MRI-guided needle localization of suspicious breast lesions: results of a freehand technique.

Magnetic resonance imaging (MRI) can detect clinically and mammographically occult breast lesions. In this study we report the results of MRI-guided needle localization of suspicious breast lesions by using a freehand technique. Preoperative MRI-guided single-needle localization was performed in 220 patients with 304 MRI-only breast lesions at our hospital between January 1997 and July 2004. Procedures were performed in an open 0.5-T Signa-SP imager allowing real-time monitoring, with patient in prone position, by using a dedicated breast coil. MRI-compatible hookwires were placed in a noncompressed breast by using a freehand technique. MRI findings were correlated with pathology and follow-up. MRI-guided needle localization was performed for a single lesion in 150 patients, for two lesions in 56 patients, and for three lesions in 14 patients. Histopathologic analysis of these 304 lesions showed 104 (34%) malignant lesions, 51 (17%) high-risk lesions, and 149 (49%) benign lesions. The overall lesion size ranged from 2.0-65.0 mm (mean 11.2 mm). No direct complications occurred. Follow-up MRI in 54 patients showed that two (3.7%) lesions were missed by surgical biopsy. MRI-guided freehand needle localization is accurate and allows localization of lesions anterior in the breast, the axillary region, and near the chest wall.

Progress report from the American College of Radiology Breast MR Imaging Lexicon Committee.

Given the wide variety of terms for abnormal findings on contrast-enhanced breast MR imaging studies, the United States Public Health Services' Office on Women's Health, the Susan G. Komen Foundation for Breast Cancer Research, and the American College of Radiology, funded a committee (or "working group") of international experts to develop a standard language for breast MR imaging reporting. During the last three years, the group members have developed a preliminary Breast MR Imaging Lexicon to describe abnormal contrast-enhancing findings in the breast on MR imaging studies, with a special focus on lesion morphology on high-resolution scans and kinetic curve data descriptions. The initial version of the Breast MR Imaging Lexicon has undergone preliminary testing and is undergoing further development and refinement based on test results. Future work on the new Breast MR Imaging Lexicon includes continued lexicon development, accumulation of a breast MR imaging case set for lexicon testing, and planning for subsequent education for general radiologists on the new lexicon.

Potential role of magnetic resonance imaging and other modalities in ductal carcinoma in situ detection.

Ductal Carcinoma In Situ (DCIS) is the earliest form of ductal cancer, with a high rate of care if treated early. This article outlines the use of breast imaging in DCIS diagnosis, including mammography, MR imaging, and nuclear medicine studies. While MR imaging and nuclear medicine show great promise in DCIS diagnosis, mammography remains the mainstay of DCIS detection by the presence of microcalcifications in early tumors on the mammogram.

Breast cancer: variables affecting sentinel lymph node visualization at preoperative lymphoscintigraphy.

PURPOSE: To compare patients with visualized sentinel lymph nodes (SLNs) and patients with nonvisualized SLNs, with a focus on variables affecting SLN visualization at preoperative lymphoscintigraphy and on nodal drainage basins as related to tumor location. MATERIALS AND METHODS: One hundred thirty-six patients who had breast cancer underwent preoperative lymphoscintigraphy before SLN biopsy. Patients with visualized and nonvisualized SLNs were compared for age; tumor site, size, and histologic findings; injection guidance method; diagnostic biopsy type; interval between biopsy and lymphoscintigraphy; intraoperative identification method; and surgical identification rate. Visualized SLN drainage basins were noted. RESULTS: Ninety-nine patients had visualized and 37 had nonvisualized SLNs, without statistically significant differences in tumor site, size, and histologic findings; injection guidance method; diagnostic biopsy type; and interval between biopsy and lymphoscintigraphy. Ninety-nine (73%) of the 136 SLNs were visualized at lymphoscintigraphy; 30 (81%) of the 37 nonvisualized SLNS were identified at surgery. Of the seven SLNs not identified at surgery, five were mapped with radiocolloid only. Patients with nonvisualized SLNs were older than those with visualized SLNs. Eleven (46%) of 24 tumors with internal mammary drainage were in the outer part of the breast. CONCLUSION: Patients with and those without visualization differed in age, SLN identification at surgery, and surgical identification method. Nonvisualized status does not preclude axillary metastasis. In older patients with nonvisualized SLNs, blue dye may aid in SLN detection, as compared with isotope-only localization.

