The persistent stapedial artery.

The persistent stapedial artery is a rare congenital vascular anomaly that may present as a pulsatile middle ear mass or that may appear as an incidental finding. Five cases of persistent stapedial artery are presented. The CT findings include the absence of the ipsilateral foramen spinosum and a soft-tissue prominence in the region of the tympanic segment of the facial nerve. Three cases were associated with an aberrant internal carotid artery. Imaging identification of this variant may obviate unnecessary surgery and may help in planning surgical or endovascular interventions.

MR imaging of compressive myelomalacia.

The authors studied retrospectively 42 patients with the magnetic resonance (MR) diagnosis of myelomalacia. Depending on MR findings, the patients were grouped into early, intermediate, and late stages of myelomalacia. Early stage myelomalacia patients presented with high intensity signal changes on T2-weighted images involving the width of the affected cord. The intermediate stage patients were characterized by varying degrees of cystic necrosis of the central gray matter, better seen on T2-weighted images. Central cystic degeneration, syrinx formation, and atrophy were prominent features of the late stage of myelomalacia. Ten patients had follow-up MR examinations within 6 months of initial imaging. Two of the four early stage myelomalacia patients showed improvement in the repeat studies. The follow-up scans of the six intermediate and late stage myelomalacia patients showed either no change or progression of disease. Early stage myelomalacia may be reversible, depending on the severity of the initial spinal cord injury. Magnetic resonance can serve as a useful tool in the assessment and management of myelomalacia patients.

MR imaging of lytic changes in Paget disease of the calvarium.

The authors present two patients with Paget disease, both showing lytic changes in the calvarium. On T1 contrast sequences, the first patient demonstrated an extraaxial soft tissue mass in the temporooccipital region. This abnormality was hypointense to the adjacent normal diploic tissue. The second patient demonstrated a hypointense frontal abnormality on the T1-weighted sequence. Intracranial extension of this lesion was associated with lysis in otherwise mixed signal pagetoid bone. The first patient had osteoclastic Paget disease or osteoporosis circumscripta. The second patient had sarcomatous degeneration.

Embolization in cataclysmal hemorrhage caused by squamous cell carcinomas of the head and neck.

Cataclysmal hemorrhage occurred in eight patients with known aggressive squamous cell tumors of the head and neck. Angiography showed neovascularity, narrowing, beading of affected arteries, and pseudoaneurysms. Postembolization residual stump formation was seen in a few patients. A total of 11 embolization procedures were performed in these eight patients. Embolization materials included polyvinyl alcohol, isobutyl-2-cyanoacrylate, and detachable balloons. Survival times ranged from 5 to 274 days, with no deaths as a direct result of hemorrhage. Only one severe complication following embolization was noted.

Primary and secondary histiocytic lymphoma of the brain: CT features.

The authors examined 19 patients with diffuse histiocytic lymphoma of the brain, including 8 with primary disease and 11 with secondary disease. Both primary disease and secondary disease involving the brainstem and deep nuclei exhibited the characteristic CT appearance, consisting of a large, solid, homogeneously enhanced mass with varying amounts of edema. However, most secondary lymphomas outside the brainstem and basal ganglia contained large areas of low attenuation consistent with necrosis. Multifocal lesions were seen only in patients with secondary lymphoma. Systemic chemotherapy for extracranial lymphoma had no effect on the CT appearance of intracranial lesions. The authors suggest that these "unusual" CT patterns are actually typical of a distinct subset of histiocytic lymphomas.

Craniofacial mucormycosis: computed tomographic and angiographic findings in two cases.

Two cases of craniofacial mucormycosis are presented, stressing computed tomographic (CT) and angiographic findings. In the first case, successful embolization of a sphenopalatine artery pseudoaneurysm is shown. The second case demonstrates CT findings of ethmoidal sinus and frontal lobe inflammatory change. Ophthalmic artery occlusion is show. Obstructive venous changes within the orbit and cavernous sinus are displayed by means of orbital venography.