Size Of Microcalcifications Research Articles

DEMOGRAPHIC CHARACTERISTICS AND RADIOLOGICAL FINDINGS OF PATIENTS WITH BREAST MICRO CALCIFICATIONS

Ponte Academic JournalFeb 2023, Volume 79, Issue 2 DEMOGRAPHIC CHARACTERISTICS AND RADIOLOGICAL FINDINGS OF PATIENTS WITH BREAST MICRO CALCIFICATIONSAuthor(s): Nilufer Bulut ,Sevinc Dagıstanli, Suleyman SonmezJ. Ponte - Feb 2023 - Volume 79 - Issue 2 doi: 10.21506/j.ponte.2023.2.2 Abstract:Background : Almost 3–21% of breast lesions have uncertain malignant potential (B3 lesions). Despite the low malignant potential of B3 lesions (0.2–5%), biopsy is performed to rule out invasive carcinoma. Materials and Methods: We retrospectively analyzed the mammography, ultrasonography, and pathological data of 109 patients with breast microcalcifications between January 2018 and March 2021. We also recorded the microcalcification size and histological type. Results: The patients had a mean age of 46.86 ± 9.65 years and mean microcalcification size of 13.78 ± 6.51 mm. Among B3 lesions, 74% and 25.9% had histopathological findings consistent and inconsistent with malignancy, respectively. Approximately 11.1% of the lesions were upgraded. The malignant potential was higher in postmenopausal patients older than 47 years with atypical ductal hyperplasia (p = 0.002). Conclusions: Breast microcalcifications require excisional biopsy in older and postmenopausal patients because of the upgrade risk; however, benign lesions can be followed with imaging and fine needle biopsy. Download full text:Check if you have access through your login credentials or your institution Username Password

Evaluation of a Generative Adversarial Network to Improve Image Quality and Reduce Radiation-Dose during Digital Breast Tomosynthesis.

In this study, we evaluated the improvement of image quality in digital breast tomosynthesis under low-radiation dose conditions of pre-reconstruction processing using conditional generative adversarial networks [cGAN (pix2pix)]. Pix2pix pre-reconstruction processing with filtered back projection (FBP) was compared with and without multiscale bilateral filtering (MSBF) during pre-reconstruction processing. Noise reduction and preserve contrast rates were compared using full width at half-maximum (FWHM), contrast-to-noise ratio (CNR), peak signal-to-noise ratio (PSNR), and structural similarity (SSIM) in the in-focus plane using a BR3D phantom at various radiation doses [reference-dose (automatic exposure control reference dose: AECrd), 50% and 75% reduction of AECrd] and phantom thicknesses (40 mm, 50 mm, and 60 mm). The overall performance of pix2pix pre-reconstruction processing was effective in terms of FWHM, PSNR, and SSIM. At ~50% radiation-dose reduction, FWHM yielded good results independently of the microcalcification size used in the BR3D phantom, and good noise reduction and preserved contrast. PSNR results showed that pix2pix pre-reconstruction processing represented the minimum in the error with reference FBP images at an approximately 50% reduction in radiation-dose. SSIM analysis indicated that pix2pix pre-reconstruction processing yielded superior similarity when compared with and without MSBF pre-reconstruction processing at ~50% radiation-dose reduction, with features most similar to the reference FBP images. Thus, pix2pix pre-reconstruction processing is promising for reducing noise with preserve contrast and radiation-dose reduction in clinical practice.

Clinical Utility of MicroPure US Imaging for Breast Microcalcifications.

PurposeTo evaluate the performance of MicroPure US imaging to detect and characterize microcalcifications.Materials and MethodsA total of 171 lesions with suspicious microcalcifications seen on mammography and B-mode US were included and simultaneously evaluated using MicroPure US imaging. The size of microcalcifications was divided into small (punctate, amorphous, fine pleomorphic, and fine linear) and large (coarse heterogeneous), and the extent was divided into narrow (grouped) and wide (others). MicroPure US imaging visibility was divided into four types based on the number of microcalcifications on the two images: B > M (more on B-mode), B = M (similar), B < M (more on MicroPure), and negative. Triple pairwise comparison was used to evaluate the imaging features according to the MicroPure US imaging visibility.ResultsAmong the 171 lesions examined, 157 lesions (91.8%) were detected by MicroPure US imaging. The proportion of Breast Imaging Reporting and Data System (BI-RADS) category 4A was significantly higher in the MicroPure positive group, and that of category 4B was significantly higher in the MicroPure negative group (p = 0.035). The other imaging features did not differ. Among the positive MicroPure subgroups, all features showed no significant difference.ConclusionMicroPure US imaging demonstrated 91.8% positivity in detecting microcalcifications on B-mode US. MicroPure US imaging visibility correlated with the BI-RADS category of microcalcifications.

