Detection and classification of breast lesions using multiple information on contrast-enhanced mammography by a multiprocess deep-learning system: A multicenter study

Objective: Accurate detection and classification of breast lesions in early stage is crucial to timely formulate effective treatments for patients. We aim to develop a fully automatic system to detect and classify breast lesions using multiple contrast-enhanced mammography(CEM) images.Methods: In this study, a total of 1,903 females who underwent CEM examination from three hospitals were enrolled as the training set, internal testing set, pooled external testing set and prospective testing set. Here we developed a CEM-based multiprocess detection and classification system(MDCS) to perform the task of detection and classification of breast lesions. In this system, we introduced an innovative auxiliary feature fusion(AFF)algorithm that could intelligently incorporates multiple types of information from CEM images. The average freeresponse receiver operating characteristic score(AFROC-Score) was presented to validate system’s detection performance, and the performance of classification was evaluated by area under the receiver operating characteristic curve(AUC). Furthermore, we assessed the diagnostic value of MDCS through visual analysis of disputed cases,comparing its performance and efficiency with that of radiologists and exploring whether it could augment radiologists’ performance.Results: On the pooled external and prospective testing sets, MDCS always maintained a high standalone performance, with AFROC-Scores of 0.953 and 0.963 for detection task, and AUCs for classification were 0.909[95% confidence interval(95% CI): 0.822-0.996] and 0.912(95% CI: 0.840-0.985), respectively. It also achieved higher sensitivity than all senior radiologists and higher specificity than all junior radiologists on pooled external and prospective testing sets. Moreover, MDCS performed superior diagnostic efficiency with an average reading time of 5 seconds, compared to the radiologists’ average reading time of 3.2 min. The average performance of all radiologists was also improved to varying degrees with MDCS assistance.Conclusions: MDCS demonstrated excellent performance in the detection and classification of breast lesions,and greatly enhanced the overall performance of radiologists.

Estimated Average Glandular Dose for 1,828 Mammography Procedures in China: A Multicenter Study

Objective To understand the distribution of the average glandular dose(AGD) in mammography by investigating 1,828 exposure parameters of 8 mammography machines in three cities, by using random sampling. Methods A survey of 8 mammography machines in three different cities, sampled using stratified random sampling methods, was performed, and 1,828 mammography exposure parameters were recorded. Incident air kerma(k) was measured by Quality-Assurance(QA) dosimeters, and AGD was calculated by series conversion coefficients based on a 3D detailed Monte Carlo breast model, published by Wang et al. Results The distribution of compressed breast thickness(CBT) fitted a normal distribution, while that of AGD fitted a skewed distribution. The mean value of CBT in a medio-lateral oblique(MLO) view was about 5.6% higher than that in the craniocaudal(CC) view, with significant statistical difference; mean value of AGD and CBT in the sample was 1.3 mGy and 4.6 cm, respectively. The AGD trended upward with increasing CBT, similar to the results of other researches. Conclusion The mean AGD and CBT levels in our study for mammography practice in China were 1.3 mGy and 4.6 cm, respectively. AGD is influenced by manufacturer-specific variation as machine response to CBT changes and target/filter combination. The present study can provide evidence for establishing a diagnostic reference level in China.

Quantification of the Pain and Physical Burden Experienced during Positioning for Craniocaudal Imaging in Mammography, Evaluated by Measurement of Muscle Activity

Mammography is carried out in a special position, i.e. “an image is taken while the breast is compressed, stretched and kept in a fixed position”. The purpose of this study was to demonstrate quantitatively and qualitatively the physical and psychological burden due to positioning and breast compression during mammography. Muscle activity of each part of the body during positioning for the standard imaging method, to obtain craniocaudal (CC) view images, was measured in 15 adult females using surface EMG. The associated pain was analyzed using visual analogue scale (VAS) scores. During positioning for the CC view, muscle activity was highest in the biceps (24.44 iEMG/s) followed by the trapezius (17.78 iEMG/s) on the imaging side. Muscle activity of the biceps and the sternocleidomastoid on the imaging side showed significant differences compared with pre-imaging activity (biceps P < 0.031, sternocleidomastoid P < 0.005). The pain during mammography was rated as moderate to severe pain (VAS = 3.3 - 6.7) for CC views. As a result, the activities of not only the muscles directly involved in mammography positioning but also those indirectly involved were high as compared with the normal state. Measurement of muscle activity during mammography is expected to be used effectively, such as in the care to reduce pain for the subjects.

