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Purpose: To evaluate the diffusion-weighted (DW) imaging characteristics of nonmalignant lesion subtypes assessed as false-positive findings at conventional breast magnetic resonance (MR) imaging., Materials and Methods: This HIPAA-compliant retrospective study had institutional review board approval, and the need for informed patient consent was waived. Lesions assessed as Breast Imaging Reporting and Data System category 4 or 5 at clinical dynamic contrast material-enhanced MR imaging that subsequently proved nonmalignant at biopsy were retrospectively reviewed. One hundred seventy-five nonmalignant breast lesions in 165 women were evaluated. Apparent diffusion coefficients (ADCs) from DW imaging (b = 0, 600 sec/mm(2)) were calculated for each lesion and were compared between subtypes and with an ADC threshold of 1.81 × 10(-3) mm(2)/sec (determined in a prior study to achieve 100% sensitivity)., Results: Eighty-one (46%) lesions exhibited ADCs greater than the predetermined threshold. The most prevalent lesion subtypes with mean ADCs above the threshold were fibroadenoma ([1.94 ± 0.38 {standard deviation}] × 10(-3) mm(2)/sec; n = 30), focal fibrosis ([1.84 ± 0.48] × 10(-3) mm(2)/sec; n = 19), normal tissue ([1.81 ± 0.47] × 10(-3) mm(2)/sec; n = 13), apocrine metaplasia ([2.01 ± 0.38] × 10(-3) mm(2)/sec; n = 13), usual ductal hyperplasia ([1.83 ± 0.49] × 10(-3) mm(2)/sec; n = 12), and inflammation ([1.95 ± 0.46] × 10(-3) mm(2)/sec; n = 10). Atypical ductal hyperplasia ([1.48 ± 0.36] × 10(-3) mm(2)/sec; n = 23) was the most common lesion subtype with ADC below the threshold. Lymph nodes exhibited the lowest mean ADC of all nonmalignant lesions ([1.28 ± 0.23] × 10(-3) mm(2)/sec; n = 4). High-risk lesions (atypical ductal hyperplasia and lobular neoplasia) showed significantly lower ADCs than other benign lesions (P < .0001) and were the most common lesions with ADCs below the threshold., Conclusion: Assessing ADC along with dynamic contrast-enhanced MR imaging features may decrease the number of avoidable false-positive findings at breast MR imaging and reduce the number of preventable biopsies. The ability of DW imaging to help differentiate high-risk lesions requiring additional work-up from other nonmalignant subtypes may further improve patient care., Supplemental Material: http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.12112672/-/DC1., (© RSNA, 2012.)

Objective: The purpose of this study was to determine the accuracy and value of breast ultrasound for primary imaging evaluation of women 30-39 years of age who present with focal breast signs or symptoms., Methods: We identified all women 30-39 years of age who underwent imaging evaluation (ultrasound and mammography) at our institution between January 1, 2002, and August 31, 2006, for focal breast signs or symptoms. Each area of concern was designated a study case. Benign versus malignant outcomes were determined by biopsy or imaging surveillance and through linkage with a tumor registry with a minimum 24-month follow-up. Overall cancer yield, sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) of ultrasound and mammography were calculated., Results: We identified 1208 cases in 954 patients. Outcomes were benign in 1185 of 1208 (98.1%) and malignant in 23 of 1208 (1.9%) cases. Sensitivities for ultrasound and mammography were 95.7% and 60.9%, respectively. Specificities for ultrasound and mammography were 89.2% and 94.4%, respectively. NPV was 99.9% for ultrasound and 99.2% for mammography. PPV was 13.2% for ultrasound and 18.4% for mammography. Mammography detected one additional malignancy in an asymptomatic area in a 32-year-old woman who was subsequently found to have a BRCA2 gene mutation., Conclusion: Breast imaging is warranted in women 30-39 years of age with focal signs or symptoms because of the small (1.9%) but real risk of malignancy. Ultrasound has high sensitivity (95.7%) and high NPV (99.9%) in this setting and should be the primary imaging modality of choice. The added value of adjunct mammography is low.

Objective: The purpose of our study was to evaluate tissue sampling methods used for MRI-detected suspicious contralateral breast lesions in the American College of Radiology Imaging Network (ACRIN) 6667 trial., Materials and Methods: Breast MRI was performed at 25 institutions in 969 women who had a recent diagnosis of unilateral breast cancer and negative contralateral mammography and clinical breast examinations. Biopsy was recommended for MRI findings in 135 women, and 121 underwent sampling. Frequencies and positive biopsy rates of sampling methods used for initial diagnosis and imaging guidance techniques were calculated and compared., Results: Sampling yielded 30 malignant and 91 benign results. Initial sampling used needle biopsy in 88 of 121 (72.7%) and surgical biopsy in 30 of 121 (24.8%) women. Surgical biopsy was excisional biopsy in 28 of 30 (93.3%) and mastectomy in two of 30 (6.7%). The remaining three of 121 (2.5%) women underwent mastectomy, but it was not documented whether this represented initial tissue sampling. Of imaging-guided procedures, 56 of 106 (52.8%) used MRI; 49 of 106 (46.2%), ultrasound; and one of 106 (1.0%), stereotaxis. MRI-guided sampling was with needle biopsy rather than wire-localized surgical biopsy in 33 of 56 (58.9%) women, whereas ultrasound used needle biopsy in 47 of 49 (95.9%). Positive biopsy rates of sampling methods were 20.5% for needle biopsy, 46.2% for excisional biopsy, and 0% for mastectomy., Conclusion: The majority of initial biopsies for MRI-detected contralateral breast lesions used needle biopsy rather than surgical biopsy. Contralateral surgery could have been avoided in most cases had needle biopsy been performed because most excisional biopsy and all mastectomy results were benign. MRI-guided biopsy was significantly more likely than ultrasound-guided sampling to use wire-localized surgical biopsy rather than needle biopsy.

Objective: The purpose of this study was to compare the differences in kinetic assessments of lesions at breast MRI performed with higher and lower temporal resolution., Materials and Methods: All consecutively evaluated BI-RADS category 4, 5, and 6 lesions imaged with breast MRI and pathologically confirmed from October 2005 to August 2009 were identified. Patients underwent MRI with one of two dynamic contrast-enhanced protocols: one with 90-second (October 2005-June 2006) and another with 180-second (July 2006-August 2009) temporal resolution. Studies were processed with a computer-aided evaluation system with initial and delayed contrast-enhanced time points with the k-space centered 90 and 450 seconds after contrast injection. Initial-phase peak enhancement, delayed-phase predominant curve type, and worst curve type were recorded and compared for benign and malignant lesions across protocols., Results: The analysis set comprised 993 lesions: 145 imaged with the 90-second acquisition (17 benign, 28 ductal carcinoma in situ [DCIS], 100 invasive cancer) and 848 imaged with the 180-second acquisition (212 benign, 145 DCIS, 491 invasive cancer). Peak enhancement was significantly higher for both benign lesions (p = 0.01) and invasive cancers (p = 0.0008) with the 180-second protocol. Peak enhancement of DCIS was similar in the two protocols (p = 0.88). Delayed-phase kinetics were similar for the two protocols for both benign and malignant lesions when defined by predominant or worst curve type., Conclusion: Although it has lower temporal resolution, a 180-second acquisition may be preferable because it allows higher spatial resolution and captures higher initial-phase peak enhancement without loss of delayed-phase kinetic information.

