Objective To study the radiological features of dynamic enhanced multi-slice spiral CT (MSCT) and CTA in pure hepatic arterio-venous fistula (AVF).Methods The radiological features of MSCT imaging and CTA of 100 patients with pure hepatic AVF were retrospectively analyzed.Results Positive signs on the arterial phase were detected in 100 patients with pure hepatic AVF.In 89 patients,they were the peripheral type and in 11 patients they were the central type.There were 128 lesions in the 100 patients.In the peripheral type,the features were (1) in the arterial phase,the lesions appeared as a wedged or a patchy enhancement area at the edge of the liver,showing a halo sign in 68 patients.In 56 patients,the PV was shown also in the early arterial phase;(2) in the arterial phase,arailway track sign was shown in 21 patients as a result of a portal vein branch showing right next to a hepatic arterial branch.In the central type and in the arterial phase,the main portal vein (or the hepatic vein) and the left/right branches of the PV (or the HV) were shown.Conclusion MSCT and CTA were useful in the diagnosis of pure hepatic AVF.

Objective:To investigate the CT and MRI features of meningiomas of the skull.Methods:A retrospective analysis was performed; the CT and MRI findings of 20 patients with meningiomas of the skull confirmed by pathology after surgery in our hospital from January 2008 to December 2020 were collected.Results:Fourteen patients had skull osteolytic destruction, 4 had osteogenic destruction, and 2 had mixed destruction. There were 12 patients with soft tissue masses and 11 with radial spicules. In 16 patients accepted CT examination, uniform density was noted in 10 and uneven density in 6; 8 had high density, 5 had equal density, and 3 had low density; 5 patients were with calcification. In 17 patients accepted MRI examination, 11 had uniform signal and 6 had un-uniform signal; T1WI had slightly low signal in 12 patients and equal signal in 5 patients; T2WI had slightly high signal in 12 patients and slightly low signal in 5 patients; diffusion weighted imaging (DWI) had high signal in 12 patients and slightly high signal in 5 patients. Totally, enhanced homogeneous enhancement was noted in 12 patients and inhomogeneous enhancement was noted in 8 patients; and there were 13 patients with "meningeal tail sign" and 11 with peritumoral edema.Conclusion:Bone in patients with meningiomas of the skull is characterized by osteolytic or osteogenic destruction with soft tissue masses and radial spicules; CT shows uniform or un-uniform tumor density, MRI shows uniform or un-uniform signals, and enhanced "meningeal tail sign" is characterized.