Objective To evaluate the myocardial microvascular obstruction induced by occlusion of single coronary artery (OSCA) and stenosis of multi-coronary arteries (SMCA) using first-pass perfusion cardiac MRI. Methods We studied 33 patients who had acute myocardial infarct and received emergency coronary angiography and angioplasty. Coronary angiogram confirmed that 15 patients had complete occlusion of the single coronary artery and 18 patients had multi-coronary artery stenosis without occlusion. Cardiac MRI (CMRI) exam was performed at 6-12 weeks after diagnosis. Results CMRI demonstrated that 15 patients had first-pass perfusion defect in the endomyocardium. The signal intensity (SI) of the perfusion defect was significant lower than that in the normal myocardium. The maximal slope of SI showed that the there were 11 patients with occlusion of the single coronary artery and 4 patients with stenosis of multi-coronary arteries. Conclusion CMRI can show the microvascular obstruction limited in the region of endomyocardium. CMRI suggests that the occlusion of the single coronary artery may induce more severe myocardial microvascular obstruction than the stenosis of multiple coronary arteries.

Objective To explore the X ray imaging of the common complications after total hip replacement (THR), in order to improve the diagnosis and differential diagnosis of the complications of THR. Methods Forty six cases were revised because of the complications of THR. The value of X ray in the diagnosis of complications was assessed by observing the radiography and comparing with surgical results. Results In these cases, after revision, 34 cases had aseptic loosening of femoral component, 13 cases had aseptic loosening of acetabular component, presenting on radiographs as the lucent zone alone the component, which was ≥2 mm in width and had the same contour as the component. 4 cases had septic loosening of femoral and (or) acetabular component, presenting on radiographs as the lucent zone alone the component, and bone destruction and sinus were also observed. The lucent zone was also ≥3 mm, but had the different contour of the component. Both kinds of loosening may accompany with migration of the component or not. 6 cases had dislocation of femoral head, presenting on radiographs as the head lying out of acetabulum in 2 cases, central migrating of the head in 2 cases, and asymmetrical position of the head in acetabulum in 2 cases. Conclusion The lucent zone and component migration had the important diagnostic value of loosening, the contour of lucent zone and sinus could help to make the differential diagnosis of aseptic and septic loosening. Asymmetrical position of the head in acetabulum and the head lying out of acetabulum were the signs of dislocation.

Objective To study the metabolic alteration in the brain of patients with cyanosed congenital heart disease (CCHD) by using 1H magnetic resonance spectroscopy ( 1H MRS) and discover the pathophysiology of chronic hypoxic brain, which will help to diagnose and treat this disease completely. Methods Twenty five patients with CCHD and 25 controls were performed PRESS 1H MRS and MRI, The areas under the resonance of metabolites were measured, the ratios of the other metabolites to Cr were calculated and compared. Results In patients with CCHD, the mean value of NAA/ Cr was significantly lower than that in controls ( P 0.05). Conclusion 1H MRS can detect brain metabolic changes in patients with cyanosed congenital heart disease in vivo noninvasively and can detect the metabolism disorder of the energy and amino acid, so the pathophysiology of this disease can be understood.

Objective To evaluate the diagnostic value of MRCP compared with ultrasound in patients with cholangiopancreatic disease by ROC curve. Methods The data of 62 patients with suspected cholangiopancreatic disease undergoing both MRCP and ultrasound were retrospectively studied. ROC analysis was performed by ROCKIT software. Results Area under the ROC curve of MRCP was 0.739. Area under the ROC curve of US was 0. 930. ROC analysis showed that these two modalities were effective in diagnosing cholangiopancreatic disease, with MRCP being more effective than ultrasound, especially for the diagosis of lower biliary tract diseases. Conclusion MRCP combined with MRCP source images is of great help in the diagnosis of pancreaticobiliary duct diseases.

PurposeDiffusion weighted imaging (DWI) can significantly improve the diagnosis of non-enlarged lymph node metastasis. This study aims to evaluate the correlation between the DWI findings and the prognosis, and to identify prognostic factors.Materials and Methods Forty-seven patients with colorectal cancer underwent MRI scan including DWI sequence before surgery. Imaging ifndings were compared with the pathologic results to determine the metastatic lymph nodes (DWI positive) or non-metastatic lymph nodes (DWI negative). Postoperative disease-free survival and overall survival for 5 years of the patients with DWI positive and DWI negative lymph nodes were compared. Correlation between the prognosis and the related factors were investigated including regional DWI-positive lymph nodes, short axis diameter and long axis diameter of the largest DWI-positive lymph node, and number of DWI-positive nodes.Results Of 47 patients,10 (21%) patients had regional DWI-positive lymph nodes showed high signal intensity on diffusion-weighted images. The patients with regional DWI negative lymph nodes had a signiifcant better ifve-year disease-free survival and overall survival (P<0.05). The short axis diameter of the largest DWI-positive lymph node was correlated with distant metastasis (AUC=0.77,P<0.05). The short axis diameter and long axis diameter of the maximum metastatic lymph nodes were correlated with overall survival (AUC=0.84 and 0.75,P<0.05). Five-year disease-free survival and overall survival of the patients with short axis diameter of the largest DWI-positive lymph node ≤9 mm were higher than the patients with lymph node short axis diameter >9 mm (P<0.05). Five-year disease-free survival and overall survival of the patients with long axis diameter of the largest DWI-positive lymph nodes ≤11 mm were higher than the patients with long axis diameter >11 mm (P<0.05). Five-year disease-free survival of the patients with all DWI positive lymph nodes resected was higher than the patient without DWI-positive lymph nodes resected (P<0.05).Conclusion The patients with regional DWI-negative lymph node had a better prognosis. Of the patients with DWI-positive lymph nodes, the patients with smaller lymph nodes have better prognosis than who have larger lymph nodes.

