The Prevalence of Incidental Mastoid Opacification and the Need for Intervention: A Meta‐Analysis

Abstract

Objectives/Hypothesis: The increasing use of cross-sectional imaging has led to the predicament of incidental mastoid opacification (IMO). We investigated the prevalence of IMO and the clinical need for ENT assessment or intervention when identified.Study Design: Systematic review and meta-analysis. Methods: The PRISMA statement standards were used to search electronic databases including Medline, Embase, PubMed, and Web of Science. The selection criteria were mastoid opacification found on computed tomography (CT) or magnetic resonance imaging (MRI) as incidental findings.Results: A total of 16 studies were identified for qualitative analysis and 15 for quantitative analysis, mainly retrospective. The pooled prevalence of IMO in 246,288 patients was 8.4% (95% CI 5.5-12.0). The prevalence of IMO was significantly higher in studies with children (17.2%, 95% CI 10.9-24.6) than those with adults (6.1%, 95% CI 3.3-9.6); smaller sample size studies (12.4%, 95% CI 8.1-17.3) compared to larger sample size studies (4.1%, 95% CI 1.5-7.8); and when IMO was detected by viewing images (14.5%, 95% CI 9.9-19.8) compared to reading reports (3.5%, 95% CI 1.3-6.6). Imaging modality was not a significant moderator due to similar IMO rate on CT (8.6%, 95% CI 1.8-19.7) and MRI (10.4%, 95% CI 4.9-17.6). Nine studies reported on clinical outcomes of patients with IMO, and none reliably reported any cases of clinical mastoiditis.Conclusions: The term "mastoiditis" on radiology reports based on IMO does not indicate a clinical diagnosis of mastoiditis, although the current body of evidence is limited. Otolaryngology review is suggested if clinical correlation detects otological signs or symptoms.

Sinus, middle-ear and mastoid radiological findings of severe acute respiratory syndrome coronavirus-2

“…Mastoiditis is a frequent incidental radiological finding on CT of the head, as fluid collects in mastoid air cells whilst the patient lies supine as the scan is performed. 25 Mughal et al . reported that 8.4 per cent of head CT scans suggested incidental mastoid opacification.…”

“…Marginally lower rates of sinus and mastoid opacification in patients with Covid-19 are reported in the literature (Table 6); [25][26][27][28][29][30] 41.8 per cent of Moonis and colleagues' cohort of 55 patients had sinus disease, yet only 7 per cent demonstrated mastoid opacification. 29 Similarly, İslamoğlu et al reported much lower levels of mastoid opacification in a cohort of 129 patients, at only 2.32 per cent.…”

“…[36][37][38] Mastoiditis is a frequent incidental radiological finding on CT of the head, as fluid collects in mastoid air cells whilst the patient lies supine as the scan is performed. 25 Mughal et al reported that 8.4 per cent of head CT scans suggested incidental mastoid opacification. 25 Acute otitis media is a common sequelae of upper respiratory tract infection, 10,30 with consequent middle-ear effusion and mastoid opacification identifiable on radiological imaging.…”

“…25 Mughal et al reported that 8.4 per cent of head CT scans suggested incidental mastoid opacification. 25 Acute otitis media is a common sequelae of upper respiratory tract infection, 10,30 with consequent middle-ear effusion and mastoid opacification identifiable on radiological imaging. 15 Thus, Covid-19 was postulated to manifest as ontological involvement.…”

“…Mortality was recorded if it occurred within 30 days of the date of imaging. Our outcomes were compared against pre-pandemic studies examining the prevalence of incidental mastoid 25 and sinus 26 opacification.

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