This was a prospective study conducted from December 2017 to March 2019 after the approval of protocol from faculty of medicine ethical committee for human research; fully informed written consent was taken from each patient after given an explanation of the procedures and the importance of the study; the confidentiality of the patient’s data was guaranteed, and the patients had the right to refuse participation in this study without giving any reason.
The study enrolled 110 patients: 92 male and 18 females with a mean age 51.7 years after fulfillment of inclusion and exclusion criteria. Inclusion criteria were patient presented with at least one hepatic focal lesion greater than 1 cm in diameter and not more than 5 cm deep from the capsule. Exclusion criteria were focal lesion previously managed by intervention radiology, patient with perihepatic ascites, and uncooperative patients.
The patients were subjected to full history taking and laboratory investigations. Real-time ultrasound and shear wave elastogaphy (SWE) was performed using Philips iU22 × MATRIX ultrasound system with a curved array transducer 3–5 MH. The patients were examined in the supine or left lateral position with right arm elevated above the head to improve intercostal access. Gray scale abdominopelvic ultrasonography was initially performed to evaluate the liver size, echogenicity, texture, outline, and focal lesions. We identified hepatic focal lesions for number, site, size, margin, and echogenicity. Then, in SWE scanning, the patient was instructed to hold his or her breath for a few seconds. We located the segment of hepatic focal lesion, and a region of interest (ROI) was adjusted upon the targeted focal lesion; we took from 5 to 8 measurements for quantitative evaluation of stiffness. Then, the machine estimated the velocity of the propagated shear wave in the ROI and automatically translates it to stiffness in kilopascals (KPs). In patient with more than one focal lesion, we ensured that all lesions have the same pathology guided by other modalities like CT and MRI, and then, we analyzed the most accessible one. Multiple successful measurements are obtained, and the results appear in the final report as the average of all measurements. Then, the data obtained by SWE scanning is compared with the results of triphasic CT and raised tumor markers in 92 patients (84%), dynamic MRI in 15 patients (13%), and 3 patients by histopathology to estimate the accuracy, sensitivity, and specificity of SWE in characterization of different hepatic focal lesions.
Statistical analysis
Data were collected, tabulated, and statistically analyzed using a personal computer with Statistical Package of Social Science (SPSS) version 20 [SPSS Inc., Chicago, IL, USA], where the two types of statistics were done.
Descriptive statistics
Quantitative data was expressed as mean ± standard deviation (SD). Qualitative data was expressed as frequency and percentage.
Analytic statistics
Independent samples t test of significance will be used when comparing between two means. Chi-square (χ2) test of significance will be used in order to compare proportions between two qualitative parameters. ROC curve is a graph called a receiver operating characteristic curve; it is a plot of the true positive rate against the false positive rate for different possible cutoffs of diagnostic test or marker. p value ≤ 0.05 was considered to be statistically significant. p value ≤ 0.001 was considered to be highly statistically significant.