Table 1.

Distribution of prominent cortical and medullary veins

		Prominent medullary vein (grade)				Total
		0	1	2	3
Prominent cortical vein (grade)	0	168	9	1	0	178
	1	14	1	2	0	17
	2	10	1	2	1	14
	3	1	0	1	2	4
Total		193	11	6	3	213