To assess the diagnostic value of artificial intelligence(AI) system in the differential diagnosis of benign and malignant breast tumors of breast imaging reporting and data system(BI-RADS) grade 4.

A retrospective study was performed on 226 female patients with BI-RADS grade 4 breast masses from January 2018 to February 2020 at the Ultrasound Department of Qingdao Municipal Hospital. All the tumors were examined by routine ultrasonography and pathological results were obtained by operation or puncture biopsy. The AI system and breast ultrasound specialists with different years of experiences (2, 4, and 6 years) were used to analyze the breast mass ultrasound images and judge the lesion nature, and the diagnostic accuracy of the AI system and the doctors with different years of experience for breast cancer were calculated by the four-fold table method, and the χ² test was used to compare the diagnostic accuracy of AI system with that of physicians with different years of experience in breast cancer masses of different sizes.

A total of 226 breast masses were confirmed by pathology, including 96 benign lesions and 130 malignant lesions. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of the AI system were 93.84%, 92.71%, 94.57%, 91.75%, and 93.36%, respectively, which were higher than those of doctors with different years of experience. There were significant differences in diagnostic accuracy between the AI system and physicians with different years of experiences (P=0.029, 0.011, and 0.002, respectively) in breast cancer masses ≤0.5 cm,＞0.5-1.0 cm, and＞1.0-1.5 cm, although there was no significant difference in diagnostic accuracy of breast cancer masses＞1.5-2.0 cm and＞2.0 cm (P=0.117 and 0.668, respectively). There were significant differences in diagnostic accuracy between the AI system and physicians with 2 years of experience (P=0.006, 0.002, and 0.001, respectively) in breast cancer masses ≤0.5 cm,＞0.5-1.0 cm, and＞1.0-1.5 cm.

The AI system has high diagnostic value in the differentiation of benign and malignant breast masses of BI-RADS grade 4, especially in the diagnosis of breast cancer whose diameter is less than 1.5 cm, and it can assist junior doctors to improve the diagnostic rate of breast cancer.

To assess the value of ultrasound combined with mammographic features and Ki-67 index in predicting the efficacy of neoadjuvant chemotherapy for breast cancer.

Sixty-eight patients with breast cancer who received neoadjuvant chemotherapy at Changzhou Second People's Hospital from November 2014 to November 2019 were examined by ultrasonography and mammography before chemotherapy. Pathological and immunohistochemically results were obtained by biopsy. According to the efficacy of neoadjuvant chemotherapy, the patients were divided into either a pathologic complete response (pCR) group or a non-pCR group. Univariate and multivariate Logistic regression analyses were performed to analyze the independent predictors of pCR after neoadjuvant chemotherapy for breast cancer.

Of the 68 patients ,12 achieved pCR and 56 did not, with a pCR rate of 17.6%. The statistically significant parameters identified in the univariate analysis, such as the type of posterior echo of tumor, the edge characteristics of tumor in mammography, and the positive expression rate of Ki-67 or estrogen receptor (ER), were included in binary logistic regression for multivariate analysis. The results showed that absence of posterior shadowing on ultrasound (odds ratio [OR]=0.045, 95% CI: 0.005-0.453), absence of mammographic spiculation (OR=0.128, 95% CI: 0.023-0.720), and high Ki-67 expression (OR=0.045, 95% CI: 0.004-0.546)were independent predictors of pCR.

The absence of posterior shadowing on ultrasound, absence of mammographic speculation, and high Ki-67 high could predict the degree of pathological remission in breast cancer patients after neoadjuvant chemotherapy. Preoperative imaging examination and immunohistochemical Ki-67 detection have appreciated guiding significance for the selection of clinical treatment for breast cancer.

To investigate ultrasound signs and clinicopathological characteristics of triple negative breast cancer (TNBC) and its risk factors of axillary lymph node metastasis.

The clinical data of 105 female patients diagnosed with TNBC and admitted to Changzhou Second People's Hospital from March 2016 to May 2020 were retrospectively analyzed.All cases were single-sided breast cancer with only one lump and underwent routine ultrasound examination before operation. According to pathological results,the patients were divided into anaxillary lymph node metastasis (LNM) group and a non-lymph node metastasis(NLNM) group.Ultrasound signs (such as tumor diameter, aspect ratio, shape, margin, echo, internal blood flow, and calcification) and clinicopathological characteristics (such as age, menopausal status, body mass index [BMI],histological grade and pathological type) of the two groups were compared to identify the factors that affect axillarylymph node metastasis in TNBC patients.

