Magnetic resonance imaging in focal liver lesions: Imaging with pathological correlation

Background: Magnetic resonance signal intensity of focal liver lesions is affected by numerous pathologic factors. Lesion histologic features, such as cellularity, vascularity, stromal component, and intratumoral necrosis or hemorrhage, strongly affect T1 and T2 relaxation times. Aim: Our study is done to assess the lesion characterization potential of MRI by evaluating unenhanced and dynamic gadolinium enhanced sequences. Materials and methods: A total of 50 consecutive patients who were diagnosed by sonography as having focal liver lesions for period of 2 years were included in the study. Results: Most of the patients are of 30 - 60 years. The mean age for malignant lesions is 51 years. Of 50 patients 32 are males and 18 are males. Male: female ratio 2:1. 65% of the lesions are located in right lobe of the liver. The most common benign lesion encountered was liver abscess followed by haemangiomas and most common malignant lesion was metastases. Abscess and hemangiomas were predominant in benign whereas metastases and hepatocellular carcinomas were predominant in malignant lesions. The difference in mean ADC values in both the groups was significant. Conclusions: MR imaging is a powerful tool for the evaluation of focal liver lesions. Pre contrast T1 weighted gradient echo images, T2 weighted images, inphase and out phase imaging, EPI - DWI and gadolinium enhanced T1 weighted images provide accurate characterization of the lesions.