Purpose: To evaluate the positive predictive values (PPVs) of Breast Imaging and Reporting Data Systems (BI-RADS) assessment categories for breast magnetic resonance (MR) imaging and to identify the BI-RADS MR imaging lesion features most predictive of cancer., Materials and Methods: This institutional review board-approved HIPAA-compliant prospective multicenter study was performed with written informed consent. Breast MR imaging studies of the contralateral breast in women with a recent diagnosis of breast cancer were prospectively evaluated. Contralateral breast MR imaging BI-RADS assessment categories, morphologic descriptors for foci, masses, non-masslike enhancement (NMLE), and kinetic features were assessed for predictive values for malignancy. PPV of each imaging characteristic of interest was estimated, and logistic regression analysis was used to examine the predictive ability of combinations of characteristics., Results: Of 969 participants, 71.3% had a BI-RADS category 1 or 2 assessment; 10.9%, a BI-RADS category 3 assessment; 10.0%, a BI-RADS category 4 or 5 assessment; and 7.7%, a BI-RADS category 0 assessment on the basis of initial MR images. Thirty-one cancers were detected with MR imaging. Overall PPV for BI-RADS category 4 and 5 lesions was 0.278, with 17 cancers in patients with a BI-RADS category 4 lesion (PPV, 0.205) and 10 cancers in patients with a BI-RADS category 5 lesion (PPV, 0.714). Of the cancers, one was a focus, 17 were masses, and 13 were NMLEs. For masses, irregular shape, irregular margins, spiculated margins, and marked internal enhancement were most predictive of malignancy. For NMLEs, ductal, clumped, and reticular or dendritic enhancement were the features most frequently seen with malignancy. Kinetic enhancement features were less predictive of malignancy than were morphologic features., Conclusion: Standardized terminology of the BI-RADS lexicon enables quantification of the likelihood of malignancy for MR imaging-detected lesions through careful evaluation of lesion features. In particular, BI-RADS assessment categories and morphologic descriptors for masses and NMLE were useful in estimating the probability of cancer., (© RSNA, 2012.)

Purpose: To develop a model incorporating dynamic contrast material-enhanced (DCE) and diffusion-weighted (DW) magnetic resonance (MR) imaging features to differentiate high-nuclear-grade (HNG) from non-HNG ductal carcinoma in situ (DCIS) in vivo., Materials and Methods: This HIPAA-compliant study was approved by the institutional review board and requirement for informed consent was waived. A total of 55 pure DCIS lesions (19 HNG, 36 non-HNG) in 52 women who underwent breast MR imaging at 1.5 T with both DCE and DW imaging (b = 0 and 600 sec/mm(2)) were retrospectively reviewed. The following lesion characteristics were recorded or measured: DCE morphology, DCE maximum lesion size, peak initial enhancement at 90 seconds, worst-curve delayed enhancement kinetics, apparent diffusion coefficient (ADC), contrast-to-noise ratio (CNR) at DW imaging with b values of 0 and 600 sec/mm(2), and T2 signal effects (measured with CNR at b = 0 sec/mm(2)). Univariate and stepwise multivariate logistic regression modeling was performed to identify MR imaging features that optimally discriminated HNG from non-HNG DCIS. Discriminative abilities of models were compared by using the area under the receiver operating characteristic curve (AUC)., Results: HNG lesions exhibited larger mean maximum lesion size (P = .02) and lower mean CNR for images with b value of 600 sec/mm(2) (P = .004), allowing discrimination of HNG from non-HNG DCIS (AUC = 0.71 for maximum lesion size, AUC = 0.70 for CNR at b = 600 sec/mm(2)). Differences in CNR for images with b value of 0 sec/mm(2) (P = .025) without corresponding differences in ADC values were observed between HNG and non-HNG lesions. Peak initial enhancement was the only kinetic variable to approach significance (P = .05). No differences in lesion morphology (P = .11) or worst-curve delayed enhancement kinetics (P = .97) were observed. A multivariate model combining CNR for images with b value of 600 sec/mm(2) and maximum lesion size most significantly discriminated HNG from non-HNG (AUC = 0.81)., Conclusion: The preliminary findings suggest that DCE and DW MR imaging features may aid in identifying patients with high-risk DCIS. Further study may yield a model combining MR characteristics with histopathologic data to facilitate lesion-specific targeted therapies. © RSNA, 2012.

Objective: Breast density is documented to reduce sensitivity and specificity of mammography. However, little is known regarding the effect of normal background parenchymal enhancement on accuracy of breast MRI. The purpose of this study was to evaluate the effect of background parenchymal enhancement on MRI diagnostic performance., Materials and Methods: A review of our established MRI data identified all women undergoing breast MRI from March 1, 2006, through June 30, 2007. Prospectively reported background parenchymal enhancement categories of minimal, mild, moderate, or marked (anticipated BI-RADS MRI lexicon definitions) and assessments were extracted from the database for each patient. Outcomes were determined by pathologic analysis, imaging, and linkage with the regional tumor registry with a minimum of 24 months of follow-up. Patients were dichotomized into categories of minimal or mild versus moderate or marked background parenchymal enhancement. Associations with patient age, abnormal interpretation rate, positive biopsy rate, cancer yield, sensitivity, and specificity were compared using chi-square and z score tests., Results: The study cohort included 736 women. Moderate or marked background parenchymal enhancement was significantly more frequent among patients younger than 50 years compared with those 50 years old and older (39.7% vs 18.9%; p < 0.0001). Moderate or marked background parenchymal enhancement was also associated with a higher abnormal interpretation rate compared with minimal or mild background parenchymal enhancement (30.5% vs 23.3%; p = 0.046). Positive biopsy rate, cancer yield, sensitivity, and specificity were not significantly different according to background parenchymal enhancement category., Conclusion: Increased background parenchymal enhancement on breast MRI is associated with younger patient age and higher abnormal interpretation rate. However, it is not related to significant differences in positive biopsy rate, cancer yield, sensitivity, or specificity of MRI.

This study investigated the relationship between apparent diffusion coefficient (ADC) measures and dynamic contrast-enhanced magnetic resonance imaging (MRI) kinetics in breast lesions and evaluated the relative diagnostic value of each quantitative parameter. Seventy-seven women with 100 breast lesions (27 malignant and 73 benign) underwent both dynamic contrast-enhanced MRI and diffusion weighted MRI. Dynamic contrast-enhanced MRI kinetic parameters included peak initial enhancement, predominant delayed kinetic curve type (persistent, plateau, or washout), and worst delayed kinetic curve type (washout > plateau > persistent). Associations between ADC and dynamic contrast-enhanced MRI kinetic parameters and predictions of malignancy were evaluated. Results showed that ADC was significantly associated with predominant curve type (ADC was higher for lesions exhibiting predominantly persistent enhancement compared with those exhibiting predominantly washout or plateau, P = 0.006), but was not significantly associated with peak initial enhancement or worst curve type (P > 0.05). Univariate analysis showed significant differences between benign and malignant lesions in both ADC (P < 0.001) and worst curve (P = 0.003). In multivariate analysis, worst curve type and ADC were significant independent predictors of benign versus malignant outcome and in combination produced the highest area under the receiver operating characteristic curve (0.85 and 0.78 with 5-fold cross validation)., (Copyright © 2011 Wiley-Liss, Inc.)

