Intracranial arterial calcification and ectasia in visual failure

Intracranial Carotid Calcification on Cranial Computed Tomography: Visual Scoring Methods, Semiautomated Scores, and Volume Measurements in Patients With Stroke

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Intracranial internal carotid artery calcification is associated with cerebrovascular risk factors and stroke, but few quantification methods are available. We tested the reliability of visual scoring, semiautomated Agatston score, and calcium volume measurement in patients with recent stroke.

Intracranial Calcifications

Brain calcifications are a common radiographic finding. The pathogenesis is diverse and ranges from benign physiological calcifications to a variety of pathological disorders. Whereas certain calcifications are considered an incidental finding, their presence can sometimes be crucial in making a specific diagnosis. Several pathological conditions affecting the brain parenchyma are associated with calcifications and their recognition and location might help in narrowing the differential. Knowledge of physiological calcifications is essential to avoid misinterpretation. This review illustrates a broad spectrum of CNS disorders associated with calcifications, and tries to highlight the salient radiological findings.

[Clinical and pathological significance of carotid siphon calcification observed on bone condition of brain CT]

PURPOSE

On plain brain computed tomography (CT), it is difficult to evaluate stenosis of internal carotid artery (ICA) because ICA is surrounded by structures, even though we can observe calcification of carotid siphon in some patients by using bone condition. However the pathologic significance has not been well known. We studied the pathologic significance of carotid siphon calcification observed on bone condition of brain CT.

METHODS

A total of 112 patients who were diagnosed or suspected as cerebrovascular diseases were registered. We classified the calcification into four levels (none, mild, moderate, severe) based on the degree of calcification. Then we compared it with the degree of stenosis of carotid siphon seen on brain magnetic resonance angiography (MRA) and with max intima-medial thickness (IMT) from common carotid artery (CCA) to ICA on carotid ultrasonography.

RESULT

The mean +/- standard deviation of max IMT to none, mild, moderate and severe in the degree of calcification were 1.03 +/- 0.64 (0.4-2.8), 1.65 +/- 0.83 (0.5-4.1), 2.03 +/- 0.83 (0.8-4.1) and 2.81 +/- 1.15 (0.7-6.5) mm, respectively. The calcification on brain CT significantly correlated with the degree of stenosis on brain MRA and with max IMT on carotid ultrasonography.

CONCLUSION

The calcification of carotid siphon on bone condition of brain CT correlated with stenosis of the same portion and atherosclerosis of CCA bifurcation. Recently, on DICOM viewer, clinicians can convert plain condition into bone condition on brain CT due to popularization of PACS. We should pay attention to calcification of carotid siphon in patients with ischemic cerebrovascular diseases because we can estimate the atherosclerosis of both carotid siphon and CCA bifurcation easily and immediately.

Incidental internal carotid artery calcifications on temporal bone CT in children

BACKGROUND

Incidental internal carotid artery (ICA) calcifications are occasionally noted on CT images of the brain and temporal bone. In adults, incidental calcifications have been correlated with increased incidence of hypercholesterolemia, cardiac disease, diabetes and carotid stenosis.

OBJECTIVE

To determine the incidence of incidental calcifications of the carotid siphon on temporal bone CT in children.

MATERIALS AND METHODS

We retrospectively reviewed 24 months of consecutive temporal bone CT examinations in children aged 18 years and younger. CT examinations on 663 patients were reviewed and the presence or absence of ICA calcifications was ranked as absent, questionable or definitive. In patients in whom definitive calcifications were identified, hospital charts were reviewed for evidence of diabetes mellitus, hypercholesterolemia, hypertriglyceridemia, hyperlipidemia and chronic renal disease as potential causes of early atherosclerosis.

RESULTS

Of the 663 patients, 25% had definitive calcifications within the wall of the ICA: 6% of children younger than 2 years and 28% of children 12-19 years of age.

CONCLUSIONS

Incidentally noted ICA calcifications are a common finding on temporal bone CT in children, most likely a physiologic response to turbulent flow at natural bends in the artery rather than secondary to underlying disease predisposing to early atherosclerotic calcification.

Clinical Implication of Cerebral Artery Calcification on Brain CT

BACKGROUND AND PURPOSE

Arterial calcification is a process of atherosclerosis, usually taking place within advanced atheromatous plaque. In the coronary arteries, calcification seen on computed tomography (CT) often indicates severe stenosis, and is noted in almost all patients with coronary symptoms. Calcification of the cerebral arteries is also frequently observed on brain CT, but its clinical significance has yet to be clarified. To evaluate the clinical significance of cerebral arterial calcification on brain CT, we investigated the angiographic and transcranial Doppler ultrasonography (TCD) findings of calcified cerebral arteries.

METHODS

The subjects were 57 patients with ischemic stroke, all of whom underwent brain CT, digital subtraction cerebral angiography and TCD. Stroke subtypes were defined according to TOAST classification. Two clinicians who were blinded in respect to the patients' clinical history and to each other's interpretation, determined the presence of cerebral arterial calcification and the degree of angiographic stenosis.

RESULTS

Cerebral artery calcification was noted in 23 patients (40%) out of a total of 46 arteries, consisting of 23 internal carotid, 15 vertebral, 5 basilar, 2 middle cerebral and 1 anterior cerebral artery. The patients with calcification were significantly older and more hypertensive than those without calcification. All the patients with calcification showed either large artery atherosclerosis or lacunar stroke. Hemodynamic alterations measured by TCD were rarely observed in calcified arteries. The severity and extent of the atherosclerotic changes were significantly greater in the patients with calcification than those without calcification.

CONCLUSION

These results suggest that cerebral arterial calcification does not directly indicate hemodynamically significant atherosclerotic stenosis involving calcified segments, but indicates the underlying etiology of either large artery atherosclerosis or lacunar stroke, and raises the possibility of a diffuse atherosclerotic process being present in the cerebral circulation.

Intracranial vascular calcifications mimicking small saccular aneurysms on CT angiography: a technical note and case description

The authors describe a case of intracranial vascular calcifications that mimicked small saccular aneurysms on CT angiography (CTA). The density of two vascular calcifications was visually similar to that of contrast in the parent vessel, making them indistinguishable from aneurysmal outpouchings. Comparison of the CTA with the non-contrast head CT (NCCT) was critical to distinguish low-density calcifications from tiny aneurysms.

Spots before the eyes: a prevalence and clinicoradiological study of senile scleral plaques

AIMS

To investigate the prevalence and clinical associations of senile scleral plaques.

METHODS

Unselected, consecutive computed tomographic (CT) images of elderly people were reviewed for the presence of calcification indicating senile scleral plaques.

RESULTS

No definite calcification was seen in 100 men or 100 women aged 60-69 years; equivocal changes were seen in one woman. There were three definite examples and one equivocal case of calcification in 100 women and four definite cases in 100 men aged 70-79 years. However, in a group of 71 men and women patients aged 80 years or more, 16 definite cases were seen, indicating a prevalence of 22%.

CONCLUSIONS

Apart from advanced age, and a mild association with the extent of calcification of the carotid siphon, no clinical or radiological features were identified which consistently characterized a total of 28 patients with this form of ocular calcification; an association with cataract probably reflected simply the recruitment base. Scleral plaques would appear to be a degenerative phenomenon without clinical significance, most likely to be detected in patients presenting with unrelated ophthalmological complaints.