Effect of couch rotation angle on non-coplanar static intensity-modulated radiotherapy plan for gastric cancer / 中国辐射卫生

Objective To investigate the effect of couch rotation angle on non-coplanar static intensity-modulated radiotherapy (IMRT) plan for gastric cancer and to provide a reference for clinical planning. Methods A retrospective analysis was conducted on patients who recently underwent postoperative IMRT for gastric cancer. Twenty patients who received radiotherapy in the centre of Radiation Oncology of Huanggang Central Hospital from August 2022 to January 2023 were selected. That were selected to receive a seven-field coplanar static IMRT plan based on a couch rotation angle of 0° as the control group. Then, based on the coplanar IMRT plan, only the couch rotation angle of gantry angles 30° and 330° was changed to 10°, 20°, 30°, 40°, 50°, 60°, 70°, 80°, and 90°, respectively, and nine different non-coplanar plans were established. The homogeneity index (HI), conformity index (CI) of the target volume, and monitor unit (MU), as well as Dmean, V20, and V30 of the left and right kidneys, Dmax, Dmean, V10, V20, and V30 of the spinal cord, and Dmax, Dmean, V10, V20, V30, and V40 of the small intestine and liver were compared among the 10 plans. The MU and the dosimetric parameters of the target volumes and When the couch rotation angle was 60°, the minimum HI and maximum CI of the target volume were 0.0714±0.0089 and 0.9271±0.0108, respectively, and the minimum MU was 438±26, with the best homogeneity and conformity in the target volume and the shortest machine treatment time (P＜0.05). When the couch rotation angle was 10°, the Dmax of the small intestine was lowest, being (4620.73±99.27) cGy. When the couch rotation angle was 60°, the Dmean of the left and right kidneys was lowest, being (1246.30±130.35) cGy and (1001.52±103.33) cGy, respectively; the V20 of the left and right kidneys was lowest, being 22.87±6.29 and 19.69±1.84, respectively; the V10 and V30 of the spinal cord were lowest, being 40.08±4.92 and 1.68±0.34, respectively (P＜0.05). Conclusion The couch rotation angle has some influence on the postoperative treatment planning for patients with gastric cancer. In the design of non-coplanar plan for gastric cancer, the couch rotation angle of 60° contributes to establishing a better radiotherapy plan.

Effects of Sling and Resistance Rotation Exercises on Pelvic Rotation and Pain in Patients with Chronic Low Back Pain

PURPOSE: This study compared the different sling and resistance exercises on pelvic rotation during active straight leg raises (ASLR) and on pain in patients with chronic low back pain (CLBP). METHODS: Twenty subjects were divided randomly into a sling group (SG) and a resistance exercise group (REG). Internal oblique (IO), external oblique (EO), rectus abdominis (RA), and rectus femoris (RF) muscle activity; pelvic rotation angle during ASLR; and visual analogue scale, pressure pain threshold were measured. Sling and resistance exercises were then performed for 30 minutes and the measurements taken again. RESULTS: Both groups showed significantly lower RF muscle activity and significantly higher EO and IO muscle activity (p < 0.05). The RA muscle activity decreased significantly in the SG, but increased significantly in the REG (p < 0.05). The pelvic rotation angle was significantly lower in the SG (p < 0.05). The pain press threshold increased significantly in both groups (p < 0.05). The visual analogue scale decreased significantly in the SG (p < 0.05). CONCLUSION: Both exercises appear to be beneficial for modifying the muscle activity and pain control in the intervention of CLBP. On the other hand, the sling was more effective in increasing the pressure threshold than resistance exercise, and the pelvic rotation angle was reduced. Therefore, both exercises can help patients with CLBP change their muscle activity and control pain. CLBP patients should use a sling for short periods of time to learn to reduce the pain and control pelvic rotation.