Breast magnetic resonance imaging (MRI) is routinely used as a problem-solving tool, but its benefit for this indication remains unclear. The records of 3001 consecutive breast MR examinations between January 1, 2003 and June 6, 2007 were reviewed to identify all those performed for the clinical indication of problem solving. Details of clinical presentation, mammography and ultrasound (US) findings, follow-up recommendations, and pathology outcomes were recorded. Benign versus malignant outcomes were determined by biopsy or 12 months of follow-up imaging and linkage with the regional tumor registry. Problem solving was the clinical indication for 204 of 3001 (7%) of all examinations. Forty-two of 204 examinations (21%) had suspicious or highly suspicious MRI assessments with recommendation for biopsy and 62 of 204 (79%) examinations were assessed as negative, benign, or probably benign. Thirty-six biopsies were performed based on MRI findings and 14 cancers were diagnosed. Biopsy was indicated for 11 of 14 (79%) cancers based on suspicious mammographic or US findings identified prior to MRI. One incidental cancer was detected by MRI alone in a patient at high risk for breast cancer, and two cancers were detected in patients with suspicious nipple discharge and negative mammogram and US. A single false-negative MRI occurred in a patient whose evaluation for a palpable lump prompted biopsy. Problem-solving breast MRI rarely identifies otherwise occult cancer and can be falsely negative in patients with suspicious findings on mammogram and US. Until the benefits and risks of problem-solving MRI are clarified, it should be used judiciously., (© 2011 Wiley Periodicals, Inc.)

We evaluated 97 cases of review-confirmed atypical ductal hyperplasia found on stereotactic vacuum-assisted breast biopsy of suspicious calcifications. The number and size of foci of atypical ductal hyperplasia and presence of a micropapillary component were noted. In addition, we recorded if a case was considered "atypical ductal hyperplasia suspicious for ductal carcinoma in situ" using specific qualitative criteria. The upgrade rate was 20.6% (20/97) for all cases and 48% (12/25) for cases suspicious for ductal carcinoma in situ. Suspicion for ductal carcinoma in situ was found to be a strong predictor of upgrade with an odds ratio of 7.4 (P = .0003). Suspicious cases with nuclear features bordering on intermediate nuclear grade had the highest upgrade rate of 75% (6/8). Cases with ≥ 3 foci had significantly higher upgrade rates (28%) than those with less than 3 foci (11%), but focal atypical ductal hyperplasia did upgrade (P = .04). In conclusion, qualitative features of atypical ductal hyperplasia on core biopsy such as suspicion for ductal carcinoma in situ may help stratify patients at the highest risk for upgrade., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Objective: The purpose of our study is to report the outcomes at a center that routinely uses breast MRI for preoperative staging, regardless of lesion histology or patient characteristics., Materials and Methods: Five hundred ninety-two patients with recently diagnosed breast cancer who underwent staging with preoperative breast MRI between January 1, 2003, and April 30, 2007, were reviewed. Five hundred seventy patients comprised the analysis set. Patient age, breast density, index tumor histology, receptor status (ER, PR, and HER2), and lymph node status were recorded. Biopsy rates, positive predictive values (PPVs) of biopsy, and overall cancer yield were calculated and compared using the chi-square test across patient age, mammographic breast density, index tumor type, receptor status, and lymph node status., Results: Biopsy was recommended and performed for 152 of 570 (27%) patients found to have one or more suspicious lesions on MRI distinct from the index cancer. Sixty-seven of 152 women who underwent biopsy had additional cancers diagnosed, for a PPV of 44%. Overall, 12% (67/570) of women had otherwise occult cancers diagnosed by MRI, with 8% having additional sites or greater extent of ipsilateral disease and 4% having unsuspected contralateral cancer detected by MRI alone. No significant differences were found in the probability of detecting an occult cancer on the basis of patient age, breast density, index tumor characteristics, or lymph node status., Conclusion: Breast MRI detects otherwise occult cancer with an overall added cancer yield of 12% and a high PPV of 44% when applied to a diverse population of patients with newly diagnosed breast cancer.

Objective: The purpose of this article is to assess the accuracy of targeted breast ultrasound in women younger than 30 years presenting with focal breast signs or symptoms., Materials and Methods: Retrospective review of the electronic medical records identified all ultrasound examinations from January 1, 2002, through August 30, 2006, performed for focal breast signs or symptoms in women younger than 30 years. BI-RADS assessments were recorded. Outcomes were determined by biopsy, 24 months of ultrasound surveillance, and linkage with the regional tumor registry. The overall cancer yield, sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV) 2, and PPV3 of ultrasound were calculated., Results: Among 830 study patients, lesions were assessed as BI-RADS category 1 or 2 in 526 (63.4%), BI-RADS category 3 in 140 (16.9%), BI-RADS category 4 in 163 (19.6%), and BI-RADS category 5 in one (0.1%) patient. Three malignancies were detected, for a cancer yield of 0.4%. No BI-RADS category 3 lesions, two BI-RADS category 4 lesions, and the single BI-RADS category 5 lesion were malignant. Ultrasound sensitivity was 100%, specificity was 80.5%, NPV was 100%, PPV2 was 1.8%, and PPV3 was 1.9%., Conclusion: Women younger than 30 years with focal breast signs or symptoms have a very low (0.4%) incidence of malignancy. The 100% sensitivity and NPV of targeted ultrasound in our study substantiates its use as an accurate primary imaging test in this clinical setting. We found no malignancies in BI-RADS category 3 lesions, supporting ultrasound surveillance over biopsy in this patient population.

Purpose: MRI is increasingly used for the detection of breast carcinoma. Little is known about breast MRI techniques among community practice facilities. The aim of this study was to evaluate equipment and acquisition techniques used by community facilities across the United States, including compliance with minimum standards by the ACRIN® 6667 Trial and the European Society of Breast Imaging., Methods: Breast Cancer Surveillance Consortium facilities performing breast MRI were identified and queried by survey regarding breast MRI equipment and technical parameters. Variables included scanner field strength, coil type, acquisition coverage, slice thickness, and the timing of the initial postcontrast sequence. Results were tallied and percentages of facilities meeting ACRIN® and European Society of Breast Imaging standards were calculated., Results: From 23 facilities performing breast MRI, results were obtained from 14 (61%) facilities with 16 MRI scanners reporting 18 imaging parameters. Compliance with equipment recommendations of ≥1.5-T field strength was 94% and of a dedicated breast coil was 100%. Eighty-three percent of acquisitions used bilateral postcontrast techniques, and 78% used slice thickness≤3 mm. The timing of initial postcontrast sequences ranged from 58 seconds to 8 minutes 30 seconds, with 63% meeting recommendations for completion within 4 minutes., Conclusions: Nearly all surveyed facilities met ACRIN and European Society of Breast Imaging standards for breast MRI equipment. The majority met standards for acquisition parameters, although techniques varied, in particular for the timing of initial postcontrast imaging. Further guidelines by the ACR Breast MRI Accreditation Program will be of importance in facilitating standardized and high-quality breast MRI., (Copyright © 2010 American College of Radiology. Published by Elsevier Inc. All rights reserved.)

