Free-Breathing Cardiac MRI for Early Detection and Risk Stratification in Duchenne Muscular Dystrophy: A Case Series

Description of Clinical Presentation: We report four patients with Duchenne muscular dystrophy (DMD) who underwent cardiovascular magnetic resonance (CMR) (Table). Cases 1 and 2, both aged 11 years, presented with proximal muscle weakness in the early ambulatory and early non-ambulatory stages, without clinical heart failure. Case 3, a 12-year-old in the early ambulatory stage, experienced a rapid systolic decline within one year of follow-up despite remaining asymptomatic. Case 4, a 15-year-old in the late non-ambulatory stage, presented with mild heart failure and advanced respiratory compromise. Collectively, these cases illustrate the heterogeneous course of DMD and underscore that cardiac involvement, often silent in early disease, is a leading cause of morbidity and mortality, highlighting the need for early surveillance.

Diagnostic Techniques and Their Most Important Findings: CMR is the gold standard for myocardial tissue characterization. However, pediatric and neuromuscular patients frequently struggle with breath-holding or require anesthesia, limiting image quality and feasibility.

To address this, all patients underwent CMR on a 1.5T scanner using a free-breathing, motion-corrected protocol incorporating balanced steady-state free precession (SSFP) cine imaging, native and post-contrast T1 mapping with Modified Look-Locker Inversion Recovery (MOLLI), and late gadolinium enhancement (LGE) imaging with phase-sensitive inversion recovery (PSIR).

Cardiac findings demonstrated the spectrum of DMD-associated myocardial involvement (Table and Figure):

• Case 1: Preserved ejection fraction (EF) with normal global native T1 and extracellular volume (ECV), but mildly elevated native T1 in the mid-inferoseptal wall without LGE.


• Case 2: Normal EF and no evidence of fibrosis, with normal native T1 and ECV, but reduced LV mass; in both cases, these subtle findings led to early initiation of cardioprotective therapy.


• Case 3: Abrupt EF decline with extensive near-transmural LGE in the anterolateral and inferolateral segments (AL/IL) and mid-wall LGE at interventricular septum with significantly elevated T1 and ECV.


• Case 4: Advanced disease with severe systolic dysfunction, patchy AL/IL LGE, and striking ECV 42% despite only mildly increased T1; the patient later died from sudden cardiac arrest due to respiratory failure.

Learning Points from this Case: Free-breathing CMR provides a reliable, non-invasive modality for early myocardial tissue characterization in DMD and enables robust image acquisition across different stages of disease without the need of sedation. Mapping techniques serve as sensitive markers of diffuse fibrosis, often preceding functional decline or overt scar formation. Routine integration of this approach into clinical practice may strengthen risk stratification, facilitate timely cardioprotective therapy, and ultimately prevent adverse outcomes in this high-risk population.

Table 1: Clinical and CMR Findings in Four Patients with Duchenne Muscular Dystrophy

Case	Age (years)	Stage	Cardiac Symptoms	LVEF(%)	LV mass index (g/m2)	LGE findings	Native T1	ECV(%)	Key clinical outcome
1	11	Early ambulatory	None	55.5	47.51	None. Increased T1 at mid-inferoseptal wall (1070 ms)	1019	25.5	Early cardioprotective therapy initiated
2	11	Early non-ambulatory	None	56	38.41	None	1014	24	Decreased LV mass; early treatment started
3	12	Early ambulatory	None	40.5	52.81	Near transmural LGE at mid anterolateral&inferolateral wall; mid-wall LGE at interventricular septum	1105	28	Sudden LVEF decline, stable on therapy
4	15	Late non-ambulatory	Mild	37	38.54	Subepicardial LGE at basal to mid anterolateral&inferolateral wall	1033	42	Died from respiratory failure 1 year post-CMR

• CMR cutoff values at our center: Native T1 >1050 ms, ECV >26%.


• Abbreviations: LVEF = Left Ventricular Ejection Fraction; LGE = Late Gadolinium Enhancement; ECV = Extracellular Volume; ms = milliseconds.

  Cardiovascular magnetic resonance (CMR) imaging in four patients with Duchenne muscular dystrophy. The figure shows steady-state free precision imaging (SSFP Cine), late gadolinium enhancement (LGE) imaging with high-resolution phase-sensitive inversion recovery (PSIR), native T1 mapping (nT1 mapping), and enhanced T1 mapping (eT1 mapping).