Diagnostic Accuracy and Utility of ZTE Added to Routine MRI

Brief Summary

Breast cancer is the most common cancer in women worldwide \[1\]. The burden is heaviest in low- and middle-income countries, where late detection, limited screening access and scarce biopsy resources delay diagnosis \[2,3\]. Accessible, non-invasive imaging that can triage patients accurately is therefore needed. Digital mammography and digital breast tomosynthesis are the reference tools for detecting microcalcifications, which are often the earliest visible sign of ductal carcinoma in situ (DCIS) and can appear before any mass or architectural distortion \[4\]. Microcalcifications also carry prognostic information that influences surgical planning and management \[5,6\]. They arise through comedonecrosis and through osteomimicry, in which tumor cells acquire bone-forming features \[6,7\]. Dynamic contrast-enhanced (DCE) breast MRI is highly sensitive for invasive cancer \[8\]. However, calcifications and metallic biopsy markers have very short T2 relaxation times and appear as signal voids that cannot be separated from air or fibrosis. Marker artifacts can measure 2-6 times the marker diameter and may obscure adjacent tumor \[9\]. Full lesion characterization may therefore need several examinations, radiation, contrast and biopsy. Zero echo time (ZTE) MRI samples signal at an echo time of about 0 ms with a three-dimensional radial acquisition. With gray-scale inversion it gives CT-like contrast without radiation or contrast agent and is established in musculoskeletal imaging \[10\]. Whether ZTE adds value to routine breast MRI is unknown. Research question: In women referred for diagnostic or staging breast MRI, does adding ZTE to the routine protocol accurately detect calcifications and improve biopsy-marker visualization compared with mammography and histopathology?