Objective To investigate the value of MR imaging in detecting occult fractures. Methods Sixteen cases with acute trauma were studied using radiography and MR imaging, three cases also underwent CT examinations. Three fractures occurred in the femur condyle, 8 in the proximal tibia and 5 in the thoracolumbar spine. Results All sixteen cases had normal radiographic results. In 11 cases with femur condyle and tibia occult fracture, MR imaging demonstrated linear low signal in the subcortical region in 3 cases and irregular low signal from articular faces to shaft in 8 cases on both T 1WI and T 2WI, and high signal changes around low signal were seen on T 2WI, and the width of low signal was less than 4 mm on both T 1WI and T 2WI. The high signal in T 1 weighted-Fat saturated sequence was more remarkable and wider than that on T 2WI. 3 cases with CT scanning showed no fracture signs. In five cases with thoracolumbar vertebral occlut fractures, MR imaging demonstrated horizontal linear low signal in the center of vertebra on both T 1WI and T 2WI, and high signal changes around low signal were seen on T 2WI. Conclusions MR imaging could early determine the diagnosis of occult fractures. MRI should be the next examination of choice when plain films fail to reveal suspected fractures in the setting of suggestive symptoms and positive physical examination.

BACKGROUND:Meniscal root damage is an important reason for meniscus extrusion. In recent years, there are many reports on the relationship between meniscus root injury and meniscus extrusion at abroad, but it is rare at home. OBJECTIVE:To investigate the correlation between knee medial meniscus extrusion and the medial meniscus posterior root tears. METHODS:A retrospective analysis of the MRI and arthroscopic findings of 84 patients with knee medial meniscus extrusion signs was conducted. Medial meniscus extrusion≥ 3 mm or length of medial meniscus extrusion/maximum diameter of meniscus extrusion ≥10%was defined as serious extrusion. The chi-square test analysis was used to analyze the correlation between posterior root tears and the medial meniscus extrusion. RESULTS AND CONCLUSION:MRI measurement results of medial meniscus extrusion (length of medial meniscus extrusion ≥ 3 mm or length of medial meniscus extrusion/maximum diameter of meniscus extrusion≥ 10%) was significantly related with the arthroscopic findings of posterior root tears (P<0.05) with the odds ratio and 95%confidence intervals of 25.04 (3.07-204.44) and 6.96 (1.38-35.19) respectively. The medial meniscus serious extrusion is closely related to posterior root tears of the medial meniscus, which is a significant feature of the meniscus posterior root tears.

BACKGROUND:There is no simple and effective method to relieve delayed muscle soreness.
OBJECTIVE:To conclude the injured mechanism and therapies of delayed muscle soreness by reviewing literature about damage and repair of the skeletal muscle.
METHODWanfang and PubMed databases (from January 1991 to January 2014) were retrieved for articles
related to morphological structure of the skeletal muscle, mechanism of delayed muscle soreness, and treatment and repair of the skeletal muscle using the keywords of“molecular mechanisms;delayed onset muscle soreness;pain;skeletal muscle;injury”in Chinese and English, respectively. Final y, 24 articles were included in result analysis.
RESULTS AND CONCLUSION:Studies have shown that skeletal muscle injury is related to calcium imbalance, energy imbalance and high concentration of active oxygen. Skeletal muscle injury includes metabolic injury, mechanical injury and inflammatory injury. Insulin-like growth factor, peroxisome proliferator-activated receptorγ-coactivator-1αpromoter and tumor necrosis factorαplay important roles in skeletal muscle repair process. Animal experiments have demonstrated that edaravone may reduce secondary damage and inflammatory infiltration by means of directly preventing rapid peroxidation injury of free radicals in the skeletal muscle. Clinical studies have shown that Chinese medicine preparations, massage and acupuncture can delay the occurrence of exercise-induced muscle injury and fatigue, to improve the speed and quality of the recovery of damaged muscles. The treatment of delayed muscle soreness can achieve satisfactory results by combining physiotherapy with traditional Chinese medicine.

