BACKGROUND:Maxillofacial bone three-dimensional(3D)printing technology has been widely used in clinical diagnosis and treatment,but the data source before performing maxillofacial bone 3D printing mainly comes from the CT scanning data.The lens,thyroid and other parts of the human body are extremely sensitive to X-rays;therefore,it is particularly important to effectively reduce the dose of CT radiation when acquiring the data source.OBJECTIVE:To explore the feasibility of low-dose CT technology in optimizing radiation dose for maxillofacial bone 3D printing.METHODS:The medical records of 65 patients who underwent maxillofacial bone 3D printing in the Department of Stomatology at the General Hospital of Northern Theater Command from March 2021 to December 2023 were retrospectively collected and categorized into a conventional CT-dose 3D printing group(conventional CT-dose,120 kVp,automated tube current modulation,n=32)and a low-CT-dose 3D printing group(low-CT-dose group,80 kVp,automated tube current modulation,n=33).The effective dose of radiation was calculated and compared between the two groups.A Likert scale was used to evaluate the quality of 3D printing in the two groups,and the measurement bias and consistency between evaluators were measured using the Bland-Altman method.RESULTS AND CONCLUSION:(1)There was no significant difference in the general demographic characteristics(age,height,weight,body mass,sex,and body mass index)between the two groups(all P＞0.05).(2)The effective dose value of the low CT-dose 3D printing group was(0.3±0.1)mSv,which was about 62.5％lower than that in the conventional CT-dose 3D printing group[(0.8±0.1)mSv].(3)There was no significant difference in the subjective scoring of 3D printing quality between the two groups(all P＞0.05).The subjective consistency among evaluators was good,with Kappa values of 0.85,0.80,and 0.76.The scatter points in the Bland-Altman for both protocols were uniformly distributed within the standard deviation line,indicating good consistency between the two groups.To conclude,low-dose CT technology can be effectively applied in maxillofacial bone 3D printing,reducing radiation dose without affecting the quality of 3D printing.

BACKGROUND:Maxillofacial bone three-dimensional(3D)printing technology has been widely used in clinical diagnosis and treatment,but the data source before performing maxillofacial bone 3D printing mainly comes from the CT scanning data.The lens,thyroid and other parts of the human body are extremely sensitive to X-rays;therefore,it is particularly important to effectively reduce the dose of CT radiation when acquiring the data source.OBJECTIVE:To explore the feasibility of low-dose CT technology in optimizing radiation dose for maxillofacial bone 3D printing.METHODS:The medical records of 65 patients who underwent maxillofacial bone 3D printing in the Department of Stomatology at the General Hospital of Northern Theater Command from March 2021 to December 2023 were retrospectively collected and categorized into a conventional CT-dose 3D printing group(conventional CT-dose,120 kVp,automated tube current modulation,n=32)and a low-CT-dose 3D printing group(low-CT-dose group,80 kVp,automated tube current modulation,n=33).The effective dose of radiation was calculated and compared between the two groups.A Likert scale was used to evaluate the quality of 3D printing in the two groups,and the measurement bias and consistency between evaluators were measured using the Bland-Altman method.RESULTS AND CONCLUSION:(1)There was no significant difference in the general demographic characteristics(age,height,weight,body mass,sex,and body mass index)between the two groups(all P＞0.05).(2)The effective dose value of the low CT-dose 3D printing group was(0.3±0.1)mSv,which was about 62.5％lower than that in the conventional CT-dose 3D printing group[(0.8±0.1)mSv].(3)There was no significant difference in the subjective scoring of 3D printing quality between the two groups(all P＞0.05).The subjective consistency among evaluators was good,with Kappa values of 0.85,0.80,and 0.76.The scatter points in the Bland-Altman for both protocols were uniformly distributed within the standard deviation line,indicating good consistency between the two groups.To conclude,low-dose CT technology can be effectively applied in maxillofacial bone 3D printing,reducing radiation dose without affecting the quality of 3D printing.

Hepatic fibrosis （HF） is a pathological process of abnormal repair of liver tissue structure caused by chronic liver injury， and its pathogenesis has not been fully clarified. Related studies have shown that programmed cell death may be associated with the onset of HF， and traditional Chinese medicine （TCM） has a significant effect in regulating programmed cell death to intervene against HF. This article reviews the main mechanism of the influence of programmed cell death on HF and discusses the possible mechanism of TCM regulation of programmed cell death in improving HF， which provides new ideas for TCM prevention and treatment of HF.

Objective To investigate the value of MR on diagnosis of intracranial primary lymphoma in immunocompetent patients.Methods The MR features of 28 cases with pathology proved intracranial primary lymphoma were analyzed retrospectively.Conventional MRI scans,enhanced MRI scan were observed.Immunohistochemical staining were done and the results were compared with the MR imaging signs. Results Twenty-eight cases were all B-cell type Non-Hodgkin's lymphoma,16 cases were single lesion (57%)and 12 cases were multiple lesions (43%).The tumors mainly located in the deep white matter,7 cases in callus corpus and grew crossing the midline supratentorial.The lesions presented mass or node (20/28),11 cases showed massive edema.On T1WI,lesions were mostly hypo-or iso-intense to gray matter.On T2WI,tumors showed iso-or hyper-intense.All lesions presented hyper-or iso-to hyper-intense on diffusion weighted imaging(DWI).Most lesions show marked mass-like or nodular-like contrast enhancement on MR imaging,8 cases presented"incision sign",5 cases showed"fist sign"and 7 cases showed"butterfly-like".Immunohistochemical staining showed that GFAP(-) was 78.6% (22/28),as well as CD20 (+)96.4% (27/28),CD79α(+)67.9% (19/28),CD10(+)10.7% (3/28),Bcl-6 (+)75% (21/28),Mum1 (+)89.3% (25/28).Ki-67 was greater than or equal to 50% (22/28).Among the 28 patients,25 cases (89.3%) showed an"activated non-germinal center B-cell(non-GCB)"in origin and 3 cases(10.7%)were considered as a"GCB"subset.Conclusion The imaging features of marked mass-kike or nodular-like on MRI enhancement scan and hyper-or iso-to hyper-intense on DWI are helpful in the diagnosis and the differential diagnosis of intracranial primary lymphoma.