FAST SCREENING OUT TRUE NEGATIVE REGIONS FOR MICROCALCIFICATION DETECTION IN DIGITAL MAMMOGRAMS

A method is proposed to avoid complex computation in finding the region of interest （ROI） in a mammogram. In the method, the true negative region （TNR） definitely containing no microcalcification clusters （MCCs） is screened out, thus obtaining ROIs, The strategy consists of three steps： （1） the mammogram is partitioned into a set of non-overlapping blocks with an equal size, and for each block, five statistical features are computed, （2） negative blocks are screened out by the threshold method through rough analyses, （3） the more accurate analysis is done by the cost-sensitive support vector machine to eliminate the block definitely containing no MCCs, Experimental results on real mammograms show that 81.71% of TNRs can be screened out by the proposed method.

Utility of an upright-type 11-gauge stereotactic vacuum-assisted biopsy device (Mammotome) for the diagnosis of breast microcalcifications

Objective: The aim of this study was to evaluate the utility of an upright-type 11-gauge stereotactic vacuumassisted biopsy device (Mammotome) for the diagnosis of breast microcalcifications Methods: Between May 2001 and October 2005, 154 biopsies in 152 patients with microcalcifications were performed using the upright-type 11-gauge stereotactic vacuum-assisted biopsy device. Patients in whom this biopsy was diagnosed as carcinoma or a borderline lesion, had a subsequent surgical excision of the lesion. Histopathological and radiological features of the two specimens were then compared with each other. Results: Microcalcification was identified on specimen mammograms and microscopic slides in 97.4% of cases. Of 154 Mammotome biopsies 98 (63.6%) were benign, 51 (33.1%) were malignant, 3 (1.9%) showed atypical hyperplasia, and 2 (1.3%) were indeterminate, respectively. Of the 48 cases that received surgical excision, 6 of 36 ductal carcinomas in situ (16.7%) upstaged to invasive ductal carcinoma and 1 of 2 atypical ductal hyperplasias was upstaged to ductal carcinoma in situ. The positive predictive value of the 11-gauge Mammotome for the diagnosis of invasion in breast cancer was 100%. Linear calcification and pleomorphic calcification linear/segmental distribution was reliable indications of malignancy. The mean follow-up time of the benign lesions was 22 months, and without evidence of lesion growth. Complications included vasovagal reactions (6.3%), bleeding (0.6%) and hematoma (2.6%). Conclusion: The upright stereotactic 11-gauge Mammotome procedure is an effective and reliable method for the diagnosis of breast microcalcifications. It has minimal side effects. For lesions diagnosed as ADH or DCIS with the 11-gauge Mammotome, subsequent surgical excision should be performed.

Comparison between Visualization of Microcalcifications by Digital Breast Tomosynthesis and Full-Field Digital Mammography

Objective: To date, few studies have compared the diagnostic performance and visibility of microcalcifications obtained using digital breast tomosynthesis (DBT) with those obtained from full-field digital mammography (FFDM). The visualization and characterization of microcalcifications with DBT remain controversial. The purpose of this study was to compare the visibility of microcalcifications and determine whether DBT exhibits a diagnostic advantage for visualizing microcalcifications over FFDM. Methods: We retrospectively reviewed 120 cases including DBT and FFDM imaging (60 histologically verified as breast cancers and 60 as benign microcalcifications or normal). DBT images with a wide scan-angle of 50° and FFDM images were obtained using a flat-panel system (MAMMOMAT Inspiration, Siemens). Images were independently reviewed by four board-certified radiologists and evaluated for the presence of microcalcifications, probability of malignancy (BI-RADS classification), and visibility. Results: In predicting the malignancy of detected microcalcifications, no significant difference was found between readers’ areas under the receiver operating characteristic curve for DBT and FFDM (p = 0.068). The visibility scores of detected microcalcifications were 3.74 ± 1.06 for DBT and 3.46 ± 0.93 for FFDM, respectively. The visibility of microcalcifications when using DBT was found to be significantly superior to that of FFDM (p < 0.05). Conclusion: Our results suggest that the image quality of DBT with a wide scan-angle is comparable or superior to that obtained with FFDM in terms of both visibility and assessment of microcalcifications.

