Ozaki Kumi, Miyayama Shiro, Ushiogi Yasuyuki, Matsui Osamu
Department of Radiology, Kanazawa University Graduate School of Medical Science, 13-1 Takara-machi, Kanazawa, 920-8641, Japan.
Abdom Imaging. 2009 Mar-Apr;34(2):265-70. doi: 10.1007/s00261-008-9377-7.
To evaluate the imaging findings in patients with renal involvement of Polyarteritis nodosa (PN) to diagnose as early as possible.
Four patients diagnosed as having PN participated in the present study. Two patients underwent abdominal dynamic CT, one underwent only pre- and post-contrast CT, and the remaining patient underwent only noncontrast CT and MR imaging, including dynamic contrast study.
The common findings of CT and MR imaging were diffuse enlargement, multiple small wedge-shaped less-enhanced areas on dynamic contrast study, and indistinctness of the margin between the cortex and medulla on equilibrium-phase CT. Renal arteriogram showed multiple microaneurysms on arterial phase image in all four cases, and PN was diagnosed. The common CT and MR findings of renal involvement of PN mimicked those of pyelonephritis, when microaneurysms were not demonstrated.
The differentiation between PN and pyelonephritis on CT and MR imaging is difficult. Therefore, the radiologist should be familiar with the imaging findings of renal involvement of PN. When PN is suspected, angiography should be performed as early as possible to make a definite diagnosis.
评估结节性多动脉炎（PN）累及肾脏患者的影像学表现，以便尽早诊断。
4例诊断为PN的患者参与本研究。2例患者接受腹部动态CT检查，1例仅接受增强前后CT检查，其余1例仅接受平扫CT及MR成像检查，包括动态增强扫描。
CT和MR成像的常见表现为弥漫性增大、动态增强扫描时多个小楔形强化减低区以及平衡期CT上皮质与髓质间界限不清。肾动脉造影显示所有4例患者动脉期图像上均有多个微动脉瘤，从而诊断为PN。当未显示微动脉瘤时，PN累及肾脏的常见CT和MR表现与肾盂肾炎相似。
在CT和MR成像上鉴别PN和肾盂肾炎较为困难。因此，放射科医生应熟悉PN累及肾脏的影像学表现。当怀疑PN时，应尽早进行血管造影以明确诊断。