Objective To observe the 3.0T MRI features of normal acetabular labrum and variation in children. Methods MR appearances of normal acetabular labra in 53 children aged from 4 days to 14 years were reviewed retrospectively. The children were divided into four groups according to the age:group A:0-3 years; group B:4-7 years; group C:8-11 years; group D:12-14 years. All of them were examined with 3.0T MR including axial and coronal sequences. Results ①MR appearances of normal acetabular labra could be classified into 3 types:triangle, flat-shape and absent in shape. Triangle was the most common (78.29%). ②There was remarkable difference in the distribution of labra morphology among different groups and different portions of hip. Triangle was most commonly observed in group D and on the anterior portion. ③High signal intensity of normal acetabular labra in MRI was most frequently seen on the anterior site of hip. Conclusion The shape and signal intensity of normal acetabular labrum in children varies in different age groups and different portions.

Objective To investigate the MRI features of children's joint tuberculosis of the appendicular skeleton, and to evaluate the diagnostic value of MR imaging. Methods Sixteen consecutive patients confirmed clinically and pathologically were examined with SE-T1WI, FSE-T2WI, FSE-PDWI and PD-SPIR in Philips Achieva 3.0T superconduct MR scanner. Axial, sagital and coronal images were obtained. Articular structure was all analyzed based on the affected parts and features of MRI. Results Hip joint and knee joint were most likely to suffer (each 25.00%). Metaphysis was affected in 13 patients with long signal intensity on T1WI and long signal intensity on T2WI. The changes of articular cartilage presented as abnormality of signal intensity in 6 patients with focal high signal intensity on T2WI. Thirteen patients presented as joint effusion. Synovial thickening in 4 patients showed moderate homogeneous signal on T1WI and slightly lower signal on T2WI. Articular soft tissue was involved in 16 patients, including the formation of cold abscess in 2 and cellulitis in 1 patient, showing long signal intensity on T1WI and long signal intensity on T2WI. Conclusion MRI has the advantage of being able to detect early abnormalities of bone marrow, cartilage damage and to evaluate joint effusion, synovial thickening and soft tissue lesions.

Objective To investigate the optimal window level and center level settings in the diagnosis of costal cartilage fracture with 256-slice spiral CT through ROC analysis. Methods Thirty patients with suspected costal cartilage fractures underwent 256-slices chest spirals CT scaning. CT value of costal cartilage was measured by three experienced radiologists. The soft copy images of three kinds of window level and window width (-100 HU/1120 HU, 100 HU/1120 HU, 300 HU/1120 HU) were analyzed independently in PACS with dual-blind method, and the diagnosis results were taken ROC analysis with SPSS 16.0 software. The diagnostic accuracy of three physicians were evaluated and compared according to the area under the ROC curve (Az). Results A total of 8 patients of costal cartilage fractures were confirmed by CT diagnosis combined with clinical follow-up. The mean CT value of 30 patients was (98.78±32.86) HU. The area under the ROC curve with the window level and center level settings of (100 HU/1120 HU) were bigger than that of other window level and window width (P=0.045,P=0.002). Kappa identity test showed that there was a powerful conformability between the diagnostic results of three physicians. Conclusion 256-slice spiral CT is a good way for the diagnosis of costal cartilage fractures with suitable window level and center level settings.

Objective:To evaluate magnetic resonance imaging(MRI) and 1 H magnetic resonance spectroscopy( 1HMRS)in the study of normal biochemical process of the brain as well as differentiation of normal senile brain from cerebral diseases related to senility.Methods:180 cases of healthy adults were selected to perform MR examination,in which,none of the subjects had the history of neurological and psychotic diseases according to MRI and clinical results.Meanwhile,60 healthy subjects were selected to perform 1 HMRS examination.The ages ranged from 18 to 80 years.They were divided into six age groups purposely.Point resolved spectroscopy sequence was required for 1 HMRS.The metabolites in the spectra included:N-acetylaspartate(NAA),choline compounds(CHO),creatine compounds(CR),myo-inosito(MI),glutamate and glutamine(Glu-n).Results:(1)In 180 cases of MRI,T 2 relation time was lowest in the deep gray matter in the same age group;T 1relation time was in low-high order,while T 2 relation time was decreased with the increase of age in the different age group.(2)The amplitudes in high-to-low order were as follows in 60 cases of 1 HMRS:NAA、CR、CHO、MI、Glu-n.No prominent difference of shape and peak arrangement was seen at the different ipsilateral site in the same age groups;while slight difference at the same site in the different age groups was present.The ratio of NAA/Cr and Glu-n CR was higher in senile age group;while that of MI/Cr was lower.The ratio of CHO/CR was in low-to high order with the difference of age.The ratio of NAA/CR and MI/CR was gradually lower from anterior to posterior part of the brain;the ratio of CHO/CR was highest in occipital cortex however,no definite changing rule was observed in the ration of Glu-n/CR.Correlation of T 1 relation time and partial metabolite ratio with age was present in gray matter.Conclusion:Quantitative study of MRI and 1 HMRS is essential for determination of normal myelinization and neuronal integrity and age-related biochemical changes in the brain.

