The Year in Cardiac Imaging

Abstract

This review is a sequel to our previous reports highlighting the most important recent literature in single-photon emission computed tomography (SPECT) myocardial perfusion imaging, cardiac positron emission tomography (PET), cardiac computed tomography (CT), and cardiac magnetic resonance imaging (MRI). In almost all cases, these studies were published in the English-language literature between April 1, 2006, and March 31, 2007. The decision to arbitrarily include some articles and exclude others is more difficult each year. Time has exposed some of our previous errors. Last year, we did not include the first case report on nephrogenic systemic fibrosis. This year, we added a whole new safety section on this topic. We can assure both authors and readers that we have done our best to put aside personal biases in reaching these difficult decisions. We have again organized this summary around topical themes in an effort to encourage a broad, multimodality approach to the application of imaging to clinical problems. Technical AdvancesPET. Although cardiac F-18 fluorodeoxyglucose (FDG)-PET imaging is a well-established technique, vascular FDG-PET imaging is not. Two studies addressed this emerging area. Tawakol et al. (1) compared the results of FDG-PET imaging with tissue samples obtained during subsequent carotid endarterectomy to demonstrate a significant correlation between FDG uptake and both carotid plaque and macrophage staining. This early study offers great promise if subsequent studies demonstrate that increased carotid FDG activity predicts subsequent cerebrovascular events. Tahara et al. (2) used FDG-PET vascular imaging in a randomized trial of 43 patients to demonstrate a decrease in FDG uptake in patients treated with simvastatin. CT. The rapid technical advances in CT continue. Early studies described the use of 256-row cone beam and dual-source CT, both introduced in last year's review. Using dual-source CT, Johnson et al. (3) demonstrated impressive temporal resolution and robust coronary artery imaging at a wide range of heart rates. Scheffel et al. ( 4) showed similar results, with excellent negative predictive value for Ͼ50% stenosis despite a lack of beta-blockade. MRI. Advances in MRI software and computer processing have lead to faster, more robust performance. There is a small-but-growing literature in which MRI acquisitions are acquired in a single breath hold, or in a free-breathing state. Attempts to decrease the breathing requirements for MRI volume measurements are summarized in Table 1 (5-10). The ability to perform MRI acquisitions in a single breath hold, or in a free-breathing state, would substantially reduce the main limitation of MRI (i.e., the level of required patient cooperation). Viability PET.Previous studies have reported conflicting data on the duration of survival of hibernating myocardium. Wiggers et al. (11) performed serial sestamibi SPECT and FDG-PET on 16 patients with chronically stunned or hibernating myocardium who were treated with medical therapy for approximatel...