Robyn L. Birdwell

BI-RADS 3, 4, and 5 Lesions: Value of US in Management—Follow-up and Outcome

PURPOSE To evaluate the use, final outcome, and positive biopsy rate of American College of Radiology ultrasonographic (US) Breast Imaging Reporting and Data System (BI-RADS) categories 3, 4, and 5 recommended for breast masses. MATERIALS AND METHODS At US, consecutive masses, palpable and nonpalpable, categorized as BI-RADS 3, 4, and 5 between January 1, 2003, and December 31, 2004, were retrospectively reviewed with institutional review board approval. Medical records provided imaging and histologic information. RESULTS After patients lost to follow-up were excluded, the study population was 767 patients with 926 masses (476 palpable, 450 nonpalpable). In BI-RADS 3 masses (n = 356), imaging follow-up of 252 masses documented stability for 6-24 months. Aspiration of 24 masses revealed cysts. Biopsy in 80 masses revealed three malignancies, all of which were diagnosed within 6 months of the index examination, were smaller than 1 cm, and were node negative (negative predictive value = 99.2%). In BI-RADS 4 masses (n = 524), aspiration results indicated 35 cysts; biopsy in 455 revealed 85 malignancies (positive predictive value [PPV] = 16.2%). Imaging follow-up only in 34 revealed no cancers 2 and more years later. Among BI-RADS 5 masses (n = 46), 43 were malignant and three benign (PPV = 93.4%). CONCLUSION Inconsistent use of BI-RADS category 3 occurred in 14.0% of cases when biopsy was recommended. Although biopsy was performed in almost equal numbers of palpable and nonpalpable masses, only 11% of palpable BI-RADS 3 and 4 masses were malignant, as compared with 22% of nonpalpable masses. Strict adherence to lexicon characteristics of probably benign lesions should improve specificity.

Background Parenchymal Enhancement at Breast MR Imaging: Normal Patterns, Diagnostic Challenges, and Potential for False-Positive and False-Negative Interpretation

At magnetic resonance (MR) imaging, both normal and abnormal breast tissue enhances after contrast material administration. The morphology and temporal degree of enhancement of pathologic breast tissue relative to normal breast tissue form the basis of MR imagings diagnostic accuracy in the detection and diagnosis of breast disease. Normal parenchymal enhancement at breast MR imaging is termed background parenchymal enhancement (BPE). BPE may vary in degree and distribution in different patients as well as in the same patient over time. Typically BPE is minimal or mild in overall degree, with a bilateral, symmetric, diffuse distribution and slow early and persistent delayed kinetic features. However, BPE may sometimes be moderate or marked in degree, with an asymmetric or nondiffuse distribution and rapid early and plateau or washout delayed kinetic features. These patterns cause diagnostic difficulty because these features can be seen with malignancy. This article reviews typical and atypical patterns of BPE seen at breast MR imaging. The anatomic and physiologic influences on BPE in women undergoing diagnostic and screening breast MR imaging are reviewed. The potential for false-positive and false-negative interpretations due to BPE are discussed. Radiologists can improve their interpretive accuracy by increasing their understanding of various BPE patterns, influences on BPE, and the potential effects of BPE on MR imaging interpretation.

If you don't find it often, you often don't find it: why some cancers are missed in breast cancer screening.

Mammography is an important tool in the early detection of breast cancer. However, the perceptual task is difficult and a significant proportion of cancers are missed. Visual search experiments show that miss (false negative) errors are elevated when targets are rare (low prevalence) but it is unknown if low prevalence is a significant factor under real world, clinical conditions. Here we show that expert mammographers in a real, low-prevalence, clinical setting, miss a much higher percentage of cancers than are missed when the mammographers search for the same cancers under high prevalence conditions. We inserted 50 positive and 50 negative cases into the normal workflow of the breast cancer screening service of an urban hospital over the course of nine months. This rate was slow enough not to markedly raise disease prevalence in the radiologists’ daily practice. Six radiologists subsequently reviewed all 100 cases in a session where the prevalence of disease was 50%. In the clinical setting, participants missed 30% of the cancers. In the high prevalence setting, participants missed just 12% of the same cancers. Under most circumstances, this low prevalence effect is probably adaptive. It is usually wise to be conservative about reporting events with very low base rates (Was that a flying saucer? Probably not.). However, while this response to low prevalence appears to be strongly engrained in human visual search mechanisms, it may not be as adaptive in socially important, low prevalence tasks like medical screening. While the results of any one study must be interpreted cautiously, these data are consistent with the conclusion that this behavioral response to low prevalence could be a substantial contributor to miss errors in breast cancer screening.