Objective: The purpose of this article is to determine the frequency, outcomes, and imaging features of high-risk lesions initially detected by breast MRI, including atypical ductal hyperplasia, atypical lobular hyperplasia, lobular carcinoma in situ, and radial scar., Materials and Methods: A retrospective review of our MRI pathology database was performed to identify all lesions initially detected with MRI (January 2003 through May 2007) that underwent imaging-guided needle biopsy yielding high-risk histopathologic abnormalities. Patient age, clinical indication, MRI BI-RADS lesion features, biopsy method, and histopathologic diagnosis were recorded. The frequencies of high-risk findings at needle biopsy and rates of upgrade to malignancy at surgical excision were compared across lesion imaging features with Fisher's exact test., Results: Four hundred eighty-two MRI-detected suspicious lesions underwent needle biopsy. High-risk histopathologic abnormalities were present in 61 (12.7%) of 482 lesions: 51 (10.6%) atypical ductal hyperplasias, six (1.2%) atypical lobular hyperplasias, three (0.6%) lobular carcinomas in situ, and one (0.2%) radial scar. Correlation between the lesion site and pathology at surgical excision was confirmed for 39 of 61 lesions. Twelve (30.8%) of those 39 lesions were upgraded to malignancy (11 atypical ductal hyperplasias and one atypical lobular hyperplasia); five (41.7%) of the 12 malignancies were invasive cancer, and seven (58.3%) were ductal carcinomas in situ. No significant lesion features predictive of subsequent upgrade to malignancy were discovered., Conclusion: There are no specific imaging features that predict upgrade for high-risk lesions when detected with MRI. Therefore, surgical excision is recommended because upgrade to invasive carcinoma or ductal carcinoma in situ can occur in up to 31% of cases, regardless of biopsy technique.

Objective: The purpose of this study was to determine whether lesion type and size affect discrimination of benign and malignant breast lesions with diffusion-weighted MRI., Materials and Methods: This study included 91 women with 116 breast lesions identified with dynamic contrast-enhanced MRI. Diffusion-weighted images were acquired during clinical breast MRI at b values of 0 and 600 s/mm(2). Differences in the apparent diffusion coefficients (ADCs) of benign and malignant lesions were compared by lesion type (mass or nonmasslike enhancement) and size ( 1 cm), and receiver operating characteristics analysis was performed to evaluate diagnostic performance based on ADC thresholds., Results: Sixteen of 71 masses and 13 of 45 lesions with nonmasslike enhancement were malignant. The mean ADC was significantly lower for malignant than for benign lesions for both masses (mean difference, 0.49 x 10(-3) mm(2)/s; p < 0.001) and lesions with nonmasslike enhancement (mean difference, 0.20 x 10(-3) mm(2)/s; p = 0.02). The area under the receiver operating characteristics curve (AUC) was greater for masses (AUC, 0.80) than for lesions with nonmasslike enhancement (AUC, 0.66). The mean ADC for malignant masses (1.25 x 10(-3) mm(2)/s) was lower than that for malignant lesions with nonmasslike enhancement (1.41 x 10(-3) mm(2)/s; p = 0.07). The median lesion size was 1.1 cm (range, 0.5-8.3 cm); 45 of 71 masses (63%) measured 1 cm or smaller, and 37 of 45 lesions with nonmasslike enhancement (82%) were larger than 1 cm. There was no relation (p > 0.05) between ADC value and lesion size for benign or malignant lesions, and there were no differences in AUC based on lesion size (p > 0.05)., Conclusion: Diffusion-weighted MRI shows promise in differentiation of benign and malignant masses and lesions with nonmasslike enhancement found at breast MRI and is not affected by lesion size. However, ADC measurements may be more useful for discriminating masses than for discriminating lesions with nonmasslike enhancement.

Purpose: To determine if patients with fewer than three foci of atypical ductal hyperplasia (ADH) who have all of their calcifications removed after stereotactic 9- or 11-gauge vacuum-assisted breast biopsy (VABB) have a rate of upgrade to malignancy that is sufficiently low to obviate surgical excision., Materials and Methods: An institutional review board-approved, HIPAA-compliant retrospective review of 991 cases of consecutive 9- or 11-gauge stereotactic VABB performed during a 65-month period revealed 147 cases of atypia. One pathologist performed a blinded review of the results of procedures performed to assess for calcifications and confirmed ADH in 101 cases with subsequent surgical excision. Each large duct or terminal duct-lobular unit containing ADH was considered a focus and counted. Postbiopsy mammograms were reviewed to determine whether all calcifications were removed. Upgrade to malignancy was determined from excisional biopsy pathology reports. Upgrade rates as a function of both number of foci and presence or absence of residual calcifications were calculated and compared by using chi(2) tests., Results: Upgrade to malignancy occurred in 20 (19.8%) of the 101 cases. The upgrade rate was significantly higher in cases of three or more foci of ADH (15 [28%] of 53 cases) than in cases of fewer than three foci (five [10%] of 48 cases) (P = .02). Upgrade rates were similar, regardless of whether all mammographic calcifications were removed (seven [17%] of 41 cases) or all were not removed (nine [20%] of 45 cases) (P = .77). Upgrade occurred in two (12%) of 17 cases in which there were fewer than three ADH foci and all calcifications were removed., Conclusion: The upgrade rate is significantly higher when ADH involves at least three foci. Surgical excision is recommended even when ADH involves fewer than three foci and all mammographic calcifications have been removed, because the upgrade rate is 12%., (Copyright RSNA, 2010)

The MR imaging BI-RADS atlas includes a category for probably benign findings, and many radiologists recommend short-term interval follow-up for breast MR imaging lesions. However, the characteristics of those MR imaging findings that could appropriately be considered probably benign are not well defined. This article reviews the published retrospective and prospective data regarding the use and cancer yield of the BI-RADS 3 assessment category as well as the morphology and kinetics of lesions that may be considered suitable for short-term follow-up. Consideration is also given to how the costs, clinical indication for the examination, experience of the reader, and availability of comparisons may affect the use of the BI-RADS 3 category. Based on the evidence that is available, an algorithm is offered with imaging examples as a guide for determining if lesions are appropriate for short-term follow-up. Additional research is needed to fully clarify the distinct morphologic and kinetic characteristics that allow patients to safely avoid biopsy without changing prognosis if malignancy is present., (Copyright 2010 Elsevier Inc. All rights reserved.)

