Short-Term Effects of Bariatric Surgery on Body Composition Assessed by Dual-Energy X-Ray Absorptiometry / 中国医科大学学报

Objective To assess the short-term effects of bariatric surgery on body composition. Methods Fifty-seven patients who underwent bariatric surgery were assessed by dual-energy x-ray absorptiometry (DEXA) before surgery, and 1 and 3 months after surgery. The body composition indexes of whole body and different regions were compared. Results The body mass index (BMI) decreased by 10.61％ and 18.51％, and the lean mass (LM) by 13.22％ and 14.35％ at 1 and 3 months after surgery, respectively. The A/G far mass (FM) decreased significantly 3 months after surgery (P ＜ 0.05). The bone mineral density (BMD) of the spine increased, but that of the pelvis decreased at 1 and 3 months after the operation, and a reduction was observed in the BMD of the whole body by 1.23％ and 1.45％, respectively (P ＜ 0.05). Compared to the baseline, the bone mineral content (BMC) of the spine, pelvis, and whole body increased at 1 and 3 months post-surgery, with a statistically significant difference (P ＜ 0.05). The FM of the whole body (9.52％ and 22.77％) and four regions (legs, trunk, android, and gynoid) reduced. A significant loss of FM (P ＜ 0.05) was observed in the android region by 15.80％ and 31.86％ at the two follow-ups. Conclusion Bariatric surgery can effectively reduce the patient's BMI and FM in the short term, and promotes the redistribution of fat; however, it may be accompanied by a reduction in LM, while the BMD and BMC change trend of pelvis and whole body are opposite.

Value and Clinical Application of Orthopedic Metal Artifact Reduction Algorithm in CT Scans after Orthopedic Metal Implantation

OBJECTIVE: To evaluate orthopedic metal artifact reduction algorithm (O-MAR) in CT orthopedic metal artifact reduction at different tube voltages, identify an appropriate low tube voltage for clinical practice, and investigate its clinical application. MATERIALS AND METHODS: The institutional ethical committee approved all the animal procedures. A stainless-steel plate and four screws were implanted into the femurs of three Japanese white rabbits. Preoperative CT was performed at 120 kVp without O-MAR reconstruction, and postoperative CT was performed at 80–140 kVp with O-MAR. Muscular CT attenuation, artifact index (AI) and signal-to-noise ratio (SNR) were compared between preoperative and postoperative images (unpaired t test), between paired O-MAR and non-O-MAR images (paired Student t test) and among different kVp settings (repeated measures ANOVA). Artifacts' severity, muscular homogeneity, visibility of inter-muscular space and definition of bony structures were subjectively evaluated and compared (Wilcoxon rank-sum test). In the clinical study, 20 patients undertook CT scan at low kVp with O-MAR with informed consent. The diagnostic satisfaction of clinical images was subjectively assessed. RESULTS: Animal experiments showed that the use of O-MAR resulted in accurate CT attenuation, lower AI, better SNR, and higher subjective scores (p < 0.010) at all tube voltages. O-MAR images at 100 kVp had almost the same AI and SNR as non-O-MAR images at 140 kVp. All O-MAR images were scored ≥ 3. In addition, 95% of clinical CT images performed at 100 kVp were considered satisfactory. CONCLUSION: O-MAR can effectively reduce orthopedic metal artifacts at different tube voltages, and facilitates low-tube-voltage CT for patients with orthopedic metal implants.

