Multi-slice spiral CT and magnetic resonance imaging features of hepatic focal nodular hyperplasia and their pathological basis

Objective To investigate the multi-slice spiral CT ( MSCT) and magnetic resonance imaging ( MRI) features of hepatic focal nodular hyperplasia ( FNH) and their pathological basis, and to improve the accuracy of diagnostic imaging. Methods A retrospective analysis was performed for the MSCT and MRI findings of 40 patients with pathologically confirmed hepatic FNH who were admitted to Wuxi Fourth People's Hospital, Affiliated Hospital of Jiangnan University, from January 2010 to December 2016. Results Of all the 30 patients who underwent MSCT, 24 showed low-density lesions on plain scan, among whom 18 had irregular lower-density shadow ( scar) in the central areas of lesions and 6 had slightly higher density ( fatty liver disease) ; as was shown by the contrast-enhanced scan, all lesions had intense enhancement in the arterial phase with even or uneven density, as well as slightly higher or equal density in the portal venous phase, and 18 patients had delayed enhancement in central low-density lesions or a reduction in the size of such lesions. MRI was performed for 40 patients, and plain scan showed that the lesions were slightly hypointense on T1WI and slightly hyperintense on T2WI and DWI, and 32 patients had star-like, striped, or mottled low signals in lesions. All lesions except scars showed intense enhancement in the arterial phase, slight hyperintensity or isointensity in the portal venous phase, and isointensity in the delayed phase. Of all 40 patients, 32 had hypointensity and delayed enhancement in lesions or a reduction in the size of such lesions, 4 had incomplete ring enhancement around the lesions in the portal venous phase and the delayed phase, and 28 had blood vessels around or inside the lesions. Conclusion MSCT and MRI are specific and accurate in the diagnosis of hepatic FNH, and a combination of these two methods can improve the diagnostic rate of hepatic FNH.