Conventional and Reduced Radiation Dose of 16-MDCT for Detection of Nephrolithiasis and Ureterolithiasis

Paulson, Erik K.; Weaver, Carolyn; Ho, Lisa M.; Martin, Lucie C.; Li, Jianying; Darsie, James; Frush, Donald P.

doi:10.2214/ajr.07.2816

Cited by 38 publications

(17 citation statements)

References 20 publications

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“…9,24,25 What is reasonable or acceptable in terms of diagnostic accuracy may change according to the clinical scenario, as well as the tolerance of the clinician and imaging specialist (and perhaps patient in a shared decision making model) for any uncertainty. 26,27 Although a reduced-dose CT may not be the most appropriate study in an elderly patient with a high potential for alternative causes of symptoms, it may be the best for determining need for intervention in young patients, many of whom receive repeated examinations with substantial radiation. 28 Gestalt pretest probability of kidney stone or an objective clinical prediction rule such as the Size Timing Onset Nausea Erthrocytes (STONE) score 19 may help select the most appropriate patients for substantial dose reduction.…”

Section: Discussionmentioning

confidence: 99%

Accuracy of Reduced-Dose Computed Tomography for Ureteral Stones in Emergency Department Patients

Moore

Daniels

Ghita

et al. 2015

Annals of Emergency Medicine

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Study objective-Reduced-dose computed tomography (CT) scans have been recommended for diagnosis of kidney stone but are rarely used in the emergency department (ED) setting. Test characteristics are incompletely characterized, particularly in obese patients. Our primary outcome is to determine the sensitivity and specificity of a reduced-dose CT protocol for symptomatic ureteral stones, particularly those large enough to require intervention, using a protocol stratified by patient size.Methods-This was a prospective, blinded observational study of 201 patients at an academic medical center. Consenting subjects underwent both regular-and reduced-dose CT, stratified into a high and low body mass index (BMI) protocol based on effective abdominal diameter. Reduceddose CT scans were interpreted by radiologists blinded to regular-dose interpretations. Follow-up for outcome and intervention was performed at 90 days.Results-CT scans with both regular and reduced doses were conducted for 201 patients, with 63% receiving the high BMI reduced-dose protocol. Ureteral stone was identified in 102 patients (50.7%) of those receiving regular-dose CT, with a ureteral stone greater than 5 mm identified in 26 subjects (12.9%). Sensitivity of the reduced-dose CT for any ureteral stone was 90.2% (95% confidence interval [CI] 82.3% to 95.0%), with a specificity of 99.0% (95% CI 93.7% to 100.0%). For stones greater than 5 mm, sensitivity was 100% (95% CI 85.0% to 100.0%). Reduced-dose CT identified 96% of patients who required intervention for ureteral stone within 90 days. Mean * Corresponding Author. Chris.Moore@yale.edu, Twitter: Chris.Moore@Yale_EUS. Author contributions: CLM, MG, and GPG conceived the study and designed the trial. CLM, DS, and CPG obtained research funding.CLM and SL supervised the conduct of the trial and data collection. SL participated in recruitment of patients. GG performed overreadings of the CT scans in the trial. CLM, SL, and AM managed the data, including quality control. AM and CPG provided statistical advice. BD, GG, AM, DS, and CPG provided advisement on study design and methodology. CLM, SL, AM, and CPG analyzed the data. CLM drafted the article, and all authors contributed substantially to its revision. CLM takes responsibility for the paper as a whole.Presented as an abstract at the Society for Academic Emergency Medicine annual meeting, May 2013, Atlanta, GA.The content of this article is solely the responsibility of the authors and does not necessarily represent the official views of the AHRQ. HHS Public Access Author Manuscript Author ManuscriptAuthor ManuscriptAuthor Manuscript reduction in size-specific dose estimate was 18.6 milligray (mGy), from 21.7 mGy (SD 9.7) to 3.4 mGy (SD 0.9). Conclusion-CT

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Section: Discussionmentioning

confidence: 99%

Accuracy of Reduced-Dose Computed Tomography for Ureteral Stones in Emergency Department Patients

Moore

Daniels

Ghita

et al. 2015

Annals of Emergency Medicine

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“…The readers graded the overall image quality of the entire data set on a 4-point Likert scale 21 : score 4, very acceptable; score 3, acceptable; score 2, marginally to fairly acceptable; and score 1, not acceptable. In addition, the visibility of each stone was rated as follows 21 : score 4, clearly delineated; score 3, moderately visualized; score 2, marginally to fairly delineated; and score 1, not able to be depicted acceptably.…”

