Retrospective Study
Copyright ©The Author(s) 2016. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Radiol. Apr 28, 2016; 8(4): 403-409
Published online Apr 28, 2016. doi: 10.4329/wjr.v8.i4.403
Comparison of computed tomography findings between bacteremic and non-bacteremic acute pyelonephritis due to Escherichia coli
Seon Jung Oh, Bo-Kyung Je, Seung Hwa Lee, Won Seok Choi, Doran Hong, Sung-Bum Kim
Seon Jung Oh, Bo-Kyung Je, Seung Hwa Lee, Doran Hong, Department of Radiology, Korea University Hospital, Gyeonggi 15355, South Korea
Won Seok Choi, Department of Internal Medicine, Korea University Hospital, Gyeonggi 15355, South Korea
Sung-Bum Kim, Department of Internal Medicine, B-um Hospital, Seoul 03663, South Korea
Author contributions: Oh SJ reviewed the clinical data and images and wrote the paper; Je BK designed the research, reviewed the clinical data and images, and supervised the report; Lee SH corrected the structural and grammatical error on the report; Choi WS provided the clinical advice; Hong D contributed to the analysis; Kim SB provided clinical advice and supervised the report.
Institutional review board statement: This study was reviewed and approved by the Ethics Committee of the Korea University Ansan Hospital and was compliant with HIPAA.
Informed consent statement: The requirement for informed consent was waived, due to the retrospective nature of this study.
Conflict-of-interest statement: We have no financial relationships to disclose.
Data sharing statement: No additional data are available.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Bo-Kyung Je, Associate Professor, Department of Radiology, Korea University Hospital, 123 Jeokkumro, Danwongu, Ansan, Gyeonggi 15355, South Korea. radje@korea.ac.kr
Telephone: +82-31-4125227 Fax: +82-31-4125224
Received: December 18, 2015
Peer-review started: December 22, 2015
First decision: January 18, 2016
Revised: January 27, 2016
Accepted: February 16, 2016
Article in press: February 17, 2016
Published online: April 28, 2016
Processing time: 123 Days and 1.1 Hours
Abstract

AIM: To identify computed tomography (CT) findings that are associated with the presence of bacteremia in patients with acute pyelonephritis (APN) due to Escherichia coli (E. coli).

METHODS: The clinical data and contrast-enhanced CT findings of 128 patients who were diagnosed with APN due to E. coli and showed renal abnormality on contrast-enhanced CT between January 2003 and November 2013 were retrospectively reviewed. The patients were divided into two groups according to the presence of bacteremia: The bacteremia group and the non-bacteremia group. The abnormality on contrast-enhanced CT were categorized into 5 renal and 4 extrarenal CT findings and compared between the two groups using the χ2 test and multivariate logistic regression.

RESULTS: Among the 128 patients, 34 patients (26.6%) were classified into the bacteremia group and 94 patients (73.4%) into the non-bacteremia group. There was no statistically significant difference in gender between the two groups (P = 0.09), but the age of the patients in the bacteremia group was higher than that of the patients in the non-bacteremia group (P < 0.01). Compared to the non-bacteremia group, 1 renal CT finding such as urothelial thickening and 3 extrarenal CT findings such as diffuse peritoneal thickening, cystitis and pulmonary congestion were more frequently observed in the bacteremia group with statistical significance. The logistic regression analysis revealed that CT findings, including urothelial thickening, diffuse peritoneal thickening, cystitis and pulmonary congestion were suggested as the predictive CT findings of bacteremic APN.

CONCLUSION: On CT, urothelial thickening, diffuse peritoneal thickening, cystitis, and pulmonary congestion are more frequently observed in patients with bacteremic APN due to E. coli.

Keywords: Escherichia coli; Pyelonephritis; Urinary tract infections; Bacteremia; Multidetector computed tomography

Core tip: This is a retrospective study to evaluate the different computed tomography (CT) findings between the bacteremic and non-bacteremic acute pyelonephritis (APN) due to Escherichia coli (E. coli). Current study includes 128 subjects diagnosed with APN due to E. coli and performed contrast-enhanced CT. The usefulness of blood culture that was routinely performed in the patients with APN have been doubted; therefore, several studies which aimed to determine the predictive model of bacteremia by using some clinical features have been published. Here, we analyzed the CT findings of APN according to the presence of bacteremia and suggested the significant CT features predicting bacteremia which were urothelial thickening, diffuse peritoneal thickening, cystitis, and pulmonary congestion.