The Experience of Mammography Based on the Memoirs of Examinees

The purpose of this study was to shed light on the pattern of the mammography experience from the examinee’s perspective based on episodic information extracted from notes written by the examinees. Using the notes is an effective approach to maintain privacy and avoid excessive stress. The study methods were qualitative inductive analyses of four sets of notes. Results showed that examinees “checked the words and actions of the medical staff” while relying on the “peace of mind instilled by the technician” before taking the mammogram. However, as breast compression became more intense, their feelings changed to a sense of “betrayal by someone on whom they were relying” since they felt that the technician was “ignoring the situation” or “considering but continuing breast compression”. They were also affected by the “shooting position which is impossible to avoid”. Breast compression during the mammography was a “pressure pain that exceeded their expectations” causing “dissatisfaction with the screening as a result of the pain” and “subconsciously created systemic tension”. Meanwhile, during the shooting, the examinees had performed “quiet countermeasures” such as “self-coping to distract themselves from the pain”. Examinees “earnestly desired a minimal shooting time” but, on the other hand, they also wanted “certainty of shooting rather than consideration of pain”. From these results, it is apparent that examinees were objectively observing the staff, even during shooting and the examinees were using self-coping measures to counter the pain. Providing support measures during mammography procedures is suggested based on the patterns of experiences.

Content-based image retrieval applied to BI-RADS tissue classification in screening mammography

AIM:To present a content-based image retrieval(CBIR) system that supports the classification of breast tissue density and can be used in the processing chain to adapt parameters for lesion segmentation and classification.METHODS:Breast density is characterized by image texture using singular value decomposition(SVD) and histograms.Pattern similarity is computed by a support vector machine(SVM) to separate the four BI-RADS tissue categories.The crucial number of remaining singular values is varied(SVD),and linear,radial,and polynomial kernels are investigated(SVM).The system is supported by a large reference database for training and evaluation.Experiments are based on 5-fold cross validation.RESULTS:Adopted from DDSM,MIAS,LLNL,and RWTH datasets,the reference database is composed of over 10000 various mammograms with unified and reliable ground truth.An average precision of 82.14% is obtained using 25 singular values(SVD),polynomial kernel and the one-against-one(SVM).CONCLUSION:Breast density characterization using SVD allied with SVM for image retrieval enable the development of a CBIR system that can effectively aid radiologists in their diagnosis.

Optical mammography:Diffuse optical imaging of breast cancer

Existing imaging modalities for breast cancer screening,diagnosis and therapy monitoring,namely X-ray mammography and magnetic resonance imaging,have been proven to have limitations.Diffuse optical imaging is a set of non-invasive imaging modalities that use near-infrared light,which can be an alternative,if not replacement,to those existing modalities.This review covers the background knowledge,recent clinical outcome,and future outlook of this newly emerging medical imaging modality.

Efficacy of Magnetic Resonance Imaging in BIRADS 3, 4 and 5 Patients Detected on Full Field Digital Mammography: Our Experience

Aim of the study: To perform Dynamic contrast enhanced MRI of breast in patients with positive findings (BIRADS 3, 4 and 5) detected on screening mammography;to correlate the findings of digital mammography and contrast enhanced MRI of breast with histopathological examinations. Settings and Design: A prospective observation study was conducted at a single centre, i.e. HCG Manavata Cancer Centre. Materials and Methods: Screening mammography was performed on patients with age > 40 years and on patients with age 35 - 40 years having positive family history. The positive mammography was reported and the lesions classified according to BIRADS criteria for mammography. Results: Mammographic examination of the breast lesions yielded an overall sensitivity of 97.67% and a specificity of 85.71%. In our study we combined both morphologic and dynamic parameters and its modification into BIRADS category for lesion classification. The sensitivity of MRI examinations was 97.67% while the specificity was 71.43%. Spiculated margins were encountered only in malignant lesions (p = 0.0006). Statistical correlation was obtained between the pathologically proven benign and malignant lesions regarding their enhancement pattern with p value of Conclusion: As per the results, dynamic contrast MRI had high sensitivity but limited specificity. We did not find any significant difference between FFDM and MRI in terms of diagnostic accuracy. The use of DWI showed high specificity at cut off point of ADC value—0.85 mm2/s. Thus, DWI can be used in addition of morphological and dynamic kinetic characteristics to increase specificity of MRI.

