Acuson s2000

All women in our second-level centre undergo a standardized ultrasound examination if referred for (1) routine or screening mammography in cases of breast density ACR C or D, or in case of (2) a suspicious finding upon mammography, (3) referral due to a suspicious finding upon clinical examination, or (4) referral from an extramural radiology practice due to suspicious imaging findings. Examinations were performed on an Acuson Sequoia, Acuson S2000 or S3000 Evolution US scanner with an 18–6 or 13.5 MHz high-resolution probe (Siemens, Erlangen, Germany) encompassing a systematic scanning of the axillary and breast regions. Focal lesions were documented in two perpendicular planes to determine the relation to surrounding tissue, size, B-mode, and Doppler properties. SE was performed by repeated controlled compression of the tumour and the surrounding tissue. Compression quality was assessed by visual inspection and by the vendor-specific quality index. Only SE images with a high quality index (>90 on Acuson S2000 or S3000, >65 on Acuson Sequoia) were used for further analysis. In addition, special attention was paid to ensure that the elastographic ROI was no more than a quarter in the chest wall in order to avoid any artefacts. Based on previously published criteria, lesions were graded according to U.S. BI-RADS criteria [19 ].

Breast ultrasound examinations were carried out by sonographers with more than 5 years of experience in breast ultrasound imaging, within 2 weeks before surgical resection. Ultrasound was performed using the LOGIQ E9 ultrasound system with a 6–15 L linear array probe and the Siemens Acuson S2000 with a 6–18 L linear array probe with radial, transverse, and longitudinal scanning on both breasts. The imaging parameters were consistent among patients: gain was about 50%; image depth was about 3.0 cm to 5.0 cm; and focus paralleled the lesion. The ultrasound image was 1164 × 873 pixels and 1024 × 768 pixels in size on the LOGIQ E9 and Siemens Acuson S2000 devices, respectively. The image of the largest section of the breast tumor with the clearest imaging was saved in the format of Digital Imaging and Communications in Medicine to maximize the preservation of the image information. Manual segmentation was performed on gray-scale ultrasound images of breast lesions. Sonographer 1 (with more than 5 years of experience in breast ultrasound imaging) with no information about the patient’s clinical history selected the largest plane of each breast lesion and drew an outline of the region of interest (ROI) by using ITK-SNAP software (version 3.4.0).

B-mode US images of the lesions were acquired with a Siemens Acuson S2000 device (Siemens Medical Solutions, Mountain View, CA, USA), using an 18 L6 HD (5.5–18 MHz) linear transducer. To evaluate the stiffness of lesions, SE was performed using a Siemens Acuson S2000 device (Siemens Medical Solutions, Mountain View, CA, USA) with a 9L4 (4–9 MHz) linear transducer. When performing SE, the freehand compression method described by Itoh et al. [1] was used. With the patient in supine position, the US transducer was positioned parallel to the breast lesion. To achieve appropriate contact with the skin, slight pressure was applied through the transducer over the breast tissue, resulting in its displacement by 1-2 mm posteriorly, and coming back to its initial location, and elastography images were acquired. The compression sufficiency was adjusted according to quality factor 60 and higher as an adequate value. A region of interest (ROI) box was placed on the targeted lesion, and another ROI box was placed on reference tissue determined to be adjacent fat tissue, to measure strain ratio. Strain ratio was calculated by comparing the strain value of the reference tissue with that of the targeted lesion.

A high-resolution ultrasound system, equipped with a 4–15 MHz transducer (Acuson S2000; Siemens, Hamberg, Germany), was used to diagnose cervical lymphatic malformation. Patients in whom the relationship between the lesion and adjacent structures was not clear by ultrasonography because of individual cysts < 1 mm in diameter underwent further evaluation by magnetic resonance imaging (MRI) (Signa; GE Medical Systems, Milwaukee, WI, USA) or contrast-enhanced computed tomography (CT). All patients underwent colour Doppler and power Doppler ultrasonography. Ultrasonographic diagnosis and differential diagnosis were based on the intracystic fluid echo, thickness of cyst wall, cyst location, and colour flow signal distribution. The macrocystic (cysts > 1 cm in diameter), microcystic (individual cysts < 1 cm in diameter), and mixed types were classified according to the cyst diameter. Cervical lymphatic malformation was diagnosed with haemorrhage, infection, and/or calcification according to increased cyst diameter (compared with prior size) and intracyst fine spot echo, local pain, increased temperature and abnormal blood test results, and calcified plaque in cyst before treatment, respectively.