A total of 105 female TNBC patients were enrolled, including 38 cases in the LNM group and 67 cases in the NLNM group, aged 25 to 88 (52±12) years.There were no significant differences in ultrasound signs of the two groups,including tumor diameter, form, aspect ratio, margin, echo, blood flow, and calcification (P＞0.05 for all). The histological grade and BMI were statistically different between the two groups (P＜0.05 for both). The proportion of patients with high histological grade (grades Ⅱ-Ⅲ and Ⅲ) and a BMI＜25 kg/m² in the LNM group were significantly higher than those in the NLNM group (χ²=4.056, 5.244, P＜0.05 for both). Binary logistic regression analysis showed that BMI＜25 kg/m² was a risk factor affecting axillary lymph node metastasis of TNBC patients (OR=0.360, P=0.024). There was no statistical difference between the two groups in age, menopausal status, or pathological type (P＞0.05 for all).

There is no predictive value of TNBC ultrasound signs in axillary lymph node metastasis. BMI＜25 kg/m² are helpful for judging axillary lymph node metastasis in TNBC patients.

To explore the application of the Model for Improvement (MFI) in the procedure of preoperative diagnosis of breast ultrasound.

Consecutive patients with breast lesions who had a preoperative diagnosis by breast ultrasound were divided into either a study group (50 patients, from July to October 2019) or a control group (50 patients, from January to April 2019). In the study group, MFI was developed and used, which involved a series of actions such as on-site review by specialized doctors, training enhancement of specialized doctors, improvement of appointment procedures, etc. In the control group, no intervention was performed. The diagnostic accuracy rate, rate of undetermined diagnosis, appointment time, and number of hospital visits were compared between two groups.

The diagnostic accuracy rates of the study and control groups were 91.7% and 70.5%, and the rates of undetermined diagnosis were 4.0% and 12.0%, respectively, with significantly statistical differences between the two groups (P＜0.05). The appointment time of the study and control group was (0.58±0.99) days and (5.76±2.35) days, and the number of hospital visits was 1.38±0.63 and 2.52±0.67, respectively, with significantly statistical differences between the two groups (P＜0.05).

MFI can optimize the procedure of preoperative diagnosis of breast ultrasound, make full use of the limited medical resources, and benefit more patients.

To investigate the value of two-dimensional speckle tracking imaginein detecting the myocardial dysfunction of the left ventriclein patients with breast cancer during neoadjuvant chemotherapy with anthracyclines (ANT).

A total of 49 female patients who received ANT treatment (ANT group) at Shengjing Hospital of China Medical University from December 2018 to March 2020 and 25 healthy volunteers (control group) were collected. Echocardiography was performed before every episode of chemotherapy (t0-t5) and before surgery (t6) to obtain routine echocardiographic parameters. Speckle tracking software was used to analyze the general parameters, including global longitudinal strain (GLS), global radial strain (GRS), global circumferential strain (GCS), apical peak rotation (AP-Prot), mitral valvular peak rotation (MV-Prot), and left ventricular twist (LV-Tw). Parameters were compared among different timepoints and between the two groups.

There was no significant difference in left ventricular parameters between the ANT group (t0) and the control group. The general echocardiography parameters E/A, left ventricular ejection fraction (LVEF), and E/e' decreased, among which LVEF decreased significantly at t4. LVEF values were 62.4%±2.0%, 62.4%±2.0%, 62.3%±2.1%, 62.0%±2.0%, 61.6%±1.8%, 61.1%±1.7%, and 60.2%±1.8% at t0 to t6,respectively (F=13.533, P＜0.05), and the mean difference between t4 and t0 and between t4 and t3 was 0.857 and 0.548, respectively (P＜0.05 for both). The strain parameters including GLS, GCS, and GRS showed a downward trend. GLS began to decrease at t1, and it was -22.0%±1.4%, -21.8%±1.4%, -21.1%±1.4%, -20.0%±1.0%, -19.3%±1.1%, -18.7%±1.2%, and -18.1%±1.2%at t0 to t6,respectively (F=62.473, P＜0.05), and the mean difference between t1 and t0 was 0.224 (P＜0.05). The absolute value of torsion parameter MV-prot did not change significantly. The absolute values of AP-prot and LV-TW decreased at t1. AP-prot decreased most obviously （t1 vs t0: P＜0.05).

