Margolis Nathaniel E, Shaver Christine M, Rosenkrantz Andrew B
From the *Department of Radiology, NYU Langone Medical Center, New York; and †Department of Radiology, New York Medical College, Valhalla, NY.
J Comput Assist Tomogr. 2013 Nov-Dec;37(6):882-6. doi: 10.1097/RCT.0b013e3182aace0d.
The purpose of this study was to compare computed tomography (CT) and magnetic resonance imaging (MRI) in terms of likelihood of providing a definitive diagnosis (DD) and a recommendation for additional imaging (RAI), when performed to evaluate indeterminate liver and renal lesions detected on ultrasound as well as in terms of impact on imaging costs.
This retrospective study was Health Insurance Portability an Accountability Act (HIPAA)-compliant and institutional review board-approved, with waiver of informed consent. We identified consecutive indeterminate liver and renal lesions detected on ultrasound that underwent contrast-enhanced CT or MRI for further characterization. Reports from follow-up studies were reviewed for whether the impression provided DD and RAI. Frequency of DD and RAI was compared between CT and MRI using the Fisher exact test. On the basis of the observed frequency of DD, anticipated imaging costs were compared in a hypothetical sample of 100 patients with indeterminate lesions between first obtaining multiphase CT for all lesions and a subsequent MRI for those lesions indeterminate on CT versus directly obtaining a multiphase MRI for all lesions.
A total of 143 renal lesions were included, of which 77 and 66 underwent CT and MRI, respectively. Magnetic resonance imaging was significantly more likely than CT to provide DD (95.5% vs 77.9%; P = 0.003) and significantly less likely to provide RAI (1.5% vs 10.4%; P = 0.038). A total of 221 liver lesions were included, of which 76 and 145 underwent CT and MRI, respectively. Magnetic resonance imaging was significantly more likely than CT to provide DD (95.2% vs 71.1%; P < 0.001) and significantly less likely to provide RAI (0% vs 10.5%; P < 0.001). Across the entire study cohort, there were 13 instances of MRI recommended after an indeterminate CT and 1 case of CT recommended after an indeterminate MRI. A DD was provided in 8 of 9 instances in which MRI was performed after an indeterminate CT. However, anticipated imaging costs were higher when directly obtaining MRI for all indeterminate lesions, compared with initially obtaining multiphase CT, for both kidney ($64,739 vs $49,759) and liver ($64,739 vs. $56,975) lesions, respectively.
For indeterminate liver and renal lesions detected on ultrasound, MRI is more likely to provide DD and less likely to provide RAI in comparison with CT, although these differences did not result in lower anticipated imaging costs.
本研究的目的是比较计算机断层扫描（CT）和磁共振成像（MRI）在对超声检查发现的肝脏和肾脏不确定病变进行评估时，提供明确诊断（DD）和额外影像学检查建议（RAI）的可能性，以及对影像学成本的影响。
本回顾性研究符合《健康保险流通与责任法案》（HIPAA）要求，并经机构审查委员会批准，无需知情同意书。我们确定了超声检查发现的连续肝脏和肾脏不确定病变，这些病变接受了对比增强CT或MRI检查以进一步明确特征。对后续研究报告进行审查，以确定诊断印象是否提供了DD和RAI。使用Fisher精确检验比较CT和MRI之间DD和RAI的频率。根据观察到的DD频率，在一个假设的100例不确定病变患者样本中，比较了首先对所有病变进行多期CT检查，然后对CT检查不确定的病变进行后续MRI检查与直接对所有病变进行多期MRI检查的预期影像学成本。
共纳入143例肾脏病变，其中77例和66例分别接受了CT和MRI检查。MRI比CT更有可能提供DD（95.5%对77.9%；P = 0.003），且提供RAI的可能性显著更低（1.5%对10.4%；P = 0.038）。共纳入221例肝脏病变，其中76例和145例分别接受了CT和MRI检查。MRI比CT更有可能提供DD（95.2%对71.1%；P < 0.001），且提供RAI的可能性显著更低（0%对10.5%；P < 0.001）。在整个研究队列中，有13例在CT检查不确定后推荐进行MRI检查，1例在MRI检查不确定后推荐进行CT检查。在9例CT检查不确定后进行MRI检查的病例中，有8例提供了DD。然而，对于肾脏（64,739美元对49,759美元）和肝脏（64,739美元对56,975美元）病变，直接对所有不确定病变进行MRI检查的预期影像学成本高于首先进行多期CT检查。
对于超声检查发现的肝脏和肾脏不确定病变，与CT相比，MRI更有可能提供DD且提供RAI的可能性更低，尽管这些差异并未导致预期影像学成本降低。