Development, standardization, and testing of a lexicon for reporting contrast-enhanced breast magnetic resonance imaging studies.

The purpose of this study was to develop, standardize, and test reproducibility of a lexicon for reporting contrast-enhanced breast magnetic resonance imaging (MRI) examinations. To standardize breast MRI lesion description and reporting, seven radiologists with extensive breast MRI experience developed consensus on technical detail, clinical history, and terminology reporting to describe kinetic and architectural features of lesions detected on contrast-enhanced breast MR images. This lexicon adapted American College of Radiology Breast Imaging and Data Reporting System terminology for breast MRI reporting, including recommendations for reporting clinical history, technical parameters for breast MRI, descriptions for general breast composition, morphologic and kinetic characteristics of mass lesions or regions of abnormal enhancement, and overall impression and management recommendations. To test morphology reproducibility, seven radiologists assessed morphology characteristics of 85 contrast-enhanced breast MRI studies. Data from each independent reader were used to compute weighted and unweighted kappa (kappa) statistics for interobserver agreement among readers. The MR lexicon differentiates two lesion types, mass and non-mass-like enhancement based on morphology and geographical distribution, with descriptors of shape, margin, and internal enhancement. Lexicon testing showed substantial agreement for breast density (kappa = 0.63) and moderate agreement for lesion type (kappa = 0.57), mass margins (kappa = 0.55), and mass shape (kappa = 0.42). Agreement was fair for internal enhancement characteristics. Unweighted kappa statistics showed highest agreement for the terms dense in the breast composition category, mass in lesion type, spiculated and smooth in mass margins, irregular in mass shape, and both dark septations and rim enhancement for internal enhancement characteristics within a mass. The newly developed breast MR lexicon demonstrated moderate interobserver agreement. While breast density and lesion type appear reproducible, other terms require further refinement and testing to lead to a uniform standard language and reporting system for breast MRI. J. Magn. Reson. Imaging 2001;13:889-895.

Freehand iMRI-guided large-gauge core needle biopsy: a new minimally invasive technique for diagnosis of enhancing breast lesions.

The lack of reliable methods for minimally invasive biopsy of suspicious enhancing breast lesions has hindered the utilization of contrast-enhanced magnetic resonance imaging (MRI) for the detection and diagnosis of breast cancer. In this study, a freehand method was developed for large-gauge core needle biopsy (LCNB) guided by intraprocedural MRI (iMRI). Twenty-seven lesions in nineteen patients were biopsied using iMRI-guided LCNB without significant complications. Diagnostic tissue was obtained in all cases. Nineteen of the 27 lesions were subsequently surgically excised. Histopathologic analysis confirmed that iMRI-guided LCNB correctly distinguished benign lesions from malignancy in 18 of the 19 lesions. The histology revealed by core biopsy was partially discrepant with surgical biopsy in 2 of the other 19 lesions. Freehand iMRI-guided LCNB of enhancing breast lesions is promising. Larger studies are needed to determine the smallest lesion that can be sampled reliably and to precisely measure the accuracy of iMRI-guided LCNB as a minimally invasive tool to diagnose suspicious lesions found by breast MRI. J. Magn. Reson. Imaging 2001;13:896-902.

Milk of calcium in the breast: appearance on prone stereotactic imaging.

Microcalcifications discovered by mammography require careful analysis, occasionally leading to core biopsy to exclude associated breast cancer. We report unrecognized milk of calcium layering on small field of view prone digital stereotactic images. We illustrate important features on prone digital images attributed to milk of calcium which can exclude breast neoplasm, suggest this diagnosis, and prevent unnecessary biopsy.

