CRD summary

This review found that contrast enhanced multi-detector computed tomography enabled diagnosis of primary acute mesenteric ischaemia with high sensitivity and specificity. This was generally a well-conducted review and these conclusions are likely to be reliable.

Authors' objectives

To determine the diagnostic accuracy of contrast enhanced multi-detector computed tomography in primary acute mesenteric ischaemia (AMI).

Searching

PubMed, EMBASE, Scopus, BIOSIS Previews, Web of Science and The Cochrane Library were searched from 1996 to September 2009 without language restrictions. Search terms were reported. Reference lists of retrieved articles were screened.

Study selection

Studies that evaluated the accuracy of contrast enhanced multi-detector computed tomography (index test) against surgery or clinical outcome (reference standard) for the diagnosis of primary AMI in consecutive patients with clinically suspected AMI or an acute or subacute abdomen of unknown origin were eligible for inclusion. Studies had to report sufficient data to construct a 2x2 table of test performance and include at least 10 patients with AMI and 10 patients without AMI.

Prevalence of AMI ranged from 5.7% to 59.6% in the included studies. Mean age, where reported, ranged from 60 to 76 years. The proportion of men ranged from 34% to 59%. In most studies scans were interpreted by the duty radiologist. The number of multi-detector rows was four in most studies; one used 16 or 40 and one used 16 rows. Some studies administered water as the oral contrast agent. Intravenous contrast agents were omnipaque 300, iomeron or non-ionic contrast agent at various dosages.

Two reviewers independently selected studies for inclusion. Disagreements were resolved through discussion.

Assessment of study quality

Study quality was assessed using the 14-item QUADAS criteria.

The authors did not state how many reviewers performed the quality assessment.

Data extraction

Two reviewers independently extracted data to construct 2x2 tables of test performance. These data were used to calculate sensitivity and specificity together with 95% confidence intervals (CIs). Disagreements between reviewers were resolved through discussion.

Methods of synthesis

Forest plots were used to display individual study estimates of sensitivity and specificity, together with 95% CIs. Summary sensitivity and specificity were estimated using the bivariate random-effects model. Heterogeneity was assessed using the Cochran Q test and the I² statistic. Heterogeneity was assessed by extending the bivariate model to include covariates individually in the model. Multivariable models were not constructed. Publication bias was assessed using funnel plots and the Egger test.

Results of the review

Six studies were included in the review (n=619). Eight patients in one study with secondary AMI were excluded from the analysis. Three studies were prospective and three were retrospective. All studies fulfilled 12 or 13 of the 14 QUADAS items. One study did not fulfill the QUADAS criteria for availability of clinical information. The reference standard was not blinded to the computed tomography results in any of the studies.

Summary sensitivity was 93% (95% CI 83% to 98%). Summary specificity was 96% (95% CI 91% to 98%). Heterogeneity was low for both sensitivity (I²=31%, p=0.21) and specificity (I²=42%, p=0.13). None of the variables was significant in the meta-regression analysis.

Authors' conclusions

Contrast enhanced multi-detector computed tomography allows the diagnosis of primary AMI with high sensitivity and specificity.

CRD commentary

The review addressed a focused question and inclusion criteria were defined. The literature search covered an appropriate range of databases for published studies. No specific attempts were made to locate unpublished data. Although publication bias was assessed in the review, methods used were not appropriate for diagnostic data. Appropriate steps were taken to minimise bias and errors when selecting studies and extracting data; it was unclear whether such steps were taken when assessing quality. Study quality was assessed using appropriate criteria and the results were clearly presented. Methods used to pool data were based on the most statistically robust models and results were clearly presented with the aid of graphical displays. Heterogeneity was assessed and formally investigated.

The author's conclusions were supported by the data and are likely to be reliable.

Implications of the review for practice and research

Practice: The author stated that contrast enhanced multi-detector computed tomography may be used as the first-line imaging method in patients with suspected AMI.

Research: The author stated that future studies should evaluate whether multi-detector scanners with more rows and higher image resolution provided similar or greater accuracy than found in this review. Studies should evaluate what type of scanner and scan protocols were sufficient to diagnose AMI

Funding

None stated.

Bibliographic details

Menke J. Diagnostic accuracy of multidetector CT in acute mesenteric ischemia: systematic review and meta-analysis. Radiology 2010; 256(1): 93-101. [PubMed: 20574087]

Original Paper URL

http://radiology.rsna.org/content/256/1/93.abstract

Indexing Status

Subject indexing assigned by NLM

MeSH

Acute Disease; Contrast Media; Humans; Ischemia /radiography; Mesenteric Vascular Occlusion /radiography; Sensitivity and Specificity; Tomography, X-Ray Computed /methods

AccessionNumber

12010004919

Database entry date

13/04/2011

Record Status

This is a critical abstract of a systematic review that meets the criteria for inclusion on DARE. Each critical abstract contains a brief summary of the review methods, results and conclusions followed by a detailed critical assessment on the reliability of the review and the conclusions drawn.