http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
대동맥내 혈전과 저속혈류의 스핀 에코 MR 소견 및 감별
정진욱 대한영상의학회 1993 대한영상의학회지 Vol.29 No.3
In order to evaluate the ability of spin-echo MR imaging to differentiate slow flow from mural thrombus in aortic diseases, we reviewed the spin-echo MR images of 13 patients with intraaortic thrombus documented by CT(n=11) or aortography (N=2). Six patients had aortic aneurysms and seven had aortic dissections. Intraaortic mural thrombi were accompanied by flow-related intraluminal signal of various patterns and extents in all 13 patients. On 10 gated MR studies. slow flow-related intraluminal signal of various patterns and extents in all 13 patients. On 10 gated MR studies, slow ? regions showed even-echo rephasing phenomenon (N=8), interslice variation of signal intensities of the intraluminal signal (N=7) and flow-related ghost artifact (N=2). However, these MR flow phenomena were obscured on two of three non-gated studies. Seven of 13 intraaortic thrombi remained hyperintense on T2-weighted second-echo images. In these circumstances, a hypointense boundary layer between slow flow and mural thrombus, which was caused by either 'boundary layer dephasing phenomenon' of slow flow or 'paramagnetic T2 shortening' of fresh clot at the edge of mural thrombus, was very useful in discriminating the area of slow flow from that of mural thrombus. Proper interpretation of spin-echo MR images may obviate the need for phase display imaging or gradient-echo imaging in differentiating slow flow and mural thrombus.
정진욱 대한영상의학회 1998 대한영상의학회지 Vol.39 No.5
Purpose : To determine the clinical usefulness of spiral computed tomographic (CT) venography for the evaluation of central venous obstruction. Materials and Methods : The authors prospectively performed a total of29 spiral CT venography procedures in 25 consecutive patients with suspected central venous obstruction. Diluted contrast media were directly injected into the peripheral veins of the hand or the foot. Scan parameters were 3mmX-ray beam collimation, table speed of 4-6 cm/sec, scan time of 32-40 sec, and injection delay of 20 sec. Axial images were reconstructed at 2-mm intervals, and using shaded surface display (SSD), maximum intensity projection(MIP), and multiplanar reformation (MPR), 3-D reconstruction was performed. In all cases, ascending venograp-hy(n=13) and/or direct catheter venography (n=21) was performed within 2 days of CT venography. With regard to site, extent, extent, severity, and cause of obstruction and collateral circulation, we compared the results of CT and contrast venography. Results : In 24 patients, a total of 56 sites of central venous obstruction or stenosis (>50%) were demonstrated. The causes of obstruction were venous thrombosis(n=6), malignant tumors (n=4),arteriovenous fistula for hemodialysis(n=5), extrinsic compression(n=2), coincidence of extrinsic compression and arteriovenous fistula (n=1), pacemaker (n=1), mediastinal inflammatory pseudotumor (n=1), spinal tuberculosis(n=1), membranous obstruction of the hepatic inferior vena cava (n=1), Behcet's disease (n=1), or unknown cause(n=1). When compared with ascending venography (n=13), CT venography was superior for evaluation of the extent and cause of obstruction and collateral circulation in two, four and one case(s), respectively. For the evaluation of site and severity of obstruction, CT venography was equal to ascending venography. In two cases, direct catheter venography (n=21) was superior to CT venography for evaluating the obstruction site, but in three, five and one case(s) respectively, CT venography was superior to direct catheter venograp-hy for evaluating the extent and cause of obstruction and collateral circulation. For the evaluation of severity of obstruction, CT and direct catheter venography were equal. Conclusion : In patients with suspected central venous obstruction, spiral CT venography can be an alternative to replace not only conventional CT but also direct contrast venography.