Pupil Size Measurement and Sucrose Ingestion for Quantifying and Decreasing Burden of Women during Mammography

Many women feel a physical burden, which usually appears as a pain, during mammography. We examined the pain-related pupil dilation response during mammography. Twenty-four healthy women participated in the examination. They were randomly assigned to water group or sucrose group. Water group and sucrose group ingested distilled water and a sucrose solution during mammography, respectively. Their pupil sizes were measured during mammography excluding X-ray irradiation. The subjective intensity of pain during mammography was also assessed using visual analogue scales (VAS). The mean pupil diameter was 2.99 mm in relaxation phase before mammography, while it was 3.15 mm in a few seconds after breast compression (pressure phase). The difference between the two was statistically significant (p p < 0.01). These results suggest that we may be able to assess objectively the degree of pain associated with mammography and sweet taste stimuli may be effective to alleviate a women’s burden received during mammography.

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.

Evaluation of Breast Masses Using Mammography and Sonography as First Line Investigations

Purpose: To study the specificity of mammography and ultrasonography separately and in combination for detection of breast masses (ultrasonography-mammography correlation);To study the investigations to evaluate various breast masses;To describe suitable indications, advantages and limitations of each technique compared with other available modalities;To study the mimics of breast masses;To have histopathology follow-up and retrospective evaluation with imaging findings to improve diagnostic skills in series of 166 patients complaining of breast mass. Material: The prospective clinical study was carried out in the department of Radiodiagnosis for a period of 2 year extending from December 2010 to December 2012 infemale patients complaining of breast mass. Well informed written consent was obtained from them. Histopathology follow up was obtained from either biopsy or post operative tissue. USG machine: Philips HD 11 XE USG of the breasts and axillary region done in supine position in presence of female attendant;Mammography machine: Allengers machine with Agfa special mammography cassettes. Cranio caudal and Medio-Lateral Oblique views are taken in the presence of female attendant. MRI: PHILIPS 1.5 T machine;CT: SIEMENS duel slice CT machine. Results: Ultrasonography and mammography was done in most of the cases were sufficient to diagnose the lesion in most of the cases especially in benign breast masses. MRI and CT scan was used in special cases to know the extent of the lesions, in mimics of breast masses, bony extensions, primary muscular and bony lesions. Total 166 patients complaining of breast mass in one or both breasts were examined and evaluated with USG and mammography. The lesions were confirmed on histopathology (FNAC/biopsy). Out of 30 diagnosed malignancies two lesions were missed on mammography and four lesions were missed on ultrasonography. One of them was missed on both. For malignancies specificity of mammography is 93.3% and that of ultrasonography is 86.67%. Combining both the modalities specificity is near 97%. Out of total 92 abnormal breasts 12 were missed on USG and 20 were missed on mammography. Combining both the modalities only 2 lesions were missed and were diagnosed on histopathology alone. Overall specificity for USG in breast masses is 86.9% and for mammography it is 78.6%. Combining both the modalities the specificity is 97.6%. The “p” value is obtained which is highly significant for combination of ultrasonography and mammography in comparison with any individual modality (p = 0.0059 & p = 0.0001 respectively). Conclusion: Our study confirms the higher combined sensitivity rate for ultrasonography and mammography for detection of breast masses including malignancies. USG is useful in cystic lesions, ectasias, infections, pregnancy-lactation, and dense breast evaluation and for image guidance, whereas mammography is useful in detecting microcalcifications, spiculated masses for early detection of malignancies and for stereotactic biopsies. To suggest single modality, ultrasonography is better in younger population and BIRAD 1, 2 & 3 lesions. Whereas, mammography is better in older population and BIRAD 4 & 5 lesions. However, sono-mammographic correlation is best in both.