Purpose: Our goal was to determine the correlations between dynamic contrast-enhanced MRI (DCE-MRI) kinetics of breast cancers and axillary nodal status (ANS) which may have prognostic value in designing radiation therapy recommendations., Methods and Materials: A retrospective review identified 167 consecutive patients treated with external beam radiotherapy for invasive breast cancer from Jan 1, 2006 to Nov 1, 2007. Patients with DCE-MRI kinetic data from our institution who underwent axillary surgical staging prior to chemotherapy were included. ANS was assessed as positive or negative by pathology record review. For each primary cancer, maximum tumor diameter and kinetic values for initial peak enhancement (PE), percent initial rapid enhancement (RE), and percent delayed washout enhancement (WE) were measured with a computer-aided evaluation program. Univariate, multivariate, and receiver operating characteristic curve analyses were performed according to the ANS., Results: Forty-six patients met study criteria, with 32 (70%) node-negative and 14 (30%) node-positive patients. Median PE was significantly greater in node-positive patients (209%) than in node-negative patients (138%, p = 0.0027). Similarly, median RE was significantly greater in node-positive patients (57%) than in node-negative patients (27%, p = 0.0436). WE was not different between groups (p = 0.9524). Median maximum tumor diameter was greater in node-positive patients (26 mm) than in node-negative patients (15 mm, p = 0.015). Multivariate analysis showed that only PE trended toward significance (p = 0.18)., Conclusions: DCE-MRI kinetics of primary breast cancers correlate with ANS. Multivariate analysis demonstrates the correlation is not due simply to underlying lesion size. If validated prospectively, DCE-MRI kinetics may aid as a tool in selecting patients or designing fields for radiation therapy.

Purpose: To investigate the diagnostic performance of diffusion-weighted imaging (DWI) for mammographically and clinically occult breast lesions., Materials and Methods: The study included 91 women with 118 breast lesions (91 benign, 12 ductal carcinoma in situ [DCIS], 15 invasive carcinoma) initially detected on dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and assigned BI-RADS category 3, 4, or 5. DWI was acquired with b = 0 and 600 s/mm(2). Lesion visibility was assessed on DWI. Apparent diffusion coefficient (ADC) values were compared between malignancies, benign lesions, and normal (no abnormal enhancement on DCE-MRI) breast tissue, and the diagnostic performance of DWI was assessed based on ADC thresholding., Results: Twenty-four of 27 (89%) malignant and 74/91 (81%) benign lesions were hyperintense on the b = 600 s/mm(2) diffusion-weighted images. Both DCIS (1.33 +/- 0.19 x 10(-3) mm(2)/s) and invasive carcinomas (1.30 +/- 0.27 x 10(-3)mm(2)/s) were lower in ADC than benign lesions (1.71 +/- 0.43 x 10(-3)mm(2)/s; P < 0.001), and each lesion type was lower in ADC than normal tissue (1.90 +/- 0.38 x 10(-3)mm(2)/s, P

Rationale and Objectives: The aim of this study was to determine the sonographic visibility of implanted collagen-based breast biopsy marker clips in the clinic and operating room., Materials and Methods: Female patients aged > or =18 years who presented for preoperative surgical evaluation within 4 weeks of ultrasound-guided breast biopsy and collagen-based marker clip placement were eligible for this pilot study. The sonographic visibility of the marker clips was rated from 1 (not visible) to 5 (clearly visible) by surgeons at the preoperative appointment, by radiologists at wire localization, and by surgeons in the operating room. Visibility was considered inadequate for values of 1 or 2 and adequate for values of 3, 4, or 5. The data were compared using Wilcoxon's signed-rank test for paired differences across physician (radiologist vs surgeon), time (preoperative visit vs day of surgery), and target (lesion vs clip)., Results: Twenty-five patients with 26 lesions were enrolled, and 19 patients returned for all imaging procedures. The mean lesion size was 12 mm (range, 5-24 mm). Adequate marker clip visibility assessed by the surgeons decreased from 80% (20 of 25) at the preoperative appointment to 65% (11 of 17) in the operating room, but the difference was not significant (P=.27). Visibilities of the lesions and clips were similar at the preoperative appointment (P=.61), but the clips were significantly less visible on the day of operation (P=.03)., Conclusion: The sonographic visibility of collagen-based marker clips is variable and likely decreases over time but may be adequate to guide intraoperative surgical excision in many cases.

Purpose: To investigate whether diffusion tensor imaging (DTI) measures of anisotropy in breast tumors are different from normal breast tissue and can improve the discrimination between benign and malignant lesions., Materials and Methods: The study included 81 women with 105 breast lesions (76 malignant, 29 benign). DTI was performed during breast MRI examinations, and fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values were measured for breast lesions and normal tissue in each subject. FA and ADC were compared between cancers, benign lesions, and normal tissue by univariate and multivariate analyses., Results: The FA of carcinomas (mean +/- SD: 0.24 +/- 0.07) was significantly lower than normal breast tissue in the same subjects (0.29 +/- 0.07; P < 0.0001). Multiple logistic regression showed that FA and ADC were each independent discriminators of malignancy (P < 0.0001), and that FA improved discrimination between cancer and normal tissue over ADC alone. However, there was no difference in FA between malignant and benign lesions (P = 0.98)., Conclusion: Diffusion anisotropy is significantly lower in breast cancers than normal tissue, which may reflect alterations in tissue organization. Our preliminary results suggest that FA adds incremental value over ADC alone for discriminating malignant from normal tissue but does not help with distinguishing benign from malignant lesions.

Objective: The purpose of our study was to investigate whether adding diffusion-weighted imaging (DWI) to dynamic contrast-enhanced MRI (DCE-MRI) could improve the positive predictive value (PPV) of breast MRI., Materials and Methods: The retrospective study included 70 women with 83 suspicious breast lesions on DCE-MRI (BI-RADS 4 or 5) who underwent subsequent biopsy. DWI was acquired during clinical breast MRI using b = 0 and 600 s/mm(2). Apparent diffusion coefficient (ADC) values were compared for benign and malignant lesions. PPV was calculated for DCE-MRI alone (based on biopsy recommendations) and DCE-MRI plus DWI (adding an ADC threshold) for the same set of lesions. Results were further compared by lesion type (mass, nonmasslike enhancement) and size., Results: Of the 83 suspicious lesions, 52 were benign and 31 were malignant (11 ductal carcinoma in situ [DCIS], 20 invasive carcinoma). Both DCIS (mean ADC, 1.31 +/- 0.24 x 10(-3) mm(2)/s) and invasive carcinoma (mean ADC, 1.29 +/- 0.29 x 10(-3) mm(2)/s) exhibited lower mean ADC than benign lesions (1.70 +/- 0.44 x 10(-3) mm(2)/s, p < 0.001). Applying an ADC threshold of 1.81 x 10(-3) mm(2)/s for 100% sensitivity produced a PPV of 47% versus 37% for DCE-MRI alone, which would have avoided biopsy for 33% (17/52) of benign lesions without missing any cancers. DWI increased PPV similarly for masses and nonmasslike enhancement and preferentially improved PPV for smaller (< or = 1 cm) versus larger lesions., Conclusion: DWI shows potential for improving the PPV of breast MRI for lesions of varied types and sizes. However, considerable overlap in ADC of benign and malignant lesions necessitates validation of these findings in larger studies.

