Purpose　To judge the value of CT in the diagnosis of acute pancreatitis. Methods　74 cases of acute pancreatitis confirmed by operation were reviewed. All patients underwent CT plain and contrast -enhanced scanning. Oral contrast agents were used. Results　According to clinical diagnosis, they were devided into edematous type(n=53),and necrotic type(n=21). 7 cases were complicated with abscesses, and 5 cases died. According to CT finding, Grade A,n=10; Grade B,n=16; Grade C,n=19; Grade D,n=16; Grade E, n=13. Conclusion　 CT is valuable in the diagnosis of acute pancreatitis, and CT grade is referable.

Objective To evaluate the functional alternations of canine renal ischemia and reperfusion injury by using MR perfusion-weighted imaging, and to correlate the imaging with the pathologic findings. Methods Using 1. 5 T MR system, four groups of three anesthetized dogs each were studied by left renal artery ligation for 30-, 60-, 90-, and 120-min, respectively, after the removal of ligation, reperfusion injury was suffered for one hour. True-FISP, TSE, and EPI sequences were performed in five different time phases ( pre-ischemia, onset-ischemia, post-ischemia, onset-reperfusion, and post-reperfusion). Finally, IR-turbo-FLASH sequence (TR 5. 8 ms, TE 3. 2 ms, TI 400 ms, FA 12?) with a temporal resolution of 1. 16 s was performed. Signal intensity (SI) in cortex, outer medulla, and inner medulla was measured. SI was plotted as a function of time. Peak height (P) , time to peak (Tp) , and the area (A) under the time-course curves after the intravenous injection of Gd-DTPA were estimated. Blood and urine examples were collected for measuring serum creatinine level and urinary protein before and after the insult. Histologic examination was performed with light and electron microscopy in all dogs. Results After arterial ligation,there was marked and significant reduction in the SI of each layer of left kidney on true-FISP, TSE, and EPI, except for the SI of inner medulla on TSE. After the removal of ligation,there were no significant differences in the SI of cortex of both kidneys, however, significant differences in the SI of outer and inner medulla of both kidneys remained on EPI in all groups. The turbo-FLASH study clearly depicted the three-phase pattern of SI changes in each layer on right kidney. The uniphasic enhancement pattern in all groups was showed in outer and inner medulla on left kidney, with the area under the curve decreased. Conclusion This preliminary study shows that MR perfusion-weighted imaging may be useful and very promising for the evaluation of renal dysfunction following normothermic ischemia and reperfusion injury.

Objective To compare the diagnostic value of conventional MRI, X ray arthrography, and MRI arthrography in revealing rotator cuff injuries. Methods Thirty two patients with suspected rotator cuff tears were prospectively examined by conventional MRI, X ray arthrography, and MRI arthrography before the examination of shoulder arthroscope. Based on the results of the arthroscopy, the diagnostic sensitivity, specificity and accuracy of those three different methods were determined for rotator cuff tears. Results The arthroscopic findings included 14 full thickness tears, 6 partial thickness tears, and 12 without tears. For the diagnosis of rotator cuff tears,the sensitivity,specificity and accuracy were 80%(16/20), 83%(10/12), and 81%(26/32) for conventional MRI,respectively; the figures were 80%(16/20),100%(12/12), and 86%(28/32)for X ray arthrography,respectively; while the data were 100%(20/20),100%(12/12), 100%(32/32) for MRI arthrography,respectively. For the diagnosis of complete tears, the sensitivity, specificity and accuracy were 79%(11/14), 83%(15/18), and 81%(26/32) for conventional MRI, respectively; the figures were 93%(13/14),94%(17/18), and 94%(30/32) for X ray arthrography, respectively; while the parameters were 100%(14/14),94%(17/18), 97%(31/32) for MRI arthrography, respectively. Conclusion MRI arthrography is one of the best methods for the diagnoses of rotator cuff tears.

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 MR arthrography for rotator cuff tear. Methods A prospective study was undertaken in 32 patients with shoulder diseases using MR arthrography. Abnormalities revealed on MR arthrography of the rotator cuff, the labrum, and the tendon of the long head of the biceps brachii muscle were recorded. The results of MR arthrography were compared with those of arthroscopy and surgery. Results Based on the results of arthroscopy and surgery, 32 patients comprised 14 complete rotator cuff tear, 6 partial rotator cuff tear, and 12 subjects without tear. For detecting rotator cuff tear, the sensitivity, specificity, and accuracy of MR arthrography were 100%, 100%, 100% respectively. For detecting complete rotator cuff tear, the sensitivity, specificity, and accuracy of MR arthrography were 100%, 94%, 97% respectively. Meanwhile, MR arthrography revealed all multi tendon tear and all abnormalities of the labrum and the tendon of the long head of the biceps brachii muscle before arthroscopy. Conclusion MR arthrography is an accurate and comprehensive method for evaluating rotator cuff tear.