Prospective Study of the Efficacy of Breast Magnetic Resonance Imaging and Mammographic Screening in Survivors of Hodgkin Lymphoma

PURPOSE Current guidelines recommend breast magnetic resonance imaging (MRI) as an adjunct to mammography for breast cancer screening in female cancer survivors treated with chest irradiation at a young age, beginning 8 to 10 years after treatment. Prospective data evaluating its efficacy in female cancer survivors are lacking. This study sought to compare the sensitivity and specificity of breast MRI with those of mammography in women who received chest irradiation for Hodgkin lymphoma (HL). PATIENTS AND METHODS We enrolled 148 women treated with chest irradiation for HL at age ≤ 35 years who were > 8 years beyond treatment. Yearly breast MRI and mammogram were performed over a 3-year period. Sensitivity and specificity of the two screening modalities were compared. RESULTS With the screening, 63 biopsies were performed in 45 women; 18 (29%) showed a malignancy. All but one of the screen-detected malignancies were preinvasive or subcentimeter node-negative breast cancers. After excluding first-screen MRI and mammogram, mammogram sensitivity was 68% as compared with 67% for MRI (P = 1.0). Sensitivity increased to 94% using both screening modalities. The specificities of mammogram alone, MRI alone, and both were 93%, 94%, and 90%, respectively. CONCLUSION In contrast to women with genetic or familial risk, in HL survivors breast MRI was not more sensitive than mammogram for breast cancer detection. However, the two screening modalities complement each other in the detection of early cases of disease. Early diagnosis is particularly important in these patients, given the breast cancer treatment challenges in patients who have received prior cancer therapy.

Pure Ductal Carcinoma in Situ : A Range of MRI Features

OBJECTIVE The purpose of this article is to describe and illustrate the variety of common morphologic features, enhancement patterns, and kinetics of pure ductal carcinoma in situ (DCIS) on dynamic contrast-enhanced MRI of the breast, using the American College of Radiology BI-RADS lexicon. CONCLUSION Breast MRI plays an important role in the detection of DCIS, which most often appears as nonmass clumped enhancement, in a ductal or segmental distribution, with variable enhancement kinetics.

Breast MRI in the Evaluation of Eligibility for Accelerated Partial Breast Irradiation

OBJECTIVE Eligibility for accelerated partial breast irradiation is generally determined by physical examination in conjunction with conventional imaging techniques such as mammography and breast sonography. MRI is recognized as a significant imaging tool in diagnosing breast cancer and has shown the ability to identify mammographically occult carcinoma. Our purpose was to retrospectively assess preoperative breast MRI examinations in women with early-stage breast cancer who were theoretically eligible for accelerated partial breast irradiation and to explore the use of MRI in selecting patients for this treatment. MATERIALS AND METHODS Seventy-nine patients with core needle biopsy-proven breast cancer, who were eligible candidates for breast-conserving surgery and accelerated partial breast irradiation, underwent bilateral breast MRI examinations. At review, the presence and location of occult tumor sites (detected on MRI only) were documented and subsequently correlated with pathology findings. RESULTS From 79 patients, a total of 126 suspicious areas, including the index tumors, were detected by MRI. Additional sites of cancer other than the index tumor were observed in 30 patients (38%). Of these, eight (10%) had an additional cancer in a different quadrant from the index tumor. CONCLUSION The treatment effect of whole-breast irradiation on microscopic tumor cells and on additional occult foci in other quadrants of the breast is lost with partial breast irradiation. Our results suggest that MRI before accelerated partial breast irradiation may be of benefit to patients to ensure they do not have multifocal or multicentric disease, remote from the lumpectomy bed.

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.

Image quality in lossy compressed digital mammograms

Abstract The substitution of digital representations for analog images provides access to methods for digital storage and transmission and enables the use of a variety of digital image processing techniques, including enhancement and computer assisted screening and diagnosis. Lossy compression can further improve the efficiency of transmission and storage and can facilitate subsequent image processing. Both digitization (or digital acquisition) and lossy compression alter an image from its traditional form, and hence it becomes important that any such alteration be shown to improve or at least not damage the utility of the image in a screening or diagnostic application. One approach to demonstrating in a quantifiable manner that a specific image mode is at least equal to another is by clinical experiment simulating ordinary practice and suitable statistical analysis. In this paper we describe a general protocol for performing such a verification and present preliminary results of a specific experiment designed to show that 12 bpp digital mammograms compressed in a lossy fashion to 0.015 bpp using an embedded wavelet coding scheme result in no significant differences from the analog or digital originals.

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. J. Magn. Reson. Imaging 2000;11:87–96.

US of Breast Masses Categorized as BI-RADS 3, 4, and 5: Pictorial Review of Factors Influencing Clinical Management

The Breast Imaging Reporting and Data System (BI-RADS) lexicon for ultrasonography (US) is based on the established lexicon used successfully in mammography and attempts to provide a common language to avoid ambiguity in interpreting, reporting, and teaching breast US. Proper and consistent use of the BI-RADS US lexicon has numerous advantages, including facilitating (a) communication of final assessment categories that clearly indicate management recommendations, (b) data tracking for self-audits, and (c) clinical review of outcome summaries. However, the literature to date does not include sufficient data on outcomes to validate clinical use of the BI-RADS US lexicon. In this article, a pictorial review of the BI-RADS US lexicon descriptors is provided, and specific cases from a retrospective review are used to highlight the challenges in using the BI-RADS US lexicon. With these examples, suggestions are offered for greater clarity in the use of this lexicon. The technical challenges in follow-up US imaging are described. The challenges in assigning final assessment categories are detailed, as well as the clinical factors that may influence decision making and the management of certain lesions.