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Purpose: To quantify the differences between normal and corticosteroid-treated Duchenne muscular dystrophy (DMD) lower limb muscle using signal intensity measurements on T(1)-weighted and gadolinium contrast-enhanced images and by measurement of muscle T(2) values, and to investigate the effect of exercise.Materials and Methods: Eleven ambulant boys with DMD were imaged at 3 Tesla (T(1)-weighted, gadolinium enhancement and T(2) measurement) before stepping exercise and again (gadolinium, T(2) measurement) 4 days later and were compared with five healthy controls imaged 4 days before and after stepping exercise. Muscle region-of-interest signal intensities were referenced to external oil and gadolinium phantoms.Results: DMD thigh muscle T(2) values were significantly higher than normal values with the exception of the gracilis muscle. Eight of nine muscles studied showed a significant increase in T(1)-w signal intensity in DMD as compared to normal muscle, suggestive of increased fat infiltration in DMD muscle. In the DMD boys, an exercise effect (increased contrast enhancement) was only seen for the tibialis anterior muscle.Conclusion: Referenced signal intensity measurements may be used to quantify differences between dystrophic and normal muscle without T(1) mapping. Stepping exercise does not have a large impact on subsequent MR imaging of dystrophic muscle. [ABSTRACT FROM AUTHOR]

Purpose: To determine whether the magnetization transfer ratio (MTR) of the globus pallidus (GP) in patients with primary biliary cirrhosis (PBC) correlates with age, disease stage, and fatigue, using T(1) and T(2) mapping to determine whether the mechanism of change is consistent with manganese deposition in the GP as suggested by previous reports.Materials and Methods: In all, 30 early-stage PBC patients, four end-stage PBC patients, and 14 female controls were recruited to age-matched groups. MTR, T(1) and T(2) measurements were performed. A bilateral region of interest (ROI)-based analysis was used to calculate GP MTR, T(1), and T(2) values. These were correlated with age, disease status, and fatigue.Results: MTR measurements showed a significant, negative correlation with age for controls and early-stage PBC patients, a positive correlation with T(2), and no correlation with T(1). Only GP T(2) is significantly lower in early-stage PBC patients than controls, while end-stage patients demonstrated a simultaneous reduction in T(1) and MTR, consistent with GP manganese deposition.Conclusion: MTR measurements correlate with age in both early-stage patient and control groups, but are not associated with manganese deposition or fatigue severity: only the end-stage disease group shows changes in MTR, T(1), T(2) that are consistent with manganese deposition. [ABSTRACT FROM AUTHOR]

A predictive technique in the management of patients with cancer could improve the therapeutic index by allowing better individualisation of treatment. The standard risk factors that are currently used do not adequately account for the unpredictable and substantial variation seen in the treatment response of patients with a similar risk profile. Dynamic contrast-enhanced (DCE) MRI is a non-invasive technique that can provide anatomical and physiological information on the tumour. The DCE-MRI data reflects the tumour microenvironment variables that are known to influence radiation response. The aim of this review is to describe the potential clinical application of DCE-MRI as a predictor of radiation response. We have reviewed the literature and identified 29 studies (total of 1194 patients) that correlate DCE-MRI with histopathological or clinical outcome data relevant to radiotherapy. [ABSTRACT FROM AUTHOR]