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1.
The purpose of this study was to investigate whether the four-fold magnification mammography (direct magnification, DIMA) technique would perform better than conventional 1.5-fold magnification mammography in the differentiation of breast microcalcifications into benign and malignant. Fifty patients with non-palpable microcalcifications detected by mammography were examined immediately prior to surgical biopsy using both a conventional (1.5-fold) and the DIMA (fourfold) magnification mammography techniques. The microcalcifications were classified by five experienced radiologists using morphological criteria. A receiver operating characteristics curve (ROC) analysis of the sensitivity and specificity of both techniques in assessing malignancy was then carried out. The DIMA mammography technique was slightly but non-significantly superior to the conventional method in detecting malignancy (p > 0.05). Coarse granular and pleomorphic calcifications were detected more frequently with the DIMA technique. Coarse calcifications were significantly more frequently associated with histologically benign findings, whereas fine granular calcifications were significantly more likely to be malignant lesions. Assessment of malignancy associated with microcalcifications using morphological criteria is not significantly improved by mammography techniques with higher magnification.  相似文献   

2.
Kim MJ  Kim EK  Kwak JY  Son EJ  Youk JH  Choi SH  Han M  Oh KK 《European radiology》2009,19(2):310-317
The aim of this study was to compare the diagnostic accuracy and image quality of microcalcifications in zoomed digital contact mammography with digital magnification mammography. Three radiologists with different levels of experience in mammography reviewed 120 microcalcification clusters in 111 patients with a full-field digital mammography system relying on digital magnification mammogram (MAG) images and zoomed images from contact mammography (ZOOM) using commercially available zooming systems on monitors. Each radiologist estimated the probability of malignancy and rated the image quality and confidence rate. Performance was evaluated by sensitivity, specificity, positive predictive value, negative predictive value, and receiver operating characteristic (ROC) analysis. All three radiologists rated MAG images higher than ZOOM images for sensitivity with statistical significance (average value, 92% vs. 87%, P < 0.05) and performance by ROC analysis improved with MAG imaging. The confidence rate for diagnosis decision and the assessment of lesion characteristics were also better in MAG images than in ZOOM images with statistical significance (P < 0.0001). Digital magnification mammography can enhance diagnostic performance when characterizing microcalcifications. Images zoomed from digital contact mammography cannot serve as an alternative to direct magnification digital mammography. This work was supported by the Korea Research Foundation Grant funded by the Korean Government (MOEHRD) (KRF-2007-313-E00363).  相似文献   

3.
Summary Introduction: The combination of direct magnification mammography and computed radiography provides an improvement in spatial resolution of storage phosphor-based digital systems. A clinical study comparing conventional and digital direct magnification mammograms was performed. Methods: 100 survey mammograms in 1.5- or 1.7-fold magnification and 50 4-fold spot magnification views were obtained with a prototype direct magnification mammography system and a storage phosphor-based digital system. An intraindividual comparison of these with previous conventional radiograms of the same patients was carried out. Results: The diagnostic value of digital survey mammograms using the direct magnification technique is comparable to that of conventional radiograms of the breast, especially with regard to the identification of microcalcifications and lesions and the clinical consequences. Spot magnification views performed with this combination of techniques allowed improvement in the evaluation of microcalcifications. In 15 % of cases, diagnostic procedures were adjusted accordingly. Conclusion: The combination of the direct magnification technique with digital storage phosphor radiography systems allows the performance of digital mammography by improving the overall spatial resolution. The diagnostic value of digital direct magnification survey mammograms was comparable to that of conventional mammograms. Digital 4-fold spot magnification views improved visualisation of the morphologic aspects of microcalcifications.   相似文献   

4.
INTRODUCTION: To present the use of digital spot mammography (DSM) in a diagnostic practice. METHODS AND PATIENTS: Digital spot images of 779 women requiring a spot compression or a spot magnification view were collected. The digital images were acquired on a digital spot upright unit using a 61 mm x 61 mm field of view. Lesions reported included masses, calcifications, and areas of distortions. RESULTS: 1065 lesions required additional views with DSM. Lesions reported included masses (n = 113), masses and microcalcifications (n = 53), spiculated masses (n = 34), architectural distortions (n = 16), and microcalcifications (n = 849). DSMs were considered to be adequate in 97.7% of patients. Unsatisfactory exams resulted from difficulties encountered in targeting the area of interest at the beginning of our experience. CONCLUSION: DSM, most commonly used to perform interventional procedures, can also be used in a diagnostic practice taking advantage of post-processing of images not available with conventional spot compression and magnification.  相似文献   

