Seung Ja Kim

Breast Mass Evaluation: Factors Influencing the Quality of US Elastography

PURPOSEnTo investigate factors influencing the quality of ultrasonographic (US) elastography in the evaluation of suspicious breast masses.nnnMATERIALS AND METHODSnThis prospective study was conducted with institutional review board approval; written informed consent was obtained. Between January 2009 and February 2009, real-time US elastography of 312 breast masses (245 benign, 67 malignant) was performed in 268 consecutive patients (mean age, 45.7 years ± 10.2 [standard deviation]) prior to US-guided core biopsy. Five breast radiologists who had performed the examinations assessed the quality of elasticity images as inadequate, low, or high without histologic information. Age, body mass index (BMI), mammographic density, lesion size, lesion depth, and breast thickness at US were analyzed for their association with image quality by using the χ(2) test, Student t test, and multivariate analysis. Sensitivities and specificities for the differentiation of benign from malignant masses on the basis of elastography were calculated and compared between groups of quality scores by using the logistic regression method.nnnRESULTSnThe quality of elasticity images was assessed as inadequate in 21 (6.7%) cases, low in 134 (42.9%), and high in 157 (50.3%). According to univariate analysis, smaller lesion size (P = .001), shallower lesion depth (P = .005), less breast thickness where the lesion was located (P < .0001), and benign pathologic finding (P = .004) were significantly associated with higher image quality. There was no correlation of image quality with age (P = .213), BMI (P = .191), mammographic density (P = .091), or distance from the nipple (P = .100). Multivariable analysis showed that breast thickness at the location of target lesions was the most important factor influencing elasticity image quality (P = .001). There were significant differences in sensitivity between higher-quality and lower-quality images (87.0% vs 56.8%, respectively; P = .015) in the differentiation of benign from malignant masses.nnnCONCLUSIONnBreast thickness at the location of the lesion was the most important factor influencing image quality at US elastography. Sensitivity for classification of benign and malignant masses improved with higher quality scores.

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.

Survival Outcomes of Breast Cancer Patients Who Receive Neoadjuvant Chemotherapy: Association with Dynamic Contrast-enhanced MR Imaging with Computer-aided Evaluation

PURPOSEnTo retrospectively evaluate whether dynamic contrast agent-enhanced (DCE) magnetic resonance (MR) imaging parameters assessed by a computer-aided evaluation program are associated with recurrence-free and overall survival in breast cancer patients who received neoadjuvant chemotherapy (NAC).nnnMATERIALS AND METHODSnThis study was institutional review board approved and informed consent was waived. Between January 2007 and December 2009, 187 consecutive women (mean age, 46.6 years; range, 24-78 years) who had undergone NAC, DCE MR imaging before and after NAC, and surgery for invasive breast cancers (mean size, 5.0 cm; range, 2.0-14.8 cm on surgical histologic analysis) were identified. The tumor size, volume, and kinetic parameters (persistent, plateau, or washout components) were measured with a computer-aided evaluation program on DCE MR images before and after NAC, and their percentage changes were calculated. The Cox proportional hazards model was used to determine the association between DCE MR imaging parameters and recurrence-free survival and overall survival after controlling for clinical-pathologic variables.nnnRESULTSnThere were 50 events, including 38 recurrences (29 distant, six local, and three both) and 12 deaths, at a mean follow-up of 47.4 months. At multivariate analysis, a smaller reduction in tumor volume (recurrence-free survival hazard ratio, 5.75; 95% confidence interval: 1.14, 8.64; and overall survival hazard ratio, 2.12; 95% confidence interval: 1.08, 5.69) and a smaller reduction in washout component (recurrence-free survival hazard ratio, 1.15; 95% CI: 1.06, 1.55; and overall survival hazard ratio, 1.26; 95% confidence interval: 1.03, 1.52) after NAC were independent significant variables for worse recurrence-free survival and overall survival.nnnCONCLUSIONnSmaller reduction in tumor volume and a smaller reduction in washout component on DCE MR images assessed with computer-aided evaluation after NAC were independent parameters of worse recurrence-free survival and overall survival in breast cancer patients who received NAC.

Aliasing artifact depicted on ultrasound (US)-elastography for breast cystic lesions mimicking solid masses.

