Objective: To compare the performances of four 64-slice CT devices, as regards radiation dose and image quality.
Methods: Effective dose was measured with thermoluminescent dosimeters in an Alderson Rando phantom (Alderson Research Laboratories, New York, NY). Quantitative image quality was evaluated in a Catphan 600 phantom (The Phantom Laboratory, New York, NY) using 3 parameters (modulation transfer function, contrast-to-noise ratio, and figure of merit). Effective and main organ doses were measured in 40 patients (10 for each CT device), who underwent an abdominal study with the same standard protocol; moreover, in these patients, clinical image quality, using a 5-grade quality score, was assessed.
Results: In-phantom measured doses and quantitative image quality showed some differences among the 4 devices. On the contrary, effective and organ doses provided to the patients were similar; no statistically significant differences were found also for clinical image quality.
Conclusions: Some differences were found among the 4 devices from a physical point of view; on the other hand, the patient data were similar.
From the *Fisica Sanitaria, Ospedale di Circolo di Varese e Fondazione Macchi; †Cattedra di Radiologia, Università degli Studi dell'Insubria, Varese; ‡UO Radiologia, and §Fisica Sanitaria, Ospedale Cardinal Massaia ASL 19, Asti; ∥UO Radiologia, Ospedale Civile di Legnano, Legnano; ¶UO Radiologia, and #Fisica Sanitaria, Azienda Ospedaliera Sant'Anna, Como; and **Dipartimento Scienze Cliniche e Biologiche, Università degli Studi dell'Insubria, Varese, Italy.
Received for publication February 10, 2010; accepted July 8, 2010.
Reprints: Monica Mangini, MD, Ospedale di Circolo e Fondazione Macchi, Università degli Studi dell'Insubria, Viale Borri 57, 21100 Varese, Italy (e-mail: firstname.lastname@example.org).
This article was supported by grants from the project "Studio sulle dosi da radiazioni in pazienti sottoposti a indagini tomografiche con tomografi di nuova generazione," Università degli Studi dell'Insubria, Varese, Italy.