5.
OBJECTIVE: The goal of this study was to assess the accuracy of an add-on stereotactic unit for core biopsy of indeterminate breast microcalcifications and to compare digital with conventional stereotactic guidance. MATERIALS AND METHODS: We conducted a retrospective review of 232 lesions with indeterminate microcalcifications in 218 women who underwent stereotactically guided breast biopsies. All biopsies were performed using a standard mammography machine with an add-on unit, 121 with conventional and 111 with digital stereotactic guidance. Successful sampling of the lesion was determined by the detection of microcalcifications on specimen radiography or at pathology. RESULTS: Using the add-on unit, 219 (94.4%) of the 232 targeted lesions were successfully sampled. The size, location, number of cores per lesion, and histology of the lesions were not different between the conventional and digital stereotactic biopsy groups (p > 0.1). Indeterminate microcalcifications were missed on biopsy in nine (7.4%) of 121 cases using conventional radiography and in only four (3.6%) of 111 cases using digital imaging. Digital stereotactic guidance allowed sampling of lesions with fewer calcifications per square centimeter (p < 0.001). CONCLUSION: Sampling of indeterminate microcalcifications using a standard mammography machine and an add-on unit has a high accuracy, similar to rates reported for dedicated prone biopsy tables. An add-on unit offers the advantage of considerable cost and space savings. Relative to conventional radiography, digital stereotactic guidance allows lesions with fewer calcifications to be sampled and achieves a greater biopsy success rate. Immediate digital images in the biopsy room also permit rapid adjustment of alignment and minimize patient movement.  相似文献   

6.
The objective of this study was a comparison of a full-field digital mammography (FFDM) system and a conventional screen-film mammography (SFM) system with respect to the detectability of simulated small masses and microcalcifications in the magnification mode. All images were obtained using 1.8 times magnification. The FFDM images were obtained at radiation dose levels of 1.39, 1.0, 0.7, 0.49 and 0.24 times that of the SFM images. A contrast-detail phantom was used to compare the detection of simulated lesions using a four alternative forced-choice reader study with three readers. The correct observation ratio (COR) was calculated as the fraction of correctly identified lesions to the total number of simulated lesions. Soft-copy reading was performed for all digital images. Direct magnification images acquired with the digital system showed a lower object contrast threshold than those acquired with the conventional system. For equal radiation dose, the digital system provided a significantly increased COR (0.95) compared with the screen-film system (0.82). For simulated microcalcifications, the corresponding difference was 0.90 to 0.72. The digital system allowed equal detection to screen-film at 40% of the radiation dose used for screen film. Digital magnification images are superior to screen-film magnification images for the detection of simulated small masses and microcalcifications even at a lower radiation dose.  相似文献   