Objective To compare the diagnosic performance of conventional 2D and 3D Cube MR imaging to identify complete and partial tears of anterior cruciate ligament(ACL).Methods Farty patients suspected of having tears of anterior cruciate ligament were prospectively studied by 3.0 T conventional 2D and 3D Cube MR imaging and arthroscopy.MR images were interpreted in consensus by two experienced radiologists,and the ACL was diagnosed as being normal,partially torn,or completely torn.Diagnostic accuracy of 2D and 3D Cube MR for the detection of both complete and partial tears of ACL was calculated using arthroscopy as the standard of reference.Area under curve (AUC) of both methods were calculated using ROC curves and were compared using Hanley& McNeil curve comparisions.Results Sixteen patients had intact ACL,12 had complete tear,and 12 had partial tear of the ACL at arthroscopy.For complete ACL tear,AUC of 2D MR and 3D Cube was 0.839 and 0.923 respectively,and there was no significant difference on ROC curves (Z =1.245,P =0.213).For partial ACL tears,AUC of 2D and 3D Cube MR were 0.643 and 0.881 respectively,and there was significant difference on ROC curves (Z =2.384,P =0.017).Conclusions Both 2D MR and 3D Cube MR have high sensitivity and specificity for identifying the complete ruptures of ACL.3D Cube MRI appears to be superior inidentifying partial rupture of ACL.

Objective To control the image quality and to optimize the scan protocols of 64 multi-slice CT coronary imaging by analyzing factors that influence the image quality.Methods Seventy-eight patients with known or suspected CAD underwent CT coronary angiography using 64 multi-slice CT.The image quality in those cases was analyzed retrospectively to derive the optimized scan protocols.The application value of the override function was discussed.The dependency of cardiac reconstruction algorithms and corresponding image quality on patient heart rates was analyzed.In addition,the relationship between heart rate and the contrast-enhancement effect was studied.Results(1)Correct use of override function could improve the quality of cardiac images.(2)For patients with heart rates below 70 beats per minute,the image quality of single-segment reconstruction was satisfactory.For patients with heart rates between 70 and 79 beats per minute,the scores of images reconstructed with two-segments were better than that of single-segment reconstruction.(3)In the group with averaged heart rate of 60.7 beats per minute,the forecast contrast quantity of 70 ml was judged insufficient in 65.7%(23/35)cases;while for the group with averaged heart of 71.1 beats per minute,52.9%(18/34)cases were enhanced well.Conclusion The use of override function,correct segment mode and appropriate contrast quantity could be selected according to the heart rate,which could improve the image quality and reliability.

Objective To determine the relationship between the delayed enhanced area on contrast enhanced MRI to the infarct area on pathologic examination in order to offer the groundwork for clinic in the assessment of myocardial viability by MRI Methods Application of short axial view of delayed contrast enhanced MRI was assessed in a pig model of nonreperfused and reperfused myocardial infarction After excision, the hearts were sectioned into short axial slices, and all slices were stained with TTC The signal intensity on the delayed contrast enhanced MRI of the infarct area was compared with that of the normal area The extent of delayed enhanced area on contrast enhanced MRI was also compared with the extent of the infarct area on TTC stained sections Results On delayed contrast enhanced MRI, the signal intensity of the 7-10 day-old infarct area was much higher than that of normal area In nonreperfusion group, the signal intensity of infarct area(20 81?6 49)was 7 76 times than that of normal area(2 68?1 10)( t =11 68, P 0 05)in nonreperfusion 7-10 day-old myocardial infarction, and the extent of delayed enhanced area (12 52?5 93)% was larger than the extent of infarct area(11 13?5 81)% ( t =-14 48, P

Objective To investigate the clinical thoracic images of SARS. Methods Thoracic images of SARS were analyzed in 175 patients with 1 060 chest plain films and 20 CT scans. Results The typical signs of SARS were multifocal air-space consolidations and progress over a day from small shadow to generalized findings. Conclusion It is necessary to make the diagnosis of SARS with thoracic plain film, and CT could detect the early pulmonary abnormality of SARS.

Objective To investigate the role of magnetic resonance (MR) imaging in the diagnosis of early rheumatoid arthritis (RA).Methods Seventy-six patients with polyarthralgia (fifty-four were finally diagnosed as RA,and twenty-two were non-RA) were selected to undergo MR scanning of bilateral hands and wrists.The signs including synovial enhancement or thickening,bone erosion,bone marrow edema,tendonitis,and effusion were observed on MR imaging.The value of various MR manifestations was evaluated.Bayes discriminant analysis was used to investigate the MR imaging criterion for the diagnosis of RA.Results MR imaging first diagnosed twelve of the fifty-four RA patients.When using bilateral synovial enhancement or thickening as criterion,the sensitivity and specificity were 85.19% and 86.36%,respectively.Conclusion MR imaging is one of the reliable diagnostic indexes of RA and it is extremely useful in early diagnosis.The diagnosis of early RA was highly suggested when bilateral synovial enhancement presented.When both the bilateral synovial enhancement or thickening and at least one of bone erosion/bone marrow edema/tendonitis/effusion presented,or when both the unilateral synovial enhancement or thickening and at least two of them presented at the same time,the diagnosis of RA should be considered.