Dissociation between improvement in angina pectoris and myocardial perfusion after transmyocardial revascularization with an excimer laser.

Xenon chloride excimer laser transmyocardial revascularization significantly reduced angina in all patients and increased regional myocardial perfusion in most patients; however, there was no correlation between symptomatic improvement and flow improvement. Patients' symptomatic improvement preceded improved perfusion by several months.

Repeatability of automatic left ventricular cavity volume measurements from myocardial perfusion SPECT.

BACKGROUND: This study sought to assess the repeatability of automatic quantitative measurements of left ventricular (LV) cavity volumes in a large patient population (N = 926), to correlate those measurements to similarly obtained LV ejection fraction (LVEF) measurements, and to investigate the relationship between ungated and gated volumes. METHODS: All 926 patients underwent ungated single photon emission computed tomography (SPECT) immediately followed by 8-frame gated SPECT. LV cavity volumes were automatically measured from ungated (V), summed gated (SUMV), end-systolic (ESV) and end-diastolic (EDV) images, and LVEFs derived from the latter 2. RESULTS: Repeatability (SUMV vs V) was very good overall (6.4%+/-6.6%), further improving for volumes >25 mL (5.7%+/-5.5%) and >40 mL (5.2%+/-5.0%). Exponential regression between ESV and LVEF (r = 0.925, SEE = 15.0 mL), EDV and LVEF (r = 0.802, SEE = 24.2 mL), and SUMV and LVEF (r = 0.867, SEE = 19.7 mL) was also very good. Summed gated volumes were closer to ESV than to EDV (43.3%+/-8.8% of EDV-ESV range). SUMV <50 mL and SUMV >110 mL were good substitutes for LVEF >50% and LVEF <40% (93.4% and 97.1%, respectively). CONCLUSION: Automatic quantitative measurements of gated and ungated volumes with our algorithm are repeatable, correlate well with other global myocardial parameters, and may contribute important additional information to that conventionally provided by myocardial perfusion SPECT studies.

Automated volume determination of the liver and spleen from Tc-99m colloid SPECT imaging. Quantification of the liver functional and nonfunctional tissue in disease.

An automated volume determination program using SPECT imaging with Tc-99m has been validated by both phantom and patient studies. Its use for monitoring change of function of the liver and change in tumor mass during different therapy regimes has been assessed. The technique is not restricted to the estimation of the hepatic functioning tissues; it therefore has many potential clinical implementations for volume determination in other organs.