Su Hyun Lee

Breast Cancer Detected with Screening US: Reasons for Nondetection at Mammography

PURPOSE To retrospectively review the mammograms of women with breast cancers detected at screening ultrasonography (US) to determine the reasons for nondetection at mammography. MATERIALS AND METHODS This study received institutional review board approval, and informed consent was waived. Between 2003 and 2011, a retrospective database review revealed 335 US-depicted cancers in 329 women (median age, 47 years; age range, 29-69 years) with Breast Imaging Reporting and Data System breast density type 2-4. Five blinded radiologists independently reviewed the mammograms to determine whether the findings on negative mammograms should be recalled. Three unblinded radiologists re-reviewed the mammograms to determine the reasons for nondetection by using the reference location of the cancer on mammograms obtained after US-guided wire localization or breast magnetic resonance imaging. The number of cancers recalled by the blinded radiologists were compared with the reasons for nondetection determined by the unblinded radiologists. RESULTS Of the 335 US-depicted cancers, 63 (19%) were recalled by three or more of the five blinded radiologists, and 272 (81%) showed no mammographic findings that required immediate action. In the unblinded repeat review, 263 (78%) cancers were obscured by overlapping dense breast tissue, and nine (3%) were not included at mammography owing to difficult anatomic location or poor positioning. Sixty-three (19%) cancers were considered interpretive errors. Of these, 52 (82%) were seen as subtle findings (46 asymmetries, six calcifications) and 11 (18%) were evident (six focal asymmetries, one distortion, four calcifications). CONCLUSION Most breast cancers (81%) detected at screening US were not seen at mammography, even in retrospect. In addition, 19% had subtle or evident findings missed at mammography.

Dual-energy computed tomography to assess tumor response to hepatic radiofrequency ablation: potential diagnostic value of virtual noncontrast images and iodine maps.

Purpose:To determine the value of dual-energy (DE) scanning with virtual noncontrast (VNC) images and iodine maps in the evaluation of therapeutic response to radiofrequency ablation (RFA) for hepatic tumors. Materials and Methods:A total of 75 patients with hepatic tumors and who underwent DE computed tomography (CT) after RFA, were enrolled in this study. Our DE CT protocol included precontrast, arterial, and portal phase scans. VNC images and iodine maps were created from 80 to 140 kVp images during the arterial and portal phases. VNC images were then compared with true, noncontrast (TNC) images, and iodine maps were compared with linearly blended images, both qualitatively and quantitatively. For the former comparison, image quality and acceptability of the VNC images as a replacement for TNC images were both rated. The CT numbers of the hepatic parenchyma, ablation zone, and image noise were measured. For the latter comparison, lesion conspicuity of the ablation zone and the additional benefit of integrating the iodine map into the routine protocol, were assessed. Contrast-to-noise ratios (CNR) of the ablation zone-to-liver and aorta-to-liver as well as the CT number differences between the center and the periphery of the ablation zone were calculated. Results:The image quality of the VNC images was rated as good (mean grading score, 1.88) and the level of acceptance was 90% (68/75). The mean CT numbers of the hepatic parenchyma and ablation zone did not differ significantly between the TNC and the VNC images (P > 0.05). The lesion conspicuity of the ablation zone was rated as excellent or good in 97% of the iodine map (73/75), and the additional benefits of the iodine maps were positively rated as better to the same (mean 1.5). The CNR of the aorta-to-liver parenchyma was significantly higher on the iodine map (P = 0.002), and the CT number differences between the center and the periphery of the ablation zone were significantly lower on the iodine map (P < 0.001). Conclusion:With DE CT scanning, VNC images can be an alternative to TNC images for evaluating the ablation zone after RFA in patients who had no a previous transcatheter arterial chemoembolization history. The iodine map improves the conspicuity of the ablation zone more than linearly blended images because of its excellent internal homogeneity and sharp ablative margin. Higher lesion-to-liver CNR on an iodine map than on standard images can be helpful for detecting residual tumors.

Added Value of Shear-Wave Elastography for Evaluation of Breast Masses Detected with Screening US Imaging

