DIAGNOSTIC ACCURACY OF STRAIN ELASTOGRAPHY FOR DIFFERENTIATION OF BENIGN AND MALIGNANT HEPATIC LESIONS KEEPING CT AS GOLD STANDARD

Abstract

Objective:
To determine the diagnostic accuracy of strain elastography in differentiating benign and malignant focal hepatic lesions, using computed tomography (CT) as the gold standard.

Methodology:
This cross-sectional diagnostic accuracy study was conducted in the radiology department of Pakistan Institute of Medical Science Islamabad. A total of 110 patients with suspected focal hepatic lesions who underwent both strain elastography and contrast-enhanced CT scan were included using a non-probability consecutive sampling technique. Patients with previous liver surgery, severe coagulopathy, or those who did not undergo CT imaging were excluded. Strain elastography was performed using a high-resolution ultrasound machine to assess tissue stiffness and calculate strain ratios for lesion characterization. CT scan findings were interpreted independently by radiologists who were blinded to elastography results and were considered the gold standard. Diagnostic performance parameters including sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and overall diagnostic accuracy were calculated using statistical software.

Results:
The mean age of the participants was 45.8 ± 13.6 years (range 20–70 years), with 68 (61.8%) males and 42 (38.2%) females. CT scan confirmed 62 (56.4%) malignant lesions and 48 (43.6%) benign lesions. Strain elastography classified 65 lesions as malignant and 45 as benign. When compared with CT findings, 56 cases were true positives, 39 true negatives, 9 false positives, and 6 false negatives. The sensitivity of strain elastography was 90.3%, specificity 81.3%, PPV 86.2%, NPV 86.7%, and overall diagnostic accuracy 86.4%.

Conclusion:
Strain elastography is a useful non-invasive imaging technique for differentiating benign and malignant hepatic lesions. However, CT remains the reference standard for definitive diagnosis and detailed lesion characterization