Department of Medical Imaging, Toronto General Hospital, University of Toronto, 585 University Ave, Toronto, ON M5G 2N2, Canada.
AJR Am J Roentgenol. 2010 Apr;194(4):977-83. doi: 10.2214/AJR.09.3375.
The objective of our study was to determine the role of negative enhancement (washout), its presence and timing, in the differential diagnosis of hypervascular liver masses on contrast-enhanced ultrasound.
One-hundred forty-six hypervascular liver lesions (mean size, 3.9 cm; range, 1.0-17.0 cm) were evaluated with contrast-enhanced ultrasound over a 6-month period. Seventy-four were benign (29 hemangiomas, 31 focal nodular hyperplasia [FNH] lesions, seven adenomas, five inflammatory lesions, two other) and 72, malignant (41 hepatocellular carcinomas [HCCs], 25 metastases, six other). Two independent reviewers retrospectively recorded the presence and timing of washout in the portal venous phase, observing until 4 minutes after injection, of a contrast agent (perflutren microspheres). Diagnoses were confirmed by histopathology (n = 68) or clinicoradiologic follow-up (n = 78). Timing of washout was compared between types of lesion using Fisher's exact test.
Washout occurred in both benign (27/74, 36%) and malignant (70/72, 97%) lesions but was more frequently seen in malignancy (p < 0.001) (kappa = 0.91). Metastases showed more rapid washout than HCCs (p < 0.001): 20 of 25 metastases showed washout by 30 seconds after injection and 23 of 41 HCCs, later than 75 seconds. All malignant lesions without washout were HCCs (2/41). Among the benign lesions, all five inflammatory lesions showed rapid washout before 75 seconds and six of seven adenomas showed washout, mostly later than 75 seconds (5/6). Washout also occurred in hemangiomas (6/29) and FNH lesions (9/31), mostly later than 75 seconds after injection (12/15).
Hypervascular malignant lesions show washout except infrequent cases of HCC. Rapid washout characterizes metastases, whereas HCCs show variable, often slow, washout. However, washout is not unique to malignancy and may be seen in benign lesions.
本研究旨在确定负性增强(洗脱)及其存在和出现时间在对比增强超声鉴别诊断富血供肝占位病变中的作用。
在 6 个月的时间内,对 146 个富血供肝病变(平均大小 3.9cm;范围 1.0-17.0cm)进行了对比增强超声评估。74 个为良性病变(29 个肝血管瘤、31 个局灶性结节增生[FNH]病变、7 个腺瘤、5 个炎性病变、2 个其他病变),72 个为恶性病变(41 个肝细胞癌[HCC]、25 个转移瘤、6 个其他病变)。两位独立的观察者回顾性记录了在门静脉期增强剂(perflutren 微球)注射后 4 分钟内的洗脱的存在和时间,观察到洗脱的存在和时间。通过组织病理学(n=68)或临床影像学随访(n=78)确诊诊断。使用 Fisher 确切检验比较不同类型病变之间的洗脱时间。
良性病变(27/74,36%)和恶性病变(70/72,97%)中均出现洗脱,但恶性病变中更常见(p<0.001)(kappa=0.91)。转移瘤的洗脱速度比 HCC 更快(p<0.001):25 个转移瘤中有 20 个在注射后 30 秒内出现洗脱,41 个 HCC 中有 23 个在 75 秒后出现洗脱。所有无洗脱的恶性病变均为 HCC(2/41)。在良性病变中,所有 5 个炎性病变均在 75 秒内出现快速洗脱,7 个腺瘤中有 6 个出现洗脱,大多在 75 秒后(6/6)。血管瘤(29/29)和 FNH 病变(31/31)也出现了洗脱,大多在注射后 75 秒后(15/15)。
富血供恶性病变出现洗脱,除了罕见的 HCC 病例。快速洗脱是转移瘤的特征,而 HCC 则表现为可变的、常为缓慢的洗脱。然而,洗脱并非恶性病变所特有,也可见于良性病变。