Bone marrow infiltration in patients with acute leukemia: dynamic contrast-enhanced MRI and its cfinicai significance

Abstract

Objective Using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) to evaluate the hemodynamic perfusion characteristics of bone marrow infiltration in patients with acute leukemia (AL). Methods Forty-seven patients with AL received coronal pelvic T1WI DCE-MRI with fast low angle shot (FLASH) sequence. Among them, 25 were initial onset untreated (IOU) patients, 22 were treated AL patients, including 14 with complete remission (CR) and 8 with non-remission ( NR). The hemodynamic perfusion parameters including maximum percentage of enhancement ( Emax ) and slope were determined based on enhancement-time curves ( ETCs ) of iliac and lumbar vertebra. The proportion of marrow myeloblasts was recorded. For all patients, quantitative perfusion parameters of bone marrow infiltration in ilium were compared with those in lumbar. The values of Emax and ES were compared among IOU,CR and NR patients. Correlations between perfusion parameters and histopathological results were assessed. Results In all the 47 patients, the Emax values of bilateral iliac bone marrow ( 15.70 ± 7.06)were slightly higher than that of lumbar bone marrow ( 11. 28 ± 5.52 ), and the difference was statistically significant (P ＜0. 01 ). There was no significant difference in the slop value between bilateral iliac bone marrow (0. 82 ± 0. 12 ) and lumbar bone marrow (0. 80 ± 0. 09 ) ( P ＞ 0. 05 ). In the 25 untreated patients,the Emax and slop values were 17. 15 ± 5.75 and 0. 98 ± 0. 13, respectively; in the 14 CR patients, they were 8. 76 ±3.93 and 0. 26 ± 0. 04, respectively, and in the 8 NR patients, they were 21.62 ± 6. 50 and 1. 38 ± 0. 02, respectively. There was significant difference in the Emax and slop values among the three groups (P＜0. 05). Compared with IOU and NR patients, both the Emax and slop values decreased significantly in iliac bone marrow of AL patients with CR (P ＜ 0. 05 ). There was no significant difference between IOU and NR patients ( P ＞ 0. 05 ). A significant positive correlation was found between Emax value of iliac bone marrow and the proportion of marrow myeloblasts ( r ＝0. 501 ,P ＜0. 05 ). There was a negative correlation between slop value of iliac bone marrow and the proportion of marrow myeloblasts ( r ＝0. 235 ,P ＞0.05). ConclusionsDCE-MRI can be used for evaluating the hemedynamic characteristics of microcirculation of bone marrow infiltration in patients with AL, which can provide useful information in evaluating prognosis and monitoring therapeutic effect. Key words: Acute leukemia; Bone marrow; Infiltration; Dynamic contrast enhancement; Magnetic resonance imaging