Joo Hee Cha

Nonpalpable Breast Masses: Evaluation by US Elastography

Objective To compare the diagnostic performances of conventional ultrasound (US) and US elastography for the differentiation of nonpalpable breast masses, and to evaluate whether elastography is helpful at reducing the number of benign biopsies, using histological analysis as a reference standard. Materials and Methods Conventional US and real-time elastographic images were obtained for 100 women who had been scheduled for a US-guided core biopsy of 100 nonpalpable breast masses (83 benign, 17 malignant). Two experienced radiologists unaware of the biopsy and clinical findings analyzed conventional US and elastographic images by consensus, and classified lesions based on degree of suspicion regarding the probability of malignancy. Results were evaluated by receiver operating characteristic curve analysis. In addition, the authors investigated whether a subset of lesions was categorized as suspicious by conventional US, but as benign by elastography. Results Areas under the ROC curves (Az values) were 0.901 for conventional US and 0.916 for elastography (p = 0.808). For BI-RADS category 4a lesions, 44% (22 of 50) had an elasticity score of 1 and all were found to be benign. Conclusion Elastography was found to have a diagnostic performance comparable to that of conventional US for the differentiation of nonpalpable breast masses. The authors conclude that BI-RADS category 4a lesions with an elasticity score of 1 probably do not require biopsy.

Correlation between high resolution dynamic MR features and prognostic factors in breast cancer.

Objective To correlate high resolution dynamic MR features with prognostic factors in breast cancer. Materials and Methods One hundred and ninety-four women with invasive ductal carcinomas underwent dynamic MR imaging using T1-weighted three-dimensional fast low-angle shot (3D-FLASH) sequence within two weeks prior to surgery. Morphological and kinetic MR features were determined based on the breast imaging and reporting data system (BI-RADS) MR imaging lexicon. Histological specimens were analyzed for tumor size, axillary lymph node status, histological grade, expression of estrogen receptor (ER), expression of progesterone receptor (PR), and expression of p53, c-erbB-2, and Ki-67. Correlations between the MR features and prognostic factors were determined using the Pearson χ2 test, linear-by-linear association, and logistic regression analysis. Results By multivariate analysis, a spiculated margin was a significant, independent predictor of a lower histological grade (p < 0.001), and lower expression of Ki-67 (p = 0.007). Rim enhancement was significant, independent predictor of a higher histological grade (p < 0.001), negative expression of ER (p = 0.001), negative expression of PR (p < 0.001) and a larger tumor size (p = 0.006). A washout curve may predict a higher level of Ki-67 (p = 0.05). Most of the parameters of the initial enhancement phase cannot predict the status of the prognostic factors. Only the enhancement ratio may predict a larger tumor size (p = 0.05). Conclusion Of the BI-RADS-MR features, a spiculated margin may predict favorable prognosis, whereas rim enhancement or washout may predict unfavorable prognosis of breast cancer.

MRI of the Breast for the Detection and Assessment of the Size of Ductal Carcinoma in Situ

Objective The aim of the study was to compare the accuracy of magnetic resonance imaging (MRI) and mammography for the detection and assessment of the size of ductal carcinoma in situ (DCIS). Materials and Methods The preoperative contrast-enhanced MRI and mammography were analyzed in respect of the detection and assessment of the size of DCIS in 72 patients (age range: 30-67 years, mean age: 47 years). The MRI and mammographic measurements were compared with the histopathologic size with using the Pearsons correlation coefficients and the Mann-Whitney u test. We evaluated whether the breast density, the tumor nuclear grade, the presence of comedo necrosis and microinvasion influenced the MRI and mammographic size estimates by using the chi-square test. Results Of the 72 DCIS lesions, 68 (94%) were detected by MRI and 62 (86%) were detected by mammography. Overall, the Pearsons correlation of the size between MRI and histopathology was 0.786 versus 0.633 between mammography and histopathology (p < 0.001). MRI underestimated the size by more than 1 cm (including false negative examination) in 12 patients (17%), was accurate in 52 patients (72%) and overestimated the size by more than 1 cm in eight patients (11%) whereas mammography underestimated the size in 25 patients (35%), was accurate in 31 patients (43%) and overestimated the size in 16 patients (22%). The MRI, but not the mammography, showed significant correlation for the assessment of the size of tumor in noncomedo DCIS (p < 0.001 vs p = 0.060). The assessment of tumor size by MRI was affected by the nuclear grade (p = 0.008) and the presence of comedo necrosis (p = 0.029), but not by the breast density (p = 0.747) or microinvasion (p = 0.093). Conclusion MRI was more accurate for the detection and assessment of the size of DCIS than mammography.

