Magnetic resonance imaging of old myocardial infarction in young patients with a history of Kawasaki disease

Background: On magnetic resonance imaging (MRI) using gadolinium diethylene triamine pentaacetic acid (Gd-DTPA) as contrast medium, images of infarct r egions are enhanced in acute myocardial infarction (AMI). In old myocardial infarction (OMI), thinning of the myocardial walls is present, but images are no longer enhanced by Gd-DTPA. On the other hand, MI in children with a history of Kawasaki disease (KD), several differences from adult MI are ob served. Hypothesis: The aim of this study was to evaluate the lesions that result f rom OMI in children with a history of KD using MRI with Gd-DTPA as a contra st medium. Methods: The subjects were 16 young patients with a history of KD who were diagnosed as having OMI. Of these, both thinning of the myocardial wall and MRI enhancement by Gd-DTPA were observed in 4 cases, thinning alone was ob served in 6 cases, Gd-DTPA image enhancement alone was observed in 3 cases, and neither thinning nor Gd-DTPA image enhancement was observed in 3 cases . Results: The Gd-DTPA-image-enhanced, OMI-induced lesions observed in patien ts with KD were different from those observed in adults; this might be attr ibutable to histologic differences. Conclusion: Magnetic resonance imaging using Gd-DTPA can evaluate myocardia l thinning and presence of circulation noninvasively at the same time and i s considered to be useful for long-term follow up of the patients with KD a nd OMI.