In the load capacity test of CT diagnosis table top, by analyzing the easy destroy area and related test data for the table top, using a simple mechanical auxiliary support structure in local area of the table top to solve the insufficient loading strength problem of table top and obtain significant results during the actual product usage.
Tomography, X-Ray Computed ; instrumentation ; methods

This article describes a phantom holder in CT couch which adjusted easily and accurately, installed easily. The holder mainly include removing and locking equipment between phantom holder and table top, move horizontally equipment between left and right, rotating equipment between left and right. After holder and table top fixed one part, holder with phantom can move horizontally, front and back, rotate between left and right in a small angle, in order to make operator test phantoms accurately and easily. At the same time, this phantom holder realized free adjustment after first adjustments, which shortened operator work time.
Equipment Design ; Tomography, X-Ray Computed ; instrumentation

Through the CT Table dynamic simulation by COSMOS Motion, analysis the hinge of table and the motor force, then optimize the position of the hinge of table, provide the evidence of selecting bearing and motor, meanwhile enhance the design quality of the CT table and reduce the product design cost.
Equipment Design ; Tomography, X-Ray Computed ; instrumentation

To assure the clinical quality and requirement of CT shelter used in field environment, the factors related with the practical application were studied. The evaluation indicators of CT equipment were investigated. Based on the technical modification of vehicle shelter CT, the scanning conditions of shelter CT were analyzed. Moreover, the comparative study was done between shelter CT and common CT in hospitals. In result, in order to meet maneuverability application in the field, vehicle shelter CT was restrictive by the field conditions, traffic impacts and running requirement. The application of vehicle shelter CT was affected by the factors, such as mechanical stabilization, moving precision, power fluctuations and variations of temperature and humidity, etc. The results were helpful to improve the clinical quality of vehicle shelter CT and made a base for the quality control study in the future.
Humidity ; Temperature ; Tomography, X-Ray Computed ; instrumentation

Taking a typical-structure CT patient table as an example, methods of CAE applications to its design are introduced in detail in this paper, and theoretical analysis for the design result is made. This has provided a precise, efficient and reliable method for CT patient tables' mechanical designing.
Equipment Design ; Tomography, X-Ray Computed ; instrumentation

After the analysis of the service and maintenance technology of CT equipment under the existing technical condition we conclude that although the CT equipment malfunctions vary with different manufacturer, they are predictable and preventable, based on the identical CT principle and similar construction of system.
Equipment Failure ; Tomography, X-Ray Computed ; instrumentation

Existence of rays with different decay rate between radiotherapy CT bed and radiotherapy bed, this paper discusses the rate induced and identified two kinds of simple solution.
Equipment Failure ; Radiotherapy ; instrumentation ; Tomography, X-Ray Computed ; instrumentation

A non-invasive detecting and analyzing method which used to monitor the working condition of rotating anode X-ray was proposed. Based on the NI development environment, accelerometer, 24-bit high resolution data acquisition card and personal computer were connected to construct the system for collecting the vibration signal of X-ray tube. Results demonstrate that the system could acquire and store the vibration data of X-ray tube quickly and efficiently. The characteristics of vibration, were extracted and processed, which proposed a new approach to detect the malfunction of rotating anode X-ray early and effectively.
Equipment Design ; Software ; Tomography, X-Ray Computed ; instrumentation ; methods ; Vibration

OBJECTIVEIn order to reduce patients' radiation doses and decrease the exposure time of the CT Tube. By summarizing experiential methods from the previous practice work, we hope to draw an optimized scheme of CT scanner.

METHODSWe analyzed the continuous clinical examples in four months, changed the different levels of parameters slowly, optimized acquisition conditions and retrospected the CT radiative dose. In the meantime, we counted the monthly CT Bulb exposure time, exposure time per capita tube data and so on.

RESULTSCompared with former result, the average CT radiative dose per person is decreased 84.72%, which conventional bone, the small joints of the bone, the brain and the heart radiation reduced respectively 83.82%, 88.80%, 86.78% and 84.49%, and the differences are statistically significant. The exposure time of optimized CT Tube is 2 031 s.

CONCLUSIONSUsing the CT scan optimization scheming has great efforts in the practice of clinical nuclear medicine, can reduce the exposure time of the CT Tube and improve the lifetime of the bulb. Therefore, it can be widely used.

OBJECTIVETo explore the dose-length product calibration method for pencil ionization chamber in cobalt beams.

METHODSThe PTW TM30009 ionization chamber was placed into the central hole of T40017 head phantom and irradiated 60 s in 20 cm x 20 cm cobalt beam. The charge was collected with UNIDOS electrometer. Absorbed doses were measured with TM30013 0.6 mL farmer-type chamber under the same condition. The CT chamber calibration factor was expressed in dose-length product. Dose linearity and spatial response were also investigated.

RESULTSThe calibration factor in dose-length product was derived from measured data. Dose linearity and spatial response were good in cobalt beams.

CONCLUSIONIt is feasible to calibrate the CT chamber in cobalt beams for patient dose evaluation in MVCT.