In fact for the mixed stone group the two methods were in agreement only in 3/19 (15.8%), in partial agreement in 4/19 (21.0%), and in disagreement in 12/19 (63.2%) cases.
On the basis of FT-IR analysis, the 48 calculi were divided into three groups: pure stone, mixed stone, and pure stone with substances in trace.
Tables 4 and 5 show that also results relative to mixed stone and pure stone with substances in trace groups were characterized by a general disagreement.
On the basis of FT-IR analysis, the 48 calculi were divided into three groups: pure stone (n = 23), mixed stone (n = 19), and pure stone with substances in trace (n = 6).
In Western countries, cholesterol gallstones predominate, whereas pigment and mixed stone are more common in Asia [ 8].
Each stone grouping features a tall capped, stone post topped by a large cut metal pictorial sign.
Gallstones are classified as cholesterol, pigment, or mixed stones [ 7] based on whether the stones consist primarily of cholesterol, bilirubin, or calcium deposits.
In black pigment stone group, stone cholestanol/cholesterol was associated with serum bile acids (r = 0.620, p = 0.018).
Moreover, there are significant differences on identification of substances present in trace in mixed stones, in fact FT-IR technique shows a high sensitivity and allows an accurate identification of stone composition.
Black pigment stone group was characterized by deteriorated cholesterol metabolism, and accumulation of cholestanol, campesterol and sitosterol in serum and stones suggesting their participation in pathogenesis.