Speckle tracking imaging is of great value in monitoring the cardiotoxicity caused by low dose ANT during neoadjuvant chemotherapy. GLS and AP-Protarethe most sensitive indicators to evaluate the cardiac injury in breast cancer patients receiving low dose ANT.

To compare the application of SonoVue and Sonazoid in the localization of sentinel lymph nodes (SLN) in early breast cancer patients.

A total of 204 patients with T1-2 breast cancer diagnosed at Peking University Third Hospital from January 1, 2018 to January 30, 2020 were included. All patients underwent axillary lymph node dissection or sentinel lymph node biopsy to obtain the pathological results, and all patients underwent contrast-enhanced ultrasound examination before operation. According to the type of contrast agent used, the patients were divided into either a SonoVue group (135 cases, including 1 male case) or a Sonazoid group (69 cases). The number and time of enhancement of SLN in the two groups were observed, and the two contrast agents were then compared with methylene blue staining.

Among the 135 patients in the SonoVue group, 210 SLNs were detected by CEUS and 297 by methylene blue staining, and the difference was statistically significant (t=6.964, P=0.000); among 69 patients in the Sonazoid group, 102 SLNs were detected by CEUS and 139 by methylene blue staining, and the difference was also statistically significant (t=3.763, P=0.000). Among the 135 patients in the SonoVue group, 1 failed in angiography localization, and 4 failed in methylene blue staining localization; all the 68 patients in the Sonazoid group all succeeded in localization, but 3 cases failed in methylene blue staining localization, with no significant difference (P=0.370, 0.244).The success rate of enhancement between in the SonoVue and Sonazoid groups was 99.3% vs 100%, and the difference was not statistically significant (P＞0.05).There was no SLN enhancement in the SonoVue group at 60 and 120 min after injection of the contrast medium. The blue stained lymph nodes in the Sonazoid group had continued enhancement in saline.

The diagnostic value of Sonazoid in sentinel lymph nodes in early breast cancer patients is not lower than that of SonoVue,and its ability of continuous enhancement of SLN is expected to be used for intraoperative confirmation of the accuracy and completeness of SLN removal.

To explore the clinical value of contrast-enhanced ultrasound (CEUS) combined with virtual?touch?tissue?imaging?and?quantification (VTIQ) in the preoperative evaluation of sentinel lymph node (SLN) metastasis inbreast cancer.

Seventy-two patients with 72 SLNs admitted to the First Affiliated Hospital of Harbin Medical University from June 2019 to January 2020 were included in the study. All patients underwent surgical treatment to obtain pathological results. All patients underwent routine ultrasound, CEUS, and shear wave elastography before operation. According to the postoperative pathological results, SLNs were divided into either a metastatic group (n=21) or a non-metastatic group (n=51). Contrast-enhanced ultrasound mode and VTIQ shear wave velocity (SWV) of SLNs were compared between the two groups. ROC curve analysis was performed to compare the performance of CEUS, SWV, and combined diagnosis in predicting SLN metastasis in breast cancer.

The CEUS enhancement mode differed significantly between metastatic and non-metastatic SLNs (χ²=25.53, P=0.000), and the differences in the maximum, minimum, and average SWV of VTIQ between the two groups were statistically significant (t=7.79, 7.12, 8.75, P=0.000). The area under ROC curve (AUC) of CEUS for the diagnosis of SLN metastasis was 0.829, and the best cut-off value was 1.5, that is, type I enhancement mode suggested non-metastatic SLN and types II, III, and IV enhancement modes suggested metastatic SLN. The sensitivity, specificity, positive predictive value, and negative predictive value of CEUS were 85.71%, 70.59%, 54.54%, and 92.31%, respectively. ROC curves of maximum, minimum and average SWV for diagnosing SLN metastasis were drawn. The AUCs of maximum, minimum and average SWV for diagnosing SLN metastasis were 0.910, 0.873, and 0.937, respectively, and the best cutoff values were 3.06, 2.23, and 2.64 m/s, respectively. The sensitivity, specificity, positive predictive value, and negative predictive value of SWV were 76.19%, 94.23%, 88.89% and 90.74%. The sensitivity, specificity, positive predictive value, and negative predictive value of CEUS combined with VTIQ in diagnosing SLN metastasis were 95.24%, 96.08%, 90.91%, and 96.08%, respectively; the AUC was 0.957.

