title: Low Dose MDCT with Tube Current Modulation: Role in Detection of Urolithiasis and Patient Effective Dose Reduction.
abstract: BACKGROUND
  Urolithiasis is one of the major, recurring problem in young individuals and CT being the commonest diagnostic modality used. In order to reduce the radiation dose to the patient who are young and as stone formation is a recurring process; one of the simplest way would be, low dose CT along with tube current modulation.
  
  
  OBJECTIVE
  Aim of this study was to compare the sensitivity and specificity of low dose (70mAs) with standard dose (250mAs) protocol in detecting urolithiasis and to define the tube current and mean effective patient dose by these protocols.
  
  
  METHODS
  A prospective study was conducted in 200 patients over a period of 2 years with acute flank pain presentation. CT was performed in 100 cases with standard dose and another 100 with low dose protocol using tube current modulation. Sensitivity and specificity for calculus detection, percentage reduction of dose and tube current with low dose protocol was calculated.
  
  
  RESULTS
  Urolithiasis was detected in 138 patients, 67 were examined by high dose and 71 were by low dose protocol. Sensitivity and Specificity of low dose protocol was 97.1% and 96.4% with similar results found in high BMI patients. Tube current modulation resulted in reduction of effective tube current by 12.17%. The mean effective patient dose for standard dose was 10.33 mSv whereas 2.92 mSv for low dose with 51.13-53.8% reduction in low dose protocol.
  
  
  CONCLUSIONS
  The study has reinforced that low-dose CT with tube current modulation is appropriate for diagnosis of urolithiasis with significant reduction in tube current and patient effective dose.
authors.affiliation: Professor, Department of Radiodiagnosis and Imaging, Kasturba Medical College, Manipal University , Manipal, Udupi District, Karnataka, India .
authors.forename: Prakashini
authors.initials: P
authors.lastname: Koteshwar
authors.affiliation: Assistant Professor, Department of Radiodiagnosis and Imaging, Dayanand Medical College and Hospital , Ludhiana, Punjab, India .
authors.forename: Chandan
authors.initials: C
authors.lastname: Kakkar
authors.affiliation: Professor, Department of Radiology, Kasturba Medical College, Manipal University , Manipal, Udupi District, Karnataka, India .
authors.forename: Smiti
authors.initials: S
authors.lastname: Sripathi
authors.affiliation: Resident, Department of Radiology, Kasturba Medical College , Manipal, Udupi, India .
authors.forename: Anushri
authors.initials: A
authors.lastname: Parakh
authors.affiliation: Associate Professor, Department of Radiology, Kasturba Medical College , Manipal, Udupi, India .
authors.forename: Rajendra
authors.initials: R
authors.lastname: Shrivastav
keywords: Body mass index; Diagnostic imaging; Low dose