Intravascular ultrasound can be used to assess borderline lesions seen on coronary angiography. A 50 year old woman with angina and objective evidence of ischaemia in the anterior wall underwent multiple coronary angiograms following recurrent admissions with angina. These failed to demonstrate any specific lesion in the left anterior descending artery that might guide an intravascular ultrasound examination. Examination of the left anterior descending artery using intravascular ultrasound showed significant obstruction …