Myokardperfusionsszintigrafie: IQ-SPECT-System und LEHR-Kollimator

Myokardperfusionsszintigrafien wurden bis vor einiger Zeit standardmäßig mit LEHR-Kollimatoren durchgeführt. Heutzutage kommt vermehrt das IQ-SPECT-System mit Smartzoom-Kollimatoren zum Einsatz. Dabei lassen Herstellerangaben und Studiendaten den Schluss zu, dass man durch die Verwendung dieses Systems bei kürzerer Akquisitionszeit eine gleichbleibende Bildqualität erreicht. In dieser Studie wurden die Herstellerangaben evaluiert und bewertet.

Abstract

Until recently, myocardial perfusion scintigraphy was standardly performed with LEHR collimators. Today, the IQ-SPECT-System^® with smartzoom collimators is becoming more popular. Information from the manufacturer as well as data from studies suggest that the use of this system allows for a consistent image quality, although the acquisition time can be shortened.

In this project, existing study data and manufacturer information were evaluated for practicality, reproducibility, and time savings using a specific thoracic phantom model. In a further experiment, the IQ-SPECT system was examined to see if an additional weight mass would lead to a better image quality compared to the conventional system without additional activity.

A SPECT thoracic phantom with a heart insert equivalent to a standard patient weighing 70±3 kg was used for the various acquisitions to simulate a study under stress conditions. The applied activity was 270 MBq.

Subsequently, image series were acquired using different acquisition times (5 s/projection, 10 s/projection, 20 s/projection) for both systems. Images of the additional weight mass were acquired using the 20 s/projection protocol. The next step was an optical and quantitative analysis of the reconstructed images with special attention to contrast and inhomogeneity.

The experimental model applied was able to demonstrate that the use of IQ-SPECT can lead to reduced inhomogeneity as well as improved contrast. The superiority of the IQ-SPECT system was particularly evident in patients with borderline or elevated BMI.

Using an acquisition time of 10 s/projection resulted in the best achievable image quality and also reduced the total examination time to approximately 4 min. As a result, using the standard protocol in combination with reduced activity would allow a reduction in ionizing radiation and reduce the burden on patients and clinical staff.

Schlüsselwörter

Myokardperfusionsszintigrafie - IQ-SPECT - LEHR - Phantomstudien - koronare Herzerkrankung

Key word

myocard perfusions scintigraphy - IQ-SPECT - LEHR - coronary heart disease

Publication History

Article published online:
08 September 2023

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