COMPARISON OF INFRARED LIGHTSCANNING AND MAMMOGRAPHY IN BREAST CANCER DETECTION

Purpose: This study is in an attempt to assess the diagnostic accuracy of infrared lightscanning by comparing with that of mammograpby- Methods: A total of 104 patients had been examined by both mammography and infrared lightscanning before surgery.All Patients were divided into two groups: cancer and non cancer. The diagnostic accuracy of these two modalities were calculated. Results: Of 104 Patients, 43 had breast cancer and 61 had benign lesions, the sensitivity and specificity for mammography were 84% and 83%, 82% and 77% for infrared lightscanning. The predictive values of positivity for mammograpby and lightscanning were 80% and 70%, the negative Predictive value for these two modalities were both 87%. Conclusion: Infrared lightscanning,being of assistance to mammography, could enhance sensitivity and predictive values of positivity in detecting breast cancer, especially, in mammographically dense breast.

Effects of mammography positioning on the autonomic nervous function

The physical and psychological burden on patients during mammography was analyzed using the autonomic function index in 34 adult females. The indices included heart rate (HR), high frequency (HF) of the R-R interval on an electrocardiogram, and the ratio of HF to LF (low frequency) (LF/HF). HR is an indicator of the degree of mental and physical activity, HF indicates the parasympathetic index and LF/HF indicates the sympathetic index. For the mediolateral oblique (MLO) view in mammography, autonomic function indices were measured before and during mammography. Statistical analysis was performed by the Mann-Whitney U test and the significance level was set at 5%. The autonomic function indices were compared before and during mammography and all showed no significant differences. The average value before imaging and the reference value at rest were compared. The results showed that HR increased 1.3-fold, HF increased 0.4-fold, and LF/HF increased 3.2-fold over reference values. Chronological changes during mammography showed that HF increased and LF/HF decreased from 120 seconds after the start of imaging. From these observations, it is evident that the state before mammography is not the same as the resting state and that the sympathetic index is dominant before imaging. They also suggest that some aspects of the psychological burden experienced during mammography are not due to the pain of breast compression alone.

Effects of Communication Robot on Distress Reduction in Mammography

Mammography is obviously useful for the early detection and diagnosis of breast diseases in women. However, it usually involves anxieties and pains. This paper aimed to explore effects of the communication robot on distress reduction in mammography. Nineteen healthy women participated in the examination. They were randomly assigned to either an experimental group (n = 9) or a control group (n = 10). The participants in the experimental group talked and played with a communication robot before mammography. PALRO (FUJISOFT Inc., Tokyo, Japan) was used as the communication robot, which was a chatty, comforting robot. PALRO can communicate with the human and has several specific applications such as dancing, singing and talking about knowledge of various things. Autonomic nervous activities were observed before and during mammography. Degrees of subjective pain associated with mammography were also assessed using a visual analogue scale (VAS). As a result, autonomic nervous activities between the experimental group and the control group were not significantly different. Unfortunately, the communication robot did not help to intensify parasympathetic nerve activities, which became dominant at rest or a relaxed state. On the other hand, the VAS scores for pain in the experimental group were significantly smaller than ones in the control group (p < 0.01). This result suggested that the communication robot was useful for relieving degrees of subjective pain associated with mammography. In conclusion, communication with a robot before mammography would yield positive emotions and it would be related to the pain alleviation during mammography.