Malignancy risk of indeterminate mammographic calcification in symptomatic breast clinics

BackgroundTo explore the potential risk factors predicting malignancy in patients with indeterminate incidental mammographic microcalcification and to evaluate the short-term risk of developing malignancy.MethodsBetween January 2011 and December 2015, one...

Malignancy risk of indeterminate mammographic calcification in symptomatic breast clinics.

To explore the potential risk factors predicting malignancy in patients with indeterminate incidental mammographic microcalcification and to evaluate the short-term risk of developing malignancy. Between January 2011 and December 2015, one hundred and fifty (150) consecutive patients with indeterminate mammographic microcalcifications who had undergone stereotactic biopsy were evaluated. Clinical and mammographic features were recorded and compared with histopathological biopsy results. In patients with malignancy, postsurgical findings and surgical upgrade, if any, were recorded. Linear regression analysis (SPSS V.25) was used to evaluate significant variables predicting malignancy. OR with 95% CIs was calculated for all variables. All patients were followed up for a maximum of 10 years. The mean age of the patients was 52 years (range 33-79 years). There were a total of 55 (37%) malignant results in this study cohort. Age was an independent predictor of breast malignancy with an OR (95% CI) of 1.10 (1.03 to 1.16). Mammographic microcalcification size, pleomorphic morphology, multiple clusters and linear/segmental distribution were significantly associated with malignancy with OR (CI) of 1.03 (1.002 to 1.06), 6.06 (2.24 to 16.66), 6.35 (1.44 to 27.90) and 4.66 (1.07 to 20.19). The regional distribution of microcalcification had an OR of 3.09 (0.92 to 10.3), but this was not statistically significant. Patients with previous breast biopsies had a lower risk of breast malignancy than patients with no prior biopsy (p=0.034). Multiple clusters, linear/segmental distribution, pleomorphic morphology, size of mammographic microcalcifications and increasing age were independent predictors of malignancy. Having a previous breast biopsy did not increase malignancy risk.

Patient Satisfaction in the Complete Removal of Giant Breast Fibroadenoma under Vacuum-Associated Breast Biopsy Procedure

INTRODUCTION: Fibroadenomas are one of the most common benign tumors of the breast in the adolescent population. They account for 68% of all breast masses and 44–94% of all biopsied breast lesions. Fibroadenomas can range from asymptomatic masses to painful and rapidly growing tumors that can cause significant esthetic distortions of the breast. With breast examinations becoming common in women as young as their 20s, excision of benign breast tumors using vacuum-assisted breast biopsy (VABB) became more common. The VABB procedure with ultrasound guiding is still used for removal benign breast tumors. CASE REPORT: A 24-year ago woman presents with complaints of a lump in the right breast for 3 years, the lump is slow growing. The mass diameter is about 6 cm and no ulcers. Ultrasound examination found a solid mass, firm boundaries, regular contours, mobile in the outer quadrant of the right breast, no specific microcalcification size 6.13 cm × 3.11 cm × 5.33 cm (BIRADS 4a). Core biopsy examination showed fibroadenoma mammae intracanalicular and pericanalicular. We used an 8G needle and got 458 slices about 100 g. After the procedure, a total removal is obtained by ultrasound examination from a previously existing mass of 6 cm. CONCLUSIONS: The VABB procedure is very effective and efficient in removing breast fibroadenoma (benign lesion) and the results are satisfactory. The advantage of this procedure apart from the cosmetic aspect which does not leave any marks is also a high level of safety. From our case, we can take complete removal with a diameter of 6 cm, whereas in the previous literature, it can only remove a mass of 3–4 cm in size.

