Logiq e9

Median nerve HRUS was performed right after the EDX study by the same examiner who performed the EDX. The examiner was not blinded to the EDX data or clinical information. The HRUS device used was a GE Healthcare Logiq E9 (GE Healthcare, Milwaukee, WI, USA) with a 12.0 MHz ML 6–15-D linear transducer. The CSA of the MN was measured by a single measurement in the transversal plane at the site of the carpal tunnel inlet, where the median nerve was at its largest, and at the distal third of the forearm. The CSA was measured with freehand tracing inside the epineurium. The WFR was calculated by dividing the wrist CSA by the forearm CSA. A total of 16 wrists in the younger group and 18 wrists in the older group lacked a forearm CSA measurement. In addition, 15 wrists in the younger group and 17 wrists in the older group lacked the needle EMG results. The wrists that lacked the forearm CSA were not included in the WFR analysis but were included in the analysis of the wrist CSA. The wrists that lacked the needle EMG results were included in other statistical analyses than those related to EMG correlations and IP group assessments.

All patients also underwent HRUS of the MN directly after the EDX. Both the EDX and HRUS were performed by the same clinical neurophysiologist or a registrar specializing in clinical neurophysiology.
The HRUS device used was GE Healthcare Logiq E9 (GE Healthcare, Milwaukee, WI) with a 12.0 MHz ML 6–15-D linear transducer. The MN cross-sectional area at the wrist was measured where the median nerve appeared to be at its largest at the proximity of the carpal tunnel inlet. To calculate the WFR, the cross-sectional area of the MN was also measured at the border of the middle and distal thirds of the forearm. The cross-sectional area was measured inside the hyperechoic epineurium by direct freehand tracing. All measurements were rounded to the nearest square millimetre.

Informed consent was obtained from all patients prior to the MWA. Contrast-enhanced ultrasound (CEUS) was performed before MWA to confirm the size and the number of tumors, and after to eliminate hemorrhage, bile leakage, and incomplete ablation.
In our institution, MWA was performed using the KY2000 microwave treatment system (Nanjing KANYOU Medical Technology Co., Ltd.). For pain management during the percutaneous MWA, pethidine hydrochloride was administered intramuscularly (50–75 mg) approximately 30 minutes before the operation; moreover, local anesthesia was induced via topical injection of lidocaine (10–15 mL) at the beginning of the MWA. Patients underwent percutaneous MWA under real-time electrocardiographic monitoring and received low-flow oxygen.
Percutaneous MWA was performed under real-time ultrasound (LOGIQ E9, GE) guidance with a 1.0 to 5.0 MHz probe. Microwave radiation from the probe induces rapid oscillation in water molecules, causing frictional heating and consequent coagulation necrosis of the tissue surrounding the probe. The MWA was delivered at a frequency of 2450 MHz and a power of 30 to 100 W for 5 to 20 minutes using a 14-gauge (200 mm) cooled shift electrode (KY2450A, KANYOU Medical Technology Co., Ltd, Nanjing, China) (Fig. 2).