128 Bright blood t2 weighted MRI has higher diagnostic precision and accuracy than dark blood stir MRI for assessment of the ischaemic area-at-risk and myocardial salvage in acute myocardial infarction

Abstract

(NICE) have released guidelines for the investigation of chest pain of recent onset (1). There is concern that the guidelines will increase the burden on cardiac imaging, requiring service reconfiguration and investment (2, 3). This study was performed to assess the impact of the guidelines on outpatient cardiology services in the UK. Methods 595 consecutive patients attending chest pain clinics at two hospitals over six months preceding release of the NICE guidelines (51% male; median age 55 yrs (range 22e94 yrs)) were risk stratified using NICE criteria. Preliminary cardiac investigations recommended by NICE were compared with existing clinical practice and the relative costs calculated. Results NICE would have recommended 443 patients (74%) for discharge without cardiac investigation, 10 (2%) for cardiac computed tomography (CCT), 69 (12%) for functional cardiac imaging and 73 (12%) for invasive coronary angiography (ICA). Relative to existing practice there would have been a trend towards reduced functional cardiac imaging (À24%; p¼0.06) and increased CCT (+43%; p¼0.436) but a significant increase in ICA (+508%; p<0.001). The cost of investigations recommended by NICE would have been £15 881 greater than existing practice. Conclusions This study suggests implementation of the NICE guidelines will require investment in cardiology services, particularly ICA. It will be necessary to establish and maintain CCT for relatively few patients; also to establish and maintain functional cardiac imaging even though referrals are likely to decline. Individual hospitals should assess their local populations prior to service reconfiguration.

Cardiac MRI: T2-Mapping Versus T2-Weighted Dark-Blood TSE Imaging for Myocardial Edema Visualization in Acute Myocardial Infarction

“…Our semiquantitative scoring showed fairly similar values for the extent of myocardial edema as assessed by T2 mapping and the extent of myocardial infarction as assessed by LGE. However, from previous studies it could have been expected that the T2 map edema score would be higher than the LGE score, since it has been shown that the edema zone is larger than the LGE zone in AMI [22,28,29]. However, the conflict between our findings and this expectation is only contrived.…”

“…In a recently published study Payne et al assessed the diagnostic performance of T2w dark-blood TSE for the detection of myocardial edema in AMI on a coronary artery perfusion territory basis. They found that T2w dark-blood TSE showed myocardial edema within the perfusion territory of the culprit coronary artery only in 61 % of cases [22]. Even though T2 mapping showed better sensitivity than T2w dark-blood TSE imaging, the sensitivity of T2 mapping is not perfect.…”

“…Since several experimental and clinical studies have confirmed the great value of myocardial edema imaging in AMI [7,19,20] as well as in inflammatory cardiomyopathies [9], great efforts have been made to overcome the limitations of T2w darkblood TSE imaging. Within the scope of these efforts, T2w brightblood SSFP sequences have been developed within the last years [13,21,22]. Even though these approaches have addressed several of the mentioned shortcomings, these sequences are not common in the clinical routine presumably due to the fact that most of these techniques tend to provide a lower contrast between edematous and remote myocardium compared to T2-weighted dark-blood TSE images [23].…”

Left ventricular strain and its pattern estimated from cine CMR and validation with DENSE

“…CMR scans were performed on a Siemens MAGNETOM Avanto (Erlangen, Germany) 1.5-Tesla scanner with an 8-element phased array cardiac surface coil. CMR protocols included breath-hold steady state free precession cine, displacement encoded with simulated echoes (DENSE) and late gadolinium enhancement (LGE) phase sensitive inversion recovery (PSIR) (Payne et al 2011). Cine, DENSE and LGE CMR scans were obtained at the same position and only short-axis scans were post-processed in this study.…”

A numerical study of a heart phantom model

“…For example, in patients with a history of myocardial infarction, cardiac MRI can reveal infarct scar, haemorrhage and oedema, all of which can be linked with function. It has been shown [5,[26][27][28] that MRI is highly informative for assessing heart function, volumes and injury (area-at-risk, scar burden, salvaged myocardium, microvascular obstruction, haemorrhage and thrombus). In fact, infarct pathologies tend to aggregate in the highest risk patients in whom MRI is most informative.…”