Dorota J. Wisner

High-resolution diffusion-weighted imaging for the separation of benign from malignant BI-RADS 4/5 lesions found on breast MRI at 3T

To determine whether readout‐segmented echo‐planar diffusion imaging (RESOLVE) improves separation of malignant versus benign lesions compared to standard single‐shot echo‐planar imaging (ss‐EPI) on BI‐RADS 4/5 lesions detected on breast magnetic resonance imaging (MRI).

The Impact of Preoperative Magnetic Resonance Imaging on Surgical Treatment and Outcomes for Ductal Carcinoma In Situ

BACKGROUND Although magnetic resonance imaging (MRI) is a useful imaging modality for invasive cancer, its role in preoperative surgical planning for ductal carcinoma in situ (DCIS) has not been established. We sought to determine whether preoperative MRI affects surgical treatment and outcomes in women with pure DCIS. PATIENTS AND METHODS We reviewed consecutive records of women diagnosed with pure DCIS on core biopsy between 2000 and 2007. Patient characteristics, surgical planning, and outcomes were compared between patients with and without preoperative MRI. Multivariable regression was performed to determine which covariates were independently associated with mastectomy or sentinel lymph node biopsy (SLNB). RESULTS Of 149 women diagnosed with DCIS, 38 underwent preoperative MRI. On univariate analysis, patients undergoing MRI were younger (50 years vs. 59 years; P < .001) and had larger DCIS size on final pathology (1.6 cm vs. 1.0 cm; P = .007) than those without MRI. Mastectomy and SLNB rates were significantly higher in the preoperative MRI group (45% vs. 14%, P < .001; and 47% vs. 23%, P = .004, respectively). However, there were no differences in number of re-excisions, margin status, and margin size between the two groups. On multivariate analysis, preoperative MRI and age were independently associated with mastectomy (OR, 3.16, P = .018; OR, 0.95, P = .031, respectively), while multifocality, size, and family history were not significant predictors. CONCLUSION We found a strong association between preoperative MRI and mastectomy in women undergoing treatment for DCIS. Additional studies are needed to examine the increased rates of mastectomy as a possible consequence of preoperative MRI for DCIS.

High-Resolution Diffusion-Weighted Imaging for Monitoring Breast Cancer Treatment Response

RATIONALE AND OBJECTIVES The aim of this work was to compare a high-resolution diffusion-weighted imaging (HR-DWI) acquisition (voxel size = 4.8 mm(3)) to a standard diffusion-weighted imaging (STD-DWI) acquisition (voxel size = 29.3 mm(3)) for monitoring neoadjuvant therapy-induced changes in breast tumors. MATERIALS AND METHODS Nine women with locally advanced breast cancer were imaged with both HR-DWI and STD-DWI before and after 3 weeks (early treatment) of neoadjuvant taxane-based treatment. Tumor apparent diffusion coefficient (ADC) metrics (mean and histogram percentiles) from both DWI methods were calculated, and their relationship to tumor volume change after 12 weeks of treatment (posttreatment) measured by dynamic contrast enhanced magnetic resonance imaging was evaluated with a Spearmans rank correlation. RESULTS The HR-DWI pretreatment 15th percentile tumor ADC (P = .03) and early treatment 15th, 25th, and 50th percentile tumor ADCs (P = .008, .010, .04, respectively) were significantly lower than the corresponding STD-DWI percentile ADCs. The mean tumor HR-ADC was significantly lower than STD-ADC at the early treatment time point (P = .02), but not at the pretreatment time point (P = .07). A significant early treatment increase in tumor ADC was found with both methods (P < .05). Correlations between HR-DWI tumor ADC and posttreatment tumor volume change were higher than the STD-DWI correlations at both time points and the lower percentile ADCs had the strongest correlations. CONCLUSION These initial results suggest that the HR-DWI technique has potential for improving characterization of low tumor ADC values over STD-DWI and that HR-DWI may be of value in evaluating tumor change with treatment.