Nanoanalytical analysis of bisphosphonate-driven alterations of microcalcifications using a 3D hydrogel system and in vivo mouse model

Vascular calcification predicts atherosclerotic plaque rupture and cardiovascular events. Retrospective studies of women taking bisphosphonates (BiPs), a proposed therapy for vascular calcification, showed that BiPs paradoxically increased morbidity in patients with prior acute cardiovascular events but decreased mortality in event-free patients. Calcifying extracellular vesicles (EVs), released by cells within atherosclerotic plaques, aggregate and nucleate calcification. We hypothesized that BiPs block EV aggregation and modify existing mineral growth, potentially altering microcalcification morphology and the risk of plaque rupture. Three-dimensional (3D) collagen hydrogels incubated with calcifying EVs were used to mimic fibrous cap calcification in vitro, while an ApoE-/- mouse was used as a model of atherosclerosis in vivo. EV aggregation and formation of stress-inducing microcalcifications was imaged via scanning electron microscopy (SEM) and atomic force microscopy (AFM). In both models, BiP (ibandronate) treatment resulted in time-dependent changes in microcalcification size and mineral morphology, dependent on whether BiP treatment was initiated before or after the expected onset of microcalcification formation. Following BiP treatment at any time, microcalcifications formed in vitro were predicted to have an associated threefold decrease in fibrous cap tensile stress compared to untreated controls, estimated using finite element analysis (FEA). These findings support our hypothesis that BiPs alter EV-driven calcification. The study also confirmed that our 3D hydrogel is a viable platform to study EV-mediated mineral nucleation and evaluate potential therapies for cardiovascular calcification.

Reduction of scatter in breast CT yields improved microcalcification visibility

The inadequate visibility of microcalcifications—small calcium deposits that cue radiologists to early stages of cancer—is a major limitation in current designs of dedicated breast computed tomography (bCT). This limitation has previously been attributed to the constituent components, spatial resolution, and utilized dose. Scattered radiation has been considered an occurrence with low-frequency impacts that can be compensated for in post-processing. We hypothesized, however, that the acquisition of scattered radiation has a far more detrimental impact on clinically relevant features than has previously been understood. Critically, acquisition of scatter leads to the reduced visibility of microcalcifications. This hypothesis was investigated and supported via mathematical derivations and simulation studies. We conducted a series of comparative studies in which four bCT systems were simulated under iso-dose and iso-resolution conditions, characterizing the dependencies of microcalcification contrast on accumulated scatter. Included among the simulated systems is a novel bCT design—narrow beam bCT (NB-bCT)—that captures nearly zero scatter. We find that current bCT systems suffer from significant levels of scatter. As validated in theory, depending on the system and size of microcalcifications, between 25% and over 70% of contrast resolution is lost due to scatter. The results in NB-bCT, however, provide evidence that by removing scatter build-up in projections, the contrast of microcalcifications in a bCT image is preserved, regardless of their size or location in the breast.

Computed Histological Quantification of Atherosclerotic Plaque Microcalcifications.

Inflammation has a central role in atherosclerotic plaque formation and rupture. Intense macrophage inflammatory activity results in microcalcifications which are strongly associated with plaque vulnerability. Microcalcifications with specific critical size between 5 and 65 μ, located in the fibrous cap producing local mechanical stress on the plaque surface and may directly contribute to plaque rupture. Hence, accurate assessment of microcalcifications size and dimension has significant clinical importance. Current invasive and noninvasive plaque imaging has limited spatial resolution which limits accurate definition of microcalcifications in the atherosclerotic plaques. We describe a new imaging technique with high spatial resolution, based on confocal microscopic analysis, using a dedicated software which allows automatic characterization of microcalcifications and quantitative assessment of their extent and localization.

High resolution microcalcification signal profiles for dedicated breast CT.

This study introduces a methodology for generating high resolution signal profiles of microcalcification (MC) grains for validating breast CT (bCT) systems. A physical MC phantom was constructed by suspending calcium carbonate grains in an agar solution emulating MCs in a fibroglandular tissue background. Additionally, small Teflon spheres (2.4 mm diameter) were embedded in the agar solution for the purpose of fiducial marking and assessment of segmentation accuracy. The MC phantom was imaged on a high resolution (34 μm) commercial small-bore μCT scanner at high dose, and the images were used as the gold-standard for assessing MC size and for generating high resolution signal profiles of each MC. High-dose bCT scans of the MC phantom suspended in-air were acquired using 1 × 1 binning mode (75 μm dexel pitch) by averaging three repeat scans to produce a single low-noise reconstruction of the MC phantom. The high resolution μCT volume data set was then registered with the corresponding bCT data set after correcting for the bCT system spatial resolution. Microcalcification signal profiles constructed using low-noise bCT images were found to be in good agreement with those generated using the μCT scanner with all differences < 10% within the VOI surrounding each MC. The MC signal profiles were used as detection templates for a non-prewhitening-matched-filter model observer for scans acquired in a realistic breast phantom at 3, 6, and 9 mGy mean glandular dose. MC detectability using signal templates derived from bCT were shown to be in good agreement with those generated using μCT.

