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.

Demonstration of interstitial collagenase in abdominal aortic aneurysm disease.

This study was performed to evaluate the presence of interstitial collagenase, now known as matrix metalloproteinase-1 (MMP-1), in specimens of abdominal aortic aneurysms (AAA). Eight AAA and four control infrarenal aortas were evaluated. After homogenization and extraction of soluble proteins, immunoblots of the extracts equalized for protein content were performed with a specific antibody to MMP-1. Under native conditions, immunoreactive material was distributed between M(r) 27 kDa to > 106 kDa. When the extracts were reduced and denatured, immunoreactive bands were detected in AAA at the expected M(r)'s of the secreted isoforms (57 and 52 kDa), whereas control aortic extracts had low levels of detectable immunoreactive material. Only extracts from AAA demonstrated significant immunoreactivity to the lower M(r) isoforms (22, 25, and 27 kDa), which correspond to reported cleavage products of MMP-1. Preliminary immunofluorescent studies of AAA localized MMP-1 to cells present in the adventitia of AAA. These findings will help to resolve disagreement in the recent literature regarding the presence of collagenolytic activity in AAA disease.

Selective coronary arteriography in infants and children.

The recent increase in incidence of Kawasaki disease with attendant coronary artery aneurysms spurred our interest in developing a technique for selective coronary arteriographic examination of infants and children. Right and left coronary artery catheters were shaped according to the aortic root diameters and ascending aorta lengths predicted from the patient's heights. Thirty-eight studies were done in 34 patients who were 7 months to 18 years of age (median 3.2 years) and no permanent sequelae resulted. Advantages of the use of selective coronary arteriography include the ability to visualize stenoses, important branches, and intercoronary anastomoses. The technique is also useful in evaluation of anomalous coronary arteries, myocardial ischemia, and coronary artery distribution before right ventricular outflow tract reconstruction.