The purpose of this study is to estimate the clinical value of contrast-enhanced ultrasound in percutaneous biopsy for liver occupied lesion.

The patients with liver neoplasms who need receive percutaneous biopsy were randomized into contrast-enhanced ultrasound(CEUS) group and conventional ultrasound(US) group.The aims include:

1. Comparison the diagnostic accuracy rate, specificity and sensitivity between CEUS and US group.
2. Comparison the diagnostic accuracy rate specificity and sensitivity between smaller(<3cm) and larger(≥3cm) nodule group.
3. To explore operating strategy of contrast-enhanced ultrasound guided biopsy.
4. To evaluate economic efficiency of contrast-enhanced ultrasound guided biopsy compared with conventional ultrasound guided biopsy.

Inclusion Criteria:

• patients with liver occupied lesion who cannot be diagnosed by imaging examination or need pathological results

Exclusion Criteria:

• severe anemia
• PLT<60000/mm3,prothrombin activityprothrombin time activity<70%
• women during menstruation, pregnancy, child birth and baby nursing period
• patients with severe mental disorder
• cardiopulmonary failure