Microcalcification detection in full-field digital mammograms: A fully automated computer-aided system

BackgroundMicrocalcification clusters in mammograms can be considered as early signs of breast cancer. However, their detection is a very challenging task because of different factors: large variety of breast composition, highly textured breast anatomy, impalpable size of microcalcifications in some cases, as well as inherent low contrast of mammograms. Thus, the need to support the clinicians’ work with an automatic tool. MethodsIn this work a three-phases approach for clustered microcalcification detection is presented. Specifically, it is made up of a pre-processing step, aimed at highlighting potentially interesting breast structures, followed by a single microcalcification detection step, based on Hough transform, that is able to grasp the innate characteristic shape of the structures of interest. Finally, a cluster identification step to group microcalcifications is carried out by means of a clustering algorithm able to codify expert domain rules. ResultsThe detection performance of the proposed method has been evaluated on 364 mammograms of 182 patients obtaining a true positive ratio of 91.78% with 2.87 false positives per image. ConclusionsExperimental results demonstrated that the proposed method is able to detect microcalcification clusters in digital mammograms showing performance comparable to different methodologies exploited in the state-of-art approaches, with the advantage that it does not require any training phase and a large set of data. The performance of the proposed approach remains high even for more difficult clinical cases of mammograms of young women having high-density breast tissue thus resulting in a reduced contrast between microcalcifications and surrounding dense tissues.

18F-Fluoride Signal Amplification Identifies Microcalcifications Associated With Atherosclerotic Plaque Instability in Positron Emission Tomography/Computed Tomography Images.

Microcalcifications in atherosclerotic plaques are destabilizing, predict adverse cardiovascular events, and are associated with increased morbidity and mortality.18F-fluoride positron emission tomography (PET)/computed tomography (CT) imaging has demonstrated promise as a useful clinical diagnostic tool in identifying high-risk plaques; however, there is confusion as to the underlying mechanism of signal amplification seen in PET-positive, CT-negative image regions. This study tested the hypothesis that 18F-fluoride PET/CT can identify early microcalcifications. 18F-fluoride signal amplification derived from microcalcifications was validated against near-infrared fluorescence molecular imaging and histology using an in vitro 3-dimensional hydrogel collagen platform, ex vivo human specimens, and a mouse model of atherosclerosis. Microcalcification size correlated inversely with collagen concentration. The 18F-fluoride ligand bound to microcalcifications formed by calcifying vascular smooth muscle cell derived extracellular vesicles in the in vitro 3-dimensional collagen system and exhibited an increasing signal with an increase in collagen concentration (0.25 mg/mL collagen -33.8×102±12.4×102 counts per minute; 0.5 mg/mL collagen -67.7×102±37.4×102 counts per minute; P=0.0014), suggesting amplification of the PET signal by smaller microcalcifications. We further incubated human atherosclerotic endarterectomy specimens with clinically relevant concentrations of 18F-fluoride. The 18F-fluoride ligand labeled microcalcifications in PET-positive, CT-negative regions of explanted human specimens as evidenced by 18F-fluoride PET/CT imaging, near-infrared fluorescence, and histological analysis. Additionally, the 18F-fluoride ligand identified micro and macrocalcifications in atherosclerotic aortas obtained from low-density lipoprotein receptor-deficient mice. Our results suggest that 18F-fluoride PET signal in PET-positive, CT-negative regions of human atherosclerotic plaques is the result of developing microcalcifications, and high surface area in regions of small microcalcifications may amplify PET signal.

Use of a Total Variation Minimization Iterative Reconstruction Algorithm to Evaluate Reduced Projections during Digital Breast Tomosynthesis.