Enhancement of Microcalcifications Based on Fractal Techniques in Mammograms

Microcalcification clusters in mammograms are an important early sign of breast cancer. The enhancement of mieroealcifications in mammograms is one of the most important preprocessing techniques for the extraction of cluster mierocalcifications. In this paper, we present a novel method for the enhancement of microcalcifications. Firstly, the initial microcaleification edges were extracted by using kirsch edge operator, and the diseontinouse edges were linked by employing fi＇aetal teehnique, Then, the continuous closed edges of microcalcifications were filled by using seed filling algorithm. The pixel values of the filled region were replaced by the corresponding pixel values in the original image. Finally, the enhancement of microcalcifications in mammograms was achieved by adding the filled image to the original image. We evaluated the performance of our algorithm by using 50 regions of interesting （ROIs） with microcalcification clusters from DDSM database. The experiment results demonstrate that our CAD system can give better enhancement effect compared with other methods.

Diagnostic value of MicroPure imaging for malignant thyroid nodule microcalcification and its correlation with the oncogene expression in nodules

Objective:To study the diagnostic value of MicroPure imaging for malignant thyroid nodule microcalcification and its correlation with the oncogene expression in nodules.Methods:Patients with thyroid nodules confirmed by ultrasound in Dongtai People's Hospital between June 2014 and October 2016 were selected and divided into those with malignant thyroid nodules and benign thyroid nodules according to the pathological results, and MicroPure imaging technology was used to judge the microcalcification and further divide the malignant thyroid nodules into microcalcification (+) and microcalcification (-). The biopsy tissue was collected to detect the expression of cyclin, cell invasion molecules and angiogenesis molecules.Results: CyclinD1, CyclinE, MCM7, MMP2, MMP13, Vimentin, N-cadherin, Twist, HIF-1α, VEGF-C,VEGFR-2, VEGFR-3, Ang-2 and Tie-2 expression in malignant thyroid nodules of microcalcification (+) group and microcalcification (-) group were significantly higher than those of benign group while CyclinG2 and P53 expression were significantly lower than those of benign group;CyclinD1, CyclinE, MCM7, MMP2, MMP13, Vimentin, N-cadherin, Twist, HIF-1α, VEGF-C, VEGFR-2, VEGFR-3, Ang-2 and Tie-2 expression in malignant thyroid nodules of microcalcification (+) group were significantly higher than those of microcalcification (-) group while CyclinG2 and P53 expression were significantly lower than those of microcalcification (-) group.Conclusion: Malignant thyroid nodule microcalcification detected by MicroPure imaging has a good correlation with cancer cell proliferation, invasion and angiogenesis.

Can microcalcifications' characteristics predict the risk of breast cancer metastasis to bone?

Aim: To correlate the microcalcifications' characteristics, such as morphology and elemental compositions, with the occurrence of bone metastatic lesions at 5 years from diagnosis. Methods: In this retrospective study, we enrolled 70 patients from which we collected one breast biopsy each. From each biopsy, paraffin serial sections were obtained to perform histological classifications, immunohistochemical analyses and Energy Dispersive X-ray evaluation. Results: Microcalcifications analysis showed a significant association between the presence of calcium crystals made of magnesium substituted hydroxyapatite and the development of bone metastasis from 5 years from diagnosis. No significant association was observed by evaluation the morphological appearance of microcalcifications. Immunohistochemical analysis displayed a significant association between the expression of bone morphogenetic proteins 2 and pentraxin-3, two osteoblast induction factors, and the formation of bone metastatic lesions. Conclusion: Results here reported highlighted the possible use of breast microcalcifications as a negative prognostic marker of bone metastatic diseases. In particular, the association between elemental composition of breast microcalcifications and the formation of bone lesions can lay the foundation for the development of new in vivo diagnostic tools based on the analysis of microcalcifications and capable to predict the formation of bone metastasis.

Predicting the pathological status of mammographic microcalcifications through a radiomics approach