Mammographic characteristics of 115 missed cancers later detected with screening mammography and the potential utility of computer-aided detection.

PURPOSE: To retrospectively determine the mammographic characteristics of cancers missed at screening mammography and assess the ability of computer-aided detection (CAD) to mark the missed cancers. MATERIALS AND METHODS: A multicenter retrospective study accrued 1,083 consecutive cases of breast cancer detected at screening mammography. Prior mammograms were available in 427 cases. Of these, 286 had lesions visible in retrospect. The 286 cases underwent blinded review by panels of radiologists; a majority recommended recall for 112 cases. Two experienced radiologists compared prior mammograms in 110 of these cases with the subsequent screening mammograms (when cancer was detected), noting mammographic characteristics of breast density, lesion type, size, morphology, and subjective reasons for possible miss. The prior mammograms were then analyzed with a CAD program. RESULTS: There were 110 patients with 115 cancers. On the prior mammograms with missed cancers, 35 (30%) of the 115 lesions were calcifications, with 17 of 35 (49%) clustered or pleomorphic. Eighty of the 115 (70%) were mass lesions, with 32 of 80 (40%) spiculated or irregular. For calcifications and masses, the most frequently suggested reasons for possible miss were dense breasts (12 of 35; 34%) and distracting lesions (35 of 80; 44%), respectively. CAD marked 30 (86%) of 35 missed calcifications and 58 (73%) of 80 missed masses. CONCLUSION: Detection errors affected cases with calcifications and masses. CAD marked most (77%; 88 of 115) cancers missed at screening mammography that radiologists retrospectively judged to merit recall.

Non-visualization of sentinel lymph node in patients with breast cancer.

Histological evaluation of the first draining lymph node (sentinel node) in the axilla of patients with breast cancer has dramatically altered the surgical approach to these patients, with sparing of the axilla if no tumour cells are identified. In a fraction of patients imaged after peri-tumoural injection of the breast, there is no visualization of the sentinel node. We retrospectively analysed the status of patients whose nodes were visualized and of patients whose nodes failed to visualize, to define the variables associated with non-visualization of the sentinel node. Seventy-four breast cancer patients were imaged following peri-tumoural injection of filtered 99Tc(m)-sulfur colloid, immediately and up to 5.5 h post-injection. The scintigraphic data were analysed with reference to the patient's age, histology, grade, site and size of tumour, previous diagnostic procedure and time interval to scan, using univariate analysis and a logistic regression model. A sentinel node was visualized in 53 of 74 women (72%). Comparison of patients with non-visualized versus visualized sentinel nodes disclosed no statistically significant univariate relation to age of the patients (P = 0.10), size of tumour (P = 0.46), site (P = 0.26), histology [invasive ductal carcinoma in 16 of 20 (80%) non-visualized cases, and in 43 of 53 (81%) visualized patients], prior excision biopsy (P = 0.36) and time interval to surgery (P = 0.29). Tumour grade was the only significant variable on univariate analysis (P = 0.03), though multivariate analysis showed that none of the independent parameters were statistically significant. In 39 patients with an upper outer quadrant tumour, the location of the sentinel node was not limited to the axilla and even crossed the midline of the breast. Our results show that none of the independent variables is associated with non-visualization of sentinel lymph node on preoperative lymphoscintigraphy of patients with breast cancer, though the tumour grade may have contributed to non-visualization of this node. The non-axillary drainage from upper outer quadrant tumours suggests the routine use of lymphoscintigraphy prior to axillary dissection.

Intensity-modulated parametric mapping for simultaneous display of rapid dynamic and high-spatial-resolution breast MR imaging data.