Sonographically Guided Core Biopsy of the Breast: Comparison of 14-Gauge Automated Gun and 11-Gauge Directional Vacuum-Assisted Biopsy Methods

Objective To compare the outcomes of 14-gauge automated biopsy and 11-gauge vacuum-assisted biopsy for the sonographically guided core biopsies of breast lesions. Materials and Methods We retrospectively reviewed all sonographically guided core biopsies performed from January 2002 to February 2004. The sonographically guided core biopsies were performed with using a 14-gauge automated gun on 562 breast lesions or with using an 11-gauge vacuum-assisted device on 417 lesions. The histologic findings were compared with the surgical, imaging and follow-up findings. The histologic underestimation rate, the repeat biopsy rate and the false negative rates were compared between the two groups. Results A repeat biopsy was performed on 49 benign lesions because of the core biopsy results of the high-risk lesions (n = 24), the imaging-histologic discordance (n = 5), and the imaging findings showing disease progression (n = 20). The total underestimation rates, according to the biopsy device, were 55% (12/22) for the 14-gauge automated gun biopsies and 36% (8/22) for the 11-gauge vacuum-assisted device (p = 0.226). The atypical ductal hyperplasia (ADH) underestimation (i.e., atypical ductal hyperplasia at core biopsy and carcinoma at surgery) was 58% (7/12) for the 14-gauge automated gun biopsies and 20% (1/5) for the 11-gauge vacuum-assisted biopsies. The ductal carcinoma in situ (DCIS) underestimation rate (i.e., ductal carcinoma in situ upon core biopsy and invasive carcinoma found at surgery) was 50% (5/10) for the 14-gauge automated gun biopsies and 41% (7/17) for the 11-gauge vacuum-assisted biopsies. The repeat biopsy rates were 6% (33/562) for the 14-gauge automated gun biopsies and 3.5% (16/417) for the 11-gauge vacuum-assisted biopsies. Only 5 (0.5%) of the 979 core biopsies were believed to have missed the malignant lesions. The false-negative rate was 3% (4 of 128 cancers) for the 14-gauge automated gun biopsies and 1% (1 of 69 cancers) for the 11-gauge vacuum-assisted biopsies. Conclusion The outcomes of the sonographically guided core biopsies performed with the 11-gauge vacuum-assisted device were better than those outcomes of the biopsies performed with the 14-gauge automated gun in terms of underestimation, rebiopsy and the false negative rate, although these differences were not statistically significant.

Ultrasound-guided vacuum-assisted biopsy of microcalcifications detected at screening mammography.

Background: Microcalcifications detected at screening mammography are frequently diagnosed by means of a stereotactic biopsy. Ultrasound (US)-guided percutaneous breast biopsy has several advantages over stereotactic biopsy, e.g., it offers real-time needle visualization, improves patient comfort, the procedure time is generally considered to be shorter, and it usually does not require ionizing radiation or dedicated equipment. Purpose: To assess the frequency of calcification retrieval and factors affecting retrieval success for US-guided 11-G vacuum-assisted biopsies of microcalcifications. Material and Methods: Seventy-five consecutive women (age range: 25–68 years, mean age: 47 years) with 75 lesions of microcalcifications detected at screening mammography underwent US-guided 11-G vacuum-assisted biopsy. Calcification retrieval was defined as being successful when calcifications were detected in radiographs of specimens. Mammographic, ultrasonographic, and histologic findings were analyzed to identify factors that affected calcification retrieval. Results: Among 75 lesions that had US-guided vacuum-assisted biopsy, calcifications were retrieved in 53 (71%) lesions. Calcification retrieval was more frequent for lesions; associated with masses or dilated ducts at US (85% [41/48] vs. 44% [12/27], P<0.001), located in the anterior or middle part of the breast vs. posterior part of the breast (81% [47/58] vs. 35% [6/17], P=0.001), of maximal diameter more than 10 mm (82% [41/50] vs. 48% [12/25], P=0.002), with a segmental or regional distribution vs. clustered distribution (95% [18/19] vs. 63% [35/56], P=0.008), or lesions of category 4c or 5 vs. category 4a or 4b (100% [8/8] vs. 67% [45/67], P=0.054) at mammography. Conclusion: US-guided 11-G vacuum-assisted biopsy retrieved calcifications from 71% (53/75) of lesions. Successful calcification retrieval was found to be related to the visibility of associated masses or dilated ducts by US, and to lesion depth, size, and distribution, and level of suspicion at mammography.

Ductographic findings of breast cancer.