Purpose We evaluated the efficacies of the adaptive steepest descent projection onto convex sets (ASD-POCS), simultaneous algebraic reconstruction technique (SART), filtered back projection (FBP), and maximum likelihood expectation maximization (MLEM) total variation minimization iterative algorithms for reducing exposure doses during digital breast tomosynthesis for reduced projections. Methods Reconstructions were evaluated using normal (15 projections) and half (i.e., thinned-out normal) projections (seven projections). The algorithms were assessed by determining the full width at half-maximum (FWHM), and the BR3D Phantom was used to evaluate the contrast-to-noise ratio (CNR) for the in-focus plane. A mean similarity measure of structural similarity (MSSIM) was also used to identify the preservation of contrast in clinical cases. Results Spatial resolution tended to deteriorate in ASD-POCS algorithm reconstructions involving a reduced number of projections. However, the microcalcification size did not affect the rate of FWHM change. The ASD-POCS algorithm yielded a high CNR independently of the simulated mass lesion size and projection number. The ASD-POCS algorithm yielded a high MSSIM in reconstructions from reduced numbers of projections. Conclusions The ASD-POCS algorithm can preserve contrast despite a reduced number of projections and could therefore be used to reduce radiation doses.

Microcalcification cluster detection using multiscale products based Hessian matrix via the Tsallis thresholding scheme

Breast cancer is an essential health issue and more than one million women die of breast cancer each year in the world. Primary prevention seems impossible since the causes of this disease still remain unknown. Early detection and diagnosis is the key for breast cancer control. Clusters of microcalcifications in mammogram have been mainly targeted as an early sign of breast cancer and their earliest detection is vital to reduce the mortality rate. Since the size of microcalcification is very tiny and may be overlooked by the observing radiologist, a Computer Aided Diagnosis (CAD) system has been developed for efficient microcalcification detection and it eliminates the operator dependency. In order to determine the presence of microcalcification clusters in the mammogram, special attention is paid to the analysis of the structure and brightness of the mammogram tissues. The detection of microcalcification clusters is achieved by the following computerized approach. The nodular structured microcalcifications in the abnormal mammogram image are detected based on multiscale products of eigenvalues of the Hessian matrix. The detected image contains calcifications along with background information. To eliminate the unnecessary background information, the response image coming out from Hessian matrix approach is passed to the thresholding technique such as probability density function based Tsallis entropy, in which the potential microcalcifications are segmented efficiently. The proposed method is evaluated with the DDSM, MIAS and UCSF databases, which included a wide spectrum of difficult-to-detect cases. The detection performance of the proposed method has been evaluated by using 234 mammograms containing 171 microcalcification clusters. The detection method has a true positive ratio of 97.08% with 0.45 false positives per image. The proposed algorithm is positively evaluated through the clinical study. The main merit of the system is that it maintains the shape and size of microcalcifications.

Comparison of digital breast tomosynthesis and 2D digital mammography using a hybrid performance test

This paper introduces a hybrid method for performing detection studies in projection image based modalities, based on image acquisitions of target objects and patients. The method was used to compare 2D mammography and digital breast tomosynthesis (DBT) in terms of the detection performance of spherical densities and microcalcifications. The method starts with the acquisition of spheres of different glandular equivalent densities and microcalcifications of different sizes immersed in a homogeneous breast tissue simulating medium. These target objects are then segmented and the subsequent templates are fused in projection images of patients and processed or reconstructed. This results in hybrid images with true mammographic anatomy and clinically relevant target objects, ready for use in observer studies. The detection study of spherical densities used 108 normal and 178 hybrid 2D and DBT images; 156 normal and 321 hybrid images were used for the microcalcifications. Seven observers scored the presence/absence of the spheres/microcalcifications in a square region via a 5-point confidence rating scale. Detection performance in 2D and DBT was compared via ROC analysis with sub-analyses for the density of the spheres, microcalcification size, breast thickness and z-position. The study was performed on a Siemens Inspiration tomosynthesis system using patient acquisitions with an average age of 58 years and an average breast thickness of 53 mm providing mean glandular doses of 1.06 mGy (2D) and 2.39 mGy (DBT). Study results showed that breast tomosynthesis (AUC = 0.973) outperformed 2D (AUC = 0.831) for the detection of spheres (p < 0.0001) and this applied for all spherical densities and breast thicknesses. By way of contrast, DBT was worse than 2D for microcalcification detection (AUC2D = 0.974, AUCDBT = 0.838, p < 0.0001), with significant differences found for all sizes (150–354 µm), for breast thicknesses above 40 mm and for heights above the detector of 20 mm and above. In conclusion, the hybrid method was successfully used to produce images for a detection study; results showed breast tomosynthesis outperformed 2D for spherical densities while further optimization of DBT for microcalcifications is suggested.

