Nieun Seo1, Mi-Suk Park1, Jun Yong Choi2,3, Joon-Sup Yeom2,3, Myeong-Jin Kim1, Yong Eun Chung1, Nam Su Ku2,3. 1. Department of Radiology, Yonsei University College of Medicine, Seoul, Republic of Korea. 2. Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea. 3. AIDS Research Institute, Yonsei University College of Medicine, Seoul, Republic of Korea.
Abstract
BACKGROUND: Radiation dose reduction is a major concern in patients who undergo computed tomography (CT) to follow liver and renal abscess. OBJECTIVES: The purpose of this study is to investigate the feasibility of ultralow-dose CT with iterative reconstruction (IR) to follow patients with liver and renal abscess. METHODS: This prospective study included 18 patients who underwent ultralow-dose CT with IR to follow abscesses (liver abscesses in 10 patients and renal abscesses in 8 patients; ULD group). The control group consisted of 14 patients who underwent follow-up standard-dose CT for liver abscesses during the same period. The objective image noise was evaluated by measuring standard deviation (SD) in the liver and subcutaneous fat to select a specific IR for qualitative analysis. Two radiologists independently evaluated subjective image quality, noise, and diagnostic confidence to evaluate abscess using a five-point Likert scale. Qualitative parameters were compared between the ULD and control groups with the Mann-Whitney U test. RESULTS: The mean CT dose index volume and dose length product of standard-dose CT were 8.7 ± 1.8 mGy and 555.8 ± 142.8 mGy·cm, respectively. Mean dose reduction of ultralow-dose CT was 71.8% compared to standard-dose CT. After measuring SDs, iDose level 5, which showed similar SD to standard-dose CT in both the subcutaneous fat and liver (P = 0.076, and P = 0.124), was selected for qualitative analysis. Ultralow-dose CT showed slightly worse subjective image quality (P < 0.001 for reader 1, and P = 0.005 for reader 2) and noise (P = 0.004 for reader 1, and P = 0.001 for reader 2) than standard-dose CT. However, the diagnostic confidence of ultralow-dose CT for evaluating abscess was comparably excellent to standard-dose CT (P = 0.808 for reader 1, and P = 0.301 for reader 2). CONCLUSIONS: Ultralow-dose CT with IR can be used in the follow-up of liver and renal abscess with comparable diagnostic confidence.
BACKGROUND: Radiation dose reduction is a major concern in patients who undergo computed tomography (CT) to follow liver and renal abscess. OBJECTIVES: The purpose of this study is to investigate the feasibility of ultralow-dose CT with iterative reconstruction (IR) to follow patients with liver and renal abscess. METHODS: This prospective study included 18 patients who underwent ultralow-dose CT with IR to follow abscesses (liver abscesses in 10 patients and renal abscesses in 8 patients; ULD group). The control group consisted of 14 patients who underwent follow-up standard-dose CT for liver abscesses during the same period. The objective image noise was evaluated by measuring standard deviation (SD) in the liver and subcutaneous fat to select a specific IR for qualitative analysis. Two radiologists independently evaluated subjective image quality, noise, and diagnostic confidence to evaluate abscess using a five-point Likert scale. Qualitative parameters were compared between the ULD and control groups with the Mann-Whitney U test. RESULTS: The mean CT dose index volume and dose length product of standard-dose CT were 8.7 ± 1.8 mGy and 555.8 ± 142.8 mGy·cm, respectively. Mean dose reduction of ultralow-dose CT was 71.8% compared to standard-dose CT. After measuring SDs, iDose level 5, which showed similar SD to standard-dose CT in both the subcutaneous fat and liver (P = 0.076, and P = 0.124), was selected for qualitative analysis. Ultralow-dose CT showed slightly worse subjective image quality (P < 0.001 for reader 1, and P = 0.005 for reader 2) and noise (P = 0.004 for reader 1, and P = 0.001 for reader 2) than standard-dose CT. However, the diagnostic confidence of ultralow-dose CT for evaluating abscess was comparably excellent to standard-dose CT (P = 0.808 for reader 1, and P = 0.301 for reader 2). CONCLUSIONS: Ultralow-dose CT with IR can be used in the follow-up of liver and renal abscess with comparable diagnostic confidence.
Authors: S Saini; P W Ralls; D M Balfe; R L Bree; D J DiSantis; S N Glick; M S Levine; A J Megibow; W P Shuman; F L Greene; L A Laine; K Lillemoe; M Brown; L Berland Journal: Radiology Date: 2000-06 Impact factor: 11.105
Authors: Ji Soo Song; Jeong Min Lee; Ji Young Sohn; Jeong-Hee Yoon; Joon Koo Han; Byung Ihn Choi Journal: Radiol Med Date: 2014-08-29 Impact factor: 3.469