• 1
    Stamatelou KK, Francis ME, Jones CA, Nyberg LM, Curhan GC. Time trends in reported prevalence of kidney stones in the United States: 1976–1994. Kidney Int. 2003; 63:181723.
  • 2
    Johnson CM, Wilson DM, O’Fallon WM, Malek RS, Kurland LT. Renal stone epidemiology: a 25-year study in Rochester, Minnesota. Kidney Int. 1979; 16:62431.
  • 3
    Hiatt RA, Dales LG, Friedman GD, Hunkeler EM. Frequency of urolithiasis in a prepaid medical care program. Am J Epidemiol. 1982; 115:25565.
  • 4
    Curhan GC, Willett WC, Speizer FE, Spiegelman D, Stampfer MJ. Comparison of dietary calcium with supplemental calcium and other nutrients as factors affecting the risk for kidney stones in women. Ann Intern Med. 1997; 126:497504.
  • 5
    Curhan GC, Willett WC, Knight EL, Stampfer MJ. Dietary factors and the risk of incident kidney stones in younger women: Nurses’ Health Study II. Arch Intern Med. 2004; 164:88591.
  • 6
    Curhan GC, Willett WC, Rimm EB, Stampfer MJ. A prospective study of dietary calcium and other nutrients and the risk of symptomatic kidney stones. N Engl J Med. 1993; 328:8338.
  • 7
    Taylor EN, Stampfer MJ, Curhan GC. Dietary factors and the risk of incident kidney stones in men: new insights after 14 years of follow-up. J Am Soc Nephrol. 2004; 15:322532.
  • 8
    Agency for Healthcare Research and Quality. Acute Onset Flank Pain – Suspicion of Stone Disease, ACR Appropriateness Criteria. Available at: Accessed May 2, 2011.
  • 9
    Cupisti A, Pasquali E, Lusso S, Carlino F, Orsitto E, Melandri R. Renal colic in Pisa emergency department: epidemiology, diagnostics and treatment patterns. Intern Emerg Med. 2008; 3:2414.
  • 10
    Sampaio FJ, Zanchetti E. [Brazilian Society of Urology. Urolithiasis: Diagnostic Investigation]. Projeto Diretrizes da Associação Médica Brasileira e Conselho Federal de Medicina. 2006, pp. 19.
  • 11
    Goldstone A, Bushnell A. Does diagnosis change as a result of repeat renal colic computed tomography scan in patients with a history of kidney stones? Am J Emerg Med. 2010; 28:2915.
  • 12
    Catalano O, Nunziata A, Altei F, Siani A. Suspected ureteral colic: primary helical CT versus selective helical CT after unenhanced radiography and sonography. AJR Am J Roentgenol. 2002; 178:37987.
  • 13
    Smith RC, Verga M, Dalrymple N, McCarthy S, Rosenfield AT. Acute ureteral obstruction: value of secondary signs of helical unenhanced CT. AJR Am J Roentgenol. 1996; 167:110913.
  • 14
    Katz SI, Saluja S, Brink JA, Forman HP. Radiation dose associated with unenhanced CT for suspected renal colic: impact of repetitive studies. AJR Am J Roentgenol. 2006; 186:11204.
  • 15
    Bogdanich W At Hearing on Radiation, Calls for Better Oversight. New York, NY: New York Times, 2010. Available at: Accessed May 2, 2011.
  • 16
    Smith-Bindman R, Lipson J, Marcus R, et al. Radiation dose associated with common computed tomography examinations and the associated lifetime attributable risk of cancer. Arch Intern Med. 2009; 169:207886.
  • 17
    Ather MH, Jafri AH, Sulaiman MN. Diagnostic accuracy of ultrasonography compared to unenhanced CT for stone and obstruction in patients with renal failure. BMC Med Imaging. 2004; 4:e2.
  • 18
    Fowler KA, Locken JA, Duchesne JH, Williamson MR. US for detecting renal calculi with nonenhanced CT as a reference standard. Radiology. 2002; 222:10913.
  • 19
    Thoeny HC, Tuma J, Hess B. [Diagnostic imaging of calculi in the upper urinary tract--sonography vs. computerized tomography] [German]. Ther Umsch. 2003; 60:738.
  • 20
    Ulusan S, Koc Z, Tokmak N. Accuracy of sonography for detecting renal stone: comparison with CT. J Clin Ultrasound. 2007; 35:25661.
  • 21
    Coll DM, Varanelli MJ., Smith RC. Relationship of spontaneous passage of ureteral calculi to stone size and location as revealed by unenhanced helical CT. AJR Am J Roentgenol. 2002; 178:101103.
  • 22
    Erdodru T, Aker O, Kaplancan T, Erodlu E. Predictive role of non-contrast spiral computerized tomography on spontaneous passage of ureteral stones. Int Braz J Urol. 2002; 28:51621.
