Objective To approach the value of combination mode of different CT post-processing technique in diagnosing rib fine fracture.Methods 98 patients suspected with rib fractures underwent multislice spiral CT(MSCT) scanning,and CT features of rib fractures were observed with the combination of three different images:(A)volume rendering(VR),curved planar reformation(CPR) and axial view;(B)maximum intensity projection(MIP),CPR and sxial view;and(C) VR+MIP,CPR and axial view.The results were respectively recorded.Results 265 rib fine fractures were found among 98 patients.The detecting rate of fine fractures with C group was higher than that with A group (χ~2＝6.67,P＜0.01) and B group (χ~2＝6.75,P＜0.01).Conclusion MSCT four step observation method can improve the detecting rate of rib fine fracture,that is of important clinical value.

Objective To study the effects of 16-detector row CT on the measurement of abdominal fat in diabetic patients. Methods Forty patients with diabetes mellitus were enrolled in this study(diabetes group), 40 healthy subjects served as control (control group). Several indexes of abdominal adipose were measured with 16-slice spiral CT including the volume of abdominal adipose (VAA)ranging within 2.5cm of the umbilicus, volume of visceral adipose (VVA) and volume of subcutaneous adipose (VSA). Meanwhile, visceral adipose area (VA) and subcutaneous adipose area (SA) were measured also. Results The volumes of VAA,VVA,VSA,VA,SA,VVA/VSA and VA/SA in diabetes group were significantly larger than that in control group (all P＜0.05).Conclusion Diabetes patients have the accumulation of abdominal fat.

Objective To investigate the value of multi-slice spiral CT (MSCT) in diagnosis of colorectal carcinoma. Methods MSCT images of 42 cases of colorectal carcinoma proved by surgery and pathology were retrospectively analyzed. Multiplanar reconstruction (MPR) in all cases, and curved planar reconstruction (CPR), shaded surface display (SSD), CT virtual colonoscopy (CTVC) and Raysum were performed in some of the cases. MSCT findings were analyzed in comparison with operative and pathologic features. Results The detecting rate and quatitative rate of colorectal carcinomas with MSCT were 100%,respectively.The accurate rates were 82.9%(29/35) and 100%(7/7) in detection of invasion of surrounding structures and metastasis in abdominal organs respectively,the sensitivity and specificity for detetion of lymph node metastasis were 71%(22/31) and 100% with MSCT imaging.Conclusion MSCT scan with multiform reconstruction techniques can make definite diagnosis of colorectal carcinoma, which is helpful for treatment plan.

Objective To study X-ray and CT methods of diagnosis of unilateral dislocation of the lower cervical vertebra(C_(3～7)).Methods 15 cases of the injury of unilateral dislocation of the lower cervical vertebra were reviewed from August 2002 to June 2008,X-ray and CT findings were observed.Results Lateral projection of X-ray showed:the anterior displacement of dislocated vertebra was less than 25% in 15 cases,the distance of posterior border of lateral mass of below vertebral body to line of neural scute changed rapidly in 13 cases,sign of "bow tie" of processus articularis superior in 12 cases.Antero-posterior projection showed that spinal process was lateral deviation.Oblique projection showed that intervertebral joints were dislocation or interlocking. CT showed:the "hamburger" sign were destroyed in 7 cases,fracture of unilateral articular process in 8 cases,rotation of vertebral body of dislocation and its superior vertebral body in 13 cases, "double ring" sign in 12 cases.Conclusion The signs of X-ray and CT in combination with the mechanism of injury and clinical situation,the unilateral dislocation of the lower cervical vertebra can be diagnosed accurately.

Objective To study the application of spiral CT three-dimensional reconstruction in diagnosing intra-articular and other bone fractures in the earthquake of Wenchuan.Methods 25 cases with joint and other bone fractures in Wenchuan earthquake underwent multi-slice spiral CT volume scanning,the images were dealed with three-dimensional reconstruction at workstation including multiplanar reconstruction (MPR) and surface shaded display(SSD) to observe the fractures.Results 36 fractures in 25 cases were found by three-dimensional reconstruction(MPR and SSD),which included knee joint bone fracture in 6,one case was avulsion fracture of the point attached to the tibia by posterior cruciate ligament and missed by X-ray;ankle fracture in 3,1 case was Pilon fracture;shoulder fracture in 5,one case with glenoid anterior labrum missed by radiography;elbow fracture in 3;spinal fractures including cervical vertebra in 2,thoracic vertebra in 4 and lumbar vertebra in 5,2 cases were burst fracture accompanied with the articular process fracture; pelvis bone fracture in 8,1 case was sacroiliac fracture accompanied with sacroiliac separation.There were open bone fractures in 4 cases,fractures with dislocation in 6 cases,soft tissue swelling in different degree around the fractures in 25 cases.Conclusion Spiral CT three-dimensional reconstruction of bone can directly and really show the fractures that will provide in-formations for the clinical diagnosis and treatment .