Imaging Features of HER2 Overexpression in Breast Cancer: A Systematic Review and Meta-analysis

Breast cancer imaging phenotype is diverse and may relate to molecular alterations driving cancer behavior. We systematically reviewed and meta-analyzed relations between breast cancer imaging features and human epidermal growth factor receptor type 2 (HER2) overexpression as a marker of breast cancer aggressiveness. MEDLINE and EMBASE were searched for mammography, breast ultrasound, magnetic resonance imaging (MRI), and/or [18F]fluorodeoxyglucose positron emission tomography studies through February 2013. Of 68 imaging features that could be pooled (85 articles, 23,255 cancers; random-effects meta-analysis), 11 significantly related to HER2 overexpression. Results based on five or more studies and robustness in subgroup analyses were as follows: the presence of microcalcifications on mammography [pooled odds ratio (pOR), 3.14; 95% confidence interval (CI), 2.46–4.00] or ultrasound (mass-associated pOR, 2.95; 95% CI, 2.34–3.71), branching or fine linear microcalcifications (pOR, 2.11; 95% CI, 1.07–4.14) or extremely dense breasts on mammography (pOR, 1.37; 95% CI, 1.07–1.76), and washout (pOR, 1.57; 95% CI, 1.11–2.21) or fast initial kinetics (pOR, 2.60; 95% CI, 1.43–4.73) on MRI all increased the chance of HER2 overexpression. Maximum [18F]fluorodeoxyglucose standardized uptake value (SUVmax) was higher upon HER2 overexpression (pooled mean difference, +0.76; 95% CI, 0.10–1.42). These results show that several imaging features relate to HER2 overexpression, lending credibility to the hypothesis that imaging phenotype reflects cancer behavior. This implies prognostic relevance, which is especially relevant as imaging is readily available during diagnostic work-up. Cancer Epidemiol Biomarkers Prev; 23(8); 1464–83. ©2014 AACR.

Breast MR imaging for extent of disease assessment in patients with newly diagnosed breast cancer.

Breast cancer staging and surgical planning are affected by the burden of pathologically proven cancer detected on clinical examination and/or imaging. Magnetic resonance (MR) imaging has superior sensitivity and accuracy for the detection of invasive and in situ breast cancer as compared with physical examination, mammography, and ultrasound but can be limited in specificity. The use of preoperative breast MR imaging for evaluating the extent of disease remains controversial at present because studies have not definitively shown it to improve overall survival, decrease re-excision rates, or to decrease the cost of care.

High resolution in vivo characterization of apparent diffusion coefficient at the tumor-stromal boundary of breast carcinomas: a pilot study to assess treatment response using proximity-dependent diffusion-weighted imaging.

To evaluate diffusion changes in the breast tumor–stromal boundary and adjacent tissue in response to neoadjuvant chemotherapy using high resolution diffusion‐weighted imaging (HR‐DWI).

Triple-Negative and Non–Triple-Negative Invasive Breast Cancer: Association between MR and Fluorine 18 Fluorodeoxyglucose PET Imaging

PURPOSE To assess the relationship between parameters measured on dynamic contrast material-enhanced (DCE) magnetic resonance (MR) imaging and fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) in primary invasive breast cancer. MATERIALS AND METHODS This HIPAA-compliant study was a retrospective review of medical records and therefore approved by the institutional review board without the requirement for informed consent. Patients with a diagnosis of invasive breast cancer from January 2005 through December 2009 who underwent both DCE MR imaging and FDG PET/CT before treatment initiation were retrospectively identified. Fractional volumes were measured for ranges of signal enhancement ratio (SER) values from DCE MR imaging data and compared with maximum standardized uptake values (SUVmax) from FDG PET/CT data. Linear regression analysis was performed to clarify the relationship between SER and SUVmax, adjusting for tumor size, pathologic grade, and receptor status. RESULTS Analyzed were 117 invasive breast cancers in 117 patients. Overall, a higher percentage of high washout kinetics was positively associated with SUVmax (1.57% increase in SUVmax per 1% increase in high washout; P = .020), and a higher percentage of low plateau kinetics was negatively associated with SUVmax (1.19% decrease in SUVmax per 1% increase in low plateau; P = .003). These relationships were strongest among triple-negative (TN) tumors (4.34% increase in SUVmax per 1% increase in high washout and 2.65% decrease in SUVmax per 1% increase in low plateau; P = .018 and .004, respectively). CONCLUSION In invasive breast carcinoma, there is a positive relationship between the percentage of high washout and SUVmax and a negative relationship between the percentage of low plateau and SUVmax. These results are stronger in TN tumors. SUPPLEMENTAL MATERIAL http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.13130058/-/DC1.

