Breslau J, Jarvik J G, Haynor D R, Longstreth W T, Kent D L, Maravilla K R
Radiological Associates of Sacramento Medical Group, CA 95816, USA.
AJNR Am J Neuroradiol. 1999 Apr;20(4):670-5.
MR contrast media are commonly used but do not have evidence-based guidelines for their application. This investigation seeks to define specific methodological problems in the MR contrast media literature and to suggest guidelines for an improved study design.
To evaluate the reported clinical efficacy of MR contrast media in neuroimaging, we performed a critical review of the literature. From 728 clinical studies retrieved via MEDLINE, we identified 108 articles that evaluated contrast media efficacy for a minimum of 20 patients per study. The articles were randomly assigned to four readers (a fifth reader reviewed all of the articles) who were blinded to article titles, authors, institutions, and journals of publication. The readers applied objective, well-established methodological criteria to assign each article a rating of A, B, C, or D.
One hundred one of 108 articles received a D rating, six received a C rating, and one received a B rating. In general, the Methods sections of the evaluated articles did not contain details that would allow the reader to calculate reliable measures of diagnostic accuracy, such as sensitivity and specificity. Specifically, a common problem was failure to establish and uniformly apply an acceptable standard of reference. In addition, images were not always interpreted independently from the reference standard. Radiologists and clinicians need to determine the applicability of any published study to their own practices. Unfortunately, the studies we reviewed commonly lacked clear descriptions of patient demographics, the spectrum of symptomatology, and the procedure for assembling the study cohort. Finally, small sample sizes with inadequate controls were presented in almost all of the articles.
Although MR contrast media are widely used and play an essential role in lesion detection and confidence of interpretation, no rigorous studies exist to establish valid sensitivity and specificity estimates for their application. On the basis of this review, we herein describe basic methods to document improvements in technology. Such studies are essential to devise measures of diagnostic accuracy, which can form the basis for further studies that will assess diagnostic and therapeutic impact and, ultimately, patient outcomes.
磁共振造影剂应用广泛，但缺乏基于证据的应用指南。本研究旨在明确磁共振造影剂文献中存在的具体方法学问题，并提出改进研究设计的指南。
为评估磁共振造影剂在神经影像学中的临床疗效报道，我们对文献进行了严格审查。通过MEDLINE检索到728项临床研究，从中确定了108篇文章，这些文章每项研究至少评估了20例患者的造影剂疗效。文章被随机分配给四位读者（第五位读者审阅所有文章），他们对文章标题、作者、机构和发表期刊不知情。读者应用客观、既定的方法学标准为每篇文章评定A、B、C或D等级。
108篇文章中有101篇被评为D级，6篇被评为C级，1篇被评为B级。总体而言，所评估文章的“方法”部分未包含能让读者计算出可靠诊断准确性指标（如敏感性和特异性）的详细信息。具体而言，一个常见问题是未能建立并统一应用可接受的参考标准。此外，图像解释并非总是独立于参考标准进行。放射科医生和临床医生需要确定任何已发表研究对其自身实践的适用性。遗憾的是，我们审查的研究通常缺乏对患者人口统计学、症状谱以及研究队列组建程序的清晰描述。最后，几乎所有文章的样本量都较小且对照不足。
尽管磁共振造影剂被广泛使用且在病变检测和解读信心方面发挥着重要作用，但尚无严格研究来确定其应用的有效敏感性和特异性估计值。基于本综述，我们在此描述记录技术改进的基本方法。此类研究对于设计诊断准确性指标至关重要，这些指标可为进一步评估诊断和治疗影响以及最终患者结局的研究奠定基础。
