The lumbar intervertebral disc is a disc-shaped fibrocartilaginous structure located between the vertebral bodies and acts as an important anatomical structure in the spine for stability. The spinal stability system consists of three subsystems: passive subsystem, active subsystem, and neural control subsystem. Lumbar intervertebral disc degeneration (IVDD), the leading cause of low back pain, induces pathological changes in other tissues of the three subsystems and interacts to degrade spinal stability. IVDD is commonly accompanied by degeneration of facet joint and ligament, Modic change, decreased vertebral blood flow, increased paraspinal muscle fat infiltration, reduced axial tension injury of the nerve, et al. Magnetic resonance imaging (MRI) is the preferred imaging modality for assessing spinal stability. Conventional MRI could completely demonstrate the morphological changes of the three subsystems in IVDD patients, and functional MRI could quantitatively evaluate the degree of pathophysiological change. We summarized the morphological and functional changes of MRI in lumbar intervertebral disc, facet joint, ligament, vertebral body, paraspinal muscle, and nerve of patients with IVDD, and then analysed the changes in spinal stability caused by IVDD, aiming to provide more imaging information for improving diagnosis accuracy and developing appropriate management of patients with low back pain.

Objective To study the value of bone marrow MR imaging in mornitoring chronic myeloid leukemia(CML).Methods 12 cases of CML underwent twice MR examination of pelvis and femur respectively at different time.MRI appearances were compared with the results of morphology and blood routine at the same time.The relation between MR findings and course was analysed.Results MR appearances of bone marrow were changed with the progression of disease.The condition of patients was improved in 2 cases and worse in 4 cases,the signal intensity of bone marrrow were increased and decreased respectively.The signal intensity of bone marrow showed no change in 6 patients whose condition kept stable.Conclusion The characteristics of MRI can reflect the progression of CML,it is of important value in mornitoring this disease.

Objective To observe bone marrow MR imaging of adult acute leukemia patients in first diagnosis and to reveal the rule of bone marrow infiltration and the role of MRI in diagnosing and predicting the prognosis of untreated acute leukemia adult patients. Methods Fifty-four adult acute leukemia patients received MRI after diagnosis relying on FAB subtype and immunophenotyping including 28 cases with AML and 26 cases with ALL. MR imaging was obtained by the short time inversion recovery and T 1W spin echo technique of pelvis and femur at one time. The examining results of morphology and blood routine were collected at the same time. 15 age-matched volunteers were selected as controls. Results MRI showed that bone marrow of all patients were infiltrated by leukemia cells. The MRI appearance was classified into five patterns based on scope of focus. MRI patters from grade 1 to grade 3 were observed in most of patients with AML and in none with ALL, however, all patients with ALL distributed in grade 4 to grade 5. The distribution of patterns had significant difference between AML and ALL (P

BACKGROUND:The patients with porcelain-fused-to-metal crowns who do examination of magnetic resonance imaging (MRI) can cause artifacts. In recent years, researching for MRI artifacts of different porcelain-fused-to-metal materials has been some progress, but there are less quantitatively reports on the MRI artifacts of different porcelain-fused-to-metal materials.
OBJECTIVE:To evaluate the artifact sizes shown on fast spin-echo T 2-weighted sequence caused by different kinds of porcelain-fused-to-metal crowns.
METHODS:Forty-eight lower right first molar crown patients who had MRI examination in MRI room were enrol ed. The patients were divided into nickel-chromium al oy group, cobalt-chromium al oy group and titanium crown group. Al patients were examined with fast spin-echo T 2-weighted sequences by means of 1.5 T MRI apparatus. MRI artifacts areas of same sequence on the MRI images of different porcelain-fused-to-metal materials were analyzed with variance test.
RESULTS AND CONCLUSION:Forty-five cases appearing to have high signal samples with clearly curved boundary zone that can be measured were selected, 15 cases for each material. Different artifact sizes were produced on the same sequence of different porcelain-fused-to-metal materials, which were (321.67±33.29) mm in the nickel-chromium al oy group, (263.53±34.95) mm2 in the cobalt-chromium al oy group, and (143.67±31.13) mm2 in the titanium crown group. There were significant differences between groups (P<0.05). The artifact size is smal est for the titanium crown and largest for the nickel-chromium al oy crown.

