平扫和动态增强MRI诊断肝脏局灶性结节增生

目的 探讨肝脏避灶性结节增生（ＦＮＨ）的平扫和动态增强的ＭＲＩ表现及诊断价值。方法 回顾分析２２例２２个手术病理证实的肝脏ＦＮＨ的平扫及动态增强ＭＲＩ资料。结果 病灶平均大小为４．０５ｃｍ，４个病灶在Ｔ１ＷＩ及Ｔ２ＷＩ上呈典型等信号肿块，１８个为不典型信号肿块。８个在平扫ＭＲ上显示中央瘢痕。２１个病灶的实质部分在增强后动脉期呈明显均匀强化，在门脉期及延迟期呈等强化或强于肝实质。２个病灶在门脉期和延

Diagnosis of hepatic focal nodular hyperplasia by combination of unenhanced and dynamic contrast enhanced MR imaging

Objective To investigate MR imaging findings of hepatic focal nodular hyperplasia (FNH) on unenhanced and dynamic contrast enhanced scans and evaluate their diagnostic value. Methods The unenhanced and dynamic gadolinium enhanced MR images of 22 FNHs proved by pathology were retrospectively analyzed. Results Average size of FNH lesions was 4.05 cm. The typical MR isointensity signal with surrounded hepatic parenchyma on T 1 and T 2 weighted images was seen in only 4 lesions, while atypical signal was encountered in 18 lesions. A central scar was noted in 8 lesions on unenhanced images. After gadolinium administration, 21 lesions had vigorous enhancement on arterial phase and prolonged enhancement on portal vein and delayed phase. The ring enhancement of capsule was noted in 2 lesions on portal vein and delayed phase. 18 lesions showed a central scar on dynamic contrast enhanced images. 19 lesions were correctly diagosed by using the combination of unenhanced and dynamic contrast enhanced MR imaging. Conclusion The combination of unenhanced and dynamic contrast enhanced MR imaging can fully show the pathologic characteristics of FNH and improve to differeniate ability from other malignant hypervascular tumors.