Objective To study the clinical significance of using MSCT(16 multi slice spiral CT,MSCT)to evaluate the patency of coronary arterial stent,and to explore the factors contributing to the image quality.Methods 32 patients with coronary arterial stent im- plantation received MSCT.The shape and position of the stent and the situation of restenosis were checked with several methods.Of the 32 patients,the results in 7 cases were further verified by X-ray coronary artery angiography.The image qualities were classified in three grades.The influence factors contributing to imaging quality were analyzed.Results The rate of good image quality for MSCT coronary artery angiography was 87.5%(28/32).The rate of good image quality for the patients with heart rate less than 60 was 94.7%,for those with heart rate of 61-70 was 88.9%,and for those with heart rate over 70 was 50.0%,there existed significant differences(X~2=16.354, P

Objective To evaluate the MR manifestation to provide guidance for the clinical diagnosis of adenomyosis.Methods The MR images of 43 cases of adenomyosis which were proved by operation and pathology were reviewed.Results Among the 43 cases of adenomyosis,26 cases were of diffuse adenomyosis and 17 of focal adenomyosis.Leiomyoma(21 cases),intra-pelvic cavity chocolate cyst (17 cases)and ovarian cyst(15 cases)were concurrently found in this group of patients.The MRI of diffuse adenomyosis demonstrated an enlarged uterus and widened uterine junction zone with ill-defined margin between junction zone and myometrium.The adenomyosis lesions showed iso-signal intensity on T_1 weighted images and iso-signal or slight low signal intensity on T_2 weighted images with scattered hyper- intense foci.The uterine cavities were irregularly narrowed due to compression of thickening junction zone.The lesions showed mild con- trast enhancement on contrast-enhanced MR images.The MRI of focal adenomyosis displayed localized myometrial masses with ill-defined margin with widening of junction zone.The lesions were round or oval in shape with iso-signal intensity on T_1 weighted images and inho- mogeneous slightly low signal on T_2 weighted images.Multiple scattered hyperintense foci could be found in the mass on the T_2 weighted images.The lesions had mild contrast enhancement on contrast-enhanced MR images.The concurrent leiomyoma,intra-pelvic cavity choc- olate cyst and ovarian cyst were also displayed by MR imaging.Conclusion The widened junction zone is the characteristic change of ade- nomyosis.MRI can demonstrate the types,size and concurrent changes in adenomyosis,and is a useful noninvasive imaging method for the diagnosis of adenomyosis.

Objective To evaluate the diagnostic value of CT and MRI in tubo ovarian masses. Methods CT scan was performed in 67 patients with tubo ovarian masses confirmed by pathology. 19 of them underwent MRI. Results (1) 20 primary malignant ovarian tumors showed cystic, solid or cystic solid masses; papillary projections on cystic wall; pelvic organs and pelvic wall invasion. Chocolate cysts with malignant degene ration exhibited small nodules on thickened cystic wall on CT and MRI.T 1WI was better for revealing the lesions. (2) Of 11 cases of metastasis to tubo ovary, 4 showed peritoneal linear enhancement. (3) There were 9 cystadenomas and 2 adenofibromas , one of the cystadenomas contained fat, two adenofibromas were similar to uterus in density on CT while showing lower signal intensity on MRI (both T 1WI and T 2WI). (4) Three cases of thecoma exhibited cystic or solid masses, solid thecomas revealed granular enhancement.(5) Teratomas were most spicific, one of them was associated with thecoma.(6) Tubo ovarian abscesses and tuberculosis depicted cystic or cystic solid masses.(7) Two cases of tubal pregnancy showed inhomogeneous soft tissue masses, the lower density areas in the centers were clot and organized tissues confirmed by pathology. Conclusion (1) CT and MRI had higher sensitivity but lower specificity for tubo ovarian masses, the diagnosis should be combined with clinical history and patients′ age. (2) Tumors of two different types may coexist and sometimes fat may be present in tumors other than teratoma.

Objective To estimate the accuracy of MR angiography(MRA) and CT angiography(CTA) in the evaluation of the carotid artery stenosis. Methods Eleven patients were studied with MRA and CTA. The results were compared with DSA, CT virtual endoscopy (CTVE), and Doppler ultrasound (DUS). MRA was performed with 2D and 3D TOF sequences. CTA was postprocessed using MIP and SSD. CTVE was performed using navigator function . Three patients with severe stenosis received carotid endarterectomy. Results There was a total of 22 carotid arteries studied, with 8 mild, 3 moderate, 5 severe stenosis, 1 occlusion, and 5 normal. Agreement on stenosis between CTA and DSA was found in 11 of 12 carotid arteries. Agreement on stenosis between MRA and DSA was found in 9. Plaques were delineated in CTA, CTVE, and confirmed by pathology in 3 cases. Postoperative MRA and CTA proved the release of stenosis. Conclusion MRA and DUS can be used as a screening technique to evaluate carotid artery stenosis and as a convenient follow up modality for post endarterectomy. CTA has a high degree of accuracy for the assessment of carotid artery stenosis compared with DSA, and it could provide information on calcified plaque.

To explore diagnostic acuity of helical CT colonscopic examination, simulated polyps were reproduced in 10 pig colons and 6 human colons obtained from colon resection. Helical CT colonoscopic scanning with different parameters was performed. The images were evaluated with Nav, Axial+MPR, SSD+Raysum. The diagnostic sensitivity of each method for the detection of simulated colonic polyps were assessed. The results indicated that the image quality of CT colonoscopy was improved with the decrease in collimation and pitch. The optimal angle of the colon lumen to the gantry was 90?. CT colonoscopy was superior to other imaging methods. Therefore, the performance of CTVC has a close relationship with the scanning parameters. The optimal scanning parameters were 5mm collimation, 1 5 pitch, and filling the colon with air. The combination of CTVC with other imaging methods would contribute to improving the diagnostic accuracy for the detection of colonic polyps.