Ductography has become the gold standard for the evaluation of patients exhibiting pathologic nipple discharges. In nine patients (age range, 29-67 years; median age, 51 years) with invasive (n=5) or intraductal (n=4) cancer, ductographic findings were recorded, then correlated with mammographic and sonographic findings. Common ductographic findings included complete ductal obstruction, multiple irregular filling defects in the nondilated peripheral ducts, ductal wall irregularities, periductal contrast extravasation, and ductal displacement. Faint microcalcifications or ill-defined masses, which were not opacified by contrast material, were often discovered adjacent to ductal abnormalities. Mammographically and sonographically occult diffusely spreading intraductal cancers often manifested as pathologic nipple discharge. In such cases, meticulous ductographic examinations and interpretations were crucial in order not to miss breast cancers.

Dynamic Contrast-enhanced Magnetic Resonance Imaging Evaluation of Vx2 Carcinoma in a Rabbit Model: Comparison of 1.0-m Gadobutrol and 0.5-m Gadopentetate Dimeglumine

Objectives:To compare the enhancement characteristics and diagnostic performance of 1.0-M gadobutrol with those of 0.5-M gadopentetate dimeglumine in rabbit VX2 tumor models. Materials and Methods:Our study was approved by the Animal Care Committee of our hospital. VX2 carcinomas were implanted in both thighs of 14 rabbits 4 days before magnetic resonance (MR) imaging. The animals underwent 2 identical MR examinations with 2 different contrast media separated by 8 hours with the use of a 3.0 T magnet. T2-, T1- weighted fast spin echo images were obtained. Sequential MR imaging with the 3-dimensional-SPGR sequence were performed before and at 1, 2, 3, 4, 5, 10, 15, 20, and 30 minutes after injection of 0.05 mmol/kg of 1.0-M gadobutrol or 0.5-M gadopentetate dimeglumine. Four rabbits without tumor implantation underwent the same MR examinations. Percentage enhancement of the tumor was assessed by 2 radiologists in consensus. Three different readers without knowledge of the histopathologic results interpreted both MR images in terms of presence of tumor. Receiver operating characteristic analysis was conducted to compare the diagnostic value of both contrast agents. Sensitivities and specificities were also calculated. In addition, lesion-to-muscle contrast, degree of lesion delineation, and global preferences of the readers were determined using a scoring system. Results:A total of 56 VX2 tumors were identified by histopathologic review. For the VX2 tumors, the percentage enhancement at each time point was consistently higher with injection of 1.0-M gadobutrol than with injection of 0.5-M gadopentetate dimeglumine (P < 0.01). The area under the receiver operating characteristic curve (Az) values for the use of 1.0-M gadobutrol-enhanced MR imaging were 0.937, 0.886, and 0.938 for readers 1, 2, and 3, respectively. The Az values for the use of 0.5-M gadopentetate dimeglumine-enhanced MR imaging were 0.908, 0.903, and 0.947. Sensitivities were 89.3%, 85.7%, and 89.3% for 1.0-M gadobutrol-enhanced MR imaging and 87.5%, 85.7%, and 89.3% for 0.5-M gadopentetate dimeglumine-enhanced MR imaging. Specificities were 87.5%, 75.0%, and 87.5% for 1.0-M gadobutrol-enhanced MR imaging and 100%, 81.3%, and 100% for 0.5-M gadopentetate dimeglumine-enhanced MR imaging. No significant differences were noted for the Az values, sensitivities, and specificities with the use of the 2 contrast agents. Lesion-to-muscle contrast, degree of lesion delineation, and global preferences of the readers were ranked significantly higher for 1.0-M gadobutrol-enhanced MR imaging in all readers (P < 0.001). Conclusion:Using a 3.0-T magnet, equivalent doses of 1.0-M gadobutrol-enhanced MR imaging showed a superior degree of enhancement for a VX2 tumor than 0.5-M gadopentetate dimeglumine-enhanced MR imaging, and a significant preference for readers was noted for 1.0-M gadobutrol-enhanced MR imaging.

LCD versus CRT Monitors for Digital Mammography: A Comparison of Observer Performance for the Detection of Clustered Microcalcifications and Masses

