ABSTRACT
Objective To evaluate the image quality,diagnosis accuracy and dose reduction of split-bolus CT urography (CTU) with low voltage scan and sinogram affirmed iterative reconstruction (SAFIRE).Methods A total of 80 cases of consecutive patients with confirmed or suspected urinary system disease needed CTU examination were divided into two groups (control group and test group) by using random number table.In control group,convention scan (120 kV) with one time injection was used.But low voltage scan (80 kV) with SAFIRE algorithm and split-bolus injection (SBI) was used in experiment group.The radiation dose,image quality and diagnosis accuracy were compared.Results A total of 77 cases completed CTU examination successfully in the two groups,including 39 cases in control group and 38 cases in test group.The effective dose reduced from (26.68 ± 4.07) in control group to (3.93 ± 0.85) mSv in test group (t =-33.78,P ＜ 0.05).Subjective image quality score was (4.49 ± 0.79) in control group and (4.39 ± 1.53) in test group,with no significantly statistical difference (Z =2.71,P ＞ 0.05).Signal-to-noise ratio (SNR) of objective image quality in test group was higher than that in control group (127.3±15.9 vs.109.6 ± 13.2,t =4.49,P＜0.05).But there was no significantly statistical difference in contrast-to-noise ratio (CNR) between control group(100.8 ± 12.9)and test group (109.0 ± 14.4,P ＞ 0.05).For diagnosis accuracy,no statistical difference were found between two groups(84.62％ and 81.58％,P ＞ 0.05).Conclusions The combination of low voltage scan with SAFIRE algorithm and split-bolus injection CTU could reduce the radiation dose significantly,but the objective image quality,CNR (except SNR) of subjective image quality and diagnosis accuracy were all unaffected obviously.
ABSTRACT
Multislice computed tomography provides high spatial and temporal resolution images in addition to high quality multiplanar and three-dimensional reconstructions. As a result of this diagnostic efficacy, the Computed Tomography Urography (Uro-CT) has become the technique of choice for evaluating the urinary tract, virtually replacing the traditional urography examination. At Padre Hurtado Hospital, Santiago, Chile, we conducted a retrospective analysis to review our experience with Uro-CT scanning and split bolus technique, which has the potential to yield a synchronous nephrographic and excretory phase of the urinary system, thus reducing radiation dose for patients, number of images and costs generated by MDCT urography. A series of 31 cases is presented, along with description of techniques applied as well as study main findings.
La tomografía computada multicorte permite obtener imágenes de alta resolución espacial y temporal además de reconstrucciones multiplananes y tridimensionales de gran calidad, lo que ha hecho que la Urografía por Tomografía Computada (UroTAC) se convierta en la técnica de elección para la evaluación del tracto urinario, reemplazando prácticamente a la urografía tradicional. En el Hospital Padre Hurtado, revisamos nuestra experiencia con UroTAC y técnica de "split bolus" que permite obtener simultáneamente una fase nefrográfica y excretora del sistema urinario mediante una sola adquisición, lo que disminuye la dosis de radiación al paciente, el número de imágenes y los costos de la UroTAC estándar. Presentamos una serie de 31 pacientes estudiados, describiendo la técnica y los principales hallazgos obtenidos en ellos.