OBJECTIVES. The echo patterns of human hepatoma vary considerably as the tumors grow. This sonographic study investigates the microanatomie basis of the echo-pattern changes in an animal model. METHODS. ACI rats (n = 35) with intrahepatically implanted Morris hepatoma 3924A were imaged with 10-MHz ultrasound from days 7 to 28 after tumor implantation. The sonograms were precisely correlated with the histologic sections and microangiograms obtained from the same section plane. RESULTS. Small hepatomas (size = 6.6 ± 1.6 mm) without necrosis demonstrated a low-echo pattern. Medium-sized tumors (size = 11.7 ± 3.3 mm) had a low-echo periphery and a high-echo center. The low-echo periphery corresponded to viable tumor and the high-echo core corresponded to central coagulation necrosis. Large tumors (size = 20.9 ± 7.5 mm) with extensive necrosis revealed an irregular mixed-echo pattern. CONCLUSIONS. The trend of increasing echogenicity of the hepatomas with tumor growth is due to the progression of coagulation necrosis.
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging
- Radiological and Ultrasound Technology