References

1.      Hiatt RA, Dales LG, Friedman GD, et al. Frequency of urolithiasis in a prepaid medical care program. Am J Epidemiol. 1982; 115:255-5

2.      Kirpalani A, Khalili K, Lee S, et al. Renal colic: comparison of use and outcomes of unenhanced helical CT for emergency investigation in 1998 and 2002. Radiology. 2005; 236:554-8.

3.      Sierakowski R, Finlayson B, Landes RR, et al. The frequency of urolithiasis in hospital discharge diagnoses in the United States. Invest Urol. 1978; 15:438-41.  

4.      Parks J, Coe F, Favus M. Hyperparath-yroidism in nephrolithiasis. Arch Intern Med. 1980; 140(11):1479-81.

5.      Burtis WJ, Brady TG, Orloff JJ, et al. Immunochemical characterization of circulating parathyroid hormone related protein in patients with humoral hypercalcemia of cancer. N Engl J Med. 1990; 322(16):1106-12.

6.      Bell NH, Stern PH, Pantzer E, et al. Evidence that increased circulating 1 alpha, 25-dihydroxyvitamin D is the probable cause of abnormal calcium metabolism in sarcoidosis. J Clin Invest. 1979:64(1):218-25.

7.      Griffith DP, Osborne CA Infection (Urease) stones. Miner Electrolyte Metab. 1987; 13(4)278-85.

8.      Pak CY, Poindexter JR, Adams-Huet B, et al. Predictive value of kidney stone composition in the detection of metabolic abnormalities. Am J Med. 2003; 115(1): 26-32.

9.      Sakhaee K, Adams-Huet B, Moe OW, et al. Pathophysiologic basis for normo uricosuric uric acid nephrolithiasis. Kidney Int. 2002; 62(3):971-9.

10.  Nicar MJ, Hill K, Pak CY. Inhibition by citrate of spontaneous precipitation of calcium oxalate in vitro. J Bone Miner Res. 1987; 2(3):215-20.

11.  Hess B, Nakagawa Y, Parks JH et al. Molecular abnormality of Tamm-Horsfall glycoprotein in calcium oxalate nephrolit-hiasis. Am J Physiol. 1991; 206:569-78.

12.  Segal AJ, Spataro RF, Linke CA, et al. Diagnosis of nonopaque calculi by computed tomography. Radiology. 1978; 129:447-50.

13.  Federle MP, Mc Aninch JW, Kaiser JA, et al. Computed tomography of urinary calculi. AJR Am J Roentgenol. 1981; 136:255-8.

14.  Smith RC, Rosen field AT, Choe KA, et al. Acute flank pain: comparison of non-contrast-enhanced CT and intravenous urography. Radiology. 1995; 194:789-94.

15.  Smith RC, Verga M, Mc Carthy S, et al. Diagnosis of acute flank pain: value of unenhanced helical CT. AJR Am J Roentgenol. 1996; 166:97-101.

16.  Levine JA, Neitlich J, Verga M, et al. Ureteral calculi in patients with flank pain: correlation of plain radiography with unenhanced helical CT. Radiology. 1997; 204(1):27-31.

17.  Mitterberger M, Pinggera GM, Pallwein L, et al. Plain abdominal radiography with transabdominal native tissue harmonic imaging ultrasonography vs unenhanced computed tomography in renal colic. BJU Int. 2007; 100:887-90.

18.  Goldwasser B, Cohan RH, Dunnick NR, et al. Role of linear tomography in evaluation of patients with nephrolithiasis. Urology. 1989; 33:253-6.

19.  Gaspari R, Horst K. Emergency ultrasound and urinalysis in the evaluation of flank pain. Acad Emerg Med. 2005; 12:1180-5.

20.  Fowler KA, Locken JA, Duchesne JH, et al. US for detecting renal calculi with nonenhanced CT as a reference standard. Radiology, 2002; 222:109-13.

21.  Ulusan S, Koc Z, Tokmak N, et al. Accuracy of sonography for detecting renal stone: comparison with CT. J Clin Ultrasound, 2005;35:256-61.

22.  Sheafor DH, Hertzberg BS, Freed KS, et al. Non-enhanced helical CT and US in the emergency evaluation of patients with renal colic: prospective comparison. Radiology. 2000; 217:792-7.

23.  Ripolles T, Agramunt M, Errando J, et al. Suspected ureteral colic: plain film and sonography vs unenhanced helical CT. A prospective study in 66 patients Eur Radiol. 2004; 14:129-36.

24.  Nordin BE, Need AG, Morris HA, et al. Biochemical variables in pre- and postmenopausal women: reconciling the calcium and estrogen hypotheses. Osteoporosis Int. 1999; 9 (4):351-7.

25.  Patlas M, Farkas A, Fisher D, et al. Ultrasound vs CT for the detection of ureteric stones in patients with renal colic. Br J Radiol. 2001; 74:901-4.

26.  Ha M, Mac Donald RD. Impact of CT scan in patients with first episode of suspected nephrolithiasis. J Emerg Med. 2004; 27(3):225-31.

27.  Varanelli MJ, Coll DM, Levine JA, et al. Relationship between during of pain and secondary signs of obstruction of the urinary tract on unenhanced helical CT. AJR Am J Roentgenol. 2001; 177:325-30.

28.  Sundaram CP, Saltzman B. Urolithiasis associated with protease inhibitors. J Endourol. 1999; 13:309-12.

29.  Hermieu JF, Prevot MH, Ravery V, et al. Nephritic colic due to indinavir . Presse Med. 1998; 27:465-67.

30.  Meagher T, Sukumar VP, Collingwood J, et al. Low dose computed tomography in suspected acute renal colic. Clin Radiol. 2001; 56:873-6.

31.  Denton ER, Mackenzie A, Greenwell T, Propert R, Rankin SC. Unenhanced helical CT for renal colic: is the radiation dose justifiable. Clin Radiol. 1999; 54:444-7.

32.  Mettler FA Jr. Huda W, Yoshizumi TT, et al. Effective doses in radiology and diagnostic nuclear medicine:a  catalog. Radiology. 2008; 248:254-63. 

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