  • 23
    Centers for Disease Control and Prevention. Ambulatory Health Care Data. Available at: Accessed May 2, 2011.
  • 24
    Reichenheim ME. Confidence intervals for the kappa statistic. Stata J. 2004; 4:4218.
  • 25
    Landis J, Koch G. The measurement of observer agreement for categorical data. Biometrics. 1977; 33:15974.
  • 26
    Korley FK, Pham JC, Kirsch TD. Use of advanced radiology during visits to US emergency departments for injury-related conditions, 1998-2007. JAMA. 2010; 304:146571.
  • 27
    Pines JM. Trends in the rates of radiography use and important diagnoses in emergency department patients with abdominal pain. Med Care. 2009; 47:7826.
  • 28
    Burt CW, Arispe IE. Characteristics of emergency departments serving high volumes of safety-net patients: United States, 2000. Vital Health Stat. 2004; 13(155):116.
  • 29
    Gardner RL, Sarkar U, Maselli JH, Gonzales R. Factors associated with longer ED lengths of stay. Am J Emerg Med. 2007; 25:64350.
  • 30
    Akoudad S, Szklo M, McAdams MA, et al. Correlates of kidney stone disease differ by race in a multi-ethnic middle-aged population: the ARIC study. Prev Med. 2010; 51:41620.
  • 31
    Strope SA, Wolf JS Jr, Hollenbeck BK. Changes in gender distribution of urinary stone disease. Urology. 2010; 75:5436.
  • 32
    Larson DB, Johnson LW, Schnell BM, Salisbury SR, Forman HP. National trends in CT use in the emergency department: 1995-2007. Radiology. 2011; 258:16473.
  • 33
    Studdert DM, Mello MM, Sage WM, et al. Defensive medicine among high-risk specialist physicians in a volatile malpractice environment. JAMA. 2005; 293:260917.
  • 34
    Pines JM, Hollander JE, Isserman JA, et al. The association between physician risk tolerance and imaging use in abdominal pain. Am J Emerg Med. 2009; 27:5527.
  • 35
    Kirsch TD, Hsieh YH, Horana L, Holtzclaw SG, Silverman M, Chanmugam A Computed tomography ccan utilization in emergency departments: a multi-state analysis. J Emerg Med. 2010; [Epub ahead of print].
  • 36
    Ginde AA, Foianini A, Renner DM, Valley M, Camargo CA Jr. Availability and quality of computed tomography and magnetic resonance imaging equipment in U.S. emergency departments. Acad Emerg Med. 2008; 15:7803.
  • 37
    Yawn B, Krein S, Christianson J, Hartley D, Moscovice I. Rural radiology: who is producing images and who is reading them? J Rural Health. 1997; 13:13644.
  • 38
    Rao VM, Parker L, Levin DC, Sunshine J, Bushee G. Use trends and geographic variation in neuroimaging: nationwide medicare data for 1993 and 1998. AJNR Am J Neuroradiol. 2001; 22:16439.
  • 39
    Parker L, Levin DC, Frangos A, Rao VM. Geographic variation in the utilization of noninvasive diagnostic imaging: national medicare data, 1998-2007. AJR Am J Roentgenol. 2010; 194:10349.
  • 40
    Smith RC, Rosenfield AT, Choe KA, et al. Acute flank pain: comparison of non-contrast-enhanced CT and intravenous urography. Radiology. 1995; 194:78994.
  • 41
    Ripolles T, Errando J, Agramunt M, Martinez MJ. Ureteral colic: US versus CT. Abdom Imaging. 2004; 29:2636.
  • 42
    Brenner DJ, Hall EJ. Computed tomography--an increasing source of radiation exposure. N Engl J Med. 2007; 357:227784.
  • 43
    Brenner D, Elliston C, Hall E, Berdon W. Estimated risks of radiation-induced fatal cancer from pediatric CT. AJR Am J Roentgenol. 2001; 176:28996.
  • 44
    Einstein AJ, Henzlova MJ, Rajagopalan S. Estimating risk of cancer associated with radiation exposure from 64-slice computed tomography coronary angiography. JAMA. 2007; 298:31723.
  • 45
    Broder J, Bowen J, Lohr J, Babcock A, Yoon J. Cumulative CT exposures in emergency department patients evaluated for suspected renal colic. J Emerg Med. 2007; 33:1618.
  • 46
    Green DE, Woodward PJ. The management of indeterminate incidental findings detected at abdominal CT. Semin Ultrasound CT MR. 2005; 26:213.
  • 47
    Kirpalani A, Khalili K, Lee S, Haider MA. Renal colic: comparison of use and outcomes of unenhanced helical CT for emergency investigation in 1998 and 2002. Radiology. 2005; 236:5548.