Contrast material-enhanced magnetic resonance (MR) imaging of the breast has variable specificity for differentiation of breast cancer from other enhancing conditions. Two principal strategies to improve its specificity are rapid dynamic MR imaging and high-spatial-resolution MR imaging. A method was developed of combining contemporaneously acquired dynamic and high-spatial-resolution MR imaging data into a single integrated display. Whole-breast rapid dynamic data were condensed into a color map by using pharmacokinetic analysis. The pharmacokinetic results were combined with the high-spatial-resolution images with a new technique that preserves underlying morphologic details. This new method was evaluated by five radiologists for eight breast lesions, and the results were compared with those of the standard method of overlaying parametric map data. The radiologists' ratings showed a statistically significant preference for the intensity-modulated parametric map display method over the overlaid parametric display method for 10 of the 12 evaluation criteria. The new method enabled simultaneous visualization of pharmacokinetic and morphologic information, facilitated assessment of lesion extent, and improved the suppression of noise in the pharmacokinetic data. The ability to simultaneously assess both dynamic and high-spatial-resolution features may ultimately improve the specificity of breast MR imaging.

Magnetic resonance imaging of breast cancer: clinical indications and breast MRI reporting system.

Magnetic resonance imaging (MRI) is well suited to the investigation of breast cancer by virtue of its noninvasive nature and its multiplanar imaging abilities. MRI investigations showed high sensitivity but modest specificity for breast cancer detection and diagnosis. Most early studies tested the ability of MRI to evaluate and diagnose findings in the breast discovered by other imaging tests or by breast physical examination (1-4). When it was discovered that MRI identified small breast cancers undetected by mammography or breast ultrasound, MRI was used to estimate breast cancer extent in known cancer cases for surgical planning (5,6). These investigations led to the use of MRI in a multitude of breast imaging applications, raising further questions about the use of MRI in everyday practice: What are the indications for breast MRI in general practice? What is its role in light of other imaging tests? What are its benefits and limitations in each setting? How do I report these studies? The purpose of this article is to review the clinical background regarding indications for the use of MRI and relevant cases in which MRI can impact patient management in breast disease, and to describe new developments in reporting breast MRI studies. J. Magn. Reson. Imaging 2000;12:975-983.

New bilateral microcalcifications at mammography in a postlactational woman: case report.

A 33-year-old woman with a strong family history of breast cancer who was referred for mammography 5 weeks after completing lactation was found to have new diffuse bilateral microcalcifications in the breast ducts. Contrast material-enhanced magnetic resonance imaging of the breast showed bilateral patchy areas of abnormal enhancement. Large-core needle biopsy showed diffuse calcifications within expanded benign ducts in a background of lactational change, without evidence of malignancy. To the authors' knowledge, these calcifications have not been previously reported and are possibly related to milk stasis or apoptosis associated with lactation.

Society of Breast Imaging residency and fellowship training curriculum.

A recently developed Society of Breast Imaging curriculum for residency training is intended to provide guidance to residents and their mentors, and to practicing radiologists who want to keep up to date in screening, diagnosis, and interventional procedures. The curriculum contains lists of key concepts in 14 subject areas: epidemiology; anatomy; pathology, and physiology; equipment and technique; quality control; interpretation; problem-solving mammography; ultrasound; interventional procedures; reporting and medicolegal aspects; screening; MR imaging; therapeutic considerations; and patient management principles. The curriculum also makes recommendations about residency training, including the number of examinations the resident should interpret, and the time the resident should spend in breast imaging. Recommendations for fellowship training are also discussed.

Characterization of breast lesion morphology with delayed 3DSSMT: an adjunct to dynamic breast MRI.

The purpose of the study was to determine the sensitivity and specificity of various morphologic criteria in distinguishing malignant from benign breast lesions using a new sequence (3DSSMT) performed immediately after dynamic breast MRI. 3DSSMT combines a water-selective spectral-spatial excitation and an on-resonance magnetization transfer pulse with three-dimensional spoiled gradient-echo imaging. Morphologic features of 87 pathologically confirmed lesions were analyzed. The presence of either skin thickening, or a combination of a spiculated or microlobulated border, with a rim, ductal, linear, or clumped enhancement pattern was 94% specific and 54% sensitive for malignancy. Conversely, the presence of either a perfectly smooth border, a well-defined margin, non-enhancing internal septations, or a macrolobulated border was 97% specific and 35% sensitive for a benign diagnosis. In conclusion, delayed 3DSSMT discriminates a significant number of benign and malignant breast lesions; it has the potential to improve the diagnostic accuracy of dynamic breast MRI.

