Background:Noncontrast computed tomography(CT)scan of the kidneys,ureter and bladder is the standard investigative modality for diagnosing and following up patients with urolithiasis.With each scan,a patient receives ...Background:Noncontrast computed tomography(CT)scan of the kidneys,ureter and bladder is the standard investigative modality for diagnosing and following up patients with urolithiasis.With each scan,a patient receives radiation of 18-34 mGy.Dose considerations become pertinent because of a 10%lifetime incidence rate and higher than 50%risk of recurrence,necessitating repeated imaging in the lifetime of a stone former.Hence,this study aimed to assess the sensitivity of"reduced-radiation"CT imaging by altering scan settings to lower than the"standard"norms.Materials and methods:Altogether,222 patients(255"kidney-ureter"stone-bearing units or"renal units")with urolithiasis and patients undergoing CT for other reasons with incidental findings of renal/ureteric calculi between 2017 and 2019 were included.All patients were subjected to 3 sequential scans at tube current settings of 250 mA(CT-N/Standard),100 mA(CT-100),and 50 mA(CT-50)at a constant voltage of 120 kV.Their clinicodemographic and radiological findings were recorded and assessed for significance.Results:Of the 255 renal units,117 were between 30 and 44 years of age,75%were men.Of the 255 patients,178(70.1%)reported a first stone episode and 77 had recurrence.Lower ureteric calculi were predominant(40.4%).All calculi were identified on CT-N;CT-100 failed to detect calculi in 1 patient,and CT-50 failed in 3 patients,where all calculi were<3 mm in size.Meanwhile,none were undetected among patients with obesity.The sensitivity was 99.61%for the CT-100 and 98.82%for the CT-50,which indicated a 2.5 and 5 times lower radiation and dose/length,respectively,than CT-N.Conclusions:The reduced-radiation CT scan is safe,sensitive,and accurate for the diagnosis and follow-up of patients with urolithiasis with significantly lower radiation exposures.Our study lays the foundation to accept low-dose CT in general and CT-50 in particular,as the new"standard of care,"and attempt further dose reduction without loss of diagnostic efficacy.展开更多
文摘Background:Noncontrast computed tomography(CT)scan of the kidneys,ureter and bladder is the standard investigative modality for diagnosing and following up patients with urolithiasis.With each scan,a patient receives radiation of 18-34 mGy.Dose considerations become pertinent because of a 10%lifetime incidence rate and higher than 50%risk of recurrence,necessitating repeated imaging in the lifetime of a stone former.Hence,this study aimed to assess the sensitivity of"reduced-radiation"CT imaging by altering scan settings to lower than the"standard"norms.Materials and methods:Altogether,222 patients(255"kidney-ureter"stone-bearing units or"renal units")with urolithiasis and patients undergoing CT for other reasons with incidental findings of renal/ureteric calculi between 2017 and 2019 were included.All patients were subjected to 3 sequential scans at tube current settings of 250 mA(CT-N/Standard),100 mA(CT-100),and 50 mA(CT-50)at a constant voltage of 120 kV.Their clinicodemographic and radiological findings were recorded and assessed for significance.Results:Of the 255 renal units,117 were between 30 and 44 years of age,75%were men.Of the 255 patients,178(70.1%)reported a first stone episode and 77 had recurrence.Lower ureteric calculi were predominant(40.4%).All calculi were identified on CT-N;CT-100 failed to detect calculi in 1 patient,and CT-50 failed in 3 patients,where all calculi were<3 mm in size.Meanwhile,none were undetected among patients with obesity.The sensitivity was 99.61%for the CT-100 and 98.82%for the CT-50,which indicated a 2.5 and 5 times lower radiation and dose/length,respectively,than CT-N.Conclusions:The reduced-radiation CT scan is safe,sensitive,and accurate for the diagnosis and follow-up of patients with urolithiasis with significantly lower radiation exposures.Our study lays the foundation to accept low-dose CT in general and CT-50 in particular,as the new"standard of care,"and attempt further dose reduction without loss of diagnostic efficacy.
