Differentiating diffuse vertebral bone marrow infiltration from red marrow reconversion by chemical shift mr imaging

Three groups of patient who were underwent vertebral convansionel MR imaging and chemical shift MR ımagıng between January 2008- May 2010 were entered our study. Group one: patients with hematological malignancies who had diffuse vertebral infiltration; group two: patients with red bone marrow reconversion; group three: control group. This study performed retrospectivly.54 patients (32 women, 22 men) were entered into this study. The mean age of patients was 46. 6 and their age range was 20- 77. 17 patients in group one, 16 patients in group two and 21 patients in group three were studied.We assessed their chemical shift MR imaging and mesaured signal intensity on vertebral corpus bone marrow on in- phase and out-of phase imaging and calculated signal intesity ratio (SIR) on our Workstation. SIRs were calculated by the formula which was used in the past studies. SIRs were calculated as the ratio of signal intensity on out- of- phase images divided by the ratio of signal intensity on in-phase images. Our study showed statistically significant diffirence between SIRs? of hematologic malignancies and red bone marrow reconversion ( p< 0.001)The mean SIRs of hematologic malignancies was 0.97 ± 0.16, the mean SIRs of red bone marrow reconversion was 0.69 ± 0.31, the mean SIRs of control group was 0.28 ± 0.35 calculated.Receiver operating characteristic (ROC) curve analysis of the mean SIRs showed a ratio cut off value of 0.82 to differentiate the hematologic malignancies and red bone marrow reconversion. In ROC curve analysis AUC 0.828 ( %95), CI: 0.647 ? 0.989, p= 0.002 was evaluated.In group one (n: 17) 15 patients? SIRs were ? 0.82, in group two (n:16) 13 patients? SIRs were ? 0.82 and in group three (n: 24) all patients? SIRs were ? 0.82. At a cut off value of 0.82, the observed sensivity of chemical shift imaging was 83.3%, specificity was 87 %, negative predictive value was 81%, positive predictive value was 88%. Our results suggest that at a cut off value of 0.82, there is a statistically significant diffirence between SIRs? of hematologic malignancies and red bone marrow reconversion (p< 0.001).As a result; chemical shift MRI is useful in order to differentiate patients with hemotogic malignancies and red bone marrow reconversion.