Impact of Rotation Sampling on Parameters of Texture Feature in Chinese Herbal Medicine Images / 世界科学技术-中医药现代化

This study was aimed to investigate the impact of rotation sampling on feature parameters of texture im-ages of Chinese herbal medicine. Four Chinese herb medicine with various shape and texture feature were taken as research materials. Images of complete and incomplete herbal medicine were collected respectively after different ro-tation angles. The 26 parameters were extracted by gray-level co-occurrence matrix and grayscale gradient matrix. The impact of rotation sampling on feature parameters was investigated through analysis of variation tendency and range of 26 parameters. The results showed that if the Chinese herbal medicine was complete, the 26 parameters were not impacted by the rotation angle, whereas the 26 parameters were impacted by the rotation angle and the im-pact will be more obvious when the shape of Chinese herb medicine was irregular. It was concluded that in order to get a high quality of images and construct a well identification model based on the parameter of texture features, we must consider the impact of rotation angle on the parameters to Chinese herbal medicine with various shapes and tex-ture features.

Measurement of fibular rotation angle：Intraoperative judgment of the success rate of inferior tibiofibular syndesmosis reduction / 中国组织工程研究

10.3969/j.issn.2095-4344.2013.26.016

The Correlation of Postoperative Femoral Component Rotation Angle and Patella Tilt Angle with Clinical Results in Total Knee Arthroplasty

PURPOSE: The aim of this study was to analyze the correlation of postoperative femoral component rotation angle and patella tilt angle with clinical results for total knee arthroplasty. MATERIALS AND METHODS: Ninety-six cases in 48 patients who underwent total knee arthroplasty between March 2002 and February 2010 were enrolled. Femoral component rotation angle (FRA) and patella tilt angle (PTA) were measured with postoperative computed tomography. Clinical results were evaluated using American Knee Society knee score & function score and Feller's patella score. We analyzed the correlation of FRA and PTA with clinical outcomes. We also compared clinical results between the PFC(R) Sigma group and the Scorpio NRG(R) group, and the patello-femoral symptom group and a symptom-free group. RESULTS: The mean FRA was 1.40degrees of internal rotation. The patellar tilt angle was 3.79degrees of lateral tilt. The mean knee score was 90.5, the function score was 77.4, and the patella score was 23.9. There was a significant difference between FRA and knee scores (p=0.031, r=-0.284). There were no significant differences between FRA and function score or patella score. The correlation of PTA and clinical results was not significant. The mean FRA was 2.00degrees of internal rotation in the PFC(R) Sigma group, and it was significantly different than for the Scorpio NRG(R) group which had 0.81degrees of internal rotation; but there were no significant differences between the two groups in clinical results. The patello-femoral symptom group deviated more from the mean FRA than did the symptom-free group. CONCLUSION: Internal rotation of the femoral component is correlated with poor clinical results after total knee arthroplasty. The correlation of patella tilt angle and clinical results was not significant.

Biomechanical Changes of the Lumbar Segment after Total Disc Replacement : Charite(R), Prodisc(R) and Maverick(R) Using Finite Element Model Study

OBJECTIVE: The purpose of this study was to analyze the biomechanical effects of three different constrained types of an artificial disc on the implanted and adjacent segments in the lumbar spine using a finite element model (FEM). METHODS: The created intact model was validated by comparing the flexion-extension response without pre-load with the corresponding results obtained from the published experimental studies. The validated intact lumbar model was tested after implantation of three artificial discs at L4-5. Each implanted model was subjected to a combination of 400 N follower load and 5 Nm of flexion/extension moments. ABAQUStrade mark version 6.5 (ABAQUS Inc., Providence, RI, USA) and FEMAP version 8.20 (Electronic Data Systems Corp., Plano, TX, USA) were used for meshing and analysis of geometry of the intact and implanted models. RESULTS: Under the flexion load, the intersegmental rotation angles of all the implanted models were similar to that of the intact model, but under the extension load, the values were greater than that of the intact model. The facet contact loads of three implanted models were greater than the loads observed with the intact model. CONCLUSION: Under the flexion load, three types of the implanted model at the L4-5 level showed the intersegmental rotation angle similar to the one measured with the intact model. Under the extension load, all of the artificial disc implanted models demonstrated an increased extension rotational angle at the operated level (L4-5), resulting in an increase under the facet contact load when compared with the adjacent segments. The increased facet load may lead to facet degeneration.

