Objective: To investigate the MRI findings of childhood granulocytic sarcoma (GS). Methods MRI data of 4 child patients with GS confirmed pathologically and immunohistochemistry were retrospectively analyzed. The location, size, morphology, signal characteristics, bone destruction and enhancement features of the tumor were observed. Results Among 4 patients, 3 cases were multiple, and 1 case was single. The lesion of 1 case was located in T3-T7 epidural intra-spinal canal and vertebral side, double side wall of maxillary sinus and sphenoid sinus, peri-orbit bone, of 1 case was located in L1-L2 epidural intra-spinal canal, of 1 case was located in T2-T4 and T10-T11 epidural intra-spinal canal, of 1 case was located in T11-T12 and L4-S2 level epidural intra-spinal canal, left side of the eye socket, sphenoid bone, and right side of the frontal sinus wall. Totally 4 cases were found soft tissue masses in the local or formed paravertebral lump through intervertebral foramen. The bone marrow signal of 3 cases was inhibited diffusely. MRI showed that T1WI signal slightly higher than normal surrounding muscles, while T2WI fat suppression showed slightly high signal intensity, and mild to moderate homogeneous enhancement. Two cases showed vertebral bone destruction, characterized by T1WI low signal obviously, T2WI fat suppression high signal obviously, and homogenous enhancement. Conclusion MRI features of GS of childhood have some characteristics, and they are helpful for diagnosis of GS.

Objective To evaluate the imaging characteristics of atypical teratoid/rhab doid tumor (AT/RT) of central nervous system(CNS), and to improve the diagnostic ability of the disease. Methods The clinical and imaging findings of 9 patients were retrospectively analyzed. There were 5 male and 4 female, ages 7 months to 5 years,median age was 1.4 years. MR enhancement studies were obtained in all the cases. One case had CT enhancement examination. Results The lesions were seen in brain in 8 cases and in lumbosacral spinal cord in one case. The tumors size varied from 4.8—7.8 cm, Necrosis was seen in nine cases, cystic change in eight cases and hemorrhage in five cases. The tumors had high signal on DWI, and low signal on ADC map. Dura matter invasion(2 cases), cerebrospinal fluid spread(2 cases)and intracerebral metastasis were seen. Conclusion There are some relatively specific imaging findings of primary CNS AT/RT that could assist their diagnosis.