PURPOSE To evaluate the additional value of shear-wave elastography (SWE) to B-mode ultrasonography (US) and to determine an appropriate guideline for the combined assessment of screening US-detected breast masses. MATERIALS AND METHODS This study was conducted with institutional review board approval, and written informed consent was obtained. From March 2010 to February 2012, B-mode US and SWE were performed in 159 US-detected breast masses before biopsy. For each lesion, Breast Imaging Reporting and Data System (BI-RADS) category on B-mode US images and the maximum stiffness color and elasticity values on SWE images were assessed. A guideline for adding SWE data to B-mode US was developed with the retrospective cohort to improve diagnostic performance in sensitivity and specificity and was validated in a distinct prospective cohort of 207 women prior to biopsy. RESULTS Twenty-one of 159 masses in the development cohort and 12 of 207 breast masses in the validation cohort were malignant. In the development cohort, when BI-RADS category 4a masses showing a dark blue color or a maximum elasticity value of 30 kPa or less on SWE images were downgraded to category 3, specificity increased from 9.4% (13 of 138) to 59.4% (82 of 138) and 57.2% (79 of 138) (P < .001), respectively, without loss in sensitivity (100% [21 of 21]). In the validation cohort, specificity increased from 17.4% (34 of 195) to 62.1% (121 of 195) and 53.3% (104 of 195) (P < .001) respectively, without loss in sensitivity (91.7% [11 of 12]). CONCLUSION The addition of SWE to B-mode US improved diagnostic performance with increased specificity for screening US-detected breast masses. BI-RADS category 4a masses detected at US screening that showed a dark blue color or a maximum elasticity value of 30 kPa or less on SWE images can be safely followed up instead of performing biopsy.

Practice guideline for the performance of breast ultrasound elastography

Ultrasound (US) elastography is a valuable imaging technique for tissue characterization. Two main types of elastography, strain and shear-wave, are commonly used to image breast tissue. The use of elastography is expected to increase, particularly with the increased use of US for breast screening. Recently, the US elastographic features of breast masses have been incorporated into the 2nd edition of the Breast Imaging Reporting and Data System (BI-RADS) US lexicon as associated findings. This review suggests practical guidelines for breast US elastography in consensus with the Korean Breast Elastography Study Group, which was formed in August 2013 to perform a multicenter prospective study on the use of elastography for US breast screening. This article is focused on the role of elastography in combination with B-mode US for the evaluation of breast masses. Practical tips for adequate data acquisition and the interpretation of elastography results are also presented.

Unilateral breast cancer: screening of contralateral breast by using preoperative MR imaging reduces incidence of metachronous cancer.

PURPOSE To investigate the clinical effect of a single magnetic resonance (MR) imaging screening examination of the contralateral breast at preoperative evaluation in women with unilateral breast cancer. MATERIALS AND METHODS The institutional review board approved this study and waived informed consent. Among women with unilateral breast cancer who underwent curative surgery from 2004 to 2008, 1323 women (mean age, 46.8 years; range, 18-81 years) underwent mammography and ultrasonography (US) alone (comparison group) between January 2004 and December 2006; 1771 consecutive women (mean age, 48.2 years; range, 22-85 years) underwent mammography, US, and MR imaging (contralateral MR imaging-screened group) between January 2007 and December 2008. The incidence of synchronous cancer and the incidence of metachronous cancer in the contralateral breast were compared between groups. Multivariate Cox analysis was performed. Median follow-up was 56 months (range, 13-94 months). RESULTS Twenty-five synchronous contralateral cancers (13 invasive cancers, 12 ductal carcinomas in situ; mean invasive size, 14 mm [range, 1-35 mm]; 92% [12 of 13] of invasive tumors were node negative) were additionally detected with MR imaging in the MR imaging-screened group. The cumulative incidence of contralateral breast cancer at 45 months was 0.5% (nine of 1771) (95% confidence interval [CI]: 0.23%, 0.96%) for the MR imaging-screened group and 1.4% (18 of 1323) (95% CI: 0.81%, 2.14%) for the comparison group (P = .02). Contralateral MR imaging screening (hazard ratio, 0.37; 95% CI: 0.15, 0.92; P = .03) and estrogen receptor negativity (hazard ratio, 3.98; 95% CI: 1.60, 9.92; P = .003) were associated with risk of contralateral cancer diagnosis in multivariate analysis. CONCLUSION A single MR imaging screening examination of the contralateral breast in women with unilateral breast cancer increased synchronous cancer detection and was associated with decreased diagnosis of metachronous contralateral cancer within 45 months.

Two-View versus Single-View Shear-Wave Elastography: Comparison of Observer Performance in Differentiating Benign from Malignant Breast Masses