Objective To investigate bone age of left-hand wrist in healthy adolescents of Shenyang and Beijing for assessing the process of skeletal development.Methods From 2008 to 2012,1333 adolescents (aged form 4.0 to 18.0 ys) of Shenyang and Beijing were enrolled in this study.Skeletal age was estimated by left hand and wrist X-ray using CHN atlas by 2 qualified radiologists.The correlation between skeletal and chronological age was analyzed using correlation analysis.Skeletal age and chronological age were compared using paired t test.The differences between skeletal and chronological age in genders and regions were compared using independent-samples t test.SPSS for Windows (version 13.0)was used for statistical analysis.P ＜ 0.05 was considered as significant difference.Results (1) Close correlation was found between skeletal age and chronological age (P ＜ 0.01) for both two genders and two regions.(2)Among 28 groups of investigation,16 groups (boys,11 groups) had higher skeletal ages than chronological ages with statistical significance,including Shenyang boys aged 6.0-18.0 ys,Shenyang girls aged 6.0-7.9 ys and 14.0-15.9 ys,Beijing boys at 6.0-15.9 ys and Beijing girls at 8.0-13.9 ys.(3) Comparison between boys and girls:5 groups showed significant difference,including 8.0-9.9 ys,10.0-11.9 ys and 16.0-18.0 ys groups in Shenyang and 6.0-7.9 ys,10.0-11.9 ys groups in Beijing.(4) Comparison between Shenyang and Beijing:6 groups showed statistical significance,including boys at 10.0-11.9 ys,12.0-13.9 ys and 16.0-17.9 ys and girls at 6.0-7.9 ys,8.0-9.9 ys and 10.0-11.9 ys.Conclusion Although CHN atlas method could reflect adolescent bone development,the skeletal age is higher than chronological age in many groups,and the difference between skeletal and chronological age is statistically different between genders and between two regions.This research can be used as a reference for the study of skeletal development and for further emendation of CHN atlas.

