Selection and application of coils in temporomandibular joint MRI.

Objective: To compare and evaluate the signal-to-noise ratio (SNR) and the contrast-to-noise ratio (CNR) values between a 15-channel phased array head coil and 6-channel dS Flex M surface coil in the MRI of temporomandibular joint.

Methods: 300 patients were randomly assigned to two groups: 150 patients were examined by using a 15-channel phased array head coil and the other 150 patients were scanned by using a 6-channel dS Flex M surface coil. All of the data were set in the same 6 regions of interest including the temporal lobe, condyle neck, lateral pterygoid muscle, parotid gland, the adipose area and an area of the background noise）.

[Clinical analysis of spectrum CT imaging reducing metal artifacts of oral and maxillofacial region].

Purpose: To assess the capability of monochromatic energy images of gemstone spectral imaging(GSI) by using spectral CT in reducing metal artifacts of oral and maxillofacial region.

Methods: Spectral CT imaging was applied to 46 patients with metallic implants with GSI sequence to measure CT numbers (expressed in Hounsfield units, HU) and SD (standard deviation) numbers of the soft tissues. 11 monochromatic-image groups were obtained, ranging from 40 keV(kiloelectronvolts) to 140 keV (every 10 keV as one group).