Background It has been reported that ultrasound (US)-elastography is helpful in differentiation of benign and malignant solid masses and in reducing benign biopsy procedures for the supplemental breast US in addition to screening mammography. Furthermore, potential application of US-elastography in distinguishing cystic lesions which is known to be a major source of benign biopsy results has been suggested. Purpose To describe the aliasing artifact on US-elastography for breast cystic lesions that mimic solid masses. Material and Methods We retrospectively reviewed 13 lesions which showed a blue-green-red pattern artifact on US-elastography in 13 women (mean age 50 years; age range 3–66 years). They disappeared immediately after a needle biopsy. Breast composition, mammography and US findings, histology and follow-up imaging findings were analyzed. Results All 13 patients showed heterogeneously dense (n = 5) or extremely dense breast parenchyma (n = 8). The most common US findings were an irregular shape (n = 7, 54%) and a circumscribed margin (n = 7, 54%). All 13 lesions had internal echogenicity and were initially considered as solid masses; 62% (n = 8) showed hypoechogenicity and 38% (n = 5) had echogenic and anechoic components. Posterior shadowing was seen in 31% (n = 4) of the lesions. All 13 lesions have been proven to be fibrocystic changes on biopsy histology. Follow-up US performed for 10 of 13 lesions showed no residual lesion (n = 9) or decreased its size (n = 1). Conclusion An aliasing artifact that appears as a blue-green-red pattern in a breast mass as depicted on US-elastography is suggestive of a possible cystic breast lesion.

Inflammatory pseudotumor of the breast: a case report with imaging findings.

Inflammatory pseudotumor, also known as inflammatory myofibroblastic tumor and plasma cell granuloma, is an uncommon low-grade lesion composed of spindle cells admixed with mature plasma cells and other inflammatory cells, such as histiocytes, lymphocytes, and eosinophils. Here, we describe the mammographic and ultrasonographic findings of a case of an inflammatory pseudotumor of the breast in a 60-year-old woman. With the suspicion of malignancy, core needle biopsy and surgical excision confirmed the mass as being an inflammatory pseudotumor of the breast.

Intraductal Mass on Breast Ultrasound: Final Outcomes and Predictors of Malignancy

OBJECTIVEnThe purpose of this study was to retrospectively investigate the final outcomes of intraductal masses on breast ultrasound and determine the clinical and radiologic variables associated with malignancy.nnnMATERIALS AND METHODSnA database search (2006-2008) was performed to find patients who had an intraductal mass on breast ultrasound. Histopathologic or ultrasound follow-up (> 24 months) data were available from 147 women (mean age, 49.8 years) with 163 intraductal masses. Clinical and radiologic variables (age, symptom, personal and family history, lesion size, and distance from the nipple) and pathologic results were collected. Ultrasound features of the intraductal masses were reviewed by two radiologists in consensus and classified into three morphologic types: mass incompletely filling the duct, mass completely filling the duct, and mass extending outside the duct. Involvement of a branch duct was also analyzed. Associations between variables and final outcomes were analyzed using chi-square tests and Student t tests.nnnRESULTSnThirteen (8%) of the 163 intraductal masses were malignant (10 ductal carcinomas in situ and three invasive ductal carcinomas). Malignancy was significantly associated with symptoms (p = 0.008) and personal history of breast cancer (p < 0.007). Malignant intraductal masses were larger than benign intraductal masses (1.4 cm vs 0.9 cm, p = 0.02). Malignant intraductal masses tended to fill the duct more completely or extend outside the duct (p < 0.001), and they more frequently involved the branch duct (p < 0.001) than did the benign intraductal masses.nnnCONCLUSIONnOur study showed that 8% of intraductal masses are malignant. Symptoms, personal history, lesion size, and ultrasound features can be possible predictors of malignancy.

