18例Citrin缺陷婴儿肝内胆汁淤积症的肝脏影像表现

Hepatic imaging features of neonatal intrahepatic cholestasis caused by Citrin deficiency： investigation of 18 patients

目的探讨Citrin缺陷导致的婴儿肝内胆汁淤积症（NICCD）的肝脏影像表现，以加深对该疾病的认识。方法回顾性分析有完整的临床和生化资料并经SLC25A13基因分析确诊的18例NICCD患儿的影像资料。其中12例行上腹部低剂量螺旋CT平扫，4例行上腹部正反相位MR成像，2例行上述2种检查。由3名有经验的腹部放射科医师分析所有患儿的CT和MR图像，评判有无脂肪肝或肝硬化，并取得一致性意见。CT上的肝／脾CT比值及MRI上的脂肪分数作为判定脂肪肝的标准。为获得对脂肪肝的客观评估，另选取18例无明确肝脏疾病且年龄匹配的患儿cT或MR图像作为对照组，由另外3名放射科医师对36例CT和MR图像进行盲法分析，观察者问行Kappa一致性检验。结果所有18例患儿均有肝内胆汁淤积的临床和生化表现，其中15例符合脂肪肝的影像诊断标准，表现为CT上肝脏密度值低于脾，肝／脾CT比值〈1。MRI上表现为反相位肝脏信号强度减低，低于正相位肝信号强度，脂肪分数（FI）〉9％；1例符合肝硬化的影像诊断标准，表现为肝叶比例失调，肝裂增宽，肝表面不光滑呈波浪状，伴有脾大和腹水；2例肝脏形态和密度无异常。3名医师对脂肪肝诊断的Kappa值为0．941（P〈0．01），显示一致性非常好。结论脂肪肝是NICCD患儿肝脏最常见的影像表现，该征象将为临床鉴别NICCD与其他黄疸性疾病提供有益的线索。

Objective To explore the hepatic radiological features of neonatal intrahepatic eholestatsis caused by Citrin deficiency （NICCD） to facilitate the clinical recognition of this disease. Methods A total of 18 NICCD patients with the whole clinical and biochemical information who were all confirmed by SLC25A13 nmtations gene analysis underwent abdominal Low-dose unenhanced spiral CT or/ and in-phase and out-of-phase MR examination. Their CT or/and MRI images were analyzed to identify hepatic steatosis or liver cirrhosis by three abdominal radiologists with over 15 years experience and decisions were reached by consensus. Multiple imaging criteria were applied in evaluate hepatic steatosis condition, including fiver-to-spleen attenuation ratio at CT and fat index on MRI. To avoid the evaluating bias for hepatic steatosis, a control group consisted of 18 patients with no known liver disease were selected. Hepatic images were reviewed independently by the other three abdominal radiologists with over 10 years experience, who were blinded the clinical information and imaging features. Interobserver agreement was measured with Kappa statistics. Results All NICCD patients presented with clinical signs and biochemical changes in consistence with intrahepatic cholestasis. Within 18 NICCD patients, 15 met the CT or/and MRI criterion for hepatic steatosis, which showed attenuation of the liver less than that of the spleen and liver-to-spleen attenuation ratio 〈 1 on CT or signal intensity loss on out-of-phase images in comparison with in-phase images and fat index （FI） more than 9% on MRI; one patient met the CT criterion for liver cirrhosis, showing reduction in size of liver lobe and irregularity of the surface of the liver together with splenomegaly or ascites; and 2 cases had normal hepatic shape and density. Overall interobserver agreement for hepatic steatosis detection was excellent, with Kappa = 0. 941 （ P 〈 0. 01 ）. Conclusions Hepatic steatosis is the commonest radiological feature of NICCD patients. This imaging finding keeps valuable to distinguish NICCD from other diseases with consistent late-onset jaundice.