Section: Qualitative Image Evaluationmentioning

confidence: 99%

“…In addition, the visibility of each stone was rated as follows 21 : score 4, clearly delineated; score 3, moderately visualized; score 2, marginally to fairly delineated; and score 1, not able to be depicted acceptably.…”

Section: Qualitative Image Evaluationmentioning

confidence: 99%

Feasibility of Single-Source Dual-Energy Computed Tomography for Urinary Stone Characterization and Value of Iterative Reconstructions

Morsbach¹,

Wurnig²,

Müller³

et al. 2014

Investigative Radiology

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PURPOSE: The purposes of this study were to demonstrate the feasibility and accuracy of single-source dual-energy (DE) computed tomography (CT) with sequential data acquisition and a coregistration motion correction algorithm for urinary stone characterization and to evaluate the value of iterative reconstructions (IRs) in DE imaging. MATERIALS AND METHODS: Thirty-five urinary stones were placed in cylindrical phantoms with diameters of 30 and 40 cm. The phantoms were scanned on a 64-section CT machine with a single-source DE protocol consisting of 2 sequential acquisitions at 80 and 140 kilovolt (peak). The phantom was moved between the 80-and 140-kilovolt (peak) scans. Images were reconstructed with weighted filtered back projection (FBP) and with IR, and data were coregistered. Two independent and blinded readers assessed data sets for stone detection, overall image quality, and visibility of stones. Image noise and Hounsfield unit values of the stones were measured, and the DE index was calculated. In addition, the data sets were analyzed on color-coded images using the standard postprocessing software for differentiating uric acid-(UA) from non-UA-containing stones. RESULTS: The motion correction algorithm achieved a good coregistration of the 2 scans with different energy levels. Both readers detected all stones on all data sets with both reconstruction types. The overall image quality was rated significantly higher in IR images in the 40-cm phantom as compared with that in FBP images (P < 0.05), whereas no significant difference was found for the 30-cm phantom. Visibility of stones was rated significantly higher for both the 30-and 40-cm phantoms on IR as compared with that on FBP images, an effect that was pronounced for UA stones (P < 0.05). Noise was significantly reduced by up to 31% in the 40-cm phantom when using IR as compared with FBP (P < 0.001). The DE index was similar in the FBP and IR data sets for the 30-(P = 0.116) and 40-cm phantoms (P = 0.544), being significantly different between UA-containing stones, cystine, and struvite stones as well as stones of other compositions (P < 0.001). The postprocessing software classified all stones correctly as UA-or non-UA-containing stones on color-coded images. In the 40-cm phantom, false-positively colored voxels were found in the FBP data sets, which were not seen when using IR instead. CONCLUSIONS: Our study indicates that single-source dual-energy CT with sequential acquisitions at different energy levels and a coregistration motion correction algorithm is feasible and accurate for characterizing urinary stone composition on the basis of phantom evaluation. As compared with reconstructions with FBP, the use of IR in dual-energy CT reduces noise, improves overall image quality and visibility of stones particularly in large phantoms, and helps to avoid false classifications of urinary stones.

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“…Paulson and colleagues showed that by decreasing tube current in CT scans in a population of patients with renal and ureteral stones, the quality and detection were not significantly affected 16 . Although their group did not look at radiation dose reduction per say, tube current is directly proportional to exposure time; thus, they were able to show that reducing tube current offers adequate imaging while working to reduce radiation dose.…”

Section: Attempts Of Radiation Dose Reduction In Ctmentioning

confidence: 99%

Comparison of Radiation Dose From Conventional and Triple-bolus Computed Tomography Urography Protocols in the Diagnosis and Management of Patients With Renal Cortical Neoplasms

Abedi

Okhunov

Lall

et al. 2014

Urology

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Conventional and Reduced Radiation Dose of 16-MDCT for Detection of Nephrolithiasis and Ureterolithiasis

Abstract: An mA as low as 70 (35 mAs) is acceptable for evaluation of nephrolithiasis. However, the evaluation of ureterolithiasis is compromised with an mA of 70.

Cited by 38 publications

References 20 publications

Accuracy of Reduced-Dose Computed Tomography for Ureteral Stones in Emergency Department Patients

Accuracy of Reduced-Dose Computed Tomography for Ureteral Stones in Emergency Department Patients

Feasibility of Single-Source Dual-Energy Computed Tomography for Urinary Stone Characterization and Value of Iterative Reconstructions

Comparison of Radiation Dose From Conventional and Triple-bolus Computed Tomography Urography Protocols in the Diagnosis and Management of Patients With Renal Cortical Neoplasms

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