Rationale and Objectives: To evaluate the associations of patient age and clinical indication with the risk of malignancy for suspicious lesions initially detected on breast magnetic resonance imaging (MRI)., Methods and Materials: After institutional review board approval, a retrospective review of our breast MRI database was performed to identify all nonpalpable, mammographically occult, MRI-detected suspicious lesions between January 1, 2003, and November 30, 2006, that underwent needle or excisional biopsy. Clinical indication and patient age were recorded and their associations with risk of malignancy were assessed using univariate and multivariate generalized estimating equations., Results: The likelihood of malignancy was significantly higher (P = .0004) for suspicious lesions found on MRI examinations performed for a patient history of known cancer/evaluate extent of disease (130/309, 42%) compared to lesions identified on examinations conducted for high-risk screening (21/96, 22%). Suspicious lesions found in patients > or = 50 years of age were also more likely to be malignant (92/209, 44%) compared to those found in patients <50 years of age (59/196, 30%) (P = .004). In a multivariable model, both clinical indication of known cancer (OR 2.39, 95% CI 1.33-4.30) and age of 50 years or older (OR 1.66, 95% CI 1.03-2.68) were independently associated with greater risk of malignancy., Conclusion: The clinical indication of known cancer/evaluate extent of disease and patient age of 50 years or older significantly increase the risk of malignancy in suspicious MRI-detected lesions.

Objective: The purpose of our study was to evaluate the predictive features of BI-RADS lesion characteristics and the risk of malignancy for mammographically and clinically occult lesions detected initially on breast MRI., Materials and Methods: We reviewed 1,523 consecutive breast MRI examinations performed from January 1, 2003, to June 30, 2005, to identify all lesions initially detected on MRI and assessed as BI-RADS 4 or 5 for which the patient underwent subsequent imaging-guided needle or excisional biopsy. BI-RADS lesion features were recorded for each case, and the risk of malignancy was assessed using generalized estimating equations. Separate multivariate models were constructed for lesions classified as masses., Results: Included in the analysis were 258 suspicious lesions in 196 women. Among all lesions, those of 1 cm or greater were significantly more often malignant (50/147, 34%) than lesions of less than 1 cm (22/111, 20%; odds ratio, 2.09; 95% CI, 1.13-3.83). For masses, size, BI-RADS margin, and enhancement pattern predicted malignancy. In multivariate analysis of combinations of features, masses of 1 cm or greater with heterogeneous enhancement and irregular margins had a 68% probability of malignancy. Masses of 1 cm or greater with smooth margins and homogeneous enhancement had the lowest predicted probability of malignancy of 3%. BI-RADS descriptors and size were not significant predictors of malignancy for nonmasslike enhancement (NMLE)., Conclusion: Combinations of BI-RADS lesion descriptors can predict the probability of malignancy for breast MRI masses but not for NMLE. If our model is validated, masses with a low probability of malignancy may be eligible for short-interval follow-up rather than biopsy. Further research focused on predictive features of NMLE is needed.

Objective: The purpose of our study was to describe the characteristics of probably benign breast MRI lesions and determine how these characteristics could be used to define the MRI BI-RADS 3 category., Materials and Methods: We prospectively collected morphology and kinetic data on lesions assessed as BI-RADS 3 in 2,569 consecutive breast MRI examinations from January 2003 through November 2006. The clinical indications for MRI, follow-up assessments, and pathology findings through May 2008 were collected from clinical records. Data were linked to the regional tumor registry to identify cases of malignancy in patients who did not follow-up at our institution. Frequency of BI-RADS 3 and cancer yield were calculated. Characteristics of probably benign lesions were analyzed for predictors of malignancy., Results: Three hundred sixty-two lesions were assessed as BI-RADS 3 in 260 (10.1%) of 2,569 examinations in 236 patients. The 362 lesions included 168 (46%) foci, 132 (36%) nonmasslike enhancements, and 62 (17%) masses. Delayed kinetic information was available in 275 lesions. The most suspicious delayed kinetic enhancement was persistent in 164 (60%) of 275, plateau in 47 (17%) of 275, and washout in 64 (23%) of 275. The cancer yield in patients with a BI-RADS 3 assessment was two (0.85%) of 236; both were ductal carcinoma in situ lesions. There were no malignancies in the 69 foci with 100% persistent enhancement., Conclusion: The characteristics of BI-RADS 3 lesions were highly variable in our population, and the risk of malignancy was low (0.85%). Assigning foci with 100% persistent enhancement to the BI-RADS 2 category can decrease the frequency of BI-RADS 3 assessment and maintain a likelihood of malignancy in less than 2% of cases.

Objective: Computer-aided evaluation (CAE) programs for breast MRI provide automated lesion kinetic information. The CAE kinetic parameters that best predict malignancy have not been established. We compared three CAE kinetic features of suspicious breast MRI lesions to determine associations with benign or malignant outcomes., Materials and Methods: From 1,532 MRI examinations, all suspicious breast lesions initially detected with MRI and having CAE kinetics and subsequent biopsy were identified. Three CAE variables were compared for benign and malignant lesions: initial phase peak enhancement (greatest percentage signal intensity increase on first contrast-enhanced sequence), delayed phase enhancement categorized by a single type of kinetics comprising the largest percentage of enhancement (washout, plateau, or persistent), and delayed phase enhancement categorized by single most suspicious type of kinetics (any washout > any plateau > any persistent)., Results: One hundred twenty-five lesions (42 malignant, 83 benign) comprised the analysis set. There were no significant differences in initial peak enhancement (p = 0.28) or delayed kinetics categorized by largest percentage enhancement types (p = 0.39) between benign and malignant lesions. There was a significant difference in delayed kinetics categorized by the most suspicious enhancement types (p = 0.005). Of lesions with washout as most suspicious (any washout), 45.7% were malignant compared with 20.0% with plateau and 13.3% with entirely persistent enhancement., Conclusion: Of CAE kinetics analyzed, only delayed enhancement categorized by most suspicious type was significantly different between benign and malignant lesions. This supports the American College of Radiology BI-RADS Breast MRI Lexicon recommendation to report the "worst looking" kinetic curve.

