Nazarian L N, Wechsler R J, Grady C K, Needleman L, Halpern E J, Copit S E, Shapiro M J, Rosato F E
Department of Radiology, Jefferson Medical College of Thomas Jefferson University, Philadelphia, PA 19107-5244.
AJR Am J Roentgenol. 1994 Oct;163(4):851-5. doi: 10.2214/ajr.163.4.8092022.
Nontumorous perfusion defects occur during CT arterial portography (CTAP) as normal variants or in cirrhosis, focal fatty infiltration, and portal vein obstruction. The purpose of this study was to determine whether delayed CT 4-6 hr after CTAP improves sensitivity to hepatic tumors and differentiates them from other hepatic perfusion defects.
CTAP was done at 1-cm increments on 26 patients for evaluation of hepatic tumors. Delayed CT scans were obtained 4-6 hr later in all patients. Two observers retrospectively reviewed the CT scans obtained during CTAP and recorded size, shape, and location of suspected hepatic tumors. Confidence levels were assigned for each tumor. The delayed CT scan was then interpreted in conjunction with the CT scans obtained during CTAP, and confidence levels were reassigned. Surgical correlation was obtained for all patients. In the 26 patients, 86 masses were found at surgery. The sensitivity and number of false-positives for both CTAP alone and CTAP combined with delayed CT were compared with a two-tailed Student t-test. Receiver-operating-characteristic analysis also was performed.
CTAP detected 73 (85%) of the 86 hepatic masses. Delayed CT had no effect on the sensitivity of CTAP. However, adding delayed CT decreased the total number of false-positives by 11, a statistically significant difference (p < .05). Receiver-operating-characteristic analysis revealed a significantly greater (p < .05) area under the curve (Az index) of 0.927 +/- 0.025 for CTAP combined with delayed CT compared with 0.886 +/- 0.032 for CTAP alone. Delayed CT was most useful for larger (> 1 cm) wedge-shaped perfusion defects and least useful for smaller (< 1 cm) round defects.
Delayed CT has no effect in detecting tumors but may be useful for differentiating tumors from other hepatic perfusion defects seen on CTAP. The greatest benefit of delayed CT is in evaluating regions obscured by large wedge-shaped perfusion defects on CT scans obtained during CTAP.
在CT动脉门静脉造影（CTAP）过程中，非肿瘤性灌注缺损可作为正常变异出现，也可出现在肝硬化、局灶性脂肪浸润和门静脉阻塞中。本研究的目的是确定CTAP后4 - 6小时延迟CT是否能提高对肝肿瘤的敏感性，并将其与其他肝灌注缺损区分开来。
对26例患者进行CTAP检查，扫描层厚为1 cm，以评估肝肿瘤。所有患者在4 - 6小时后进行延迟CT扫描。两名观察者回顾性分析CTAP期间获得的CT扫描图像，记录可疑肝肿瘤的大小、形状和位置。为每个肿瘤指定置信度。然后将延迟CT扫描与CTAP期间获得的CT扫描图像结合解读，并重新指定置信度。对所有患者进行手术相关性分析。在这26例患者中，手术发现86个肿块。采用双侧t检验比较单独CTAP和CTAP联合延迟CT的敏感性及假阳性数量。还进行了受试者操作特征分析。
CTAP检测到86个肝肿块中的73个（85%）。延迟CT对CTAP的敏感性无影响。然而，增加延迟CT可使假阳性总数减少11个，差异有统计学意义（p < 0.05）。受试者操作特征分析显示，CTAP联合延迟CT的曲线下面积（Az指数）为0.927±0.025，显著大于（p < 0.05）单独CTAP的0.886±0.032。延迟CT对较大（> 1 cm）的楔形灌注缺损最有用，对较小（< 1 cm）的圆形缺损最无用。
延迟CT对检测肿瘤无作用，但可能有助于将肿瘤与CTAP上所见的其他肝灌注缺损区分开来。延迟CT的最大益处在于评估CTAP期间获得的CT扫描上被大的楔形灌注缺损遮挡的区域。