The Effect of Humorous Stimuli on Alleviating Pain during Mammography: A Preliminary Study

Mammography is widely performed as a standardized procedure for breast cancer screening;however, women often feel some degree of pain during this procedure. Currently, there are limited options available for alleviating pain related to mammography. A non-medicinal approach to the alleviation of pain involves the effects of laughter on physical and psychological wellbeing. We therefore examined the possibility that humorous stimuli would alleviate the physical burden on women undergoing mammography. We assessed 29 women, 15 women received only conventional mammography (neutral group), while 14 women (humor group) watched a funny video during the same examination. The intensity of pain experienced during mammography was assessed by visual analogue scale (VAS) and the VAS results showed a statistically significant difference (P = 0.007) between the two groups, with the humor group experiencing less pain. In an additional experiment, 14 women in the humor group also underwent conventional mammography without exposure to the funny video and pain was assessed by VAS. We found that the pain experienced during conventional mammography without the funny video was significantly greater than the pain experienced during the same mammography but with the funny video (P = 0.047). These findings suggested the possibility of alleviating pain during mammography by humorous stimuli.

Intraductal papillary carcinoma of the breast: Analysis of mammography and MRI manifestations

Objective:To explore the diagnostic value of mammography and MRI in breast intraductal papillary carcinoma(IDPC)and compare the diagnostic value of the two methods.Methods:Collected 28 IDPC patients who underwent mammography and MRI from March 2011 to June 2019 and were confirmed by surgery and pathology.The imaging manifestations were analyzed and the accuracy of IDPC diagnosis was compared between the two methods.Results:Mammography of mammography:24 cases showed masses,3 cases showed asymmetric dense shadow with calcification,1 case showed large duct dilation in the areola area,and 6 cases showed short burrs on the edge of the tumor.MRI scan:28 cases of lesions had low signal intensity on T1WI and high signal on T2WI.19 cases showed cystic solid masses with small nodules on the cyst wall.25 cases showed obvious uneven enhancement lesions.The diagnostic accuracy of MRI was 89.3%.(25/28),the accuracy rate of mammography X-ray examination was 75.0%(21/28).There was no statistical difference in the diagnostic accuracy between the two methods,and it was not statistically significant(P=0.29).The combined use of the two inspection methods has a diagnostic accuracy rate of 96.4%.The combined two methods are more valuable than relying solely on mammography(P=0.03).Conclusion:IDPC is characterized by lobular or round masses.Large cysts with small nodules may be a special MRI manifestation of this cancer.Combining mammography and MRI can further improve the diagnosis of IDPC.

Initial Experience with Contrast Enhanced Digital Mammography (SenoBright)—In a Comprehensive Clinical Breast Center

Objective: The purpose of initiating contrast enhanced digital mammography in our center was to evaluate the complimentary benefit of this technology with screening digital mammography and real time ultrasound in equivocal cases and high risk patients with dense breast. The intended goal was to reduce the incidence of further diagnostic and invasive procedures. Methods: Patients thought to be candidates who had good renal function confirmed by serum Blood Urea Nitrogen (BUN) and Creatinine were offered the procedure, and 225 patients had the procedure during the period of March 2013 through November 2014. The contrast enhanced digital mammograms (SenoBright) are performed on the Senograph Essential Unit. A total of 8 images are obtained: 4 conventional digital mammograms and 4 contrast enhanced digital mammograms. The patients with a positive SenoBright study had a tissue diagnosis of the lesion obtained by either a stereotactic needle biopsy, ultrasound guided core biopsy, or ultrasound directed open excisional biopsy. Results: The 225 patients who had the procedure included high risk patients with dense breast (41), patients with abnormal mammograms (92), and patients with equivocal clinical, mammographic and real time ultrasound findings (92). 31 studies were interpreted as positive and 194 as negative. 33 biopsies were performed, with 31 patients having a positive study and 2 patients with a negative study. 22 cancers were detected. Conclusion: We found that the addition of dynamic contrast enhanced digital subtraction mammography (SenoBright) was helpful in distinguishing malignant from non-malignant lesions. It was also effective in demonstrating multifocal lesions and identifying non-palpable occult carcinomas in the dense breast. It proved to be a valuable complimentary adjunctive diagnostic modality for a comprehensive clinical breast center.