Objective: Data remain sparse to guide the use of targeted sonography for suspicious breast lesions found with MRI. The purpose of our study was to determine the usefulness of sonography in this setting., Materials and Methods: Retrospective review of our breast MRI database was performed to identify all nonpalpable, mammographically occult MRI-detected suspicious lesions from January 1, 2003, to December 30, 2004, that underwent targeted sonography followed by imaging-guided biopsy. Frequency of sonography detection was determined, and MRI features (BI-RADS lesion type and size), histopathology outcomes, and positive biopsy rates of sonographically detected and occult findings were compared using chi-square analysis., Results: Targeted sonography was performed for 167 of 201 MRI lesions. Outcomes were benign in 120 (72%) and malignant in 47 (28%) findings. Lesions assessed on sonography were 84 (50%) masses, 53 (32%) nonmasslike enhancements, and 30 (18%) foci, with mean size of 16 mm. Overall, 76 of 167 (46%) lesions were detected with sonography. Depiction was significantly more frequent for masses (58%) than for nonmasslike enhancement (30%) or foci (37%) (p = 0.003). Lesion size did not affect the frequency of detection. Sonographically depicted findings had a significantly higher positive biopsy rate (36%) than sonographically occult lesions (22%) (p = 0.05)., Conclusion: Targeted sonography detected nearly half (46%) of MRI lesions evaluated, with depiction being most frequent for masses. Sonographically occult lesions had a probability of malignancy (22%), which warrants biopsy despite lack of sonographic detection.

Objective: Our goals were to determine the frequency and upgrade rate for atypical ductal hyperplasia (ADH) diagnosed with stereotactic 9-gauge vacuum-assisted breast biopsy and to compare the frequencies and upgrade rates of ADH between 9- and 11-gauge vacuum-assisted breast biopsy., Materials and Methods: We retrospectively reviewed the pathology results of 991 consecutive 9- or 11-gauge stereotactic vacuum-assisted breast biopsy procedures from February 2001 through June 2006 and identified lesions diagnosed as ADH. The final diagnosis after surgical excision was determined from medical records. The frequencies and upgrade rates to carcinoma were calculated for all ADH lesions and compared between 9- and 11-gauge procedures. The number of core samples was recorded and compared., Results: One hundred forty-one of 991 (14.2%) lesions yielded a diagnosis of ADH at 9- or 11-gauge stereotactic vacuum-assisted breast biopsy. Upgrade to ductal carcinoma in situ or invasive carcinoma occurred in 26 of 123 (21.1%) patients. The frequency of ADH was 83 of 600 (13.8%) lesions for 9-gauge and 58 of 391 (14.8%) lesions for 11-gauge vacuum-assisted breast biopsy. The 9-gauge upgrade rate was 16 of 74 (21.6%) lesions compared with 10 of 49 (20.4%) lesions for 11-gauge vacuum-assisted breast biopsy. There was no significant difference between the number of core samples obtained with each device (p=0.40). Neither the frequency of ADH (p=0.66) nor the upgrade rates (p=0.87) were significantly different between 9- and 11-gauge vacuum-assisted breast biopsy., Conclusion: Compared with an 11-gauge vacuum-assisted breast biopsy device, the use of a larger 9-gauge vacuum-assisted breast biopsy needle does not decrease the upgrade rate of ADH. Our frequency of ADH at vacuum-assisted breast biopsy is higher than any previously reported and may reflect regional differences in the incidence of breast cancer or practice patterns of the pathologist.

Background: Our goal was to determine the upgrade rate for lesions described as focal atypical ductal hyperplasia (ADH) after 9- or 11-gauge stereotactic vacuum-assisted breast biopsy (VABB) to determine whether surgical excision is indicated in this setting., Methods: We retrospectively reviewed the results of 991 consecutive 9- or 11-gauge stereotactic core VABB procedures from February 2001 through June 2006 and identified lesions diagnosed as ADH. On the basis of the descriptions in pathology reports each lesion was placed in one of three categories: (1) focal ADH, (2) ADH suspicious for ductal carcinoma-in-situ, or (3) ADH not otherwise specified. The final diagnosis after surgical excisional biopsy was determined from medical records. The frequencies and upgrade rates to carcinoma were calculated and compared for all lesions and for each ADH category., Results: A total of 141 (14.2%) of 991 lesions yielded ADH at stereotactic core VABB, and 123 (87.2%) of 141 underwent surgical excisional biopsy of the stereotactic core VABB site. A total of 56 (45.5%) of 123 were categorized as focal ADH, and 7 (12.5%) of 56 were upgraded to carcinoma. A total of 49 (39.8%) of 123 were categorized as ADH not otherwise specified, and 11 (22.4%) of 49 were upgraded. Eighteen (14.6%) of 123 were categorized as suspicious for ductal carcinoma-in-situ, and 8 (44.4%) of 18 were upgraded. Neither the frequency of ADH (P = .66) nor the upgrade rates (P = .87) were significantly different between 9- and 11-gauge VABB., Conclusion: Surgical excisional biopsy is indicated to exclude carcinoma in cases of focal ADH discovered at 9- or 11-gauge VABB.

To identify the Breast Imaging Reporting and Data System magnetic resonance imaging (MRI) enhancement characteristics of ductal carcinoma in situ (DCIS). A retrospective review of consecutive patients who underwent breast MRI for newly diagnosed breast carcinoma prior to surgery was conducted. This yielded 381 lesions in 361 patients with pathologic confirmation of either DCIS alone, invasive carcinoma alone, or mixed invasive and in-situ disease. Presence or absence of a MRI lesion at the site of the documented carcinoma was recorded, and for all identified MRI lesions the Breast Imaging Reporting and Data System morphology patterns were recorded. MRI features of the different malignancy types were compared utilizing Fisher's exact tests; 64/381 (16.8%) lesions had DCIS, 101/381 (26.5%) had invasive carcinoma, and 216/381 (56.7%) had mixed invasive/in situ carcinoma. A MRI lesion corresponding to the known cancer was identified in 55/64 (85.9%) cases of DCIS, 98/101 (97.0%) cases of invasive carcinoma, and 212/216 (98.1%) cases of mixed invasive and in-situ carcinoma. For pure DCIS lesions, 38/64 (59.4%) exhibited nonmass-like enhancement (NMLE), 9/64 (14.1%) were masses, and 8/64 (12.5%) were a focus. For pure invasive carcinomas 79/101(78.2%) were masses, 16/101 (15.8%) were NMLE, and 3/101 (3.0%) were a focus. For mixed lesions 163/216 (75.5%) were masses, 44/216 (20.4%) demonstrated NMLE, and 5/216 (2.3%) were a focus. The most common NMLE patterns of pure DCIS were segmental distribution and clumped internal enhancement. Although there is overlap in the MRI morphology and enhancement pattern of in situ and invasive breast carcinoma, DCIS more frequently manifests as NMLE than does invasive carcinoma.

Purpose: To evaluate the cancer yield, frequency of use, and follow-up compliance of breast MR examinations assessed as "probably benign.", Materials and Methods: We retrospectively reviewed our MR database of 809 consecutive examinations between January 2003 and June 2004. We identified all examinations that ultimately received an MR breast imaging reporting and data system (BI-RADS) 3 assessment and recommendation for a short-interval follow-up MR with or without an antecedent targeted ultrasound. The clinical indication for breast MR, date of the follow-up examination, follow-up assessment, and any pathology findings through June 2005 were collected from clinical records and radiology and pathology reports. Frequency of BI-RADS 3 use, follow-up compliance, and cancer yield were calculated., Results: A total of 160 out of 809 (20%) examinations comprise the study population. A total of 100 out of 160 (63%) women returned for the recommended follow-up MR, in which three out of 100 (3%) were upgraded to BI-RADS 4 with biopsy recommended. One patient underwent biopsy and the result was benign. A total of seven out of 160 (4%) underwent mastectomy in lieu of MR for known cancer elsewhere in the breast. One out of seven mastectomy specimens contained malignancy that corresponded to the probably benign finding, resulting in a cancer yield of one out of 160 (0.6%)., Conclusion: Our data suggest that follow-up MR is a valid alternative to biopsy for MR BI-RADS 3 lesions., ((c) 2007 Wiley-Liss, Inc.)