Objective The study aimed to develop a machine learning(ML)-coupled interpretable radiomics signature to predict the pathological status of non-palpable suspicious breast microcalcifications(MCs).Methods We enrolled 463 digital mammographical view images from 260 consecutive patients detected with non-palpable MCs and BI-RADS scored at 4(training cohort,n=428;independent testing cohort,n=35)in the First Affiliated Hospital of Nanjing Medical University between September 2010 and January 2019.Subsequently,837 textures and 9 shape features were subsequently extracted from each view and finally selected by an XGBoostembedded recursive feature elimination technique(RFE),followed by four machine learning-based classifiers to build the radiomics signature.Results Ten radiomic features constituted a malignancy-related signature for breast MCs as logistic regression(LR)and support vector machine(SVM)yielded better positive predictive value(PPV)/sensitivity(SE),0.904(95%CI,0.865–0.949)/0.946(95%CI,0.929–0.977)and 0.891(95%CI,0.822–0.939)/0.939(95%CI,0.907–0.973)respectively,outperforming their negative predictive value(NPV)/specificity(SP)from 10-fold crossvalidation(10FCV)of the training cohort.The optimal prognostic model was obtained by SVM with an area under the curve(AUC)of 0.906(95%CI,0.834–0.969)and accuracy(ACC)0.787(95%CI,0.680–0.855)from 10FCV against AUC 0.810(95%CI,0.760–0.960)and ACC 0.800 from the testing cohort.Conclusion The proposed radiomics signature dependens on a set of ML-based advanced computational algorithms and is expected to identify pathologically cancerous cases from mammographically undecipherable MCs and thus offer prospective clinical diagnostic guidance.

TWIN SUPPORT TENSOR MACHINES FOR MCS DETECTION

Tensor representation is useful to reduce the overfitting problem in vector-based learning algorithm in pattern recognition.This is mainly because the structure information of objects in pattern analysis is a reasonable constraint to reduce the number of unknown parameters used to model a classifier.In this paper, we generalize the vector-based learning algorithm TWin Support Vector Machine(TWSVM) to the tensor-based method TWin Support Tensor Machines(TWSTM), which accepts general tensors as input.To examine the effectiveness of TWSTM, we implement the TWSTM method for Microcalcification Clusters(MCs) detection.In the tensor subspace domain, the MCs detection procedure is formulated as a supervised learning and classification problem, and TWSTM is used as a classifier to make decision for the presence of MCs or not.A large number of experiments were carried out to evaluate and compare the performance of the proposed MCs detection algorithm.By comparison with TWSVM, the tensor version reduces the overfitting problem.

Calcified and Non-Calcified Ductal Carcinoma <i>in Situ</i>: Contrast-Enhanced MRI Features and Pathological Correlation

Background: Early detection of ductal carcinoma in situ (DCIS) is essential for improving the prognosis of breast cancer. Among mammographically detected DCIS cases, approximately 10% - 20% of DCIS cases are manifested as non-calcified. Purpose: To evaluate differences in MRI findings and histological features between mammographically evident non-calcified and calcified DCIS. Material and Methods: This study included 84 cases of pathologically proven DCIS in 82 patients who underwent preoperative breast MRI. The lesions were divided into non-calcified and calcified DCIS according to the presence of calcifications on mammography. MRI features were analyzed according to the enhancement pattern. The pathologic features were also reviewed. Results: Among the 84 DCIS cases, 30 (36%) were classified as non-calcified DCIS, and 54 (64%) as calcified DCIS on mammography. On MRI, 27% (8/30) of non-calcified DCIS and 17% (9/54) calcified DCIS presented as mass enhancement, 73% (22/30) non-calcified DCIS and 83% (45/54) calcified DCIS presented as non-mass enhancements. No significant difference in the type of lesion was observed between non-calcified and calcified DCIS (p = 0.274). Histopathologically, high nuclear grade, presence of necrosis, and presence of HER-2 status were more common in calcified DCIS than in non-calcified DCIS (p Conclusion: There were no significant differences in MRI findings between non-calcified and calcified DCIS. However, calcified DCIS had more aggressive histological features than non-calcified DCIS.

Diffuse Sclerosing Variant of Papillary Thyroid Carcinoma with Concomitant Thyrotoxicosis: A Case Report and Literature Review

Diffuse sclerosing variant of papillary thyroid carcinoma (DSVPC) is a rare variant of conventional papillary thyroid carcinoma which was first reported in 1985. It appears to be more aggressive than conventional type of papillary thyroid carcinoma. We present a case in a 14-year-old girl who initially presented with thyrotoxicosis and was later diagnosed with DSVPC on subsequent ultrasound and fine need leaspiration when cervicallymph node was evident on clinical examination. Concomitant thyrotoxicosis in thyroid carcinoma is uncommon. The prevalence, clinical presentation, characteristic radiological and histological features, management and prognosis of DSVPC are discussed with literature review. We also hope to illustrate through this case that ultrasound as a non-invasive imaging modality is an invaluable tool for workup in functional thyroid problems and concomitant malignancy may not be that uncommon, so that we could provide prompt treatment to our patients.

