Atypical, unusual, and misleading imaging presentations of spondylolysis.

Although lumbar spondylolysis is a widely known and easily recognizable condition in its typical presentation, there are some less well-known forms that may occasionally be challenging and/or demand special attention on imaging. Examples include: acute and/or incomplete lesions; unilateral defects; lesions at unusual levels (cervical, upper lumbar, and multi-level spondylolyses); iatrogenic lesions; non-isthmic spondylolysis; and spondylolysis related to underlying diseases. In addition to their atypical, uncommon or confusing imaging presentations, these forms of spondylolysis are far rarer than the classic type and have been described, to a great extent, in the surgical literature, thus reducing the awareness of radiologists about them and raising the potential for misdiagnosis and inadequate treatment.

Unilateral dysgenesis of the internal carotid artery: spectrum of imaging findings.

Objective: Dysgenesis of the internal carotid artery (ICA) is a broad term comprising hypoplasia, aplasia and agenesis of the vessel. It is a rare anomaly, often clinically silent, that can be confidently diagnosed by means of noninvasive imaging methods.

Methods: After a review of teaching files, 7 patients with unilateral carotid dysgenesis were found, 2 with agenesis of the ICA, 3 with carotid aplasia, and 2 with hypoplasia of the vessel.

Cavernous angioma of the cavernous sinus: imaging findings.

Cavernous angiomas (cavernomas) of the cavernous sinus are uncommon, with only scattered reports in literature. Unlike their parenchymatous counterparts, they are intensely enhancing para-sellar masses, iso/hypointense in T1- and hyperintense in T2-weighted images. Differential diagnosis with para-sellar meningiomas and schwannomas can be difficult.