Objective To study the spatial variation of T2 relaxation time of cartilage of knee in healthy adults.Methods T2 values of cartilage of knee in 21 asymptomatic young male adults ( age ranged 24 to 39 years ; mean age , 30 years) were calculated by using a multiecho,spin-echo MR imaging sequence at 1.5T MR scanner on sagittal T2 maps,including the patellar,distal femoral weight and non-weight-bearing as well as proximal tibial weight-bearing cartilages,the differences in the spatial variation between them were analysed using F test.Results All 21 asymptomatic volunteers demonstrated a consistent pattern of spatial variation of T2 values cartilage of knee with longer T2 values near the subchondral bone,decreased in deep zoon and increased in articular surface , there was difference between them (F=70.892 , P＜0.05 ) . The greates spatial variation occurred in the patella.T2 value(26.56 ms±4.4 ms) in the deeper zoon of cartilage of the patella was obviously lower than that of the weight-and non-weight-bearing articular cartilage (P = 0.001 ) . Lateral femoral weight-bearing articular cartilage showed lower T2 value ( 35.2 ms ± 6.31 ms) in the outer transitional superficial zone than thatof the patella and non-weight-bearing cartilage,P=0.002,P=0.000 respectively.Lateral tibial weight-bearing articular cartilage showed showed lower T2 value(37.11 ms±6.6 ms)in the outer transitional superficial zone than that of non-weight-bearing cartilage(P=0.000). Conclusion The spatial variation of T2 relaxation time of cartilage of knee in the vivo in the asymptomatic young adults is like slightly concave curve at 1.5T MR system,that is of reference value in study of degenerative osteoarthritis.

Objective To investigate the diagnostic value of low-field MR imaging in lumbar disc degeneration with end-plate osteochondritis. Methods Imaging data of 504 patients with lumbar disc degeneration diagnosed by MRI were retrospectively analyzed. Among these cases, the total of 330 end-plate osteochondritis in 148 patients was found. According to MR signal findings of end-plate and it's adjacent vertebra, the lesions were classified as 4 types. Results 330 end-plates were involved in 148 patients,including type I in 68(20.6%),type II in 53(16.1%),type III in 174(52.7%) and type IV in 35(10.6%).Among all 148 patients,the end-plates at one lumbar disc,two disci and over three disci involved in 98(66.2%),42(28.4%) and 8(5.4%),respectively.The lesions were usually found in the lower lumbar vertebra.Conclusion MR imaging could accurately show the end-plate osteochondritis and degenerative lumbar disc.

Objective To explore imaging fingdings of pigmented villonodular synovitis (PVS) so as to improve the diagnostic accuracy of PVS. Methods Imaging data of 12 patients with PVS confirmed by operation and pathology were analyzed retrospectively.12 cases were all examined with X-ray and MR imaging,5 cases examined with CT.Results In total 12 cases, swelling of soft tissue was seen in 8 cases on plain films.CT showed subcartilaginous bony erosion in 3 cases.MRI showed synovium nodular hyperplasia irregularly, deposition of paramagnetic hemosiderin-containing in all cases,and the invasion of ligament in 5 cases , menisci in 1 case and infrapatellar fat pad in 3 cases; subcartilaginous and cartilaginous erosion in 3 cases, joint effusion in 9 cases. Conclusion PVS has typical imaging characteristics,PVS can be diagnosed accurately with MRI.

Objective To suty the MRI manifestations of juvenile acute articular cartilage injury of the knee joint.Methods MRI findings of cartilage,subcartilage low signal line and subcarilage bone were analysed retrospectively in 53 juvenile patients (ranged in age from 4~27 years) with acute articular cartilage injury confirmed by arthroscopy.Results Sixty-nine cartilage injuries were showed by MRI in 53 patients,including patellas in 25,femoral lateral condyles in 22,femoral medial condyles in 11,trochlea of the femur in 2,and tibial plateau in 9.Acute articular cartilage injury appeared as pure cartilage fracture in 46, including complete split of the cartilage in 22 sites,partly split of the cartilage in 20 sites,and fissur-like fracture in 4 sites.Osteochondral fracture were observed in 23 sites,including avulsion fracture in 13 and osteochondral subsided in 10.Articular cartilage loose bodies and osteochondral loose bodies were found by MRI in 6 and 13,respectively.Conclusion MRI is the best non-invasive method for studying cartilage injury.

Objective To study the CT features of small hepatocellular cancer.Methods 37 patients with small hepatocellular cancer proved histopathologically underwent spiral CT examinations including plain scans and contrast-enhanced scans.The arterial phase scan,the portal phase scan and delayed phase scan started at 25th second,70th second and 5th minute respectively after injecting the contrast medium with the high pressure syringe,the velocity was 2.5 ~3 ml/s,and the dose was 1.5 ml/kg.Results 73% (27/37) of tumors showed hyperdensity in arterial phase,65%(24/37) of tumors was hypodensity and 35% (13/37) had hyperdensity during portal phase,of which eight showed hypodensity in equilibrium phase.Conclusion Spiral CT can display the features of blood supply of small hepatocellular carcinoma that is of benefit in early diagnosis.