A generalization of the atherosclerotic index and its application

A generalized atherosclerotic index with n types of lesions I(n) was defined in the form of an inner product of the profile vector alpha and the weight vector beta as: I(n) = 100 (alpha, beta), alpha = 1/A(alpha 0, alpha 1, ..., alpha n) and beta = 1/Wn(0, W1, ..., Wn), where A is the total area examined, alpha i(0 less than or equal to i less than or equal to n) is the area of the i-the type of lesion, the subscript 0 refers to the normal portion, and Wi is the weight to be given to the corresponding lesions, with only the restriction 0 less than or equal to W1 less than or equal to ... less than or equal to Wn. It was further extended to a composite, index of m arterial systems in matrix multiplication from as I(m,n) = 100 PQR, P and R being weight matrices and Q an observation matrix. As an example of its application, results obtained from our autopsy series were shown. In a total of 288 cases classified into four disease groups, the cerebral infarction group was highest in the severity of aortic atherosclerosis both in the customary index and in a modified index in which relatively small weight was given to the complicated lesion. The order of the other three groups was more clearly represented in the latter index than in the former.