Clear cell papillary renal cell carcinoma (CCPRCC) is a newly classified renal cell carcinoma with a low degree of malignancy. Its imaging features have not been studied deeply. Therefore, we reviewed the imaging features of CCPRCC. Solid CCPRCC shows high echo or isoecho mass on conventional ultrasound. Contrast enhanced ultrasound shows "fast forward and slow backward, uneven high enhancement". Computed tomography shows high enhancement and maximum enhancement in the cortical-medullary phase. Magnetic resonance imaging shows slightly low T1WI and high T2WI. This article aims to improve the understanding of CCPRCC by clinical radiologists and promote the accurate.

Abstract Objectives To evaluate the effects and benefits of training radiology residents on contrast-enhanced ultrasound (CEUS) according to the Liver Imaging Reporting and Data System (LI-RADS). Methods In total, 234 patients at high risk of hepatocellular carcinoma (HCC) who underwent CEUS were enrolled, including 27 lesions in the education set and 207 lesions in the test sets (a–d). Forty-five radiology residents and 4 radiology experts involved in CEUS LI-RADS training individually reviewed the test sets before, immediately after, and 3-months after training. The consistency with kappa values of the description of CEUS features, the classification of focal liver lesions (FLLs), and the diagnostic performance were evaluated. Results The level of agreement between the radiology experts and residents improved after training (all p < 0.05), while there were no significant differences between the post-training and 3-months post-training results (all p > 0.05). The sensitivity, specificity, positive predictive value, and area under the curve (AUC) based on the CEUS LI-RADS classification of the radiology experts in the diagnosis of HCC were 62.9%, 96.4%, 96.3%, and 0.796, respectively. The diagnostic performance of the radiology residents significantly improved after training (all p < 0.05). Misunderstanding of definitions and subjective interpretation of images were the main reasons for disagreement with multiple responses. Conclusion Dedicated CEUS LI-RADS training improved the performance of radiology residents in diagnosing FLLs and their agreement with radiology experts on CEUS features. Images and videos to explain typical features of the training were essential to improve agreement between the radiology experts and residents. Critical relevance statement Agreement on lesion descriptors between radiology experts and residents can improve with training. Key Points The diagnostic performance of less experienced radiologists for diagnosing HCC could be improved by training. Images and videos to explain typical features during training were essential. Agreement on lesion descriptors between radiology experts and residents improved after training. Graphical Abstract

本文报道1例散发型杂合性嗜酸细胞/嫌色细胞肾肿瘤超声造影表现。患者女，52岁，因“体检发现左肾占位1个月”入院，术前超声造影表现为慢进、慢退、均匀高增强，提示良性病变可能性大，而增强CT提示为恶性肿瘤。患者行左肾根治性切除术，术后一般情况良好，定期复查肾脏CT平扫无明显异常。

患者男,59岁,因体检发现双肾囊肿10年就诊,自述无血尿,无腰痛,实验室检查未见明显异常.常规超声检查:双肾内见多个无回声,较大者位于左肾上极,大小约5.2 cm×4.9 cm;左肾中部见一大小约1.1 cm×1.4 cm低至无回声,边界清晰,凸出于肾表面(图1);超声造影检查:左肾中部病灶灌注相晚于肾皮质增强,呈均匀稍低增强;消退相早于肾皮质消退,呈慢进快退低增强(图2).

Primary squamous cell carcinoma of the liver (PSCCL) is rare. PSCCL's lack of specific clinical manifestations and laboratory tests necessitate preoperative diagnosis via imaging examination. Conventional ultrasound (US) demonstrates a mass with mixed echogenicity, and contrast-enhanced US shows a circular pattern of "fast forward, fast backward or slow backward, high enhancement." Enhanced computed tomography (CT) showed enhancement in the center or edge of the lesion, and the density of the enhanced lesion was lower than that of the liver tissue in the same layer. Positron emission tomography-CT demonstrates an inhomogeneous low-density mass with increased 18F-FDG metabolism. Magnetic resonance imaging shows low signal intensity on T1-weighed images (T1WI) and high signal on T2-weighed images (T2WI). By summarizing the imaging characteristics of PSCCL, this review aims to improve clinicians' understanding of PSCCL and its diagnosis.

1 病例简介 男,44岁,主诉:右下腹疼痛伴发热1个月,近2个月体重下降5 kg.患者1年前于外院确诊为鼻腔NK/T细胞淋巴瘤,后于我院行鼻腔NK/T细胞淋巴瘤I期放疗后出院.入院后查体及实验室检查均未见异常.超声(图1A、B)提示:考虑右肾占位.超声造影(图1C、D)提示:右肾占位,考虑乏血供癌.肾脏增强CT(图1E)提示:右肾上极占位,考虑肾细胞癌可能性大.临床诊断为右肾肿瘤,行腹腔镜根治性右肾切除术,术后病理结果显示:右肾肿瘤,符合结外鼻型NK/T细胞淋巴瘤( extranodal nasal NK/T cell lymphoma,ENKTCL).病理镜下见肿瘤组织内血管数量较少,主要为分布不均匀的小血管和毛细血管.免疫组化:CD3(+),CD56(+),GrB(+),EBER (+),TIA-1(+),Ki-67(70％+),CD30(+), P53(80％+),CD8(-),CD4(-).