Motion correction and lipid suppression for 1H magnetic resonance spectroscopy.

Spectral/spatial spin-echo pulses with asymmetric excitation profiles were incorporated into a PRESS-based localization sequence to provide lipid suppression while retaining a sufficient amount of water to allow for correction of motion-induced shot-to-shot phase variations. 1H magnetic resonance spectroscopy data were acquired at 1.5 Tesla from a motion phantom and in vivo from the human liver, kidney, and breast. The results demonstrated that lipids in the chemical shift stopband were completely suppressed and that full metabolite signal intensity was maintained after implementation of a regularization algorithm based on phasing the residual water signal. Liver and kidney spectra contained a large resonance at 3.2 ppm that was ascribed to trimethylammonium moieties (betaine plus choline) and a weaker signal at 3.7 ppm that may result from glycogen. A breast spectrum from a histologically proven invasive ductal carcinoma displayed a highly elevated choline signal (3.2 ppm) relative to that from a normal volunteer.

Treatment of breast abscesses with US-guided percutaneous needle drainage without indwelling catheter placement.

PURPOSE: To assess ultrasonographically (US) guided needle aspiration of breast abscesses as an alternative to surgical incision and drainage or indwelling catheter placement. MATERIALS AND METHODS: The authors reviewed hospital records from 1995 to 1997 for patients undergoing US-guided aspiration of breast abscesses. Two radiologists reviewed the US, mammographic, and US-guided aspiration studies for the size, appearance, and drainage of abscesses. The medical records were reviewed for follow-up data. RESULTS: Thirteen patients aged 15-69 years underwent US-guided percutaneous aspiration of 13 breast abscesses. All patients presented with a palpable mass, nine of which were retroareolar. At US, four abscesses were oval, nine (including three with septa) were irregularly shaped, and five had a thick rind. Of seven abscesses 2.4 cm or smaller, two were almost completely drained and five were completely aspirated. All seven abscesses resolved without surgery. Of six women with incompletely aspirated abscesses larger than 2.4 cm (one 3 cm, four 4 cm, one 7 cm), five required surgical referral; one of these cases was referred after repeat aspiration had been performed. CONCLUSION: Percutaneous aspiration of breast abscesses can enable diagnosis of abscesses and be used to treat small abscesses if they are completely drained. Partial drainage of abscesses larger than 3 cm may be palliative, but incision and drainage still may be necessary for definitive treatment.

Radiofrequency ablation of breast cancer: first report of an emerging technology.

HYPOTHESIS: Radiofrequency (RF) energy applied to breast cancers will result in cancer cell death. DESIGN: Prospective nonrandomized interventional trial. SETTING: A university hospital tertiary care center. PATIENTS: Five women with locally advanced invasive breast cancer, aged 38 to 66 years, who were undergoing surgical resection of their tumor. One patient underwent preoperative chemotherapy and radiation therapy, 3 patients received preoperative chemotherapy, and 1 had no preoperative therapy. All patients completed the study. INTERVENTIONS: While patients were under general anesthesia and just before surgical resection, a 15-gauge insulated multiple-needle electrode was inserted into the tumor under sonographic guidance. Radiofrequency energy was applied at a low power by a preset protocol for a period of up to 30 minutes. Only a portion of the tumor was treated to evaluate the zone of RF ablation and the margin between ablated and nonablated tissue. Immediately after RF ablation, the tumor was surgically resected (4 mastectomies, 1 lumpectomy). Pathologic analysis included hematoxylin-eosin staining and enzyme histochemical analysis of cell viability with nicotinamide adenine dinucleotide-diaphorase (NADH-diaphorase) staining of snap-frozen tissue to assess immediate cell death. MAIN OUTCOME MEASURE: Cancer cell death as visualized on hematoxylin-eosin-stained paraffin section and NADH-diaphorase cell viability stains. RESULTS: There was evidence of cell death in all patients. Hematoxylin-eosin staining showed complete cell death in 2 patients. In 3 patients there was a heterogeneous pattern of necrotic and normal-appearing cells within the ablated tissue. The ablated zone extended around the RF electrode for a diameter of 0.8 to 1.8 cm. NADH-diaphorase cell viability stains of the ablated tissue showed complete cell death in 4 patients. The fifth patient had a single focus of viable cells (<1 mm) partially lining a cyst. There were no perioperative complications related to RF ablation. CONCLUSIONS: Intraoperative RF ablation results in invasive breast cancer cell death. Based on this initial report of the use of RF ablation in breast cancer, this technique merits further investigation as a percutaneous minimally invasive modality for the local treatment of breast cancer.

