MR Proton Relaxivities of Some Ions, Albumin, and Cholesterol Added to Odontogenic Jaw Cysts

Abstract

The relaxation rates (1/T(1) and 1/T(2)) in cysts have already been analyzed in terms of materials such as albumin, cholesterol, manganese, iron, and copper. However, the relaxivities of these materials have not been determined yet. In this work, five sets containing the ions, albumin, and cholesterol were prepared by addition of increasing concentration of one material to each set. The relaxation times in these sets were measured by MRI, and the relaxation rates were fitted versus concentrations. The slopes of the fits were used as relaxivities. The (r(1), r(2)) values of manganese, iron, and copper in mM(-1) s(-1), and those of albumin and cholesterol in (g/dl)(-1) s(-1) were found to be (32.64, 89.77), (0.31, 1.19), (0.5, 1.479), (0.01, 0.066) and (0.03, 0.458), respectively. The r(2)/r(1) ratio ranged from 2.75 to 15.27. Manganese is an efficient relaxer, but iron and copper are poor ones. Albumin and cholesterol are efficient relaxers for only T(2). The contribution of water associated with native manganese of the cystic fluid to T(1) was 0.268 s(-1), whereas those of water associated with native manganese, albumin, cholesterol, and iron to T(2) were 0.736, 0.185, 0.092, and 0.076 s(-1), respectively. The other contributions were much smaller than 0.076 s(-1). Manganese is most likely the compound altering T(1)-weighted images between different jaw cysts, whereas manganese and albumin are most likely the compounds altering the T(2)-weighted images. Present data suggest that such alterations may be used to separate jaw cysts from other jaw masses. The high r(2)/r(1) suggests that T(2) is a more convenient parameter than T(1) for diagnostic use.

Total Relaxivities of Material Content in Various Cysts and Ameloblastoma: Implications for Discriminating Different Fluids

“…The MC is determined by weighing a certain amount of the sample before and after drying it at 120°C for 10 h. Table 1. The (r 1 , r 2 ) of iron and copper in hemorrhagic cysts are on the order of those in odontogenic cysts [15]. Higher r 2 relaxivity of γ-globulin in the cyst is consistent with that in serum [4].…”

“…The collection of samples, classification of cysts, preparation of phantoms, determination of concentrations of individual cystic materials, and nuclear MR measurements were made as those in previous works [15,20]. In order to provide a clear understanding, all details are repeated here.…”

“…The relaxation rates of water in a fluid are altered by water bound to individual solids or water in hydration sphere of paramagnetic ions [3,4,[15][16][17]. For this reason, effective paramagnetic ions (iron and copper) and main hydrated components of total protein (albumin and γ-globulin) were selected for determination of individual relaxivities.…”

“…The T 1 and T 2 relaxivities (r 1 and r 2 ) of effective paramagnetic ions and hydrated solids, existing naturally in cysts, have been determined for odontogenic cyst [15]. Manganese, iron, copper, and albumin were found to be major components of the total T 1 and T 2 relaxivities (r 1t and r 2t ) of cystic fluid content in odontogenic cysts.…”

“…Manganese, iron, copper, and albumin were found to be major components of the total T 1 and T 2 relaxivities (r 1t and r 2t ) of cystic fluid content in odontogenic cysts. Since manganese is the most effective relaxer in various fluids (water, serum, blood, and odontogenic cysts), there is no doubt on the high relaxivity of manganese in hemorrhagic cysts [3,[15][16][17]. However, the relaxivities of iron, copper, albumin, and γ-globulins may change for hemorrhagic cysts since hemorrhagic cysts contain red blood cells.…”