Cone beam breast CT with a high pitch (75 μm), thick (500 μm) scintillator CMOS flat panel detector: visibility of simulated microcalcifications.

To measure and investigate the improvement of microcalcification (MC) visibility in cone beam breast CT with a high pitch (75 μm), thick (500 μm) scintillator CMOS/CsI flat panel detector (Dexela 2923, Perkin Elmer). Aluminum wires and calcium carbonate grains of various sizes were embedded in a paraffin cylinder to simulate imaging of calcifications in a breast. Phantoms were imaged with a benchtop experimental cone beam CT system at various exposure levels. In addition to the Dexela detector, a high pitch (50 μm), thin (150 μm) scintillator CMOS/CsI flat panel detector (C7921CA-09, Hamamatsu Corporation, Hamamatsu City, Japan) and a widely used low pitch (194 μm), thick (600 μm) scintillator aSi/CsI flat panel detector (PaxScan 4030CB, Varian Medical Systems) were also used in scanning for comparison. The images were independently reviewed by six readers (imaging physicists). The MC visibility was quantified as the fraction of visible MCs and measured as a function of the estimated mean glandular dose (MGD) level for various MC sizes and detectors. The modulation transfer functions (MTFs) and detective quantum efficiencies (DQEs) were also measured and compared for the three detectors used. The authors have demonstrated that the use of a high pitch (75 μm) CMOS detector coupled with a thick (500 μm) CsI scintillator helped make the smaller 150-160, 160-180, and 180-200 μm MC groups more visible at MGDs up to 10.8, 9, and 10.8 mGy, respectively. It also made the larger 200-212 and 212-224 μm MC groups more visible at MGDs up to 7.2 mGy. No performance improvement was observed for 224-250 μm or larger size groups. With the higher spatial resolution of the Dexela detector based system, the apparent dimensions and shapes of MCs were more accurately rendered. The results show that with the aforementioned detector, a 73% visibility could be achieved in imaging 160-180 μm MCs as compared to 28% visibility achieved by the low pitch (194 μm) aSi/CsI flat panel detector. The measurements confirm that the Hamamatsu detector has the highest MTF, followed by the Dexel detector, and then the Varian detector. However, the Dexela detector, with its thick (500 μm) CsI scintillator and low noise level, has the highest DQE at all frequencies, followed by the Varian detector, and then the Hamamatsu detector. The findings on the MC visibility correlated well with the differences in MTFs, noise power spectra, and DQEs measured for these three detectors. The authors have demonstrated that the use of the CMOS type Dexela detector with its high pitch (75 μm) and thick (500 μm) CsI scintillator could help improve the MC visibility. However, the improvement depended on the exposure level and the MC size. For imaging larger MCs or scanning at high exposure levels, there was little advantage in using the Dexela detector as compared to the aSi type Varian detector. These findings correlate well with the higher measured DQEs of the Dexela detector, especially at higher frequencies.

Digital breast tomosynthesis and digital mammography: A comparison of figures of merit for various average glandular doses

Previous studies on the application of tomosynthesis to breast imaging have demonstrated the potential of digital breast tomosynthesis (DBT). DBT can improve the specificity of digital mammography (DM) through improved marginal visibility of lesions and early breast cancer detection for women with dense breasts. To investigate possible improvements in the accuracy of lesion detection with DBT systems as compared to DM, we conducted a quantitative evaluation by using simulated lesions embedded in a breast phantom. A prototype DBT and dedicated DM system were used in this study. For the DBT system, the average glandular dose (AGD) was calculated using a formalism that was a simple extension of mammography dosimetry. The DBT and the DM images were acquired with average glandular doses (AGDs) ranging from 1 to 4 mGy. To analyze the results objectively, we calculated metrics for in-plane lesion visibility in the form of the contrast-to-noise ratio for the in-focus plane from the DBT reconstruction image and from the craniocaudal (CC) image from the DM system. The imaging performance of DBT was quantitatively compared with that of DM in terms of the figure of merit. Although the DM showed better results in terms of the contrast-to-noise ratio (CNR) of the mass due to the reduced overlapping of tissue and lesion, an increase in breast thickness of over 3 cm increased the CNR of the mass with the DBT system. For microcalcification detection, the DBT system showed significantly higher CNR than the DM system and gave better predictions of the microcalcification size. We compared the performances of the DM and the DBT systems for various AGDs and breast thicknesses. In conclusion, the results indicate that the DBT systems can play an important role in the detection of masses or microcalcifications without severe compression.