Changes in energy metabolism in the quadriceps femoris after a single bout of acute exhaustive swimming in rats: a ³¹P-magnetic resonance spectroscopy study / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Little is known about the value of (31)P-magnetic resonance spectroscopy ((31)P-MRS) in in vivo assessment of exhaustive exercise-induced injury in skeletal muscle. We aimed to evaluate the value of a (31)P-MRS study using the quadriceps femoris after a single bout of acute exhaustive swimming in rats, and the correlation between (31)P-MRS and histological changes.</p><p><b>METHODS</b>Sixty male Sprague-Dawley rats were randomly assigned to control, half-exhaustive, and exhaustive exercise groups. (31)P-MRS of the quadriceps femoris of the right lower limb was performed immediately after swimming exercise to detect Pi, PCr, and β-ATP. The Pi/PCr, Pi/β-ATP, PCr/β-ATP, and PCr/(PCr+Pi) were calculated and pH measured. Areas under the receiver operating characteristic curve (AUCs) were calculated to evaluate the diagnostic potential of (31)P-MRS in identifying and distinguishing the three groups. HE staining, electron microscopy and desmin immunostaining after imaging of the muscle were used as a reference standard. The correlation between (31)P-MRS and the mean absorbance (A value) of desmin staining were analyzed with the Pearson correlation test.</p><p><b>RESULTS</b>Pi, PCr, Pi/PCr, and PCr/(PCr+Pi) showed statistically significant intergroup differences (P < 0.05). AUCs of Pi, PCr, Pi/PCr, and PCr/(PCr+Pi) were 0.905, 0.848, 0.930, and 0.930 for the control and half-exhaustive groups, while sensitivity and specificity were 90%/85%, 95%/55%, 95%/80%, and 90%/85%, respectively. The AUCs of Pi, PCr, Pi/PCr and PCr/(PCr+Pi) were 0.995, 0.980, 1.000, and 1.000 for the control and exhaustive groups, while sensitivity and specificity were 95%/90%, 100%/90%, 100%/95%, and 100%/95%, respectively. The AUCs of Pi, PCr, Pi/PCr, and PCr/(PCr+Pi) were 0.735, 0.865, 0.903, and 0.903 for the half-exhaustive and exhaustive groups, while sensitivity and specificity were 80%/60%, 90%/75%, 95%/65%, and 95%/70%, respectively. In the half-exhaustive group, some muscle fibers exhibited edema in HE staining, and the unclear Z-discs and the mitochondria with vacuolar degeneration under electron microscopy. Compared with the half-exhaustive group, muscle fiber edema was increased in the exhaustive group, and the Z-discs were broken and the mitochondria exhibited marked vacuolar degeneration under electron microscopy. There were significant difference in A values of desmin staining in the right vastus lateralis among the control, half-exhaustive, and exhaustive groups with 0.58 ± 0.06, 0.30 ± 0.04, and 0.21 ± 0.02, respectively (P < 0.05). Histological examination also showed injury-induced changes in the vastus lateralis among the different intensities groups. Statistically a moderate correlation between (31)P-MRS and desmin was observed, the correlation coefficients of Pi, PCr, Pi/PCr, and PCr/(PCr+Pi) were -0.706, 0.709, -0.726, and 0.791, respectively (P < 0.01).</p><p><b>CONCLUSIONS</b>(31)P-MRS can effectively reflect the changes in energy metabolism in the skeletal muscle after a single bout of acute exhaustive swimming in rats. Based on the significant correlation between (31)P-MRS parameters and histological changes, the changes of Pi, PCr, Pi/PCr, and PCr/(PCr+Pi) can indirectly reflect the degree of exercise-induced injury.</p>

Damage to skeletal muscle cells leads to delayed muscle soreness:how to effectively improve muscle recovery both in recovery speed and quality / 中国组织工程研究

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.

Evaluation of bone age of wrist-hand in adolescent of Shenyang and Beijing / 中华放射学杂志

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.

Association between knee joint medial meniscus extrusion and posterior root tears:Magnetic resonance imaging analysis / 中国组织工程研究

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.

Dynamic changes of capillary bed blood volume in acute ischemic denervated hindlimb of rabbits: an evaluation on 256-slice CT perfusion imaging / 中华放射学杂志

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.

