Correlation between Non-Alcoholic Fatty Liver Disease and Visceral Adipose Tissue in Non-Obese Chinese Adults: A CT Evaluation

OBJECTIVE: To investigate the correlation between non-alcoholic fatty liver disease and visceral adipose tissue in non-obese Chinese adults using computed tomography (CT). MATERIALS AND METHODS: The study included 454 subjects undergoing abdominal CT scan. Degree of CT attenuation in liver and spleen, and the degree of fat infiltration in liver were evaluated according to three indices: the attenuation value of liver parenchyma (CTLP), the attenuation ratio of liver and spleen (LSratio) and the attenuation difference between liver and spleen (LSdif). Visceral fat area (VFA) and total fat area (TFA) at L2/3 and L4/5 levels were measured, and the abdominal subcutaneous fat area (SFA) was calculated. Bivariate correlation analysis was carried out to determine the correlation among these factors. RESULTS: In men, VFA, SFA and TFA at L2/3 and L4/5 levels showed significant differences in terms of the three indices to distinguish fatty liver from non-fatty liver (all, p < 0.001). In men, all the three indices showed negative correlation with TFA, SFA and VFA (all, p < 0.001). The negative correlation between the three indices and VFA at the L2/3 level was higher than at L4/5 level (r = −0.476 vs. r = −0.340 for CTLP, r = −0.502 vs. r = −0.413 for LSratio, r = −0.543 vs. r = −0.422 for LSdif, p < 0.001, respectively). The negative correlation between LSratio, LSdif and VFA at L2/3 and L4/5 levels was higher than SFA at the corresponding level. In women, all the three indices showed negative correlation with VFA and TFA at L2/3 and L4/5 levels, and the negative correlation between CTLP and VFA was higher at L2/3 level than at L4/5 level (r = −0.294 vs. r = −0.254, p < 0.001). CONCLUSION: In non-obese Chinese adults, the degree of hepatic fatty infiltration showed a strong correlation with abdominal fat on CT. VFA at L2/3 level was more closely related to fatty liver compared with VFA at L4/5 level.

Relationship Between Body Fat Indices and Hypertension Level by Quantitative CT: A Multicenter Study in Chinese Population / 中国循环杂志

Objectives: To explore the relationship between body fat indexes and hypertension levels by quantitative CT (QCT) study. Methods: A total of 1488 participants from "prospective urban-rural epidemiology (PURE) study" were enrolled. The participants' age were from 42 to 82 years; based on blood pressure (BP) they were divided into 2 groups: Non-hypertension group, n=783 and Hypertension group, n=705. QCT fat measurement software was used to examine L2 level abdominal visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT); body mass index (BMI), waist circumferences (WC), hip circumferences (HC) and waist-to-height ratio (WHtR) were measured and calculated; liner Logistic regression analysis and 2-classified Logistic analysis were conducted to study the relationships between hypertension and anthropometric indices, abdominal VAT, SAT respectively. Results: Compared with Non-hypertension group, Hypertension group had increased BMI, WC, HC, WHtR, abdominal VAT and SAT, P<0.05. BMI, WC, HC, WHtR, abdominal VAT and SAT were related to both systolic BP (SBP) and diastolic BP (DBP), P<0.05. Multivariable Logistic regression analysis indicated that WHtR, abdominal VAT, SAT were the independent impact factors of SBP and WC, abdominal VAT were the independent impact factors of DBP; further investigation showed that abdominal VAT and WC were the independent impact factors of hypertension. Conclusions: Abdominal VAT was robustly related to hypertension in Chinese population, it might be helpful for risk stratification in hypertension patients.