Experimental study of rotational DSA on image deformation and measurement error / 中国医学影像技术

Objective To evaluate the image deformation and measurement error of rotational DSA by model experiment. Methods Five steel balls (diameter: 20 mm) were placed in a horizontal space of 30 mm, the middle of which was as the isocenter for rotational DSA acquisition. Another 5 steel balls (diameter: 10 mm) were placed in a vertical space of 30 mm with the same alignment for rotational DSA acquisition. The screen was divided into five regions and the morphological changes of the ball image were observed at each rotation angle. The experimental images of the left anterior oblique ball images at 20°, 40°and 60° among each two groups were selected and measured by automatic isocenter calibration and sphere calibration respectively, and compared with the actual diameters of balls to calculate the image magnification. Results Except the center one, other balls were of deformation at different rotation angles due to the distance to the detector leading to enlargement and reduction. With automatic isocenter calibration, only the diameter of the center ball corresponded with the actual one, the distance away from the center or the rotation angle was inversely proportional to measurement error (maximum magnification 12.42%).With sphere calibration, the measurement results in various regions at different rotation angle were basically the same, with smaller measurement error (maximum magnification 3.41%). Conclusion Placing the organ of interest in the center area can reduce image distortion in rotational DSA imaging. Selecting reasonable measuring technology according to the lesion location is helpful to control measurement errors.

Spatial changes of the maxillary molar following unilateral derotation with the precision TPA / 대한치과교정학회지

The purpose of this study was to evaluate the spatial changes of mesial-in rotated maxillary molar and opposite anchor tooth during derotation by the precision transpalatal arch (TPA) with the use of a new typodont simulation system, the Calorific machine system, which was designed to observe the whole process of tooth movement. The maxillary right first molar was used for the anchor tooth and the maxillary left first molar was used for the mesial-in rotated tooth, and the angle of rotation was increased to 20, 40, and 60. A passive precision TPA was fabricated and then activated by bending the left arm to 20, 40, and 60. Each experiment was repeated five times under the same conditions and analyzed by ANOVA and Tucky's Studentized Range (HSD) test. In the occlusal plane, when the bending angle of precision TPA was increased, the mesiobuccal cusp of the rotated molar moved more buccally (p<0.001) and less distally (p<0.001) while the distolingual cusp moved in the mesiopalatal direction. In the sagittal plane, the palatal roots of the derotated molar moved mesially (p<0.001). In the traverse plane, the derotated molar showed slight extrusion (p<0.001). The upper right first molar, which was used as an anchor tooth, showed clinically insignificant movement across all three planes.

An Experimental Study and Clinical Investigation on Rotational Deformity in Supracondylar Fracture of the Humerus in Children / 대한정형외과학회잡지

In children, the supracondylar fractures of the humerus are common in elbow region, and often associated with various complications and problems in treatment (ie,Volkmann's ischemic contracture, cubitus valgus or varus deformity, rotational deformity). The results of reduction can be measured by Baumann's angle, carrying angle, trochlea-capitellum angle, and displacement of distal radial styloid process on radiological study. So we have made experiments on the process which various three dimensional displacements reflected into two dimensional Baumann's angle and humerocapitellar angle. And we investigated the process of rotation, through various radiological studies by means of molded models of humerus. The results were as follows:l. In experiments, AP & lateral X-ray studies showed no change in rotation of proximal segment of fracture with fixed distal segment of fracture. 2. On the other hand, AP & lateral X-ray showed significant change, in rotation of proximal fracture segment with distal segment of fracture. 3. Supracondylar rotation angle(S.R.A.)depicted as the ratio of the length of proximal fracture width minus that of the distal fracture width in lateral view, to the length of distal fracture width in AP view minus that of the distal fracture width in lateral view. 4. According to the modified Mitchell result, S.R.A. to the result of treatment was average 7.6 degree in excellent group, 15.2 degree in good group and 29.3 degree in unsatisfactory group.