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Purpose: The objective of this trial was to investigate the capacity of gated perfusion SPECT (GPS) to detect left ventricular aneurysm (ANV) by comparing QGS and 4D-MSPECT (4DM) algorithms with radionuclide ventriculography (RVG). Secondarily, the comparison of GPS ejection fraction (EF) measurements with those of contrast left ventriculography (LVG) and RVG was aimed., Methods: Twenty-five patients with ANV confirmed by LVG were studied. The patients underwent RVG and rest Tc-99m-tetrofosmin GPS 1 week after LVG. A 9-segment model was used both in RVG and GPS evaluation. Aneurysm was defined by scoring the wall motion (WM) and phase analysis in RVG; perfusion, wall thickening and WM in GPS., Results: The detection rate of ANV was 96%, 84% and 52% for RVG, QGS and 4DM, respectively. The LVG mean EF (43.52% +/- 16.93%) was significantly higher (P < 0.01) than those of RVG (29.40% +/- 10.90), QGS (30.04% +/- 13.25%) and 4DM (34.92% +/- 13.01%). Moderate to high EF correlation values were obtained between LVG and GPS (r = 0.71-0.79) and GPS-RVG (r = 0.69). There was no significant EF difference between the radionuclide methods except between 4DM-EF and RVG-EF (5.52%, P < 0.05). Wide Bland-Altman limits were observed between the radionuclide methods in EF comparisons (range: 30.5-38.5%)., Conclusion: GPS seems to have a role in the non-invasive investigation of ANV. QGS-GPS proved to be more reliable (84%) than 4DM-GPS (52%) in the ANV detection. The localization and the extent of the aneurysm itself as well as perfusion and function of adjacent segments may affect aneurysm diagnosis by means of GPS. RVG, QGS-GPS and 4DM-GPS seem not to be interchangeable for routine EF calculation in ANV patients.

Objectives: The accuracy of viability and defect size detection by Tc-tetrofosmin has been discussed by several authors. The lower myocardial extraction fraction of the latter compared with Tc-sestamibi or Tl has often been emphasized. We hypothesized that the intracoronary (i.c.) injection of tracer activity, i.e. higher than that theoretically achievable in the case of intravenous (i.v.) administration, could demonstrate the clinical relevance of this finding intra-individually. In this study, myocardial perfusion images obtained after tracer injection down the infarct-related artery were compared with i.v. injection images in the same patients. The trial also provided us with the opportunity to compare the wall motion values calculated using conventional Tc-tetrofosmin gated single-photon emission computed tomography (SPECT) studies with those obtained using optimal target/background ratios after i.c. injection., Methods: Fourteen patients with acute myocardial infarction, no history of previous cardiac events, single vessel disease and no visible collaterals in the coronary arteriogram were included in the study. Electrocardiogram gated SPECT was carried out separately after i.c. and i.v. injections of the tracer within 5-7 days following thrombolytic therapy. Myocardial perfusion patterns were compared by contingency table analysis after semi-quantitative visual scoring. Segmental wall motion was compared using quantified polar map data in a subset of patients (eight of 14) with normal to moderately hypoperfused myocardium supplied by the left coronary artery., Results: Visual perfusion scores of both studies showed good concordance (kappa, 0.70), with complete agreement in 94 of 119 segments. Nearly all of the discordant segments (24 of 25) were mildly better scored in i.c. studies than in i.v. studies. The mean wall motion values calculated on polar maps of 78 segments for i.c. and i.v. studies were 8.4 +/- 1.2 mm and 8.2 +/- 1.3 mm (mean Delta wall motion=0.23 mm), respectively. High segmental wall motion correlation was observed (R=0.90; P<0.0001)., Conclusion: It can be concluded that infarct-related myocardial perfusion scores obtained after i.c. and i.v. injections of Tc-tetrofosmin compare favourably, with a total agreement rate of 79%. However, the additional information obtained in 21% of the total number of myocardial segments by i.c. injection may indicate a mild underestimation of myocardial viability by i.v. injection. Conventional gated SPECT using i.v. Tc-tetrofosmin was demonstrated to be a reliable technique in the detection of true wall motion.