7.
The purpose of this study was to determine whether the interpretation of microcalcifications assessed on images zoomed (× 2.0) from digital mammograms is at least equivalent to that from digital magnification mammography (× 1.8) with respect to diagnostic accuracy and image quality. Three radiologists with different levels of experience in mammography reviewed each full-field digital mammography reader set for 185 patients with pathologically proven microcalcification clusters, which consisted of digital magnification mammograms (MAGs) with a magnification factor of 1.8 and images zoomed from mammograms (ZOOM) with a zoom factor of 2.0. Each radiologist rated their suspicion of breast cancer in microcalcific lesions using a six-point scale and the image quality and their confidence in the decisions using a five-point scale. Results were analysed according to display methods using areas under the receiver operating characteristic curves (Az value) for ZOOM and MAGs to interpret microcalcifications, and the Wilcoxon matched pairs signed rank test for image quality and confidence levels. There was no statistically significant difference in the level of suspicion of breast cancer between the ZOOM and MAG groups (Az = 0.8680 for ZOOM; Az = 0.8682 for MAG; p = 0.9897). However, MAG images were significantly better than ZOOM images in terms of visual imaging quality (p < 0.001), and the confidence level with MAG was better than with ZOOM (p < 0.001). In conclusion, the performance of radiologists in the diagnosis of microcalcifications using ZOOM was similar to that using MAGs, although image quality and confidence levels were better using MAGs.Magnification mammography produces better spatial resolution and signal-to-noise ratio than does contact mammography. It is well established as a valuable adjunct to contact mammography, especially for the diagnosis of microcalcifications, despite the additional radiation exposure and increased radiation dose because of the shorter distance between the breast and X-ray source during examination [14].However, with respect to full-field digital mammography (FFDM), a few studies using zoomed images from contact mammograms have recently been reported and, as a result, a debate has arisen over whether a digital zooming system of FFDM can replace the magnification view of digital mammography [57]. Whereas Fischer et al [5] reported that zoomed images of a digital contact mammogram were equivalent to direct magnification of FFDM for the interpretation of microcalcifications, our previous report suggested that magnification mammography yielded better sensitivity and receiver operating characteristic (ROC) analysis than did zoomed images [7]. However, that study compared images zoomed by a factor of 1.3 with images magnified by a factor of 1.8. Therefore, we wondered whether using a zooming factor comparable to a magnification factor of 1.8 would yield the same results.The purpose of this study was to determine whether the diagnostic accuracy and image quality of microcalcification assessments using images twice zoomed from contact mammograms were equivalent to those obtained using digital magnification mammography by a magnification factor of 1.8.  相似文献   

8.
A new dual-screen, dual-emulsion-film combination that allows a decrease in radiation dose of approximately 66% was compared with a widely used single-screen, single-emulsion-film system in contact and magnification mammography. Clustered microcalcifications randomly superimposed on a breast phantom were detected, and the location and number of individual calcifications were determined by four observers. The detectability of calcifications, determined with a receiver operating characteristic (ROC) analysis area, was 0.92 for magnification and 0.82 for contact mammography with the single-emulsion-film system, compared with 0.84 and 0.72, respectively, with the dual-emulsion-film system. More clusters were correctly located and more individual calcifications were counted with magnification than with contact mammography. The dual-emulsion-film system with the magnification technique performs as well as the single-emulsion-film system with the contact technique, while retaining a decrease in required dose of approximately 40%.  相似文献   

9.
The authors evaluated 127 cases (31 infiltrating carcinomas, 22 intraductal carcinomas, 74 benign lesions) of breast microcalcifications with no palpable lesions. The patients had undergone mammography, stereotaxic cytology and direct magnification (87 cases). Blind interpretation of standard films and of direct magnification was performed by two independent readers (A, B), who classified the cases according to radiologic pattern (annular, punctate, granular, linear, branching), degree of suspicion and need for surgical biopsy. The study confirmed the association of different types of microcalcifications with breast cancer (predictivity: annular, punctate, granular, linear, branching; A = 25%, 15%, 40%, 92%, 86%; B = 14%, 26%, 39%, 90%, 100%). However, diagnosis was not very accurate (sensitivity: A = 83%, B = 71.1%; specificity: A = 83%, B = 78.4%); it was also observed that most cancers can be diagnosed only at a relatively high cost in terms of unnecessary biopsies. Interobservers' agreement was high relative to diagnosis (negative/dubious vs. suspicious/positive = -88.9%; K = 58.5) and low for pattern attribution (52%). Direct magnification allowed better detail definition but if sensitivity improved (A = 87% vs. 80.6%; B = 64.5% vs. 51.6%), specificity was negatively affected (A = 73.2% vs. 80.4%; B = 69.6% vs. 80.3%), due to an excess of false positives. Stereotaxic cytology [inadequacy rate = 26%, sensitivity and specificity (ex inadequates) = 80% and 100%, respectively] was more accurate than mammography as far as the decision for surgical biopsy was concerned, and was correct in identifying most (A = 6/7, B = 7/11) of the cancers which had been misdiagnosed as benign at conventional and magnification mammography. Stereotaxic cytology should be routinely performed in cases of microcalcifications with no associated palpable lesions.  相似文献   