The Diagnosing Value of Diffusion-weighted Magnetic Resonance Imaging of the Cranial Bone in Pituitary Adenomas Patients with Different Prolactin Level / 中国医科大学学报

Objective To study the changes of apparent diffusion coefficient（ADC）values and the feature of the cranial bone in the pituitary adenomas patients with different levels of prolactin（PRL）.Methods A total of 37 patients with pituitary adenoma and 20 healthy volunteers（serum prolactin 7.5～21.7 ng/ml,as control group G1）underwent routine MR and axial EPI-DWI scan（b=0,500 s/mm2）.The patients were divided into group G2（PRL 26.72 ng/ml,n =7）,group G3（PRL 26.72~200 ng/ml,n =17）,and group G4（PRL200 ng/ml,n =13）.The signal intensity of the interested regions（ROIs）was measured on DWI maps containing frontal,parietal,occipital bone marrow.The averaged ADC values were calculated among the 4 groups and compared with case groups and control group.The correlation between prolactin levels in patients with pituitary adenomas and ADC values of their skull bone marrow was explored.Results All patients had a hyperintensity of skull bone marrow signal on DWI maps.The ADC values of frontal,parietal and occipital bone marrow were as follows：G1（1.11±0.21,1.18±0.18,1.16±0.15×10-3 mm2/s）,G2（0.95±0.20,0.86±0.12,1.09±0.11×10-3 mm2/s）,G3（0.99±0.16,0.83± 0.21,0.98±0.25×10-3 mm2/s）,G4（0.81±0.20,0.69±0.16,0.83±0.28×10-3 mm2/s）.The ADC values of G3 and G4 were lower than those of G1（P 0.05）.There was no significant difference（P 0.05）between G2 and G1.Conclusion The ADC values of skull bone marrow were negatively correlated with serum prolactin levels in patients with pituitary adenomas.DWI examination might be beneficial for the identification of pituitary adenomas.

Optimal window width and center level settings in 256-slice spiral CT diagnosis of costal cartilage fracture / 中国医学影像技术

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.

MRI features of joint tuberculosis of the appendicular skeleton in children / 中国医学影像技术

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.

3.0T MRI features of normal acetabular labrum in children / 中国医学影像技术

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.

Acute crush injuries of skeletal muscle of mice with ice-compression therapy: a dynamic study with diffusion tensor imaging / 中华放射学杂志

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.

