Suppression of ghost artifacts arising from long T1 species in segmented inversion-recovery imaging.

PURPOSE: We demonstrate an improved segmented inversion-recovery sequence that suppresses ghost artifacts arising from tissues with long T1 ( > 1.5 s). THEORY AND METHODS: Long T1 species such as pericardial fluid can create bright ghost artifacts in segmented, inversion-recovery MRI because of oscillations in longitudinal magnetization between segments. A single dummy acquisition at the beginning of the sequence can reduce oscillations; however, its effectiveness in suppressing long T1 artifacts is unknown. In this study, we systematically evaluated several test sequences, including a prototype (saturation post-pulse readout to eliminate spurious signal: SPPRESS) in simulations, phantoms, and patients. RESULTS: SPPRESS reduced artifact signal 90% ± 25% and 74% ± 28% compared with Control and Single-Dummy methods in phantoms. SPPRESS performed well at 1.5 Tesla (T) and 3T, with steady-state free precession (SSFP) and fast low-angle shot (FLASH) readout, with conventional and phase-sensitive reconstruction, and over a range of physiologic heart rates. A review of 100 consecutive clinical cardiac MRI scans revealed large fluid collections (eg, regions with long T1 ) in 14% of patients. In a prospectively enrolled cohort of 16 patients with visible long T1 fluids, SPPRESS appreciably reduced artifacts in all cases compared with Control and Single-Dummy methods. CONCLUSION: We developed and validated a new robust method, SPPRESS, for reducing artifacts due to long T1 species across a wide range of imaging and physiologic conditions. Magn Reson Med 78:1442-1451, 2017. © 2016 International Society for Magnetic Resonance in Medicine.

Ambulatory cardiac single-photon emission computed tomography at the primary care physician's office: a descriptive study.

Ambulatory cardiac single-photon emission computed tomography stress testing for the evaluation of coronary artery disease at the primary care physician's office is increasingly utilized without data supporting its safety. In this 2-year prospective pilot study of 1266 consecutive stress-myocardial perfusion imaging studies done in the primary care physician's office using a mobile nuclear cardiology laboratory, adverse events were mild and rare. There were no recorded events of myocardial infarction, serious arrhythmias, severe bronchospasm, hospitalization, or death. This suggests that this practice is safe in this population with these providers. This finding may not apply to a higher-risk population. Further evaluation of referral appropriateness and long-term prognostic value is needed.