More and more medical devices can capture different features of human body and form three dimensional (3D) images. In clinical applications, usually it is required to fuse multiple source images containing different and crucial information into one for the purpose of assisting medical treatment. However, traditional image fusion methods are normally designed for two dimensional (2D) images and will lead to loss of the third dimensional information if directly applied to 3D data. Therefore, a novel 3D magnetic image fusion method was proposed based on the combination of newly invented beyond wavelet transform, called 3D band limited shearlet transformand (BLST), and four groups of traditional fusion rules. The proposed method was then compared with the 2D and 3D wavelet and dual-tree complex wavelet transform fusion methods through 4 groups of human brain T2* and quantitative susceptibility mapping (QSM) images. The experiments indicated that the performance of the method based on 3D transform was generally superior to the existing methods based on 2D transform. Taking advantage of direction representation, shearlet transform could effectively improve the performance of conventional fusion method based on 3D transform. It is well concluded, therefore, that the proposed method is the best among the methods based on 2D and 3D transforms.
Magnetic susceptibility is an intrinsic physical quantity which describes the relationship between material magnetization and applied external magnetic field. Quantitative susceptibility mapping (QSM) is an MRI technology which can quantify the buck magnetic susceptibility of tissue in vivo. It is particularly effective at elucidating anatomy with paramagnetic or diamagnetic components. QSM technology is a method for solving the ill-pose problem of un-conventional de-convolution of the measured tissue magnetic field with the unit magnetic dipole field to obtain the susceptibility source map. Many multi orientation scan based QSM and clinically acceptable single orientation QSM methods have been proposed to solve this ill-posed problem. In this paper, the QSM concept is introduced and the various QSM methods are systematically categorized and discussed. The aim of this paper is to summarize the current research progress of QSM, popularize the knowledge of QSM and promote the improvements and the rational application of QSM in clinical field.
ObjectiveTo evaluate the effectiveness of double pedicled flap and technique of geometric broken line (GBL) for primary repair of serious dog bite wound. MethodsBetween October 2006 and December 2014, 9 patients with serious dog bite wound were treated. There were 3 males and 6 females with an average age of 34.5 years (range, 8-68 years), and with a mean disease duration of 4 hours (range, 30 minutes to 24 hours). The defect ranged from 1.7 cm×0.5 cm to 15.0 cm×8.0 cm, with the mean depth of 0.5 cm (range, 0.3-0.8 cm). Deep tissue exposure was observed. After routine debridement, a vacuum sealing drainage (VSD) was equipped to suck and irrigate for 1 day, then wound was repaired. The superomedial edge of defect was trimmed, then a GBL shape mainly with square and rectangular was designed. According to defect size, a double pedicled flap was designed at the lateroinferior edge of defect, which size ranged from 1.7 cm×1.5 cm to 18.0 cm×15.0 cm. The donor site was sutured directly. VSD was used for 3 days after operation. ResultsAll flaps survived and wound healed, and donor site incision healed well, with invisible scar. All patients were followed up 6 months to 8 years (mean, 4 years). The wounds were repaired well, and the patients had good facial appearance. No rabies attack was observed during follow-up. ConclusionIt is an ideal repair method to chose double pedicled flap and technique of GBL for primary repair of dog bite wounds. Satisfactory cosmetic appearance can be obtained.