In the process of positron emission tomography (PET) data acquiring, respiratory motion reduces the quality of PET imaging. In this paper, we present a correction method using three level grids B-spline elastic method to correct denoised and reorganized sinograms for respiratory motion correction. Using GATE simulates NCAT respiratory motion model to generate raw data which are used in experiment, the experiment results showed a significantly improved respiratory image with higher quality of PET, and the motion blur and structural information were fixed. The results proved the method of this paper would be effective for the elastic registration.
Magnetic resonance (MR) images can be used to detect lesions in the brains of patients with multiple sclerosis (MS). An automatic method is presented for segmentation of MS lesions using multispectral MR images in this paper. Firstly, a Pd-w image is subtracted from its corresponding T1-w images to get an image in which the cerebral spinal fluid (CSF) is enhanced. Secondly, based on kernel fuzzy c-means clustering (KFCM) algorithm, the enhanced image and the corresponding T2-w image are segmented respectively to extract the CSF region and the CSF-MS lesions combinatoin region. A raw MS lesions image is obtained by subtracting the CSF region from CSF-MS region. Thirdly, based on applying median filter and thresholding to the raw image, the MS lesions were detected finally. Results were tested on BrainWeb images and evaluated with Dice similarity coefficient (DSC), sensitivity (Sens), specificity (Spec) and accuracy (Acc). The testing results were satisfactory.
ObjectiveTo review the current research status of in situ three-dimensional (3-D) printing technique and future trends. MethodsRecent related literature about in situ 3-D printing technique was summarized, reviewed, and analyzed. ResultsBased on the cl inical need for surgical repair, in situ 3-D printing technique is in the preliminary study, mainly focuses on in situ dermal repair and bone and cartilage repair, and succeeds in experiments, but there are still a lot of problems for cl inical application. ConclusionWith the development of in situ 3-D printing technique, it will provide patients with real-time and in situ digital design and 3-D printing treatment with a timely and minimally invasive surgical repair process. It will be widely used in the future.
ObjectiveTo assesse the effectiveness of anterior cervical discectomy and fusion with Cage alone in treating multi-level cervical degenerative disease. MethodsBetween August 2010 and August 2012, 62 eligible patients with multi-level cervical degenerative disease were treated, and the clinical data were reviewed. Of 62 patients, 32 underwent anterior cervical discectomy and fusion with Cage alone (group A), and 30 underwent anterior cervical discectomy and fusion with plate fixation (group B). Both groups showed no significant difference in gender, age, disease duration, lesion types, and affected segments (P>0.05), it had comparability. Clinical outcomes were assessed using Japanese Orthopedic Association (JOA) score and visual analogue scale (VAS) score; the fused segment height, subsidence rates of Cages, global cervical lordosis, and fusion rates were also compared. ResultsThe operation time of group B[(109.7±11.2) minutes] was significantly more than group A[(87.8±6.9) minutes] (t=-2.259, P=0.037). Primary healing of incisions was obtained in all patients of 2 groups. All patients were followed up; the follow-up period ranged from 8 to 27 months (mean, 15.8 months) in group A, and from 9 to 28 months (mean, 16.4 months) in group B. There was no complication and internal fixation failure. The JOA score and VAS score were significantly improved at last follow-up when compared with preoperative scores in 2 groups (P<0.05). According to Robinson standard for axial symptom severity, the results were excellent in 20 cases, good in 9, fair in 2, and poor in 1, with an excellent and good rate of 90.63% in group A; the results were excellent in 19 cases, good in 7, fair in 3, and poor in 1, with an excellent and good rate of 86.67% in group B; and no significant difference was found between 2 groups (χ2=0.765, P=0.382). The fused segment height at immediate after operation and at last follow-up and global cervical lordosis at last follow-up were significantly improved when compared with preoperative ones in 2 groups (P<0.05). There was no significant difference (P>0.05) between groups A and B in the Cage subsidence height[(1.4±0.9) mm vs. (1.2±1.6) mm], Cage subsidence rate[9.52% (8/84) vs. 7.59% (6/79)], and fusion rate[95.24% (80/84) vs. 96.20% (76/79)]. ConclusionAnterior cervical discectomy and fusion with Cage alone can obtain good clinical results and radiologic indexes, avoid plate-related complications and reduce operation time. It is a safe and effective surgical option in the treatment of multi-level cervical degenerative disease.