MRI manifestations and differentiated diagnosis of postoperative spinal complications / 华中科技大学学报（医学）（英德文版）

To analyze MR manifestations of postoperative spinal complications and investigate the value of MRI in the diagnosis and differentiated diagnosis, 114 cases of spinal postoperative complications were analyzed retrospectively and compared with the clinical data. The results showed that the main postoperative spinal complications included spinal stenosis (n=33, consisting of 21 cases of epidural fibrosis and 12 cases of epidural hematoma or epidural abscess), lack of spinal stability (n=43), infection (n=23, consisting of 7 cases of para-spinal soft-tissue infection, 5 cases of vertebral discitis, 4 cases of vertebral and appendix infection, 3 cases of epidural abscess, 2 cases of myelitis, 2 cases of spinal arachnoiditis), others (n=28, consisting of 12 cases of inner fixation failure, 9 cases of epidural hematoma, 7 cases of cerebrospinal fluid gusher). It is concluded that MRI can specifically display all kinds of postoperative spinal complications, and is of significant value in the diagnosis and differentiated diagnosis of postoperative spinal complications.

Application of Multislice Spiral CT for Guidance of Insertion of Thoracic Spine Pedicle Screws: An in vitro study / 华中科技大学学报（医学）（英德文版）

To investigate the value of the guidance of three dimensional (3-D) reconstruction of multi-slice spiral CT (MSCT) for the placement of pedicle screws, the 3-D anatomical data of the thoracic pedicles were measured by MSCT in two embalmed human cadaveric thoracic pedicles spines (T1-T10) to guide the insertion of pedicle screws. After pulling the screws out, the pathways were filled with contrast media. The PW, PH, TSA and SSA of developed pathways were measured on the CT images and they were also measured on the real objects by caliper and goniometer. Analysis of variance demonstrated that the difference between the CT scans and real objects had no statistical significance (P＞0.05). Moreover, the difference between pedicle axis and developed pathway also had no statistical significance (P＞0.05). The data obtained from 3-D reconstruction of MSCT demonstrated that individualized standards, are not only accurate but also helpful for the successful placement ofpedicle screws.

Experimental Study of Multi-slice Spiral CT Perfusion Imaging in VX2 Soft-tissue Tumor of Rabbits / 华中科技大学学报（医学）（英德文版）

An experimental animal model of malignant soft-tissue tumor was established to investigate the applied value of multi-slice spiral CT perfusion imaging preliminarily. Ten New Zealand white rabbits which were implanted with VX2 tumor in either proximal thigh were subjected to CT plain scan and perfusion scan two weeks later respectively, then the original perfusion images were transmitted to AW4.0 Workstation. The functional maps and perfusion parameters including blood flow (BF), blood volume (BV), mean transit time (MTT) and permeability surface (PS) were computed and analyzed. All the values of BF, BV and PS in VX2 soft-tissue tumors were obviously higher while the MTT-values were lower than those in the normal muscular tissues significantly. It was suggested that multi-slice spiral CT perfusion imaging is an accurate, convenient and relatively safe functional imaging technique, and can give a quantitative assessment to angiogenesis and blood perfusion of soft-tissue tumors.

Experimental study of multi-slice spiral CT perfusion imaging in VX2 soft-tissue tumor of rabbits / 华中科技大学学报（医学）（英德文版）

An experimental animal model of malignant soft-tissue tumor was established to investigate the applied value of multi-slice spiral CT perfusion imaging preliminarily. Ten New Zealand white rabbits which were implanted with VX2 tumor in either proximal thigh were subjected to CT plain scan and perfusion scan two weeks later respectively, then the original perfusion images were transmitted to AW4.0 Workstation. The functional maps and perfusion parameters including blood flow (BF), blood volume (BV), mean transit time (MTT) and permeability surface (PS) were computed and analyzed. All the values of BF, BV and PS in VX2 soft-tissue tumors were obviously higher while the MTT-values were lower than those in the normal muscular tissues significantly. It was suggested that multi-slice spiral CT perfusion imaging is an accurate, convenient and relatively safe functional imaging technique, and can give a quantitative assessment to angiogenesis and blood perfusion of soft-tissue tumors.

