Optimization of imaging conditions for technetium-99m dimercaptosuccinic acid single photon emission computed tomography examinations in neonates.

Abstract

Objective: This study validated the optimal acquisition and reconstruction conditions for technetium-99m dimercaptosuccinic acid single-photon emission computed tomography examinations in neonates.

Methods: We developed renal phantoms representing neonatal and adult kidneys, derived from clinical data to achieve this. The radioactivity concentration to be encapsulated in the renal part was adjusted according to the Japanese consensus guidelines for the appropriate implementation of pediatric nuclear medicine examinations. The evaluation of optimal acquisition conditions considered factors such as acquisition time and magnification ratio, while the determination of optimal reconstruction conditions focused on the cutoff frequency of the Butterworth filter and the appropriate correction methods. The physical evaluation assessed defect contrast and background coefficient of variation, while the visual evaluation assessed the ability of the images to depict the defect.

Results: The defect contrast was almost constant after acquisition times of 10 min for neonates and 12 min for adults. For the magnification ratio, the effect was greater for neonates than for adults. In addition, in contrast to adults, the use of resolution recovery significantly decreased scores in visual evaluation in neonates.

Conclusion: Our study suggests better images can be obtained in neonates with shorter acquisition times than adults. In addition, the optimal reconstruction conditions are shown to differ between neonates and adults.