Chest x-ray generator distance predicts CMR artefact burden in patients with cardiac devices

Abstract Background Cardiac MRI (CMR) is increasingly performed in patients with cardiac implantable electronic devices (CIEDs) using standardised safety protocols. However, device-related artefacts may compromise diagnostic quality. Chest radiography (CXR) facilitates screening, but its value in predicting CMR image quality is uncertain. Purpose: To evaluate the utility of CXR in anticipating CIED-induced artefacts and image interpretability. Methods We retrospectively analysed patients with conditional CIEDs referred for 1.5T clinical CMR between January 2022 and February 2025. Generator-to-heart distance was measured from the generator edge to the mid anterolateral border of the cardiac silhouette on anteroposterior CXR. Cine and late gadolinium enhancement (LGE) sequences were tailored to device type. Image quality was independently rated as diagnostic, partially diagnostic (including limited/minimal artefacts), or non-diagnostic. Associations between generator distance and LGE quality were assessed using Mann–Whitney U test and ROC analysis, stratified by device type (ICD vs PPM). Optimal thresholds were identified using Youden’s index. Results 44 patients (median age 62 years IQR 48–72; 75% male) including 25 dual-chamber PPMs and 19 ICDs 11 single-lead, 3 dual-chamber, 3 subcutaneous S-ICD, 2 extravascular (EV)-ICD completed CMR without complications. LGE image quality was at least partially diagnostic in 95.5% of cases, the two non-diagnostic cases occurred in ICD patients, one of which preceded the introduction of wideband sequences. Median generator distance was greater in diagnostic vs non/partially diagnostic scans (6.9 cm vs 4.4 cm, p = 0.010). ROC analysis showed good overall discrimination (AUC = 0.73; optimal cutoff ≥5.3 cm). Stratified analysis showed similar performance (ICD: AUC = 0.79, cutoff ≥ 5.6 cm; PPM: AUC = 0.76, cutoff ≥ 6.6 cm), with corresponding sensitivity/specificity of 100%/71% for ICDs and 56%/100% for PPMs (Figure 1 wideband LGE was preferred in ICDs (n=18). No artefacts were observed in EV-ICD scans. Conclusion Pre-scan chest radiography provides a simple, accessible metric for anticipating CMR image quality in patients with CIEDs. Generator-to-heart distance on CXR is significantly associated with LGE interpretability, with device-specific thresholds offering clinically useful discrimination. These findings suggest that CXR-based assessment may help inform pre-CMR triage and imaging protocol selection, particularly in ICD recipients.