The generator matrix

 1  0  0  0  1  1  1  1  2  1  2  2  2  1  1  1  1  1  1  1  0  0  2  1
 0  1  0  0  0  1  0  1  1  2  1  1  0  2  3  1  3  1  2  3  1  1  2  1
 0  0  1  0  1  1  0  0  3  1  0  1  1  2  1  0  3  0  2  2  0  2  1  0
 0  0  0  1  1  0  1  1  1  2  3  0  1  2  3  0  1  1  2  1  3  2  1  3
 0  0  0  0  2  0  0  2  0  2  0  2  2  2  2  2  0  0  2  2  2  0  2  0
 0  0  0  0  0  2  0  2  2  0  2  0  2  2  2  0  0  2  2  2  0  0  0  2
 0  0  0  0  0  0  2  0  0  2  2  2  2  0  2  0  0  2  2  2  0  2  2  0

generates a code of length 24 over Z4 who´s minimum homogenous weight is 18.

Homogenous weight enumerator: w(x)=1x^0+144x^18+302x^20+369x^22+425x^24+389x^26+269x^28+115x^30+26x^32+7x^34+1x^36

The gray image is a code over GF(2) with n=48, k=11 and d=18.
This code was found by Heurico 1.16 in 4.03 seconds.