Purpose: To retrospectively determine the sensitivity of kinetic features measured with computer-aided evaluation at breast magnetic resonance (MR) imaging in discriminating benign from malignant lesions, with histopathologic findings used as the reference standard., Materials and Methods: Institutional review board approval was obtained for this HIPAA-compliant study. Informed consent was waived. Suspicious breast lesions visible only at MR imaging and in which biopsy had been performed with MR imaging guidance were retrospectively evaluated with a computer-aided evaluation program. Computer-generated kinetic features for each lesion were recorded, and those of benign and malignant lesions were compared. Features analyzed included the presence or absence of computer-aided evaluation "threshold enhancement" at 50% and 100% minimum thresholds; degree of initial peak enhancement; and enhancement profiles composed of lesion percentages of washout, plateau, and persistent enhancement. The Fisher exact test and Student t test were used to assess differences in these analyses., Results: One hundred fifty-four consecutive lesions (41 malignant, 113 benign) in 125 women (age range, 27-86 years; mean age, 52 years) were evaluated. The presence of threshold enhancement at computer-aided evaluation was sensitive for malignancy, with 38 of 41 (93%) malignant lesions demonstrating enhancement at both the 50% and 100% thresholds. Absence of threshold enhancement at computer-aided evaluation helped improve the discrimination between benign and malignant lesions when compared with that at initial interpretation by the radiologists. False-positive rates were reduced by 8.8% at the 50% enhancement threshold (not significant) and by 23.0% at the 100% enhancement threshold (P=.02) when compared with that at initial interpretation. Analyses of initial peak enhancement values and enhancement profiles did not demonstrate further improvements in lesion discrimination., Conclusion: The use of computer-aided evaluation for breast MR imaging significantly helped improve the discrimination of benign from malignant lesions when compared with that at initial interpretations by radiologists., ((c) RSNA, 2007.)

Objective: We sought to compare the accuracy of breast MRI interpretations with and without a new software application (CADstream) that provides automated evaluations of breast MR examinations., Materials and Methods: Thirty-three consecutive lesions seen only on MRI (nine malignant, 24 benign) were evaluated with and without the automated software system. Automated analyses of kinetic enhancement for each lesion were recorded at 50%, 80%, and 100% enhancement thresholds. Computer-assisted analyses included presence or absence of "significant" enhancement and classification of enhancement patterns into percent volumes of washout, plateau, and persistent enhancement. Fisher's exact tests were performed to compare the likelihood of malignancy based on the presence of software-defined significant enhancement at the three thresholds. Enhancement profiles of malignant versus benign lesions were compared using the Student's t test., Results: All malignant lesions showed significant enhancement at all thresholds. Compared with the unassisted interpretations, the computer-assisted analyses yielded false-positive rates that were reduced by 25% at a 50% threshold (not significant [NS]), 33% at an 80% threshold (p = 0.05), and 50% at a 100% threshold for enhancement (p < 0.01). There were no significant differences between enhancement profiles of benign and malignant lesions, with all lesions showing a wide range of washout, plateau, and persistent patterns of enhancement., Conclusion: New automated software applied to interpret breast MR examinations accurately showed significant enhancement in all the malignant lesions while depicting 12 of 24 benign lesions as showing insignificant enhancement. If these results are validated by a larger study, the number of unnecessary biopsies of MR lesions could be reduced without a concomitant decrease in cancer detection.

Rationale and Objectives: MRI has shown promise in assessing breast cancer patients undergoing neoadjuvant chemotherapy. Computer-aided detection (CAD) for MRI can automatically display tumor enhancement parameters. This study was performed to determine the utility of CAD applied to breast MRI in this patient population., Materials and Methods: Fifteen patients with 16 newly diagnosed locally advanced breast cancers were evaluated with MRI before and after neoadjuvant chemotherapy. CAD assessments, including presence or absence of significant enhancement, enhancement profiles, and maximum sizes, were recorded. Pre-chemotherapy and post-chemotherapy enhancement profiles were compared. Sizes were compared to those measured by the radiologist and at final pathology., Results: Prior to chemotherapy, all tumors demonstrated CAD-assessed significant enhancement. Following chemotherapy, 7/16 tumors showed no residual significant enhancement, but all had residual disease at pathology. In those patients with residual enhancement, comparison of the post-chemotherapy to pre-chemotherapy CAD enhancement profiles showed a significant decrease in percentage of washout enhancement (P = 0.0147) in patients with less than 5 mm of residual microscopic disease. Radiologist-measured tumor sizes demonstrated better correlation with sizes at pathology (r = 0.60) than did CAD-generated tumor sizes (r = 0.32)., Conclusion: CAD may be helpful in assessing changes in MRI enhancement profiles of tumors following chemotherapy. However, CAD-assessed significant enhancement following chemotherapy can be falsely negative for residual malignancy, and CAD tumor sizes are less accurate than those measured by the radiologist in predicting size of residual malignancy. CAD may complement but should not replace the radiologist's assessment of tumors in this patient population.

Objective: The objective of our study was to evaluate a new commercially available method of MRI-guided vacuum-assisted breast biopsy using an open coil and a closed 1.5-T scanner., Materials and Methods: Consecutive MRI-guided vacuum-assisted breast biopsies of 38 lesions in 28 women performed between May and September 2003 at two practice sites in the United States were retrospectively reviewed. Lesion characteristics including size, morphology, and enhancement were recorded. Times to perform each procedure, defined as the time from the start of the first localizing scan to the final scan after biopsy, were recorded. Histologic results for all lesions were obtained, and surgical, imaging, or clinical follow-up was performed., Results: Enhancing masses and foci ranged from 2.5 to 19 mm. Nonmasslike enhancements ranged from 6 to 70 mm. All 38 biopsies (100%) were technically successful, and no complications were associated with any of the biopsy procedures. The average time to perform the 19 single-site MRI-guided procedures was 38 min (range, 23-57 min). The 11 multiple-site biopsies performed in a single breast averaged 59 min (range, 51-68 min), and eight bilateral biopsies averaged 64 min (range, 46-80 min). Histologic results from vacuum-assisted breast biopsy revealed malignancy in 14 lesions (37%), atypical ductal hyperplasia in two lesions (5%), and benign findings in 22 lesions (58%). One of two lesions with atypical ductal hyperplasia was upgraded to ductal carcinoma in situ after surgery, for an overall cancer yield of 40% (15/38)., Conclusion: This new method of MRI-guided vacuum-assisted breast biopsy is a safe, effective, and time-efficient means of MRI-guided tissue sampling.