Objective To study the appearance of magnetic resonance imaging (MRI) in early stages of cartilage degeneration and to detect its values.Methods Intra articular injection of 5 units of papain causing a reversible loss of cartilage proteoglycan in the New Zealand rabbit knees.Rabbits were scanned with magnetic resonance imaging,using a 0 3 T Hitachi magnet with 16 cm coil.Gradient echo sequences and spin echo sequences were performed in the sagittal planes at 0,24,48 and 72 hours after intra injection of papain.Then signal intensity and thickness of cartilage were measured.The proteoglycan content was measured biochemically and histochemically.Results The cartilage thickness and signal intensity decreased significantly in treated knees compared with control knees at 24 and 48 hours ( P 0 05) after injection of papain.These changes on magenetic resonance (MR) images were consistent with the changes of proteoglycan concentration measured by biochemical analysis and histochemical staining of cartilage.Conclusion It is possible for MRI to detect the early stages of cartilage degeneration.

In order to observe the feature of age-related marrow conversion and maturation of epiphyseal cartilage and analyze the distribution of red and yellow marrow in the proximal femur at STIR MR imaging, STIR and T(1) weighted MR imaging of the proximal femur in 52 subjects, aged 4 months to 25 years old, were retrospectively analyzed for the distribution and appearance of red and yellow marrow. The subjects with no known bone marrow abnormalities were divided into 6 age groups. The signal intensity of the marrow in the proximal epiphysis, proximal metaphysis, proximal diaphysis, distal diaphysis and greater trochanter was compared with the signal intensity and homogeneity of surrounding muscle and fat and graded by two observers. The results showed that the conversion of hematopoietic marrow in the proximal femur followed a well-defined sequence, occurring first in the proximal epiphysis, followed by the distal diaphysis, and then greater trochanter and metaphysis. STIR in combination with T(1)-weighted imaging could display clearly the origin of ossification center and the course of conversion from red to yellow marrow in proximal epiphysis and greater trochanter. STIR imaging showed that the marrow conversion in proximal metaphysic began below epiphyseal plate and intertrochanter. The site of red yellow was distributed in weight-bearing axis by 20 years of age. The marrow conversion of diaphysis was from distal end to proximal end, and the consequence of conversion was that distal diaphysis contained yellow marrow but proximal diaphysis partly red marrow connected with the red marrow of metaphysic. The epiphyseal cartilage had different characters of signal-intensity with age in STIR sequence. The distribution of red marrow in STIR imaging was more close to that of anatomy than T(1)-weighted imaging. It was concluded that STIR could dynamically display the feature of marrow conversion and the development of epiphyseal cartilage and accurately reveal the age-related distribution of red and yellow marrow on STIR imaging in the proximal femur.
Age Factors ; Bone Marrow/*anatomy & histology ; Bone Marrow/physiology ; Epiphyses/anatomy & histology ; Femur/*anatomy & histology ; Image Enhancement/*methods ; Magnetic Resonance Imaging/*methods ; Retrospective Studies ; Young Adult

Objective To analyze effects of thoracoscopy in the diagnosis and treatment of suspected diaphragmatic injury after thoracoabdominal stab wound.Methods Sixty-eight patients who received thoracoscopic diagnosis and management of diaphragmatic injuries due to thoracoabdominal stab wounds from April 2000 to October 2011 were retrospectively analyzed.Results Occult diaphragmatic injuries were found in 11 patients.Seven patients underwent thoracoscopic suture,of which five had synchronous laparotomy for inspected abdominal organ injuries.Pulmonary parenchymal lacerations occurred in 15 patients who received thoracoscopic repair or resection.Coagulated hemothorax in 13 patients were removed.Postoperative complications included pleural effusion in one patient,pneumonia in two and pulmonary atelectasis in one.Hospital stay was(7.9±13.5)days,without ICU stay.The length of drainage,operation time and intraoperative blood loss were(3.3±1.5)days,(45.6±78.1)minutes and(57.8±24.3)ml respectively.There was no conversion to thoracotomy.Thoracic CT scan was performed six months postoperatively,without hernias.The accuracy of thoracoscopy in diagnosing diaphragmatic injury was 100％.Conclusion Thoracoscopy should be performed for the thoracoabdominal stab wounds with stable hemodynamics,with definite significance especially for the diagnosis and treatment of wounds at the 7-9th intercostal spaces.