Computer-Aided Detection in Digital Mammography: False-Positive Marks and Their Reproducibility in Negative Mammograms

Background: There are relatively few studies reporting the frequency of false-positive computer-aided detection (CAD) marks and their reproducibility in normal cases. Purpose: To evaluate retrospectively the false-positive mark rate of a CAD system and the reproducibility of false-positive marks in two sets of negative digital mammograms. Material and Methods: Two sets of negative digital mammograms were obtained in 360 women (mean age 57 years, range 30–76 years) with an approximate interval of 1 year (mean time 343.7 days), and a CAD system was applied. False-positive CAD marks and the reproducibility were determined. Results: Of the 360 patients, 252 (70.0%) and 240 (66.7%) patients had 1–7 CAD marks on the initial and second mammograms, respectively. The false-positive CAD mark rate was 1.5 (1.1 for masses and 0.4 for calcifications) and 1.4 (1.0 for masses and 0.4 for calcifications) per examination in the initial and second mammograms, respectively. The reproducibility of the false-positive CAD marks was 12.0% for both mass (81/680) and microcalcification (33/278) marks. Conclusion: False-positive CAD marks were seen in approximately 70% of normal cases. However, the reproducibility was very low. Radiologists must be familiar with the findings of false-positive CAD marks, since they are very common and can increase the recall rate in screening.

Heparin-Coated Angiographic Catheters: An In Vivo Comparison of Three Coating Methods with Different Heparin Release Profiles

We evaluated in vivo anti-thrombogenic effects of three different heparin-coated angiographic catheters with different heparin release profiles. Three different types of heparin-coated 5 French angiographic catheters (rapidly-heparin-releasing, slowly-heparin-releasing, and heparin-adherent catheters) were prepared by coating amphiphilic or hydrophobic heparin derivatives in order to regulate heparin elution. After incubation time of 30 minutes in the arteries of dogs, the amount of thrombus deposition, measured as dry weight, was compared in 10 sets of the three heparin-coated catheters and a non-coated catheter used as control. The surface morphology of catheters after their withdrawal was studied by scanning electron microscopy. The amount of thrombus deposition on the non-coated catheter (374.6 ± 11.6 mg, mean ± SD) was significantly larger than those on the rapidly-heparin-releasing (52.0 ± 12.6), slowly-heparin-releasing (70.4 ± 23.1), and heparin-adherent catheters (103.7 ± 39.9) (p < 0.001, each). The thrombus weights in the three heparin-coated catheters were not statistically different. The scanning electron microscopy showed crusts on the catheter surface, which were thickest in the non-coated catheters. We concluded that the thrombus formation inside a catheter is significantly decreased if the catheter is treated with any of the three heparin-coating methods used in this study. The in vivo anti-thrombogenic effects of these coating methods are not significantly different despite their different heparin release profiles.

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.

Detection of prostaglandin E2-induced dendritic cell migration into the lymph nodes of mice using a 1.5 T clinical MR scanner

The control of dendritic cell (DC) migration into lymph nodes (LNs) is important for the development of more effective DC‐based immunotherapies. This study was undertaken to evaluate, dynamically and noninvasively, prostaglandin E2 (PGE2)‐enhanced migration of DCs using a 1.5 T clinical MR scanner. DC2.4 cells were labeled with superparamagnetic iron oxide (SPIO), a clinically approved MRI contrast agent. DCs were stimulated with tumor necrosis factor‐α and interferon‐γ in the presence or absence of PGE2. Before and after subcutaneous injection of labeled DCs into the hind leg footpads of mice, MRI detailing the extent of DC migration into popliteal LNs was performed using a 1.5 T clinical MR scanner. SPIO labeling did not influence the viability, endocytic activity, migratory ability and/or co‐stimulatory molecule expression of DCs. PGE2 enhanced significantly chemokine receptor‐7 expression and the migration of DCs (pu2009<u20090.05). After subcutaneous injection of DCs, there were decreases in MR signal intensity in popliteal LNs at 24u2009h post‐injection; in PGE2‐treated cells, the MR signal intensity was significantly lower (decrease of 86.6u2009±u20092.5%) than in PGE2‐untreated cells (decrease of 70.0u2009±u20094.2%) (pu2009<u20090.05). Histological analyses with the conventionally used Prussian blue stain demonstrated that the PGE2‐treated DCs migrated more deeply into the center of LNs. PGE2‐enhanced migration of SPIO‐labeled DCs into LNs can be detected using a 1.5 T clinical MR scanner. Our results suggest that inu2009vivo MRI of DC migration is a useful imaging method to predict DC therapy with a high rate of efficacy and to improve DC‐based immunotherapy, thereby reducing costs compared with current treatments in clinical trials. Copyright