Chen C K, Yeh L R, Pan H B, Yang C F, Lu Y C, Wang J S, Resnick D
Department of Radiology, Kaohsiung Veterans General Hospital, Taiwan.
Skeletal Radiol. 1999 Feb;28(2):75-80. doi: 10.1007/s002560050477.
To define the imaging characteristics of intra-articular tophi of the knee.
Twelve patients with intra-articular tophi in the knee were studied with routine MR imaging, gadolinium (Gd)-enhanced MR imaging, and CT over a 4-year period. There were 11 men and one woman, 25-82 years of age (mean age 48 years). Four patients did not have a documented history of gout at the time of the MR examination. The diagnosis of intra-articular tophi was provided by arthroscopy and histological examination (5 patients), by microscopic study of joint fluid (5 patients), or by characteristic clinical, laboratory and imaging findings (2 patients).
In 15 MR examinations the tophi were located purely intra-articularly in 10 knees. In the remaining five MR studies, periarticular soft tissues or bone, or both, were involved. All the intra-articular tophi manifested low to intermediate signal intensity on both T1- and T2-weighted images. All five Gd-enhanced MR examinations demonstrated a heterogeneous peripheral enhancement. All 10 CT scans showed varying degrees of stippled calcifications within the tophi. The nature of the calcifications was confirmed on histological examination in three patients.
Presenting clinical manifestations of gout may relate to intra-articular tophaceous deposits. Such deposits present as masses on MR images with low to intermediate signal intensity on both T1- and T2-weighted images and a characteristic enhancement pattern following intravenous Gd administration. These features relate primarily to internal calcifications, which are most evident on CT images. MR evaluation (including Gd administration) supplemented, in some cases, with CT scanning allows accurate diagnosis of intra-articular tophaceous deposits.
明确膝关节内痛风石的影像学特征。
在4年时间里，对12例膝关节内有痛风石的患者进行了常规磁共振成像（MR）、钆（Gd）增强MR成像及CT检查。其中男性11例，女性1例，年龄25 - 82岁（平均年龄48岁）。4例患者在MR检查时无痛风病史记录。膝关节内痛风石的诊断通过关节镜检查和组织学检查（5例）、关节液显微镜检查（5例）或特征性的临床、实验室及影像学表现（2例）得以确定。
在15次MR检查中，痛风石仅位于关节内的有10个膝关节。在其余5次MR检查中，关节周围软组织或骨骼或两者均受累。所有关节内痛风石在T1加权像和T2加权像上均表现为低至中等信号强度。所有5次Gd增强MR检查均显示周边不均匀强化。所有10次CT扫描均显示痛风石内有不同程度的点状钙化。3例患者经组织学检查证实了钙化的性质。
痛风的现有临床表现可能与关节内痛风石沉积有关。此类沉积在MR图像上表现为肿块，在T1加权像和T2加权像上均为低至中等信号强度，静脉注射Gd后有特征性强化模式。这些特征主要与内部钙化有关，在CT图像上最为明显。MR评估（包括注射Gd）在某些情况下辅以CT扫描可准确诊断关节内痛风石沉积。