PURPOSE To determine whether two-view shear-wave elastography (SWE) improves the performance of radiologists in differentiating benign from malignant breast masses compared with single-view SWE. MATERIALS AND METHODS This prospective study was conducted with institutional review board approval, and written informed consent was obtained. B-mode ultrasonographic (US) and orthogonal SWE images were obtained for 219 breast masses (136 benign and 83 malignant; mean size, 14.8 mm) in 219 consecutive women (mean age, 47.9 years; range, 20-78 years). Five blinded radiologists independently assessed the likelihood of malignancy for three data sets: B-mode US alone, B-mode US and single-view SWE, and B-mode US and two-view SWE. Interobserver agreement regarding Breast Imaging Reporting and Data System (BI-RADS) category and the area under the receiver operating characteristic curve (AUC) of each data set were compared. RESULTS Interobserver agreement was moderate (κ = 0.560 ± 0.015 [standard error of the mean]) for BI-RADS category assessment with B-mode US alone. When SWE was added to B-mode US, five readers showed substantial interobserver agreement (κ = 0.629 ± 0.017 for single-view SWE; κ = 0.651 ± 0.014 for two-view SWE). The mean AUC of B-mode US was 0.870 (range, 0.855-0.884). The AUC of B-mode US and two-view SWE (average, 0.928; range, 0.904-0.941) was higher than that of B-mode US and single-view SWE (average, 0.900; range, 0.890-0.920), with statistically significant differences for three readers (P ≤ .003). CONCLUSION The performance of radiologists in differentiating benign from malignant breast masses was improved when B-mode US was combined with two-view SWE compared with that when B-mode US was combined with single-view SWE.

MOLECULAR CHARACTERIZATION OF T-TYPE Ca2+ CHANNELS RESPONSIBLE FOR LOW THRESHOLD SPIKES IN HYPOTHALAMIC PARAVENTRICULAR NUCLEUS NEURONS

The hypothalamic paraventricular nucleus (PVN) is composed of functionally heterogeneous cell groups, possessing distinct electrophysiological properties depending on their functional roles. Previously, T-type Ca(2+) dependent low-threshold spikes (LTS) have been demonstrated in various PVN neuronal types, including preautonomic cells. However, the molecular composition and functional properties of the underlying T-type Ca(2+) channels have not been characterized. In the present study, we combined single cell reverse transcription-polymerase chain reaction (RT-PCR), immunohistochemistry and patch-clamp recordings to identify subtypes of T-type Ca(2+) channels expressed in PVN cells displaying LTS (PVN-LTS), including identified preautonomic neurons. LTS appeared at the end of hyperpolarizing pulses either as long-lasting plateaus or as short-lasting depolarizing humps. LTS were mediated by rapidly activating and inactivating T-type Ca(2+) currents and were blocked by Ni(2+). Single cell RT-PCR and immunohistochemical studies revealed Cav3.1 (voltage-gated Ca(2+) channel) as the main channel subunit detected in PVN-LTS neurons. In conclusion, these data indicate that Cav3.1 is the major subtype of T-type Ca(2+) channel subunit that mediates T-type Ca(2+) dependent LTS in PVN neurons.

Effects of celecoxib on hematoma and edema volumes in primary intracerebral hemorrhage: a multicenter randomized controlled trial

We investigated the effect of celecoxib, a selective inhibitor of cyclo‐oxygenase 2, in patients with intracerebral hemorrhage (ICH).

Shear-wave elastographic features of breast cancers: comparison with mechanical elasticity and histopathologic characteristics.

ObjectiveThe objective of this study was to compare the quantitative and qualitative shear-wave elastographic (SWE) features of breast cancers with mechanical elasticity and histopathologic characteristics. Materials and MethodsThis prospective study was conducted with institutional review board approval, and written informed consent was obtained. Shear-wave elastography was performed for 30 invasive breast cancers in 30 women before surgery. The mechanical elasticity of a fresh breast tissue section, correlated with the ultrasound image, was measured using an indentation system. Quantitative (maximum, mean, minimum, and standard deviation of elasticity in kilopascals) and qualitative (color heterogeneity and presence of signal void areas in the mass) SWE features were compared with mechanical elasticity and histopathologic characteristics using the Pearson correlation coefficient and the Wilcoxon signed rank test. ResultsMaximum SWE values showed a moderate correlation with maximum mechanical elasticity (r = 0.530, P = 0.003). There were no significant differences between SWE values and mechanical elasticity in histologic grade I or II cancers (P = 0.268). However, SWE values were significantly higher than mechanical elasticity in histologic grade III cancers (P < 0.001), which have low amounts of fibrosis, high tumor cellularity, and intratumoral necrosis. In addition, color heterogeneity was correlated with intratumoral heterogeneity of mechanical elasticity (r = 0.469, P = 0.009). Signal void areas in the masses were present in 43% of breast cancers (13 of 30) and were correlated with dense collagen depositions (n = 11) or intratumoral necrosis (n = 2). ConclusionsQuantitative and qualitative SWE features reflect both the mechanical elasticity and histopathologic characteristics of breast cancers.

Reduced severity of strokes in patients with silent brain infarctions

Background:  Silent brain infarctions (SBIs), leukoaraiosis (LA), and microbleeds (MBs) are ischaemic silent radiologic abnormalities that act as predictors of subsequent strokes. This study investigated the independent effect of silent radiologic abnormalities on initial stroke severity and short‐term outcome.