Application of multislice spiral CT for guidance of insertion of thoracic spine pedicle screws: an in vitro study / 华中科技大学学报（医学）（英德文版）

To investigate the value of the guidance of three dimensional (3-D) reconstruction of multi-slice spiral CT (MSCT) for the placement of pedicle screws, the 3-D anatomical data of the thoracic pedicles were measured by MSCT in two embalmed human cadaveric thoracic pedicles spines (T1-T10) to guide the insertion of pedicle screws. After pulling the screws out, the pathways were filled with contrast media. The PW, PH, TSA and SSA of developed pathways were measured on the CT images and they were also measured on the real objects by caliper and goniometer. Analysis of variance demonstrated that the difference between the CT scans and real objects had no statistical significance (P > 0.05). Moreover, the difference between pedicle axis and developed pathway also had no statistical significance (P > 0.05). The data obtained from 3-D reconstruction of MSCT demonstrated that individualized standards, are not only accurate but also helpful for the successful placement of pedicle screws.

Epiphyseal and Physeal Cartilage: Normal Gadolinium-enhanced MR Imaging / 华中科技大学学报（医学）（英德文版）

To evaluate the normal appearance of epiphyseal and physeal cartilage on Gadolinium (Gd)-enhanced MR imaging. The appearance and enhancement ratios of 20 proximal and distal femoral epiphyses in 10 normal piglets were analyzed on Gd-enhanced MR images. The correlation of the MR imaging appearance with corresponding histological findings of immature epiphyses was examined. Our results showed that Gd-enhanced MRI could differentiate the differences in enhancement between physeal and epiphyseal cartilage and show vascular canals within the epiphyseal cartilage. Enhanced ratios in the physeal were greater than those in the epiphyseal cartilage (P＜0.005). It is concluded that Gd-enhanced MR imaging reveals epiphyseal vascular canals and shows difference in enhancement of physeal and epiphyseal cartilage.

Gadolinium-enhanced MR Imaging of Epiphyseal and Metaphyseal Marrow in Normal Piglets / 华中科技大学学报（医学）（英德文版）

The purpose of this study is to define the appearance of normal epiphyseal and metaphyseal marrow and normal changes of marrow due to fatty conversion on Gadolinium (Gd)-enhanced MR Imaging. Unenhanced and enhanced T1-weighted MR imaging were performed in proximal and distal femoral ends of 8 healthy piglets at the ages of 2, 4, 6 and 8 weeks, respectively. The changes with age in signal intensity and enhancement ratio of the epiphyseal and tnetaphyseal marrow with age were examined. The correlation of MRI characteristics with histological findings was studied. Our study showed that marrow of the metaphysis and of periphery of the 2nd ossification center were well vascularized hematopoietic marrow and had great enhancements. The enhancement ratio of metaphysis was greater than that of epiphyseal marrow and both enhancement ratios degraded gradually with age. The central regions of the epiphyseal ossification center and of the diaphysis were of fatty marrow and had little enhancement. It is concluded that on Gd-enhanced MR imaging the hematopoietic marrow of metaphysis and of periphery of the 2nd ossification center had greater enhancement than that of fatty marrow of central region of the 2nd ossification center. All of their enhancements decreased gradually with age.

Gadolinium-enhanced MR imaging of epiphyseal and metaphyseal marrow in normal piglets / 华中科技大学学报（医学）（英德文版）

The purpose of this study is to define the appearance of normal epiphyseal and metaphyseal marrow and normal changes of marrow due to fatty conversion on Gadolinium (Gd)-enhanced MR Imaging. Unenhanced and enhanced T1-weighted MR imaging were performed in proximal and distal femoral ends of 8 healthy piglets at the ages of 2, 4, 6 and 8 weeks, respectively. The changes with age in signal intensity and enhancement ratio of the epiphyseal and metaphyseal marrow with age were examined. The correlation of MRI characteristics with histological findings was studied. Our study showed that marrow of the metaphysis and of periphery of the 2nd ossification center were well vascularized hematopoietic marrow and had great enhancements. The enhancement ratio of metaphysis was greater than that of epiphyseal marrow and both enhancement ratios degraded gradually with age. The central regions of the epiphyseal ossification center and of the diaphysis were of fatty marrow and had little enhancement. It is concluded that on Gd-enhanced MR imaging the hematopoietic marrow of metaphysis and of periphery of the 2nd ossification center had greater enhancement than that of fatty marrow of central region of the 2nd ossification center. All of their enhancements decreased gradually with age.

