Analysis of petrous apex meningocele associated with meningioma: is there any relation with chronic intracranial hypertension?

PURPOSE: Petrous apex meningocele (PAM) is an uncommon cystic lesion involving the petrous apex. The underlying cause of PAM may be related to chronic elevated intracranial pressure. The aim of the study was to explore the relationship between PAM and meningioma and between PAM and other intracranial hypertension findings. METHODS: Two hundred seventy-eight consecutive patients with meningiomas were retrospectively studied. Fifty age- and gender-matched controls were also enrolled in this study. The incidence of PAM, empty sella, tortuosity of the optic nerve, and hydrops of optic nerve sheath was evaluated. The maximum width, area, volume of each PAM, or Meckel's cave and volume of meningioma were measured in controls and patients, separately. RESULTS: One hundred fifty-nine (57.19%) patients were detected with coexistent PAMs. One hundred twenty-five patients had bilateral PAMs, 34 had unilateral lesions, and the remaining 119 did not have PAM. Two subjects (4/50) had unilateral PAMs in normal controls. The maximum width, area, volume of PAM, or Meckel's cave were significantly larger in the patients with bilateral PAM group than those in the unilateral PAM group, in the group without PAM, and those in control group (p = 0.000). The volume of meningioma was positively correlated with the PAM volume (r = 0.48). There was a positive correlation for the incidence between PAM and (1) empty sella (r = 0.901) and (2) tortuosity of the optic nerves and hydrops of the optic sheath (r = 0.825). CONCLUSION: Coexistence of PAMs with meningiomas is not rare in incidence, and it suggests a potential role for chronically elevated intracranial pressure and disturbance of CSF circulation in their pathophysiology.

The putaminal abnormalities on 3.0T magnetic resonance imaging: can they separate parkinsonism-predominant multiple system atrophy from Parkinson's disease?

BACKGROUND: The putaminal abnormalities detected on 1.5 T magnetic resonance imaging (MRI), such as putaminal atrophy, slit-like hyperintense rim, and hypointensity in the putamen on T2-weighted (T2W) imaging are important signs on differentiating multiple system atrophy with parkinsonism (MSA-P) from Parkinson's disease (PD). However, the putaminal abnormalities may have different manifestations on 3.0 T from those on 1.5 T. PURPOSE: To investigate the diagnostic value of putaminal abnormalities on 3.0 T MRI for differentiating MSA-P from PD. MATERIAL AND METHODS: The study included a MSA-P group (9 men, 9 women), a PD group (12 men, 14 women), and a control group (11 men, 13 women). All subjects were examined with 3.0 T MRI using the conventional protocol. Putaminal atrophy, T2-hypointensity in the dorsolateral putamenat, and a slit-like hyperintense rim on the lateral putamen were evaluated in each subject. RESULTS: There were no significant differences in the slit-like hyperintense rim (P = 0.782) or T2-hypointensity in the dorsolateral putamen (P = 0.338) among the three groups. Bilateral putaminal atrophy was found in 44.4% (8 of 18) of the MSA-P patients, in only 7.7% (2 of 26) of the PD patients, and in none of the controls. The proportion of subjects with putaminal atrophy was significantly higher in the MAS-P group (P = 0.008) and control group (P < 0.001). The specificity and sensitivity of putaminal atrophy for distinguishing MSA-P from PD was 92.3% and 44.4%, respectively. CONCLUSION: The signal changes in the putamen on T2W imaging on 3.0 T MRI, including slit-like hyperintense rim and putaminal hypointensity, are not specific signs for MSA-P. Putaminal atrophy is highly specific for differentiating MSA-P from PD and healthy controls, but its insufficient sensitivity limits its diagnostic value.

Reproducibility of high-resolution MRI for the middle cerebral artery plaque at 3T.

