were inversely related to NPV, and therefore have clinical implications. This was not shown for SCBX studies, and probably reflects an inability to correctly identify non-representative tissue biopsies. The main advantage for including cytologic methods with stereotaxic breast biopsy is immediate sample assessment, and this advantage can also be applied to core needle procedures.

Prostatic adenocarcinoma metastatic to the breasts: report of a case with diagnosis by fine needle aspiration biopsy.

Metastases of tumors of extramammary origin to the breast are extremely uncommon. We report the case of an 81-year-old man with a history of prostatic adenocarcinoma treated with adjuvant estrogen therapy, who presented with bilateral palpable mammary masses. Mammographic study showed irregular solid nodules. Fine needle aspiration (FNA) biopsy was performed. The aspiration smears showed single cells with high nuclear/cytoplasmic ratios, prominent nucleoli, and rare acinar formations. Immunocytochemical studies using antibodies against prostate-specific antigen and prostate-specific acid phosphatase confirmed the diagnosis of metastatic prostatic adenocarcinoma, allowing appropriate treatment.

Stereotaxic aspiration biopsy in the evaluation of mammographically detected clustered microcalcification.

BACKGROUND: Stereotaxic fine-needle aspiration biopsy (SFNA) of mammographically detected nonpalpable lesions of the breast provides accurate diagnosis and may eliminate many unnecessary excisional biopsies of areas of microcalcification. METHODS: SFNA of microcalcification of indeterminate radiologic significance was performed on 125 patients (1991-1994), yielding 130 specimens (2 sites in 2 patients and bilateral aspirations in 3 patients). Stereotaxic localization was performed, and samples from within the area of microcalcification were obtained using 22-gauge needles. Smears stained with a Giemsa-type stain were prepared and studied by a cytopathologist during the procedure to determine the adequacy of each specimen. RESULTS: Of 130 specimens, 104 (80%) were cytologically benign, 13 (10%) were atypical, 6 (4.6%) were suspicious, and 7 (5.3%) were malignant. All malignant diagnoses were confirmed by subsequent operative biopsy. Follow-up was available in 74 of 104 benign cases (71%): surgical excisions (all benign) in 8 cases and follow-up mammograms at 6 months to 5.8 years in 66 cases (no radiologic change in 64 cases and 2 [1.9%] cases with new radiologic findings [SFNAs of the new radiographic abnormality revealed adenocarcinoma in both]). CONCLUSIONS: SFNA is a reliable and cost-effective method of evaluating indeterminate microcalcification; however, mammographic follow-up is indicated because of the possibility of subsequent and independent cancers.

Invasive lobular and ductal carcinoma: mammographic findings and stage at diagnosis.

The authors reviewed 316 cases of breast carcinoma diagnosed from January 1, 1986, to December 31, 1989. Clinical data and mammograms were available for all patients. Of the 316 carcinomas, 272 (86.1%) were invasive; 37 (13.6%) of these represented pure invasive lobular carcinoma (ILC). Twenty-five (68.5%) of the 37 patients with ILC and 161 (70.3%) of the 229 patients with invasive ductal carcinoma (IDC) presented with clinically palpable masses. Asymmetric opacities and architectural distortion were the predominant mammographic signs in 21 (57%) of the cases of ILC but only 32 (13.6%) of the cases of IDC. Malignant calcifications were not present in any of the patients with ILC but were present in 110 (47%) of those with IDC. Of the ILC lesions, 29 (85%) [corrected] had the same opacity as that of normal fibroglandular tissue, and the mammographic findings were often subtle and seen initially on one view only. There was no substantial difference in the TNM stage at diagnosis between the two study groups.