CEUS combined with VTIQ technique can improve the diagnostic efficiency for lymph node metastasis of breast cancer and provide a reliable basis for axillary lymph node assessment before breast cancer operation.

To assess the application value of quantitative and qualitative parameters of shear wave elastography (SWE) in evaluting Ki-67 expression levels in breast cancer.

A total of 82 lesions in 80 patients diagnosed pathologically with breast cancer were collected from March 2019 to January 2020 at the First Affiliated Hospital of Soochow University. The maximum diameter and elastic modulus of breast lesions and the 1-mm and 2-mm marginal zones around the lesions were quantitatively measured by gray-scale ultrasound and SWE. The stiff rim sign was observed by SWE imaging. Using the immunohistochemical analysis after surgery or puncture biopsy as the gold standard, ROC curve analysis was performed to obtain the optimal qualitative and quantitative indicators to predict the level of Ki-67 expression in breast cancer and to assess the efficiency of the combination of the optimal quantitative parameters and qualitative indicator for Ki-67 index grading.

Among the 82 lesions, 33 had low Ki-67 expression and 49 had high expression. The area under the ROC curve (AUC) of the maximum diameter (≥2 cm) measured by gray-scale ultrasound was 0.741, with a sensitivity of 63.3% and specificity of 84.8%. The AUC of stiff rim sign was 0.837, and the sensitivity and specificity were 79.6% and 87.9%, respectively. The maximum value of elastic modulus in the 2-mm marginal zones around the lesions (E2Smax) in the high-expression group was significantly higher than that in the low-expression group (P＜0.001); it had the highest AUC value (0.719) among the SWE quantitative indexes (cut-off value, 95.86kPa; sensitivity, 69.4%; specificity, 72.7%). The AUC of the combination of the stiff rim sign and the maximum diameter was 0.889, with a sensitivity of 91.8% and specificity of 78.8%. The AUC of the combination of E2Smax and the maximum diameter was 0.808, with a sensitivity of 83.7% and specificity of 69.7%.

The quantitative parameters and qualitative indexes of gray-scale ultrasound and SWE of breast cancer lesions and the marginal zones around the lesions have good application value in evaluating Ki-67 expression, among which the maximum diameter, the stiff rim sign, and E2Smax have higher diagnostic efficiency, especially the combination of the stiff rim sign and the maximum diameter, which can provide an objective and reliable basis for early diagnosis of tumor invasiveness and prognosis evaluation after treatment.

To evaluate the value of conventional ultrasound combined with contrast-enhanced ultrasound (CEUS) in differentiating benign from malignant complex cystic and solid breast masses in different ultrasonic subgroups.

A total of 111 patients with 111 complex cystic and solid breast masses admitted to the First Affiliated Hospital of Soochow University from April 2017 to November 2019 were retrospectively selected. The lesions were divided into three groups according to the proportion and distribution of cystic/solid components (Group A: thick outer wall and/or thick internal septa; Group B: predominantly cystic component; Group C: predominantly solid component). Based on pathological results, the sonographic features of conventional ultrasound and CEUS in each group were analyzed.

Among the 111 breast lesions, 28 were classified into group A (24 benign lesions, 4 malignant lesions), 36 in group B (28 benign lesions, 8 malignant lesions), and 47 in group C (29 benign lesions, 18 malignant lesions). The patient age and maximum diameter of malignant masses in groups B and C were significantly greater than those in benign masses (P＜0.05 for all). In group A, most malignant masses had no smooth margin and thicker wall/septum on CEUS, with statistically significant differences from benign masses (P＜0.05). In groups B and C, malignant masses were usually characterized by rough solid margin (both on conventional ultrasound and CEUS) and the enhancement range of solid components beyond the basilar part, with statistically significant differences from benign masses (P＜0.05). The differences in shape, posterior echo, calcification, and blood supply between benign and malignant masses in Group C were statistically significant (P＜0.05 for all).

Conventional ultrasound combined with CEUS is of great significance in differentiating benign and malignant complex cystic and solid breast masses, which can provide a reliable diagnostic basis for clinical evaluation.

To assess the value of combined percutaneous and transvenous contrast-enhanced ultrasound (CEUS) in the diagnosis of sentinel lymph nodes (SLN) in patients with breast cancer.