Objective To evaluate the clinical application of spiral CT pulmonary angiography(SCTPA) in the diagnosis of pulmonary embolism(PE) and its limitation.Methods 52 cases of PE were analyzed.SCTPA were performed in all cases with slice thickness 3 mm,pitch 1.5~2.0,scanning time 0.8 s,reconstruction thickness 1mm.The reconstructions of SCTPA included MIP,MPR and SSD.Results 2898 pulmonary arteries in 52 cases were observed.The direct manifestations of PE were showed in 927 pulmonary arteries(32.0%) by SCTPA,in which superior segmental and inferior segmental of pulmonary arteries were involved respectively.The indirect manifestations of PE were showed by plain scan in 113 cases.Conclusion SCTPA is a high effective and noninvasive method in the diagnosis of PE especially for the PE of superior segmental.

Objective To evaluate the clinical applications and limitations of helical CT virtual cystoscopy (CTVC).Methods CTVC was performed in 36 patients suspected bladder diseases, all cases were confirmed by conventional cystoscopy and pathology. CTVC images were generated from the volumetric data of the excretory phase using helical CT. The results were then compared with the findings of axial images and conventional cystoscopy in a double-blinded manner. Results CTVC could clearly display the normal anatomic structures of bladder, 11 ureteric orifices were visualized at CTVC in 7 of 8 normal bladders. The location, size, numbers, configuration and extension of lesions showed on CTVC were corresponded well with that of conventional cystoscopy. The sensitivity to vesical carcinoma was 94.7%,2 tumors smaller than 5 mm depicted on CTVC images were not seen on the axial images, whereas areas of wall thickening and extravesical invasions were more readily appreciated on axial and MPR images. There was 1 false lesions detected on CTVC images. Conclusion CTVC has proved to be a noninvasive and reliable technique in the detection and diagnosis of bladder lesions, but the optimal evaluation requires adequate bladder filling with contrast medium, and should combine with the interpretation of axial and MPR images.

Objective To evaluate the clinical applications of helical CT scans in the ureteral diseases.Methods The precontrast and four-phase postcontrast helical CT scans were performed in 110 patients with ureteral diseases confirmed by clinic and pathology, and the multiplanar reformation (MPR) and three-dimensional reconstruction (3D) images were generated from the volumetric data.The ability of helical CT in detecting and diagnosing the ureteral diseases was investigated.The results were then compared with the findings of the other imaging techniques and surgery.Results Combined with axial and MPR images, the location, size, morphology, extension, and the urinary obstruction of the ureteral diseases could be clearly demonstrated in 97.3% cases, and the curved MPR was useful in directly detecting the lesions.The findings of ureteral lesion on helical CT images corresponded well with that of surgery in 81 cases. 3D reconstruction could produce a three-dimensional image that mimics conventional urography, and was useful in displaying the ureteral lesions from multiple views.Helical CT could compensate for some disadvantages of the other imaging techniques.Conclusion Helical CT, with large scanning area and high resolution, can provide comprehensive information about the ureteral diseases, and the curve MPR has the highest value.

Objective　To evaluate the clinical application of helical CT multiplanar reformation (MPR), three-dimensional reconstruction (3D) and virtual laryngoscopy (CTVL) in laryngeal and hypopharyngeal carcinoma. Methods　Axial helical CT scans were performed in 22 patients with laryngeal or hypopharyngeal carcinoma, along with MPR, 3D and CTVL. These results were compared with the findings of fiber optic laryngoscopy and surgery. Results　Combining axial and MPR images, both the accuracy in preoperative tumor staging and the diagnosis of metastatic lymph nodes were 95%. MPR demonstrated more information about the extent of tumor than axial images in 23% cases; 3D image displayed clearly the extension of tumor, the vessels and airway from multiple views. The location, size and extent of tumors found in cranio-caudal CTVL corresponded well with that of laryngoscopy, and CTVL demonstrated the relationship between the tumor and vocal cords and anterior commissure by caudo-cranial approach, which was inaccessible to fiber optic laryngoscopy in 3 cases. Conclusions　Axial images of helical CT clearly demonstrate the location, size and extent of laryngeal and hypopharyngeal carcinoma, while MPR and 3D images are useful in displaying the three-dimensional images and anatomical relation of the tumor. CTVL can clearly display the mucosal surface structures of the larynx and hypopharynx and is a good complementary method of laryngoscopy.

Objective To evaluate the clinical applications and limitations of CT virtual endoscopy (CTVE) in the auditory ossicular chain. Methods CTVE of the auditory ossicular chain was performed with 1.0 mm collimation at pitch 1.0, bone algorithm, 9.6 cm field of view, and 0.1 - 0.2 mm reconstruction interval in 40 patients with middle ear diseases. 30 cases were confirmed by surgery. Results were compared with the findings of axial high resolution CT (HRCT) and multiplanar reformation (MPR) images and surgery. Results The accuracy of CTVE images in detecting ossicular destruction was 92.6%, significantly higher than that of axial HRCT (83.9%) and multiplanar reformation (76.5%) images. CTVE could also clearty reveal the postoperative condition and congenital dysplasia of the auditory ossicular chain. Conclusions CTVE can clearly demonstrate a three-dimensional image of the auditory ossicular chain and is useful in evaluating diseases of the ear, especially the auditory ossicles. CTVE could not clearly demonstrate abnormal soft tissue within the tympanic cavity, abnormal changes of the tympanic membrane and tympanic walls, and could be easily influenced by artificial factors.