15283-B-Blokker

107 Accuracy of MIA for the detection of ischemic heart disease 6 reference standard. MRI without biopsies showed a high specificity, but low sensitivity for acute and chronic MI. High CT Agatston calcium score (>400) was a good predictor for chronic MI, but not for acute MI. We found a lower sensitivity of MRI as a standalone test for acute MI (0.50) compared to other studies investigating MRI. Ruder et al. reported that with MRI acute MI (within 3 hours after onset) could be detected in ex vivo porcine hearts in which they correctly detected acute infarctions in all twenty-one cases. 161 Forensic studies showed that with MRI acute and chronic MI (up to 100% sensitivity) could be accurately diagnosed in human subjects. Importantly, MRI could diagnose peracute MI (onset within 3 hours) in cases not yet showing histological changes, but with a matching coronary stenosis at conventional autopsy. 153,154,158 The differences in sensitivity and specificity among studies can be explained by the differences in studied population and clinical setting; most are forensic studies that investigated subjects who died under the suspicion of an out-of-hospital-cardiac- arrest and as such had a high pre-test probability. Also, these studies often involve high-resolution cardiac imaging at 3T scanners using surface coils and relatively long scan time for imaging only the heart (approximately 1 hour). 157 Conversely, we scanned in a hospital setting and performed total-body imaging to diagnose both cardiac and non-cardiac cause of death. So as not to interfere with the patient workflow at the MR scanner, we were restricted to one-hour scan time for imaging the entire body. The addition of biopsies to MRI increased the sensitivity substantially. This highlights the importance of extensive sampling, even when no changes are visible yet on MRI. The big difference between sensitivity of MRI and MRI combined with biopsies can be explained by the quantity of sampling. From each biopsy location, at least 5 samples were taken, e.g. from the lateral wall also the mid and posterior segments were biopsied. Furthermore in those cases where there was a clinical suspicion of myocardial ischemia and the MRI showed no signal abnormalities, extra biopsies were taken from the septum, anterior and posterior wall (both mid and posterior segments). The noninvasive approach (CT and/or MRI) is less expensive than the minimally invasive approach (imaging plus biopsy). CT is now widely used as a stand-alone modality because of its high accessibility, short examination time and robust performance. CT can provide better mortality statistics than the cause of death determined by the clinician, and is useful for excluding certain diagnoses. However, for diagnosing acute myocardial infarction, our results show that the diagnostic accuracy of CT as stand- alone test is insufficient. 162,163 To improve CT performance, in particular for ischemic heart disease, more recent studies report on the diagnostic value of CT angiography. Grabherr et al. extensively performed feasibility studies on CTA using different contrast agents and perfusion