One hundred and seventy-four patients with breast cancer who underwent surgical treatment at Department of Breast Surgery of the Affiliated Hospital of Nanjing University of Chinese Medicine from November 2016 to June 2018 were selected. All patients underwent percutaneous CEUS for SLN localization, conventional ultrasound, and transvenous CEUS. Using the methylene blue staining method and pathological results as the standard, the effectiveness of conventional ultrasound and combined percutaneous and transvenous CEUS in diagnosing SLN was compared and analyzed.

The rates of methylene blue staining and percutaneous CEUS for locating SLN were 99.4% and 96.0%, respectively, and there was no significant difference between them (P=0.067). Pathological results showed that 56 out of 175 SLN had metastasis. The specificity, sensitivity, and accuracy of conventional ultrasound in diagnosing SLN were 71.4%, 64.3%, and 69.1%, respectively. The specificity, sensitivity, and accuracy of combined percutaneous and transvenous CEUS in diagnosing SLN were 84.0%, 76.8%, and 81.7%, respectively. The accuracy of combined percutaneous and transvenous CEUS in diagnosing SLN was significantly higher than that of conventional ultrasonography (Chi-square value=7.46, P＜0.05). According to the surgical and pathological characteristics, 175 SLN were divided into macrometastasis (n=38), micrometastasis (n=18), and non-metastasis groups (n=119). The accuracy of routine ultrasound in the diagnosis of SLN in the macrometastasis group, micrometastasis group, and non-metastatic group was 71.1%, 50.0%, and 71.4%, separately. The accuracy of combined percutaneous and transvenous CEUS in the diagnosis of SLN in these three groups was 86.8%, 55.6%, and 84.0%, separately.

Percutaneous CEUS is an important technique for localization of SLN before surgery. The combination of percutaneous and transvenous CEUS has good qualitative diagnostic value for SLN metastasis of breast cancer.

To assess the diagnostic value of automated breast volume scanning (ABVS) in comparing and observing the peripheral signs of breast tumors on three orthogonal sections.

A retrospective analysis was performed on 206 women with 292 breast tumors who underwent breast surgery and postoperative pathological diagnosis at Shanxi Provincial Cancer Hospital from April 2017 to May 2019. ABVS was performed in all patients before operation to compare the diagnostic efficacy of ABVS on three different orthogonal sections for breast benign and malignant tumors, and to analyze the overall diagnostic efficacy of ABVS on three orthogonal sections for breast benign and malignant tumors.

Of the 292 lesions, 148 were benign and 144 were malignant. Using the postoperative pathological results as the "gold standard", the sensitivity of coronal burr sign (68.05%) was significantly higher than that of transverse (17.36%) and sagittal (13.19%) sign (P<0.05). The sensitivity of coronal edge angulation (42.36%) was also significantly higher than that of transverse (26.38%) and sagittal (22.22%) edge angulation (P<0.001).There was no significant difference in the sensitivity of lobular and marginal fuzzy signs for the diagnosis of breast cancer (P>0.05). The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of edge microlobulation, burr, edge angulation, and edge blur on ABVS were 81.94%, 86.48%, 85.50%, 83.11%, and 84.24%), 68.75%, 96.62%, 95.19%, 76.06%, and 82.87%, 47.22%, 95.27%, 91.89%, 64.97%, and 71.57%, and 54.16%, 57.43%, 55.31%, 56.29%, and 55.82%, respectively.

Coronal burr sign and marginal angulation on ABVS are superior to those on sagittal and transverse sections in the evaluation of benign and malignant breast tumors with regard to diagnostic sensitivity. Compared with other peripheral features, micro-lobulation is the most sensitive and accurate surface feature for the diagnosis of malignant nodules.

To explore the value of shear wave elastography (SWE) and kindlin-2 were used to determine the degree of breast nodule fibrosis.

A total of 102 breast nodules from 102 patients who underwent ultrasound elastography before surgery or core needle biopsy were included in this study. The obtained tissues were subjected to Sirius red staining and immunohistochemical staining. According to the pathological results, they was divided into two groups: benign (64 nodules from 64 patients: 43 cases of fibroadenoma, 11 cases of adenopathy, and 10 cases of intraductal papilloma) and malignant (38 nodules from 38 patients: all were invasive ductal carcinoma). The SWE parameters (Emax, Emean, and Emin) and collagen and Kindlin-2 expression levels were compared between the two groups by the t test. The diagnostic efficaly of Emax and Emean was analysised by the operating charaeterist cure. Pearson correlation analysis was performed to explore the correlation of collagen and Kindlin-2 expression levels with SWE parameters.

