Magnetic resonance relaxation times of percutaneously obtained normal and abnormal body fluids

Seventy-three fluid samples obtained via percutaneous aspiration and drainage were analyzed by proton magnetic resonance spectroscopy. The fluids included abscess contents, bile, ascitic fluid, cyst and pseudocyst fluid, urine, hematomas, pleural fluid, lymphoceles, seromas, cerebrospinal fluid, pancreatic ductal fluid, and necrotic tumor. They were grouped by their clinical etiology and analyzed with respect to their inherent magnetic relaxation properties. In addition, some of the samples were tested for the following chemical parameters which were correlated with T1 and T2 values: total protein content (n = 36), osmolality (n = 24), specific gravity (n = 11), and amylase levels (n = 23). A large overlap was found in the T1 (spin-lattice) and T2 (spin-spin) relaxation times of the fluids; however, the mean T1 values of abscesses and hematomas were significantly lower than those of other fluids. Similar variability was seen in T2 values, though hematomas and abscesses again could be distinguished by shorter relaxation times. The spin-lattice (1/T1) and spin-spin relaxation rates (1/T2) showed a moderate correlation with total protein content, osmolality, and specific gravity. It is concluded that there is some predictability to MR analysis of body fluids, though the overlap in magnetic relaxation times limits specificity.