title: Comparison of conventional and simulated reduced-tube current MDCT for evaluation of suspected appendicitis in the pediatric population.
abstract: OBJECTIVE
  The purpose of this study was to compare CT with conventional and simulated reduced-tube current in the evaluation for acute appendicitis in children.
  
  
  METHODS
  Validated noise-addition (tube current-reduction) software was used to create 50% and 75% tube current reductions in 60 CT examinations performed for suspected appendicitis, resulting in 180 image sets. Three blinded pediatric radiologists scored the randomized studies for the following factors: presence of the normal appendix or appendicitis (5-point scale; 1=definitely absent and 5=definitely present), presence of alternate diagnoses, and overall image quality (1=nondiagnostic and 5=excellent). Truth was defined by the interpretation of the conventional examination.
  
  
  RESULTS
  For conventional examinations, the total number of reviews (60 cases×3 readers=180) in which the normal appendix was identified was 120 of 180 (66.7%), compared with 108 of 180 (60%) in the 50% (p=0.19) and 91 of 180 (50.6%) in the 75% (p=0.002) tube current-reduction groups. Appendicitis was identified in a total of 39 of 180 (21.7%), 38 of 180 (21.1%), and 37 of 180 (20.6%) examinations, respectively (p>0.05). This translates to sensitivities of 97% and 95% for the 50% and 75% tube current-reduction groups, respectively. Alternate diagnoses were detected in 14%, 16%, and 13% of scans, respectively. Compared with conventional-tube current examinations, reader confidence and assessment of image quality were significantly decreased for both tube current-reduction groups.
  
  
  CONCLUSIONS
  Simulated tube current-reduction technology provides for systematic evaluation of diagnostic thresholds. Application of this technology in the setting of suspected appendicitis shows that tube current can be reduced by at least 50% without significantly affecting diagnostic quality, despite a decrease in reader confidence and assessment of image quality.
authors: Duke University School of Medicine, Duke University Medical Center, Durham, NC, USA. cswanick@mdanderson.org
authors: Cameron W
authors: CW
authors: Swanick
authors: Ana M
authors: AM
authors: Gaca
authors: Caroline L
authors: CL
authors: Hollingsworth
authors: Charles M
authors: CM
authors: Maxfield
authors: Xiang
authors: X
authors: Li
authors: Ehsan
authors: E
authors: Samei
authors: Erik K
authors: EK
authors: Paulson
authors: Matthew B
authors: MB
authors: McCarthy
authors: Donald P
authors: DP
authors: Frush
mesh_terms: D000293:Adolescent; D001064:Appendicitis / Q000000981:diagnostic imaging*; D002648:Child; D002675:Child, Preschool; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D011829:Radiation Dosage; D016032:Randomized Controlled Trials as Topic; D012189:Retrospective Studies; D012984:Software; D014057:Tomography, X-Ray Computed / Q000379:methods*
references: Radiology. 2005 Jun;235(3):879-85
references: 15833993
references: Radiology. 2003 Aug;228(2):352-60
references: 12893897
references: Biomed Imaging Interv J. 2006 Jul;2(3):e35
references: 21614244
references: N Engl J Med. 2007 Nov 29;357(22):2277-84
references: 18046031
references: Radiology. 2011 Jun;259(3):793-801
references: 21467249
references: Med Phys. 2011 Jan;38(1):397-407
references: 21361208
references: Radiology. 2005 Nov;237(2):641-6
references: 16170015
references: AJR Am J Roentgenol. 2001 Feb;176(2):289-96
references: 11159059
references: Radiology. 2008 Oct;249(1):97-106
references: 18682583
references: AJR Am J Roentgenol. 2008 Jan;190(1):151-7
references: 18094305
references: Radiology. 2011 Mar;258(3):889-905
references: 21163918
references: J Urol. 2011 Mar;185(3):910-4
references: 21239024
references: Radiology. 2012 Jun;263(3):778-85
references: 22535565
references: Med Phys. 2011 Jan;38(1):408-19
references: 21361209
references: AJR Am J Roentgenol. 2010 Jan;194(1):191-9
references: 20028923
references: Radiology. 1997 Feb;202(2):453-7
references: 9015073
references: Am J Epidemiol. 1990 Nov;132(5):910-25
references: 2239906
references: Med Phys. 2011 May;38(5):2609-18
references: 21776798
references: Radiology. 2013 Jul;268(1):208-18
references: 23513245
references: Ann Emerg Med. 2010 Aug;56(2):126-34
references: 20074835
references: Invest Radiol. 2010 Apr;45(4):202-10
references: 20177389
references: AJR Am J Roentgenol. 2010 Jun;194(6):1611-9
references: 20489103
references: AJR Am J Roentgenol. 2002 Nov;179(5):1107-13
references: 12388482
references: N Engl J Med. 2012 Apr 26;366(17):1596-605
references: 22533576
references: Radiology. 2010 Aug;256(2):460-5
references: 20529988
references: AJR Am J Roentgenol. 2009 Jan;192(1):143-9
references: 19098193