Background: Magnetic resonance imaging (MRI) was compared with triple assessment (clinical examination, cytology and mammography) in the differentiation of post-treatment changes from local recurrence of breast carcinoma.
Methods: Thirty patients treated previously by breast conservation surgery and radiotherapy with clinical suspicion of local recurrence were evaluated prospectively by triple assessment and MRI. Breast MRI was performed on a 1-tesla scanner using a T1-weighted three-dimensional fast low angle shot pulse sequence before and after contrast enhancement.
Results: Local recurrence was confirmed histologically in 14 patients. Of these, mammography identified seven (sensitivity 50 per cent), cytology 11 (sensitivity 79 per cent) and breast MRI 13 (sensitivity 93 per cent). Compared with histological measurement, breast MRI allowed an accurate estimation of the extent of local recurrence (r2 = 0.98). Morphologically abnormal areas without contrast enhancement correlated with postradiation changes. False-positive contrast enhancement was seen in two patients (specificity 88 per cent) in whom histology confirmed inflammatory changes only.
Conclusion: Breast MRI is useful in the evaluation of patients with a high clinical suspicion of local recurrence within the irradiated conserved breast.