Monzawa S, Ohtomo K, Oba H, Nogata Y, Kachi K, Uchiyama G
Department of Radiology, Yamanashi Medical College, Japan.
AJR Am J Roentgenol. 1994 Jun;162(6):1347-51. doi: 10.2214/ajr.162.6.8191996.
Chronic hepatic schistosomiasis japonica is a disorder characterized by broad fibrous septa in the liver. The ability to recognize these septa on MR images might enable distinction of this lesion from other cirrhotic disorders. The purpose of this study was to analyze the MR appearance of these septa.
MR images of 18 patients who had typical calcifications of hepatic septa on CT scans were reviewed. The diagnosis was proved by biopsy in six patients. In the remaining 12, stool examinations were positive for schistosomiasis. T1-weighted MR images and T2-weighted and intermediate (long repetition time and short echo time) MR images acquired with the use of gradient-moment nulling were obtained in all 18 patients. In eight of 18 patients, additional T2-weighted and intermediate images were obtained without gradient-moment nulling. Fifteen patients had contrast-enhanced T1-weighted images. The presence of abnormal MR signal and its intensity at sites corresponding to the septa seen on CT scans were studied.
MR images showed the septa as linear abnormalities frequently seen in the subdiaphragmatic portion of the right lobe of the liver. On T1-weighted images, septa had low signal intensity and were identified in nine of 18 patients. On T2-weighted images obtained with gradient-moment nulling, septa had high signal intensity and were seen in 13 of 18 patients. On T2-weighted images obtained without gradient-moment nulling, the septa had primarily low signal intensity and were seen in five of eight patients. On intermediate MR images obtained with gradient-moment nulling, the septa had primarily high signal intensity and were seen in nine of 18 patients. On intermediate images obtained without gradient-moment nulling, the septa had primarily low signal intensity and were seen in four of eight patients. In nine of 15 patients, septa were visualized as high-signal-intensity lesions on contrast-enhanced T1-weighted images. In 14 of 18 patients, the septa were detected in one or more sequences.
Our experience suggests that MR imaging in patients with chronic schistosomiasis of the liver depicts the morphologic features of hepatic septa. MR signal characteristics of septa are not unique, but use of gradient-moment nulling alters the signal intensity of septa, similar to that of blood vessels, on intermediate and T2-weighted images.
慢性日本血吸虫性肝病的特征是肝脏内出现广泛的纤维间隔。在磁共振成像（MR）图像上识别这些间隔的能力可能有助于将该病变与其他肝硬化性疾病区分开来。本研究的目的是分析这些间隔的MR表现。
回顾了18例CT扫描显示肝脏间隔典型钙化的患者的MR图像。6例患者经活检证实诊断。其余12例患者粪便检查血吸虫病呈阳性。18例患者均获得了使用梯度矩归零技术采集的T1加权MR图像、T2加权和中等权重（长重复时间和短回波时间）MR图像。18例患者中的8例还获得了未使用梯度矩归零技术的额外T2加权和中等权重图像。15例患者进行了对比增强T1加权成像。研究了在CT扫描上所见间隔对应部位异常MR信号的存在及其强度。
MR图像显示间隔为肝脏右叶膈下部分常见的线性异常。在T1加权图像上，18例患者中有9例间隔呈低信号强度。在使用梯度矩归零技术获得的T2加权图像上，18例患者中有13例间隔呈高信号强度。在未使用梯度矩归零技术获得的T2加权图像上，8例患者中有5例间隔主要呈低信号强度。在使用梯度矩归零技术获得的中等权重MR图像上，主要高信号强度的间隔在18例患者中有9例可见。在未使用梯度矩归零技术获得的中等权重图像上，8例患者中有4例间隔主要呈低信号强度。15例患者中有9例在对比增强T1加权图像上间隔显示为高信号强度病变。18例患者中有14例在一个或多个序列中检测到间隔。
我们的经验表明，肝脏慢性血吸虫病患者的MR成像可描绘肝间隔的形态特征。间隔的MR信号特征并非独特，但使用梯度矩归零技术会改变间隔在中等权重和T2加权图像上的信号强度，类似于血管的信号强度。