Effects of Structural Changes in Subchondral Bone on Articular Cartilage in a Beagle Dog Model / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>Using MR T2-mapping and histopathologic score for articular cartilage to evaluate the effect of structural changes in subchondral bone on articular cartilage.</p><p><b>METHODS</b>Twenty-four male Beagle dogs were randomly divided into a subchondral bone defect group (n = 12) and a bone cement group (n = 12). Models of subchondral bone defectin the medial tibial plateau and subchondral bone filled with bone cement were constructed. In all dogs, the left knee joint was used as the experimental sideand the right knee as the sham side. The T2 value for articular cartilage at the medial tibial plateau was measured at postoperative weeks 4, 8, 16, and 24. The articular cartilage specimens were stained with hematoxylin and eosin, and evaluated using the Mankin score.</p><p><b>RESULTS</b>There was a statistically significant difference (P < 0.05) in Mankin score between the bone defect group and the cement group at postoperative weeks 16 and 24. There was a statistically significant difference in the T2 values between the bone defect group and its sham group (P < 0.05) from week 8, and between the cement group and its sham group (P < 0.05) from week 16. There was significant difference in T2 values between the two experimental groups at postoperative week 24 (P < 0.01). The T2 value for articular cartilage was positively correlated with the Mankin score (ρ = 0.758, P < 0.01).</p><p><b>CONCLUSION</b>Structural changes in subchondral bone can lead to degeneration of the adjacent articular cartilage. Defects in subchondral bone cause more severe degeneration of cartilage than subchondral bone filled with cement. The T2 value for articular cartilage increases with the extent of degeneration. MR T2-mapping images and the T2 value for articular cartilage can indicate earlycartilage degeneration.</p>

Magnetic resonance imaging and histopathological analysis of experimental muscle injuries in a rabbit / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To investigate the correlation of magnetic resonance imaging (MRI) with histopathological changes, and to evaluate T2 mapping in assessing muscle trauma in a rabbit model of muscle injury.</p><p><b>METHODS</b>We divided 35 rabbits into seven groups that each represented a different time point after intramuscular hemorrhage and muscle injury. Hemorrhage was created by injecting autologous blood into the left legs, and muscle injury was created by scalpel incision of the biceps femoris of the right legs. At different time points, the rabbits underwent T1-weighted imaging and T2-weighted imaging (T1WI and T2WI) and T2 mapping. T2 relaxation times were measured, and the corresponding samples were evaluated for pathological changes</p><p><b>RESULTS</b>After 2 h, the intramuscular hemorrhage model demonstrated an increased signal intensity on both T1WI and T2WI. Histological examination showed erythrocytes within the muscle bundle. On days 1 and 3, the MRI signals were decreased, and there were no significant changes after day 7. From 2 h to 3 days, the muscle-injury model showed a high signal on both T1WI and T2WI. Corresponding pathological changes included rupture and edema of muscle fibers, and inflammation. The abnormal signals were reduced on day 7. After day 14, the T2WI intensity remained high. T1WI showed no abnormal changes, but some models showed a high signal, representing fresh bleeding and fatty tissue. T2 relaxation times were significantly different between the central and marginal regions, and between the marginal and normal regions.</p><p><b>CONCLUSION</b>MRI clearly demonstrates intramuscular hemorrhage and muscle injury, which correlate well with histopathological changes. T2 mapping is useful in assessing the extent of injury.</p>

Study of pedicle screw placement assisted by intraoperative three-dimensional navigation in lumbar vertebrae with axial rotation / 中华外科杂志

