ObjectiveTo study the CT values of certain phantoms scanned by various CT scanners with dissimilar parameters.Methods The CT values of tissue equivalent inserts was measured in the TM164 and CIRS-062 phantom scanned by TOSHIBA AQUILIONTM,SIEMENS SOMATOMTMSENSATIONTM 64 and SIEMENS SOMATOMTM SENSATIONTM OPEN with different voltages,currents and slice thicknesses and then the corresponding CT-to-density curves was compared. Results There are no significant differences of CT values with various currents and slice thicknesses and also for low atom number materials scanned by different scanners with various tube voltages.The CT values of high atom number materials have obvious differences scanned with tube voltage,the maximum is about 400 HU.There are also significant differences between CT-density curves of two phantoms in the range from soft tissues to dense bone,the maximum is up to 500 HU.ConclusionsCT-density curves were highly affected by materials of phantoms,scanners and tube voltages.It is necessary to measure the curve with a comfortable phantom and certain scanner to assure the accuracy for dose calculation for treatment planning system.

Objective:To analyze the characteristics of eyes with congenital optic disc pits (ODPs) through multimodal imaging.Methods:A cross-sectional study was conducted.Thirty-eight patients (38 eyes) diagnosed with congenital ODPs in the Second Hospital of Hebei Medical University from January 2009 to January 2020 were enrolled.A comprehensive summary analysis of the imaging results including fundus photography, spectral domain-optical coherence tomography (SD-OCT), infrared imaging, fundus autofluorescence (FAF), fluorescein fundus angiography (FFA) and indocyanine green angiography (ICGA) was performed.This study protocol adhered to the Declaration of Helsinki and was approved by an Ethics Committee of The Second Hospital of Hebei Medical University (No.2021-P011). Written informed consent was obtained from each subject prior to any medical examination.Results:Among the 38 eyes, there were 32 eyes with ODPs located in or below the temporal side of optic disc, 4 eyes with ODPs located above the temporal side of optic disc, and 2 eyes with ODPs located at the center of optic disc, which were round or quasi-circular pale depression, and dark red eminences with clear or unclear boundaries between milk spots were found in 29 eyes with optical-disc macular degeneration (ODP-M) by fundus photography.SD-OCT examination showed that the structure of lamina cribrosa in the lesion area in all ODPs patients was incomplete, which presented a dark area with no tissue reflection, and the fissure led to the deep optic nerve.Fluid was found in the outer nuclear layer in all ODP-M patients, and there were 27 eyes with fluid in the inner nuclear layer, 13 eyes in the ganglion cell layer, and 4 eyes under the inner limiting membrane.Among the 29 eyes with ODP-M, there were 21 eyes with retinoschisis in outer layer, 27 eyes with neuroepithelial detachment.In the 27 eyes with neuroepithelial detachment, spot-like high reflection and reduced or disappeared ellipsoid band reflectance were seen above the neuroepithelium in 18 eyes.In infrared images, there were circular or quasi-circular low-reflection areas in the temporal side of the optic disc, and the lesion of ODP-M eyes presented low-reflection areas.FAF examination showed that in 27 eyes with ODP-M, there was a hypofluorescent region at the posterior pole consistent with the lesion range, among which, there was a granular or sheet-like hyperfluorescence at the center of the hypofluorescent region in 18 eyes.FFA showed that the optic disc depression in the arterial phase of patients was in a localized hypofluorescence state.During the venous phase, fluorescein dye extravasation along the temporal side of the optic disc could be found.A strong fluorescent arc with unclear boundaries at the temporal edge of the optic disc was formed in the late stage of angiography.Among the 29 eyes with ODP-M, the area of the macular lesion showed hyperfluorescence during the late stage of angiography in 27 eyes with neuroepithelial detachment, and no extension of dye toward the macula was found.ICGA showed that the optic disc depression of ODPs patients presented a localized hypofluorescence, and the lesion showed hyperfluorescence in 27 of the 29 ODP-M eyes with neuroepithelial detachment.Conclusions:Multimodal imaging can be helpful to realize the early diagnosis, etiology analysis of ODPs and make treatment plan.

Toxoplasma gondii is an obligate intracellular parasite and causes serious harm to human and ani-mal health.In recent years,a large amount of research has been conducted on the immunological mechanism of toxo-plasmosis,especially in the immune privileged regions of the host,such as brain,eyes,and placenta.This review summaries the immunological mechanism required for resistance to toxoplasmosis,which may provide a valuable ref-erence for the diagnosis,treatment,and prevention studies.