PURPOSE: To assess the reproducibility of HR-MRI for the identification of MCA atherosclerotic plaque components and quantification of stenosis. MATERIALS AND METHODS: Seventy-three consecutive subjects who initially had ischemic stroke or asymptomatic MCA stenosis (>50%) were enrolled in the study. All subjects were scanned using 3.0T MRI. Two independent readers reviewed all images and one reader reevaluated all images four weeks later. The tissue components of plaques were analyzed qualitatively and the vessels were quantitative measured. RESULTS: HR-MRI displayed the artery wall and lumen clearly. The intra-observer reproducibility was excellent for the identification of plaques (kappa [κ]=0.96; 95% CI: 0.83-1.04) and contrast enhancement (κ=0.89; 0.78-0.95); it was substantial for intra-plaque hemorrhage (κ=0.79; 0.57-0.96) and the fibrous cap (κ=0.65; 0.42-0.86). The inter-observer reproducibility was excellent for plaques (κ=0.92; 0.73-1.06), substantial for contrast enhancement (κ=0.80; 0.65-0.93), intra-plaque hemorrhage (κ=0.68; 0.47-0.92) and moderate for the fibrous cap (κ=0.58; 0.44-0.79). Both intra-observer and inter-observer reproducibility were excellent for quantitative vessel, lumen and wall measurements with intraclass correlation coefficients ranging from 0.91 to 0.97 and 0.87 to 0.96, respectively. However, vessel and wall areas and the intervals defined by the Bland-Altman plots were wide in comparison to the mean. CONCLUSIONS: The identification of MCA atherosclerotic plaque components and the quantification of vessel and lumen measurements are reproducible. The reproducibility is overall acceptable. HR-MRI may provide a useful tool for clinical risk evaluation in MCA atherosclerosis.

Basilar artery atherosclerotic plaques distribution in symptomatic patients: a 3.0T high-resolution MRI study.

PURPOSE: To investigate basilar artery atherosclerotic plaque distribution characteristics in symptomatic patients using 3.0T high-resolution MRI. MATERIALS AND METHODS: Thirty-eight patients with recent ischemic strokes or transient ischemic attacks were included. Conventional angiographic luminal imaging of these patients showed at least 30% basilar artery stenosis. Patients then underwent basilar artery high-resolution MRI examinations (T2WI, T1WI and post-contrast enhanced T1WI in short axial and long axial views). The narrowest lumen plaque distribution was evaluated by cross-section division into four equal arcs (right, ventral, left and dorsal arcs) on the short axial T2-weighted images. The percent plaque fraction was calculated as arc plaque area/luminal area×100, with each compared by analysis. RESULTS: The basilar artery lumens and walls were clearly shown in all 38 patients. The median plaque area sizes were 2.73mm(2) (range: 1.04-5.29mm(2)) on the ventral wall, 0.59mm(2) (range: 0-1.50mm(2)) on the left wall, 0.87mm(2) (range: 0-2.68mm(2)) on the dorsal wall, and 0.36mm(2) (range: 0-1.80mm(2)) on the right wall. The mean plaque fraction percentages were 21.6% (range: 7.9-34.0%) on the ventral wall, 4.6% (range: 0-10.0%) on the left wall, 6.3% (range: 0-16.3%) on the dorsal wall, and 2.6% (range: 0-12.9%) on the right wall. On the ventral wall, the plaque fraction percentage was significantly greater than the remaining three arcs (P=.000). CONCLUSIONS: Basilar artery atherosclerotic plaques were mainly distributed at the ventral site of the artery. High-resolution MR examination may provide helpful information to minimize endovascular therapy risk complications in basilar artery atherosclerotic disease.

Pleomorphic xanthoastrocytoma in the lateral ventricle with extensive subarachnoid dissemination: report of a case and review of the literature.

Pleomorphic xanthoastrocytoma (PXA) is a rare benign tumor that is usually located in the superficial cerebral hemisphere. Most reports of PXAs have included only a single case or small series. Therefore, the data with respect to the natural history of this tumor are fragmentary. We report a case of a PXA in the unusual location of the right lateral ventricle with extensive subarachnoid dissemination. To our knowledge, this is a rare case of PXA in the lateral ventricle. In addition, extensive subarachnoid space dissemination of this distinctly benign type of glioma is exceedingly rare. In our case, there was meningeal dissemination and metastases to the bilateral trigeminal nerves and oculomotor nerves. The neuroradiographic features, tumor location, and dissemination were reviewed.