<p><b>OBJECTIVE</b>To evaluate the effect of axial rotation of lumbar vertebrae on the accuracy of pedicle screw placement using the traditional method, as well as to assess the value of intraoperative three-dimensional (3D) navigation in improving the accuracy.</p><p><b>METHODS</b>Sixteen lumbar simulation models at different degrees of axial rotation (0°, 5°, 10° and 20°), with every four assigned with the same degree, were equally divided into two groups (traditional method group and intraoperative 3D navigation group). Random placement of pedicle screws was carried out, followed by CT scan postoperatively. Then the outer pedicle cortex contours were depicted from reconstructed sectional pedicle images using Photoshop. The accuracy of pedicle screw placement was evaluated by determining the interrelationship between screw trajectory and pedicle cortex (qualitative) and measuring the shortest distance from pedicle screw axis to outer cortex of the pedicle (quantitative).</p><p><b>RESULTS</b>Eighty pedicle screws were implanted respectively in each group. In traditional method group, statistical difference existed in the accuracy of pedicle screw placement at different axial rotational degrees (P < 0.05). With degrees increasing, the accuracy declined. The accuracy of intraoperative 3D navigation group was higher than traditional method group in vertebrae with axial rotation (P < 0.01). In qualitative evaluation, the accuracy of the two methods had statistical difference when the degree was 20°, and in quantitative evaluation, statistical difference existed in 5°, 10° and 20° of vertebral axial rotation.</p><p><b>CONCLUSIONS</b>Screw malposition can be caused by vertebral axial rotation in lumbar spine using traditional method. Accuracy of pedicle screw placement declines with the increase of axial rotational degrees. However, the accuracy can be improved by using intraoperative 3D navigation.</p>

Solitary pulmonary nodules: comparison of multi-slice computed tomography perfusion study with vascular endothelial growth factor and microvessel density / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The solitary pulmonary nodule (SPN) is one of the most common findings on chest radiographs. The objectives of clinical practice are to differentiate malignant nodules from benign nodules in the least invasive way and to make a specific diagnosis. This study was aimed to evaluate the correlation between perfusion imaging features and microvessel density (MVD) and vascular endothelial growth factors (VEGF) in SPNs using multi-slice computed tomography (MSCT); and to provide the theoretical basis for SPN blood flow pattern and blood flow quantitative features. Also, the study called for the discussion of the method's clinical application value in the differential diagnosis of benign and malignant SPNs.</p><p><b>METHODS</b>Sixty-eight patients with SPN underwent multi-location dynamic contrast enhanced (nonionic contrast material was administrated via the antecubital vein at a rate of 4 ml/s) MSCT. Precontrast and postcontrast attenuations on every scan was studied. Perfusion, peak height, and the ratio of the peak height of the SPN to that of the aorta were analyzed. Perfusion was calculated using the maximum gradient of the time-density curves (TDC) and the peak height of the aorta. The quantitative parameters (perfusion, peak height, ratio of peak height of the SPN to that of the aorta) of the blood flow pattern were compared with MVD and the VEGF expression of immunohistochemistry.</p><p><b>RESULTS</b>The perfusion peak heights of malignant ((96.15 +/- 11.55) HU) and inflammatory ((101.15 +/- 8.41) HU) SPNs were significantly higher than those of benign ((47.24 +/- 9.15) HU) SPNs (P < 0.05, P < 0.05). Ratios of SPN-to-aorta of malignant and inflammatory SPNs were significantly higher than those of benign SPNs (P < 0.05, P < 0.05). No significant differences were found between the peak height and SPN-to-aorta ratio of malignant SPNs and inflammatory SPNs (P > 0.05, P > 0.05). The precontrast densities of inflammatory SPNs were lower than those of malignant SPNs (P < 0.05). Perfusion values of malignant and inflammatory SPNs were significantly higher than those of the benign SPNs (P < 0.05, P < 0.05). The VEGF positive expressions appeared in 32 patients with malignant SPNs and 2 patients with benign SPNs, and the average value of the MVD was higher in patients with malignant SPNs (36.88 +/- 6.76) than in patients with either benign (4.51 +/- 0.60) or inflammatory (26.11 +/- 5.43) SPNs (P < 0.05, P < 0.05). There were statistically significant correlations between the CT perfusion feature and the MVD. The highest correlation was between the peak height of SPN and the MVD (r = 0.657, P < 0.05).</p><p><b>CONCLUSIONS</b>Tumor microvessel density and VEGF expression facilitate the exploration of the pathophysiological basis of CT perfusion in SPNs. Multi-slice CT perfusion has shown strong positive correlations with angiogenesis in SPNs.</p>

