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
