Dynamic MRI is useful for distinguishing high-flow from low-flow vascular malformations, especially when the contrast rise time of the lesion is measured.

Asymmetric dilatation of the RIPA as an indicator of extrahepatic collateral of HCC can be demonstrated on the right diaphragmatic crus with arteriographic images of biphasic helical CT.

A 28-year-old Japanese woman with Balo's concentric sclerosis developed a rapidly progressive form of encephalopathy. Magnetic resonance imaging (MRI) showed multiple concentric lesions in the central white matter and the cerebellum. The administration of corticosteroid regimen resulted in little benefit. Immunoadsorption plasmapheresis led to a remission within 1 month of onset. Serial MRI study was described here for the first time, which allowed us to observe the development of concentric structures. The observation indicated that, initially, a central core, a round demyelinated area, and surrounding edema appeared around a vessel. Subsequently, concentric demyelinated bands formed simultaneously, not centrifugally, with diminution of the edema. Analysis of cerebrospinal fluid showed elevated levels of interleukin-6 and tumor necrosis factor-alpha. The success of immunoadsorption plasmapheresis therapy in this patient suggests that both humoral demyelinating factors and cell-mediated immunity may be involved in the pathogenesis of this disorder.

The CT features of poor contrast enhancement, thin rim enhancement, and dark fan sign are valuable for identifying acute torsion of USL.