10.
The detectability of malignant tumor-derived microcalcifications with conventional mammography was compared to that with digital images (2000 X 2510 pixels by 10 bits) derived from a storage phosphor-based digital radiography system capable of 5 line pair/mm resolution at identical exposure factors (30 kVp, 250 mAs, 65 cm film-focus distance). Microcalcifications (50-800 microns in diameter) were randomly superimposed on a preserved human breast specimen. ROC analysis based on 480 observations made by four readers indicated that the ability to detect the calcifications with digital images (ROC area = 0.871 +/- 0.066) was equivalent to conventional mammography (ROC area = 0.866 +/- 0.075) despite lower spatial resolution. With digital mammography, 62% of all clusters were correctly localized, but only 23.6% of the individual calcifications were counted. With conventional mammography 61% of all clusters were correctly localized, but significantly more of the individual calcifications (31.5%) were counted.  相似文献   

11.
The goal of this prospective study was to compare a full-field digital mammography system (FFDM) to a conventional screen-film mammography system (SFM) for the detection and characterization of microcalcifications. Fifty-five patients with 57 isolated microcalcification clusters were examined using a FFDM system (Senographe 2000D, GE Medical Systems, Milwaukee, Wis.) and a SFM system (Senographe DMR, GE Medical Systems, Milwaukee, Wis.). A conventional screen-film mammogram and a digital contact mammogram were obtained of each cluster. The image quality and the number of calcification particles were evaluated, and a characterization (BI-RADS 1–5) of microcalcifications was given by four experienced readers. Histopathology revealed 16 benign lesions (sclerosing adenosis, dysplasia, hamartoma, radial scar) in 15 patients and 21 malignant tumors (in situ carcinoma, invasive carcinoma) in 20 patients. Twenty patients had benign changes verified by long-term follow-up. Image quality of FFDM was assessed as superior to SFM in more than 50% of the cases. The FFDM showed more calcifications in 41% of all cases. Sensitivity and specificity for FFDM vs SFM were 95.2 vs 91.9% and 41.4 vs 39.3%, respectively. Moreover, FFDM demonstrated a higher diagnostic accuracy (deviation: 0.86 BI-RADS steps) compared with FSM (deviation 0.93 BI-RADS steps). The FFDM system with a 100-μm pixel size provides better image quality than SFM in patients with mammographic microcalcifications. The FFDM has a higher sensitivity and a higher reliability in characterizing microcalcifications. Electronic Publication  相似文献   

12.
Mammographic and histologic correlations of microcalcifications   总被引:1,自引:0,他引:1  
The majority of microcalcifications found on mammograms are associated with benign disease; however, some types accompany malignant disease. By correlating histologic with mammographic findings, the radiologist may gain an understanding of the morphologic characteristics and distribution of microcalcifications. We present radiologic and histologic images from a series of cases of nonpalpable, clustered microcalcifications. Such microcalcifications can be divided into two basic histologic groups: lobular and ductal. Although rounded, similarly shaped lobular calcifications can be differentiated mammographically from ductal calcifications with their irregular margins and varying size and shape, both types can be associated with benign and malignant processes. Biopsy is usually needed to confirm the diagnosis when clustered microcalcifications are found at mammography.  相似文献   

13.
Matched contact and microfocal-spot-magnified images of 31 breasts, each containing a cluster of microcalcifications within a biopsy-proved benign (n = 21) or malignant (n = 10) lesion, were evaluated. Each matched set consisted of one image magnified 1.5 or 2.0 times by a microfocal spot; one contact film-screen mammogram; and one television-digitized, enhanced, and optically magnified contact film-screen mammogram. Three experienced mammographers and three senior diagnostic radiology residents with 2 weeks of training in mammography interpreted the calcifications. The average area under the receiver-operating-characteristic curve for the experienced mammographers was 0.60 for contact radiographs, 0.61 for the television-digitized images, and 0.69 for the microfocal-spot-magnified radiographs. The less experienced senior residents scored below a random choice, 0.44, for the television-digitized images; 0.51 for contact radiographs; and 0.69 for the microfocal-spot-magnified radiographs. We conclude that when evaluating microcalcifications, radiologists without extensive experience in mammography should not substitute television-digitized and enhanced contact mammograms for microfocal-spot-magnified mammograms; rigorous clinical evaluation is needed before this system is accepted for clinical use.  相似文献   

