Assessment of Ventricular Function Using Gated Blood Pool Scan and Gated Blood Pool SPECT / 대한핵의학회잡지

Non-invasive evaluation of cardiac function by nuclear medicine technologies are one of the major contribution of nuclear medicine. Gated cardiac blood pool scan was once a novel and robust technique which enabled evaluation of ventricular function. Concept of EKG gating was one of the major breakthrough in nuclear cardiology. According to the evolution of echocardiographic techniques, and as the evaluation of myocardial perfusion by perfusion SPECT became feasible, number of gated blood pool study done in nuclear medicine laboratory is declining. And recently, evaluation of ventricular function with gated perfusion SPECT further decreased the use of gated blood pool scan. In this article, assessment of ventricular function using gated blood pool scan is discussed including some insight about the role of gated blood pool SPECT.

Evaluation of Hepatic Hemangioma by Tc-99m Red Blood Cell Hepatic Blood Pool Scan / 대한핵의학회잡지

Hemangioma is the most common benign tumor of the liver, with a prevalence estimated as high as 7%. Tc-99m red blood cell (RBC) hepatic blood pool scan with single photon emission computed tomography (SPECT) imaging is extremely useful for the confirmation or exclusion of hepatic hemangiomas. The classic finding of absent or decreased perfusion and increased blood pooling ("perfusion/blood pool mismatch") is the key diagnostic element in the diagnosis of hemangiomas. The combination of early arterial flow and delayed blood pooling ("perfusion/blood pool match") is shown uncommonly. In giant hemangioma, filling with radioactivity appears first in the periphery, with progressive central fill-in on sequential RBC blood pool scan. However, the reverse filling pattern, which begins first in the center with progressive peripheral filling, is also rarely seen. Studies with false-positive blood pooling have been reported infrequently in nonhemangiomas, including hemangiosarcoma, hepatocellular carcinoma, hepatic adenoma, and metastatic carcinomas (adenocarcinoma of the colon, small cell carcinoma of the lung, neruroendocrine carcinoma). False-negative results have been also reported rarely except for small hemagniomas that are below the limits of spatial resolution of gamma camera.

Technical Refinement of 99mTc-RBC Scrotal Scan for Evaluating Varicocele / 대한남성과학회지

PURPOSE: The association of varicoceles and subfertility has been well documented. Although varicoceles remain the most common surgically correctable cause of male infertility the subjective diagnosis of varicocele, especially the small ones remains a challenge. MATERIALS AND METHODS: We evaluated 40 young men (16 volunteers, 24 varicocele patients) with scrotal blood pool scan using 99mTc RBC. RESULTS: Complete correlation between physical findings and the scrotal scan was found. The postoperative scans of 12 patients with surgically corrected high grade varicoceles demonstrated symmetrical photon accumulation in the scrotum. The technique which most accurately correlated the clinical grade was the varicocele index using total count at Valsalva maneuver. CONCLUSIONS: We believe that the 99mTc RBC scrotal scan with technical refinement is a useful procedure in the objective diagnosis and followup of varicoceles.

Differences in Left and Right Ventricular Function between Different Infarct Sites: An ECG-Gated Blood Pool Study

BACKGROUND: Ventricular function is one of the important prognostic factors in patients with coronary artery disease. Among noninvasive approaches for the evaluation of ventricular performance, radionuclide ventriculo-graphy has shown to be of particular values in the patients with myocardial infarction. We have evaluated ven-tricular function with ECG-gated blood pool scan (GBPS) in patients with myocardial infarction of different locations and compared right and left ventricular functions. METHOD: Left and right ventricular function was assessed with multigated blood pool scan in 49 patients at 2-3 weeks after acute myocardial infarction (anterior infarction=23, inferior infarction=19, and lateral infarction=7). Left ventricular ejection fraction (LVEF), right ventricular ejection fraction (RVEF), maximal emptying rate, maximal filling rate, phase angle and full width at half maximum (FWHM) of phase angles were measured during rest. RESULTS: 1) LVEF was signifi-cantly lower in the patients with anterior myocardial infarction (32.2%) than that of inferior (46.5%, p<0.001) or lateral infarction (45.5%, p<0.05), but not different between inferior and lateral infarction. 2) RVEF was significantly lower in the patients with inferior myocardial infarction (24.6%) than that of anterior (30.5%, p<0.05) or lateral infarction (36.1%, p<0.001), and RVEF of anterior infarction was significantly lower than that of lateral infarction (p<0.05). 3) Phase angle and FWHM of left ventricle and right ventricle phase histogram were not significantly different among the patients groups with different infarct sites. CONCLUSIONS: Ventricular function was differently affected by different infarct sites. Inferior infarction resulted in a greater reduction in right ventricular ejection fraction. In contrast, LVEF was greatly depressed in anterior infarction than in inferior infarction.

Assessment of Ventricular Function and Phase Abnormality by Gated Blood Pool Scan in Dilated Cardiomyopathy

Gated blood pool scan(GBPS) may be used for evaluating patients with dilated cardiomyopathy(DCM) where it can assist in the diagnosis, and evaluation of severity, disease progression or therapeutic efficacy. In addition to the routine parameters that have been available by GBPS, relatively simple mathematical manipulations of the equilibrium time activity curve can derive parameters relating to the degree and sequence of ventricular emptying. This first harmonic phase analysis may enable quantitative and more specific measurements of wall motion abnormalities in DCM and may thus be useful for more accurate assessments in these patients. Thus, in an attempt to evaluate the findings of phase analysis in DCM and to determine their possible usefulness in this entity, we measured parameters of phase analysis from the resting GBPS of 25 DCM patients and 11 normal controls, and compared these with other parameters of ventricular function from GBPS or echocardiography. Parameters of the systolic as well as diastolic function were markedly depressed for both left and right ventricles (all p<0.001), and echocardiographic LV systolic diameter was increased in all patients. Phase analsis showed the mean and standard deviation of phase angle(Mph & SDph) of both ventricles to be singificantly greater, and the mean amplitude smaller in DCM patients compared to controls(p<0.01). SDph appeared to be a sensitive parameter(LV 100%, RV 92%), and LV SDph showed significant correlations with other GBPS parmeters such as LV ejection fraction(LVEF) and LV peak ejection rate(LVPER) (r=-0.85 and 0.75, respectively) (all p<0.001), and with LV systolic diameter (r=0.78, p<0.001). Also, LV mean amplitude correlated well with LVEF (r=0.79, p<0.001). Thus, phase analysis of GBPS was able to show and quantify significant asynchronity in contraction of both ventricles in DCM, and these parameters may by useful in evaluating ventricular performance in these patients.