title: [Measurement of carotid diastolic flow by ultrasonography using the Doppler effect, and its value in diagnosis (authors transl)].
abstract: Blood supply to the brain is related to carotid diastolic flow, which is a function of cardiac output and distal arterial resistance. It is used to calculate the resistance index (Ir) of Planiol and Pourcelot which enables quantitative measurement of distal circulatory resistance. The Ir is of no value in young subjects with satisfactory arterial compliance and in atheromatous subjects with flattened curves from loss of elasticity of the arterial walls. More precise information can be obtained by calculating the ratio of the areas under the curves. Diastolic flow may be reduced (Ir tending towards 1) or increased (Ir lower than normal) either uni- or bilaterally, with very different diagnostic significance. Unilateral flow reduction results from partial obstruction while bilateral reduction occurs during the course of general affections. Angiomas cause a unilateral increase in flow. Variations in the results of repeated examinations can also supply useful information.
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D001927:Brain Diseases / Q000175:diagnosis*; D001932:Brain Neoplasms / Q000134:cerebrospinal fluid / Q000175:diagnosis; D002339:Carotid Arteries; D002560:Cerebrovascular Circulation; D002561:Cerebrovascular Disorders / Q000175:diagnosis; D003971:Diastole; D006801:Humans; D007427:Intracranial Pressure; D008875:Middle Aged; D008881:Migraine Disorders / Q000175:diagnosis; D014463:Ultrasonography; D014655:Vascular Resistance
vernacular_title: Le flux diastolique carotidien en ultrasonographie par effet Doppler moyens d'étude et valeur sémiologique.