Stafford-Johnson D B, Francis I R, Eckhauser F E, Knol J A, Chang A E
Department of Radiology, University of Michigan Medical Center, Ann Arbor 48109-0030, USA.
J Comput Assist Tomogr. 1998 Mar-Apr;22(2):335-9. doi: 10.1097/00004728-199803000-00034.
The aim of this study was to evaluate the utility of dual-phase imaging in the assessment of nonfunctioning islet cell tumors (NFITs).
Six patients with histologically and biochemically proven NFIT were evaluated by arterial and portal venous dual-phase helical CT. Scan delay was 20 s for the arterial phase and 70 s for the portal phase. Each phase was assessed by consensus reading and specifically evaluated for tumor conspicuity, hepatic metastases, vascular encasement by tumor, and presence of lymphadenopathy.
Overall, tumor conspicuity was greater in the arterial phase (5/6) than in the portal venous phase (1/6) with a mean tumor/normal pancreas attenuation difference of 31.8 HU in the arterial phase compared with 19.2 HU in the portal venous phase. The arterial phase detected a total of 17 liver metastases compared with 9 seen in the portal phase. Lymph node enlargement was noted in three patients, which, although visible in both phases, was more easily discernible in the arterial phase. Venous encasement by tumor was better evaluated on the delayed portal venous phase than the arterial phase.
Dual-phase helical CT scanning leads to improvement in the detection and staging of NFITs.
本研究旨在评估双期成像在无功能胰岛细胞瘤（NFITs）评估中的效用。
对6例经组织学和生化检查证实为NFIT的患者进行动脉期和门静脉期双期螺旋CT检查。动脉期扫描延迟时间为20秒，门静脉期为70秒。各期均通过共同阅片进行评估，并特别评估肿瘤的显影情况、肝转移、肿瘤对血管的包绕以及有无淋巴结肿大。
总体而言，动脉期（5/6）的肿瘤显影情况优于门静脉期（1/6），动脉期肿瘤与正常胰腺的平均衰减差值为31.8 HU，而门静脉期为19.2 HU。动脉期共检测到17处肝转移，而门静脉期为9处。3例患者出现淋巴结肿大，虽然在两期均可见，但在动脉期更易辨别。肿瘤对静脉的包绕在门静脉延迟期比动脉期评估得更好。
双期螺旋CT扫描可改善NFITs的检测和分期。
