COMPARISON OF ULTRASOUND ELASTOGRAPHY VERSUS B-MODE ULTRASOUND IN DIFFERENTIATING MALIGNANT FROM BENIGN CERVICAL LYMPH NODES

ABSTRACT Objective: To compare the diagnostic accuracy of ultrasound elastography with B-mode ultrasonography in differentiating malignant from benign cervical lymph nodes, keeping histopathology as gold standard. Study Design: Comparative cross-sectional study. Place and Duration of Study: Radiology department of Combined Military Hospital, Rawalpindi, from May to Oct 2016. Methodology: After approval from hospital ethical committee a total of 246 patients with palpable cervical lymph node and age 20-50 years of either gender were collected by non probability purposive sampling. Patients with already proven histopathology, any chronic disease, history of prior irradiation, malignancy and trauma were excluded. The demographic details including name, age, gender, location race was noted on a predesigned research proforma. First of all, the registered patients underwent B mode ultrasound of cervical lymph nodes as benign or malignant on the basis of ultrasound features. All these patients were subjected to ultrasound elastography and categorized from score 1-4 on the basis of elastographic tissue stiffness. Patients with score of 1 and 2 were labeled as benign, while 3 and 4 were labeled as malignant. The tissue diagnosis/ histopathology was taken as reference gold standard for both B-mode ultrasound and ultrasound elastography findings. Results: A total number of 246 patients with a mean age of 36.63 ± 8.52 years were registered. Mean size of lymph node was 2.32 ± 1.07 cm. The positive predictive value was found to be 94.70%, negative predictive value 92.6%, sensitivity 95.33%, specificity 91.67% and diagnostic accuracy of 93.90% for ultrasound elastography while that of B-mode USG positive predictive value was found to be 92.05%, negative predictive value 80.0%, sensitivity 87.97%, specificity 86.36% and diagnostic accuracy of 87.40%. Conclusion: The study results concluded that diagnostic accuracy of ultrasound elastography was higher compared to B-mode ultrasonography in non invasively differentiating benign from malignant cervical lymph nodes.