Dynamic Contrast Enhanced Magnetic Resonance Imaging of Diffuse Spinal Bone Marrow Infiltration in Patients with Hematological Malignancies

OBJECTIVE To investigate the significance of the dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) parameters of diffuse spinal bone marrow infiltration in patients with hematological malignancies. MATERIALS AND METHODS Dynamic gadolinium-enhanced MR imaging of the lumbar spine was performed in 26 patients with histologically proven diffuse bone marrow infiltration, including multiple myeloma (n = 6), acute lymphoblastic leukemia (n = 6), acute myeloid leukemia (n = 5), chronic myeloid leukemia (n = 7), and non-Hodgkin lymphoma (n = 2). Twenty subjects whose spinal MRI was normal, made up the control group. Peak enhancement percentage (E(max)), enhancement slope (ES), and time to peak (TTP) were determined from a time-intensity curve (TIC) of lumbar vertebral bone marrow. A comparison between baseline and follow-up MR images and its histological correlation were evaluated in 10 patients. The infiltration grade of hematopoietic marrow with plasma cells was evaluated by a histological assessment of bone marrow. RESULTS Differences in E(max), ES, and TTP values between the control group and the patients with diffuse bone marrow infiltration were significant (t = -11.51, -9.81 and 3.91, respectively, p < 0.01). E(max), ES, and TTP values were significantly different between bone marrow infiltration groups Grade 1 and Grade 2 (Z = -2.72, -2.24 and -2.89 respectively, p < 0.05). E(max), ES and TTP values were not significantly different between bone marrow infiltration groups Grade 2 and Grade 3 (Z = -1.57, -1.82 and -1.58 respectively, p > 0.05). A positive correlation was found between E(max), ES values and the histological grade of bone marrow infiltration (r = 0.86 and 0.84 respectively, p < 0.01). A negative correlation was found between the TTP values and bone marrow infiltration histological grade (r = -0.54, p < 0.01). A decrease in the E(max) and ES values was observed with increased TTP values after treatment in all of the 10 patients who responded to treatment (t = -7.92, -4.55, and 5.12, respectively, p < 0.01). CONCLUSION DCE-MRI of spine can be a useful tool in detecting diffuse marrow infiltration of hematological malignancies, while its parameters including E(max), ES, and TTP can reflect the malignancies' histological grade.