Reliability and Diagnostic Performance of CT Imaging Criteria in the Diagnosis of Tuberculous Meningitis

Abstract

IntroductionAbnormalities on CT imaging may contribute to the diagnosis of tuberculous meningitis (TBM). Recently, an expert consensus case definition (CCD) and set of imaging criteria for diagnosing basal meningeal enhancement (BME) have been proposed. This study aimed to evaluate the sensitivity, specificity and reliability of these in a prospective cohort of adult meningitis patients.MethodsInitial diagnoses were based on the CCD, classifying patients into: ‘Definite TBM’ (microbiological confirmation), ‘Probable TBM’ (diagnostic score ≥10), ‘Possible TBM’ (diagnostic score 6–9), ‘Not TBM’ (confirmation of an alternative diagnosis) or ‘Uncertain’ (diagnostic score of <6). CT images were evaluated independently on two occasions by four experienced reviewers. Intra-rater and inter-rater agreement were calculated using the kappa statistic. Sensitivities and specificities were calculated using both ‘Definite TBM’ and either ‘Definite TBM’ or ‘Probable TBM’ as gold standards.ResultsCT scan criteria for BME had good intra-rater agreement (κ range 0.35–0.78) and fair to moderate inter-rater agreement (κ range 0.20–0.52). Intra- and inter-rater agreement on the CCD components were good to fair (κ = ranges 0.47–0.81 and 0.21–0.63). Using ‘Definite TBM’ as a gold standard, the criteria for BME were very specific (61.5%–100%), but insensitive (5.9%–29.4%). Similarly, the imaging components of the CCD were highly specific (69.2–100%) but lacked sensitivity (0–56.7%). Similar values were found when using ‘Definite TBM’ or ‘Probable TBM’ as a gold standard.DiscussionThe fair to moderate inter-rater agreement and poor sensitivities of the criteria for BME suggest that little reliance should be placed in these features in isolation. While the presence of the CCD criteria of acute infarction or tuberculoma(s) appears useful as rule-in criteria, their absence is of little help in excluding TBM. The CCD and criteria for BME, as well as any new criteria, need to be standardized and validated in prospective cohort studies.

A New Scoring System for the Differential Diagnosis between Tuberculous Meningitis and Viral Meningitis

“…2) Probable TBM: clinical meningitis with extra-neural TB evidence or with neuroimaging findings suggestive of TBM (hydrocephalus or tuberculoma) 18 …”

IP-10 and MIG Are Compartmentalized at the Site of Disease during Pleural and Meningeal Tuberculosis and Are Decreased after Antituberculosis Treatment

“…The clinical criterion for diagnosis of TBM was over 2 weeks of fever, headache, and neck stiffness. Diagnosis of TBM was confirmed if a patient had microbial and/or cytochemistry evidence of TB in CSF and a clinical response to anti-TB treatment (21). Nontuberculous meningitis (non-TBM) was defined as clinical meningitis with no evidence of TB and a confirmation of an alternative cause.…”

Tuberculous meningitis in children

“…The triad of radiological findings in TBM includes hydrocephalus, infarctions and basal meningeal enhancement45. The five major computed tomography (CT) features which support the TBM diagnosis include infarcts, hydrocephalus, tuberculomas, basal meningeal enhancement and pre-contrast basal hyperdensities46. Hydrocephalus and meningeal enhancement are important signs of TBM in CT scan, observed in 80 and 75 per cent of children with TBM, respectively274748.…”