Objective To investigate the capillary blood volume (BV) changes in acute ischemic denervated hindlimb of rabbits and the value of 256-slice detector computed tomography (CT) perfusion imaging in evaluation.Methods A total of 40 healthy, adult white rabbits underwent either right hindlimb femoral artery excision combined femoral nerve denervation (combined modeling group, n = 10), simple femoral artery excision (iachemia group, n = 10), simple femoral nerve denervation (denervation group,n = 10), or simple femoral artery separation (sham-surgery group, n = 10).At 1,7, 14, 21, and 28 days following surgery, CT perfusion scanning (Philips Brilliance 256-row) was performed and CT perfusion images were processed using maximum-slope method with Function CT software on EBW workstation.The ratio of BV (rBV) in muscle tissue between right and left hindlimbs was calculated in each group.At 14 and 28 days, following sacrifice, rabbit bilateral adductor was harvested for immunohistochemical staining.The ratio of microvessei density (rMVD) in muscle tissue between right and left hindlimbs was calculated.The significance of the difference of rBV at each time point was assessed using analysis of variance of factorial design (2 ×2).Pearson correlation analysis was used to study the relationship between rBV and rMVD.Results After surgery, the 1st day rBV of combined modeling group, combined modeling group,denervation group and sham-surgery group is 0.31 ± 0.15 ( n = 6), 0.29 ± 0.12 (n = 6), 0.98 ± 0.08 ( n =6), 0.98 ± 0.07 ( n = 6) respectively.The 7th day following surgery rBV is 1.69 ± 0.45 ( n = 5 ), 1.63 ±0.43(n=6), 0.99 ±0.07(n =6), 1.00 ±0.08(n =6).The 14th day is respectively 1.58 ±0.18(n=5), 1.49 ±0.25(n =6), 0.94 ±0.08(n =6), 1.01 ±0.05(n =6).The 21th day is 1.42 ±0.41 (n=4),1.43 ±0.31(n=4), 0.94 ±0.05(n =5), 1.02 ±0.05(n =5),and the 28th day is 1.00 ±0.25(n=4),0.99 ±0.08(n=4), 0.92 ±0.09(n =5), 1.02 ±0.13(n=5).At each time point with exception of postoperative 28 days(F(A) =0.214,P>0.05), ischemia produced main effects on rBV(F(A) =274.268,30.044,65.787,18.886 ,P < 0.01 ), while simple denervation did not show main effects on each time point.Ischemia and denervation did not yield interaction effects on each time point, rMVD from each group supported above-mentioned changes.The correlation coefficient of rBV to rMVD was r = 0.862 ( P < 0.01 ).Conclusions BV in acute ischemic denervated hindlimb of rabbits shows a dynamic change, and denervation does not obviously influence this process.256-slice detector CT perfusion imaging can be used to noninvasively and semi-quantitatively evaluate the dynamic changes of capillary bed in acute ischemie denervated hindlimb of rabbits.

Objective To evaluate the value of ice-compression therapy in mice skeletal muscle after acute crush injuries and correlate treatment effect with different compression time by MR DTI. Methods Forty Weistar mice were randomly divided into 4 groups by random number table method: control group (A), 5 min compression time group( B), 15 min compression time group(C) and 30 min compression time group(D). Diffusion tensor imaging examinations were performed before, immediately after, 24, 48 and 72 hours after injuries. ADC and FA values were calculated by fiber tracking tool. The morphological changes were confirmed by histopathology, and immunohistochemical methods were used for the assessment of Desmin expression with mean of A value. Statistical analysis by LSD-t test and Spearman rank correlation.Results (1) For every group before injuries, ADC valueswere (1.38±0.04) ×10-3,(1.38±0.08) ×10-3, ( 1.34 ± 0. 05 ) × 10 -3, ( 1.36 ± 0. 09 ) × 10 -3 mm2/s respectively, FA value were 0. 46 ± 0. 05,0. 45 ±0. 03,0. 45 ± 0. 05,0. 48 ± 0. 04 respectively. ADC values increased significantly and FA values reduced in each group immediately after injuries compared with pre-injury values. ADC values were ( 1.84 ±0. 10) × 10-3, ( 1.79 ±0. 09) × 10-3, ( 1.55 ±0. 07) × 10-3, ( 1.57 ±0. 04) × 10 -3mm2/s respectively,FA value were 0. 21 ±0. 04, 0. 26 ±0. 03, 0. 31 ±0. 02, 0. 30 ±0. 04 respectively. ADC values were still higher and FA values lower than pre-injury values at 24 hours after injury in A, B groups. ADC values were (1.54±0.13) ×10-3, (1.57±0.13) × 10-3mm2/s, FA value were 0.25 ±0.03, 0.26±0.02. (2)DTT showed fibers distorted and the number of fiber bundles reduced, some separation and displacement in each group immediately after injury. C, D groups improved more than A, B groups over time. (3) The disorder arrangement of skeletal muscle cells with edema and filaments separation were found in HE staining after injury, but the degree mitigated in C, D groups. Desmin staining became lighter with fuzzy edge immediately and 24 hours after injury, and changed more than 72 hours after injury. (4) The correlation coefficients of ADC, FA values and A value were respectively - 0. 789 and 0. 763 ( P ＜ 0. 05 ). Conclusions DTI can non-invasively reflect the pathological changes after acute crush injuries of muscles of mice and ice compression therapy. It is a useful method to guide ice compression treatment after acute crush injuries.