Susanna In-Sun Lee MD, PhD, Presenter: Nothing to Disclose

Anuradha Saokar MBBS, Abstract Co-Author: Nothing to Disclose

Jeffrey B. Weilburg MD, Abstract Co-Author: Nothing to Disclose

James Hunter Thrall MD, Abstract Co-Author: Nothing to Disclose

Peter Florin Hahn MD, Abstract Co-Author: Nothing to Disclose

Radiologic examinations are the fastest growing medical cost sector in the United States. The goal of this study was to determine significance of repeat exams in the volume and growth of high cost imaging studies.

From a database containing all radiology exams (>1.4 million) reported at our institution from 5/96-6/03, query by exam code produced a dated list of head, chest and abdomen CT, brain and spine MRI, pelvic ultrasound and nuclear cardiology. Custom software identified patients with prior studies and computed the time between repeats. Accuracy of the software was confirmed manually on 1% of the results by two radiologists independently. For each month from 1/97-6/03, incidence of studies duplicating a prior study <2 weeks, 2 weeks-2 months, or 2-7 months before was analyzed by linear regression.

In 2002, 3,903/17,899 (22%) of MRI’s, 26,875/609,884 (44%) of CT’s, 1,023/6,810 (15%) of ultrasound and 554/7,551 (7%) nuclear cardiology studies were studies repeated after a prior study < 7 months. The highest repeat rates were in head CT < 2 weeks (4,418/16,132, 27.4%), mostly for stroke patients, and in chest and abdomen CT 2-7 months (9,409/40,266, 23.3%), mostly for cancer patients on therapy. Among MRI’s, highest repeat rates were in cervical and lumbar spine 2-7 months (375/6,780, 5.5%) for pain patients failing conservative therapy. Repeat study rates are increasing at 0.48%/year for MRI, 2.1%/year for CT, 1.1%/year for ultrasound (all p<.0001) and 0%/year for nuclear cardiology. The fastest growing time frame for repeated studies is 2-7 months: brain MRI (0.47%/year), chest CT (0.97%/year) and abdomen CT (1.33%/year), mostly representing cancer patients under treatment.

Repeat exams represent a significant proportion of high cost radiology studies with CT repeat rates being the highest. The rate of repeat exam ordering has increased in the past six years. Repeat exams are performed most commonly on patients undergoing treatment for cancer.

Lee, S, Saokar, A, Weilburg, J, Thrall, J, Hahn, P, Repeat Ordering of Exams: A Significant Factor in the Growing Volume of High Cost Imaging Studies?.  Radiological Society of North America 2004 Scientific Assembly and Annual Meeting, November 28 - December 3, 2004 ,Chicago IL. http://archive.rsna.org/2004/4415569.html