Age-related pattern of normal cranial bone marrow: MRI study / 中华放射学杂志

Objective To investigate the age-related pattern of normal skull bone marrow with 3. 0 T MR T1WI. Methods Cranial MR T1WI images which were defined to be normal were retrospectively reviewed in 360 cases. Patients with known diffuse bone marrow disease, focal lesions, history of radiation treatment or steroid therapy were excluded, while patients whose cranial MRI and follow-up visits were all normal were included in this study. All the subjects were divided into 7 groups according to the age: < 1, 1--2,3--5, 6--14, 15--29, 30--49, >50 years group. Mid- and para- sagittal T1WI images were used to be analyzed and the type of cranial bone marrow was classified according to the thickness of diploe and the pattern of the signal characteristics. Statistical analysis was conducted to reveal the relationship between the age and the type. Results The normal skull bone marrow could be divided into four types as follows: (1) Type- Ⅰ : 115 cases, 47 of which appeared type- Ⅰ a and the mean thickness was ( 1.24±0. 31 ) mm; 68 of which appeared type- Ⅰ b and the mean thickness was ( 1.76 ± 0. 37 ) mm. Type- Ⅱ : 57 cases and the mean thickness was (2.78 ±0.69) mm. Type-Ⅲ: 148 cases, 18 of which appeared type-Ⅲ a and the mean thickness was (2. 33±0. 65) mm; 88 of which appeared type-Ⅲ b and the mean thickness was (4. 01 ± 0. 86) mm; 42 of which appeared type-Ⅲ c and the mean thickness was (4. 31±0. 73) mm. Type-Ⅳ: 40 cases, 25 of which appeared type-Ⅳ a and the mean thickness was (5. 17 ± 1.02) mm; 15 of which appeared type-Ⅳ b and the mean thickness was (5.85±1.45) mm. (2) <1 year group: 40 cases, 20 of which appeared type- Ⅰ a, 20 type- Ⅰ b and the mean thickness of this group was ( 1.47 ± 0. 42 ) mm. 1-- 2 years group: 40 cases, 16 of which appeared type- Ⅰ a, 18 type- Ⅰ b, 6 type- Ⅱ and the mean thickness of this group was ( 1.68±0. 52) mm. 3--5 years group: 40 cases, 8 of which appeared type- Ⅰ a, 18 type-Ⅰb, 14 type-Ⅱ and the mean thickness of this group was (1.84±0.73) mm. 6--14 years group: 60 cases, 3 of which appeared type- Ⅰ a, 12 type- Ⅰ b, 27 type-Ⅱ , 12 type-Ⅲb, 6 type-Ⅲc, and the mean thickness of this group was (2.92±1. 00) mm. 15--29 years group: 60 cases, 7 of which appeared type-Ⅱ , 5 type-ma, 27 type-Ⅲb, 15 type-Ⅲc, 6 type-Ⅳa and the mean thickness of this group was (3.95 ± 0.97) mm. 30---49 years group: 60 cases, 3 of which appeared type-Ⅱ , 7 type-Ⅲa, 29 type-Ⅲb, 15 type-Ⅲc, 3 type-Ⅳa and 3 type-Ⅳb and the mean thickness of this group was (4. 30 ± 1.35) mm. ≥50 years group: 60 cases, 6 of which appeared type-Ⅲ a, 20 type-Ⅲb, 6 type-Ⅲc, 16 type-Ⅳa and 12 type-Ⅳb and the mean thickness of this group was (4.51 ± 1.40) mm. (3) There is a linear relationship between ages and types that is revealed by chi-square test (x2 = 266. 36, P < 0. 01 ). Conclusion There is characteristic in the distribution of normal skull bone marrow with age growing. And skull bone marrow transforms gradually from type- Ⅰ to Ⅳ with aging.

Quantitative study of MR T1 and T2 relaxation times and 1HMRS in gray matter of normal adult brain / 中华医学杂志(英文版)

<p><b>OBJECTIVE</b>To evaluate magnetic resonance (MR) Imaging and (1)H magnetic resonance spectroscopy ((1)HMRS) in the study of normal biochemical process of the brain, as well as differentiation of normal senile brain from cerebral diseases related to senility.</p><p><b>METHODS</b>One hundred and eighty healthy adult volunteers were selected for MR examination and 60 other healthy subjects for (1)HMRS examination. Ages of subjects ranged from 18 to 80 years. They were divided into six age groups. A 0.35 T superconductive MR system was used to perform MR examination. 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-inositol (MI), glutamate and glutamine (Glu-n).</p><p><b>RESULTS</b>In 180 cases of MR, the shortest T(2) relaxation time occurred in the deep gray matter within the same age group while the length of T(1) relaxation time was ordered from low to high compared to age groups. T(2) relaxation time decreased as age increased. The peaks, ordered from high to low, were as follows in 60 cases of (1)HMRS: NAA, CR, CHO, MI, Glu-n. The ratios of NAA/CR and Glu-n/CR were higher in the senile age group, while that of MI/CR was lower. The ratio of CHO/CR was increased as age decreased. The ratio of NAA/CR and MI/CR gradually decreased in relation to movement from the anterior to the posterior part of the brain; the ratio of CHO/CR was highest in the occipital cortex. Correlation of T(1) relaxation time and partial metabolite ratios to age were present in gray matter.</p><p><b>CONCLUSIONS</b>Quantitative studies of MR T(1) and T(2) relaxation times and (1)HMRS are essential to evaluation of normal myelinization processes, neuronal integrity and age-related biochemical changes in the brain.</p>

MR imaging of occult fractures / 中华放射学杂志

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.

Quantitative Study of MRI and~1H MRS in Normal Adult Brain / 实用放射学杂志

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.