MRI characteristics and transverse relaxation time measurements in normal growing cartilage / 华中科技大学学报（医学）（英德文版）

To determine the characteristics of magnetic resonance (MR) signals of normal growing cartilage and identify the difference in transverse relaxation times between physeal and epiphyseal cartilage in vivo. 24 distal femora of 12 two-week-old piglets were imaged on a 1.5 Tesla GE MR scanner. Comparison was made between signal intensity on MR images and the structure shown in corresponding histologic sections. T2 values were measured in eight piglets by means of multiecho spin-echo sequences. Our results showed that MR imaging delineated five regions between the secondary ossification center and the metaphysis, which histologically correspond to the zone of provisional calcification of the secondary ossification center, physis of the secondary ossification center, epiphyseal cartilage, physis and zone of provisional calcification. The T2 value in the physeal cartilage was much larger than that in the epiphyseal cartilage (P<0.05). It is concluded that MRI findings could differentiate the different regions of growing cartilage. T2 is longer in physeal than in epiphyseal cartilage, perhaps reflecting differences in water binding by proteoglycans.

MRI characteristics and transverse relaxation time measurements in normal growing cartilage / 华中科技大学学报（医学）（英德文版）

To determine the characteristics of magnetic resonance (MR) signals of normal growing cartilage and identify the difference in transverse relaxation times between physeal and epiphyseal cartilage in vivo. 24 distal femora of 12 two-week-old piglets were imaged on a 1.5 Tesla GE MR scanner. Comparison was made between signal intensity on MR images and the structure shown in corresponding histologic sections. T2 values were measured in eight piglets by means of multiecho spin-echo sequences. Our results showed that MR imaging delineated five regions between the secondary ossification center and the metaphysis, which histologically correspond to the zone of provisional calcification of the secondary ossification center, physis of the secondary ossification center, epiphyseal cartilage, physis and zone of provisional calcification. The T2 value in the physeal cartilage was much larger than that in the epiphyseal cartilage (P<0.05). It is concluded that MRI findings could differentiate the different regions of growing cartilage. T2 is longer in physeal than in epiphyseal cartilage, perhaps reflecting differences in water binding by proteoglycans.

Extranodal imaging manifestations of non-Hodgkin's lymphoma / 华中科技大学学报（医学）（英德文版）

A series of imaging features of extranodal, multi-systemic involvements in Non-Hodgkin's lymphoma (NHL) were investigated. The clinical data and imaging findings of 16 patients with pathologically proved NHL were retrospectively analyzed. The related literatures were reviewed. Of the 16 cases of NHL, skeletal involvement was found in 4, nasal cavity and nasal sinuses were involved in 4, too. Lesion in the thorax was seen in 3 patients, hepatic involvement occurred in one case, cerebral ventricle was affected in 3 cases, mesentery was involved in one case. Even though extranodal involvement of NHL exhibited extremely variable patterns, there were some relatively typical imaging findings. Emphasized in this report were the relatively specific imaging manifestations of different systems, which may mimic infectious or other neoplasms of different sites. The importance of imaging studies lies in the availability for diagnosis, staging and follow-up of NHL. Combined with the clinical and other related information, the diagnostic accuracy can be further improved, thus, providing reliable evidence in guiding clinical management.

The application of three dimensional contrast enhanced subtraction MRA in the diagnosis of extremity musculoskeletal diseases / 中华放射学杂志

Objective To study the value of three dimensional contrast enhanced subtraction MRA (3D CES MRA) in the diagnosis of extremity musculoskeletal diseases. Methods Fifteen cases of extremity musculoskeletal diseases proved by operation and pathology were studied, including upper extremity ( n =5), lower extremity ( n =10), soft tissue and vascular lesions ( n =8), and skeletal lesions ( n =7). All examinations were performed with GE 1.5 T MRI scanner. Sagittal scout images were obtained by 2D FMPSPGR sequences. Before and after contrast enhancement, coronal 3D FSPGR sequence was performed in the same parameters within 32 seconds. The plain source images were subtracted by enhanced source images in the workstation. The subtracted images were processed by MIP technique, such method is so called 3D CES MRA. Results All lesions were demonstrated accurately by 3D CES MRA, including vascular lesions ( n =6), tumors in the soft tissue ( n =3), benign skeletal tumors ( n =1), and malignant skeletal tumors ( n =3). Compared with pathology, the diagnosing accuracy rate of 3D CES MRA was more than 90%. Conclusion 3D CES MRA is an advanced, safe, and noninvasive method in diagnosing extremity musculoskeletal diseases, further more, it can save time and resources. In general, 3D CES MRA has a great value in clinical application.