15283-B-Blokker

104 Chapter 6 MRI MR images were reconstructed and evaluated in the short axis view. Two radiologists with expertise in cardiac radiology (ACW, APP) independently evaluated MR images and in case of disagreement, consensus was reached in joint sessions. Myocardial infarctions were classified according to a modified classification by Jackowski et al. 153,157,158 Peracute infarction (within 6 hours after onset) is characterized by T2 hypointense signal in the necrotic center, caused by a state of hypoperfusion. In the acute phase (within 6 hours – 1 week after onset) the marginal areas become edematous and show T2 hyperintense signal, T1 signal in the center is isointense and the edematousmarginal regions can show T1 hypointense signal. Subacute infarction (>1 week after onset) shows T2 hyperintense signal in the infarcted area when the area becomes reperfused, while the marginal areas show normal T1 and T2 signal. Chronic infarction (>2 months after onset) shows wall thinning and scar tissue reflected by T1 and T2 hypointense signal and foci of T1 hyperintense signal can be seen due to fatty infiltration. In our analysis peracute and acute infarctions were grouped into one category and defined as acute MI (<1 week old infarction). Subacute and chronic infarctions were grouped into one category and defined as chronic MI (>1 week old infarction). MRI criteria for determining infarction age are detailed in table 2. Conventional autopsy The day after MIA, a resident in pathology, supervised by the attending pathologist, performed conventional autopsy according to the departmental protocol. The autopsy report included medical history, postmortem diagnoses, a presumed cause of death, and answers to specific clinical questions, and was authorized by the pathologist. Macroscopic evaluation consisted of sectioning of the heart in slices of 0.5 to 1 cm and visual inspection of the myocardium. Lactate dehydrogenase (LDH) staining was performed on a mid-ventricular slice. Hematoxylin and Eosin (HE) was used for histologic staining. 159 When there was a discrepancy between the histology of the MIA and conventional autopsy, a pathologist with expertise in cardiac pathology (JHT) reviewed the histology.. The following criteria for myocardial infarction age were used (separately or in combination): Acute MI: hypereosinophilia and loss of cross striation within myocardial fibers, contraction band necrosis, coagulation necrosis with or without granulocyte infiltration or hemorrhage, and various degrees of nuclear pyknosis, karyolysis, granulocyte infiltration and myocardial edema. Chronic MI: fibroblasts with loose connective tissue formation, angiogenesis (subacute), paucicellular collagenous fibrosis (chronic). 153