Logiq e9 system

Time–intensity curve (TIC) analysis was performed as a quantitative tool to analyze the difference between the initial HCC and recurrent HCC lesions. The stored DICOM data were evaluated using the built-in TIC analysis software of the LOGIQ E9 system (GE, USA). A region of interest (ROI), mainly including the liver lesion, was selected to obtain the TIC. The ROI sampling frame was chosen in lesions around the central and liver tissues as same a depth as possible to avoid the great vessels and tumor necrosis area. The enhanced time was calculated from the time of contrast agent injection to the contrast agents arrived lesions. The peak time was considered from the contrast agents injected to the contrast agent reaching the maximum level. The washout time referred to lesions with echo intensities lower than the time needed for the liver parenchyma.

CEUS examinations were performed during clinical routine by a single radiologist with 20 years of experience in abdominal ultrasound (10 years specifically in CEUS), unblinded to previous CT and/or MRI findings, using a Logiq E9 system (General Electric Healthcare, Milwaukee, WI, USA). This radiologist did not correspond to the study coordinator.
After preliminary grayscale and color Doppler investigation, CEUS was set with low acoustic power to achieve minimum microbubble destruction (mechanical index of 0.12). Each lesion confirmed by preliminary ultrasound investigation (100%) was evaluated separately after intravenous administration of a 2.4 ml dose of a sulfur hexafluoride-filled microbubble contrast agent (SonoVue, Bracco, MIlan, Italy), followed by a 10 ml saline flush. Per-index lesion digital cine-clips were acquired from the start of contrast injection to at least 2 min thereafter, together with static images, and sent to the picture archiving and digital system (PACS) (Suitestensa, Ebit AET, Genova, Italy) for subsequent review.

All patients included in this study underwent CE-TRUS before prostate biopsy. The ultrasound equipment used was the LOGIQ E9 system (GE Healthcare, Milwaukee, WI, USA) with a transrectal probe operating at a frequency of 3–9 MHz. During CE-TRUS, 2.4 mL of SonoVue (Bracco, Milan, Italy) was administered intravenously as a rapid bolus injection, followed by a 5 mL saline flush. The acoustic power of the equipment was set at a mechanical index of 0.10. The contrast imaging plane was considered the transverse plane of the CE-TRUS abnormality. The results of the imaging examinations were saved in a DICOM format.

Ultrasound SWE was performed on all plaques using a General Electric Logiq E9 system (GE Healthcare, Wauwatosa, WI, USA) with a 9 L linear array transducer and with ∼5–15 acquisitions retrieved in the longitudinal (L) and transverse (T) imaging views, respectively, for each plaque. For each acquisition, the plaque was centered inside a manually positioned imaging window, with the cross-section having the most significant stenosis chosen as the representative view for each plaque. If such a view was obstructed by excessive shadowing from intraplaque calcifications, a neighboring cross-section was chosen. For the SWE, a dual-sided acoustic radiation force push was used, utilizing two focused push beams simultaneously triggered at the left- and right-hand sides of the region-of-interest (ROI), respectively (similar to the setup in Song et al.^{20 (link)}). A push frequency of 4.1 or 5.0 MHz was utilized with a push duration of 400 μs, followed by time-aligned sequential acquisition (frequency: 5 MHz)^{21 (link)}. From each acquisition, in-phase/quadrature (IQ) data was exported, at a resolution of approximately 0.30 mm² and with recordings lasting for around 18 ms each.

SSM and LSM by 2D-SWE were performed using a LOGIQ E9 system (GE Healthcare, Wauwatosa, WI, USA) (version 2.0), using the C1-6-D convex probe. The SWE ROI was placed in a well-visualized area of the splenic parenchyma, at the level of the superior pole of the spleen. In some cases (spleen size <12 cm) when a homogeneous load of the ROI was not obtained, the measurement was performed closer to the centre of the spleen. For LS, the ROI was placed at least 1–2 cm below the liver capsule, in an area free of large vessels. While the patient was asked to suspend breathing, image acquisition was initiated. The system records several second loops and then the measurements are performed frame by frame. A circular measurement ROI is placed in each frame and the measurement is obtained. A single measurement was performed in each loop and ten consecutive measurements are acquired for each subject. The average stiffness, expressed in terms of Young's Modulus within each measurement region, was automatically recorded by the system in a worksheet. The system consequently calculates the median value and IQR of the valid measurements. Reliable SSM/LSM were defined as the median value of 10 measurements acquired in a homogenous area, with an IQR/M <0.30. Measurements were considered failures when no value was obtained after 10 attempts.

For each patient, we collected 5–8 frames of grayscale image and CDFI for screening suitable images and finally used one grayscale image and one CDFI for training and evaluation of the DLM. Most of the research was done using a 7–14 MHz linear array probe for image acquisition on a HITACHI AIRETT 70 or GE LOGIQ E9 system under the default parameter conditions of the instrument. At the same time, comparative scan and dynamic scan should be carried out when the image is collected to compare and dynamically observe the boundary and scope of the lump. If the lump is deep or large, appropriate pressure should be applied. We ensured that each case contained at least one grayscale image and one CDFI.