Negative pressure fixation device to reduce motion artifacts on contrast-enhanced MRI of the breast: a clinical feasibility study.

PURPOSE: To investigate the effect of a negative pressure fixation device on misregistration artifacts in contrast-enhanced (CE) MR subtraction images. MATERIALS AND METHODS: Nine patients, two of which had been previously diagnosed with breast cancer, were examined with T2-weighted (T2-w) turbo spin-echo (TSE) and three-dimensional (3D) spoiled gradient-recalled echo (SPGR) CE dynamic MRI. Baselines images were subtracted from the dynamic images. A device consisting of two stiff plastic domes was placed on the breasts of each patient. Negative pressure of 27 to 37 mmHg within the domes was maintained. The patient was positioned prone in the coil without the device and imaged as a baseline. Subsequently, the patient was placed into the negative pressure domes and reimaged. One of the nine patients was also imaged supine to establish feasibility for this positioning. RESULTS: With the use of the negative pressure fixation device, a reduction in misregistration artifact has been demonstrated in prone imaging. Patients reported improved comfort with the device and feasibility has been shown for supine imaging. CONCLUSION: The device was shown to be MRI-compatible and successfully applied in this pilot study, opening other avenues of exploration. Supine positioning for breast imaging makes possible better access for biopsy and intervention. Further modifications to the device are in order for this purpose and to eliminate motion due to breathing in the prone position.

MRI-directed, wire-localized breast excisions: incidence of malignancy and recommendations for pathologic evaluation.

Magnetic resonance imaging (MRI) has an evolving role in the evaluation of breast lesions and is currently being used for the screening of high-risk patients (eg, women with a personal or family history of breast cancer), for the evaluation of extent of disease in patients with a current diagnosis of cancer, and for patients with suspicious, but indeterminate, findings by other imaging modalities. If a suspicious lesion detected by MRI is not well visualized by another method, an MRI-directed core biopsy or breast excision may be performed. MRI cannot be used to verify the lesion in the specimen because MRI lesion detection is dependent on uptake of gadolinium after intravenous injection. Accordingly, these breast excisions present unique challenges to pathologists. The purpose of this report is to define the surgical pathology issues involved in processing MRI-localized excisions. Retrospective review of 85 consecutive MRI-directed breast excisions from 77 patients was performed. Malignant lesions were present in 20 (24%) of 85 excisions, including 10 cases of invasive carcinoma (median size, 0.4 cm), 9 cases of ductal carcinoma in situ, and 1 case of lymphoma. Most of the malignancies (85% or 17/20) had no associated gross finding and only 5 (25%) of 20 of these malignancies were associated with a definite finding on the specimen radiograph. This study demonstrates that gross examination and specimen radiography do not identify most of the malignancies in MRI-localized biopsies and, therefore, optimal processing requires complete microscopic examination of these specimens.

The age at which women begin mammographic screening.

BACKGROUND: The American Cancer Society recommends yearly mammographic screening for women starting at the age of 40 years. The authors examined the age at which women began screening at a large tertiary care center. METHODS: Utilization of mammography was assessed in a population of 72,417 women who received 254,818 screening mammograms at the Massachusetts General Hospital Avon Comprehensive Breast Center from January 1, 1985 to February 19, 2002, of which 940 received their first mammogram between January 16, 2000 and February 19, 2002. RESULTS: The median age at first mammogram for women in the population as a whole was 40.4 years. Sixty percent of women had their first mammogram by the end of their 40th year, and almost 90% had begun screening by age 50 years. However, these reassuring findings were not seen in several specific subpopulations of women. Black women began screening at a median age of 41.0 years, 0.7 years later than white women. Hispanic women began screening at a median age of 41.4 years, 1.1 years later than non-Hispanic women. Obese women began screening at a median age of 41.2 years, 1.6 years later than thin women. Women without a primary care physician began screening at a median age of 42.1 years, 1.8 years later than women with a primary care physician. Women without private health insurance began screening at a median age of 46.6 years, 6.3 years later than women with private health coverage. Women who did not speak English began screening at a median age of 49.3 years, 9.0 years later than women for whom English was the primary language. Women who both lacked private health insurance and spoke a language other than English began screening at a median age of 55.3 years, 15.2 years later than women without these characteristics. CONCLUSIONS: The analysis presented in the current study provided one of the most detailed descriptions of the age at screening initiation to be performed to date. Most women in the study population began screening by the end of their 40th year. This contrasted with the widespread failure of women to return promptly for subsequent annual examinations. However, specific subpopulations of women were at risk for not beginning screening on time, including women without private insurance, women without a primary care physician, and women who did not speak English. These findings suggest that there is little to be gained from populationwide efforts to encourage entry into the screening process, and that public health efforts should be focused on those subpopulations of women at highest risk for not using screening. These results also indicate that public health efforts to encourage women to start screening may be less critical than interventions to improve prompt return once they have entered the screening system.