Background: There are two types of soft-copy display of digital mammograms, cathode-ray tube (CRT) and liquid-crystal display (LCD) monitors, and these present different resolutions and noise characteristics. Purpose: To compare observer performances for the detection of clustered microcalcifications and masses in digital mammograms, using LCD and CRT monitors. Material and Methods: Four radiologists evaluated 100 digital mammograms. Of these, 28 mammograms depicted clustered microcalcifications (12 benign, 16 malignant), 18 depicted masses (10 benign, eight malignant), and 54 depicted no apparent abnormality. The images were stored uncompressed as Digital Imaging and Communications in Medicine (DICOM) files and randomized for two sessions of soft-copy reading. The readers independently read all cases displayed on two 5-megapixel LCD and two CRT monitors with an interval of 3 months. Observers were asked to rate using a five-point scale the likelihoods of microcalcifications and masses independently. Receiver operating characteristic analysis was used to analyze results. Results: For the LCD and CRT monitors, average area-under-the-curve (Az) values for microcalcification detection were 0.977 (0.976, 0.970, 0.980, and 0.983 for the four readers) and 0.958 (0.910, 0.990, 0.976, 0.956), respectively. Corresponding Az values for masses were 0.971 (0.955, 0.990, 0.949, 0.989) and 0.944 (0.928, 0.966, 0.955, 0.925). No statistically significant difference was detected between the two monitor types (P>0.05). Conclusion: The LCD and CRT monitors are comparable in terms of detecting clustered microcalcifications and masses in digital mammograms.

Predictive Clinicopathologic and Dynamic Contrast-Enhanced MRI Findings for Tumor Response to Neoadjuvant Chemotherapy in Triple-Negative Breast Cancer

OBJECTIVEnThe purpose of this study is to investigate whether clinicopathologic factors and dynamic contrast-enhanced MRI (DCE-MRI) features are associated with pathologic tumor response to neoadjuvant chemotherapy (NAC) in patients with triple-negative breast cancer (TNBC).nnnMATERIALS AND METHODSnSeventy-three patients with TNBC who underwent pre-NAC MRI, completed NAC, and underwent surgery between January 2009 and December 2010 were included in the study. MRI features and clinicopathologic factors for predicting pathologic responses were analyzed, and residual tumor sizes, as measured using MRI and surgical specimens, were evaluated.nnnRESULTSnOf 73 study patients, 20 (27%) had a pathologic complete response (pCR). Homogeneous enhancement on pre-NAC MRI (odds ratio from multivariate analysis, 14.66) and a concentric shrinkage pattern of tumor volume reduction on post-NAC MRI (odds ratio, 8.63) were independently associated with pCR. Residual tumor sizes, as measured using MRI and surgical specimens, showed a strong correlation (r = 0.652, p < 0.001). The correlation for residual tumor sizes was stronger for patients with pCR (r = 0.600, p < 0.001) and those with a concentric shrinkage pattern (r = 0.818, p < 0.001) than for patients with a response other than near pCR or pCR (i.e., the non-pCR group) (r = -0.128, p = 0.590) and patients with a dendritic shrinkage pattern of tumor volume reduction (r = 0.270, p = 0.182).nnnCONCLUSIONnHomogeneous enhancement of tumors on pre-NAC MRI and the presence of a concentric shrinkage pattern after NAC are associated with pCR in patients with TNBC. Residual tumor sizes on MRI and surgical specimens tended to show a stronger correlation in the pCR group or the concentric shrinkage group than in the non-pCR group or the dendritic shrinkage group.

Association of BRCA Mutation Types, Imaging Features, and Pathologic Findings in Patients With Breast Cancer With BRCA1 and BRCA2 Mutations

OBJECTIVEnThe purpose of this study is to retrospectively evaluate the relationships between the BRCA mutation types, imaging features, and pathologic findings of breast cancers in BRCA1 and BRCA2 mutation carriers.nnnMATERIALS AND METHODSnWe identified patients with breast cancer with BRCA gene mutations from January 2000 to December 2014. After excluding patients who underwent lesion excision before MRI, 99 BRCA1 and 103 BRCA2 lesions in 187 women (mean age, 39.7 and 40.4 years, respectively) were enrolled. Mammographic, sonographic, and MRI scans were reviewed according to the BI-RADS lexicon (5th edition). Pathologic data were reviewed, including the immunohistochemistry findings. The relationships between the BRCA mutations and both imaging and pathologic findings were analyzed.nnnRESULTSnThe distribution of molecular subtypes of tumors significantly differed by the mutation type. BRCA1 tumors were associated with the triple-negative subtype, whereas BRCA2 tumors were associated with the luminal B subtype (p = 0.002). At MRI, breast cancers with BRCA1 mutations exhibited a circumscribed margin (p = 0.032) and rim enhancement (p = 0.013). No significant differences in mass shape or kinetic features were observed at MRI. Cancers in BRCA1 mutation carriers tended to develop in the posterior location in the breast (p = 0.034). At mammography, no significant difference in the prevalence of calcifications was observed according to the mutation type. At sonography, BRCA1 lesions were found to be associated with posterior acoustic enhancement (p < 0.0001).nnnCONCLUSIONnBreast cancers with BRCA1 mutations tend to exhibit benign morphologic features at MRI, mammography, and sonography, compared with BRCA2 mutations. Lesion location may represent another difference on imaging among various genetic phenotypes.