Methods of compliance with Mammography Quality Standards Act regulations for tracking positive mammograms: survey results.

OBJECTIVE: We sent a questionnaire to fellows of the Society of Breast Imaging to determine how breast imaging facilities comply with regulations mandated by the Mammography Quality Standards Act for tracking patients whose mammograms show positive findings. SUBJECTS AND METHODS: We surveyed the Society of Breast Imaging fellows to determine practice types, follow-up methodology, additional time and personnel required, and end points of radiologists' responsibility for follow-up of mammograms with positive findings. RESULTS: Forty-six (68%) of 68 surveyed practices responded, including 21 academic, 16 private, and nine mixed practices that averaged 15,761 mammograms a year (range, 300-50,000). The 46 practices used computers (n = 30) or handwritten paper (n = 16) audits. Radiologists (n = 8), technologists (n = 6), other personnel (n = 10), or a combination (n = 22) tracked procedures and patients with abnormal mammographic results. Average time spent tracking was given as a few hours a week (n = 28), 2-4 hr a day (n = 11), and 40 hr a week (n = 5). The remaining two practices indicated that less than 1 hr per month was required (n = 1) or that they used two full-time data managers (n = 1). Accepted tracking end points included surgical biopsy (n = 30), referring physician recommended other management (n = 16), patient refused recommendation (n = 27), medical care transfer (n = 27), patient moved (n = 22), or patient lost to referring physician follow-up (n = 16). CONCLUSION: Among dedicated mammographers, the methodology in the task of tracking patients with positive findings on mammography varies. All methodologies described in responses to our survey involved considerable time and effort.

Silicone breast implant rupture: pitfalls of magnetic resonance imaging and relative efficacies of magnetic resonance, mammography, and ultrasound.

The objective of this study was to evaluate the relative efficacies of magnetic resonance (MR) imaging, ultrasonography, and mammography in implant rupture detection and to illustrate pitfalls in MR image interpretation. Thirty patients referred by plastic surgeons with suspected breast implant rupture were prospectively evaluated using MR, ultrasonography, and mammography. Imaging examinations were interpreted independently and blindly for implant rupture and correlated to operative findings. Surgical correlation in 16 patients (53 percent) with 31 implants showed 13 (42 percent) were intact, 5 (16 percent) had severe gel bleed, and 13 (42 percent) were ruptured. MR sensitivity was 100 percent and specificity was 63 percent. Accuracy for rupture was 81 percent with MR, higher than with ultrasonography and mammography (77 and 59 percent, respectively). We describe a specific pitfall in MR interpretation, the "rat-tail" sign, composed of a medial linear extension of silicone along the chest wall. Seen in eight cases (four intact, three ruptures, one gel bleed), the rat-tail sign may lead to misdiagnosis of implant rupture if seen in isolation. Magnetic resonance imaging is more accurate and sensitive than ultrasonography and mammography in detecting breast implant rupture. We describe a new sign (rat-tail sign) composed of medial compression of the implant simulating silicone extrusion as a potential false-positive MR finding for rupture. This article presents clinical experience with magnetic resonance, mammography, and ultrasound in the diagnosis of implant rupture and defines and illustrates potential pitfalls of MR interpretation, including the new rat-tail sign.