Objective To determine the val ue of five MR imaging signs in diagnosing the bucket handle tears (BHT) of menisci of the knee. Methods MR imaging of 139 knees with subsequent arthroscope exams were retrospectively evaluated. Based on the results of arthroscopy, 19 knees had BHT of menisci. Two radiologists evaluated each MR exam independently, with discrepancies resolved by consensus. Each MR exam was analyzed for five signs: a double posterior cruciate ligament sign, a flipped meniscus sign, an absent bow tie sign, an internal displaced fragment sign, and an abnormal circumferential meniscus sign. Sensitivity, specificity, positive and negative predictive values, and accuracy for diagnosing BHT of menisci were calculated for the presence of each individual sign. Results The sensitivities of these five signs ranged between 52.6% and 89.5%, and specificities ranged between 83.3% and 98.3%, respectively. Positive and negative predictive values ranged between 42.9% and 88.2%, and between 92 7% and 98.3%, respectively. The accuracy of these five signs ranged between 82.7% and 96 4%. Conclusion BHT of menisci may have many signs on MR imaging. The diagnostic sensitivities of the internal displaced fragment sign and the abnormal circumferential meniscus sign are the highest. The double posterior cruciate ligament sign has the highest specificity and positive predictive value, while the internal displaced fragment sign has the highest negative predictive value and accuracy.

Objective Calcium overload has important effect on cell injury in the ischemic stroke MR DWI/PWI mismatch may display the ischemic penumbra We try to explain the relationship between the characters of MR DWI/PWI and intracellular Ca 2+ in the different ischemic region through the model of focal cerebral ischemia Methods Twenty-eight rabbits underwent permanent middle cerebral artery occlusion (MCAo) From 0 5 h to 36 h after the onset of occlusion, diffusion-, perfusion-, and T 2-weighted MR imaging were performed to generate ADC, CBF, CBV parameters and anatomic images After the MR scanning, the same brain slices were incubated with Fluo-3/AM followed by the examination using laser confocal scanning microscope (LCSM) At different ischemic time, fluorescence intensity (FI) of the intracellular Ca 2+ in the DWI/PWI match region and mismatch one was recorded FI match /FI contralateral and FI mismatch /FI contralateral were produced and analyzed Results (1) MR outcome: The DWI/PWI match was located in the lateral caudoputamen and the DWI/PWI mismatch was mainly located in the frontoparietal cortex At 0 5 h after MCAo, CBF and CBV of lateral caudoputamen and frontoparietal cortex in the affected side deceased marked and the rCBF and rCBV of lateral caudoputamen were less then that of frontoparietal cortex in all groups ( t =-11 74, P

Objective To evaluate the effects of percutaneous long sheath aspiration embolectomy for the treament of acute superior mesenteric artery embolism. Methods 7 cases (atrial fibrillation 4 cases; left atrium myxoma 2 cases and chronic mesenteric ischemia 1 cases) of acute measenteric artery embolism were treated with percutaneous emlolectomy using long sheath (Optimed, Germany) aspiration. Results Successful recanalizations were observed in all of the 7 cases of superior mesenteric arteries. 5 cases out of the 7 cases recovery; 1 case underwent laparotomy; 1 case died in 24 hours. Conclusions Percutaneous embolectomy using long sheath aspiration is a sample and effective method for the treatment of acute superior mesenteric artery embolism.

Objective To determine the diagnostic value of indirect MRI arthrography for meniscal tears.Methods 75 cases of routine MRI of the knee and 64 cases of indirect MRI arthrography of the knee were retrospectively reviewed.These patients all had subsequently arthroscopic examination.Based on the results of arthroscopic examination,the diagnostic value for meniscal tear of routine MRI and indirect MRI arthrography were compared.Results For medial meniscal tears,the indirect MRI arthrography gave a sensitivity of 72%,specificity of 100%,accuracy of 89.1%,positive predictive value of 100% and negative predictive value of 84.8%.For lateral meniscal tears,the indirect MRI arthrography gave a sensitivity of 83.8%,specificity of 90.9%,accuracy of 87.5%,positive predictive value of 89.6% and negative predictive value of 85.7%.No matter for medical meniscal tears or lateral meniscal tears,the diagnostic differences between the indirect MRI arthrography and the routine MRI were not statistical significant.Conclusion Although the diagnostic value of indirect MRI arthrography for meniscal tears was quite high,it was not different with routine MRI statistically.

Objective To summarize the appearances of MS lesions on DWI, and to quantitatively study the ADC and AI values in different clinical MS subgroups Methods One hundred and eighty seven lesions were studied in 18 cases of MS at different clinical stages Routine MR and DWI were performed in all cases ADC and AI were calculated in the lesions,NAWM, and normal control group Results Hyperintensity (edema like on T 2WI) was demonstrated on DWI at acute primary progressive MS lesions Hyperintense ring sign was found at acute relapse MS lesions ADC increased in all subgroups of MS Significant difference of ADC was demonstrated among MS lesions, NAWM, and normal control groups Significant decrease of AI was demonstrated at later stages Hyperintensity was found in all MS lesions on T 2WI The hyperintensity lesions on DWI had enhanced or non enhanced appearances on CE T 1WI The ADC value of enhanced MS lesions was less than that of the non enhanced lesions ( t =4 19, P 0 05) Conclusion DWI could give quantitative information for different pathological changes in MS lesions of different clinical subgroups Quantitative measurement of diffusion has great potential value in the diagnosis, differential diagnosis, and the prediction of prognosis in MS