Lebtahi N, Gudinchet F, Nenadov-Beck M, Beck D, Bischof Delaloye A
Department of Radiology, University Hospital, Lausanne, Switzerland.
J Nucl Med. 1997 Sep;38(9):1389-92.
Of 10 patients with neuroblastoma who had both 123I-MIBG scintigraphy and MRI at diagnosis, four presented with bone marrow metastasis that was diagnosed by both imaging modalities and confirmed by bone marrow biopsy and smears. This report focuses on the follow up of the four patients with bone marrow metastasis. MIBG scintigraphy and MRI were concordant in two patients, a case of normalization and a case of relapse in the seventh dorsal vertebra confirmed by surgical biopsy. The last two patients presented a normalized MIBG scan for marrow infiltration after chemotherapy but persistent abnormal MRI signal of several vertebrae, suggesting marrow infiltration, up to 27 mo after the end of chemotherapy in one case. In the second patient, MRI bone marrow aspect returned to normal 4 mo after the end of chemotherapy. Bone marrow biopsy remained negative in these two MIBG-negative patients. These cases suggest that in presence of complete normalization of the MIBG scan after chemotherapy, the persistence of a hypointense signal on bone marrow on T1WI does not necessarily indicate persistence of disease but may be due to delayed normalization. Therefore, attention must be paid to the delay of signal normalization on MRI (which can be as long as more than 2 yr after the end of chemotherapy) in order to avoid false-positive interpretation.
在10例诊断时同时接受了123I-MIBG闪烁扫描和MRI检查的神经母细胞瘤患者中，4例出现骨髓转移，两种影像学检查均诊断出骨髓转移，并经骨髓活检和涂片证实。本报告重点关注这4例骨髓转移患者的随访情况。MIBG闪烁扫描和MRI在2例患者中结果一致，1例为正常化，1例经手术活检证实为第七胸椎复发。最后2例患者化疗后骨髓浸润的MIBG扫描结果正常化，但多个椎体的MRI信号持续异常，提示骨髓浸润，其中1例在化疗结束后长达27个月仍如此。在第二例患者中，化疗结束后4个月，MRI骨髓表现恢复正常。这2例MIBG阴性患者的骨髓活检结果均为阴性。这些病例表明，化疗后MIBG扫描完全正常化时，T1WI上骨髓低信号的持续存在不一定表明疾病持续存在，可能是由于信号正常化延迟。因此，必须注意MRI上信号正常化的延迟情况（化疗结束后可能长达2年以上），以避免假阳性解读。