Clinical research of correlation between osteonecrosis and steroid / 中华外科杂志

<p><b>OBJECTIVE</b>To explore the correlation between the dosage of corticosteroid, time of onset and incidence of osteonecrosis (ON) in patients with SARS.</p><p><b>METHODS</b>From July 2003 to January 2004, general survey carried out for ON in 551 patients with SARS. Five hundred and fifty-one patients except 12 were administrated by corticosteroid from 80 mg to 30 000 mg. The age of patients was (33 +/- 9) years old ranging from 19 to 59 years old. One hundred and thirty-one were male, and four hundred and twenty were female. MRI and X-ray film were taken in all patients including both hips, knees, shoulders, ankles and wrists. CT scan was taken in partial patients. Common classification system were used for staging of hip (ARCO), knee (Lotka) and shoulder (Cruess). Independent test, rank-sum test and multiple factor logistic regression analysis were used for statistical analysis.</p><p><b>RESULTS</b>No osteonecrosis was detected in 12 patients without corticosteroid. Osteonecrosis was detected in 176 patients (32.7 percent) among 539 patients. There were ON of femoral head in 130 cases (210 hips), ON of knee in 98 cases (130 knees), ON of humeral head in 21 cases (36 shoulders), ON of talus and calcaneus in 16 cases (26 ankles), ON of scaphoid and lunate in 11 cases (17 wrists), ON of patella in 3 cases (4 patella), ON of ilium in 1 case and bone infarction (femur, tibia) in 18 cases. One hundred and nineteen cases (195 hips) with ONFH were in stage I (IA 45 hips, IB 77 hips, IC 73 hips). Eleven cases (15 hips) were in stage II. All osteonecrosis of the knee and humoral head was stage I. Thirty-four patients with ON had one joint affected, 45 patients had 2 joints, 93 patients had more than 3 joints. The dosage of corticosteroid was (5842 +/- 4988) mg in ON group and (2719 +/- 2571) mg in non-ON group (P < 0.0001). The duration of steroid was (38 +/- 17) d in ON group and (27 +/- 15) d in non-ON group (P < 0.01). The dosage of pulse treatment was (340 +/- 207) mg/d in ON group and (211 +/- 160) mg/d in non-ON group (P < 0.01). The duration of pulse treatment was (28 +/- 13) d in ON group and (18 +/- 11) d in non-ON group (P < 0.01). All patients with ON were detected within 6 months from administration.</p><p><b>CONCLUSION</b>About one-third patients with SARS who were treated with a high dose of corticosteroid occurred osteonecrosis. ON is frequently multiple focuses. The actual time of onset of ON is early of steroid used. MRI is golden standard for early diagnosis of ON. The patients who were treated with a high dose of corticosteroid should be inspected initially by MRI.</p>

The utility of different planes of CT scan in classification of radial head fracture / 中华放射学杂志

Objective To analyze and compare images of radial head fracture of 50 patients acquired by computed radiology(CR),coronal plane and axial plane of CT scan.And to determine routine plane of CT scan for radial head fracture.Methods Images of of radial head were acquired by CR,coronal plane and axial plane of CT scan on 50 patients with radial head fracture initially diagnosed by orthopedists. classify all the cases of radial head fracture into type Ⅰ、Ⅱ、Ⅲ and Ⅳ according to the classification proposed by Mason.Results The positive incidence of CT and CR were 96%(48)and 78%(39) respectively.Cases of 94%o(47)through CT coronal scan and 82%(41)eases through CT axial scan were exactly classified.Conclusion The designation of the plane of CT scan is significant to the classification of the radial head fracture.Coronal plane CT scan can meet the need of imaging clinical classification and is recommended to be routine plane of radial head fracture.In order to ensure the exact classification axial plane and 3D reconstruction technique should be added for type Ⅲ and type Ⅳ of radial head fracture.