Cardiac and sternocleidomastoid muscle involvement in Duchenne muscular dystrophy: an MRI study.
OBJECTIVE
To examine the extent of cardiac muscle and sternocleidomastoid muscle (SCM) involvement detected by MRI measurement of T2 relaxation time in patients with Duchenne muscular dystrophy (DMD) and no cardiorespiratory symptoms.


METHODS
Prospective controlled study.


METHODS
Teaching referral hospital and university hospital.


METHODS
Seventeen patients with DMD (age range, 7 to 25 years) and 17 age-matched control subjects. All patients were free of cardiac or respiratory complaints and had normal ECG, echocardiograph, and Holter monitor examination findings.


METHODS
We assessed respiratory function by means of standard pulmonary function testing. MRI measurements included the T2 relaxation time of the myocardium and the SCM in patients and control subjects.


RESULTS
The FVC and FEV1 values were lower in patients with DMD than in age-matched control subjects, whereas the FEV1/FVC ratio was normal in all subjects. Patients with DMD had lower T2 relaxation time of the heart (37.8 +/- 6.1 ms vs 58.1 +/- 7.1 ms, p < 0.001) and lower T2 relaxation time of the right SCM (24.5 +/- 2.6 ms vs 42.2 +/- 1.3 ms, p < 0.001) and left SCM (23.2 +/- 3.2 ms vs 42.2 +/- 1.6 ms, p < 0.001), compared to control subjects (+/- SD). In children (< 12 years of age), the T2 of the SCM was lower than that of the control subjects, but T2 of the heart did not differ between the two groups. In the patient group, T2 relaxation time of the heart decreased with age (r = - 0.80, p < 0.001). In patients with FVC < 80% of predicted, the T2 values of the heart were lower than the T2 values of patients with FVC > or = 80% of predicted (35.6 +/- 5.8 ms vs 41.8 +/- 4.6 ms, p < 0.05).


CONCLUSIONS
MRI measurements of the T2 relaxation time in the myocardium and SCM of patients with DMD and no cardiorespiratory symptoms are abnormal, indicating altered tissue composition. These measurements may prove a clinically useful test for monitoring cardiac and respiratory muscle involvement in these patients.
Mavrogeni
Sophie
S
Onassis Cardiac Surgery Center, Athens, Greece. soma@aias.gr
Tzelepis
George E
GE
Athanasopoulos
George
G
Maounis
Themistoklis
T
Douskou
Marouso
M
Papavasiliou
Antigoni
A
Cokkinos
Dennis V
DV
D000293:Adolescent; D000328:Adult; D002648:Child; D003430:Cross-Sectional Studies; D005541:Forced Expiratory Volume; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D018482:Muscle, Skeletal / Q000473:pathology*; D020388:Muscular Dystrophy, Duchenne / Q000473:pathology* / Q000503:physiopathology; D009206:Myocardium / Q000473:pathology*; D011446:Prospective Studies; D012129:Respiratory Function Tests; D014797:Vital Capacity