Objective: To investigate the imaging features of adult bones Langerhans cell histiocytosis (LCH). Methods: The DR, CT, and MRI findings of 25 adults patients with LCH from January 2008 to June 2019 in Yueqing Sixth People′s Hospital of Zhejiang Province (3 cases), Yueqing Third People′s Hospital of Zhejiang Province (7 cases) and Wenzhou People′s Hospital of Zhejiang Province (15 cases) were retrospectively analyzed. Results: Among the 25 patients, the lesions located in the skull in 5 cases, in the spine in 5 cases, in the long bones in 10 cases, in the other flat bones in 3 cases, and in multiple bones in 2 cases. DR features (17 cases) showed: cystic destruction in 11 cases (6 cases with dilated changes), osteolytic damage in 6 cases; peripheral bone cortex thickening in 5 cases, bone lesions with less smooth inner edge in 4 cases, soft tissue mass around the lesion in 12 cases; 'hole set cave sign' in 2 cases, 'flat vertebra' in 2 cases, and 'button-like dead bone' in 1 case. CT features (15 cases) showed: cystic destruction in 9 cases (5 cases with dilated changes), osteolytic damage in 6 cases; 'hole set cave sign' in 2 cases, 'flat vertebra' in 2 cases, and 'button-like dead bone' in 1 case. MRI features (14 cases) showed: cystic destruction in 9 cases (5 cases with dilated changes), osteolytic damage in 5 cases; in the bone destruction area, 8 cases had low T₁WI signal and high T₂WI signal, 4 cases had equal T₁WI signal and higher mixed T₂WI signal, 2 cases had slightly higher T₁WI signal and higher mixed T₂WI signal; STIR lipoprotein sequence showed high signal in 11 cases, and isointense signal in 3 cases; DWI showed high signal. Conclusions The imaging performance of adults LCH has certain characteristics, and the diagnostic accuracy can be improved according to the imaging performance and the clinic.

OBJECTIVE: To compare 3 commonly used methods for drug delivery via the lumbar spinal subarachnoid space in rats. METHODS: We compared the effects of 3 methods for drug delivery via the lumbar spinal subarachnoid space in Sprague Dawley rats, namely acute needle puncture, chronic catheterization via laminectomy, and non-laminectomized catheterization. Body weight changes of the rats were measured, and their general and neurological conditions were assessed after the surgeries. The motor function of the rats was examined using rota rod test both before and after the surgeries. Nociceptive tests were performed to assess nociception of the rats. HE staining was used to examine local inflammation caused by the surgeries in the lumbar spinal cord tissue, and lidocaine paralysis detection and toluidine blue dye assay were used to confirm the precision of drug delivery using the 3 methods. RESULTS: Both needle puncture and catheterization via laminectomy resulted in a relatively low success rate of surgery and caused neurological abnormalities, severe motor dysfunction, hyperalgesia, allodynia and local inflammation. Catheterization without laminectomy had the highest success rate of surgery, and induced only mild agitation, slight cerebral spinal fluid leakage, mild sensory and motor abnormalities, and minimum pathology in the lumbar spinal cord. Catheterization without laminectomy produced less detectable effects on the behaviors in the rats and was well tolerated compared to the other two methods with also higher precision of drug delivery. CONCLUSIONS Catheterization without laminectomy is a safe, accurate and effective approach to lumbar drug delivery in rats.