Thomas Zacharia MD, PRESENTER: Nothing to Disclose

Abstract: HTML Purpose: Our aim was to study the use of computed tomography in the follow up evaluation of renal calculus disease. We sought to evaluate how often excess radiation is given to patients during follow up evaluation due to CT scans. Methods and Materials: Records of 100 consecutive patients (age 14-75) with unenhanced helical CT positive for nephrolithiasis or urolithiasis were reviewed retrospectively. All patients were evaluated with unenhanced helical CT(UHCT), without oral or intravenous contrast, using the standard stone protocol performed in our department. The initial and follow up CT scans were evaluated and quantified for presence or absence of ureteral or renal stones, exact location of the stone, complications like hydroureteronephrosis and additional pathologies that were seen. Results: 61 of 100 patients had follow up CT scans within a period of 1 to 6 months. The number of follow up CT scans in these patients were 1(n=37),2 (n=9),3 (n=4), 4 (n=4), 5 (n=3) or more than 5 (n=4). The indications for follow up CT scans (n=125) included recurrence of renal colic (n=76), to determine passage of ureteral stone (n=16), hematuria (n=8) and to assess response to therapy (n=25). Patients were stratified by age, <20 years (n=2), 20-50 (n=46), >50 (n=52). 56 follow up CTs showed a change in size (n=32), location (n=12), interval resolution (n=8), or complications like hydronephrosis (n=4). Follow up CT showed no significant change in the remaining scans (n=69). Other abdominal radiological procedures included KUB (n=47), IVU (n=6) and ultrasound (n=12). Conclusion: Follow up CT scans did not reveal any significant change (n=69), compared to the initial CT. The number of follow up CT scans done was twice compared to the number of ultrasounds and abdominal radiographs combined (n=59). Frequent follow up CT scans often irradiate relatively young patients, provide limited added information, and should be replaced whenever possible by imaging modalities giving less radiation. Patients with nonobstructive urolithiasis may be reimaged only if obstructive symptoms develop clinically. Younger patients with obstructive urolithiasis may be followed up by ultrasound.       Questions about this event email: tzacharia@partners.org

Zacharia MD, T, Can Excess Radiation due to Follow-up CT Scans in Patients with Renal Calculus Disease Be Avoided? An Analysis of 100 Patients.  Radiological Society of North America 2003 Scientific Assembly and Annual Meeting, November 30 - December 5, 2003 ,Chicago IL. http://archive.rsna.org/2003/3102788.html