14.
AIM: To compare the performance of a direct digital mammography system with normal-view and magnified-view conventional screen-film methods using quality control phantoms. MATERIALS AND METHODS: Using a Siemens Mammomat((R))3000 and an Opdima((R))digital spot imaging and biopsy attachment, film and direct digital images of two phantoms [DuPont and TOR (MAM)] were obtained under normal operating conditions. These were assessed by three groups of observers with differing expertise - radiologists, radiographers and medical physicists. Each observer was asked to compare the direct digital image with films taken in standard view and magnified view, providing scores for object visibility and confidence. For the digital images, observers were allowed to vary the image presentation parameters. RESULTS: Both phantoms showed that overall the direct digital view and the magnified view film performed significantly better (P < 0.05) than standard view film. For certain small or low contrast objects the differences became very highly significant (P < 0.001). CONCLUSION: Only the TOR (MAM) phantom showed any significant difference between digital and magnified modalities, with magnified views performing better for fine, faint filaments and digital acquisition better for low contrast objects. Almost no difference existed between the three observer groups. Undrill, P. E. (2000). Clinical Radiology53, 782-790.  相似文献   

15.
RATIONALE AND OBJECTIVES: To compare information drawn from magnification mammography with that extracted from electronic magnification, processing, and display of the digitized contact images. METHODS: Contact and magnification images of a mammographic statistical phantom were obtained. The magnification films versus the computer-enhanced, digitized images of the corresponding contact mammograms were separately presented to three observers. Receiver operating characteristic analysis was used to compare lesion detectability. The contact and magnification mammograms of 86 patients with subtle microcalcifications were also studied. The breast imaging reporting and data system (BI-RADS) scheme was used to compare the magnification patient films versus the corresponding digitized contact images. Differences in mammographic assessment were evaluated by using the kappa statistic. The dose to breast tissue from contact and magnification mammography was measured to evaluate dose reduction in instances where magnification mammography was to be avoided. RESULTS: Lesion detectability was found to be similar when either the digitized film image or the magnification hard-copy film was inspected. Interpretation of patient images by inspection of the contact and magnification screen-film mammograms on a view-box was in excellent agreement with that yielded by inspection of the contact image on a view-box and the computer-enhanced, digitized contact image on a display monitor. CONCLUSIONS: Electronic magnification and processing of the digitized contact image may provide valuable information concerning subtle microcalcifications, rendering magnification mammography unnecessary for many patients with such lesions.  相似文献   

16.
OBJECTIVE: The comedo subtype of ductal carcinoma in situ (DCIS) is more aggressive than noncomedo DCIS. Differentiating noncomedo DCIS from the more aggressive comedo subtypes on mammography would allow the surgeon to excise comedo DCIS with a wider margin. The mammographic features of microcalcifications associated with nonpalpable comedo DCIS, noncomedo DCIS and benign disease were compared to determine the usefulness of this finding in diagnosis of comedo DCIS. METHODS: The authors retrospectively and blindly reviewed the mammograms of 91 consecutive patients in whom DCIS was diagnosed by needle localization and surgical excision. An equal number of cases of benign microcalcifications were also reviewed. Microcalcifications were evaluated with respect to pattern, density, configuration and size. These results were correlated with the pathologic findings. RESULTS: All 16 cases (100%) of linear branching calcifications and 34 (80%) of the 43 cases of linear calcifications were associated with comedo DCIS (p < 0.001). The number of calcifications, the density and the size of clustering were not diagnostic of comedo DCIS. Granular calcifications occurred in noncomedo DCIS and in benign disease associated with noncalcifying DCIS. CONCLUSION: Comedo DCIS is suggested by the presence of linear and linear branching microcalcifications on mammography.  相似文献   

17.
PURPOSE: This study compared screen-film mammography (SFM) with full-field digital mammography (FFDM) of the same patients. MATERIALS AND METHODS: Twenty-four patients underwent surgery or biopsy, including 17 with carcinoma. Patients underwent both SFM and FFDM after providing informed consent. The abnormal findings consisted of 10 masses and 15 areas of microcalcification. The optical density of the breast tissue surrounding any lesion or mass was measured. Three readers evaluated the visibility of the masses and calcifications (contrast, margin, and type) by consensus from hard copies of the images. When evaluating FFDM, SFM was used as the standard of comparison. RESULTS: FFDM showed greater contrast of mass than SFM. The contrast of mass on FFDM was judged visually superior or equivalent to that of SFM, and microcalcifications were the same in most cases. The margin of the mass was better defined by FFDM in two cases. Determination of the type of microcalcification was similar for SFM and FFDM. CONCLUSION: FFDM provided greater contrast than SFM. FFDM might be helpful for detecting masses and observing their margins. Although FFDM may be of some use for detecting calcification, it has no advantage when determining the type of calcification.  相似文献   