Recognizing Artifacts and Optimizing Breast MRI at 1.5 and 3 T

OBJECTIVE This article will discuss routine 1.5 and 3 T MRI of the breast as well as illustrate several examples of patient-related and technical artifacts one might encounter. Suggestions to help eliminate these artifacts and optimize images will be provided. CONCLUSION Artifacts seen on breast MR images can degrade image quality and obscure important findings. Recognizing artifacts and understanding how to address and troubleshoot them is essential for any radiologist interpreting breast MRI.

Inter-reader Variability in the Use of BI-RADS Descriptors for Suspicious Findings on Diagnostic Mammography: A Multi-institution Study of 10 Academic Radiologists

RATIONALE AND OBJECTIVES The study aimed to determine the inter-observer agreement among academic breast radiologists when using the Breast Imaging Reporting and Data System (BI-RADS) lesion descriptors for suspicious findings on diagnostic mammography. MATERIALS AND METHODS Ten experienced academic breast radiologists across five medical centers independently reviewed 250 de-identified diagnostic mammographic cases that were previously assessed as BI-RADS 4 or 5 with subsequent pathologic diagnosis by percutaneous or surgical biopsy. Each radiologist assessed the presence of the following suspicious mammographic findings: mass, asymmetry (one view), focal asymmetry (two views), architectural distortion, and calcifications. For any identified calcifications, the radiologist also described the morphology and distribution. Inter-observer agreement was determined with Fleiss kappa statistic. Agreement was also calculated by years of experience. RESULTS Of the 250 lesions, 156 (62%) were benign and 94 (38%) were malignant. Agreement among the 10 readers was strongest for recognizing the presence of calcifications (k = 0.82). There was substantial agreement among the readers for the identification of a mass (k = 0.67), whereas agreement was fair for the presence of a focal asymmetry (k = 0.21) or architectural distortion (k = 0.28). Agreement for asymmetries (one view) was slight (k = 0.09). Among the categories of calcification morphology and distribution, reader agreement was moderate (k = 0.51 and k = 0.60, respectively). Readers with more experience (10 or more years in clinical practice) did not demonstrate higher levels of agreement compared to those with less experience. CONCLUSIONS Strength of agreement varies widely for different types of mammographic findings, even among dedicated academic breast radiologists. More subtle findings such as asymmetries and architectural distortion demonstrated the weakest agreement. Studies that seek to evaluate the predictive value of certain mammographic features for malignancy should take into consideration the inherent interpretive variability for these findings.

Features of occult invasion in biopsy-proven DCIS at breast MRI

The purpose of this study is to determine if MRI BI‐RADS criteria or radiologist perception correlate with presence of invasive cancer after initial core biopsy of ductal carcinoma in situ (DCIS). Retrospective search spanning 2000–2007 identified all core‐biopsy diagnoses of pure DCIS that coincided with preoperative MRI. Two radiologists fellowship‐trained in breast imaging categorized lesions according to ACR MRI BI‐RADS lexicon and estimated likelihood of occult invasion. Semiquantitative signal enhancement ratio (SER) kinetic analysis was also performed. Results were compared with histopathology. 51 consecutive patients with primary core biopsy‐proven DCIS and concurrent MRI were identified. Of these, 13 patients (25%) had invasion at excision. Invasion correlated significantly with presence of a mass for both readers (p = 0.012 and 0.001), rapid initial enhancement for Reader 1 (p = 0.001), and washout kinetics for Reader 2 (p = 0.012). Significant correlation between washout and invasion was confirmed by SER (p = 0.006) when threshold percent enhancement was sufficiently high (130%), corresponding to rapidly enhancing portions of the lesion. Radiologist perception of occult invasion was strongly correlated with true presence of invasion. These results provide evidence that certain BI‐RADS MRI criteria, as well as radiologist perception, correlate with occult invasion after an initial core biopsy of DCIS.