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Hongcheng Shi

Publications and source records attributed to Hongcheng Shi.

3 recordsLinked to original sources
PubMed2006

Apical hypertrophy caused by glycogen storage disease creating artifacts in myocardial perfusion imaging.

A 46-year-old man with atrial fibrillation and coronary artery disease was referred for myocardial perfusion imaging for the evaluation of chest pain. The patient underwent adenosine stress and rest dual-isotope myocardial perfusion imaging. There was no adenosine-induced chest pain or EKG changes specific for ischemia. Myocardial perfusion images demonstrated an apical "hot spot" and decreased tracer activity in the base of the heart. The polar plots showed a bright center with a rim of significant (>2.5 SD) defect around the base of the myocardium. Ischemia in the base of the heart, with the apex of the heart seemingly normal, was rather puzzling and correlation with magnetic resonance images (MRI) showed apical hypertrophy. Examination of the history revealed that the patient was diagnosed with restrictive cardiomyopathy 2 years ago and endocardial biopsy showed intramyocardial glycogen on electron microscopy, suggesting glycogen storage disease. The case illustrates a "hot spot" resulting from apical hypertrophy creating artifactual fixed defects in myocardial perfusion images and in polar maps.

Atrial Fibrillation↗
PubMedDate not supplied

Automated quality control of emission-transmission misalignment for attenuation correction in myocardial perfusion imaging with SPECT-CT systems.

BACKGROUND: Emission-transmission misalignment with single-photon emission computed tomography (SPECT)-computed tomography (CT) systems can impair attenuation correction (AC) in myocardial perfusion imaging. This study was performed to develop automated quality control (Auto-QC) to detect critical misalignment that can significantly impact AC. METHODS AND RESULTS: Auto-QC was developed to segment myocardium and mediastinum from emission and transmission reconstructions, respectively. Myocardium-mediastinum mismatch was used as the quality-control index (QCI). The QCI threshold for acceptable AC was determined with NCAT (NURBS [nonuniform rational B-spline]-based cardiac torso phantom) simulation and verified with 2 patients with minimal misalignment. Compromised data sets, generated by shifting the attenuation maps by 0.5, 1.0, 1.5, and 2.0 pixels along left-right, up-down, and head-foot directions, respectively, were qualitatively and quantitatively compared with the unshifted data sets. Auto-QC was tested with the 2 verification patients and 41 additional patients. Shifts by more than 1 pixel along any direction compromised AC. Auto-QC with the QCI threshold (3%) had highly concordant results with manual quality control in the detection of critical misalignment (sensitivity of 88% and 90% and specificity of 93% and 95% for the tests by use of the 2 verification patients and 41 additional patients, respectively). CONCLUSION: QCI quantitatively represented the severity of misalignment. Auto-QC can help clinicians be aware of critical misalignment and can assist in realignment of SPECT and CT images.

Algorithms↗