Mammographic Findings Associated with Accelerated Partial Breast Irradiation Using Single Fraction Intraoperative Radiotherapy

Purpose: To evaluate the mammographic findings of women treated with accelerated partial breast irradiation (APBI) using single-fraction intraoperative radiotherapy (IORT). Materials/Methods: Women ≥ 40 years of age with unifocal invasive or intraductal carcinoma ≤ 2.5 cm on physical examination, mammography, and ultrasound were enrolled on an APBI trial using single fraction IORT. Post-treatment mammographic imaging was obtained at 6 months, 1 year, and then annually. Results: Between 12/02 and 6/04, 17 women underwent IORT at the time of lumpectomy (median age = 60 years;range = 40 - 83). The initial post-IORT mammogram showed increased density at the lumpectomy site in 11 patients (65%), while six patients (35%) had architectural distortion in the area of the irradiated tissue. Fifteen patients (88%) had numerous punctate, benign-appearing calcifications corresponding to the irradiated region. There was focal skin thickening near the incision in 13 patients (76%). At a median of 67 months, architectural distortion had stabilized and the benign-appearing calcifications remained stable in number and character. Eight patients (47%) had mammographic findings consistent with fat necrosis, ranging in size from 0.5 - 4 cm. Conclusions: After lumpectomy and IORT, mammographic changes include increased density and benign appearing calcifications in the irradiated region with focal skin thickening. These changes appear to stabilize over time and are consistent with post-treatment changes. These changes are important to identify in order to characterize benign changes from recurrent tumor.

On Wavelet Transform General Modulus Maxima Metric for Singularity Classification in Mammograms

Continuous wavelet transform is employed to detect singularities in 2-D signals by tracking modulus maxima along maxima lines and particularly applied to microcalcification detection in mammograms. The microcalcifications are modeled as smoothed positive impulse functions. Other target property detection can be performed by adjusting its mathematical model. In this application, the general modulus maximum and its scale of each singular point are detected and statistically analyzed locally in its neighborhood. The diagnosed microcalcification cluster results are compared with health tissue results, showing that general modulus maxima can serve as a suspicious spot detection tool with the detection performance no significantly sensitive to the breast tissue background properties. Performed fractal analysis of selected singularities supports the statistical findings. It is important to select the suitable computation parameters-thresholds of magnitude, argument and frequency range-in accordance to mathematical description of the target property as well as spatial and numerical resolution of the analyzed signal. The tests are performed on a set of images with empirically selected parameters for 200 μm/pixel spatial and 8 bits/pixel numerical resolution, appropriate for detection of the suspicious spots in a mammogram. The results show that the magnitude of a singularity general maximum can play a significant role in the detection of microcalcification, while zooming into a cluster in image finer spatial resolution both magnitude of general maximum and the spatial distribution of the selected set of singularities may lead to the breast abnormality characterization.

Specimen Radiography for MRI-Guided Biopsies

Background: Specimen radiography is important for the biopsy of breast microcalcifications, and MRI is limited in the detection of microcalcifications. It is unknown whether or not the presence of microcalcifications on MRI-guided biopsies is significant. Purpose: To determine whether specimen radiography of MRI-guided biopsy samples provides any added benefits in tissue assessment. Materials and Methods: This is an IRB-approved, HIPPA-compliant retrospective review of MRI-guided biopsy reports whose tissue underwent specimen radiography from 2010 to 2017. Pathology reports were queried to compare samples with and without calcium and reviewed to determine if calcifications correlated with the lesion of interest. If there was a correlation, the original MRI was reviewed. Final pathology reports were also reviewed if excision was performed. Results: A total of 889 patients ages 22 - 85 were included with 140 (15.7%, 140/889) containing calcifications. Of 140 specimens, 119 (85.0%, 119/140) cases separated the calcifications. A total of 41 (34.5%, 41/119) were malignant or high-risk lesions/atypia of which 15 (36.6%, 15/41) showed a higher-grade lesion in the specimen containing calcium. Out of these 15, 4 (26.7%, 4/15) were pathologically associated with calcium;however, pathologic diagnosis was not dependent on the presence of calcifications. All 4 were high-risk lesions and none were malignancies. MRI in these cases showed three enhancing masses and one non-mass enhancement. None were upgraded at excision. Conclusion: The presence of microcalcifications on MRI-guided biopsies does not aid in tissue assessment and does not impact pathologic diagnosis. Specimen radiography provides no added benefits in the setting of MRI-guided biopsies.