engleski

OPHTHALMIC COLOR FLOW IMAGING IN DETECTION OF CAROTID STENOSIS OR OCCLUSION

Background and purpose: In order to examine the influences of internal carotid artery (ICA) stenosis on ophthalmic artery (OA) flow, we investigated patients with ICA occlusive disease by means of carotid and ophthalmic color Doppler flow imaging (CDFI). Patients and methods: We investigated 48 consecutive patients with ICA stenosis by means of carotid and ophthalmic CDFI. The degree of ICA stenosis was classified as no or mild, moderate, severe and occlusion. OA were visualized, and angle corrected velocities were measured. Systolic, mean and diastolic blood flow velocities (BFV) were measured, pulsatility indexes (PI) and systolic/diastolic (S/D) velocity ratio were calculated, and flow direction was determined. Side to side asymmetry was determined as > 50% systolic BFV. Data were entered into the personal computer, and presented as means and SD. Cut-off criteria for OA disturbed flow were: retrograde flow or side to side asymmetry. Sensitivity (SE), specificity (SP), accurate diagnosis (AD), negative predictive values (NPV) and positive predictive value (PPV) of disturbed OA flow for detection of severe stenosis or occlusion was calculated. Results: The data of 48 patients, 96 ICA were analyzed. There were 23 no or mild, 18 moderate, 20 severe ICA stenosis and 10 ICA occlusion. Physiological symmetric flow was present in all no or mild ICA stenosis, 78% moderate, 50% severe and 20% ICA occlusion. Asymmetry but physiological flow direction was present in 11% moderate, 20% severe stenosis and 40% ICA occlusion. SE of OA disturbed flow to determine severe stenosis or occlusion was 64%, SP 92%, AD 74%, PPV 80%, NPV 84%. There were no changes of PI or S/D ratio among groups. Conclusion: OA CDFI is helpful in evaluation of severe carotid stenosis or occlusion, although not an independent criteria for its detection. Lower sensitivity of impaired OA flow was probably obtained due to the presence of other collateral pathways.

ophthalmic artery; ultrasound; carotid stenosis

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