18.
RATIONALE AND OBJECTIVES: To determine the effects of three image-processing algorithms on diagnostic accuracy of digital mammography in comparison with conventional screen-film mammography. MATERIALS AND METHODS: A total of 201 cases consisting of nonprocessed soft copy versions of the digital mammograms acquired from GE, Fischer, and Trex digital mammography systems (1997-1999) and conventional screen-film mammograms of the same patients were interpreted by nine radiologists. The raw digital data were processed with each of three different image-processing algorithms creating three presentations-manufacturer's default (applied and laser printed to film by each of the manufacturers), MUSICA, and PLAHE-were presented in soft copy display. There were three radiologists per presentation. RESULTS: Area under the receiver operating characteristic curve for GE digital mass cases was worse than screen-film for all digital presentations. The area under the receiver operating characteristic for Trex digital mass cases was better, but only with images processed with the manufacturer's default algorithm. Sensitivity for GE digital mass cases was worse than screen film for all digital presentations. Specificity for Fischer digital calcifications cases was worse than screen film for images processed in default and PLAHE algorithms. Specificity for Trex digital calcifications cases was worse than screen film for images processed with MUSICA. CONCLUSION: Specific image-processing algorithms may be necessary for optimal presentation for interpretation based on machine and lesion type.  相似文献   

19.
AIM: This comparative study was carried out to assess the effect of using digital images compared to conventional film-screen mammography on the accuracy of core biopsy of microcalcifications using upright stereotactic equipment. MATERIALS AND METHODS: The biopsy results from a consecutive series of 104 upright stereotactic 14-gauge core biopsies performed with conventional X-ray (Group A) were compared with 40 biopsies carried out using stereotaxis with digital imaging (Group B). In all cases specimen radiography was performed and analysed for the presence of calcifications. Pathological correlation was then carried out with needle and surgical histology. RESULTS: The use of digital add-on equipment increased the radiographic calcification retrieval rate from 55 to 85% (P < 0.005). The absolute sensitivity of core biopsy in pure ductal carcinoma in situ (DCIS) cases rose from 34 to 69% (P < 0.03), with the complete sensitivity increasing from 52 to 94% (P < 0.005). For DCIS with or without an invasive component the absolute sensitivity rose from 41 to 67% (P = 0.052), while the complete sensitivity was 59% before and 86% after the introduction of digital imaging (P < 0.04). CONCLUSION: Digital equipment improves the performance of upright stereotactic core biopsy of microcalcifications, giving a significantly increased success rate in accurately obtaining calcifications. This leads to an improvement in absolute and complete sensitivity of core biopsy when diagnosing DCIS.  相似文献   

20.
LEARNING OBJECTIVES: (1)Understand images of breast specimens with microcalcifications obtained by use of micro-focus CT. (2)Learn the relationship between mammographic features, pathologic characteristics, and micro-focus CT images. (3)Learn the usefulness of three-dimensional images in understanding of detailed structures and patterns of microcalcifications without cutting the specimen. ABSTRACT: Microcalcifications are one of the important sign for early detection of breast cancer by use of mammography, and has resulted in the detection of nonpalpable cancer. However, it is difficult to distinguish between benign and malignant microcalcifications, thus causing high false-positive rate. Micro-focus CT employs a x-ray tube of a focal spot size less than 10 microns, and has high spatial resolution, thus resulting in more accurate visualization of structures of microcalcifications. We investigated the relationship between micro-focus CT images of breast specimens with microcalcifications, mammographic features and pathologic characteristics. Micro-focus CT imaging was comparable to pathologic images in terms of resolution and contrast. Microcalcifications were more clearly detected in micro-focus CT imaging than specimen radiographs. Three-dimensional imaging on microcalcifications provided a tool for studying the shape and distribution of calcifications. Micro-focus CT for breast imaging was very useful for understanding of structures and patterns of microcalcifications without cutting the specimen.  相似文献   

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