THE VALUE OF NEW MRI TECHNIQUES IN ADRENOLEUKODYSTROPHY

Purpose. To evaluate the significance of new techniques in MRI examina tions of the brain in children with X-linked adrenoleukodystrophy (ALD ). Materials and methods. Five patients aged between 2 and 15 years wi th childhood ALD were examined with MRI, Following conventional spin-e cho (CSE) sequences, a fast spin-echo (FSE) sequence with T2 contrast was performed in four patients, an FSE turbo-inversion-recovery (TIR) sequence in two, magnetization transfer contrast (MTC) imaging in two, and localized proton spectroscopy (MRS) in four patients. Results. FS E compared favorably with CSE with a time saving of 70 %. On TIR image s the contrast between normal and demyelinated white matter was greate r than on CSE and FSE images. Calculated MTC values revealed a severe MTC loss within the demyelinated regions and a moderate reduction in t he border zones. In this way, calculation of MTC might be useful to di fferentiate between edematous changes and areas of irreversible demyel ination. MRS revealed a reduction in N-acetylaspartate and an elevatio n in choline (Cho), The degree of MRS changes paralleled the severity of demyelination. A Cho elevation may precede visible demyelination on T2-weighted images. Conclusion. T2-weighted FSE sequences can replace CSE without any disadvantages and with effective time saving, The ind ication for MTC imaging and MRS in children with ALD is not yet finall y defined. These new techniques may reveal the earliest signs of cereb ral involvement or of disease progression, a matter of great importanc e in selecting the optimal therapeutic approach.