Why is microcalcification missed on mammography?

Ductal carcinoma in situ (DCIS) is often only mammographically evident as microcalcification. Although the overall percentage of screening cases with histologically proven DCIS microcalcification is small, the clinical relevance of missing this finding is significant. The current guidelines in Australia for breast screening departments are for double reading of mammograms to reduce both perceptive and interpretative error. This retrospective study identified patients from a state screening program with histologically proven DCIS whose mammograms showed microcalcification. The initial double reader results were documented according to the 5-point grading scale of BreastScreen Tasmania, and discrepancies between readers were noted. Mammographic factors such as breast density, lesion location, morphology, distribution, size and presence on previous imaging were assessed for significant influence on inter-reader discrepancy. Histological evidence of invasion and grade of malignancy were also analysed. Of 65 identified cases, 29 (45%) showed that one of the two readers had not flagged the microcalcification on the report. Analyses revealed no significant difference in reader discrepancy with any of the analysed factors including breast density, size of microcalcification or presence on previous imaging. Twenty-five of 29 (86%) cases of discrepancy were perceptive. Breast screening reading for microcalcification is poorly correlated to mammographic or histological features. The majority of errors were perceptive rather than interpretative. Double reading is advocated as standard practice to reduce perceptive error.

Detection of Microcalcification Clusters Using Hessian Matrix and Foveal Segmentation Method on Multiscale Analysis in Digital Mammograms

Mammography is the most efficient technique for detecting and diagnosing breast cancer. Clusters of microcalcifications have been mainly targeted as a reliable early sign of breast cancer and their earliest detection is essential to reduce the probability of mortality rate. Since the size of microcalcifications is very tiny and may be overlooked by the observing radiologist, we have developed a Computer Aided Diagnosis system for automatic and accurate cluster detection. A three-phased novel approach is presented in this paper. Firstly, regions of interest that corresponds to microcalcifications are identified. This can be achieved by analyzing the bandpass coefficients of the mammogram image. The suspicious regions are passed to the second phase, in which the nodular structured microcalcifications are detected based on eigenvalues of second order partial derivatives of the image and microcalcification pixels are segmented out by exploiting the foveal segmentation in multiscale analysis. Finally, by combining the responses coming out from the second order partial derivatives and the foveal method, potential microcalcifications are detected. The detection performance of the proposed method has been evaluated by using 370mammograms. The detection method has a TP ratio of 97.76% with 0.68 false positives per image. We have examined the performance of our computerized scheme using free-response operating characteristics curve.

Accuracy of a Preoperative Model for Predicting Invasive Breast Cancer in Women with Ductal Carcinoma-in-situ on Vacuum-Assisted Core Needle Biopsy

Core needle biopsy (CNB) diagnoses of ductal carcinoma-in-situ (DCIS) may represent understaged invasive breast cancer (IBC). We aimed to develop a model that helps identify preoperatively women with IBC after a CNB diagnosis of DCIS. Retrospective study of all women with DCIS on vacuum-assisted CNB of microcalcifications (1999-2008), with prospective classification of imaging variables independently by two radiologists. Variables included lesion size and level of suspicion on imaging, morphology and distribution of microcalcifications, DCIS nuclear grade on CNB, number of cores, and age. Multivariate logistic regression models of the probability of IBC were developed; the accuracy of these models was examined for each radiologist. Excision histology showed IBC in 77 (17.4%) of 442 subjects with DCIS on CNB. Lesion size on imaging yielded the best model fit and highest accuracy, and had the highest agreement between radiologists. Addition of grade to a model which included size improved model fit (P<0.0001). However, model fit and accuracy were not improved by inclusion of any other variables. A model based on size and grade had similar areas under the receiver operating characteristic curve (accuracy of 74%) for each radiologist. Modeled sensitivity, specificity, and predictive values for different combinations of size and grade thresholds are reported. If the imaging lesion is >50mm and the CNB grade is high, the model's positive predictive value is ≥50%. A model based on imaging size of microcalcifications and CNB nuclear grade can identify women at high risk of having IBC with moderate accuracy and may be used to guide informed preoperative discussion in women with newly diagnosed DCIS on CNB.