Feasibility of MR imaging-guided breast lumpectomy for malignant tumors in a 0.5-T open-configuration MR imaging system.

RATIONALE AND OBJECTIVES: The authors performed this study to develop the technology for and evaluate the utility of a 0.5-T vertical open-configuration magnetic resonance (MR) imaging system for imaging-guided breast lumpectomy of malignant tumors. MATERIALS AND METHODS: Twenty women with breast cancer underwent MR imaging-guided lumpectomy in a 0.5-T vertical open-configuration MR system. During lumpectomy, pre- and postresection images were acquired with and without contrast material. Images were used both for tumor localization and to monitor resection. If residual enhancement was observed, additional resection was performed in an effort to secure negative pathologic margins. RESULTS: The procedure evolved over time with technology innovations and improvements. Specifically, instruments were acquired that were compatible with MR imaging breast procedures, the echo time with the Dixon technique was modified to optimize image quality, contrast material injection was timed for maximum lesion enhancement, breath-hold image acquisition was instituted, and the biopsy cavity was filled with saline and the incision closed before image acquisition. CONCLUSION: All breast lesions were identified despite limited spatial resolution and fat-suppression techniques. The evolved techniques facilitated intraoperative margin evaluation and prompted additional surgical margin resection in five patients, sparing four from an additional surgical procedure. Intraoperative MR imaging has the potential to improve the complete pathologic excision of invasive breast cancer.

Mammographic and Sonographic Features of Angiolipoma of the Breast.

The mammographic and sonographic appearance of angiolipomas of the breast is presented. This rare benign variant of lipoma usually presents as a painless breast mass. The imaging characteristics of angiolipomas of the breast are variable, overlapping with both other benign breast neoplasms and with malignancies. The most common mammographic appearance of angiolipomas of the breast in this series was an oval or round, isodense, circumscribed mass. The most common sonographic features were oval shape, circumscribed borders, and iso- to slight hyperechogenicity. These imaging features are nonspecific and biopsy is required for definitive diagnosis.

Sonographic Evaluation of Clinically Palpable Breast Cancers Invisible on Mammography.

The purpose of this study was to determine the utility of sonography in the evaluation of palpable breast cancers invisible on mammography. A retrospective review of the pathology department's database was used to identify patients with palpable breast cancers. Consecutive patients that had excision between January 1992 and September 1997 were included. Mammograms and breast ultrasounds were reviewed retrospectively and correlated with pathologic and surgical findings. During the study period 298 women presented with a palpable breast cancer for imaging at our institution. Of these, 38 cancers (12.8%) were not seen on mammography. In 32 patients where no mammographic abnormality was found, ultrasound was able to detect a mass corresponding to the area of clinical concern. Histologic tumor types included 30 invasive ductal carcinomas, 5 ductal carcinomas in situ, and 3 invasive lobular carcinomas. Mammographic density was mild with scattered fibroglandular densities in 2 (5%), heterogeneously dense in 12 (32%), and extremely dense in 24 (63%). Thirty-one masses (97%) were hypoechoic and 1 (3%) was echogenic. Lesion margins were irregular in 23 (72%), lobulated in 5 (16%), and well-circumscribed in 4 (12%). In this group of patients the combination of mammography and ultrasound of the mass demonstrated 99% of the palpable cancers. In patients presenting with a breast mass on physical examination in whom mammography fails to demonstrate an abnormality, supplemental ultrasound is helpful in most instances to further characterize the lesion.

Lactating Adenoma: Sonographic Features.

The lactating adenoma is a benign breast lesion occurring as a palpable mass in pregnant or lactating patients. The ultrasound characteristics of 15 lactating adenomas in 15 patients were reviewed retrospectively. Most of the lactating adenomas in this series (10 of 15) had one or more typically benign features such as circumscribed borders, smooth lobulations, or an echogenic pseudocapsule. The remaining five, however, had features typically associated with malignancy, including irregular, angulated, or ill-defined margins, or posterior acoustic shadowing.