Meta-analysis of the diagnostic value of three imaging techniques in Crohn's disease

Abstract

Objective To evaluate the diagnostic value of computed tomography enteroclysis/enterography (CTE),magnetic resorance enteroclysis/enterography (MRE) and ultrasonography (US) in Crohn's disease (CD) by Meta-analysis.Methods Segmental intestinal wall thickening and strengthening was taken as image diagnostic indicators in CD.Endoscopic and histopathologic findings and follow-up results were set as diagnostic standard.Retrieve and literature inclusion criteria were developed.The papers of CD diagnosed by CTE,MRE and US which met the criteria were searched and screened.The quality of the papers was evaluated by quality assessment of diagnostic accuracy studies (QUADAS).The diagnostic efficacy of CTE,MRE and US was compared,which included sensitivity,specificity,positive likelihood ratio and negative likelihood ratio,positive predictive value (PPV) and negative predictive value (NPV).Results Among the 2197 retrieved literature,a total of 12 papers met the criteria and nine of which were blinded study.The papers were grouped by three different imaging techniques and underwent QUADAS scale scoring.One paper was about CTE and MRE comparative study,so there were six papers in CTE group,the scores of all the six papers were over 10 and all of them were blinded study.There were four papers in MRE group,the scores of three papers were over 10 and all of them were blinded study.There were three papers in US group,the score of one paper was over 10 and two of these three papers were blinded study and one with unclear evaluation.The sensitivity of CTE group was the highest (89 ％),while the specificity (90 ％) was lower than that of US group (95％).The PPV (93％),NPV (95％),positive likelihood ratio (15.16) and negative likelihood ratio (0.17) of US group were the highest,those of CTE were secondary (PPV 91％,NPV 82％,positive likelihood ratio 6.25 and negative likelihood ratio 0.15).The sensitivity (74％),specificity (84％),PPV (80％),NPV (80％),positive likelihood ratio (4.18) and negative likelihood ratio (0.33) of MRE group were lower than both US group and CTE group.Conclusions The sensitivity of CTE in CD diagnosis is better than that of MRE and US,while other diagnostic indicators are poorer than US.Even though US has high diagnostic value in CD,more well designed large sample study were still needed for further evaluation. Key words: Crohn disease; Tomography, X-ray computed; Magnetic resonance imaging; Ultrasonography; Meta-analysis