BACKGROUND:To establish a tumor-bearing animal model of the head and neck is of clinical significance for further studying pathogenesis and transfer mechanisms and for actively finding an effective diagnosis and therapeutic regimen. OBJECTIVE:To compare the growth, lymphatic metastasis and distant metastasis characteristics of head and neck tumors in animals. METHODS:VX2 tumor cel lines were resuscitated and passaged to establish tumor-bearing rabbit models. Under anesthesia, the tumor was stripped from the tumor-bearing site to make tumor cel suspension. Then, thecel suspension was injected into the thigh muscle of rabbits and then passaged 2 weeks later. Tumor samples were harvested from the thigh of passage rabbits to make VX2 tumor cel suspension that was injected into the ear, tongue and nasopharynx of rabbits to make a VX2 tumor model of the head and neck in the rabbit. RESULTS AND CONCLUSION: The three groups of rabbits had significant differences in spirit, diet, activity and so on. Rabbits with tumor xenograft of the ear were significantly better than those with tumor xenograft of the tongue and nasopharynx. At 2 weeks after injection of VX2 tumor cel suspension, the VX2 tumor models of the head and neck were made successfuly in rabbits, and the tumor formation rate was 100% (15/15) at the ear, 93% (14/15) at the tongue and nasopharynx. VX2 tumors at different sites experienced rapid growth period, central necrosis period, surface ulceration period, and the life cycle was about 4-6 weeks. Lymph node metastasis in head and neck and pulmonary metastasis were found in the al three groups. Hematoxylin-eosin staining showed that VX2 tumor tissues and metastatic lymph nodes were confirmed as moderately to poorly differentiated squamous cel carcinoma. These findings indicate that tumor-bearing rabbit models of the head and neck established by VX2 cel suspension are characterized by short modeling cycle, good stability, easy to repeat, high tumor formation rate and simple operation. VX2 tumors in the different sites of the head and neck of rabbits have different characteristics, so we can choose the different implanting sites according to the different research purposes.

Multiple myeloma (MM) is a hematological malignancy characterized by proliferation of monoclonal plasma cells in bone marrow,mostly resulting in bone marrow infiltration and bone destruction.X-ray plain film is a primary imaging modality for MM,and it is also used for Durie-Salmon staging and risk stratification of MM.Currently,advanced imaging techniques,such as CT,MRI,PET/CT and PET/MRI have been widely used in the diagnosis and treatment of MM,providing important references for staging accurately,prognostic evaluation and therapeutic monitoring in patients with MM.The imaging progresses in MM were reviewed in this article.

ObjectiveUsing dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) to evaluate the hemodynamic perfusion characteristics of bone marrow infiltration in patients with acute leukemia (AL). MethodsForty-seven patients with AL received coronal pelvic T1WI DCE-MRI with fast low angle shot (FLASH) sequence. Among them, 25 were initial onset untreated (IOU) patients, 22 were treated AL patients, including 14 with complete remission (CR) and 8 with non-remission ( NR). The hemodynamic perfusion parameters including maximum percentage of enhancement ( Emax ) and slope were determined based on enhancement-time curves ( ETCs ) of iliac and lumbar vertebra. The proportion of marrow myeloblasts was recorded.For all patients, quantitative perfusion parameters of bone marrow infiltration in ilium were compared with those in lumbar. The values of Emax and ES were compared among IOU,CR and NR patients.Correlations between perfusion parameters and histopathological results were assessed. ResultsIn all the 47 patients, the Emax values of bilateral iliac bone marrow ( 15.70 ± 7.06)were slightly higher than that of lumbar bone marrow ( 11. 28 ± 5.52 ), and the difference was statistically significant (P ＜0. 01 ).There was no significant difference in the slop value between bilateral iliac bone marrow (0. 82 ± 0. 12 ) and lumbar bone marrow (0. 80 ± 0. 09 ) ( P ＞ 0. 05 ). In the 25 untreated patients,the Emax and slop values were 17. 15 ± 5.75 and 0. 98 ± 0. 13, respectively; in the 14 CR patients, they were 8. 76 ±3.93 and 0. 26 ± 0. 04, respectively, and in the 8 NR patients, they were 21.62 ± 6. 50 and 1. 38 ± 0. 02, respectively. There was significant difference in the Emax and slop values among the three groups (P＜0. 05).Compared with IOU and NR patients, both the Emax and slop values decreased significantly in iliac bone marrow of AL patients with CR (P ＜ 0. 05 ). There was no significant difference between IOU and NR patients ( P ＞ 0. 05 ). A significant positive correlation was found between Emax value of iliac bone marrow and the proportion of marrow myeloblasts ( r ＝0. 501 ,P ＜0. 05 ). There was a negative correlation between slop value of iliac bone marrow and the proportion of marrow myeloblasts ( r ＝0. 235 ,P ＞0.05).ConclusionsDCE-MRI can beused for evaluating the hemedynamic characteristics of microcirculation of bone marrow infiltration in patients with AL, which can provide useful information in evaluating prognosis and monitoring therapeutic effect.