Psychosocial Factors Affecting the Use of Mammography Testing for Breast Cancer Susceptibility: An Eight-Month Follow-Up Study in a Middle-Aged Japanese Woman Sample

We examined the psychosocial factors affecting middle-aged Japanese women’s intentions to undergo mammography, as well as their actual usage of mammography by applying the Parallel Processing Model (PPM) of self regulation longitudinally. A total of 1030 middle-aged women living in all parts of Japan participated in this study through internet research from September 2010 to May 2011. The participants were evaluated on the basis of a battery of questionnaires mainly including demographics, perceived breast cancer risk, worry about breast cancer, mammography testing beliefs, intentions to use mammography, seeking information about mammography, and actual usage of mammography thrice over an eight-month period. The main results were as follows: 1) Perceived risk and cancer worry affected the intention of undergoing mammography, and this effect was mediated by beliefs about mammography testing. 2) Intention to use mammography and past mammography usage predicted future usage of mammography, with past mammography usage being the strongest predictor. 3) Information seeking about mammography was the strongest predictor of using mammography during the eight-month follow-up period of middle-aged women who had not undergone any mammography testing. PPM was a useful model to explain the mechanism behind middle-aged Japanese women’s intentions to use mammography, as well as their actual usage of mammography. In addition, past mammography experience was the strongest predictor of regular mammography usage and information seeking was a critical factor for the first-usage of mammography.

Indications and the Outcome of the Mammography at Douala General Hospital (Cameroon)

Background: Recent reports indicate that the use of mammography in breast screening plays a major role in reducing breast cancer-related deaths. It helps to improve quality of care and patient information. However, in Cameroon, there are no organized general breast screening programs which give women the opportunity to regularly screen their breasts, except for the few who take their own initiative for breast screening. Purpose: This study aimed to list indications and results of mammography and/or breast ultrasounds at Douala General Hospital in order to determine the proportion of routine mammographic screening. Method: This descriptive cross-sectional study was carried out at Douala General Hospital using pre-established data sheets. The study recruited all patients who met the selection criteria and reported to the radiology and medical imaging department for breast screening using physical examinations, mammography and/or ultrasounds. Results: The study recruited 372 patients, 96.8% of whom were between 40 to 50 years old. The reasons given for the medical consultation were systematic screening (33.01%);pain (27.18%) and lumps (25.24%). Breast examination by inspection was normal in 87.1% of women, and by palpation in 66.7%. Mammography revealed nodular opacities (18.3%), spiculated images (4.3%) and micro calcifications (3.2%), while ultrasound identified fibroadenomas (16.48%) and cysts (6.18%). Suspicious lesions (ACR 4 and 5) were discovered in 7.6% of cases by mammography and 8.51% of cases by ultrasound. The results indicated that there was no significant association between the use of clinical examination and mammography (p = 0.754). The use of clinical examination alone for breast screening may not be sufficient. Conclusion: Our findings indicate that in Cemaroon, the routine screening mammography accounts for less than one-third (33.1%) of all indications. Benign lesions were most common, however 7.6% and 8.51% of suspicious malignant lesions were observed using mammography and ultrasound respectively.

Lossless compression of digital mammography using base switching method

Mammography is a specific type of imaging that uses low-dose x-ray system to examine breasts. This is an efficient means of early detection of breast cancer. Archiving and retaining these data for at least three years is expensive, diffi-cult and requires sophisticated data compres-sion techniques. We propose a lossless com-pression method that makes use of the smoothness property of the images. In the first step, de-correlation of the given image is done using two efficient predictors. The two residue images are partitioned into non overlapping sub-images of size 4x4. At every instant one of the sub-images is selected and sent for coding. The sub-images with all zero pixels are identi-fied using one bit code. The remaining sub- images are coded by using base switching method. Special techniques are used to save the overhead information. Experimental results indicate an average compression ratio of 6.44 for the selected database.

Quantitative Analysis of Pain during Mammography Using Electrical Stimulation

In order to quantitatively measure the degree of pain during mammography, we used a visual analog scale (VAS) and a device for quantitative analysis of perception and pain and performed regression analysis of the relationship between pain degree and VAS score. Twenty-four subjects underwent a typical mammogram and we found no correlation between pain degree using the device compared with VAS scoring. It is presumed that the system enables quantitative measurement and comparison more accurately than subjective markers such as VAS in quantitation of a pain produced in an examination with clearly defined physical size (such as mammography).