Emax, Emean, collagen expression, and Kindlin-2 expression were significantly higher in invasive ductal carcinoma than in benign nodules [(139.74±98.77) kPa vs (35.42±19.42) kPa, (65.91±60.71) kPa vs (18.29±13.83) kPa, 80.25±8.51 vs 30.77 ±5.32, 231.77±4596.01 vs 885.75±417.77; t=9.830, 7.196, 36.170, 14.300; P<0.05 for all]. The best cutoff values of Emax and Emean for malignant nodules were 55.86 kPa and 20.40 kPa, respectively; the sensitivities were 83.30% and 72.20%, and specificities were 88.90% and 77.80%, respectively. Both collagen expression (r=0.89, P<0.001) and Kindlin-2 expression (r=0.88, P<0.001) were correlated with Emax.

Emax and Kindlin-2 and collagen expression levels are related to the malignant degree of breast nodules. SWE combined with Kindlin-2 can determine the degree of breast nodule fibrosis and be used to diagnose invasive ductal carcinoma.

To assess the diagnostic value of ultrasound-guided needle biopsy in non-mass breast lesions.

Ninety-three patients with 93 non-mass breast lesions that were classified as Breast Imaging Report and Data System (BI-RADS) 4a and above at the Department of Ultrasound, Hangzhou First People's Hospital were selected from January 2017 to December 2018. All lesions underwent ultrasound-guided needle biopsy and were confirmed by surgical pathology. The fourfold table was used to assess the diagnostic value of ultrasound-guided needle biopsy in non-mass breast lesions.

The surgical pathology results showed that there were 47 malignant lesions and 46 benign lesions. In contrast, the results of ultrasound-guided needle biopsy showed 43 malignant lesions and 50 benign lesions. Four malignant lesions were missed by biopsy, which were classified as BI-RADS 4b by ultrasound but finally confirmed as ductal carcinoma in situ in three cases and invasive carcinoma in one case by surgical pathology. The sensitivity of ultrasound-guided needle biopsy was 91.4% (43/47), the specificity was 100% (46/46), the false negative rate was 8.6% (4/47), and the diagnostic accuracy rate was 95.7% (89/93).

Although ultrasound-guided needle biopsy has a certain false negative rate in the diagnosis of non-mass breast lesions, it has appreciated diagnostic value with regard to a relatively high specificity, sensitivity, and diagnostic accuracy rate.

To summarize the sonographic characteristics of breast fat necrosis at different locations, and estimate the diagnostic value of high frequency ultrasound for fat necrosis.

Clinical and imaging data of 63 patients with breast fat necrosis confirmed by surgery were retrospectively analyzed from January 2014 to September 2019 at Beijing Tiantan Hospital, Capital Medical University. The 63 patients with 69 lesions were all examined by ultrasound before operation. According to the location (fat layer, both fat layer and gland, and gland), the lesions were divided to extra-glandular type, junctional type, and intra-glandular type. Ultrasonic features of different types were summarized and compared.

Of the 63 patients, 22 had a history of trauma or surgery and 7 had previous inflammatory lesions. The patients were mostly asymptomatic or the mass was discovered accidentally. According to the location of the 69 lesions in ultrasound images, excluding two missed cases, 31 belonged to extra-glandular type, 26 belonged to junctional type, and 10 belonged to intra-glandular type. There were no statistically significant differences in sonographic findings between the extra-glandular and intra-glandular types (P>0.05). We observed statistically significant differences in some sonographic features between the junctional type and extra-glandular or intra-glandular type, including shape, boundary, blood flow, relationship with adjacent tissues and skin, and enlargement of ipsilateral axillary lymph nodes (P=0.045, 0.001, 0.025, 0.001, 0.01, and 0.019, respectively). There was no significant difference in capsule, echo type, calcification type, posterior echo condition, or the number of lesions among the tree types (P>0.05). Two (2/69, 2.9%) lesions were missed by ultrasound, and five (5/67, 7.5%) were diagnosed as potential malignancies (BI-RADS 4b).

The sonographic and clinical manifestations of breast fat necrosis are diverse. Obtaining sonographic manifestations of lesions in different locations by high frequency ultrasound, inquiring relevant history and associated diseases, especially trauma or surgical history, and acquiring other clinical information are very helpful to make a correct diagnosis of breast fat necrosis.