Assessment of ventricular function is an important diagnostic and prognostic tool in coronary heart disease (CHD). The objective of this study was to compare radionuclide ventriculography (RVG), echocardiography (ECHO) and gated planar tetrofosmin myocardial scintigraphy (GPTF) in patients with CHD. Radionuclide ventriculography in left anterior oblique (LAO) and left lateral (LLT) projections was performed in 44 patients. Two days later, rest tetrofosmin perfusion tomoscintigraphy (SPECT) and rest GPTF in RVG identical parameters and projections were acquired. Within the two following days, the patients underwent two-dimensional ECHO. GPTF studies were processed and interpreted in original (NI-GPTF) and image inverted, RVG like form (I-GPTF). All visual interpretations were evaluated with a semi-quantitative scoring system. Quantitative analysis was performed on parametric images by means of segmental regions of interest. Linear regression and contingency analysis were carried out in overall analysis and on a segmental basis separately by accepting the RVG as the standard for the whole investigation. In overall cine-mode evaluation, NI-GPTF (r = 0.77, p < 0.001, complete agreement (CA) = 84%) was superior to I-GPTF (r = 0.73, p < 0.001, CA = 82%) and ECHO (r = 0.39, p < 0.001, CA = 78%), compared to RVG. On a segmental basis, NI-GPTF showed the best RVG-correlations except for inferoapical, mid-inferior, mid-anterior and anterobasal segments. In visual analysis of functional images, the best RVG-agreement was observed in I-GPTF (r = 0.72, p < 0.001, CA = 77%). On a segmental basis, I-GPTF showed the best RVG-correlations except for posterolateral, mid-inferior, mid-anterior and anterobasal segments. In overall quantitative evaluation, amplitude values in both I-GPTF (r = 0.76, p < 0.001) and NI-GPTF (r = 0.75, p < 0.001) studies were well correlated with RVG amplitude. I-GPTF gave the best RVG-correlation of phase (r = 0.59, p < 0.001). The mean phase and standard deviation RVG-correlations of I-GPTF were r = 0.92, p < 0.001 and r = 0.53, p < 0.001 respectively. In segmental quantification, amplitude values of all segments in I-GPTF were better RVG-correlated than in NI-GPTF. In conclusion, GPTF could be a time saving alternative to ECHO in the evaluation of wall motion by the nuclear medicine physician. Because of differing segmental RVG correlations, NI-GPTF and I-GPTF should be both interpreted to improve the diagnostic value of the method. Cine-mode and parametric image interpretations in GPTF studies should be done simultaneously since the former is more closely correlated to RVG.

The authors prospectively investigated the uptake and kinetics of Tc-99m tetrofosmin (Tetro) in benign and malignant lung lesions and the effect of radiotherapy, chemotherapy, or both on Tc-99m Tetro uptake in malignant lung tumors. Dynamic and planar Tetro imaging were performed in 45 patients with pulmonary lesions during a period of 28 months (34 untreated malignant tumors, 11 benign lesions). Tetro uptake was visibly increased in 26 of 34 malignant tumors, with a mean lesion to contralateral normal tissue ratio of 1.44 +/- 0.29 and a tumor washout rate of 28.4 +/- 6.6% 30 minutes after injection. In 3 of 11 benign lesions, Tetro uptake was observed. Of the 26 patients with malignant tumors and positive Tetro uptake, nine had repeated imaging 6 to 8 weeks after therapy. The patients were treated with radiotherapy, chemotherapy, or both. Reduction in radiological tumor size was used as the clinical response parameter. In five of nine patients, the course of Tetro uptake in follow-up imaging was in accordance with that of radiological tumor size. Two of four remaining patients had only slight discordance between the alteration of Tetro uptake and radiological tumor size. The sensitivity of Tetro to detect malignant lung lesions in our patients was 77%. The specificity and accuracy of the method were 73% and 76%, respectively. Tetro has limited diagnostic value in detecting lung cancer. It may be useful to monitor the response to therapy in malignant lung tumors with initial tracer uptake. Broader trials on this matter are needed for further clarification.